JPH0477660B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Fields] The composite molded product of the present invention can be used as lining insulation materials for the main body and doors of refrigerators, door materials for show window cases and unit baths that require heat insulation, and automobiles that require cushioning properties. It is useful as automobile interior materials such as bumpers and door trims, surfboards, etc. [Prior art] Acrylonitrile-butadiene-styrene copolymer, which is a styrene resin, is used for the body and doors of refrigerators to prevent rust on the baked-on stainless steel or steel plate structural base material (outer frame) and to form shelves. (Commonly known as "ABS") sheet is provided with a lining material obtained by vacuum forming, pressure forming, or forming using a combination of vacuum and pressure (hereinafter, these forming methods are collectively referred to as thermoforming). Furthermore, instead of the ABS lining material, it has been proposed to use a polypropylene lining material with excellent surface gloss and low water absorption. In order to improve the heat insulation properties of these lining materials, it has been proposed to interpose foamed polyurethane between the structural gas and the base lining material (Japanese Patent Application Laid-Open No. 1983-1993).
−97841). Furthermore, the door materials for unit baths are currently made from polyvinyl chloride sheets, but when used at high temperatures, the aluminum sash frame has the problem of corroding due to the chlorine gas generated by decomposition. In order to improve the door, we are considering attaching two polypropylene sheets to an aluminum sash frame instead of using polyvinyl chloride sheets, and filling the space between the aluminum sash frame and the sheet with foamed polyurethane to give it more rigidity as a door. ing. Furthermore, with the transition from metal to resin for interior materials such as automobile door trims, filling polyurethane foam by injection method is being considered for the purpose of cushioning or heat insulation. As described above, there is a demand for composites of resin materials and foamed polyurethane in resin products with various complex shapes. [Problems to be solved by the invention] However, resin materials are usually used as sheets or made into molded products by thermoforming or injection molding, and when polyolefin resin in such a shape is used, foaming Due to the insufficient adhesion to polyurethane, voids are formed, which has the disadvantage that the purpose of rigidity and heat insulation cannot be fully achieved. In order to improve the adhesive strength between this resin material and foamed polyurethane, it is possible to apply liquid adhesive or adhesive liquid or treat the surface with chemicals (Japanese Patent Application Laid-Open No. 60-97841).
However, the addition of complicated steps due to an increase in the number of coating steps and surface treatment steps is not preferable. The present invention eliminates such processing steps and improves the adhesive strength with urethane foam by blending ABS or the like into the olefin resin that adheres to urethane foam. (Structure of the Invention) The present invention provides a composite molded product having a structure in which an olefin resin molded product and a urethane foam are integrally laminated via the following adhesive layer. Adhesive composition (A) Olefin resin 40-85% by weight (B) Ethylene-acrylic acid copolymer with MFR less than 30 g/10 minutes 60-15% by weight. (Olefin resin molded product) Olefin resins for forming the olefin resin molded product include polyethylene, polypropylene,
Nonpolar olefin resins such as ethylene/propylene copolymer, ethylene/propylene/butene copolymer, ethylene/acrylic acid random copolymer,
Carboxyl of ethylene/methacrylic acid random copolymer, acrylic acid grafted polyethylene, methacrylic acid grafted polyethylene, maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, maleic anhydride grafted ethylene/vinyl acetate copolymer, itaconic acid grafted polyethylene, etc. Group-containing olefinic resins can be used, which can be used alone or in mixtures. This olefin resin is made of polyamide, ABS,
Resins such as ethylene/vinyl acetate copolymers, stabilizers, rubbers, pigments, and inorganic fillers may also be blended. Alternatively, the olefin resin may be formed into a layered structure, and each layer may have a specific function. For example, if the olefin molded product is a skin material for a show window case or refrigerator interior material, the surface layer is a homogeneous polypropylene film with good gloss.
A sheet of the following composition having good vacuum formability is used for the base material layer. (a) Polypropylene 20-80% by weight, preferably 40-70% by weight (b) Polyethylene 10-80% by weight, preferably 10-55% by weight (c) Styrenic resin 0-35% by weight, preferably 5-55% by weight 25% by weight (d) Inorganic fine powder 0-65% by weight, preferably 5-55% by weight. The polypropylene component (a) contributes to the adhesion of the surface gloss layer to the homopolypropylene. Component (b) polyethylene improves the deep drawability of the laminated sheet during vacuum forming. The styrene resin of component (c) contributes to reducing the sag of the laminated sheet softened or melted by heating due to its own weight. (d)
The inorganic fine powder component not only increases the rigidity of the olefin resin molded article, but also contributes to improving the cooling cycle when vacuum forming the laminated sheet. The polypropylene component (a) is a homopolymer of propylene, a random copolymer or block copolymer of propylene as the main component, and an olefin such as ethylene, butene-1, hexene, 4-methylpentene-1, etc. Coalescing, maleic anhydride grafted polypropylene, etc. can be used. Component (b) polyethylene includes high density polyethylene, low density polyethylene, linear polyethylene, ethylene/vinyl acetate copolymer, ethylene/vinyl acetate copolymer,
Acrylic acid copolymer, ethylene/methacrylic acid copolymer, Surlyn (trade name manufactured by DuPont), etc. can be used. As the styrene resin of component (c), polystyrene, styrene/butadiene/styrene block copolymer (SBS), styrene/acrylonitrile copolymer (SA), ABS, high impact polystyrene (HIPS), etc. can be used. As the inorganic fine powder of component (d), talc, calcium carbonate, diatomaceous earth, calcined clay, titanium oxide, etc. can be used. (Adhesive layer) The adhesive resin composition between the urethane foam and the olefin resin molded article is (A) olefin resin 40-85
Weight% and (B) ethylene/acrylic acid copolymer 60~
It is a 15% by weight mixture. This mixture may contain a styrene resin, ethylene/propylene copolymer rubber, styrene/butadiene rubber, etc., which will be described later. As the olefin resin of component (A), the olefin resins mentioned in the section of the base layer, such as polypropylene and polyethylene, can be used. Preferably, the same type of olefin resin as the base material layer is used. For example, if the olefin resin in the base material layer is a mixture of homogeneous polypropylene and high-density polyethylene, the olefin resin in the adhesive layer may be a propylene/ethylene random copolymer, a propylene/ethylene block copolymer alone, or a homogeneous olefin resin. A mixture of polypropylene and high density polyethylene is used. Preferably, when a propylene/ethylene block copolymer is used, the surface of the adhesive layer extruded into a film from an extruder will be similar to that of a film adhesive layer obtained from homogeneous polypropylene or a propylene/ethylene random copolymer. Since the surface is rougher than the surface, it has the advantage of improving adhesion with the urethane foam and the base material layer. The ethylene/acrylic acid copolymer of component (B) is
MFR measured at 190℃ according to JIS K-6760
is less than 30 g/10 min, preferably 2 to 20 g/10 min, and is a relatively high molecular weight resin obtained by random copolymerization of 70 to 99 wt. It is resin. These products are “Yukalon EAA A221M” from Mitsubishi Yuka Co., Ltd.
“Yukalon EAA A200K”, “Yukalon EAA
XA210S” (all product names).In the adhesive resin composition, this component (B), ethylene,
When the concentration of acrylic acid copolymer is less than 15% by weight,
The adhesion between the urethane foam and the adhesive layer is low.
Not practical. On the other hand, if it exceeds 60% by weight, the mold release properties will be poor when the laminate sheet is vacuum formed, press formed, pressure formed, or injection molded. However, in the case of blow molding, the surface of the adhesive layer becomes the inner surface of the hollow molded product, so such problems with mold releasability can be ignored. In order to improve such mold releasability, a styrene resin may be added if necessary to reduce the amount of ethylene/acrylic acid copolymer added. Such styrene resins include polystyrene, ABS, SBS,
SA, HIPS, etc. can be used. Among these
ABS has a higher adhesion between the urethane foam and the adhesive layer. However, the olefin resin as component (A) in the adhesive alone does not have adhesive properties with the urethane foam. The adhesive layer can be formed together with the olefin resin molded article. For example, the resin compositions forming the gloss layer, base material layer, and adhesive layer are each melt-kneaded using separate extruders, then fed to a single coextrusion die, and the layers are laminated within the die. Then, it is extruded into a sheet or parison shape, and then vacuum formed, compression molded, or blow molded, and is used as a laminate for refrigerator lining materials and surfboards. In the case of a molded object such as a bumper, an adhesive resin composition is first injected into a mold, then this adhesive injection molded product is transferred into another mold, and then polypropylene for the skin material is injected. It is molded into a laminate. The thickness of the laminate is 0.5 to 15 mm, preferably 2 to 5 mm, and the thickness of the adhesive layer is 5 to 100 microns (extrusion molded product).
Or 0.5 to 2 mm (injection molded product). The surface of these laminates may be subjected to corona discharge treatment or plasma treatment, if necessary. FIG. 2 is a cross-sectional view of the laminate 2, in which 2a represents a surface gloss layer, 2b represents a base material layer, and 2c represents an adhesive layer. (Composite molded product) The composite molded product is obtained by bonding the olefin resin molded product and urethane foam together through an adhesive layer. A surf-in board is manufactured by injecting a foaming urethane liquid into the hollow portion of the blow-molded laminate and causing the foam to form. When used as an interior material for a refrigerator, as shown in FIG. 1, a foamable urethane solution 4 is injected into a cavity 3 formed by a mold 1 made of a decorative steel plate and the vacuum-formed laminate 2, and then By foaming and curing, a multilayer structure in which the mold 1, the urethane foam 4', and the lining material 2 are integrated is manufactured. Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that parts and percentages in the examples are based on weight. Example of manufacturing sheet 1 () Resin for glossy surface layer: MFR2.0g/10
A crystalline propylene homopolymer with a residual amount of 99% by weight after extraction with boiling heptane was used. () Resin used for deep drawing layer: 30% by weight of crystalline propylene-ethylene block copolymer with ethylene content of 5% by weight, MFR of 0.5g/10 minutes, boiling heptane extraction residue of 98% by weight, and density of 0.950g/cm. ² ,
A mixture consisting of 50% by weight of polyethylene with an MFR of 0.6g/10 minutes and 20% by weight of talc having a particle size of 1.5μ was kneaded in an extruder, extruded into a strand, and cut into pellets. () Adhesive resin on the side to be bonded to the urethane foam: ethylene content 5% by weight, MFR 0.5g/
80% by weight of a crystalline propylene/ethylene block copolymer with a residual amount of 98% by weight after extraction with boiling heptane for 100 minutes, and ethylene/acrylic acid (8.5% by weight) copolymer “EAA A221M” manufactured by Mitsubishi Yuka Co., Ltd. A mixture of 20% by weight (trade name, MFR7g/10min) was kneaded using an extruder, extruded into strands, and cut into pellets. The resin pellets for the deep drawing layer shown in () above have a diameter of 90.
The adhesive resin composition () for the glossy layer () was fed to a three-layer multi-manifold die with a width of 700 mm at 230°C using a 40 mm diameter extruder, and the adhesive resin composition () was fed to a 3-layer multi-manifold die with a width of 700 mm using a separate extruder with a diameter of 40 mm. The same die was fed at 220°C. The temperature of the die was 220°C. The molten sheet extruded from the die was sequentially cooled and solidified using three rolls each having a width of 700 mm, and then subjected to corona discharge treatment to obtain a laminate sheet for vacuum forming. The temperature of the rolls was 40°C, 95°C, and 50°C starting from the roll closest to the die, and the rotational speed of the rolls was 1.5 m/min. The total sheet thickness was 1.6 mm, the glossy surface layer was 0.15 mm, the deep drawing layer (intermediate layer) was 1.35 mm, and the adhesive resin layer side with the urethane foam was 0.1 mm. Examples 2 to 9 Laminate sheets were obtained in the same manner as in Example 1, except that the composition of the adhesive resin layer was changed as shown in Table 1. The abbreviations in the table are as follows. PP: Propylene/ethylene block copolymer E/AA: Ethylene/acrylic acid copolymer A200K: Ethylene/acrylic acid copolymer manufactured by Mitsubishi Yuka Co., Ltd. (acrylic acid content 7% by weight, MFR5
g/10 minutes)
MFR17g/10min) A221M: Ethylene/acrylic acid copolymer manufactured by Mitsubishi Yuka Co., Ltd. (acrylic acid content 8.5% by weight,
MFR7g/10min) A500W: Ethylene/acrylic acid copolymer manufactured by Mitsubishi Yuka Co., Ltd. (acrylic acid content 20% by weight,
(MFR300g/10 minutes) PS: Polystyrene "Dialex HT516" (trade name) manufactured by Mitsubishi Monsanto Chemical Co., Ltd. SBS: SBS "Tuffrene A" (trade name) manufactured by Asahi Kasei Corporation Example 1 Three layers obtained in Example 1 above The laminate sheet was guided into a heating furnace set at approximately 230°C using a vacuum/pressure forming machine, and plug-assisted molding was performed using a combination of compressed air (5.0 Kg/cm ² ) and reduced pressure (-600 mmHg) (drawing ratio H /D
= 1/1). The release properties of the sheet were good, and the plug was easily separated from the sheet. After drilling an injection port in a part of this shaped sheet, this sheet is inserted into a stainless steel frame that is the frame of the refrigerator body, and then the space (cavity) formed by the frame and the shaped sheet is inserted. When a two-component foaming urethane solution "HM-1510" (trade name) manufactured by Polyurethane Kagaku Kasei Co., Ltd. was injected into the space from the injection port, foaming started after 10 seconds, and after 1 minute, the space was filled with urethane. Completely filled with foam.The density of this urethane foam is 0.05g/cm ³
It was hot. The same operation was repeated 20 times to obtain 20 composite molded body samples. After 24 hours, the sheet to which the urethane foam had been adhered was cut out, and the adhesion between the urethane foam and the sheet was measured using the following method. After separating the urethane foam from the sample piece by hand, use a knife to cut 100 1 mm squares into the sheet containing the remaining urethane foam, then stick adhesive tape on the squares and forcefully pull the adhesive tape from the sheet. When the sheet was removed, the squares of urethane foam remaining on the sheet side were examined. The results are shown in Table 1. The evaluation criteria for adhesion are as follows. ○: Cohesive failure of urethane foam ×: Adhesion between the urethane foam and the adhesive layer is weak, and the sheet is easily peeled off from the interface with the urethane foam. Examples 2 to 6, Comparative Examples 1 to 3 Laminate sheets were used in place of those in Example 1 to Examples 2 to 9.
A composite molded body was obtained in the same manner except that the above was replaced. Table 1 shows the adhesion between the urethane foam and the sheet of these composite molded bodies.

[Table] Example 7 A mixture of 80% by weight of the propylene/ethylene block copolymer used in Example 1 and 20% by weight of the ethylene/acrylic acid copolymer "A221M" was used as an adhesive.
Homopolypropylene is used as the skin layer, and each layer is melt-kneaded at approximately 220°C using separate extruders, fed into one die, laminated in the die, extruded into a parison shape, and then hollow-formed to surf-in. A molded body for a board was obtained. A two-component urethane solution was injected into the hollow part of this molded body and foamed to obtain a surf inboard. The adhesion between the urethane foam and the adhesive layer of this product was stronger than that of Example 2. Example 8 () Resin supplied to glossy layer: MFR2.0g/10
A crystalline propylene homopolymer with a residual amount of 99% by weight after extraction with boiling heptane was used. () Resin supplied to the deep drawing layer (intermediate layer): 40% by weight of a crystalline propylene-ethylene block copolymer with an ethylene content of 5% by weight, an MFR of 0.5g/10 minutes, and a boiling heptane extraction residue of 98% by weight; density
0.950g/cm ² , MFR 0.6g/10min polyethylene
A composition consisting of 40% by weight of talc and 20% by weight of talc having a particle size of 1.5μ was kneaded using an extruder, extruded into strands, and cut into pellets. () Adhesive resin: The same resin as in Example 1 was used (PP 80% by weight, E/EA "A221M" 20% by weight). The above () resin pellets for deep drawing are made with a diameter of 90 mm.
Using an extruder with a diameter of 40 mm, the resin for the glossy layer was fed to a three-layer multi-manifold die with a width of 700 mm at 230°C using an extruder with a diameter of 40 mm. The extruder was used to feed the same die at 220°C. The temperature of the die was 230°C. The molten sheet extruded from the die has a width of 700 mm
The mixture was sequentially cooled and solidified using three rolls of 3 mm diameter, and then subjected to corona discharge treatment to obtain a three-layer vacuum forming sheet.
The temperature of the roll is 40℃, 95℃ from the roll closest to the die.
℃, 50℃, and the rotation speed of the roll is 1.5
m/min. The total sheet thickness was 1.6 mm, the gloss layer was 0.20 mm, the deep drawing layer was 1.25 mm, and the adhesive layer was 0.15 mm. This was vacuum formed in the same manner as in Example 1, and further mounted in a frame and urethane foam molded to obtain a composite molded body. The results are shown in Table 1.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention;
FIG. 2 is a sectional view of the sheet. In the figure, 1 is a stainless steel frame, 2 is a laminated sheet for differential pressure molding (lining material), 2a is a glossy surface layer, 2b
is a deep drawing layer, 2c is an adhesive layer, 3 is a cavity,
4' is a urethane foam, and 5 is an injection port.

Claims (1)

[Scope of Claims] 1. A composite molded product having a structure in which an olefin resin molded product and a urethane foam are integrally laminated via the following adhesive layer. Adhesive composition (A) Olefin resin 40-85% by weight (B) Ethylene-acrylic acid copolymer with MFR of less than 30 g/10 minutes 60-15% by weight 2 The olefin resin molded article is made of homogeneous polypropylene. The composite molded article according to claim 1, which is a laminate having a surface layer and a base layer made of the following composition. Base layer composition (a) Polypropylene 20-80% by weight (b) Polyethylene 10-80% by weight (c) Styrenic resin 0-35% by weight (d) Inorganic fine powder 0-65% by weight. 3. The composite molded article according to claim 1, wherein the olefin resin of the adhesive composition is polypropylene.