Title of Invention

PROCESS FOR PRODUCING PHENOLIC NOVOLAK RESIN

Abstract A process in which a continuous reactor is used to advantageously produce in a short time a phenolic novolak resin containing substantially no unreacted aldehyde remaining therein, while preventing higher-order condensates from generating. The process for phenolic novolak resin production uses a continuous reactor (10) having a long reaction tube (12) to react a phenol with an aldehyde in the presence of an acid catalyst to thereby continuously produce a phenolic novolak resin, wherein a heating zone (26) and a temperature control zone (32) are disposed along the longitudinal direction for the reaction tube (12). In this process, the reactants are heated to at least a temperature at which heat of reaction generates, in the heating zone (26), which is located upstream in the liquid-passing direction. In the temperature control zone (32), which is located downstream, the liquid mixture heated by this heating operation and by the heat of reaction is pressurized so that the pressure inside the reaction tube (12) increases to or above the water vapor pressure, while cooling the mixture.
Full Text SPECIFICATION
PROCESS FOR PRODUCING PHENOLIC NO VOLAR RESIN
TECHNICAL FIELD
[0001] The present invention relates in general to a process
for producing a phenolic novolak resin. More particularly, the
present invention relates to a technique for advantageously
producing the phenolic novolak resin by using a continuous
reactor.
BACKGROUND ART
[0002] As it is well known, the phenolic novolak resin is
produced by heating and reacting at least one of phenols and at
least one of aldehydes in the presence of an acidic catalyst. In
detail, the phenolic novolak resin is produced by repeating an
addition reaction, in which an intermediate is formed by an
addition of the at least one of aldehydes to the at least one of
phenols, and a condensation reaction, in which the at least one of
phenols is condenced with the intermediate. The molecular
weight of the phenolic novolak resin is adjusted based on a
blending ratio of the at least one of phenols and the at least one
of aldehydes. For this reason, if the phenolic novolak resin is
made from a phenol and a formaldehyde, for instance, the
blending ratio is generally determined, so that the molar ratio of
the at least one of aldehydes (F) to the at least one of phenols (P)
is not more than one, i.e., (F/P) = 1.
[0003] In producing the phenolic novolak resin, there are

employed a production technique for a batch process or a
continuous process. However, in the latter production process for
the continuous process, in which the reaction of the at least one
of phenols with the at least one of aldehydes are progressed in a
long reaction tube, while raw materials are continuously flowed
into the reaction tube, there is easily generated an insoluble and
non-melting higher order condensation product (scale) on an
internal surface of the reaction tube. Accordingly, there is a
tendency of deteriorating a heat transfer performance of the
reaction tube which makes a temperature control difficult and
deteriorating a quality of a product. For this reason, there are
mainly adopted the former technique for the batch process and a
method, in which the technique for the batch process is
automated.
[0004] Also, in the former technique for the batch process,
the raw materials accommodated in a reactor is simultaneously
reacted at one time. Accordingly, there is a defect that a
production volume of the resin is limited according to a capacity
of the reactor, and there is a problem that it is difficult to reduce
the production time. Therefore, the technique for the batch
process is basically poor in its productivity. In addition, in the
technique for the batch process, there is needed to respectively
accommodate the raw materials in the reactor, heating the
reactor, and removing the product from the reactor for each batch,
whereby the technique for the batch process is troublesome,
compared with those of the technique for the continuous process.
[0005] In producing the phenolic novolak resin, generally
the blending quantity of the at least one of aldehydes is
determined to be a small amount, so that the above—described
molar ratio (F/P) of the at least one of aldehydes (F) and the at
least one of phenols (F) is not higher than one. In case of the
batch process, even if the amount of the at least one of aldehydes
is made much smaller than that of the at least one of phenols, a
few % of the at least one of aldehydes is unreacted and remained
in a reaction product in liquid phase after the reaction is
completed, which causes a problem of requiring an expenditure
for removing the unreacted aldehyde (residual monomer). Also, if
the reaction product in liquid phase is distilled under reduced
pressure after the reaction is completed so as to remove the
unreacted compounds and moisture from the reaction product,
there is a tendency that the unreacted aldehyde is gradually
reacted during the distillation, so that a molecular weight of the
phenol resin just after the reaction is not the same as that of the
phenol resin after an aftertreatment.
[0006] In Patent Document 1, there is proposed a process
for producing a phenol formaldehyde resin by using a continuous
reactor. In Patent Document 1, a reaction tube is divided into
several sections of reaction zones and respectively heating the
reaction zones, so that the temperature of the reaction tube
gradually increases. However, as a result of a study of the
inventors of the present invention, there was revealed that if the
phenol formaldehyde resin is produced by adopting the above
process, there was generated higher order condensation products
on the internal surface of the reaction tube. Therefore, there was
needed to further improve such method.
[0007] Patent Document l: JP-A-51-130498
DISCLOSURE OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0008] The present invention was developed in view of the
above situations. It is therefore an object of the invention to
provide a process for advantageously producing, in a short period
of time, a phenolic novolak resin, in which substantially no
unreacted aldehyde is remained, while there is prevented a
generation of higher order condensation products, by using a
continuous reactor.
MEANS FOR SOLVING THE PROBLEM
[0009] As a result of an extensive study of the inventors of
the present invention, there was found that a total amount of the
at least one of aldehydes, which is used as one of raw materials,
can be substantially reacted, by devising a heating operation and
a temperature control operation of a mixture of the raw materials
including the at least one of phenols, the at least one of
aldehydes, and the acidic catalyst, as well as setting a pressure
within the continuous reactor to a pressure not less than a
predetermined pressure. In addition, there can be
advantageously produced a phenolic novolak resin of an excellent
quality, with which no higher order condensation product is
mixed.
[0010] The present invention was made based on the above

findings, and a first form of the present invention provides a
process for continuously producing a phenolic novolak resin by
reacting at least one of phenols with at least one of aldehydes in
the presence of an acidic catalyst, by using a continuous reactor
which has a long reaction tube,
characterized by comprising the steps of-
providing the reaction tube of the continuous reactor with
a heating zone and a temperature control zone in a longitudinal
direction of the reaction tube;
continuously supplying a mixture, which includes the at
least one of phenols, the at least one of aldehydes, and the acidic
catalyst, into the reaction tube of the continuous reactor, while a
pressure in the reaction tube is kept to be not lower than a vapor
pressure of water;
heating the mixture at the heating zone, which is located
on an upstream side of the reaction tube in a direction of a flow of
the mixture, to a temperature which is not less than a
temperature, at which a reaction heat is generated, for thereby
initiating an addition condensation reaction between the at least
one of phenols and the at least one of aldehydes in the mixture!
and
introducing the mixture, whose temperature is increased
by the heating operation and the reaction heat of the addition
condensation reaction, to the temperature control zone, which is
located on a downstream side of the reaction tube in the direction
of the flow of the mixture, and progressing the addition
condensation reaction while only the cooling operation of the

mixture is conducted.
[OOll] Also, in a second form of the process for producing
the phenolic novolak resin according to the present invention,
a pipe diameter of at least a portion of the reaction tube,
which is located on a downstream side of the temperature control
zone with respect to the direction of the flow of the mixture, is
made smaller than a pipe diameter of a portion of the reaction
tube which is located on the heating zone, so as to enhance a flow
rate of the mixture located within the portion of the reaction tube
of which the pipe diameter is made smaller.
[0012] Moreover, in a third form of the present invention, a
static mixer is positioned inside the reaction tube, so that the
mixture being flowed in the reaction tube is stirred in the
reaction tube.
[0013] In addition, in a fourth form of the present invention,
the flow rate of the mixture flowing inside the reaction tube is
not less than 0.3m/second.
[0014] Also, in a fifth form of the process for producing the
phenolic novolak resin according to the present invention, a
length of the heating zone is shorter than a length of the
temperature control zone.
ADVANTAGEOUS EFFECT OF THE INVENTION
[0015] According to the above-mentioned first form of the
process for producing the phenolic novolak resin according to the
present invention, the heating zone is provided on the upstream
side of a longitudinal reaction tube, in the direction of the flow of

the mixture (liquid) of the raw materials, and the mixture is
promptly heated to a temperature, which is not less than the
temperature, at which the reaction heat is generated. In this case,
in the present invention, it is desirable to adopt, as a minimum
heating temperature, a temperature (about 80°C ~ about 100°C),
with which an addition condensation reaction is substantially
initiated and a sufficient reaction heat is generated. Meanwhile,
it is desirable to adopt, as a maximum temperature, a
temperature (about 160°C ~ about 180°C), which enables the
temperature control, although these temperatures are influenced
by an amount and a kind of the catalyst. The temperature of thus
heated mixture is controlled only by the cooling operation at a
temperature control zone, which is provided on the downstream
side of the reaction tube with respect to the direction of the flow
of the mixture, so as not to exceed 180°C and not to be lower
than 90°C. For this reason, according to the present invention,
the phenolic novolak resin which has a desired molecular weight
can be highly advantageously produced. In addition, according to
the present invention, a speed of the production of the intended
resin is enhanced, whereby a distribution of molecular weight of
thus produced resin is preferable, and a generation of the higher
order condensation products to be the scale is effectively
restrained, compared with a conventional method, in which the
temperature is gradually increased. In the present invention, the
"temperature, at which the reaction heat is generated" means a
temperature, at which a rate of increase of the mixture
temperature at the heating zone is enhanced.

[0016] In addition, in the process for producing the
phenolic novolak resin according to the present invention, the
pressure in the reaction tube is kept to be not lower than the
vapor pressure of water. Accordingly, there is advantageously
restricted a vaporization of water which is used as a solvent and
which is generated as a result of the condensation reaction.
Accordingly, the at least one of aldehydes is efficiently provided
for the reaction, and there can be effectively prevented the
unreacted at least one of aldehydes from remaining in the
mixture, after the reaction is completed. Owing to this
arrangement, there is not needed to previously introduce a
somewhat larger quantity of the at least one of aldehydes,
anticipating a quantity of the at least one of aldehydes to be
unreacted. In addition, there is not needed an operation of
removing the unreacted at least one of aldehydes after the
reaction, so that a production cost can be advantageously
reduced.
[0017] Also, in the second form of the process for
producing the phenolic novolak resin according to the present
invention, the pipe diameter of at least the portion of the
reaction tube, which is located on the downstream side of the
temperature control zone with respect to the direction of the
flow of the mixture, is made smaller than the pipe diameter of
the portion of the reaction tube which is located on the heating
zone, so as to enhance the flow rate of the mixture located
within the portion of the reaction tube of which the pipe
diameter is made smaller. Accordingly, even if a viscosity of

the mixture flowing at the downstream in the direction of the
flow of the mixture is increased, there is highly effectively
prevented the generation of the scale inside the reaction tube.
[0018] Moreover, according to the third form of the present
invention, the static mixer is positioned inside the reaction tube,
so that the mixture being flowed in the reaction tube is stirred in
the reaction tube. Accordingly, the reaction of the at least one of
phenols with the at least one of aldehydes is effectively
progressed, and the generation of the higher order condensation
products can be effectively restrained.
[0019] In addition, if the flow rate of the mixture is not less
than 0.3m/second according to the above fourth form of the
process for producing the phenolic novolak resin of the present
invention, there can be more effectively prevented the generation
of the higher order condensation products.
[0020] Also, in the fifth form of the process for producing
the phenolic novolak resin according to the present invention, the
length of the heating zone is shorter than the length of the
temperature control zone, so that the mixture of the raw
materials is promptly heated to the temperature, which is not
less than a temperature, at which the reaction heat is generated.
Accordingly, there can be ensured a sufficient length of the
temperature control zone, which progresses the reaction of the at
least one of phenols with the at least one of aldehydes. Therefore,
the intended phenolic novolak resin can be more advantageously
produced.

BRIEF DESCRIPTION OF THE DRAWING
[0021] [Fig.1] This is a schematic diagram showing one
example of the continuous reactor used in the present invention.
DESCRIPTION OF REFERENCE NUMERALS
[0022] 10: Continuous reactor
12: Reaction tube
12a~12j: Pipe
14
18
22
24
26
32
Raw material-storage tank
Reaction product-storage tank
Pump
Pressure-regulating valve
Heating zone
Temperature control zone
BEST MODE FOR CARRYING OUT THE INVENTION
[0023] The phenolic novolak resin is produced by the
reaction of the at least one of phenols, the at least one of
aldehydes, and the acidic catalyst, which are used as essential
components, as described above. As examples of the phenols,
which are among the raw materials, there can be used-* phenol,"
orthocresoL' methacresoL' paracresol; resorcinol' xylenol;
bisphenols; ortho-substituted phenols having a hydrocarbon
radical, which has at least three carbons, preferably 3~10
carbons, at its ortho position; para - substituted phenols having a
hydrocarbon radical, which has at least three carbons, preferably
3~18 carbons at its para position,' and other substituted phenols.
Any one of, or any combination of these phenols are used.
[0024] Among the above-mentioned phenols, there can be
used, as the bisphenols, bisphenol A, bisphenol F,
bis(2-methylphenol) A, bis(2-methylphenol) F, bisphenol S,
bisphenol E, bisphenol Z, or the like. As the ortho-substituted
phenols, there can be used 2-propylphenol, 2-isopropylphenol,
2-sec-butylphenol, 2-tert-butylphenol, 2-phenylphenol,
2-cyclohexylphenol, 2-nonyl phenol, 2-naphthylphenol, or the
like. In addition, there can be used, as the para-substituted
phenols, 4—propylphenol, 4—isopropylphenol, 4—sec—butylphenol,
4-tert-butylphenol, 4-phenylphenol, 4-cyclohexylphenol,
4-nonylphenol, 4—naphthylphenol, 4-dodecylphenol,
4—octadecylphenol, or the like.
[0025] Meanwhile, there can be exemplified conventionally
known various aldehydes, such as formaldehyde, formalin,
paraformaldehyde, trioxane, acetic aldehyde, paraaldehyde,
propionaldehyde, or the like. Any one of, or any combination of
these aldehydes are used. These aldehydes are solved in water
and used in a form of an aqueous solution, as needed.
[0026] Generally, the phonols (P) and the aldehydes (F), as
described above, are respectively used in an amount of 0.1~1.0
mol, preferably in an amount of 0.3~0.9 mol per 1 mol of the at
least one of phenols.
[0027] The catalyst to be employed for the addition
condensation reaction of the phenols and aldehydes is not
particularly limited, as long as the catalyst is an acidic catalyst.
There is suitably selected from among known various acidic
catalysts, which are conventionally used for a manufacture of the
phenolic novolak resin. Examples of the acidic catalyst for the
production of the phenolic novolak resin can include: acids such
-
as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, maleic
acid, phosphoric acid, and oxalic acid; and divalent metal salts
such as zinc chloride, zinc acetate, and manganese acetate. Any
one of, or any combination of these catalysts are used.
[0028] An amount of use of the cataryst is not particularly
limited, and is preferably determined based on a composition of
the raw materials, etc. Generally, there is adopted a ratio of 0.5~
50 parts by mass of the catalyst per 1000 parts by mass of the at
least one of phenols.
[0029] Accordingly, there is produced the phenolic novolak
resin by using the at least one of phenols, the aldehydes, and the
acidic catalyst, as described above. In the production of such
phenolic novolak resin of the present invention, there is not used
a conventionally used batch process reactor, but there is used a
continuous reactor which excels in productivity.
[0030] In particular, in Fig. 1, there is shown an outline of
a schematic diagram which shows one embodiment of a
continuous reactor to be adopted in the present invention. A
continuous reactor 10 is formed including a reaction tube 12,
which has a shape of a long pipe, in which the at least one of
phenols and the at least one of the aldehydes are substantially
reacted with each other, similar to a conventional process.
Described more specifically, the reaction tube 12 has ten
straight-shaped metal pipes 12a ~ 12j, each of which has a
conventionally known double pipe structure consisting of
coaxially located internal and external tubes, and the metal pipes
12a ~ 12j are connected to each other in series, by being

connected at the internal pipes by using metal connecting pipes
13 which roughly have U-shapes. As a whole, the reaction tube
12 has a structure, corresponding to a long cylindrical pipe which
has a plurality of U-shaped bent portions, wherein each pair of
adjacent bent portions are provided at predetermined intervals.
[0031] An internal diameter and a length of the reaction
tube 12 (in detail, connected internal tubes) are not particularly
limited, and can be suitably determined based on a kind, a flow
rate, heating temperature, etc. of the mixture (liquid) of the raw
materials flowing in the reaction tube 12. As the internal
diameter, there is generally adopted a size in a range of about
10mm~ about 200mm. Meanwhile, as the total length of the
reaction tube 12, there is adopted a length within a range of
about 10m~ about 2000m, so that an excellent productivity can
be suitably ensured.
[0032] Also, to one of ends of the reaction tube 12 (pipe 12a
side), comprising the above-mentioned series of pipes 12a~12j,
there is connected a supply passage 16, which is formed of a
cylindrical pipe and is intended to introduce the mixture of the
raw materials stored in a storage tank 14 for raw material to the
reaction tube 12. Meanwhile, to the other end of the reaction tube
12 (pipe 12j side), there is connected a delivery passage 20, which
is formed of a cylindrical pipe and intended to deliver the
mixture, which has been reacted within the reaction tube 12, to a
storage tank 18 for reaction product.
[0033] Moreover, on a supply passage 16, there is provided
a pump 22, which has a known structure. Due to an operation of

this pump 22, the mixture of the raw materials stored in the raw
material-storage tank 14 is introduced to the inside the reaction
tube 12 and flowed within the reaction tube 12, and then the
mixture is stored in the reaction product-storage tank 18 via the
delivery passage 20. According to this arrangement, the mixture
can be continuously flowed within the continuous reactor 10 in a
specific direction (in a direction A in Fig. 1).
[0034] In addition, there is provided a pressure-regulating
valve 24 on the delivery passage 20, which is located at the
downstream side of the reaction tube 12 relative to the flowing
direction of a flow of the mixture. The pressure-regulating valve
24 is particularly configured, so that the pressure of an inside of
the reaction tube 12 can be kept to a certain pressure, by
operating the pressure-regulating valve 24.
[0035] In the present embodiment, two pipes 12a, 12b,
which are located at the upstream side of the reaction tube 12
with respect to the direction of the flow of the mixture, are made
as a heating zone 26, at which the heating operation is executed.
The heating zone includes a couple of pipes 12a, 12b, and a high
temperature steam is flowed in a space, which is located at an
outermost part within each of the double-pipe-structured pipes
12a, 12b and which has an annular cross section (a space
between the internal and external pipes). Described in detail, by
operating each valve 30 positioned on steam supply passage 28
connected to a high-temperature steam generator (not shown), a
predetermined amount of a high-temperature steam can be
introduced into each of the pipes 12a, 12b. There is arranged that,

if the high-temperature steam is flowed from one of the ends of
the pipes 12a, 12b (right side in Fig. 1) to the other ends of the
pipes 12a, 12b (left side in Fig. 1) and is discharged, a heat of the
high-temperature steam is transmitted to the mixture flowing in
the innermost part within the pipes 12a, 12b, whereby the
mixture of the raw materials are heated in the heating zone 26 at
one stroke.
[0036] Meanwhile, a portion which is formed by eight pipes
12c~12j located downstream of the reaction tube 12 with respect
to the direction of the flow of the mixture is made as a
temperature control zone 32. In the space which has the annular
cross section (in the annular space between the internal and
external tubes) of the eight pipes 12c~12j which form the control
zone 32, a cooling water is flowed as needed, unlike the
above-described heating zone 26.
[0037] Described in detail, by controlling each of valves 36
located on each of cooling water ducts 34, which are
communicated with a cooling water tank, not shown, a
predetermined flow rate of the cooling water is introduced to each
of the annular spaces of the pipes 12c~12j. Due to this cooling
water, a generation of an excessive heat of the mixture flowing
within the internal pipes of the pipes 12c~12j, which have
double pipe structures. Accordingly, temperature of the mixture
can be advantageously controlled to a desired temperature.
Namely, the temperature control at the temperature control zone
32 can be executed only by a necessary cooling operation, without
executing any heating operation. According to this arrangement,

the temperature of the mixture can be extremely easily
controlled, without causing the runaway reaction. Therefore,
there can be stably produced the phenolic novolak resin of an
excellent quality, in which higher order condensation products
are not mixed. In Fig. 1, two adjacent pipes of the temperature
control zone 32, in particular, 12c and 12d, 12e and 12f, 12g and
12h, and 12i and 12j from the upstream end of the temperature
control zone 32, respectively constitute one pair of pipes. The
cooling water is arranged to be flowed from the downstream side
to the upstream side of the respective pairs of the pipes, and then
flowed out of the pipes.
[0038] In order to continuously produce an intended
phenolic novolak resin by using the continuous reactor of the
present embodiment, which has a structure as described above,
there may be adopted procedures such as the followings.
[0039] That is, first of all, the raw materials such as the at
least one of phenols, the at least one of aldehydes, the acidic
catalyst, etc., as described above, and a solvent such as water and
other additives, as needed, are introduced in a raw
material-storage tank 14, in which the raw materials are
temporarily stored, continuously or at intervals of a
predetermined time. The raw materials etc. introduced in the for
raw material-storage tank 14 are stirred in a stirrer (not shown)
within the raw material-storage tank 14, and made into a
uniform mixture. At this time, the temperature of the mixture in
the raw material-storage tank 14 is a room temperature ~
about 60°C.

[0040] By an operation of the pump 22, the mixture stored
in the raw material-storage tank 14 is continuously delivered to
the reaction tube 12 via the supply passage 16. In this case, it is
desirable that the flow rate of the mixture flowing writhin the
reaction tube 12 is not less than 0.3m/second, preferably not less
than 0.5m/second. By adopting such flow rate, there can be
advantageously prevented the generation of the higher order
condensation products, which are to be the scale. The upper limit
of the flow rate of the mixture is not particularly limited,
however, it is practically not higher than 10m/second.
[0041] The mixture introduced to the reaction tube 12 is
heated to a temperature, which is not less than a temperature, at
which the reaction heat is generated, at the heating zone 26
located upstream at the reaction tube 12 in the direction of the
flow of the mixture, by a high temperature steam. Due to this
heating operation, the reaction of the at least one of phenols with
the at least one of aldehydes is substantially initiated. If the
temperature of the mixture does not achieve the temperature at
which the reaction heat is generated, at the heating zone 26, a
heating value of the reaction heat generated by the reaction of
the at least one of phenols and the at least one of aldehydes is
insufficient. Accordingly, a progress of the reaction at the
temperature control zone 32 slows down and the reaction is not
completed before the mixture reaches the reaction
product-storage tank 18, whereby unreacted monomers are
remained. Meanwhile, although the maximum heating
temperature is not particularly limited, if the temperature of the

mixture is too high, a heat is remarkably generated and the
reaction becomes out of control. In this case, even if the mixture
is cooled, the temperature of the mixture can no longer be
controlled, so that there is caused a problem in respect of a safety
and there are easily generated the higher order condensation
products.
[0042] Described in detail, it is desirable that the heating
temperature is determined depending on an amount of use
and/or a kind of the catalyst. It is desirable that the heating
temperature is 80°C~180°C, preferably 100°C~160°C, and more
preferably 120°C~150°C. For instance, in a case the catalyst is
used in the ratio of about 5 parts by mass per 1000 parts by mass
of the at least one of phenols, if the temperature at the outlet of
the heating zone 26 exceeds 170°C, there is a tendency of causing
a runaway reaction and the temperature control cannot be
conducted at the temperature control zone 32. In this case, if the
temperature at the outlet of the heating zone 26 is lower than
90°C, there is a tendency not to generate the reaction heat.
Meanwhile, if the catalyst is used at the ratio of about 10 parts
by mass per 1000 parts by mass of the at least one of phenols, the
reaction heat is generated even if the temperature at the outlet of
the heating zone 26 is about 90°C, so that the phenol resin can be
produced without any problem, even at the temperature as
mentioned above. Also, if the catalyst is used in a ratio of about 2
pars by mass per 1000 parts by mass of the at least one of
phenols, there is not caused the runway reaction even if the
temperature at the outlet of the heating zone 26 is 180°C, so that

the phenol resin can be produced without any problem.
[0043] The heating time in the heating zone 26 is not
particularly limited, but is suitably adjusted depending on an
internal diameter and a length of the reaction tube 12 and a flow
rate of the mixture, etc. However, if a productivity is taken into
consideration, it is desirable to execute the heating operation in a
minimum period of time.
[0044] Afterwards, the mixture, which is heated within the
heating zone 26 to a predetermined temperature, is introduced to
the inside of the temperature control zone 32, which is located at
a downstream of the reaction tube 12 in the flowing direction, (in
this embodiment, from the heating zone 26, immediately) after
the temperature of the mixture has been achieved at a
predetermined control temperature. In the temperature control
zone 32, the addition condensation reaction between the at least
one of phenols and the at least one of aldehydes are progressed,
while only the cooling operation of the mixture is conducted. In
this case, it is desirable that the liquid temperature of the
mixture in the temperature control zone 32 is kept within 90°C~
180°C, preferably 130°C ~ 160°C.
[0045] In the temperature control zone 32 of this
embodiment, there is arranged that each pair of the pipes are
respectively cooled by the cooling water, and the mixture
introduced from the heating zone 26 is suitably cooled.
[0046] Also, in the present embodiment, a length of the
heating zone 26 is sufficiently shorter than that of the
temperature control zone 32. In detail, the length of the heating

zone 26 is about one fourth of the length of the temperature
control zone 32, for instance, which means that the length of the
temperature control zone 32 is sufficiently assured, so that the
reaction of the at least one of phenols with the at least one of
aldehydes can be advantageously progressed. If the length of the
heating zone 26 with respect to the total length of the reaction
tube 12 is too long, compared with the length of the temperature
control zone 32, there may be easily generated the scale on the
internal surface of the reaction tube 12, or the reaction may not
be sufficiently progressed and the unreacted aldehyde may be
remained, similar to a conventional method.
[0047] Further, in this embodiment, the pressure within
the reaction tube 12 is kept to be not lower than a vapor pressure
of water. That is, the pressure within the reaction tube 12 is
suitably determined by the pressure-regulating valve 24, so that
a portion of the reaction tube 12 which has a temperature not
less than the temperature at which the reaction heat is
generated, the pressure is not less than 1 atm (0.10 MPa). For
instance, if the temperature is 130°C, the pressure is not less
than 0.27 MPa, and if the temperature is 160°C, the pressure is
not less than 0.62 MPa. According to this arrangement,
vaporization of water included in the mixture can be effectively
prevented. As a result, the at least one of aldehydes, which are
provided at the state of being solved in water, are effectively
reacted with the at least one of phenols, so that there can be
effectively prevented the unreacted aldehydes from being
remained. Although an upper limit of the pressure within the

reaction tube 12 is not particularly limited, it is practically
desirable that the pressure is not higher than 3.0MPa.
[0048] As an addition condensation reaction of the at least
one of phenols with the at least one of aldehydes is progressed in
the reaction tube 12, the intended phenol resin is generated, as
the reaction progresses. If the phenol resin is produced in this
way, while the mixture is flowed within the temperature control
zone 32 and then the reaction within the reaction tube 12 is
completed, the phenol resin is brought out to delivery passage 20,
and is stored in the reaction product-storage tank 18 via the
delivery passage 20.
[0049] Then, the reaction product stored in the reaction
product-storage tank 18 is subjected to known aftertreatments,
such as a treatment of a water washing and a distillation
treatment, whereby the intended phenolic novolak resin is
produced. In thus produced phenolic novolak resin, no higher
order condensation product is mingled, and a desired distribution
of molecular weight is advantageously realized, so that an
excellent quality is assured.
[0050] Also, according to the above-mentioned method, no
unreacted aldehyde is dissolved in reaction product, or a
concentration of the unreacted aldehyde in the reaction product
is almost zero, so that there is exhibited a characteristic that a
total amount of the aldehydes, which are used as the raw
materials, is substantially reacted. In addition, there can be
advantageously prevented the scale formed of the higher order
condensation products from adhering and accumulating on the

internal surface of the reaction tube 12.
[0051] While the preferred embodiment of the present
invention has been described in detail, for illustrative purpose
only, it is to be understood that the present invention is not
limited to the details of the illustrated embodiment.
[0052] For instance, in the above embodiment, the mixture
flowing within the reaction tube is flowed at a fixed flow rate, by
controlling a number of revolutions of the pump 22 which is
intended to supply the mixture of the raw materials to a fixed
number. It is also possible to enhance the flow rate of the mixture
located at a portion of the reaction tube, by making a pipe
diameter of the portion, at the downstream side of the reaction
tube in the direction of the flow of the mixture, smaller than a
pipe diameter of a portion, at the upstream side of the reaction
tube in the direction of the flow of the mixture.
[0053] Described in detail, a viscosity of the mixture is
increased as the reaction progresses, in other words, the viscosity
of the mixture tends to increase as the mixture flows towards
downstream in the direction of the flow of the mixture. In this
case, if a pipe diameter (internal diameter) of at least a portion of
the reaction tube, which is located on a downstream side of the
temperature control zone 32 with respect to the direction of the
flow of the mixture, is made smaller than a pipe diameter
(internal diameter) of a portion of the reaction tube which is
located on the heating zone 26, there can be enhanced a flow rate
of the mixture located within the portion of the reaction tube, of
which the pipe diameter is made smaller. Accordingly, there can

be highly effectively prevented a generation of a scale on an
internal surface of the reaction tube 12. In addition, a resin layer
comprising the phenols, etc., and a water layer including the
aldehyde are advantageously stirred and mixed with each other.
[0054] If the pipe diameter of at least a portion of the
reaction tube is made smaller so as to partially enhance the flow
rate as described above, there can be enjoyed advantages that a
length of the reaction tube 12 can be arranged to be short so that
there can be avoided making a large-sized reactor, compared with
a case, in which a flow rate of all the mixture within overall the
reaction tube 12 by, e.g., increasing a number of rotation (in this
case, the flow rate of overall the reactor is increased, so that
there is needed to make the reactor longer to ensure a sufficient
reaction time). Also, the pipe diameter of the reaction tube 12
may be arranged, so as to be gradually narrowed as the pipe is
closer to the downstream side with respect to the direction of the
flow of the mixture (as the viscosity of the mixture increases).
[0055] There may also be arranged a static mixer, which
has a known structure, at the reaction tube 12, so as to improve a
performance for stirring the mixture flowing within the reaction
tube 12. If the static mixer is used, the mixture is effectively
stirred, so that there can be restricted the generation of the
higher order condensation products and advantageously
enhanced an efficiency of the reaction between the at least one of
phenols and the at least one of aldehydes. If the static mixer is
positioned as described above, the mixture flowing within the
reaction tube 12 is advantageously stirred, so that the flow rate
of the mixture flowing within the reaction tube 12 can be
arranged lower than the mixture which is flowing within the
reaction tube without the static mixer. In detail, if the static
mixer is not used, it is desirable to set the flow rate of the
mixture flowing within the reaction tube to not less than
0.3m/second as described above. Meanwhile, if the static mixture
is used, it is desirable to set the flow rate of the static mixer to
not less than 0.1m/second. In addition, if the flow rate is set to a
low rate, the length of the reaction tube 12 can be arranged to be
short, so that there can be avoided making a large-sized reactor.
A type of or a position to arrange the static mixer is not
particularly limited. There can be adopted an arrangement to
position commercially available static mixers keeping a
predetermined distance apart from each other, e.g., positioning a
static mixer having a suitable number of elements at an inlet
side of each of the pipes 12c ~ 12j which constitute the
temperature control zone 32.
[0056] Also, in the above example, there is adopted, as the
pipe which constitutes the reaction tube 12, a tube which has a
structure of a duplex tube comprising an external tube and an
internal tube which is coaxially located within the external tube.
With this tube, the mixture was heated or cooled by flowing the
high-temperature steam or the coolant through the space
between the internal and external tubes. However, the method of
heating or cooling is not limited to the above example. Instead,
there can be adopted any conventionally known methods, such as
a heating method by using a band heater. In addition, each of the

pipes may be respectively heated or cooled, or a plurality of the
pipes may be collectively heated or cooled.
[0057] In addition, in the above embodiment, the heating
zone 26 is formed by two pipes 12a, 12b, while the temperature
control zone 38 is formed by eight pipes 12c~12j. It is needless to
mention that the number of pipes to be allocated in each zone is
not limited to that of the above example.
[0058] It is to be understood that the present invention
may be embodied with various other changes and modifications
which may occur to those skilled in the art, without departing
from the spirit and scope of the invention defined in the attached
claims.
EXAMPLES
[0059] To further clarify the present invention, there will
be described some examples of the present invention. It is to be
understood that the present invention is not limited to the details
of the following examples.
[0060] At first, there was prepared a continuous reactor
(10), which had a structure as shown in Fig. 1. As a tube
diameter (internal diameters) of a reaction tube (12), there was
adopted 25mm or 20mm, as shown in TABLE 1 below. Also, there
were respectively allocated a thermometer and a manometer at
an outlet of each pipe (12a~12j) which constitutes the reaction
tube (12) and an inlet of a pipe (12a) located at the uppermost
stream side of the tube, so that a temperature of a mixture
flowing in the tube and a pressure of inside the tube could be

measured. Meanwhile, as raw materials, there were respectively
prepared at least one of phenols: a phenol, at least one of
aldehydes: 47% aqueous solution of a formaldehyde, and an
acidic catalyst: oxalic acid.
[0061] Also, a generation of a reaction temperature was
confirmed by observing a change of a curve which represents an
increase of a temperature of the mixture in each of the pipes (12a,
12b), by respectively measuring a temperature of the outlet of
each of the pipes and a temperature of the inlet of the pipe (12a).
[0062] (continuous process)>
The phenol, the 47% aqueous solution of the
formaldehyde, and the oxalic acid were introduced in a raw
material-storage tank (14), so as to fulfill the ratio shown in
TABLE 1 below, and were sufficiently stirred so as to obtain an
uniform mixture. Afterwards, a pump (22) was operated and the
mixture within the raw material-storage tank (14) was supplied
to the inside the reaction tube (12), so as to fulfill the flow rate as
shown in TABLE 1 below. Then, the mixture was heated at the
outlet of the heating zone (26) located at the upstream in the
direction of the flow of the mixture, until the temperature of the
mixture becomes as shown in TABLE 1 below. Thereafter, the
mixture delivered from the heating zone (26) was reacted, while
it was suitably cooled at a temperature control zone (32), and
then the mixture was accommodated in a reaction
product-storage tank (18). During this operation, the pressure
within the reaction tube (12) was enhanced by using a

pressure-regulating valve (24).
[0063] Also, during the production of the phenolic novolak
resin as described above, the pressure within the reaction tube
(12) and the temperature of the mixture were measured. Then,
thus measured pressure and maximum and minimum values of
the mixture temperature at the temperature control zone (32) are
collectively shown in TABLE 1 below.
[0064] After the reaction had been completed, there was
checked whether the higher order condensation products to be
the scale had been generated by visually observing the inside of
the reaction tube (12), and thus obtained results are shown in
TABLE 1 below. Also, the reaction products stored in the reaction
product-storage tank (18) was taken out, and an amount of a
residual volume of the formaldehyde was measured in accordance
with a method prescribed by ISO 9397. Thus obtained results are
also shown in TABLE 1 below.
[0065] Also, there was measured a weight average
molecular weight (Mw) of a resin phase of the reaction products
stored in the reaction product-storage tank (18), and thus
obtained results are shown in TABLE 1 below. In this EXAMPLE,
the weight average molecular weight is a weight average
molecular weight of polystyrene conversion obtained by a
measurement by gel permeation chromatography. In particular,
the molecular weight is a standard value of the polystyrene
conversion, obtained by a measurement by using a gel filtration
chromatograph SC - 8010 (column: G1000Hxl + G2000HXl,
detector: UV254nm, carrier: tetrahydrofuran 1ml/min, and

temperature of the column: 38 °C) available from TOSOH
CORPORATION (JAPAN).
[0066]
Phenol, 47% aqueous solution of formaldehyde, and
oxalic acid were introduced into a reactor, which has an overspill,
a thermometer, and a stirrer, so as to meet a ratio as shown in
TABLE 1 below. Subsequently, a temperature within the reactor
was gradually increased up to a reflux temperature (100°C).
Further, these raw materials were reacted at the reflux
temperature for three hours, whereby a phenolic novolak resin
(reaction product) was obtained.
[0067] Similar to the above Examples for the continuous
process, by visually observing the inside of the reactor, there was
checked whether the higher order condensation products were
generated, and there were measured the weight average
molecular weight and the amount of the residual formaldehyde.
Thus obtained results are collectively shown in TABLE 1 below.
[0068]
For the sake of a comparison, there was also
produced a phenolic novolak resin, by a method as disclosed in
the above-mentioned Patent Document 1. Namely, the phenol,
the 47% aqueous solution of formaldehyde, and the oxalic acid
were respectively introduced in a raw material-storage tank, so
as to fulfill the ratio as shown in TABLE 1 below, and were
sufficiently stirred so as to obtain an uniform mixture.
Afterwards, the pump was operated and the mixture within the
raw material-storage tank was supplied to the inside the reaction
tube, so as to flow at a flow rate similar to that of the Examples
(0.3m/second) shown in TABLE 1 below. In this way, a phenolic
novolak resin was produced. Similar to the above Examples for
the continuous process, visually observing whether the higher
order condensation products had been generated, and there were
measured the weight average molecular weight and the amount
of the residual formaldehyde. Thus obtained results are
collectively shown in TABLE 1 below.
[0069] [TABLE 1]

[0070] As is apparent from the results of TABLE 1, in
Examples 1~11, in which the mixture was heated in the heating
zone under the pressure not lower than the vapor pressure of
water to a temperature which was not less than a temperature,
at which the reaction heat was generated, and then the addition
condensation reaction was progressed at the temperature control
zone only by the cooling operation, no higher order condensation
product was generated, and there was no residual formaldehyde.
Therefore, there is recognized that an entire amount of the
formaldehyde which was used as one of the raw materials was
effectively reacted. In addition, in terms of the weight average
molecular weight, intended values of molecular weights were
obtained in Examples 1~11, and a high quality of the phenolic
novolak resin was produced in a short period of time.
[0071] On the other hand, in Comparative Example 1,
there was not generated the reaction heat at the heating zone, so
that the reaction was not sufficiently progressed. Accordingly, the
formaldehyde remained in the reaction product which was
obtained after the reaction, and a value of the weight average
molecular weight is also low. Meanwhile, in Comparative
Example 2, the liquid temperature of the mixture was excessively
increased at the heating zone, so that an extraordinary heat
generation was caused. Accordingly, there was not able to
continue the reaction, for the sake of the safety.
[0072] In Comparative Example 3, there was adopted the
batch process and an open system. Accordingly, there was not
able to pressurize within the reaction system, and the reaction

was conducted at 100°C. For this reason, although there was able
to produce the phenolic novolak resin which had the intended
weight average molecular weight, there remained unreacted
formaldehyde, and the production time was longer than that of
the continuous process.
[0073] In addition, in Comparative Example 4, in which
the heating operation was gradually conducted at overall the
reaction tube without conducting the cooling operation, there
were generated the higher order condensation products on the
internal surface of the reaction tube.
[0074]
In order to determine an effect of a static mixer
positioned within the reaction tube (12), there was conducted an
experiment as described below. Namely, in Experiment 1, there
was used, as the reaction tube (12), a reaction tube, in which a
static mixer including six elements (a spiral mixer available from
TAH Industries, Inc., U.S.A.) was positioned at an inlet of each of
the pipes (12c~12j) which constitutes the temperature control
zone (32). Meanwhile, in Experiment 2, there was used a reaction
tube at which no static mixer was positioned.
[0075] Similar to the above Example 1, the phenol, the 47%
aqueous solution of formaldehyde, and the oxalic acid were
introduced in the raw material-storage tank (14), so as to fulfill
the ratio as shown in TABLE 2 below, and were sufficiently
stirred within the raw material-storage tank (14), so as to obtain
an uniform mixture. Afterwards, the pump (22) was operated and
the mixture within the raw material-storage tank (14) was
supplied to the inside the reaction tube (12) at a low flow rate
(0.1m/second). Then, the mixture was heated at the heating zone
(26) located at the upstream side of the reaction tube (12) in the
direction of the flow of the mixture, so that the temperature of
the mixture became 130°C. Thereafter, the mixture delivered
from the heating zone (26) was suitably cooled at the
temperature control zone (32), and was reacted while its
temperature was kept in a range of 130oC~160°C. Then the
mixture was accommodated in the reaction product-storage tank
(18). In this operation, the pressure within the reaction tube (12)
was kept to be not lower than the vapor pressure of water by
using the pressure-regulating valve (24).
[0076] The phenolic novolak resin was continuously
produced by using the continuous reactor as described above for
one hour or six hours. Thereafter, there were observed generation
of the higher order condensation products, the weight average
molecular weight, and the amount of the remaining aldehydes,
similar to the above Example 1. Thus obtained results are shown
in TABLE 2 below.
[0077] [TABLE 2]
[0078] As is apparent from the results of TABLE 2, if the
flow rate is as low as 0.1m/second, there is a higher tendency of

the generation of the higher order condensation products, as the
period of time for the production is longer (see Experiment 2). In
this case, there is recognized that if the static mixer is used, the
performance for stirring the mixture in the reaction tube,
whereby the generation of the scale (the higher order
condensation products) can be advantageously prevented.

WE CLAIM:
1. A process for continuously producing a phenolic novolak resin by reacting at least one
of phenols, such as herein described, with at least one of aldehydes, such as herein described,
in the presence of an acidic catalyst, such as herein described, by using a continuous reactor
which has a long reaction tube,
comprising the steps of:
providing said reaction tube of the continuous reactor with a heating zone and a
temperature control zone in a longitudinal direction of the reaction tube;
continuously supplying a mixture, such as herein described, which includes the at least
one of phenols, the at least one of aldehydes, and the acidic catalyst, into the reaction tube of
the continuous reactor, while a pressure in the reaction tube, such as herein described, is kept
to be not lower than a vapor pressure of water;
heating the mixture at the heating zone to a temperature of 80°C ~ 180°C, which is
located on an upstream side of the reaction tube in a direction of a flow of the mixture, to a
temperature which is not less than a temperature, at which a reaction heat is generated, for
thereby initiating an addition condensation reaction between the at least one of the phenols and
the at least one of aldehydes in the mixture; and
introducing the mixture, whose temperature is increased by the heating operation and
the reaction heat of the addition condensation reaction, to the temperature control zone so that
the temperature of the mixture becomes 90°C ~ 180°C, which is located on a downstream side
of the reaction tube in the direction of the flow of the mixture, and progressing the addition
condensation reaction while only cooling operation of the mixture at the said temperature
control zone is conducted.
2. The process for producing a phenolic novolak resin as claimed in claim 1,
wherein a pipe diameter of at least a portion of the reaction tube, which is located on a
downstream side of the temperature control zone with respect to the direction of the flow of
the mixture, is made smaller than a pipe diameter of a portion of the reaction tube which is
located on the heating zone, so as to enhance a flow rate of the mixture located within the
portion of the reaction tube of which the pipe diameter is made smaller.
3. The process for producing a phenolic novolak resin as claimed in claim 1 or 2,
wherein a static mixer is positioned inside the reaction tube, so that the mixture being
flowed in the reaction tube is stirred in the reaction tube.
4. The process for producing a phenolic novolak resin as claimed in any one of claims 1
to 3,
wherein the flow rate of the mixture flowing inside the reaction tube is not less than
0.3m/second.
5. The process for producing a phenolic novolak resin as claimed in any one of claims 1
to 4,
wherein a length of the heating zone is shorter than a length of the temperature control
zone.
6. The process for producing a phenolic novolak resin as claimed in any one of claims 1
to 5,
wherein said at least one of aldehydes are used in an amount of 0.1 ~ 1.0 mol per 1 mol
of said at least one of phenols.
7. The process for producing a phenolic novolak resin as claimed in any one of claims 1
to 6,
wherein said acidic catalyst is used within a ratio of 0.5 ~ 50 parts by mass per 1000
parts by mass of said at least one of phenols.
8. The process for producing a phenolic novolak resin as claimed in any one of claims 1
to 7,
wherein the reaction tube has an internal diameter of 10 ~ 200mm and a length of 10 ~
2000m.
9. The process for producing a phenolic novolak resin as claimed in any one of claims 1
to 8,
wherein the reaction tube has a structure of a duplex tube comprising an external tube
and an internal tube which is coaxially located within the external tube, and
wherein said heating or cooling operation is conducted by flowing a heating steam or a
cooling water in a space between the external and internal tubes.

A process in which a continuous reactor is used to advantageously produce in a short time a phenolic novolak resin containing substantially no unreacted aldehyde remaining therein, while preventing higher-order condensates from generating. The process for phenolic novolak resin production uses a continuous reactor (10) having a long reaction tube (12) to react a phenol with an aldehyde in the presence of an acid catalyst to thereby continuously produce a phenolic novolak resin, wherein a heating zone (26) and a temperature control zone (32) are disposed along the longitudinal direction for the reaction tube (12). In this process, the reactants are heated to at least a temperature at which heat of reaction generates, in the heating zone (26), which is located upstream in the liquid-passing direction. In the temperature control zone (32), which is located downstream, the liquid mixture heated by this heating operation and by the heat of reaction is pressurized so that the pressure inside the reaction tube (12) increases to or above the water vapor pressure, while cooling the mixture.

Documents:

00470-kolnp-2007 assignment.pdf

00470-kolnp-2007 correspondence-1.2.pdf

00470-kolnp-2007 form-3-1.1.pdf

00470-kolnp-2007 g.p.a.pdf

00470-kolnp-2007-correspondence-1.1.pdf

00470-kolnp-2007-form-18.pdf

0470-kolnp-2007-abstract.pdf

0470-kolnp-2007-claims.pdf

0470-kolnp-2007-correspondence others.pdf

0470-kolnp-2007-description(complete).pdf

0470-kolnp-2007-drawings.pdf

0470-kolnp-2007-form-1.pdf

0470-kolnp-2007-form-3.pdf

0470-kolnp-2007-form-5.pdf

0470-kolnp-2007-international publication.pdf

0470-kolnp-2007-international search authority report.pdf

0470-kolnp-2007-pct form.pdf

0470-kolnp-2007-priority document.pdf

470-KOLNP-2007-ABSTRACT-1.1.pdf

470-kolnp-2007-assignment.pdf

470-KOLNP-2007-CANCELLED DOCOMENT.pdf

470-KOLNP-2007-CLAIMS-1.1.pdf

470-KOLNP-2007-CORRESPONDENCE-1.1.pdf

470-kolnp-2007-correspondence-1.2.pdf

470-KOLNP-2007-CORRESPONDENCE.pdf

470-KOLNP-2007-DESCRIPTION COMPLETE-1.1.pdf

470-kolnp-2007-examination report.pdf

470-KOLNP-2007-FORM 1-1.1.pdf

470-kolnp-2007-form 18.pdf

470-KOLNP-2007-FORM 3-1.1.pdf

470-kolnp-2007-form 3.pdf

470-kolnp-2007-form 5.pdf

470-KOLNP-2007-FORM-27-1.pdf

470-KOLNP-2007-FORM-27.pdf

470-kolnp-2007-gpa.pdf

470-kolnp-2007-granted-abstract.pdf

470-kolnp-2007-granted-claims.pdf

470-kolnp-2007-granted-description (complete).pdf

470-kolnp-2007-granted-drawings.pdf

470-kolnp-2007-granted-form 1.pdf

470-kolnp-2007-granted-specification.pdf

470-kolnp-2007-reply to examination report-1.1.pdf

470-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf

abstract-00470-kolnp-2007.jpg


Patent Number 247500
Indian Patent Application Number 470/KOLNP/2007
PG Journal Number 15/2011
Publication Date 15-Apr-2011
Grant Date 12-Apr-2011
Date of Filing 08-Feb-2007
Name of Patentee ASAHI ORGANIC CHEMICALS INDUSTRY CO., LTD.
Applicant Address 5955, NAKANOSE-CHO 2-CHOME, NOBEOKA-SHI, MIYAZAKI 882-8688
Inventors:
# Inventor's Name Inventor's Address
1 INADUMI, TOMONORI C/O ASAHI ORGANIC CHEMICALS INDUSTRY CO., LTD. 26-4, AZA SHINZU, OAZA MINAMIYAMANA, FUSO-CHO, NIWA-GUN, AICHI 480-0105
2 KAI, HIROTO C/O ASAHI ORGANIC CHEMICALS INDUSTRY CO., LTD. 26-4, AZA SHINZU, OAZA MINAMIYAMANA, FUSO-CHO, NIWA-GUN, AICHI 480-0105
PCT International Classification Number C08G 8/00
PCT International Application Number PCT/JP2005/012384
PCT International Filing date 2005-07-05
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2004-239060 2004-08-19 Japan