JPH0457773B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to elastic yarns, and particularly to elastic yarns with low permanent deformation and excellent elastic properties. Conventionally, rubber, polyurethane, etc. have been used as elastic threads. Although these materials are excellent in terms of elastic recovery, they have drawbacks such as excessive elongation and poor heat resistance and light resistance. On the other hand, in recent years, polyether/polyester block copolymer elastomers have been proposed for resin applications. When made into thread, this elastic body is not as good as polyurethane in elongation recovery rate, but it exhibits a relatively good recovery rate under low elongation, and also has the advantage of being able to be melt-spun. This polyether
Unlike polyurethane, which uses hydrogen bonds, polyester block copolymer elastomer uses hard segment crystals to connect the flow of molecules, so the bonding force is not necessarily sufficient, and it is susceptible to external forces received during the spinning process. The disadvantage is that the elastic properties are easily affected. The inventors of the present invention have made extensive studies to solve this problem, and as a result, have found that the problem can be solved by blending a specific inorganic fine powder, and have arrived at the present invention. That is, the present invention uses a dicarboxylic acid component mainly consisting of terephthalic acid, a glycol component mainly consisting of tetramethylene glycol, and an average molecular weight of 800.
~3000 polyoxyalkylene glycol as a constituent component, and the content ratio of the polyoxyalkylene glycol component (soft segment component) is 50 to 85
Based on 100 parts by weight of polyether/polyester block copolymer, china clay,
Kaolin, calcium carbonate, calcium phosphate,
This is an elastic thread made of a polyether/polyester block copolymer composition containing 0.01 to 15 parts by weight of at least one type of inorganic fine powder selected from titanium oxide. The polyether/polyester block copolymer of the present invention has terephthalic acid as the main acid component, polyester having tetramethylene glycol as the main glycol component as the hard segment, and polyoxyalkylene glycol as the soft segment. Here, "main" usually means
It means 70 mol% or more, preferably 80 mol% or more. Examples of the polyoxyalkylene glycol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymers thereof. The molecular weight of polyoxyalkylene glycol is preferably 800 to 3000. The hard segment/soft segment ratio of the polyether/polyester block copolymer (hereinafter abbreviated as block copolymer) can vary over a wide range depending on the required performance.
It ranges from 15/85 to 50/50 on a weight basis. The degree of polymerization of such block copolymers can vary widely depending on the required performance, but
The reduced specific viscosity measured as an orthochlorophenol solution at 35°C is preferably about 1.0 to 2.5. The above block copolymer can be easily produced by a common method for producing copolyesters. Specifically, terephthalic acid or its ester-forming derivative, tetramethylene glycol, and polyoxyalkylene glycol are usually charged into a reactor, subjected to a direct esterification reaction or transesterification reaction in the presence or absence of a catalyst, and further under vacuum. A method of carrying out a polycondensation reaction until a desired degree of polymerization is achieved is adopted. Further, the polyoxyalkylene glycol may be added at any other arbitrary point, for example, at the beginning of the polycondensation reaction. In addition, the block copolymer contains, as well as ordinary polyester such as polyethylene terephthalate, a matting agent such as titanium oxide, a pigment such as carbon black, an antioxidant such as a hindered phenol compound or a hindered amine compound, a benzophenone compound, Ultraviolet absorbers such as benzotriazole compounds and salicylate compounds and other additives may also be included. The inorganic fine powder to be blended into the block copolymer may be any inorganic fine powder that does not affect the crystallinity of the block copolymer, and may include china clay, kaolin, calcium carbonate, calcium phosphate, titanium oxide, etc., which have an lubricity effect. It is preferable to have the following. The blending amount of inorganic fine powder is 100% block copolymer.
0.01 to 15 parts by weight are required, especially
0.5 to 10 parts by weight is preferred. In addition, the particle size of the inorganic fine powder only needs to be at a level that does not cause trouble during the spinning process; if the particle size is too large, the pack pressure during spinning is likely to increase and yarn breakage is likely to occur; on the other hand, if the particle size is too small, Unless the blending amount is increased, it will be difficult to obtain the expected effect. A particle size of about 0.1 to 10 μm is preferable, and the optimum particle size may be selected as appropriate depending on the stabilization of the process, the improvement of physical properties, the intended use of the elastic yarn, and the fineness. Further, the inorganic fine powder can be added at any stage during the production of the block copolymer, or even at any stage until the melt spinning is completed. The block copolymer composition described above can be made into an elastic yarn by melt spinning, and can be drawn and/or heat treated continuously or discontinuously after spinning, if necessary. . The elastic yarn of the present invention thus obtained has a reduced initial modulus. This is considered to be due to the advanced amorphization of the soft segment portion, which is preferable for elastic yarns. In addition, this elastic thread has reduced frictional resistance,
Since the winding property is improved, there is an advantage that no special means is required for winding, and there is also an advantage that tension fluctuations due to guides and the like during spinning and post-processing are reduced. Furthermore, this elastic yarn exhibits good stretch recovery under low elongation of 100% or less, especially 50% or less, and
In the medium deformation stretch field, it has better post-processability compared to polyurethane elastic yarns. The present invention will be explained in detail with reference to Examples below. Note that parts and percentages in the examples are parts by weight and percentages by weight, and the performance of the product elastic yarn was measured by the following method. 1. Stretch recovery (1) Instantaneous stretch recovery rate Apply a load corresponding to 50% or 100% stretch to a 10 cm sample, quickly stretch it by 50% or 100%, remove the load after 5 seconds, and quickly reduce the sample length to 1 cm. Read and calculate using the following formula. Instantaneous elongation recovery rate = 10 - (l - 10) / 10 × 100 (%) (2) Elongation modulus JIS L1073 (1977) Synthetic fiber yarn test method, elongation modulus B method 10
%, elongation modulus at 50% or 100% elongation. (3) Long-term elongation recovery rate A load equivalent to 100% elongation is applied to a 10 cm long sample and left for 4 hours (sample length at this time is 1 cm), then the load is removed and the recovery rate after being left for 4 hours. Measure the sample length l'cm and calculate it using the following formula. Long-term extension recovery rate = l-l'/10 x 100 (%) 2 Permanent set When measuring long-term extension recovery rate Permanent set = l'-10/10 x 100 (%) Examples 1 to 9 and comparison Examples 1 to 3 167.3 parts of dimethyl terephthalate, 105 parts of tetramethylene glycol, 325 parts of polytetramethylene glycol with a number average molecular weight of 2000, 0.35 parts of tetrabutyl titanate and 0.5 parts of pentaerythritol were charged into a reactor, and esterification was carried out at an internal temperature of 170°C. An exchange reaction was carried out. When about 70% of the theoretical amount of methanol had been distilled off, the inorganic fine powder shown in Table 1 was added in the amount shown in the table (this inorganic fine powder was added as a 20% tetramethylene glycol slurry). Next, the temperature in the system was raised and the pressure started to be reduced to 30 mmHg over about 30 minutes, then to 3 mmHg over a further 30 minutes, and then a polycondensation reaction was carried out for 240°C at an internal temperature of 245°C under vacuum of 1 mmHg. The performance of the obtained polymer was evaluated first.
Shown in the table. After drying the polymer thus obtained,
Melt at ℃, flow rate 20g/min, winding speed 1100m/
I wound it up in minutes. The obtained elastic yarn was treated under the conditions listed in Table 1, and its properties were measured, and the results are shown in Table 1. As is clear from the table, as the amount of inorganic fine powder added according to the present invention increases, the elastic properties become better. In addition, the coefficient of friction of the elastic yarn of the present invention hardly changes when post-treated, but the elastic properties are changed by heat treatment at a constant length of 5 seconds at 85°C in a moist heat state or by stretching at a magnification of 1.5 times (at room temperature).
It has improved with treatment. In addition, it is recognized that there is no change in crystallinity depending on the presence or absence of blending of inorganic fine powder.

【table】

[Table] Example 10 and Comparative Example 4 The same procedure as Example 5 was carried out except that 325 parts of polyethylene glycol with a number average molecular weight of 3000 was used in place of the polytetramethylene glycol used in Example 5. Shown in the table. For comparison, the same procedure as in Example 10 was conducted except that no inorganic fine powder was used, and the results are shown in Table 2 as Comparative Example 4. As is clear from Table 2, the elastic properties of the elastic yarns in the examples are good and the coefficient of friction is small.
Further, in the examples, no trouble occurred during either melt spinning or winding. Further, no change in crystallinity was observed depending on the presence or absence of inorganic fine powder.

【table】

Claims (1)

[Claims] 1 dicarboxylic acid component mainly consisting of terephthalic acid,
The constituent components are a glycol component mainly consisting of tetramethylene glycol and a polyoxyalkylene glycol having an average molecular weight of 800 to 3000, and the content of the polyoxyalkylene glycol component is 50 to 50.
0.01 to 15 parts by weight of at least one type of inorganic fine powder selected from china clay, kaolin, calcium carbonate, calcium phosphate, and titanium oxide is blended with 100 parts by weight of a polyether/polyester block copolymer containing 85% by weight. An elastic thread made of a polyether/polyester block copolymer composition.