JP3212413B2 - Laminated sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to interior materials for automobiles; housings for office automation equipment and home electric appliances;
The present invention relates to a laminated sheet used for covering parts that may be touched by humans, such as sanitary; daily necessities;

[0002]

2. Description of the Related Art Heretofore, in order to give a good feeling of contact to a part touched by a person, a sheet in which a surface is embossed with a polyvinyl chloride layer and a foam is laminated as a covering sheet. Have been. However, a sheet using polyvinyl chloride has a problem that it lacks flexibility and requires a plurality of steps for lamination in its production.

As a means for solving the above problems, for example, Japanese Patent Publication No. 14023/1989 discloses a blend of a polyolefin resin and a partially crosslinked ethylene / α-olefin copolymer rubber. There is proposed a covering sheet in which a thermoplastic elastomer layer embossed and a polyethylene or polypropylene foam layer are laminated.

However, this sheet has a drawback that the sheet itself has low rubber elasticity and, for example, when stretch forming such as vacuum forming is performed, the sheet is not stretched uniformly and the thickness tends to be uneven.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a laminated sheet which is excellent in flexibility and hardly causes uneven thickness during stretching and the like.

[0006]

Means for Solving the Problems The laminated sheet of the present invention comprises:
A surface layer composed of a thermoplastic urethane elastomer, a thermoplastic polyolefin-based elastomer, and a gel fraction of 50 to 9;
Base layer of 0% silane cross-linking olefin resin is a sheet stacked.

The thermoplastic urethane elastomer used in the present invention is one which exhibits rubber elasticity at normal temperature, is plasticized at high temperature and can be subjected to various molding processes, and is generally a rubber component having entropic elasticity in the molecule. (Soft segment) is made of polyether, polyester, or polycarbonate, and a molecular constraint component (hard segment) for preventing plastic deformation is made of urethane bonds. The thermoplastic urethane elastomer,
As long as the molding is possible, it may have a partial crosslink in the molecule.

[0008] The thermoplastic urethane elastomer is preferably in the range of -50 to 20 ° C, because if the glass transition point is too high, the low-temperature impact resistance decreases, and if it is too low, the scratch resistance decreases. If the molecular weight is too low, the rigidity of the sheet is reduced, and if it is too high, the flexibility of the sheet is impaired.
Those in the range of 000 are preferred. The hardness varies depending on the hardness and thickness of the other layers to be laminated, but is generally preferably 50 to 98 in JIS A hardness.

Examples of the thermoplastic urethane elastomer include PN3429 (trade name, manufactured by Asahi Glass Co., Ltd.) and T7890 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.).

The thermoplastic urethane elastomer may be added with particles of an ABS resin or cross-linked polymethyl methacrylate in order to change the feel, if necessary, or may be provided with a colorant, an antioxidant, an ultraviolet ray inhibitor, Stabilizers and the like may be added. As the coloring agent, those used in paints can be used, and examples thereof include coloring agents such as titanium oxide, iron oxide, carbon black, cyan, quinacridone, azo, anthraquinone, indigoid, and stilbenzene. If necessary, particles such as aluminum flake, nickel powder, gold powder, and silver powder may be added.

When the amount of these additives is large, the scratch resistance of the thermoplastic urethane elastomer is reduced, and when the amount is too small, the effect as an additive is not produced. , 2
The amount is preferably 100 parts by weight, more preferably 5 to 50 parts by weight.

Further, elastic fine particles may be added to the thermoplastic urethane elastomer in order to make the surface of the thermoplastic urethane elastomer have irregularities and improve the suede feeling. The elastic fine particles have a shape exhibiting elastic recovery when the pressure is released after being pressed, and the shape is not particularly limited. For example, the elastic fine particles may be hollow.

The elastic fine particles preferably do not undergo plasticization or decomposition during molding such as extrusion, and a crosslinked resin is generally used. For example, polyurethane, polystyrene, polyacrylate, acryl-urethane copolymer, styrene-isoprene copolymer and the like can be mentioned. These may be used alone or in combination of two or more.

If the particle size of these elastic fine particles is too small, the suede feeling of the sheet is reduced, and if the particle size is too large, cracks tend to occur on the surface when the sheet is stretched. Are preferred.

On the other hand, if the amount of addition is small, sufficient unevenness cannot be obtained, and the suede feeling is lowered. On the other hand, if the amount is too large, cracks are likely to be generated on the surface when the sheet is stretched. The amount is preferably 20 to 200 parts by weight, more preferably 50 to 150 parts by weight, based on 100 parts by weight of the plastic urethane elastomer.

The base layer of the present invention is made of a thermoplastic polyolefin elastomer and the silane cross-linking olefin resin. The thermoplastic polyolefin-based elastomer,
It shows rubber elasticity at room temperature and is plasticized at high temperature to enable various molding processes. Generally, the rubber component (soft segment) having entropy elasticity in the molecule is composed of polyethylene, ethylene and a small amount of diene. Or a partially crosslinked product thereof, and a molecular constraint component (hard segment) for preventing plastic deformation is made of polypropylene. The hardness of these thermoplastic polyolefin-based elastomers varies depending on the intended use, but is generally 50 to 98 in JIS A hardness.
Are preferred.

The thermoplastic polyolefin-based elastomer includes, for example, Mirastoma 8030N and Mirastomer 5030N (trade names, manufactured by Mitsui Petrochemical Co., Ltd.).

[0018] The upper SL silane cross-linking olefin resin, polypropylene, polyethylene, polybutene, poly (4-
Methylpentene-1) and the like, and these are resins obtained by crosslinking with silane .

The crosslinking ratio of the silane cross-linking olefin resin,
If the ratio is too low, the fluidity increases, and uniform stretching cannot be performed. On the other hand, if the ratio is too high, the sheet is likely to be broken during stretching, so that the gel fraction is 50 to 90 %. The gel fraction was determined by the following formula using a xylene boiling point extraction method in which the olefin resin sample after crosslinking was wrapped in a 240-mesh stainless steel net and the sample was immersed at 120 ° C. for 24 hours to determine the weight change of the sample. It is a thing. Gel fraction (%) = (weight after dipping / weight before dipping) × 100

The amount of the silane cross-linking olefin resin,
Too little and improvement of stretchability is not sufficient, since such tear the sheet occurs during stretching and too much Conversely, the ratio of the thermoplastic polyolefin elastomer and the silane cross-linking olefin resin, in a weight ratio of 95: 5 ６０60: 40 is preferred, and more preferably 90: 10-65: 35.

[0021] the base material layer in order to improve the press-molded properties, it may be added further polypropylene or linear polyethylene or the like, the rubber elasticity decreases when the addition amount is too large, the thermoplastic polyolefin Elastomers and sila
Preferably 70 parts by weight or less relative to 100 parts by weight of the total amount of the emission cross-linking olefin resin, more preferably not more than 25 parts by weight.

The surface layer and the base material layer may be integrally formed by heat fusion at the time of lamination by co-extrusion, or may be integrally formed via an adhesive layer. Is also good. The co-extrusion method is a method in which a plurality of layers are integrally laminated by a plurality of extruders, and examples thereof include a feed block method, a multi-manifold method, and a multi-throttle die method. The resin temperature at the time of co-extrusion varies depending on the elastomer or the like used.
0 ° C, the substrate layer has a temperature of 190 to 230 ° C.

As a material for forming the adhesive layer, a polymer compatible with the base material layer is preferably used. That is, a polymer containing a compound having a functional group such as a hydroxyl group, an amide group, an epoxy group, a carboxylic acid group, or a carboxylic acid ester group in a main chain or a side chain is preferable. For example, an acid-modified styrene-butadiene-styrene copolymer is preferable. Coalesced acid, acid-modified styrene-ethylene-butylene copolymer, acid-modified polypropylene, acid-modified polyethylene and the like.

Further, instead of providing the above-mentioned adhesive layer, an adhesiveness-imparting agent may be added to the base material layer. Examples of the adhesion-imparting agent include a hydroxyl group, an amide group,
An olefin-based polymer or oligomer having at least one functional group selected from the group consisting of an epoxy group, a carboxylic acid group, and a carboxylic acid ester group is exemplified, and those having a carboxylic acid group are particularly preferred. As the amount of the carboxylic acid group, the acid value of the polymer is 10 to 60 mg KOH.
/ G is preferred.

When the weight-average molecular weight of the adhesion-imparting agent is too large, the adhesiveness is reduced, and when it is too small, the adhesive holding force is reduced.
Is preferred. If the softening point is too low, the heat resistance of the sheet will be poor, and if it is too high, the effect of imparting adhesiveness will be reduced.

[0026] If the amount of adhesion promoter is too small, the total amount of the thermoplastic polyolefin elastomer and the silane cross-linking olefin resin for adhesion is not improved, impair the physical properties of the too large substrate layer 100 1 to 3 parts by weight
The amount is preferably 0 parts by weight, more preferably 3 to 15 parts by weight.

Further, a foam layer made of a synthetic resin may be further laminated on the base material layer so as to have a cushioning property. Examples of foams include polyolefin resins such as polypropylene and polyethylene; polystyrene,
Polystyrene resins such as styrene-maleic anhydride copolymers; polyurethane resins; polyvinyl chloride resins; foams such as various thermoplastic elastomers;
Polyolefin resin foams that can be laminated without an adhesive layer are particularly preferred. The expansion ratio of this foam is not particularly limited, but in order to impart a soft feeling,
It is preferably 50 times, more preferably 10 to 30 times.

The structure of the laminated sheet of the present invention is as described above. The thickness of the laminated sheet is not particularly limited and may be appropriately determined according to the intended use. 100 μm, base layer 200 to 300
0 μm, adhesive layer formed as required is 5 to 100 μm
m, the thickness of the foam layer is 1000 to 3000 μm.

The laminated sheet of the present invention may be provided with a conductive material, a photochromic compound, an anti-condensation agent, a rust inhibitor, a bactericidal / mildew-proof agent, a matting agent, in order to impart various functions as required. Additives such as may be added. The surface of the laminated sheet of the present invention may be provided with a pattern such as printing or graining, if necessary.

EXAMPLES The present invention will be described in more detail with reference to Examples. FIG. 1 is a cross-sectional view of a cup-shaped vacuum forming die used for vacuum stretching of the laminated sheet of the present invention, and FIG. 2 is a cross-sectional view of a formed body formed by the vacuum forming die of FIG.

The composition of each layer used in the examples is described below. Surface layer Thermoplastic urethane elastomer (manufactured by Asahi Glass Co., Ltd .: Trade name P)
N3429, JISA hardness 85). Surface layer Thermoplastic urethane elastomer (manufactured by Asahi Glass Co., Ltd .: Trade name P)
N3429, JISA hardness 85) 100 parts by weight, elastic fine particles (manufactured by Sekisui Plastics Co., Ltd., urethane beads: trade name UB2)
0-black, average particle size 20 μm)
Kneaded at ℃. Surface layer Thermoplastic urethane elastomer (manufactured by Dainippon Ink and Chemicals, Inc .: trade name T7890, JIS A hardness 91).

Adhesion layer Acid-modified polyolefin (trade name: ADMER QF551, manufactured by Mitsui Petrochemical Co., Ltd.). Adhesive layer Acid-modified styrene-ethylene-butylene-styrene copolymer (trade name: Tuftec M194, manufactured by Asahi Kasei Corporation)
3).

Base layer 70 parts by weight of a thermoplastic polyolefin-based elastomer (trade name: Mirastomer 8030N, manufactured by Mitsui Petrochemical Co., Ltd.), linear low-density polyethylene (trade name: U, manufactured by Mitsui Petrochemical Co., Ltd.)
Z2921L) 10 parts by weight, polypropylene (manufactured by Mitsui Petrochemical Co., Ltd .: F650), 10 parts by weight, silane crosslinkable high-density polyethylene (manufactured by Mitsubishi Yuka Co., Ltd .: trade name HM-60)
0A) 20 parts by weight kneaded at 220 ° C. Base material layer 70 parts by weight of thermoplastic polyolefin-based elastomer (Mitsui Petrochemical Co., Ltd .: trade name Mirastomer 5030N), linear low density polyethylene (Mitsui Petrochemical Co., Ltd .: trade name U)
Z2921L), 10 parts by weight, polypropylene (manufactured by Mitsui Petrochemical Co., Ltd .: F650), 10 parts by weight, silane crosslinkable high-density polyethylene (manufactured by Mitsubishi Yuka: XPM-8)
00H) 30 parts by weight kneaded at 220 ° C. Base layer 50 parts by weight of thermoplastic polyolefin-based elastomer (Mitsui Petrochemical Co., Ltd .: trade name: Mirastomer 8030N), 30 parts by weight of thermoplastic polyolefin-based elastomer (Mitsui Petrochemical Co., Ltd .: trade name: Mirastomer 5030N), linear low density Polyethylene (Mitsui Petrochemical Co., Ltd .: UZ
A mixture obtained by kneading 10 parts by weight of 2921L) and 10 parts by weight of polypropylene (trade name: F650, manufactured by Mitsui Petrochemical Co., Ltd.) at 220 ° C.

Examples 1-4, Comparative Examples 1-2

Coextrusion was performed using a coextrusion apparatus so that each layer had a predetermined thickness shown in Table 1, to obtain a laminated sheet. The extrusion device is a three-layer co-extrusion device having a feed block and a mold, and having three extruders.
An extruder of φ, 60φ was used. Further, the resin temperature of each layer was 200 ° C., 210 ° C., 220 ° C., and the temperature of the die was 190 ° C. The obtained sheet is placed in warm water of 80 ° C. for 2 hours.
The substrate was immersed for 0 minutes to crosslink the crosslinkable olefin resin in the base material layer to obtain a laminated sheet.

Next, the gel fraction of the crosslinked olefin resin in the base material layer was determined by the above-mentioned xylene boiling point extraction method, and is shown in Table 1.

In Examples 2 to 4, the surface of the base material layer was heated to 190 ° C., a foam layer was laminated, and laminated through a take-off roll.

The obtained sheet was subjected to vacuum stretching using the cup-shaped vacuum forming die 1 (inner diameter = 100 mm, depth = 30 mm, corner R = 5 mm) shown in FIG. The temperature of the sheet at the time of molding was maintained at 140 ° C. for the surface layer and 150 ° C. for the adhesive layer and the base material layer in contact with the mold, and a molded body 3 having the shape shown in FIG. 2 was obtained.

The results of measuring the thickness of the bottom A and the corner B of the obtained molded product are shown in Table 1 as indices of uneven wall thickness. Further, the load when the surface of the surface layer was damaged was shown as a value of scratch resistance using a scratch tester on the surface of the molded body.

The suede feeling of the surface layer was evaluated by a sensory test by 10 humans according to the following rating. The total score is shown in Table 1 as a high touch feeling. Very good feeling 5 points Slightly good feeling 3 points Normal 0 point Slightly bad feeling -3 points Very bad feeling -5 points

[Table 1]

[0040]

The structure of the laminated sheet of the present invention is as described above. Since the fluidity at the time of heating is high, uneven thickness hardly occurs even in a portion such as a corner portion where stretching is large, and stretch forming of a complicated shape is performed. Excellent dimensional stability at the time.

[0041]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a vacuum forming die used when forming a laminated sheet of the present invention in an example.

FIG. 2 is a cross-sectional view of a molded article vacuum-stretched using the mold of FIG.

[Explanation of symbols]

 Reference Signs List 1 cup-shaped vacuum forming die 2 suction hole 3 molded body A bottom wall thickness B corner wall thickness

Claims (1)

(57) [Claims] 1. A surface layer comprising a thermoplastic urethane elastomer, a thermoplastic polyolefin-based elastomer and a gel component.
Laminated sheet rate is characterized by comprising a base material layer made of 50-90% of a silane cross-linking olefin resin.