Process For Manufacturing Fibrous Structure Having Excellent Recovery From Extension By Treatment With Polyorganosiloxane And A Polyethylene Glycol Or Derivative Thereof

Abstract

This invention is directed to fibrous structures such as crimped yarns and fabrics made therefrom having excellent extensibleness, recovery from extension and no water repellency. The process of the invention comprises applying to said structures an aqueous emulsion of polyorganosiloxane comprising essentially methyl hydrogen polysiloxane having specified viscosity and subsidiarily dimethyl polysiloxane if required, polyethylene glycol or a derivative thereof and a catalyst for polymerization of polysiloxane and curing preferably in a dry condition. Important fibrous structures are composed of composite fibers or of conventional mechanically crimped fibers. Crimp developing for the former or heat setting of the latter can be advantageously effected simultaneously with the aforementioned curing.

Description

This invention relates to a process for manufacturing fibrous structures, such as crimped yarns, knitted and woven fabrics composed thereof and the like, which are provided with an excellent recovery from extension, and more particularly to a method for improving the hand and tensile elasticity of fibrous structures as such by an application of polyorganosiloxane thereto followed by a heat treatment.

By the term "fibrous structure" used in this specification and claims is meant a structure composed of staple fibers, continuous filaments or a mixture thereof, such as a yarn, strand, net, knitted goods, woven fabrics, nonwoven fabrics, felt, filter cloth, substrate for synthetic leather, garment and the like. The most important fibrous structures in the present invention are crimped yarns and knitted and woven fabrics composed thereof.

For manufacturing stretchable fibrous structures, there are various well-known expedients, for instance, employment of polyamide or polyester-textured crimped yarn as materials for fibrous structures, utilization of elastic yarn such as rubber and polyurethane elastomer yarns, and postfinish of knitted or woven fabrics. However, polyamide or polyester yarn employed as material for fibrous structures does not have satisfactory tensile recovery, i.e., recovering force from extension, so that fibrous structures made therefrom according to conventional process have not always been provided with satisfactory tensile recovery. Particularly, polyester fibers prevailing in the market such as polyethylene terephthalate fibers are quite inferior in tensile recovery and accordingly, in the past, highly stretchable knitted or woven fabrics composed of polyester fibers have scarcely been produced.

Furthermore, there have so far been proposed numerous composite filaments wherein at least two adherent components of synthetic fiber forming polymer differing in heat shrinkability are disposed in an eccentric relation with each other along the entire length of the filament, which can be manufactured by separately melting said polymers and by extruding the melt simultaneously from the same spinneret orifice to form a unitary filament. A principal object for manufacturing such composite filaments is to produce a crimped yarn having a woollike bulkiness, covering power and elastic or tensile recovery. It can not always be said, however, that composite filaments produced by a conventional process possess satisfactory woollike properties. Namely, most of conventional crimped composite filaments have some disadvantages which have to be obviated, particularly such that they are not provided with a woollike crimp recovering ability, whereas wools have an excellent crimp recovering ability, so that their crimps can readily return to their original configuration, even after suffering remarkably large compressive, tensile or bending stress.

For instance, although a composite filament obtained by melt-spinning concurrently from the same orifice, polyethylene terephthalate and a copolymer of 90 mole percent of polyethylene terephthalate with 10 mole percent of polyethylene hexahydroisophthalate is excellent with respect to crimpability, and can develop extremely superior crimps. However its crimps are so inferior in the ability to recover from extension that the crimps hardly return to their original form after the removal of a load 1 gram per denier which has been applied on the filament for 2 minutes.

On the other hand, the postfinish often impairs the original preferable hand of fibrous structures. It has heretofore been known that a highly stretchable fibrous structure can be obtained by applying polyorganosiloxane to the fibrous structure such as of natural fibers and of synthetic fibers and then subjecting it to a heat treatment. Such a conventional process as mentioned above usually provides the fibrous structure with extensibleness as well as water repellency, together with a waxy hand. Accordingly, it is effective to improve the stretchability of a special fibrous structure which requires water repellency and waxy hand, but it is not appropriate for manufacturing a highly stretchable and elastic fibrous structure which does not require the aforementioned properties. Namely, for manufacturing an article that requires water repellency or water-proofing ability, such as a raincoat, practical use has so far been made of a process which comprises applying to a knitted or woven fabric a methyl hydrogen polysiloxane or a mixture of methyl hydrogen polysiloxane with dimethyl polysiloxane, together with a catalyst for polymerization of the polysiloxanes, and then subjecting the resultant fabric to a dry heat treatment. Yet it cannot be denied that the conventional process as mentioned above essentially provides a fibrous structure with water repellency, while it impairs the original hand of the structure.

We, the inventors, have made various studies and investigations, to overcome the above-mentioned difficulties, on the finishing of fibrous structures, particularly such as knitted or woven fabrics, to impart an excellent stretchability thereto and at last accomplished the present invention.

It is an object of the present invention to obtain fibrous structures, particularly knitted or woven fabrics provided with excellent stretchability and preferable hand, which have neither water repellency nor waxy hand.

Another object of the present invention is to provide a useful crimped yarn by imparting more excellent crimp-recovering ability to a crimped composite filament.

Still another object of the present invention is to manufacture knitted or woven fabrics having extremely high stretchability with the aforementioned crimped yarn.

Other objects and attending advantages will become apparent from the following description of the invention.

The present invention is characterized in that an aqueous emulsion of polyorganosiloxane comprising methyl hydrogen polysiloxane having a viscosity at 25.degree. C. of 10-40 centistokes is homogeneously applied to a fibrous structure together with a catalyst for polymerization of said polyorganosiloxane and thereafter the fibrous structure is subjected to a curing treatment.

As a polyorganosiloxane to be applied to the present invention, the most suitable is that consisting substantially of methyl hydrogen polysiloxane having a viscosity at 25.degree. C. of 10-40 centistokes or a blend of the methyl hydrogen polysiloxane and dimethyl polysiloxane having a viscosity at 25.degree. C. of 100-50,000 centistokes. It is preferable that the blended polyorganosiloxane which is most suitably applied to the present invention contains at least 5 percent by weight of methyl hydrogen polysiloxane and as long as the blend contains such an amount of methyl hydrogen polysiloxane, the blending ratio of methyl hydrogen polysiloxane, and dimethyl polysiloxane may be arbitrarily determined.

If the viscosity of polysiloxanes is lower than the lower limits of the above-mentioned preferable ranges, silicone film having sufficient stability, adhesivity and elasticity is difficult to form on the fibrous structures upon a heat treatment in a dry state, due to the low degree of polymerization thereof, while on the contrary, if the viscosity of polysiloxanes is higher than the upper limits of the above-mentioned preferable ranges, elastic silicone film having an excellent stability and adhesivity is difficult to form as well and moreover, even when the amount of polysiloxane applied is rather small, a sticking phenomenon may be brought about on fibrous structures, and thus in either case, fibrous structures comprising crimped fibers provided with a satisfactory crimp recovery from extension cannot be obtained.

The aqueous emulsion of polyorganosiloxane to be employed in the process of the present invention is prepared by the addition of an ordinary surface-active agent, for instance, a nonionic surface-active agent such as polyethylene lauryl ether and polyoxyethylene octyl phenol ether, or a cationic surface active agent such as lauryl amine acetate and the like to the polysiloxane in an amount of 1-10 percent by weight based on the polysiloxane and the resultant polysiloxane is emulsified to form a homogeneous dispersion in water. The concentration of polyorganosiloxane in the aqueous emulsion usually lies in the range of 0.1-2.0 percent by weight, but it may be higher than the above under certain circumstances.

Application of the mixture of polyorganosiloxane and catalyst for its polymerization onto fibrous structures can be performed in various manners, such as an application roller means by which the emulsion is applied to running yarn before it is wound on a bobbin or a pirn in a spinning or drawing process; soaking of yarn on a bobbin having many perforations thereon or on a skein in the aqueous emulsion, followed by removal of excess liquid on the yarn; and soaking fabric such as knitted fabrics, woven fabrics and the like in the aqueous emulsion in an ordinary way, followed by squeezing by means of a roller mangle or by another appropriate means to remove excess liquid. As far as the predetermined amount of the polyorganosiloxane or of the polyorganosiloxane together with the catalyst which can be incorporated to the fibrous structure, the method of application is not specifically limited.

In the process of the present invention, the amount of the polyorganosiloxane fixed on the fibrous structure is preferably in the range of 0.05-10 percent by weight based on the fibrous structure and more preferably in the range of 0.2-5 percent by weight. If the above-mentioned fixing amount is less than 0.05 percent by weight, an elastic silicone film having excellent durability and adhesivity is difficult to form on fibrous structures because the amount of polyorganisiloxane is too small, while if the fixing amount is in excess of 10 percent by weight, not only is the formed film insufficient with respect to stability and adhesivity like the above, but also too much polyorganosiloxane fixed on the structure may cause sticking between fibers in the fibrous structure, and thus in either case, fibrous structures provided with a high recovery from extension cannot be obtained. When the amount of polyorganosiloxane fixed upon the fibrous structure is in the above-mentioned preferable range, an elastic silicone film of three dimensional structure which possesses an extremely high durability and an excellent adhesivity to fibers can be formed on fibers, so that fibrous structures having a superior recovery from extension can be obtained.

The amount of polyorganosiloxane fixed upon fibers can be determined, for instance, by the under-mentioned method.

A predetermined amount of fibrous structures on which polyorganosiloxane has been fixed is taken as a specimen, and dried at 60.degree. C. under a reduced pressure for 5 hours and then weighed to determine its weight (a) grams. Further, another predetermined amount of fibrous structure having no polyorganosiloxane fixed thereupon is taken, dried under the same conditions as above and weighed to determine its weight (b) grams. Then, from the respective specimens as mentioned above the polyorganosiloxane is extracted with benzene as a solvent in a Soxhlet fat-extraction apparatus for 8 hours and thereafter the specimens are dried at 60.degree. C. under a reduced pressure for 5 hours and weighed to determine their respective weights (c) grams and (d) grams. The amount of polyorganosiloxane fixed upon fibers is determined by the following equation:

The amount of polyorganosiloxane fixed (percent by weight)

An aqueous emulsion of polyorganosiloxane to be employed in the practice of the present invention should contain a catalyst for polymerization of the polyorganosiloxane in order to facilitate the formation of elastic silicon films having a satisfactory durability and a sufficient adhesivity to fibrous materials, which films are to be formed by a cross-linking reaction of the polyorganosiloxane adhered to fibers in the fibrous structure, and further to provide the fibrous structure with an excellent elastic recovery from extension. As substances having such catalytic abilities, mention may be made of organic metal compounds, for instance, a metal salt such as: a naphthenic acid salt, octylic acid salt and isooctylic acid salt, of a metal such as tin, zinc, lead and zirconium; dibutyl tin acetate; dibutyl tin laurate; butyl titanate or the like. These catalysts may be used either individually or in combinations of more than one.

The amount of the above-mentioned catalyst to be admixed with polyorganosiloxane is suitably selected according to the kind of the catalyst as well as of the polyorganosiloxane, concentration of the polyorganosiloxane in the aqueous emulsion, treating conditions, etc., and for the good result of the invention, 0.01-5.0 percent by weight of the catalyst based on the polyorganosiloxane component may be usually employed.

Fibrous structures to which a polyorganosiloxane and a catalyst have been applied are preliminarily dried at a temperature between room temperature and about 60.degree. C. and thereafter subjected to a heat treatment, preferably in a dry state, at 80.degree.-200.degree. C. for 10 seconds to 10 minutes, preferably at 120.degree.-170.degree. C. for 30 seconds to 2 minutes, under a tensioned or a relaxed condition. By the preliminary drying treatment, solvent, i.e., water in the polyorganosiloxane aqueous emulsion is evaporated and expelled and which treatment, however, may be omitted as the case may be. By the above-mentioned heat treatment, a polymerization reaction of the polyorganosiloxane is performed, so that highly elastic silicone films having a durability and a sufficient adhesivity to fibers are formed on the fibers in the fibrous structure. Thus, a fibrous structure provided with an excellent tensile elasticity is readily obtainable substantially without deteriorating either its conformation or its hand that the fibrous structure has originally been provided with.

Moreover in the process of the present invention, in addition to the above-mentioned catalyst, at least one organic silane compound, such as an isocyanate of silane compound, an alkoxysilane, an acetate of silane compound, etc., may be further added to the emulsion as an accelerator of the cross-linking reaction, for the purpose of improving adhesivity of the polyorganosiloxane to fibers in the fibrous structure. If such an accelerator of the cross-linking reaction is employed, it is possible to improve remarkably the adhesivity to fibers constituting fibrous structures, of elastic silicone films having a three dimensional molecular structure which has been formed by the cross-linking reaction of the polyorganosiloxane, and to provide the resultant fibrous structure with an everlasting and excellent tensile elasticity.

Furthermore, as the most preferable embodiment of the process of the present invention, we, the inventors have disclosed a method comprising incorporating a polyethylene glycol or its derivative having its molecular weight of 350-6,000 to the aforementioned aqueous emulsion of polyorganosiloxane together with a catalyst for polymerization of the polyorganosiloxane. Namely, such a method is carried out by treating fibrous structures with an aqueous emulsion of polyorganosiloxane which has been incorporated with a predetermined amount of the polyethylene glycol or its derivative. Differing from a conventional simple treatment with polyorganosiloxane that aims at a waterproof finish, the above-mentioned method is appreciably effective in obtaining a fibrous structure of an improved quality that has been provided with a highly increased tensile elasticity without imparting thereto water repellency and waxy hand as inherent to the conventional polyorganosiloxane finish. In the practice of the method mentioned above, a suitable amount of polyorganosiloxane to be applied to fibrous structures is 0.05-10 percent by weight and preferably 0.2-5 percent by weight, and a relevant amount of polyethylene glycol or its derivative is also 0.05-5 percent by weight and preferably 0.1-2 percent by weight. The proportion of polyorganosiloxane to polyethylene glycol or its derivative to be applied to fibrous the structure is preferably 9:1-1:2 and more preferably 3:1-1:1, and still however it is changeable arbitrarily in accordance with the stretchability, water repellency, waxy hand, etc., desired. If the proportion of polyorganosiloxane to polyethylene glycol or its derivative is more than 9:1, that is, too much polyorganosiloxane is employed compared with polyethylene glycol or its derivative, undesirable water repellency and waxy hand of the fibrous structure increase, though its stretchability can be improved. On the contrary, if said proportion is less than 1:2, namely, too much polyethylene glycol or its derivative is used as compared with polyorganosiloxane, a fibrous structure provided with satisfactory stretchability as well as recoverability is difficult to obtain.

Polyethylene glycols and derivatives thereof are represented by the following general formula:

RO--(CH.sub.2 CH.sub.2 0).sub.n --R'

where, R and R' are respectively a hydrogen atom, an alkyl group having its 1-20 carbon atoms or an alkyl-phenyl group having at least one alkyl group of 1-20 carbon atoms, and at least one of the terminal groups thereof is a hydroxy group. n has a value such that the molecular weight of such polyethylene glycol or its derivative is preferably in the range of 350-6,000. If polyethylene glycol or its derivative having a molecular weight of less than 350 is employed, it is difficult to attain the aforesaid objects of the present invention, since the treated fibrous structure is not satisfactory in its stretchability, though it does not exhibit waxy hand and water repellency. On the other hand, if the molecular weight is in excess of 6,000, although the stretchability of the structure may be improved to a great extent, it is not preferable, because not only is it difficult to decrease the waxy hand and water repellency to a satisfactory degree, but also a rather stiff and harsh hand is imparted to the fibrous structure.

As fiber materials which constitute fibrous structures to be applied to the present invention, mention may be made of natural fibers such as wool, silk, cotton, hemp and the like; regenerated cellulosic fibers such as viscose rayon, cupra, cellulose acetate, cellulose triacetate and the like; synthetic fibers such as polyamides, polyesters, polyester ethers, polyurethanes, polyureas, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyolefins and the like; and their blends. Those fiber materials may be in the form of staple, filament, spun yarn or their mixture and further crimpable or crimped composite filament, textured yarn and the like are effectively usable. Particularly, filaments consisting of a fiber-forming synthetic condensation polymer, specifically, of a linear polyamide and of a linear polyester, and knitted and woven fabric therefrom lead to a good result of the present invention.

The term hereinafter referred to as "polyesteric fibers" implies fibers consisting essentially of either polyester or polyester ether.

The above-said polyester means polyethylene terephthalate, a modified polyesters manufactured by copolymerizing or polymer blending a predominant component of polyethylene terephthalate and a subsidiary component different therefrom.

The modified polyesters include, for instance, a copolymer of components of polyethylene terephthalate with a small amount of at least one of: an aliphatic dicarboxylic acid such as adipic acid, sebacic acid, 1, 10-decane dicarboxylic acid and the like; an aromatic dicarboxylic acid such as isophthalic acid, sodium sulfoisophthalic acid, naphthalene dicarboxylic acid and the like; an alicyclic dicarboxylic acid such as hexahydro terephthalic acid and the like; an aliphatic diol such as trimethylene glycol, tetramethylene glycol, diethylene glycol, polyethylene glycol and the like; and an alicyclic diol such as 1, 4-cyclohexane dimethanol, 1,4 -cyclohexane diol and the like. Among the above, the modified polyesters also include a polymer blend of polyethylene terephthalate and a small amount of polymer or copolymer manufactured from a combination of dicarboxylic component and diol component selected from those listed above, and further include polyethylene terephthalate blended with a small amount of polyalkylene ether.

The aforementioned polyester ether means poly ethylene paraoxybenzoate or a modified polyester ether manufactured by copolymerizing a predominant component of polyethylene paraoxybenzoate with at least one subsidiary component selected from the group listed in the foregoing paragraph, or by polymer blending a predominant amount of polyethylene paraoxybenzoate and a small amount of polymer of copolymer same as mentioned in the illustration of polymer blend of polyethylene terephthalate in the foregoing paragraph.

The polyamide to be applied to the process of the present invention is a fiber-forming linear polymer or copolymer manufactured by polymerizing at least one polyamide-forming material selected from the group consisting of cyclic lactams such as .epsilon.-caprolactam, enantholactam, laurylolactam and the like, and nylon salts formed from a diamine such as tetramethylene diamine, hexamethylene diamine, nonamethylene diamine, undecamethylene diamine, metaxylylene diamine, paraxylylene diamine, N,N'-bis(.gamma.-aminopropyl) piperazine, .gamma.,.gamma.'-aminopropyl ether and the like and a dicarboxylic acid such as adipic acid, sebacic acid, terephthalic acid, isophthalic acid, hexahydroterephthalic acid and the like.

It is desirable that a fibrous structure to be applied to the process of this invention possess an extensibleness of at least 5 percent, because treatment of fibrous structures with polyorganosiloxane cannot newly impart extensibility and recoverability from extension to the fibrous structure which has originally had neither extensibility nor recoverability from extension, but does improve elastic properties such as extensibility and recoverability which has been originally possessed by the fibrous structure. Namely, if the extensibleness of a fibrous structure is lower than 5 percent, it may be very difficult to improve substantially its extensibleness and recoverability from extension by the polyorganosiloxane treatment.

From the reason as stated above, it is preferable for a fibrous structure which is to be subjected to the polyorganosiloxane treatment according to the present invention to have a extensibleness of at least 5 percent at least in the direction towards which imparting of a high tensile elasticity has been contemplated. In case the extensibleness of a fibrous structure such as knitted and woven fabrics to be treated is lower than 5 percent, it is hard to provide the structure with an excellent tensile elasticity.

In the present invention, for instance, "a knitted or woven fabric having its extensibleness of 5 percent" is defined as follows:

A rectangular test piece having a width of 5 cm. and a length of 10 cm. is cut out of a knitted or woven fabric. The both lengthwise ends of the test piece are clasped by clamps so that the distance between clamps may be 8 cm. and the extended length of the test piece between the clamps, when a load of 2 kg. has been applied to one end thereof, is measured. If the percentage of the difference between the extended length and the original length (8 cm.) against the original length be 5, then such a fabric is defined to have an extensibleness of 5 percent.

A fibrous structure to be applied to the present invention may be composed of crimped fibers which have been processed in a conventional mechanical crimping process such as a false-twisting process, stuffing box process and the like. In case fibers or yarns are subjected to a process according to the present invention in advance, whereupon they are cured simultaneously with the mechanical crimping, then the fibers or yarns can be given concurrently a high tensile elasticity and crimps. A process for treating a textured crimped yarn as such will be illustrated hereinafter in detail.

Polyester fibers or polyamide fibers to which polyorganosiloxane has been applied may be subjected to a preliminary drying which is followed by a heat treatment in a dry state at 80.degree. - 200.degree. C. under a tensioned or relaxed condition as explained hereinbefore, and thereafter crimped by a conventional mechanical crimping process such as false-twisting and stuffing box. Further those fibers which have been through the preliminary drying step may be subjected directly to the crimping process without performing the independent step of curing. Still further, omitting the preliminary drying step, the crimping process may succeed the heat treatment. In either way, there can be obtained crimped fibers having a high tensile elasticity and having desirable characteristics inherent to the original fibers, bulkiness, workability, etc., which have not at all been impaired.

Especially, when fibers are subjected to a crimping process comprising steps of mechanical deforming and of heat setting, immediately after a drying process, without performing the independent step of heating, it is extremely advantageous from an industrial viewpoint that the three dimensional cross-linking reaction of polyorganosiloxane and the heat setting of fibers are simultaneously effected.

It has been ascertained by the inventors' experimental works that the most preferable period of time (t seconds) for keeping the fibers in the heater during the heat setting process satisfies the following inequality:

where, D is total denier of the fiber and T(.degree.C) is the temperature of the heater.

If the above condition is not satisfied, the reaction of polyorganosiloxane is insufficiently performed, and therefore elastic silicone films having a durability and an excellent adhesivity are difficult to form on fibers, so that the stretchability and recovery from elongation of the resultant the fibers are not entirely satisfactory.

Another important embodiment of fibrous structures to be suitably applied to the present invention is that composed of composite filaments having latent crimps which are manufactured by melting separately two fiber-forming thermoplastic polymers differing in heat shrinkability and by extruding the two melts simultaneously from the same spinneret orifice to form a unitary filament wherein said two polymers are disposed in an eccentric relation with each other extending throughout the entire length of the filament, which fibrous structure is a yarn or a knitted or woven fabric composed thereof that exhibits an extensibleness of at least 5 percent in the direction to which extension has been originally required.

Composite filaments which have been through a dry heat treatment in a tensioned or restrained condition develop excellent crimps by further subjection to a conventional crimp-developing treatment in a relaxed condition providing crimped filaments which have excellent extensibility and recoverability of crimps. Moreover, in case the dry heat treatment is conducted in a relaxed condition, the crimp frequency of the resultant crimped filaments varies according to the kind of conjugated components forming the composite filaments, temperature of the curing treatment and degree of relaxation of the filament during the curing treatment. Accordingly, if the curing treatment is conducted in a relaxed condition as above, the three-dimensional cross-linking reaction of polyorganosiloxane and crimp development are simultaneously effected, which is extremely advantageous from an industrial viewpoint.

A knitted or woven fabric having an excellent stretchability which is one of the objects of the present invention is obtainable by knitting or weaving into fabric a composite filament yarn on which polyorganosiloxane has been applied solely or together with a catalyst for the polymerization thereof and thereafter a curing treatment has been effected, or in addition to those steps, a crimp-developing treatment has been further performed, and then by crimp developing or shrinking the resultant fabric in hot or boiling water.

A knitted or woven fabric comprising composite filaments to be applied to the precess of this invention is either a fabric that has developed its crimps by a heat treatment after fabrication from the composite filaments, or that has developed its crimps after fabrication from the composite filaments which have been through a preliminary crimping process prior to the fabrication. Individual fibers which constitute such a structure retain their respective crimps in the structure or adjacent fibers are not in close contact with each others, so that they may be movable in the structure and, therefore, when a tensile stress acts upon the structure, individual fibers can move freely according as the tensile stress.

Polymers to be conjugated, manner of conjugation and proportion of polymers to be conjugated for a crimpable composite filament to be applied to the process of this invention are appropriately selected in consideration of the adhesivity of two polymers employed, crimpability required for the composite filament to possess and so forth.

Various composite filaments are obtainable in combinations of the aforementioned numerous polymers and preferable combinations of polymers which provide composite filament having an excellent crimpability are those of polyamides with polyesters or polyester ethers, those of homopolyamides with copolyamides or modified polyamides, those of polyethylene terephthalate with copolyesters or modified polyesters, those of polyethylene terephthalate with polyethylene oxybenzoate, copolyester ethers or modified polyester ethers and those of two polyethylene terephthalates differing in their degree of polymerization.

Thus, according to the process of the present invention, polyorganosiloxane applied to composite filaments forms, upon a curing treatment, elastic films having excellent durability and adhesivity to fibers and a three-dimensional molecular structure, on the composite filaments, so that there can be obtained composite filaments and knitted or woven fabrics therefrom having excellent extensibleness and recoverability of their crimps, and further without deterioration of any bulkiness and crimp extensibility inherent to composite filaments.

The present invention will be illustrated in detail with reference to examples hereinafter. The word "part" used in the examples means "part by weight." The inherent viscosity of the polyamide was determined in m-cresol solution at 30.degree. C. and that of polyesters and polyester ethers was determined in o-chlorophenol solution at 30.degree. C.

Methods for determining degree of crimp, recovery of crimp and residual crimp in the examples are as follows:

A specimen of multifilament yarn of 20 composite filaments is soaked in boiling water under a relaxed condition and dried. An initial load of 2 mg. per denier is applied to the specimen, the length (l.sub.o) of which is then measured. Next, a load of 100 mg. per denier is applied to the specimen and two minutes later, its length (l.sub.1) is measured. And then, after a load of 500 mg. per denier is applied to the specimen for 2 minutes, the load is exchanged for a load of 100 mg. per denier and 2 minutes later, its length (l.sub.2) is measured. Finally the load is exchanged for the initial load and 2 minutes later, the length (l.sub.3) of the specimen is measured. Degree of crimp, recovery of crimp and residual crimp are calculated by the following equations: ##SPC1##

Methods for determining total shrinkage, linear shrinkage, crimp shrinkage and C.R. value are as follows:

A specimen of multifilament yarn of 20 filaments having a length of L.sub.0 is soaked in boiling water for 10 minutes, water on the yarn is removed by filter paper and air-dried. The length (L.sub.1) of the air-dried specimen is measured, a load of 100 mg. per denier is then applied thereto and 30 seconds later, the length (L.sub.2) is measured. The load is exchanged for a load of 2 mg. per denier and 2 minutes later, the length (L.sub.3) of the specimen is measured.

Total shrinkage (percent)=(L.sub.0 -L.sub.1)/L.sub.0 .times.100

Linear shrinkage (percent)=(L.sub.o -L.sub.2)/L.sub.0 .times.100

Crimp shrinkage (percent)=(L.sub.2 -L.sub.1)/L.sub.0 .times.100

C.R. value (percent)=(L.sub.2 -L.sub.3)/L.sub.2 .times.100

Tensile elasticity of knitted or woven fabrics is determined by the following procedure:

A specimen having an effective length of 20 cm. and a width of 5 cm. is stretched on an Instron universal tension tester at a stretching rate of 2 inches per minutes to a predetermined degree of elongation, allowed to stand for 1 minute and the length (L cm. ) is recorded. The specimen is restored to a relaxed condition and 1 minute later, the length (L' cm.) of the specimen is measured. Tensile elasticity is represented by the following formula:

Tensile elasticity (percnt)=(L-L')/(L-20).times.100

With respect to waxy hand, a fabric that no waxy hand had been appreciated on was designated as grade 1, that a slight waxy hand appreciated on was as grade 2, that a waxy hand is clearly appreciated on was as grade 3, that a waxy hand is much appreciated on was as grade 4, that a waxy hand is extremely appreciated on was as grade 5 and evaluations made by 10 persons was averaged.

Measurement of water repellency is conducted according to JIS (Japanese Industrial Standard)-L-1079-19665.24.2: Water repellency-A method (spraying method).

EXAMPLE 1

One hundred parts of dimethyl terephthalate, 70 parts of ethylene glycol and 0.02 part of zinc acetate were put into a stainless steel autoclave. After they had been reacted at 190.degree. C. for 4 hours, methanol was distilled off. Then 0.02 part of antimony trioxide and 0.02 part of tricresyl phosphate were added to the reaction mixture, the temperature was raised up to 230.degree. C. to distil out while excess ethylene glycol, and thereafter the temperature was further raised while reducing the pressure, up to 280.degree. C. at which temperature a condensation polymerization was effected under a pressure of 0.5 mm. Hg to yield polyethylene terephthalate having an inherent viscosity of 0.63 which was later formed into chips.

In an extruder, those chips were melted at 280.degree. C. and the melt was extruded from a nozzle having a diameter of 0.3 mm. to form a filament yarn which was subsequently wound on a bobbin at a winding speed of 500 meters per minute. The yarn was then drawn to 4.07 times its original length at 90.degree. C. to obtain polyester fiber (A) of 70 denier of 36 filaments.

An aqueous emulsion comprising 3 parts of methyl hydrogen polysiloxane having a viscosity of 25 centistokes at 25.degree. C., 0.08 part of zinc octoate, 0.01 part of nonionic surface-active agent and 100 parts of water was applied on the yarn by means of an application roller before the yarn was wound on a bobbin, and the yarn was air-dried. The amount of methyl hydrogen polysiloxane fixed on the air-dried yarn was 0.8 percent by weight. The resultant dried undrawn yarn was drawn to 4.07 times its original length at 90.degree. C. to obtain polyester fiber (B) of 70 denier.

Thus-obtained polyester fibers (A) and (B) were false-twisted under conditions of: the number of twist of 3,000 turns per meter, the heater temperature of 210.degree. C., the heater length of 60 cm., the first feeding rate of 2.0 percent, the second feeding rate of +10.0 percent and the winding speed of 40 meters per minute, to manufacture respective textured yarns (A) and (B).

Characteristics of the crimps of the resultant textured yarn are shown in the table 1 which follows: --------------------------------------------------------------------------- TABLE 1

Item Total Linear Crimp C.R. shrinkage shrinkage shrinkage value Specimen (%) (%) (%) (%) __________________________________________________________________________ Textured yarn(A) (Comparative) 81.0 5.9 75.1 29.4 Textured yarn(B) (present invention) 82.7 5.3 77.4 39.2 __________________________________________________________________________

As is apparent from the above table 1, the yarn manufactured according to the present invention had a remarkably large C.R. value in comparison with the comparative yarn, though they showed substantially the same crimp shrinkage. This face proved that the yarn manufactured according to this invention possessed an excellent crimp recoverability.

Furthermore, even after the textured yarn (B) had been washed continuously for 2 hours at 25.degree. C. in a bath having a bath ratio of 50:1 and containing 2 g/l. of Monogen (a trade name of a neutral soap manufactured by Daiichi Kogyo Seiyaku K.K.) in a reversible automatic washing machine, yet its C.R. value was not lowered and its excellent durability was ascertained.

EXAMPLE 2

A polyester false-twist textured yarn of 75 denier of 36 filaments manufactured by a conventional process having a twist of S direction and another polyester yarn as such having a twist of Z direction were combined into a two-ply yarn having a twist of Z direction 150 turns. A plain fabric having densities of its warp and filling respectively of 70 per inch was woven with the above-mentioned yarn. After soaking in boiling water for 30 minutes in a relaxed condition, the fabric was subjected in sequence to desizing, scouring, presetting and dyeing processes in conventional manners. The resultant woven fabric exhibited an extensibleness in the warp direction of 12 percent and that in the weft direction of 7 percent.

Six pieces of the fabric thus obtained were soaked in respective aqueous emulsions of six kinds consisting of 0.2 part of methyl hydrogen polysiloxane having a viscosity of 30 centistokes at 25.degree. C., 0.3 part of dimethyl polysiloxane having a viscosity of 1,000 centistokes at 25.degree. C., 0.02 part of zinc issootoate and 100 parts of water, which emulsions further containing polyoxyethylene lauryl ether having an average molecular weight of about 800 in such different amounts that proportions of the polysiloxane to the polyoxyethylene lauryl ether in emulsion were 10:1, 7:1, 3:1, 1:1, 1:2 and 1:4 respectively, squeezed by means of a roller mangle to the pickup of 100 percent, dried at 100.degree. C. in hot air and subjected to 1-minute cure at 170.degree. C. to obtain fabrics (C), (D), (E), (F), (G) and (H). On the other hand, the aforementioned dyed fabric was subjected to 1-minute cure at 170.degree. C. without subjecting to the polysiloxane treatment and thus fabric (I) was obtained. With respect to all those fabrics, an elastic recovery at 10 percent extension, waxy hand and water repellency were measured and the results is shown in table 2 which follows: --------------------------------------------------------------------------- TABLE

2 Elastic recovery Water at 10% extension Waxy repel- Specimen (%) hand lency __________________________________________________________________________ C (comparative) 90.3 4.6 90 D (present invention 89.5 3.4 70 E (present invention) 89.0 1.3 0 F (present invention) 88.6 1 0 G (present invention) 87.7 1 0 H (comparative) 84.1 1 0 I (comparative) 82.5 1 0 __________________________________________________________________________

As is apparent from the above table 2, the fabrics treated according to the process of the present invention had a satisfactory recovery from extension and a desirable hand free from waxy hand and water repellency.

EXAMPLE 3

According to a conventional process, chips of a copolymer of 90 mole percent of polyethylene terephthalate and 10 mole percent of polyethylene isophthalate, having a inherent viscosity of 0.6 in o-chlorophenol solution at 30.degree. C., and chips of polyethylene terephthalate having an inherent viscosity of 0.63 in o-chlorophenol solution at 30.degree. C. were respectively manufactured and the two kinds of chips were spun, according to a conventional conjugate spinning method, with an extrusion ratio of one to one, to produce a crimpable polyester composite filament yarn of 75 denier of 36 filaments, which yarn was then fed at a rate of 200 meters per minute into a stainless steel tube having an inside diameter of 2 mm. and a length of 500 mm., heated at 170.degree. C. and withdrawn at a rate of 125 meters per minute to obtain a crimped yarn. To the resultant crimped yarn was imparted a Z-twist of 150 turns per meter and the twisted yarn was doubled into a unitary doubled yarn with which a plain fabric having a warp density of 70 and a weft density of 70 was woven according to a conventional method. After relaxing for 30 minutes in boiling water, the fabric was scoured, preset and dyed according to a conventional manner. The resultant fabric exhibited an elongation of 15 percent in the warp direction and that of 10 percent in the weft direction, and the fabric was then soaked in an aqueous emulsion consisting of 1.2 parts of methyl hydrogen polysiloxane having a viscosity of 15 centistokes at 25.degree. C., 0.8 part of dimethyl polysiloxane having a viscosity of 10,000 centistokes at 25.degree. C., 0.7 part of polyoxyethylene octylphenol ether having an average molecular weight of about 800, 0.02 part of zinc naphthenate and 97.6 parts of water; squeezed to remove an excess solution up to a pickup of 100 percent by weight based on the fabric; and thereafter subjected to a preliminary drying at 100.degree. C., followed by one minute cure at 170.degree. C. Thus, a fabric (J) having an excellent elastic recovery from extension and decreased waxy hand and water repellency resulted. The elastic recoveries at 15 percent extension in the warp direction with respect to the fabric (J) as well as a fabric (K) which had not been subjected to the treatment of the present invention were determined, that of the former being 93.8 percent and that of the latter being 88.2 percent. The values of waxy hand of those fabrics (J) and (K) were determined as 1.3 and 1.0 respectively and the values of water repellency of those fabrics were both 70.0.

EXAMPLE 4

One hundred parts of dimethyl terephthalate, 70 parts of ethylene glycol and 0.02 part of zinc acetate were put into a stainless steel autoclave. After they had been reacted at 190.degree. C. for 4 hours, methanol was distilled off. Then 0.02 part of antimony trioxide and 0.02 part of tricresyl phosphate were added to the reaction mixture, the temperature was raised up to 230.degree. C. to distil out excess ethylene glycol, and thereafter the temperature was further raised, while reducing the pressure, up to 280.degree. C. at which temperature a condensation polymerization was effected under a pressure of 0.5 mm. Hg to yield polyethylene terephthalate having an inherent viscosity of 0.63 which was later formed into chips.

One hundred parts of .beta.-hydroxyethoxy benzoic acid methyl ester, 0.02 part of zinc acetate and 0.03 part of antimony trioxide were put into a stainless steel autoclave equipped with an agitator. After they had been reacted at 240.degree. C. for 1 hour in an environment of nitrogen gas, the temperature was raised up to 260.degree. C. and the polymerization reaction was carried out for 5 hours under a pressure of 0.5 mm. Hg to yield polyethylene oxybenzoate having an inherent viscosity of 0.60 which was later formed into chips.

Into two hoppers, thus obtained two kinds of chips were separately supplied, which were then melted individually at 280.degree. C. and the melts were simultaneously extruded from the same orifices of a spinneret provided with 36 orifices having diameters of 0.4 mm., in a side-by-side relation with an extrusion ratio by weight of one to one to form a composite filament yarn which was wound up on a tube at a winding speed of 500 meters per minute and which was thereafter drawn to 4.07 times its original length at 90.degree. C. During the drawing operation, before winding on a pirn, to the drawn yarn was applied, by means of an application roller, an aqueous emulsion consisting of 0.3 part of dimethyl polysiloxane having a viscosity of 10,000 centistokes at 25.degree. C., 0.045 part of methyl hydrogen polysiloxane diol having a viscosity of 30 centistokes at 25.degree. C., 0.008 part of zinc octoate, 0.01 part of a nonionic surface active agent and 99.7 parts of water. The amount of polysiloxane adhered to or adsorbed by the yarn was 0.2 percent by weight. After air drying, the yarn was fed at a rate of 200 meters per minute into a stainless steel tube having an inside diameter of 2 mm. and a length of 500 mm., heated at 170.degree. C., withdrawn at a rate of 130 meters per minute, soaked in boiling water for 10 minutes under a tensionless condition and air dried to obtain a crimped fiber yarn (M).

For the purpose of comparison, a crimped fiber yarn (N) was manufactured according to the same process as above with the exception that it was not treated with the aqueous emulsion of polysiloxane.

Characteristics of crimps with respect to the crimped fiber yarns (M) and (N) are shown in table 3 which follows:

TABLE 3

Item Degree of Recovery of Residual crimp crimp crimp Specimen (%) (%) (%) __________________________________________________________________________ Yarn (M) (present invention) 27.1 75.1 20.3 Yarn (N) (comparative) 31.4 70.5 22.1 __________________________________________________________________________

The aforementioned composite filament yarns which had been subjected to the heat treatment in the stainless steel pipe followed by the relaxed treatment were doubled into respective two-ply yarns were then woven into respective plain fabrics having both warp and weft densities of 70 per inch. The resultant fabrics were soaked in boiling water for 30 minutes, then scoured and dyed. A recovery at 10 percent extension in the direction of the weft was determined with respect to the thus obtained fabrics and the result is shown in table 4 which follows: --------------------------------------------------------------------------- TABLE

4 Item Recovery at Tensile 10% extension stress (kg.) Specimen (% __________________________________________________________________________ Fabric of the invention 91.5 2.2 Comparative 87.3 3.2 __________________________________________________________________________

As is apparent from the above tables 3 and 4, it was proved that articles manufactured according to the present invention were extremely excellent in their elastic recoverability from extension.

Furthermore, for the purpose of comparison, the aforementioned composite filament yarn consisting of polyethylene terephthalate and polyethylene oxybenzoate was subjected to a polysiloxane application treatment, cure and crimp developing treatment in the same process and under the same conditions as the above with the exception that dimethyl polysiloxane having a viscosity of 80,000 centistokes at 25.degree. C. and methyl hydrogen polysiloxane having a viscosity of 60 centistokes at 25.degree. C. was employed in lieu of the above-mentioned mixed polysiloxane. However, the resultant crimped fiber yarn exhibited considerable stickiness and its crimp recovery at 10 percent extension was no more than 79.7 percent.

EXAMPLE 5

One hundred parts of hexamethylene diammonium adipate together with 10 parts of water and 0.3 part of acetic acid was put into a stainless steel autoclave and polymerized at 250.degree. C. for 2 hours under a pressure of 6 kg./cm..sup.2. Then the temperature was raised up to 270.degree. C. the pressure reduced to atmospheric pressure in 1 hour and the reaction was carried out for 3 hours in an environment of nitrogen gas, which was followed by further 2 hour polymerization under a reduced pressure of 100 mm. Hg, to yield nylon-66 having an inherent viscosity of 1.10 which was later formed into chips.

The thus obtained nylon-66 chips and polyethylene terephthalate chips prepared in the foregoing example 4 were individually supplied into two hoppers, which were then melted separately at 280.degree. C. and the melts were simultaneously extruded from the same orifices of a spinneret provided with its 24 orifices having their diameter of 0.4 mm. with an extrusion ratio by weight of one to two, to form a composite filament yarn, individual filament of which consisted of an eccentric core of nylon-66 and of a sheath of polyethylene terephthalate.

In the spinning process, an aqueous emulsion consisting of 1 part of a conventional spinning oil, 2 parts of dimethyl polysiloxane having a viscosity of 5,000 centistokes at 25.degree. C., 1 part of methyl hydrogen polysiloxane having a viscosity of 30 centistokes at 25.degree. C., 0.01 part of dibutyl tin laurate and 97 parts of water, was applied to the as-spun yarn by means of a rotatory application roller before the yarn was wound on a takeup tube. The undrawn yarn was air dried and drawn at 90.degree. C. to 4.19 times its original length to obtain a composite filament yarn of 70 denier. The drawn composite filament yarn had 0.43 percent by weight of polysiloxane adhered thereon.

The resultant composite filament yarn was then taken up on a skein which was allowed to stand under a relaxed condition in a dryer heated at 190.degree. C. to obtain a crimped yarn (O).

For the purpose of comparison, a crimped yarn (P) was prepared in the same manner as the above with the exception that the polysiloxane was not applied to it.

Characteristics of crimps determined with respect to the crimped yarns (O) and (P) are shown in table 5 which follows: --------------------------------------------------------------------------- TABLE

5 Item Degree Recovery Residual of crimp of crimp crimp (%) Specimen (%) (%) __________________________________________________________________________ Crimped yarn (O) (present invention) 54.7 73.8 40.3 Crimped yarn (P) (Comparative) 56.2 65.1 36.6 __________________________________________________________________________

The crimped yarns (O) and (P) were knitted into respective knitted fabrics, of which an elastic recovery from 100 percent extension was determined. The knitted fabric which had been knitted from the crimped yarn manufactured according to the present invention had its value of 94.5 percent, whereas the knitted fabric from the comparative crimped yarn exhibited the recovery of 88.2 percent

EXAMPLE 6

Polyethylene oxybenzoate chips having an inherent viscosity of 0.6 and polyethylene terephthalate chips having an inherent viscosity of 0.63 which were prepared in a conventional process, were separately melted and extruded simultaneously in a side-by-side relation from the same orifices of a spinneret with an extrusion ratio of one to one to form a polyesteric composite filament yarn which was thereafter drawn in a conventional manner to obtain a crimpable drawn yarn of 75 denier of 24 filaments. The drawn yarn was fed at a rate of 200 meters per minute into a stainless steel tube having an inside diameter of 2 mm. and a length of 500 mm., heated at 170.degree. C. and withdrawn at a rate of 180 meters per minute, whereby the yarn developed its crimps. A two-ply yarn of 75 denier of 24 filaments provided with an S-twist of 150 turns per meter was prepared from the above-obtained yarn, and employing the said two-ply yarn as warps and wefts, a fabric was woven with designed densities of 70 per inch both of warp and of weft. After soaking and relaxing in boiling water for 30 minutes, the woven fabric was desized, scoured, preset and dyed according to a conventional manner. The resultant fabric exhibited an extensibleness of 15 percent in the warp direction and that of 22 percent in the weft direction.

The thus obtained fabric composed of crimpable polyester composite filament yarns was soaked sufficiently in an aqueous emulsion consisting of 0.3 part of dimethyl polysiloxane having a viscosity of 5,000 centistokes at 25.degree. C., 0.045 part of methyl hydrogen polysiloxane having a viscosity of 30 centistokes at 25.degree. C., 0.08 part of zinc octoate, 0.01 part of a nonionic surface active agent and 99.7 parts of water; withdrawn from the emulsion; squeezed to remove excess liquid; preliminarily dried at 80.degree. C. and cured at 170.degree. C. for 1 minute. The treated fabric had 0.5 percent by weight of polysiloxane fixed thereupon. The fabric treated according to the process of the present invention showed an elastic recovery at 15 percent extension of 90.2 percent in the warp direction and of 92.5 percent in the weft direction, whereas the same fabric before treated with polysiloxane showed an elastic recovery at 15 percent extension of 85.7 percent in the warp direction and of 88.7 percent in the weft direction. Thus, a remarkable improvement in elastic extensibleness effected and attained by the present invention has been proved by comparison of the two fabrics mentioned above.

Claims

What is claimed is:

1. A process for manufacturing a fibrous structure having an excellent recovery from extension and reduced water repellency and waxy hand which comprises applying homogeneously to a fibrous structure an aqueous emulsion of 0.1 to 2.0 percent by weight based on the emulsion of polyorganosiloxane comprising methyl hydrogen polysiloxane having a viscosity at 25.degree. C. of 10-40 centistokes and polyethylene glycol or a derivative thereof having an average molecular weight of 350-6,000, of the formula,

RO-(CH.sub.2 CH.sub.2 O).sub.n -R'

wherein R and R' are the same or different, and may each be an hydrogen atom, an alkyl group having 1-20 carbon atoms or an alkylphenyl group having at least one alkyl group of 1-20 carbon atoms, with the proviso that at least one of said R and R' is a hydrogen atom, and Mn has a value sufficient to give the said molecular weight M, the weight ratio of said polyorganosiloxane to said polyethylene glycol or derivative thereof being in a range of 9:1 to 1:2, and a catalyst for polymerization of said polyorganosiloxane and thereafter subjecting the fibrous structure to a curing treatment.

2. A process as claimed in claim 1, wherein the polyorganosiloxane consists substantially of said methyl hydrogen polysiloxane.

3. A process as claimed in claim 1, wherein the polyorganosiloxane consists of at least 5 percent by weight of said methyl hydrogen polysiloxane and at most 95 percent by weight of dimethyl polysiloxane having a viscosity at 25.degree. C. of 100-50,000 centistokes.

4. A process as claimed in claim 1, wherein the amount of polyorganosiloxane applied and fixed to the fibrous structure is 0.05-10 percent by weight, based on said structure and the amount of said polyethylene glycol or its derivative applied to the fibrous structure is 0.05-5 percent by weight based on said structure.

5. A process as claimed in claim 1, wherein the amount of polyorganosiloxane applied and fixed to the fibrous structure is 0.2-5 percent by weight based on said structure and the amount of said polyethylene glycol or its derivative applied to the fibrous structure is 0.1-2 percent by weight based on said structure.

6. A process as claimed in claim 1, wherein said catalyst is at least one organic metal compound selected from the group consisting of: salts of a metal selected from the class consisting of tin, zinc, lead and zirconium with an organic acid selected from the class consisting of naphthenic acid, octylic acid and isooctylic acid; dibutyl tin acetate; dibutyl tin laurate; and butyl titanate.

7. A process as claimed in claim 6, wherein said catalyst is contained in the aqueous emulsion in an amount of 0.01-5.0 percent by weight based on the polyorganosiloxane.

8. A process as claimed in claim 1, wherein the fibrous structure that said aqueous emulsion has been applied to is subjected to a preliminary drying at a temperature between a room temperature and 60.degree. C. prior to the curing treatment.

9. A process as claimed in claim 1, wherein the curing treatment is conducted at a temperature of 80.degree.-200.degree. C. for 10 seconds to 10 minutes.

10. A process as claimed in claim 1, wherein the curing treatment is conducted at 120.degree.-170.degree. C. for 0.5-2 minutes.

11. A process as claimed in claim 1, wherein the curing treatment is conducted for a period of time which satisfies the formula,

where, D is the total denier of fiber in denier, T is the curing temperature in .degree.C. and t is the period of time for curing in seconds.

12. A process as claimed in claim 1, wherein said emulsion further contains at least one organic silane compound as a cross-linking agent selected from the class consisting of isocyanates of silane compounds, alkoxysilanes and acetates of silane compounds.

13. A process as claimed in claim 1, wherein said fibrous structure has substantially no water repellency or waxy hand and wherein said polyorganosiloxane and said polyethylene glycol or derivative thereof are applied to the fibrous structure in a proportion by weight of 3:1-1:1.

14. A process as claimed in claim 1, wherein the fibrous structure comprises filaments of at least one fiber-forming thermoplastic synthetic condensation polymer selected from the class consisting of linear polyamides, linear polyesters and linear polyester ethers.

15. A process as claimed in claim 1, wherein the fibrous structure, before the application of said emulsion, has an extensibleness of at least 5 percent.

16. A process as claimed in claim 15, wherein the fibrous structure is a filament yarn.

17. A fibrous structure having excellent recovery from extension and reduced water repellency and waxy hand prepared in accordance with the process of claim 1.