JPH0261181A - Leather-like sheet and production thereof - Google Patents

Abstract

PURPOSE:To obtain a soft leather-like sheet having good formability by laminating a surface layer composed of a specific polyurethane polymer and a non- porous finishing layer composed of a polymer containing a colorant and having a softening point higher than that of the polymer of the surface layer. CONSTITUTION:The objective soft leather-like sheet having high abrasion strength can be produced by laminating (A) a porous or non-porous surface layer of a polymer composed mainly of a polyurethane having a softening and forming temperature of 130-185 deg.C and (B) a non-porous finishing layer of a polymer containing a colorant and having a softening and forming temperature higher than that of the surface-layer polymer by >=30 deg.C on (C) a surface of a fiber substrate layer such as web or interlocked nonwoven fabric composed of ultrafine synthetic fibers, etc., and embossing the laminate at a temperature to soften the surface layer polymer while preventing the flow deformation of the finishing layer polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a leather-like sheet with a soft texture and good shapeability. Furthermore, the present invention relates to a leather-like sheet having excellent bending fatigue resistance.

[Conventional technology]

Conventionally, in the manufacturing method of leather-like sheets, surface patterning is an important step in product planning. The mainstream of patterning on the surface is embossing, that is, embossing using a heated roll or hot plate. In the conventional heat embossing method, for example, a polyurethane foam layer made of a specific polyurethane with a softening point of 150°C or more is added to the fiber base material, and a polyurethane foam layer made of a specific polyurethane with a softening point of 15Qc or more,
100% modulus 20-2 (10 kg/aft) Synthetic leather for hot press molding with a layer of polyurethane laminated thereon is described in Japanese Patent Publication No. 6l-43t718. When the film is stretched to
．． Japanese Patent Publication No. 61-44993 discloses an artificial leather that forms one finger layer of polyurethane persimmon having a particle size within the range of 6 to 0.9 and has a more detailed and clear grain pattern. A porous coating layer made of a polymer, a non-porous coating layer made of a polymer mainly made of polyurethane with a softening temperature of 160°C or higher, and a non-porous polymer made mainly of a specific polyurethane with a softening temperature of 80 to 160°C. A leather-like sheet material suitable for use in shoelaces consisting of a coating layer was disclosed in Japanese Patent Application Laid-Open No. 1986-
Publication No. 228088 further discloses a type in which a non-porous layer of polyurethane made with a specific composition is laminated on the surface of a porous coating layer to form a leather-like sheet, thereby preventing reproduction of fine enphos patterns. A leather-like sheet material with good pressability is described in JP-A-60-119278.

[Problem to be solved by the invention]

For conventional leather-like sheet materials, proposals have been made regarding material composition and embossing conditions to faithfully form fine engraved patterns. Further, material compositions that make the imprinted pattern clearer have also been proposed. However, in order to clearly form a deep uneven pattern or a rhinoceros pattern on a conventional leather-like sheet, embossing must be performed using a high-pressure embossing device. However, since leather-like sheets are porous and have low density, when deep embossing is performed, the porosity is lost and a plate-like structure is formed, which is not only flexible and drapeable, but also has a low density. The texture becomes noticeably worse. Further, disadvantages occur such as poor bending fatigue resistance and poor processability into secondary products.

The present invention has clear formability when embossing insects or deep uneven patterns, has a small decrease in flexibility, and does not impair bending fatigue resistance or processability of secondary products. The object of the present invention is to provide a leather-like sheet with good compatibility.

[Means to solve the problem]

The present invention provides a porous or non-porous surface layer composed of a polymer mainly composed of polyurethane having a softening temperature of 130 to 185°C on at least one surface of the fibrous base layer;
A leather-like sheet with good moldability, characterized in that it is laminated with a non-porous finishing layer of a polymer containing a colorant whose softening molding temperature is at least 30°C lower than that of the polymer constituting the surface layer. It is.

Further, the present invention includes a porous or non-porous surface layer composed of a polymer mainly composed of polyurethane having a softening temperature of 130 to 185° C. on at least one surface of the fibrous base layer; At least 30°C below the constituent polymers
A non-porous finishing layer of a polymer containing a colorant having a high softening temperature and a non-porous finishing layer of a polymer containing a coloring agent is laminated, and the sheet-like material is formed at a softening temperature of the polymer constituting one surface layer and a finish layer polymer having a high softening temperature. This is a method for producing a leather-like sheet, which is characterized by embossing at a temperature that does not cause fluid deformation.

History 1. The present invention provides a fiber structure having a softening temperature of 130°C on at least one surface of a fibrous base layer containing a polymer mainly composed of an elastic polymer having a higher softening temperature than the polymer constituting the surface layer. ~185°C porous or non-porous surface layer composed of a polyurethane-based polymer, and at least 30"C4 from the polymer constituting the surface layer
at least two polymers having a high softening temperature.
This is a leather-like sheet with good moldability, characterized in that a non-porous layer is laminated thereon, and a finishing layer made of a polymer containing a colorant is laminated on at least the surface layer side.

That is, the present invention uses a polymer mainly composed of polyurethane, which can be soften-molded or melt-molded at a lower temperature than the constituent materials of other layers, for the surface layer constituting the middle curved portion of the fibrous base layer and the surface finishing layer. By doing so, the deformation of the base layer can be reduced and sharp shaping can be performed.

The fibrous base layer of the present invention includes polyester fibers, polyamide fibers, polyolefin fibers, acrylic fibers, polyvinyl alcohol fibers, rayon, collagen fibers,
Or a web made using at least one type of fiber selected from among these fibers with special shapes (for example, streaked fibers, ultrafine fiber bundles, special porous array fibers, irregular cross-section fibers, etc.) Fiber structures such as fiber-entangled nonwoven fabrics subjected to fiber entanglement treatment, a-cloths, pile or raised woven fabrics, knitted fabrics, pile or raised knitted fabrics, or composites thereof. One type of fiber structure selected from these fiber structures may be used as is or at least one type of elastic material selected from the group such as polyurethane, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, etc. The base layer is a sheet-like material selected from fibrous sheet-like materials in which a polymer or a polymer mainly composed of elastic claws is contained in a fibrous structure in a porous or non-porous state. be. Preferably, the porous material has an apparent density of 0.25 to 0.55 y/ai and contains a polymer mainly composed of an elastic polymer having a softening temperature at least 30°C higher than the softening temperature of the polymer constituting the surface layer. It is a fibrous base layer.

Next, the surface layer of the present invention is a necessary part for shaping the appearance of a leather-like sheet. In particular, in order to form a deep uneven pattern, a surface layer of a certain thickness is applied. Moreover, in the present invention, in order to minimize the deformation of the base layer and form the entire deep uneven pattern, the polymer constituting the surface layer is composed of the main fibers and main polymers constituting the base layer, and also the finish layer composition. The purpose is to use a polyurethane-based polymer having a softening and forming temperature that is at least 30° C. lower than the softening and deforming temperature of the polymer. The preferred softening temperature of the polymer is in the range of 130-185°C. As for the softening molding temperature, it is desirable to be able to mold at a low temperature, but at a low temperature of less than 130°C, the pattern may be deformed or melted under normal use conditions. For example, when processed into a pole, it may melt and deform due to friction with the floor, and when processed into clothing, it may deform due to ironing or drying temperature, which is undesirable.

On the other hand, if the temperature exceeds 185°C, it will produce the same sound as conventional leather-like sheets, and it will be necessary to perform embossing at high temperature and pressure. Softening molding temperature is 130~! Polymers mainly composed of polyurethane in the range of 85°C are polymer diols with an average molecular weight of 700 to 3,000, such as polyester diols obtained by condensation polymerization of low molecular weight diols and aliphatic or alicyclic dicarboxylic acids, and ring-opened polymers. At least one polymer diol selected from the group of polyether thread diol obtained by polymerization or condensation polymerization, polylactone diol or polycarbonate diol obtained by ring-opening polymerization of lactam, and polyester/ether block copolymer diol. Organic diisocyanates, e.g.
At least one organic diisocyanate selected from the group of aromatic ring-containing organic diisocyanates, naphthalene ring-containing organic diisocyanates, and aliphatic or alicyclic organic diincyanates. It is a polyurethane obtained by reacting a low-molecular compound having two active hydrogen atoms such as a low-molecular diol, a low-molecular diamine, a low-molecular dihydrazide, or a hydroxyamine, and converts this polyurethane into a polymer at a desired softening temperature. For example, increasing the polymer diol component in the polymer diol/organic diisocyanate/chain extender composition (75 to 55% by weight of the polymer diol component in the polymer composition), Selection of type or method of preparing a composition of multiple organic diisocyanates (for example, composition of aromatic organic diisocyanate and alicyclic or aliphatic organic diisocyanate, organic diisocyanate having a side chain, etc.), type of chain extender selection or composition of multiple organic low-molecular compounds (e.g. diols with a large number of carbon atoms, diols with a large number of carbon atoms and/or diamines having side chains, etc.); one polymerization method (e.g. In contrast, the polymerization reaction is carried out using a poor solvent or swelling agent thread]
By carrying out a polymerization reaction by combining one or more of the following methods.

It is possible to produce polyurethane that fully demonstrates its performance as a leather-like sheet and has a low softening temperature. Also,
It is also preferable to add synthetic rubber, polyvinyl chloride or vinyl chloride copolymer, polyester elastomer, vinyl acetate copolymer, etc. to polyurethane as necessary for shapeability or shape stabilization.

The method of processing a polyurethane-based polymer into a surface layer involves dissolving a polyurethane-based polymer in a solvent or dispersing it in a dispersant to form a slurry, and adding colorants and fillers as necessary. A polymer solution obtained by adding an additive selected from , a coagulation regulator 1, a blowing agent, etc., is incorporated into (a) a fibrous structure and (b) a fibrous structure containing the polymer solution or dispersion.

The polymer is coated on at least one surface of either an uncoagulated fibrous substrate or (c) a fibrous substrate containing and solidifying a fibrous structure containing a polymer, and immersed in a non-solvent for the polymer. solidify. Alternatively, the polymer is solidified by heating.

Alternatively, the polymer is solidified into a porous or non-porous structure by a method such as solidifying the polymer by freezing. Polyurethane is produced by casting a solution or dispersion of a polymer mainly composed of polyurethane onto a releasable support, and solidifying the polymer by immersing it in a non-solvent for the polymer or solidifying the polymer by heating. A fibrous base layer and a polyurethane-based polymer are obtained by bonding the polymer sheet to at least one surface of the fibrous base. A sheet-like product consisting of a combined surface layer is obtained. Further, the thickness of the surface layer constituting the leather-like sheet of the present invention is ensured to be sufficient for patterning. Generally, it is in the range of 0.1 to 2.0 m.

Next, the finishing layer applied to the first surface layer is composed of a polymer having a softening temperature at least 30° C. higher than that of the polyurethane constituting the surface layer.

If the softening temperature is in the same range as that of the polymer forming the surface layer, it will not be easy to release the mold during embossing. Not only will it become deformed or scratched if left inside, damaging its appearance, but
This results in a decrease in surface properties. The polymer used to form the finishing layer is, for example, a polyurethane obtained by reacting a polymer diol, an organic polyisocyanate, and a chain extender;
It is at least one polymer selected from the group of amino acid resins, polyurethane/polyamino acid block copolymers, polyester elastomers, polyamide elastomers, polyamides, crosslinked polyamides, crosslinked polyurethanes, and the like. Preferably, the polyurethane has a high softening temperature of at least 180°C. The polymer is dissolved in a solvent or dispersed in a dispersant, and the polymer solution is applied directly to the surface layer or on a releasable support, and most of the solvent or dispersant of the polymer is removed. After that,
A finishing layer is laminated on the surface layer by a method such as transferring to the surface layer. The thickness of the finishing layer varies depending on the intended use of the leather-like sheet, but the preferred thickness range is from 3 to 30 μm in view of the required surface strength, color tone, heat resistance, crease pattern, etc. Furthermore.

The finishing layer contains a coloring agent. The colorant may be colored by adding a pigment or dye to the polymer liquid in advance, or the polymer may be colored by dyeing with a dye after forming the finishing layer, or a combination of both may be used. The preferred coloring method is determined by the product design of the leather-like sheet. For example, in the case of sporting goods, a coloring agent mainly composed of pigments is added to the polymer liquid to form a finishing layer.

In addition, for interior use or clothing/accessories, a coloring agent mainly consisting of dyes is added to the polymer liquid to form a finishing layer, or a leather-like sheet with a finished layer is dyed with a dye. In order to adjust surface gloss, improve light stability, improve tactile sensation, prevent colorant migration, etc., the number sheet containing a colorant in at least the finishing layer has a thin layer of monomer or polymer composition. It is preferable to further provide 81 finishing layers.

The embossing of the skin layer-like sheet of the present invention does not involve conventional embossing at high temperature and high pressure, which causes rough deformation of the base layer, but at a temperature sufficient to soften and mold the polymer constituting the surface layer. Then, embossing is carried out at the lowest possible pressing pressure using an embossing roll or embossing plate heated to a temperature of 170 to 185° C. that does not cause flow deformation of the finished polymer. In addition, applying a silicone-based, fluorine thread, or polyamide-based mold release agent to the surface of the leather-like sheet before embossing produces a clear embossed product with good texture and deep uneven patterns. It is preferable to obtain it. In addition, in embossing, adjusting the length of winding around the embossing roll and the tension applied to the leather-like sheet are effective means for creating deep patterns.

The embossed leather-like sheet obtained in the present invention is a raw fabric for basketball poles with a deep uneven pattern.

It is a flexible leather-like sheet with a good appearance (and strong surface strength) and excellent texture that makes it suitable for use in fabrics for clothing, bags, etc. with reptile patterns.

〔Example〕

Next, embodiments of the present invention will be explained using specific examples.

Note that parts and percentages in the examples are by weight unless otherwise specified.

The softening temperature of the polymer in the examples is -720 to JI8
6-1982r Vicat Softening Temperature Test Method for Thermoplastic Plastics.

Example 1 Polyurethane with a softening temperature of 211°C obtained by polymerizing polyethylene propylene azihate glycol/4.4-diphenylmethane diisocyanate/ethylene glycol was contained in a porous state in an entangled nonwoven fabric of polyethylene terephthalate ultrafine fiber bundles mm. A porous fibrous substrate having a thickness of 1.2 M and an apparent density of 0.41 g was prepared.

On the other hand, polybutylene adipate glycol 1 mol% 4
．． 3 moles of 4-diphenylmethane diisocyanate and 2 moles of a mixed diol of butanediol (0,6) and 3-methyl-1,5-bentanediol (0,43) were reacted to produce polyester thread polyurethane with a softening temperature of 165°C. Using (I), a polyurethane composition liquid containing 17% polyurethane (1), 0.596% brown pigment, 0.5% coagulation regulator, 196% water, and 81% dimethylformamide was prepared. After applying the amount of polyurethane on the sheet in an amount of 10 V, it was coagulated in a dimethylformamide 4096 aqueous solution.

A porous polyurethane sheet (J) with a thickness of 0.36 m and an apparent density of 0.32 y/ai was bonded to one surface of a porous fibrous substrate using a solvent adhesive method, and the surface layer was Formed.

Next, for the finishing of the surface layer, the same polyurethane as the polyurethane constituting the base was used to prepare a brown pigment-colored ink for forming the finishing layer. This colored ink is applied to the surface layer using a 150 mesh gravure roll with an average coating thickness of approximately 10 μm.
Apply the amount of liquid equal to m.

Dry. Furthermore, a finishing layer-forming ink for gloss adjustment and texture adjustment, which is made by adding fine silica powder to the same polymer composition of 70% polyurethane and 30% polycarbonate, was applied in two stages using the same gravure roll to form a porous sheet. I got something like that.

Embossing roll temperature 175℃1 on this porous sheet material
Engraving a crocodile skin pattern with surface pressure s krt/cd (deep g approx.
When embossing was carried out using an embossing roll made using the following methods, a clear uneven pattern was formed. The difference in the unevenness of this leather-like sheet is an average of 0.41 mm (molding rate 8296
), but almost no decrease in the thickness of the base layer was observed, and the sheet had a soft texture, good feel, and a leather-like appearance.

Comparative Example 1 In producing the leather-like sheet of Example 1, a porous sheet-like material was produced using the same polyurethane as the polyurethane forming the base layer as the polyurethane forming the first surface layer.

That is, a wet-coagulated porous polyurethane sheet consisting only of polyurethane was obtained in the same manner as in Example 1, using the polyurethane (softening temperature: 211° C.) as the substrate of Example 1. This porous polyurethane had a thickness of 0.34 mm and an apparent density of 0.33 g/li. This porous polyurethane sheet was then adhered to a fibrous substrate in the same manner as in Example 1, and a finishing layer of the same polyurethane was applied to give the Suuda porous sheet the same crocodile skin-like embossing as in Example 1. went. As a result, under the same embossing conditions as in Example 1, the embossing depth remained at 0.22 m (forming rate: 44%). Not only that, but the thickness of the fibrous base layer is about 0.
Decreased by 1■.

Furthermore, in order to approximate the state of the embossed pattern in Example 1, the embossing conditions were changed and the embossing roll temperature was set to 185.
The embossing depth was 0.33 m (forming rate 66%).

The thickness of one fibrous base layer was reduced by about 0.2511I, and the back surface also had an embossed uneven pattern.

In addition, the sheet-like material after embossing had a hard texture similar to that of a rubber plate.

Comparative Example 2 Obtained in Example 1. When finishing the surface of a sheet-like material in which a porous polyurethane sheet is adhered to one side of a porous fibrous substrate, polyurethane [I] (softening temperature 16
5°C] in the same manner as in Example 1, and the surface was colored and finished in the same manner as in Example 1 using the adjusted ink. After forming a finishing layer, the same embossing treatment as in Example 1 was performed. .

As a result, the embossing roll adhered strongly to the surface of the sheet-like material, making it difficult to release it and occasionally causing destruction of the surface layer, making it impossible to perform stable embossing.

Therefore, we changed the embossing conditions and changed the embossing roll temperature to 1.
Processed at 55°C and surface pressure of 10 kg A4.

The depth of the embossed surface was only 0.17 m (molding rate 3496), the embossed state was unclear, and the sheet was a leather-like sheet with a surface pattern lacking in three-dimensional effect.

Example 2 Using the polyurethane [I] for the surface layer composition of Example 1, polyurethane CI) 2096, brown pigments o and s9,
Prepare a polyurethane composition liquid consisting of 79.5% solvent,
The mixture was cast onto a plastic sheet, and the solvent was evaporated by heating to obtain a non-porous polyurethane sheet with an average thickness of about 0.20 m1. This polyurethane sheet was adhered to one surface of the porous fibrous substrate of Example 1 by a solvent adhesive method to form a surface layer. Next, using the same polyurethane as the polyurethane that makes up the base, apply a brown colored ink that has been adjusted to: A to the surface layer with a gravure roll with a mesh of 140 to an average coating thickness of about 15 mm.
After applying the liquid in an amount of 150 μm and drying, apply a surface gloss adjusting ink prepared by adding fine silica powder to the same polyurethane using a gravure roll with 150 mesh openings to obtain an average coating thickness of approximately 2 μm. A certain amount of the liquid was applied and dried to obtain a porous sheet-like material.

Next, the embossing roll temperature was 170°C on the porous sheet material.
, basketball/L under the condition of surface pressure cuff kV'al.
/ Embossed roll with grain pattern engraved (grain depth 0/
70 trrm) was used for embossing.

As a result, the embossing depth was 0.57 mm (molding rate 81%)
A clear embossed pattern surface was obtained. On the other hand, the thickness change of the base layer was only reduced by about 0.05 ra, and the flexibility was hardly impaired.

Comparative Example 3 A non-porous polyurethane sheet with an average thickness of about 0.2011111 was made using the same dry method as in Example 2 using the polyurethane that constituted the substrate of Example 1, and a solvent was applied to one side of the porous fibrous substrate of Example 1. The sheet-like material obtained by adhering with an adhesive method to form a surface layer, applying a finishing mt using the same method and conditions as in Example 2, and embossing it has an embossing depth of 0.25111.
1 (molding rate 3696), and furthermore, the thickness change of the base layer decreased by about 0.15 m, the texture was rubber-like hardness, and the embossed pattern was unclear and lacked a three-dimensional effect. there were.

〔Effect of the invention〕

The leather-like sheet of the present invention is suitable for embossing a deep uneven pattern, and the deep uneven pattern can be formed clearly, and the leather-like sheet after embossing has little thickness deformation, has a soft texture, and has a strong surface. difference.

For example, it is strong in friction strength due to friction and impact, and has excellent processability into secondary products.

Further, the embossed leather-like sheet of the present invention is suitable for use in sports equipment such as raw material for basketball poles, shoes, bags, clothing, and the like.

Claims (2)

[Claims] (1) On at least one side of the fibrous base layer, a porous or non-porous surface layer made of a polymer mainly composed of polyurethane with a softening temperature of 130 to 185°C, and a polymeric material constituting the surface layer. A leather-like sheet with good moldability, characterized in that it is laminated with a non-porous finishing layer of a polymer containing a colorant whose softening temperature is at least 30° C. higher than that of the combined material. (2) On at least one side of the fibrous base layer, a porous or non-porous surface layer made of a polymer mainly composed of polyurethane with a softening temperature of 130 to 185°C, and a polymeric material constituting the surface layer. A non-porous finishing layer of a polymer containing a colorant is laminated with a non-porous finishing layer having a softening temperature at least 30° C. higher than the temperature at which the polymer constituting the surface layer is softened. A method for producing a leather-like sheet, characterized in that embossing is carried out at a temperature that does not cause flow deformation of the finishing layer polymer.