JPH0424467B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a sheet-like article with excellent dimensional stability. More specifically, the present invention relates to a method for producing a sheet-like product with excellent dimensional stability that does not cause excessive shrinkage due to dry heat or wet heat treatment when the sheet-like product is sewn into a product. BACKGROUND ART Conventionally, it has been widely known to impregnate a polyurethane elastomer into a base fabric mainly composed of ultrafine fibers and to obtain artificial leather-like materials by raising the ultrafine fibers. The quality of such an artificial leather-like product can be designed arbitrarily by the combination of the base fabric and polyurethane elastic body used, but in order to obtain an artificial leather-like product that has both graceful surface quality and a firm and flexible texture, The inventor is JP-A-Sho.
No. 53-61766 has already proposed a method in which a fiber sheet made of a combination of ultrafine fibers of 0.5 denier or less and knitted fabrics is used as a base fabric, and this is impregnated with an elastic material such as a polyurethane elastic material. The feature of this method is that it uses knitted fabrics that are intertwined with ultra-fine fibers as a component of the base fabric, so it has the strength and elongation required for clothing, shoes, bags, gloves, etc. It can be applied relatively easily depending on the design of knitted fabrics, and ultrafine fibers are used as a component to express graceful surface quality, and polyurethane elastic bodies mainly provide a soft texture that is comfortable to hold in the hand. The major advantage is that each component can be designed basically independently. Therefore, the type and amount of polyurethane elastomer can be selected without any special restrictions depending on the purpose.
The inventors of the present invention focused on the fact that conventional artificial leather-like materials could only have a rubber-like texture and firmness compared to high-quality wool fabrics used for suits, etc., and made efforts to improve the texture. By using a polyurethane elastomer made of polytetramethylene glycol, organic diisocyanate, and a glycol chain extender as the polyurethane elastomer, it has become possible to obtain an extremely soft texture. However, there is an attempt to industrially produce a sheet material obtained by impregnating a base fabric made of ultrafine fibers of 0.5 denier or less and knitted fabrics with a polyurethane elastomer made of polytetramethylene glycol, organic diisocyanate, and a glycol chain extender. I discovered that there was a surprising problem. In other words, when processing such a sheet-like material into a suede-like artificial leather-like material, finishing processes such as dyeing, brushing, antistatic, water repellent, and stain-proofing are required, but this is not possible industrially. are often processed using long objects, which inevitably causes excessive tension in the warp direction.As a result, when the resulting sheet-like objects are sewn into coats, blazers, etc.
It has been found that the heat of steam or ironing causes the garment to shrink significantly, causing fatal defects such as uneven puckering, which makes it impossible to form a shape as a garment. As a result of further investigation into the improvement of the above-mentioned sheet-like material made of the specified base fabric and polyurethane elastic material, which have excellent surface quality, texture, and physical properties, the present inventor finally found the present invention. This invention has been achieved. That is, the present invention is obtained by impregnating a base fabric made of a combination of a nonwoven fabric made of ultrafine fibers of 0.5 denier or less and a knitted fabric with a polyurethane elastomer made of polytetramethylene glycol, an organic diisocyanate, and a glycol chain extender. When finishing a sheet-like article, the material has excellent dimensional stability, characterized in that relaxation heat treatment is performed at a temperature equal to or higher than the softening point of the polyurethane elastomer between the above finishing steps or following these finishing steps. The method is for manufacturing a sheet-like product. The manufacturing method of the present invention will be explained in detail below. The material and fiber length of the ultrafine fibers used for the base fabric can be selected arbitrarily, but the fineness should be 0.5 denier or less in order to obtain the fine surface quality and riding effect of suede-like or pack-like sheets. It is necessary that Preferred examples of the material include polyester, polyamide, polyacrylonitrile, cellulose, and kyupracellulose. The fiber length may be short fibers cut to 1 to 50 mm, or longer than 100 mm or substantially long fibers depending on the purpose. As a method for producing such ultrafine fibers, the known sea-island fiber method, mixed fiber method, direct spinning method, melt blow method, spunbond method, etc. can be used. As knitted fabrics, knitted fabrics such as weft knits and tricot knits, and fabrics with textures such as plain weave, twill weave, satin weave, and patterned weave are preferably used, and raw yarns for the knitted fabrics include straight yarn and false twist. Processed yarn is preferred. To obtain a base fabric consisting of ultrafine fibers and knitted fabrics,
For example, a non-woven fabric is formed using random webber, cross-layering, or papermaking, and then a knitted fabric is inserted in the middle to form a non-woven fabric, and then the ultra-fine fibers are layered together or the ultra-fine yarn and the knitted fabric are layered together using needle punching, high-pressure columnar water jets, etc. It can be obtained by intertwining and integrating them. The polyurethane elastic material impregnated into the base fabric is flexible,
In order to obtain a texture that does not have a stiff, rubber-like hardness and is resistant to wrinkles, a polyurethane consisting of polytetramethylene glycol, an organic diisocyanate, and a glycol chain extender is required. Polytetramethylene glycol has a molecular weight of
Preferably, a range of 500 to 4000 is used. As the organic diisocyanate, diphenylmethane
Aromatic diisocyanates such as 4,4'-diisocyanate, tolylene diisocyanate, and xylylene diisocyanate are preferred, but aliphatic diisocyanates such as hexamethylene diisocyanate, isoforone diisocyanate, and fatty acids such as dicyclohexylmethane-4,4'-diisocyanate are preferred. Cyclic diisocyanates can be used. As the chain extender, it is necessary to use glycols. When diamines are used, especially when applied to the above-mentioned base fabric, the texture becomes paper-like and hard, which is not preferable. Glycols include low molecular weight glycols such as ethylene glycol, 1,4
-butanediol and the like are particularly preferred. Methods for imparting such a specific polyurethane elastic body to the base fabric of the present invention include the usual dry coagulation method,
A wet coagulation method can be applied, but the polyurethane elastomer is dissolved in an organic solvent such as dimethylformamide or dimethylacetamide, and the base fabric is impregnated with the solution. A wet coagulation method in which coagulation is performed using a mixed solution or the like is particularly preferred from the viewpoint of soft texture. The sheet-like material thus obtained is subjected to dyeing, napping, and, if necessary, finishing processes such as antistatic, water repellent, and antifouling. When carried out industrially, among these finishing processes, the dyeing process is performed using a winch type dyeing machine, a loco type liquid jet dyeing machine,
A circular jet dyeing machine, a Jitzger dyeing machine, etc. can be used. In the raising process, machines such as a drum sander, belt sander, and cloth raising machine can be used. In antistatic, water repellent, antifouling, etc., solutions or dispersions of the respective chemicals are squeezed at a predetermined squeezing rate using a pad or dip, and dried using a pin tenter, grip tenter, or the like. Between these finishing steps or following these finishing steps, a relaxation heat treatment step is applied at a temperature equal to or higher than the softening point temperature of the polyurethane elastomer. The softening temperature of the polyurethane elastomer referred to herein is the temperature at which it begins to flow when a polyurethane dry film 2.5 cm wide and 5 cm long is stretched under a load of 1 kg. For example, when the organic diisocyanate component of the polyurethane elastomer used in the present invention is diphenylmethane-4,4'-diisocyanate, the temperature range is 100 to 130°C, so the relaxation heat treatment temperature should be 100 to 130°C or higher. good. If the temperature of the relaxing heat treatment is below the softening point, the relaxing effect will not be sufficient and the resulting sheet material will shrink significantly due to the heat during sewing, making it unsuitable as a clothing material. The time for the relaxation heat treatment is about 1 to 10 minutes, preferably 1 to 5 minutes. When subjected to relaxation heat treatment for a period of 10 minutes or more, the polyurethane elastomer may decompose, and the texture becomes hard, which is not preferable. Industrial methods for loosening include shaking it off with a can while applying overfeed with a dryer such as a pin tenter or grip tenter;
Alternatively, a method of rolling it up with a low tension of 100 g/cm or less, a method of relaxing treatment with a tumbler dryer, etc. can be used. When the sheet-like article of the present invention obtained by the above method is used for clothing, it can be used with steam from a Hoffman press used for finishing molds during sewing, or with dry heat used for adhering interlining and dividing seams. Alternatively, the present invention provides clothes with excellent tailoring that do not substantially shrink even when subjected to heat treatment using a moist heat iron or the like. Hereinafter, aspects of the present invention will be explained using Examples. The numerical values used in the examples are those expressed by the following evaluation method. (1) Flexibility: Value measured by JIS L-1079 45° cantilever method (mm) (2) Wrinkle resistance: Value measured by JIS L-1096 wire method (%) (3) Shrinkage rate: 100℃° Area shrinkage rate (%) when treated in boiling water for 3 minutes. According to studies conducted by the present inventors, the shrinkage rate in this evaluation method, which allows good tailoring to be obtained by sewing, is 3% or more. Example 1 Polyethylene terephthalate (hereinafter referred to as PET) with a single fiber fineness of 0.1 denier obtained by a direct spinning method.
It is abbreviated as ) The fiber was cut into 3 cm pieces. On the other hand, short fibers of polyvinyl alcohol (hereinafter abbreviated as PVA) with a single filament fineness of 1 denier and a cut length of 3 mm were prepared and mixed at a PET/PVA ratio of 70/30% by weight.
A sheet with a basis weight of 80 g/m ² was obtained using the papermaking method. A woven fabric made of 75d/36f PET false-twisted yarn and having a basis weight of 50 g/m ² was inserted between the two sheets in a sandwich pattern to form a laminated sheet. The front and back sides of this laminated sheet were alternately treated with water jets at a pressure of 15 kg/cm ² from multiple nozzles with 0.2 mm orifices to thoroughly entangle the ultrafine fibers and the fabric in three dimensions. Next, after drying this intertwined sheet, the front and back sides were raised using a belt cider equipped with 240 mesh emery paper. The brushed surface was coated with carboxymethyl cellulose (CMC) to a thickness of 0.1 mm using a doctor knife and dried. A separately prepared prepolymer obtained from polytetramethylene glycol with a molecular weight of 2000 and diphenylmethane-4,4'-diisocyanate was chain-extended with ethylene glycol, and the molecular weight was approximately 5 and the softening point.
The interlaced sheet was impregnated with a 15% dimethylformamide solution of polyurethane at 120°C, coagulated in water at 20°C, and then dried. Thereafter, the PVA fibers and CMC were extracted and dried in boiling water for about 20 minutes. The sheet-like material thus obtained was dyed with a disperse dye Sumikaron Red-SBL 10% owf using a roller dyeing machine, and then hydrosulfite soda 5% owf.
Cleaned with reduction. Furthermore, the sheet was impregnated with a 1% aqueous dispersion of an acrylic acid ester antistatic agent and a silicone water repellent, and after squeezing the liquid with a mangle, a pin tenter dryer set at a temperature of 140°C was used to overfeed the sheet by 3%. The mixture was dried at a temperature of 5 minutes with a residence time of 5 minutes. The sheet-like material obtained by this relaxation heat treatment has a suede-like fine surface nap, has an excellent writing effect, and is surprisingly flexible and wrinkle-resistant with a flexibility of 38 mm and a wrinkle resistance of 83%. It was hot. Moreover, the shrinkage rate was 0.8%. When this sheet-like material was sewn as fabric for a men's blazer, it did not shrink at all even after undergoing heat treatments such as interlining adhesion (130°C), seam splitting (120°C), and finishing press (140°C). The blazer was well tailored. Comparative Examples 1 and 2 A sheet-like material obtained in the same manner as in Example 1 after reduction cleaning was impregnated with a 1% water dispersion of an acrylic acid ester antistatic agent and a silicone water repellent, and squeezed with a mangle. After the liquid, it was dried using a pin tenter dryer set at temperatures of 90°C and 110°C with an overfeed rate of 3% and a residence time of 5 minutes. The sheet-like material obtained by this relaxation heat treatment had suede-like fine surface naps, was soft, and was resistant to wrinkles, but had the disadvantage of a high shrinkage rate. The physical properties of this product are shown in Table 1. When this sheet-like material was used to sew a men's blazer in the same manner as in Example 1, puckering occurred at the back seam due to heat shrinkage, resulting in a very poor tailored look. 【table】

Claims (1)

[Claims] 1. Polytetramethylene glycol, organic diisocyanate,
When finishing a sheet material obtained by impregnating a polyurethane elastomer made of a glycol chain extender, the temperature is higher than the softening point of the polyurethane elastomer during or following the above finishing steps. A method for producing a sheet-like product with excellent dimensional stability, characterized by subjecting it to relaxation heat treatment.