JPH0663180B2 - Method for producing a leather-like sheet with a good surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has a good stretchability, and a silver-like leather-like sheet material having excellent surface smoothness that leaves little wrinkles on the surface even if stretched. It is about.

[Conventional technology]

Many silver-like leather-like sheet materials have been proposed in the past, but all of them are obtained by coating an elastic polymer film on the surface of a substrate having low elasticity. For example, in JP-A-60-7876, JP-A-60-21980, and JP-A-60-71777, a silver surface layer is formed on a composite in which a resin is contained in a fiber structure of ultrafine fibers or a bundle thereof. Artificial leather to which is added is proposed. Further, the present inventors have already proposed a stretchable sheet composed of elastic fibers and non-elastic fibers in JP-A-59-211664 and JP-A-59-211666.

[Problems to be solved by the invention]

In all of the conventional silver-like leather-like sheet materials, a surface coating layer is provided on a substrate having low elasticity. Since such a silver-like leather-like sheet material does not undergo repeated stretching action or large elongation, the stretchability of the surface coating layer has not been a problem. Therefore, a polyurethane elastomer has been widely used as a polymer for forming a surface coating layer, but conventional polyurethane elastomers have emphasized heat fixing property and surface strength. Further, even a silver-like leather-like sheet material used for clothing is not required to have elasticity because it is thin and has flexibility.

Therefore, even if a conventionally used polyurethane elastomer film is applied to a highly stretchable base to finish it into a leather-like sheet with silver, repeated stretching will cause wrinkles and wrinkles on the surface, which will not only impair the appearance. However, the scratch resistance of the surface is extremely reduced. On the other hand, it is not possible to obtain a silver-like leather-like sheet material having a good appearance, such as a large wrinkle and a good surface property, by simply providing a film having a high elasticity to the substrate.

[Means for solving problems]

INDUSTRIAL APPLICABILITY The present invention provides a silver-like leather-like sheet having high elasticity, leaving almost no wrinkles in the surface coating layer even when subjected to repeated expansion and contraction, having excellent surface smoothness, and having good surface physical properties. It is in.

That is, the present invention provides a stretchable entangled nonwoven fabric formed by blending non-elastic fibers and elastic fibers into an integrated material, or a stretchable entangled nonwoven fabric containing an elastic polymer in the stretchable entangled nonwoven fabric to provide a coating layer of the elastic polymer. In the method for producing elastic stretchable leather-like sheet material, the elasticity of the elastic entangled non-woven fabric and the elastic polymer film was measured according to JIS L-1096, 6.13.1A method, and was 30%. The elastic recovery rate during stretching is at least 70% after 30 seconds after unloading, and the recovery rate of elastic entangled nonwoven fabric
Es, recovery ratio Eg of elastic polymer film Eg / Hs is 0.98 ≦ Eg /
A method for producing a leather-like sheet material with a good surface, comprising a material satisfying the condition of Es ≦ 1.15.

The stretchable entangled nonwoven fabric as the substrate of the present invention comprises an ultrafine fiber bundle-generating multicomponent fiber or / and a single inelastic fine fiber composed of at least two kinds of inelastic polymers having different solubilities.
90-40% by weight, 10-60% by weight of sea-island cross-section structure fiber or core-sheath cross-section structure fiber composed of non-elastic polymer and elastic polymer is mixed to form a web, and then the needle punch method or /
And fibers which are entangled by a fluid injection method to form an entangled non-woven fabric, which is optionally contracted and / or impregnated with a solution or dispersion of an elastic polymer and solidified, and then made of a non-elastic polymer and an elastic polymer. By treating with a treatment agent which is a solvent or decomposing agent for the non-elastomeric polymer, and is a solvent, decomposing agent or swelling agent for the non-elastomeric polymer of the ultrafine fiber bundle-generating multi-component fiber, The ultrafine fiber bundle generating multi-component fiber is an ultrafine fiber bundle, and one is an entangled non-woven fabric in which both fibers are mixed and mixed with each other. In this case, shrinkage occurs in the entangled nonwoven fabric, but if the shrinkage rate is small, the elasticity of the product is small, so if the area shrinkage rate is less than 20%, further heat treatment, hot water treatment, chemical treatment, etc. Shrinkage is given to have an area shrinkage of 30%, and if necessary, the surface is made into a smooth surface by buffing, slicing, calendering, etc. to make an entangled nonwoven fabric. The stretchability of this entangled nonwoven fabric is JIS L
-1096 6 ・ 14 ・ 2 Elasticity measured according to BI method is 0.8mm in thickness, 50mm in width, 300mm in length when one end is fixed and 1.5kg load is hung at the other end, it is at least 25 %, And the elastic recovery after 30 seconds after unloading is at least 70%, which is flexible and highly stretchable.

In addition, the elastic polymer film constituting the surface coating layer of the present invention impairs the appearance as a silver-skin leather-like sheet even if the elastic recovery rate is excessively high or low, so the elastic recovery rate is important. Is. Therefore, in the present invention, the stretchability of the stretchable entangled nonwoven fabric and the elastic polymer film is JIS L-10966.
・ The elastic recovery rate at 30% elongation measured in accordance with 13.1A method is at least 70% after 30 seconds after unloading, and the recovery rate Es of the entangled nonwoven fabric and the recovery rate Eg of the elastic polymer film are Ratio Eg / Es
Is to be made of a material satisfying the condition of 0.98 ≦ Eg / Es ≦ 1.15. The surface of which the elastic recovery ratio of the constituent materials is smaller than 0.98 causes wrinkles and damages the appearance. On the other hand, if it is larger than 1.15, winding is caused so that the substrate side becomes the surface, or a large wavy state occurs, which is not preferable.

The ultrafine fiber bundle generating multi-component fiber constituting the entangled nonwoven fabric of the present invention dissolves at least two kinds of inelastic polymers having different solubilities in the same dissolution system and utilizes the dispersion state of the inelastic polymer. Then, at least one polymer is used as a dispersion medium component, and another polymer is used as a dispersion component, and the fibers are spun into a sea-island structure. Dissolve with different melt yarns, regulate with a spinning head or spinneret, and use one polymer as a dispersion medium component, and another polymer as a dispersion component to form a sea-island structure or a multicore sheath structure in the cross-sectional shape of the fiber. Spin it. It is melted in different melting systems and spun into joint-type split fibers that can be split into a large number of fine fibers by regulating with a spinneret. An ultrafine fiber bundle fiber is obtained by treating the sea component or the sheath component in the sea-island structure or the core-sheath structure fiber, and the single component solvent, the decomposing agent or the swelling agent in the joining type split fiber. Is obtained. The ultrafine fibers have an average fiber of less than 0.3 denier.

Further, the non-elastic fine fiber is a single component obtained by high speed spinning, super draw method, flash spinning, etc. and has an average fineness of less than 0.5 denier. The ultrafine fiber bundle fiber or the fine fiber is a fiber made of a polymer having fiber performance, for example, a polyester having 80 mol% or more of terephthalate such as polyethylene terephthalate and polybutylene terephthalate. Polyamides such as nylon-6, nylon-6,6, nylon-6,10, nylon-12. Acrylonitrile copolymers, polyolefins such as polyethylene and polypropylene, regenerated cellulose, polyvinyl alcohol and the like are used. On the other hand, the polymer to be removed may be one which does not have good spinnability in a single spinning, but is generally a high-fluidity polyethylene, polystyrene, polyvinyl chloride, ethylene-vinyl acetate copolymer, an aliphatic type and / or an aromatic compound. Group polyester is used.

On the other hand, the non-elastic polymer and the elastic polymer make fibers that control the elasticity of the product, the non-elastic polymer is a component to be removed, the above-mentioned polymer can be applied, but preferably stretchability, It has fixing property, crimping property, and carding property. Further, as the elastic polymer, the tension state is released by removing the non-elastic polymer after forming the fiber, and the rubber elastic behavior is exhibited. For example, acrylonitrile-butadiene copolymer, butadiene, isoprene,
Polyurethane elastomers and polyester elastomers are preferred, but polyurethane elastomers and polyester elastomers are preferred from the viewpoints of spinnability, heat resistance, elasticity adjustment and the like. Polyurethane elastomer has an average molecular weight of 500-3
000 polyester diols, polyether diols,
A polymer obtained by reacting at least one kind of polymer diol selected from polyester ether diol, polycarbonate diol and polycaprolactone diol with an organic diisocyanate and a low molecular weight compound having two active hydrogen atoms. The polyester elastomer is a polymer obtained by condensation polymerization of the above-mentioned polymer diol and aromatic carboxylic acid. Then, the fibers made of the non-elastic polymer and the elastic polymer are melted and spun in the same dissolution system.
Fibers having a sea-island structure or a multi-core sheath structure are obtained by melting in different melting systems and regulating with a spinning head or spinneret and spinning. Alternatively, it is melted in a different melting system and is spun into joint-type split fibers which are regulated by a spinneret and can be split into a large number of fine fibers. The spun fiber is drawn at least twice and crimped to give a fiber length of 20.
Cut to ~ 150mm before use.

Next, in the present invention, the mixing ratio of the ultrafine fiber bundle-generating multicomponent fiber or / and the single non-elastic fine fiber, the fiber composed of the non-elastic polymer and the elastic polymer is 90 to 40% by weight for the former, and the latter is 10 to 60% by weight. When the blending ratio of the fibers that finally become the elastic fibers is small, not only the elasticity is small, but also the drape property is reduced, and the feeling of texture is lost. On the other hand, when the blending ratio is high, the stretchability is improved, but the texture becomes less stiff, and not only does it become like a rubber cloth, but also the workability when making a secondary product by sewing is deteriorated. Then, after mixing a predetermined amount of both fibers, a web is made by a random webr method, a cross-lapper method or a wet method, laminated in an amount suitable for a desired product, and the fibers are entangled by needle punching and / or a fluid injection method to form a tertiary web. The original entangled non-woven fabric. The weight of the entangled nonwoven fabric is selected in the range of 150 to 1500 g / m ² . If necessary, the entangled nonwoven fabric is impregnated with a solution or dispersion of an elastic polymer such as polyurethane elastomer or polyacrylate, and then solidified. If this elastic polymer is contained in a large amount, the texture and stretchability are impaired. Therefore, the texture is improved and the basic physical properties are improved with a small amount of use.

The entangled non-woven fabric removes the inelastic polymer that constitutes the fiber. For example, when the non-elastic polymer is a high-fluidity polyethylene or polystyrene, it is treated with hot toluene or hot perkrene. In the case of polyester, ultrafine fiber bundle fibers and elastic fibers are obtained by alkali hydrolysis treatment.

The elastic polymer forming the surface coating layer of the stretchable entangled nonwoven fabric of the present invention is preferably a polymer mainly composed of a polyurethane elastomer whose elastic behavior is easily adjusted after elastic. The polyurethane elastomer is a solvent-soluble cotton-like polymer or a solvent-insoluble cross-linking polymer which is crosslinked after forming a coating layer.
That is, at least one polymer diol selected from polyester diols, polyether diols, polyester ether diols, polylactone diols, polycarbonate diols and block copolymer diols having an average molecular weight of 500 to 6000 and aromatics having a molecular weight of 500 or less. Diisocyanate, alicyclic diisocyanate,
Polyurethane or polyurethaneurea obtained by reacting at least one organic diisocyanate selected from aliphatic diisocyanate and isophorone diisocyanate with a chain-extending low molecular weight compound having a molecular weight of 500 or less and having at least two active hydrogen atoms, a polymer diol The elastic recovery rate of the polyurethane or polyurethaneurea is selected in a desired range by the composition ratio of the organic diisocyanate and the chain-extending low molecular weight compound and the selection of each component. In the relationship of the ratio Eg / Es of the elastic polymer film recovery rate Eg of the present invention to the elastic recovery rate Es of the elastic entangled nonwoven fabric,
It is assumed that the condition of 0.98 ≦ Eg / Es ≦ 1.15 is satisfied.

Formation of the surface coating layer of the leather-like sheet material with silver of the present invention,
A polyurethane solution or dispersion that forms a surface coating layer on a releasable support is applied, and if necessary, a polyurethane solution or dispersion to which a colorant is added is applied, and the applied coating layer is still tacky. A transfer method in which the entangled non-woven fabric is joined and integrated while there is some time, or the dried film layer is joined and integrated with the entangled non-woven fabric with a soft adhesive.
The polyurethane solution or dispersion is applied to the entangled non-woven fabric with a scoring roll and dried, or applied by a roll coating method or the like, wet-coagulated, dried, and then surface-colored to form a surface coating layer, which is embossed. The surface coating layer is formed by a coating method of processing and finishing.

If the surface finish of the silver-covered leather-like sheet having the surface coating layer is insufficient, a polyurethane solution containing a colorant and / or no colorant is further applied to adjust the color and gloss. Finishing treatment such as softening treatment, dyeing, and water repellent treatment is added to obtain a leather-like sheet with silver.

〔Example〕

Next, embodiments of the present invention will be specifically described with reference to examples. Parts and% in the examples relate to weight unless otherwise specified.

Example 1 Production of Entangled Nonwoven Fabric Two-component fiber A (fineness 10 dr.) Having a sea-island structure consisting of 60 parts of polyester-based polyurethane having polybutylene adipate as a soft segment (island component) and 40 parts of high-fluidity polyethylene (sea component). And a bicomponent fiber B (fineness 10 dr.) Having a sea-island structure consisting of 60 parts of 6-nylon (island component) and 40 parts of high-fluidity polyethylene (sea component), each obtained by melt spinning, and further at 70 ° C. Draw 2.5 times in warm water, apply fiber oil agent, dry by mechanical crimping, cut into fiber length 51 mm to make staples, mix two-component fibers A and B in 50:50, respectively Then, a web having a basis weight of 500 g / m ² was formed by a cross-lap method, and then a total of 560 P / cm ² was alternately punched from both sides with a needle of needle number # 40 to make an entangled nonwoven fabric. This non-woven fabric has a basis weight of 540 g / m ² , apparent density
It was 0.170 g / cm ³ .

Next, the entangled non-woven fabric is introduced into hot water of 98 ° C for shrinkage treatment (area shrinkage of 50%), and after drying, the polyethylene component of the fiber is dissolved and removed with a solvent and dried to form an ultrafine fiber bundle. A entangled nonwoven fabric I of fibers was obtained. This entangled non-woven fabric has a basis weight of 770 g / m ² ,
The apparent density is 0.371 g / cm ³ . This entangled non-woven fabric is sliced into 2 pieces, and the sliced surface is buffed to make a 0.80 mm thick 2 piece.
Sheets of entangled nonwoven fabrics I _A and I _B were obtained and used as the base material for the leather-like sheet with silver.

The entangled nonwoven fabric I _A thickness 0.80 mm, apparent density 0.375 g / cm ³
The elastic recovery rate at 30% elongation was 89% in the length direction and 91% in the width direction, indicating good elasticity.

Manufacturing average molecular weight of surface film and leather-like sheet with silver
The solution viscosity of the polyurethane urea elastomer obtained by reacting mixed diol obtained by mixing 2000 polytetramethylene ether glycol and 2000 polycaprolactone glycol having an average molecular weight of 1: 1 with isophorone diisocyanate, isophorone diamine and hydrazine hydrate is It is 273 poise / 30 ° C at a concentration of 25%. The elongation elastic recovery rate of the non-porous film having a thickness of 20 μm formed from this polyurethane urea elastomer solution was 95%.

A film-forming composition liquid was prepared by adding a pigment to the polyurethane urea elastomer, and the composition liquid was applied to a leather-patterned release paper in an amount to give a film thickness of about 20μ. After drying, polyether diol and aromatic Prepare a cross-linkable polyurethane composition liquid consisting of polyisocyanate and polyamine
applying a liquid amount of g / m ^2, was allowed to evaporate most of the solvent, the entangled nonwoven fabric I superimposing _A, after Kiyua, grain-leather-like sheet was peeled off from the release paper I _{A -1} was obtained.
The extension elastic recovery rate of the polyurethane film of the adhesive layer is 91.
%, And the elongation elastic recovery rate of the laminated polyurethane film as the surface layer was 92.5% on average. Therefore, the elastic recovery rate ratio of the materials forming the leather-like sheet material A ₁ with silver
Eg / Es is 1.04 in the length direction and 1.02 in the width direction.

This silver-like leather-like sheet material A ₁ was in a good surface state without leaving wrinkles on the surface even after repeated elongation and recovery for 30 times.

Comparative Example 1 In the laminated polyurethane film forming the surface layer of Example 1, a composition having a high degree of crosslinking by shortening the cure time by increasing the amounts of aromatic polyisocyanate and polyamine in the crosslinking polyurethane composition liquid of the adhesive. And The elongation elastic recovery rate of this crosslinked polyurethane film was 80.5%, and the elongation elastic recovery rate of the laminated polyurethane film as the surface layer was 84.6% on average. This and the laminated polyurethane film superposed entangled nonwoven fabric I _B of Example 1, after Kiyua to obtain grain-finished leather-like sheet B ₁ was peeled off from the release paper.
The elastic recovery ratio Eg / Es of the material forming this silver-like leather-like sheet is 0.95 in the length direction and 0.93 in the width direction.
As the number of times of repeated extension and recovery was increased, the wrinkle state remained as the number of times increased, and the surface irregularities that were scattered were remarkable.

Example 2 Production of Entangled Nonwoven Fabric The blending ratio of the bicomponent fibers A and B of Example 1 was 15:85,
30/70 and 40/60 are mixed, and a web with a basis weight of about 400 g / m ² is made by the cross-lap method. A total of 560 P / cm from both sides.
Needle punch ² to make entangled nonwoven fabric, then 9
Shrinkage treatment was performed in hot water of 8 ° C., and dried. The morphology and shrinkage rate of the entangled nonwoven fabric are shown in Table 1.

The entangled non-woven fabric was prepared by dissolving and removing polyethylene to form an ultrafine fiber bundle fiber. Next, one side of the entangled nonwoven fabric was sliced to a thickness of 1.0 mm, and the sliced surface was buffed to obtain a entangled nonwoven fabric for a base material for making a silver-like leather-like sheet material having a thickness of 0.8 mm. The apparent density of this entangled nonwoven fabric and
The elastic recovery rate at 30% elongation is shown in Table 2.

Then, the entangled nonwoven fabric for base material of entangled nonwoven fabric II,
III and IV.

Manufacture of leather-like sheet (1) Using the entangled nonwoven fabrics III and IV as a base material, overlaying the laminated polyurethane film (elongation elastic recovery rate 84.6%) used in Comparative Example 1 on the buffed surface, and curing. The silver-like leather-like sheet material obtained by peeling from the release paper does not leave wrinkles on the surface even after repeated elongation recovery of 30 times,
With a good surface condition, there was almost no feeling of gripping or rubber repulsion.

The elastic recovery ratio Eg / Es is 1.08-
The entangled non-woven fabric IV was 1.01 to 0.99.

(2) For comparison, the entangled nonwoven fabric II was used as a base material, and the laminated polyurethane film (elongation elastic recovery rate 84.6%) used in Comparative Example 1 was superposed on the buffed surface and cured, and then peeled from the release paper. The obtained silver-leathered leather sheet was repeatedly stretched and recovered 30 times, and as the number of times increased, winding occurred with the surface inside, and the feeling of gripping also caused a rubber repulsion sensation.

Furthermore, as a result of making a leather-like sheet-like material on the surface layer with the laminated polyurethane film used in Example 1 (extension elastic recovery rate 92.5%), the elastic recovery of the surface is large, so that the surface is wound inside. It was possible and had a great feeling of rubber repulsion.
The elastic recovery ratio Eg / Es in this case was 1.31-1.27.

〔The invention's effect〕

The silver-like leather-like sheet material of the present invention is highly stretchable, and has little unevenness or wrinkles on the surface even after repeated stretching, has excellent surface smoothness, and is a flexible leather-like sheet with a clear embossed pattern. It is a thing.

Claims (5)

[Claims] 1. A stretchable entangled nonwoven fabric formed by blending non-elastic fibers and elastic fibers together, or a stretchable entangled nonwoven fabric containing an elastic polymer in the stretchable entangled nonwoven fabric, is provided with an elastic polymer coating layer. Then, in the production of the elastic silver-like leather-like sheet material, the elasticity of the elastic entangled non-woven fabric and the elastic polymer film was measured in accordance with JIS L-1096, 6.13.1 A method.
The elastic recovery rate at 0% elongation is at least 70% after 30 seconds after unloading, and the ratio Eg / Es of the recovery rate Es of the elastic entangled nonwoven fabric and the recovery rate Eg of the elastic polymer film is 0.98 ≦ Eg. /Es≦1.15
1. A method for producing a silver-like leather-like sheet material having a good surface, which is characterized by comprising a material satisfying the above conditions. 2. The production method according to claim 1, wherein the entangled nonwoven fabric is a mixed cotton containing 90 to 40% by weight of non-elastic fibers and 10 to 60% by weight of elastic fibers. 3. The method according to claim 1, wherein the non-elastic fiber is an ultrafine fiber and / or a bundle fiber thereof. 4. An elastic fiber is a fiber obtained by spinning a non-elastic polymer and a multi-component fiber obtained by spinning an elastic polymer into an entangled nonwoven fabric, and then removing the non-elastic polymer. The production method according to item 1 or 2. 5. The method according to claim 1, 2 or 4, wherein the elastic fiber is a polyurethane elastomer.