US3599418A

US3599418A - Heat cleanable coating for glass fibers

Info

Publication number: US3599418A
Application number: US690053A
Authority: US
Inventors: Homer G Hill
Original assignee: Owens Corning Fiberglas Corp
Current assignee: Owens Corning
Priority date: 1967-12-13
Filing date: 1967-12-13
Publication date: 1971-08-17
Anticipated expiration: 1988-08-17

Abstract

Glass fibers coated with an easily heat cleanable size comprising a high boiling organic lubricant and a methacrylate polymer or copolymer.

Description

A limited States Patent Inventor Appl. No.

Filed Patented Assignee Homer G. Hill Newark, Ohio Dec. 13, 1967 Aug. .17, 1971 Owens-Corning Fiberglas Corporation HEAT CLEANABLE COATING FOR GLASS FIBERS 12 Claims, No Drawings GR, 126 GS, 126 GO; 65/3; 57/1.4

References Cited UNITED STATl-IS PATENTS 12/1948 ll/1954 l/1966 8/1969 Ebaugh Radke Vanderbilt Marzocchi et a1. Kolek et a1 Primary Examiner-William D. Martin Assistant Examiner-David Cohen Attorneys-Staelin and Overman and William P. Hickey 117/126X 1l7/126X l17/126X 117/126X ABSTRACT: Glass fibers coated with an easily heat cleanable size comprising a high boiling o methacrylate polymer or copolymer.

rganic lubricant and a Glass fibers are produced by several different methods. In one method, small molten streams of glass are attenuated by the pulling action of a winding drum on which they are wound in excess of 10,000 feet per minute. Before reaching the drum and while in a solid state, the attenuated fibers are brought together into a strand which is traversed back and forth across the winding drum. In another process of making glass fibers, molten streams of glass are attenuated by a confined downward blast of air which attenuates and projects the fibers onto a perforated collecting drum through which air is continually exhausted. The fibers which collect upon the surface of the drum are randomly oriented, and are discontinuous with the average fiber length being approximately 1 foot long. The veil of fibers which is collected on the surface of the drum is withdrawn and pulled axially through a small cylinder that is revolved by a turbine to collect and twist the discontinuous fibers into a sliver. The sliver is passed over a winder traverse and wrapped around a tube to produce a wound package of the sliver.

Both the continuous filament strand and the discontinuous filament sliver have many uses, one of which is in the making of woven fabrics. Fibers made by no matter what process, are extremely susceptible to abrasion and must be protected by an organic film former which both separates the fibers and lubricates the surface thereof to prevent abrasion by the guide surfaces of the processingequipment. The glass fibers by both processes described above are used to make woven fabrics, the manufacture of which, requires the strand or sliver, as the case may be, to go through a number of operations including twisting, quilling, beaming and weaving. In order to protect the fibers from abrasion during these processing steps, an organic film former is applied to the fibers at forming prior to or during the gathering of the fibers together into the strand or sliver, as the case may be. In some respects, the abrading ac tion of the air turbine used to gather discontinuous filaments into a sliver is more severe than the abrading action of the equipment which produces the strand. The film former which is applied to the filaments forming the sliver must be capable of not only forming a film which protects the filaments, but must also have lubricating properties to protect the air turbine.

The lubricating properties that are required to be provided in the protective coatings are so peculiar that very few materials will provide them, and those materials which provide the lubricity will not provide a surface which can be dyed and will not provide lasting protection. The coatings which are applied at forming, therefore, are removed after the fibers are woven into a fabric. This is usually accomplished by a heat-cleaning process in which the woven fabric is passed through an oven having a temperature of above approximately 900 F. to oxidize and remove the coatings. This heat treatment also sets the weave of the fabric, and immediately thereafter a finish,

usually a colored protective coating, is applied.

The problem to which the present invention is directed concerns the burn off of the protective coating applied at forming. The principal problem involved with most protective coatings is that they leave black carbon deposits as a result of the heat treating of the fabric. The protective coatings that are applied to the sliver contain an organic lubricant which leaves a pronounced carbon residue upon burn off. The present invention, therefore, is directed to a film forming material which contains an organic lubricant and which will nevertheless have a substantially complete burn-off during the heat-cleaning operation of the fabric.

The principal object of the present invention is the provision of a new and improved protective coating for application bu e le to glassfibersat forming which,will havesubstantially,

f i -prst mstslx210; er entqtthesmmnm Another object of the invention is the provision of new and improved coated glass fibers, the coating of which can be completely removed during heatcleaning without leaving a carbon deposit.

SUMMARY OF THE INVENTION The invention relates generally to a coating material for glass fibers which will completely protect the fibers against abrasion even when twisted by an air turbine and which is completely removable without carbon deposit during conventional heat-cleaning operations. These coatings are sometimes called forming sizes, and the forming sizes of the present invention include an organic lubricant which may be of any suitable type, preferably a mineral oil at least the backbone of which is a hydrocarbon. According to the invention, it has been found that a forming size containing such a lubricant can be heat cleaned without leaving carbon deposits provided the forming size includes an appropriate amount of a generally noncrosslinked polymer of an olefin and having disubstituted olefinic carbon. The exact reason. for the complete removal of the mixture during heat cleaning is not known precisely, but it is believed to involve an unzipping of the polymer at or substantially near the heat cleaning temperature to provide volatile hydrocarbons. The sudden flash of the polymer into volatile material sweeps away the partial pressure of the mineral oil to displace the mineral oil from the fibers prior to complete pyrolysis of the mineral oil. The unzipping of the polymer will also provide free :radicals which may induce break down and free radical formation of the mineral oil. The mineral oil and polymer will not usually be soluble in each other at room temperature, but may at higher temperature, and the polymer will usually be a :solid having good film forming properties. In order that the above mixture can be conveniently applied to the fibers at forming, they preferably are dissolved in a mutual solvent which will largely flash away after the size is applied to the fibers to leave a lubricous coating on the surface of the fibers. The forming size may also include other materials such as cationic lubricants which are attracted to the surface of the glass, and may further include thixotropic gel producing agents which convert the size to a gel which can be applied to the fibers under shear conditions wherein the size is a solution and immediately following which it is transformed to a gel.

The lubricating oils which are used can be vegetable oils, but preferably are high boiling mineral oils which are predominately hydrocarbons such as naphthenes. A particularly desirable mineral oil is a retfined petroleum base white oil.

The polymer having disubstituted olefinic carbon can be of any suitable type, as for example: an acrylic ester polymer, a poly methylstyrene, a polyisobutylene, etc. The radicals attached to the disubstituted olefinic carbon may include lower alkyl radicals, phenol radicals, halogens, hydroxyl groups, acetoxy groups, amine groups, etc. The polymeric film former need not be formed entirely of the disubstituted olefinic carbon containing material, but may be a copolymer containing such material, since the free radicals generated during the unzipping" produce lower polymers such as the dimers and trimers which are volatile at the heat cleaning temperatures.

The solvents which are used can be of any suitable type, and need not be mutual solvents where the polymer to be applied is an emulsion or dispersion. Where acrylic ester polymers are used, Cellosolve acetate is a particularly good mutual solvent of both the acrylic ester polymer and the mineral oil. The lubricant to polymer ratio should. preferably be less than 1. Sizes of the invention to be applied to the fibers as a solution preferably contain: from approximately I to approximately 25 percent by weight of a high boiling lubricant preferably a mineral oil having a hydrocarbon backbone, from approximately 5 to approximately 30 percent by weight of a polymer of an olefin having disubstituted olefinic carbon, and up to approximately, 22.5, percentof a mptualsolvent and usually ap- BEST AVAILABLE 3 DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred binder of the present invention consists essentially of a highly refined petroleum white oil which is a hydrocarbon composed principally of naphthenes, and an acrylic ester polymer formed from at least some polymer containing disubstituted olefinic carbon.

EXAMPLE 1 A liquid binder is made from the following ingredients in percent by weight:

The binder is prepared by dissolving the cationic lubricant in approximately one tenth of the Cellosolve acetate to form a premix. The acrylic ester polymer is thinned with approximately one half of the Cellosolve acetate in a Waring blender following which the cationic lubricant premix and the white oil are added, thoroughly mixed, and then diluted with the remainder of the Cellosolve acetate.

The binder prepared as above described is applied to a sliver formed as described in the Marzocchi-Rammel US. Pat. No. 3,033,719. The binder is sprayed onto the filaments before they are collected on the collecting drum. The coating on the silver comprises approximately 2.0 percent of the total weight and is essentially solvent free.

A sliver coated as above described and weighing 0.10 pounds per thousand feet, was woven into a fabric using 54 pick per inch and 56 fill per inch. This fabric was heat cleaned in an oven at 900 F. No traces of carbon remained.

' Cellosolve acetate This material is prepared by adding the cationic lubricant to approximately one tenth of the Cellosolve acetate and heating until dissolved to form a premix. Thereafter the polymer,

white oil and remaining portion of the Cellosolve acetate are added to a Waring Blender and thoroughly mixed, following which the cationic lubricant premix is added. Thereafter the thixotropic gelling agent is added and the total ingredients blended at a temperature of l 15 F. to produce a size which is thixotropic at room temperature.

I The above prepared thixotropic gel is applied to the sliver produced as described in the Marzocchi-Rammel US. Pat. No. 3,033,7l9 using the roll applicator described in application Ser. No. 573,348 filed Aug. I6, 1966 now US. Pat. No. 3,498,262, and assigned to the assignee of the present invention. The roll applicator is positioned to contact the fibers im- A i mediatelybefore -bing pulled -into' the air turbine. The sliver I prepared with this thixdtropi'c gel" material when *wdiinihto a fabric and heat cleaned as above described in Example I has no detectable carbon deposit.

The ability of materials to be removed from glass fibers by heat cleaning without leaving a carbon deposit can be determined by mixing the material with fine crushed glass, placing the mixture in depressions in a porcelain tray, and placing the tray in an oven having an air atmosphere at 900 F.,Table l is a v list of various materials subjected to this burn-off test, and opposite the materials is a numeral designation of the degree of burn-off of the material under consideration. In this table, 0 indicates a complete removal, numeral 1 indicates a perceptible trace, numeral 2 is the maximum allowable amount, and 3, 4 and 5 are gradually increasing heavy amounts of remaining carbon. The mixture used in these tests in every instance comprised 2 parts of the fine crushed glass and 0.5 parts by weight of the organic mixture.

TABLE I Organic Materials Burn-off rating results I part acrylic ester polymer (50:50 methyl I methacrylate-ethyl acrylate), l part white mineral oil, I part Cellosolve acetate I part acrylic ester polymer (50:50 methyl 1 methacrylate-ethyl acrylate), l part white mineral oil, I part toluol 1 part methyl methacrylate, l part white 3 mineral oil, I part Cellosolve acetate 1 part poly methylstyrene, l part white I mineral oil, 1 part Cellosolve acetate l part poly isobutylene, l part white I mineral oil, 1 part Cellosolve acetate l part acrylic ester polymer given above, I l part l part 've 1 part acrylic ester polymer given above, I l

1 part soya oil, I part Cellosolve acetate 1 pan acrylic ester polymer, l part white I mineral oil, I part Cellosolve acetate, one-half octadecyl amine acetate l part poly ethyl acetate, 1 part white 3 mineral oil, 1 part Cellosolve acetate l part acrylic ester polymer, l part SAE-IO 1 motor oil, I part Cellosolve acetate FFE In general, materials burn off more poorly in the tray test than they do as a coating on glass fibers. This is probably true because the materials on the try are raised to elevated tem peratures considerably more slowly than are coatings on the fibers of a woven fabric; so that the decomposition of the polymer on the tray is less gradual and the volatile products of decomposition do not sweep away the partial pressure of the oil as efiectively. It will also be apparent that cationic lubricants, nonionic lubricants, and other low melting organic materials that do not contain metal ions can be present in the size material without changing the synergistic affect of the disubstituted olefinic carbon polymers on the high boiling organic materials.

The polymer of an olefin having disubstituted olefinic carbon may be used in an amount ranging from an amount approximately equal to the high boiling organic lubricant to an amount approximately 10 times the organic lubricant. The weight of the polymer and lubricant in the coating on the fibers will usually comprise from approximately 1 to approximately 5 percent by weight of the coated fibers in order to adequately lubricate and protect the fibers. in order that good bum-off is had, the fibers should be dry at the time of burn-off. Preferably, the coated fibers should have less than 0.1 percent of moisture before bum-off is attempted.

As previously indicated, the sizing materials of the present invention have particular advantages for the protection of glass fibers as they pass through sliver producing machinery. The size thereafter also provides improved protection for the fibers during the yarn making operation wherein several slivers, usually three or more, are uncoiled from packages,

6 that the yarn can thereafter be quilled, beamed and woven, without further application of a lubricant or protective coating. As previously indicated, the size provides greatly improved burnoff of the woven fabric and/or the sliver, yarn or other multiple filament form of the coated glass fibers.

While the invention has been described in considerable detail, 1 do not wish to be limited to the particular embodiments shown and described; and it is my intention hereby to cover all adaptations, modifications and arrangements thereof which come within the practice of those skilled in the art and which are covered by the following claims.

1 claim:

1. Glass fibers having a coating thereon consisting essentially of: .1 part by weight of a high boiling organic lubricant material; and from approximately 1 part to approximately parts by weight of a methacrylate ester polymer or copolymer, said coating comprising from approximately 1 to approximately 5 percent of the weight of the coated fibers.

2. The glass fibers of claim 1 wherein the high boiling material is a mineral oil having a hydrocarbon backbone.

3 The glass fibers of claim 1 wherein the lubricant and polymer are deposited from a mutual solvent.

4. The glass fibers of claim 1 wherein the solvent is monoalkyl ethers of ethylene glycol acetate, or dialkyl ethers of ethylene glycol acetate, or mixtures thereof.

5. The glass fibers of claim 1 including a gelling agent in sufficient quantity to form a gel at room temperature.

6. The glass fibers of claim 1 wherein the coating consists essentially of a mineral oil having a hydrocarbon backbone and a methacrylate ester polymer or copolymer in approximately a 19 to parts by weight ratio.

7. The glass fibers of claim 1 comprising the following solids in percent by weight: approximately 19 percent of a mineral oil having a hydrocarbon backbone; approximately 70 percent of a methacrylate ester polymer or copolymer; approximately 0.5 percent of a cationic lubricant; and approximately 10 percent of a gelling agent.

8. Sliver formed of the coated glass fibers of claim 1.

9. Yarn formed of the sliver of claim 8.

l0. Woven fabric formed of the yarn of claim 9.

1 l. The process of producing heat cleanable sliver comprising: attenuating molten streams of glass into nascent fibers, coating said nascent fibers with a material consisting essentially of: from approximately 1 to approximately 25 percent by weight of a mineral oil having a hydrocarbon backbone, from approximately 5 percent to approximately 30 percent of a methacrylate ester polymer or copolymer, and up to approximately 92.5 percent by weight of monoalkyl ethers of ethylene glycol acetate, or dialkyl ethers of ethylene glycol acetate, or mixtures thereof.

12. The process of claim 11 followed by twisting several slivers together to form a yarn.

Claims

2. The glass fibers of claim 1 wherein the high boiling material is a mineral oil having a hydrocarbon backbone.
3. The glass fibers of claim 1 wherein the lubricant and polymer are deposited from a mutual solvent.
4. The glass fibers of claim 1 wherein the solvent is monoalkyl ethers of ethylene glycol acetate, or dialkyl ethers of ethylene glycol acetate, or mixtures thereof.
5. The glass fibers of claim 1 including a gelling agent in sufficient quantity to form a gel at room temperature.
6. The glass fibers of claim 1 wherein the coating consists essentially of a mineral oil having a hydrocarbon backbone and a methacrylate ester polymer or copolymer in approximately a 19 to 70 parts by weight ratio.
7. The glass fibers of claim 1 comprising the following solids in percent by weight: approximately 19 percent of a mineral oil having a hydrocarbon backbone; approximately 70 percent of a methacrylate ester polymer or copolymer; approximately 0.5 percent of a cationic lubricant; and approximately 10 percent of a gelling agent.
8. Sliver formed of the coated glass fibers of claim 1.
9. Yarn formed of the sliver of claim 8.
10. Woven fabric formed of the yarn of claim 9.
11. The process of producing heat cleanable sliver comprising: attenuating molten streams of glass into nascent fibers, coating said nascent fibers with a material consisting essentially of: from approximately 1 to approximately 25 percent by weight of a mineral oil having a hydrocarbon backbone, from approximately 5 percent to approximately 30 percent of a methacrylate ester polymer or copolymer, and up to approximately 92.5 percent by weight of monoalkyl ethers of ethylene glycol acetate, or dialkyl ethers of ethylene glycol acetate, or mixtures thereof.
12. The process of claIm 11 followed by twisting several slivers together to form a yarn.