JP2003311934A - Tacky sheet for cleaning screen printing plate wound in roll - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tacky sheet for cleaning a screen printing plate which prevents paper dust from being generated during winding back the tacky sheet, and removes a paste finding its way around to the back of a screen printing plate, by securely making the paper dust stick to the tacky sheet, even when the tacky sheet is of such a type wound in roll. <P>SOLUTION: This tacky sheet for cleaning the screen printing plate wound in roll is constituted of a base material and a pressure-sensitive adhesive layer formed on one side of the base material, while the other side is a releasable face, and wound in roll with the pressure-sensitive layer superposed on the releasable face. Further, a winding core used for winding the tacky sheet in roll is made of plastics. The releasable face on the other side of the base material may be back-treated using a back treating agent. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning pressure-sensitive adhesive sheet for removing paste (ink) on the back side of a screen printing plate during screen printing.

[0002]

2. Description of the Related Art In screen printing, after a certain number of times of printing, the paste (ink) backs up on the screen printing plate to contaminate the printed material or bleeding of the printed image, resulting in accurate and beautiful printing. It will be in a state where you can not. Conventionally,
In order to prevent such bleeding at the time of screen printing, a method is known in which the paste lined on the back side of the plate is removed using an adhesive sheet.

Such a pressure-sensitive adhesive sheet is usually provided by winding a long sheet in a roll shape, and is applied to a screen printing plate while rewinding a necessary amount of the pressure-sensitive adhesive sheet at the time of use. However, when the pressure-sensitive adhesive sheet is rewound, paper dust or the like is generated from the core, and the paper dust adheres to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet, and the paste that has spread around the back side of the screen printing plate can be removed cleanly. However, there is a problem in that the removal of the paste becomes uneven (for example, the paste is left behind).

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to prevent the generation of paper dust during rewinding of the pressure-sensitive adhesive sheet even when the pressure-sensitive adhesive sheet for cleaning a screen printing plate is wound in a roll shape. Then, it is an object of the present invention to provide a pressure-sensitive adhesive sheet for cleaning a screen printing plate, which is capable of surely adhering and removing the paste coated on the back side of the screen printing plate and having a high cleaning effect.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object, and as a result, when the core of the pressure-sensitive adhesive sheet wound into a roll is a plastic molded product, the pressure-sensitive adhesive sheet is obtained. It has been found that generation of paper dust and the like is prevented at the time of rewinding, and as a result, it is possible to surely and promptly attach and remove the paste backing on the back side of the screen printing plate. The present invention has been completed based on these findings.

That is, the present invention comprises a base material and a pressure-sensitive adhesive layer formed on one surface of the base material, and the other surface of the base material is a release surface. A pressure-sensitive adhesive sheet for screen printing plate cleaning, wherein the pressure-sensitive adhesive layer is superposed on and wound in a roll, wherein the core when wound in a roll is a plastic core. Provided is a pressure-sensitive adhesive sheet for cleaning a screen printing plate, which is wound in a roll shape.

The peeling surface on the other surface of the base material may be a surface that has been subjected to a back treatment with a back treatment agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Adhesive sheet for cleaning a screen printing plate of the present invention (may be simply referred to as "adhesive sheet")
Then, it is an important point that it is wound in a roll shape using a plastic core. Thus, the pressure-sensitive adhesive sheet of the present invention, since the core when winding in a roll is a plastic core, the occurrence of paper dust when rewinding the pressure-sensitive adhesive sheet wound in a roll There is no fear of this, and the generation of such paper dust is effectively prevented. Therefore, when the pressure-sensitive adhesive sheet is adhered to the screen printing plate to remove the paste spread on the back side of the screen printing plate, the pressure-sensitive adhesive sheet is peeled from the pressure-sensitive adhesive layer side surface of the pressure-sensitive adhesive sheet to form a pressure-sensitive adhesive sheet. Even when rewound, paper powder etc. does not adhere to the pressure-sensitive adhesive sheet (particularly the surface of the pressure-sensitive adhesive layer), so the adhesiveness with the screen printing plate is excellent and the reduction in the removability of the paste is suppressed or prevented. Therefore, the paste can be surely attached to the pressure-sensitive adhesive sheet and can be removed neatly.

The material of the plastic core is not particularly limited as long as it is a plastic material.
Polyolefin resin such as polyethylene, polypropylene, ethylene-propylene copolymer; polyester resin such as polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate; methacrylate resin such as polymethylmethacrylate (PMMA); polystyrene, acrylonitrile −
Styrene-based resins such as styrene copolymer (AS resin) and acrylonitrile-butadiene-styrene copolymer (ABS resin); polyamide; polycarbonate (PC);
Polyacetal; Polyimide; Polybutyl acrylate,
Polyacrylic acid esters such as polyethyl acrylate; polyvinyl chloride; epoxy resin; polyurethane;
Examples include plastic materials such as phenolic resin; melamine resin; fluororesin. The plastic materials may be used alone or in combination of two or more.

The size and shape of the plastic core are not particularly limited, and can be appropriately selected depending on the target pressure-sensitive adhesive sheet wound into a roll. For example, the shape of the plastic winding core may be a cylindrical shape or the like. As for the size of the plastic core, in the case of a cylindrical core, the inner diameter thereof is usually about 2.0 to 8.0 cm.

As described above, the pressure-sensitive adhesive sheet of the present invention has the pressure-sensitive adhesive layer formed on one surface of the base material, the other surface of the base material functions as a peeling surface, and is made of plastic. It has a state or form in which a pressure-sensitive adhesive layer is superposed on the release surface by a winding core and wound in a roll shape.
As such a peeling surface, the surface of the base material itself may be used as it is, but it is preferable that it is a surface that has been subjected to a back surface treatment with a back surface treating agent (back surface treated surface). That is,
On the release surface (other surface) side of the base material, a release treatment layer composed of a back surface treatment agent can be formed. Specifically, the pressure-sensitive adhesive sheet of the present invention is composed of a base material, a pressure-sensitive adhesive layer formed on one surface of the base material, and a release treatment layer formed on the other surface of the base material. Further, a pressure-sensitive adhesive sheet can be used in which a pressure-sensitive adhesive layer is superposed on the release surface (the surface of the release treatment layer) by a plastic core and wound in a roll.

The base material in the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but a polyolefin film such as a polyethylene film or a polypropylene film; a plastic film such as a polyester film such as a polyethylene terephthalate film may generate paper dust. It is preferably used without. Depending on the application, paper, foam, non-woven fabric, cloth, metal foil or the like can be used as the substrate.

The thickness of the base material is not particularly limited and may be appropriately set in consideration of strength, workability and the like, but generally 10 to 5
The thickness is 00 μm, preferably 12 to 200 μm, and more preferably 15 to 100 μm.

The substrate may have a single-layer form or a multi-layer form.

In the present invention, a base material having releasability can also be used as the base material.

The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention is not particularly limited as long as it has a paste (ink) removing function, and examples thereof include a rubber-based pressure-sensitive adhesive (for example, a natural rubber-based pressure-sensitive adhesive). Any pressure-sensitive adhesive such as pressure-sensitive adhesive, styrene-butadiene copolymer-based pressure-sensitive adhesive, polyisobutylene-based pressure-sensitive adhesive, styrene-isoprene-styrene copolymer-based pressure-sensitive adhesive), acrylic pressure-sensitive adhesive, etc. can be used. Among these adhesives, acrylic adhesives are preferable. The adhesive can be used alone or in combination of two or more.

The acrylic pressure-sensitive adhesive is generally formed of a main monomer that imparts tackiness, a comonomer that imparts cohesiveness, and a functional group-containing monomer that improves tackiness or forms a cross-linking point. Examples of the main monomer include ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2-acrylic acid acrylate.
_Examples thereof include acrylic acid C _2-10 alkyl esters such as ethylhexyl, nonyl acrylate, and decyl acrylate.

The comonomers which impart the aggregating property include
For example, methyl acrylate; methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate; vinyl esters such as vinyl acetate; styrene-based monomers such as styrene, α-methylstyrene, vinyltoluene; acrylonitrile, etc. Can be mentioned. Among these, vinyl esters and acrylonitrile are preferable.

Examples of the functional group-containing monomer include carboxyl group or acid anhydride group-containing monomer such as acrylic acid, methacrylic acid, itaconic acid, maleic anhydride; 2-hydroxyethyl acrylate, methacrylic acid 2
-Hydroxy group-containing monomers such as hydroxyethyl and hydroxypropyl methacrylate; epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; amide group-containing monomers such as N-methylol acrylamide and N-methylol methacrylamide; dimethylamino methacrylate Examples thereof include amino group-containing monomers such as ethyl and t-butylaminoethyl methacrylate. Among these, as a functional group-containing monomer,
A carboxyl group- or acid anhydride group-containing monomer such as acrylic acid is preferable.

The proportions of the main monomer, comonomer and functional group-containing monomer forming the acrylic pressure-sensitive adhesive can be appropriately selected depending on the type of paste (ink) to be removed (type of solid content and type of solvent) and the like. , For example, as a ratio to the total monomer components, the main monomer is
40-98% by weight, preferably 50-95% by weight, the comonomer is 0-50% by weight, preferably 2-40% by weight, and the functional group-containing monomer is 0.5- It is about 15% by weight, preferably about 1 to 10% by weight.

In the pressure-sensitive adhesive layer, in addition to the pressure-sensitive adhesive polymer (base polymer), various additives such as a crosslinking agent (for example, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a urea-based crosslinking agent, a melamine-based crosslinking agent). Agent, carboxylic acid or acid anhydride-based crosslinking agent, metal compound-based crosslinking agent, etc.), tackifier [for example, terpene resin (terpene resin, terpene phenol resin, aromatic modified terpene resin, hydrogenated terpene resin, etc.), Petroleum resin (aliphatic, aromatic, alicyclic), rosin resin (rosin, hydrogenated rosin ester, etc.), coumarone / indene resin, styrene resin, etc.],
Surfactants (phosphate-based, sulfate-based, sulfonic acid-based, carboxylic acid-based anionic surfactants;
Cationic surfactants such as amine salt type and quaternary ammonium salt type; Nonionic type surfactants such as ester type, ether type, ester ether type and alkanolamide type; amphoteric surface active agents such as carboxybetaine type and glycine type Agent), plasticizer, antioxidant, colorant, antistatic agent,
A filler, a foaming agent, etc. may be contained. Preferred crosslinking agents include isocyanate crosslinking agents, and preferred tackifiers include terpene resins such as terpene phenolic resins.

The amount of these additives used can be appropriately selected within a range that does not impair the tackiness and the like. For example, the amount of the crosslinking agent used is, for example, about 1 to 30 parts by weight, and preferably 2 to 100 parts by weight of the adhesive polymer (base polymer).
It is about 15 parts by weight.

In the present invention, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer may be composed only of a component insoluble in the solvent contained in the screen printing paste to be removed. For example, additives other than the cross-linking agent, particularly plasticizers and surfactants, are easily eluted in the solvent contained in the screen printing paste, so it is preferable to keep the amount to the minimum necessary, and further, it is contained in the paste. It is preferable not to add those soluble in a solvent (those that can be eluted by the solvent).

The thickness of the pressure-sensitive adhesive layer can be arbitrarily set within the range in which the above-mentioned characteristics of the present invention are obtained, and for example, 5 to 5000 μm.
The thickness is preferably about 10 to 2000 μm.

In the pressure-sensitive adhesive sheet of the present invention, when the release surface is the back surface treated with the back surface treatment agent (that is, when the back surface treatment layer is formed), the back surface treatment agent (release agent)
Is not particularly limited, depending on the type of adhesive,
It can be appropriately selected and used from publicly known or commonly used back surface treating agents. Specifically, examples of the back surface treatment agent include long chain alkyl back surface treatment agents (for example, long chain alkyl back surface treatment agents composed of alkyl acrylate polymer or long chain alkyl modified polymer), alkyl pendant system Examples include back surface treatment agents, silicone-based back surface treatment agents, and fluorine-based back surface treatment agents. The back surface treating agent can be used alone or in combination of two or more kinds.

The thickness of the back surface treatment layer can be arbitrarily set within the range in which the above characteristics of the present invention are obtained, and for example, 0.01 to 5 μm.
The thickness is about m, preferably about 0.03 to 3 μm.

As described above, the pressure-sensitive adhesive sheet of the present invention (screen printing plate cleaning pressure-sensitive adhesive sheet) comprises a base material, a pressure-sensitive adhesive layer formed on one surface of the base material, and the other surface of the base material. When the pressure-sensitive adhesive sheet is composed of a backside treatment layer formed in, a conventional method such as a coating method is used.
It can be manufactured by forming a pressure-sensitive adhesive layer on one surface of a substrate and forming a backside treatment layer on the other surface. Of course, when the backside treatment layer is not formed, the pressure-sensitive adhesive sheet can be manufactured by forming the pressure-sensitive adhesive layer on one surface of the substrate by using a conventional method such as a coating method. Further, the pressure-sensitive adhesive sheet is further rolled into a roll by using a plastic core and winding the roll in a state where the surface of the pressure-sensitive adhesive layer is overlapped with the sheet back surface (for example, the surface of the backside treatment layer). It is possible to manufacture an adhesive sheet wound around.

Since the pressure-sensitive adhesive sheet of the present invention has a core made of plastic even if it is wound into a roll,
When rewinding the adhesive sheet that is wound in a roll,
The generation of paper dust does not occur, and the contamination of the adhesive surface due to the attachment of paper dust or the like to the adhesive surface is prevented, and the adhesion to the screen printing plate can be improved. Therefore, after rewinding the pressure-sensitive adhesive sheet that has been wound into a roll, and then pasting it on the back side of the screen printing plate, the paste (ink) that has spread around the back side of the screen printing plate
Can be reliably adhered and the paste can be efficiently removed from the screen printing plate. That is, the pressure-sensitive adhesive sheet of the present invention has a high cleaning effect and can reduce printing defects due to bleeding or the like during screen printing. Therefore, the pressure-sensitive adhesive sheet of the present invention is suitable for cleaning the screen printing plate by removing the paste (ink) on the back side of the screen printing plate.

In the present invention, the pressure-sensitive adhesive strength of the pressure-sensitive adhesive sheet before use is 4 N by a method according to JIS Z 0237 (using SUS430BA as a test plate, and measuring 1 minute after pressure-bonding the pressure-sensitive adhesive sheet to the test plate). / 25 mm
(400 gf / 25 mm) or less (for example, 0.01 to 4)
N / 25 mm) is preferable, and more preferably 3 N /
25 mm (300 gf / 25 mm) or less (for example, 0.
It is about 03 to 3 N / 25 mm).

[0030]

According to the pressure-sensitive adhesive sheet of the present invention, since the core for winding in a roll shape is a plastic core, paper powder for rewinding the pressure-sensitive adhesive sheet in a roll shape is used. It is possible to effectively prevent the occurrence of such a phenomenon, and it is possible to surely attach the backing paste (ink) to the back side of the screen printing plate and remove it. Therefore, it is possible to reduce defective removal of the paste that has spread to the back side of the screen printing plate and improve productivity.

[0031]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples.

Preparation Example 1 of Adhesive Sheet 1 On one side of a polyethylene film (base material) having a thickness of 0.06 mm, an acrylic adhesive [butyl acrylate / acrylic acid (weight ratio: 100/15) copolymer 100 weight Division +
15 parts by weight of an isocyanate-based cross-linking agent (trade name "Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd.)] is applied so that the thickness after drying is 10 μm, and dried to form a pressure-sensitive adhesive layer. The adhesive sheet A may be referred to as “adhesive sheet A”).

Example 1 The pressure-sensitive adhesive sheet A prepared in Preparation Example 1 of the pressure-sensitive adhesive sheet was coated with the surface of the acrylic pressure-sensitive adhesive layer using a core made of acrylonitrile-butadiene-styrene copolymer (ABS). The back surface (the surface of the polyethylene film) was superposed and wound in a roll shape to prepare a roll-shaped pressure-sensitive adhesive sheet (may be referred to as “roll-shaped pressure-sensitive adhesive sheet B”).

The pressure-sensitive adhesive sheet B was rolled at a temperature of 23
After storing for 10 days under the condition of ℃, humidity: 65% RH,
When it was rewound, no paper dust was generated. Then, in the actual screen printing process, when the paste was pasted on the back side of the screen printing plate, the paste on the back side of the screen printing plate could be surely adhered and removed, and the paste removability was good. It was

Example 2 A pressure-sensitive adhesive sheet wound in a roll shape (“Roll-shaped pressure-sensitive adhesive sheet C”) was prepared in the same manner as in Example 1 except that a polyethylene (PE) core was used as the core. May be called).

When the roll-shaped pressure-sensitive adhesive sheet C was stored for 10 days at a temperature of 23 ° C. and a humidity of 65% RH and then rewound in the same manner as in Example 1, paper dust was generated. There wasn't. Then, in the same actual screen printing process as in Example 1, when the paste was pasted on the back side of the screen printing plate, the backing paste on the back side of the screen printing plate could be surely attached and removed. The removability was good.

Comparative Example 1 Example 1 was repeated except that a paper core was used as the core.
In the same manner as above, a pressure-sensitive adhesive sheet wound in a roll shape (may be referred to as “roll-shaped pressure-sensitive adhesive sheet D”) was produced.

Further, when the rolled adhesive sheet D was stored for 10 days at a temperature of 23 ° C. and a humidity of 65% RH and then rewound in the same manner as in Example 1, paper powder was generated. Paper powder was attached to the surface of the pressure-sensitive adhesive layer of the rewound pressure-sensitive adhesive sheet. Then, in an actual screen printing process similar to that in Example 1, when the paste was attached to the back side of the screen printing plate, the paste backed on the back side of the screen printing plate could not be surely adhered and removed cleanly. However, uneven removal occurred, the removability of the paste was insufficient, and printing defects (bleeding) occurred.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09J 201/00 C09J 201/00 F term (reference) 2C035 FD29 2C250 FA05 FB14 4J004 AA04 AA05 AA07 AA10 AB01 CA04 CA06 CB03 DA02 DA04 EA02 FA10 4J040 BA202 DB032 DB072 DB082 DE022 DF011 DF041 DF042 DF051 DF052 DF082 DF091 DG001 DN032 DN072 EC002 HB22 HC19 HC25 HD43 JA09 JB09 KA16 MA10 MA11 NA21 PA23

Claims (2)

[Claims] 1. A pressure-sensitive adhesive layer comprising a base material and a pressure-sensitive adhesive layer formed on one surface of the base material, the other surface of the base material being a release surface, and the pressure-sensitive adhesive layer on the release surface. Is a screen printing plate cleaning pressure-sensitive adhesive sheet which is wound in a roll shape by being superposed, in a roll shape characterized in that the core at the time of winding in a roll shape is a plastic core Rolled screen printing plate cleaning adhesive sheet. 2. The pressure-sensitive adhesive sheet for cleaning a screen printing plate wound in a roll according to claim 1, wherein the peeling surface on the other surface of the substrate is a surface which has been subjected to a back surface treatment with a back surface treatment agent.