JPS5919149A - Foamed-body laminated sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to foam #1 layer sheets. More specifically, the present invention relates to a foam laminate sheet formed by laminating a polyvinyl 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 flexible polyvinyl chloride resin sheet has the advantages of the polyolefin foam's lightness, moisture retention, and cushioning properties, and the excellent appearance of the flexible polyvinyl chloride resin sheet. As a laminated material that has a pseudo-leather feel and starch resistance, it is widely used in our daily lives as FF materials for construction, vehicle interior materials, industrial materials, agricultural materials, etc.

However, such laminated foam sheets have the following drawbacks in terms of manufacturing and physical properties.

First, in terms of production, since polyolefin is non-polar and crystalline, it generally adheres to other polymers and requires a complicated bonding operation to bond them together. When adhering a polyolefin foam sheet to a flexible polyvinyl chloride sheet, since there is no simple adhesion method, it is necessary to apply a solvent-based polyurethane adhesive to the polyolefin foam sheet, heat it, and then distill off the solvent. , a method of press-bonding via a tacky adhesive layer, or a method of heating and press-bonding a polyolefin foam sheet coated with a polyurethane adhesive in advance to a soft polyvinyl chloride sheet in the melted portion shown in Table 17ij. is actually used industrially. However, when a single-solvent type adhesive is used, it not only requires equipment for applying and drying the adhesive, but also causes problems such as contamination of the working environment and the risk of fire due to the solvent used.

In order to avoid the undesirable problems encountered when using such solvent-based adhesives, it is desired to develop a solvent-free hot melt adhesive method.

However, until now, no hot-melt adhesive technology having an adhesive strength level that can be used industrially has been developed. One problem with this problem is that liquid plasticizers such as dioctyl phthalate used in flexible polyvinyl chloride sheets migrate to the adhesive layer, causing a 0ζ1 decrease in adhesive strength over time. Therefore, in the development of hot melt adhesives, it is important to find an adhesive that maintains the desired initial adhesive strength level and that does not cause a decrease in adhesive strength over time. .

In addition, in terms of physical properties, this liquid plasticizer may volatilize, causing a sticking phenomenon, causing changes in rigidity over time, or transferring to the sheet surface and making it sticky. There are some drawbacks to this. Thus, most of these undesirable phenomena are caused by liquid nJ
This is due to the properties of the plastic agent.

The inventors believe that such W! Jj Solve X%1<
As a result of various studies, it was found that ethylene-vinyl acetate-oxidized vinyl acetate, which has the same plastic properties as liquid iJ plastics but does not cause migration or volatilization, was used as a plastic agent. Carbon copolymer resin is used as the laminate material, and ethylene-vinyl ester copolymer resin or ethylene-α,β-unsaturated cabesylboxylic acid copolymer resin is used as a thermal adhesive between the polyolefin foam sheet and the polyvinyl chloride resin layer. It has been found that adhesive lamination is extremely effective.

Therefore, the present invention relates to a foamed laminated sheet, which has a polyolefin foam sheet coated with an ethylene-vinyl ester copolymer resin or an ethylene-α, β-, β-carboxylic acid ester on one or both sides of the polyolefin foam sheet. A homogeneous mixed layer of a vinyl acetate resin and an ethylene-vinyl acetate-carbon oxide copolymer resin is laminated via a polymeric resin thermal adhesive layer.

To explain the content of the present invention in more detail, it was already known in 1983 that ethylene-vinyl acetate-carbon oxide copolymer resin could be effectively used as a plasticizer for polyvinyl chloride resin.
It is described in Japanese Patent No. 5-50063. However, as in the present invention, such plasticized polyvinyl chloride resins are applied to the special lamination field as outer skins of polyolefin foams that require pseudo-leather feel (through embossing) and scratch resistance. It is important that this material shows practical physical properties that are comparable to those plasticized with conventional liquid plasticizers, and that it also overcomes the drawbacks caused by the use of liquid 0T plasticizers.

Additionally, the use of ethylene-vinyl acetate-merized carbon copolymer as a plasticizer reduces the initial adhesion level and decreases adhesive strength over time when conventional liquid plastics are used. Even with the ethylene-vinyl ester copolymer resin and the ethylene-α,β-unsaturated carbonester copolymer resin j1, which were not used, a high initial adhesive strength level and no decrease in adhesive strength over time were observed. It must be said that it is extremely significant that this has led to the adoption of the hot-melt adhesive method, which is industrially advantageous in terms of manufacturing costs and workability, as a method of attachment.

Note that instead of the thermal adhesive used in the present invention, a polyolefin adhesive known as a film adhesive, such as ethylene-α, β-, β-carboxylic acid or a metal salt thereof, or a modified polyolefin resin, etc. may be used. However, the desired level of adhesion may not be obtained. This can be said to further increase the industrial importance of the present invention.

Examples of polyolefin foam sheets include low-density polyethylene, high-density polyethylene, polypropylene, and L-bD.
pE (ethylene-α-olefin copolymer resin), ethylene-vinyl ester copolymer resin with a vinyl ester content of not more than about 9 mol%, preferably not more than about 3 mol%, α, β
- about 9 mol% or less of a bottle containing an unsaturated carboxylic acid ester;
Preferably, at least one kind of ethylene-α,β-unsaturated carboxylic acid ester copolymer resin of about 3 mol % or less is used as a raw material resin, and a blowing agent and a blowing aid are added thereto to form a foaming agent of about 1.5 to 3 mol %. 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.

The polyvinyl chloride resin used to form a homogeneous mixed layer of polyvinyl chloride resin and ethylene-vinyl acetate-carbon oxide copolymer resin laminated on one or both sides of these polyolefin foam sheets is a monopolymer of vinyl chloride. In addition to coalescence, vinyl chloride and other comonomers, such as α-olefins such as ethylene and propylene, vinyl esters such as vinyl acetate, α, β-unsaturated carboxylic acid esters such as acrylic esters, etc. vinyl ethers such as vinyl ethers,
Copolymers with other vinyl compounds such as styrene, acrylonitrile, vinylidene chloride, or vinylidene compounds may be mentioned.

Ethylene-vinyl acetate-carbon oxide copolymer resins used as plasticizers for such polyvinyl chloride resins include:
40 to 80% ethylene, preferably about 60 to 70%, vinyl acetate about 15 to 60%, preferably about 20 to 35%, and about 5 to 30% carbon oxide, all by weight;
It is preferably a terpolymer copolymerized at a ratio of about 5 to 15%, and if necessary, other comonomers are copolymerized. Details of the manufacturing method are as follows. For example, it is described in Japanese Patent Publication No. 55-50063. The plasticizer copolymer resin is generally used in an amount of about 5 to 150 parts by weight, preferably about 10 to 100 parts by weight, per 100 parts by weight of the polyvinyl chloride resin.

The polyvinyl chloride resin and the ethylene-vinyl acetate-carbon oxide copolymer resin are used by adding various known stabilizers, lubricants, fillers, and colorants thereto to form a homogeneous mixture, if necessary.

The homogeneous mixture is prepared by tri-blending or melt-blending the components simultaneously or sequentially. In the case of tri-blend, the components are uniformly melt-mixed in an extruder or calender roll in the bonding process 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 11' single-screw extruder, twin-screw extruder, roll, etc.

Lamination of the polyolefin foam sheet and the layer of this homogeneous mixture is carried out using an ethylene-vinyl ester copolymer resin or an ethylene-α, β-, β-carboxylic acid ester copolymer resin as a thermal adhesive.

Ethylene-vinyl ester copolymer resin is a copolymer of ethylene and vinyl ester such as vinyl acetate or vinyl propionate, which is produced by high-pressure radical polymerization method.
is also widely used. In addition, ethylene-α,β-unsaturated carboxylic acid ester copolymer resins are also produced by the high-pressure radical nail method, and α,β-unsaturated carboxylic acid ester copolymer resins are produced by the high-pressure radical nail method. Ethyl, n-butyl, isobutyl esters, etc. are used, and generally methyl or ethyl esters are widely used.

There are no particularly strict restrictions on the comonomer content and melt index of these ethylene copolymer resins, but vinyl esters or α, β are particularly effective when used as the thermal adhesive of the present invention. - a copolymer having an unsaturated carboxylic acid ester content of about 3 to 25 mol % or about 3 to 22 mol %, preferably about 7 to 15 mol %, and a melt index of about 0.8 to 100; It is a polymeric resin.

Specifically, in the case of ethylene-vinyl acetate copolymer resin, if the vinyl acetate content is approximately 3 mol% (approximately 9% by weight) or less, the concentration of polar groups in the copolymer resin is low, so It is unsuitable for use because it does not exhibit adequate adhesive strength and does not reach the level of adhesive strength required for practical use. On the contrary, about 2
If it is more than 5 mol% (approximately 50% by weight), processability and heat resistance will be poor. For the same reason, even with ethylene-ethyl acrylate copolymer resin, about 3 to 2
A range of 2 mol% (approximately 10-50% by weight) is selected.

The flF layer heat-sealable sheet is manufactured, for example, by the following method.

(2) Sand winch lamination method polyolefin foaming by heating appropriately all or part of a polyolefin foam sheet, a thermoadhesive resin sheet, and a plasticized polyvinyl chloride resin sheet. (8) Extrusion coating method A method of thermocompression bonding a plasticized polyvinyl chloride resin sheet and a plasticized polyvinyl chloride resin sheet via a thermoadhesive molten resin film (8) Extrusion coating method PVC resin gold extrusion coating method (4) Coextrusion coating method On the polyolefin foam sheet, thermal adhesive and TJ
A method of co-extrusion coating of f plastic and polyvinyl chloride resin at the same time. The laminated sheet is
The adhesive lamination method is simple, and similarly, ethylene-vinyl acetate-carbon oxide copolymer resin is used as the plasticizer for polyvinyl chloride resin, so it does not cause the fogging phenomenon that occurs when liquid plasticizers are used. Not only is there no generation, change in rigidity over time, or stickiness, but also ethylene-vinyl acetate copolymer resin or ethylene-α, β
- Since an unsaturated carboxylic acid ester copolymer resin is used as the rIA adhesive, no decrease in adhesive strength is observed over time.

The decline in adhesive strength over time is prevented not only by the use of such a specific thermal adhesive, but also by the use of ethylene-vinyl acetate-carbon oxide as a plasticizer for polyvinyl chloride resin. The use of polymeric resin is also related to bud adhesion, and even if the same thermal adhesive is used, liquid plasticizer is not used.
f When a plasticized polyvinyl chloride resin layer is laminated on a polyolefin foam sheet, this foam seed layer sheet does not have this effect (effect of preventing a decrease in adhesive strength over time).

Next, the present invention will be explained with reference to examples.

Example 1 Polyvinyl chloride resin (average degree of polymerization 1300) 100 parts (weight, same below), ethylene-vinyl acetate-carbon oxide copolymer resin (vinyl acetate content 28% by weight, -oxidation habit material content 9) Heavy spear%, melt index 35) 100
1 part, 4 parts of tin maleate, 1 part of polyethylene wax, and 1 part of magnesium oxide.
Knead for 4 minutes at I''p4 to make a homogeneous mixture, and then take a T-die with a width of 400 (= J digit 40 oval diameter single screw extrusion 4-chi (/= 22) and set the extrusion temperature to 1"j Extruded into a sheet at 180℃, 200μm thick iJ'9'rjj
A polyvinyl chloride resin sheet was molded.

High pressure polyethylene (density 0.923'jAt/(,
A cross-linked polyethylene foam sheet (expansion ratio: 30 times, thickness: 3 mm) molded using a melt index of 37) and a plasticized polyvinyl chloride resin sheet were combined into an ethylene-vinyl acetate copolymer resin ( W ML containing vinyl acetate:
28 m 141%, melt index 15) was used as an adhesive layer, and a heat sealer was used to seal the film at 160°C and pressure 0.5.
Heat welding was performed under conditions of τ2 and time of 2 seconds to form a foam laminated sheet.

After leaving the foam fi1-layer sheet at 80°C between 1O and 1O, its adhesion was tested using a peel test method (peel rate: 200C).
Although the FF value was determined by Wlr/'y+), it was found that the polyethylene foam sheet layer only destroyed the base material and maintained good adhesion.

Examples 2 to 4, Comparative Example 1 In Example 1, another ethylene-vinyl acetate copolymer resin was used. Regarding the obtained foam laminated sheet,
A similar adhesion evaluation was conducted and the results are shown in Table 1 below.

Vinyl acetate content (weight%) 40 33
19 8 Melt Index (dg/min) 55
30 2.5 2 [Adhesiveness]
○ ○ △ × (Evaluation of adhesion) ○: Base material destruction of polyethylene foam sheet layer △: Mainly base material destruction, some interfacial destruction ×: Interfacial destruction Examples 5 to 6, Comparative Example 2 In Example 1 , ethylene-ethyl acrylate copolymer resin was used instead of ethylene-vinyl acetate copolymer resin. The obtained foam laminated sheet was subjected to the same valuation as in Examples 2 to 4 (J9 g' of 311),
The results are shown in Table 2 below.

Table 2 ``Kabuto Hamaguri J + 1-16 Comparative Example 2 [Ethylene-ethyl acrylate 1 route IBt (q (Ji?') Ethyl acrylate content (total %) 25 19
9 Melt Index 5
5 6CiIfp adhesion] ○
△ ×Example 65 ntm (ji extrusion Using machine (”/, =28),
Similarly, the ethylene-vinyl acetate copolymer resin used in Example 1 was extruded at a resin temperature of 230° C. and a take-up speed of 20 m/min, and sandwich laminated to a thickness of 40 μm.

? When the same adhesiveness evaluation as in Example 1 was performed on the i# foamed sheet with a foam volume of a little less than 1, it was found that the polyethylene foam sheet layer exhibited good adhesion to the extent that the base material was destroyed.

Example 8 Plasticized polyvinyl chloride resin having the same composition as in Example 1 was
5rMn diameter extruder, resin temperature 180℃, thickness 200μ
Also, ethylene-vinyl acetate copolymer resin (vinyl acetate content 25% by weight, melt index 2) was extruded using a 40-diameter extruder at a resin temperature of 160℃ and a thickness of 20μ
After co-extrusion at 10 m, the two are combined in a die, and the ethylene-
The crosslinked polyethylene foam sheet used in Example 1 was layered on the vinyl acetate copolymer resin layer side, and passed between rolls to produce a foam laminate sheet.

The resulting laminated foam sheet was evaluated for adhesion in the same manner as in Example 1, and showed good adhesion of 1 M degree, at which the polyethylene foam sheet layer would break.

Representative Patent Attorney Yoshi 1) Toshio -27

Claims (1)

[Claims] 1. On one or both sides of the polyolefin foam sheet,
Uniform mixed layers of polyvinyl chloride resin and ethylene-vinyl acetate-carbon oxide copolymer resin are laminated via a thermal adhesive layer of ethylene-vinyl ester copolymer resin and ethylene-α,β-unsaturated carboxylic acid ester copolymer resin. A laminated foam sheet. 2. The foam laminate sheet according to claim 1, wherein the polyolefin foam sheet is a polyethylene foam sheet. 3. Crosslinked polyolefin foam sheet 4. The foam laminate sheet according to claim 1, wherein an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of about 9 to 50% by weight is used. 5. The foamed laminated sheet according to claim 1, wherein an ethylene-ethyl acrylate copolymer resin having an ethyl acrylate content of about 10 to 50% by weight is used.