JPH0545943B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Industrial Application Field The present invention relates to a light-shielding adhesive laminate in the form of a sheet or tape, which is formed by providing a light-shielding adhesive layer on one side of a plastic support. More specifically, it relates to a sheet-like or tape-like light-shielding adhesive laminate that has light-shielding properties and adhesive properties, and can be pasted on necessary parts or cut and pasted to create photolithography, various original drawings, etc. . (b) Prior art In general, light-shielding adhesive sheets and tapes (hereinafter abbreviated as light-shielding adhesives) are made by forming a light-shielding adhesive layer on one side of a plastic sheet or tape, which contains an adhesive and a light-shielding dye as essential components. It is a laminated product, and when it is attached to an adherend, the light-shielding dye is transferred to the adherend. Therefore, the following methods have been proposed to prevent the light-shielding dye from being transferred to the adherend. That is, a colored plastic film support is used to give the support a function as a light-shielding layer (Japanese Unexamined Patent Publication No. 7364/1983), or a pressure-sensitive adhesive layer is used between the plastic film support and the support. Alternatively, a colored layer as a light-shielding layer may be provided on the back side of the plastic film support (Japanese Utility Model Publication No. 58-28842, Japanese Utility Model Application Publication No. 59-9058), or a colored layer may be provided as a light-shielding layer between the plastic film supports. It has a structure with colored layers sandwiched between them. (Unexamined Japanese Patent Publication No. 1983-
Publication No. 45990). Moreover, it is a masking film formed by sequentially laminating a colorless and transparent base film layer, a light-shielding adhesive layer, and a protective film layer, and when the protective film layer is peeled off together with the light-shielding adhesive layer, this light-shielding adhesive layer is removed. A masking film formed by sequentially laminating a colorless and transparent base film layer, a light-shielding adhesive layer, and a protective film layer so that a part of the layer does not remain on the base film layer, the base film layer being As the critical surface tension is 35dynes/
A plastic film with a critical surface tension of less than 35 dynes/cm is used as the protective film layer.
A device using the above plastic film has been proposed (Japanese Patent Application Laid-open No. 49356/1983). (c) Problems to be Solved by the Invention However, since the above-mentioned light-shielding adhesive uses a colored plastic film support, there is no risk of the light-shielding dye transferring to the adherend; Furthermore, even if the light-shielding dye transfers to the adhesive layer, it is extremely difficult to confirm during actual use; If this happens, the light transmittance will decrease, and if this transfer is significant, other unnecessary objects will also be blocked from light. In addition, the same problems as those mentioned above remain with the light-shielding adhesive described above, and when a light-shielding colored layer is provided on the back side of the plastic film support, it is difficult to unwind the light-shielding adhesive. Then, the dye in the light-shielding colored layer transfers to the surface of the adhesive layer,
Furthermore, this dye may be redeposited onto the adherend and become unusable. The same problems as above remain with the above-mentioned light-shielding adhesive, and the process is complicated because it uses two plastic films as supports, and each has its own primer, adhesive, and colored resin layer. As a result, the cost increases, and the thickness of the entire light-shielding adhesive increases, making it difficult to obtain the required flexibility. Furthermore, in the above masking film, the base film layer has a critical surface tension.
A plastic film with a critical surface tension of less than 35 dynes/cm is used as the protective film layer.
Since a plastic film of 35 dynes/cm or more is used, when the protective film layer is peeled off along with the light-shielding adhesive layer, there is no risk that part of this light-shielding adhesive layer will transfer to the base film layer, making it extremely superior. However, when this is applied to an adherend, there is a risk that the light-shielding dye may transfer to the adherend.Furthermore, two films, a base film layer and a protective film layer, are used, resulting in increased costs. However, there is a problem in that it is difficult to obtain the required flexibility due to the increased overall thickness. (d) Means for Solving the Problems As a result of intensive studies to solve the above problems, the inventors of the present invention have developed a light-shielding material based on an acrylic adhesive and a light-shielding dye added thereto. We have discovered that when a polyvalent isocyanate as a crosslinking agent and a urea resin or melamine resin as a curing agent are added to the adhesive composition and used in combination, the transfer of the light-shielding dye to the adherend can be prevented. This led to the completion of the invention. That is, the light-shielding adhesive laminate of the present invention is formed by laminating a light-shielding adhesive layer on one side of a transparent plastic support, and the light-shielding adhesive layer contains an acrylic adhesive, a light-shielding dye, and a polyvalent adhesive layer. It is characterized by being made of isocyanate and urea-based resin or melamine-based resin. The present invention will be explained in detail below. Transparent plastic supports used in the present invention include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate, aliphatic polyamides such as polyε-caprolactam, polyhexamethylene carbamide, and polymetaphenylene isophthalate. Aromatic polyamides such as amides, polyolefins such as polyethylene and polypropylene, vinyl resins such as polystyrene, polyvinyl chloride, and polyvinylidene chloride, cellulose diacetate,
Examples include films and sheets made of cellulose-based resins such as cellulose triacetate, engineering plastics such as polycarbonate, PPS, PES, and PEEK, and films and sheets made of these, stretched or unstretched, as well as tapes made of these. However, among these, films, sheets, or tapes made of biaxially stretched polyester, which have excellent strength and dimensional stability, and are inexpensive, are particularly suitable, particularly films, sheets, or tapes made of polyethylene terephthalate or polybutylene terephthalate. It is used. If necessary, one side of the plastic support may be subjected to surface treatment such as corona treatment to improve the adhesive strength with the light-shielding adhesive layer. The thickness of the above-mentioned plastic support is not particularly limited as long as it does not cause problems in terms of strength and handling.
A range of 75 μm is preferable. If the thickness of the above-mentioned plastic support is less than 5 μm, the practical strength may be insufficient and handling may be extremely poor;
If it exceeds this, the required flexibility may be lacking or transparency may be impaired, and either case is undesirable. In addition, the acrylic adhesive used in the present invention uses ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. as the main monomer, and vinyl acetate, acrylonitrile, acrylamide (CH2 ₎ as the comonomer.
=CH-CONH ₂ ), styrene, methyl methacrylate, methyl acrylate, etc. are used, and as functional group-containing monomers, methacrylic acid, acrylic acid, itaconic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, acrylamide ( AM) CH ₂ =CHCONH ₂ ), methylol acrylamide, glycidyl methacrylate, maleic anhydride, etc. are used. It is preferable that two or more of these monomers are copolymerized so that the adhesive force and cohesive force of the copolymer are adjusted to an appropriate range. Generally, a soft main monomer (acrylic acid ester) with a low Tg that provides tackiness is used, a small amount of a hard comonomer with a high Tg that provides adhesiveness and cohesion is used, and a functional group is added to improve crosslinking and adhesion. The contained nomonomers are copolymerized. A feature of the present invention is that a light-shielding adhesive composition is prepared by adding a light-shielding dye to the above-mentioned acrylic adhesive as a base, a polyvalent isocyanate as a crosslinking agent, and a urea resin or melamine as a curing agent. The point is that a system resin is added or used in combination. The light-shielding dye used in the present invention is one that is soluble in organic solvents, compatible with the acrylic pressure-sensitive adhesive, and has light-shielding properties. A dye, a pigment, or a mixture of a dye and a pigment can be used as a coloring agent for imparting light-shielding properties to the adhesive composition, and examples of the dye include oil dyes, organic solvent-soluble dyes, and metal complex dyes. It is preferable to use a dye that has good compatibility with the adhesive composition and has little change in color tone when exposed to heat or ultraviolet rays, but there are no particular restrictions on the color tone or structure of the dye, as long as it satisfies the light-shielding properties as a masking material. It is not something that will be done. The above-mentioned light-shielding dye is appropriately selected and used depending on the required light-shielding property. The blending ratio of the light-shielding dye may be any amount sufficient to exhibit light-shielding properties, for example, 0.5 parts by weight per 100 parts by weight of the resin solid content of the acrylic adhesive material.
It is preferable that the amount is in the range of ~10 parts by weight.
If the blending ratio of the light-shielding dye is less than 0.5 parts by weight, the desired light-shielding property may not be obtained; on the other hand, if it exceeds 10 parts by weight, it may adversely affect the adhesive force of the adhesive, which is not preferable. . As the polyvalent isocyanate used in the present invention, 2,4-tolylene diisocyanate 2.6-Toluylene diisocyanate 1.5-Naphthalene diisocyanate Diphenylmethane-4,4'-diisocyanate polymeric isocyanate Aromatic polyisocyanates, aliphatic polyisocyanates, mixtures thereof, and block polyisocyanates are used. Polyisocyanates are preferably used. The blending ratio of the above polyvalent isocyanate is as follows:
Per 100 parts by weight of acrylic adhesive (solid content)
It is preferable to use it in a range of 0.5 to 5 parts by weight,
If it is less than 0.5 parts by weight, it will have little effect as a crosslinking agent;
On the other hand, if it exceeds 5 parts by weight, the dye scavenging effect when used in combination with a urea resin or melamine resin will be weakened, and the properties as an adhesive will deteriorate, which is not preferable. Furthermore, as for the urea resin or melamine resin used as a curing agent component in the present invention, those mainly used for paints are preferably used. As the above-mentioned urea resin or melamine resin, resins such as urea, guanamine, benzoguanamine, melamine, butylated melamine are used, but from the viewpoint of preventing the transfer of light-shielding dyes to the adherend, butylated melamine resin is used. is most preferably used. Regarding the blending ratio of the above-mentioned urea-based resin or melamine-based resin, using an excess amount of the urea-based resin or melamine-based resin relative to the polyvalent isocyanate has a great effect of trapping the light-shielding dye in the acrylic adhesive. Yes, it is desirable. According to the experimental results of the present inventors, urea resin or melamine resin can be used in the range of 1.0 to 10 parts by weight per 100 parts by weight of the acrylic adhesive (solid content), but the isocyanate, which is a crosslinking agent, It is necessary to always use an excess amount. In the above blending ratio, if the blending ratio of urea-based resin or melamine-based resin is less than 1.0 parts by weight, the effect of preventing transfer of light-shielding dye will be poor;
If the amount exceeds 10 parts by weight, the cohesive force of the pressure-sensitive adhesive layer will be significantly increased and the entire adhesive layer will become hard, which is not preferred in practice. Examples of the solvent for the light-shielding adhesive composition include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, toluol, xylol, and the like. In the present invention, the above-mentioned plastic support and/or light-shielding adhesive layer may be appropriately matted to prevent light reflection, or may be treated with antioxidants, stabilizers, ultraviolet absorbers,
Compounding agents such as antiblocking agents and antistatic agents may be mixed. Examples of the matting agent include inorganic powder (eg, hydrated silica) with a particle size of 10 μm or less. The matting agent is preferably added and mixed in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the resin solid content of the plastic support or light-shielding adhesive layer. The antistatic agent is not limited as long as it can be dissolved in the light-shielding adhesive composition, and cationic antistatic agents are particularly preferred. Examples of the antistatic agent include alkylyl (about 8 to 24 carbon atoms), aminopropyldimethylhydroxyethylammonium, alkylamine salts, and quaternary ammonium salts (for example, N,N,N,N-tetraalkyl, where the alkyl group is At least one of them has about 8 to 24 carbon atoms or more, and the remaining ones have about 1 to 5 carbon atoms. The antistatic agent may be added in an amount sufficient to prevent the generation of static electricity, and the amount of the antistatic agent may be sufficient to prevent the generation of static electricity.
It is preferably in the range of 1 to 10 parts by weight per 100 parts by weight. In addition, the blending ratio of other compounding agents is 100% of the resin solid content of the plastic support or light-shielding adhesive composition.
The amount is preferably 0.1 to 5 parts by weight. (e) Effect In the present invention, when urea resin or melamine resin and polyvalent isocyanate are added to the acrylic light-shielding adhesive layer, the light-shielding dye in the light-shielding adhesive layer is transferred to the adherend. Although it is not clear why the acrylic light-shielding adhesive layer is crosslinked with polyvalent isocyanate and urea-based resin or melamine-based resin, the mobility of the light-shielding dye is suppressed as much as possible. Or, it is presumed that the functional group of the light-shielding dye reacted with a free amine group or isocyanate group and became fixed to the resin. (f) Examples Hereinafter, the present invention will be explained in detail based on Examples, but the present invention is not limited thereto. Production of polybutyl acrylate Polybutyl acrylate (PAB) used in the following examples and comparative examples was produced by the following method. That is, 80 parts by weight of butyl acrylate (BA) and 18 parts by weight of 2-ethylhexyl acrylate (2-EHA) as main monomers, 2 parts by weight of acrylic acid (AA) as a functional group-containing monomer, and acrylonitrile (AN) as a comonomer component. ) and 1 part by weight of acrylamide (AM) was mixed with benzoyl peroxide (catalyst) in a nitrogen stream.
Add 100 parts by weight to 1 part by weight and heat to 65% by weight.
It was obtained by polymerizing at ℃ for 8 hours. Example As an adhesive composition, 100 parts by weight of the above-mentioned polybutyl acrylate (PAB), 0.5 parts by weight of polyvalent isocyanate (Coronate L, manufactured by Nippon Polyurethane Co., Ltd.),
3.0 parts by weight of butylated melamine (manufactured by Dainippon Ink Co., Ltd., Superbetsukamine J-820) was mixed and dissolved in methyl ethyl ketone to obtain a solid content of 25% by weight.
A solution of the adhesive composition was obtained. A light-shielding dye, manufactured by Hodogaya Chemical Industry Co., Ltd. under the trade name Spilon Orange, is added to the solution of this adhesive composition.
8 parts by weight of 2RH was mixed and stirred until a uniform solution was obtained, thereby preparing a coating solution for a light-shielding adhesive composition. This solution had a viscosity of 1500 centipoise at a temperature of 23°C. On the other hand, as a plastic support, a biaxially stretched polyethylene terephthalate film with a thickness of 25 μm, which was corona-treated so that the critical surface tension was 43 dyn/cm on the front side and 50 dyn/cm on the back side, was used, and a release agent was used on the front side. BP manufactured by Nitto Electric Industry Co., Ltd.
-110 was diluted with toluene to a solid content of 0.1% by weight, coated on one side with a kiss coater, and heated to
After drying at 100° C. for 5 minutes, the release layer is uniformly adhered to a weight of 12.5 g/m ² . Next, apply the above coating solution to the corona-treated side of the back side of the support using a roll coater so that the coating thickness after drying is
Coat to a thickness of 13 μm and apply at a temperature of 100 to 120℃.
After drying for a minute, a light-shielding adhesive layer was laminated, and then cut with a slitter to obtain a light-shielding adhesive tape. The thus obtained light-shielding adhesive laminate of the present invention, as shown in FIG. 1, is composed of a light-shielding adhesive layer 2 laminated on one side of a transparent plastic support 1, that is, the corona-treated surface 1a. The light-shielding adhesive layer 2 is made of an acrylic adhesive, a light-shielding dye, a polyvalent isocyanate, and a melamine resin. Note that 1b is a release layer. Comparative Example In the above example, a material obtained in the same manner as in the above example was used, except that butylated melamine and polyvalent isocyanate were not used. Table 1 shows the results of each characteristic test for the above Examples and Comparative Examples.

[Table] The adhesive residue phenomenon in Table 1 was observed on each adherend [polyester film (PET), Proceed coating film] under normal conditions (temperature 23°C and relative humidity 65%) in the above examples and comparative examples. A test piece (12 mm width) is attached and left to stand for 10 minutes, after which the adhesive residue and dye transfer to each adherend are investigated. The light-shielding adhesive laminate of this example has light-shielding properties as a basic property, and as is clear from Table 1, it has dimensional stability after being attached to a masking film for plate making or a polyester film. It was also good, with no adhesive residue or dye transfer to the adherend after peeling. On the other hand, the comparative example has light-shielding properties as a basic property and also has excellent dimensional stability after being attached to a masking film for plate making or a polyester film, but as is clear from Table 1,
There may be adhesive residue after peeling or transfer of dye to the adherend.
Furthermore, the adhesive on the slit surface was removed and pinholes were observed during exposure. (g) Effects of the Invention The light-shielding adhesive laminate of the present invention has the above-mentioned structure, and even when it is attached to an adherend, the dye in the light-shielding adhesive layer of the light-shielding adhesive laminate does not adhere. As a result, there is no adhesion to the body or adhesive residue, and as a result, it has the effect of allowing precise photoengraving to be performed. In addition, by forming a single layer structure in which a light-shielding dye is mixed into the light-shielding adhesive layer, it has the desired flexibility, and the manufacturing process is simple and can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Plastic support, 1a...Corona-treated surface, 1b...Peeling layer, 2...Light-shielding adhesive layer.

Claims (1)

[Claims] 1. A light-shielding adhesive layer is laminated on one side of a transparent plastic support, and the light-shielding adhesive layer contains an acrylic adhesive, a light-shielding dye, a polyvalent isocyanate, and a urea resin. Alternatively, a light-shielding adhesive laminate characterized in that it is formed of a melamine-based resin. 2. The light-shielding adhesive laminate according to claim 1, wherein the plastic support is formed of a polyester film. 3. The light-shielding adhesive laminate according to claim 2, wherein the polyester film is a film made of polyethylene terephthalate or polybutylene terephthalate.