JPH0813351A - Nubucklike leathery sheet and its production - Google Patents

Abstract

PURPOSE:To obtain a nubucklike leathery sheet by grinding protruding parts of a skin layer, comprising a polyethereal polyurethane resin and having an uneven pattern formed on a substrate. CONSTITUTION:This nubucklike leathery sheet is obtained by forming a skin layer, made of a polyethereal polyurethane resin and having an uneven pattern on a substrate of a woven or a nonwoven fabric comprising natural or synthetic fibers and then grinding protruding parts of the skin layer. Furthermore, the method for producing the leathery sheet is to apply a solution of the polyethereal polyurethane resin onto, e.g. a sheet of matte mold release paper, bond the resultant skin layer having at least 5mum difference in level of recessed parts and protruding parts to the substrate of the woven or nonwoven fabric comprising the natural or synthetic fibers and then grind the protruding parts of the skin layer with a sandpaper, etc. The resultant nubucklike leathery sheet has a firm surface touch and is excellent in surface strength having a waxy touch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nubuck-like leather-like sheet having an appearance and texture similar to that of natural leather nubuck (suede) and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a nubuck leather-like sheet, napped fibers of ultrafine fibers are formed on the surface of the epidermis and sanded (buffing) to make short hairs, or polyurethane resin is used. It has been put into practical use that it is applied to a substrate by impregnation or coating, and the skin layer on the surface on which the microporous film is formed is ground and removed by a wet method. In general, the nubuck tone often refers to the latter process. However, this method requires a long time for the manufacturing process, the manufacturing equipment to be used is limited, and therefore the price of the product is high. is there.
On the other hand, a so-called dry method (which does not form a microporous film), which is produced by applying a skin layer and an adhesive layer to release paper and bonding the same to a base material, does not use a wet method. Although the manufacturing equipment of the method is not required and the cost is advantageous, the final product does not have the same appearance and the touch of the surface, and there is a problem in quality.

[0003]

The present invention is not limited to a wet process manufacturing facility, and can be manufactured at a manufacturing cost close to a dry process, and the quality is similar to that of a wet process, and a nubuck leather-like sheet and its manufacture. It provides a method.

[0004]

According to the present invention, a skin layer made of a polyether-based polyurethane resin having a mat-like concavo-convex pattern is provided on a substrate, and the convex portions of the skin layer are ground. A nubuck leather-like sheet characterized by the above is provided. Further, according to the present invention, a skin layer made of a polyether-based polyurethane resin having a matte uneven pattern on the surface is adhered to a base material, and then a convex portion on the surface of the skin layer is ground. A method for manufacturing a nubuck leather-like sheet is provided.

[0005]

[Function] By grinding the surface of the convex portion of the matte uneven pattern on the surface of the skin layer, the luster of the concave portion and the convex portion are brought close to each other, and the entire surface of the skin layer is matte and the dark color feeling is strong. In addition, by forming the skin layer with a flexible polyether polyurethane resin, the nubuck leather is rich in elasticity and wet, and has a moist and slimy feel and excellent surface strength. Such a sheet is obtained.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to preferred embodiments. The nubuck leather-like sheet of the present invention has a structure in which a skin layer is adhered to a base material, a matte uneven pattern is formed on the surface of the skin layer, and only the convex portions of the pattern are ground. is there. The base material used in the present invention may be woven or non-woven fabric of natural fibers and synthetic fibers which have been conventionally used for leather-like sheets, and is not particularly limited.

The skin layer is formed without forming a microporous film, and from the viewpoint of the formability of a matte uneven pattern on the surface and the quality of the product such as elasticity, wet feeling and slimy feeling. A coating of polyether polyurethane resin is particularly suitable. In order to impart such quality, polyurethane resin has 100% modulus of 150 kg / cm.
² or less is desirable. The polyether-based polyurethane resin is preferably a polyether / ester-based or polyether / carbonate-based polyurethane resin, more preferably at least 50% by weight of polyether in the polyurethane. The thickness of the epidermis layer is usually 20 to 40 μm. Various pigments for coloring and other compounding agents can be added to the polyether polyurethane resin.

The method of forming a matte uneven pattern on the surface of the skin layer is not particularly limited. A preferred method is to use a release paper having a mat-like uneven pattern, and to apply a polyether-based polyurethane resin solution to the release paper by coating or the like, or to generate the polyurethane resin on the release paper. This is a method in which a matte pattern is transferred to the surface of the coating by peeling the release paper after forming the resin coating. In the leather-like sheet of the present invention, only the convex portion of the matte uneven pattern on the surface of the skin layer is ground, and the height difference of the unevenness (the depth of the grain) is required to grind only the convex portion. Is preferably at least 5 μm.

The skin layer thus obtained is adhered to the substrate. The adhesive used is not particularly limited as long as it can firmly bond the both and does not impair the quality of the product, but it is a preferred polyurethane adhesive. The total thickness of the skin layer and the adhesive layer is required to be at least 40 μm from the viewpoint of the texture and strength of the leather-like sheet, but if it exceeds 80 μm, the texture becomes worse, which is not preferable.

Finally, only the skin layer on the surface of the projections of the uneven pattern on the surface of the skin layer is ground. Grinding is usually performed with sandpaper or the like, but other methods may be used. By grinding only the surface of the convex part, the gloss of the concave part and the convex part becomes closer,
The entire surface of the skin layer is matte finished. A schematic view of the leather-like sheet of the present invention is shown in FIG.

[0011]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. Unless otherwise noted, all parts and percentages in the following examples and comparative examples are by weight.

Example 1 Polyether polyurethane resin solution having a 100% modulus of 20 kg / cm ² [methyl ethyl ketone (MEK) / dimethylformamide (DMF) = 30% solid content =
1/1 solution] 100 parts of a solution prepared by mixing 20 parts of a black colorant (carbon black content of 15%) and 25 parts of DMF and MEK as a diluting solvent, respectively, and releasing paper (Asahi Release Co., Ltd., Ultra Suede ) About 150 gr / m ²
(Wet basis) It was applied and dried to obtain a film having a thickness of 30 μm for forming a skin. Furthermore, a polyether-based two-component polyurethane [ME with a solid content of 40% is used as an adhesive on it.
About 120 gr of a mixture of 100 parts of K / toluene / DMF and 10 parts of a cross-linking agent was applied and bonded to a substrate.
After the cross-linking was completed, the release paper was peeled off (the total film thickness of the polyurethane of the dried skin layer and adhesive layer applied on the substrate was about 60 μm). The convex portion of the skin of the leather-like sheet thus obtained was ground with No. 240 sandpaper to obtain a final product. The obtained product had a matte appearance and a blackness, and the surface had a moist feel.

Example 2 A polyether / ester (6/4) type polyurethane resin solution having a 100% modulus of 50 kg / cm ² (MEK / DMF = 1/1 solution having a solid content of 30%) was used, but the above was used. A nubuck leather-like sheet was obtained in the same manner as in Example 1.

Example 3 Polyether polyurethane resin solution having a 100% modulus of 90 kg / cm ² (MEK / DM having a solid content of 30%)
A nubuck leather-like sheet was prepared in the same manner as in Example 1 except that (F = 1/1 solution) was used.

Example 4 Using a polyether / ester (7/3) type polyurethane resin solution having a 100% modulus of 50 kg / cm ² (MEK / DMF = 1/1 solution having a solid content of 30%) as a release paper. Lintec EV130TPD (R-8)
A nubuck leather-like sheet was obtained in the same manner as in Example 1 except that was used.

Comparative Example 1 Polyester polyurethane resin solution having 100% modulus of 90 kg / cm ² (MEK / DM having a solid content of 30%)
A nubuck leather-like sheet was obtained in the same manner as in Example 1 except that (F = 1/1 solution) was used and EV130TPD (R-8) manufactured by Lintec Co., Ltd. was used as the release paper.

Comparative Example 2 Polyester polyurethane resin solution having 100% modulus of 30 kg / cm ² (DMF solution having a solid content of 30%)
Colorant in 100 parts (carbon black content 15%) 2
A solution containing 0 part, an appropriate amount of a film-forming aid, and 40 parts of DMF was applied to a substrate at about 1000 gr / m ^{2 and} immersed in water for about 15 minutes to remove DMF to solidify the polyurethane. Furthermore,
A microporous polyurethane film was obtained by washing with warm water of about 50 ° C. for 1 hour to completely remove DMF, and then dehydration and drying. A nubuck leather-like sheet was obtained by grinding the entire surface with sandpaper.

[0018]

[Evaluation Results] With respect to the nubuck leather-like sheets of the above Examples and Comparative Examples, the texture, the degree of blackness, and the manufacturing cost were evaluated according to the following evaluation criteria. The results are shown in Table 1. Evaluation Criteria (1) Texture ◎ Very soft touch and extremely high practical value. ○ Practical with a soft, slightly slimy feel. △ It is not practical because it has no soft feel. × It has a rough texture and is completely unusable. (2) Blackness ◎ Matte-like blackness and very high practical value. ○ Matte tone with blackness makes it practical. △ Matte, but not practical due to lack of blackness. × Practically impractical due to lack of matte tone and blackness. (3) Manufacturing cost ◎ The dry method of Comparative Example 1 is marked with ◎. ○ Practical in the middle of Comparative Example 1 and Comparative Example 2. × The wet method of Comparative Example 2 is marked with ×.

[0019]

[Table 1]

[0020]

The nubuck leather-like sheet of the present invention is rich in elasticity, has a wettability and a slimy feel,
It has a matte appearance and gives a deep-colored appearance and is excellent in surface strength, and is useful as a material for various clothing. Also,
This nubuck leather-like sheet can be easily ground by grinding only the protrusions of the matte uneven pattern on the surface layer of the skin.
Moreover, it can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 shows a production example of a nubuck leather-like sheet of the present invention.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Isao Kondo 1-7-6 Nihonbashi-Bakurocho, Chuo-ku, Tokyo Inside Dainichiseika Kogyo Co., Ltd.

Claims (6)

[Claims] 1. A skin layer made of a polyether-based polyurethane resin having a matte uneven pattern is provided on a substrate,
A nubuck leather-like sheet characterized in that the convex portion of the skin layer is ground. 2. The nubuck leather-like sheet according to claim 1, wherein the height difference between the concave portion and the convex portion of the skin layer is at least 5 μm. 3. The nubuck leather-like sheet according to claim 1, wherein the skin layer is adhered to a substrate with a polyurethane resin adhesive. 4. A nubuck leather which is characterized in that after a skin layer made of a polyether-based polyurethane resin having a matte uneven pattern on the surface is adhered to a substrate, the convex portion on the surface of the skin layer is ground. Sheet manufacturing method. 5. The nubuck leather-like sheet according to claim 4, wherein the polyether polyurethane resin is a polyurethane resin containing 50% by weight or more of polyether as a polyol component and having a 100% modulus of 150 kg / cm ² or less. Manufacturing method. 6. The method for producing a nubuck leather-like sheet according to claim 4, wherein the skin layer produced by applying a polyether polyurethane resin solution onto a matte release paper is adhered to a base.