JP2000230156A - Adhesive sheet and method for doubly adhering adhesive sheets - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare an adhesive sheet which has excellent durability, even when directly adhered to a deteriorated existing vinyl chloride resin sheet, and to provide a method for doubly adhering the adhesive sheets, which has excellent adhesion applicability and has excellent durability also after adhered. SOLUTION: This adhesive sheet is obtained by laminating an adhesive layer to one surface of a vinyl chloride resin sheet through a primer layer. Therein, the primer layer is formed by adding 0.5-4 pts.wt. of a UV light absorbent to 100 pts.wt. of chloroprene rubber, adjusting the mixture with an organic solvent to give a solid content of 5-50%, coating the obtained primer liquid to the sheet and then drying the coated liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive sheet having excellent durability for use in outdoor signboards and the like, and a method for laminating and applying a pressure-sensitive adhesive sheet having excellent durability and workability.

[0002]

2. Description of the Related Art For signs and advertisements used outdoors or the like, an adhesive sheet based on a colored vinyl chloride resin sheet is cut and pasted into designs or characters instead of conventional painting. . However, a signboard or the like several years after construction is deteriorated, and the resin sheet is deteriorated and discolored or discolored. It is difficult to peel off the existing colored vinyl chloride resin sheet (hereinafter referred to as “existing sheet”) during rebuilding. In general, the existing sheet is not peeled off, and new coloring using the vinyl chloride resin sheet is performed on it. Adhesion of an adhesive sheet (hereinafter referred to as “new adhesive sheet”) is performed.

However, due to deterioration of the existing sheet, the stabilizer contained therein is lost and its content is decreasing. If a new pressure sensitive adhesive sheet is directly adhered on top of this, the UV absorber mixed with the base material of the new pressure sensitive adhesive sheet will migrate to the existing sheet, and as a result, the weather resistance of the new pressure sensitive adhesive sheet will be reduced, Deterioration will be accelerated. In order to avoid this problem, a sheet other than the new adhesive sheet is discarded and pasted on the entire surface of the existing sheet, and the new adhesive sheet is installed on this, but extra cost and construction are required And

JP-A-51-91944 discloses a barrier film anchoring agent having improved interlayer adhesion between a laminated film of a polypropylene film and another resin film. This is used for the purpose of improving the interlayer strength when manufacturing a laminated film, and prevents the deterioration of the new adhesive sheet due to the loss of the UV absorber when the new adhesive sheet is applied on the existing sheet. It cannot achieve its purpose.

[0005]

SUMMARY OF THE INVENTION The present invention provides a pressure-sensitive adhesive sheet having excellent durability even when applied directly to an existing vinyl chloride resin sheet which has been used outdoors and deteriorated, and has excellent workability, and It is an object of the present invention to provide a method for laminating an adhesive sheet having excellent durability.

[0006]

According to the first aspect of the present invention, there is provided a pressure-sensitive adhesive sheet comprising a vinyl chloride resin sheet and a pressure-sensitive adhesive layer laminated on one side of the pressure-sensitive adhesive layer via a primer layer. 0.5 to 4 parts by weight of an ultraviolet absorber is added to the parts by weight, and a primer solution having a solid content adjusted to 5 to 50% by an organic solvent is applied to the film and dried. It is.

[0007] In the method of laminating an adhesive sheet according to the second aspect of the present invention, the primer liquid used in the first aspect of the present invention is applied on an existing adhesive sheet and dried to form a primer layer. It is characterized in that the surface of the pressure-sensitive adhesive layer is formed by laminating a pressure-sensitive adhesive layer on one side of a vinyl chloride resin sheet on the surface of the primer layer.

The primer solution used in the first aspect of the present invention has a solid content of 5 to 50%, comprising 0.5 to 4 parts by weight of an ultraviolet absorber and an organic solvent, based on 100 parts by weight of chloroprene rubber. . The ultraviolet absorber is not particularly limited as long as it has good compatibility with chloroprene rubber and low volatility and migration property. Examples thereof include benzophenone-based, benzotriazole-based, and salicylic acid derivative-based ones.

The amount of the ultraviolet absorber added is 0.5 to 4 parts by weight based on 100 parts by weight of chloroprene rubber. 0.5
If the amount is less than parts by weight, the migration speed of the ultraviolet absorbent contained in the base material of the new pressure-sensitive adhesive sheet cannot be reduced, and as a result, the weather resistance of the new pressure-sensitive adhesive sheet is reduced. Also,
If the amount exceeds 4 parts by weight, the ultraviolet absorber migrates to the pressure-sensitive adhesive layer of the new pressure-sensitive adhesive sheet, reduces the adhesive strength with the existing sheet, and causes peeling over time due to poor bonding. The preferable addition amount of the ultraviolet absorber is 1.0 to 2.5 parts by weight.

There is no problem if the organic solvent used in the primer solution is compatible with the formulation of the primer solution and has a boiling point of 150 ° C. or lower. For example, toluene, xylene, ethyl acetate and the like can be used. It can be suitably used. However, ketone solvents are not suitable because they dissolve the vinyl chloride resin sheet.

The organic solvent functions as a diluent for imparting good coatability to the primer solution, and the primer layer has an optimum thickness of 0.5 to 2 μm after drying. The primer solid content of chloroprene rubber and ultraviolet absorber is adjusted so as to be 5 to 50%. If the solid content is less than 5%, the applied amount increases to secure the above thickness, which may result in poor drying in the drying step. On the other hand, if it exceeds 50%, the viscosity of the primer solution is so high that streaks may occur at the time of coating, which may cause peeling of the new adhesive sheet. Preferred solids content is 5
~ 35%.

[0012] A tackifier resin may be added to the primer solution for adjusting the tackiness and adhesive strength. As the tackifier resin, rosin-based, terpene-based, aliphatic petroleum resin, aromatic petroleum resin, styrene resin, xylene resin, alkylphenol resin and the like can be used. The compounding amount of the tackifier resin is preferably 2 to 20 parts by weight based on 100 parts by weight of chloroprene rubber.

The kind of the pressure-sensitive adhesive is not particularly limited, but an acrylic pressure-sensitive adhesive is preferable in terms of weather resistance, and the thickness after coating and drying is preferably 20 to 40 μm. If it is less than 20 μm, sufficient adhesive strength cannot be obtained, and if it exceeds 40 μm, the drying property is poor, the line speed decreases, and the cost is disadvantageous.

Next, in the method of laminating an adhesive sheet according to the second aspect of the present invention, the primer solution used for the adhesive sheet according to the first aspect of the present invention is applied on an existing vinyl chloride resin sheet and dried. In this method, a primer layer is formed, and a new pressure-sensitive adhesive sheet is attached to the surface of the primer layer. It is preferable that the amount of the primer solution applied from above the existing sheet is about 0.1 to 2.0 μm after drying. A method of drying the applied primer solution may be natural drying since it is outdoors, but hot air or hot air may be blown as necessary.

The new pressure-sensitive adhesive sheet used in the construction method according to the second aspect of the present invention may have the above-mentioned primer layer provided between the vinyl chloride resin sheet and the pressure-sensitive adhesive layer. Since the primer layer is formed on the surface, it is not always necessary to have the primer layer.

(Function) In the pressure-sensitive adhesive sheet according to the first aspect of the present invention, a vinyl chloride resin sheet and a pressure-sensitive adhesive layer are laminated via a primer layer, and the primer layer absorbs ultraviolet light with respect to 100 parts by weight of chloroprene rubber. Since 0.5 to 4 parts by weight of an agent was added and the primer solution having a solid content adjusted to 5 to 50% by an organic solvent was applied to the above film and dried, The migration of the ultraviolet absorber to the existing sheet is eased, and the weather resistance of the new adhesive sheet is maintained for a long time. Further, the adhesion between the vinyl chloride resin sheet and the pressure-sensitive adhesive layer is improved by the primer layer.

According to the method of laminating an adhesive sheet according to the second aspect of the present invention, there is no need to separately discard a new sheet on an existing sheet, and the application can be performed only by applying and drying a primer solution. Construction can be done
In addition, since the transfer of the ultraviolet absorbent from the new pressure-sensitive adhesive sheet to the existing sheet is eased after construction, the progress of deterioration of the new pressure-sensitive adhesive sheet is remarkably slowed, and the sheet can be used for a long time.

[0018]

Embodiments of the present invention will be described below. (Examples 1 to 3 and Comparative Examples 1 to 3) According to the composition shown in Table 1, chloroprene rubber, a benzotriazole-based ultraviolet absorber (trade name "Tinuvin P", manufactured by Ciba Geigy) and toluene were mixed uniformly. To prepare a primer solution, and apply this to a vinyl chloride resin sheet (50 μm thick,
Sekisui Chemical Co., Ltd., product name "Tac Paint")
The coating was dried using a Mayer bar to form a primer layer having a thickness of 0.7 μm. As an existing sheet, a vinyl chloride adhesive sheet (trade name “Tac Paint TPS196” manufactured by Sekisui Chemical Co., Ltd.) is attached to the painted steel plate,
Degraded by a tester for a period equivalent to 6 years of outdoor exposure. Examples 1 to 3 and Comparative Examples 1 on the existing sheet
The new pressure-sensitive adhesive sheet prepared in 3 was overlaid and subjected to the same accelerated exposure again, and the color difference was measured using a color difference meter (manufactured by Minolta, CM-3700d). The results are shown in Table 1.

[0019]

[Table 1]

According to Table 1, the pressure-sensitive adhesive sheet of the present invention has a slow change in color difference due to deterioration even when the sheet is overlaid on a deteriorated existing sheet and exposed outdoors, and the deterioration of the pressure-sensitive adhesive layer is suppressed. I understand.

(Examples 4 to 6, Comparative Examples 4 to 6) Example 1
The chloroprene rubber, benzotriazole-based ultraviolet absorber (Ciba Geigy, trade name "Tinuvin P") and toluene were uniformly mixed with the composition shown in Table 2 on the existing sheet deteriorated in the same manner as in Examples 1 to 3. To prepare a primer solution, apply and dry this to a thickness of 0.5 μm
A primer layer is formed, and a vinyl chloride adhesive sheet (Tak Paint TPS26, manufactured by Sekisui Chemical Co., Ltd.)
1)), and the same accelerated exposure was performed again. Then, the color difference was measured, and the results are shown in Table 2.

[0022]

[Table 2]

[0023]

According to the pressure-sensitive adhesive sheet of the present invention, the migration of the ultraviolet absorbent from the vinyl chloride resin base material of the new pressure-sensitive adhesive sheet to the existing sheet is eased, so that the deterioration becomes slow and the durability is excellent. Further, the adhesion between the vinyl chloride resin sheet and the pressure-sensitive adhesive layer is improved by the primer layer. In addition, according to the method for applying and laminating an adhesive sheet of the present invention, there is no need to separately discard a new sheet on an existing sheet, and the application can be performed only by applying and drying a primer solution, so that the workability is excellent. Furthermore, since the transfer of the ultraviolet absorbent from the new pressure-sensitive adhesive sheet to the existing sheet is eased after construction, the durability of the new pressure-sensitive adhesive sheet is excellent.

Claims (2)

[Claims] 1. A pressure-sensitive adhesive sheet comprising a vinyl chloride resin sheet and a pressure-sensitive adhesive layer laminated on one side via a primer layer, wherein the primer layer is 0.5 to 4 parts by weight of an ultraviolet absorber with respect to 100 parts by weight of chloroprene rubber. And a primer liquid having a solid content adjusted to 5 to 50% with an organic solvent, applied to the film and dried. 2. A primer solution comprising 100 parts by weight of chloroprene rubber, 0.5 to 4 parts by weight of an ultraviolet absorber and a solid content of 5 to 50% comprising an organic solvent is applied on an existing pressure-sensitive adhesive sheet and dried to form a primer layer. And a method of laminating the pressure-sensitive adhesive sheet, characterized in that the surface of the pressure-sensitive adhesive layer is formed by laminating a pressure-sensitive adhesive layer on one side of a vinyl chloride resin sheet on the surface of the primer layer.