JPH0782231B2 - Light-shielding masking film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a light-shielding masking film in which a light-shielding release layer is provided on a transparent support.

[Conventional technology]

The light-shielding masking film comprises a transparent plastics film support and a light-shielding release layer provided on the support, so that by peeling off the release layer, the peeled portion becomes transparent. It is used for photoengraving and the like by utilizing this characteristic.

The characteristics required of the light-shielding masking film are:
The peeling layer has high strength, the plastic film support has good transparency, the peeling property of the peeling layer is excellent, and even if a cut is made in the peeling layer portion with a cutter knife, it floats on the non-peeling portion. Does not occur, the cut edge of the release layer with a cutter knife is sharp, it has excellent light-shielding properties, it has flexibility, and there is no stickiness on the surface.
For example, you can get a precise image.

As a light-shielding masking film, for example, Japanese Patent Publication No. 51-2
No. 5478 discloses one having a release layer made of a polyurethane resin and a fibrin acetate resin.
Does not satisfy all the characteristics of.

JP-B-58-46011 discloses a light-shielding masking film using a release layer containing a vinyl chloride-vinyl acetate copolymer and nitrile rubber, and JP-A-61-12336 discloses vinyl chloride-vinyl acetate. A light-shielding masking film using a release layer containing a copolymer and polyurethane is disclosed, but the characteristics of the masking film can be broadly changed depending on the mixing ratio of vinyl chloride-vinyl acetate copolymer and nitrile rubber or polyurethane resin. For example, when the ratio of nitrile rubber or polyurethane resin increases, the peel strength increases, but the blocking property (stickiness) tends to occur, and the peel layer tends to stretch during peeling. It was Further, if the proportion of the vinyl chloride-vinyl acetate copolymer is high, the peeling layer will be easily broken at the time of peeling and peeling will be difficult, and the adhesive strength between the peeling layer and the support will be reduced, and therefore peeling will occur due to impact or strain. There is a drawback that the layer floats easily from the support and peels off easily, and even if the mixing ratio of the vinyl chloride copolymer and the nitrile rubber or urethane resin is adjusted, the various properties required for the masking film are sufficient. Could not be satisfied with.

[Problems to be Solved by the Invention]

Therefore, the object of the present invention is that there is no blocking and stickiness of the peeling layer, peeling is easy (good pick-up property, no overstretching or breakage occurs), and various handling masking films after peeling required parts It is an object of the present invention to provide a light-shielding masking film in which a peeling layer in a non-peeling portion does not rise or peel off from a support due to an impact or a strain applied to a miking film during working.

[Means for Solving the Problems]

On the transparent support, the above-mentioned object is (A) maleic acid diester, fumaric acid diester,
A light-shielding release layer containing a copolymer of vinyl chloride and at least one monomer selected from the group consisting of itaconic acid diester and vinyl propionate, (B) rubber, and (C) a colorant. And a light-shielding masking film.

The present invention will be described in detail below.

As the transparent support constituting the light-shielding masking film of the present invention, polyethylene terephthalate, polyester such as polybutylene terephthalate, aliphatic or aromatic polyamide, polyethylene, polyolefin such as polypropylene, polystyrene, polycarbonate, polyvinyl chloride, polychloride Synthetic resin films made of vinylidene, semi-synthetic resin films such as cellulose acetate, synthetic resin films, synthetic resin films and semi-synthetic resin films, and synthetic resin films and /
Alternatively, a laminate film of a semi-synthetic resin film and paper can be used.

The support is preferably colorless and transparent. It is also possible to knead an antistatic agent into the support in order to prevent static electricity of the support, or to provide an antistatic layer on one side of the support and to provide a light-shielding release layer on the opposite side. Among them, the polyethylene terephthalate film is particularly preferable because it has high tensile and tear strengths and excellent dimensional stability. This support has a thickness of 50-250μ
m is better. The film constituting this support may be stretched or non-stretched depending on its production method.

Examples of the maleic acid diester in the copolymer of the component (A) used in the present invention include maleic acid dialkyl ester and maleic acid dialkenyl ester, specifically, dimethyl maleate, diethyl maleate and maleic acid. Examples include diisopropyl, di-n-butyl maleate, diisobutyl maleate, di-2-ethylhexyl maleate, diallyl maleate and mixtures of two or more thereof.

Examples of the fumaric acid diester in the copolymer of the component (A) used in the present invention include fumaric acid dialkyl esters, specifically, dimethyl fumarate, diethyl fumarate, diisopropyl fumarate and di-n-fumarate. -Butyl,
Examples include diisobutyl fumarate, di-sec-butyl fumarate, di-2-ethylhexyl fumarate, and mixtures of two or more thereof.

Examples of the itaconic acid diester in the copolymer of the component (A) used in the present invention include itaconic acid dialkyl esters, specifically, dimethyl itaconic acid, diethyl itaconic acid, diisoprovir itaconic acid, diaconic acid di n −
Butyl, di-2-ethylhexyl itaconate and mixtures of two or more thereof.

In addition, a copolymer of vinyl propionate and vinyl chloride is used as the component (A) of the present invention.

The composition ratio of each copolymer component in the copolymer of the component (A) used in the present invention is such that vinyl chloride is 60 to 95% by weight, preferably 70 to 90% by weight, and the other copolymerizable components are 40 to 90% by weight. 5% by weight, preferably 30 to 10% by weight is suitable, and a multi-component copolymer resin containing a copolymerizable monomer other than the above may be used. In the case of a multi-component copolymer, the proportion of the other copolymerizable monomer is 10% by weight or less, preferably 3% by weight or less. Examples of such monomers include monomethyl maleate, monobutyl maleate, mono-2 maleate.
-Ethylhexyl, monomethyl itaconate, monobutyl itaconate, acrylic acid, methacrylic acid, maleic anhydride, itaconic anhydride, hydroxyethyl acrylate, hydroxyethyl methacrylate and the like.

Vinyl chloride-maleic acid diester copolymers are commercially available products such as BASF's LAROFLEX 452 and Huls' VILIT MB30, V
ILIT MC31 etc. are supplied.

The rubber of the component (B) used in the present invention may be either synthetic rubber or natural rubber, and is appropriately selected from those having a good compatibility with the copolymer of the component (A). Preferred examples include nitrile rubber, urethane rubber, acrylic rubber, vinyl chloride-urethane copolymer and the like.

As the nitrile rubber, one containing butadiene and acrylonitrile as main components is used.

Examples of such a resin include an acrylonitrile-butadiene copolymer, an acrylonitrile-butadiene-copolymer, and a terpolymer resin containing a monomer having a carboxyl group. In the present invention, the content of acrylonitrile is 18 to 53% by weight, preferably 25 to 43%.
Those in the range of weight% are preferable.

Examples of the urethane rubber include polyurethane resins made of diisocyanate, triisocyanate and the like and adipic acid polyester, polyoxypropylene glycol and the like.

As acrylic acid ester that constitutes acrylic rubber,
Alkyl (preferably having 1 to 4 carbon atoms) esters such as ethyl ester and butyl ester are preferred, and acrylonitrile and the like are blended as other components. Specific examples of the acrylic rubber include butyl acrylate-acrylonitrile copolymer, and the composition ratio thereof is butyl acrylate 85 to 90% by weight, acrylonitrile 15 to 9.
5% by weight, 2-hydroxyethyl methacrylate 0.5-2
It is preferably in the weight%.

The colorant used in the present invention is for imparting a light-shielding property to the light-shielding masking film, and examples of such a colorant include dyes and / or pigments.

The dye is an oil-soluble dye, has good compatibility with the above-mentioned components (A) and (B), and has little change in color tone or fading due to heat, light, or other factors, and the necessary light shielding. The color tone and the dye structure are not particularly limited as long as they have properties.

The pigment is not particularly limited as long as it has good compatibility with the above-mentioned components (A) and (B) and the same performance as that of the dye is satisfied.

The amount of the colorant added is appropriately determined depending on the light-shielding property of the colored release layer, but is usually about 2 to 100% by weight, preferably about 5 to 50% by weight, based on the entire release layer.

The use ratio (weight ratio) of the copolymer of the component (A) and the rubber of the component (B) is 55/45 to 85/15, preferably 60/40.
~ 80/20 is good. When the amount of the component (A) used is too small, the coating film becomes soft, the adhesion to the support becomes strong, and the pick-up property deteriorates. In addition, when they are placed on top of each other, they tend to form blocks. Furthermore, the coating film to be peeled easily extends and the peeling work becomes difficult.

On the contrary, when the amount of the component (A) used is too large, the adhesion to the support becomes weak and the coating film to be peeled off easily breaks.

The masking film of the present invention can be obtained by uniformly applying a composition comprising the above-described component composition on one surface of a transparent support by an arbitrary method and then drying it. The thickness of the light-shielding release layer is usually 10 to 50 μm, and preferably 20 to 30 μm. At this time, if necessary, a suitable organic solvent, for example, alcohol-based, ketone-based, ester-based,
Organic solvents such as hydrocarbons and halogenated hydrocarbons can be used.

Further, the composition may be appropriately blended with a matting agent such as silica, a leveling agent, an antiblocking agent, a plasticizer, a filler, etc., as long as the object of the present invention is not impaired.

〔The invention's effect〕

The light-shielding masking film of the present invention is free from blocking and stickiness of the release layer, is easy to release, has good pick-up property, does not cause excessive elongation or breakage, and the release layer of the non-released part floats from the support. It does not fall off.

Examples 1 to 9 and Comparative Examples 1 to 4 A biaxially stretched polyethylene terephthalate film support having a thickness of 100 μm was coated with a composition for forming a release layer having the composition shown in Table 1 below and dried at 110 ° C. for 5 minutes. Thus, a light-shielding masking film having a light-shielding release layer having a thickness of 25 μm was produced.

The properties of these films were investigated by the following test methods. The results are shown in Table 1.

Test method Blocking resistance A masking film is layered so that the polyethylene terephthalate surface, which is the support, and the light-shielding release surface are in contact, and the temperature is
Apply a load of 30 kg / m ^{2 in} an atmosphere of 40 ° C and 80% relative humidity, and
Leave for 4 hours. The state of blocking after standing was examined.

◎: No blocking occurred ○: Blocking occurred only partly △: Blocking occurred in 20 to 50% ×: Blocking occurred in the whole surface Lifting and peeling-off property 5 mm of light-shielding peeling layer of 3 cm square sample The sample was cut into sections, and the back surface of the sample was flipped with a finger to give an impact, and the release layer was lifted up and peeled off was observed.

◯: Uplifting, peeling and falling off does not occur Δ: Uplifting, peeling and falling off occurs in part ×: Uplifting, peeling and falling off occurs entirely Peeling property Light-shielding peeling layer with good pickability by a cutter knife, and peeling Occasionally, comprehensive evaluation is made for those in which the release layer does not extend too much or break.

Good: Good Fair: Good Poor: In Examples 1 to 9 of the present invention, excellent results were obtained in terms of blocking resistance, rising, peeling-off property, and peeling property. Example 2 with the addition of silica,
It can be seen that in Examples 4 and 6, the blocking resistance is further improved as compared with Examples 1, 3 and 5 containing no silica. In Comparative Example 1 in which the ratio of vinyl chloride-maleic acid dimethyl ester-maleic acid diethyl ester terpolymer is low, blocking resistance and peeling property are poor, and in Comparative Example 2 in which the ratio is high, blocking resistance is good. However, lifting of the non-peeling portion occurs. Furthermore, in Comparative Example 3 in which a vinyl chloride-vinyl acetate-terpolymer was used instead of the vinyl chloride-maleic acid dimethyl ester-maleic acid diethyl ester terpolymer, the blocking resistance was inferior, and the non-peeling part floated. Occurs. Further, in Comparative Example 4 in which silica is added to this, although the blocking resistance is improved, the lifting of the non-peeling portion is not prevented.

Examples 10 to 17 Instead of the vinyl chloride-maleic acid dimethyl ester-maleic acid diethyl ester terpolymer in Example 7, a vinyl chloride-maleic acid diethyl ester copolymer (vinyl chloride 80% by weight) (implementation) Example 10), vinyl chloride-maleic acid diisopropyl ester copolymer (vinyl chloride 80% by weight) (Example 11), VILIT MC31 from Hüls (vinyl chloride, maleic acid ester and a third component containing a carboxy group) Ternary copolymer, vinyl chloride in the copolymer is 75
% By weight, acid value 6 mg KOH / g) (Example 12), vinyl chloride-
Fumaric acid diethyl ester copolymer (vinyl chloride 80% by weight) (Example 13), vinyl chloride-itaconic acid diethyl ester copolymer (vinyl chloride 80% by weight) (Example 14),
Vinyl chloride-vinyl propionate copolymer (vinyl chloride
70% by weight) (Example 15), vinyl chloride-vinyl propionate-maleic acid copolymer (weight ratio 70: 27: 3) (Example 1)
6) and vinyl chloride-maleic acid dimethyl ester-maleic acid diethyl ester terpolymer (weight ratio 81: 8: 1
1) A light-shielding masking film was prepared using a mixture of 40 g and 35 g of vinyl chloride-vinyl propionate-maleic acid copolymer (weight ratio 80: 19: 1) (Example 17), respectively. When the test was conducted by the test method, as shown in Table 2, almost the same results as in Example 7 were obtained.

Claims (2)

[Claims] 1. On a transparent support, (A) a copolymer of vinyl chloride with at least one monomer selected from the group consisting of maleic acid diester, fumaric acid diester and itaconic acid diester; ) Rubber and (C) a colorant are contained, and the weight ratio of component (A) and component (B) is 55 / 45-8.
A light-shielding masking film having a light-shielding release layer of 5/15. 2. A transparent support containing (A) a copolymer of vinyl pyropionate and vinyl chloride, (B) a rubber, and (C) a colorant, and the components (A) and (B). ) Weight ratio is 55/45 ~ 8
A light-shielding masking film having a light-shielding release layer of 5/15.