JP3516845B2 - Synthetic leather with three-dimensional appearance with excellent surface properties - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic leather having extremely high surface strength and peeling strength, an excellent three-dimensional effect, and cushioning property, and particularly to the surface physical properties and design of balls, bags and shoes. TECHNICAL FIELD The present invention relates to a synthetic leather that can be widely used for necessary applications.

[0002]

2. Description of the Related Art A sheet made of a polymer such as polyurethane or polyvinyl chloride and a fibrous substrate, that is, synthetic leather or artificial leather is used as an alternative to natural leather for shoes, clothing,
It is widely used in various fields such as bags, balls, and decorations. Of course, these materials must have excellent physical properties and texture to the extent that they can be used in their respective applications, but the surface color and embossed pattern also greatly affect the commercial value, so both surface physical properties and appearance are compatible. Is always a user request. Furthermore, recently, it is strongly desired to add fashionability and design effects for differentiation.

Conventionally, as a method for producing a synthetic leather having a three-dimensional appearance, a polyurethane solution is applied onto a release paper having a pattern, dried to form a film, and the film is then adhered to the surface of a substrate with an adhesive. A method of laminating and releasing the release paper (dry method), or applying a polyurethane solution on the surface of a fibrous base material to form a porous polyurethane layer by a wet coagulation or a dry coagulation method, and then a colorant A method (embossing) for forming a concavo-convex pattern with an embossing roll is widely used, after a resin solution containing is applied and dried to form a colored layer.

Among them, embossing roll embossing is generally used for forming a deep relief pattern having a three-dimensional effect, and many patents have been filed. For example, Japanese Patent Publication Sho 6
In KOKAI Publication No. 1-42019, the K / S value is 0.5 to 7.0.
Described is a fibrous sheet having an embossed pattern with a depth of 80 μm or more on the surface of and having a difference in K / S value of concave portions and K / S value of convex portions of 1.0 or more and having an excellent three-dimensional color feeling. Has been done. Further, in Japanese Patent Application Laid-Open No. 53-62803, a synthetic leather in which a synthetic resin melt is extruded in a film shape using an extruder on a synthetic resin layer formed on a substrate to integrate and emboss the surface. Is described.

Further, various methods have been provided for improving the surface strength of a fibrous sheet having an uneven pattern. For example, Japanese Unexamined Patent Publication No. 4-333674 describes a method of embossing on a sheet having a coat layer made of polyurethane containing Brinell particles having a hardness of 20 to 100 on the outermost surface. Further, a leather-like sheet using a one-component polyurethane having 100% modulus 100 kg / cm ² or more on the outermost surface, and a leather-like sheet having a silicon-modified polyurethane layer on the outermost surface and having improved scratch resistance by sliding the surface. Is also known.

On the other hand, regarding a sheet having a transparent surface layer and a concavo-convex pattern, for example, Japanese Patent No. 2600958 describes a stretched polyester having a light transmittance of 55% or more through a colored layer on a polyester film containing a filler. A pseudo-leather-like sheet in which films are laminated and an uneven pattern is formed on the surface is described. Also, the actual fair 7-36742
The publication describes a decorative sheet in which a transparent surface layer, a transparent embossed resin layer and a light reflecting layer are laminated.

[0007]

A sheet-like material having irregularities on its surface is subject to abrasion particularly at the convex portions and the corners of the convex portions in applications where a strong impact is applied such as ball for ball games, shoes for ball games, etc. Grading gradually deteriorates. This is particularly remarkable in the case of a pattern with deep irregularities. Among the methods conventionally proposed for improving surface properties, in the case of polyurethane containing fine particles having a Brinell hardness of 20 to 100, the glossiness is easily adversely affected, and when exposed to the surface, it promotes scratches. It had the drawback of being connected.
In addition, the outermost surface has a 100% modulus of 100 kg / cm ²
A sheet using the above one-component polyurethane, a sheet using a silicone-modified polyurethane layer on the outermost surface, and Patent No. 2
Also in the sheet described in Japanese Patent No. 600958, abrasion of the uneven pattern was unavoidable as long as the surface had unevenness. In addition, the decorative sheet described in Japanese Utility Model Publication No. 7-36742 has a smooth surface, but since the layers are in close contact with each other, the three-dimensional effect of the unevenness is insufficient, and the texture is hard and it is difficult to use for synthetic leather applications. is there. The present invention provides a synthetic leather having extremely high surface strength and peeling strength, an excellent three-dimensional effect, cushioning properties, and a wide range of uses such as balls, bags and shoes.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a fibrous material coated with a polymer layer composed mainly of polyurethane having an uneven pattern with a depth of 50 μm or more. On the surface of the base material, a transparent non-porous layer having a thickness of 150 μm or more, which is mainly composed of polyurethane, is laminated while leaving an air layer in the concave portion, and the total area of the bonding portion of the convex portion and the non-porous layer is The present inventors have found that a synthetic leather having strong surface physical properties and cushioning properties and having a three-dimensional effect can be obtained by adhering the synthetic leather so that the surface area of the synthetic leather is 50 to 90%. Furthermore, a two-component polyurethane resin having a number average molecular weight of 20,000 to 100,000 and a two-component polyurethane resin having a number average molecular weight of 130,000 to 280,000 are made of a resin crosslinked with a polyisocyanate-based curing agent and are transparent. It has been found that the scratch resistance of the surface can be further improved by providing the layer on the outermost surface.

That is, the synthetic leather of the present invention has a depth of 50.
On the surface of the coating layer of the fibrous base material having a concavo-convex pattern of μm or more and coated with a polymer layer mainly composed of polyurethane, a transparent non-porous layer mainly composed of polyurethane and having a thickness of 150 μm or more is laminated. In the synthetic leather described above, an air layer is present between at least a part of the concave portion and the non-porous layer, and the convex portion and the non-porous layer are adhered to each other. The total surface area of the synthetic leather is 50 ~
It is characterized by being 90%.

The present invention will be described in detail below. First, the fibrous base material used in the present invention can be used as long as it is a sheet having an appropriate thickness and a sense of fulfillment and having a soft texture. Therefore, various fibrous base materials that have been used in conventional methods for producing leather-like sheets can be used as they are in the present invention. For example, synthetic fibers such as polyester, polyamide, polyacrylonitrile, polyolefin, and polyvinyl alcohol, chemical fibers such as regenerated cellulose, natural fibers, or fibers of a special form, for example, ultrafine fibers such as polyester, polyamide, polyacrylonitrile, or bundled fibers thereof. An entangled nonwoven fabric sheet, a knitted woven fabric sheet, and a fibrous base material in which a polymer elastic material such as polyurethane is contained as a binder between fibers of the sheet.

Among them, a non-woven fabric composed of ultrafine fiber bundles contains a polymer elastic body as a suitable fibrous base material, from the viewpoint of imparting an uneven pattern in the present invention and having a texture closest to that of natural leather. A fiber sheet is mentioned. In this case, the fineness of the fibers constituting the ultrafine fiber bundle is preferably 0.5 denier or less, particularly preferably 0.1 denier or less, and the total denier of the ultrafine fiber bundle is 0.5 to 10 denier. A denier range is preferred.

The polymer elastic body is a resin which has been conventionally used for producing leather-like sheets, and includes polyurethane resin, polyvinyl chloride resin, polyvinyl butyral resin, polyacrylic acid resin, polyamino acid resin. resin,
Examples thereof include silicone-based resins and mixtures of these resins, and these resins may of course be copolymers. These are impregnated into the fiber material as an aqueous emulsion or an organic solvent solution and then solidified to form a substrate composed of the fiber material and the elastic polymer. As the polymer elastic body constituting at least the surface portion of the fibrous base material, the same kind as the thermoplastic elastomer used for the surface finish is preferable in terms of adhesiveness, and particularly polyurethane is capable of obtaining strength and natural leather-like performance. It is preferable in terms.

As the polyurethane impregnated into the fibrous material,
All conventionally known materials can be applied. For example, polyester geo-polymer having an average molecular weight of 500 to 3000
At least one kind of polymer diole selected from the group consisting of diol, polyether ether, polycarbonate diol, 4,4'-diphenylmethane diisocyanate and isophorodiisocyanate. , At least one diisocyanate selected from aromatic, alicyclic, and aliphatic diisocyanates such as hexamethylene diisocyanate, and two or more active hydrogen atoms , At least one low molecular weight compound having a molecular weight of 300 or less, for example, ethylene glycol, propylene glycol,
At least one selected from diols such as butanediol and 3-methyl-1,5-pentanediol, diamines such as ethylenediamine, isophoronediamine, piperazine and phenylenediamine, and hydrazides such as adipic acid hydrazide and isophthalic acid dihydrazide. And
It is a polyurethane obtained by reacting at a predetermined molar ratio. Polyurethane may be a polymer composition to which a polymer such as synthetic rubber or polyester elastomer is added, if necessary.

The thickness of the fibrous base material can be arbitrarily selected depending on the use of the obtained synthetic leather and is not particularly limited, but preferably 0.3 mm to from the viewpoint of balance with the intermediate layer and the surface layer. 3 mm, particularly preferably 0.5 mm
The range is 2.0 mm. The weight ratio of the fibers constituting the fibrous base material to the elastic polymer is 90:10 by weight.
A range of 40:60 is preferred.

The surface of the fibrous base material is first coated with a polymer layer mainly composed of polyurethane. As the resin to be laminated, known resins such as polyester-based polyurethane, polyether-based polyurethane, polycarbonate-based polyurethane, and mixed systems thereof and modified polyurethane resins such as silicon-modified polyurethane are used, and can be selected according to the application. . If necessary, additives such as antioxidants, other colorants, pigments, ultraviolet absorbers and the like may be added within a range that does not significantly impair the object of the present invention. The 100% modulus of the resin may be selected according to the application, but from the viewpoint of texture, it is 30 to 100 kg / cm.
A range of ² is preferred.

The lamination method is a coating method of coating by knife coating, gravure coating or the like and drying, a dry method of coating a release paper with a resin, adhering it to a substrate and drying, and then peeling the release paper. Then, a wet method in which coagulation is caused in a coagulation bath that is a non-solvent for polyurethane and is miscible with the organic solvent in which polyurethane is dissolved, or W / Conventionally known methods such as a method of coating an O type emulsion and then selectively evaporating an organic solvent to solidify polyurethane, a method of coating a molten resin on a substrate and cooling and solidifying the same are used.

The thickness of the coating layer can be arbitrarily selected depending on the use of the obtained synthetic leather and is not particularly limited, but from the viewpoint of the balance with the base layer and the surface layer, it is 10-4.
The thickness is 00 μm, preferably 50 to 200 μm. If the thickness is less than 10 μm, the depth of the uneven pattern becomes insufficient, or the fiber texture appears on the surface, making it difficult to obtain a smooth feeling on the surface, which is not preferable. On the other hand, 400
If it exceeds μm, it is not preferable in that the texture becomes rubber-like and the productivity decreases. Also, prior to lamination, coloring, relaxation treatment to improve texture, etc.
Pretreatment of the substrate is possible.

Next, a concavo-convex pattern is formed on the fibrous base material whose surface is coated with a polymer layer mainly composed of polyurethane. The uneven pattern can be formed on the leather surface pattern, any pattern,
The heat embossing method, which is usually used for patterning a leather-like sheet, can be applied by using a metal roll, a metal plate or a metal belt engraved in a geometric pattern. The depth of the unevenness due to the embossing is 50 μm or more, and preferably 100 to 300 μm in order to emphasize the three-dimensional effect of the product. If the thickness is less than 50 μm, it is difficult to express a three-dimensional effect, and at the time of laminating the non-porous layer described later, the resin or the adhesive of the non-porous layer penetrates into the concave portion and the non-porous layer and the concave portion The air layer, which is a feature of the present invention, is not formed between them, and it becomes difficult to obtain the desired three-dimensional effect and cushioning property. The pressing pressure, temperature and time may be set under conditions that satisfy the moldability and the adhesive strength, depending on the fluidity of the thermoplastic elastomer.

Next, the non-porous layer to be laminated on the surface of the fibrous base material having the uneven pattern will be described. The surface layer is
There are many items related to quality such as surface physical properties and touch, and the optimum conditions may be appropriately selected depending on the application, but thermoplastic polyurethane is most suitable because strength, durability and natural leather-like performance can be obtained. As the polyurethane, conventionally known polyester-based, polyether-based, polycarbonate-based and the like can be used, but various kinds of mixtures may be used, and other thermoplastic elastomers may be blended. If necessary, it is also possible to mix additives such as an antioxidant and an ultraviolet absorber, and may be colored with a coloring agent,
The non-porous layer may be colored but must be substantially transparent so that the textured surface of the fibrous substrate is visible. The Brinell hardness is preferably 80 to 95.
When it is lower than 80, the resin is soft, and therefore, when it is laminated with the fibrous substrate, it is easily affected by the unevenness of the surface, and it becomes difficult to obtain the smoothness of the surface. When it is higher than 95, the balance with the fibrous base material is deteriorated and the flexibility is deteriorated.

The thickness of the non-porous layer varies depending on the type and performance of the thermoplastic elastomer, but is required to be 150 μm or more in order to satisfy the surface strength, especially the abrasion strength. Further, in order to enhance the three-dimensional effect of the uneven pattern, the thickness is preferably 300 to 500 μm. If the thickness is less than 150 μm, satisfactory abrasion resistance cannot be obtained, and when laminated with a fibrous substrate, it is easily affected by surface irregularities, and it becomes difficult to obtain surface smoothness. Thickness is 500μ
When it exceeds m, abrasion resistance and smoothness are improved, but there are drawbacks such that the balance with the fibrous substrate becomes poor and the manufacturing cost increases.

As a method for molding the surface layer, a coloring agent, an antioxidant and the like are added to thermoplastic elastomer chips, if necessary, and the mixture is melted and kneaded in an extruder under heating and pressure, and then T-die. In general, a method of extruding into a film in a molten state can be used. A dry method in which a polyurethane solution is applied on a release paper and dried to form a film can be used, but it cannot be denied that the productivity is lowered when a nonporous film having a thickness of 150 μm or more is formed.

Next, the non-porous layer is laminated on the surface of the fibrous base material on which the concavo-convex pattern is formed. At this time, an air layer is provided between at least a part of the concave portion and the non-porous layer. Exists,
In addition, the convex portion and the non-porous layer are adhered so that the total area of the adhered portion is 50 to 90% of the surface area of the synthetic leather. When the adhesion area is less than 50%, it is not preferable because the non-porous layer and the convex portion may be peeled off when worn as a product such as shoes. Further, if it exceeds 90%, it becomes difficult to obtain the desired three-dimensional effect. In order to achieve both a three-dimensional effect and adhesive strength, the more preferable range of the adhesive area is 60% to 80%. Also, due to the presence of the air layer,
As compared with the case where the refractive index changes and the concave portion is filled with resin or the like, it is possible to further enhance the three-dimensional effect of the unevenness, and at the same time, to provide the cushioning property.

As a method for adhering, a fibrous substrate having an uneven pattern and a non-porous film are superposed and then pressed by heating for a certain period of time under pressure, and a non-porous film is coated on one side with two layers. Examples of the method include a method of applying a liquid type adhesive, drying it, and then pasting it on a fibrous substrate in a state where it is still tacky just before the completion of drying and pressing it for adhesion. In any case, it is necessary to set conditions such as pressure, temperature and time so that resin or adhesive does not enter the recess.

The synthetic leather of the present invention is manufactured as described above, but depending on the application, it may be required to have scratch resistance, particularly resistance to instantaneous scratches. This can be solved by laminating the crosslinked elastic polymer resin as the outermost surface layer on the surface of the non-porous layer. In the present invention, the type of polyurethane constituting the crosslinked elastic polymer resin is not particularly limited, and examples thereof include polyester-based, polyether-based, polycarbonate-based, blends thereof or modified products thereof, and durability and physical properties. Considering the above, a polyether type or a polycarbonate type is preferable, but in general, when a cross-linking elastic polymer resin is used, defects such as a hard texture and poor flex resistance occur. The constitution of the cross-linkable elastic polymer resin for eliminating these drawbacks will be described below.

The resin used in the present invention as the outermost surface layer is
A crosslinked product of a blend of a two-component polyurethane resin (a) having a number average molecular weight of 20,000 to 100,000 and a two-component polyurethane resin (b) having a number average molecular weight of 130,000 to 280,000, which is a polyurethane (a). The blend weight ratio (a) / (b) of the polyurethane and the polyurethane (b) is preferably 0.05 to 4, and when it is less than 0.05, abrasion resistance, abrasion resistance and slipperiness are good, but bending resistance is high. It has bad drawbacks. When (a) / (b) exceeds 4, tackiness on the outermost surface is excessive and slipperiness deteriorates. In addition, there is a drawback that blocking occurs due to high surface tackiness.

Further, when it is used as a single polyurethane resin having a number average molecular weight of less than 100,000, there is a problem in passingability such as sewing since there is considerable tack after the surface is made. When used, the tack after fabrication is good, but there is a problem that abrasion resistance and flex resistance are deteriorated. Further, when it is used as a single polyurethane resin having a number average molecular weight of 100,000 to 130,000, scratch resistance is not sufficient, and tack is generated, which causes a problem in sewing and other process passability.

Further, in the case of a blend of a polyurethane resin having a number average molecular weight of 100,000 to 130,000 and a polyurethane resin having a number average molecular weight of 20,000 to 100,000, there is a drawback that tack remains, and a polyurethane having a number average molecular weight of 100,000 to 130,000 is used. In the case of a blend of a resin and a polyurethane resin having a number average molecular weight of 130,000 to 280,000, there is a drawback that the bending resistance becomes poor.
Also, in the case of a blend of a polyurethane resin having a number average molecular weight of less than 20,000 and a polyurethane resin having a number average molecular weight of 130,000 to 280,000, there is a drawback that tack remains, and a polyurethane having a number average molecular weight of more than 280,000 is present. Even in the case of blending resins, there is a drawback that the bending resistance becomes poor. Accordingly, the polyurethane resins to be blended are a two-component polyurethane resin having a number average molecular weight of 20,000 to 100,000 and a two-component polyurethane resin having a number average molecular weight of 130,000 to 280,000, and the blending resin ratio (weight) of the polyurethane. (A) / (b) is preferably in the range of 0.05 to 4,
More preferably, (a) / (b) is blended at a ratio of 0.2 to 2.

As the polyisocyanate curing agent to be added, an adduct of trimethylolpropane (TMP) and tolylene diisocyanate (TDI), TMP and 4,
4'-methylenebis (cyclohexyl isocyanate)
Examples include organic polyisocyanates such as (HMDI) adduct, TMP and HDI adduct, TMP and IPDI adduct, and HMDI trimer. As the organic polyisocyanate used in the present invention, two or more different organic polyisocyanates may be used in combination, and in particular, an aliphatic or alicyclic polyisocyanate may be used in combination with an aromatic polyisocyanate. Polyisocyanate curing agent is added to polyurethane resin in a solid content weight ratio of 10
If it is less than%, abrasion resistance and abrasion resistance are deteriorated,
If it exceeds 75%, the bending resistance will deteriorate, so 10-75
% Range is good. More preferably, it is in the range of 20 to 50%. Further, if necessary, within a range that does not hinder the reaction of the curing agent, an antioxidant, an ultraviolet absorber, a dye, a surfactant,
Various additives such as an antistatic agent, a flame retardant, an anti-adhesive agent, and a filler may be added, or collagen powder or the like may be added, but the non-porous layer is formed in order to make the uneven surface pattern of the fibrous substrate visible. It should be a substantially transparent layer.

As a method for producing the cross-linkable elastic polymer layer, it is preferable to use a method in which a polyurethane resin (c) is coated on a release paper coated with a polyolefin resin. In addition, there are release papers coated with alkyd resin, amino acrylate resin, acrylic resin on the outermost surface, but these release papers in the present invention have the disadvantage that they are difficult to peel off because they have too good adhesion with the coating resin. There is. Therefore, it is preferable in the present invention that the outermost surface coating layer of the release paper is made of polyolefin resin.

The coating method is a knife coater on release paper,
Comma coater, roll coater, reverse coater,
A method of applying by a means such as a rotary screen coater is used. The thickness of the surface layer (C) after drying is 5 to 100 μm, preferably 10 to 50 μm. 5
If it is less than μm, there is a problem that the wear resistance is poor, and if it is more than 100 μm, there is a problem that the surface is too good and the texture is poor.

Further, in the present invention, a design pattern is provided in a part between the layers of the non-porous layer and the fibrous base material, and an air layer is substantially present between the pattern and the non-porous layer. By making it exist in the non-existing state, a further design effect can be imparted. That is, the unevenness of the fibrous substrate and the air layer existing in the recesses have a visual effect that the design pattern looks as if it were floating in the air, and it is possible to differentiate the product as a product. The design pattern may be a manufacturer's mark, a character pattern, or the like.

A schematic view of an example of the synthetic leather of the present invention is shown in FIGS. 1 and 2. FIG. 1 shows a cross section, but from the surface of the synthetic leather, a crosslinked resin layer (1), a non-porous layer (2),
The fibrous base material (4) is laminated in this order, and the air layer (3) is present in a part between the layers of the non-porous layer and the fibrous base material. And
The fibrous base material has irregularities, but the surface of the synthetic leather is smooth. FIG. 2 is a view of the synthetic leather of the present invention seen from the surface. From the surface, the irregularities of the fibrous base material are three-dimensionally seen through the transparent non-porous layer, and the design pattern ( A) (the reference numeral 5) has a pattern,
It looks like it floats.

[0033]

EXAMPLES The present invention will now be specifically described with reference to Examples.
The invention is not limited to these examples. The parts and% in the examples relate to weight unless otherwise specified. In the following examples and comparative examples,
The Taber abrasion, the three-dimensional effect, the smoothness, and the scratch resistance were measured or evaluated according to the following methods. The layer thickness is measured by a scanning electron microscope.

[Taber Wear] It was measured according to the Taber wear test method of JIS K7204. That is, the leather-like sheets obtained in Examples and Comparative Examples had a diameter of 12 cm.
A circular test piece was cut out. A wear wheel (H-22) was applied to the surface side of the circular test piece, and the circular test piece was rotated 10,000 times with a load of 1 kgf to perform a wear test. The weight of the test piece was subtracted to obtain the weight (mg) reduced by abrasion. In addition, the state of wear was judged by continuously rotating 100,000 times. ◯: Most of the surface layer remains. Δ: More than half of the surface layer is worn. X: Even unevenness is worn.

[Three-dimensional effect and smoothness] 1 arbitrarily selected
Evaluation result by 0 panelists ◯: Good. Δ: Slightly defective. X: Bad.

[Depth of recess] Three arbitrary cross sections were photographed with a scanning electron microscope, and the average of the measured values was calculated.

[Scratch resistance] The scratch resistance of the leather-like sheets obtained in Examples and Comparative Examples is about 2 kg with nails.
The condition of whitening scratches after rubbing at a speed of about 30 to 50 km per hour was determined by adjusting so as to apply the load. The condition of whitening scratches is evaluated as follows. ◯: No whitening scratches. B: Whitening scratches appear thin. X: Whitening scratches are noticeable.

Example 1 50 parts by weight of polyethylene as a sea component and 50 parts by weight of 6-nylon as an island component were melt-spun in the same melting system to produce a composite fiber having a single fiber fineness of 10 denier. This composite fiber was drawn 3.0 times, crimped, cut into a fiber length of 51 mm, defibrated with a card, and then made into a web with a cross wrapper webber. Next, a fiber entangled nonwoven fabric having a basis weight of 650 g / m ^{2 was obtained} by needle punching. 18 parts by weight of a polyurethane composition mainly composed of polyester polyurethane and 8 parts by weight of dimethylformamide were added to the nonwoven fabric.
After being impregnated with a solution of 2 parts by weight, coagulated and washed with water, polyethylene in the composite fiber is extracted and removed, and a thickness of 6-nylon ultrafine fiber bundle fiber made of ultrafine fiber of 0.005 denier and polyurethane A 1.3 mm fibrous substrate (A) was obtained.

On one surface of the fibrous substrate (A), a polyurethane mainly comprising polyurethane obtained by polymerization of polycarbonate diol, polytetramethylene glycol, polyethylene glycol, 4,4'-dicyclohexylmethane diisocyanate, titanium oxide A polyurethane composition solution to which white color was added was applied onto release paper and dried to obtain a film. Then, on top of that, a two-component polyurethane, a polycisocyanate curing agent, as an adhesive layer,
The fibrous substrate (A) is coated with a mixed solution of an amine-based catalyst and a solvent, dried, and has a tackiness immediately before completion of drying.
It was pressed and stuck together. After that, the release paper was peeled off after being left at 60 ° C. for 48 hours, and the thickness of the surface layer was 2
The thickness of the adhesive layer was 0 micron and the thickness of the adhesive layer was 30 micron. Then, using an embossing roll having a ridge-valley pattern with an average depth of recesses of 400 microns, heating embossing was performed under conditions of a roll temperature of 170 degrees and a cylinder air pressure of 10 kg / cm ² to obtain an embossing sheet having a depth of 170 microns (B). ) Got.

Separately, for a non-porous surface layer, thermoplastic polyurethane pellets obtained by polymerizing from polyester diol obtained from polymethylpentanediol and adipic acid, butanediol and 4,4'-diphenylmethane diisocyanate are prepared. Using an extruder and a T-die, a transparent film (C) having an average thickness of 400 μm was formed at a melting zone temperature of 215 ° C. and a die introduction part temperature of 220 ° C. Next, the polyurethane composition solution is applied to the convex portion of the embossed sheet (B) by a gravure roll, the film (C) is overlaid before drying, and the laminated sheet (D) is pressed by a press roll and dried. Obtained. This laminated sheet (D)
Has an average depth of the recesses of 120 microns, an air layer is present between the recesses and the non-porous layer, and the projections and the non-porous layer are bonded to each other, The total area of the bonded portion occupied 70% of the surface area of the synthetic leather. Table 1 shows the physical properties of the obtained synthetic leather.

Example 2 13 parts by weight of a polyurethane composition mainly composed of polyester polyurethane and dimethylformamide 87 were added to an entangled nonwoven fabric composed of polyester fibers having a fineness of 2.5 denier.
On one side of the impregnated substrate impregnated with a solution of 1 part by weight, the same resin as the impregnating polyurethane was used, and 25 parts by weight of a polyurethane composition toned in white and dimethylformamide 75
A solution consisting of 1 part by weight is coated, coagulated, washed with water and dried to give a fibrous layer thickness of 1.2 mm and a porous layer thickness of 0.3.
A fibrous base material (E) having a weight of 550 g / m ² and a basis weight of 550 mm was prepared.

Polyurethane obtained by polymerizing polycarbonate diol, polytetramethylene glycol, polyethylene glycol, 4,4'-dicyclohexylmethane diisocyanate and butanediol on the porous layer surface of the fibrous substrate (E), and titanium oxide. Was added to apply a polyurethane composition solution that was toned to white with a gravure roll and dried. The thickness of this layer was 10 μm. Then, using a metal plate having a ridge-valley pattern with an average depth of the recesses of 400 μm, a flat plate press was used to emboss under conditions of a temperature of 170 ° C., a press pressure of 3 kg / cm ² , and a time of 10 seconds.
The depth of the concave portion of the obtained embossed sheet (F) was 270 μm.
Met. Then, the uneven surface of the embossed sheet (F) is overlaid with the film (C) having the same average thickness of 400 μm as in Example 1 and further overlaid with mirror release paper, and then the temperature is 160 ° C. with a flat plate press. , Press pressure 3kg / cm
^{2. The} laminated sheet (G) was melt-bonded under the condition of 10 seconds for ² hours. In this laminated sheet (G), a part of the convex portion was smoothed at the time of fusion bonding, so that the average depth of the concave portion was 150 μm.
However, there is an air layer between the concave portion and the non-porous layer, and the convex portion and the non-porous layer are bonded, and the total area of the bonded portion is 85% of the surface area of synthetic leather
Was occupied. Table 1 shows the physical properties of the obtained synthetic leather.

Example 3 Two-component polyurethane (a) (1,6-hexane polycarbonate polyol, tolylene diisocyanate, dimethylformamide solution of polyurethane polymerized from ethylene glycol, solid content concentration: 70%, number average molecular weight:
70,000) 10 parts and two-component polyurethane (b) (1,6-hexane polycarbonate polyol, tolylene diisocyanate, dimethylformamide solution of polyurethane polymerized from ethylene glycol, solid content concentration: 30%,
Number average molecular weight: 170,000) 90 parts, (a) / (b) =
Blended at a blend ratio of 0.26. To 100 parts of this blended resin (c), 6 parts of titanium oxide powder as a pigment, polyisocyanate curing agent (d) (TMP and HD
Adduct of I with 75% solid concentration ethyl acetate solution) 1
5 parts (solid content ratio of curing agent to polyurethane resin 3
3%), 5 parts of an amine-based catalyst (e) (solid content 4%) as a curing accelerator, and dimethylformamide 40 as a diluting solvent.
Parts, and 40 parts of methyl ethyl ketone were added, uniformly mixed, coated on release paper, and dried to form a crosslinked film having a thickness of 50 μm. On top of that, two-component polyurethane as an adhesive layer,
A mixed solution of a polycisocyanate curing agent, an amine-based catalyst, and a solvent was applied, dried, and pressed and laminated on the laminated sheet (D) of Example 1 in a state of having tackiness immediately after drying. After that, the release paper was peeled off after standing at 60 ° C. for 48 hours to obtain a laminated sheet (H).

Comparative Example 1 A laminated sheet (I) was obtained in the same manner as in Example 1 except that the non-porous layer film had an average thickness of 75 μm. In this laminated sheet (I), an air layer was present between the concave portion and the non-porous layer, but the surface smoothness and wear resistance were poor.

COMPARATIVE EXAMPLE 2 Instead of the embossed sheet (B), an embossing roll with a skin grain pattern having an average depth of recesses of 50 μm was used, and the heating temperature was 170 ° C. and the cylinder air pressure was 10 kg / cm ^2. A laminated sheet (J) was obtained in the same manner as in Example 1 except that an embossed sheet having an uneven depth of 40 μm that was pressed was used. This laminated sheet (J) has an uneven depth of 25.
In μm, the total area of the convex portion and the non-porous layer bonded portion occupies 95% of the surface area of the synthetic leather, and although the surface smoothness and abrasion resistance are excellent, it lacks a three-dimensional effect. It was

Comparative Example 3 At the time of bonding the embossing sheet (B) and the film (C), an adhesive was poured on the uneven surface of the embossing sheet (B) to set the clearance between the surface of the sheet (B) and 50 μm. A laminated sheet (K) was obtained in the same manner as in Example 1 except that the film (C) was overlaid, cut with a press roll, and dried after the liquid was cut with the knife. This laminated sheet (K)
Had excellent surface smoothness and wear resistance, but lacked a three-dimensional effect, cushioning properties, and a hard texture because an adhesive was present in the recesses and there was no air layer.

Example 4 In the manufacturing process of Example 1, the non-porous film (C)
A logo mark was printed at a distance of about 5 cm using a screen roll on the surface to be bonded to the fibrous base material. Then, in the same manner as in Example 1, the polyurethane composition solution was applied to the convex portions of the embossed sheet (B) with a gravure roll, the films were overlapped before drying, and the film was pressed with a press roll and dried to obtain a laminated sheet. (L) was obtained. When this laminated sheet (L) was viewed from the surface, the logo mark seemed to float in the air. Further, the smoothness, the depth of irregularities, the surface physical properties, and the texture were all the same as those of the laminated sheet (D) obtained in Example 1.

[0048]

[Table 1]

[0049]

As described above, according to the present invention, (1) a three-dimensional effect due to an uneven pattern having a depth of 50 μm or more, (2) 150 μm
Enhance the three-dimensional effect by changing the refractive index of the non-porous layer of m or more and the air layer existing in the recess, (3) 150μ in the uneven pattern
Strong surface properties by laminating non-porous layers of m or more,
(4) Synthetic leather in which sufficient adhesion strength is imparted by adhering such that the total area of the bonded portion of the convex portion and the non-porous layer is 50 to 90% of the surface area of the synthetic leather. Moreover,
By providing a crosslinked resin layer on the outermost surface, it is a synthetic leather whose surface scratch resistance is greatly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing a synthetic leather of the present invention.

FIG. 2 is a surface view of the synthetic leather of the present invention.

[Explanation of symbols] 1 Crosslinked resin layer 2 Non-porous layer 3 air layer 4 Fibrous base 5 Design pattern

Claims (4)

(57) [Claims] 1. A transparent material having a thickness of 150 μm or more, which is mainly composed of polyurethane, is formed on the surface of the coating layer of a fibrous base material which is covered with a polymer layer which is mainly composed of polyurethane and has an uneven pattern having a depth of 50 μm or more. In a synthetic leather in which a non-porous layer is laminated, an air layer exists between at least a part of the concave portion and the non-porous layer, and the convex portion and the non-porous layer adhere to each other. The synthetic leather is characterized in that the total area of the bonded portion is 50 to 90% of the surface area of the synthetic leather. 2. A two-component polyurethane resin having a number average molecular weight of 20,000 to 100,000 and a two-component polyurethane resin having a number average molecular weight of 130,000 to 280,000 on the surface of the non-porous layer according to claim 1. ,
Synthetic leather in which a transparent layer made of a resin cross-linked with a polyisocyanate curing agent is laminated. 3. A design pattern exists in a part between the non-porous layer and the fibrous base material, and there is substantially no air layer between the pattern and the non-porous layer. The synthetic leather according to claim 1. 4. A ball for ball game comprising the synthetic leather according to claim 1.