JP4248084B2 - Foamed polyolefin leather - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a leather in which a foamed synthetic resin layer and a non-foamed synthetic resin layer are sequentially provided on the surface of a fiber base layer.
[0002]
[Prior art]
Conventionally, leather used as a skin material for automobile seats, bicycle and motorcycle saddles, chairs, sofas, etc. is a polyvinyl chloride leather in which a soft polyvinyl chloride layer is laminated on the surface of a textile substrate such as woven fabric, knitted fabric, and nonwoven fabric. Has been used. However, in recent years, polyolefin-based leather in which a polyolefin-based elastomer layer is laminated on a fiber base material has been used, and there has been a demand in the market for polyolefin-based foamed leather that has a good texture and a high-class feeling. And with respect to this polyolefin-based foamed leather, there is a demand from customers for improved flex resistance and flexibility. In addition, a sheet-like article made of a polyolefin-based resin has a defect that it swells and deforms (waves) due to human body stains (oily components from the human body). Conventionally, in order to eliminate this drawback, it has been proposed to provide an ultraviolet curable coating layer on the surface. However, when this method is applied to polyolefin-based leather, there is a problem that the flexibility of the leather is impaired.
[0003]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a foamed polyolefin-based leather excellent in flex resistance and flexibility, and further a foamed polyolefin-based leather excellent in stain swell resistance. .
[0004]
[Means for Solving the Problems]
The present invention relates to a fiber base layer, a foamed layer comprising a mixture of 30 to 95% by weight of an ethylene-α olefin copolymer elastomer and 70 to 5% by weight of a styrene copolymer elastomer, and a non-foamed material comprising a polyolefin elastomer. A foamed polyolefin leather characterized in that the layers are sequentially laminated. Further, it is a foamed polyolefin leather in which a coating layer of a fluorine treatment agent is provided on the surface of a non-foamed layer made of the above polyolefin elastomer.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The fiber base layer in the present invention is a woven fabric (such as Jinshi, plain weave), a knitted fabric (single-sided knitted fabric, double-sided knitted fabric etc.) or a nonwoven fabric. Natural fiber such as cotton and linen; Recycled fiber such as rayon; Semi-synthetic fiber such as acetate; Polyamide fiber such as nylon 6 fiber; Polyester fiber such as polyethylene terephthalate fiber; Acrylic fiber such as polyacrylonitrile fiber Polyolefin fibers such as fibers and polypropylene fibers, and synthetic fibers such as vinylon; inorganic fibers such as glass fibers and carbon fibers are used. The fiber base material may be made of long fibers of the above fibers, or may be made of short fibers, or may be one or a combination of two or more fibers. In particular, since the knitted fabric has good elasticity, it is suitable for leather used for automobile seats, saddles, chairs, sofas and the like.
[0006]
The foamed layer comprising a mixture of 30 to 95% by weight of an ethylene-α-olefin copolymer elastomer and 70 to 5% by weight of a styrene copolymer elastomer will be described. The ethylene-α-olefin copolymer elastomer is preferably a random copolymer of ethylene and another α-olefin. Examples of other α olefins include propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene and 1-decene. Of these, propylene and 1-butene are preferably used. In particular, an ethylene-1-butene copolymer is particularly preferable because it softens appropriately at a foaming temperature of around 200 degrees.
[0007]
This ethylene-α olefin copolymer elastomer has an action of improving the flexibility of the foam layer. From the viewpoint of this softening effect, a random copolymer having an ethylene content of 35 to 95 mol% is preferable, and a random copolymer having 40 to 92 mol% is particularly preferable. Furthermore, from the viewpoint of the softening effect, a copolymer having a crystallinity measured by an X-ray diffraction method of 0 to 30% is preferable, and a copolymer of 0 to 20% is particularly preferable.
[0008]
In addition, the styrene copolymer elastomer includes a styrene-butadiene-styrene block copolymer, a styrene-butadiene block copolymer, a styrene-isoprene-styrene block copolymer, a styrene-isoprene block copolymer, a styrene- Examples thereof include SBR-styrene block copolymers and styrene-SBR block copolymers, and those obtained by hydrogenating these are particularly preferable. In the hydrogenated copolymer, not all the double bonds are necessarily saturated. Examples of commercially available products include Tough Tech manufactured by Asahi Kasei Kogyo Co., Ltd., Hibler manufactured by Kuraray Co., Ltd., and Clayton G manufactured by Shell Chemical Co., Ltd. The copolymer is preferably a random copolymer, and particularly preferably a hydrogenated product of a styrene-butadiene random copolymer. Examples of this commercially available product include Dynalon manufactured by JSR. By blending this styrenic copolymer, the softening temperature range that is more flexible at normal temperature and more suitable for foaming can be expanded to facilitate foaming.
[0009]
The ethylene-α olefin copolymer elastomer and the styrene copolymer elastomer are mixed in a weight ratio of 30 to 95:70 to 5, preferably 60 to 80:40 to 20. The foam layer is prepared by blending a chemical foaming agent into the above mixture to prepare a foamable composition, and forming this foamable composition on a fiber substrate by calendering or coating, and then heating to form a chemical foaming agent. Form by foaming. Examples of the chemical foaming material include azodicarbonamide (ADCA), p, p'-oxybisbenzenesulfonyl hydrazide (OBSH), paratoluenesulfonyl hydrazide (TSH), dinitropentamethylenetetramine (DPT), and the like. A mixture of two or more of these can also be used. The expansion ratio of the foamed layer is not particularly limited, but about 1.5 to 4 times the product is preferable because the texture is good.
[0010]
When forming the foamable composition layer on the fiber base material by calendering or coating, the foamable composition may be formed as it is on the fiber base material. It is preferable to leave. As the adhesive, an adhesive rich in flexibility and bending resistance is preferable. For example, a polyurethane adhesive obtained by reacting a polyol such as polyester polyol or polyether polyol with a diisocyanate such as tolylene diisocyanate or diphenylenemethane diisocyanate. preferable. Further, an ethylene-methyl methacrylate copolymer or an ethylene-methyl methacrylate-maleic anhydride copolymer layer may be formed on the fiber base material, and the above foam layer may be formed thereon.
[0011]
The non-foamed polyolefin elastomer in the present invention forms a leather surface, is flexible and tough, and is obtained by mechanically mixing an olefin rubber (such as ethylene-propylene copolymer rubber) and a polyolefin resin. Blended elastomer, partially cross-linked blended elastomer obtained by adding organic peroxide to a mixture of olefin rubber and polyolefin resin, kneading and partially cross-linking, and olefin rubber partially cross-linked using organic peroxide And a partially crosslinked blend type elastomer obtained by mixing a polyolefin resin and a fully crosslinked blend type elastomer of an olefinic rubber and a polyolefin resin. In particular, a partially cross-linked blend type elastomer, for example, an elastomer obtained by dynamically cross-linking polypropylene resin and ethylene-propylene rubber is preferably used because it has good heat resistance and does not cause trouble during foaming. Examples of commercially available products include Miralastomer manufactured by Mitsui Chemicals.
[0012]
For the foamed layer and non-foamed layer, antistatic agents, phenolic and phosphorous antioxidants, light stabilizers such as hindered amine compounds, lubricants, ultraviolet absorbers, pigments, and inorganic fillers as necessary. You may add various additives, such as. As this type of additive, known ones used for olefinic resins are preferably used.
[0013]
Moreover, the fluorine-type processing agent layer in this invention is a layer provided in order to prevent hand swelling swelling property on the surface of the non-foamed layer which consists of polyolefin-type elastomers. By forming a normal fluororesin layer, it is possible to prevent hand swelling, but the folding flexibility (deformability) of the present invention is impaired. The fluorine-based treatment agent used in the present invention is a two-component curable solution obtained by dissolving a solvent-soluble fluororesin for room temperature curable paint in an appropriate solvent. When this treatment agent is used, the above problems are solved. Is done. Examples of the fluorine treatment agent include vinylidene fluoride polymers, fluoroolefin / hydrocarbon olefin copolymers, fluoroacrylate copolymers, and fluoroepoxy compounds. Among them, a fluoroacrylate copolymer is particularly preferable in that it can impart stain swell resistance without impairing the flexibility and flex resistance of leather.
[0014]
The fluorine-based treatment agent layer is provided by applying a solvent solution of the fluorine-based treatment agent. Since the fluorine-based treatment agent has low adhesion to the non-foamed layer of the polyolefin-based elastomer, it is preferable to perform primer treatment using a binder. As the binder, a known adhesive having adhesiveness to the fluororesin and the polyolefin, for example, a urethane binder is used. Further, by blending a gloss adjusting agent such as silica powder with a fluorine-based processing agent, it is possible to combine the anti-stain swelling treatment and the gloss adjusting treatment. Further, marble printing may be performed between the primer treatment and the fluorine treatment. Further, the narrowing process may be performed after the foaming process. This squeezing treatment may be performed before or after the fluorine-based treatment agent layer is provided. Alternatively, the treatment with the fluorinated treatment agent may be performed after the squeezing treatment, and the fluorinated treatment agent layer may be provided only at the top of the squeezing.
[0015]
Example 1.
A double-sided rayon knitted fabric having a thickness of 0.35 mm was used as the fiber base material. A urethane adhesive was applied to one side. Furthermore, 70 parts by weight of Tuffmer TX-612 (Mitsui Chemicals, ethylene-1-butene copolymer), 30 parts by weight of Dynalon 1320P (JSR, hydrogenated styrene-butadiene random copolymer), chemical A foamable mixture consisting of 3 parts by weight of a foaming agent (azodicarbonamide) and a small amount of a lubricant is sheeted to a thickness of 0.2 mm with a calender, and further to Miralastomer 5030NH (Mitsui Chemicals, partially crosslinked polyolefin elastomer). A mixture containing a small amount of each of an antioxidant, an ultraviolet absorber, a light stabilizer and a lubricant was sheeted with a calendar to a thickness of 0.2 mm. Next, this laminate was passed through a furnace at 225 ° C. to foam the chemical foaming agent. Furthermore, a leather was obtained by performing a drawing process, a primer process, a marble print, and a gloss process. In the measurement after the squeezing treatment, the thickness of the foam layer was 0.45 mm, and the expansion ratio was 2.25 times. The leather thus obtained was excellent in flexibility and bending resistance.
[0016]
Example 2
A double-sided rayon knitted fabric having a thickness of 0.35 mm was used as the fiber base material. A urethane adhesive was applied to one side. Furthermore, 70 parts by weight of Tuffmer TX-612 (Mitsui Chemicals, ethylene-1-butene copolymer), 30 parts by weight of Dynalon 1320P (JSR, hydrogenated styrene-butadiene random copolymer), chemical A foamable mixture consisting of 3 parts by weight of a foaming agent (azodicarbonamide) and a small amount of lubricant is sheeted with a calender to a thickness of 0.2 mm, and on top of that, it is resistant to Miralastomer 5030NH (partially crosslinked polyolefin elastomer). A mixture containing a small amount of each of an oxidizing agent, an ultraviolet absorber, a light stabilizer and a lubricant was sheeted with a calender to a thickness of 0.2 mm. Next, LU-4304 / LU3017C (a urethane binder manufactured by Dainichi Seika Kogyo Co., Ltd.) was applied twice as a primer to the sheeting surface of Miralastomer 5030NH. On top of that, a fluorine surface treating agent FA5753 / FA5759 / Coronate HL) (manufactured by Seiko Kasei Co., Ltd .: FA5753, FA5759 is a fluoroacrylate copolymer, and Coronate HL is an isocyanate curing agent) was applied twice. The laminate thus prepared was passed through a furnace at 225 ° C. to foam the chemical foaming agent. Further, a narrowing process was performed. The thickness of the foamed layer after the squeezing treatment was 0.45 mm, and the foaming ratio was 2.25 times. The leather thus obtained was excellent in flexibility and bending resistance. In addition, when artificial skin (oil and fat close to hand) was applied to this and heated to 60 ° C., no swelling was observed even after 6 hours. On the other hand, the leather without the treatment with the above-described fluorine-based surface treatment agent swelled greatly in 1 hour.
[0017]
【The invention's effect】
The leather of the present invention is rich in flexibility and flexibility despite the use of polyolefin resin. In addition, by providing a coating layer of a fluorine-based treatment agent on the surface of this leather, so-called hand swelling can be prevented. Therefore, the foamed polyolefin-based leather of the present invention is extremely useful as a skin material for automobile seats, bicycle and motorcycle saddles, chairs, sofas and the like.

Claims (2)

A fiber base layer, a foam layer composed of a mixture of 30 to 95% by weight of an ethylene-α-olefin copolymer elastomer and 70 to 5% by weight of a styrene copolymer elastomer, and a non-foamed layer composed of a polyolefin elastomer Foamed polyolefin leather characterized by being laminated. 2. The foamed polyolefin-based leather according to claim 1, wherein a coating layer of a fluorine treatment agent is provided on the surface of a non-foamed layer made of a polyolefin-based elastomer.