JPH10140102A - Production method of adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a pressure-sensitive adhesive tape, particularly a pressure-sensitive adhesive tape in which the facing material is a flexible or semi-rigid polyvinyl chloride film with a glossy surface and is kept glossy even in a finished sheet. SOLUTION: The production process comprises coating a release sheet with a pressure-sensitive adhesive, drying the adhesive and sticking the coated sheet to a facing material with laminator rolls. In this process, the facing material should be a film of a polyvinyl chloride containing at least 5wt.% placsticizer, and the temperature of the facing material and that of the release sheet should be each 50 deg.C or below when they are stuck to each other with a laminator rolls.

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, and more particularly to a pressure-sensitive adhesive sheet having a glossy surface made of a soft or semi-rigid polyvinyl chloride film as a surface substrate and having a glossiness even after finishing the pressure-sensitive adhesive sheet. And a method for producing the same.

[0002]

2. Description of the Related Art Adhesive sheets are widely used in the form of labels, stickers, patches, delivery slips and the like for commercial use, office work, process management, distribution management, home use, and the like. To explain the general structure of this adhesive sheet,
This is a state in which an adhesive is sandwiched between the surface base material and the release sheet, and paper, foil, film, or the like is used as the surface base material. Examples of the release sheet include high-density base paper such as glassine paper, clay-coated paper, kraft paper or high-quality paper, etc., laminated with a resin film such as polyethylene, or kraft paper, high-quality paper, etc. with polyvinyl alcohol, starch, etc. A resin-coated base paper or the like provided with a coating layer mainly containing a water-soluble polymer or the like and a pigment is coated with a release agent such as a silicone compound or a fluorine compound. Emulsions such as rubber-based, acrylic-based, vinyl ether-based, urethane-based and styrene-butadiene-based adhesives, and various types of solvent-based or solvent-free adhesives are used as the adhesive. Thus, pressure-sensitive adhesive sheets are provided in various forms by combining a surface substrate, a release substrate, and a pressure-sensitive adhesive.

[0003]

However, when a soft or semi-rigid polyvinyl chloride film having a high surface gloss (hereinafter abbreviated as a soft or semi-rigid PVC film) is used as the surface substrate, There has been a problem that the glossiness of the surface of the rigid PVC film is extremely reduced, and the commercial value is lost.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on a pressure-sensitive adhesive sheet using a soft or semi-rigid PVC film. Soft or semi-rigid PVC films are
Dioctyl phthalate, phthalates such as dibutyl phthalate, dioctyl adipate, linear dibasic acid esters such as dioctyl azelate, because it contains a large amount of low-molecular plasticizers such as phosphates, When producing a pressure-sensitive adhesive sheet having a soft or semi-rigid PVC film as a surface base material, the glossiness of the surface of the flexible PVC film is extremely reduced if the film is wound at a high temperature under a strong pressure,
We found that the product value was lost.

In view of this situation, the present inventors have applied the adhesive to the release sheet, dried it, and then bonded the surface substrate with a laminator roll at a specific substrate temperature. Found that
The present invention has been completed.

According to the present invention, there is provided a method for producing a pressure-sensitive adhesive sheet by applying a pressure-sensitive adhesive to a release sheet, drying the resultant, and then bonding the surface substrate with a laminator roll. A method for producing a pressure-sensitive adhesive sheet, comprising the above-mentioned polyvinyl chloride film, wherein the temperature of the surface substrate and the release sheet when the surface substrate is bonded by a laminator roll is 50 ° C. or less.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a pressure-sensitive adhesive is applied to a release sheet, dried and then adhered to a surface substrate with a laminator roll to produce a pressure-sensitive adhesive sheet. The temperature at the time of bonding is an important requirement, that is, the temperature of the surface substrate and the release sheet at the time of bonding with a laminator roll is 50 ° C. or less. When the temperature of the surface substrate or the release sheet exceeds 50 ° C., the low-molecular plasticizer present in the soft or semi-rigid PVC film further plasticizes the PVC resin from room temperature, and causes fine irregularities on the back surface of the release sheet (hereinafter referred to as “recess”). In some cases, the glossiness of the surface of the soft or semi-rigid PVC film is extremely reduced, and the commercial value is lost. In addition, the pressure at the time of laminating with a laminator roll is 30 kg / cm.
The following is particularly preferred. By the way, when the pressure at the time of bonding exceeds 30 kg / cm, it may be due to copying the unevenness on the back surface of the release sheet, or by using soft or semi-hard P
The glossiness of the VC film surface is extremely reduced. In particular, when the temperature exceeds 50 ° C. and the pressure during bonding is 30
If it exceeds Kg / cm, the gloss is remarkably reduced.

[0008] Further, when the laminator roll is a cooling roll, the substrate temperature can be kept low even when running for a long time, which is one of the preferred embodiments.

The surface substrate used in the present invention is a soft or semi-rigid PVC film, and phthalic acid esters such as dioctyl phthalate and dibutyl phthalate, adipine are added to 100 parts by weight of the rigid PVC resin. Low molecular weight plasticizers such as linear dibasic acid esters such as dioctyl acid and dioctyl azelate, and phosphoric esters;
可塑 60 parts by weight are blended to form a film (one containing 5 to 24 parts by weight of a plasticizer is called semi-hard, and one containing 25 parts by weight or more is called soft).

The pressure-sensitive adhesive used in the present invention is not particularly limited, and may be a rubber type, an acrylic type, a vinyl ether type,
Emulsions such as urethane type and styrene-butadiene type, and various types of pressure-sensitive adhesives of the solvent or non-solvent type may be mentioned. More preferably, the following acrylic graft polymer is dissolved in an organic solvent as described in JP-A-8-165462. (A) or the following acrylic block polymer (b) in a dissolved and / or dispersed state. (A) Presence of a high glass transition temperature type polymer having a glass transition temperature of 273 K or more which is incompatible with a polymer of the monomer mixture containing the alkyl (meth) acrylate monomer. An acrylic graft copolymer produced by a production method including a polymerization step of copolymerizing under the following conditions. (B) An acrylic block polymer produced by a production method including a preparation step, a first polymerization step, an addition step, and a second polymerization step. In addition, the preparation process was performed using a polyvalent mercaptan and 273.
This is a step of preparing a first mixture containing a first α, β-unsaturated monomer capable of producing a high glass transition temperature type polymer having a glass transition temperature of K or higher. The first polymerization step starts with the mercapto group of the polyvalent mercaptan as a starting point.
Is a step of obtaining a reaction mixture by performing radical polymerization of α, β-unsaturated monomers. The adding step is a reaction in which a monomer mixture containing a (meth) acrylic acid alkyl ester monomer, which can form a polymer incompatible with the high glass transition temperature type polymer, is obtained in the first polymerization step. Second in addition to the mixture
This is a step of obtaining a mixture. The second polymerization step is a step of performing radical polymerization of the monomers contained in the second mixture.

Further, the monomer mixture used for producing the acrylic graft polymer (a) or the acrylic block polymer (b) contains a reactive functional group-containing α,
It may contain a β-unsaturated monomer. When the monomer mixture contains a reactive functional group-containing α, β-unsaturated monomer, the monomer mixture may contain a crosslinking agent having at least two functional groups capable of reacting with the reactive functional group.

The pressure-sensitive adhesive of the present invention may contain a tackifier usually used for a pressure-sensitive adhesive, if necessary. Examples of the tackifier include (polymerized) rosin type, (polymerized) rosin ester type, terpene type, terpene phenol type, cumarone type, coumarone indene type, styrene resin type, xylene resin type, phenol resin type, petroleum resin type, etc. Is mentioned. These can be used alone or in combination of two or more. The amount of the tackifier is, for example, 5 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the acrylic copolymer (a) or (b). If the amount is less than 5 parts by weight, the adhesive strength to the adherend may not be improved, and if it exceeds 100 parts by weight, tackiness may decrease and adhesiveness may decrease.

The pressure-sensitive adhesive of the present invention may contain a filler, a pigment, a diluent, an antioxidant, and an ultraviolet absorber, which are usually used for the pressure-sensitive adhesive, whether or not they contain a tackifier. , At least one additive selected from the group consisting of UV stabilizers and the like.

In the method for forming the pressure-sensitive adhesive sheet of the present invention, a pressure-sensitive adhesive is coated on the release layer of the release sheet, and if necessary, dried to form a pressure-sensitive adhesive layer. The back surface of the film is bonded and finished under the above specific conditions. In addition, as an apparatus for applying an adhesive, for example, a reverse roll coater, a knife coater, a bar coater, a die coater, a gear-in die coater, a slot die coater, an air knife coater,
A reverse gravure coater, a vario gravure coater, or the like is appropriately used. The coating amount of the adhesive is 5 to 5% by dry weight.
40 g / m ^2, and more preferably is adjusted in the range of about 15 to 30 g / m ^2. By the way, when the coating amount is less than 5 g / m ² , the adhesive performance of the obtained pressure-sensitive adhesive sheet becomes insufficient, and when the coating amount exceeds 40 g / m ² , the adhesive protrudes or cohesive failure occurs at the time of peeling. May cause.

The release sheet for covering the pressure-sensitive adhesive layer is not particularly limited, and paper such as high-density base paper such as glassine paper, clay-coated paper, kraft paper or high-quality paper laminated with a film such as polyethylene, Fluorine resin, silicone resin, etc. are applied on paper coated with polyvinyl alcohol, acrylate copolymer resin, etc. to a dry weight of about 0.1 to 3 g / m ² , and then heat cured or ionized radiation. What provided the release agent layer by hardening etc. is used suitably. As a coating device in this case, a bar coater, an air knife coater, a direct gravure coater, an offset gravure coater, a multi-stage roll coater, or the like is appropriately used.

[0016]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto. In addition, all parts and weights in the examples are indicated by solid content weight unless otherwise specified.

Example 1 [Production of adhesive sheet] Release paper (trade name "Separate 11")
0EPS (P) Blue ", Oji Paper Co., Ltd.) to the acrylic pressure-sensitive adhesive (trade name" Arosetto XYM4-4D ", coating with a knife coater so that the 23 g / m ² by dry weight manufactured by Nippon Shokubai), and dried Then, semi-hard milky white P as a surface substrate
VC film (glossy) (Product name "Aponil # 100",
(A plasticizer content of 15.25%, manufactured by Riken Vinyl Co., Ltd.) was laminated with a laminator roll under the conditions shown in Table 1 to obtain an adhesive sheet of the present invention.

Example 2 [Production of adhesive sheet] Release paper (trade name "Separate 11")
0EPS (N) Cream ", Oji Paper Co., Ltd.) to the acrylic pressure-sensitive adhesive (trade name" Arosetto XYR-21D ", coated with a knife coater so that the 25 g / m ² by dry weight manufactured by Nippon Shokubai), and dried Then, a semi-rigid milky white PVC film (glossy) (trade name “APONYL # 10
0 ", a plasticizer content of 15.25%, manufactured by Riken Vinyl Co., Ltd.) with a cooling laminator roll under the conditions shown in Table 1 to obtain an adhesive sheet of the present invention.

Example 3 An adhesive sheet was obtained in the same manner as in Example 2 except that the temperature, pressure, and tension for laminating the surface base material with a laminator roll were changed.

Example 4 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the temperature, pressure, and tension for laminating the surface substrate with a laminator roll were changed.

Example 5 [Production of adhesive] 210 parts by weight of ethyl acetate, polystyrene (trade name "Stylon 666R", manufactured by Asahi Kasei Corporation)
00 parts by weight was charged into a four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet tube, a reflux condenser, and a dropping funnel, and polystyrene was dissolved in ethyl acetate. Then, 139.6 parts by weight of 400 parts by weight of a monomer mixture of 379.6 parts by weight of butyl acrylate, 20 parts by weight of acrylic acid, and 0.4 parts by weight of 2-hydroxyethyl acrylate were added to the flask.
3.3 parts by weight were charged. While stirring the content of the flask under a nitrogen stream and maintaining the content at 80 ° C., the content was added to the content with an organic peroxide as a polymerization initiator (trade name “Niper BMT-K4”).
0 "(manufactured by NOF Corporation) was added to initiate polymerization. Ten minutes after the start of the polymerization, the remainder (266.7 parts by weight) of the monomer mixture, 76 parts by weight of toluene, 76 parts by weight of ethyl acetate, and an organic peroxide (trade name: Niiper BM)
0.8 parts by weight of “T-K40”, manufactured by NOF CORPORATION) over 1.5 hours.
3 parts by weight of toluene, 490 parts by weight of toluene, and 1.2 parts by weight of 2,2′-azobis (2-methylbutyronitrile) (manufactured by Nippon Hydrazine Industry) were reacted at 85 ° C. for 5 hours. 5%, viscosity 3670 cps (25 ° C.,
(B-type viscometer) to obtain a solution of an acrylic copolymer. A polyisocyanate compound (trade name “Coronate L”) was added to a solution (solid content: 100 parts by weight) of the acrylic copolymer.
55E "(manufactured by Nippon Polyurethane) (55% solids) was mixed in an amount of 0.55 part by weight to produce a pressure-sensitive adhesive composition.

[0022] [Adhesive Sheet production] release paper (trade name "Separate 110EPS (P) Blue", Oji Paper Co., Ltd.) coated with a knife coater so that the 23 g / m ² by dry weight of the above acrylic adhesive After drying, a semi-rigid milky white PVC film (glossy) (trade name "Aponil # 100", plasticizer content 15.25%, manufactured by Riken Vinyl) was used as a surface substrate with a laminator roll under the conditions shown in Table 1. The adhesive sheet of the present invention was obtained by bonding.

Example 6 [Production of pressure-sensitive adhesive sheet] Release paper (trade name "Separate 11")
0EPS (P) Blue ", Oji Paper Co., Ltd.) to the acrylic pressure-sensitive adhesive (trade name" Nikasol KP-1954 ", the coating with a knife coater so as to 23g / m ² by dry weight of the Nippon Carbide), and dried Then, a semi-rigid milky white PVC film (glossy) (trade name “APONYL # 10
0 ", a plasticizer content of 15.25%, manufactured by Riken Vinyl Co., Ltd.) with a cooling laminator roll under the conditions shown in Table 1 to obtain an adhesive sheet of the present invention.

Comparative Example 1 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the temperature, pressure and tension used for laminating the surface substrate with a laminator roll were changed.

Table 1 shows the conditions at the time of bonding and the results of visual judgment of the appearance (gloss) of the product in the above Examples and Comparative Examples.

The evaluation criteria for the appearance of the product are shown below. A: It is glossy and very excellent as a PVC tack film. ：: The gloss is slightly lowered, but is at a practically usable level as a PVC tack film. X: There is no gloss and the level cannot be used as a PVC tack film.

[0027]

[Table 1]

From Table 1, it can be seen that the temperature at which the laminator roll is used to bond the surface base material to 50 ° C. or less is
It can be seen that the product shows an excellent product appearance as a VC film tack.

[0029]

As is clear from the examples, the pressure-sensitive adhesive sheet obtained by the production method of the present invention does not decrease in gloss and shows excellent product appearance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 220: 12) (C08F 297/00 220: 12)

Claims (5)

[Claims] 1. A method for producing a pressure-sensitive adhesive sheet by applying a pressure-sensitive adhesive to a release sheet, drying the pressure-sensitive adhesive, and then laminating the surface substrate with a laminator roll, wherein the surface substrate contains 5% or more of a plasticizer. A method for producing a pressure-sensitive adhesive sheet, wherein the temperature of the surface substrate and the release sheet when the surface substrate is bonded with a laminator roll is 50 ° C. or less. 2. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein the pressure at the time of laminating the surface substrate with the laminator roll is 30 kg / cm or less. 3. The adhesive according to claim 1, wherein the pressure-sensitive adhesive contains the following acrylic graft copolymer (a) or the following acrylic block copolymer (b) dissolved and / or dispersed in an organic solvent. The method for producing the pressure-sensitive adhesive sheet according to the above. (A) using a (meth) acrylic acid alkyl ester monomer mixture at a temperature of 273 K which is incompatible with the polymer of the monomer mixture;
An acrylic graft copolymer produced by a production method including a polymerization step of copolymerizing in the presence of a high glass transition temperature type polymer having the above glass transition temperature. (B) An acrylic graft copolymer produced by a production method including the following preparation step, first polymerization step, addition step, and second polymerization step. Preparing step: preparing a first mixture containing a polyvalent mercaptan and a first α, β-unsaturated monomer capable of producing a high glass transition temperature type polymer having a glass transition temperature of 273 K or higher. First polymerization step: A step of obtaining a reaction mixture by performing radical polymerization with a first α, β-unsaturated monomer starting from a mercapto group of a polyvalent mercaptan. Addition step: A reaction mixture obtained in the first polymerization step, which is capable of forming a polymer incompatible with the high glass transition temperature type polymer and containing a monomer mixture containing an alkyl (meth) acrylate monomer Obtaining a second mixture in addition to the above. Second polymerization step: a step of performing radical polymerization of the monomers contained in the second mixture. 4. The method according to claim 1, wherein the tension at the time of laminating the surface substrate with the laminator roll is 200 g / cm or less.
4. The method for producing a pressure-sensitive adhesive sheet according to 3. 5. The method according to claim 1, wherein the laminator roll is a cooling roll.