JPS6044355B2 - Colored adhesive sheet with excellent weather resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a colored adhesive sheet for outdoor use with excellent weather resistance and an ultra-weather-resistant colored adhesive sheet for outdoor use with a colored metallic tone. Pigments are relatively easy to disperse and they are used as packaging tape.

These rubber-based adhesives are sensitive to sunlight, humidity, temperature changes, etc., and have not been used as weather-resistant adhesive sheets for outdoor use. On the other hand, adhesives based on polyacrylic esters have very good weather resistance, but because they are highly polar and have many types of active groups, they may react with pigments and fail to develop color, gel, or have poor dispersion. It was very difficult to carry out, and it was unsuitable as a weather-resistant colored adhesive sheet for outdoor use. Traditionally used outdoor colored adhesive sheets are made by kneading pigments and dispersion into a resin, especially polyvinyl chloride resin, and then forming this into a film, applying an adhesive to the back side, and finally applying the adhesive. The surface is protected with release paper.

The colored adhesive sheet obtained in this way is affected by the dispersant and pigment used during kneading and dispersion, as the resin serving as the surface material acts as a binder. Properties such as tensile strength, elongation, and flexibility are significantly reduced. In addition, since the pigments are unevenly exposed on the surface of the film and there is no surface protective layer, the weather resistance is greatly influenced by the weather resistance and dispersion degree of the pigment itself. do not have. Furthermore, if the compatibility between the resin and the pigment is poor, or if the resin deteriorates, the pigment is likely to change color or fade due to decomposition gas.
In addition, the surface condition is rough and lacks smoothness because the pigments are exposed, and excellent gloss cannot be expected. Among the above disadvantages, the lack of surface smoothness is caused by resin coating,
Although some defects can be covered by special treatments such as calendar pressing, improving the weather resistance of the film itself and preventing discoloration, fading, and discoloration are still difficult issues. Ta. In order to eliminate the various drawbacks mentioned above, the present inventors used a transparent plastic film with good weather resistance as a base material on the surface, and applied a pre-activated adhesive based on polyacrylic acid ester on the back side of the base material. A colored adhesive made by cross-dispersing highly weather-resistant pigment particles whose surface is coated with base-free acrylic resin is applied.
Protect the adhesive surface with release paper. This is a completed ultra-weather-resistant colored adhesive sheet for outdoor use, which is characterized by a combination of a highly weather-resistant plastic film and a colored adhesive whose main ingredient is the above-mentioned highly weather-resistant polyacrylic acid ester. That is.

The transparent film with good weather resistance used in the present invention is made of a resin selected from the group consisting of vinyl chloride resin, acrylic resin, methylmethacrylic resin, fluororesin, and the like.

In addition, the polyacrylic esters used in the present invention include methyl acrylate, ethyl acrylate, butyl acrylate,
It is a polymer of a monomer selected from the group consisting of 2-ethylhexyl acrylate or a mixture thereof. In the present invention, a highly weather-resistant pigment that has been pulverized in advance to a particle size of approximately 0.1 to 1.0 μm is coated with an acrylic resin that does not have active groups to a coating thickness of approximately 0.05 to 1.0 μm. Use overturned dry coated pigments.

Next, approximately 1 to 10 parts by weight of the dried coated pigment is added in small portions to 100 parts by weight of an adhesive based on polyacrylic ester with excellent weather resistance, depending on the desired hue and concentration. By kneading, a colored adhesive with extremely good dispersibility can be easily obtained due to the compatibility between the adhesive and the pigment coating.

Such good dispersibility is achieved by forming an acrylic resin film having no active groups on the surface of the pigment by the method of the present invention, thereby improving the compatibility between the encapsulated pigment and the adhesive. This is thought to be due to the method of manufacturing the colored pressure-sensitive adhesive sheet of the invention. Conventionally, dispersants, mainly surfactants, were required to uniformly disperse pigments, but dispersants significantly impair the adhesive performance of adhesives, reduce viscosity, and The functional group reacts with the end group of the pigment, causing color development to be inhibited.

In the present invention, the end of the pigment is wrapped in an acrylic resin that does not contain active groups to isolate the pigment and the adhesive, and the high degree of compatibility between the adhesive mainly composed of polyacrylic ester and the acrylic resin is achieved without using a dispersant. By using this method, we achieved cross-dispersion between the pigment and the adhesive, and obtained a colored adhesive with a large shielding power.

Furthermore, in the present invention, in addition to the pigment, metal powder such as gold powder, silver powder, aluminum powder, copper powder, etc. is kneaded into an adhesive whose main ingredient is polyacrylic acid ester, and the resulting colored adhesive is used. By coating the adhesive on the back side of a transparent plastic film with excellent weather resistance and protecting the surface with a release paper, it was possible to obtain a colored adhesive sheet for outdoor use with excellent weather resistance and excellent weather resistance similar to that obtained using pigment alone.

In this case, the weight ratio of the adhesive based on polyacrylic ester, the pigment coated with acrylic resin, and the metal powder is adjusted within the range of about 100:1 to 100:1 to 100. The polyacrylic ester which is the main ingredient of the highly weather-resistant transparent film and adhesive used in this invention is selected from within the same range as those containing no metal powder.

In this case, the particle size of the pigment used and the thickness of the acrylic resin film are also within substantially the same range as in the case where no metal powder is included. Furthermore, the colored pressure-sensitive adhesive sheet of the present invention has the great advantage that a patterned decorative sheet can be easily obtained. In other words, when printing is applied to the surface of a film made by kneading resin and pigment using the conventional method and making it into a decorative sheet for exterior use, the abrasion resistance, weather resistance, and solvent resistance of the printed surface should be considered and the surface protected. In order to achieve this, it was also necessary to provide a clear layer for polishing purposes. In addition, when using an alternative method to the conventional method, printing is performed on the back side of a transparent film, a full peta printing layer is provided on top of it to provide hiding properties, and a colorless adhesive is applied on top of that, which is then peeled off. A very troublesome method of pasting paper had to be used. According to the method of the present invention, the necessary pattern printing is applied to the back side of a transparent, weather-resistant plastic film, and after drying, a colored adhesive sheet based on polyacrylic acid ester is applied, and release paper is placed on top of it. It is possible to obtain a colored decorative sheet with a pattern that is simple to apply, simple to operate, and extremely weather resistant.

It is also clear that by incorporating metal powder in addition to the pigment in this method, an ultra-weather-resistant metallic decorative sheet can be obtained. Next, an example of manufacturing a super weather-resistant colored adhesive sheet of the present invention and a comparative example of weather fastness of the obtained adhesive sheet and a colored adhesive sheet obtained by a conventional method will be shown.

Example 1 An ethyl acetate solution (containing 43% solid content) of a copolymer consisting of ω parts of butyl acrylate, 10 parts of ethyl acrylate, 2 parts of 2-ethylhexyl acrylate, 8 parts of vinyl acetate, and 2 parts of acrylic acid was prepared. In addition, dynamic color SZ
762O Blue (manufactured by Dainichiseika) with acrylic resin LR (
(manufactured by Mitsubishi Rayon Co., Ltd.) with a thickness of approximately 0.

Add 30 parts of a pigment coated to a thickness of 1 to 1.0μ to make a colored adhesive with sufficient cross-dispersion, and dry this onto high-quality polylaminated release paper (manufactured by Honshu Paper Industries) to a thickness of 35 to 45μ.
A transparent PVC film (manufactured by Bando Chemical Co., Ltd.) is applied as a surface material on the colored adhesive layer.
A colored adhesive sheet (sample A) according to the present invention was prepared.

Example 2 A metal powder-containing colored pressure-sensitive adhesive sheet (sample) was prepared by adding W parts of aluminum powder (particle size 5 to 10p) to the pigment-added part obtained by the manufacturing method of Example 1, but otherwise in the same manner as the sample. B) was obtained.

Samples (A) and (B) obtained in Examples 1 and 2 above and a colored PVC product (manufactured by Bando Chemical Co., Ltd.) serving as a comparison standard were designated as sample (C), and the samples (A), (B) and (
C) was irradiated with a sunshine type weatherometer and the time for discoloration and fading was measured, and the following results were obtained. Irradiation test results

Claims (1)

[Claims] 1. A thin layer of a colored adhesive obtained by homogeneously kneading and dispersing an adhesive based on polyacrylic acid ester and pigment particles coated with an acrylic resin without active groups. A colored adhesive sheet with excellent weather resistance, which is sandwiched between a transparent film with good weather resistance and a release paper. 2 The polyacrylic ester is methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
- A polymer of a monomer selected from the group consisting of ethylhexyl or a mixture thereof, and the transparent film is a resin selected from the group consisting of vinyl chloride resin, acrylic resin, methyl methacrylic resin, and fluororesin. A colored pressure-sensitive adhesive sheet according to claim 1, which is made from. 3 The mixing ratio of the adhesive and the pigment particles is 10 by weight.
The colored pressure-sensitive adhesive sheet according to claim 1, wherein the ratio is within the range of 0:1 to 100. 4 The pigment particles have a particle size within the range of 0.1 to 1.0μ and 0.05 to 1.0μ.
The colored pressure-sensitive adhesive sheet according to claim 1, having an acrylic resin film thickness within the μ range. 5 Weather-resistant thin layer of colored adhesive obtained by homogeneously kneading and dispersing a polyacrylic acid ester-based adhesive, pigment particles coated with acrylic resin without active groups, and metal powder. An ultra-weather-resistant, metallic-colored adhesive sheet that is sandwiched between a transparent film and release paper. 6 The polyacrylic ester is methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
- A polymer of a monomer selected from the group consisting of ethylhexyl or a mixture thereof, and the transparent film is a resin selected from the group consisting of vinyl chloride resin, acrylic resin, methyl methacrylic resin, and fluororesin. The colored pressure-sensitive adhesive sheet according to claim 5, which is made from. 7. The colored adhesive sheet according to claim 5, wherein the mixing ratio of the adhesive, pigment particles, and metal powder is in the range of 100:1 to 100:1 to 100 by weight. 8. The coloring according to claim 5, wherein the pigment particles have a particle size within the range of 0.1 to 1.0 μ and an acrylic resin coating thickness within the range of 0.05 to 1.0 μ. adhesive sheet.