Removable water-dispersible acrylic pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet

Abstract

A removable water-dispersible acrylic pressure-sensitive adhesive composition according to the present invention includes an acrylic emulsion polymer (A), a water-insoluble crosslinking agent (B), and a carboxylic-acid-containing acrylic polymer (C). The polymer (A) includes a (meth)acrylic alkyl ester and a carboxyl-containing unsaturated monomer as essential constitutive monomers and has a content of the (meth)acrylic alkyl ester of 70 to 99.5 percent by weight and a content of the carboxyl-containing unsaturated monomer of 0.5 to 10 percent by weight, each based on the total amount of constitutive monomers. The polymer (C) includes (meth)acrylic acid as an essential constitutive monomer and has a total content of acrylic acid and methacrylic acid of 11 percent by weight or more based on the total amount of constitutive monomers.

Description

technical field [0001] The present invention relates to a repeelable water-dispersible acrylic adhesive composition. More specifically, the present invention relates to a re-peelable water-dispersed adhesive layer capable of reducing appearance defects such as dents, having excellent appearance characteristics, excellent performance in preventing an increase in adhesive force over time, and excellent low-contamination properties. Acrylic adhesive composition. Moreover, this invention relates to the PSA sheet provided with the PSA layer formed from this PSA composition. Background technique [0002] In the manufacturing and processing of optical components (optical materials) represented by optical films such as polarizing plates, retardation plates, and anti-reflection plates, in order to prevent surface damage and contamination, improve cutting processability, and suppress cracks, etc., in optical components It is used by attaching a surface protection film to the surface...

AI Technical Summary

Problems solved by technology

[0006] However, in a water-dispersible acrylic adhesive composition using a water-insoluble crosslinking agent like the above-mentioned adhesive composition, the large particles of the water-insoluble crosslinking agent are not sufficiently dispersed and remain in the adhesive composition. , thus, when the adhesive layer is formed, appearance defects such as "dents" are likely to occur on the surface of the adhesive layer

Therefore, especially when a water-insoluble crosslinking agent is used for the adhesive layer of the surface protection film, there may be problems such as difficulty in inspecting the adherend in the state where the surface protection film is attached.

[0007] Therefore, the current situation is that it is not yet possible to obtain a re-adhesive layer that can form an adhesive layer that is excellent in adhesiveness and re-peelability (especially the performance of preventing an increase in adhesive force), reduces appearance defects such as "sinking", and has excellent appearance characteristics. Releasable water-dispersed acrylic adhesive composition

[0008] In addition, in surface protection film applications (especially surface protection film applications for optical components), the adhesive remains on the surface of the adherend (optical components, etc.) Contamination of the surface of the adherend due to the transfer of the components contained in the adhesive layer to the surface of the adherend, etc., causing adverse effects on the optical characteristics of the optical part, etc.

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