US3167468A

US3167468A - Method of applying an aqueous size to strands formed of glass filaments and product produced thereby

Info

Publication number: US3167468A
Application number: US112631A
Authority: US
Inventors: Joe B Lovelace; William E Patterson
Original assignee: Pittsburgh Plate Glass Co
Current assignee: PPG Industries Inc
Priority date: 1961-05-25
Filing date: 1961-05-25
Publication date: 1965-01-26
Anticipated expiration: 1982-01-26
Also published as: DE1469181A1; GB997051A; NL278607A; BE618146A

Description

Jan. 26, 1965 J. B. LOVELACE ETAL 3,167,468

METHOD OF APPLYING AN AQUEOUS SIZE TO STRANDS FORMED OF GLASS FILAMENTS AND PRODUCT PRODUCED THEREBY Filed May 25, 1961 2 Sheets-Sheet l 1965 J. B. LOVELACE ETAL 3,167,468

METHOD OF APPLYING AN AQUEOUS SIZE TO STRANDS FORMED OF GLASS FILAMENTS AND PRODUCT PRODUCED THEREBY Fqlled May 25, 1961 2 Sheets-Sheet 2 YARDS cmvus NO sanos 3 ZIS 4 B Mu/fl 5 P4775250 A "aw/5r United States Patent C 3,167,468 METHGD 9F APPLYING AN AQUEGUS SEZE T STRANDS FGRMED 0F GLASS FELAMENTS AND PRDDUQT PRQDUCED THEREEY Joe B. Lovelace, Eilenboro, and Wiliiarn E. Patterson, Kings Mountain, N.C., assignors to Pittsburgh Plate Glass Company, Pittsburgh, Pa a corporation of Pennsylvania Filed May 25, 196i, Ser. No. 112,631 10 Qiaims. ((Jl. 161-475) This invention relates to a process for preparing glass fibers and it has particular relation to the application of a size to continuous filament glass fiber strand during the formation of the strand.

In the production of continuous filament glass fiber strand, a number of individual glass filaments are drawn from an electrically heated, platinum alloy bushing containing a molten supply of the glass. The glass passes through tips which define orifices in the bottom of the bushing and forms inverted cones of glass at the ends of the tips. individual filaments are drawn from the cones of glass at a high rate of speed, i.e., 5,000 to 20,000 feet per minute, and are grouped into a strand as they pass over a suitable guide. The strand is thereafter wound on a rapidly rotating forming tube.

There is no twist in the strand as it is thus formed and an aqueous size composed of an aqueous dispersion of a binder and a lubricant, such as dextrinized corn starch and a vegetable oil, is applied to the individual filaments prior to the tie they are grouped into the strand and wound on the tube in order to bond them together and maintain the integrity of the strand. The strand is wound on the tube with a slight traverse so that succeeding turns cross each other at an angle rather than being parallel to each other so the strand can be more easily removed from the tube.

One problem which occurs in the manufacture of continuous filament strand in this manner is that of size strand forming package dries on the forming tube, the

water moves from the inside of the forming package next to the tube to the outside of the forming package. This movement of the watercarries with it some of the starch and oil of'the size so that the strand in'the outside layers of the package has a much higher size solids content than the strand in the layers beneath the surface.

Size migration creates a number of problems in subsequent fabrication of the strand. In twisting, plying, warpingyquilling and weaving of glass fiber yarn there are a number of winding and unwinding operations where the tension exerted on the yarn is important. The tension exerted on the yarn during these operations must be relatively constant. if the tension on the yarn is uneven during these operations, the individual filaments making up the yarn are likely to be broken and produce fuzzy yarn. Fuzzy yarn clogs up the fabricating equipment and causes yarn breakout. Uneven tension on the yarn can be created by non-uniform size content on the yarn through out its length. Thus, it is desired that the size content on the yarn be uniform throughout its length.

Another fabricating operation where uneven size content on the yarn is troublesome is in the process of texturing yarn. Textured yarns are those continuous fila- Edfilidd ice ment yarns which have been bulked by an air jet such as described in US. Patent No. 2,783,699. The size content of the yarn which is textured determines the resistance of the yarn to being textured or bulked by the air jet. A variation in size content along the length of the yarn results in a variation in the degree of bulking. Any variation in the degree of bulking of the yarn shows up in the fabric and may be serious enough to result in rejection of the piece of goods.

An additional problem due to size migration is encountered when woven fabrics are heat treated. The strand with the higher size solids content shows up differently than the strand with the lower size solids content when the twisted strand is woven into a fabric and the fabric is heated to remove the size and set the fibers in the fabric. This heating is conducted at a temperature of about 1200 to 1400 F. for 30 to 40 seconds and is sufficient to volatilize the solids and remove them from the fabric and to soften the fibers in the fabric to set them in their new position. This process is described in greater detail in US. Patent No. 2,845,364. After the heat treatment, the strand from the outside of the forming package which originally had the higher size solids contents shows up as a band in the fabric which reflects light to a different extent than the rest of the fabric. Sometimes this band exhibits a moire efiect. This results in an imperfection in the fabric which is of sufiicient magnitude to cause rejection of the piece of goods. It is not known exactly what causes the difference in the yarn in the fabric; however, it is believed that it may be due to incomplete re moval of the size or it may be due to a difference in the orientation of the individual filaments in the yarn due to the increased heating activity which occurs in the areas of increased size solids content when the fabric has been sufiiciently heated to remove all of the size throughout the fabric. In any event, this difference has definitely been noted and has been a cause for serious concern with the yarn manufactue-rs and weavers. The above defects have also occurred in fabrics woven with textured, continuous filament glass yarns.

As can be surmised from the description above concerning the defects in woven fabrics caused by size migra tion, this problem has been a most serious problem and has required drastic steps to overcome it. These steps have involved the stripping or running off of the strand on the outside of the forming package to remove that portion of the forming package which contains strand having a higher size content than the remainder of the package. This represents a substantial loss in the production of strand and also requires a costly and undesirable intermediate step between the forming and twisting of the strand.

Apart from the problems which are created by size migration, conventional starch-oil sizes have been ditilcult to texturize by the air jet process mentioned above. The starch binder has been observed to powder and be blown off of the yarn being subjected to the jet. This creates an atmosphere problem which is annoying to the operators. it also clogs the texturing jet and results in uneven texturing of the yarn. Deposits of starch build up. in the jet, and reduce the texturing effect as they are buiit up; The back pressure in the jet then builds up until finally the pressure is sufficient to blow out all of the starch accumulation at once and the complete texturing effect is again resumed. This results in a chattering effect in the jet and uneven texturing of the yarn passing through the jet.

It is, therefore, an object of this invention to provide an aqueous size which can be easily applied to glass fiber strand during its formation in uniform, controlled amounts and whose non-aqueous constituents will not migrate in the strand forming package upon drying of the package on the forming tube. It is a further object of the invention to provide such a size which will permit the strand to be twisted, uniformly textured if desired, quilled or warped, and woven into cloth with uniform tension and with a minimum of broken filaments in these various fabricating operations. It is also an object of the invention to provide an aqueous size whose solids constituents can be readily and completely removed from a woven fabric by the conventional heat treatments which are applied to fabrics to remove the size ingredients and set the fibers in the fabric.

The objects of the invention are achieved by the application to a strand during its formation of an aqueous size containing as the binder ingredient a starch-amine reaction product. The size also contains other ingredients such as a vegetable oil as a lubricant, a fungicide such as formaldehyde, a softening agent and a wetting agent. Small amounts of additional film forming ingredients other than starch may be included, such as for example, gelatin or polyvinyl alcohol to make a more durable strand. The term starch includes any amylaceous substance such as untreated starch, as Well as starch derivatives including dextrinized, hydrolyzed, oxidized, esterified and etherified starches still retaining amylaceous material. The starches may be derived from any sources including corn, wheat, potato, tapioca, waxy maize, sago or rice.

The starch-amine reaction products which are useful in the invention are made by reacting starch with an esterification or etherification reagent which will serve to introduce an amine group to the starch. Said reagent may be selected from the group of nitrogen containing compounds consisting of amino alkyl anhydrides, alkyl imines, alkyl epoxides and alkyl amino halides, as Well as the corresponding compounds containing aryl groups in addition to the alkyl groups. All of the various types of reagents listed herein have the common characteristic of reacting with hydroxyl groups in the starch to introduce an ester or ether linkage and thereby introduce an amine radical into the starch.

Representative examples of specific reagents for the purpose of making such starch derivatives include ethylene imine; propylene imine; isatoic anhydride; quinolinic anhydride; b-diethyl amino ethyl chloride; bmethyl amino isopropyl chloride; b-dimethyl amino ethyl chloride; 3-diethyl amino 1,2-epoxypropane; 3-dibutyl amino 1,2-epoxypropane; Z-bromo-S-diethyl amino pentane hydrobromide; N-(2,3-epoxypropyl)-piperidine; and N,N-(2,3-epoxypropyl) methyl aniline. The various halides (eg. chloro-, bromo-, etc.) can be used interchangeably. In the above reagents, where the free amines have been indicated (e.g. b-diethyl amino ethyl chloride), one can also use the hydrochloride or other salts of these reagents (e.g. b-diethyl amino ethyl chloride hydrochloride). In fact it is ordinarily preferred to use the salts since these are often less toxic and more convenient to handle. The hydrochloride moiety takes no part in the reaction. It Will be seen that besides the alkyl, aryl and aralkyl types, the reagents may also include those containing cyclic groups. Therefore when reference is made to the alkyl, aryl and'aralkyl groups, it will be understood that the cyclic reagents are equivalents of these types. The starch-amine reaction product may also be treated so as to result in the quaternary ammonium salt.

The starch-amine reaction products can be produced by known methods such as those set forth in US. Patents Nos. 2,813,093 and2,946,70 5. In making the starchamine reaction products, the starch is preferably treated with any of the previously described reagents in the presence of an alkaline medium. This is accomplished by suspending the starch in water, to Which has been added (either before or after the addition of the starch) suflicient base, such as alkali metal hydroxide, alkaline earth hydroxide, quaternary ammonium hydroxide, or the like,

to maintain the mixture in an alkaline state during the reaction. The required amount of the amine reagent is then added, agitation being maintained until the desired reaction is complete. Heat may be applied if desired in order to speed the reaction since the usual time temperature relation applies. The proportion of etherification tor esterification reagent used varies with the particular reagent chosen (since they vary in reactivity and reaction efficiency) and the degree of substitution desired. The amine-starch reaction product may contain 0.5 to 30 percent by weight of an amine introducing reagent based on the weight of the starch.

The starch-amine reaction product can be prepared in either gelatinized or ungelatinized form. In order to avoid gelatinization of the starch during the reaction with the amine in those cases where the degree of alkalinity or heat is such as would ordinarily cause gelatinization to occur, a gelatinization retarding chemical, such as sodium sulfate, is added to the starch-alkali-water-reagent mixture.

The starch-amine reaction product as thus produced is broadly described by the following structural formula:

group consisting of substituted alkyl, hydroxyl alkyl, acyl or aroyl radicals,'and' each of R and R is a radical selected from the group consisting ofhydro'gen, alkyl or aralkyl radicals. If the derivative is in the form of the salt, or if it is in the form of the quaternary salt, the formula is then represented as follows:

Ilh

wherein X is again starch, R is again a radical selected from the group consisting of substituted alkyl, hydroxyl alkyl, acyl or aroyl radicals, and each of R and R is 'a radical selected from the group consisting of hydrogen, alkyl or aralkyl radicals, and where R, is hydrogen or an alkyl group and Y is a chloride, bromide or an' iodide radical.

Examples of the glass fiber strand size are set forth below: 1

Example I The following table lists various sizing formulations which are useful forthe practice of the invention wherein the starch-amine reaction product is an alkyl amino halide salt resulting from the reaction of corn starch with b-diethyl amino ethyl chloride hydrochloride.

Parts by Weight (grams) Ingredient Starch-amine Formaldehyde, cc. 17 17 17 17 17 17 17 pH 4.0 4.0 4.0 3.9 4.5 3.5 3.3 5.0 Percent s01ids 6.41 7.17 6.27 5.47 6.0 5.15 4.59 6.0 Percent application 0.97 1.02 1.16 0.84 1.04

The above formulations are given in the amounts required for making five gallon mixtures of the size. All of the amounts are in grams as indicated in the heading for the table with the exception of the formaldehyde which is set forth in cubic centimeters. The starch-amine reaction product is prepared by reacting corn starch with b-diethyl amino ethyl chloride hydrochloride in the following manner. Four pounds of sodium hydroxide are dissolved in 150 pounds of water and 50 pounds of sodium sulfate are added. Agitation is continued until the reagents have wherein X is a starch, R is a radical selected from the dissolved and 100 pounds of corn starch are then added with continued agitation. When the suspension is uniform, there is added a solution of 4 pounds of b-diethyl amino ethyl chloride hydrochloride and 25 pounds of Water. Agitation is maintained for 24 hours, at which time enough dilute hydrochloric acid solution is added to adjust the pH to approximately 3. The starch product is then filtered, washed thoroughly with water and dried in the form of a powder. The Pureco oil in the formulations is a partially hydrogenated vegetable oil made by the Capital City Products Company. The Tween 81 is a wetting agent and is an ethylene oxide derivative of a sorbital ester made by Atlas Powder Company. Cation X is. I

a textile softener and is an alkyl imidazoline reaction product of tetraethylene pcntamine and stearic acid as made by the Onyx Oil and Chemical Company.

The size is prepared by first adding 2 /2 gallons of water to a mixing kettle. The starch-amine reaction product is then added to the water to form a slurry and the pH of the slurry is adjusted to 3.5 plus or minus 0.2 with acetic acid. The slurry is heated to 200 F. and held at this temperature for about 15 minutes in order to gelatinize the starch-amine reaction product. The gelatinized starcharnine reaction product in the aqueous diluent is then cooled to 160 F. The Pureco oil is added next. The Pureco oil is a solid material having the consistency of lard and it is first melted and then emulsified with water, Tween 81 and a small amount (200 to 400 cubic centimeters) of the gelatinized starch-amine reaction product before it is added to the main portion of the gelatinized starch-amine reaction product. Cation X, dispersed in about gallon of water, is next added to the size and formaldehyde is thereafter added. The size as thus prepared is adjusted to a pH of about 3.3 to 5 by the addition of acetic or hydrochloric acid. The size has a viscosity of about 1 to 20 centipoises at 20 C. and a solids content of about 4 to 7.5 percent by weight of the size as shown in the examples.

When glycerine is employed in the size, it is added prior to the addition of the Pureco oil. This is accomplished by just pouring it into the cooked starch-amine reaction product and mixing it therewith. The gelatin is dispersed in water at 140 F. with vigorous agitation and it also is added to the gelatinized starch-amine reaction product prior to the addition of the Pureco oil. Elvanol (polyvinyl alcohol sold by du Pont) is dissolved inwater at 140 F. and is added in the size preparation right after the Pureco oil.

Example 11 The following is an example of a size formulation utilizin a reaction product of starch and an alkylene imine. The hydroxyethyl ether of corn starch is reacted in the manner described in Example I with 30 percent by weight-of ethylene imine based upon the weight of, the hydroxyethyl ether of corn starch. A size is prepared in the same manner as in Example I utilizing the following ingredients:

Ingredient: Parts by Weight Starch-ethylene irnine reaction product 800. Hydrogenated vegetable oil 410.5. Wetting agent (T-ween 81) 40.9. Softener (Cation X) 44.3. Glycerine 80.0. Formaldehyde 17 cubic centimeters per gallon size mix.

Example III A size utilizing the reaction product of corn starch and 5 percent by weight of propylene imine based upon the weight of the corn starch is prepared in the same manner as set forth in Example ll.

6 Example IV The following is an example of a size formulation utilizing a reaction product of starch and an alkyl amino epoxide. Sago starch is reacted in the same manner as set forth in Example I with 10 percent by weight of 3- dibutyl amino 1,2-epoxy propane based upon the weight of the sago starch. The size is prepared in the same manner as described in Example I utilizing the following ingredien-ts:

Ingredient: Parts by weight Sago starch-epoxide reaction product 780. Pureco oil 322. Tween 81 32. Cation X 68.

Gelatin 5. Polyvinyl alcohol 7. Formaldehyde 17 cubic centimeters per 5 gallon size mix.

Example V The following is an example of a size formulation utilizing a reaction product of starch and an amino alkyl anhydride. Potatostarch is reacted in'the same manner as set forth in Example I with 20 percent by weight of isatoic anhydride based'upo-n the weight of the potato starch. The size is prepared in the same manner as described in Example I utilizing the following ingredients:

Example VI A size utilizing the reaction product of corn starch and 10 percent by weight of quinoline anhydr-ide based upon the weight of the corn starch is prepared in the same mannor as set forth in Example V.

Example VII The following is an example of a size formulation utilizing a reaction product of starch and an alkyl amino anhydride. Tapioca starch is reacted in the same manner as set forth in Example. I with 3 percent by weight of b-dimethyl amino isoprcpyl chloride based upon the weight of the tapioca starch. The size is prepared inthe same manner as described in Example I utilizing the following ingredients:

Ingredient: Parts by weight tarch-alkyl amino halide reaction product 1000.

Pureco oil 308.

Tween 81 40.9. Cation X -Q 44.3.

Formaldehyde 17 cubic. centimeters per 5 gallon size Example "VIII The following is an example of a size formulation utilizing a reaction product of starch and an alkyl amino halide which is difierent from that set forth in Example V. Corn starch, which is acid-converted to a degree known in the trade as 60 fluidity, is reacted in the same manner as set forth in Example I with 0.5 percent by weight of b-dimethyl amino ethyl chloride based upon the weight of corn starch. The size is prepared in the same manner as described in Example I utilizing the following ingredients:

Ingredient: Parts by weight Corn starch 780. Pureco oil 322.

Tween 81 32. Cation X 68.

Gelatin 5.

Polyvinyl alcohol 7. Formaldehyde 17 cubic centimeters per gallon size mix. Example IX Potato starch is reacted with 1 percent by weight of 2- bromo-S-diethyl amino pentane hydrobromide based upon the weight of the potato starch. The size is prepared in the same manner as described in Example I utilizing the following ingredients:

Ingredient: Parts by weight Potato starch arnino reaction product 600 Pureco oil 410 'Tween 81 40.9 Cation X 88.6

Glycerine 100 Example X A starch-amine reaction product suitable for use in the invention is prepared in the manner set forth in Example I by reacting waxy maize starch with 25 percent by weight of N-(2,3 epoxypropyl) piperidine based upon the weight of the waxy maize. The size is prepared in the same manner as described in Example I utilizing the following ingredients:

Ingredient: Parts by weight Waxy maize 910. Pureco oil 210.

Tween 81 21. Cation X 44.

Gelatin 5. Polyvinyl alcohol 11. Formaldehyde 17 cubic centimeters per 5 gallon size mix. Example XI A size utilizing the reaction product of rice starch and 30 percent by weight of N,N-(2,3 epoxypropyl methyl aniline) based upon the weight of the rice starch is prepared in the same manner as set forth in Example X.

The size is added to the fibers during their forming while it is at an elevated temperature, i.e. 125 to 135 F for example about 130 F. This is necessary in order to keep all of the ingredients of the size, especially the hydrogenated vegetable oil and the starch-amine reaction product, uniformly dispersed in the size. If the size is allowed to cool to, say for example room temperature, these ingredients tends to separate from the size. The

method of adding the size to the strands and an analysis of the amount of size on the strand after forming and conditioning is further described in conjunction with a description of the drawings in which:

FIG. 1 is a diagrammatic elevation of a continuous filament, glass fiber strand operation; and

FIG. 2 is a graph illustrating the improvement of the present invention over-the prior art with respect to size migration in the forming package.

In FIG. 1 of the drawing there is shown a glass melting furnace or forehearth thereof containing a supply of molten glass 11 and having an electrically heated, platinum alloy bushing 13 attached to the bottom of the furnace. The bushing is provided with a series of orifices in the form of tips 14 through which the glass flows and forms in small inverted cones 15 suspended from the bottoms of the tips 14. The tips are usually formed in a number of rows, for example, 4 to 20 or more rows, having a great many tips in each row so that the total number of tips is about 200 to 400 or more in number.

Glass filaments 16 are pulled from the cones of glass 15 at a very high rate of speed, i.e., 5,000 to 20,000 feet per minute, and wound on the rapidly rotating forming tube 18. The glass filaments are grouped into a strand 22 as they pass over the guide 24 prior to their being wound on the tube 18. As the strand 22 is wound on the tube 18, it is rapidly traversed by means of traverse 26. The size is applied to the individual filaments in the strand prior to the time they pass over the guide. The

size is supplied to a reservoir 28 which has a rotating roller or belt 30 mounted so as to dip into the size in the reservoir. The size is transferred from the rotating roller or belt to the filaments as the filaments pass over the surface of the wetted roller or belt. A suitable size applicator is shown in US. Patent No. 2,873,718.

The sizes of the present invention are easily applied to the strand during its formation and the strand forming proceeds smoothly. After each forming package containing about 3.5 pounds of 150 strand is'formed (204 filaments having a diameter such that there are 15,000 yards to the pound of strand), the forming tube and package are removed from the winder and the end of the strand is found onthe forming package. The forming package, containing about 9 percent by weight moisture, is then allowed to sit in an atmosphere of about 75 to 85 F. and to percent relative humidity for about 21 hours in order to reduce the moisture content on the strand to a range of about 5 to 7 percent by weight. Thereafter the strand is removed from the. forming package and twisted into yarn. Glass fiber strand having glycerine in its size is easier to end-find than strand without the glycerine in its size. The twisting is accomplished on conventional textile apparatus with very few broken filaments. The twisted yarn is.

warped or transferred onto quills for weaving, and the yarn weaves very well with very few broken filaments. The woven material can be heat treated satisfactorily. The heat treated fabrics woven from yarn having glycerine in its size are'slightly less brittle and more crease resistant than heat treated fabrics woven with yarn coated with a size not having the glycerine.

In FIG. 2, the graph shows the size solids content of the strand in the forming package produced according to the present invention as compared with. the prior art. The ordinate shows the percent of size solids on the strand after 21 hours conditioning at 45 to 55 percent relative humidity and to degrees F. The abscissa shows the number of yards of strand as it is removed from the outside to the inside of the forming package. The dotted line represents the amount of solids of a conventional dextrinized corn starch-vegetable oil size and the solid line representsthe amounts of solids of the starch-amine reaction product size described in this invention "as illustrated by sizeNo. 5 of the table in Example I at'various points along .the strand in the forming package after conditioning as described above.

It Will be noted from this that virtually no size migraing steps, the strand (or yarn) handles well and there are very few filaments broken during these fabricating steps. The yarn as sized according to the method de scribed above is exceptionally useful for bulking by means of the texturing air jet described in the abovementioned patent. The uniformity of size content on the yarn permits uniform conditions in the texturing operation and the production of acceptable textured yarn. The size does not blow off of the yarn during the texturing as does the conventional dextrinized corn starch-oil size. Heat treated fabrics Woven from twisted strand formed in accordance with the present invention are free from the appearance defects discussed above which are due to size migration in the strand forming package.

In various trials of the invention different amounts of the various ingredients were used in the size. Water makes up about 91 to 96 percent by weight of the size. The starch-amine reaction product makes up about 4 to 7 percent by weight of the size, preferably about percent by Weight of the size. The lubricant is present in the size in amounts of 25 to 70 percent by weight of the starch-amine reaction product, preferably about 45 percent by weight of the starch-amine reaction product.

Various textile softeners which are equivalent to Cation X can be employed in the size in amounts which are sufficient to provide a softening action to the sized strand, such amounts being for example 4 to 15 percent by weight of the starch-amine reaction product, preferably about percent by weight of the starch-amine reaction product. Suitable textile softeners are alkyl imidazoline derivatives such as described in US. Patents Nos. 2,200,815; 2,267,965; 2,268,273 and 2,355,837. The Cation X is an example of such a material wherein the alkyd imidazoline derivative is the reaction product of stearic acid, tetraethylene pentamine and acetic acid. A stearic acid-chromic chloride complex sold by du Pont under the tradename Quilon may serve as a softener. An acid solubilized water dispersible stearic amide, an anhydrous acid solubilized, water dispersible lower molecular weight fatty acid amide or an anhydrous acid solubilized polyunsaturated, lower molecular Weight fatty acid amide may be used as :a softener. Some of these softeners also serve as wetting agents, for example the alkyl imidazoline derivatives.

Likewise, various wetting agents similar to Tween 81 may be employed in the size in sufficient amount to permit adequate wetting of the sizing ingredients to the glass surface; suitable amounts ranging from 8 to 13 percent by weight of the lubricant, preferably about 10 percent by weight of the lubricant. cetyl or stearyl monoarnine hydrochloride or acetate, dodecylamine, hexadecylamine and secondary and tertiary derivatives of the same, for example, dodecylmethylamine and salts thereof. Quaternary ammonium compounds such as trimethyl stearyl or cetyl amonium bromides and chlorides and generally any of the amine compounds that dissociate in water systems to provide a positive radical containing a group of more than 8 and preferably 12 or more carbon atoms may be used. These materials are cationic active substances. Non-ionic wetting agents may also be used. They are not as active as cationic wetting agents and therefore must be used in greater amounts to provide the same degree of wetting. Examples of suitable non-ionic wetting agents include polyalkylene oxide derivatives of esters, fatty acids, fatty alcohols, fatty amides, alkyl phenyl ethers and other derivatives.

A fungicide, such as formaldehyde, is usually used in sufficient amount to prevent mold attack on the starchamine reaction product. Suitable effective amounts of the fungicide are about 3 milliliters to one gallon of the size. I

Glycerine is believed to serve as a plasticizer for the starch-amine reaction roduct. The glycerine is preferably present in amounts of about 5 to 20 percent by weight of the starch-amine reaction product, preferably about 10 Suitable wetting agents include i percent by weight of the starch-amine reaction product. Glycerine has been found to be useful in the size in order to make end-finding of the strand easier and to lessen the brittleness of the strand.

The combination of gelatin and polyvinyl alcohol in the size is desirable because of the added film strength properties which these materials impart. The ratio of polyvinyl alcohol to gelatin when used in combination ranges from about 1:1 to 2:1. The combined amount of gelatin and polyvinyl alcohol in the size is about 0.1 to 0.2 percent by weight of the starch-amine reaction product.

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

We claim:

1. A method of forming glass fibers which comprises drawing glass filaments from a molten supply of glass at a high rate of speed, gathering the filaments and combining them into a strand, applying an aqueous size to the filaments as they are being drawn, said size being at an elevated temperature at the time of application and consisting essentially of an aqueous dispersion containing about 4 to 7 percent by weight of a starch-amine reaction product selected from the class consisting of starchamine reaction products having the following structural formulae:

wherein X is starch, R is a radical selected from the group consisting of substituted alkyl, hydroxyalkyl, acyl, and aroyl radicals, and each of R and R is a radical selected from the group consisting of hydrogen, alkyl, and aralkyl radicals, and

lsY

wherein X is starch, R is a radical selected from the group consisting of substituted alkyl, hydroxyl alkyl, acyl and aroyl radicals, and each of R and R is a radical selected from the group consisting of hydrogen, alkyl and aralkyl radicals and where R, is a radical selected from the group consisting of hydrogen and alkyl radicals, and Y is a radical selected from the group consisting of chloride, bromide and iodide radicals, about 25 to 70 percent by weight of a lubricant based upon the weight of the starchamine reaction product and an efifective amount of a fungicide, said size having a viscosity of about 1 to 20 centipoises at 20 C., winding the sized strand on a rapidly rotating forming tube and conditioning the strand wound on the forming tube to reduce the moisture content of the strand to that amount which is acceptable for twisting the strand into yarn on conventional textile twisting apparatus.

2. The method as described in claim 1 wherein the size contains 8 to 13 percent by weight of a Wetting agent based upon the weight of the lubricant and 4 to 15 percent by weight of a textile softener based upon the weight of the starch-amine reaction product.

3. The method as described in claim 1 wherein the size contains 5 to 20 percent by weight of a plasticizer for the starch-amine reaction product based upon the Weight of the starch-amine reaction product.

4. The method as described in claim 1 wherein the size contains about 0.1 to 0.2 percent by weight of gelatin and polyvinyl alcohol, based upon the weight of the starchamine'reaction product, with the Weight ratio of polyvinyl alcohol to gelatin ranging from about 1:1 to 2:1.

5. The method as described in claim 1 wherein the size contains 8 to 13 percent by weight of a wetting agent based upon the Weight of the lubricant, 4 to 15 percent by weight of a textile softener based upon the Weight of the l 1 starch-amine reaction product, 5 to 20 percent by Weight of a plasticizer for the starch-amine reaction product based upon the weight of the starch-amine reaction product and 0.1 to 0.2 percent by Weight of gelatin and polyvinyl alco hol based upon the weight of the starch-amine reaction product, with the Weight ratio of polyvinyl alcohol to gelatin ranging from about 1:1 to 2:1.

6. A strand produced according to the method of claim 1.

7. A strand produced according to the method of claim 2.

8. A strand produced according to the method of claim 3.

9. A strand produced according to the method of claim 4.

- 10. A strand produced according to the method of claim 5.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. A METHOD OF FORMING GLASS FIBERS WHICH COMPRISES DRAWING GLASS FILAMENTS FROM A MOLTEN SUPPLY OF GLASS AT A HIGH RATE OF SPEED, GATHERING THE FILAMENTS AND COMBINING THEM INTO A STRAND, APPLYING AN AQUEOUS SIZE TO THE FILAMENTS AS THEY ARE BEING DRAWN, SAID SIZE BEING AT AN ELEVATED TEMPERATURE AT THE TIME OF APPLICATION AND CONSISTING ESSENTIALLY OF AN AQUEOUS DISPERSION CONTAINING ABOUT 4 TO 7 PERCENT BY WEIGHT OF A STARCH-AMINE REACTION PRODUCT SELECTED FROM THE CLASS CONSISTING OF STARCHAMINE REACTION PRODUCTS HAVING THE FOLLOWING STRUCTURAL FORMULAE: X-O-R-N(-R1)-R2 WHEREIN X IS STARCH, R IS A RADICAL SELECTED FROM THE GROUP CONSISTING OF SUBSTITUTED ALKYL, HYDROXYALKYL, ACYL, AND AROYL RADICALS, AND EACH OF R1 AND R2 IS A RADICAL SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, ALKYL, AND ARALKYL RADICALS, AND X-O-R-N(-R1)(-R2)-R3-Y WHEREIN X IS STARCH, R IS A RADICAL SELECTED FROM THE GROUP CONSISTING OF SUBSTITUTED ALKYL, HYDROXYL ALKYL, ACYL AND AROYL RADICALS, AND EACH OF R1 AND R2 IS A RADICAL SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, ALKYL AND ARALKYL RADICALS AND WHERE R3 IS A RADICAL SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND ALKYL RADICALS, AND Y IS A RADICAL SELECTED FROM THE GROUP CONSISTING OF CHLORIDE, BROMIDE AND IODIDE RADICALS, ABOUT 25 TO 70 PERCENT BY WEIGHT OF A LUBRICANT BASED UPON THE WEIGHT OF THE STARCHAMINE REACTION PRODUCT AND AN EFFECTIVE AMOUNT OF A FUNGICIDE, SAID SIZE HAVING A VISCOSITY OF ABOUT 1 TO 20 CENTIPOISES AT 20*C., WINDING THE SIZED STRAND ON A RAPIDLY ROTATING FORMING TUBE AND CONDITIONING THE STRAND WOUND ON THE FORMING TUBE TO REDUCE THE MOISTURE CONTENT OF THE STRAND TO THAT AMOUNT WHICH IS ACCEPTABLE FOR TWISTING THE STRAND INTO YARN ON CONVENTIONAL TEXTILE TWISTING APPARATUS.

6. A STRAND PRODUCED ACCORDING TO THE METHOD OF CLAIM 1.