US3869308A - Forming size for glass fibers and resulting product - Google Patents

Abstract

A method of producing an improved sized glass fiber strand suitable for plastisol coating is shown wherein glass fiber strand is treated with a starch based forming size comprising a starch, the salt of a polyamino-functional polyamide resin and a carboxylic acid, a wax and a fatty triglyceride. The novel sized strands produced are particularly adapted for further coating with a resinous material, preferably a plastisol resin, to provide glass fiber strands useful for the fabrication of insect screening and filtration fabrics.

Description

Muted States Patent 1 1 1 3,869,308 Graham Mar. 4, 1975 [54] FORMING SIZE FOR GLASS FIBERS AND 3 6l5,3ll 10/1971 lgnatius 65/3 RESULTING PRODUCT 3.664,855 5/l972 Morrison et a]. 65/3 X 3.676095 7/1972 Stalego r. 65/3 [75] Inventor: Roy R. Graham, Lexington, NC. [73] Assignee: PPG Industries, Inc., Pittsburgh, Pa. U' y Attorney, Agent, or Firm-Robert DCMiijlStffi [22] Filed: Apr. 27, 1973 [21] Appl. No.: 355,238 ABSTRACT A method of producing an improved sized glass fiber 5 u 17 I 1 7 2 G strand suitable for plastisol coating is shown wherein ii} iii; 8? .......f??.?ff..?if... $02155)? glass fiber is with a based form- [58] Field of Search 65/3; 117/126 GB 126 GO ing size comprising a starch, the salt of a polyaminofunctional polyamide resin and a carboxyltc acid, a [56] References Cited wax and a fatty triglyceride. The novel sized strands produced are particularly adapted for further coating UNITED STATES PATENTS with a resinous material, preferably a plastisol resin, to 2 7/1961 Gagno" a1 117/126 GO X provide glass fiber strands useful for the fabrication of gfiig i g g 23? i2 insect screening and filtration fabrics. 33472.682 10/1969 Rammel et al 65/3 x 14 Claims, No Drawings FORMING SIZE F OR GLASS FIBERS AND RESULTING PRODUCT DESCRIPTION OF THE PRIOR ART 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 a bushing such as is shown in US. Pat. No. 2,133,238. During formation the filamentsare coated while moving at a speed on the order of 5,000 to 20,000 feet per minute with a size which contains ingredients to give strand formed from the sized filaments integrity and workability for any standard textile or reinforcement use. After the glass filaments are formed and coated, they are drawn together by a gathering shoe into one or more glass fiber strands. The drawing of the filaments from the bushing is effected by the use of a winder, said winder being also used to accumulate the glass fiber strands on a forming package. If a stand so produced does not have proper integrity, fuzzing occurs during these operations and eventually the strand breaks. Sizes typically contain a lubricant for the filaments to prevent the destruction of strands during formation caused by abrasion of the individual filaments against each other or against glass fiber handling equipment.

Yarn or twisted strand (single end on bobbin) is made according to conventional textile twisting techniques by removing strand from forming packages and winding them on a twist frame and collecting them on a bobbin.

During the gathering and twisting operations, the glass strands are subjected to pressure from the apparatus involved in the forming, twisting and gathering operations. Further, strands are often subjected to pressure from other strands being wound on top of each other. This pressure tends to cause the strands to fiatten rather than to form a cross-sectional circular configuration. This flattening is particularly disadvantageous when strands or yarn are to be coated with a plastisol resin as single strands useful for insect screening, filtration fabrics and like purposes.

The process for producing fiber reinforced screening such as used for insect screening, filtration fabrics and like purposes entails pouring the molten plastisol resin onto a straight twisted strand or yarn and drawing said coated strand through a circular die thus forming a single cylindrical plastisol coated strand. A multiplicity of said strands are then woven in a crosshatched pattern and fused at their intersection to form screening or fab- NC.

The manufacturers of this screening encounter difficulty in uniformly coating glass fiber strands due to the cross-sectional flattening caused by the pressure exerted on the strands in the forming, gathering and twisting operations used to produce strand. Such lack of uniform coating results in uncoated areas on the twisted strand or yarn, necessarily exposing the fiber glass substrate thus inducing poor weathering characteristics to the finished product. Hence there has been encountered great difficulty in arriving at a proper sizing agent for fiber glass strand or yarn to be used for screening applications.

SUMMARY OF THE INVENTION Thus, in accordance with this invention a method of sizing glass fibers which enables the glass fibers to be processed without breaking, without fuzzing and with generally good handling characteristics during forming is provided. Further the instant invention provides sized fiber glass strand which is readily capable of being uniformly coated with resinous materials and more particularly with plastisol resins. Still further, this invention produces a sizing composition with the above properties which can be deposited out of water, hence obviating the use of organic solvents which present fire and physiological toxicity hazards.

Thus, in accordance with the practice of this invention, glass fiber strands are treated during their formation with an aqueous size solution whose solids comprise 28 percent to percent by weight of a starch, 4 percent to 52 percent by weight of the salt of a polyamino-functional polyamide resin and a carboxylic acid having 1 to 5 carbon atoms, 5 to 25 percent by weight of a wax and 9 percent to 77 percent by weight of a fatty triglyceride. The aqueous size used in accordance with the instant invention has a viscosity which is suitable for glass fiber strand forming sizes. The size of the instant invention further permits adequate pickup of size by the glass strand, provides good glass strand integrity and prevents the destruction of glass strand by abrasion of the individual fibers against each other during forming operations.

The starch constituent of the size of the instant invention is incorporated to bind the fibers together into a strand in order that the strand will have enough integrity to withstand the winding and twisting operations encountered in processing strand. The starch constituent can be any starch from the commercially available starches such as those derived. from corn, potato, wheat, sago, tapioca and arrowroot and which has been modified by crosslinking or other means, such as distarch phosphates and the like. Also a high amylose unmodified starch may be used.

The salt of the polyamino-functional polyamide resin and carboxylic acid is formed by the addition of said carboxlic acid to said polyamino-functional polyamide resin. The polyamino-functional polyamide resin can be any such resin but preferably is one which has an amine value between and 400. These resins are formed normally by the condensation reaction of a polycarboxylic acid such as a dimerized or trimerized fatty acid and a polyamine such as tetraethylene pentamine, ethylene triamine, diethylene triamine, diethylene tetramine and the like. The carboxylic acid constituent of the aforementioned salt is chosen from the group of organic carboxylic acid having 1 to 5 carbon atoms, such as formic acid, acetic acid, acrylic acid, methacrylic acid, butyric acid, chloroacetic acid, pentanoic acid or the like. The hypothesized function of the polyamino salt is to provide the strand with internal lubricity in order that the individual fibers do not abrade each other and break causing fuzzing and reduction in tensile strength of the individual strand during processing. The polyamino salt in conjunction with the starch provides the proper internal lubricity and internal integrity required to allow the strand to be uniformly coated with resinous materials for use as coated fiber glass strands.

The wax component of the sizing composition of this invention can be any suitable wax selected from the group consisting essentially of vegetable waxes such as Carnauba, Japan, bayberry, candelilla and the like, animal waxes such as beeswax, Chinese wax, hydrogenated sperm oil wax and the like; mineral waxes such as ozocerite, montan, ceresin and the like; and synthetic' waxes such as polyethylenes, polyethylene glycols, polyethylene esters, chloronapthalines, sorbitols, polychlorotrifluoroethylene, microcyrstalline, paraffin and the like. The hypothesized function of the wax is to act as an external lubricant for the fiber glass strand, allowing the strand to endure the abrasion caused by strands to adhere to the resinous coating which will be applied to the strands thus imparting improved moisture resistance to a finished product. Coupling agents which may be used in the aqueous size compositions in the practice of this invention include silane and siloxane materials. For example, hydrolyzable vinyl, allyl, beta chloropropyl, phenyl, thio-alkyl, thio-alkaryl, amino-alkyl, m ethacrylato, epoxy and mercapto silanes, their hydrolysis products and polymers of the hydrolysis products and polymers of the hydrolysis products and mixtures of any of these are suitable for such use. Some of the silanes are disclosed in U.S. Pat. Nos.

3,207,623 and 3,211,684, the disclosures of which are incorporated herein by reference.

Another class of coupling agents which has been found to be useful are the basic (hydroxy containing) metal salts of a strong mineral acid, such as, for example, a basic chromium chloride, basic chromium sulfate, etc. These compounds are ones having a trivalent metal ion selected from the group consisting of chromium, cobalt, nickel, copper and lead, at least one hydroxyl group attached to the metal, and at least one anion of a strong mineral acid attached to the metal (as well as coordinate complexes of these compounds and mixtures thereof).

Another type of coupling agent which may be used in the practice of this invention is a complex compound of the Werner type in which a trivalent nuclear atom,

such as chromium, is coordinated with an organic acid such a methacrylic acid, i.e., a methacrylic acid complex of chromic chloride. Such agents are described in U.S. Pat. No. 2,611,718. Other Werner type coupling agents having vinyl alkyl amino, epoxy, mercapto, thioalkyl, thio-alkaryl, and phenyl groups are suitable for incorporation in the size of the invention. Mixtures of two or more of any of these coupling agents may be used.

In addition, if desired, other known fiber glass lubricants can be added to the primary components of the invention such as alkyl imidazoline derivatives which includes compounds of the class n-alkyl N-amidoalkyl imidazolines which may be formed by causing fatty acids to react with polyalkylene polyamines under conditions which produce ring closure. The reaction of tetraethylene pentamine with stearic acid is exemplary of such reaction. These imidazolines are described more fully in U.S. Pat. No. 2,200,815. Other suitable imidaz olines are described in U.S. Pat. Nos. 2,267,965, 2,268,273 and 2,355,837.

The above alkyl imidazoline derivative may be used in combination with or replaced-by a quaternary pyridinium compound which may be represented by the general formula:

wherein X is an anion; R is an organic group containing from one to 30 carbon atoms selected from the group consisting of alykl, arylalkyl, aryl, alkenyl and acyl; and R R R R and R are each members selected from the group consisting of hydrogen, alkyl, aryl. arylalkyl. heterocyclic, halogen, alkenyl, carboxylic, alkoxy. ketonic, amido and substituted amido. Thus, the anionic group X may be, for example, chloro, fluoro, iodo, bromo, hydroxyl, nitrate, sulfate, phosphate, etc. The group R may be, for example, methyl, ethyl, butyl, hexyl, lauryl, oleyl, benzyl, phenyl, acetyl, propionyl, benzoyl, etc. The groups R R R R and R may be, for example, methyl, ethyl, propyl, cyclohexyl, furyl, pyrryl, benzyl, phenyl, chloro, bromo, iodo, fluoro, oleyl, methoxy, acetoxy, benzoxy, acetonyl, acetamido, etc. These compounds are prepared in accordance with methods common in the art by the quaternization of the corresponding pyridine bases such as, pyridine, niacin, nicotin-amide, nicotine, nicotyrine, nikethamide, 2-benzylpyridine, 3,5-dibromopyridine, 4- chloropyridine, 3-ethylpyridine, 4-methoxypyridine, 3-phenylpyridine, 2-picoline, 3-picoline, 4-picoline, 2-picoline-4,6-dicarboxylic acid, 2,4-lutidine, 2,6- lutidine, 3,4-lutidine, 2,4-pyridine dicarboxylic acid, 4-ethyl-3-methylpyridine, 3-ethyl-4-methylpyridine, 2,4,6-trimethylpyridine, etc.; with for example, an alkyl halide.

The size utilized in accordance with the instant invention may also include a wetting agent. The wetting agent is preferably cationic or non-ionic and it may also serve as an additional lubricant. Any material can be used which is conventionally known to be useful as such and which will reduce the surface tension of the aqueous size so that it is about 25 to 35 dynes per square centimeter.

The total solids (non-aqueous) content of the aqueous size of the invention is about 2 to 20 percent by weight of the sizing solution, preferably about 3 to 10 percent by weight of the sizing solution. In all events the total solids should be adjusted to a level whereby the viscosity of the sizing solution is acceptable for application to the glass filaments, i.e., 10 to 50 cps. at 60C.

DESCRIPTION OF PREFERRED EMBODIMENTS The following example is illustrative of one method of practicing the instant invention.

The size applied to the fiber glass strand in accordance with this invention was composed of the ingredients listed in Table l.

Table l Ingredients Difilarch phosphate Paraffin wax Hydrogenated corn oil Polyoxyethylunu l5) Sorhitan Mnnoolcate (emulsifying agent) 5 vcation Xtalkyl substituted imidaloline derivative. Onyx Chemical Co.) '1. ()ctylphenoxy lethylencoxyl ethanol Lardsurfactant) 7. Biomet 6o (biocide: hist tri-n-hutyltinl oxide and N-ulkyl (C, dimcthyl benzyl ammonium chloride) 8. (iamma-mcthacryloxy propytrimethoxy silane Acetic acid Vcrsamide I40 (General Mills; polyaminofunctional polyamide resin. amine value 370-400) I. Acetic acid 2. Water Parts by Weight (grams) Sufficient to make 10 gals. of size solution a solids 5.40 r 0.20% (1H 5.x 2 0.:

An aqueous size was prepared as follows:

The starch heated to 225i'2F. and cooled to below 212F., was mixed with an oil and water emulsion of the paraffin wax, the hydrogenated corn oil and the polyoxyethylene (5) sorbitan monooleate; such emulsion formed by agitating the above ingredients with an Eppenbach agitator while adding enough water to emulsify; the cation X, after being dissolved in sufficient water to form a homogeneous dispersion, is added to the above starch containing emulsion. The Biomet 66 and the octylphenoxy (ethyleneoxy) ethanol are then added to the mixture. The gamma-methacryloxypropyltrimethoxy silane is added to the mixture after hydrolysis with 2.5 grams of acetic acid in water solution. The Versamide 140 is reacted with the 52 grams of acetic acid in water solution to form a salt; the sizing solution is completed by the addition of the salt solution and dilution to a total volume of 10 gallons. During the entire procedure for combining the above ingredients, agitation is employed to effect a homogeneous mixture.

The size of Table I prepared as described above is then applied to individual glass fibers as they are drawn from orifices in an electrically heated, platinum alloy bushing containing molten glass to form filaments of 0.00036 inch in diameter. The sizes are applied to the filaments prior to the time they are grouped together to form a strand containing 200 filaments, by means of a roller applicator which is partially submerged in the sizing solution contained in a reservoir. Such an applicator is shown in more detail in US. Pat. No. 2,728,972. The fibers are then grouped into strands by a gathering shoe and wound on a forming package rotating at approximately 4,420 rpm to produce a strand travel speed of approximately 14,000 feet per minute.

The glass fiber strands wound on the forming package are then dried. This may be done by any number of known methods sufficient to reduce the moisture After the strands are dried, they may be twisted by conventional tehcniques to form twisted strands (single end on bobbin) and are then ready for use in a coating operation. The single twisted strand or yarn may be then coated with a resinous material, particularly a plastisol resin by adequate known techniques to form a cylindrical single coated strand suitable for fabrication into insect screening.

A plastisol resin is a dispersion of a high polymer in a non-volatile media. Virtually any high polymer can be used as the dispersed phase in a plastisol resin, however, preferentially the polymers used are homopolymers of vinyl halides such as polyvinyl chloride, polyvinyl fluoride and the like, and interpolymers of the vinyl halides such as copolymers of vinyl chloride and diethy maleate, copolymers of vinyl chloride and vinyl fluoride and the like. The resinous component, which is ofa fine particle size (0.05 to 1.0 micron), has a preferred fusion point of less than 400F., such fusion point being desirable in order that decomposition of the polymer does not occur and. that the dispersing media remain non-volatile during the processing.

The non-volatile dispersing media is known in the art as a plasticizer. Such plasticizers can be of the chemical composition of esters such as dibutyl phthalate, di-2- ethylhexyl phthalate and the like; ketones such as ethyl-O-benzoyl benzoate and the like; amides such as N- diethyl stearamide, dibutyl stearamide and the like; and other similar compounds.'The requisites of a plasticizer are that they are compatible with the film former, have a slight solvent action on the film former, are low in vapor pressure or volatility from the film, and possess other desirable coating and processing properties.

The twisted strands prepared as above described are coated with a plastisol coating utilizing conventional coating techniques. It is found that the coated strand has good inherent strength and a coating which is uniform and continuous. While certain fiber diameter and filament counts per strand are used in the above example, it will be obvious that other filaments and other strand compositions may be employed without departing from the spirit of the invention.

Although the present invention has been described with respect to specific details of certain embodiments thereof, it is not intended that such details act as limitations upon the scope of the invention insofar as set forth in the accompanying claims.

I claim:

1. A method of forming an improved, sized glass fiber strand suitable for coating with a resinous material comprising:

drawing glass streams through orifices in a bushing to form individual glass fibers;

moving the fibers away from the bushing at a high rate of speed and forming then into a strand;

applying to the fibers while they are moving at this speed and before they are formed into strand a starch based aqueous sizing solution and non-aqueous components thereof consisting essentially of 28 percent to 75 percent by weight of a starch; 4 percent to 52 percent by weight of the salt of a polyamino functional polyamide resin, said polyaminofunctional polyamide resin salt being formed from the condensation reaction product of a polycarboxcylic acid and a polyamine, said polyamine having greater than 2 amine groups per molecule, and a carboxcylic acid having 1 to carbon atoms; 5 to 25 percent by weight of a wax from the group consisting of animal waxes, vegetable waxes, mineral waxes and synthetic waxes; and 9 percent to 77 percent by weight of a fatty triglyceride; and collecting the glass strands so produced.

2 The method of claim 1 wherein the size contains 1.5 percent to 20 percent by weight of a coupling agent.

3. The method of claim 1 wherein the fatty triglyceride is hydrogenated corn oil.

4. The method of claim 1 wherein the starch is distarch phosphate.

5. The method of claim 1 wherein the carboxylic acid is acetic acid.

6. The method of claim 1 wherein the wax is paraffin wax.

7. The method of claim 1 wherein the size contains 10 to 45 percent by weight of an alkyl imidazoline.

8. An improved glass fiber strand suitable for the application of resin thereto and having disposed on the glass fibers an amount from about 0.80 percent to about 2.5 percent by weight of the glass, the dried residue of an aqueous size consisting essentially of 28 percent to 75 percent by weight of a starch; 4 percent to 52 percent by weight of the salt of a polyaminofunctional polyamide resin, said polyaminofunctional polyamide resin salt being formed from the condensation reaction product of a polycarboxcylic acid and a polyamine, said polyamine having greater than 2 amino groups per molecule and the carboxcylic acid having 1 to 5 carbon atoms; 5 to 25 percent by weight of a wax from the group consisting of animal waxes, vegetable waxes, mineral waxes and synthetic waxes and 9 percent to 77 percent by weight of a fatty triglyceride.

9. The strand of claim 8 wherein the dried residue on the strand contains 1.5 percent to percent by weight of a coupling agent.

10 to 45 percent by weight of an alkyl imidazoline.

Claims (14)

1. A method of forming an improved, sized glass fiber strand suitable for coating with a resinous material comprising: drawing glass streams through orifices in a bushing to form individual glass fibers; moving the fibers away from the bushing at a high rate of speed and forming then into a strand; applying to the fibers while they are moving at this speed and before they are formed into strand a starch based aqueous sizing solution and non-aqueous components thereof consisting essentially of 28 percent to 75 percent by weight of a starch; 4 percent to 52 percent by weight of the salt of a polyamino functional polyamide resin, said polyaminofunctional polyamide resin salt being formed from the condensation reaction product of a polycarboxcylic acid and a polyamine, said polyamine having greater than 2 amine groups per molecule, and a carboxcylic acid having 1 to 5 carbon atoms; 5 to 25 percent by weight of a wax from the group consisting of animal waxes, vegetable waxes, mineral waxes and synthetic waxes; and 9 percent to 77 percent by weight of a fatty triglyceride; and collecting the glass strands so produced.

2. The method of claim 1 wherein the size contains 1.5 percent to 20 percent by weight of a coupling agent.

3. The method of claim 1 wherein the fatty triglyceride is hydrogenated corn oil.

4. The method of claim 1 wherein the starch is distarch phosphate.

5. The method of claim 1 wherein the carboxylic acid is acetic acid.

6. The method of claim 1 wherein the wax is paraffin wax.

7. The method of claim 1 wherein the size contains 10 to 45 percent by weight of an alkyl imidazoline.

8. AN IMPROVED GLASS FIBER STRAND SUITABLE FOR THE APPLICATION OF RESIN THERETO AND HAVING DISPOSED ON THE GLASS FIBERS AN AMOUNT FROM ABOUT 0.80 PERCENT TO ABOUT 2.5 PERCENT BY WEIGHT OF THE GLASS, THE DRIED RESIDUE OF AN AQUEOUS SIZE CONSISTING ESSENTIALLY OF 28 PERCENT TO 75 PERCENT BY WEIGHT OF A STARCH; 4 PERCENT TO 52 PERCENT BY WEIGHT OF THE SALT OF A POLYAMINOFUNCTIONAL POLYAMIDE RESIN, SAID POLYAMINOFUNCTIONAL POLYAMIDE RESIN SALT BEING FORMED FROM THE CONDENSATION REACTION PRODUCT OF A POLYCARBOXYCLIC ACID AND A POLYAMINE, SAID POLYAMINE HAVING GREATER THAN 2 AMINO GROUPS PER MOLECULE AND THE CARBOXYCLIC ACID HAVING 1 TO 5 CARBON ATOMS; 5 TO 25 PERCENT BY WEIGHT OF A WAX FROM THE GROUP CONSISTING OF ANIMAL WAXES, VEGETABLE WAXES, MINERAL WAXES AND SYNTHETIC WAXES AND 9 PERCENT TO 77 PERCENT BY WEIGHT OF A FATTY TRIGLYCERIDE.

9. The strand of claim 8 wherein the dried residue on the strand contains 1.5 percent to 20 percent by weight of a coupling agent.

10. The strand of claim 9 wherein the coupling agent is gammamethacryloxypropyltrimethoxy silane.

11. The strand of claim 8 wherein the fatty triglyceride is hydrogenated corn oil.

12. The strand of claim 8 wherein the starch is distarch phosphate.

13. The strand of claim 8 wherein the carboxylic acid is acetic acid.

14. The strand of claim 8 wherein the size contains 10 to 45 percent by weight of an alkyl imidazoline.