JPH0812948A - Adhesive film or tape - Google Patents

Abstract

PURPOSE:To obtain an adhesive film or tape suitable for surface protection and masking by forming an adhesive layer of e.g. a block rubber on one surface of a polyolefin resin film and forming a polyvinyl alcohol coating film on the other surface. CONSTITUTION:An adhesive layer (B) of a polyisobutylene or block rubber is formed on one surface of a support (A) made of a film or tape of e.g. a polyolefin resin, and a coating film based on polyvinyl alcohol (C) is formed on the other surface to make an adhesive film or tape. Examples of component (B) used include polyisobutylene, butyl rubber or a block copolymer composed of a styrene polymer and a butadiene polymer or the like. When the affinity of the back for layer (C) is lowered by adding a polyolefin resin or a silicone oil to the adhesive layer, the tape or film can be easily rewound from a rolled winding. It is desirable that layer (C) has a degree of saponification of 75% or above and that it is applied while it is in low-molecular weight and then crosslinked later.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an adhesive film or tape. More specifically, synthetic resin board, decorative plywood,
A surface protection film or printed circuit board, which is used to protect the surface of metal plates, painted steel plates, etc., to prevent dust from adhering or scratching, and other electronic parts, photographic film, etc. The present invention relates to an adhesive film or tape exhibiting excellent properties as a surface protection or masking tape.

[0002]

2. Description of the Related Art A surface protective film or masking tape has a structure in which an adhesive layer is formed on one surface of a base material made of thermoplastic resin or paper, has an appropriate adhesive force (temporary adhesion), and is used after use. It must be possible to easily peel off the surface of various adherends without contaminating the surface with an adhesive.

When it is used for a wide surface protection film, or conversely, for electronic parts or photographic films that require fine processing, when the surface protection or masking tape is peeled off from the surface of various adherends after use, Adhesive tape of another kind is laminated and attached near the end of the surface protection film or the masking tape, and the surface protection film or the masking tape can be easily peeled off by peeling with the tape, or,
When these pressure-sensitive adhesive films or tapes are used for masking tapes in the painting or plating process, it is often the case that different types of pressure-sensitive adhesive tapes are laminated and stuck in the same manner as above.

[0004]

As the surface protective film, for example, Japanese Examined Patent Publication No. 58-30911 and Japanese Patent Laid-Open No. Sho 6-63 can be used.
Japanese Patent Laid-Open No. 1-103975 discloses a surface protection film in which a block rubber adhesive layer is provided on one surface of a base material layer made of a thermoplastic resin such as a polyolefin resin. However, if a release treatment is applied to the back surface of the surface protection film or the masking tape, it becomes difficult to bond the above-mentioned adhesive tape of another type, and further, when the base material is made of the polyolefin resin,
Since the adhesiveness to the acrylic pressure-sensitive adhesive tape is low, there is a problem that the adhesiveness of the overlapping portion where these pressure-sensitive adhesive tapes are overlapped and adhered is insufficient. This causes a problem that the pressure-sensitive adhesive tape and the surface protective film are peeled off during the peeling step, and causes a problem that sufficient shielding property cannot be obtained for masking use. Anchor coating on the back side to solve this problem makes it difficult to unwind when rolled up into a roll, necessitating the use of a separator inevitably, resulting in poor workability and high cost. It has the problem of.

As a result of intensive research aimed at solving the above-mentioned conventional problems, the present inventors have found that polyvinyl alcohol as a main component is provided on the back surface of an adhesive tape having an adhesive layer of polyisobutylene type or block rubber type. The present invention is completed based on the finding that the coating film has excellent initial adhesiveness to an adhesive tape, particularly an acrylic adhesive tape, and can be easily unwound from a roll-shaped wound body without using a separator. Was reached.

[0006]

According to a first aspect of the present invention, a polyisobutylene-based or block rubber-based pressure-sensitive adhesive layer is provided on one surface of a substrate, and polyvinyl alcohol is a main component on the other surface. The gist of the present invention is an adhesive film or tape characterized in that a coating film is provided.

The present invention according to claim 2 has as its gist the adhesive film or tape according to claim 1, characterized in that the substrate comprises a polyolefin resin film or tape.

The substrate used in the present invention according to claim 1 is a polyolefin resin such as polyethylene or polypropylene, a polyester resin, a polyamide resin, a polyimide resin, a polyvinyl alcohol resin, a polyvinyl chloride resin or the like plastic film or paper. , Cellophane,
It is appropriately selected from a simple substance and a complex substance such as cloth, non-woven fabric, metal foil and metal vapor deposition film.

The substrate used in the present invention according to claim 2 comprises a polyolefin resin film or tape, and the polyolefin resin includes low density polyethylene, medium density polyethylene, high density polyethylene, and linear low resin. Density polyethylene, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-n-butyl acrylate copolymer Examples thereof include polymers and polypropylene (homopolymers, random copolymers, block copolymers). It is also possible to use mixtures of any of the above.

The substrate may be a single film or tape of the above, but may be a composite film or tape of two or more kinds. Although the base material may be colorless and transparent, it can be used for various purposes by coloring or printing the above raw materials.

The polyisobutylene-based pressure-sensitive adhesive used in the present invention according to claims 1 and 2 is mainly composed of, for example, polyisobutylene, butyl rubber and modified products thereof (hereinafter referred to as "polyisobutylene-based elastomer"). , A tackifying resin, a softening agent, and the like. The cohesive force of the polyisobutylene elastomer can be adjusted by further adding a vulcanizing agent or a filler.

Further, the block rubber type adhesive has the general formula A-
A block copolymer represented by BA and a block copolymer represented by the general formula AB (where A is a styrene polymer block, B is a butadiene polymer block, an isoprene polymer block, or those. A composition in which a tackifier resin, a softening agent, and the like are mainly mixed with an olefin polymer block (hereinafter, referred to as “styrene-based thermoplastic elastomer”).

In the above block rubber adhesive, the styrene polymer block A has an average molecular weight of 4,000 to 1
About 15,000 is preferable, and 8,000 to
It is more preferably about 60,000. The glass transition temperature is preferably 20 ° C. or higher.

The butadiene polymer block, the isoprene polymer block or the olefin polymer block B obtained by hydrogenating them has an average molecular weight of 20,0.
It is preferably about 00 to 450,000, and further 5
It is more preferably about 30,000 to 300,000. The glass transition temperature is preferably −20 ° C. or lower.

The preferred weight ratio of the A component and the B component is A / B = 5/95 to 50/50, more preferably A / B = 10/90 to 30/70. When the value of A / B exceeds 50/50, the rubber elasticity of the polymer becomes small and the tackiness is difficult to develop, and when it is less than 5/95, the styrene domain becomes sparse and the cohesive force is insufficient, resulting in the desired adhesion. I can't get the power.

Furthermore, by adding a polyolefin resin to the above-mentioned pressure-sensitive adhesive, it is possible to further reduce the affinity with the back surface provided with a layer of a release agent containing polyvinyl alcohol as a main component. Examples of the polyolefin resin include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-α olefin copolymer, and propylene-α.
Examples thereof include an olefin copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-vinyl acetate copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-n-butyl acrylate copolymer and a mixture thereof.

The polyolefin resin preferably has a low low-molecular weight content, and specifically, the low-molecular weight content extracted by boiling point dry distillation with n-pentane is preferably less than 1.0% by weight. If the low molecular weight component exceeds 1.0% by weight, the low molecular weight component adversely affects the adhesive properties and reduces the adhesive force according to temperature changes and aging changes.

Further, the compounding amount thereof is the above polyisobutylene elastomer or styrene thermoplastic elastomer 1.
About 300 parts by weight or less is preferable to 00 parts by weight,
It is more preferably 10 to 200 parts by weight. Compounding amount is 3
When it exceeds 100 parts by weight, the development of the tackiness of the pressure-sensitive adhesive is inhibited.

Further, by adding silicone oil to the above-mentioned pressure-sensitive adhesive, it is possible to further reduce the affinity with the back surface provided with a coating film containing polyvinyl alcohol as a main component. This silicone oil is a polymer compound having a polyalkoxy siloxane chain in the main chain, which enhances the hydrophobicity of the pressure-sensitive adhesive layer and further bleeds to the adhesive interface, that is, the surface of the pressure-sensitive adhesive layer, thus suppressing the adhesive force of the pressure-sensitive adhesive. , Has the function of making it difficult for the adhesion promotion phenomenon to occur. The molecular weight of the silicone oil is preferably about 1,000 to 1,000,000, more preferably 10,000 to 500,000.
Is. When the molecular weight exceeds 1,000,000, the compatibility with the polyisobutylene-based elastomer or the styrene-based thermoplastic elastomer becomes insufficient, and when it is less than 1,000,
There is a lot of bleeding to the adhesive interface, and the desired adhesive strength cannot be obtained. Further, the blending amount thereof is preferably about 2 parts by weight or less, more preferably 1 part by weight or less with respect to 100 parts by weight of the polyisobutylene-based elastomer or the styrene-based thermoplastic elastomer. If the blending amount exceeds 2 parts by weight, the desired adhesive strength of the adhesive cannot be obtained.

The same effect can be obtained by using polyethyleneimine having a higher alkyl group introduced therein instead of the silicone oil as the pressure-sensitive adhesive. The above-mentioned polyethyleneimine having a higher alkyl group introduced therein is a polymer made hydrophobic by the introduction of a higher alkyl group, and its molecular weight is preferably about 1,000 to 30,000. The alkyl group is 0.5 to 1.0 equivalent, preferably 0.7 to 1.0, based on the imino group of polyethyleneimine.
Those having 1.0 equivalent are preferably bonded, and the higher alkyl group is preferably an alkyl group having 12 or more carbon atoms,
Particularly, an octadecyl group is preferably used. In order to introduce a higher alkyl group into polyethyleneimine, for example, a method in which an excess higher alkylisocyanate is added to polyethyleneimine and an addition reaction is performed with heating and stirring is employed.

The amount of polyethyleneimine having a higher alkyl group introduced is about 5 parts by weight or less, preferably 3 parts by weight or less, based on 100 parts by weight of the polyisobutylene elastomer or styrene thermoplastic elastomer. If the amount of polyethyleneimine having a higher alkyl group introduced exceeds 5 parts by weight, a large amount of bleed-out occurs on the surface of the pressure-sensitive adhesive layer, and the adherend is contaminated.

The tackifying resin used in the present invention is arbitrarily selected as long as it is selectively compatible with the polyisobutylene elastomer or the styrene thermoplastic elastomer. For example, aliphatic petroleum resin, terpene resin,
A coumarone / indene resin, an aromatic petroleum resin, a rosin resin, an alicyclic petroleum resin and the like are preferably used. The amount of the tackifying resin compounded is 10 to 200 parts by weight, and preferably 20 to 1 part by weight, relative to 100 parts by weight of the polyisobutylene elastomer or styrene thermoplastic elastomer.
It is 50 parts by weight, and more preferably 30 to 100 parts by weight. If the blending amount is less than 10 parts by weight, the tackiness is difficult to develop, and conversely, if it exceeds 200 parts by weight, the cohesive force becomes small and the adhesive remains on the adherend.

In addition to the above, a stabilizer such as an antioxidant may be added to the pressure-sensitive adhesive of the present invention, if necessary. For example, the antioxidant "Irganox 101" may be added.
"0" (manufactured by Ciba Geigy) is effective against heat deterioration.

In the present invention, the method for laminating the pressure-sensitive adhesive layer on the substrate is not particularly limited, but the method by coextrusion molding is preferable because the production apparatus and production process are simple, the lamination strength is high and the production efficiency is good. .

The polyvinyl alcohol used in the present invention is a water-soluble polymer, has a large amount of hydroxyl groups in the molecule, is extremely hydrophilic, and has the ability to easily form a film by coating. . The polyvinyl alcohol has a molecular weight of 1,000 to 3,000,000.
It is preferably about 0. When the molecular weight is less than 1,000, the mechanical strength of the coating film is low, and the coating film is peeled from the base material by rubbing or transferred to the pressure-sensitive adhesive layer to reduce the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer. On the contrary, the molecular weight is 3,000
When it exceeds 50,000, the viscosity becomes high, the surface smoothness of the coating film is impaired, and the tackiness is exhibited, so that the performance as a release agent is lost.

Polyvinyl alcohol is produced by saponification of polyvinyl acetate. The polyvinyl alcohol used in the present invention preferably has a saponification degree of about 50 to 100%, more preferably 75% or more. Further, the polyvinyl alcohol, after being applied to the surface of the substrate opposite to the adhesive layer provided, polyisocyanate,
It may be crosslinked using a crosslinking agent such as polycarboxylic acid (anhydride), dialdehyde, metal alkoxide. Thus, after coating, the method of causing a crosslinking reaction, it is possible to use a low molecular weight polyvinyl alcohol during coating, good coating performance is exhibited, after the crosslinking reaction, the high molecular weight polyvinyl alcohol film obtained, It is a preferable method because it can have preferable mechanical properties.

The degree of crosslinking of the polyvinyl alcohol is measured by gel fraction and is preferably 80% or more, more preferably 90%. When the gel fraction is less than 80%, the strength of the coating film cannot be sufficiently obtained, and the coating film is partially adhered to the pressure-sensitive adhesive layer and peeled off, so that the desired effect cannot be obtained. In the method for measuring the gel fraction, 0.2 g of the crosslinked polyvinyl alcohol was sampled, immersed in 100 ml of water at 23 ° C. for 24 hours with stirring, and then filtered with a stainless 200 mesh filter. Then, it was dried at 105 ° C. for 3 hours in a gear oven, and the gel content was weighed to calculate the gel fraction.

If necessary, a crosslinking accelerator, a plasticizer, a filler, a coloring agent, a stabilizer, an ultraviolet absorber and the like are added to the polyvinyl alcohol. Further, the coating amount of the polyvinyl alcohol is individually designed depending on the application of the product, but in consideration of the properties of the pressure-sensitive adhesive used and the adhesiveness of the laminated pressure-sensitive adhesive tape to the coated surface of the polyvinyl alcohol, it is generally Is about 0.2 to 5 g / m ² . The polyvinyl alcohol coating method may be, for example, a Mayer bar coater, a gravure coater, or a roll coater. Further, in order to improve the adhesion to the base material, it is also effective to previously subject the coated surface of the base material to surface treatment such as corona discharge treatment, rubbing treatment, and sand mat treatment. However, in the present invention, the surface tension of the coated surface of the substrate is 40 by the corona discharge treatment.
It is preferably adjusted to dynes / cm or more.

[0029]

In the pressure-sensitive adhesive film or tape of the present invention according to claims 1 and 2, a polyisobutylene-based or block rubber-based pressure-sensitive adhesive layer is provided on one surface of the substrate, and these pressure-sensitive adhesive layers are formed on the other surface. Since a coating film mainly composed of polyvinyl alcohol, which has a different affinity and a low affinity, is provided, the adhesive film or tape wound body has good releasability from its own back surface. Very easy to deploy from the heavy body. Further, on the back surface of the pressure-sensitive adhesive film or tape of the present invention, it is possible to attach a tape having a large number of polar groups in the molecule, for example, a tape using an acrylic pressure-sensitive adhesive, with high adhesive strength, and therefore, the adherend of the present invention Adhesive film or tape can be easily peeled off, and when used for masking, there is no floating or peeling of the overlapping part, high shielding property is obtained, and work can be performed easily and reliably. Can be done. Since the base material of the adhesive film or tape of the present invention according to claim 2 is a polyolefin resin film or tape, it is very good with the polyisobutylene or block rubber adhesive layer coated on one surface thereof. As described above, the coating film containing polyvinyl alcohol as a main component and the adhesive layer applied to the other surface of the base material have a low affinity, and thus have good releasability. Therefore, this adhesive film or tape-wound body can be developed very easily.

[0030]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, the releasability and the adhesive strength of the laminated adhesive tape to the back surface of the adhesive film were tested and evaluated by the methods described below.

1. Release performance Measured according to JIS Z1522 (cellophane adhesive tape). The pressure-sensitive adhesive films obtained in Examples and Comparative Examples were pressure-bonded to a stainless steel plate with a 2 kg roller at a speed of 300 mm / min. After pressure bonding, adhesion was promoted under the condition of 23 ° C. × 65% RH to prepare a sample. Therefore, it is the same kind of adhesive film as the laminated adhesive film. The adhesive film laminated on its back surface was then kept in an atmosphere of 50 ° C. for 24 hours, and then the peeling speed was 300 mm.
/ Min and 50 m / min, low and high speed.
For the measurement of the peeling speed of 50 m / min, a high-speed peeling tester TF-701 manufactured by Tester Sangyo Co., Ltd. was used.

2. Adhesive force of the adhesive tape to the back surface of the adhesive film It was measured according to JIS Z1522 (cellophane adhesive tape). The pressure-sensitive adhesive films obtained in Examples and Comparative Examples were pressure-bonded to a stainless steel plate with a 2 kg roller at a speed of 300 mm / min. After pressure bonding, adhesion was promoted under the condition of 23 ° C. × 65% RH to prepare a sample. As an adhesive film laminated, acrylic adhesive film (made by Sekisui Chemical Co.,
Product name: CUTRON 810). The acrylic pressure-sensitive adhesive films laminated on the back surface of the pressure-sensitive adhesive films obtained in Examples and Comparative Examples were then held in an atmosphere of 23 ° C. for 20 minutes, after which the peeling speed was measured at 300 mm / min.

(Example 1) Polyisobutylene (PIB manufactured by Exxon Co., trade name: Vistanex MML-100)
100 parts by weight, tackifying resin (TF manufactured by Arakawa Chemical Industry Co., Ltd.,
Trade name: Ester gum H) 100 parts by weight, low density polyethylene (Mitsui Petrochemical Co., Ltd., trade name: Mirason 12) 5
A pressure-sensitive adhesive composition consisting of 0 parts by weight was sufficiently mixed in a nitrogen atmosphere at 180 ° C., and a hot melt coater was used to form a base polyester resin film (manufactured by Nimura Chemical Co., Ltd., trade name:
(PET-FE2000, thickness 38 μm) A composite film having a 40 μm thick adhesive layer provided on one surface thereof was obtained.
Next, the other surface of the base material is subjected to corona discharge treatment to have a surface tension of 54 dyne / cm, and polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name: PVA117, molecular weight 80,0).
00, saponification degree 98.5%) isopropanol / water = 1
A 10% by weight solution of 1/1 was applied and dried at a coating amount of 0.8 g / m ² with a Meyer bar coater to obtain an adhesive film. The performance of the obtained adhesive film is shown in Table 1.

Example 2 Polyisobutylene of Example 1 (PIB manufactured by Exxon Co., trade name: Vistanex MML)
-100) 100 parts by weight, and instead of 100 parts by weight of tackifying resin (TF manufactured by Arakawa Chemical Industry Co., Ltd., trade name: Ester gum H), styrene thermoplastic elastomer (SBS manufactured by Shell Chemical Co., trade name: Califlex TR) -1107) 1
An adhesive film was obtained in the same manner as in Example 1 except that 00 parts by weight and 100 parts by weight of tackifying resin (TF manufactured by Tonex Co., Ltd., trade name: Escoletz) were used. The performance of the obtained adhesive film is shown in Table 1.

Example 3 A polyester resin film as a base material of Example 2 (manufactured by Nimura Chemical Co., Ltd., trade name: PET-FE)
2000, thickness 38 μm), low density polyethylene (Mitsui Petrochemical Co., Ltd., trade name: Mirason 16) was used by extrusion molding to form a film with a thickness of 38 μm, and the other side of the substrate was used. An adhesive film was obtained in the same manner as in Example 2 except that the surface tension was changed to 43 dynes / cm by the corona discharge treatment. The performance of the obtained adhesive film is shown in Table 1.

Example 4 100 parts by weight of the styrene-based thermoplastic elastomer (SBS manufactured by Shell Chemical Co., trade name: Califlex TR-1107) of Example 3, tackifying resin (TF manufactured by Tonex Co., trade name: Escoletz) ) 1
Styrene-based thermoplastic elastomer (SIS manufactured by Kuraray Co., Ltd., trade name: Septon 2063) 10 instead of 00 parts by weight
0 parts by weight, tackifying resin (produced by Yasuhara Yushi Kogyo Co., Ltd., trade name:
An adhesive film was obtained in the same manner as in Example 3 except that 100 parts by weight of Clearon P-115) was used. The performance of the obtained adhesive film is shown in Table 1.

(Comparative Example 1) The same substrate and the same adhesive composition as in Example 4 were used, the back surface of the substrate was untreated, and the adhesive film was prepared according to the methods of Examples 1 to 4. Got The performance of the obtained adhesive film is shown in Table 1.

Comparative Example 2 Polyisobutylene of Example 1 (PIB manufactured by Exxon, trade name: Vistanex MML)
-100) 100 parts by weight, 100 parts by weight of a tackifying resin (TF manufactured by Arakawa Chemical Industry Co., Ltd., trade name: ester gum H), and replaced by an acrylic adhesive (manufactured by Soken Chemical Industry Co., Ltd., trade name: SK).
Dyne 1700) 100 parts by weight, an isocyanate curing agent (manufactured by Soken Chemical Industry Co., Ltd., trade name: L-45) was used in the same manner as in Example 1 except that a comma coater was used as a coating machine. An adhesive film was obtained. The performance of the obtained adhesive film is shown in Table 1.

(Comparative Example 3) Using the same substrate and the same adhesive composition as in Example 4, the surface tension of the other surface of the substrate was adjusted to 43 dynes / cm by corona discharge treatment, and polyvinyl alcohol ( Kuraray Co., Ltd., trade name: PVA117, molecular weight 80,000, saponification degree 98.5%) in place of a 10 wt% solution of isopropanol / water = 1/1, a non-silicone release agent (manufactured by Nippon Shokubai Chemical Co., Ltd. , Product name: RP-1
An adhesive film was obtained in the same manner as in Example 4 except that 8) was used. The performance of the obtained adhesive film is shown in Table 1.

[0040]

[Table 1]

[0041]

The pressure-sensitive adhesive film or tape of the present invention according to claims 1 and 2 is provided with a polyisobutylene-based or block rubber-based pressure-sensitive adhesive layer on one surface of the substrate and these pressure-sensitive adhesives on the other surface. Since a coating film containing polyvinyl alcohol having a polarity different from that of the agent layer and having a low affinity is provided, the adhesive film or the tape wound body has a good releasability from its own back surface. It is extremely easy to deploy from a tape wound body.
Further, on the back surface of the pressure-sensitive adhesive film or tape of the present invention, it is possible to attach a tape having a large number of polar groups in the molecule, for example, a tape using an acrylic pressure-sensitive adhesive, with high adhesive strength, and therefore, the adherend of the present invention Adhesive film or tape can be easily peeled off, and when used for masking, there is no floating or peeling of the overlapping part, high shielding property is obtained, and work can be performed easily and reliably. Can be done. Since the base material of the adhesive film or tape of the present invention according to claim 2 is a polyolefin resin film or tape, it is very good with the polyisobutylene or block rubber adhesive layer coated on one surface thereof. An anchor that is
As described above, the polyvinyl alcohol-based coating film applied to the other surface of the base material and the above-mentioned pressure-sensitive adhesive layer have a low affinity, and therefore have good releasability. The wound body can be developed extremely easily.

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Claims (2)

[Claims] 1. A surface of the substrate is provided with a polyisobutylene-based or block rubber-based adhesive layer, and a coating film containing polyvinyl alcohol as a main component is provided on the other surface of the substrate. Adhesive film or tape to be used. 2. The adhesive film or tape according to claim 1, wherein the base material is a polyolefin resin film or tape.