US2576915A - Method of sizing yarns and composition therefor - Google Patents

Description

. Patented Dec. 1951 METHOD OF SIZING YARNS AND COMPOSITION THEREFOR Gerald R. Barrett, Winchester, Mass., assignor to Monsanto Chemical Company, St. Louis, Mo., a

corporation of Delaware No Drawing. Application April 29, 1948 Serial No. 24,112

14 Claims. (Cl. 2613-29-6) The present invention relates to improvements in the art of sizing polyamide yarns such as nylon yarns. It also relates to improvements in the art of sizing other textile yarns which stretch or elongate when subjected to a relatively slight stress or strain inherent in loom operation and which almost immediately return to their original length after such stress or strain is removed.

One of the difliculties heretofore experienced in the weaving of sized polyamide yarns such as sized nylon warps is that the size tends to shed or dust from the yarns. The extent to which the size sheds or dusts varies depending upon the size employed, but this phenomenon is common to all of-th commercially known nylon sizes as, for example, starch, gelatine, polyvinyl alcohol and the like. The dusting or shedding of size from nylon yarns during the weaving operation is objectionable for several reasons, among these being the creation of dust and other-undesirable conditions in the ,weave shed. However, one of the most important objections is that the yarn loses part of its protective coating and is subject to damage by the mechanical moving parts of the loom as, for example, the heddles, etc. The damage referred to is generally of two types, namely-:' (1) yarn breakage which causes a loom stoppage, or (2) yarn defects such as stripped back filaments, thin yarns and the like which appear as defects in the finished cloth. Yarn breakage during weaving decreases the efiiciency of the loom in respect to fabric production per unit of time and can only be remedied by constant supervision and the use of adequate personnel to repair the breaks quickly. This in turn renders the operation of the weave shed less efiicient and less economical. Yarn defects of the type described above are usually readily apparent in the finished fabric and may require a down grading of the fabric on inspection, i. e., classifying the fabric as second quality.

In accordance with the present invention the above described difficulties are substantially eliminated and the weaving efliciencyof nylon warp yarns and other textile yarns of similar elastic characteristics is markedly improved.

One object of the present invention is to provide an improved and efiicient sizing composition for nylon yarns and for other textile yarns having elastic characteristics similar to nylon yarns.

A further object of the invention is to provide a sized nylon yarn or other textile yarn which has elastic properties similar to nylon yarns, which sized yarn is characterized by a tough, smooth size coating which is substantially free of loom yarns and at the same time materially increasing the quantity of first quality fabric which can be produced from such yarns.

Still further objects and advantages of the invention will appear from the following description and the appended claims.

The ob ects of the invention, in general, are attained by first applying to the naked or presized nylon yarn or other textile yarn having elastic characteristics similar to nylon yarn a Water solution comprising essentially a watersoluble or dispersible alkali-metal salt of a copolymer Of an ethylene a,p-dicarboxyllc acid or anhydride or an alkyl acid ester of such acid or anhydride and preferably those alkyl acid esters having not more than 3 carbon atoms in the alkyl group, or combinations thereof, with styrene or a substituted styrene such as nuclear substituted methyl styrene, dimethyl styrene, chloro styrene, dichloro styrene or the like; and a polyalkylene glycol which is capable of plasticizing suchcopolymeric salt, preierably a polyethylene glycol having the general formula:

where a: is an integer from 3 to 9. After the sizing solution, which 15 generally maintained at elevated temperatures, is applied to the textile yarns in suitable manner as, for example, by passing the warp yarns through a conventional size box contaimng such solution, the sized yarns are dried in a suitable manner, that is, rendered nontacky, preferably by passing them over heated drying cans of the type conventionally employed in warp slashing operations.

The nylon yarns or other yarns which have elastic properties similar to nylon yarns which are sized by such procedure have a tough, elastic and smooth size coating thereon which does not substantially dust or shed when the yarns are subsequently woven in a loom at 50 to relative humidity. Moreover, such size coating is easily removed from the yarns by washing the woven goods in warm water. In addition, the woven fabrics prepared in the manner described contain fewer defects than fabrics woven from similar yarns which have been sized with commerically known sizes of the prior art and more first quality fabric is thus produced by carrying primary importance in increasing the weaving.

efliciency of other multifilament yarns and spun yarns which stretch or elongate under relatively slight stress or strain and which quickly return substantially to their original length when such stress or strain is alleviated. As examples of such yarns are multifilament yarns spun from solutions comprising copolymers of vinyl chloride and vinyl acetate, polyvinylidene chloride, copolymers of vinylidene chloride and vinyl chloride and the like, or spun yarns which are made from staple fibers prepared from such copolymers or polymers.

The water-soluble or dispersible copolymeric salts employed in the practice of the invention may be prepared in various ways. In general, they are prepared by first forming a copolymeric material by the conjoint polymerization of an ethylene c,;3-dicarboxylic acid or anhydride such as maleic acid, fumaric acid, maleic anhydride and the like, or alkyl acid esters thereof such as methyl acid maleate, methyl acid fumarate, ethyl acid maleate, ethyl acid fumarate, isopropyl acid maleate, propyl acid maleate and the like or mixtures of such compounds with styrene 01' a similar polymerizable vinyl aromatic hydrocarbon of the type hereinbefore described in a molal ratio of about 1:1.0 to 2, preferably a molal ratio of about 121.0 to 1.5 and then reacting the resulting product with an alkali base such as NaOH, KOH, LiOI-I or the like, preferably by adding the copolymer to an aqueous solution of such alkali metal base.

When such copolymer is prepared by the wellknown mass polymerization method the polymerizable components are copolymerized at temperatures between about 100 to 300 F. for several hours. The copolymer is obtained in the form of a hard, glassy resin which is then converted to a salt by adding it to an aqueous solution containing a quantity of alkali metal base suflicient to dissolve the copolymer.

Another method which may be used to prepare such copolymeric materials is known as the solvent-non-solvent process which involves copolymerizing the above described components in the presence of a solvent such as xylene, benzene and the like which is capable of dissolving both of the starting materials, but not the copolymeric material. This reaction is usually carried out at the boiling point of the solvent. The copolymer, which is precipitated during the reaction, is separated from the solvent and unreacted monomers by filtration, centrifuging or the like and is then dried. The alkali metal salt of this copolymer is then prepared as hereinbefore described.

In a preferred embodiment of the invention the copolymeric material employed is prepared by copolymerizing maleic anhydride and a small proportion of methyl acid maleate, preferably from about 0.05 to 50% by weight based on the maleic anhydride, and styrene in essentially equimolecular proportions by one of the foregoing methods, and then reacting the product with an alkali metal base, preferably aqueous NaOH or KOH solutions or mixtures thereof, to form a water-soluble material.

It has now been found that when such copolymeric salts are plasticized with certain polyalkylene glycols in a water solution that a sizing composition is formed which is particularly useful in the sizing of nylon yarns and other textile yarns having elastic properties similar to nylon yarns. In general, polyalkylene glycols which have a high boiling point, that is, those which boil above about 290 C. at atmospheric pressure and which are water-soluble or soluble in an aqueous solution of the copolymeric salt are useful for plasticizing such copolymeric salt. Those which are particularly useful in this connection are the polyethylene glycols having the general formula:

where :z: is a positive integer from 3 to 9. As examples of these are tetraethylene glycol, hexaethylene glycol, octaethylene glycol, nonaethylene glycol and the like or mixtures thereof. It is also possible to use polypropylene glycols which have the general characteristics described above for plasticizing the copolymeric salts hereinbefore described. It has also been found that sugars and sugar alcohols such as dextrose, sucrose mannitol, sorbitol and the like or watersoluble derivatives thereof may be used to modify the above described polyglycol plasticizers and thus decrease the quantity of such plasticizer required. Such sugars and sugar alcohols, however, are not, generally, plasticizers per se for the copolymeric salts employed herein.

The sizing compositions used in the practice of the invention are employed as aqueous compositions. Such sizing compositions generally comprise from about 2 to 10% of such copolymeric salt and from about 40 to 100% by weight, based on said copolymeric salt, of a polyalkylene glycol plasticizer therefor, the remainder being water. However, suitable adjuvants may also be used in such sizing compositions and as examples of these may be mentioned wetting agents, softening agents and the like. In general the quantity of copolymeric salt applied to the yarn depends upon the construction of the yarn as, for example, the number'of filaments, the twist, the denier of the yarn, etc., and whether the yarn has been presized. A particularly suitable sizing composition for nylon yarn comprises from about 5 to 8% by weight of the sodium salt of the copolymer of styrene, maleic anhydride and methyl acid maleate in the amount of about 10 to 30% based on the maleic anhydride, the maleic components and styrene being copolymerized in the molal ratio of about 1:1, and from about 60 to by weight, based on said sodium salt, of a polyethylene glycol having the general formula:

where a: is an integer from 3 to 9. In general, the quantity of polyalkylene glycol plasticizer used will depend upon the copolymeric salt employed and the nature of the plasticizer. For example, the quantity of polyethylene glycol used will depend upon the polymerizable components in the copolymer and, whether the alkali metal salt thereof is the lithium salt, the sodium salt or the potassium salt since each of these copolymeric salts will require varying amounts of such plasticizer in order to be an eifective size for nylon yarns.

In the sizing of nylon yarns any conventional sizing apparatus or means may be employed for applying such sizing compositions to the warp yarns. One procedure for carrying out application of the size is to first pass a large number of unsized or presized nylon warp ends, which have been wound on a beam, through a conventional size box which contains the above described sizing compositions. The sizing composition or solution is generally maintained at a temperature of about 130 to 150 F. The warp yarns are then passed through squeeze rolls to remove excess sized yarn ends are then taken up on a beam or suitable take-up device and are ready for the weaving operation. By using this procedure from about 1 to of copolymeric salt is applied to the yarn depending upon the concentration of the composition and the percent pick-up. Normally a pick-up of 70 to 100% is efiected.

Although the above described sizing apparatus is most commonly used commercially for the sizing of nylon yarns, other sizing procedures and apparatus can be suitably adapted for applying the sizing compositions described herein. Moreover, such sizing compositions can be applied at any convenient and practical stage of the yarn manufacturing operation. Thus, the sizing compositions may be applied after the yarn has been twisted by passing the yarn through the size solution or over rollers or surfaces of a suitable device wherein the rollers or surfaces are coated with the sizing composition. The sized yarn is then suitably dried until it is non-tacky and then packaged. Another method of sizing is to dip the yarn while in the form of a skein in the sizing composition and then dry it until it is non-tacky. Still another method is to unwind the yarn from a package, pass it through the sizing composition or over rollers coated therewith after which it is dried until it is non-tacky and then taken up on another package. It is obvious that other methods of sizing may be employed in addition to those described.

'Most nylon weaving mills operate their looms in weaving sheds where the relative humidity of the air is maintained at about 60 to 65%. When nylon yarns which have been sized in accordance with the present invention are woven into fabrics under such conditions there is substantially no shedding or dusting of the size or weaving defects in the finished goods, that is, thin yarns, stripped back filaments, knots, etc., in the fabric are substantially eliminated with the result that a very high percentage of the woven fabric is first quality.

A further understanding of the advantages of the present invention will be obtained from the following examples which are intended to be illustrative, but not limitative of the scope of the invention, parts and percentages being by weight unless otherwise specified.

EXAMPLE I 1. Preparation of copolymeric'salt Three-tenths molecular proportion of methanol was reacted with '1 molecular proportion of maleic anhydride at a temperature of about 65 C. until a constant acid value (as determined by titration) was obtained on continued heating. This product was then copolymerized with 1.1 molecular proportion of styrene, in which reaction the temperature 'was maintained at,about '65" C. during the period of rapid heat evolution and the temperature was then raised to about C. to complete the reaction. Eighteen parts of the resulting copolymeric material, which was obtained in the form of a hard, glassy resin, was dissolved in 279 parts of water containing 5 parts of NaOH which resulted in a solution having a copolymeric salt content of about 7%.

2. Sizing of nylon warp I To 200 parts of the above solution were added 9.8 parts ofcommercial tetraethylene glycol and 80 parts of water and this solution was poured in a conventional size box of a nve can silk slasher and malntamed at a temperature of about F. Three thousand seven hundred and forty ends comprising 2100 yards of 70/34/202 unsized (naked) nylon (polyhexamethylene adipamide) marquisette warp were passed through the sizing solution at the rate of 30 yards/mmute thence through squeeze rolls and finally over the drying cans whicnwere generally maintained at a temperature of 150160-1'l0--16015o" F. The sizing was accomplished without the use of split rods and without stretching the yarn. The sized warp in which the individual yarns remained well separated was taken up on a conventional beam. After sizing, the drying cans were inspected and were found to be substantially free of size accumulation.

This sized warp was woven in a conventional loom at a relative humidity of 60% without appreciable shedding or dusting of the size and the weaving efliciency of the sized yarns was excellent. Moreover, the number of loom stoppages normally encountered in weaving sized nylon yarns was materially reduced. The finished fabric was graded as a first quality material. The size on the finished fabric was easily removed by washing the fabric in warm water.

EXAMPLE II A size solution was prepared as described in Example I and was then diluted with an equal quantity of water. This size solution was poured into the conventional size box of a five can silk slasher and maintained at a temperature of 150 F. Six thousand, four hundred and eight ends comprising 572 yards of 40/34/7 nylon (polyhexamethylene adipamide) yarn (presized with polyvinyl alcohol) were passed through this sizing solution at the rate of 25 yards/minute, thence through conventional squeeze rolls and finally over the drying cans which were generally maintained at a temperature of l60-170-- -170-150 F. The sizing was accomplished without the use of split rods and without stretching the yarn. The sized warp in which the individual yarns remained well separated was taken up on a conventional beam. After sizing, the drying cans were inspected and were found to be substantially free of size acprocedure was easily removed by washing the fabric 'in warm water.

EXAMPLE III 1. Preparation of copolymeric salt Five-tenths molecular proportion of isopropyl alcohol, 0.3 molecular proportion of methanol and 1 molecular proportion of maleic anhydride were reacted at a temperature of about 70 C. until the reaction mixture attained a constant acid value (as determined by titration) on continued heating. This mixture was copolymerized with about 1.25 molecular proportions of styrene, in the presence of .002 molecular proportion of benzoyl peroxide and at a temperature of about 70 C. during the period of rapid heat evolution. The temperature was then raised to about 120 C. to complete the reaction. On cooling the reaction mixture, a hard, glassy resin was obtained. Nineteen parts of this resin or copolymer was dissolved in 298 parts of water containing 5 parts of KOH. The resulting solution contained about 7% by weight of copolymeric salt.

2. Sizing of nylon warp yarns The above composition was diluted with water until it contained about 5% by weight of copolymeric salt. Fifty per cent by weight, based on the copolymeric salt, of commercial hexaethylene glycol was added to the aqueous copolymeric salt solution and dissolved therein. A warp of 70/34/202 unsized nylon (polyhexamethylene adipamide) yarn was passed through this composition which was maintained at 140 F., thence through squeeze rolls and finally over drying cans which were maintained at about 170 F. Sizing was accomplished without the use of split rods and without stretching the yarn. The warp yarns remained well separated during the sizing operation and were beamed after leaving the drying cans.

The sized warp was thenwoven into a fabric on a conventional loom at a relative humidity of 60% and there was no appreciable shedding or dusting of the size during the weaving operation. Moreover, the number of loom stoppages was markedly reduced in contrast to the normal number of loom stoppages encountered when weaving nylon warps which have been sized with prior art sizing agents. The woven fabric was substantially free of defects such as knots, thin yarns and strip backed filaments.

EXAMPLE IV 1. Preparation of copolymeric salt About 1 molecular proportion of styrene and 1 molecular proportion of maleic anhydride were copolymerized. The temperature of the reaction mixture was maintained at about 60 C. during the period of rapid heat evolution and was then raised to 125 C. to complete the reaction. On

- cooling the reaction mixture a hard, glassy resin was obtained. Eighteen parts of this resin was dissolved in 279 parts of water containing 5.5 parts of NaOH. The copolymeric salt content of this solution is about 7% by weight.

'2. Sizing of nylon yarns To 200 parts of the above aqueous copolymeric salt solution were added 80 parts of Water and 11.2 parts of commercial hexaethylene glycol. The resulting solution was poured into a conventional size box of a five can silk slasher and was maintained at 140 F. during the subsequent r 70/34/20Z of unsized nylon (polyhexamethylene adipamide) yarn were sized with the above composition using the procedure described in Example I. After the warp was sized, the drying cans were inspected and found to be substantially free of size accumulation.

The sized warp was woven into a fabric on a conventional loom at a relative humidity of 65% without appreciable dusting or shedding of the size. The woven fabric was substantially free of defects such as broken ends, thin yarns and stripped-back filaments.

Moreover, the number of loom stoppages normally encountered in the weaving of sized nylon warps was markedly reduced.

What is claimed is:

1. A method of sizing nylon yarn and other textile yarn having elastic characteristics similar to nylon yarn whereby the sized yarn is characterized by a tough, smooth coating which does not substantially shed or dust during a subsequent weaving operation, which comprises applying to said yarn an aqueous solution comprising (1) an alkali metal salt of a copolymer of ethylene from the group consisting of maleic acid, fumaric acid, maleic anhydride and alkyl acid esters thereof, in which the alkyl group contains from 1 to 3 carbon atoms, and mixtures thereof with a polymerizable vinyl aromatic hydrocarbon se lected from the group consisting of styrene, methyl styrenes and chloro styrenes and (2) a. polyalkylene glycol plasticizer for said alkali metal salt selected from the group consisting of polyethylene glycols and polypropylene glycols, and drying said yarn preparatory to weaving same.

2. A method of sizing nylon yarn and other textile yarn having elastic characteristics similar to nylon yarn whereby the sized yarn is charac-- terized by a tough, smooth coating which does not substantially shed or dust during a subsequent weaving operation, which comprises applying to said yarn an aqueous solution comprising (1) an alkali metal salt of a copolymer of ethylene a,e-dicarboxylic compounds selected from the group consisting of maleic acid, fumaric acid, maleic'anhydride and alkyl acid esters thereof, in which the alkyl group contains from 1 to 3 carbon atoms, and mixtures thereof with styrene and (2) a polyalkylene glycol plasticizer for said alkali metal salt selected from the group consisting of polyethylene glycols and polypropylene glycols, and drying said yarn preparatory to weaving same.

3. A method of sizing nylon yarn prepared from polyhexamethylene adipamide whereby the sized yarn is characterized by a tough, smooth coating which does not substantially shed or dust during the subsequent weaving operation, which comprises applying to said yarn an aqueous solution comprising (1) an alkali metal salt of the copolymer of maleic anhydride, a minor proportion of methyl acidmaleate and styrene and (2) a polyethylene glycol plasticizer for said alkali metal salt having the general formula:

where a: is an integer from 3 to 9, and drying said yarn preparatory to weaving same,

4. A method of sizing nylon yarn prepared from polyhexamethylene adipamide whereby the sized yarn is characterized by a tough, smooth coating which does not substantially shed or dust during the subsequent weaving operation, which coma,fl-dicarboxylic compounds selected 4 prises applying to said yarn an aqueous solution comprising (1) from about 2 to by weight of an alkali metal salt of a copolymer of styrene, maleic anhydride and a minor proportion of methyl acid maleate and (2) from about 40 to 100% by weight, based on said alkali metal salt, of a polyethylene glycol plasticizer therefor having the general formula:

where x is an integer from 3 to 9, and drying said yarn preparatory to weaving same.

5. A method of sizing nylon yarn prepared from polyhexamethylene adipamide whereby the sized yarn is characterized by a tough, smooth coating which does not substantially shed or dust during the subsequent weaving operation which comprises applying to said yarn an aqueous solution comprising (1) from about 2 to 10% by weight of the sodium salt of a copolymer of maleic anhydride, a minor proportion of methyl acid maleate and styrene and (2) from about 60 to 80% by weight, based on said sodium salt, of a polyethylene glycol plasticizer therefor having the general formula:

where :c is an integer from 3 to 9, and drying said yarn preparatory to weaving same. a

6. A sizing composition for nylon yarns and other textile yarns having elastic properties simi-l.

lar to nylon yarns comprising an aqueous solu: tion of (1) an alkali metal salt of a copolymer of an ethylene 8-dicarboxylic compound selected from the group consisting of maleic acid, fumaric acid, maleic anhydride and alkyl acid esters thereof, in which the alkyl group contains from 1 to 3 carbon atoms. and mixtures thereof with a polymerizable vinyl aromatic hydrocarbon se where a: is an integer from 3 to 9. j,

8. A sizing composition for nylon yarns com; prising an aqueous solution of 1) an alkali metal salt of a copolymer of styrene and maleic an;- hydride and (2) a polyethylene glycol plasticizer for said alkali metal salt having the general where a: is an integer from 3 to 9.

9. A sizing composition for nylon yarns cemprising an aqueous solution of (1) a sodium salt of a copolymer of styrene, maleic anhydride'and a minor proportion of methyl acid maleate'and ('2) a pohrethylene glycol plasticizer for said copolymer salt having the general formula:

HO-CH2-(CH2OCH3)r-CH2Ofi where a: is an integer from 3 to 9.

'10. A nylon yarn and other textile yarn having elastic properties similar to nylon yarn coated with an alkali metal salt of a copolymer of ethylene ,s-dicarboxylic compounds selected from the group consisting of maleic acid, fumaric acid, maleic anhydride and alkyl acid esters thereof, in which the alkyl group contains from 1 to 3 carbon atoms, and mixtures thereof with a polymerizable vinyl aromatic hydrocarbon selected from the group consisting of styrene, methyl styrenes and chloro styrenes, which salt includes a polyalkylene glycol plasticizer therefor selected from the group consisting of polyethylene glycols and polypropylene glycols.

11. A nylon yarn prepared from polyhexamethylene adipamide and coated with an alkali metal salt of a copolymer of styrene, maleic anhydride and a minor proporton of a methyl acid maleate, which salt includes a polyethylene glycol plasticizer therefor having the general formula:

where :c is an integer from 3 to 9.

12. A nylon yarn prepared from polyhexamethylene adipamide and coated with an alkali metal salt of a copolymer of styrene and maleic anhydride, which salt includes a polyethylene glycol plasticizer therefor having the general formula:

tion comprising (1) an alkali metal salt of a copolymer of styrene and maleic anhydride and (2) a polyethylene glycol plasticizer for said alkali metal salt having the general formula:

where a: is an integer from 3 to 9, and drying said yarn preparatory to weaving said yarn.

14. A sizing composition comprising an aqueous solution of (l) a sodium salt of a copolymer of styrene and maleic anhydride and (2) a polyethylene glycol plasticizer for said copolymer salt having the general formula:

HOCI'IZ (CHIOCH2)I CHQ-OH where z is an integer from 3 to 9.

GERALD R. BARRETT.

REFERENCES CITED The following references are of record in the die of this patent:

UNITED STATES PATENTS Number Name Date 1,976,679 Fikentscher et al. Oct. 9, 1934 2,047,398 Voss et a1 July 14, 1936 2,300,074 Strain Oct. 27, 1942 2,324,601 Spanagel July 20, 1943 2,324,739 Stoops et a1 July 20, 1943 2,469,407 Powers et al. May 10, 1949 OTHER REFERENCES Synthetic Organic Chemicals. 12th ed., July 1, 1948, carbide a Carbon chem. Corn, page 21.

Claims (1)

1. A METHOD OF SIZING NYLON YARN AND OTHER TEXTILE YARN HAVING ELASTIC CHARACTERISTICS SIMILAR TO NYLON YARN WHEREBY THE SIZED YARN IS CHARACTERIZED BY A TOUGH, SMOOTH COATING WHICH DOES NOT SUBSTANTIALLY SHED OR DUST DURING A SUBSEQUENT WEAVING OPERATION, WHICH COMPRISES APPLYING TO SAID YARN AN AQUEOUS SOLUTION COMPRISING (1) AN ALKALI METAL SALT OF A COPOLYMER OF ETHYLENE A,B-DICARBOXYLIC COMPOUNDS SELECTED FROM THE GROUP CONSISTING OF MALEIC ACID, FUMARIC ACID, MALEIC ANHYDRIDE AND ALKYL ACID ESTERS THEREOF, IN WHICH THE ALKYL GROUP CONTAINS FROM 1 TO 3 CARBON ATOMS, AND ADMIXTURES THEREOF WHICH A POLYMERIZABLE VINYL AROMATIC HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF STYRENE, METHYL STYRENES AND CHLORO STYRENES AND (2) A POLYALKYLENE GLYCOL PLASTICIZER FOR SAID ALKALI METAL SALT SELECTED FROM THE GROUP CONSISTING OF POLYETHYLENE GLYCOLS AND POLYPROPYLENE GLYCOLS, AND DRYING SAID YARN PREPARATORY TO WEAVING SAME.