JPH0139341B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foam laminate sheet. More specifically, the present invention relates to a foam laminate sheet formed by laminating a vinyl chloride resin layer on a polyolefin foam sheet. A foam laminated sheet made of a polyolefin foam sheet such as a polyethylene foam sheet and a soft (plasticized) vinyl chloride resin sheet has the advantages of the polyolefin foam sheet such as light weight, heat retention, and cushioning properties, and the soft vinyl chloride resin sheet. As a laminated material that has an elegant appearance, a pseudo-leather feel, and scratch resistance, it is widely used in our daily lives in fields such as construction materials, vehicle interior materials, industrial materials, and agricultural materials. There is. Such foam laminated sheets are currently industrially
It is manufactured by bonding a polyolefin foam sheet and a soft vinyl chloride sheet using a polyurethane adhesive. However, this foamed laminated sheet has the following drawbacks in practical terms. The first drawback is due to the presence of liquid plasticizers such as dioctyl phthalate used in flexible vinyl chloride resin sheets, and as a result, the liquid plasticizers migrate to the sheet surface and further volatilize.
There are problems in that the sheet becomes sticky, a sticking phenomenon occurs, and the rigidity changes over time, and the adhesive strength changes over time. The second drawback is due to polyurethane adhesives, and when a large amount of solvent-based adhesive is applied to prevent changes in adhesive strength over time, the foamed laminated sheet may be damaged during post-processing processes such as vacuum forming. When heated, the solvent remaining in the adhesive layer evaporates, causing undesirable problems such as blistering. Therefore, in order to widely and effectively apply the excellent properties of foam laminated sheets of polyolefin foam sheets and flexible vinyl chloride resin sheets, it is strongly required to solve the above problems. This is the current situation. As a result of various studies to solve this problem, the present inventors have found that ethylene-ethylene, which generally has the same plasticizing performance as liquid plasticizers and does not cause migration or volatilization, is used as a plasticizer for vinyl chloride resin. It is extremely effective to use a vinyl acetate-carbon monoxide copolymer resin instead of a liquid plasticizer and to use a chloroprene adhesive layer as an adhesive between the polyolefin foam sheet and the soft vinyl chloride resin layer for adhesion and lamination. I found that. Accordingly, the present invention relates to a foam laminated sheet, which is made of a polyolefin foam sheet with a vinyl chloride resin and ethylene-vinyl acetate-monoxide formed on one or both sides of the polyolefin foam sheet through a chloroprene adhesive layer. It is made by laminating homogeneous mixed layers of carbon copolymer resin. To explain the content of the present invention more specifically, it has already been described in Japanese Patent Publication No. 55-50063 that ethylene-vinyl acetate-carbon monoxide copolymer resin can be effectively used as a plasticizer for vinyl chloride resin. ing. However, as in the present invention, such plasticized vinyl chloride resin is applied to the field of special laminates as outer skins of polyolefin foams that require pseudo-leather-like feel and scratch resistance through embossing. It is important that this material has practical physical properties that are comparable to those plasticized with a liquid plasticizer, and that the disadvantages caused by the use of a liquid plasticizer have been overcome. be. Furthermore, the use of ethylene-vinyl acetate-carbon monoxide copolymer resin as a plasticizer makes it difficult to employ conventional liquid plasticizers due to the initial adhesion level and the decline in adhesion over time. Not only did we find that even when using an old chloroprene adhesive, we found that the initial adhesive strength was high and no decline in adhesive strength was observed over time, but this was probably due to the high affinity between the plasticizer and the adhesive. However, it must be said that the discovery that good adhesive strength can be obtained even with a very small amount of chloroprene adhesive applied is extremely significant. Examples of polyolefin foam sheets include low-density polyethylene, high-density polyethylene, polypropylene, L-LDPE (ethylene-α-olefin copolymer resin), ethylene-vinyl ester copolymer resin, and ethylene-α,β-unsaturated carboxylic acid ester. At least one type of copolymer resin is used as a raw material resin, and a foaming agent and a foaming aid are added to this to create a foaming agent of approximately 1.5
A foam that has been expanded to about 40 times is used. Particularly preferred is a crosslinked polyolefin foam sheet crosslinked with a chemical crosslinking agent or radiation, which forms a foam with a high expansion ratio and excellent mechanical properties, heat resistance properties, and the like. PVC resin and ethylene are laminated on one or both sides of these polyolefin foams.
The vinyl chloride resin used to form the uniform mixed layer of vinyl acetate-carbon monoxide copolymer resin includes not only vinyl chloride homopolymers, but also vinyl chloride and other comonomers, such as ethylene, propylene, etc. -Olefins, vinyl esters such as vinyl acetate, α,β-unsaturated carboxylic acid esters such as acrylic esters, vinyl ethers such as alkyl vinyl ethers, and other vinyl halides such as vinyl bromide and vinyl fluoride , styrene, acrylonitrile, vinylidene chloride, and other vinyl compounds or copolymers with vinylidene compounds. The ethylene-vinyl acetate-carbon monoxide copolymer resin used as a plasticizer for such vinyl chloride resin contains about 40 to 80% ethylene, preferably about 60 to 70%, and about 15 to 60% vinyl acetate by weight. %, preferably about 20-35%, and about 5-30% carbon monoxide.
%, preferably about 5 to 15%, and if necessary, further copolymerized with other comonomers, and its production method Details are described in the above-mentioned patent publications.
This plasticizer copolymer resin is generally made of vinyl chloride resin.
About 5 to 150 parts by weight per 100 parts by weight, preferably about 10 parts by weight
It is used in a proportion of ~100 parts by weight. Further, for the purpose of improving the extrusion processability of a homogeneous mixture of vinyl chloride resin and this copolymer resin, a liquid plasticizer such as dioctrate can also be used in combination. However, if the amount of liquid plasticizer added increases, as described above, undesirable phenomena will occur due to its migration and volatilization, so the amount added must be less than the amount of plasticizer copolymer resin added. The vinyl chloride resin and the plasticizer copolymer resin are used by forming a homogeneous mixture after adding various known stabilizers, lubricants, fillers, colorants, etc. thereto as necessary. The homogeneous mixture is prepared by dry blending or melt blending the components simultaneously or sequentially. In the case of dry blending, the above-mentioned components are uniformly melt-mixed in an extruder or calender roll in the lamination step described below. In the case of a melt blend, if necessary, the mixture may be mixed using a Banbury mixer, Henschel mixer, etc., and then melt-mixed using a single-screw extruder, twin-screw extruder, roll, etc. Lamination of the plasticized vinyl chloride resin to the polyolefin foam sheet is carried out using a chloroprene adhesive. Chloroprene-based adhesives preferably have non-sulfur-modified polychloroprene as a main component, which has a low crystallization rate, because the dry film is flexible and does not feel hard, and is especially suitable for adhesion to foam cells. In order to prevent penetration of the agent, a Mooney viscosity ML ₁₊₄ (at 100°C) of approximately 20 to 130 is preferred. The adhesive also contains metal oxides such as magnesium oxide and zinc white as stabilizers or vulcanization accelerators, and 2,2'-methylenebis(4-methyl-6-th) as a non-staining anti-aging agent. Hindered phenol compounds such as (3-butyl) phenol are added. Chlorobrene-based adhesives can be used as a latex type with silica-based fillers added to improve their adhesive strength, but in order to speed up the application process, it is more advantageous to use them as a solvent-based adhesive. It is. The solvent used in the preparation of solvent-based adhesives prevents the adhesive from penetrating the foam cells, quickly eliminates the tackiness after application of the adhesive, and prevents blocking between adhesive surfaces. Therefore, it is preferable to use a mixed solvent with a high volatilization rate, such as acetone/heptane or methyl acetate/hexane mixed solvent. Lamination is carried out using an adhesive with a coating amount of about 0.2 to 50 g/m ² , for example, by the following method. (1) Thermocompression bonding method A method in which a chloroprene adhesive is applied to a polyolefin foam sheet or a plasticized vinyl chloride resin sheet in advance or immediately before lamination, and other sheets are heated and pressed as appropriate. (2) Extrusion coating method A method in which a chloroprene adhesive layer is applied on a polyolefin foam sheet in advance or immediately before lamination, and then a plasticized vinyl chloride resin is extrusion coated onto the adhesive layer. In this way, a foamed laminated sheet in which a homogeneous mixture of vinyl chloride resin and ethylene-vinyl acetate-carbon monoxide copolymer resin is laminated on one or both sides of a polyolefin foam sheet via a chloroprene adhesive layer. Not only does this product not exhibit any of the fogging phenomena that occur when liquid plasticizers are used, changes in rigidity over time, or stickiness, but it also shows no decrease in adhesive strength over time and remains stable throughout the period of use. Give products the effect of guaranteeing quality. Next, the effects of the present invention will be explained with reference to Examples. Example 1 100 parts (weight, same below) of polyvinyl chloride (average degree of polymerization 1300), ethylene-vinyl acetate-carbon monoxide copolymer resin (vinyl acetate content 28% by weight),
Carbon monoxide content 9% by weight, melt index
35) 100 parts, 4 parts of tin maleate, 1 part of polyethylene wax and 1 part of magnesium oxide were mixed in a Banbury mixer (jacket 3Kg/cm ² steam).
A homogeneous mixture was prepared by kneading for 4 minutes at a rotor rotation speed of 60 times/min. In addition, high-pressure polyethylene (density 0.923g/cm ³ ,
A chloroprene adhesive layer consisting of the following ingredients was applied to a cross-linked polyethylene foam sheet (30x expansion ratio, 3 mm thickness) molded using a melt index of 3.7) at a fixed rate of 5 g/m ² and then heated and dried. I let it happen. (Chloroprene adhesive layer) Polychloroprene (Showa neoprene product; Neoprene WRT) 100 parts Magnesium oxide 4 parts Anti-aging agent [2,2'-methylenebis(4-methyl-6-tert-butyl)phenol] 2 Zinc white 5 Acetone/heptane (volume ratio 30/70) 400 The homogeneous mixture of plasticized vinyl chloride resin,
Using a 40 mm diameter single screw extruder (L/D = 22) equipped with a 400 mm wide T-die, a plasticized vinyl chloride resin layer was added to the chloroprene adhesive layer of the crosslinked polyethylene foam sheet at 180°C. Thickness is 300μm
Extrusion coating was performed to obtain a foamed laminated sheet. The obtained foam laminated sheet showed good adhesion not only immediately after lamination, but also after being left at a temperature of 80°C for 10 days.
mm/min), the polyethylene foam sheet suffered substrate failure. Comparative Example 1 In Example 1, extrusion coating was performed without applying a chloroprene adhesive layer. The resulting laminated foam sheet had such poor adhesion that each layer was easily peeled off. Examples 2-3, Comparative Examples 2-3 In Example 1, dioctyl phthalate (DOP) was used in combination or alone in place of 100 parts of the ethylene-vinyl acetate-carbon monoxide copolymer resin. Immediately after laminating foam laminated sheets or at 80℃−
The results of the peel test after standing for 10 days are shown in the following table. 【table】

Claims (1)

[Claims] 1 A homogeneous mixed layer of vinyl chloride resin and ethylene-vinyl acetate-carbon monoxide copolymer resin is laminated on one or both sides of a polyolefin foam sheet via a chloroprene adhesive layer. Foam laminated sheet. 2. The foam laminate sheet according to claim 1, wherein the polyolefin foam sheet is a polyethylene foam sheet. 3. The laminated foam sheet according to claim 1, wherein the polyolefin foam sheet is a polypropylene foam sheet. 4. The foam laminate sheet according to claim 2 or 3, in which a crosslinked polyolefin foam sheet is used.