JPH05117605A - Releasable layer, pressure-sensitive adhesive member and separator - Google Patents

Abstract

PURPOSE:To obtain a releasable layer excellent in the adhesion to a supporting base material so that it is hardly fallen off the material and also excellent in releasability from the bonding surface, and a pressure-sensitive adhesive member and a separator both having such releasable layers. CONSTITUTION:A releasable layer 1 comprising a film composed of a polymer layer 13 well-adherent to a supporting base material 2 and a releasability- imparting layer 11, a pressure-sensitive adhesive member having the releasable layer on one side of a supporting base material and a pressure-sensitive adhesive layer on the other side thereof, and a separator having the releasable layer or layers on one side or both sides of a supporting base material. Thus, there can be obtained those characteristically having an easily controllable adhesive force against the bonding surface while maintaining strong adhesion to the supporting base material, hence exhibiting a weak adhesive force against the bonding surface and a good releasability therefrom and having strong adhesion to the hardly bondable supporting base material so that they are scarcely fallen off the material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a releasable treatment layer having excellent adhesion to a supporting substrate and releasability from an adhesive surface, and an adhesive member and a separator having the releasable treatment layer.

[0002]

2. Description of the Related Art Heretofore, various types of release agents such as silicone type and long chain alkyl type have been known as release agents used for back treatment of adhesive members and formation of separators for protecting adhesive surfaces. In such a release agent, strong adhesion to a supporting substrate and releasability from an adhesive surface are basic performances required for the release agent film. However, it is difficult to make them compatible, and it has been a long-standing problem.
In particular, a release agent film having a weak adhesive force to the adhesive surface and a good release property, and having a property of firmly adhering to the supporting base material and hardly coming off has not yet been proposed. Absent. A release agent film having such characteristics is used as a surface protection adhesive member such as a wide adhesive tape or a metal plate.
This is particularly advantageous in the case of large area adhesives.

In order to develop the above-mentioned properties, it was attempted to surface-treat a supporting substrate with a polymer having good adhesion and to apply a release agent on the surface-treated layer to superimpose a release agent film. However, because the surface of the supporting substrate and the surface treatment layer of the good adhesion polymer are substantially equivalent in terms of the adhesiveness with the release agent film, the problem of falling off of the release agent film cannot be overcome and satisfactory results can be obtained. I couldn't get it. The problem of detachment of the release agent film appears as a problem of transfer to the adhesive surface, and the adhesive strength is reduced due to contamination of the adhesive surface. The problem of detachment is particularly remarkable in the case of a soft polyvinyl chloride-based or polyolefin-based hardly-adhesive supporting base material.

[0004]

DISCLOSURE OF THE INVENTION The present invention is directed to the development of a releasable treatment layer having excellent adhesion to a supporting substrate and also excellent releasability from an adhesive surface, and an adhesive member having the releasable treatment layer. And to obtain a separator.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a release treatment layer characterized by comprising a polymer layer having good adhesion on a supporting substrate and a peeling imparting layer, and a support substrate. Having the peelable treatment layer on one side of the material, an adhesive member characterized by having an adhesive layer on the other side, and having the peelable treatment layer on one or both sides of the supporting substrate, It is intended to provide a separator.

[0006]

[Function] A release treatment layer comprising a layer-separating film comprising a polymer layer having good adhesion to a supporting substrate and a release-providing layer is a mixed layer in which the polymer layer and the release-providing layer penetrate into each other at the layer separation interface. Probably because of the strong bond chemically or physically formed by forming a layer, it shows a particularly excellent adhesion state compared to the coating superposed film of each layer, and the respective properties of the polymer layer and the peelability imparting layer are It is fully demonstrated. Therefore, while controlling the adhesive force (peelability) with the adhesive surface depending on the type of the release agent used, it is possible to provide strong adhesion that does not easily fall off the supporting base material.

[0007]

[Exemplary constituent elements of the present invention] The release treatment layer of the present invention comprises a polymer layer having good adhesion to a supporting substrate and a release-providing layer, which are separated into layers. An example is shown in FIG. Reference numeral 1 is a release treatment layer, 11 is a release property imparting layer, and 13 is a polymer layer. In addition, 12 is a mixed layer at the separation interface between the peelability imparting layer 11 and the polymer layer 13, and 2 is a supporting base material.

The release treatment layer of the present invention is formed, for example, by applying a mixed liquid of a polymer having good adhesion and a release agent onto a supporting substrate using a suitable device such as a squeeze coater,
The coating layer can be appropriately treated by heating or radiation to form a solidified film.
In that case, the layer-separated structure is usually formed in the application process of the mixed solution without any special treatment, and the polymer layer is separated on the side of the supporting substrate. Therefore, the strippable treatment layer can be formed in a conventional manner except that the above mixed solution is used instead of the conventional stripping agent.

As the polymer, an appropriate polymer may be used which exhibits good adhesion depending on the supporting substrate to be treated. Generally, an acrylic copolymer containing an alkyl ester of acrylic acid or methacrylic acid whose alkyl group has 8 or less carbon atoms, a vinyl polymer such as polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, NBR,
Various synthetic rubbers such as SBR, IR and BR, rubber-based polymers such as natural rubber, polyurethane-based polymers, unsaturated polyester resins, epoxy resins such as aromatic or alicyclic resins are used.

An appropriate release agent may be used. Generally, condensation-type or addition-type thermosetting silicone release agents, radiation-curable silicone release agents by ultraviolet rays or electron beams, acrylic acid or methacrylic acid fluorine-containing esters and alkyl groups having 8 or less carbon atoms. , A fluorine-based release agent containing an acrylic copolymer composed of an alkyl ester of acrylic acid or methacrylic acid, etc., an alkyl ester of acrylic acid or methacrylic acid having a long-chain alkyl group having 12 to 22 carbon atoms, and alkyl A long-chain alkyl-based release agent containing an acrylic copolymer composed of an alkyl ester of acrylic acid or methacrylic acid whose group has 8 or less carbon atoms (Japanese Patent Publication No. 29-3144).
JP-B-29-7333) and the like are used.

The amount of the release agent used is 50 to 50 per 100 parts by weight of the polymer having good adhesion to the supporting base material, based on the solid content, in terms of the adhesiveness to the supporting base material and the releasability from the adhesive surface.
0 weight part, especially 100-250 are preferable. The mixed solution of the polymer and the release agent may be prepared by an appropriate method such as a method of dissolving them in an appropriate common solvent.

The thickness of the release treatment layer formed on the supporting substrate is preferably 0.1 to 5 μm, and more preferably 0.15 to 3 μm.
If the thickness is less than 0.1 μm, it may be difficult to form a film having a weak adhesion to the adhesive surface, but if it exceeds 5 μm, the peelability-imparting layer is easily transferred to the adhesive layer side.

The thickness of the polymer layer in the release treatment layer is preferably 0.05 to 3 μm, and more preferably 0.1 to 2.5 μm. If the thickness is less than 0.05 μm, the adhesion to the supporting substrate may be poor. On the other hand, the thickness of the releasability-providing layer in the releasability-treated layer is preferably 0.05 to 3 μm, and more preferably 0.1 to 2.5 μm. Its thickness is 0.05 μm
If it is less than the range, the peeling performance may be poor. If the thickness of the polymer layer and the release property imparting layer exceeds 3 μm, the contribution of performance improvement becomes poor, which is disadvantageous in terms of thinning.

The pressure-sensitive adhesive member of the present invention is one in which the release treatment layer is provided on one surface of the supporting substrate and the pressure-sensitive adhesive layer is provided on the other surface. The formation can be performed according to a conventional method for forming an adhesive tape or a surface protective sheet, for example, a method of applying an adhesive to the other surface of a supporting substrate provided with a release treatment layer.
As the adhesive, for example, an appropriate adhesive such as an acrylic adhesive or a rubber adhesive may be used.

The separator of the present invention comprises one side of a supporting substrate,
Or, the release treatment layer is provided on both sides. The separator is, for example, adhered to an adhesive surface of a surface protective sheet, a double-sided adhesive tape or the like, and is used for the purpose of protecting the adhesive surface until it is put into practical use.

In the above, there is no particular limitation on the supporting base material on which the release treatment layer is provided. Generally, for example, paper, plastic laminated paper, cloth, plastic laminated cloth, plastic film, metal foil and the like are used. In particular, in the present invention, the present invention can be advantageously applied to a difficult-adhesive supporting base material such as a soft polyvinyl chloride film, a polyethylene laminated paper, a polypropylene film, etc., in which a release agent film is easily detached in the related art. The release treatment layer of the present invention can be applied to various uses other than the above-mentioned adhesive member and separator.

[0017]

The release treatment layer of the present invention comprises a layer-separated film of a polymer layer having good adhesion to a support substrate and a release property imparting layer. Excellent in releasability. In addition, it is possible to easily control the adhesive force (peelability) to the adhesive surface while having a strong adhesive force to the supporting base material, and to show a good adhesive property to the adhesive surface by showing a weak adhesive force. It is also possible to easily obtain a material which has the property of firmly adhering to the supporting base material having the above-mentioned resistance and being hard to come off, and which is hard to drop off.

[0018]

【Example】

Example 1 Acrylic copolymer obtained by polymerizing 40 parts of butyl acrylate (parts by weight, the same applies hereinafter), 55 parts of methyl methacrylate, and 5 parts of acrylic acid in toluene using azobisisobutyronitrile as an initiator. 100 parts of the combined product (40 wt% solution) (solid content, the same applies hereinafter), 100 parts of addition reaction type silicone release agent (KNS-305 manufactured by Shin-Etsu Chemical Co., Ltd.) and its curing catalyst (PL-7 manufactured by the same company). 1 part was added, and toluene was added thereto to prepare a mixed solution (5% by weight), which was applied onto a 20 μm-thick low-density polyethylene layer laminated on one side of kraft paper, and then at 100 ° C. for 3 minutes. A heat treatment was applied to form a layer-separated release treatment layer having a thickness of about 2 μm to obtain a separator. The thickness of the acrylic copolymer layer in the layer-separable release treatment layer was about 1.0 μm, and the thickness of the silicone release agent layer was about 1.0 μm.

Example 2 Acrylic copolymer 100 obtained by polymerizing 30 parts of 2-ethylhexyl acrylate, 60 parts of ethyl acrylate and 3 parts of acrylic acid in toluene using azobisisobutyronitrile as an initiator. To the parts, 120 parts of addition reaction type silicone release agent (KS-772 manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.5 parts of its curing catalyst (PL-3 manufactured by the same company) are added, and toluene is added to the mixed liquid. (2% by weight) was prepared and applied to a corona-treated surface of a polyethylene film having a thickness of 20 μm, and heat-treated at 100 ° C. for 3 minutes to give a thickness of about 0.
A 4 μm layer-separated release treatment layer was formed to obtain a separator. The thickness of the acrylic copolymer layer in the layer-separable release treatment layer was about 0.18 μm, and the thickness of the silicone release agent layer was about 0.22 μm.

Example 3 100 parts of a urethane / vinyl chloride copolymer (NP-Alter MN, manufactured by Toagosei Co., Ltd.), 130 parts of a condensation reaction type silicone release agent (KS-705F, manufactured by Shin-Etsu Chemical Co., Ltd.) and its curing catalyst. 2 parts (manufactured by the same company, PS-1) were dissolved in toluene to prepare a mixed solution (2% by weight), and the mixed solution was made to have a thickness of 20
Apply to one side of μm soft polyvinyl chloride film, 1
A heat treatment was carried out at 20 ° C. for 2 minutes to form a layer-separable release treatment layer having a thickness of about 0.6 μm to obtain a separator. The urethane-vinyl chloride copolymer layer in the layer-separable release treatment layer had a thickness of about 0.26 μm, and the silicone release agent layer had a thickness of about 0.34 μm.

Example 4 100 parts of an ethylene / vinyl acetate copolymer (vinyl acetate content 45 mol%) and 250 parts of a fluorine-based release agent were dissolved in ethyl acetate to prepare a mixed solution (5% by weight). Is coated on a low-density polyethylene layer having a thickness of 20 μm laminated on one side of kraft paper and heat-treated at 100 ° C. for 2 minutes to form a layer-separable release treatment layer having a thickness of about 2 μm.
A separator was obtained. The thickness of the ethylene / vinyl acetate copolymer layer in the layer-separated release treatment layer is about 0.57 μm,
The thickness of the fluorine-based release agent layer was about 1.43 μm. Note the fluorine-based release agent, 40 parts of 2-hydroxyethyl methacrylate, _{formula: C 2 F 5 (C 2} F 4) n C 2 H 4 OC
(O) A fluorine-containing acrylic copolymer obtained by polymerizing 60 parts of a fluorine-based monomer represented by C (CH ₃ ) = CH ₂ in toluene using azobisisobutyronitrile as an initiator.

Example 5 Unsaturated polyester resin (manufactured by Toyobo Co., Ltd., Byron 30)
0) 100 parts and 200 parts of long-chain alkyl-based release agent are dissolved in ethyl acetate to prepare a mixed solution (3% by weight), which is applied to the corona-treated surface of a polyethylene film having a thickness of 20 μm, and the temperature is 100 ° C. Heat treatment for 2 minutes at a thickness of about 0.3
A layer-separated release treatment layer having a thickness of μm was formed to obtain a separator. The unsaturated polyester resin layer in the layer-separable release treatment layer had a thickness of about 0.1 μm, and the long-chain alkyl release agent layer had a thickness of about 0.2 μm. The long-chain alkyl-based release agent is composed of an acrylic copolymer obtained by polymerizing 50 parts of octadecyl methacrylate and 100 parts of acrylic acid in toluene with azobisisobutyronitrile as an initiator.

Comparative Example 1 Condensation reaction type silicone release agent (KS-705F) 10
A mixed solution (1% by weight) was prepared by dissolving 0 part and 1 part of the curing catalyst (PS-1) in toluene to prepare a mixed solution having a thickness of 20 μm.
Apply to one side of soft polyvinyl chloride film of m, 12
A heat treatment was performed at 0 ° C. for 2 minutes to form a release agent film having a thickness of about 0.2 μm to obtain a separator.

Comparative Example 2 A solution of the fluorine-based release agent used in Example 4 in ethyl acetate (5
Weight%) laminated on one side of kraft paper to a thickness of 2
Coat on 0μm low density polyethylene layer, 100 ℃
Was heated for 2 minutes to form a release agent film having a thickness of about 2 μm to obtain a separator.

Comparative Example 3 On one side of a soft polyvinyl chloride film having a thickness of 20 μm,
The toluene solution (2% by weight) of the urethane / vinyl chloride copolymer used in Example 3 was applied and heat-treated at 120 ° C. for 2 minutes to form a urethane / vinyl chloride copolymer layer having a thickness of about 0.3 μm. After formation, a condensation reaction type silicone release agent (KS-705F, which is formed thereon according to Example 3)
A toluene solution (2% by weight) of the curing catalyst PS-1 (containing 2 parts) was applied, and heat-treated at 120 ° C. for 2 minutes to give a thickness of 0.
A 3 μm silicone-based release agent film was formed to obtain a separator (thus, the total thickness of the urethane / vinyl chloride copolymer layer and the silicone-based release agent film is about 0.6 μm).

Comparative Example 4 A 20 μm thick low density polyethylene layer laminated on one side of kraft paper was coated with the ethyl acetate / vinyl acetate copolymer ethyl acetate solution (3% by weight) used in Example 4, After heat treatment at 100 ° C. for 2 minutes to form an ethylene / vinyl acetate copolymer layer having a thickness of about 1.0 μm, an ethyl acetate solution of the fluorine-based release agent used in Example 4 (3% by weight) was formed thereon. ) Was applied and heat-treated at 100 ° C. for 2 minutes to form a fluorine-based release agent film having a thickness of about 1.0 μm to obtain a separator (hence, ethylene / vinyl acetate copolymer layer and fluorine-based release agent). The total thickness of the coating is about 2 μm).

Evaluation Test The following characteristics of the separators obtained in Examples and Comparative Examples were examined. Non-detachability The peelability-imparting surface of the separator was strongly rubbed with a finger, and the case where the peelability-imparting layer (release agent film) was not observed was evaluated as ◯, and the case where it was observed was evaluated as x.

Peelability The peelability-imparting surface of the separator at 20 ° C. and 65% RH is
Commercially available adhesive tape with a width of 50 mm (Nitto Denko Corporation, No. 31
B) is pressure-bonded by reciprocating a rubber roller having a weight of 2 kg once, and left at 20 ° C. for 24 hours under a load of 50 g / cm ² on the adhesive tape. Then, release the load 2
After leaving at 0 ° C. and 65% RH for 2 hours, the obtained adhesive tape was peeled off by a shopper at a speed of 300 mm / min (180 degree peeling), and the force required for the peeling was measured.

The above results are shown in Table 1.

[Table 1]

From Table 1, in each case, the layer-separable release treatment layer provided in the Examples is less likely to fall off than the supporting base material and has excellent adhesiveness, and is excellent in peelability from the adhesive surface. Also proves to be excellent.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

[Explanation of symbols]

1: Releasability treatment layer 11: Releasability imparting layer 12: Separation interface (mixing layer) between the releasability imparting layer and the polymer layer 13: Polymer layer 2: Support substrate Patent applicant Nitto Denko Corporation Rihito Fujimoto Study

Claims (3)

[Claims] 1. A releasable treatment layer comprising a support layer and a releasability-imparting layer which are separated into a polymer layer having good adhesion to a supporting substrate. 2. A pressure-sensitive adhesive member comprising a supporting substrate having the release treatment layer according to claim 1 on one surface and an adhesive layer on the other surface. 3. A separator comprising the supporting substrate having the release treatment layer according to claim 1 on one side or both sides thereof.