Title of Invention

SIZED GLASS STRANDS, SIZING COMPOSITION AND COMPOSITES COMPRISING THE SAID STRANDS.

Abstract The invention relates to glass strands coated with an essentially aqueous sizing composition which comprises the combination - of at least one bissilane (A) of formula in which: R1, R2, R3, R4, R5 and R6, which are identical or different, represent a C1-C2, preferebly C1-C3, alkyl radical. Z represents a C1-C12 hydrocarbonaceous chain which can comprise one or more N, O and/or S heteroatoms, - and of at least one unsaturated monocilane (B) chosen from vinylsilanes and (meth) acrylocitanes. The glass strands obtained exhibit an improved ability to be cut which renders them capeble of being used to reinforce polymers, in particular by moulding by simultaneous spraying.
Full Text Sized Glass Strands, Sizing Composition And Composites
Comprising The Said Strands
The invention relates to glass strands coated with a sizing composition which are
intended to reinforce organic materials of the polymer type, to the sizing compositions
used to coat these strands and to the composites including these strands.
Glass strands used for reinforcing are generally produced industrially from
streams of molten glass flowing from the multiple orifices of a spinneret. These streams
are drawn mechanically in the form of continuous filaments and are then gathered
together into base strands, which are subsequently collected, for example by winding off
on a rotating support. Before they are gathered together, the filaments are coated with a
sizing composition by passing over a suitable device, such as coating rolls.
The sizing composition proves to be essential in several respects. First of all, it is
involved in the manufacture of the strands by protecting the glass filaments from the
abrasion which occurs when the latter rub at high speed over the members which are
used to guide them and to collect them. Next, the sizing composition makes it possible to
give cohesion to the strand by creating bonds between its constituent filaments. The
strand thus being rendered more integral is thereby easier to handle. Finally, the sizing
composition promotes the wetting and the impregnation of the glass strands by the
polymer to be reinforced, which, at this stage, has the appearance of a fluid resin. The
mechanical properties of the final composite are for this reason markedly improved.
The materials to be reinforced can combine with the glass strands in various
forms: continuous or cut strands, fabrics, mats of continuous or cut strands, and the like.
The composites incorporating cut glass strands can be obtained, inter alia, by the
"contact moulding" technique, which consists in coating the inside of an open mould,
without a countermould, with the resin to be reinforced and glass strands of variable
length. In the specific process of "moulding by simultaneous spraying", the resin and the
cut glass strands are sprayed together onto the inside walls of the mould by means of a
"spray gun" comprising a cutter capable of severing the strands drawn off from one or
more wound packages, generally in the form of rovings, and a device for feeding with
resin, for example a pneumatic pump. This process, which is.simple and which can be
adjusted both with regard to the size and the shape, is particularly suited to the
manufacture of one-off or short-run components based on thermosetting polymer from the
family of the polyesters or epoxides.
The quality of the composites obtained by this process depends largely on the
properties introduced by the glass strands and thus on the sizing composition which coats
them. The target is in particular sizing compositions which can be easily wetted or
impregnated at the surface by the resin, that is to say which are capable of providing
close contact between the strands and the resin, so that the expected mechanical
reinforcing properties can be obtained.
It is also desired for these compositions to make fast processing possible, in
particular for the strand/resjn mixture which is sprayed onto the mould in the form of
overlapping strips to be able to spread out uniformly, and for the subsequent rolling stage,
intended to remove the air bubbles and to provide better distribution of the strands in the
resin, to be of short duration.
Furthermore, however, it is necessary for the sizing composition to have a degree
of "incompatibility" with the resin, that is to say not to be too soluble in the resin in order
to prevent the strand/resin mixture, after spraying onto a vertical wall, from "collapsing" by
simple gravity.
It is just as necessary for the cut strands to retain their integrity and not to open
with the release of their constituent filaments, both during the spraying and during the
rolling/debubbling.
It is thus seen that such compositions are difficult to develop as the targeted
properties are rarely compatible with one another and that it is for this reason necessary
to achieve compromises.
One of the problems encountered during the implementation of the process for
moulding by simultaneous spraying is the excessively short lifetime of the blades with
which the spray gun is equipped. Although being made of hard steel, the blades of the
cutter have a tendency to rapidly wear out on contact with the glass, which leads to "false
cuts" and the appearance of cut strands with a length greater than the desired length.
Depending upon the number of blades, their degree of wear and the position which they
occupy on the cutter, it is possible to obtain a mixture of strands with a length
f-
corresponding to a whole multiple of the expected length. The false cuts result in an
unevenness in the sheet of sprayed fibre, which is harmful to the quality of the moulded
component and necessitates an interruption in the manufacture in order for the old blades
to be changed, leading to a fall in productivity.
Glass strands suited to the production of components by moulding by
simultaneous spraying are disclosed in particular in FR-A-2 755 127. These strands are
coated with a composition which comprises, in addition to adhesion agents capable of
providing the sizing function, the combination of an aminosilane and an unsaturated
silane. Although presented as improving the ability of the strand to be cut, the
combination of the two abovementioned silanes does not make it possible to achieve the
desired objective, namely that the longevity of the blades is insufficient to meet current
productivity standards, which require being able to operate continuously for approximately
ten hours.
An aim of the invention is to develop glass strands coated with a sizing,
composition which is particularly suited to the process for moulding.by simultaneous
spraying and which makes it possible to increase the lifetime of the blades of the cutter
without, however, modifying the processing conditions and without affecting the other
properties of the strands, namely their ability to be impregnated by the resin. As was
indicated above, this is because it is essential for the strands to be able to be rapidly
impregnated by the resin as there is, in this instance, no prior blending of the strands and
the resin before the spraying stage.
A subject-matter of the present invention, is therefore glass strands coated with an
essentially aqueous sizing composition which is characterized in that it comprises the
combination
in which:
R1. R2, R3. R4, R5 and R6, which are identical or different, represent a C1- C6,
preferably C1 C3, alkyl radical
Z represents a C1-C16 hydrocarbonaceous chain which can comprise one or more N,
O and/or S heteroatoms
- and of at least one unsaturated monosilane (B) chosen from vinylsilanes and
(meth)acrylosilanes.
In the present invention, the term "glass strands coated with a sizing composition"
is understood to mean glass strands "which have been coated with a sizing composition
which comprises ...", that is to say not only glass strands coated with the composition in
question as they are obtained at the immediate outlet of the sizing member(s) but also
these same strands after they have been subjected to one or more other treatments, for
example a stage(s) of drying, for the purpose of removing the solvent from the
composition, and/or of polymerization/crosslinking of some constituents of the said
composition.
Still in the context of the invention, the term "strands" should be understood as
meaning the base strands resulting from the gathering together under the spinneret of a
multitude of filaments and the products derived from these strands, in particular the
assemblages of these base strands into ravings. Such assemblages can be obtained by
simultaneously reeling off several wound base strand packages and by then gathering
them together into slivers which are wound off onto a rotating support. It can also be
"direct" ravings with a count (or mass per unit length) equivalent to that of the assembled
ravings obtained by gathering together filaments directly under the spinneret and winding
onto a rotating support
Still according to the invention, the term "essentially aqueous sizing, composition"
is understood to mean a composition which comprises at least 90% by weight of water,
preferably at least 93% and better still at least 94%, at least one adhesion agent and at
least one lubricant.
According to a preferred embodiment of the invention, the glass strands are
coated with a sizing composition, the bissilane (A) of which corresponds to the formula
R1, R2, R3, R4, R5 and R6 have the meaning given above,
A, B and C, which are identical or different, represent a C1-C16 hydrocarbonaceous
chain, the sum of the carbon atoms of A, B and C being less than or equal to 16,
n is equal to 0,1, 2 or 3,
R7 and R8, which are identical or different, represent H or a methyl or ethyl radical.
Preferably, the sizing composition comprises the bissilane (A) of abovementioned
formula in which:
R1, R2, R3. R4, R5 and R6, which are identical, represent a methyl or ethyl radical,
A and C, which are identical or amerent, represent a meinyiene, emyene 01
propylene radical,
B represents an ethylene radical,
n is equal to 0 or 1,
R7 and R« represent a hydrogen atom.
In a particularly preferred way, the bissilane (A) corresponds to the preceding
formula, in which:
R1. R2. R3. R4, R5 and R6, which are identical, represent a methyl radical,
A and C represent a propylene radical,
n is equal to 0,
R7 and R8 represent a hydrogen atom.
According to another embodiment of the invention, the glass strands are coated
with a sizing composition, the unsaturated monosilane (B) of which is chosen from
(meth)acrylosilanes.
The combination of the bissilane (A) and of the unsaturated monosilane (B)
proves to be advantageous for forming glass strands exhibiting an improved ability to be
cut. it has been found that the bissilane (A) is a very effective agent for embrittling glass :
a very dilute aqueous solution of this bissilane, of the order of 0.01% by weight, is
sufficient to produce the desired effect. It seems that the embrittling effect is related to the
high affinity of the bissilane for glass: this is explained by the formation of relatively
strong bonds between the silicon atoms carried by the bissilane and the oxygen of the
free hydroxyl groups of the glass, which bonds lead to embrittlement of the glass at the
surface. By introducing the moncsilane (B) into the composition, which monosilane acts
as a "protective" agent opposing the cutting action of the bissilane (A), it is possible to
adjust the ability of the strand to be cut. Generally, entirely satisfactory results are
obtained with a bissilane (A)/monosilane (B) ratio by weight of between 0.1 and 6,
preferably 0.3 and 3 and better still 0.6 and 2.
Mention may be made, as examples of preferred monosilanes (B), of
- for the vinylsilanes: vinyttrialkoxysilanes, in particular vinyltriethoxysilane and
vinyltri(methoxyethoxy)silane,
- for the (meth)acrylosilanes [(meth)acryloxyalkyl]trialkoxysilanes, in particular
(methacryloxypropyl)triethoxysilane, and (meth)acrylamidoalkyltrialkoxysilanes,
in particular methacrylamidopropyltrialkoxysilane.
(Meth)acrylamidoalkyltrialkoxysilanes are particularly preferred.
Glass strands coated with a sizing composition combining
aminobis(propyltrimethoxysilane) and methacrylamidopropyltrialkoxysilane have proved to
be particularly advantageous for the targeted application of moulding by simultaneous
spraying.
In accordance with the definition given above, the sizing composition coating the
glass strands comprises at least one adhesion agent. This adhesion agent is generally
chosen from homopolymers or copolymers based on vinyl acetate, polyurethanes, epoxys
and polyesters.
Mention may be made, by way of examples of vinyl acetate homopolymers, of
poly(vinyl acetate)s having a low molecular mass, that is to say of less than or equal to
60 000, preferably of between 40 000 and60 000, and better still of the order of 50 000
Mention may be made, by way of examples of copolymers based on vinyl acetate,
of copolymers of vinyl acetate and of at least one other monomer capable of
copolymerizing with the latter, such as an unsaturated monomer, in particular ethylene
and N-methylolacrylamide, or a monomer including an epoxide functional group.
Mention may be made, by way of examples of polyurethanes, of the compounds
obtained by reaction of at least one polyisocyanate and of at least one polyol. The
polyurethanes resulting from polyols with aliphatic; and/or cycloaliphatic chains are
preferred.
Mention may be made, by way of examples of epoxys, of the compounds
exhibiting an epoxide number of less than 450, preferably of greater than 180, resulting in
particular from the reaction of bisphenol A and epichlorohydrin, in the form of an aqueous
emulsion, or modified in order to render them soluble in water.
Mention may be made, by way of examples of polyesters, of saturated or slightly
unsaturated polyesters. These polyesters are generally used in the form of an aqueous
emulsion.
The composition advantageously comprises the combination of at least two
adhesion agents, at least one of which is a poly(vinyl acetate) or a polyurethane.
Preferably, the choice is made to combine a poly(vinyl acetate) or a polyurethane and a
copolymer based on vinyl acetate, or a poly(vinyl acetate) and a polyurethane. In a
particularly preferred way, a poly(vinyl acetate) and a vinyl acetate/N-methylolacrylamide
copolymer, a polyurethane and a vinyl acetate/epoxide or ethylene/vinyl acetate (EVA)
copolymer, and a polyurethane and a poly(vinyl acetate) are combined.
In addition, a plasticizing agent can be introduced into the sizing composition, the
role of which plasticizing agent is to render more flexible the constituent polymer chains of
the adhesion agent(s), in particular when they are homopolymers or the vinyl acetate/N-
methylolacrylamide copolymer. The plasticizing agent makes it possible to lower the glass
transition temperature (Tg) of the adhesion agents, which improves the "conformability" of
the blend of cut strands and resin, that is to say the ability to match the shape of the
mould, and for this reason proves to be particularly advantageous when the shape is
complex. The plasticizing agent is generally chosen from glycol derivatives, such as
alkylene glycol dibenzoates and preferably ethylene and/or propylene glycol dibenzoates.
The amount of plasticizing agent in the sizing composition very obviously depends
on the degree of flexibility which it is desired to confer on the strand, it being understood
that the strand must, however, be sufficiently stiff to allow it to be correctly distributed
within the resin. When one or more vinyl acetate homopolymers is/are used, in
combination or not in combination with the vinyl acetate/N-methylolacrylamide copolymer,
this amount is such that the ratio by weight of the plasticizing agent to the sum of the
homopolymers and of the vinyl acetate/N-methylolacrylamide copolymer is between 0.05
and 0.2, preferably 0.10 and 0.15, expressed on a dry basis.
The composition can also comprise at least one lubricating and/or antistatic
agent, the role of which is in particular to protect the strands from mechanical abrasion
during their manufacture. This agent is generally chosen from cationic compounds of the
polyalkyleneimide type and nonionic compounds of the esters of fatty acids and of
poly(alkylene glycol)s poly(oxyalkylene) type, such as poly(ethylene glycol) monolaurate,
or of the poly(oxyalkylenated) fatty amides type, such as polyoxyethylenated
hydrogenated tallow amides.
The glass strands coated with the sizing composition in accordance with the
invention exhibit a loss on ignition of less than 1.5%, preferably of between 0.9 and 1.3%.
Generally, the glass strands in accordance with the invention exist in the form of
wound base strand packages which are subjected to a heat treatment. This treatment is
intended essentially to remove the water introduced by the sizing composition and, if
appropriate, to accelerate the crosslinking of the adhesion agents. The conditions for the
treatment of the wound packages can vary according to the mass of the wound package.
The drying is generally carried out at a temperature of the order of 110 to 140°C for
several hours, preferably 12 to 18 hours.
As has already been said, the base strands thus obtained are generally removed
from the wound package and combined with several other base strands into a sliver which
is subsequently wound off onto a rotating support to form a roving. It has unexpectedly
been found that the application of a composition including a cationic antistatic agent of the
quaternary ammonium salt type to the strands makes it possible to reinforce the ability of
the strands to be cut. Thus, by depositing the abovementioned composition on the base
strands, after removing from the wound package and gathering together to form the sliver,
the lifetime of the blades is significantly improved. The strands are preferably coated with
an aqueous composition comprising 20 to 35% and preferably of the order of 25% by
weight of cocotrimethylammonium chloride.
The strands coated with the sizing composition according to the invention, if
appropriate with the composition described in the preceding paragraph, can be composed
of glass of any nature provided that it is suitable for fiberizing, for example made of E, C
or AR glass and preferably of E glass.
These same strands are composed of filaments with a diameter which can vary
within a wide range, for example from 9 to 24 urn, and preferably 10 to 15 pm, and better
still 11 to 13 pm.
The strands advantageously have a count of between 40 and 70 tex and better
still of the order of 57 tex. For this reason, even when filaments with a relatively large
diameter are used, the strand retains an acceptable stiffness and remains capable of
perfectly matching the shape of the mould. In add"tion, the cut glass strands are evenly
and homogeneously distributed within the resin during the simultaneous spraying, which
makes it possible to have excellent reinforcement.
Another subject-matter of the invention relates to the sizing composition capable
of coating the said glass strands, which composition is characterized in that it comprises :
at least one bissilane (A) corresponding to the abovementioned formula,
at least one monosilane (B),
at least one adhesion agent,
at least one lubricating agent,
and water.
Preferably, the sizing composition comprises :
0.05 to 0.4% by weight of bissilane (A),
0.05 to 0.4% by weight of monosilane (B),
3.9 to 6.8% by weight of adhesion agent,
0.01 to 0.4% by weight of lubricating agent,
and at least 90% of water.
Preferably, the sizing composition comprises at least 93% by weight of water and
better still at least 94%.
it is possible to introduce other silanes into the sizing composition. In this case,
the total content of silanes does not exceed 1% by weight of the composition, preferably
0.8%.
The solids content of the sizing composition is generally between 2 and 10%,
preferably 4 and 8%, and advantageously of the order of 6%.
A subject-matter of the invention also relates to the composites comprising the
glass strands coated with the sizing composition. Such composites comprise at least one
thermosetting polymer material, preferably a polyester and/or an epoxy, and glass
strands, all or part of which is/are composed of glass strands in accordance with the
invention. The level of glass within the composite is generally between 20 and 40% by
weight and preferably between 25 and 35%. In addition to their improved ability to be cut,
the glass strands according to the invention are noteworthy in that they allow the material
which they reinforce to have better behaviour towards ageing. This is reflected in
particular by a greater resistance to flexural stress and shear stress, as indicated
subsequently in the following implementational examples, which are intended to illustrate
the invention without, however, limiting it.
EXAMPLE 1 (COMPARATIVE)
Preparation is carried out of a sizing composition comprising (as % by weight):
- diaminosilane(1) 0.30
- vinyltriethoxysilane(2> 0.30
- adhesion agent: poly(vinyl acetate)0" (MW 50 000) 7.75
- adhesion agent: copolymer of vinyl acetate and of
N-methylolacrylamide(4) 3.00
- plasticizer: mixture of diethylene glycol dibenzoate and of
propylene glycol dibenzoate(5} (50:50 ratio by weight) 0.70
- nonionic lubricant: polyethylene glycol 400 monolaurate(6> 0.30
- lubricant: polyethyleneimide with free amide functional groups"7* 0.05
- water q.s. for 100
- formic acid q.s. for obtaining a pH equal to 4,
3 600 litres of the sizing composition are prepared in the following way :
The aminosilane and then, 20 minutes later, the vinyltriethoxysilane are
introduced into a first vessel containing a solution composed of 1 800 I of water and 1.5
kg of formic acid (80% by volume). If appropriate, the pH of the solution is adjusted to
approximately 4.5 by addition of formic acid.
The two adhesion agents are successively introduced into a second vessel, the
mixture is diluted with stirring to approximately 400 litres with water, and the plasticizer
and the nonionic lubricant(6) are added. The mixture is left stirring for at least 15 minutes
and is diluted with water to 1 000 litres.
By virtue of the combination of the plasticizer and the nonionic lubricant, this
"plasticization" stage is short.
The lubricant(7) is introduced into a third vessel and is diluted to 10-20 times its
weight with water.
The plasticized mixture of the second vessel and the lubricant of the third vessel
are introduced into the first vessel and the volume is made up with water until a volume of
3 600 I is obtained. If necessary, the pH of the sizing composition thus obtained is
adjusted to approximately 4 by addition of formic acid. The solids content of this
composition is 7%.
The sizing composition thus obtained is used to coat, in a known way, filaments of
E glass with a diameter of approximately 12 mm drawn from streams of molten glass
flowing from the 2 400 orifices of a spinneret, the filaments subsequently being gathered
together in the form of a wound base strand package with a count equal to 57 tex.
The wound package is subsequently dried at 130°C for 12 hours.
The base strands are removed from the wound package and are gathered
together into rovings composed of 42 base strands, constituting a first batch. A second
batch of rovings is obtained by removing the base strands from the wound package and
application, to the assembled sliver, of an aqueous antistatic solution comprising 25% by
weight of cocotrimethylammonium chloride (pH adjusted to 4 by addition of formic acid;
level deposited on a dry basis: 0.06 %).
The strand unwound from the roving is inserted into a cutting device comprising
two blades, a blade made of hard steel and a blade made of rapidly wearing "soft" steel
(heat treatment at 550°C), and strength and temperature sensors. The cutting, carried out
at 20°C under a relative humidity of 40%, is adjusted in order to form cut strands with a
length of 25 mm. The ability to be cut is measured by the mass of the glass strands which
can be cut until the appearance of a strand with twice the length (2 x 25 mm). The value 1
is assigned to the mass of cut strands obtained with the strands which have been
subjected to the additional stage of antistatic treatment, which value is used here as
reference value for measuring the ability to be cut. With the untreated glass strands, the
ability to be cut is 0.7.
EXAMPLE 2
The preparation is carried out under the conditions of Example 1, modified in that
the silanes participating in the sizing composition are composed of (as % by weight):
- bissilane: aminobis(propyltrimethoxysilane)(9) 0.20
- unsaturated monosilane: mixture of methacrylamidopropyltrimethoxysilane and of
methacrylamidopropyltriethoxysilane(10) 0.25
The measurement of the ability to be cut of the strands coated and not coated with
the antistatic agent is 4.5 and 1.5 respectively.
EXAMPLE 3
The preparation is carried out under the conditions of Example 2, modified in that
the content of silanes(9) and(10) is 0.16 and 0.20% by weight respectively.
The measurement of the ability to be cut of the strands coated with the antistatic
agent is 4.5.
EXAMPLE 4
The preparation is carried out under the conditions of Example 2, modified in that
the content of silanes(9) and is 0.10 and 0.125% by weight respectively.
The measurement of the ability to be cut of the strands coated with the antistatic
agent is 1.8.
EXAMPLE 5
The preparation is carried out under the conditions of Example 2, modified in that
the content of silanes(9) and(10) is 0.15 and 0.25% by weight respectively.
The measurement of the ability to be cut of the strands coated and not coated with
the antistatic agent is 1.3 and 0.6 respectively.
EXAMPLE 6
The preparation is carried out of a sizing composition comprising (as % by weight):
- bissilane: aminobis(propyltrimethoxysilane)(9) 0.20
- unsaturated monosilane: mixture of methacrylamidopropyltrimethoxysilane and of
methacrylamidopropyltriethoxysilane(10) 0.20
- adhesion agent: aliphatic/cycloaliphatic polyurethane(11) 4.10
- adhesion agent: vinyl acetate/epoxide copolymer(12) 7.70
- lubricant: polyoxyethylenated hydrogenated tallow amide"13" 0.14
- lubricant: polyethyleneimide with free amide functional groups(7) 0.02
- LiCI 0.10
- water q.s. for 100
- formic acid q.s. for obtaining a pH equal to 5.
The solids content of the sizing composition is 5.85%.
The measurement of the ability to be cut of the strands not coated with the
antistatic agent is 2.2.
EXAMPLE 7
The preparation is carried out under the conditions of Example 6, modified in that
the content of silane(10) is 0.10% by weight.
The measurement of the ability to be cut of the strands not coated with the
antistatic agent is 6.0.
EXAMPLE 8
The preparation is carried out under the conditions of Example 6, modified in that
the content of each of the silanes(9) and(10) is 0.17% by weight.
The measurement of the ability to be cut of the strands not coated with the
antistatic agent is 2.5.
EXAMPLES
The preparation is carried out under the conditions of Example 6, modified in that
the content of each of the silanes(9) and is 0.23% by weight.
The measurement of the ability to be cut of the strands not coated with antistatic
agent is 2.2.
EXAMPLE 10
The preparation is carried out under the conditions of Example 6, modified in that
the content of silanes(9) and(10) is 0.17 and 0.23% by weight respectively.
The measurement of the ability to be cut of the strands not coated with the
antistatic agent is 1.3.
EXAMPLE 11
The preparation is carried out under the conditions of Example 6, modified in that
the content of silanes(9) and(10) is 0.23 and 0.17 % by weight respectively.
The measurement of the ability to be cut of the strands not coated with the
antistatic agent is 5.2.
EXAMPLE 12
The preparation is carried out under the conditions of Example 11, modified in
that the adhesion agent (12) is replaced by 6.5% by weight of ethylene/vinyl acetate
copolymer(14).
The measurement of the ability to be cut of the strands coated and not coated with
the antistatic agent is 8.1 and 2.7 respectively.
EXAMPLE 13
The preparation is earned out under the conditions of Example 11, modified in
that the adhesion agent(12) is replaced by 8.7% by weight of poly(vinyl acetate)(15).
The measurement of the ability to be cut of the strands not coated with the
antistatic agent is 5.0.
EXAMPLE 14
The preparation is carried out under the conditions of Example 13, modified in
that the content of adhesion agent(11) is 2.55% by weight.
j
The measurement of the ability to be cut of the strands coated and not coated with
the antistatic agent is 3.5 and 2.3 respectively.
The preparation is carried out under the conditions of Example 13, modified in
that the content of adhesion agent(15) is 6.8% by weight.
The measurement of the ability to be cut of the strands not coated with the
antistatic agent is 4.1.
EXAMPLES 16 TO 18
j
The properties of the glass strand coated with the sizing composition are
evaluated under the following conditions:
dry spraying
The glass strand removed from the roving is introduced into a spray gun (Venus
from Matrasur) which makes it possible to cut it and to spray it horizontally without
addition of resin. The quality of the reeling off of the strand and the properties of the cut
strands (stiffness, defibration and "dumping") are thus assessed.
simultaneous spraying
The evaluation is carried out under the conditions of the dry test of the preceding
paragraph, this time in the presence of unsaturated orthophthalic polyester resin
(Norsodyne S 2010 V, sold by Cray Valley) which has a viscosity of 5.6 poises at 18°C
and a moderate reactivity and is non-thixotropic. The resin and the cut strands are
sprayed simultaneously onto the walls of a mould in the form of a staircase which
comprises a vertical wall with a height of 1 m, then a stair with a depth of 0.2 m arid a
height of 0.2 m, and finally a horizontal wall with a length of 1 m. The appearance of the
carpet, the wetting speed, the final impregnation ("core") and the vertical wall strength are
evaluated. The content of glass in the final composite is of the order of 30%.
mechanical properties of the composites
The glass strand is used to form a plaque with parallel strands according to
Standard ISO 9291. Test specimens are cut out from this plaque and are usec for
measuring the flexural and shear tensile strengths under the conditions of Standards ISO
14125 and 14130 respectively.
The results, corresponding to the glass strands of Examples 1, 2 and 4 Which
have been subjected to the stage of treatment by the antistatic agent, are collated in
Table 1 (Examples 16,17 and 18 respectively).
In this table, the evaluations relating to the dry spraying and to the simultaneous
spraying are defined according to the following scale of values: 1 = very poor, 2 = poor,
3 = fairly good, 4 = good and 5 = very good.
On reading Table 1, it is found that the glass strands of Examples 17 and 18 in
accordance with the invention behave on spraying, in particular on dry spraying, similarly
to the strands of the prior art illustrated by Example 16. As regards more particularly the
simultaneous spraying, it is noticed that, with the strands according to the invention, an
improvement in the final impregnation and in the vertical wall strength is even obtained.
Although exhibiting a lower level of performance, the appearance of the carpet and the
wetting speed remain within limits which are entirely satisfactory for the targeted
application.
Furthermore, it should be noted that, in an entirely unexpected way, the
composites incorporating the glass strands according to the invention exhibit a markedly
j
improved resistance to ageing. This is because the measurements of flexural tensile
strength and shear tensile strength are reflected by a loss (in %) which is less than that of
the composites of the comparative example, in particular with the composite using the
strands of Example 17.
The glass strands coated with the sizing composition which combines the bissilane
(A) and the unsaturated monosilane (B) are therefore remarkable in that they have a
better ability to be cut, make possible retention of the mechanical reinforcing properties
and make possible better behaviour under ageing conditions, under conventional
conditions of use.
(1) so«d under the reference "Silquest*A-1126" by WITCO
(2) sold under the reference "Silquest* A-151" by WITCO
(3) sold under the reference "Vinamul*8852" by VINAMUL
(4) sold under the reference "Vinamul*8828" by VINAMUL
(5) sold under the reference "K-Flex* 500" by AKZO CHEMICAL
(6) sold under the reference "Nopalcol® 4L" by HENKEL CORPORATION
(7) sold under the reference "Emery* 671V by HENKEL CORPORATION
(8) sold under the reference "Arquad* C35" by AKZO NOBEL CHEMICALS
(9) sold under the reference "Silquest* A-1170" by WITCO CORPORATION
(10) sold under the reference "SUquest* y-5897" by CK WITCO CORPORATION
(11) sold under the reference "Neoxil* 9851" by DSM ITALIA
(12) sold under the reference "Fulatex* 8022" by H. B. FULLER FRANCE
(13) sold under the reference "Ethomid* HT23" by AKZO CHEMICAL
(14) sold under the reference "Vinamul* 1367" by VINAMUL
(15) sold under the reference "Mowilith* D43" by HOECHST
We Claim:
1. Glass strand coated with a sizing composition, characterized in that
the said composition comprises the combination
- of at least one bissilane (A) of formula
in which
R1, R2, R3, R4, R5 and R6, which are identical or different, represent
. a C1-C6 preferably C1-C3, alkyl radical
Z represents a C1-C16 hydrocarbonaceous chain comprising one or
more N, O and/or S heteroatoms, Z not comprising exclusively O,
- and of at least one unsaturated monosilane (B) chosen from
vinylsilanes and (meth)acrylosilanes.
Glass strand as claimed in claim 1, wherein the bissilane (A)
corresponds to the formula
in which:
R1, R2, R3, R4, R5 and R6 have the meaning given above,
A, B and C, which are identical or different, represent a C1-C16
hydrocarbonaceous chain, the sum of the carbon atoms of A, B and
C being less than or equal to 16,
n is equal to 0, 1,2 or 3,
R7 and R8, which are identical or different, represent H or a methyl
or ethyl radical.
Glass strand as claimed in claim 2, wherein the bissilane (A)
corresponds to the abovementioned formula in which:
R1, R2, R3, R4, R5 and R6, which are identical, represent a methyl or
ethyl radical,
A and C, which are identical or different, represent a methylene,
ethylene or propylene radical,
B represents an ethylene radical,
n is equal to 0 or 1,
R7 and R8 represents a hydrogen atom.
Glass strand as claimed in claim 3, wherein the bissilane (A)
corresponds to the above mentioned formula in which:
R1, R2, R3, R4, R5 and R6, which are identical, represent a methyl
radical,
A and C represents a propylene radical,
n is equal to 0,
R7 and R8 represent a hydrogen atom.
Glass strand as claimed in one of claims 1 to 4, wherein the
monosilane (B) is chosen from (meth)acrylosilanes.
Glass strand as claimed in claim 5, wherein the monosilane (B) is
chosen from [(meth)acryloxyalkyl]trialkoxysilanes and
(meth)acrylamido-alkyltrialkoxysilanes.
Glass strand as claimed in one of claims 1 to 6, wherein the
bissilane (A)/monosilane (B) ratio by weight is between 0.1 and 6,
preferably 0.3 and 3.
Glass strand as claimed in one of claims 1 to 7, wherein the sizing
composition additionally comprises at least one adhesion agent
such as herein described.
Glass strand as claimed in one of claims 1 to 8, wherein the
composition additionally comprises at least one lubricating agent
such as herein described.
10. Glass strand as claimed in one of claims 1 to 9, wherein it is
composed of filaments having a diameter varying from 9 to 24 fim.
11. Glass strand as claimed in one of claims 1 to 10, wherein it
exhibits a count of between 40 and 70 tex.
12. Glass strand as claimed in one of claims 1 to 11, wherein it
exhibits a loss on ignition of less than 1.5%, preferably of between
0.9 and 1.3%.
13. Sizing composition intended to coat the glass strands as claimed in
one of claims 1 to 12, characterized in that it comprises:
- at least one bissilane (A) corresponding to the above mentioned
formula,
- at least one monosilane (B),
- at least one adhesion agent,
- at least one lubricating agent,
- - and water.
14. Composition as claimed in claim 13, wherein it comprises:
- 0.05 to 0.4% by weight of bissilane (A),
- 0.05 to 0.4% by weight of monosilane (B),
- 3.9 to 6.8% by weight of adhesion agent,
- 0.01 to 0.4% by weight of lubricating agent,
- and at least 90% of water.
15. Composition as claimed in either of claims 13 and 14, wherein it
exhibits a solids content of between 2 and 10% by weight,
preferably 4 and 8%.
16. Composite comprising at least one thermosetting polymer material
and glass reinforcing strands, wherein all or part of the strands
is/are composed of strands as claimed in one of claims 1 to 12.
17. Composite as claimed in claim 16, wherein it includes 20 to 40%
by weight of glass.
18. Composite as claimed in either of claims 16 and 17, wherein the
polymer material is a polyester and/or an epoxy.
Glass strand coated with a sizing composition, characterized in that the said
composition comprises the combination
- of at least one bissilane (A) of formula
in which
R1, R2, R3, R4, R5 and R6, which are identical or different, represent a C1-C6
preferably C1-C3, alky 1 radical
Z represents a C1-C16 hydrocarbonaceous chain comprising one or more N,
O and/or S heteroatoms, Z not comprising exclusively O,
- and of at least one unsaturated monosilane (B) chosen from vinylsilanes
and (meth)acrylosilanes.

Documents:

00836-kolnp-2003-abstract.pdf

00836-kolnp-2003-claims.pdf

00836-kolnp-2003-correspondence.pdf

00836-kolnp-2003-description (complete).pdf

00836-kolnp-2003-form 1.pdf

00836-kolnp-2003-form 18.pdf

00836-kolnp-2003-form 2.pdf

00836-kolnp-2003-form 26.pdf

00836-kolnp-2003-form 3.pdf

00836-kolnp-2003-form 5.pdf

00836-kolnp-2003-letter patent.pdf

00836-kolnp-2003-reply first examination report.pdf

00836-kolnp-2003-translated copy of priority document.pdf

836-KOLNP-2003-FORM-27.pdf


Patent Number 216896
Indian Patent Application Number 836/KOLNP/2003
PG Journal Number 12/2008
Publication Date 21-Mar-2008
Grant Date 19-Mar-2008
Date of Filing 27-Jun-2003
Name of Patentee SAINT-GOBAIN VETROTEX FRANCE S.A
Applicant Address 130, AVENUE DES FOLLAZ, F-73000 CHAMBERY
Inventors:
# Inventor's Name Inventor's Address
1 GONTHIER, MICHEL 28 ROUTE DU SECHERON, F-73000 JACOB BELLECOMBETTE
PCT International Classification Number C03C 25/40
PCT International Application Number PCT/FR01/04066
PCT International Filing date 2001-12-19
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 01/00910 2001-01-24 France