JPH11106713A - Adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sheet having an excellent anchoring strength to realize an intended color through an increased hiding capability while maintaining properties intrinsic to the substrate sheet, by coating a surface of a synthetic resin sheet with an adhesive composed of a specific ratio of an adhesive base polymer and a pearl pigment. SOLUTION: Used as the synthetic resin sheet is a sheet formed by calendering a soft polyvinyl chloride, etc. It should be >=40 μm and <=120 μm in thickness. A pref. polyvinyl chloride for use is one polymerized in an emulsion or microsuspension, having a particle size of 0.3-0.5 μm and a degree of polymerization of 1,000-5,000. The adhesive is pref. of an acrylic type. A pearl pigment is blended to give a hiding capability to the adhesive. A pref. pearl pigment is a mica coated with titanium dioxide. The coated surface area is 20-50% of the surface area of the mica. The blended amt. is 2-40 pts.wt. based on 100 pts.wt. of the adhesive base polymer.

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 which is cut out into pictures or characters and used for decoration or marking indoors or outdoors, and more particularly to a concealing property for a stuck portion, and an anchor between a base sheet and a pressure-sensitive adhesive. The present invention relates to an adhesive sheet having excellent properties.

[0002]

2. Description of the Related Art Conventionally, there has been known a pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer is formed on one surface of a base material such as a polyvinyl chloride sheet containing a pigment, and laminated on a release sheet via the pressure-sensitive adhesive layer. ing. This adhesive sheet is cut out to a desired picture or character by a cutting machine, attached to a material to be displayed or decorated using an adhesive layer, and exerts a decorative effect by the color or pattern on the surface side of the film. It is. In recent years, it has been used in the field of display such as labels and stickers, signs and advertisements, and the field of fleet marking such as vehicle decoration, instead of painting.

[0003] In the pressure-sensitive adhesive sheet, sheets of colors having weak concealing properties (white, yellow, red, etc.)
When applied to a dark colored adherend, the color of the ground appears mixed,
There is a problem that a desired color cannot be obtained clearly.
In order to solve this problem, it is necessary to enhance the concealment of the sheet.

[0004] For this purpose, the entire surface of the adherend is applied and then applied, the amount of pigment in the sheet is increased, the thickness of the sheet or the pressure-sensitive adhesive layer is increased, the print layer is provided, Is a multi-layered structure, using a gray-colored adhesive to which a white pigment and a black pigment are added.
-43846) and the like.

[0005] According to the above method, the cost and the number of man-hours are very large because a film as a base is applied to the entire surface of the adherend. According to the method (1), the strength of the sheet is reduced, the sheet is easily torn, and the workability is deteriorated. According to the method described above, the stiffness of the sheet is increased, and the workability on a curved surface is deteriorated.
In either method, the number of manufacturing steps is increased, resulting in an increase in cost. Is an effective method, but depending on the color of the sheet, the color of the adhesive may appear and the color saturation of the sheet may decrease.

[0006] Further, since the positioning of the pressure-sensitive adhesive sheet used in the above-mentioned applications is important at the time of construction, the adhesive sheet is frequently peeled off and re-stretched during the construction, and further, after the elapse of a certain period of time after the construction, re-placing is performed. Sometimes. At this time, if the adhesive strength between the base sheet and the pressure-sensitive adhesive layer (hereinafter referred to as "anchor force") is low, a large amount of adhesive remains on the adherend, and the work of wiping it with a solvent or the like becomes necessary, thereby increasing the amount of work on site. I do.
As a means for solving this problem, it is known that a base sheet is subjected to a primer treatment or a corona discharge treatment to increase the anchoring force (for example, see JP-A-51-919).
No. 44).

[0007] The treatment method described in the above publication and other conventional primer treatments and corona discharge treatments require extra work in the manufacturing process, and require equipment and an environment for treatment. There is a problem of inviting high prices.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, improves the concealment property while maintaining the original physical properties of the base sheet, and enables the desired color to be exhibited. It is an object to provide a pressure-sensitive adhesive sheet having the same.

[0009]

Means for Solving the Problems The pressure-sensitive adhesive sheet of the present invention comprises:
On one side of the synthetic resin sheet, an adhesive base polymer 100
It is characterized in that an adhesive comprising 2 parts by weight and 2 to 40 parts by weight of a pearl pigment is laminated.

The synthetic resin sheet used in the present invention includes:
Soft polyvinyl chloride, polyethylene terephthalate, polyurethane and the like can be mentioned, but soft polyvinyl chloride is particularly preferred from the viewpoint of flexibility, weather resistance and the like. As the soft polyvinyl chloride sheet, a calender-formed sheet or a cast-molded sheet obtained by casting a vinyl chloride sol dispersed in a solvent on a process paper, drying and curing the resultant is used. If the thickness of the synthetic resin sheet is less than 40 μm, the tensile strength is low and the workability is poor, and if it exceeds 120 μm, the sheet is hard and the workability is poor.

When polyvinyl chloride is used, the particle diameter of the polymerized emulsion or microsuspension is 0.3 to 0.5 μm, and the degree of polymerization is 1000 to 500.
0 is preferred. Further, polyvinyl chloride is usually used by adding a plasticizer, a pigment, a solvent, a heat stabilizer, an extender, an ultraviolet absorber and the like.

As the plasticizer, tributyl phosphate,
Phosphate plasticizers such as tri-2-ethylhexyl phosphate and triphenyl phosphate, diethyl phthalate, and di-phthalate
Phthalic acid plasticizers such as 2-ethylhexyl and diisononyl phthalate, dibutyl adipate, and di-n-adipate
And adipic acid plasticizers such as hexyl, di-2-ethylhexyl adipate and diisononyl adipate.

As the pigment, those conventionally used for coloring, such as azo type, phthalocyanine type, sullen type, dye lake, carbon black and titanium white, are used.

Solvents for polyvinyl chloride sols include a dispersion solvent which slightly swells the resin at room temperature to promote dispersion, and a diluting solvent which is insoluble in the resin to lower the sol viscosity and suppress the swelling of the dispersion solvent. Are mixed and used.

Examples of the heat stabilizer include epoxidized alicyclic compounds such as epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil, organic heat stabilizers such as epoxidized polybutadiene and tributyl phosphite, and Ba. / Zn
And a metal-based heat stabilizer such as a Ba / Pb-based or Ca / Zn-based metal. In particular, epoxidized soybean oil is preferable because it functions not only as a heat stabilizer but also as a plasticizer.

Examples of the extender include calcium carbonate, talc, kaolin and the like. Examples of the ultraviolet absorber include salicylic acid, O-hydroxybenzophenone, O-hydroxyphenylbenzotriazole and the like.

The adhesive used in the present invention may be a general-purpose adhesive such as a rubber type, an acrylic type and a silicone type.
Acrylic materials are preferred in terms of weather resistance and the like. A pearl pigment is blended with the pressure-sensitive adhesive in order to impart hiding power. Even if titanium oxide other than the pearl pigment is added to the adhesive, the concealing property can be obtained, but using the pearl pigment increases the concealing property even with the same blending amount. This is probably because the pearl pigment is composed of two layers having different refractive indices, a titanium dioxide layer and a mica layer, and reflects light well. Examples of the pearl pigment include mica, fish scale, bismuth, and lead, and mica coated with titanium dioxide is preferable in consideration of the effect on the environment.

Titanium dioxide-coated mica refers to titanium dioxide deposited as oxyhydroxide on the surface of mica,
By roasting, the mica surface is coated with titanium dioxide. The coating of the mica with titanium dioxide is not complete and is 20-50% of the mica surface area. The finer the particle size, the better the concealing property is, but the particle size is preferably 5 to 80 μm. If it exceeds 80 μm, the concealing property may be poor even with the same compounding amount.

The pearl pigment is blended in an amount of 2 to 40 parts by weight based on 100 parts by weight of the base polymer of the pressure-sensitive adhesive. If the pearl pigment is less than 2 parts by weight, the concealing effect is hardly exhibited, and if it exceeds 40 parts by weight, the concealing property is increased but the anchoring property to the synthetic resin sheet is significantly reduced.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below. Molding of flexible polyvinyl chloride sheet Polyvinyl chloride (manufactured by Kaneka Chemical Co., product number "PSH-10") 100 parts by weight Polyester plasticizer (manufactured by Asahi Denka Co., product number "P-300") 30 parts by weight White pigment ( 20 parts by weight of heat stabilizer (manufactured by Asahi Denka Co., Ltd., product number "MARK AR551") 5 parts by weight UV absorber (manufactured by Sumitomo Chemical Co., Ltd., trade name "Sumisorb 140") 1 part by weight Solvent (manufactured by Exxon Chemical Co., trade name "Solvesso 100") 60 parts by weight The above polyvinyl chloride sol is cast on process paper and has a thickness of 50 parts.
A μm sheet was obtained.

(Examples 1 to 7) After the compositions shown in Table 1 were stirred, both sides of high-quality paper were polyethylene-laminated, coated on a release paper that had been subjected to a release treatment, and dried to obtain a 30 μm-thick pressure-sensitive adhesive layer. Was formed. The pressure-sensitive adhesive layer was bonded to the polyvinyl chloride sheet at 40 ° C. to obtain a pressure-sensitive adhesive sheet. FIG. 1 is a cross-sectional view showing the pressure-sensitive adhesive sheet of the above embodiment, wherein 1 is a polyvinyl chloride sheet, 2 is a pressure-sensitive adhesive layer, and 3 is a release paper.

(Comparative Examples 1 to 8) Using the compounds shown in Table 2, adhesive sheets were obtained in the same manner as in the examples.

[0023]

[Table 1]

[0024]

[Table 2] [Note] Acrylic adhesive: (manufactured by Soken Chemical Co., Ltd., product number "SK
-1335 ") Curing agent: (manufactured by Soken Chemical Co., product number" M-5A ") Pearl pigment: (manufactured by Merck Japan, product number" Irio "
din103 "and" Iriodin111 ") Titanium oxide: (manufactured by Dainichi Seika Co., Ltd.) Carbon black: (manufactured by Nishimura Graphite Co., Ltd.) The compounding amount is part by weight.

The pressure-sensitive adhesive sheets obtained in the above Examples and Comparative Examples were evaluated for the following items. (1) Total light transmittance A turbidimeter (manufactured by Nippon Denshoku Co., model number "NDH-300A") is used. (2) Concealing property The adhesive surface of the prepared sample was coated with a white marking film (manufactured by 3M, trade name “Scotch Film 3650”, thickness 50 μm) and a black marking film 3M,
(Product name "Scotch film 3655", thickness 50μm)
And cut into 10 cm × 10 cm. The two colors were visually compared, and the concealment was measured according to the following evaluation criteria. (Evaluation criteria) ◎ ・ ・ ・ No difference ○ ・ ・ ・ There is a slight difference, but there is no problem in use △ ・ ・ ・ Slight difference, sometimes unusable × ・ ・ ・ There is a difference, use Impossible

(3) Anchor Force An anchor agent (manufactured by Nippon Shokubai Co., Ltd., trade name "Polyment NK-350") is applied to one surface of a stainless steel plate at a thickness of 1 μm, and the above sample cut into a width of 25 mm is pressed by 2 kg. After the roller was reciprocated two times and left at 23 ° C. for 36 hours, the anchor was broken by a tensile tester, and the 180 ° peeling force was measured.

(4) Adhesive Remaining Property The sample cut into a width of 25 mm on one surface of a stainless steel plate was adhered by reciprocating a 2 kg pressure roller two times.
After standing at 144 ° C. for 144 hours, a peeling test (peeling speed: about 1000 mm / min) was performed manually.
The adhesive residue was measured according to the following evaluation criteria. (Evaluation criteria) 5: No glue residue 4 ... Glue residue 10% or less 3 ... Glue residue 20% or less 2 ... Glue residue 50% or less 1 ... Overall glue residue

The above results are shown in Tables 1 and 2.

As is clear from Tables 1 and 2, the pressure-sensitive adhesive sheet according to the present invention was satisfactory in all items, but none of the comparative examples was practical.

[0030]

According to the pressure-sensitive adhesive sheet of the present invention, a pressure-sensitive adhesive containing 100 parts by weight of a pressure-sensitive adhesive base polymer and 2 to 40 parts by weight of a pearl pigment is used. It has an anchor property. In addition, it is possible to enhance the concealing property while maintaining the original physical properties of the synthetic resin sheet, so that a desired color can be obtained. Further, since the pearl pigment is used, a higher concealing property can be obtained as compared with the case where titanium oxide is used in the same amount. Therefore, it can be suitably used for decoration and marking indoors and outdoors.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the pressure-sensitive adhesive sheet of the present invention.

[Explanation of symbols]

 1: polyvinyl chloride sheet 2: adhesive layer 3: release paper

Claims (1)

[Claims] 1. A pressure-sensitive adhesive sheet comprising a synthetic resin sheet and a pressure-sensitive adhesive comprising 100 parts by weight of a pressure-sensitive adhesive base polymer and 2 to 40 parts by weight of a pearl pigment laminated on one surface of the synthetic resin sheet.