JPS601403B2 - Composite fiber with high shrinkability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite fiber comprising an inelastic synthetic polymer and a novel elastic copolyester.

It is well known that composite fibers, which are made by eccentrically composing two components with different shrinkability in the cross section of a single filament, have latent crimp properties, and develop helical crimp when heat treated. .

Conventionally, A is a combination of two composite components, and B is a combination of polymers with the same composition but different viscosities.
Combination C of Different Polymers Combinations of homopolymers and copolymers or blend polymers have been proposed.

However, composite systems using composite components with different viscosity levels (A) tend to cause problems during spinning, such as yarn bending on the spinneret surface, and it is not possible to use materials with a sufficient viscosity difference. It was difficult to obtain a material with good vertical properties.

In addition, in the combination of different polymers (B), there is an imbalance in the thermal properties of both components, poor adhesion, and peeling on the composite surface.
Various problems have occurred, including problems during dyeing due to differences in dyeability and insufficient shrinkage due to insufficient difference in shrinkage, and so far no product of interest has been obtained.

Several products of the combination of homopolymer and copolymer (C) have been commercialized because the two components with good shrinkage development properties are relatively easily available.

However, it has been found that all of these products have the disadvantage that the densities are stretched out by repeated stretching and contraction, resulting in poor stretchability (so-called "bending"). This is because the copolymer used has poor elastic recovery properties, resulting in netting stretching during stretching. For this reason, despite great expectations placed on composite systems obtained from homopolymers and copolymers, they have not been able to replace conventional textured yarns, and are only used in small quantities in specific fields. It's just that. In response to this situation, attempts were made to use a thermoplastic elastomer as a composite component in order to eliminate the vertical "bending" caused by repeated expansion and contraction.

The first thermoplastic elastomer to appear was a thermoplastic polyurethane elastomer, followed by styrene-butadiene block copolymers, block polyether esters, and the like. However, polyurethane elastomers have poor thermal stability because they have urethane bonds in their molecules, and their melting temperature and thermal decomposition temperature are abnormally close to each other, so they cannot be stably spun.

Further, Telefloc copolymers such as styrene-butadiene or styrene-isoprene have an essential drawback of extremely poor heat resistance because the glass phase of styrene is a non-rubber phase. Furthermore, in recent years, it has been discovered that a block copolyether ester containing polybutylene terephthalate as a hard segment and poly(tetramethylene oxide) glycol as a soft segment can be used as a thermoplastic elastomer, and this can be used as a component of a composite system. However, such block copolymer 7 Lester has the disadvantage that it has poor heat resistance and light resistance, and in an atmosphere exposed to sunlight or ultraviolet rays, it causes discoloration and a decrease in the degree of polymerization, resulting in a decrease in mechanical properties. Ta.

As stated above, attempts to use thermoplastic elastomer as a component of a composite system in order to obtain a composite system with excellent elasticity have been made.
So far no success.

Therefore, as a result of investigating a new copolymer component that takes advantage of the heat resistance, chemical resistance, mechanical strength, moldability, etc. of crystalline polyester and also provides flexibility and elastic recovery, the present inventors completely surprisingly discovered that a copolymer of polybutylene terephthalate and polybutylene phthalate has very specific and excellent elastic properties and good heat resistance, light resistance, adhesive properties, etc. The present invention was achieved based on the discovery that a composite system with excellent elastic properties can be obtained by forming a composite paper yarn with a non-elastic synthetic polymer and a non-elastic synthetic polymer. This type of polyester is completely unknown and has excellent heat resistance and light resistance, and the inventors have discovered that by using it as a component of a composite system, the conventional disadvantages can be eliminated. It is. An object of the present invention is to provide a composite system that has excellent heat resistance, light resistance, and high strength by spinning a novel elastic copolymerized polyester and an inelastic synthetic polymer. It is in.

Therefore, the gist of the present invention is that at least two
A composite fiber in which components are eccentrically composited in the cross section of a single filament, in which an inelastic synthetic polymer is one component, and polybutylene terephthalate (hereinafter referred to as
(abbreviated as PBT) and polybutylene phthalate (hereinafter referred to as
It is a conjugate fiber having a high degree of strength and having a polymeric polyester elastomer having a molar ratio of PBO (abbreviated as PBO) in the range of 8, 20 to 4, 60 as a polymeric component. The copolyester used in the present invention is mainly a coester polymerized compound of terephthalic acid and phthalic acid or their ester-forming derivatives as the dicarpone brewing component, and 1,4-butadiol as the glycol component. A village where the molar ratio of PBT obtained from acid and 1,4-butanediol and PBO obtained from phthalic acid and 1,4-butanediol is 8, 20 to 4
It means something in the range of 0 to 60.

In the present invention, it is important to use 1,4-butanediol as the main glycol component of the copolymerized polyester in order to provide the copolymerized polyester with excellent heat resistance, crystallinity, and thread-spinning property. Regarding the polymerizability of forming a polymer, the glycol component must be mainly composed of 1,4-butanediol.

Other aliphatic diols instead of 1,4-butanediol,
For example, when ethylene glycol is used, the degree of polymerization is low and it is difficult to obtain a polymer with a high degree of polymerization.

On the other hand, in the present invention, it is necessary to use terephthalic acid and phthalic acid as the main dicarboxylic acid components of the copolymerized polyester, and when isophthalic acid is used instead of phthalic acid, the elastic modulus is high and the flexibility is high. However, when an aliphatic dicarboxylic acid such as sebacic acid or adipic acid is used in place of phthalic acid, the elastic modulus becomes sufficiently low that it becomes flexible. ,
Poor elastic recovery.

Furthermore, in the copolymerized polyester of the present invention, PBT
In order to set the molar ratio of PBO to 80:20 to 40:60, the molar ratio of terephthalic acid and phthalic acid of the dicarboxylic acid component should be in the range of 8% to 20% to 4% to 60%. There is a need to.

The molar ratio of terephthalic acid and phthalic acid, i.e. PBT and P
The molar ratio of 80 to 20 is greater than 80:20 (PBT is 80
If the elastomer has sufficient flexibility and elastic recovery properties (more than 4 mol%), the elastomer may not have sufficient flexibility and elastic recovery, and if the molar ratio is 4.
It is smaller. If the PBT content is less than 40 mol %, it is not preferable because it cannot be put to practical use in terms of thermal properties and the polymerization reactivity and spinning properties are also poor. That is, the present invention
The molar ratio of terephthalic acid/phthalic acid is 80/20~40'
A copolyester with a PBT/PBO ratio of 80/20 to 40/60 obtained from a 60-dicarbonate brewing component and 1,4-butanediol is a thermoplastic material with exceptional flexibility, elastic recovery, thermal properties, and yarn-spinning properties. It discloses providing an elastomer, using such a copolymerized polyester as a composite component and an inelastic high molecular weight polymer as a pond component,
By eccentrically spinning these two components into composite fibers, it was possible to obtain a composite fiber with a high degree of streaking. Thus, the composite fiber of the present invention has a copolymerized polyester having PBT/PBO of 80'20 to 40'60 as a composite component as a main component, but up to about 20 mol% of each of the brewing component and the glycol component. It is also possible to add other copolymerization components and carry out polymerization depending on the intended use.

Examples of the third dicarboxylic acid that can be copolymerized include isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, diphenylp-p'-dicarboxylic acid, bis(p-carboxyphenyl)methane, and anthracene dicarboxylic acid. acids, aromatic dicarboxylic acids such as 4,4'-diphenyl ether dicarboxylic acid, ethylenebis-p-benzoic acid, 1,4-tetramethylenebis-P-benzoic acid, p-phenylene diacetic acid, adipic acid, suberic acid, Mention may be made of aliphatic and cycloaliphatic dicarboxylic acids such as azelaic acid, sebacic acid, dodecanedioic acid, 1,4-cyclohexanedicarboxylic acid. In addition, examples of the second diol that can be copolymerized include ethylene glycol, 1,2- and 1,3-propylene glycol, 1,3-butanediol, 1,5-pentanediol, neobentyl glycol, 1,6- Hexanediol, decamethylene glycol, diethylene glycol, 1.31 and 1.
4-cyclohexanedimethanol, p-dihydroxymethylbenzene, m-dihydroxymethylbenzene, 2.
Examples include 2-di(p-hydroxyphenyl)propane.

Furthermore, depending on the case, polyfunctional components such as polycarboxylic acids, polyols, and polyoxycarboxylic acids may be added, and by adding such polyfunctional components, the melt viscosity of the polymer can be increased or the polymerization rate can be increased. It is also possible to increase it. The amount of polyfunctional components that can be added is 0 to the dicarboxylic acid and diol components forming the polymer, respectively.
．． 02-3.0 mol%, preferably 0.05-3.0
It is mole%. Those that can be used as polyfunctional components include trimellitic acid, trimesic acid, pyromellitic acid, 3,3,4,4-benzophenonetetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, and Examples include derivatives thereof such as acid esters and acid anhydrides, glycerin, bentaerythritol, and the like. For the production of copolyester made of these components, conventional copolyester production methods can be applied as they are.

That is, dimethyl terephthalate and dimethyl phthalate are normally prepared in the presence of a molar excess of 1,4-butanediol, that is, about 1.05 to 2.0 times the mole, and a conventional esterification catalyst at a temperature of about 150 to 250 oo. pressure,
A heating reaction is carried out to perform transesterification, methanol is removed, and then the mixture is heated under reduced pressure of 3 Yanagi Hg or less at 200 to 2,600 Hg.
PBT/PBO copolymer can be obtained by heating and polycondensing at 0.0. In addition to the method using dimethyl ester, it is of course possible to synthesize it directly from dicarboxylic acid and glycol.
- Polymerization of pis(hydroxybutyl) terephthalate and phthalic anhydride from butanediol and bis(hydroxybutyl) phthalate from 1,4-butanediol, or polymerization of terephthalic acid and phthalic anhydride all at once. Esterification and military condensation may also be carried out from a mixture of these compounds and 1,4-butanediol.

Furthermore, homopolymers PBT and PBO are melt-blended, and by taking advantage of the fact that transesterification progresses smoothly in the presence of a small amount of transesterification catalyst, the polymers are randomized, thereby producing PBT/PBO, which is the object of the present invention. P
It is also possible to use BO copolyester, and the melt blending time may be about 10 minutes or more, but preferably about 15 to 90 minutes.

Although a wide variety of catalysts can be used, particularly preferred results are obtained using organic titanates, such as tetrabutyl titanate, alone or in combination with magnesium, calcium or zinc acetates. Also,
Mg [HTi(OR)4] derived from alkoxides of alkali or alkaline metals and titanate esters
A titanate body such as [2] is also one of the preferred catalysts. The composition of the present invention is an elastomer with excellent heat resistance and light resistance, but if higher stability is required depending on the application, stabilizers such as antioxidants and ultraviolet absorbers may be added. The stability can be further improved by Typical stabilizers include hindered phenol compounds and N/N'-bis(8-naphthyl).
Aromatic amines such as -p-phenylene diamine, etc. can be mentioned. It goes without saying that colorants, matting agents, inorganic fillers, organic modifiers, and the like can be added as necessary. On the other hand, in the present invention, as the pond component, that is, the non-elastic synthetic polymer to be composited with the elastic copolyester, known fiber-forming polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene isophthalate, etc. Polyesters consisting of a copolymer as the main structural unit within a range that does not inhibit crystallinity: polygocapramide (N6), a generally known amino acid-type polyamide containing amino acids as a component, polyhexamethylene adiper. mido (N66) and polyhexamethylene sebamide (N
Homopolyamides made of diamine dibasic acid type polyamides such as 610), polyamides copolymerized at a copolymerization ratio of 7% or less that has little effect on crystallinity, and polyamides made of melt blends of these polymers. Types: Polyolefins such as polystyrene and polyvinyl chloride can be used.

It goes without saying that these polymers can contain a light-resistant agent, a heat-resistant agent, a matting agent, a pigment, and other fillers, if necessary. The above two components are supplied to a well-known composite spinning machine according to a conventional method, and are melted and measured separately, guided into a composite spinneret, and formed into composite paper yarn in an eccentric thin sheath type or side-by-side type. The composite ratio of both components is 30/70
A range of 70/30 is preferred. The spun yarn may be cooled with cold air, applied with a spinning oil, and wound up in an unstretched state, or it may be subsequently stretched 3 to 5 times and then wound up. The drawn yarn is applied to knitted fabrics, woven fabrics, etc., either as it is or after heat treatment. As described above, the composite fiber of the present invention contains an inelastic synthetic polymer as one component, and PBT
Since the copolymerized polyester elastomer in which the molar ratio of PBO and PBO is in the range of 8 to 4 to 60 is used as a pond component, it has a high degree of sapon condensation without any tendency to cause condensation.
It also has excellent heat resistance and light resistance, and when such composite fibers are used for purposes such as women's stockings, a high-quality product with good shrinkage and excellent heat and light resistance can be obtained. The effects of the invention are significantly demonstrated. EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

In addition, the initial elongation rate, initial recovery rate, recovery rate after repeated stretching and contraction, as well as the strength retention rate and elongation retention rate by heat treatment or ultraviolet irradiation of the stockings used in the examples were measured as follows.

'11 Initial elongation rate and initial recovery rate of stockings The length of finished stockings was measured under no load.

shall be. Next, let us suspend a load of 2k9 and measure the length after 1 minute. If the length after 1 minute after removing the load of 2k9 is 2, it is given by the following equation.

Fine treatment rate = moxibustion side Initial recovery rate = Kojihiro X.

. (2) Recovery rate after repeated stretching and contraction of stockings Measure the length of the stockings under no load, then hang a 2k9 load, and measure the length after 1 minute. Repeat the operation 10 times, and then apply the 2k9 load for the 10th time. Remove the length of the stockings at the bottom.
9.2k9 The length after removing the load is 2.

Then, it is given by the following formula. Recovery rate after repeated expansion and contraction =; Shotei , , If the elongation is E, it is given by the following equation.

Strong retention rate = Poetry x・oo Extension = Long X・oo Example 1 In an 85% aqueous solution of caprolactam, 1/700 mole of acetic acid per mole of lactam and 3 parts per part by weight of lactam were added. 10-3 parts by weight of titanium oxide was added thereto, and the mixture was subjected to normal pressure under normal pressure at 257q0 for 1 hour according to a conventional method, and then spun and cut to form pellets.

This was washed twice with hot water for 6 hours to remove unreacted monomers and low polymers, and then dried with 98% sulfuric acid.
) was obtained. Next, a 50% aqueous solution of hexamethylene diammonium adipate and 1/300 acetic acid per mole of the above salt were added to the autoclave, the atmosphere was purged with nitrogen, the autoclave was sealed, and the pressure was increased to 210 pm. It was heated to 17.5k9'.

Heating was continued for another 2 hours while maintaining the pressure at 17.5 k9/base, and then the pressure was gradually reduced to 180 bar Hg.
After holding for 0 minutes, it was embossed by nitrogen pressure, cut into chips, and 98% sulfuric acid, relative viscosity 2.45, melting point 255.
00 polyhexamethylene adipamide (B) was obtained. 113.5 parts of dimethyl terephthalate, 6 parts of dimethyl phthalate
1.1 parts and 121.5 parts of 1,4-butanediol were placed in an autoclave equipped with a stainless steel helical ribbon fly wing along with 0.08 parts of titanium tetrabutoxide, and heated at 210 CO for 2 hours to produce methanol. It was distilled out of the reaction system.

The amount of methanol distilled off was 52.0 parts, 90% of the theoretical amount.
corresponds to Next, the reaction temperature was raised to 245° C., the pressure in the system was reduced to 0.1 Hg over about 1 hour, and the polycondensation reaction was continued at this pressure for 3 hours to obtain a transparent sticky steel polymer (C).
The PBT/PBO composition of polymer (C) is 65'35, the intrinsic viscosity at 25q○ in orthochlorophenol is 1.3, and the lipolymer melting point (DSC peak temperature) is 170.
It was ℃. For comparison, polymerization was attempted by changing 1,4-butanediol to ethylene glycol in the polymerization of polymer (C), and polymer (0) was obtained, but the polymerization reaction rate was low and it was difficult to make a product with a high degree of polymerization. could not.

In addition, in the polymerization of polymer (C), dimethyl phthalate was replaced with dimethyl isophthalate and dimethyl sebacate, and the other conditions were the same, and the copolymerized polyester composition P
Polymers (E) and (F) of BT/polybutylene isophthalate = 65/35 and PBT/polybutylene sebacate = 65/35 were produced, respectively.

Polymer properties of polymers (B) and (F) were that the viscosities were 1.28 and 1.35, and the melting points were 168° C. and 170 pm, respectively. Using polymers (A) to (F), they were combined as shown in Table 1 and fed to a composite yarn machine to form a bimetallic yarn with a composite ratio of 50/50.
The yarn was taken off at min. and stretched 4.1 times to obtain a 20 denier 1-filament yarn.

This is fed to a stocking sog knitting machine with a 4-head yarn feeding system, knitted as the leg part of stockings, and after scouring and dyeing, it is fitted into a foot shape.
Finishing setting was done for 1 minute at 10qo. The physical properties (initial elongation rate, initial recovery rate, and recovery rate after repeated stretching and contraction) of the stockings M to ■ obtained were as shown in Table 1.

Table 1 As is clear from Table 1, stocking No. 1 and no. Sample No. 4 had a high elongation rate and also showed a small decrease in recovery rate after repeated stretching and contraction.

On the other hand, stocking No. 1 obtained from a polymer combination other than the present invention. In No. 2, peeling of the two composite components occurred and the physical properties were also poor. Also, stocking No. In case 3, a fairly high level of initial elasticity was obtained, but
Due to repeated stretching and contraction, the recovery properties were poor, resulting in stockings with long twilight. Example 2 Dimethyl terephthalate 5-contact 1,4-butanediol B was added, and 3 x 10-4 parts by weight of cobalt chloride and 2 x 104 parts by weight of calcium acetate were added to 1 part by weight of terephthalic acid. In addition, 19,000 while condensing
After the methanol was distilled off, the temperature was raised to 25,000 ℃, the pressure was gradually reduced, and the pressure was kept at 1 Hg or less for 2 hours to obtain a viscous polymer.

This was extruded into a gut shape, cooled with water, and then cut to obtain polybutylene terephthalate (G) having an orthochlorophenol intrinsic viscosity of 1.31 and a melting point of 228°C. In the same manner as for polymer (C) in Example 1, the molar ratio of dimethyl terephthalate and dimethyl phthalate was adjusted to 90'10.7.
Polymerization was carried out by changing the ratio to 0'30, 50/50, 30'70, and PBT/PBO was 90/10 and 70'3, respectively.
0.50/50.30'70 polymer (H) (1)
・(J)・(K) were obtained. Polymer (K) did not have a sufficient degree of polymerization and was not worthy of evaluation. Polymer (H)
・The viscosities of (1) and (J) are 1'27 and 1.28, respectively.
・1.28 melting point is 21500, 18600, 1 respectively
It was 3500. Under the same conditions as Example 1, polymer (G
) and polymers (H), (1), and (J) were spun, stockings (5) to (7) were knitted, and the physical properties of the stockings were evaluated. The results are shown in Table 2.

Table 2 Stockings No. obtained from composite systems other than the present invention. 5 is
Stocking No. 1 obtained from the composite system of the present invention was rough and hard and had poor elasticity. 6 and no. No. 7 had good elasticity and did not suffer from poor elasticity even after repeated expansion and contraction.

Example 3 1.9 parts of terephthalic acid, 1.18 parts of phthalic anhydride, 1
．． 3.6 parts of 4-butanediol and 0.0384 parts of trimellitic anhydride were placed in an esterification reactor, and 21
After reacting for 4 hours at 0°C, the temperature was raised to 23'0 and the system was brought to a vacuum of 0.3 side Hg with 7 females, then 2450
The temperature was raised to 0 and polymerization was carried out for 3 hours to obtain a copolymer (L).

The obtained copolymer (L) had an intrinsic viscosity of 1.25 and a melting point of 16r0.

From 196.8 parts of terephthalic acid, 200 parts of poly(tetramethylene oxide) glycol with a number average molecular weight of 1,000, and 177 parts of 1,4-butanediol, poly(tetramethylene oxide) glycol was converted into a soft segment according to a conventional method. A block copolyether ester (M) was prepared.

The melting point of this block copolymer (M) is 16 mm, the intrinsic viscosity is 1.26, the hard segment is PBT, the soft segment is poly(tetramethylene oxide) glycol, and the ratio of hard segment to soft segment in the polymer. is approximately 5 to 50. Commercially available thermoplastic polyurethane “Paraprene 26” (manufactured by Nippon Polyurethane,
Raw material composition: Polybutylene adibate as a soft segment, methane diisocyanate as a diisocyanate, and 1,4-butanediol as a chain extender) are used as a polymer (N).

Polymer (C) of Example 1 and the above polymer (L)
(M) and (N) are melt-spun by a normal method, and the third
Single component yarn M. I got 8, 9, 10, and 11.

Thread No. 8 and no. Although yarn No. 9 could be drawn satisfactorily, paper yarn No. 9 could be drawn well. 10 and no. When No. 11 was wound with a drawn yarn, the adhesion between the fibers was large, resulting in frequent yarn breakage during the drawing process, and yarn unevenness was also large.

(The obtained drawn fibers were heat-treated in an oven at 110° C. for 5 minutes, and then the yarn physical properties (strength retention and elongation retention) were tested.

In addition, using a fade meter, the fibers were irradiated with ultraviolet light at 4000°C for 5 hours, and then the yarn physical properties (strength retention and elongation retention) and discoloration were examined.

The results are shown in Table 3. Yarn No. of the present invention. 8 and no. In No. 9, there was very little deterioration in strength and elongation due to heat treatment and ultraviolet treatment.

On the other hand, yarn No. obtained from polyurethane. No. 11 is a yarn fabric made of block polyester ester and has poor heat resistance and light resistance. Sample No. 10 had good heat resistance but extremely poor light resistance. Table 3

Claims (1)

[Claims] 1 A composite fiber in which at least two components are eccentrically composited in the cross section of a single filament, in which an inelastic synthetic polymer is one component, and polybutylene terephthalate and polybutylene phthalate are combined in a molar ratio of 80: A conjugate fiber having a high degree of sacrificial shrinkage, the other component being a copolymerized polyester elastomer having a ratio of 20 to 40:60.