JPH03182575A - Surface covering material - 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 [Field of Industrial Application] The present invention relates to a surface coating material used for masking materials, packaging materials, etc.

[Background of the invention]

This kind of surface covering materials such as masking materials and packaging materials are made by providing an adhesive layer on the surface of paper, plastic sheets, etc., and are attached to the surface of the masking object, packaging object, etc. via the adhesive layer, It is peeled off after surface treatment, transportation, etc. During peeling, it is required that the adhesive layer does not peel off from the base material and transfer to the surface of the object. However, if the substrate has low affinity for the adhesive layer, such as polyolefins such as polyethylene or polypropylene, or if it is exposed to high temperatures during surface treatment, or after long-term storage or transportation, the adhesive layer may migrate to the target surface. Prevention is extremely difficult.

[Conventional technology]

Conventionally, methods to prevent such migration of the adhesive layer to the target surface include creating a slightly crosslinked structure in the adhesive layer to improve cohesive strength, or adding a release agent to impart release properties. was being carried out.

[Problem to be solved by the invention]

However, in the method of making the adhesive layer into a slightly crosslinked structure, the adjustment of the crosslinking density is extremely delicate, and if the crosslinking density is slightly higher than the appropriate crosslinking density, the adhesiveness will be extremely reduced, and conversely, if it is slightly lower than the appropriate crosslinking density, the cohesive force will not improve and the target surface It is not possible to prevent the adhesive layer from migrating to the surface, and the method of adding a mold release agent results in a decrease in tackiness and a decrease in heat resistance and weather resistance.

[Means to solve the problem]

The present invention, as a means for solving the above-mentioned conventional problems,
Oxidized starch is added to the adhesive layer.

The base material used in the present invention is polyethylene, polypropylene,
Plastic sheets such as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, polystyrene, polyamide, polyester, etc., and foams of the above plastics. Sheets, textile knitted fabrics, non-woven fabrics,
These materials are similar to conventionally used base materials such as fibrous sheets such as paper, hardboard, and insulation boards, synthetic resin-impregnated fiber sheets obtained by impregnating the fibrous sheets with synthetic resin, and thin metal films. The base material may be shaped to match the shape of the surface of the object to be coated.

The above plastic sheet or plastic foam sheet may be mixed with an inorganic filler. The inorganic fillers mixed into the above plastic sheet or plastic foam sheet include calcium carbonate, talc,
Inorganic powders such as bentonite, titanium white, carbon black, red iron, glass powder, ceramic powder, blast furnace slag, and ply ash. The inorganic filler is usually mixed into the plastic sheet or plastic foam sheet in an amount of 5 to 80% by weight, preferably 10 to 60% by weight. When inorganic fillers are mixed into plastic sheets or plastic foam sheets in this way,
The strength and heat resistance of the masking material are improved, and the material cost of the masking material is reduced because plastic materials and plastic foam materials are saved by adding the inorganic filler. Furthermore, when incinerating the masking material after use, the combustion energy is reduced by the amount of inorganic filler added, and damage to the incinerator is reduced accordingly.

The adhesive used in the present invention is of an emulsion type in order to uniformly mix the oxidized starch, and examples of such adhesives include natural rubber, styrene-butadiene rubber,
Natural or synthetic rubber latex such as styrene-butadiene block copolymer, styrene-isoprene block copolymer, acrylonitrile-butadiene rubber, isoprene rubber, chloroprene rubber, butyl rubber, polyisobutylene rubber, polybutene rubber, graft rubber, etc.

Acrylic acid ester resin, methacrylic acid ester resin, vinyl acetate resin, vinyl propionate resin, vinyl acetate-ethylene copolymer resin, vinyl acetate-maleic acid copolymer resin, styrene resin, vinyl chloride resin , a vinyl chloride-ethylene copolymer resin, a vinyl chloride-vinyl acetate copolymer resin, a vinylidene chloride resin, a polyvinyl ether resin, and other synthetic resin emulsions that exhibit tackiness at room temperature are used. Two or more of the above synthetic rubber latexes and synthetic resin emulsions may be mixed, and in that case, it is sufficient that the mixture exhibits tackiness at room temperature, and each latex or emulsion does not necessarily need to show tackiness at room temperature. There isn't. Furthermore, a plasticizer or softener such as dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, or terpene dimer may be added to the latex or emulsion, and in this case as well, the composition of the plasticizer or softener is It is not necessary for each latex or emulsion to exhibit tackiness at room temperature, as long as it shows tackiness.

Furthermore, the adhesive of the present invention includes tackifiers such as rosin, petroleum resin, coumaron resin, rosin derivative, terpene resin, phenol resin, alkylphenol resin, toluene, xylene, ethyl acetate, n-butyl acetate, methyl ethyl ketone, Even if organic solvents or wetting agents such as methyl isobutyl ketone, cellosolve acetate, n-butyl cellosolve, ethylene glycol, diethylene glycol, propylene glycol, glycerin, polyethylene glycol, polypropylene glycol, fillers such as talc, bentonite, calcium carbonate, etc. are added. good. In addition, pigments, dyes, fungicides, preservatives, etc. may be added.

Oxidized starch used in the present invention is oxidized by adding oxidizing agents such as chlorine, saran powder, hypochlorous acid, periodic acid, manganese oxide, potassium permanganate, and hydrogen peroxide to an aqueous suspension of starch. It is thought that the aldehyde groups and primary alcohol groups of starch are oxidized to carboxyl groups, and the secondary alcohol groups of starch are oxidized to ketone groups through the above oxidation.

The amount of the oxidized starch added to the adhesive is usually 0.
．． 1 to 30% by weight (hereinafter simply referred to as %), preferably 0.
It is 1 to 20%. Addition amount of the above oxidized starch is 30%
When the amount of oxidized starch is exceeded, the tackiness tends to decrease, but for adhesives with sufficient tackiness, the amount of oxidized starch added
Even if the amount exceeds 0%, the adhesiveness may not decrease in some cases, and the above values do not limit the present invention. Also, if the amount of oxidized starch added is less than 0.1%, the adhesive layer will be prevented from transferring to the object. The effect of Oxidized starch is usually added to an emulsion-type adhesive later, but it may be added to the aqueous phase in advance during the production of the adhesive emulsion (emulsion polymerization or emulsification of resin, etc.). Further, oxidized starch is added in a solid form such as a powder or in a solution such as an aqueous solution.

To produce the surface coating material of the present invention, a mixture of an adhesive emulsion and oxidized starch is applied to the object contacting surface of the base material, and if desired, the mixture is dried by heating at 80°C or higher or drying at room temperature. An adhesive layer is formed by heating to 80°C or higher. The adhesive layer is usually 50~
It is formed on the base material with a weight of about 300 g/n (approximately 300 g/n).The surface of the base material is subjected to electrical discharge treatment prior to applying the adhesive emulsion.

Primer treatment or the like may be performed.

[Effect]

The effects of the present invention are as follows.

Oxidized starch is mixed into the adhesive to improve the cohesiveness of the adhesive and to provide mold release properties.

Also, oxidized starch does not easily soften even at high temperatures.

〔Effect of the invention〕

Therefore, even if the surface coating material of the present invention is adhered to the surface of an object and exposed to high temperatures in this state, and even after a long period of time, when the surface coating material is peeled off, the adhesive layer will be removed from the substrate. It does not migrate to the surface.

In particular, even when the base material is a polyolefin sheet such as polyethylene or polypropylene that has low affinity with the adhesive layer, if the adhesive of the present invention is used, no migration of the adhesive layer from the base material to the surface of the object will be observed. . Furthermore, peeling of the coating material from the base material due to softening of the adhesive at high temperatures can be prevented. In addition, regardless of the surface temperature of the object when it is pasted, it has good adhesion and does not peel off during storage, and when the surface coating material is peeled off, it easily peels off from the base material of the adhesive layer to the surface of the object. No transition is seen.

〔Example〕

Example 1 An adhesive emulsion consisting of 70 parts by weight of 50% natural rubber latex and 30 parts by weight of an emulsion of 50% terpene resin was added with oxidized starch in the ratio shown in Table 1 to form a plate-shaped polyethylene foam. 50g/r on one side
A surface coating material was prepared by coating with rr and drying. The test results for the surface coating material are shown in Table 2.

(Unit double placement part) Table 2 Table 2 (1) Adhesive strength Peel strength: Surface coating material is pasted on a painted board through the adhesive coated surface, and 180 degree peel strength at 20°C one day later Measure.

(2) Adhesive persistence: A surface coating material is attached to a painted board through the adhesive-applied surface, and it is left at 20°C for 1 and 30 days, then peeled off and whether or not the adhesive has migrated to the painted board. I looked into it.

(3) Adhesive persistence when heated = (2) Adhesion of surface coating material to a painted board in the same way as for (2) Adhesive persistence, and after 1 day, left at 80°C for 1 hour, and adhesion to the painted board at 80°C The presence or absence of migration of the agent was investigated.

O None 0 Slightly present Δ Considerably × Mostly present Example 2 50% adhesive emulsion 1 prepared with a monomer ratio of 70 parts by weight of n-butyl acrylate and 30 parts by weight of vinyl acetate
00 parts by weight and oxidized starch in the ratio shown in Table 3 was added to one side of a plate-shaped polystyrene foam.
A surface coating material was prepared by coating with rrr and drying. The test results for the surface coating material are shown in Table 4.

(Margin below) (Unit double placement part) Table 4 (4) Adhesive Peel Strength A surface coating material was attached to a Ni-Aluminum plate through the adhesive coated surface, and 180 degrees peeled at 20°C one day later. Measure strength.

(5) Adhesive Residue A surface coating material is attached to the aluminum plate through the adhesive-coated surface, and after being left at 20°C for 1 day and 30 days, it is peeled off to check whether or not the adhesive has migrated to the aluminum plate. Examined.

(6) Adhesive persistence when heated = (5) Adhesion of the surface coating material to the painted board in the same manner as in (5) Adhesive persistence, and 1 day later, left at 80°C for 1 hour, and adhesion to the aluminum plate at 80°C. The presence or absence of migration of the agent was investigated.

O None 0 Slightly present Δ Considerably present X Mostly present Example 3 50 parts by weight of ethyl acrylate and 50 parts by weight of methyl methacrylate
A 51% adhesive emulsion was obtained by adding 10 parts by weight of a 60% gin emulsion to 90 parts by weight of a 50% adhesive emulsion prepared at a seven-part weight ratio. Oxidized starch was added to 100 parts by weight of this adhesive emulsion in the ratio shown in Table 5, and 50 pc/r was added to one side of kraft paper.
A surface coating material was prepared by coating with rr and drying. The test results for the surface coating material are shown in Table 6.

(Units: parts by weight) Table 6 (7) Adhesive force Peel strength: The surface coating material is attached to the painted board through the adhesive coated surface, and the 180 degree peel strength at 20°C after 1 day is measured. Measure.

(8) Adhesive persistence: Affix the surface coating material to the painted board through the adhesive-applied surface, leave it at 20°C for 1 day and 30 days, then peel it off and check whether the adhesive has migrated to the painted board. I looked into it.

O No O Slightly present Δ Very present 30% by weight of oxidized starch added in the ratio shown in Table 7.
A surface coating material was prepared by applying 100 g/sheet of calcium carbonate to one side of a polypropylene sheet and drying it. The test results for the surface coating material are shown in Table 8.

(Unit double placement part) Table 8 (blank below) Table 8 (9) Adhesive persistence after heat aging: A surface coating material was attached to a painted board through the adhesive coated surface and heated at 40°C. After 1 day, 1 month, 3 months, and 6 months of heat aging, it was peeled off and the presence or absence of adhesive transfer to the painted board was examined.

No O O slightly Δ Quite a bit × is almost always

Claims (1)

[Claims] A surface coating material characterized in that an adhesive layer is formed by applying an emulsion type adhesive containing oxidized starch to one surface of a base material and drying it.