CA1115876A

CA1115876A - Storage stable polyolefin compatible size for fiber glass strands

Info

Publication number: CA1115876A
Application number: CA314,189A
Authority: CA
Inventors: Chester S. Temple
Original assignee: PPG Industries Inc
Current assignee: PPG Industries Inc
Priority date: 1978-08-14
Filing date: 1978-10-25
Publication date: 1982-01-05
Also published as: IT7923770A0; IT1192742B; NL7810824A; NL178411B; FR2433604A1; NL178411C; BE872343A; JPS5738538B2; GB2030611B; CH642034A5; DE2853755C2; DE2853755A1; GB2030611A; JPS5527889A

Abstract

ABSTRACT OF THE DISCLOSURE
Continuous glass fiber forming packages with a sizing composed of a coupling agent, a stabilizer, a maleonated or acrylic modified poly-propylene lubricant, a non-crosslinking film-forming polymer and a self-reactive crosslinking film-forming polymer are disclosed for utilization in polyolefin polymer reinforcement. The article formed and formation method for fiber combination with a polyolefin polymer are also disclosed.

Description

lS~S876 STORAGE STABLE POLYOLEFIN COMPATIBLE SIZE
FOR FIB~R GLASS STRANDS

Background of the Invention l Field of the Invention The present invention relates to glass fiber strand treatment and particularly relates to treating glass fibers during or after forming with an aqueous sizing which prepares the glass fibers for bonding to polyolefins in the reinforcement of polyolefin materials and further has long shelf life and can be used from forming packages.

2. Description of the Prior Art It is known that glass fibers in the form of continuous strands, chopped strands or mats can be used successfully to reinforce polyolefins.
And it is known that without effective coupling between the glass and the polyolefin, the adhesion between the two will be weak and separation will occur under shear or tensile stresses. It is further known that the affinity of glass for water aggravates bond weakness when glass is inade-quately bonded to polyolefins.
A workable method has been disclosed which permits bonding glass to "lower" polyolefins which are essentially crystalline plastics formed from monomers having three or more carbon atoms. As discloset in U.S. Patent No. 3,013,915 at column 2, lines 38-46, glass bonding to polyolefins may be improved by "cleaning the glass surface, apply-ing a coupling agent to it, treating with a chemical agent which is a source of dehydrogenating or oxidizing radicals, contacting the poly-olefin with the glass, and fusing it by heating the polyolefin above ~' ~3 lS87~

its melting point to complete the interbonding." At column 4, lines 16-1~, the disclosure reveals a preference for radical sources having low decomposition points below 180F. and at columr. 4, lines 69-71, U.S. Patent No. 3,849,148 proposes the method of sizing fiber glass strsnds with an aqueous sizing containing a coupling agent, a heat stable organic peroxide, a non-ionic surfactant and a lubricant.
This process was successful in giving some storage capability to the sized strands but did not result in long storage life and further remains susceptible to degradation by high storage temperatures.
U.S. Patent No. 3,882,068 discloses the sizing composition for glass fibers in several plastic resin systems wherein the size comprises a coupling agent and a polyolefin emulsion.
U.S. Patent No. 3,437,550 discloses a method of increasing the bonding of glass fibers to polyolefins by treating the fiber with a crystalline polypropylene matrix polymer. The preferred modifiers disclosed are maleic anhydride and acrylic acid.
U.S. Patent No. 3,883,333 discloses a method and apparatus for forming a continuous glass fiber mat of sized fibers that are suitable for bonting with polyolefins. The process and apparatus, although continuous, tiscloses lay down of the fibers immediately after formation of strands.
While the above processes and compositions were useful, there remains a need in the art for a sizing to promote the binding of polyolefins to continuous glass fiber strands with increased adhesion. Further, there remains a need for a sizing for glass fiber strands which will allow the formation of the sized fiber into forming packages that may be stored indefinitely prior to use. Effective sizings containing peroxides have limited shelf-life since they are very sensitive to elevated temperature 1~15876 variations during drying of the fibers and high temperatures during ~torage which can cause premature degradation of the peroxides thus reducing the effectiveness of the sizlng in binding the glass fiber strands to th~
polypropylene matrix.
Summary of the Invention It 18 an ob~ect of thls inventlon to overcome the dlsadvantages of the prior processes and composltlons.
It is another ob~ect of this invention to provide a storage stable polyolefin bonding sizing for contlnuous glass fibers.
It i8 another ob~ect of this invention to produce polyolefin glass fiber composites using glass fibers from forming packages.
It is further additional ob~ect to produce storage stable forming packages of polyolefln compatable glass fiber strands.
It 18 another ob~ect to create a polyolefln bonding sizing not susceptible to thermal degradation during the drying operation.
These and other ob~ects of the invention are generally accom-plished by applying a sizing comprising a cDupling agent, a stabllizer, a maleonated or acrylic modified polypropylene lubricant, a non-crossllnking film-former, a self-reactive crosslinking film former, and an aqueous carrier to a glass fiber strand. The sized strand is then wound into a forming package and dried for later use as a reinforcement for polypropylene material.
In a preferred embodiment of the invention, an aqueous sizing comprising a coupling agent of gamma-amino-propyltriethoxysilane, a stabilizer comprising cis-butenedioic acid, a lubricant of an emulsion of maleonated amorphous polypropylene, a non-crosslinking film former of vinyl acetate homopolymer, and a self-reactive copolymer of vinyl acetate and N-methylol-acrylamide are applied in an aqueous sizing to a glass fiber 80 as to

- 3 -~15~7~

impregnate the strand and improve its ability to reinforce polypropylene articles. The strand after being wound as a forming package and drying to remove the aqueous carrier may be withdrawn from the forming package and laid down on a mat which is contacted with polypropylene sheet and under heat and pressure formed into a fiber reinforced article.

Description of the Preferred Embodiments The utilization of the sizing system of the instant invention results in numerous advantages over the prior processes. The utili-zation of a storage stable sizing with no shelf-life limitation improves production capability because it allows the storing and distribution of forming packages of sized glass fiber strand. Prior to the instant inventionJ
it was necessary that the sized fiber be used shortly after forming or be immediately formed into a mat for forming composite articles. Further, the drying of the sized fiber was difficult as the drying temperature conditions were limited by a necessity to not decompose the peroxide, an important ingretient of the siæing. With utilization of the instant system, it is possible to form forming packages of sized glass fiber strands at a central location. These may be then shipped without limitations as to temperature or stmosphere during shipping to distant points for fabrication into composite polyolefin glass-fiber-reinforced articles. This offers consid-erable improvement since the forming of glass strands no longer must be carried out at the same location that the polyolefin glass fiber reinforced article is formed. Thus as can be seen that although the individual ingredients had been used in other sizings, the instant combination of ingredients allows the achievement of numerous advantages not present in prior systems.

1~158~76 Any glass suitable for reinforcing and for dra~ing in fiber form may suitably be treated in accordance with the present invention. Soda-lime glasses and borosilicate ("E") glasses are particularly suited for this practice.
The glass fiber strands to be treated according to this invention may be typically produced according to the teachings of U.S. Patent No.
2,133,238. The glass fiber strands are composed of a multitude of fine glass filaments which are formed by being drawn at a high rate of speed from molten cones of glass located at the tips of small orificeg in a bushing. During formation, the filaments are coated with the aqueous sizing prepared according to the description below. Coating of the fila-ments takes place while they are moving at a speed of the order of 1,000 to 20,000 feet per minute. The coating is accomplished in the immediate vicinity of the hot bushings and the glass furnace in which the glass is melted, and after coating, the glass fiber strands move a short distance onto collecting means. After the strands have been ~ized, they may be dried to drive off residual moisture from the sized glass.
The aqueoufi sizing to contact, impregnate and coat the gla~s fiber strand is composed of a coupling agent, a stabilizer, a maleonated or acrylic modlfied polypropylene lubricant, a non-crosslinking film former and a self-reactive crosslinking film former.
The coupling agent may be any interfacial boundary area adhesive compound which acts to unite the surface of the glass fiber strand with the polyolefin polymer. Among typical coupling agents for uniting glass fiber strand and polymer~ are metal salts of the strong metal acids such as basic chromium chloride, basic chromium sulfide having a trivalent metal ion 3elected from the group consisting of chromium, cobalt, nickel, copper, and lead having at least one hydroxyl group attached to the metal and at least lilS876 one anion of a strong mineral acid attached to the metal; ~erner type complexes in which a trivalent nuclear atom such as chromium is coordinated with an organic acid such as methacrylic acid, for instance, methacrylic C
r ~¦ql~a acid complex of~Pe~c chloride, and other Werner type coupling agents, having vinyl alkyl amino, epoxy, mercapto, thioalkyl, thioalkyl and phenol groups. Suitable for the utilization in the instant invention are coupling agents from the silane and siloxane groups. Typical of such coupling agents are hydrolyzable, vinyl, allyl, beta-chloropropyl, phenyl, thio-alkyl, thio-alkaryl, amino-alkyl, methacrylato, epoxy, and mercapto silanes their hydrolysis products and polymers of hydrolysis products and mixtures of any of these. A preferred coupling agent is gamma-aminopropyltriethoxysilane as this material has been found to provide very good coupling between the glass fiber strand and polyolefin polymers at low concentrations and with good stability.
Any stabilizer may be selected which acts as a secondary coupler to improve the stability of the sizing system, assists in crosslinking, improves the coupling agent fiber innerface and assists the action of the silane in coupling. Typical of stabilizers for sizes suitable for the instant invention are ethylenically unsaturated mono or di-carboxylic acids or anhydrides. Examples of such acids and anhydrides include maleic acid, fumaric acid, itaconic acid, citrconic acid, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, mesaconic acid, himic anhydride, maleic anhydride? itaconic anhydride and citraconic anhydride, and mixtures thereof. A preferred stabilizer is maleic acid (cis-butenedioic acid) that gives a stable system and improves the coupling action of the silane coupling agent.

1~15876 The material that acts as a lubricant to aid film forming and assist the coupling which may be used as the lubricant of the in~ention are chemically modified propylenes. These are maleonated or acrylic modified polypropylenes as they result in a sized flber with good storage properties and ability to feed from the formlng package.
The polymer whlch forms the non-crosslinked film former material of the sizing of the system of the instant invention may be any material that provides strand integriey to aid in the process-ability of the glass fiber strand allowing strand removal from a forming package. The non-crosslinked polymer provides the desired level of plasticity to the sizesuch that the sized fiber of the instant system has an extended shelf-life and also the processability to allow successful needling of a mat formed of the sized fibers of the instant invention. The non-crosslinking polymer generally is a homopolymer or mixtures of homopolymers that will not crossllnk in the conditions of the sizing and molding operations to which the sized fiber is sub~ected in the drying of the aqueous sizing from the fiber and molding with an olefin homopolymer such as polypropylene.
Typical of non-crosslinked film-forming polymers suitable for the instant invention are epoxies, polyesters, polyurethanes and acrylics. A preferred non-crosslinked fllm-forming material is vinyl acetate ho polymer as vinyl acetate homopolymer i8 low in cost, does not degrade at the instant forming temperatures, and provide good strand integrity when used on a glass fiber strand.
The self-reactive crosslinked polymer of the instant system may be any polymer or copolymer that contributes to the formability, strand integrity (hardness), strand lay, non-scroopy finish, and needleability lt 1 5876 and is capable of auto-co-reaction and cross-linking. These self-reactable cro~slinking polymers may be definet as a polymer or copolymer capable of becoming crosslinked without addition of further materials in the conditions encountered during the drying of the sized gtrand forming package. Typical of self-reactive crosslinking polymers are vinylacetate~ epoxies, polyesters, polyurethanes and acrylic polymerg. A preferred polymer is a self-reactive vinyl acetate-N-methylolacrylamide copolymer that has the advantage of compatabllity with the polyolefin polymers particularly polypropylene, low cost, and stability at the forming temperatures of polyolefins.
The sized glass fibers may be formed and the size applied by the known methods of fiber formation and sizing application. Representative of a method of fiber formation and sizlng application is the process illu-strated in Figure 2 of U.S. Patent No. 3,849,148. Glass fiber filaments emerge from orifices of an electrically heated bushing. These fibers are attenuated and by means of a strand pulling device these filaments are gathered to form a strand of glass fiber which may comprise numerous individual fibers. The sizing 18 applied to the fibers by a conventional size appllcator such as a kiss appllcator or a belt applicator devlce.
Detail of a slzing appllcator is shown in U.S. Patent No. 2,728,972. The filaments after exiting the bushing are cooled by air or preferably water.
The filaments are gathered into bundles by a gathering shoe and are then led to a strand pulling device such as illustrated in U.S. Patent No.
3,292,013 as well as in the above referenced, U.S. Patent No. 3,849,148.
The glass fiber strand or strands, if the filaments exiting from the bushing have been separated into several strands, are then wound onto a forming tube on a collet rotating at approximately 7,500 rpm to produce a strand travel of approximately 12,000 to 15,000 feet per minute.

~' 1~15876 The glass fiber strand forming packsges are then dried. This generally is accompllshed by baking the packages of fiber at a tempersture and for a length of time sufficient to remove ~ubstantislly all of the water.
Generally a curing time for the ingtant size is about ll hours at 270F.
After drying the forming tube may be removed resulting in a forming package of sized gla~s fiber. These formlng packages may be stored virtually indefinitely when sized with the instant sizing. When the forming package is desired for use in forming a polyolefin composite article, a group of the forming packages are arranged 80 that the strands may be drawn from the packages and laid down to form a mat of fibers such as disclosed in U.S. Patent No. 3,883,333 or U.S. Patent No. 3,664,909. The mat i~ then needled and combined or impregnated with polyolefin resin or laminated with polyolefin sheets to form relnforced polyolefin articles which are heated at a temperature in the rsnge of 400F. to about 430F. at a pressure of about 9250 pounds per square inch for about 5 to about 20 minutes to bind the sized glass fibers of the invention to the polyolefin. The laminated polyolefin glass fiber mat articles may then be stamped or molded by a varlety of means, including that of U.S. Patent No. 3,664,909 to produce reinforced polyolefin lamlnates suitable for use as contalner~ or for other low-cost, hlgh strength and low temperature uses.
The coupling agent may be utilized in amounts which re~ults in good interfacial boundary area adhesion between the glass fiber strand and the polyolefin. A sllane coupling agent concentration of about .2 to about 18 percent by weight of the solids of the sizing concentration has been found to be suitable. A preferred percent of silane has been found to be about 6 percent by weight of the solids in the sizing of the silane to give maximum adhesion with minimum cost.

1~15~76 The maleonated or acrylic modified polypropylene lubricant may be utilized in any amount which results in good stability of the sizing system. A suitable amount has been found to be about 30 to about ~0 percent by weight of solids in the sizing solution. A preferred amount of the maleonated amorphous polypropylene for good forming and fabrication processability has been found to be about 60 percent by weight of the solid's in the sizing emulsion.
The stabilizer may be used in any amount which results in good lnterface bonding of the film-forming materials to the glass fiber strand.
A suitable amount has been found to be about 1 to about 9 percent stabilizer to the solids of the sizing emulsion, A preferred amount of stabllizer has been found to be about one-half the amount of the silane coupling agent to give good adhesion of the film formers to the coupling agent.
The non-crosslinking-fllm forming material and the self-reactive crosslinking material are blended to give the desired handling properties to the æized strand. The non-crosslinkable polymer, preferably vinyl acetate h opolymer imparts plasticity to the fiber and its use is dependent on the hardness of brittleness of the self-reactive crossllnking film former. The self-reactive crosslinklng film former act~ to provide integrity to the glass fiber strand 80 that it does not come apart into filaments during processing or cutting operations. A normal range of the non-crosslinkable polymer would be between about 5 and 40 percent by weight of the solids in the sizing emulsion. A suitable amount of self-reactive crosslinking material would be between about 10 and about 50 percent by weight of the solids in the sizing emulsion. A preferred amount of the self-reactive crosslin~ing material would be about 22 percent of the solids in the sizing emulsion such that the fiber has good integrity.
A preferred amount of the non-crosslinking vinyl acetate homopolymer is about 9 percent by weight of the solids in the sizing emulsion to give optimum handability.

~ e sizing emulsion generally contains between about 95 percent and about 80 percent water. It is preferred in the use of a kiss roll applicator to have between 83 and 93 parts by weight water in the sizing solution. Thus, solids amount is greatly dependent on the applicator that is used to size the fiber strand.
lhe sized fiber forming packages of the instant system may be utilized to reinforce any polymeric resin article. However, the instant fibers find greater functionality in the reinforcement of polyolefinic resin polymers including polyethylene and 5-methyl pentene polymers. A
preferred polyolefinic polymer for utilization with the instant sized glass fiber strand is polypropylene since this polymer binds very well with the instant sizing, is relatively low cost and gives good strength properties when glass reinforced. The ratio of polyolefinic polymer to glass may be selected in any ratio that gives the desired properties to the finished article. Generally a ratio of about 10 to about 60 percent glass by weight is suitable. A preferred amount is about 35 to about 45 percent by weight glass in a polypropylene molded article to give a good balance of cost, properties and structural strength.
The amount of the sizings used on the glass may be any amount which results in good structural strength of the finished polyolefin fiber composite, good fiber integrity and handleability. A suitable amount of sizing is about .02 to about 1 percent by weight sizing solids to total weight of the sized strand of glass. A preferred range is about .6 percent to give good fiber integrity and handleability.
The following Example is a preferred embodiments of the instant invention. The parts and percentages are by weight unless otherwise indicated.

~S15876 E~AMPLE I
-Ingredient Parts by Weight Percent of Functional Identification Chemical Identification Of Sizing Size Solids Coupling agent gamma-aminopropyltriethoxy- .7 6 silane , B (Union Carbide A-1100) Stabilizer cis-butenedioic acid .35 3 Lubricant emulsion of maleonated amorphous polypropylene 7.3 60 22% active 10% surfactant and KOH
68% water surfactant = alkoxylated phenol Non-crosslinking film vinylacetate homopolymer 1.1 9 former emulsion 54% solids (National Starch Resyn 25-1031) Self-reactive film emulsion of vinyl acetate-n- 2.6 22 methyolacrylamide 52% solids (National Starch Resyn 25-2828 ~
Water 87.95 ~ r~ad~ ~

~lS876 The glass fiber strand sizing is prepared by adding most of the necessary deionized water to the mix tank and then slowly adding the lubricant to the mix tank as it is agitated. The coupling agent is then added to the mix tank followed by adding the maleic acid with continued agitation. After the addition of the maleic acid, stirring is carried out for about 20 minutes to dissolve the acid. Then the non-crosslinking film-forming material is added to the tank followed by the addition of the crosslinkable polymeric emulsion which is diluted with an equal quantity of cold deionized water prior to addition. Additional make-up water necessary is added and the batch is checked to determine that the specifications are within the range of about a pH of about 6 and a solids of about 5 percent solids.
In a preferred embodiment, the aqueous sizing mixture is applied to fiber filaments that are formed from a 400-hole bushing. The filaments are treated by a kiss roll applicator to coat about .6 percent solids by weight of the glass onto the filaments. The filaments are gathered into four strands or more then wound onto the collets to form packages of about 20 pounds or more each. The formed packages are cured for about 11 hours st 270F. Following the curing the forming package can be stored indefinitely at ambient conditions. The forming packages are then utilized to form a mat of continuous fibers which is then needled and laminated with poly-propylene polymer in the weight of about 60 parts by weight of polypropylene polymer to 40 parts by weight of the needled mat. The polyolefin resin and mat are combined via a temperature range of about 400F. at a pressure of about 9C pounds per square inch for about 5 minutes to bond the reinforcing glass fibers to the polyolefin. The heating is carried out between stainless steel belts. The laminate of sized fiber matting and polypropylene is then ~lS876 stamped into test tubs such as described at column 6 through column 7 of U.S. Patent No. 3,849,148 and tested for structural strength and structural modulus. The flexural strength averages at least about 23,000 pounds per square inch and the flexural modulus about 1 x 106 pounds per square inch. This example shows that the polypropylene reinforcing sized glass fiber strands of the instant invention provide satisfactory strong rein-forced articles even after extended storage period of the forming packages.
While the invention has been described with reference to several embodiments, those skilled in the art will recognize that variations may be made to the described methods and devices without departing from the substance of this invention. For instance, a pigment or dye could be added to the sizing solution without interference with its effect.
As will be apparent to those skilled in the art, the present system may be modified and equivalent elements or processes may be employed in combination therewith without departing from the spirit of the invention.
For instance, an application device for the sizing could be utilized which would not require as large an amount of water in the sizing emulsion.
Further, the fiber forming packages of the instant invention could be utilized in the reinforcing of polymeric materials other than polyolefins.
Also, a combination of the sized fiber forming packages of this invention could be utilized with fibers sized with a different material, with unsized fibers or with chopped strand sized with the sizing of this invention.
Thus, the present disclosure of preferred embodiments is not intended to limit the scope of the applicant's invention.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Glass fibres having the dried residue of a sizing composition comprising a coupling agent, a stabilizer, a maleonated or acrylic modified polypropylene lubricant, a non-crosslinked film forming polymer and a self-crosslinked film forming polymer.

2. The glass fibres of Claim 1 wherein said coupling agent is selected from the group consisting of silanes and siloxanes.

3. The glass fibres of Claim 1 wherein said coupling agent is an aminosilane.

4. The glass fibres of Claim 1 wherein said stabilizer comprises a mono or difunctional acid selected from the group con-sisting of ethylenically unsaturated carboxylic acid and anhydrides.

5. The glass fibres of Claim 1 wherein said stabilizer comprises cis-butenedioic acid.

6. The glass fibres of Claim 1 wherein said lubricant comprises an emulsion of maleonated or acrylic modified polypro-pylene.

7. The glass fibres of Claim 1 wherein said sizing comprises between about 2 and 18 weight percent coupling agent, between about l and about 9 weight percent stabilizer, between about 30 and 80 weight percent of a maleonated or acrylic modified polypropylene lubricant, between about 5 and about 40 part by weight non-crosslinkable film former and between about 10 and 50 parts by weight self-crosslinked film former.

8. The glass fibres of Claim 1 wherein said lubricant is an emulsion of maleonated amorphous polypropylene.

9. The glass fibres of Claim 1 wherein said non-crosslinked film-forming polymer comprises a member selected from the group consisting of epoxy polymers, polyester polymers, poly-urethanes, acrylic polymers and mixtures thereof.

10. The glass fibres of Claim 1 wherein said non-crosslinked polymer is a vinyl acetate homopolymer.

11. The glass fibres of Claim 1 wherein said self-crosslinked film-forming polymer is selected from the group con-sisting of epoxy polymers, polyester polymers, polyurethanes, acrylic polymers and copolymers and mixtures thereof.

12. The glass fibres of Claim 1 wherein said self-crosslinked polymer is a vinyl acetate copolymer.

13. An article comprising a polyolefin polymer rein-forced with glass strands wherein said glass strands are impreg-nated with a sizing composition comprising a coupling agent, stabilizer, maleonated or acrylic modified polypropylene lubricant, non-crosslinked film-forming polymer and a self-crosslinked film-forming polymer.

14. The article of Claim 13 wherein said polyolefin is selected from the group consisting of polypropylene, polyethylene, 5-methyl pentene and mixtures thereof.

15. The article of Claim 13 wherein said coupling agent is selected from the group consisting of silanes and siloxanes.

16. The article of Claim 13 wherein said coupling agent is an aminosilane.

17. The article of Claim 13 wherein said stabilizer comprises a difunctional acid selected from the group consisting of ethylenically unsaturated carboxylic acid and anhydrides.

18. The article of Claim 13 wherein said stabilizer comprises cis-butenedioic acid.

19. The article of Claim 13 wherein said lubricant comprises an emulsion of maleonated or acrylic modified polypro-pylene.

20. The article of Claim 13 wherein said sizing com-position comprises between about 2 and 18 weight percent coupling agent, between about 1 and about 9 weight percent stabilizer, between about 30 and 80 weight percent maleonated or acrylic modified polypropylene lubricant, between about 5 and 40 part by weight non-crosslinked film former and between about 10 and 50 parts by weight self-crosslinked film former.

21. The article of Claim 13 wherein said lubricant comprises maleonated amorphous polypropylene,

22. The article of Claim 13 wherein said non-crosslinked film-forming polymer comprises a member selected from the group consisting of epoxy polymers, polyester polymers, acrylic polymers and mixtures thereof.

23. The article of Claim 13 wherein said non-crosslinked polymer is a vinyl acetate homopolymer.

24. The article of Claim 13 wherein said crosslinked film-forming polymer is selected from the group consisting of epoxy polymers, polyester polymers, acrylic polymers, and copolymers and mixtures thereof.

25. The article of Claim 13 wherein said self-cross-linked polymer is a vinyl acetate copolymer.

26. A method of forming a composite article comprising bringing together polyolefin polymer and sized glass strands and applying pressure wherein said sized glass strands are impregnated with a sizing composition comprising coupling agent, maleonated or acrylic modified polypropylene lubricant, non-crosslinked polymer and self-crosslinked polymer.

27. The method of Claim 26 wherein said glass strands are in the form of a mat.

28. The method of Claim 26 wherein said polyolefin polymer is selected from the group consisting of polyethylene, polypropylene 5-methyl pentene and mixtures thereof.

29. The method of Claim 26 wherein said glass strands comprise about 10 to about 60 percent by weight of said article.

30. The method of Claim 26 wherein said coupling agent is selected from the group consisting of silanes and siloxanes.

31. The method of Claim 26 wherein said coupling agent is an aminosilane.

32. The method Claim 26 wherein said stabilizer comprises a mono or difunctional acid selected from the group consisting of ethylenically unsaturated carboxylic acid and anhydrides.

33. The method of Claim 26 wherein said stabilizer com-prises cis-butenedioic acid.

34. The method of Claim 26 wherein said lubricant com-prises an emulsion of maleonated or acrylic modified polypropylene.

35. The method of Claim 26 wherein said sizing compo-sition comprises between about 2 and 18 weight percent coupling agent, between about 1 and 9 weight percent stabilizer, between about 30 and 80 weight percent maleonated or acrylic modified polypropylene lubricant, between about 5 and about 40 part by weight non-crosslinked film former and between about 10 and 50 parts by weight self-crosslinked film former.

36. The method of Claim 26 wherein said lubricant com-prises maleonated amorphous polypropylene.

37. The method of Claim 26 wherein said non-crosslinked film-forming polymer comprises a member selected from the group consisting of epoxy polymers, polyester polymers, acrylic polymers and mixtures thereof.

38. The method of Claim 26 wherein said non-crosslinked polymer is a vinyl acetate homopolymer.

39. The method of Claim 26 wherein said crosslinked film-forming polymer is selected from the group consisting of epoxy polymers, polyester polymers, acrylic polymers, and co-polymers and mixtures thereof.

40. The method of Claim 26 wherein said self-crosslinked polymer is a vinyl acetate copolymer.

41. A forming package of glass fibre strand comprising a strand of glass impregnated with a sizing composition comprising gamma-aminopropyl-triethyoxysilane, cis-butenedioic acid, maleonated amorphous polypropylene, vinylacetate homopolymer and vinyl-acetate-N-methylolacrylamide copolymer.

42. The forming package of Claim 41 wherein said sizing composition comprises about .6 percent by weight of said sized fibre.

43. The package of Claim 42 wherein said sizing compo-sition comprises about 6 percent by weight of said silane, about 3 percent by weight of said cis-butenedioic acid, about 60 percent by weight of said maleonated amorphous polypropylene, about 9 percent by weight of said vinylacetate homopolymer and about 22 parts by weight of said vinylacetate-N-methylolacrylamide copolymer.

44. The package of Claim 1 wherein said stabilizer comprises himic anhydride.

The article of Claim 13 wherein said stabilizer comprises himic anhydride.

46. An aqueous sizing composition comprising a coupling agent, stabilizer, a maleonated or acrylic modified polypropylene lubricant, a non-crosslinkable film forming polymer, and a self-reactive crosslinking film-forming polymer and a liquid carrier.

47. The sizing composition of Claim 46 wherein the coupling agent is selected from the group consisting of silanes and siloxanes.

48. The sizing composition of Claim 46 wherein said coupling agent is an amino silane.

49. Sizing composition of Claim 46 wherein stabilizer comprises a mono of difunctional acid selected from the group consisting of ethylenically unsaturated carboxylic acid and anhy-drides.

50. Sizing composition of Claim 46 wherein said stabili-zer comprises cis-butenedioic acid.

51. Sizing composition of Claim 46 wherein said male-onated or acrylic modified polypropylene lubricant comprises an emulsion of maleonated or acrylic amorphous polypropylene.

52. Sizing composition of Claim 46 wherein said sizing composition comprises between about 2 and 18 weight percent coupling agent, between about 1 and 9 weight percent stabilizer, between about 30 and 80 weight percent maleonated or acrylic modified polypropylene lubricant, between 5 and 40 weight percent non-crosslinkable film former, and between 10 and 50 weight percent self-reactive crosslinking film-forming polymer.

53. Sizing composition of Claim 46 wherein said non-crosslinkable film-forming polymer comprises a member selected from the group consisting of epoxy polymers, polyester polymers, poly-urethanes, acrylic polymers and mixtures thereof.

54. Sizing composition of Claim 46 wherein said non-crosslinkable polymer comprises a vinylacetate homopolymer and said self-reactive crosslinking film former comprises a vinylacetate copolymer.

55. The sizing composition of Claim 46 wherein said self-reactive crosslinking film forming polymer is selected from the group consisting of epoxy polymers, polyester polymers and polyurethanes, acrylic polymers and copolymers and mixtures thereof.