JPH07242900A - Split leather - Google Patents

Abstract

PURPOSE:To enable efficient and inexpensive production of reusable split leather which is excellent in surface smoothness, uniform appearance, touch or hand, roughening caused by stretching, in other words, and useful as a semi-natural leather having a high class surface layer closely resembling to the silver face of natural leather. CONSTITUTION:In this split leather comprising a surface leather layer of polyurethane resin 3 laminated through a synthetic resin adhesive onto the surface of a bed leather 6, the adhesive in the adhesive layer is composed of 100 pts.wt. of a synthetic resin and 10 to 60 pts.wt. of a filler 5a. As the filler 5a, at least one selected from particles of calcium carbonate, magnesium carbonate, clay or silicate ores of 0.2 to 70mum average particle size and 0.15 to 0.55g/ml apparent density is cited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a split leather in which a surface layer of a polyurethane resin is provided on the surface of a floor leather excluding a silver surface from natural leather, and more specifically, a split leather surface having the surface texture of the floor leather. The present invention relates to a split leather that has an excellent appearance and texture with reduced influence on the leather.

[0002]

2. Description of the Related Art Natural leather is generally divided into silver surface and floor leather, of which the silver surface is so-called natural leather in shoes, bags, bags, sundries, furniture, vehicles, office supplies, and various other fields. Used as a surface material.

On the other hand, floor leather is generally used as follows. (A) A surface layer of synthetic resin is provided on the surface, and it is used as a so-called split leather in the same field as the above-mentioned silver surface. (B) It is tanned by various methods and used as an inexpensive backskin in industrial gloves and other fields similar to the above-mentioned silver surface, or as a part of these products. (C) After being crushed or extracted, it is used as a raw material for collagen, glue, gelatin or the like.

Of these, the split leather of (A) is
Generally, (1) a step of tanning, buffing, and dyeing a floor leather from which the silver surface has been removed to prepare a floor leather base material. (2) Polyurethane resin solution (usually a one-component polyurethane resin solution) is applied to release paper on which an uneven pattern similar to a silver surface irregularity diaphragm is formed, dried, and aged if necessary. A step of sending to the step, terminating the crosslinking reaction of the polyurethane resin coating film, and forming a skin layer. (3) Adhesive of synthetic resin on the skin layer of synthetic resin (usually one-component or two-component polyurethane resin adhesive)
Step of sticking the floor leather base material obtained in (1) through the above, sending it to the aging step if necessary to complete the crosslinking reaction of the adhesive, and then peeling off the release paper to obtain the product split leather. . It is manufactured by the manufacturing method (generally called “release paper transfer method”).

[0005]

However, in the conventional split leather manufactured as described above, surface irregularities due to the coarseness and fineness of the fiber structure of the floor leather adversely affect the surface of the product split leather, and While the smoothness is impaired, the difference in the surface irregularity due to the difference between the abdomen side and the back side of the floor leather base material will appear as the difference in the appearance of the product split leather surface as it is. There was a problem that the yield deteriorated. In addition, when used as a shoe skin material, etc., when the split leather is hung in a mold, the skin made of synthetic resin is pulled and affects the thinned skin, which causes so-called "arabi". there were.

As means for solving the above-mentioned problems, the thickness of the skin layer is made thicker, or JP-A-5-34538 is used.
As proposed in No. 4, a foam layer or a porous layer is interposed as an intermediate layer between the skin layer and the floor leather base material to prevent surface irregularities of the floor leather from appearing on the surface of the product split leather. However, in the former case, there is a problem that the cost increases due to the thicker skin layer and the workability deteriorates. In the latter case, the manufacturing process becomes complicated, so split leather is used. Has the drawback of being expensive.

Because of the various problems described above, the amount of floor leather used as split leather is still small compared to the amount of silver surface used, and most of the floor leather has been described above. At present, it is used in products with low commercial value such as (B) and (C).

According to the present invention, a large amount of natural material, that is, floor leather, is provided with excellent properties (the suede-like appearance of natural collagen fibers and excellent moisture absorption / release).
Split leather that does not have the above problems, in other words, surface smoothness, uniform appearance, texture, arabic resistance due to tension, moisture absorption and desorption, etc. An object of the present invention is to provide split leather, which has a very similar high-quality skin layer and can be regenerated as a so-called semi-natural leather, efficiently and at low cost.

[0009]

The split leather of the present invention comprises a synthetic resin adhesive containing a skin layer consisting of a floor leather and a polyurethane resin in an amount of 10 to 60 parts by weight of a filler per 100 parts by weight of the resin. It is characterized in that they are laminated through. As the filler, one or more selected from calcium carbonate, magnesium carbonate, clay and silicate minerals can be preferably used.

The present invention will be described below with reference to the drawings. FIG. 1 is a partially enlarged sectional view showing an embodiment of the split leather of the present invention.

The floor leather 6 used in the present invention is a conventional split leather which is tanned after removing the silver surface, and subjected to buffing, dyeing, press working, etc., as required. Exactly the same thing can be used.

As the polyurethane resin constituting the skin layer 3 of the split leather 1 of the present invention, either one-pack type or two-pack type can be used, but the one-pack type is preferable, and the polyester-based polyurethane resin and polyether. Polyurethane resin, polycaprolactone polyurethane resin,
Any of ester / ether copolymer polyurethane resin, polycarbonate polyurethane resin, amino acid / urethane copolymer resin and the like can be used. Further, it may be a copolymer of the above polyurethane resin with another monomer such as vinyl chloride, or a mixture with another synthetic resin or synthetic rubber.

If necessary, the polyurethane resin may include various kinds of antioxidants, ultraviolet absorbers, pigments, dyes, surfactants, antistatic agents, flame retardants, anti-adhesive agents, fillers, crosslinking agents and the like. You may add an appropriate amount of additives. Further, fine collagen powder or the like can be added if necessary.

The above polyurethane-based resin has a 100% modulus of 20 to 200 kg / cm ² , preferably 4
The thing of 0-150 kg / cm < ² > can be used. 100%
Split leather obtained when modulus is too low 1
If the mechanical strength of No. 1 is reduced and conversely 100 modulus is too high, the texture becomes hard.

The thickness of the skin layer 3 of the split leather 1 of the present invention may be appropriately set depending on the conditions such as the thickness of the floor leather 6, the thickness of the adhesive layer 5 and the thickness of the intermediate skin layer 4 which will be described later. However, if the skin layer 3 is too thick, not only the cost will increase, but also the workability will deteriorate. Therefore, it is preferable to set the thickness to about 10 to 50 μm.

In the split leather 1 of the present invention, as shown in FIG. 2, an intermediate skin layer 4 made of a polyurethane resin can be provided between the skin layer 3 and the floor leather 6 described above. The inner skin layer 4 may have the same composition as the outer skin layer 3 or may have a different composition, but preferably has a 100 modulus of 40 to 150 kg / cm ² . Further, the thickness of the mesothelial layer 4 is preferably about 10 to 50 μm.

As the synthetic resin adhesive for adhering the skin layer 3 made of a polyurethane resin and the floor leather 6, any adhesive which is used as an adhesive for adhering the skin layer of the conventional split leather and the floor leather can be used. Any material can be used, but generally, an adhesive made of the same polyurethane resin as that of the skin layer is used. As the polyurethane resin adhesive, either a one-component type or a two-component type can be used, but it is common to use a one-component type for wet lamination and a two-component type for dry lamination. is there.

The above-mentioned synthetic resin adhesive forming the adhesive layer 5 of the present invention is 10 to 6 with respect to 100 parts by weight of the resin.
0 parts by weight, preferably 15 to 45 parts by weight of filler 5a are added. If the amount of the filler 5a added is too small, the surface irregularities of the floor leather 6 adversely affect the surface of the split leather 1, and if it is too large, the fluidity of the adhesive decreases and it is difficult to apply it uniformly. It becomes difficult and the physical properties of the adhesive deteriorate. As the above-mentioned filler 5a, known ones are used, but calcium carbonate, magnesium carbonate, clay, silicate minerals and the like are particularly preferable. Also, the filler 5
a has an average particle size of 0.2 to 70 μm, preferably 5 to 40
Those having an apparent specific gravity of 0.15 to 0.55 g / ml, preferably 0.2 to 0.45 g / ml are used. When the average particle size and the apparent specific gravity of the filler 5a added to the adhesive are out of the above ranges, the surface of the obtained split leather 1 is bent outward or is hung in a mold as a shoe sack material. In addition, there is a possibility that a problem such as unevenness appearing on the surface may occur.

The above-mentioned adhesive has a 100% modulus (in the case of a two-component type, 100 modulus after the crosslinking reaction is completed) of 5 to 70 kg / cm ² , preferably 15 to 5
Those of 0 kg / cm ² can be used. If the 100% modulus is too low, the peel strength will decrease, and conversely, if the 100% modulus is too high, the texture will be hard.

The thickness of the adhesive layer 5 is the floor leather 6 to be used.
The thickness may be appropriately determined depending on the conditions such as the thickness or the unevenness of the surface, but if it is too thick, not only the cost increases but also the workability deteriorates.
It is about 200 μm.

In order to manufacture the split leather 1 of the present invention having the above-mentioned layer structure, for example, a release paper transfer method is adopted in the same manner as the above-mentioned conventional method for manufacturing split leather.
On the release paper 2 with a squeezing pattern having an uneven pattern similar to that of a silver surface, a known polyurethane resin solution for forming a skin layer such as a doctor knife, comma doctor, roll coater, gravure coater, and rotary screen is used. After coating with a means, drying and sending it to an aging step as needed to complete the crosslinking reaction of the polyurethane resin coating film and form the skin layer 3 of the polyurethane resin, the filler 5a is formed on the skin layer 3. An adhesive solution containing is applied, and the floor leather 6 prepared in advance is attached by wet lamination or dry lamination. Then, if necessary, it is sent to an aging step to complete the crosslinking reaction of the adhesive, and then the release paper 2 is peeled off, whereby the uneven pattern on the surface of the release paper 2 is transferred, and a surface unevenness very similar to natural leather is obtained. A split leather 1 having is obtained.

In the split leather 1 of the present invention, a surface treatment agent such as a matting paint, an enamel paint, a slime paint or the like may be applied to the surface side of the skin layer 3, if necessary, by the above-mentioned appropriate means or by spraying means. Alternatively, rubbing processing or the like may be performed to form wrinkles that closely resemble natural leather on the entire split leather 1.

[0023]

In the split leather of the present invention, since the adhesive containing a specific amount of the filler is present between the floor leather and the skin layer, unevenness of the surface of the floor leather may appear on the product split leather. In addition, there is no difference in the product split leather due to the difference between the back side and the abdomen side of the floor leather, and the yield is improved. Also, by adding a filler to the adhesive, the penetration of the adhesive into the floor leather when the floor leather and the skin layer are laminated is controlled, and the texture of the product split leather becomes soft. Furthermore, the split leather of the present invention described above is subjected to a rubbing process or the like to form wrinkles similar to those of natural leather, so that a split leather close to natural leather can be obtained.

[0024]

EXAMPLES The present invention will be described in more detail below with reference to specific examples, but the present invention is not limited to the following examples.

[Example 1] 1 on a release paper with a pore drawing pattern
One-component polyester-based polyurethane resin with a 00% modulus of 70 kg / cm ² (Crisbon NB-631
S: manufactured by Dainippon Ink and Chemicals, Inc.) 20% methyl ethyl ketone
A dimethylformamide solution (containing 20 parts by weight of a colorant) was applied by a knife coater to a dry thickness of 25 μm, and dried in a oven with hot air at 100 ° C. for 3 minutes to form a skin layer. Then, on the skin layer, an average particle size of 3
A two-component polyester-based polyurethane resin (Crisbon 4070: manufactured by Dainippon Ink and Chemicals, Inc.) having a 100% modulus of 26 kg / cm ² for forming an adhesive layer, which contains 35 parts by weight of calcium carbonate having an apparent specific gravity of 0.23 g / ml. A 50% toluene-dimethylformamide solution was applied with a knife coater so that the dry thickness was 100 μm,
After drying in an oven with hot air at 90 ° C. for 4 minutes, a 1.2 mm thick floor leather substrate was laminated. Then, the mixture was left standing at room temperature for 48 hours to complete the crosslinking reaction, and the release paper was peeled off to obtain a split leather of the present invention. The split leather obtained had not only excellent surface smoothness but also a uniform appearance and a soft texture. Also, even if you try to bend this split leather outward,
There was no unevenness in the bent portion, and no arabi was generated when it was hung in a shoe-making mold.

[Example 2] A one-component polyester-based polyurethane resin (resamin) having a 100% modulus of 80 kg / cm ² containing 20 parts by weight of collagen fine powder having an average particle size of 5 µm on release paper with a pore-striking pattern. ME-44L
P: made by Dainichiseika Co., Ltd.) 20% methylethylketone-dimethylformaldehyde solution (containing 20 parts by weight of colorant) was applied with a knife coater so that the dry thickness would be 30 μm, and 3 at 100 ° C. in an oven. Dry for 5 minutes with hot air to form a skin layer. On this skin layer, an average particle size of 25
Kaolin clay 3 with μm and apparent specific gravity of 0.27 g / ml
55 of a two-component polyester polyurethane resin (Resamine UD-750: manufactured by Dainichiseika Co., Ltd.) containing 0 part by weight and having a 100% modulus of 20 kg / cm ² for forming an adhesive.
% Toluene-dimethylformamide solution to a dry thickness of 1
It was coated with a knife coater so as to have a thickness of 20 μm, and was dried with hot air at 90 ° C. for 4 minutes in an oven, and then a 1.5 mm thick floor leather base material was laminated. Then, the mixture was left standing at room temperature for 48 hours to complete the crosslinking reaction, and the release paper was peeled off to obtain a split leather of the present invention. The obtained split leather had a smooth feel, had not only excellent surface smoothness, but also had a uniform appearance and had a soft texture. Further, even when this split leather was bent outward, no unevenness was generated in the bent portion, and when it was hung in a shoe making mold, no arabic was generated.

[Embodiment 3] On a release paper with a leather pattern, 10
One-component polyester-based polyurethane resin with 0% modulus of 120 kg / cm ² (Resamine ME-3118L
P: Dainichiseika Co., Ltd.) 25% methylethylketone-dimethylformamide solution (containing 5 parts by weight of colorant) was applied with a knife coater to a dry thickness of 10 μm,
A skin layer was formed by drying in an oven with hot air at 100 ° C. for 2 minutes. On this epidermis layer, 100% modulus is 60
² kg of one-component polyester polyurethane resin (Resamine ME-3614LP: manufactured by Dainichiseika Co., Ltd.) of kg / cm 2
A 0% methyl ethyl ketone-dimethylformamide solution (containing 20 parts by weight of a colorant) was applied by a knife coater so that the dry thickness was 20 μm, and the mixture was placed in an oven for 10
It was dried with hot air at 0 ° C for 3 minutes to form an epidermal layer and a mesothelial layer.
An average particle size of 20 μm and an apparent specific gravity of 0.25 on this mesothelial layer.
Two-component polyester-based polyurethane resin containing 25 parts by weight of magnesium carbonate (g / ml) and having a 100% modulus of 25 kg / cm ² for forming an adhesive layer (Resamine UD
-577: 50% toluene-dimethylformamide solution (manufactured by Dainichiseika Co., Ltd.) was applied with a knife coater to a dry thickness of 150 μm, and the mixture was heated in an oven at 90 ° C. for 5 hours.
After drying with hot air for a minute, a floor leather base material having a thickness of 1.5 mm was laminated. Then, the mixture was left standing at room temperature for 48 hours to complete the crosslinking reaction, and the release paper was peeled off to obtain a split leather of the present invention. The split leather obtained had not only excellent surface smoothness but also a uniform appearance and a soft texture. Further, even when this split leather was bent outward, no unevenness was generated in the bent portion, and when it was hung in a shoe making mold, no arabic was generated.

Comparative Example 1 Split leather was obtained in the same manner as in Example 1 except that calcium carbonate was not contained in the adhesive layer. The obtained split leather was not only inferior in surface smoothness, but also had a hard texture. Also, when this split leather was bent outward, irregularities were generated in the bent portion, and when it was hung in a shoe-making mold, arabic formation was also observed.

Comparative Example 2 Splitting was carried out in the same manner as in Example 1 except that the adhesive layer contained 7 parts by weight of calcium carbonate having an average particle size of 30 μm and an apparent specific gravity of 0.23 g / ml. Got leather. The obtained split leather was slightly inferior in surface smoothness and had a slightly hard texture. Further, when this split leather was bent outward, slight unevenness was generated in the bent portion, and when it was hung in a shoe making mold, generation of arabic was also observed.

A summary of the surface smoothness, the appearance uniformity, the texture, the prevention of unevenness during folding, and the prevention of arabic generation during shoe hanging of the split leather obtained in each of the above Examples and Comparative Examples. Is shown in Table 1. As is clear from the table, the split leather of the present invention obtained in Examples 1 to 3 has a surface smoothness, a uniform appearance, as compared with the conventional split leather obtained in Comparative Example 1. It can be seen that there are remarkable effects in terms of texture, prevention of unevenness during bending, and prevention of arabic generation during hanging of shoes.

[Table 1]

[0031]

[0032]

INDUSTRIAL APPLICABILITY The split leather of the present invention is excellent in all of the aspects of surface smoothness, uniformity of appearance, texture, prevention of unevenness during bending, and prevention of arabic generation during suspension of shoes, and it is natural. Like leather, it is preferably used as a surface material in various fields such as shoes, bags, bags, sundries, furniture, vehicles, office supplies and the like. Moreover, the split leather of the present invention can be produced by the same production method as that of the conventional split leather, and the filler added to the adhesive layer is an inexpensive raw material that is often present in nature. It is possible to provide the split leather having the above-mentioned various properties, which is manufactured from the above-mentioned materials and has almost the same cost as that of the conventional split leather.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view showing an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Split Leather 2 Release Paper 3 Skin Layer 4 Middle Skin Layer 5 Adhesive Layer 5a Filler 6 Floor Leather

Claims (3)

[Claims] 1. In split leather, wherein a skin layer made of a polyurethane resin is laminated on the surface of a floor leather via an adhesive layer made of synthetic resin, the adhesive forming the adhesive layer is based on 100 parts by weight of the resin. Split leather containing 10 to 60 parts by weight of a filler. 2. The split leather according to claim 1, wherein the filler has an average particle size of 0.2 to 70 μm and an apparent specific gravity of 0.15 to 0.55 g / ml. 3. The split leather according to claim 1, wherein the filler is one or more selected from calcium carbonate, magnesium carbonate, clay, and silicate minerals.