Title of Invention

PROCESS FOR PRODUCING COATED PAPER AND COATED PAPER

Abstract To produce a coated paper having quality required of coated papers while attaining heightened productivity and coping with reduction in weight and coating amount. [Means for Solving Problems] For forming coating layers on a surface of a base paper, coating apparatuses differing in coating method are used. Thus at least two coating layers are formed on the surface layer of the base paper. In particular, the base paper is coated by a combination of coating by a roll coater (60) and coating by a blade coater (65A).
Full Text -1-
DESCRIPTION
PROCESS FOR PRODUCING A COATED PAPER AND COATED PAPER
Technical Field
[0001]
The present invention relates to a process and
apparatus for producing a coated paper.
In particular, the present invention involves using,
as means for forming coating layers on a surface of a base
paper, coating apparatuses differing in coating method, for
example, coating apparatuses including a combination of a
roll coater and a blade coater that form, at least two
coating layers on a surface layer of the base paper. The
present invention suitably relates to a process for
producing a coated paper that can efficiently carry out
production with high quality at a speed of 1300 m/min or
more, particularly at a high speed of 1550 m/min or more
integratedly from paper to finally finished products by
means of on-machine technology, and coated paper.
Background Art
[0002]
In response to recent promotion of visualization and
changes to multimedia, needs have been rapidly increased to
highly qualify such as to visualize and colorize even
printed matters having been widely used as media such as
publications, advertisements, and posters. With changes in
such user demands, an increase in the replacement of a
conventional uncoated printing paper by a coated paper for
printing rapidly leads to increasing demand for the coated
paper for printing.
[0003]
In addition, printing steps more and more severely
request the qualities of handling properties of printing
paper and traveling stability on a printer, which are

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involved in improvement in workability and efficiency.
[0004]
Of the quality requests, paper manufacturing
industries have implemented involvements with wider and
more highly speedy paper machines in order to save energy
and reduce manufacturing costs.
[0005]
In the quality request for a coated paper and power
saving and manufacturing cost reduction, the trend lies in
lower grams per square meter of a base paper and ultra
lightweight coating. In manufacturing premises,
reformation is strongly invoked for techniques of producing
a coated paper for printing having more excellent printing
properties while maintaining characteristics of high-speed
running ability.
[0006]
In response to these quality demands, a technique is
disclosed that involves, in an offset printing paper to be
coated including an undercoat coated layer having a pigment
and an adhesive and an overcoat coated layer, containing in
a base paper 3 to 20 weight % of a needle or columnar soft
calcium carbonate as an internal loading material based on
the weight of the base paper, containing in the undercoat
coated layer a styrene/butadiene copolymer latex having a
gel content of from 75 to 90 weight % and having an average
particle diameter of from 40 to 70 mm, and containing in
the overcoat coated layer a styrene/butadiene copolymer
latex having a gel content of from 40 to 70 weight %' and
having an average particle diameter of from 40 to 80 mm
(Patent Document 1). Also disclosed is a process of
producing a to-be-coated paper for applying a coating
liquid having a pigment and an adhesive to a paper base, in
which a wet paper is water-squeezed using a shoe press in a
press part of a base paper machine; the dried base paper
and/or undercoat coated paper produced by applying a
coating liquid to the base paper is treated by means of a

-3-
soft calender constituted by a metal roll and an elastic
roll at a metal roll surface temperature of from 40 to 90°C
at a linear pressure of from 30 to 150 kg/cm, and then a
coating liquid having a pigment and an adhesive is applied
thereto (Patent Document 2).
[0007]
However, the re-examination of the formulation of a
coated layer, improvement by means of a press part, or the
like is a simple extension of prior art. Even if the
technique improves print visual quality, operability and
productivity in production premises are not improved, and
thus, such a technique is not a basic solution.
Patent Document 1: Japanese Patent Application Laid-Open
No. 11-279992
Patent Document 2: Japanese Patent Application Laid-Open
No. 11-001891
Disclosure of the Invention
Problems to be Solved by the Invention
[0008]
Therefore, a primary problem of the present invention
is to increase productivity and also produce a coated
paper with quality required for a coated paper, while a
basis weight of a product is decreased to less than 64 g/m2
and ultra lightweight coating is performed attributable to
reduction in recent paper cost.
[0009]
Another problem is to obtain a coated paper of good
print visual quality having a glossiness of 55% or more,
more desirably 60% or more. Still another problem is to
be capable of producing a coated paper with high
productivity while coping with environmental problems even
if a waste paper has a high blend degree of 10% or more.
Further problems will be clarified by descriptions, below.
Means for Solving the Problems

-4-
[0010]
The present invention having solved the above
problems is as described below.

A process for producing a coated paper in which
continuous steps are incorporated successively within on-
machine, the process comprising:
a step of making a paper with a twin wire former in
which a paper material is injected from a head box between
two wires each of which loops to form a paper layer;
an undercoating step of applying an undercoating
liquid to a dry web by a size press;
a step of drying the undercoating liquid
a first flattening treatment step of performing a
flattening treatment by a pre-calender;
a face coating step of applying a face coating liquid
by selecting a single coating step of (1) or (2) as
follows, or a coating step of performing the step (2)
after performing the step (1) ,
(1) a roll coater coating step of roll-coating one
side and the other side of a paper to be coated with an
aqueous coating liquid consisting mainly of an adhesive
and a pigment, and then drying the coated paper,
(2) a blade coater coating step of blade-coating one
side and the other side of a paper to be coated with an
aqueous coating liquid consisting mainly of an adhesive
and a pigment, and then drying the coated paper; and
a step of subjecting the coated paper to a flattening
treatment using a heat soft calender comprising a
combination of a metal roll and an elastic roll- formed in
a multi-stage having at least two nips.
[0011]

The process for producing a coated paper according to
claim 1, wherein the pre-calender comprises a heated metal
roll as at least one roll of a pair of rolls.

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[0012]

The process for producing a coated paper according to
claim 1 or 2, wherein the pre-calender comprises a pair of
a metal roll and an elastic roll and the metal roll is
heated to a temperature of 100 to 300'"C.
[0013]

The process for producing a coated paper according to
any one of claims 1 to 3, wherein the flattening treatment
is performed by the pre-calender comprising the metal roll
heated to a temperature of 230°C or more.
[0014]

A coated paper produced by the process for producing
according to any one of claims 1 to 4.
[0015]
[00151
The coating apparatuses include a size press, a
calender sizing, a wire bar, an air knife coater, a roll
coater (gate roll coater or the like: a coating system of
transferring a coating liquid using a roll), a blade
coater (bill blade coater or the like: a method of removing
a coating liquid with a blade to form a coated layer) and a
spray. In Europe many apparatuses are run using a roll
coater due to production efficiency priority, and in Japan
blade coaters are run due to quality priority.
[0016]
However, there are no precedents for a process for
producing a coated paper constituted by a combination of
different coating apparatuses and for a coated paper, which
are proposed by the present invention. Further, there is
no example of finally flattening a surface of a coated
layer by means of a flattening apparatus including a metal
roll and an elastic roll.
[0017]

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A coated paper is actively produced using a similar
kind of roll coater or blade coater. However, a
combination of different coating apparatuses, for example,
a combination of a roll coater and a blade coater, makes
its apparatus structure complicated and requires diverse
knowledge also from the viewpoint of maintenance, and thus
has not been adopted.
[0018]
In a coated paper manufacturing facility including a
combination of blade coaters of the same type, the facility
flow becomes very long and needs wide placement space. In
the production of a coated paper having low grams per
square meter and a high blend of waste paper also, the
problem of frequent paper breakage affected by a blade
touch pressure occurs due to a problem of a decrease in
paper strength, at a high speed paper making, for example,
a speed exceeding 1300 m/min. Although there are some
measures of restraining a paper making speed and a blade
touch pressure, the production efficiency is worsened and
the adjustment of a coating amount become difficult.
[0019]
Although needing few placement space, a combination
of roll coaters of the same type makes the smoothness of a
coated face inferior to that by a blade coater because of
coating by transfer from a roll, thereby being incapable of
satisfying a demand of high glossiness and high printing
suitability.
[0020]
A brief comparison between roll coating and blade
coating makes clear their superiority and inferiority from
a correlation between the coating amounts per face. In
other words, at 8 g/m2 or more, blade coating is superior
in coating properties and smoothness, while roll coating'
readily makes the surface lips and dips depending on the
lips and dips of a base paper and thus is inferior. On the
other hand, at 6 g/nr or less, blade coating tends to

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render the lip portion of the base paper to be exposed only
when a coating liquid is placed within the dip portion and
thus is inferior, while roll coating is superior in coating
properties. In addition, basically regardless of the
amount of coating, the case of blade coating is high in the
ratio of paper breakage (the higher the speed or the larger
the amount of a waste paper blended, the more apparent the
trend), while the case of roll coating is low in the ratio
of paper breakage. Even at a small amount of coating of 6
g/m2 or less, the use of clay with a high aspect ratio, for
example, delaminated clay (thin planar crystal structure
clay), which obtains high coating properties and gross as a
pigment, increases the viscosity during high speed coating.
For this reason, roll coating is more suitable. In roll
coating, when the amount of coating becomes 8 g/m2' or more,
the profile in the width direction is difficult to control
and also a so-called orange peel pattern is generated, so
that face feel and the adhesion of ink become inferior. On
the other hand, blade coating generally does not pose such
problems. Blade coating enables high concentration coating
of, for example, a coating concentration of 65% or more,
while roll coating requires the coating concentration to be
56% or less. Thus, drying energy cost per kilogram of
paper is lower in blade coating.
As such, roll coater coating and blade coater coating
indicated different trends.
[0021]
For manufacturing a coated paper, including foreign
countries and Japan, an off-machine coater in which a paper
making machine and a coating machine are separated from
each other and an on-machine coater in which a coating
machine is incorporated into a paper making machine are
known. For an off-machine coater, a paper is generally
passed through a size press at a paper making stage.
Passing a paper through a pre-calender is not implemented
so long as the inventor knows. In the case of an on-

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machine coater, passing a paper through a size press is
conducted in few cases. instead, passing a paper through a
pre-calender device is carried out (an apparatus including
the both does not seem to exist).
[0022]
In particular, in a coating apparatus using an off-
machine, a coating base paper of a low basis weight poses a
large problem of paper breakage during splicing by auto-
splicer.
[0023]
An auto-splicer is an apparatus that carries out
paper splicing without stopping a coater for the purpose of
production efficiency improvement. Since the paper
splicing section forms a lip portion constituted by
adhesion means such as an adhesion tape disposed between
pieces of base paper, paper breakage is unlikely generated
at a coating speed of 1000 m/min or less. However, at a
speed exceeding 1000 m/min, particularly a speed exceeding
1300 m/min, a fine deviation of a winding rotational tuning
speed as well as paper breakage by contact of a paper
splicing section with a doctor blade edge are readily
generated.
[0024]
For the improvement of paper breakage, measures of
improving the tensile strength of the base paper itself are
adopted. According to the knowledge of the inventor,
however, at least the tensile strength (MD) needs 3.0 kN/m
or more. In a waste paper of low grams per square meter
obtained by highly blending a waste paper having a low
tensile strength, measures such as internal addition of a
large amount of a paper strength additive are required, and
therefore a large increase in cost is unavoidable.
[0025]
In' coating by an on-machine, an auto splicer is
unnecessary and the strength of the base paper itself can
be also set low. In the present situations, however, the

-9-
running speed (not a design speed) is at most about 1200
m/min.
[0026]
Trying to obtain a higher paper making speed (running
speed) exceeding 1300 m/min requires a tensile strength
(MD) of 2.6 kN/m or more. In coating by an on-machine,
particularly for a high blend of waste paper, as in an off-
machine, measures such as internal addition of a paper
strength additive are needed, and therefore an increase in
cost is unavoidable.
[0027]
Different from a waste paper consisting essentially
of a virgin pulp, a recent waste paper in which a waste
paper pulp is largely blended exhibits a remarkable tensile
strength decrease and prominent foreign matter
(contaminants) mixing. In the case where coating is
carried out in a basis weight of paper of about 30 to
about 45 g/m: at a speed of 1000 m/min, particularly at a
speed exceeding 1300 m/min, the problem of paper breakage
is always created.
[0028]
Paper breakage in a blade coater is liable to occur
by pushing pressure by a blade. In particular, since paper
breakage by an on-machine stops a series of apparatuses
from a paper making machine to a coating apparatus,
decreases in production loss and production efficiency are
extremely large. Thus, in the present situations, the
production of a coated paper of low grams per square meter
is generally implemented by coating by an off-machine.
[0029]
The present inventors have found out a technique
capable of providing a coated paper having good print
visual quality with low grams per square meter and high
blending of waste paper by use of a high speed paper
machine, which is an object of the present invention. The
coated paper is provided firstly by forming at least two

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coated layers on a surf-ace of a base paper by use of a
coating apparatus comprising a combination of different
coating apparatuses, preferably a combination of a roil
coater and a blade coater as means for forming coated
layers on a surface of a base paper, and secondly by
flattening the surface of the coated layer by a combination
of a metal roll and an elastic roll. This has lead to the
completion of the present invention.
[0030]
The present invention can continuously perform a
coating' step passing through a step of making paper and
applying an undercoating liquid of starch or the like onto
a dry paper web by size press and through a step of
performing a flattening treatment on the resulting web by a
pre-calender device.
[0031]
The coating step is a coating step of selecting a
single coating step of (1) or (2) as follows, or a coating
step of performing the step (2) after performing the step
(1)
(1) A roll coater coating step of roll-coating one
side and the other side of a paper to be coated with an
aqueous coating liquid consisting mainly of an adhesive and
a pigment, and then drying the coated paper.
(2) A blade coater coating step of blade-coating one
side and the other side of a paper to be coated with an
aqueous coating liquid consisting mainly of an adhesive and
a pigment, and then drying the coated paper.
[0032]
Thereafter, the paper to be coated is subjected to a
flattening treatment using a heat soft calender comprising
a combination of a metal roll and an elastic roll formed in
a multi-stage having at least two nips.
[0033]
The selection of the coating step can be carried out,
in one line, according to, for example, base paper grams

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per square meter, the presence or absence of waste paper,
the amount of waste paper blended, the amount of coating,
the line speed, product grams per square meter, glossiness
to be required, and qualities of smoothness and the like.
This makes it possible to commonly produce an ultra
lightweight coated paper, a fine coated paper, an A3 coated
paper, and an A2 coated paper as required. Although these
classifications are not clear for those skilled in the art,
for example, a blade coater can be used for an A3 coated
paper of 64.0 g/m? or 60.2 g/m2 or more, a blade coater or
a roll coater for a fine coated paper of 58.0 g/m-' or 54.2
g/rrr, and a roll coater for a lightweight coated paper of
51.2 g/rrr or less.
[0034]
A first feature of the present invention is to
incorporate into an on-machine coater a step of coating an
undercoating liquid of starch or the like using a size
press and a step of performing a flattening treatment by a
pre-calender.
[0035]
Implementation of undercoating of starch by a size
press enables the rigidity and paper strength by the starch
to be increased and enables the prevention of paper
breakage also by lower grams per square meter of a base
paper or high blending of a waste paper (in particular, in
the case of blade coating) as well as restrains the
protrusion of contaminants and contributes to flattening of
a subsequent coating liquid.
[0036]
Subsequently, a flattening treatment is desirably
performed by a pre-calender. A pre-calender contributes to
the flattening and also, in particular, to homogenization
of the profile in the width direction after the subsequent
coating step. That is, the flattening treatment serves to
homogenize the surface of a paper onto which an
undercoating liquid of starch or the like has been applied.

-12-
In particular, where a target paper width is 7000 mm or
more, the profile in the width direction after coating is
greatly broken, while the implementation of the flattening
treatment by a pre-calender can homogenize the surface. In
particular, subsequently, in the case where coating of 8
g/m: or more is carried out by a roll coater, profile
control in the width direction is difficult by a roll
coater, while the adoption of a pre-calender enables the
homogenization of the profile in the width direction. In
addition, in the case where blade coating is performed for
the homogenization of the surface in the width direction, a
pre-calender uniforms tne touch of a blade and thereby also
contributes to the prevention of paper breakage.
[0037]
A second feature is that the invention is that the
selective coating step or apparatus described above is
provided. The advantage of this respect has been described
previously and thus is not'described again.
[0038]
A third feature is inclusion of a step or apparatus
for performing a flattening treatment using a heat soft
calender comprising a combination of a metal roll and an
elastic roll formed in a multi-stage having at least two
nips. In particular, 6-stage, more preferably 8-stage (7-
nip) or 10-stage multi-nip calender is most appropriate.
[0039]
With a lower coating amount, flattening properties
and glossiness become difficult to secure. On the other-
hand, the inclusion of a step of flattening treatment of
the present invention enables a coated paper having a
target glossiness of 55% or more, particularly 60% or more
to be obtained, for example, even in the case where the
coating amount is 7 g/m2 or less, particularly 6 g/m2 or
less, the product grams-per square meter is less than 54.2
g/m2 and the base paper grams-per square meter is 4 5.0 g/m2
or less.

-13-
[0040]
Although disposing a (heat soft calender) multi-nip
calender itself is well-known, adoption examples are not so
many. Needless to say, a combination of undercoating for
coating by a size press and a pre-calender is just a
beginning for any of off-machines and on-machines. These
combinations according to the present invention enable even
the production of ultra lightweight coated paper of 51.2
g/m or less from the viewpoint of the provision of high
smoothness and high glossiness.
[0041]
After the implementation of coating by a roll coater,
it is possible to carry out coating by a blade coater. As
described previously, in the case by a roll coater, coating
properties of paints are good even in a low coating amount.
Then, first, when coating is carried out by a blade coater
after implementation of coating by a roll coater, a second
coating layer is coated by a blade coater excellent in
smoothness on a first coating layer exhibiting good coating
properties. For this reason, even if a low coating amount
(ultra lightweight coat) of 6 g/m2 or less as the total
coating amount or a coating amount of about 7 to 9 g/m2 per
face is used, a coated paper can be obtained that is
excellent in coating properties, smoothness and glossiness.
[0042]
Moreover, the first coating layer is allowable if the
coating properties can be secured, so that a high quality
coating liquid is not required to be used. Hence, an
advantage is that a coating liquid at a low cost is coated
by a blade coater to be capable of forming a high quality
coating layer.
[0043]
Furthermore, disposing a size press enables
undercoating of starch or the like, and also enables the
use of a pigment and an adhesive for coating.
[0044]

-14-
The present invention enables the production of an
ultra lightweight coat paper of low grams per square meter
at a paper making speed of 1300 m/min or more or exceeding
it, particularly at a running speed of 1550 m/min or more,
at from 1600 m/min to 1800 m/min. When the running speed
becomes 1300 m/min or more, the mode of technical problems
for quality to be demanded is completely changed compared
with the case of a running speed of 1300 m/min or less, a
running speed of 1200 m/min that is presently regarded as a
high speed. Needless to say, for an on-machine coater,
problems that are difficult to solve are extremely many.
[0045]
With a base paper of the present invention, a paper
material is ejected from a head box into between two wires
that each make loops to form a paper layer. For example,
the base paper is subjected to a size press, after passing
through a step of making a paper using a twin wire former
of a cap type and a step of forming a wet paper by
dewatering means using a suction (forming) roll and/or a
blade in a wire part. The base paper that is made using a
twin wire former of a cap type preferably has sufficient
paper strength even in low grams per square meter.
[0046]
Application of starch by a size press can further
improve paper strength.
[0047]
Furthermore, the improvement of flattening properties
of the base paper surface (particularly, in the width
direction) by a pre-calender makes it possible to have
sufficient paper strength and flattening properties even if
a touch pressure of a blade is high, but not leading to
paper breakage, in a coating apparatus. After coating,
flattening treatment at a high speed and a high temperature'
by means of a multi-stage multi-nip calender comprising an
elastic roll and a metal roll can obtain flattening
properties and high glossiness of the surface of the

-15-
coating layer.
[0048]
The present inventor has found that disposing a size
press and further a pre-calender in a pre-step of a roll
coater is extremely effective means for solving print
visual quality failure and damage generation and improving
printing and glossiness unevenness due to coating profile
unevenness that is a specific problem of a roll coater in
low grams-per square meter, in order to cope with
technically demanded, low grams-per square meter and high
blending of a waste paper that is friendly to the
environment and to obtain high quality good look printing
suitability and glossiness.
[0049]
Additionally, in a coating liquid by size press, a
surface sizing agent, an antifoaming agent, an antiseptic,
a thickener, etc., which are usually as required used, are
used together as appropriate.
[0050]
Moreover, it is necessary to perform a flattening
treatment to a paper at high temperature without paper
break in order to obtain evenness and glossiness of the
surface of a coated paper while maintaining rigidity
required in printing suitability, i.e., stiffness of paper.
A conventionally generally adopted fattening treatment
using a plurality of stacks not only needs placement space,
but is difficult to make an apparatus high temperature and
is extremely bad in flattening efficiency to a base paper.
For this reason, it is impossible to increase a paper
making speed in order to obtain evenness and glossiness
with maintenance of rigidity while substantially avoiding
paper breakage, thereby having to perform the production at
a sheet making speed of 1200 m/min or less.
[0051]
A more preferred aspect of the present invention
includes a flattening apparatus comprising a combination of

-16-
a metal roll and an elastic roll in the present invention,
for example, a combination with a multi-nip calender. As a
still more preferred aspect of a multi-nip calender, a
jacket roll is applied to a metal roll of a multi-nip
calender. A multi-nip calender includes a combination of a
metal roll and an elastic roll in a multi-stage. Each nip
pressure per roll is individually increased to about 450
kN/m. Making the number of rolls 6 to 12 stages
sufficiently enables a flattening treatment even to a paper
making speed of 1300 m/min or more and further even a high
speed coating of 1600 m/min or more.
[0052]
In some cases, each interval between rolls is opened
with one to two nips closed, and a coated paper of a mat
pattern can be also produced. However, a flattening
treatment with a roll number of 6 to 12 stages can obtain a
coated paper of a white paper glossiness of 55% or more,
particularly 60% or more, even at a high speed paper making
speed of 1300 m/min.
Advantages of the Invention
[0053]
According to the present invention, a brilliant high-
quality coated paper can be produced at a high production
efficiency even for a base paper with low grams per square
meter and high blending of a waste paper. The advantage of
the present invention is clarified by examples and
comparative examples that have been diligently studied for
a long period of time and are described below.
[0054]
A high quality coated paper excellent in glossiness,
smoothness, printing suitability, etc., can be produced,
with extremely good operationability being secured, in high
speed paper making at a paper making speed of exceeding
1300 m/min by means of a process for producing a coated
paper according to the present invention using paper making

-17-
equipment (online machine) integratedly from a paper raw
material to a product.
[0055]
The present invention is intended to produce, for
example, a coated paper or ultra lightweight coated paper
having 10% or more of a waste paper blended in its raw
material as a raw material pulp, with paper grams per
square meter of from 28 to 80 g/m2 (particularly from 35 to
48 g/m-) , product grams per square meter of from 30 to 103
g/m* (particularly from 35 to 64 g/nr) and a one-side
coating amount of from 2 to 23 g/m' (particularly from 4 to
9 g/m2) continuously and integratedly from paper making to
winding at a paper making speed of 1300 m/min or more, for
example, at a high speed of an average paper making speed
of from 1600 m/min to 1800 m/min. In addition, desirably,
the coating amount is from 2 to 10 g/m2 (particularly from
5 to 7 g/m2) at one side in roll coating, and from 6 to 15
g/m" (particularly from 7 to 9 g/m;) at one side in blade
coating. Usually, both-face coating is desirably carried
out, and thus the amount is twice the above one-side
coating amount.
[0056]
The present invention can make the number of
operators smaller. In re-reeler equipment of re-reeling
and off-calender requiring running termination and paper
joining, a total of 16 operators (4 groups (each 4
operators) and three shifts) are generally required.
However, the present invention can remove the 16 operators.
Best Mode for Carrying Out the Invention
[0057]
Next, a best mode for carrying out the present
invention will be described with reference to the drawings
and further the present invention will be set forth in
detail.
Referring to FIG. 1, a paper making machine is placed

-18-
in which a paper is made by a gap type twin wire former 10
for forming a paper layer by ejecting a paper material J
from a head box 3 into between two wires (a first wire 1
and a second wire 2) each of which loops. The paper
material J is ejected into between a suction (forming) roll
4A and a roll 4B facing each other and between the wires in
the wire part thereby to form a paper layer. The paper
layer is dewatered to, for example, about a raw material
concentration of about 20% while passing through the
suction (forming) 4A, a blade 5, a suction couch roll 6, a
suction box 7, etc.
[0058]
Here, a combination use form of roll means and blade
dewatering means in the illustration shown is indicated as
a dewatering mechanism, and preferably the both are used,
but only one is possibly used.
[0059]
The head box 3 is in a vertical or downstream
inclined state and upward disposed. As enlargedly shown in
FIG. 6, an ejection angle Q which the paper material
ejection direction line makes the horizontal line is
desirably from 50° to 90°. In high speed paper making
intended by the present invention, an upward head box in
which the influence of the fiber weight is small is
desirable from the viewpoints of texture, the Z axis
strength, front and back difference, fiber orientation
angles, etc. In a gap type twin wire former, when the head
box is horizontal or the like, desirable properties are
difficult to obtain in high speed paper making.
[0060]
A paper layer in the wire part moves- to the press
part and further dewatered. The press part in an
embodiment, in which a first press 21 and a second press 22
respectively have shoe presses 21a, 22a, is made to be a
configuration in which a paper layer is straightly nipped
to remove open draw and prevent paper breakage. In

-19-
addition, a belt in the second press 22 is placed on the
bottom side relative to the first press 21 of a double
felt, and the press is configured so as to prevent wetting
again and improve dewatering. Where the basis weight is as
high as 60 g/m: or more and the amount of dewatering is
large, a double felt is desirable.
[0061]
A wet paper of a moisture of about 50% having passed
through the press part, as referred to FIG. 2, moves to a
pre-dryer part of a single deck system and is dried. An
illustrated dryer part is a single deck dryer of no open
draw system and is configured so as to include an
appropriate number of rolls, with the upper side being a
heating roll 31 and the lower side being a vacuum roll 32.
A single deck dryer has little paper breakage in high speed
paper making at 1300 m/min or more that is a target of the
present invention, can perform drying at a high efficiency
and is excellent in quality and operation. Although a
system can be taken into account in which a double deck
system is used for drying, it poses problems from the
viewpoints of operation properties such as canvas marks in
high speed paper making, paper breakage in high speed
drying, cockles and paper joining.
[0062]
In the initial period in a dryer, desirably,
partitioned groups are made many for draw adjustment and a
suction box 33 is disposed for improvement of air passing
through paper and sheet traveling.
[0063]
A paper web dried in the pre-dryer part, as shown in
FIG. 3, is coated with a sizing agent such as starch and,
as required, an undercoating liquid such as a pigment
coating liquid in a size press 40 of a film transfer
(system) between the pre-dryer part and an after dryer
part. The size press 40 accepts a gate roll coater 40A or
the like, in addition to an illustrated rod metaling size

-20-
pre-coater.
[0064]
The undercoating liquids that can be used include,
besides starch as mentioned above, starch derivatives such
as oxidized starch, estrified starch, enzyme-modified
starch and etherified starch, and natural adhesives such as
soy bean protein, yeast protein and cellulose derivatives.
As required, a pigment may be added thereto. The pigments
include kaolin, clay, barium sulfate, light calcium
carbonate, heavy calcium carbonate, aluminum hydroxide,
satin white, titanium dioxide, calcium sulfite, zinc
sulfate, and plastic pigments. The pigment, a usual
pigment for a coated paper, is blended depending on
respective pigment properties. Moreover, the adhesives
that, can be used include usual additives for a coated paper
including synthetic resin adhesives such as alkali non-
sensitive or alkali sensitive synthetic resin emulsions,
for example, conjugated diene copolymer latexes such as
styrene/butadiene copolymers and
methylmethacrylate/butadiene copolymers, acrylic polymer
latexes such as polymers or copolymers of acryl and/or
methacrylate esters and vinyl acetate copolymer latexes
such as ethylene/vinyl acetate copolymers. As required, a
variety of assistants can be blended that include a
dispersing agent, a flow-modified agent, an antifoaming
agent, a dye, a lubricant, a water resistant additive and a
water retention agent. The coating amount of a base
coating agent is preferably from 0.01 to 4 g/m2,
particularly preferably from 0.2 to 3 g/m2.
[0065]
Examples of the coating means of a film transfer
system that can be used include a gate roll coater, a sim
sizer, and a blade metaling size press or a rod metaling
size press. Particularly desired is a rod metaling size
press. When this rod metaling size press coater is
employed, a rod having a smooth surface is desirably used

-21-
to avoid streak generation in operation. Setting the rod
diameter to be from 15 to 50 mm can obtain more preferable
operation properties and quality. A rod having a diameter
of less than 15 mm is liable to lead to decreasing in film
forming capability and becoming inferior in surface. For a
rod having a diameter of more than 50 mm, the effect is not
changed, and thus a particularly large diameter is not
required. A rod with a groove, a rod winding a wire
therearound, or the like can be also used as the rod.
[0066]
After coating of an undercoating liquid, an auxiliary
drying device 42 using an air turn bar 41 and an infrared
ray is desirably disposed in advance in an after dryer part
in order to avoid the generation of surface dirt.
[0067]
In the illustrated after dryer part of a single deck,
a sizing agent and a pigment coating liquid are dried.
[0068]
Thereafter, in a coater part, an aqueous coating
liquid having an additive and a pigment (clay or the like)
as primary components is applied. In this case, roll-
coating an aqueous coating liquid is adopted from the
viewpoint of the quality of the resulting coated paper
because a flat coated layer is required, at a paper making
speed of 1300 m/min or more so as not to generate paper
breakage and not to generate paper breakage in a second
blade coating apparatus.
[0069]
As such, prior to roll coating of an aqueous coating
liquid, a surface coated with a sizing agent is desirably
flattened by a pre-calender 50 in order to secure higher
smoothness. The pre-calender 50 of the embodiment has a
metal roll 51 on an upper side and an elastic roll 52 on a
lower side.
[0070]
In operation conditions in the pre-calender 50, a

-22-
heat roll instead of a metal roll is desirable. Desirably,
the temperature is set at, for example, from 100 to 300°C,
particularly from 150 to 250°C, and the linear pressure is
set at 50 KN/m. Both the rolls can be metal rolls and
further a caliper control roll can also be used in order to
control the profile in the width direction.
[0071]
A coater part of the present invention subsequent to
the pre-calender 50 has a first roll coating step to both
the faces of a paper to be coated and a second blade
coating step to both the faces of a paper to be coated and
selectively carries out coating.
[0072]
In other words, when passed through the first roll
coating step, the paper to be coated is coated on its both
faces by a roll coater 60. After passed through an air
turn bar 61, the resulting paper, in the width direction,
is dried by a temperature controllable auxiliary drying
device 62 using an infrared ray (having the same function
as in other cases), a first gas-type air dryer 63A, an
infrared ray auxiliary drying device 63A, an infrared ray
auxiliary drying device 67A and a first canvas dryer 64.
Thereafter, the resulting paper is passed through a bypass
pathway Y, dried by a second canvas dryer 68, and then led
to a calender 70.
[0073]
Where passed through the second blade coating step,
the paper is passed through the pre-calender 50 and then
through a bypass pathway X. The paper is, without being
passed through the roll coater, directly led to a first
blade coater 65A, where one face of the paper is coated.
After coated, the paper is dried by an infrared ray
auxiliary drying device 66A, the first gas-type air dryer
63A, the infrared ray auxiliary drying device 67A and the
first canvas dryer 64.
[0074]

-23-
Thereafter, the paper is, without being passed
through the bypass pathway Y, led to a second blade coater
65B, where the other face is coated. After coated, the
resulting paper is dried by an infrared ray auxiliary
drying device 66B, a second gas-type air dryer 63B, an
infrared ray auxiliary drying device 67B and the second
canvas dryer 68, and led to a calender 70.
[007 5]
Where, the paper to be coated is subjected to lower
layer coating on its both faces by the roll coater 60 via a
bypass pathway Z and can also be subjected to upper layer
coating by use of the first blade coater 65A and the second
blade coater 65B.
[0076]
The above-mentioned infrared ray auxiliary drying
devices can be used for temperature control in the width
direction in order to mainly each adjust moisture contents,
and their adoption can be selected as appropriate.
[0077]
In the first blade coater 65A and the second blade
coater 65B, a coating amount of 7 g/m: or more per face may
be required in the case of high speed paper making. In
such a case, a jet fountain system capable of making high
speed liquid provision as an applicator is desirable and
raking off is made by a blade. When a coating amount of
less than 7 g/m2 for one face is required, a short dwell
blade coater improved for high speed is also acceptable.
[0078]
In blade coating, as shown in FIG. 10, a fountain
angle a of an applicator 90 in the case where the coating
of a jet fountain system is adopted from 30 to 90 degrees,
more desirably from 40 to 60 degrees, in order to remove
coating unevenness in the flow and width directions for
roll coating. When the fountain angle a is out of the
above range, a rough surface and coating unevenness are
generated. A system having a bevel angel 6 of from 30 to

-24-
50 degrees in a blade edge is desirable. The thickness of
a blade is desirably from 0.45 to 0.60 mm. For the
possession of a high hardness, the blade edge is
constituted by a thermal spraying material having tungsten
or alumina oxide as a primary component. For example, a
system, having excellent conditions in coating properties,
has a constitution produced by thermally spraying tungsten
to a base material making up the edge of a blade and has a
Vickers hardness of from 1000 to 1700 Hv.
[0079]
In this case, after blade exchange, cooling means
such as water shower cooling is desirably disposed to
prevent blade burning at a high speed paper making at a
time of new blade touch.
[0080]
Finally, an on-machine calender 70 constituted by a
thermal soft calender is disposed and calender treatment is
implemented. The illustrated calender 70 is a multiple
calender of one stack type of 9 nips of vertical placement
of an optiload type. One stack type of 7 nips can also be
used and also Janus type inclined placement, illustrated
together, that makes the influence of roll dead weight
small is allowable.
[0081]
The calender 70 affects final smoothness and
glossiness. Hence, a variety of considerations are
required in terms of this and high speed paper making.
[0082]
The number of stages of the calender 70 is not
limited so long as the calender has at least two nips, and
a flattening treatment is desirably implemented by a
thermal soft calender comprising a combination of a metal
roll M and an elastic roll D formed in a multi-stage. In
particular, a multi-nip calender, more desirably a multi-
nip calender of 6, 8 or 10 stages is most suitable.
[0083]

-25-
On the other hand, a thermal calender may be a
calender in which a thermal medium such as oil is
circulated and heated, but this has a limit of a surface
temperature of about 180°C. For the implementation of
paper making at a high speed, as shown in FIGS. 7 to 9, the
metal roll M includes an internal heating device having
electromagnetic induction action capable of split
temperature control in its width direction, and treatment
is desirably carried out at a surface temperature of the
metal roll M of 230°C or more, particularly from 230 to
500°C. A specific example is a roll in which an induction
coil 71 is wound around an iron core 72 within a shell 74
and a heat medium passed through a jacket chamber 73 is
heated.
[0084]
A surface treatment is performed at a temperature of
from 2 50°C to 380°C of the metal roll M, particularly at a
temperature of from 300°C exclusive to 380°C inclusive, and
a paper is not broken throughout the entire layer at as low
a nip pressure as possible to be capable of preventing a
decrease in bulk and of restraining a decrease in opacity,
whereby operation can also be implemented. In short, it is
a mode in which an iron at an extremely high temperature is
contacted for a short time.
[0085]
The methods of controlling the surface temperature of
a metal roll that are particularly excellent for elevated
temperature treatment of the present invention include, in
addition to a method of circulating hot water or oil into a
metal roll, as described above, a method by an "internal
heating device by electromagnetic induction action" that
involves disposing an induction coil around an iron core
disposed in an inside as a non-rotation portion, flowing an
alternating current into its induction coil to generate a
magnetic flux in the coil and induce an induction current
inside an external shell (external cylinder) as a rotation

-26-
port on and self heat releasing (induction heat release)
the duts de shell (external cylinder) by its resistance
heat. In addition, according to the internal heating
device by the electromagnetic induction action, there' is an
advantage that an induction coil is divided (e.g., 3 to 6
divisions) in the width direction (longitudinal direction
of the roll itself) and an alternating current amount
flowed into a corresponding induction coil is controlled
based on a temperature signal from a temperature sensor
disposed in the shell, so that the temperature control in
the width direction particularly on the surface is possible
at high precision.
[0086]
In this case, a structure in which jacket pathways
particularly extended in the longitudinal direction inside
the shell are disposed in large numbers, from 10 to 90
pathways, in the peripheral direction at intervals, in
which these are connected to each other, and in which a
heat medium is enclosed in the inside, is more excellent
from the viewpoints of heat due to self heat releasing of
the shell being aosorbed and the heat being uniformed on
the entire roll surface.
[0087]
A surface treatment at elevated temperature according
tc the present invention increases not only the temperature
of the surface layer portion of a paper but the temperature
of the inner layer portion. As a result, not only the
surface layer portion of the paper but the entire layer is
liable to break, so that the bulk is lowered. Therefore,
where a paper is passed for a short time by further high
temperature treatment, heat transfer to the inner layer
portion can be prevented extremely, thereby being capable
of preventing a decrease in bulk.
[0088]
On the contrary, with increased temperature of the
surface temperature of a metal roll, the stress in the

-27-
width direction in the shell of a metal roll is generated
and the roll profile is likely to be destroyed, whereby the
controlling of a thick paper profile is decreased. In
addition, when a metal roll depends on an internal heating
device by electromagnetic induction action, the temperature
response of the surface temperature of the metal roll per
time does not seem to be good. Moreover, due to this, the
temperature response in the width direction is bad, which
is a cause of yield decrease because of bad temperature
controlling. Thus, at least either an external heating
device by electromagnetic induction action capable of
division temperature control in the roll width direction or
a cooling apparatus capable of cooling temperature control
in the roll width direction is desirably provided in the
vicinity of the metal roll M.
[0089]
This example will be primarily described in reference
to FIG. 8. The metal roll M includes a shell 74, an
induction coil 71, an iron core 72, a temperature sensor
75, an alternating current source 76 and a jacket pathway
73. With this metal roll M, an internal heating device 77
by electromagnetic induction action capable of division
temperature control in the roll width direction is disposed
in the vicinity of the metal roll M to constitute a high
temperature nip region of a base paper."
[0090]
The internal heating device 77 is an application of
the principle of electromagnetic induction heating. As
shown in the drawing, the internal heating device 77
entails flowing an alternating current (e.g., a high
frequency of from 3 to 20 kHz) from an alternating current
source (inverter) 77B to a work coil 77A to generate a
magnetic field, generating an eddy current on a shell 74
surface portion, and self heat releasing. The separation
distance between the work coil 77A and the shell 74 surface
is desirably from 2 to 20 mirg particularly desirably

-28-
roughly from 2 to 5 mm. In addition, a unit work coil is
desirably inclination-disposed so as to cross the shaft of
the metal roll M for the purpose of texture of a profile,
for heating purposes. The zone control pitch in the roll
width direction is roughly from 75 to 150 mm, and the
rating electric power per zone can be set at from 4 to 20
kW.
[0091]
An example of a cleaning apparatus 78 capable of
cooling temperature control in the roll width direction is
as follows. As shown in FIG. 9, air is sent from a fan 78a
to a header 78b and the air is sent into a temperature
adjusting chamber 78d through an adjusting plate 78c having
communicated pores formed therein. Then, a coil 78e
disposed within the temperature adjusting chamber 78d ie
cooled by temperature adjusting means 78f to control the
ventilation temperature passing through a dispersion plate
78g having small pores.
[0092]
The nip pressure in the calender 70' is desirably from
200 KN/m to 450 KN/m, particularly desirably from 300 KN/m
to 450 KN/m. The paper flattening treated by the calender
70 is finally wound by a reel 80, and a winder (not shown)
for finishing winding for subdivision is disposed in the
final portion of the machine.
[0093]
In place of the multi-nip calender shown in FIG. 4,
as illustrated in FIG. 5, for example, a soft calender 70A
including the metal roll M constituted by 1 nip and 4
stacks and the,elastic roll D is acceptable.
EXAMPLES
[0094]
Advantages of the present invention will be clarified
by means of examples and comparative examples.
Factors such as a wire part mode, a placement angle

29-
of the head box, a suction mode, a coating mode, a thermal
soft calender and a paper making speed, of the present
invention, were changed and quality of paper were
evaluated. In addition, each of the examples did not newly
dispose individual lines for each of all the factors and
testing examples by testing plants were primarily newly
replaced.
[0095]
Quality evaluations of paper are in the following.
1. Contaminants: The area of contaminants was
evaluated by connecting a CCD camera to an optical
microscope and measuring one sheet AA paper at a
magnification of 8 pm per pixel via an image analyzing unit
(LUZEX AP) and then averaging them for 10 cm'. In
addition, contaminants of 0.005 mm' or less could not
visually be recognized, and thus were neglected.
2. Texture evaluation: The texture evaluation
stipulated in the example was implemented by obtaining the
variation of a transmitted light amount as a time sequence
signal using a sheet texture tester available from TOYO
SEIKI KOGYO CO., LTD. This measuring device can measure 28
points in the wavelength range of unevenness of from about
0.16 to about 80 mm. However, because 14 points in the
range of from 4.0 to 80 mm in the example were closely
related.to texture indicated by large shades in watermark
texture by sensory inspection, the sum of the coefficients
of variation in the range was determined. When the
unevenness index is less than 6%, the texture is very in
uniform, the glossiness unevenness of a coated paper
surface attributable to texture unevenness hardly occurs,
the-formation of a coated layer is uniform, and printing
unevenness at printing, printing glossiness unevenness,
etc. disappear, so that printing suitability is improved.
3. Paper breakage: A test operation was conducted at
a paper making speed of 1500 m/min at a constant drying
temperature for 3 hours using a test plant equivalent to an

-30-
actual machine and the number of paper breaks due to the
difference of drying methods was evaluated.
o: Number of paper breaks, 0 time; : one time; *:
one or more times.
4. Cockle: A test operation was conducted at a paper
making speed of 1300 m/min at a constant drying temperature
for 3 hours using a test plant and the number of cockles
due to the difference of drying methods was evaluated. o:
Number of cockles, 0; : one; x: one or more.
5. Specific volume: Measured in accordance ,with JIS P
8118 (1976).
6. Glossiness: Was measured at an angle of 75 degrees
in accordance with JIS P 8142.
7. Glossiness unevenness: Test paper sheets of an A4
size were prepared, and were visually evaluated by five
females and five males on the basis of five criteria.
Level 3 or higher was regarded allowable.
8. Printing unevenness: Test paper sheets of a
duodecimo size were prepared, and printed using a Rowland
offset printer, left to stand for 24 hours at a constant
temperature. Then, solid printed portions of samples,
overprinted with four colors of black, magenta, cyan and
yellow, were visually evaluated by five females and five
males on the basis of five criteria. Level 3 or higher was
regarded allowable.
9. Rigidity: Determined in accordance with JIS P
8115.

10. Yellow change (by calender treatment): A product
was prepared to a duodecimo size and the extent of yellow
of the product was visually evaluated by five females and
five males on the basis of five criteria. Level 3 or
higher was regarded allowable.
11. Productivity: stability of a wet end, dewater
properties in a press part, generation states of drainage
and streaks, etc. in each example in a test machine were
observed by five operators, and each of the evaluation

-31-
results was collected and evaluated based on 5 criteria.
Level 3 or higher was regarded allowable.
12. Overall evaluation: All of the quality attributes
were all totally evaluated on the basis of four criteria.
: Good production efficiency/quality, o: No problems in
production efficiency/quality, : Some problems, * :
Problems.
In addition, the roll hardness of a roll coater is
the A hardness value of JIS K 6301, and the hardness of a
blade is the Hv (hard Vickers). The roll surface roughness
indicates the central line average roughness in accordance
with JIS P 0601.
[0096]
Base paper conditions are as follows:

A base paper having pulp below and a basis weight
(absolute dry) of 60 g/nr was made to produce a paper base
material.

A pulp was prepared according to the example tables.
In the present invention, paper breakage was frequently
generated due to the affect of contaminants in high speed
paper making. For this reason, a raw material pulp was
prepared such that the amount of contaminants in a product
was 0.010 mmVlO cm2 or less per A4 size sheet in the
measuring amount in contaminant measuring means and used.
A paper base material was prepared using the above
pulp blending and the internal additive agent blending
below.

- Soft calcium carbonate: 10 weight parts (average particle
diameter: 3.4 μ, calcite-based)
- Commercially available alkylketene dimmer-based internal
sizing agent (AKD): 0.03 weight part
- Commercially available cationized starch: .0.2 weight part
- Commercially available cation-based polyacrylamide yield

-32-
improving agent: 0.03 weight part

A starch coating liquid was applied in an amount of
0.5 g/m: onto the above paper base material and dried.

The coating liquid having the blend below was applied
onto a paper base material after the above size press using
a. roll coater and a blade coater according to examples and
dried.

Blending is as follows:
(Pigments)
- Spindle-shaped soft calcium carbonate (TPI121 available
from OKUTAMA KOGYO CO., LTD., 3.4 μm): 30 weight parts
- Commercially available fine particle kaolin (Amazon 88,
average particle diameter: 0.8 μm) : 70 weight parts
(Binders and additives)
- Commercially available phosphoric acid esterified starch
(MS4400 available from NIHON SHOKUHIN KAKO CO., LTD.): 1
weight part
- Styrene/butadiene latex (0617 available from JSR
CORPORATION): 12 weight parts
- Commercially .available polyacrylic acid-based dispersing
agent: 0.1 weight part
- Commercially available calcium stearate: 0.3 weight part
- Sodium hydroxide: 0.15 weight part
[0097]
Under the conditions above and the conditions
indicated in Tables, a variety of factors were searched and
the results listed in Tables 1 to 36 were obtained.
Examples 1 to 42 indicate examples of a combination of roll
coating and blade coating only, Examples 43 to 56 indicate
examples of roll coating only, and Examples 57 to 69
indicate examples of blade coating only.

-33-


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-35-


-36-


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-39-


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-41-


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-47-


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-54-


-55-


-56-


-57-


-58-


-59-


-60-


-61-


-62-


-63-
[0134]
"Discussions"
Examples according to the present invention shows
that high quality paper can be obtained albeit in high
speed paper making, as compared with the cases in
Comparative Examples.
Brief Description of the Drawings
[0135]
FIG. 1 is a schematic explanatory diagram showing a
first zone of an apparatus constitution example of a paper
making machine.
FIG. 2 is a schematic explanatory diagram showing a
second zone of an apparatus constitution example of a paper
making machine.
FIG. 3 is a schematic explanatory diagram showing a
third zone of an apparatus constitution example of a paper
making machine.
FIG. A is a schematic explanatory diagram showing a
forth zone of an apparatus constitution example of a paper
making machine.
FIG. 5 is a schematic explanatory diagram showing a
modified example of the calender part in the forth zone of
an apparatus constitution example of a paper making
machine.
FIG. 6 is a schematic explanatory diagram showing the
ejection of paper stock of a head box.
FIG. 7 is a schematic explanatory diagram showing a
heating metal roll.
FIG. 8 is a schematic explanatory diagram showing an
example of an internal heating device by electromagnetic
induction action.
FIG. 9 is a schematic explanatory diagram showing an
example of a cleaning apparatus.
FIG. 9 is a schematic explanatory diagram showing an
example of a blade coating machine.

-64-
Description of the Symbols
[0136]
1: First wire, 2: Second wire, 3: Head box, 5: Blade
10: Twin wire former, 21: First press, 22: Presses 22, 40:
Size press, 41: Air turn bar, 50: Pre-calender, 51: Metal
roll, 52: Elastic roll, 60: Roll coater, 65A: First blade
coater, 70: On-machine calender, M: Metal roll, D: Elastic
roll, 80: Reel, 90: Applicator, 91: Blade.

-65-
CLAIMS
1. (Amended) A process for producing a coated paper
in which continuous steps are incorporated successively
within on-machine, the process comprising:
a step of making a paper with a twin wire former in
which a paper material is injected from a head box between
two wires each of which loops to form a paper layer;
an undercoating step of applying an undercoating
liquid to a dry web by a size press;
a step of drying the undercoating liquid
a first flattening treatment step of performing a
flattening treatment by a pre-calender;
a face coating step of applying a face coating liquid
by selecting a single coating step of (1) or (2) as
follows, or a coating step of performing the step (2)
after performing the step (1),
(1) a roll coater coating step of roll-coating one
side and the other side of a paper to be coated with an
aqueous coating liquid consisting mainly of an adhesive
and a pigment, and then drying the coated paper,
(2) a blade coater coating step of blade-coating one
side and the other side of a paper to be coated with an
aqueous coating liquid consisting mainly of an adhesive
and a pigment, and then drying the coated paper; and
a step of subjecting the coated paper to a flattening
treatment using a heat soft calender comprising a
combination of a metal roll and an elastic roll formed in
a multi-stage having at least two nips.
2. (Amended) The process for producing a coated paper
according to claim 1, wherein the pre-calender comprises a
heated metal roll as at least one roll of a pair of rolls.
3. (Amended) The process for producing a coated paper
according to claim 1 or 2, wherein the pre-calender
comprises a pair of a metal roll and an elastic roll and

-66-
the metal roll is heated to a temperature of 100 to 300°C.
4. (Amended) The process for producing a coated paper
according to any one of claims 1 to 3, wherein the
flattening treatment is performed by the pre-calender
comprising the metal roll heated to a temperature of 230~'C
or more.
5. (Amended) A coated paper produced by the process
for producing according to any one of claims 1 to
4.

To produce a coated paper having quality required of coated papers while attaining heightened productivity and coping
with reduction in weight and coating amount.
[Means for Solving Problems]
For forming coating layers on a surface of a base paper, coating apparatuses differing in coating method are used. Thus at least two coating layers are formed on the surface
layer of the base paper. In particular, the base paper is coated by a combination of coating by a roll coater (60) and coating by a blade coater (65A).

Documents:

00279-kolnp-2008-abstract.pdf

00279-kolnp-2008-claims.pdf

00279-kolnp-2008-correspondence others.pdf

00279-kolnp-2008-description complete.pdf

00279-kolnp-2008-drawings.pdf

00279-kolnp-2008-form 1.pdf

00279-kolnp-2008-form 3.pdf

00279-kolnp-2008-form 5.pdf

00279-kolnp-2008-gpa.pdf

00279-kolnp-2008-international publication.pdf

00279-kolnp-2008-others.pdf

00279-kolnp-2008-pct request form.pdf

279-KOLNP-2008-(07-10-2013)-ANNEXURE TO FORM 3.pdf

279-KOLNP-2008-(07-10-2013)-CORRESPONDENCE.pdf

279-KOLNP-2008-(18-07-2013)-AMANDED CLAIMS.pdf

279-KOLNP-2008-(18-07-2013)-ANNEXURE TO FORM 3.pdf

279-KOLNP-2008-(18-07-2013)-CORRESPONDENCE.pdf

279-KOLNP-2008-(18-07-2013)-OTHERS.pdf

279-KOLNP-2008-(30-11-2012)-ABSTRACT.pdf

279-KOLNP-2008-(30-11-2012)-ANNEXURE TO FORM 3.pdf

279-KOLNP-2008-(30-11-2012)-CLAIMS.pdf

279-KOLNP-2008-(30-11-2012)-CORRESPONDENCE.pdf

279-KOLNP-2008-(30-11-2012)-DESCRIPTION (COMPLETE).pdf

279-KOLNP-2008-(30-11-2012)-DRAWINGS.pdf

279-KOLNP-2008-(30-11-2012)-FORM-1.pdf

279-KOLNP-2008-(30-11-2012)-FORM-2.pdf

279-KOLNP-2008-(30-11-2012)-OTHERS.pdf

279-KOLNP-2008-(30-11-2012)-PA.pdf

279-KOLNP-2008-(30-11-2012)-PETITION UNDER RULE 137.pdf

279-KOLNP-2008-ASSIGNMENT.pdf

279-KOLNP-2008-CORRESPONDENCE OTHERS 1.1.pdf

279-KOLNP-2008-CORRESPONDENCE OTHERS-1.1.pdf

279-KOLNP-2008-CORRESPONDENCE OTHERS-1.2.pdf

279-kolnp-2008-form 18.pdf

279-KOLNP-2008-FORM 3-1.1.pdf

279-KOLNP-2008-PCT PRIORITY DOCUMENT NOTIFICATION.pdf

279-KOLNP-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-00279-kolnp-2008.jpg


Patent Number 258234
Indian Patent Application Number 279/KOLNP/2008
PG Journal Number 51/2013
Publication Date 20-Dec-2013
Grant Date 19-Dec-2013
Date of Filing 18-Jan-2008
Name of Patentee DAIO PAPER CORPORATION
Applicant Address 2-60, MISHIMAKAMIYACHO SHIKOKUCHUO-SHI, EHIME
Inventors:
# Inventor's Name Inventor's Address
1 MATSUSHIMA TADAHIRO C/O DAIO PAPER CORPORATION, 5-1, MISHIMAKAMIYACHO, SHIKOKUCHUO-SHI, EHIME 799-0492
PCT International Classification Number D21H 19/82
PCT International Application Number PCT/JP2006/312058
PCT International Filing date 2006-06-15
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2005-179111 2005-06-20 Japan
2 2005-332733 2005-11-17 Japan