JPH0417145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to flexible polyvinyl chloride laminates for covering sheet materials, and more specifically to molded products produced by thermoforming (e.g. injection molded products, press molded products). )
The present invention relates to a flexible polyvinyl chloride laminate that is applied as a sheet material for coating, has a very soft feel, good cushioning properties, and has excellent productivity.

PRIOR ART AND PROBLEMS TO BE SOLVED This type of coated sheet material is being applied, for example, to the production of coated molded articles in one step using only an injection molding machine. That is, a sheet material is clamped between a fixed mold and a movable mold in the mold of an injection molding machine, a thermoplastic resin for the core material is injected into it, and the pressure and heat of the molten resin during injection causes the mold to The purpose is to press the sheet material against the opposing mold surfaces and mold the sheet material and core material in one step.

Conventionally, soft polyvinyl chloride (hereinafter referred to as PVC) has been used as the above-mentioned sheet material, but the conditions for injection molding of resins commonly used as core materials (for example, in the case of ABS resin, Temperature 220~260℃ and pressure 400~1200
Kg/ ^cm2 ) is extremely harsh for PVC sheet materials, as can be seen from the fact that the forming temperature of PVC sheet materials by ordinary vacuum forming is generally around 170 to 200℃. tear,
This results in bruising and rough skin. In order to deal with this problem, the thickness of the sheet material must be increased, and the resulting coated molded product has an increased weight and a hard surface with poor quality.

In view of the current situation, the inventors of the present invention have carried out intensive research to solve the various problems mentioned above, and as a result, the above-mentioned
We have discovered that by incorporating a specific heat-resistant/durable layer and elastic extensibility layer into a PVC sheet material, the problems of tearing, crinkling, and thickening of the film can be solved, and a laminate useful as a covering sheet material can be obtained. The present invention has now been completed.

That is, the present invention provides a covering sheet material comprising a soft PVC sheet layer, a crosslinked soft PVC sheet layer, and a layer of knitted, woven, or nonwoven fabric made from natural fibers, recycled fibers, and/or synthetic fibers. The present invention provides a soft PVC laminate for use.

Structure and Effects of the Invention In the present invention, a crosslinked soft PVC sheet layer (hereinafter referred to as a crosslinked layer) is used to impart heat resistance and durability to a normal soft PVC sheet layer.
is capable of maintaining heat resistance strength (strength and elongation) during molding, and a crosslinking-reactive composition (hereinafter referred to as a crosslinking composition) is usually used to form the layer,
Specifically, they are divided into the following three categories.

(a) PVC having a crosslinkable functional group [for example, vinyl chloride and a monomer having a hydroxyl group or carboxyl group in the molecule (2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate,
(hydroxybutyl vinyl ether, methacrylic acid, monobutyl maleic acid, etc.), hydrolysates of vinyl chloride/vinyl ester copolymers, hydrolysates of vinyl chloride/acrylic acid ester copolymers, vinyl chloride/epoxy groups Acid-treated vinyl monomer copolymers (hereinafter referred to as crosslinked PVC) contain functional groups that can react with hydroxyl groups or carboxyl groups (for example, isocyanate groups, carboxyl groups, hydroxyl groups, epoxy groups, amino groups, etc.). A combination of crosslinking agents having two or more of the following in the molecule (for example, tolylene diisocyanate, diphenylmethane diisocyanate, adipic acid, phthalic acid, triglycidyl isocyanurate, epoxy resin, triethyltetramine, methylolmelamine, butoxymethylmelamine, etc.),
This is combined with the usual plasticizers (preferably phthalate esters such as dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, phthalic acid, diisodecyl, dilauryl phthalate, diundecyl phthalate, butylbenzyl phthalate) and stabilizers ( Contains dibutyltin laurate, epoxidized soybean oil, Ba/Zn system, etc.)
Fillers (calcium carbonate, etc.) if necessary,
Products prepared by adding appropriate amounts of pigments, blowing agents, flame retardants, antioxidants, ultraviolet absorbers, etc., and kneading them using conventional methods. Note that it is preferable to blend the above-mentioned foaming agent to impart foamability to the crosslinked layer. Also cross-linked PVC
Does not have a normal crosslinking functional group instead of a part of
PVC (hereinafter commonly referred to as PVC) may be used in combination; in this case, the proportion of the combination is cross-linked PVC and
The weight ratio of PVC is 1/1 or more, preferably 7/1
The number may be selected to be 3 or more.

(b) A combination of normal PVC and a specific crosslinking agent capable of directly crosslinking the PVC, such as a triazinethiol compound (Koumenshi, 29 (7), 527-530 Mitsugu, 1980), and the same various types as in (a) above. Contains appropriate additives.

(c) Usually PVC-reactive plasticizers, e.g. (meth)
A combination of polymerization initiators such as acrylic esters (trimethylolpropane trimethacrylate, etc.), phthalic esters (diallyl phthalate, etc.), and benzoyl peroxide,
Contains the same various additives as in (a) above as appropriate.

A desired crosslinked layer can be formed using each of these crosslinked compositions (a) to (c), but composition (a) is most preferred from the viewpoint of maintaining strength and elongation during molding. Furthermore, it goes without saying that the crosslinking composition may be prepared by combining combinations of crosslinking mechanisms in each composition.

The composition (hereinafter referred to as ordinary composition) used to form the ordinary flexible PVC sheet layer (hereinafter referred to as ordinary layer) used in the present invention is a substitute for the crosslinked PVC in the above crosslinked composition (a). normally to
The composition is the same except that PVC is used. Also in this case, it is preferable to add a foaming agent to impart foamability.

The layer of knitted fabric, woven fabric, or nonwoven fabric (hereinafter referred to as the fabric layer) used for imparting elastic extensibility in the present invention has an elongation greater than the molding magnification of the coated molding and a modulus less than the molding pressure. It is made using single or blended yarns of natural fibers, recycled fibers, and synthetic fibers. Specifically, yarns with elongation retained in the yarn itself (e.g. woolly yarn, spandex yarn, etc.), yarns with woven structure, knitted structure (e.g. stockinette, tricot, etc.)
(nonwoven fabric, etc.) and a combination of both.

The flexible PVC laminate for covering sheet material according to the present invention essentially includes the above-mentioned normal layer, crosslinked layer, and cloth layer, and is constructed by using one layer or two or more layers of each layer and laminating them in an appropriate arrangement. In particular, the fabric layer improves the followability of the laminate sheet material during the molding process of the covered molded product, and contributes to the evacuation of air that may be trapped in the fixed mold. It is preferable to be located at .
Although the thickness of each layer is not particularly limited, it is generally preferred that the thickness be about 0.10 to 3.0 mm for the normal layer, 0.10 to 3.0 mm for the crosslinked layer, and 0.2 to 2.0 mm for the cloth layer.

Next, to create the laminate of the present invention, ordinary soft
Processing methods and conditions similar to those for PVC sheets and PVC leather may be employed, and for example, the following steps may be used.

(1) First, the normal composition and the crosslinked composition are applied onto a release carrier and then melted and/or foamed, or sheet layers are created from each composition by calendering or extrusion processing. A sheet layer consisting of a normal layer and a crosslinked layer is formed by thermally welding or laminating and bonding the sheet layers with an adhesive.

(2) Next, an adhesive is applied to the sheet layer, and the cloth layer is laminated using a laminating machine, or the cloth layer is laminated by calendering or extrusion processing.

Note that the method of (1) above, in which a cloth layer is bonded and laminated on the release carrier at the same time as the normal layer and the crosslinked layer are formed, may be adopted.

In addition, in order to improve the surface feel of the laminate, prevent plasticizer from bleeding, treat the surface with gloss, and add patterns, so-called surface treatment may be performed using a roll coater or the like using a thermoplastic resin solution according to a conventional method.

The laminate of the present invention produced as described above can be used as a covering sheet material in the above-mentioned one-step injection molding or ordinary press forming, thereby controlling the flow of the core material resin. It has been found that it is possible to provide a lightweight, high-quality coated molding with uniformity, improved adhesion, and a very soft surface and good cushioning feel. In the laminate of the present invention, it is possible that air pockets may partially occur depending on the shape of the coated molding, resulting in a decrease in adhesive strength. By providing fine ventilation holes mechanically and chemically to the extent that the surface appearance is not impaired (for example,
-10836, 36-22268), it is recognized that a high-quality coated molded product with improved adhesive strength can be provided.

Next, the present invention will be described in more detail with reference to Examples.

Example 1 (1) Compounding composition of a normal composition: Normal PVC (trade name "Vinica P-470" manufactured by Mitsubishi Monsanto, average degree of polymerization 3500) ...100 parts dioctyl phthalate ...80 parts dibutyltin laurate (Akishima) (manufactured by Kagakusha)
... 2 parts epoxidized soybean oil ... 3 parts pigment ... 10 parts (2) Blend composition of cross-linked composition: Cross-linked PVC (trade name "P" manufactured by Mitsubishi Monsanto Chemical Co., Ltd.)
-100A'') ...100 parts diundecyl phthalate ...65 parts Ba/Zn stabilizer (manufactured by Adeka Argus)
...3-part epoxidized soybean oil (manufactured by Adeka Argus)
...3 parts Calcium carbonate ...10 parts Pigment ...10 parts Hydrogenated blocked isocyanate crosslinking agent (manufactured by Takeda Pharmaceutical Company) ...3 parts (3) Cloth layer: Woolly yarn knitted (0.45 mm thick) was used.

The normal composition and the crosslinked composition having the above-mentioned composition are sequentially applied onto a release paper to form a sheet layer each having a thickness of 0.5 mm (that is, a total thickness of 1 mm), and then the above-mentioned composition is used as an adhesive layer to form a sheet layer having a thickness of 0.10 mm. After applying the above fabric layer to this, it was melted and cross-linked for 2 minutes in a heating oven at 210°C.
Obtain a sheet material (laminate) with a thickness of mm.

Reference example 1 The sheet material obtained in Example 1 was set in a predetermined position between the molds of an injection molding machine, and ABS resin was heated to temperature.
The sheet is injected onto the crosslinked layer side at 220° C. and an injection pressure of 600 Kg/cm ² . Next, after being left under pressure for a predetermined holding time, the product is cooled to obtain a soft PVC-coated molded product. Such a coated molded product had no breakage of the sheet material and had an excellent surface feel.

Claims (1)

[Scope of Claims] 1. Consisting of a soft polyvinyl chloride sheet layer, a crosslinked soft polyvinyl chloride sheet layer, and a layer of knitted, woven, or nonwoven fabric made from natural fibers, recycled fibers, and/or synthetic fibers. Soft polyvinyl chloride laminate for covering sheet material. 2. The laminate according to item 1 above, wherein at least one of the flexible polyvinyl chloride sheet layer and the crosslinked flexible polyvinyl chloride sheet layer has foamability. 3. The laminate according to item 1 or 2 above, wherein layers of knitted fabric, woven fabric, or nonwoven fabric are located on both the front and back surfaces. 4. The laminate according to any one of items 1 to 3 above, wherein the soft polyvinyl chloride sheet layer and the crosslinked soft polyvinyl chloride sheet layer have fine ventilation holes that do not impair surface appearance. .