JPS6249356A - Masking film and its production - Google Patents

Abstract

PURPOSE:To obtain the title film having both properties of an adhesion to a protective film and a suitable peeling from a base layer by using a plastic film having a specific critical surface tension to the base film layer and the protective film layer respectively. CONSTITUTION:The plastic film having <35dynes/cm the critical surface tension is used to the base film layer, and the plastic film having >=35dynes/cm the critical surface tension is used to the protective film in the masking film 1 laminated a colorless transparent base film layer 4, a sticking agent layer 3 having a shading property and the protective film layer 2 in order. The sticking agent layer having the shading property provided on the protective film layer comprises a sticking composition such as an acrylic resin or a gum and also, a thermoplastic resin having a compatibility and capable of mixing with said sticking composition and having the sticking property may be used. The acrylic sticking composition having the excellent weather ability and sticking property is more preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a masking film in which a base film layer, a light-shielding adhesive layer and a protective film layer are laminated, and a method for manufacturing the same.

(b) Prior Art Conventionally, the following are known as typical masking films for photolithography.

1st 77)? Skinning films are made by applying a rubber-based pressure-sensitive adhesive onto a peelable sheet layer based on glassine paper, wax paper, vinyl chloride or vinyl chloride-based copolymers, and applying a nitrocellulose-based lacquer as a masking layer. It is a multi-coated laminate (for example, US Pat. No. 3,576,491).

- The second masking film has a base film layer of polyethylene terephthalate, on which dye-containing vinyl chloride is applied.

(c) Problems to be solved by the invention However, the first masking film is susceptible to dimensional changes due to the influence of the temperature and humidity of the working atmosphere, and also expands and contracts due to the heat of the light source used when creating the photographic original plate. There were problems with heat resistance dimensional stability and moisture absorption dimensional stability.

In addition, in the case of nitrocellulose lacquer, since the layer is relatively thick, the thickness between the peelable sheet layer and the protective film causes misalignment between the actual image and the actual object, resulting in the need for precise realism. It was an unsuitable product.

Furthermore, the base film that has been peeled off and separated from the protective film layer has disadvantages such as insufficient strength and susceptibility to breakage and elongation.

On the other hand, once the vinyl chloride layer of the second masking film is peeled off, it is virtually impossible to reattach it to the base film or to attach it to a silk screen or photographic plate.

Furthermore, recently, a light-shielding adhesive layer has been commercially available, which is considered to be an improved type of the above, in which a polypropylene film is used as the base film layer and the protective film layer, and a dye is added to the adhesive to form a light-shielding adhesive layer. Since the layer and the protective film layer are made of the same film, in order to separate the protective film layer from the base film layer, it is necessary to perform a mold release treatment on the base film layer. The following problems arose.

First of all, the first problem is that when using it as a masking film, it is difficult to use a CAD graph or a cut knife.
In order to create a specified design, cutting is done from the protective film layer, but since the base film layer has been subjected to mold release treatment, lifting occurs along the cut surface, and the edges become unclear during photoengraving. there were.

The second problem is that when the protective film layer formed with the light-shielding adhesive is peeled off from the base film layer, the dye contained in the light-shielding adhesive layer is transferred to the base film scraps. However, there was a problem that the light transmittance of the base film was poor.

(d) Means for Solving Problem 7α As a result of various studies to solve the above problems, the inventors have found that the base film lli [film layer is clearly separated] and the base film waste has a critical surface. We use a colorless and transparent plastic film with low tension to maintain the above-mentioned properties! l
A plastic film with a large critical surface tension is used for the l film layer, thereby making the above base film/l
The present invention was completed based on the discovery that the adhesive strength of the light-shielding adhesive layer can be differentiated between the light-shielding adhesive layer and the protective film layer.

In other words, the adhesion of the light-shielding adhesive layer is correlated with the critical surface tension of the protective film layer and the base film layer, and the difference in critical surface tension makes it possible to improve the adhesion to the protective film layer. This makes it possible to achieve both base film layer strength and appropriate peelability.

That is, the first inflection of the present invention 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 the base film layer has a critical surface tension of 35. dynes/ c11
Using a plastic film of less than 1 and the above-mentioned maintenance, 11
! The film layer has a critical surface tension of 35 dynes/
It is characterized by using a plastic film with a rating of am or higher.

The present invention will be explained in detail below.

The plastic film used for the base film layer has a critical surface tension of less than 35 dynes/cry, particularly desirably a critical surface tension of 15 to 32 dynes/ca+. If the critical surface tension is less than 15 dynes/am, the light-shielding adhesive layer may have poor adhesion. Even if the force is increased, the peelability becomes large and the masking film may peel off naturally during handling or processing.On the other hand, when the critical surface tension is 35dy
This is because if it exceeds nes/am, even if the adhesive force is reduced, the adhesiveness to the base film layer will be strong and the releasability of the light-shielding adhesive layer will be poor.

In the present invention, critical surface tension refers to the relationship between cos θ and γ, where θ is the contact angle exhibited by a homologue of a liquid hydrocarbon or other organic liquid compound on an open book surface, and γ is the surface tension of the liquid. Regardless of the type of congener, it often forms a straight line.

At this time, the value of γ corresponding to θ=0, that is, eO3θ=1, is called the critical surface tension of the solid.

As the base film layer, for example, polystyrene,
Examples include plastic films such as polyethylene, polyvinyl butyral, polyvinyl fluoride, polyvinylidene fluoride, polypropylene, and polyethylene fluoride. Among these plastic films, there are materials that have the required critical surface tension, heat resistance, moisture resistance, and dimensional stability. They are selected and used as appropriate, taking into account gender, etc.

Both stretched and unstretched plastic films can be used as this base film layer, but biaxially stretched plastic films are preferred from the viewpoint of film strength and dimensional stability. 7 is preferably about 6 to 300 μm, particularly 12 to 300 μm from the viewpoint of handling, processability, etc.
150 μm is desirable.

Furthermore, the plastic film used for the protective film layer used in the present invention has a critical surface tension of 35 dynes/c.
m or more, especially critical surface tension of 38 to 60dy11eS/
Cl11 is preferred. critical surface tension is 35 dynes
/ cm, the adhesive strength of the light-shielding adhesive layer becomes almost the same as that of the base film, and as a result, the base film requires release treatment, etc. On the other hand, when the critical surface tension is 60 dynes/am or more, This is because it is difficult and undesirable to produce a homogeneous plastic film.

As the protective film, any transparent or translucent plastic film can be used, such as polyester films or polyether films such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate, polyoxybenzoate, and polyisobutylene oxide. , nylon 6
, polyamide films such as nylon 6.6, nylon 10, nylon 11, and nylon 12, cellulose derivative films such as cellulose acetate and cellulose butyrate, vinylidene chloride, vinyl chloride, polymethyl methacrylate, polyurethane, polyvinyl alcohol, polysulfone, Examples include plastic films such as polyimide, which are appropriately selected and used in consideration of required critical surface tension, heat resistance, moisture resistance, dimensional stability, etc.

As this protective plastic film, either stretched or unstretched plastic film can be used, but a 2-stretched plastic film is preferred from the viewpoint of film strength and dimensional stability, and its thickness is 3 to 150 μm.
The grade is preferably 6 to 8 from the viewpoint of handleability, processability, etc.
0 μm is most desirable.

The light-shielding adhesive layer provided on the protective film layer may be an acrylic or rubber-based adhesive composition, or a thermoplastic a (Jl
ff or the like can be used, but an acrylic adhesive composition that has excellent weather resistance and adhesiveness is particularly preferred.

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, growth solvent-soluble dyes,
Examples include metal complex dyes, which have good compatibility with the adhesive composition and whose color tone does not change much when exposed to heat or ultraviolet rays. The structure is not particularly limited.

Solvents for the above adhesive composition and colorant include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, doluol,
In addition, the above-mentioned protective film layer and/or light-shielding adhesive layer may be appropriately matted to prevent light reflection, or may be treated with antioxidants, stabilizers, etc. Compounding agents such as ultraviolet absorbers, antiblocking agents, and antistatic agents may be mixed.

As the matting material, inorganic powder (eg, hydrated silica) having a particle size of 10 μm or less can be used. 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 solid resin content of the 11 film or the light-shielding adhesive layer.

The antistatic agent is not limited as long as it can be dissolved in the adhesive composition, and cationic antistatic agents are particularly preferred. Examples of the antistatic agent include aluminumloyl (about 8 to 24 carbon atoms) aminopropyldimethylhydroxyethylammonium, alkylamine salts, and fjS quaternary ammonium salts (for example, N , N , N
, Ntetraalkyl, and at least one of the alkyl groups has about 8 to 24 carbon atoms, and the remaining ones have about 1 to 5 carbon atoms. ) etc. are exemplified.

The antistatic agent may be added in an amount sufficient to prevent the generation of static electricity, and is preferably 1 to 10 parts by weight based on 100 parts by weight of the resin solid content of the protective film or adhesive composition. preferable.

In addition, the amount of the compounding agent in the pond is 100ff of the resin solid content of the protective film or adhesive composition! 0.1 to part
Preferably, the amount is 5 parts by weight.

The second aspect of the present invention relates to the method of manufacturing the masking film of the present invention.

This will be explained in detail below.

In producing the masking film of the present invention, the above-mentioned adhesive composition is dissolved in the above-mentioned solvent to form a uniform solution, and then, after adding the colorant and optionally the above-mentioned compounding agents, the above-mentioned adhesive composition is uniformly dissolved. Mix until combined.

The light-shielding adhesive composition solution obtained in this way is coated on one side of the protective film layer using a roll coater or a transfer method.
After drying, a light-shielding adhesive layer is laminated on one side of the protective film layer. Next, a colorless and transparent base film layer is laminated on the exposed surface of this light-shielding adhesive 1ffi so that no air bubbles are introduced therebetween, and the film is bonded with a rubber pressure roll.

(e) Effect The masking film of the present invention has a colorless and transparent base film layer and a protective film layer each having a difference in critical surface tension, whereby the adhesive force of the light-shielding adhesive M layer is stronger than that of the base film layer. The light-shielding adhesive layer is in close contact with the protective film layer, and the adhesive strength of the base film is relatively small, so there is no need to perform peeling treatment on the base film. In addition, when the protective film layer is peeled off, in other words, when the light-shielding adhesive layer is peeled off, a part of the light-shielding adhesive layer does not remain on the base film.

Also, save! The light-shielding adhesive layer that adheres to one film layer is flexible and can be repeatedly attached to the base film layer, so the base film layer can be masked many times or used for silk screen or photographic printing. It has the ability to be pasted many times.

Further, according to the manufacturing method of the present invention, first, a light-shielding adhesive layer is formed on the protective film layer, and then the light-shielding adhesive layer is brought into close contact with the protective film layer. First, a light-shielding adhesive layer is adhered to a protective film layer with strong adhesive strength, and then a base film layer is laminated on the exposed surface of this light-shielding adhesive layer. This has the effect of producing a masking film of stable quality without causing problems such as part of the light-shielding adhesive layer peeling off.

(r) Examples Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 An adhesive composition consisting of 85 parts by weight of butyl acrylate, 14 parts by weight of acrylonitrile, and 1 part by weight of 2-hydroxyl methacrylate had a molecular weight of about 600,000 (number average molecular f
f1) using acrylic rubber.

This was dissolved in methyl ethyl ketone so that the solid content concentration was 10% by weight.

To this adhesive composition solution, 8 parts by weight of Subiron Orenno 2 RH (manufactured by Hosei Kagaku Kogyo Co., Ltd.), which is a light-shielding dye, and 41 fLf of dodecaroylaminoprobylnomethyl-2'-hydroxyethylammonium, which is a cationic antistatic agent, are added.
fi part was mixed and sufficiently stirred until a homogeneous solution was obtained, and then diluted with methyl ethyl diluted so as to have a solid content concentration of 6.0% by weight to obtain a light-shielding coating solution.

The solution had a viscosity of 900 centivoids at a temperature of 23°C.

On the other hand, as the protective film layer (2), a transparent stretched polyester film with a critical surface tension of 43 dynes/ce% and a thickness of 25 μω was used, and the above coating solution was coated on one side with a roll coater after drying. The film was coated to a thickness of 10 μm and dried at a temperature of 100 to 110° C. for 5 minutes.

In this way, the light-shielding adhesive WJ (3) was previously formed on the protective film 1vi (2).

Next, the colorless and transparent base film A11 (4) has a critical surface tension of 23 dynes/car and a thickness of 60 dynes/car.
"mtf" polypropylene film is used as the light-shielding adhesive WJ (3) in the protective film layer (2).
The masking film (1) of the present invention was obtained by laminating it on the exposed side of the film.

Comparative Example The same light-shielding coating solution as in Example 1 was used,
Transparent as a protective film layer with a critical surface tension of 23 dy
Using a polypropylene film with a thickness of 25 μm, apply the above-mentioned light-shielding coating solution to one side of the protective 3a film layer using a roll coater so that the film thickness after drying is 1.
The coating was applied to a coating thickness of 0 μm and dried at a temperature of 100 to 110° C. for 5 minutes.

In this way, a light-shielding adhesive layer was formed on the protective film layer.

Next, the colorless and transparent base film layer has a thickness of 60 μm.
m polypropylene film was used.

On the other hand, 1 part by weight of a platinum catalyst (trade name PL-3; manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the solid content of 100 parts by weight of a 301% toluene solution of addition-polymerized dimethylpolysiloxane, which is a known stripping agent. After stirring and mixing the mixture until it becomes homogeneous, dilute with toluene until the solid content becomes 3% by weight.

A solution of the above release agent is applied to one side of the base film layer using a kiss coater, so that the amount of release agent after drying (solid content) is 0.
Apply it evenly so that it is 1 g/m2 and keep it at a temperature of 10
It was dried at 0 to 110°C for 5 minutes.

The light-shielding adhesive layer side of the protective film layer was bonded to the release-treated side of the base film layer to obtain a masking film similar to that of a commercially available product.

Example 2 Adhesive composition: 90 parts by weight of acrylic rubber with a molecular weight of approximately 600,000, consisting of 85 parts by weight of butyl acrylate, 14 parts by weight of acrylonitrile, and 1 part by weight of 2-hydroxyethyl methacrylate, 90 parts by weight of vinyl chloride, and vinyl acetate. 10 parts by weight of vinyl copolymer (average degree of polymerization 750
) 10 parts by weight of the mixture was completely dissolved in methyl ethyl ketone (solid content concentration 10% by weight), and the light-shielding dye Subiron Orange 2RH (maintenance dye) was added to 100 parts by weight (solid content) of this adhesive composition solution. 8 parts by weight of Kagaku Kogyo Co., Ltd. g1) were blended and mixed uniformly.

Solid content of the thus obtained light-shielding adhesive composition solution: 100
ffl amount of hydrated amorphous silicon dioxide (silicon oxide containing fi 9
7fi amount% or more) was mixed to obtain a light-shielding coating solution.

Next, the light-shielding coating solution was applied to the release surface of a commercially available silicone-treated release paper so that the film thickness after drying was 15 μm.
Coat it with a roll coater and apply it with a temperature of JR100.
After drying at ~110'C for 5 minutes, a light-shielding adhesive RIJ (3) was formed on the release paper.

In addition, the protective film layer (2) is transparent and has a thickness of 50 μm.
The light-shielding adhesive layer (3) is pressure-bonded and transferred onto one side of the protective film layer (2) using a polyvinylidene chloride film of 100 m, thereby applying the light-shielding adhesive layer (3) to one side of the protective film layer (2). A resistive layer (3) was formed.

On the other hand, as a colorless and transparent base film 1 (4), J'
A polyvinyl fluoride film of 1M 100 μm is used, and this base film layer (4) is coated with the light-shielding adhesive layer (
3) Bonding: The 7-skin film (1) of the present invention was obtained by laminating it with the light-shielding adhesive Ir3 (3) in the 11 film (2).

Table 1 shows the characteristic results of each of the above examples and comparative examples.

(Margins below) From the Pt51 table, it is clear that the masking film of the present invention does not cause lifting when cut, the light-shielding adhesive layer does not remain on the base film layer after the protective film layer is peeled off, and there is no re-adhesion. It is recognized that the sample has characteristics that are superior to the comparative examples, such as having high properties.

(g) Effects of the Invention The masking film of the present invention has a colorless i-light adhesive film layer and a protective film layer with different critical surface tensions, thereby making the adhesive strength of the light-shielding adhesive layer stronger than that of the base film layer. The protective film layer is made larger, and as a result, there is no need to perform peeling treatment on the base film layer, and when a cut is made in the protective film layer with a cutter knife, etc., the base film In addition to almost no lifting, when the protective film layer is peeled off from the base film layer, it has excellent effects such as no light-shielding adhesive layer remaining on the base film layer.

Furthermore, after the masking film of the present invention has been peeled off, the protective film layer can be reattached to the base film layer, or it can be attached to a silk screen or photographic plate many times. , easy to handle and extremely useful.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of the main part of the masking film of the present invention. (1)...Masking film, (2)...Holding: 1
1 film layer, (3)...light-shielding adhesive layer, (4)...
...Base film layer. Fig. 1 1・-, Masking film 2-・q Italy, Ministry (Film scrap 3-・- system optical fiber 14A agent layer 4-1... To・-Sfi I system waste procedure correction band (self-motivated) 1988 Patent Application No. 188928 (October 16, 1988) 2, Name of the invention: Masking film and its manufacturing method 3, Relationship with the case of the person conducting the procedure Patent applicant Address: 2-7-1 Ninomiya, Fukui City Name: Shinko Kagaku Kogyo Co., Ltd. Specification (1) In the specification, page 10, line 9, "matting" is corrected to "matting agent." (2) Same, page 15, line 3 [23 dynes/cmJ]
is corrected to [31dynes/c bite]. (3) Same, 115i line 11 “23 dynes/c
Correct mJ to "31 dynes/cmJ." (4) Same, page 15, line 18, "As a base film layer", [critical surface tension is 31 dynes/c+]
Add "a de". (5) Same, page 17, line 16, ``transparent'' is corrected to ``transparent, critical surface tension is 40 dynes/cn,''. (6) Add "critical surface tension 28 dynes/cm," next to "tojite," on the second line of page 18.

Claims (2)

[Claims] (1) A masking film formed by sequentially laminating a colorless and transparent base film layer, a light-shielding adhesive layer, and a protective film layer, in which a plastic film with a critical surface tension of less than 35 dynes/cm is used as the base film layer. In addition, the critical surface tension of the protective film layer is 3.
A masking film characterized by using a plastic film of 5 dynes/cm or more. (2) Forming a light-shielding adhesive layer on the protective film layer in advance,
A method for producing a masking film, characterized in that a colorless and transparent base film layer is then laminated.