JPH0525450A - Pressure-sensitive adhesive composition and pressure-sensitive adhesive tape, label, or sheet - Google Patents

Abstract

PURPOSE:To reduce the strength of peeling from a release paper without detriment to other properties by compounding a pressure-sensitive adhesive compsn. contg. a specific (meth)acrylic copolymer, a solvent, a cross-linker, etc., with a fluorocarbon surfactant. CONSTITUTION:The objective compsn. is prepd. by compounding a (meth)acrylic copolymer mainly comprising a 4-18C alkyl (meth)acrylate (e.g. a 2-ethylhexyl acrylate/n-butyl acrylate/acrylic acid/2-hydroxyethyl methacrylate copolymer), a solvent (e.g. toluene), a cross-linker (e.g. an isocyanate compd.), a tackifying resin (e.g. a heterogenized rosin ester resin), and a fluorocarbon surfactant (e.g. disodium N-perfluorooctanesulfonylglutamate). The compsn, is suitable for preparing a pressure-sensitive adhesive tape, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive composition which forms a pressure-sensitive adhesive layer having a small peel strength from a release paper without impairing other physical properties, and a pressure-sensitive adhesive composition thereof. The present invention relates to a pressure-sensitive adhesive tape, label or sheet using a product.

[0002]

2. Description of the Related Art Acrylic pressure-sensitive adhesives are excellent in pressure-sensitive adhesives such as pressure-sensitive adhesives, cohesive strengths, etc. Widely used as an adhesive to form.

Polyethylene-laminated paper treated with silicone is usually used as the release paper for such acrylic pressure-sensitive adhesive tapes, labels or sheets, but the trouble of release failure has been constant.

[0004]

As a means for solving such poor release of the release paper, the properties of the (meth) acrylic acid ester-based polymer which is the main component in the acrylic pressure-sensitive adhesive composition. Various methods have been proposed to improve the above.

For example, it is conceivable to copolymerize a monomer component such as ethyl (meth) acrylate or methyl (meth) acrylate, which raises the glass transition point, into a (meth) acrylic acid ester-based polymer. There is a problem that the cold resistance of the pressure-sensitive adhesive layer deteriorates.

Further, it is considered to increase the copolymerization ratio of a carboxyl group-containing monomer such as acrylic acid, methacrylic acid or itaconic acid in the (meth) acrylic acid ester type polymer, but the adhesiveness to olefin is poor. There is a problem that

The present invention solves the above-mentioned conventional problems and forms a pressure-sensitive adhesive composition having a small peel strength from a release paper without impairing other physical properties, And a pressure-sensitive adhesive tape, label or sheet using the pressure-sensitive adhesive composition.

[0008]

The invention according to claim 1 of the present application comprises a (meth) acrylic copolymer mainly composed of a (meth) acrylic acid ester in which an alkyl group has 4 to 18 carbon atoms, and a solvent. The pressure-sensitive adhesive composition contains a fluorosurfactant in contrast to the pressure-sensitive adhesive composition containing a crosslinking agent and, if necessary, an adhesive resin.

The invention of claim 2 of the present application is a pressure-sensitive adhesive tape, label or sheet using the pressure-sensitive adhesive composition of claim 1. The (meth) acrylic copolymer used in the present application is a copolymer of a (meth) acrylic acid ester having an alkyl group with 4 to 18 carbon atoms and another monomer having a copolymerizable vinyl group. Is.

Examples of the (meth) acrylic acid ester having an alkyl group having 4 to 18 carbon atoms include, for example, n-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate and 2-ethylhexyl (meth). ) Acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and the like.

As the monomer having a copolymerizable vinyl group, for example, acrylonitrile, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate as a cohesive force imparting monomer, Cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, styrene, α-methylstyrene, vinyl acetate, N-
Examples thereof include vinyl-2-pyrrolidone, benzyl (meth) acrylate, N-phenylmaleimide, N-cyclohexylmaleimide, and the like. As a crosslinkable monomer, a carboxyl such as acrylic acid, methacrylic acid, itaconic acid, or fumaric acid. Examples of the monomer include a group-containing monomer, 2-hydroxyethyl (meth) acrylate, a hydroxyl group-containing monomer such as 2-hydroxypropyl (meth) acrylate, (meth) acrylamide, and N-methylol (meth) acrylamide.

Examples of the solvent used in the present application include toluene, xylene, ethyl acetate, acetone, methyl ethyl ketone, n-hexane and cyclohexane.

The cross-linking agent used in the present application includes
Examples thereof include isocyanate-based, epoxy-based, metal-based and aziridine-based crosslinking agents. In the present application, an adhesive resin can be used if necessary, and specific examples thereof include rosin, rosin ester, disproportionated rosin, disproportionated rosin ester, rosin maleic acid, rosin maleate ester, rosin phenol. Derivatives such as rosin derivatives and hydrogenated rosin derivatives, polyterpenes, terpene derivatives such as terpene phenols and hydrogenated terpene derivatives, petroleum resins and hydrogenated petroleum resins, xylene resins, alkylphenol resins, cyclopentadiene resins, coumarone indene Resin etc. are mentioned.

Fluorine-based surface active agent used in the present application
Examples of the agent include fluoroalkyl (C₂~ C₂₀)
Carboxylic acid, N-perfluorooctane sulfonyl glycol
Disodium tamate, 3- [fluoroalkyl (C₆
~ C₁₁) Oxy] -1-alkyl (C₃~ C_Four) Sulfo
Sodium acid salt, 3- [ω-fluoroalkanoyl (C
₆~ C₈) -N-Ethylamino] -1-propanesulfon
Sodium acid salt, N- [3- (perfluorooctane
Rufonamido) propyl] -N, N-dimethyl-N-carb
Ruboxymethylene ammonium betaine, perfluoro
Alkylcarboxylic acid (C₇~ C₁₃), Perfluorooctane
Tansulphonic acid diethanolamide, perfluorooctane
Tansulfonic acid diethanolamide, perfluoroalcohol
Kill (C _Four~ C₁₂) Sulfonate (Li, K, Na),
N-propyl-N- (2-hydroxyethyl) perflu
Orooctane sulfonamide, perfluoroalkyl
(C ₆~ C_Ten) Sulfonamidopropyltrimethylan
Monium salt, perfluoroalkyl (C₆~ C_Ten) ─N
-Ethylsulfonylglycine salt (K), bis (N-phosphate)
-Perfluorooctylsulfonyl-N-Ethylamino
Ethyl), monoperfluoroalkyl (C₆~ C₁₆) D
Examples thereof include tyl phosphate ester.

The content of the fluorine-based surfactant used in the present application is the pressure-sensitive adhesive composition containing a (meth) acrylic copolymer, a solvent, a cross-linking agent and, if necessary, an adhesive resin. It is preferably used in the range of 0.001 to 3 parts by weight, more preferably 0.01 to 1 part by weight, based on 100 parts by weight of the solid content.

[0016]

Since the pressure-sensitive adhesive composition of the present invention contains a fluorine-based surfactant, the fluorine group of the fluorine-based surfactant is oriented at the interface between the pressure-sensitive adhesive layer and the release paper, and the pressure-sensitive adhesive is formed. The adhesiveness between the agent layer and the release paper can be reduced.

Since the pressure-sensitive adhesive tape, label or sheet of the present invention uses the above pressure-sensitive adhesive composition, the release paper provided on the pressure-sensitive adhesive layer can be easily peeled off. .

[0018]

EXAMPLES Examples of the present invention will be described below. Example 1 (1) Production of (meth) acrylic copolymer 2- 50 parts by weight of ethylhexyl acrylate, 47 parts by weight of n-butyl acrylate, 3 parts by weight of acrylic acid, 2-
0.1 parts by weight of hydroxyethyl methacrylate and 80 parts by weight of ethyl acetate were placed in a four-necked flask equipped with a condenser, 0.15 parts by weight of benzoyl peroxide was added, and polymerization was carried out by a conventional method. After completion of the polymerization, the mixture was cooled, and 42 parts by weight of toluene was added to dilute the mixture to obtain a uniform (meth) acrylic copolymer base (B-1) solution having a solid content concentration of 45% (see Table 1).

(2) Production of pressure-sensitive adhesive label 80 parts by weight of solid content of copolymer base (B-1), pentaerythritol ester of disproportionated rosin as disproportionated rosin ester resin (softening point 115 ° C.) 20 parts by weight, fluorine-based surfactant (manufactured by Mitsubishi Metals Co., Ltd .: trade name “EFT”
OP EF-351 ") 0.2 parts by weight and 2 parts by weight of an isocyanate crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd .: trade name" Coronate L-55E "solid content 55% by weight) are mixed by stirring to obtain a pressure-sensitive adhesive. A composition was obtained. It is coated on a release paper with a doctor blade so that the thickness of the pressure-sensitive adhesive layer after drying is 25 μm, dried at 80 ° C. for 5 minutes, and then 25 μm.
Attach the polyethylene terephthalate film of
A pressure sensitive adhesive label was produced.

(3) Measurement of physical properties This pressure-sensitive adhesive label was aged for 7 days in a thermo-hygrostat at 20 ° C. and 65% RH to obtain PE adhesion, holding power, and peel strength with release paper (separation). Table 2 shows the results of measuring the physical properties of strength and cold resistance.

The physical properties were measured under the following conditions. PE Adhesiveness A test piece was attached to a polyethylene plate according to JIS Z0237, and the peel strength after 20 minutes was measured. The tensile speed was 300 mm / min.

Holding power According to JIS Z0237, a test piece is attached to a SUS304 test plate with an adhesion area of 20 × 20 mm, left in an oven at 40 ° C. for 20 minutes, and then a static load of 1 kg is applied,
The deviation distance or the drop time after 60 minutes was measured.

Peel Strength with Release Paper (Separation Peeling Force) A pressure-sensitive adhesive label cut into a width of 50 mm was used as a test piece, and a polyethylene terephthalate film and release paper were sandwiched between both chucks of a universal tensile tester at a temperature of 20 ° C. The T-shaped peel strength was measured with. Pulling speed is 300mm /
Went in minutes.

According to the test method of cold resistance PE adhesive strength, bonding is performed at 0 ° C.,
The PE adhesion was measured at 0 ° C. ambient temperature.

Example 2 except that the fluorosurfactant was 0.5 part by weight.
A pressure-sensitive adhesive label was produced in the same manner as in Example 1 and its physical properties were measured. The results are shown in Table 2.

Example 3 A pressure-sensitive adhesive label was produced in the same manner as in Example 1 except that 20 parts by weight of a tempelphenol resin (softening point 140 ° C.) was mixed in place of the disproportionated rosin ester resin, The physical properties were measured. The results are shown in Table 2.

Example 4 Example 4 except that the fluorosurfactant was 0.5 part by weight and 20 parts by weight of a tempelphenol resin (softening point 140 ° C.) was mixed in place of the disproportionated rosin ester resin. A pressure-sensitive adhesive label was produced in the same manner as in 1, and the physical properties were measured. The results are shown in Table 2.

Comparative Example 1 A pressure-sensitive adhesive label was produced in the same manner as in Example 1 except that the fluorine-containing surfactant was 0 part by weight, and the physical properties were measured. The results are shown in Table 2.

Comparative Example 2 2-ethylhexyl acrylate 50 parts by weight, n-butyl acrylate 40 parts by weight, acrylic acid 10 parts by weight, 2
— (Meth) acrylic copolymer base (B-2) produced in the same manner as in Example 1 using 0.1 part by weight of hydroxyethyl methacrylate, 0.01 part by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate. A pressure-sensitive adhesive label was produced in the same manner as in Example 1 except that the solution (see Table 1) was used and the fluorine-based surfactant was 0 part by weight.
The physical properties were measured. The results are shown in Table 2.

Comparative Example 3 20 parts by weight of 2-ethylhexyl acrylate, 37 parts by weight of n-butyl acrylate, 40 parts by weight of ethyl acrylate, 3 parts by weight of acrylic acid, 0.1 parts by weight of 2-hydroxyethyl methacrylate, lauryl mercaptan 0.0.
A (meth) acrylic copolymer base (B-3) solution (see Table 1) prepared in the same manner as in Example 1 using 5 parts by weight and 80 parts by weight of ethyl acetate was used, and a fluorosurfactant was used. A pressure-sensitive adhesive label was produced in the same manner as in Example 1 except that the amount was 0 parts by weight, and the physical properties were measured. The results are shown in Table 2.
Shown in.

[0031]

[Table 1]

[0032]

[Table 2]

As is clear from Table 2, in all the examples of the present invention, the peel strength from the release paper is low without impairing the PE adhesive force, the holding force and the cold resistance. On the other hand, in the case of the comparative example, although the peeling strength from the release paper can be lowered, other adhesive properties are impaired.

[0034]

[Effect] Since the pressure-sensitive adhesive composition of the present invention is configured as described above, the pressure-sensitive adhesive tape has a small peel strength between the release paper and the pressure-sensitive adhesive layer without impairing other physical properties. It can be used as a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer of a label or a sheet.

Since the pressure-sensitive adhesive tape, label or sheet of the present invention uses the above pressure-sensitive adhesive composition, the release paper provided on the pressure-sensitive adhesive layer can be easily peeled off. It can be preferably used for applications where a releasing speed is required, for example, high-speed label punching and double-sided adhesive tape.

Claims (2)

[Claims] 1. A (meth) acrylic copolymer mainly composed of a (meth) acrylic acid ester having an alkyl group having 4 to 18 carbon atoms, a solvent, a crosslinking agent and, if necessary, an adhesive resin. A pressure-sensitive adhesive composition, characterized in that a fluorine-based surfactant is contained in the pressure-sensitive adhesive composition. 2. A pressure-sensitive adhesive tape, label or sheet comprising the pressure-sensitive adhesive composition according to claim 1.