JPS61271372A - Strippable treating agent - Google Patents

Abstract

PURPOSE:To provide the titled treating agent having excellent adhesion to hydrophilic substrates and well-balanced properties between stripping and bonding, by reacting a saponified polyvinyl acetate with a long-chain alkyl glycidyl ether. CONSTITUTION:A long-chain 16-20C alkyl glycidyl ether (e.g. octadecyl glycidyl ether) is grafted onto a saponified polyvinyl acetate having a degree of saponification of 30-90% and an average degree of polymn. of 100-3,000 by heating in an org. solvent (e.g. xylene) in the presence of an alkali (e.g. KOH) to obtain a strippable treating agent. The agent is dissolved in an org. solvent and applied to a substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a releasable treatment agent that exhibits excellent adhesion even to polyvinyl acetate-long chain alkyl glycidyl ether hydrophilic substrates.

Conventional technology For tapes that are stored in the form of rolls, such as adhesive tapes that are made of a base material with an adhesive layer on one side, and that are unwound when used, it is easy to unwind from the back side of the tape. In order to
A releasable treatment layer made of a releasable treatment agent is provided on the back surface of the base material.

Among the various general properties required of this releasable treatment agent, in particular, the releasable treatment layer must not fall off from the base material (adhesion), and the components in the treatment layer must be on the adhesive side. It does not migrate and contaminate the adhesive surface (prevents reduction in adhesive strength on the adhesive surface), and the adhesiveness and peelability from the adhesive surface are moderately buffed, preventing deformation and stickiness such as bamboo shoot phenomenon of rolled tape. It is important that the agent does not migrate to the back side of the base material.

Conventionally, the releasable treatment agents used are heat-curable silicone-based ones, octadecyl acrylate-acrylic acid copolymer-based ones (Japanese Patent Publication No. 3144/1983), r
N-rivinyl alcohol-octadecyl isocyanate type (Japanese Patent Publication No. 29-7333), polyvinyl alcohol-octadecyl isocyanate-polyfunctional isocyanate type (JP-A-54-56638)
0 Problems to be Solved by the Invention However, the treatment layer of heat-curable silicone-based products has excessive releasability, resulting in problems such as poor lamination performance and deformation of rolled objects. The problem is that octadecyl acrylate-acrylic acid copolymer-based products and polyvinyl alcohol-octate VILI isocyanate-based products have poor adhesion to hydrophilic substrates such as cellulose films, and the treated layer has poor adhesion to hydrophilic substrates such as cellulose films. There was a problem with it falling off. On the other hand, a polyvinyl alcohol-octadecyl isocyanate-polyfunctional isocyanate-based product, which has been proposed as a modification of the poor adhesion of the octadecyl isocyanate-based product to the hydrophilic substrate, has an adhesive property of VCVyIF, which is required for peeling. The problem was that it had a lot of power.

Means for Solving the Problems The present inventors have overcome the above-mentioned problems, and have achieved satisfactory adhesion even to hydrophilic substrates, and also have good adhesion between the back surface of the substrate and the surface of the adhesive. As a result of intensive research to develop a releasable treatment agent that can form a treatment layer with excellent adhesive puffiness, we discovered that 40, a polyvinyl acetate-long chain alkyl glycidyl ether system, could achieve this purpose. , the present invention was accomplished.

That is, the present invention provides a stripping treatment agent consisting of a reaction product of Ken-based polyvinyl acetate and a long-chain alkyl glycidyl ether. The degree of oxidation is 30~
90% is preferred. If the degree of saponification is too low, the f# layer treated with the releasable treatment agent obtained will have poor releasability, while if it is too high, the reaction completion will be poor and a uniform reaction product will not be produced. It becomes difficult to obtain. Furthermore, the Ken-based polyvinyl acetate preferably has an average degree of polymerization of 100 to 8,000. If the average degree of polymerization is too low, the resulting layer treated with the release treatment agent will have poor heat resistance), while if it is too high, the reactivity and solubility will be poor, making it undesirable for practical use. .

Examples of the long-chain alkyl glycidyl ether used in the present invention and represented by the general formula include alkyl groups represented by heptadecyl glycidyl ether, heptadecyl glycidyl ether, octadecyl glycidyl ether, nonadecyl glycidyl ether, eicosi M glycidyl ether, etc. carbon number is 1
6 to 20 is desirable.

The releasable treatment agent of the present invention is obtained, for example, by heating in an organic solvent in the presence of an alkali to cause a long-chain alkyl glycidyl ether to react with a long-chain alkyl glycidyl ether via its glycidyl group by heating in an organic solvent in the presence of an alkali. It consists of a reaction product of Ken-based polyvinyl acetate and long-chain alkyl glycidyl ether. The releasability of the treated layer using this releasable treatment agent, and ultimately the peel-adhesion buffing/removal properties, are controlled by the ratio of long-chain alkyl glycidyl ether introduced. On the other hand, the introduction ratio of the long-chain alkyl glycidyl ether is determined by the degree of saponification of the resin-based polyvinyl acetate and the blending ratio of the long-chain alkyl glycidyl ether to the polyvinyl acetate during the reaction. In the present invention, the ether is used in an equivalent amount to the saponification group of the polyvinyl acetate, and the treatment with a stripping agent provides a reaction method in which the introduction ratio of the ether is controlled by the degree of saponification of the polyvinyl acetate. It is desirable in terms of physical properties and performance such as adhesion of the layer to the hydrophilic base material. From this point of view, it is appropriate that the degree of saponification of the polyvinyl acetate used in the reaction is from 30 to 90%.

The releasable treatment agent of the present invention is applied to a substrate, for example, as an organic solvent solution.

Effects of the Invention According to the polyvinyl acetate-long chain alkyl glycidyl ether-based releasable treatment agent of the present invention, adhesive properties ( Anchoring property) K Excellent and does not fall off from the base material
In addition, it is possible to form a releasable treated layer with excellent peel-adhesion balance.

Examples Example 1 Saponification degree of 88% in a Mitsuro flask equipped with a reflux condenser
, 20 parts of polyvinyl acetate/l with an average degree of polymerization of 500 (parts by weight, the same applies hereinafter) and 205 parts of Xyref were heated at 120°C.
The system was made alkaline by adding a small amount of xylene solution of potassium hydroxide, and 117 parts of octadecyl glycidyl ether/l was reacted for 10 hours to obtain the stripping treatment agent as the desired product. Obtained.

Examples 2 to 5 20 parts of polyvinyl acetate with a degree of saponification of 8896 and an average degree of polymerization L400 and 117 parts of octadecyl glycidyl ether (
Example 2) Polyvinyl acetate with a degree of saponification of 88% and an average degree of polymerization of λ300/
l/20 parts, 117 parts of octadecyl glycidyl ether (3), polyvinyl acetate 2 with saponification degree of 80% and average degree of polymerization of 500.
0 parts and eicosyl glycidyl ether A/105 parts (4), 20 parts of polyvinyl acetate with saponification degree of 38%, average degree of polymerization L 400 and 38 parts of eicosyl glycidyl ether (4)
) A releasable treatment agent was obtained in the same manner as in Example 1, except that the same procedure as Example 1 was used.

Comparative Example 1.2 Polyvinyl acetate/L with a degree of saponification of 88% and an average degree of polymerization of 500
/20 parts and 105 parts of octadecyl isocyanate (Comparative Example 1), polyvinyl acetate 1 with a degree of saponification of 88% and an average degree of polymerization L400
20 parts of V and 105 parts of Octade VIL/Isocyanate (
A releasable treatment agent was obtained in the same manner as in Example 1, except that 2) was used.

Toluene was added to the reaction solution containing the release treatment agent obtained in the evaluation test examples and comparative examples to make a solution with a solid content of 1% by weight, and this was used to prepare one side of a cellophane film K O, 05f/? A peelable treated film was obtained by coating and drying so that the coating amount was as follows.

Next, a polyester adhesive tape (manufactured by Nitto Wt Kanko Kogyo Co., Ltd., 7131B) was applied to the treated surface of the releasable treated film.
After moving the kg loaf back and forth once, the adhesive tape was crimped, and then the adhesive tape was peeled off at 180 degrees using the beer method.
The peeling force at that time was measured.

On the other hand, the ability of the treated layer to come off from the base material was examined by rubbing the treated surface of the film with a finger. The case where there was no falling off was evaluated as ◯, and the case where there was falling off was evaluated as ×.

The results are shown in the table.

From the table, the layers treated with the peelable treatment agent of the present invention in Examples are as follows:
It can be seen that the adhesiveness to the substrate and the peel-adhesion balance are excellent.

Claims (1)

[Scope of Claims] 1. A stripping treatment agent comprising a reaction product of saponified polyvinyl acetate and long-chain alkyl glycidyl ether. 2. The processing agent according to claim 1, wherein the saponified polyvinyl acetate has a degree of saponification of 30 to 90%. 3. Saponified polyvinyl acetate has an average degree of polymerization of 100 to 3,
000, the processing agent according to claim 1. 4. Claim 1, wherein the alkyl group in the long-chain alkyl glycidyl ether has 16 to 20 carbon atoms.
Treatment agent described in section.