JP3224682B2 - Manufacturing method of sheet for coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to housings for automobile interiors, office automation equipment, home electric appliances, etc.
The present invention relates to a method for producing a covering sheet having excellent abrasion resistance, the surface of which is hardly scratched, which is used by covering molded articles such as stationery, sanitary goods, daily necessities, and interior building materials.

[0002]

2. Description of the Related Art Heretofore, as such a coating material, a sheet comprising a vinyl chloride resin layer whose surface is embossed and, if necessary, a foam layer laminated thereon has been used. However, sheets using vinyl chloride resin
The sheet lacks flexibility and requires multiple steps in manufacturing. It is known that a polyolefin-based thermoplastic elastomer layer is extruded into a sheet and fused to a crosslinked foam sheet without using a vinyl chloride resin (for example, see Japanese Patent Publication No. 1-14023).

[0003]

A sheet using a vinyl chloride resin or a sheet using a polyolefin-based thermoplastic elastomer as described in the above-mentioned publications has abrasion resistance due to the rubber elasticity of the sheet and the contact resistance of the surface. Was bad.

[0004] In order to impart abrasion resistance, there is a method in which an acrylic resin is coated after a primer layer is provided (for example, JP-A-63-27254).
However, since an organic solvent is used, there is a problem in terms of safety and health.

[0005] The production of such a covering sheet comprising a laminated sheet is usually carried out by a co-extrusion molding method. By the way, the material and thickness of each layer constituting the covering sheet are quality,
It is required to select a material suitable for the characteristics of each layer and to set the thickness in terms of cost. Therefore, from the viewpoint of cost, the surface layer and the adhesive resin layer, which are expensive, tend to be thinner, and the inexpensive base material layer tends to be thicker.

However, if the thickness of the base material layer is increased to pursue only the cost advantage, the melt viscosity of the resin of each layer and the flow velocity difference are adversely affected at the molding stage, and the thickness accuracy of each layer cannot be obtained. The interface may be rough and the appearance may be impaired. Also, in order to thicken the base material layer, a two-layer sheet of a surface layer and an adhesive layer is prepared in advance, and then the base material layer is extruded, and one side of the molten base material layer is formed of a two-layer sheet. A laminated sheet composed of a surface layer, an adhesive layer, a base material layer, and a foam, passed between a pair of rolls in a state of being laminated so that the other surface is in contact with the adhesive layer and the other surface is in contact with the foam, and fused and integrated. There is a way to get However, in this case, it is difficult to produce a thin two-layer sheet, and even if it can be made thin, it is difficult to handle the sheet when laminating it with the base material layer, and the two-layer sheet can be wrinkled before lamination. There is.

The present invention solves the above-mentioned conventional problems, and has excellent flexibility and abrasion resistance, has a good appearance, and can be applied along a surface even to a molded article having irregularities or curved surfaces. It is an object of the present invention to provide a method for manufacturing a sheet for use.

[0008]

According to the present invention, there is provided a method for producing a coating sheet comprising a surface layer mainly composed of a thermoplastic urethane elastomer, a base layer composed of an adhesive layer and a thermoplastic elastomer, and a foam layer. Is a method for producing a laminate formed by laminating in this order , a surface layer, an adhesive layer, and a base sheet are co-extruded with a laminated sheet in which the base layer is arranged in this order, and at least the base layer is in a molten state. In the base layer of the laminated sheet,
The base sheet layer and the base sheet layer of the foamed sheet made of foam are overlapped, and while the base sheet layer of the stacked sheet is in a molten state, the stacked sheet and the foam sheet are pasted by passing between at least two rolls. It is characterized by matching.

The thermoplastic urethane elastomer used for the surface layer has rubber elasticity at room temperature, is plasticized at high temperature and can be subjected to various molding processes. Generally, a rubber component having entropic elasticity in the molecule ( Examples of the soft segment include a polyether polyester, a polycarbonate, and a segment composed of urethane bonds as a molecular constraint component (hard segment) for preventing plastic deformation. As long as it can be molded, it may have a partially crosslinked structure in the molecule, but does not have a wide-range three-dimensional stitch structure.

The thermoplastic urethane elastomer preferably has rubber elasticity at room temperature to exhibit abrasion resistance, and particularly preferably has a glass transition point in the range of -50 to 20 ° C. When the glass transition point is −50 ° C. or lower, the strength is insufficient and the abrasion resistance is lowered. When the glass transition point is higher than 20 ° C., the glass becomes hard and the flexibility is lowered.

If the average molecular weight of the thermoplastic urethane elastomer is too low, the rigidity of the sheet is reduced, and if it is too high, the flexibility of the sheet is impaired. Therefore, the weight average molecular weight is in the range of 20,000 to 3,000,000. Is preferred.

The hardness of the surface layer varies depending on the hardness and thickness of the base material layer and the foam layer laminated on the back surface.
Those having an A hardness of about 50 to 98 are preferred.

When durability such as weather resistance and heat resistance is required, a non-yellowing type thermoplastic urethane elastomer using an aliphatic isocyanate is preferred.

Further, the surface layer may contain elastic fine particles. By containing the elastic fine particles, fine irregularities are formed on the surface, the mat becomes a matte state, and the touch is very soft and soft touch. The above-mentioned elastic fine particles have a property of recovering the shape by elasticity when the pressure is released after pressing until the shape is deformed. For example, polyurethane, acrylic resin (preferably acrylic-urethane resin), polystyrene, Although what consists of a styrene-isoprene copolymer is mentioned, what does not cause plasticization or decomposition | decomposition by extrusion conditions is preferable.

The shape of the elastic fine particles is not limited to a spherical shape, and non-spherical particles obtained by means such as freezing and pulverization can be used, and those having a maximum particle size distribution of 1 to 100 μm are preferable. If the particle size is smaller than 1 μm, the surface irregularities are too small, so that the obtained sheet does not have a sufficient suede feeling (soft touch feeling). If the particle size exceeds 100 μm, the surface of the sheet is stretched when the sheet is stretched. Cracks easily occur in

On the other hand, if the amount of the elastic fine particles is less than 20 parts by weight, the surface of the sheet is poor in unevenness and a suede feeling cannot be sufficiently obtained. If the amount exceeds 150 parts by weight, the surface is cracked when the sheet is stretched. Is more likely to occur. Therefore, the addition amount is preferably 20 to 150 parts by weight based on 100 parts by weight of the resin.

The above-mentioned elastic fine particles are not limited to one kind, and two or more kinds may be used in combination. When a flexible thermoplastic urethane elastomer is used or the sheet-like laminate surface may have a slightly hard feel, for example, hard beads made of an inorganic material such as cross-linked polymethyl methacrylate or silica gel are mixed with the elastic fine particles. May be.

The material constituting the adhesive layer includes a surface layer,
An adhesive polymer having compatibility with the resin constituting the base layer is used. For example, when using a polyolefin-based thermoplastic elastomer for the base material layer, 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 ester group in a main chain or a side chain. Is used. For example, acid-modified styrene-butadiene-styrene copolymer (SBS), acid-modified styrene-ethylene-butylene-styrene copolymer (SBS)
EBS), acid-modified polyethylene, acid-modified polypropylene, and the like.

As the thermoplastic elastomer constituting the substrate layer, any of polyolefin, polyester, polyamide and the like may be used, but a polyolefin thermoplastic elastomer excellent in moldability and cost is preferred. As the above-mentioned polyolefin-based thermoplastic elastomer, those having polypropylene as a hard segment and having an ethylene-propylene-methylene bond having ethylene as a soft segment, and those having an ethylene-propylene-diene methylene bond having a small amount of a diene component together with ethylene , And mixtures thereof,
Some of the above are partially crosslinked by adding an organic peroxide.

The hardness of the thermoplastic elastomer varies depending on the feel to be obtained, but generally, the JIS A hardness is 5
Those having a range of 0 to 98 are preferred.

The base material layer may be mixed with a polyolefin resin (polypropylene, linear low-density polyethylene, etc.) in order to improve the extrudability and vacuum formability of the base material layer.

The means for producing a laminated sheet in which the above surface layer, adhesive layer and base layer are arranged in this order is not particularly limited, but a coextrusion molding method which does not require a plurality of steps and has excellent adhesion to each layer is preferred. . Co-extrusion uses two or more extruders,
This is a method in which respective resins extruded from a mold are combined in a layer state to form a sheet-like laminate. Such co-extrusion molding includes multi-manifold method, multi-throttle method,
A feed block method and the like can be mentioned.

If the thickness ratio of the base material layer of the laminated sheet is too large as compared with the other layers, when extruded using a feed block, irregularities such as wood grain are formed on the surface layer, resulting in poor appearance. For this purpose, it is preferable that the thickness ratio of the base material layer is 10 times or less the total thickness of the surface layer and the adhesive layer.

In order to enhance the design, the laminated sheet may be patterned by printing or the like. In such a case, the surface layer should have transparency and should be applied to the surface on the base material layer side. Is preferred.

When the base material layer of the laminated sheet is extruded from the mold and is in a molten state, the base material layer and the base material layer of the foamed sheet made of a foam are bonded together to be integrated. The base material layer of the foamed sheet is selected from those used for the base material layer of the laminated sheet.

As the foam material, polypropylene,
Polyolefin resins such as polyethylene, polystyrene, polystyrene resins such as styrene-maleic anhydride copolymer, polyurethane, polyurethane resins such as polyether urethane, vinyl chloride resins such as vinyl chloride resins, thermoplastic elastomers, and the like, and These mixtures and the like can be mentioned, but it is preferable to contain the same type of resin as the base layer, particularly a polyolefin-based resin, so that the adhesion to the base layer is improved without using an adhesive.

The foamed resin is preferably crosslinked at least partially because the foamed cells are fine and uniform after foaming, have good cushioning properties, and have high strength.

If the expansion ratio of the foam is low, sufficient cushioning properties cannot be imparted. If the expansion ratio is too high, the strength is reduced. Therefore, the expansion ratio is preferably about 5 to 50 times, more preferably 10 to 30 times. It is about twice.

If necessary, a coloring agent such as a pigment or a dye, an antioxidant,
You may add a light stabilizer, such as an ultraviolet absorber and a hindered amine.

As the colorant, pigments and dyes used as paints can be used. Titanium oxide as a pigment,
Dyes include iron oxide, carbon black, cyanine dyes, quinacridone dyes, and the like, and examples of dyes include azo dyes, anthraquinone dyes, indigoid dyes, and stilbene dyes. Further, metal powder such as aluminum flake, nickel powder, gold powder, and silver powder may be used as the coloring agent. The amount of the colorant to be added varies depending on the application, but when a colorant having a high concealing property is used, the range of 2 to 400 parts by weight is generally preferable for 100 parts by weight of the solid content of the resin.

The means for laminating the foam and the base material layer to form a foamed sheet is not particularly limited. For example, a method of laminating and bonding by using an adhesive, or a method of laminating at least one surface of the base material layer and the foam. A heat lamination method in which the resin is heated and melted, or a resin that forms a base layer and an unfoamed foamable resin are manufactured as a laminate by co-extrusion molding, and then heated to a foaming temperature to form the foamable resin. And the like.

The thickness of the coating sheet is 5 to 100 for the surface layer.
μm, adhesive layer 5-100 μm, base material layer 200-30
It is preferable that the thickness is 00 μm and the foam is 1000 to 5000 μm.

An example of the method for producing the coating sheet of the present invention will be described. An extruder extrudes a resin serving as a base material layer of a foamed sheet. When the extruded resin is in a molten state, a sheet-like foam is laminated on one surface thereof, and this is passed between a pair of pressure rolls. A foam sheet in which the foam is laminated and integrated with the material layer is obtained. In the case where the adhesiveness between the base material layer of the foam sheet and the foam is poor, a primer layer or an adhesive layer may be provided in advance on the surface of the foam on the base material layer side.

Next, three extruders equipped with a feed block and a mold melt the surface layer, the adhesive layer, and the base layer, respectively, of the resin constituting the laminated sheet, and simultaneously extrude and laminate in a molten state. To form a laminated sheet. In a state where at least the base material layer of the laminated sheet is in a molten state, the base material layer of the foamed sheet is superimposed on the base material layer of the laminated sheet in the molten state, and by passing between a pair of pressure rolls, The base materials of the sheet are fused together.

Thus, the surface layer, the adhesive layer, the base material layer,
A covering sheet in which the foams are arranged in this order is obtained.
Therefore, the base layer of the obtained covering sheet is composed of the base layer of the laminated sheet and the base layer of the foamed sheet.
The step of manufacturing the foamed sheet and the step of manufacturing the laminated sheet may be performed separately as described above, or may be performed in a continuous step.

Since the thermoplastic urethane elastomer used for the surface layer has a hygroscopic property, it is preferable to sufficiently extrude and extrude in an extruder during extrusion molding. For this purpose, air containing water vapor in the barrel of the extruder is preferably used. It is preferable to extrude while sufficiently discharging the water from the vent.

Further, the co-extruded laminated sheet is laminated with a foamed sheet, passed through a pressure roll, and cooled. If this compression roll or the next roll is used as an embossing roll having a roughened surface, a coating sheet having a surface layer embossed can be obtained.

The covering sheet obtained by the present invention can be used for interiors of automobiles (eg, skins of doors, skins of dashboards, etc.), housings for office automation equipment, home electric appliances, etc., stationery, sanitary goods, daily necessities, building materials for interiors. It is used as a surface material for molded products such as. As a method of use, the foam side of the covering sheet is adhered to the material before molding of the molded article, and the molded sheet is molded by vacuum molding, pressure molding, thermoforming, or the like. After preforming, closing the mold and injecting resin
Also, there is a stamping molding method in which a resin is introduced into a mold after the laminated sheet is preformed and the mold is closed.

[0039]

The base layer of the laminated sheet has a thickness ratio not large relative to the total thickness of the surface layer and the adhesive layer. Since the layers are bonded and laminated and integrated, an excellent appearance can be obtained without roughening the interface of the resin layer. Further, since the thickness of the base material layer can be increased and the thickness ratio between the base material layer and other layers can be increased, a product that is advantageous in terms of cost can be obtained. In addition, since the surface layer mainly contains a thermoplastic urethane elastomer, scratch resistance and flexibility can be obtained.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for producing a coating sheet according to the present invention will be described below with reference to the drawings. Surface layer Surface layer 1 Thermoplastic urethane elastomer resin (manufactured by Asahi Glass Co., Ltd., trade name: PN3429-215, JIS A hardness 85) Surface layer 2 Thermoplastic urethane elastomer resin (manufactured by Asahi Glass Co., trade name: PN3429-215, JIS A hardness) 85) 10
0 parts by weight elastic fine particles (urethane beads manufactured by Dainippon Ink and Chemicals, Inc., trade name: Burnock CFB101-40 Clear,
50 parts by weight of the above mixture Surface layer 3 Thermoplastic urethane elastomer resin (trade name: T7890, JIS A hardness 91, manufactured by Dainippon Ink and Chemicals, Inc.)
100 parts by weight Elastic fine particles (urethane beads manufactured by Sekisui Chemical Co., Ltd., trade name: UB20-Black, average particle size 20 μm) 80 parts by weight The above mixture

Adhesive layer Adhesive layer 1 Maleic acid-modified polypropylene (trade name: Admer QF551, manufactured by Mitsui Petrochemical Industry Co., Ltd.) Laminated layer 2 maleic acid-modified SEBS (trade name: Tuftec M1943, manufactured by Asahi Kasei Corporation)

Base layer A and B Base layer 1 Thermoplastic olefin elastomer resin (Mitsui Petrochemical Co., Ltd., trade name: Mirastomer 8030N) 50 parts by weight Thermoplastic olefin elastomer resin (Mitsui Petrochemical Co., Ltd., trade name) : Mirastomer 5030N) 30 parts by weight Linear low density polyethylene (manufactured by Mitsui Petrochemical Co., Ltd., trade name: UZ2021L) 10 parts by weight Polypropylene (Mitsui Petrochemical Co., Ltd., trade name: F6)
50) 10 parts by weight of the above mixture Base layer 2 50 parts by weight of a thermoplastic olefin elastomer resin (manufactured by Mitsui Petrochemical Co., Ltd., trade name: Mirastomer 8030N) Linear low density polyethylene (manufactured by Mitsui Petrochemical Co., Ltd., trade name: UZ2021L) 10 parts by weight polypropylene (trade name: F6, manufactured by Mitsui Petrochemical Industries, Ltd.)
50) 10 parts by weight of the above mixture Foam Foam 1 Foamed polypropylene sheet (manufactured by Sekisui Chemical Co., Ltd., trade name: Softlon, thickness 2 mm, foaming ratio 25 times)

(Examples 1 to 4) Manufacture of foamed sheet Manufacture of the foamed sheet is performed by an extruder (50 mm in diameter, not shown)
And a feed block 7 and a T-die 8 as shown in FIG.
(Width 500 mm), the resin temperature was 230 ° C. at the time of being introduced into the mold, the mold temperature was also 230 ° C.
The temperature of 6 was controlled at 50 ° C. In FIG. 1, reference numeral 9 denotes a resin flow path from the extruder to the feed block 7.

The foam 12 is fed out while extruding the resin of the base layer A shown in Table 1 from the extruder, and is superimposed on the base layer A11 in a molten state just before entering the pressure rolls 6, 6; To form a foam sheet 1 and wind it up.

Production of Coating Sheet As shown in FIG. 2, the apparatus used was a three extruder (not shown), a feed block 7 and a T-die 8 (500 m wide).
m), and the extruders that extrude the surface layer 21, the adhesive layer 23, and the base material layer B22 have diameters of 40 mm, 40 mm, and 50 mm, respectively. Surface layer 21,
The resin to be the adhesive layer 23 and the base material layer B22 was melted by the respective extruders and supplied from the feed block 7 to the T-die 8 to form the laminated sheet 2 by co-extrusion. The resin temperature was 205 ° C. on the surface layer and
90 ° C, base layer 230 ° C, T-die mold temperature 230 ° C
I went in. The temperature of the pressure roll was controlled at 50 ° C. The press rolls 6, 6 used in Example 3 used had a leather-like grain on the surface. 91 and 92 are resin flow paths from the extruder to the feed block 7.

The foamed sheet 1 is supplied from the side of the base material layer B22 of the laminated sheet 2 extruded from the T die 8, and the base material B22 of the extruded and molten laminated sheet 2 is added to the base material layer B22 of the foamed sheet 1. The material layers A11 were overlapped, passed through a pair of pressure rolls 6, and fused and integrated to obtain a covering sheet 3.

(Comparative Example 1) The resin shown in Table 1 was extruded using the apparatus shown in FIG. 1, and the foam 12 used in the example was laminated on the molten base material A11. In this state, the sheet was passed between a pair of pressure rolls 6, 6, fused and integrated to form a coating sheet 4. The resin temperature was controlled at 230 ° C. when introduced into the T-die, the mold temperature was also controlled at 230 ° C., and the pressure roller was controlled at 50 ° C.

(Comparative Example 2) Using the apparatus shown in FIG. 2, the resin to be the surface layer, the adhesive layer and the base material layer B was arranged in this order by 3
The layers are co-extruded and passed through a pair of pressure-bonding rolls 6 in a state where the same foamed sheet foam as that used in the examples is in contact with the base material layer B in a molten state. This was integrated to obtain a covering sheet (not shown). The respective resin temperature and mold temperature are the same as in the embodiment.

Comparative Example 3 As shown in FIG. 3, two extruders (not shown), a feed block 7 and a T-die 8
(Width: 500 mm).
As the extruder for extruding the surface layer 41 and the adhesive layer 42, an apparatus having a diameter of 40 mm was used. The resin to be the surface layer 41 and the adhesive layer 42 shown in Table 1 was melted by each extruder and supplied to the T-die 8 to form the laminated sheet 4 by co-extrusion. The resin temperature was 205 ° C. of the surface layer and 190 ° C. of the adhesive layer when introduced into the mold, and the temperature of the T-die was 230 ° C. The temperature of the pressure roll was controlled to be 50 ° C.

Next, as shown in FIG. 4, the resin to be the base material layer 50 is melted by an extruder (50 mm in diameter, not shown),
The adhesive layer 41 of the laminated sheet 4 is extruded from a die 8 (500 mm in width) and extruded from one side of the base layer 50 in a molten state.
And the foam 5 on the other surface of the base layer 50.
1 was supplied, passed through a pair of pressure bonding rolls 6, 6, and laminated and integrated to obtain a covering sheet 5 including a surface layer 41, an adhesive layer 42, and a foam 51. The temperature of the resin was 230 ° C. when introduced into the mold, and the temperature of the T-die was also 230 ° C.
The temperature of the pressure roll was controlled to be 50 ° C.

Evaluation The abrasion resistance and appearance of the covering sheets obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated by the following methods.
It was shown to. (1) Scratch resistance The load at the time of scratching was measured with the product name “Tavers Clutch Tester” manufactured by Toyo Seiki Seisakusho. (2) Appearance A. Judgment by visual observation Measurement of Surface Roughness by Surface Roughness Meter The maximum height (Rma) of the cross-sectional curve is measured using “Surfcom” (trade name, manufactured by Tokyo Seimitsu Co., Ltd.) based on JIS B0601.
x) and 10-point average roughness (Rz)
The average value after the measurement was shown. The measurement length is 30 mm.

[0052]

[Table 1]

As is clear from Table 1, in Examples 1 to 4, the interface between the base material layer and the layer in contact with the base material was rough even if the thickness ratio of the base material layer was higher than the other layers. Because of the absence of the surface layer, an excellent appearance was obtained, and the surface layer was hardly damaged. In addition, a molded product having a curved surface, which was adhered to a molding material of a door interior material of an automobile and which had a good fit with the curved surface and had no wrinkles, was obtained.

On the other hand, in Comparative Example 1, the appearance was good, but there was no surface layer, so that it was very easy to be damaged. In Comparative Example 2, the foam was directly fused to the base material layer of the laminated sheet. In the case of Comparative Example 3, the laminated sheet having no base material layer B was fused to the base material layer in the molten state, and the thin surface layer was wrinkled, resulting in poor appearance. Could not be used as.

[0055]

The method for producing a coating sheet according to the present invention has the above-mentioned structure, and the thickness ratio of the base material layer can be made larger than the other layers to be laminated, and the interface of the resin layer is roughened. Thus, a product having an excellent appearance can be obtained without causing any trouble, and the thickness of the base material layer can be increased, so that a product advantageous in terms of cost can be obtained. The coating sheet obtained by the present invention is
Since the surface layer is mainly composed of a thermoplastic urethane elastomer, it has excellent scratch resistance and is hardly damaged, and it has excellent flexibility, so that it can easily conform to the surface of molded products having irregularities or curved surfaces. It can be pasted together.

[0056]

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a method for manufacturing a laminated sheet used in the present invention.

FIG. 2 is a side view showing an embodiment of the method for producing a covering sheet of the present invention.

FIG. 3 is a side view illustrating a method for manufacturing a laminated sheet in Comparative Example 3.

FIG. 4 is a side view showing a method for manufacturing a covering sheet according to Comparative Example 3.

[Explanation of symbols]

 1: Foamed sheet 2: Laminated sheet 3, 4, 5: Sheet for covering 6: Crimping roll 7: Feed block 8: T die 11, 51: Base layer A 12, 51: Foam 21, 41: Surface layer 22 : Base layer B 23, 42: Adhesive layer 50: Base layer

Claims (1)

(57) [Claims] And 1. A surface layer mainly composed of thermoplastic urethane elastomers, the adhesive layer and the heat made of thermoplastic elastomer substrate layer, a foam layer is a method for producing a laminate which are laminated in this order , A surface layer, an adhesive layer, and a base layer are co-extruded to form a laminated sheet in which the base layer and the base material layer are arranged in this order. And laminating the laminated sheet and the foamed sheet by passing between at least two rolls while the substrate layer of the laminated sheet is in a molten state. A method for producing a covering sheet.