CA1221184A - Chrome-free sizing for glass fiber gun roving - Google Patents

Abstract

CHROME-FREE SIZING FOR GLASS FIBER GUN ROVING

ABSTRACT OF THE DISCLOSURE

Chrome-free aqueous sizing composition for glass fiber gun roving contains a mixture of emulsified film-forming polymers, titanium acetyl acetonate, silylated polyazamide, cationic lubricant and methacryloxypropylsilane.

Description

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This invention relates to the field oE sizing compositions for glass fibers, and more particularly, for glass fiber gun roving, and to glass ibers coated therewi-th.
Glass fibers used as reinforcing elements in poly-meric or resinous matrix materials are usually coa-ted with a very ligh-weight size coating which serves to protect the fibers from damage by abrasion during processing, handling and/or use, -to bind the individual Eibers into more-or-less tightly integrated multi-Eiber bundles or strands, and/or to enhance the reinforcing in-teraction between the fibers and the resinous matrix in which they are imbedded as reinforcing elements. Such sizing compositions are frequently applied to the glass fibers at -the time of their initial production, which is ordinarily by pulling a p].urality of streams of molten glass issuing from a reservoir thereof through a sub-stantially corresponding plurality of sui-table orifices so as to attenuate these streams to the desired Eiber diameter as they cool and solidify. The sizing composition is typically applied to the individual fibers in-line as soon ~s they have cooled sufficiently below the solidification temperature, which cooling may be accelerated by wetting the newly solidi-fied but still hot ~ S`A
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fibers with water. Liquid sizing compositions are applied in such situations by spraying, by drawing the fibers across a suitable roll, belt, apron, pad, etc. wet with the liquid sizing composition, or other conventional liquid coat-ing methods. After the liquid sizing composition has beenapplied to the individual advancing glass fibers, they are typically brought together while still at least partially wet with the liquid sizing composition into one or more multifiber bundles or strands, which may be collected into a :suitable package for further processing, storage and/or shipment, as by winding onto a rotation collet. The wet fibers or strands are normally dried, before and/or after such collection, to deposit the non-volatile residue of the liquid sizing composition on-to the surfaces of the fibers.
Liquid sizing compositions suitable for such application to glass fibers ordinarily are dilute solutions, dispersions and/or emulsions, often in aqueous media, of a film-forming polymer or resin, a lubricant and a coupling agent. Other components, such as anti-static agents (especially where the sized glass fibers are to be chopped into short lengths while dry), emulsifying or solubilizing agents, viscosity modifying agents, etc. have also sometimes been incorporated in such liquid sizing compositions.
One of the uses for glass fibers i5. as gun roving, which desirably consists of a plurality of continuous strands weakly integrated together, with each strand consisting of a plurality of individual glass fibers tightly integrated to-gether by the size coating on the fibers. Such gun roving is used by feeding it through a suitable chopper incorporated in or closely associated with a suitable gun for spraying a fluid resin composition together with the chopped roving onto a mold or other suitable target so that the chopped roving or pieces of strand separated therefrom becomes imbedded in the fluid resin, which will subsequently be solidified by cooling ,~, tr~ ~

and/or by curing by chemical reaction. Representative equipment and corresponding methods for such use of ylass fibers in gun roving are described in U.S. Patent No.
3,111,440, entitled DEVICES ~ND METIIODS ~OR APPLYING S~ANDS, issued November 19, 1963 or an invention of William II.
Prentice. Typically, the chopped pieces are from abou-t 1.27 cm to about 5.0~ cm (1/2 to about 2 inches) in length.
Glass fiber gun roving has heretofore been coated with liquid sizing composltions containing Werner-type chrome complexes, such as methacrylato chromic chloride, which is thought to function in part at least as a glass-resin coupling agent, although such chrome complexes have sometimes been used togetller with conven-tional organosilane glass-resin coupling agents. Before the present inventioIl it had not been though possible to achieve a satisactory balance of desirable properties in glass fiber gun roving wi-thout the inclusion of a chrome complex in the sizing composition for the constituen-t fibers thereof, and particularly to achieve a desirable ease and completeness of chopping in conventional equipment, while also achieveing desirably rapid an~ complete wetting of the chopped reinforcement by the liquid ma-trix resin composition and providing a desirable enhancement of the physical properties of the resinous matrix while holding the generation of ~uzz, from breakage of fibers during processing of the continuous strand or roving, and "fly", i.e., static-dispersed pieces of chopped roving strand or partially or fully fibrillated residues thereof accompanying the chopping and spraying at the gun, to desirably low incidence.
Accordingly, the invention provides a substantially chrome-free aqueous sizing composition for glass fiber gun roving which comprises (A) a mixture of emulsified film-forming polymers comprising a polymer of vinyl ace-tate and ethylene, a polymer of vinyl acetate and an epoxy-functional vinyl monomer, and an t~

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unsaturated polyester resin; (B) titanium acetyl acetonate;
(C) a silylated polyaminopolyamide hydrochloride or hydrolysate thereof; (D) a cationic lubricant; and (E~ 3-methacryloxy-propyltrimethoxysilane or hydrolysa-te thereof.
The emulsified film-forming polymer components o~
the present invention can be any emulsified polymers oE -the types called for which will coalesce to form coherent films, and which preferably will so coalesce at normal ambient work-place temperatures. A small amount of suitable plasticizer to aid in such coalescence, of which many are known and available, may be blended and co-emulsiied with one or more ~f the polymers, if desired, but it is ordinarily found possible and preferable to select polymers which do not require such addi-tives to exhibit advantageous characteristics in use.
However, it is none-theless desirable and preferred to include a latently reactive unsaturated plasticizer with the unsatur-ated polyester resin to ultima-tely react with -this unsa-turated polyester and with an unsaturated polyester matrix resin to more intimately bond the glass fibers to each other and to the matrix in which they are embedded as reinforcing elements.
A particularly suitable emulsified polymer of vinyl acetate and ethylene is available as Airflex 410 (TM/Air Products and Chemicals Co.), an aqueous emulsion containing about 55% by weight non-vola-tiles comprising a vinyl acetate-ethylene copolymer having a glass transition temperature of about 2C. non-ionically emulsified as particles of about 0.3~m average diameter.
A particularly suitable emulsified polymer of vinyl acetate and an epoxy-functional vinyl monomer is available 30 as Resyn 25-1971 (TM/National S-tarch and Chemical Corp.), an aqueous emulsion containing about 54.5-~1% by weight non-volatiles comprising a copolymer of vinyl acetate with about

2% by weight of glycidyl methacrylate non-ionically emulsified.

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A particularly suitable unsaturated polyester resin is available as MR70D (TM/Uni-ted States Ste~l Corp.), an approximately 60:40 by weight blend of an unsatura-ted poly-ester and diallyl phthala-te, a latently reactive plasticizer, which was non-ionically emulsified to form an aqueous emulsion containing about 59~ by weight non-volatiles and designated PE-700.
A particularly suitable titanium acetylacetona-te is available as Tyzor AA (TM/E.I. duPont de Nemours, Inc.), a 75~ by weight solution or dispersion of bis(2, 4-pentanedio-na-te-0,0')bis(2-propan~lato) titanium in isopropanol.
A particularly suitable silylated polyamino poly-amide hydrochloride is available as Y-g567 (TM/Union Carbide Corp.), an 80% by weight dispersion or solution in methanol of a hydrochloric acid salt of CH3 ~NHCH2CH2N(CH3)CH2CH2C(=0~ x NHcH2cH2NcH2cH2c ( =O ) ~ NHcH2cH2N~cH3 CH2CH2CH2si(OCH3)3 y where x + ~ is a number from about 3 to about 10. Such materials and their preparation are described in detail in U.S. Patent No~ 3,746,738, entitled SILICON CONTAINING POLY-AZIMIDES issued July 17, 1973 for an inven-tion of Enrico J.
Pepe and James G. Marsden.
A particularly suitable cationic lubricant is a weak acid salt of a partial fatty amide of a polyamine such as Emery 6760 U (TM/Emery Industries, Inc.), a 65~ by weight aqueous solution or dispersion of an ace-tic acid salt of a partial amide of mixed fatty acids having about 6 to 8 carbon atoms with a polyethylenamine. The same material has also been available undiluted as Emery 6717.
A particularly suitable 3-methacryloxyproplytri-methoxysilane is available in a blend with a proprietary sta-bilizer as A-174 (TM/Union Carbide Corp.). The silane is preferably hydrolyzed in ~f dilute aqueous weak acid before use.
While the proportions of the various components of the aqueous sizing compositions of the invention are not narrowly critical, it is preferred that they be within about the following ranges:
Preferred Component Weight %
Emulsified polymer of vinyl 1-5 acetate and ethylene Emulsified polymer of vinyl 1-5 acetate and an epoxy-functional vinyl monomer Emulsified unsa-turated 0.5-1.5 polyester resin Titanium acetyl acetonate 0.5-1.5 Silylated polyaminopolyamide0.01-0~2 hydrochloride Cationic lubricant 0.005-0.1

3-methacryloxypropyltrimethoxy 0.005-0.1 silane Other components can be included, if desired, but in order to ensure that the advantages of the invention are realized, it is preferred that other components be omitted unless it is found that no significant diminution of those advantages results from the inclusion -thereof. In par-ticular, since it is a principal object of the invention to provide a chrome-free sizing composition for glass fiber gun roving, no chromium compounds or complexes should be included in sizing compositions of the invention. However, since some of the components, e.g. the titanium acetyl acetonate, the silylated polyaminopolyamide, and the cationic lubricant, are solubilized by acids and/or lower alcohols, the inclusion of minor additional amounts of alcohols such as methanol, ethanol, propanol, isopropanol, etc. and/or acids such as hydrochloric or ace-tic may be found desiLable.
The aqueous sizing compositions of the invention can be prepared following generally accepted mixing practices.
These sizing compositions can be applied to the glass fibers using any convenient method. The amount of aqueous sizing composition applied is no-t narrowly critical, but is preferably controlled so as to deposi-t on the glass fibers a size coat-ing comprising the in situ dried residue of the aqueous sizing composition of the invention in an amount from abou-t 0.5 to abou-t 2 percent of the weight of the glass, taking into account the dilution of the non-volatile components in the aqueous sizing composition and the ~usual mechanical loss of some of the aqueous composition initially applied to the fibers before it is dried -thereon.
Preferably, the aqueous sizing composition is applied to the glass fibers as they are produced by continuous drawing from the melt. While the aqueous sizing composition on the fibers may be at least partially dried beEore collection into a package, it is entirely satisfac-tory to gather the wet fibers into strands, preferably with about 100 to about 300 and more preferably about 200 individual fibers to each strand, collecting these strands into packages as by winding on a collet, which also provides the tension for drawing the ~ibers, and then heating the package in a conventional cir-culating hot air oven to drive off volatile materials and deposit the non-vola-tile components of the sizing compo-sition as a size coating on the fibers which will also bindtogether the individual fibers into a tightly integrated strand.
The integrated continuous glass fiber strands can be roved together in weakly integrated roving, preferably of about 30 to about 70 strands each to produce a continuous glass fiber gun roving. While the diameter of the individual glass fibers is not narrowly critical, diameters from about lO~m to about 13~m are preferred.

Particularly advantageous chrome-free aqueous sizing compositions for glass fiber gun roving, ~..
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representa~ive of the present invention, were prepared accord-ing to the following formulations:
Weight %
Component A B
As rec'd. Active As rec'd. Active Airflex 410 (55~) 5.10 2.80 5.10 2.80 Resyn 25-1971 (54.5%) 4.45 2.43 4.45 2.43 P~-700 (59%) 1.25 0.7~ 1.25 0.7~
Tyzor AA (75%) 1.10 0.82 1.10 0.82 10 Y-9567 (80%) 0.03 0.024 0.10 0.08 Emery 67600 (65%) 0.03 0.02 0.03 0.02 A-174 0.0150.015 0.015 0.015 Isoproponol 2.00 -- 2.00 --Acetic acid 0.0050.005 0.005 0.005 15 D~ I. Water Balance Balance Both A and B formulations had non-volatile content of about 6.0~0.5 percent by weight and pH of about 3.8 to 4.9.
These compositions were applied to both H-fibers (about 10.1 to about 11~4~m in diameter) and J-fibers (about 20 11.4 to about 12.7~m diameter) with a conventional applicator as they were drawn from the melt, the wet fibers gathered into strands of about 200 individual fibers and wound into pack-ages on a rotating collet in groups of 4 strands. The pack-ages were dried in a conventional circulating hot air oven 25 maintained at about 130C (265F) for about 12-14 hours, de-pending on the size of the package. The dried size coating thus deposited on the glass fibers constituted about 1.0 to about 1.3 percent of the weight of the glass and tightly integrated the strar.ds. The strands from 13 packages of each type of H-fibers and 11 packages of each type of J-fibers were roved separately into weakly integrated gun roving by conven-tional means.
The glass fiber gun rovings so produced were found to exhibit exceptionally advantageous combinations of pro-perties, particularly in view of the sizing compositionsbeing chrome-free. Thus, they were found -to chop easily ~:~r~ and cleanly, to produce advantageously low levels of fuzz and fly, to wet out rapidly and fully with conventional unsaturated polyester matrix resins (the H-fiber roviny being especially useful wi-th unfilled matrix resin systems and the J-fiber roving with more viscous filled matrix resin systems, both of which can be chemically thickened, if desired). The dried strands unwound freely from the packages during roving with little or no disintegration of the strands, and the strands were sufficiently integrated in the roving so that post-cure of the size coating after roving was not required, but upon chopping and spraying at the gun, the pieces of roving separated advantageously in-to pieces of strand, which maintained good integrity.
The unsaturated polyester resin laminates formed with these rovings exhibi-ted excellent tensile strength and modulus, flexural strength and modulus both dry and after immersion in boiling water for 24 hours, impact strength, and other desirable characteristics.
Numerous variations and modifications of the invention as particularly described herein will be apparent to those skilled in the art, and such variations and modifications are intended to be comprehended within the scope of the invention.
INDUSTRIAL APPLICABILITY
The invention described herein is readily applicable to the glass fiber industry.

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Claims (14)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A substantially chrome-free aqueous sizing composition for glass fiber gun roving which comprises (A) a mixture of emulsified film-forming polymers comprising a polymer of vinyl acetate and ethylene, a polymer of vinyl acetate and an epoxy-functional vinyl monomer, and an unsatur-ated polyester resin; (B) titanium acetyl acetonate; (C) a silylated polyamino-polyamide hydrochloride or hydrolysate thereof: (D) a cationic lubricant; and (E) 3-methacryloxy-propyltrimethoxysilane or hydrolysate thereof.

2. An aqueous composition according to claim 1 wherein the proportions by weight of the components relative to the total weight of -the aqueous composition, are about:
(A) 1 to 5% of said emulsified polymer of vinyl-acetate and ethylene. 1 to 5% of said emulsified polymer of vinyl acetate and epoxy-functional vinyl monomer, and 0.5 to 1.5% of said emulsified polyester resin;
(b) 0.5 to 1.5% of said titanium acetyl acetonate;
(C) 0.01 to 0.2% of said silylated polyamino-poly-amide hydrochloride;
(D) 0.005 to 0.1% of said cationic lubricant; and (E) 0.005 to 0.1% of said silane.

3. An aqueous composition according to claim 2 wherein said epoxy-functional vinyl monomer is glycidyl acrylate or methacrylate, said unsaturated polyester resin comprises a minor proportion by weight at an unsaturated plasticizer latently reactive therewith, and said cationic lubricant is a weak acid salt of a partial fatty acid amide of a polyamine.

4. A glass fiber coated with the in situ dried residue of an aqueous composition according to claim 1.

5. A glass fiber coated with the in situ dried residue of an aqueous composition according to claim 2.

6. A glass fiber coated with the in situ dried residue of an aqueous composition according to claim 3.

7. A coated glass fiber according to claim 4 wherein the coating comprises about 0.5 to about 2 percent of the weight of the glass.

3. A glass fiber according to claim 5 wherein the coating comprises about 0.5 to about 2 percent of the weight of the fiber.

9. A glass fiber according to claim 6 wherein the coating comprises about 0.5 to about 2 percent of the weight of the fiber.

10. A glass fiber gun roving comprising a plurality of coated glass fibers according to claim 4.

11. A glass fiber gun roving comprising a plurality of coated glass fibers according to claim 5.

12. A glass fiber gun roving comprising a plurality of coated glass fibers according to claim 6.

13. A glass fiber gun roving according to claim 12 wherein the fibers are about 10 to about 13µm in diameter.

14. A glass fiber roving according to claim 13 comprising about 30 to about 70 strands weakly integrated with each other, each strand comprising about 100 to about 300 of said coated glass fibers tightly integrated into said strand by the coating on said fibers.