|Title of Invention||
A SUBSTANTIALLY NON-DISCOLORING SIZING COMPOSITION FOR REINFORCING FIBRE MATERIALS AND A METHOD OF ITS MANUFATURE
|Abstract||A substantially non-discoloring sizing composition consisting essentially of: a grafted polyolefin emulsion, the grafted polyolefin including at least one reactive functional group selected from the group consisting of acid anhydride, carboxylic acid, hydroxyl, amino, amide, ester, isocyanate, double bonds and epoxy; at least two C8-C36 saturated fatty acids; and at least one silane coupling agents comprising at least one functional group selected from the group consisting of amino, epoxy, ester, vinyl, alkyl, methacryloxy, ureido, isocyanato and siloxane.|
|Full Text||SIZED REINFORCEMENTS, AND MATERIALS REINFORCED
WITH SUCH REINFORCEMENTS
TECHNICAL FIELD AND INDUSTRIAL
APPLICABILITY OF THE INVENTION
The present invention relates to a sizing composition for coating glass or other
reinforcing fiber materials that are used in the manufacturing of composites, which have
desirable properties such as high strength and high resistance to chemical degradation.
The sizing composition of the present invention also yields composites of more
neutral or natural coloring, and minimizes or eliminates discolorations associated with
conventional sizing compositions without requiring the use of an optical brightener.
The sizing composition of the present invention may also be used to coat
reinforcing fibers for use in composites that may subsequently be pigmented to obtain a
desired color. In this regard, the composition advantageously provides better color
matching during the pigmentation process without the need for color compensating
BACKGROUND OF THE INVENTION
The reinforced composite industry has historically used reinforcing fibers, such as
glass, in the form of continuous or chopped fibers, strands, and rovings to reinforce
polymer matrices. These are used to make a wide range of composite products that
possess a high degree of resilience and load-bearing ability. Such composite products may
also be manufactured to possess decorative characteristics such as patterns, surface
embossing, and coloration.
Glass reinforced polyolefin composites can be found in automotive, electrical and
household appliance industries. Their use often requires combinations of specific
mechanical, physical, chemical, and aesthetic properties. In many reinforced polyolefin
composite applications, high strength, high resistance to chemical degradation, and
improved coloring are highly desirable properties. It is also highly desirable to produce
polyolefin composites with mechanical properties such as low tensile creep and high
resistance to fatigue. These parameters are considered when predicting the composite
parts useful life span, and also when designing the composite part, often affecting its final
thickness and weight.
The sizing composition plays a key role in determining the properties of the
reinforced composite part. During manufacturing of the composite part, the sizing
composition forms an interphase between the reinforcing fiber and the polymer matrix.
When a load is applied to the composite part, force is transferred from the matrix to the
fibers. A strong interphase is desired for high composite strength. High composite
strength can be achieved with good adhesion of the fiber surface to the interphase, as well
as from good adhesion between the interphase and the polymer matrix.
Good adhesion between the interphase and polymer matrix is generally acheived by
the use of an appropriate sizing composition applied to the fibers. Although it may be
relatively easy to tailor and improve a single specific property of the composite, it is
difficult to improve several properties at the same time. For example, a sizing
composition may be used to form a composite part with good initial strength. However,
this composition may not form a composite with other properties such as good hydrolysis
and detergent resistance, or good resistance to discoloration.
Therefore, it is desirable that the sizing composition form an interphase that is
strong, resistant to thermal degradation, resistant to chemical degradation, provides good
adhesion between the fiber and sizing composition, and provides good adhesion between
the sizing composition and the polymer matrix. Also, the sizing composition must be
compatible with both the reinforcing fibers, which may be inorganic, and the polymer
matrix, which may be organic.
In order to achieve composites with improved color, it is necessary to have a sizing
composition comprising thermally stable ingredients that provide high resistance to
oxidation and yellowing.
Traditionally, sizing compositions used in polypropylene composites are
characterized by an aqueous emulsion of a film former having a highly modified
polypropylene resin of low molecular weight. For example, ChemCorp 43N40, an
aqueous emulsion of a maleic anhydride grafted polypropylene resin (E43 from Eastman
Chemical Company) may be used as the main film forming agent in a sizing composition.
E43 has an average molecular weight of 9000, and represents a resin with relatively low
molecular weight Although a sizing composition based on this film former would be
compatible with the reinforcing fibers and the polypropylene matrix resin, the final
interphase formed is not strong due to the lower mechanical strength of this film former.
Composite parts made from this sizing composition may possess insufficient short-term
and long-term mechanical properties.
Additionally, in many similar sizing compositions, the surfactant package used in
the film former emulsion contains low molecular weight chemicals which may be
unsaturated, nave one or more amine groups, or have amino groups which may be
characterized as canonic in nature. These chemicals contribute to poor composite
properties such as the discoloration of the composite part. Examples of these chemicals
are unsaturated fatty acids (such as oleic, linoleic, and linolenic acids) and amine based
neutralizing agents (such as triethyiamine and nitrogen containing canonic surfactants).
These agents can further cause yellowing and discoloration of the composite. Such
properties make the final composite part unsuitable for many applications, and limit then-
use. Therefore, there is a need for a sizing composition which overcomes these problems.
Discoloration in molded composite products, or in the materials used to
manufacture molded composite products, may arise from the presence of contaminants in
one or more materials that make up the composite formulation, or from the presence of
impurities in the ingredients that are used to form fiber-reinforced composites. These
ingredients may be materials used in sizing compositions for coating reinforcing fibers
before they are molded into composites. For example, conventional sizing compositions
often impart a yellow color or other discoloration to fiber reinforcements after such sizings
are applied These discolorations are then carried over into the composite product when
the reinforcements are molded. These discolorations may be caused by oxidative
decomposition of unsaturated chemicals, such as fatty unsaturated surfactants and/or
lubricants, which are of low thermal stability. These discolorations may also be caused by
nitrogen containing compounds, such as amides, imides, cationic surfactants or amine-
based chemicals, which are used, for example, as neutralizing agents.
Historically, the problem of discoloration has been partially addressed by adding
ingredients to the composite formulation to counteract the discoloration before the
composite formulation is molded Frequently, antioxidants are used in the compounding
formulations to minimize thermal degradation and associated discoloration. Also, the
added ingredient may be a colorant, for example, pigment or dye, that changes the color of
the composite formulation. For example a blue pigment or dye may be added to the
composite formulation to combat a yellow discoloration and, as a result, the finished
molded composite appears whiter.
A more recently developed method of correcting discoloration has been adapted to
fiber-reinforced composite manufacturing. Although, it has traditionally been used in
compositions applied to paper products, clothing, and plastics to create a brilliant white
appearance. This method involves adding an optical brightener, such as a fluorescent
whitening or brightening agent, to the composite formulation or to the sizing compositions
that are applied to the fiber reinforcements used to mold composites. U.S. Patent No.
5,646,207, for example, describes a sizing composition that includes a fluorescent
whitening agent in addition to other sizing ingredients such as a carboxylated
polypropylene, a silane coupling agent, and a lubricant. However, compositions such as
those disclosed in this patent rely specifically on the presence of the fluorescent whitening
agent to reduce discoloration in the composite product.
Use of an optical brightener does not, however, satisfactorily solve the problem of
discoloration in the molded composite. According to U.S. Patent No. 5,646,207,
discoloration problems in the molded composite remain when the fluorescent whitening
agent is added to the composite formulation because, in order to prevent discoloration
satisfactorily, the fluorescent whitening agent must be well dispersed into the matrix
polymer of the composite formulation. At the same time, the patent notes that uniform
dispersion of the fluorescent brightener in the matrix polymer is difficult to achieve.
Other technical and economic problems stem from the use of optical brighteners
such as a fluorescent whitening agent in composite formulations and in particular, in sizing
compositions for fiber reinforcements. Technical problems may compromise the quality
of the composite product, including degradation of the composite matrix polymer or
undesirable interactions with other composite ingredients. For example, an optical
brightener typically accelerates degradation of the matrix polymer when it is exposed to
ultraviolet (UV) light or other forms of radiant energy. Moreover, optical brighteners
themselves can degrade chemically over time, and thus contribute to yellowing or other
discoloration of molded composite articles. Another observed problem arises when an
optical brightener reacts with other ingredients such as an antioxidant that may be added to
the composite formulation. In this regard, combining the optical brightener and the
antioxidant reduces the efficiency of both ingredients, and ultimately results in
discoloration of the composite.
Additionally, it has been observed that color matching of composite batches is
difficult to achieve when the composite contains optical brighteners. In order to
compensate for these difficulties in color matching, varying amounts of pigments or other
additives have been added to the composite, which makes it difficult to maintain consistent
color between batches. The difficulties encountered in turning out composite batches
having consistent color, in turn, increases the cost of production by requiring more starting
materials and higher labor costs, and therefore poses an economic disadvantage in addition
to the technical problems. Further, color analysis of molded articles that contain optical
brighteners is difficult because the articles behave differently under different lighting types
and conditions. These problems with color analysis also increase the costs of producing
the fiber reinforcements and/or the composite product. The use of optical brighteners
further contributes to increased production costs simply because they are expensive
In some applications, such as the manufacturing of washing machine parts, it may
be desired that the molded composite product have a white color. In this regard, whitening
pigments have been added directly to the composite molding composition to provide the
white coloration. One such typically used whitening pigment is powdered titanium
dioxide (TiC^). However, the addition of whitening pigments such as Ti02 results in
damage to the reinforcing glass fibers and dramatically reduces the mechanical strength of
Therefore, there is a need in the art for a cost-effective sizing composition which,
when applied to reinforcing fibers used in a composite molding process, provides
increased whiteness, brightness and/or color compatibility in the molded composite
product, without requiring the use of an optical brightener, while maintaining the desirable
strength properties of the molded composite product. There is also a need for a sizing
composition that is stable to oxidation degradation and which, when applied to reinforcing
fiber materials used in the manufacture of molded composites, will not result in
discoloration of the molded composite product. There is also a need for a sizing
composition that is stable to oxidation degradation and resistant to thermal degradation
thereby creating a stronger interphase, which provides desirable short-term and long term
mechanical properties, and increased resistance to chemical and thermal breakdown of the
reinforced composite part.
SUMMARY OF THE INVENTION
One or more needs in the prior art, as described above, is met by the present
invention. The invention relates to a substantially non-discoloring sizing composition for
reinforcing fiber materials, comprising an emulsion comprising a grafted polyolefin, a
blend of two or more saturated fatty acids, and one or more silane coupling agents.
The invention also relates to a fiber coated with a substantially non-discoloring
sizing composition, for example, for reinforcing materials, comprising an emulsion
comprising a grafted polyolefin, a blend of two or more saturated fatty acids, and one or
more silane coupling agents.
The invention also relates to a method of making a substantially non-discoloring
sized reinforcing fiber material, comprising preparing a sizing composition comprising an
emulsion comprising a grafted polyolefin, a blend of two or more saturated fatty acids, and
one or more silane coupling agents; contacting the surfaces of a plurality of filaments of a
reinforcing fiber material with the sizing composition; and allowing the sizing
composition to solidify on the surfaces of the plurality of filaments to form a substantially
non-discoloring reinforcing fiber material.
The invention further relates to a method of making a fiber-reinforced composite,
comprising applying a substantially non-discoloring sizing composition comprising an
emulsion comprising a grafted polyolefin, a blend of two or more saturated fatty acids, and
one or more silane coupling agents on the surfaces of a reinforcing fiber material to form a
sized reinforcing fiber material; and molding the sized reinforcing fiber material with a
matrix resin to form a fiber-reinforced composite having minimal discoloration.
The invention further relates to a composite comprising a fiber coated with a
substantially non-discoloring sizing composition for reinforcing fiber materials, that
provides enhanced short term and long term composite strength, higher resistance to
chemical degradation (due to hydrolysis or detergents) comprising an emulsion comprising
a grafted polyolefin, a blend of two or more saturated fatty acids, and one or more silane
Further objects, features, and advantages of the invention will become apparent
from the detailed description that follows.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
In one embodiment, the present invention comprises a composition that is suitable
for sizing reinforcing fiber materials to be used in the manufacturing of fiber reinforced
composites. The sizing composition provides improved short-term mechanical
performance of a fiber-reinforced composite such as increased strength. The sizing
composition also provides improved long-term mechanical performance of the composite
such as increased resistance to creep and fatigue. In another embodiment, the sizing
composition provides a composite with higher resistance to thermal and chemical
breakdown, including breakdown due to hydrolysis.
Properties such as whiteness, neutral coloring and ease of color matching of the
fiber reinforced composite are desired in addition to good short-term and long-term
mechanical performance, and good resistance to thermal and chemical breakdown.
Although not completely understood, it is believed that the discoloration associated with
the thermal oxidation or thermal degradation of the sizing composition relates to
degradation of the interphase. This causes poor adhesion between the fiber and polymer
matrix leading to decreased overall mechanical performance of the composite. The
present invention provides improved performance of the reinforced composite by selecting
components of the sizing composition that resist thermal oxidation or thermal degradation.
In another embodiment, the present "invention comprises a substantially non-
discoloring sizing composition. The term "substantially non-discoloring" or "having
minimal discoloration", as used herein, is intended to mean mat the sizing composition
does not cause any discoloration of either the reinforcing fiber material treated with the
sizing, or the composite formed therefrom, or alternatively, the sizing composition causes
only de minimis coloration such that the whiteness or neutral color in the reinforcing fiber
material or the resulting molded composite is optimized. The term is also intended to
mean that the reinforcing fiber material or molded composite product maybe color
matched with other batches of similar materials without the technical and economic
difficulties typically associated with variations in color caused by the inclusion of an
While the reason for the substantially non-discoloring effect of the sizing
composition of the present invention has not been definitively established, the inventors
believe that it may be due, in part, to the fact that the selected sizing composition
components provide better resistance to thermal or oxidative degradation. The
components are preferably based mainly on molecular species having no reactive double
bonds or very few reactive double bonds, for example, they are highly saturated. The term
"highly saturated", as used herein with respect to particular sizing composition
components, is intended to mean that the proportion of unsaturated organic bonds in such
ingredients is nearly zero or up to a maximum of 0.35, as quantified by the ingredient's
Iodine Value. This means that the components are also free of any highly unsaturated
molecular species, such as unsaturated chemicals, unsaturated surfactants, unsaturated
lubricants, unsaturated wetting agents, unsaturated antifoaming agents and other
It is believed that the unsaturation or double bonds in these unsaturated compounds
causes them to be more reactive to chemical degradation mechanisms, such as oxidation.
As a result, the compounds are more prone to develop discoloring reaction products in the
sizing formulation or in the composite formulation. The substantially non-discoloring
effect may also be partly attributable to the preferred absence of nitrogen containing
compounds, such as some amines, imides, and amides, including fatty amines, fatty
amides, and nitrogen containing canonic surfactants which cause discoloration. Similarly,
nitrogen containing compounds which do not discolor may be used while maintaining the
non-discoloring property. In contrast to the'aforementioned types of compounds, the
sizing composition of the present invention is based on highly saturated chemicals, or
chemicals having no or very few double bonds, that are oxidatively and thermally more
stable than the unsaturated compounds conventionally used in this field of endeavor.
The sizing composition of the present invention includes one or more film forming
polymers selected from the group of grafted or chemically modified polyolefins. The term
"grafted polyolefin" or "chemically modified polyolefin", as used herein, is intended to
mean a polymeric olefin that has been chemically modified and functionalized to
incorporate one or more reactive groups into the main polyolefin polymer chain.
Reactive functional groups are groups that are capable of undergoing further
chemical reactions with other chemical species. Some examples of such reactive
functional groups are acid anhydride, carboxylic acid, hydroxyl, amino, amide, ester,
isocyanate, double bonds, and epoxy. Although many types of reactive functional groups
can be attached to the polyolefLn chains, Jhe most preferred groups are acid anhydrides.
Generally, the level of grafted functional groups is in the range of 0.05% to 15% by
weight, based on the total weight of the polymer.
A suitable grafted polyolefin for use in the present invention is added to the sizing
composition as an aqueous emulsion. Examples of grafted polyolefins that may be used to
form such emulsions include grafted or modified polypropylenes, grafted or modified
polyethylenes and mixtures thereof. Examples of a preferred grafted polyolefin are
polypropylenes grafted with maleic anhydride. Preferred emulsions are commercially
available as an aqueous emulsion under the tradename ME 91725 (nonionic polypropylene
emulsion), or ME 91735 (nonionic polypropylene emulsion) obtained from Michelman,
Inc. headquartered in Cincinnati, Ohio, United States of America.
Typically, the amount of the grafted polyolefin emulsion in the sizing composition
ranges from about 1% by weight to about 99% by weight, based on the total weight of the
sizing composition. Preferably, the amount of grafted polyolefin emulsion used is from
about 4% by weight to about 80% by weight. Most preferably, the amount is between
about 35% to about 70% by weight.
The substantially non-discoloring sizing composition of the present invention also
includes a blend of two or more saturated fatty acids. In one aspect, this blend of fatty
acids serves as a nucleating agent, which is believed to affect the size and rate of crystallite
(serite) growth in the reinforced composite. The rate of formation and the size of the
resulting crystallites have a direct and proportionate effect on the performance of the
reinforced composite. Therefore including an effective amount of the fatty acid blend as a
nucleating agent has the effect of optimizing the performance of the composite, especially
In another regard, the blend of saturated fatty acids serves as a lubricant in the
sizing composition. Whereas sizing compositions previously known in the prior art
included lubricants such as the cationic fabricant disclosed in WO 048957A1, the sizing
composition of the present invention eliminates the need for a lubricant as a separate
ingredient in addition to the fatty acid hfimd. In the sizing composition of the present
invention, the lubricant effect is provided by the fatty acid blend and protects the fibers
from breakage and shear stress. Also, ft will generally reduce damage to the filaments
during fiber production, handling and caaaposite manufacturing ensuring better composite
performance. It is also believed, that the fatty acid blend acts as a wetting agent providing
better coverage of the fiber filaments by the sizing composition during fiber production
which protects the fibers and further enhances the performance of the reinforced polyolefin
composites. It is also believed that the fatty acid blend acts, to a certain extent, as a mold
releasing agent during the molding operation thereby providing better surface finish to the
composite parts and faster molding cycle operations.
A suitable blend of saturated fatty acids for use in the sizing composition of the
present invention may be selected from two or more Cg - C36 saturated fatty acids, the salts
of these fatty acids, or mixtures thereof. Preferably, the blend of fatty acids comprises a
mixture as a solution, dispersion, suspension or emulsion of highly saturated Cs - C36 fatty
acids, or salts thereof, in an aqueous or nonaqueous medium. Most preferably, the blend
of fatty acids is provided as an aqueous mixture of two or more Cg - C36 fatty acids, such
as myristic, palmitic, pentadecanoic, margeric, stearic, behenic or sebacic acids. An
example of a blend of such fatty acids is a combination of palmitic, sebacic and stearic
acids, which, for example, may be obtained commercially as an aqueous emulsion under
the tradename "MoldPro 1327" from Witco Polymer Additives, a subsidiary of Crompton
Corp., Memphis, TN, United States of America. The amount of the blend of fatty acids
may range from 0.05% by weight to about 80% by weight, based on the total weight of the
sizing composition. Preferably, the blend of fatty acids is present in a concentration ranges
from about 0.90% to about 50% by weight Most preferable is a concentration of 2% to
30% by weight.
The substantially non-discoloring sizing composition of the present invention also
includes a silane coupling agent. The silane coupling agent improves the adhesion
between the reinforcing fiber material and the polymer matrix resin to be reinforced. The
silane is believed to form a "bridge" between the glass fibers and the matrix resin.
Reactive functional groups on the silane interact with the surface functional groups on the
fibers and also with the film forming agent of the sizing composition. As discussed above,
the film forming component of the sizing composition is chosen to be compatible to the
matrix resin, and eventually enters the matrix resin and may chemically bond with the
matrix resin. The silane coupling agent which reacts with the glass surface chemical
groups can also react with the matrix resin chemical groups.
Silane coupling agents which may be used include those characterized by the
following functional groups: amino, cpoxy, ester, vinyl, alkyl, methacryloxy, ureido,
isocyanato, and siloxane. Aminosilanes are commercially available from OSi Specialties,
Inc., located in Tarrytown, NY, United States of America, Dow Corning, Inc. located in
Midland, Michigan, United States of America, or Degussa-Huls AG located in Frankfurt,
Germany. Preferred silane coupling agents include silanes containing one or more
nitrogen atoms in the form of one or more of the following functional groups: amine
(primary, secondary, tertiary or quaternary), amino, imino, amido, imido, ureido,
isocyanateo, or azamido. Examples of these nitrogen containing silanes include, but are
not limited to: phenylaminosilane, commercially available under the tradename 'T-9669"
from OSi Specialties, Inc.; n-2-(\dnylbenzylammo)^myl-3-animopropyltrimethoxysilane-
monohydrogen chloride, commercially available under the tradename "Z-6032" from Dow
Coming; and ganmia-aminopropymiethoxysilane, commercially available under the
tradename "A-l 100" from OSi Specialties, Inc. Other useful amino silanes commercially
available from Osi Specialties, Inc. include, but are not limited to products with the
following trade names A-l 101, A-l 102, A-l 106, A-l 108, A-l 110, A-l 120, A-l 126, A-
1128, A-l 130, A-l 160, A-l 170, A-1310, A-2120, Y-1387, Y-11343, Y-11542, and
VS142. A preferred amino silane coupling agent is garnma-aminopropyltriethoxysilane.
Although gamrna-aminopropyltriethoxysilane may be used alone, it may also be used in
combination with other amino silane agents, with silanes with functional groups other than
amino functional groups, or with silanes containing no nitrogen. Examples of silanes
having functional groups other than amino functional groups include, but are not limited
to: vinyltrimethoxysilane (commercially available as A-l71),
glycidyloxypropyltrimethoxysilane (commercially available as A-187), and
methaciyloxypropyltrimethoxysilane (commercially available as A-l 74), all of which are
available from Osi Specialties, Inc.
The silane coupling agent is generally included in the sizing composition at a
concentration of about 0.05% to about 40% by weight, based on the total weight of the
sizing composition. Preferably, the silane coupling agent is used in an amount of from
about 0.2% to about 25% by weight. Most preferably, the amount is between about 2% to
about 15% by weight
The sizing composition may also include one or more additives useful to improve
the wettability or dispersion of the sized reinforcing fiber material in the composite matrix,
as well as to improve the ease of processing and the reduction of fuzz in the sized product.
Such agents may be selected from the group of coupling agents that enhance the
compatibility of the sized reinforcing fiber material with the matrix resin. The group
includes, but is not limited to antioxidants, antifoaming agents, processing aids, wetting
agents, lubricants, antistats, and other conventionally known additives.
An antifoaming agent may be added to the sizing composition to reduce foam
generation during mixing and handling of the sizing composition before the sizing
composition is applied to the reinforcing fiber material. Various types of antifoaming
agents may be used, such as those which are silicone based or silicone free. Examples of
suitable antifoaming agents include, but are not limited to, those commercially available
from BYK Chemie located in Wesel, Germany under the trade names BYK-011, BYK-
018, BYK-020, BYK-021, BYK-022, BYK-023, BYK-024, BYK-025, BYK-028, BYK-
031, BYK-032, BYK-033, BYK-034, BYK-035, BYK-036, BYK-037, BYK-045, or
BYK-0S0. An antifoaming agent may be added in any amount up to 2% by weight, based
on the total weight of the sizing composition. Preferably, the antifoaming agent is between
about 0.001% and about 0.5% by weight. Most preferable is between about 0.005% and
about 0.2% by weight.
The sizing composition may be prepared by combining the ingredients thereof
according to any method known to one of ordinary skiD in the art. Preferably, the sizing
composition maybe made by blending the individual components of the sizing
composition with a diluent to form a solution or suspension. Most preferably, the diluent
The sequence of combining the ingredients can be important to forming a stable
sizing composition. Preferably, the emulsion of grafted polyolefin and an aqueous fatty
acid blend are blended together in water before the addition of the silane coupling agent.
The silane coupling agent is preferably added last to minimize the reactions between the
ingredients, and primarily to control the viscosity of the sizing composition. The sizing
composition of the present invention provides viscosity, on the order of from about 8 cPs
to about 150 cPs. Changes in viscosity are desirably minimized because differences in
viscosity can lead to variations in the thickness of the layer of sizing composition that is
deposited on the surface of the reinforcing fiber material. An increase or decrease in the
thickness of the layer of sizing composition can affect the performance of the sized
reinforcing fiber material in the composite.
The components such as the emulsion of grafted polyolefin polymer, the blend of
fatty acids, the coupling agent, and the lubricant, as well as any of the aforementioned
other optional additives are preferably combined in amounts effective to formulate the
sizing composition as a stable dispersion having a storage stability of up to about 72 hours
at temperatures of from about 10°C (49.9°F) to about 32°C (89.6°F). Although pH of the
sizing composition is not critical, it is preferred that the final sizing composition formed by
combining all the aforementioned ingredients have a pH in the range of from about 6.5 to
The sizing composition of the present invention may be applied to the reinforcing
fiber material by any suitable method to form a coated reinforcing fiber material. The
reinforcing fiber material to which the sizing composition of the present invention can be
applied may be selected from any reinforcing fiber materials known in the art. Suitable
reinforcing fiber material may be selected in any given form from materials such as glass
fibers, polymer fibers (including nylon, polyaramid fibers, polyester fibers and the like),
carbon or graphite fibers, natural fibers such as jute, hemp, flax, kenaf, and sisal, and any
combination thereof. Preferably, a suitable reinforcing fiber material for use in this
invention is a strand comprised of glass, polymer, or a blend thereof.
The reinforcing fiber material may be in the form of individual filaments, twisted
yams, strands or rovings. The sized reinforcing fiber material maybe used, in continuous
or discontinuous form, in the manufacture of fiber reinforced composites. The term
"continuous", as used herein with regard to the reinforcing fiber material, is intended to
include reinforcing fiber materials that are in the form of unbroken filaments, threads,
strands, yams or rovings, which may either be sized directly after formation in a
continuous fiber-forming operation, or which may be formed and wound into packages
that can be unwound at a later time to allow application of the sizing composition. The
term "discontinuous", as used herein with regard to the reinforcing fiber material, is
intended to include reinforcing fiber materials that have been segmented by chopping or
cutting, or which are formed from a process designed to form segmented fibers, such as a
fiber-forming spinner process. The segments of discontinuous reinforcing fiber material
that are used in the present invention may vary in length, ranging from about 2 mm to
about 25 mm in length.
Accordingly, the sizing composition may be applied, for example, to continuous
filaments of a reinforcing fiber material immediately after they are formed in an in-line
operation. Alternatively, the sizing composition may be applied off-line to unwound
strands of reinforcing fiber material that were previously formed and packaged. The sizing
may also be applied to a reinforcing fiber material that has been woven into a fabric or
applied to a non-woven fibrous mat. Means for applying the sizing composition include,
but are not limited to, pads, sprayers, rollers or immersion baths, which allow a substantial
amount of the surfaces of the filaments of the reinforcing fiber material to be wetted with
the sizing composition.
Preferably, the sizing composition is applied to a plurality of continuously forming
filaments of a reinforcing fiber material as soon as they are formed from a fiber-forming
apparatus such as a bushing. The bushing is preferably equipped with small apertures to
allow passage of thin streams of a molten reinforcing fiber material. As the streams of
molten material emerge from the bushing apertures, each stream is attenuated and pulled
downward to form a long, continuous filament. The continuously forming filaments may
then be gathered into strands and chopped or cut in an in-line operation, or they may be
gathered into strands for winding into forming packages or doffs. The chopped strands or
the forming packages are then dried. Typically, chopped strands are dried in an oven using
a temperature ranging from about 60°C (140°F) to about 200°C (392°F). Typically,
forming packages are dried in a static oven for a period of about 7 hours to about 23 hours
at a temperature of about 129°C (264.2°F), after which they are ready for use in composite-
The resulting sized reinforcing fiber material may be utilized to form a composite
material having substantially no discoloration due primarily to the use of the non-
discoloring sizing composition of the present invention deposited on the fibers. Suitable
matrix resins for this purpose may be thermoplastic polymers, thermoset polymers,
solution processable polymers, aqueous based polymers, monomers, oligomers, and
polymers curable by air, heat, light, x-rays, gamma rays, microwave radiation, UV
radiation, infrared radiation, corona discharge, electron beams, and other similar forms of
electromagnetic radiation. Suitable matrix resins include, but are not limited to,
polyolefins, modified polyolefins. saturated or unsaturated polyesters, polyamides,
polyacrylamides, polyimides, polyethers, polyvinylethers, polystyrenes, polyoxides,
polycarbonates, polysiloxanes, polysulfones, polyanhydrides, polyimines, polymer blends,
alloys and mixtures, epoxy, polyacrylics, polyvinylesters, polyurethane, maleic resins, urea
resins, melamine resins, phenol resins, and furan resins.
Preferably, the matrix resin is a polyolefin. One example of such a polyolefin is a
polypropylene homopolymer commercially available as "Moplen KF 6100" from Basel!
Polypropylene GmbH in Mainz, Germany. The composite formulation may also include
one or more conventionally known additives such as coupling agents, compatibilizers,
flame retardants, pigments, antioxidants, lubricants, antistats and fillers. Examples of
suitable antioxidants used during the compounding process are commercially available
under the tradenames "HP2215" and "HP2225" from Ciba Specialty Chemicals Inc.,
The process of compounding and molding the sized reinforcing fiber material and
the matrix resin to form a composite may be accomplished by any means conventionally
known in the art Such compounding and molding means include, but are not limited to,
extrusion, wire coating, compression molding, injection molding, extrusion-compression
molding, extrusion-injection-compression molding, and long fiber injection. In a preferred
embodiment of the present invention, when using polyolefin composites, the chopped fiber
strand is coated with the sizing composition and is extruded with polyolefin resin matrix to
form pellets. These chopped pellets then are suitably injection molded into a desired
composite molded part.
The amount of matrix resin included in the composite is generally about 1% to
about 99% by weight, based on the total weight of the composite formulation. Preferably,
the percent composition of matrix resin is between about 30% and about 95% by weight.
Most preferable is about 60% to about 95% by weight, based on the total weight of the
The sizing composition of the present invention provides a coating on the
reinforcing fibers which improves compatibility and adhesion with the resin matrix, and
results in composites with more desirable properties such as higher short-term and long-
term mechanical performance, and increased resistance to chemicals, detergents,
oxidation, and hydrolysis. Although the mechanism is not fully understood, in composites,
it is generally observed that the chemicals, detergents, and water that attack the matrix
resin and other ingredients present in the composite formulation, also attack the glass-
matrix interphase region that is responsible for the composite performance, thus lowering
the adhesion and the composite performance.
Where a specific coloration of the final composite product is a desired, pigments or
other color-enhancing additives may be added to the composite formulation before or
during the molding process. Additionally, it may be desired that the composite
formulation not contain any inherent discoloration that could affect the desired color of the
molded composite product. Therefore, it is desirable that the composite have a clear or
neutral coloration. In other applications, it may be preferable that the composite
formulation be white, in which case a white pigment may be added. In preparing white
composite formulations, it is also desirable that discoloration of the composite be kept to a
The sizing composition disclosed above may suitably comprise, consist of, or
consist essentially of an emulsion comprising a grafted polyolefin, saturated fatty acids,
silane coupling agents, additives and antifoaming agents. The invention illustratively
disclosed herein may be practiced in the absence of any element which is not specifically
The following examples are representative, but are in no way limiting as to the
scope of this invention.
Sizing compositions of the present invention were prepared according to the
formulations listed in Table 1. These sizing compositions were used to prepare the
chopped strands also listed in Table 1. The chopped strands described in Table 1, were
extrusion compounded according to the compounding formulations listed in Table 2.
Table 2 also refers to the injection molded composite test pieces used for further testing
purpose. Each of the prepared composite test pieces was subjected to testing to measure
properties like short-term and long-term mechanical properties, long term hydrolysis and
detergent aging resistance, and coloring. The results of the various tests are reported in
Tables 3 through 6.
Chopped Strand Fiber Examples (A-H. J-LV
Various chopped glass fiber strands were prepared according to sizing formulations
of the present invention. Chopped strands A-H and J-L were all produced at different
times. The sizing formulation used with chopped strand K contains an optical brightener,
whereas the sizing formulation used with chopped strand J does not. Table 1 reports the
chopped glass fibers and the sizing formulation used in-their production.
The order that the ingredients are added to make the size composition may not be
critical. However, preferably, 10 liters of each formulation were prepared by first adding
an emulsion of polypropylene grafted with maleic anhydride to water (the diluent), then
adding the aqueous saturated fatty acid blend. The mixture was blended by stirring for
between approximately 5 minutes to 30 minutes, while the temperature of the mixture
during stirring was preferably maintained at approximately 25°C (76.9°F). After the
mixture was thoroughly blended, the amino silane coupling agent was added to the
composition, and the water content adjusted to provide a viscosity of preferably about 5
cps to 20 cPs.
The sizing composition can be applied to the fibers by any method known in the
art, either during their production or at a later stage. Each sizing composition was applied
to glass fiber strands using a submerged applicator roller process. In this process, the
fibers pick up the sizing composition during their production by making contact with the
surface of a rotating applicator which is submerged in a circulating bath of sizing
composition. Therefore, the sizing composition is applied to the fibers during the
continuous fiber production. This type of process is often referred to as an in-line process.
The amount of sizing composition that is picked up by the fibers from the surface of the
rotating applicator can be influenced by several factors such as speed of the applicator roll,
concentration of the sizing composition, and the amount of water sprayed during the fiber
production. In an in-line process, the sizing composition can be applied to fibers of
different diameters, but the diameter range of 9-27u is preferred, and the range of 11-1 7u
is most preferred. The sizing compositions of the present invention were applied to fibers
of approximately 12-14u in diameter as shown in Table 1.
Next in the production process, the fibers are gathered to form a strand that is
chopped into strands using an in-line chopping process called the Cratec* process, as
named by Owens Coming. During this process, the glass fibers are chopped in-line using
a chopper and cot during their manufacturing. The chopped length of the strand may be
varied from about 3 mm to 25 mm. The preferred range of the chopped strand length is
from 3.5 mm to 13 mm. The most preferred range of the chopped length is from 3.5 mm
to 4.5 mm. The most preferred range of the length is also suitable for high shear extrusion
processes. The chopped strands are then conveyed over the belt to the drying oven to
solidify the sizing composition on the glass fibers. Before drying, chopped strands may
optionally be sent through the Cratec Plus® process, as named by Owens Coming, to form
strand bundles of a size that are suitable for further handling and processing. The Cratec
Plus® process is an extension of the Cratec® process in which the glass fibers are chopped
in-line using the Cratec® process, then processed in-line in a tumbler to produce strand
bundles larger than those obtained with the Cratec® process. The Cratec® and Cratec
Plus processes and related processes are described for example, in U.S. Patent Nos.
5,578,535, 5,693,378, 5,868,982, and 5,945,134, each is incorporated by reference. In the
drying oven, the chopped strands are dried and the sizing composition on the fibers is
solidified using hot air flow of controlled temperature. The dried fibers are then passed
over screens to remove longs, fuzz balls, and other undesirable matter to finally collect the
chopped strands in a more desirable form.
Compounding Formulations (Examples 1-14 and Ref 1-3,2a, 3a):
In Table 2, the compounding formulations are used on chopped strands coated with
the sizing formulation of the present invention, and on reference chopped strands.
In the embodiments of Table 2, 30% (by weight) dried chopped strands are
combined with 70% (by weight) polypropylene matrix resin, in a twin-screw extruder of
type ZSK 30/2 from Werner & Pfleiderer, to form compounded pellets. During the
extrusion compounding, a coupling agent such as Polybond PB 3200 from Uniroyal, may
optionally be combined and mixed with the polymer matrix resin to improve the final
composite's performance. Such a coupling agent can be mixed during compounding with
the resin matrix using 0.1 % to 10% coupling agent by weight, based on the total weight of
the glass and matrix resin, preferably 0.3% to 5%, and most preferably 0.5% to 3% by
weight Also, during the extrusion compounding, various types of antioxidants such as
phenolic, phosphite, or lactone based, may be combined and mixed with the matrix resin
for optimum performance of the composite. Such antioxidants may be formulated using
0.1 % to 3% antioxidant by weight based on the total weight of the mixture of glass and
matrix resin, preferably 0.3% to 2% (by weight), and most preferably 0.5% to 1% (by
weight). Antioxidants such as HP 2215 and HP 2225 from Ciba Specialty Chemicals may
be used in the compounding formulations because these antioxidants are based on
combinations of phenolic, phosphite, and lactone based antioxidants, thereby offering a
more balanced effect in controlling the thermal degradation, especially during the
processing. Optionally, to.pigment the pellets, a color compensating additive such as ZnS
(a white pigment available commercially under the trade name "Sachtolith HDS" from
Sachtleben Chemie) may be mixed with matrix resin in the range of 0.05% to 10%
pigment by weight based on the total weight of the mixture of glass and matrix resin,
preferably 0.1% to 5% (by weight), and most preferably 0.5% to 3% (by weight).
Subsequently, the extrusion compounded pellets are fed into any suitable standard
molding equipment to form the composite parts. In one embodiment of the present
invention, molding is done using a Demag D80 injection molding machine (available from
Demag Hamilton Plastics Ltd.) to produce composite test samples which were used to
measure composite performance. Thus, each of the extrusion compounded pellets of
Table 2 were further molded into composite test pieces by standard injection molding.
Therefore, all the final injection molded composite pieces refer to the same number and
nomenclature as mentioned in Table 2.
The resulting composite parts were then tested to measure certain physical
characteristics, including tensile strength, izod and charpy impact strength, tensile fatigue,
and tensile creep. The parts were also tested to simulate aging by testing the parts for
resistance to hydrolysis and detergents. The results of the various tests are reported in
Tables 3 through 6.
Short-Term Mechanical Performance and Coloring:
(Examples 1-12, Ref 1-3, Ref 2a. 3a):
Test results reported in Table 3 are the measurement of short-term (dry as molded)
mechanical performance like tensile strength and impact strength, as well as measurements
relating to color for the composite molded pieces according to Examples 1-12, Ref 1-3,
and Ref 2a, 3a.
Tensile strength is a measure of resistance when an elongating force is applied, and
was measured using a universal testing machine from Zwick, according to ISO method
3268, and the results reported in MPa. Impact testing was carried out using impact testing
machine from Zwick. IZOD impact strength, measured in KJ/m2, is a measure of the
degree of impact force that the composite can withstand, was measured according to ISO
Method 179/1D in un-notched specimens, and according to ISO Method 180 in notched
specimens (which were notched 2mm). Charpy strength is also a measure of impact
strength and was measured as resistance in KJ/m2. Charpy strength is measured according
to the ISO I79/D method.
The color of the composite samples was quantified using a Minolta CIELab color
meter equipped with ChromaControll software. When measuring color, the standard
molded pieces in disc shape were used. Color was determined in terms of whiteness
(reported as an "L" value), red-green coloration (reported as an "a*" value), and blue-
yellow coloration (reported as a "b*" value). A higher "L" value indicates a whiter or
lighter coloring of the test piece with higher reflectance. A higher positive "a*" value
indicates more red is the test piece, and a higher negative "a*" value indicates more green
is the test piece.
Similarly, a higher positive "b*" value indicates more yellow in the test piece, and
a higher negative "b*" value indicates more blue in the test piece. In order to achieve
whiteness or to match any color, color compensating additives are commonly added.
However, such compensating additives lead to complex color formation, making it very
difficult, time corisurning, and more costly to match the color of the final composite part.
For example, to hide or mask the yellow color of a part having high "b*" value,
compensating blue color using a bluing agent may be added to shift the "b*" values to a
lower value. The bluing agent may also change the original "a*" value resulting in an
undesirable coloration. Such color compensating additives are not necessary, but may be
used with the present invention.
In the case of non-pigmented extrusion compounding formulations, each of the
composites in Examples 1-6 were compared to composite samples Ref 1, Ref 2, and Ref 3.
In the case of pigmented extrusion compounding formulation, each of the composite
Examples 7-12 was compared to composite samples Ref 2a and Ref 3a. The results of the
testing are reported in Table 3.
Long-Term Aging Performance:
Hydrolysis Testing and Detergent Testing (Examples 1-6. 13. 14. and Ref 2, Ref 31:
Tensile strength testing was performed on Examples 1-6, 13, and 14, and Ref 2 and
Ref 3 after they had been subjected to hydrolytic and detergent conditions. These
conditions were intended to simulate hydrolysis and detergent aging conditions that may
be experienced by a laundry or washing machine tub composite part. In such a situation,
wet strength and the maximum retention of the properties of the composite over an
extended period of time at elevated temperature is desirable. To approximate conditions to
test detergent aging resistance, samples of each composite that were molded according to
the formulation of Examples 1-6, and Ref 2 and Ref 3, were immersed in a bath containing
a 1% detergent solution that was maintained at a temperature of about 94°C (201.2°F) for
up to 30 days. The detergent solution was changed every day.
Similarly, for the preparation of samples to measure hydrolysis aging resistance,
the samples of each composite, molded according Examples 13 and 14, and Ref 2 and Ref
3, were immersed in water bath that is maintained at a temperature of about 94°C
(201.2°F). In both detergent and hydrolysis testing, the samples were removed at intervals
of 1, 3,5,10, 20, and 30 days, at which time the tensile strength of each sample was
measured. The results of detergent aging resistance, testing for tensile strength and impact
strength, are recorded in Table 4. The results of the hydrolysis aging resistance, testing for,
tensile strength and impact strength, are reported in Table 5.
Long-term Mechanical Performance:
Tensile Creep and Fatigue (Examples 13. Ref 2, Ref 3):
In order to measure long-term mechanical performance, tensile fatigue and tensile
creep testing was performed on Example 13, Ref 2 and Ref 3. The results are reported in
Table 6. The results in Table 6 report the absolute values as well as relative %
improvement shown by an example of the present invention compared to the Ref 2 and
Ref 3 samples, the testing was performed as follows:
Instron 1331 servohydraulic testing machine with clamps in a Thermotron
environmental chamber to condition molded specimens at 80°C (176°F). Testing
controlled by an IBM compatible PC running Instron MAX software
Tensile creep is measured by placing a 0.5 inch (127 cm) taper molded bar in an
Instron 1331 servohydraulic machine, in load control, using a fixed mean level of 120 kg,
and an amplitude of zero. The elevated temperature is 80°C (176°F). Failure time (hours
to creep rupture) were averaged for three specimens.
Fatigue is measured by placing specimen in the Instron servohydraulic machine, in
load control, using a sinusoidal wave form. The ratio of minimum to maximum stress on
each cycle is 0.05. The test frequency is 6 Hz. Three stress levels were often chosen,
8400, 8900, and 10,000 psi. For the composite pieces of the present invention, a load of^?
8400 psi (about 57.92 MPa) is used. The cycles to failure were averaged for three,
Summary of Results:
As seen in Table 3, the composite samples made with the sizing composition of the
present invention in non-pigmented compounding formulations, show much more
desirable short-term (dry as molded) mechanical properties (for example, tensile strength,
impact strength) compared to the reference composite samples Ref 1 and Ref 3, although
they are similar to Ref 2.
In pigmented compounding formulations, the composite samples made with the
sizing composition of the present invention show more desirable short-term mechanical
properties compared to Ref 2a and Ref 3a. The lowest short-term mechanical performance
is measured for Ref 3a, both in pigmented as well as non-pigmented compounding
In non-pigmented compounding formulations, the composites made with the sizing
composition of the present invention have lower "a*" and "b*" values indicating more
neutral coloring compared to Ref 1, Ref 2, and Ref 3. In pigmented compounding
formulations, the composites made with the sizing composition of the present invention
have better whiteness compared to Ref 2a, but are similar to Ref 3a. Composite samples
made with the sizing composition of the present invention and 12u fibers show higher
tensile strength than any composites made with 14jx fibers.
As shown in Table 4, composites made using the sizing composition of the present
invention show better long-term aging and detergent resistance compared to the reference
composites. As is seen by the results, the composites made using the sizing composition
of the present invention have higher absolute values for initial strength and strength after
detergent aging of up to 30 days when compared to the references Ref 2 and Ref 3. Also,
the composites made using the sizing composition of the present invention retain a higher
percentage of their initial mechanical strength after aging for up to 30 days when compared
to the references Ref 2 and Ref 3. Thus, after 30 days of detergent aging, up to 85% of the
initial tensile strength and up to 62% of the initial impact strength (CharpyUnnotched)
was retained by the composite made using the sizing composition of the present invention.
However, only about 79% of the initial tensile strength and about 49% of the initial impact
strength was retained by Ref 2 during the same 30 day period.
Similarly, as seen from the results in Table 5, composites made with the sizing
composition of the present invention show higher absolute values for initial strength and
for strength after hydrolysis aging of up to 20 days when compared to the references Ref 2
and Ref 3. Also, composites made with the sizing composition of the present invention
retain a higher percentage of their initial mechanical strength after hydrolysis aging testing
for up to 20 days when compared to the references Ref 2 and Ref 3. Thus, after 20 days of
hydrolysis aging testing, up to 96% of the original tensile strength and up to 73% of the
original impact strength (CharpyUnnotched) was retained by composites made with the
sizing composition of the present invention. However, only 90% and 93% of the original
tensile strength could be retained by Ref 2 and Ref 3, respectively, and only 65% and 66%
of the original impact strength could be retained by Ref 2 and Ref 3 respectively.
The results of long-term mechanical performance for the composites are reported.
in Table 6. As seen form the results, it is clear that composites made with the sizing
composition of the present invention provide a large improvement, both in tensile fatigue
and tensile creep performance, over both the Ref 2 and the Ref 3. Thus, for tensile fatigue,
the % improvement of the long-term mechanical performance for the composite made with
the sizing composition of the present invention, versus Ref 2 was 35% and versus Ref 3
was 152%. Similarly, for tensile creep, the % improvement of the long-term mechanical
performance for the composite made with the sizing composition of the present invention
versus Ref 2 was 31% and versus Ref 3 was 629%.
Thus the composite parts made using the fibers coated with sizing composition of
the present invention, offer better short-term mechanical properties, improved long-term
mechanical properties, improved detergent and hydrolysis aging resistance, higher
retention of initial strength after aging, and better coloring.
It is believed that Applicants' invention includes many other embodiments which
are not herein specifically described. Accordingly this disclosure should not be read as
being limited to the foregoing examples or preferred embodiments.
1. A substantially non-discoloring sizing composition consisting
- a grafted polyolefin emulsion, the grafted polyolefin including
at least one reactive functional group selected from the group
consisting of acid anhydride, carboxylic acid, hydroxyl, amino,
amide, ester, isocyanate, double bonds and epoxy;
- at least two C8-C36 saturated fatty acids; and
- at least one silane coupling agents comprising at least one
functional group selected from the group consisting of amino,
epoxy, ester, vinyl, alkyl, methacryloxy, ureido, isocyanato and
2. The sizing composition as claimed in claim 1, wherein the
emulsion comprises an aqueous solvent.
3. The sizing composition as claimed in claim 1, wherein the grafted
polyolefin comprises a homopolymer of polypropylene or a
random copolymer of propylene and ethylene.
4. The sizing composition as claimed in claim 1, wherein the grafted
polyolefin comprises a grafted portion selected from the group
consisting of acid anhydride, carboxylic acid, hydroxyl, amino,
amide, ester, isocyanate, double bonds, and epoxy.
5. The sizing composition as claimed in claim 1, wherein the sizing
composition is without a color compensating additive.
6. The sizing composition as claimed in claim 1, wherein the grafted
polyolefin has a level of grafting between 0.05% to 15% by weight
based on the total weight of the grafted polyolefin.
7. The sizing composition as claimed in claim 1, wherein the
saturated fatty acids comprise at least two saturated fatty acids
selected from the group consisting of myristic acid, palmitic acid,
pentadecanoic acid, margeric acid, stearic acid, behenic acid, and
8. The sizing composition as claimed in claim 1, wherein the
saturated fatty acids comprise an aqueous mixture of palmitic acid,
sebacic acid, and stearic acid.
9. The sizing composition as claimed in claim 1, wherein the
emulsion comprises a grafted polyolefin comprising an aqueous
emulsion of a polypropylene grafted with maleic anhydride.
10. The sizing composition as claimed in claim 1, wherein the silane
coupling agent is an amino silane coupling agent.
11. The sizing composition as claimed in claim 1, further comprising
an antifoaming agent.
12. The sizing composition as claimed in claim 1, having a viscosity of
from8cPsto 150 cPs.
13. A fiber coated with the sizing composition as claimed in claim 1.
14. A composite comprising the fiber as claimed in claim 13.
15. A method of preparing a sizing composition comprising:
mixing a grafted polyolefin emulsion, the grafted polyolefin
including at least one reactive functional group selected from the
group consisting of acid anhydride, carboxylic acid, hydroxyl,
amino, amide, ester, isocyanate, double bonds and epoxy, at least
two Cg-C36 saturated fatty acids, and at least one silane coupling
agents including at least one functional group selected from the
group consisting of amino, epoxy, ester, vinyl, alkyl,
methacryloxy, ureido, isocyanato and siloxane.
A substantially non-discoloring sizing composition consisting essentially of: a grafted polyolefin emulsion, the grafted polyolefin including at least one reactive functional group selected from the group consisting of acid anhydride, carboxylic acid, hydroxyl, amino, amide, ester, isocyanate, double bonds and epoxy; at least two C8-C36 saturated fatty acids; and at least one silane coupling agents comprising at least one functional group selected from the group consisting of amino, epoxy, ester, vinyl, alkyl, methacryloxy, ureido, isocyanato and siloxane.
1341-kolnp-2003-granted-reply to examination report.pdf
|Indian Patent Application Number||1341/KOLNP/2003|
|PG Journal Number||20/2010|
|Date of Filing||17-Oct-2003|
|Name of Patentee||OWENS CORNING|
|Applicant Address||ONE OWENS CORNING PARKWAY, TOLEDO, OH|
|PCT International Classification Number||C03C 25/26|
|PCT International Application Number||PCT/US2002/12781|
|PCT International Filing date||2002-04-24|