JP2003166181A - Synthetic resin leather - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic resin leather having flexibility, excellent in resistance to surface damage, capable of carrying out welding by a high-frequency welder, having frame retardance and not causing spreading of seam. <P>SOLUTION: This synthetic resin leather is obtained by providing a mixed resin layer having 60-80 Shore A hardness and composed of 50-95 wt.% thermoplastic polyurethane having 65-90 Shore A hardness and 50-95 wt.% acrylic flexible resin having 50-80 Shore A hardness on at least one side of a base. A woven fabric, a knitted fabric or a nonwoven fabric is used as the base. A flexible foam sheet or a laminate of the woven fabric, the knitted fabric or the nonwoven fabric with the flexible foam sheet can be used as the base. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a synthetic resin leather using a mixed resin of thermoplastic polyurethane and an acrylic soft resin.

[0002]

2. Description of the Related Art Synthetic resin leather used for automobile interior materials, bag materials, furniture skin materials, etc. is required to be flexible and strong.
Alternatively, it is general that a soft polyvinyl chloride layer is formed on the surface of a sheet base material such as a polyolefin foam. This soft polyvinyl chloride has various hardness, and for general film use, polyvinyl chloride 10
30 parts of plasticizer (diethylhexyl phthalate) in 0 parts by weight
The hardness is about 50 to 50 parts by weight, but when used for leather, the hardness is about 70 to 100 parts by weight of the plasticizer, that is, the one is considerably soft. By the way, due to the recycling problem in recent years, instead of soft polyvinyl chloride, random polypropylene, ethylene-
A polyolefin resin leather using vinyl acetate resin, hydrogenated styrene butadiene rubber, etc. has been proposed.

However, the surface of polyolefin-based leather is more easily scratched than that of soft polyvinyl chloride leather,
There are problems such as lack of high-frequency welder property and insufficient softness. Furthermore, since it is inferior in flame retardance, it does not have flame retardance to withstand regulation unless phosphoric acid type or boric acid type flame retardant is blended. There is a problem. Therefore, the present applicant has previously proposed an acrylic soft resin layer provided on at least one side of a base material as a synthetic resin leather which is flexible and has excellent surface scratch resistance and can be welded by a high frequency welder. A resin resin leather has been proposed (see Patent Document 1). This acrylic resin leather is excellent as a synthetic resin leather that can replace conventional soft polyvinyl chloride leather, but when sewn with a sewing machine, the seams spread,
I learned that it has a problem that it is easy to tear from the seam. Thermoplastic polyurethane leather is also known, but it is rubber-like, has a high resilience, and does not have a natural softness due to delayed elasticity such as soft polyvinyl chloride, and thus has a poor feel. Further, in order to obtain the softness, it is necessary to add a large amount of a plasticizer, there are problems such as migration of the plasticizer and bloom, and calender processability is low.

[0004]

[Patent Document 1] Japanese Patent Laid-Open No. 2002-155477

[Patent Document 2] Japanese Patent Laid-Open No. 6-263828

[Patent Document 3] Japanese Unexamined Patent Publication No. 9-100385

[Patent Document 4] Japanese Unexamined Patent Publication No. 11-71437

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has a high tear strength without impairing the excellent properties of the acrylic resin leather described above, and when sewn with a sewing machine or the like, It is an object of the present invention to provide a synthetic resin leather in which defects such as widened seams and easy tears from the seams are eliminated.

[0006]

That is, according to the present invention, 50 to 95% by weight of a thermoplastic polyurethane having a Shore A hardness of 65 to 90 and a Shore A hardness of 50 are provided on at least one surface of a substrate.
A mixed resin layer with 50 to 5% by weight of acrylic soft resin of 80 to 80, and the Shore A hardness of the mixed resin layer is 6
It is a synthetic resin leather characterized by being 0 to 80. A woven fabric, a knitted fabric, or a non-woven fabric is used as the substrate. The base material may be a soft foam sheet, or a laminate of a woven fabric, a knitted fabric or a non-woven fabric and a soft foam sheet.

The present invention also has a Shore A hardness of 65 to 90.
Of 50 to 95% by weight of thermoplastic polyurethane and 50 to 5% by weight of acrylic soft resin having Shore A hardness of 50 to 80 are calendered to form a sheet, and the sheet and the base material are laminated and integrated. The method for producing a synthetic resin leather described above is characterized by the following. In order to facilitate this calendering, a (meth) acrylic polymer or calcium carbonate may be added to the mixed resin.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The synthetic resin leather of the present invention comprises thermoplastic polyurethane 50-95 on at least one side of a substrate.
It is a synthetic resin leather provided with a mixed resin layer of 50% by weight of acrylic soft resin and 50% by weight of acrylic soft resin. A woven fabric, a knitted fabric, or a non-woven fabric is used as the substrate. Materials for these knitted fabrics include polyamide fibers, polyester fibers, acrylic fibers, polypropylene fibers, cotton, rayon, and mixed yarns of these. The knitted fabric may be a double-sided knitted fabric, a plain knitted fabric, or the like, and the woven fabric may be a plain woven fabric, a twilled fabric, a satin woven fabric, or the like. A soft foam sheet can also be used as the base material. This soft foam sheet is polypropylene foam, electron beam crosslinked polypropylene foam, polyethylene foam, electron beam crosslinked polyethylene foam, polyurethane foam, or the like. Further, a woven fabric, a knitted fabric, or a laminate of a soft foam sheet can be used as the substrate. In this case, it is preferable to adopt a structure of woven fabric, knitted fabric or nonwoven fabric-soft foam sheet-mixed resin layer.

The thermoplastic polyurethane used in the present invention is
It can be obtained by reacting a diisocyanate compound with a compound having two or more hydroxyl groups. Above all, a polyurethane-based thermoplastic elastomer (T containing a so-called soft segment and a hard segment, which is composed of a long-chain polyol, a diisocyanate, and a chain extender (T
PU) can be preferably used. Those having a Shore A hardness of 65 to 90, particularly 70 to 80, are preferable. The Shore A hardness in the present invention is a value measured by ASTM D 2240 (measurement temperature 2
3 ° C).

Examples of diisocyanate compounds for synthesizing thermoplastic polyurethane include tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated dicyclohexylmethane diisocyanate and isophorone. Diisoianate or the like is used.

As the compound having two or more hydroxyl groups, a polyester polyol which is a condensation reaction product of a dibasic acid such as adipic acid or phthalic acid with a glycol such as ethylene glycol or 1,4-butanediol;
A polycarbonate-based polyol which is a reaction product of a carbonate such as ethylene carbonate and a glycol; a polyether-based polyol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol-polypropylene glycol, or the like is used. In the synthetic resin leather of the present invention, it is preferable to use a polyether polyol because of its physical properties. Further, the thermoplastic polyurethane using a polyether polyol as a raw material has good aging resistance and calender processability, and is also preferable from this viewpoint.

As the chain extender, ethylene glycol,
Low molecular weight polyhydric alcohol such as 1,2-propylene glycol, 1,3-propylene glycol, butane 1,2 diol, butane 1,3 diol, butane 1,4 diol, butane 2,3 diol, hexane diol, or diamine , Water is used.

The acrylic soft resin used in the present invention is a resin having flexibility like ordinary polyvinyl chloride at room temperature. This acrylic soft resin has a Shore A hardness of 5
Those of 0 to 80, and especially those of 55 to 65 are preferably used. The acrylic soft resin is preferably a multi-layered polymer, that is, a particulate polymer in which two or more kinds of acrylic polymers form a core-shell type multi-layered structure. These acrylic soft resins exhibit good flexibility at room temperature, have bending durability, and are excellent in weather resistance.

An example of the acrylic soft resin used in the present invention will be shown. 30 to 99.9% by weight of at least one alkyl acrylate ester having an alkyl group having 1 to 12 carbon atoms, 0 to 70% by weight of at least one methacrylic acid alkyl ester having an alkyl group of 1 to 8 carbon atoms, copolymerization The Tg obtained by polymerizing a monomer mixture composed of 0 to 30% by weight of an unsaturated monomer and 0.1 to 10% by weight of a polyfunctional crosslinking monomer and / or a polyfunctional grafting monomer is possible. 10 to 90 parts by weight of at least one polymer layer [A] at 30 ° C. or lower, and 30 to 99% by weight of at least one alkyl acrylate ester having an alkyl group having 1 to 12 carbon atoms,
The Tg obtained by polymerizing a monomer mixture consisting of 1 to 70% by weight of at least one alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms and 0 to 30% by weight of a copolymerizable unsaturated monomer is At least 1 which is -20 to 50 ° C
The polymer layer [B] is a multi-layered polymer comprising a combination of 90 to 10 parts by weight, and the outermost layer is the polymer layer [B].
Is an acrylic soft multi-layer structure resin (Patent Document 2)
reference).

Another example of the acrylic soft resin will be shown. 60 to 99.5% by weight of alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, 0 to 39.5% by weight of a monofunctional monomer having one copolymerizable vinyl group, and a vinyl group or vinylidene. Rubber layers 30 to 8 obtained by polymerizing 0.5 to 5% by weight of a polyfunctional monomer having at least two groups
Monomers having 0 parts by weight, 40 to 100% by weight of methyl methacrylate, 0 to 60% by weight of alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, and a copolymerizable vinyl group or vinylidene group. It is an acrylic soft multilayer structure resin composed of 20 to 70 parts by weight of a hard resin layer obtained by polymerizing 0 to 20% by weight, and the outermost layer is a hard resin layer (see Patent Document 3).

Further, another example of the acrylic soft resin will be shown. (A) 80 to 98.99% by weight of methyl methacrylate, 1 to 20% by weight of alkyl acrylate having an alkyl group having 1 to 8 carbon atoms, and a polyfunctional grafting agent of 0.0
5 to 30 parts by weight of the innermost hard polymer layer obtained by polymerizing a monomer mixture consisting of 1 to 1% by weight and a polyfunctional crosslinking agent 0 to 0.5% by weight; (B) a carbon number of 1 to 8 70 to 99.5% by weight of alkyl acrylate having an alkyl group of
Methyl methacrylate 0-30% by weight, polyfunctional grafting agent 0.5-5% by weight and polyfunctional crosslinking agent 0-5% by weight
20 to 45 parts by weight of a hard polymer layer as an intermediate layer obtained by polymerizing a monomer mixture consisting of: (C) methyl methacrylate 9
The outermost hard polymer layers 50 to 7 obtained by polymerizing a monomer mixture of 0 to 99% by weight and 10 to 1% by weight of an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms.
It is an acrylic soft multilayer structure resin composed of 5 parts by weight and having an average particle size of 0.01 to 0.3 μm (see Patent Document 4).

In the synthetic resin leather of the present invention, the blending ratio of the thermoplastic polyurethane and the acrylic soft resin is 50 to 95% by weight of the thermoplastic polyurethane, 60 to 5% by weight of the acrylic soft resin, and preferably the thermoplastic polyurethane. 60-90% by weight, acrylic soft resin 40-1
0% by weight, more preferably thermoplastic polyurethane 70-
90% by weight and 30 to 10% by weight of the acrylic soft resin. If the thermoplastic polyurethane is less than 50% by weight, the tear strength is not sufficient and the seams are widened or easily torn, while if the thermoplastic polyurethane exceeds 95% by weight, it has a hard feel and is not suitable for use as a leather. There is a problem that the processing temperature rises and it decomposes.

By incorporating a plasticizer into the mixed resin layer, the flexibility and feel of the product can be improved. In addition, the blending of the plasticizer can lower the processing temperature of the calendar processing of the mixed resin, and therefore can suppress the decomposition of the thermoplastic polyurethane during processing. Examples of the plasticizer include phthalic acid esters such as di-2-ethylhexyl phthalate, isobutyl phthalate and diisodecyl phthalate; trimellitic acid esters such as tri-2 ethylhexyl trimellitate; di-2 ethylhexyl adipate and di-isononyl adipate. , Di-2
Aliphatic dibasic acid esters such as ethylhexyl sebacate; epoxidized soybean oil, epoxy plasticizers such as butyl epoxystearate, phosphate ester systems such as tricresyl phosphate, and citric acid esters such as tributyl acetylcitrate To be Among these, aromatic carboxylic acid esters such as phthalic acid esters and trimellitic acid esters are particularly preferably used from the viewpoints of high plasticization efficiency and less problems such as bleeding. The blending amount of the plasticizer is 0 based on 100 parts by weight of the mixed resin.
-50 parts by weight, preferably 3-20 parts by weight. Mixing in a large amount is not preferable because it causes migration and bleeding.

The mixed resin layer may further contain, if necessary, a lubricant, an ultraviolet absorber, a light stabilizer, a pigment, an antibacterial agent and the like which are usually used for compounding synthetic resins. As the lubricant, aliphatic metal salts of stearic acid such as calcium, magnesium, zinc and barium, polyethylene wax, stearic acid, alkylenebis fatty acid amide and the like are used. As the UV absorber, a benzotriazole-based UV absorber such as 2- (2′-hydroxy-5′-methylphenyl) benzotriazole is used.
As the light stabilizer, a hindered amine light stabilizer such as bis- (2,2,6,6-tetramethyl-4-piperidyl) sebacate is used. As the antibacterial agent, a silver-based inorganic antibacterial agent or the like is used.

The mixed resin layer provided on at least one surface of the base material of the present invention preferably has a Shore A hardness of 60-80. This hardness can be obtained by using a thermoplastic polyurethane having a Shore A hardness of 65 to 90 and an acrylic soft resin having a Shore A hardness of 50 to 80. Then, by setting this hardness, polyvinyl chloride 1
7 parts of plasticizer (diethylhexyl phthalate) to 00 parts by weight
A leather having the same softness, touch and feel as the leather having a soft polyvinyl chloride layer blended in an amount of 0 to 100 parts by weight can be obtained.

The synthetic resin leather of the present invention is manufactured as follows. That is, for example, thermoplastic polyurethane and acrylic soft resin are mixed in a predetermined ratio, and if necessary, additives such as a plasticizer and a lubricant are blended, kneaded well, and then calendered or extruded. 0.
A mixed resin sheet is prepared by molding into a sheet having a thickness of 1 to 5 mm. An adhesive is applied to the knitted fabric of the base material, and the mixed resin sheet is overlaid on the adhesive-applied surface and heated and pressed to some extent,
Adhere to the extent that it does not slip. Then, if necessary, marble printing is performed, a matting agent is applied, and then the sheet is heated to 150 to 200 ° C. and pressed by a squeeze roll. By this pressurization, the base material and the mixed resin sheet are integrated to obtain a leather. Moreover, you may provide a mixed resin layer on both surfaces of the knitted fabric of a base material. In addition, an adhesive is applied to a soft foam sheet such as a polypropylene foam sheet or a polyurethane foam sheet, and the soft foam sheet surface is
A leather may be formed by forming a mixed resin layer in the same manner as above. In particular, when a polyurethane foam sheet is used as the soft foam sheet, it can be integrated without an adhesive.

To bond the base material to the mixed resin sheet, an ethylene-vinyl acetate copolymer emulsion, polyvinyl chloride paste, two-component polyurethane adhesive, etc. are used. This adhesive may be applied to the base cloth surface or the mixed resin sheet surface. In order to bond the base material and the polypropylene foam sheet, and the polypropylene foam sheet and the mixed resin sheet, a primer layer for improving adhesion such as a polyurethane primer layer or an epoxy resin primer layer is provided on the laminated surface of the polypropylene foam sheet. It may be provided.

The above-mentioned mixed resin is preferably formed into a sheet by calendering. However, by blending the mixed resin with a (meth) acrylic polymer, the melt tension during calendering can be adjusted and calendering can be performed. Can be smooth. The (meth) acrylic polymer is, for example, 50 to 90% by weight of methyl methacrylate and 50 to 90% of another ethylenically unsaturated monomer copolymerizable therewith.
A copolymer having a molecular weight of 500 to 5,000,000 obtained by copolymerizing 5% by weight is preferable. Other ethylenically unsaturated monomers are
For example, methacrylic acid ester of alcohol having 2 to 18 carbon atoms, acrylic acid ester of alcohol having 2 to 18 carbon atoms, styrene, α-methylstyrene, acrylonitrile, maleic acid, itaconic acid and the like. The blending amount of the (meth) acrylic polymer is 0 to 30 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the mixed resin.

Further, by mixing inorganic carbonate powder such as calcium carbonate, antimony oxide, colloidal silica, magnesium silicate and magnesium hydroxide into the mixed resin layer, the tackiness during calendering is reduced and calendering is performed. Can be smoothed. Calcium carbonate is particularly preferable. The amount of the inorganic compound is 100% of the mixed resin.
The amount is 0 to 30 parts by weight, preferably 5 to 20 parts by weight.

The synthetic resin leather of the present invention is used for vehicle interiors such as automobiles (seats, headrests, tonneau covers, sun visors, ceilings, etc.), interior interior materials, motorcycle saddle skin materials, furniture (chairs, sofas, etc.). It is used for skin materials, bag materials such as bags, kappa, and apron. Further, a base material having a mixed resin layer on both sides of a knitted fabric is used as a material for a flexible container. In addition, leather using a soft foam sheet as a base material is also used for vehicle interiors (instrument panels, doors, ceilings, etc.).

[0026]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. Examples 1-5, Comparative Examples 1-2 As Examples 1-5, thermoplastic polyurethane (UHE-
75A: Mitsubishi Chemical Co., polyurethane using special ether-based polyol, Shore A hardness 77), thermoplastic polyurethane (UE-80: Mitsubishi Chemical Co., using ether-based polyol, Shore A hardness 80), acrylic soft Resin (SA-1000P: manufactured by Kuraray Co., Ltd., Shore hardness 70), methyl methacrylate-alkyl acrylate copolymer (Metabrene P-530A: manufactured by Mitsubishi Rayon Co., Ltd.), calcium carbonate (NS-A: Nitto Koka Kogyo) Company), antioxidant (PEP-36: Asahi Denka Kogyo Co., Ltd.), plasticizer (# 124: Kao Corporation, phthalate ester), lubricant (polyethylene wax), ultraviolet absorber (benzotriazole type). The proportions of the light stabilizer (HALS) and the pigment shown in Examples 1 to 5 and Comparative Examples 1 and 2 in Table 1 (the numbers are parts by weight). (Shown) and were calendered to form a sheet having a thickness of 0.25 mm. An ethylene-vinyl acetate emulsion adhesive was applied to a plain knitted fabric of 7: 3 mixed yarn of rayon and polyester fibers. The above-mentioned sheet was placed on this adhesive-coated surface, heated and pressed to some extent, and bonded so as not to shift. After that, the sheet was heated to 180 ° C. and pressed with a squeeze roll and a rubber roll at room temperature. The synthetic knitted fabric and the mixed resin sheet were integrated, and synthetic resin leather with a tie pattern was obtained. The leather produced in this example and the comparative example were examined for surface scratch resistance, cold resistance, high frequency welder property, flexibility, seam spread state, roll processability, heat resistance, and light resistance. The results are also shown in Table 1.

[0027]

[Table 1]

In Table 1, the surface scratch resistance is JIS
It measured based on K7204. However, wear wheels are CS
-10, the load was 1 kgf x 2000 times. Cold resistance showed the lowest temperature which passed according to JIS K 6772. The high-frequency welder property was evaluated by performing a welding process using a commercially available machine and adhering the mixed resins to each other by a peeling test. ◯ indicates material destruction during peeling, and x indicates interfacial peeling during peeling. As for flexibility, each produced leather is touched by hand, and the feel is soft polyvinyl chloride leather (a polyvinyl chloride composition in which 100 parts by weight of a synthetic resin layer is mixed with 100 parts by weight of plasticizer diethylhexyl phthalate as a plasticizer). It was evaluated in comparison with a certain leather). ◯ means that the feel is equivalent to that of soft polyvinyl chloride leather, Δ means that the feel is slightly harder than that of soft polyvinyl chloride leather, and that x means that the feel is hard and the soft polyvinyl chloride leather cannot be replaced.

The spread state of the seam was observed by visually observing the state of the seam by stitching the top of the chair by sewing using each leather. ○ indicates that the seam does not spread, and × indicates that the seam spreads and the product is not commercially available. The roll processability was evaluated by the adhesiveness after 30 minutes at the calendering temperature (which is an appropriate melting temperature). ○ is moderately sticky,
Δ indicates slightly tacky, and x indicates tacky. Heat resistance is 110 ° C
Discoloration after standing for 500 hours was measured and evaluated. The light resistance is 30 with an ultraviolet carbon arc type light resistance tester with a black panel temperature of 83 ° C. according to JIS-B-7751.
The discoloration after 0 hour irradiation was evaluated.

[0030]

EFFECT OF THE INVENTION The synthetic resin leather of the present invention has the same flexibility and feel as conventional soft polyvinyl chloride leather,
It has good restoration properties, cold resistance, and resistance to surface scratches, and has the advantage that it can be welded by a high-frequency welder, and when sewing with a sewing machine etc., the seams do not spread or tear from the seams. Therefore, it is a synthetic resin leather which is useful as a vehicle interior material for automobiles, a bag material, and a skin material for furniture, and which can replace conventional soft polyvinyl chloride leather.

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Claims (6)

[Claims] 1. A Shore A hardness of 6 on at least one side of a substrate.
A mixed resin layer of 50 to 95 wt% of thermoplastic polyurethane of 5 to 90 and 50 to 5 wt% of acrylic soft resin of Shore A hardness of 50 to 80 is provided, and the Shore A hardness of the mixed resin layer is 60 to. 80 synthetic resin leather. 2. The synthetic resin leather according to claim 1, wherein the mixed resin layer contains a plasticizer. 3. The synthetic resin leather according to claim 1, wherein the base material is a woven fabric, a knitted fabric, a non-woven fabric or a soft foam sheet. 4. A sheet is formed by calendering a mixed resin of 50 to 95% by weight of a thermoplastic polyurethane having a Shore A hardness of 65 to 90 and 50 to 5% by weight of an acrylic soft resin having a Shore A hardness of 50 to 80. The synthetic resin leather manufacturing method according to claim 1, wherein the sheet and the base material are laminated and integrated. 5. The method for producing synthetic resin leather according to claim 4, wherein a (meth) acrylic polymer is blended with the mixed resin. 6. The method for producing a synthetic resin leather according to claim 4, wherein calcium carbonate is mixed with the mixed resin.