DE1494658C3 - Process for the production of composite thread consisting of sheath and core for textile purposes - Google Patents

Description

The invention relates to a method for producing a composite thread consisting of a sheath and a core for textile purposes, in which the sheath polymer mass is partially in the top layer of it different core polymer has penetrated.

From US-PS 28 62 284 such threads with a porous core are known, the core polymer of which is coated with a different sheath polymer mass, part of the sheath polymer mass has penetrated into the pores of the core polymer composition and precipitated there. These threads will obtained by superficially applying a blowing agent to the extruded threads from the core polymer composition stored, then the cooled threads through a bath containing the jacket polymer mass. carried out and then heated to elevated temperatures.

The invention is based on the object of finding an improved manufacturing method which without the use of blowing agents a firm anchoring of the sheath polymer in the Core polymer mass is achieved.

To solve this problem it is proposed according to the invention that a solution of the core polymer composition is extruded into a coagulating bath which dissolves the shell polymer composition in a solvent contains, which at the same time represents a precipitant for the core polymer composition, the threads obtained be transferred into a second coagulating bath which contains a precipitant for the shell polymer mass and then the composite thread obtained is drawn and dried in a known manner.

According to a preferred embodiment of the method according to the application, the coagulation is the sheath polymer mass effected by means of a hot gas.

Any polymer or copolymer can be used as the core polymer composition suitable for the production of fibers or threads by means of the wet spinning process. Are suitable for this for example polymers and copolymers of acrylonitrile, vinyl acetate, vinyl chloride and vinylidene chloride, including those copolymers in which each of these monomers with one of the other named monomers or with one or more other monoethyienically unsaturated monomers is copolymerizable. Examples of such unsaturated monomers are

Acrylic acid, a-chloroacrylic acid and methacrylic acid, Acrylates such as methyl acrylate, ethyl acrylate, methoxymethyl acrylate, jJ-chloroethyl acrylate and the corresponding esters of methacrylic and ίο (X-chloroacrylic acid, vinyl bromide, 1-chloro-1-bromoethylene, methacrylonitrile, acrylamide and methacrylamide, α-chloroacrylamide or its Monoalkyl substitution products, methyl vinyl ketone, vinyl carboxylates such as Vinyl chloroacetate, vinyl propionate and vinyl stearate, N-vinylimides such as N-vinylphthalimide and N-vinyl succinimide, methylenemalonic acid ester, N-vinyl carbazole, vinyl furan, alkyl vinyl ester, Vinylsulfonic acid and vinylbenzenesulfonic acids, ethylene-a.jS-dicarboxylic acids, their anhydrides or derivatives such as diethyl citraconate, diethyl mesaconate, styrene, vinyl naphthalene and vinyl substituted tertiary N-heterocyclic amines such as vinyl pyridines and vinyl imidazoles and numerous other copolymerizable monoolefinic monomers.

For the core polymer composition, polymers such as polyvinyl alcohol, polyester, e.g. B. polyethylene terephthalate and modifications thereof, polyolefins, e.g. B. polyethylene and polypropylene, polyamides, e.g. B. Polyhexamethylene adipamide, polycaprolactam, polyurethanes and segmented polyurethanes, cellulose derivatives, z. B. Cellulose acetate, diacetate and triacetate, cellulose ethers and regenerated protein materials, z. B. pea protein, casein or the like., Are used.

Any of the abovementioned polymers or copolymers can be used as the sheath polymer material or other addition or condensation products are used, provided they differ from the Differentiate core polymer mass.

The known solvents for the aforementioned can be used as organic and inorganic solvents Polymers which are suitable for wet spinning processes can be used. This subheading includes

Water in the case of polyvinyl alcohol; Acetone, acetonitrile, methylene chloride,
Carbon tetrachloride, chloroform and chlorinated aliphatic compounds for cellulose derivatives; Dimethylacetamide, dimethylformamide, dimethylpropionamide, dimethyl sulfoxide and dimethyl sulfone for acrylonitrile polymers and copolymers, polyurethane polymers and segmented polyurethanes and regenerated protein polymers; Moist nitromethane, ethylene carbonate, propylene carbonate, γ-butyrolactone, tetramethylene sulfone, malononitrile and succinic nitrile for acrylonitrile polymers and copolymers; Cyclohexanone, methyl ethyl ketone and tetrahydrofuran for vinyl and vinylidene chloride polymers and copolymers; Formic acid, phenol and polyphenols such as pyrocatechol, resorcinol and cresols, chlorinated phenols, alcoholic solutions of inorganic salts for polyamides, phenols, polyphenols such as the cresols, pyrocatechol and resorcinol and chlorinated phenols and

Hexamethylphosphoramide for polyester and

Polyolefins; aqueous solutions of metal salts

for acrylonitrile polymers and

- copolymers.

The solvents are up in each individual case selected on the basis of the core polymer composition.

The threads obtained from the first coagulating bath consist of an inner core made from the core polymer material in a relatively porous state with a layer of a solution of the sheath polymer material is covered. This thread is then introduced into a second coagulating bath, which generally consists of Water or from solutions diluted with water in the first coagulating bath or another suitable solution There is coagulation or precipitation medium in which the coagulation of the shell polymer material takes place. According to an alternative embodiment, the thread is heated to remove what is still present on the thread To evaporate solvent or solvent mixture and in this way the shell polymer to fail.

Irrespective of the type of coagulation of the shell polymer mass, its presence leads to it on the surface of the core polymer material to penetration of the dissolved shell polymer material into the inner pores of the thread core, while the core polymer material coagulates and in a very porous This results in a firm connection between the sheath polymer material and the Core polymer composition even in the case of polymers which are normally incompatible with one another. the The thread obtained in this way is then subjected to the usual stretching, washing and drying treatments subject.

The percentage of the core polymer mass in the spinning solution can be between 8 and 30% by weight. while the percentage of the coating polymer mass in the first coagulating bath is between 0.2 Can be up to 10% by weight. The temperatures are chosen so that a formation of threads or Fibers with useful physical properties is made possible.

Microscopic examination shows that the thread obtained consists of a core with in general between 80 and 99% by weight of the core polymer mass and a shell of greater or lesser size Starch generally in the range from 20 to 1% by weight of the shell polymer composition, with both parts are inextricably linked. This quality causes the special properties of the thread, which basically defines the physical and chemical properties of the core polymer which are improved or modified by those of the sheath polymer composition. If the two polymer compositions shrink under dry heat, in boiling water or in Steam is different, the individual threads take a helical three-dimensional configuration and in this way acquire the ability to curl. The curl obtained by the one how it is obtained by ordinary mechanical means is different is reversible. she can so removed by stretching and then again by subsequent heating of the thread in a relaxed state be regressed.

If the sheath polymer compound is not flammable, this property is imparted to the entire thread. Furthermore, if the shell polymer composition can be easily colored by a certain class of dyes, the fiber has an affinity for this class of dyes. Furthermore, changes can also be made to other physical Properties are obtained. The fabrics or textile products obtained from those obtained according to the invention Fibers or threads are produced, have good dimensional stability in hot-humid treatments and while washing. The volume or bulk will also increase after various treatments retained, which improves texture and "feel".

The invention is explained in more detail using examples in which all parts and Percentages are based on weight, unless otherwise indicated.

example 1

A spinning solution was prepared by dissolving an acrylic copolymer with a content of 94% acrylonitrile and 6% vinyl acetate and a specific viscosity of 0.15 in dimethylacetamide. The spinning solution, which contained about 25% of the copolymer, was ^{extruded at 40 °} C. into a bath of 45 parts of dimethylacetamide, 50 parts of carbon tetrachloride and 5 parts of polyvinyl chloride with a specific viscosity of 0.2.

The threads thus obtained were washed with a mixture of 50 parts of water and 50 parts of acetone, then washed with water and stretched by customary methods and finally dried.

After the threads have been subjected to a treatment with boiling water at 100 ° C, they had a curl index of about three crimps per cm and a curl number of 24. The term "curl number" is understood herein as the value given by the following equation is determined:

T = 100

where I _{x is} the length of the drawn thread and I _{0 is} the length of the crimped thread

Investigations carried out after treating the threads for five minutes in boiling water and subsequent drying under a load of 0.05 g / den and subsequent re-treatment in boiling water revealed that the threads retained a satisfactory crimp.

On the other hand, threads that consist of a single polymer component are subjected to such a treatment is subjected, no curling is obtained. If this is necessary, mechanical ones must be used Procedures are resorted to. However, a mechanically generated crimp is not reversible, d. H. the crimp disappears completely when the threads in the above treatment sequence hot water and drying under tension.

In the table below, the curl index and curl count values are those generated above Threads in comparison with mechanically crimped threads, which are made solely from an acrylic copolymer 94% acrylonitrile and 6% vinyl acetate consist and one

have a specific viscosity of 0.15, together and 50% acrylonitrile with a specific viscosity

represents:
Table I.

1) bicomponent threads

2) single component threads

1 = 3 T = 24
/ = 3
T = 20

/ = 2.25 T = 1.45 / = 0 T = O

T =

T =

2.4 5.9 0 0

Herein mean:

A (I) = the initial crimp, which was obtained by treating the above-mentioned two-component fibers with water at 100 ⁰ C.

A (2) = the crimp produced by mechanical means in the above monocomponent yarns was obtained.

B (I) and (2) is the crimp of the two threads that are after boiling in water for 5 minutes and then drying at room temperature under a load of 0.05 g / denier is obtained.

C (I) and (2) is the crimp obtained from the filaments after the above-described treatment (B) and an additional treatment in boiling water for 5 minutes and subsequent drying Room temperature is shown in a relaxed state.

/ = Crimp index (number of crimps per cm),

T = crimp number.

The mechanical properties of the bicomponent yarns obtained in the manner described above are completely satisfactory, since they are approximately the same as those of threads that only have a single thread polymeric component, as shown in the table below, in which the values of the two the various types of thread described above are compared.

Table IA

Titer Firm fracture speed strain the/ g / den % thread

1) Two components- 24.85 3.12 41 threads 2) Single component threads 25.1 3.02 38

of 0.15 extruded. The thread thus obtained is treated with a solution of 0.5% sodium bicarbonate in water then washed with water, stretched in the usual way and dried.

The crimp values which were obtained with the tests described in Example 1, as well as the mechanical properties of the threads thus obtained are summarized in Table II below.

Table II
Ripple values

1) bicomponent threads

Mechanical properties

/ 3.5
T 5.8

U
2

2
3.5

40

45

50

The bicomponent threads also have a much better flame resistance than the above tested one-component threads. The concentric structure of the filaments is microscopic Examination of a cross-section clearly visible in polarized light.

Example 2

A spinning solution is prepared by dissolving the same acrylic copolymer with a content of 94% acrylonitrile and 6% vinyl acetate and a specific viscosity of 0.15. The solution, which contained about 25% of the copolymer, was stirred at 6O ⁰ C into a coagulating bath of 52 parts of dimethylacetamide, 42.5 parts water, 1.5 parts of concentrated sulfuric acid (D 2 O = 1.86) and 4 parts of a copolymer of 50 % Methyl vinyl pyridine

Titer Firm fracture speed strain the/ g / den (o / o) thread

1) Two-component 5.6
threads

2.50

31

Since in this case the copolymer that forms the jacket can be dyed with acidic dyes, the two-component threads can also be dyed with such dyes. For example, good dyeing results are obtained if these threads are treated with a 5% strength aqueous sulfuric acid bath with a concentration of 1% of a blue dye (Color Index Acid Blue 45; CI. 63010) at a ratio of fiber to dye bath of 1:40 and a temperature of 6O ⁰ C stains under the same conditions is a thread that the Zweikomponten fiber consists of a single polymer component of the same copolymer as the core, not dyeable.

Example 3

A spinning solution was prepared by adding an acrylic copolymer in dimethylacetamide a content of about 94% acrylonitrile and 6% vinyl acetate and a specific viscosity of 0.15 solved. The spinning solution, which contained about 25% of the copolymer, was at a temperature of 45 ° C in extruded a coagulating bath of 45 parts of dimethylacetamide, 50 parts of water and 5 parts of polyvinyl alcohol The threads were then placed in a bath of 15% sodium sulfate solution in water, followed by dried, exposed to formaldehyde fumes and then stretched as usual. Treatment with vapor Formaldehyde is required to make the polyvinyl alcohol in water and common solvents to make insoluble.

If one compares the loss of moisture that occurs during drying as a function of the weight of the dry fiber (cf. Kirk-Othmer, "Encyclopedia of Chemical Technology", The Interscience Encyclopedia, Inc., New York, 1954, Vol. 13, p. 914) this gives a value for the threads obtained in this example of 3.5 compared to a value of 1.5 for threads made entirely of acrylonitrile-vinyl acetate copolymers

sat with the same composition, at 65% relative humidity and a temperature of 25 ° C.

The mechanical properties of the bicomponent threads according to this example are as follows:

Titer
the / thread

strength
g / den

Elongation at break

2.45

33

Example 4

A spinning solution was prepared by adding an acrylic copolymer in dimethylacetamide a content of 94% acrylonitrile and 6% vinyl acetate and a specific viscosity of 0.15 in solution brought. The spinning solution, which contained about 25% copolymer, was at a temperature of 20 ° C in a Coagulating bath made from 80 parts of acetone, 10 parts of dimethylacetamide and 10 parts of a copolymer extruded from 95% vinyl chloride and 5% vinyl acetate with a specific viscosity of 0.1. The received Filament was washed with water in a room temperature bath, drawn and dried. From two-component threads obtained from these copolymers show improved flame-retardant properties, as well as improved dyeability with dispersed acetate dyes.

Example 5

A spinning solution was prepared by adding an acrylic copolymer in dimethylacetamide a content of 94% acrylonitrile and 6% vinyl acetate and a specific viscosity of 0.15 in solution brought. The spinning solution, which contained about 25% copolymer, was at a temperature of 20 ° C in a Bath of 85 parts of acetone and 11 parts of dimethylacetamide and 4 parts of polymethyl methacrylate with a specific viscosity of 0.40. The received Threads were washed in water at room temperature, drawn and dried. These threads possessed Self-curling properties indicated by the values given in Table III below are:

Table III

1) bicomponent threads

A B C

/ 5.69 1.2 2.3

Γ 15.8 2 2.8

a specific viscosity of 0.12 with formation of a 26% strength solution of the polymer in solution brought. The spinning solution was at a temperature of 60 ° C in a coagulating bath with a content of 52 Parts of dimethylacetamide, 42.5 parts of water, 1.5 parts of concentrated sulfuric acid and 4 parts of acrylic copolymer, Consists of 50% methylvinylpyridine and 50% acrylonitrile, with a specific viscosity of 0.15 extruded. The threads thus obtained were washed with an aqueous solution of 0.5% sodium bicarbonate and then washed again with water and then stretched and dried. The threads according to this Example can be dyed with acidic dyes, while threads made only of polyvinyl chloride exist, cannot be dyed. The mechanical properties of the threads obtained are completely satisfactory and as follows:

Titer
(the / thread)

The threads also showed improved affinity for dispersed acetate dyes.

Example 6

A spinning solution was prepared by mixing a polyvinyl chloride polymer with strength in dimethylacetamide
(g / den)

strain

2.8

22nd

Example 7

A spinning solution was prepared by converting polyvinyl chloride in dimethylacetamide with a specific Bred viscosity of 0.12 to a content of 26% polymer in solution. The dope was at a temperature of 20 ° C in a bath of 58 parts of zinc chloride dissolved in 37 parts of water with a Content of 5 parts of an acrylic copolymer of 94% acrylonitrile and 6% vinyl acetate with a specific viscosity of 0.15 extruded. The threads obtained were then in a bath of 15% Zinc chloride in water at a temperature of 10 ° C. and then washed again with water, stretched and dried. The threads obtained can be dyed with basic dyes, e.g. B. with Sevron Blue 2G (CI. Basic Blue 22).

Examples

A spinning solution was prepared by adding polyhexamethylene adipamide with a relative viscosity Dissolved from 0.37 to a content of 12% of the polymer in a solvent which was composed of 50 Parts of zinc chloride and 50 parts of ethanol. This spinning solution was at a temperature of 30 ° C in extruded a bath containing 50 parts of zinc chloride, 45 parts of water and 5 parts of an acrylic copolymer a content of 94% acrylonitrile and 6% vinyl acetate and a specific viscosity of 0.15. the The resulting filaments were then introduced into a second bath consisting of 10 parts of zinc chloride and 90 parts Water at 10 ° C, and were then washed with water, stretched as usual and dried. The threads obtained according to this example can be acidic as well as basic Dyes are stained.

709 615/6

Claims (2)

Patent claims: 1. Process for the production of composite thread consisting of sheath and core for textile purposes, in which the sheath polymer mass is partially in the top layer of the different from it Core polymer has penetrated, characterized in that a solution of the Core polymer mass is extruded into a coagulating bath, which the shell polymer mass in one Contains solvent in solution, which at the same time represents a precipitant for the core polymer composition, the threads obtained are transferred to a second coagulating bath, which is a precipitant for the Contains sheath polymer composition and then the composite thread obtained in a known manner is stretched and dried. 2. The method according to claim 1, characterized in that the coagulation of the sheath polymer material is effected by means of a hot gas.