JPH07188629A - Pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:To obtain a pressure-sensitive adhesive composition excellent in initial adhesive power, tack and cohesive power particularly to nonpolar adherend by using a specified copolymer and a specified compound each in a specified amount as the constituents. CONSTITUTION:This composition contains 100 pts.wt. copolymer consisting of 70-98.9wt.% 4-12C alkyl (meth)acrylate monomer (e.g. 2-ethylhexyl acrylate) units, 0.1-10wt.% alpha,beta-unsaturated carboxylic acid monomer (e.g. acrylic acid) units and 1-29.9wt.% other vinyl monomer (e.g. acrylonitrile) units (the total of those units being 100wt.%) and 0.5-30 pts.wt. of at least one compound selected from among a rosin derivative esterified with a monohydric alcohol containing 1-10C alkyl, a terpene resin having a weight-average molecular weight of 200 to 500 and an aromatic hydrocarbon/formaldehyde resin having a weight- average molecular weight of 200 to 1,000 (e.g. a hydrogenated rosin methyl ester resin).

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 excellent in initial adhesive strength and tack and having good cohesive strength, and particularly to initial adhesive strength for non-polar adherends and low to high temperatures. The present invention relates to a pressure-sensitive adhesive composition which is excellent in sealing corrugated board in a wide temperature range and is useful for applications such as pressure-sensitive adhesive tapes.

[0002]

BACKGROUND OF THE INVENTION Adhesives include natural rubber-based, synthetic rubber-based and acrylic ester-based adhesives. These adhesives are applied to base materials and used in a wide variety of applications in the form of adhesive tapes and adhesive labels. Has been done. Among the above-mentioned pressure-sensitive adhesives, acrylic acid ester-based pressure-sensitive adhesives containing an acrylic acid alkyl ester-based copolymer as a main component have excellent adhesiveness and weather resistance, and have been widely spread in recent years.

However, the pressure-sensitive adhesive tape using the acrylic ester-based pressure-sensitive adhesive is not suitable for adherends having a small polarity such as polyethylene resin and polypropylene resin.
The adhesive strength is smaller than that of rubber adhesives. In particular, when the pressure is applied with a light force, the initial adhesive force is significantly reduced. Therefore, there is a problem that the tape is easily peeled off immediately after the tape is attached to the non-polar adherend.

In order to solve the above problems, an emulsified alkyl acrylate copolymer (hereinafter referred to as "copolymer emulsion") is plasticized or the molecular weight of the copolymer is reduced. To improve the adhesive strength, or to add a tackifier having a high softening point. However, in all of these methods, the cohesive force of the pressure-sensitive adhesive is reduced, and the corrugated board sealing property becomes insufficient. Further, in the case of blending a tackifier having a high softening point, although the adhesion to a nonpolar adherend is improved,
There has been a problem that the initial adhesive strength to various adherends, tack, etc. are reduced.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides an acrylic ester-based pressure-sensitive adhesive having excellent initial adhesion to a non-polar adherend, good tack and cohesive strength, and corrugated board sealing property in a wide temperature range. Is what you are trying to do.

[0006]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that a specific low molecular weight compound (hereinafter referred to as “tackifier”) is added to an alkyl acrylate copolymer for adhesives. The present invention has been completed by finding that the pressure-sensitive adhesive obtained by containing the above) has excellent initial adhesive strength and tack, and also has good cohesive strength.

That is, the present invention (a) has 4 to 1 carbon atoms.
Consisting of an alkyl acrylate and / or methacrylic acid alkyl ester monomer unit having 2 alkyl groups, (b) an α, β-unsaturated carboxylic acid monomer unit, and (c) another vinyl monomer unit, And, based on the total amount of all monomer units, the above (a) is 70 to 98.
9% by weight, 0.1 to 10% by weight of (b) and 1 to 29.9% by weight of (c) per 100 parts by weight of a copolymer (hereinafter, simply referred to as "copolymer"), Carbon number 1
Rosin derivative esterified with monohydric alcohol having 10 alkyl groups, weight average molecular weight of 200 to 5
00 terpene resin or weight average molecular weight of 200-
A pressure-sensitive adhesive composition comprising 0.5 to 30 parts by weight of at least one compound of 1000 aromatic hydrocarbon formaldehyde resins.

(Copolymer) Hereinafter, the copolymer will be described in detail. In the following, acrylic and / or methacrylic will be referred to as (meth) acrylic. (A) having an alkyl group having 4 to 12 carbon atoms (meth)
Acrylic acid alkyl ester monomer unit

The (meth) acrylic acid alkyl ester monomer for introducing this monomer unit into the copolymer has a chain or cyclic alkyl group having 4 to 12 carbon atoms, and particularly carbon atom (Meth) acrylic acid ester having a chain or cyclic alkyl group of 4 to 9 is preferable. In the case of an alkyl group having 3 or less carbon atoms, the tack of the obtained pressure-sensitive adhesive may be reduced, and in the case of an alkyl group having 13 or more carbon atoms, the cohesive force, adhesive force and tack of the obtained pressure-sensitive adhesive are poorly balanced. There is a risk of becoming.

Specific examples of alkyl (meth) acrylates include n-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, and (meth) acrylic. 2-ethylhexyl acid, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate,
Examples thereof include decyl (meth) acrylate and lauryl (meth) acrylate. Particularly preferred types are n-butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, and (meth) acrylate. Cyclohexyl acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate,
Examples thereof include isononyl (meth) acrylate.

The proportion of the (meth) acrylic acid ester monomer unit in the copolymer is 70 to 9 based on the total amount of the monomer units (a), (b) and (c).
It is 8.9% by weight, preferably 75 to 97% by weight. If it is less than 70% by weight, the adhesive strength, initial adhesive strength and tack of the resulting pressure-sensitive adhesive are poor. On the other hand, if it exceeds 98.9% by weight, the holding force of the obtained pressure-sensitive adhesive and the sealing property of the corrugated board near room temperature are deteriorated.

(B) α, β-Unsaturated Carboxylic Acid Monomer Unit Specific α, β-unsaturated carboxylic acid for introducing this monomer unit into the copolymer is (meth) acryl. Acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, cinnamic acid, etc. are mentioned, and preferable (alpha), (beta)-unsaturated carboxylic acid is (meth) acrylic acid.

The ratio of the α, β-unsaturated carboxylic acid monomer units in the copolymer is 0.1 based on the total amount of the monomer units (a), (b) and (c). ~ 1
It is 0% by weight, preferably 0.3 to 5% by weight.
If it is less than 0.1% by weight, the adhesive strength of the resulting adhesive and the sealing property of the corrugated board near room temperature are poor. Further, if it exceeds 10% by weight, the adhesive strength, initial adhesive strength and tack of the obtained pressure-sensitive adhesive are poor.

(C) Other vinyl monomer units Other vinyl monomers for introducing this monomer unit into the copolymer include methyl (meth) acrylate, ethyl (meth) acrylate, 1 to 3 carbon atoms such as isopropyl (meth) acrylate and n-propyl (meth) acrylate
(Meth) acrylic acid alkyl ester having an alkyl group of styrene; vinyl aromatic monomers such as styrene, α-methylstyrene, vinyltoluene, itaconic acid monoethyl ester, fumaric acid monobutyl ester, maleic acid monobutyl ester, etc. An unsaturated dicarboxylic acid monoalkyl ester; 2-hydroxyethyl (meth) acrylate,
2-Hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3
-Vinyl group-containing vinyl monomers such as phenoxypropyl (meth) acrylate, glycerol (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and polyethylene glycol-polypropylene glycol mono (meth) acrylate; acrylamide , N-methylolacrylamide, N-methoxymethylacrylamide, N-methoxybutylacrylamide, and other ethylenically unsaturated carboxylic acid amides and N
Substituted compounds; unsaturated alcohols such as allyl alcohol;
Cyano group-containing vinyl monomers such as (meth) acrylonitrile and α-chloroacrylonitrile; methacrylic acid glycidyl acrylate, vinyl acetate, vinyl chloride, vinylidene chloride and the like.

Preferred monomers include (meth) acrylonitrile, methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-methylolacrylamide and styrene. , Vinyl acetate, glycidyl (meth) acrylate, and the like.

The proportion of the other vinyl monomer units in the copolymer is 1 to 29.9% by weight based on the total amount of the monomer units (a), (b) and (c). ,
It is preferably 2 to 10% by weight.

The copolymer can be obtained by radically polymerizing each of the above monomers by employing a known emulsion polymerization method, solution polymerization method, suspension polymerization method or the like. Among them, the aqueous emulsion polymerization method is preferable in that the obtained copolymer has a large cohesive force and does not use an environmentally harmful organic solvent. At the time of polymerization, a chain transfer agent, a plasticizer or the like may be added, if necessary. After polymerization, a thickener,
A leveling agent, a cross-linking agent, an antiseptic agent, a rust preventive agent, a pigment, a filler, an antifreezing agent, a high boiling point solvent or an antifoaming agent may be added as appropriate.

(Tackifier) The rosin derivative used in the present invention is a rosin compound esterified with a monohydric alcohol having an alkyl group having 1 to 10 carbon atoms, and preferably the alkyl group has carbon atoms of 1 to 7. When the alkyl group has 11 or more carbon atoms, the obtained adhesive composition has poor initial adhesive strength and tack. Examples thereof include gum rosin, tall rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin and the like, and compounds esterified with the above alcohols.

The terpene resin used in the present invention is a terpene compound having an average weight molecular weight of 200 to 500, and a preferable weight average molecular weight is 250 to 400.
When the weight average molecular weight is less than 200, the obtained pressure-sensitive adhesive composition has poor holding power, and when the weight average molecular weight exceeds 500, the obtained pressure-sensitive adhesive composition has poor initial adhesion and tack. As its type, α-pinene type, β-pinene type,
Examples thereof include terpene resins such as limonene-based resins, hydrocarbon-modified terpene resins, hydrogenated terpene resins and terpene-phenolic resins.

The aromatic hydrocarbon formaldehyde resin used in the present invention has a weight average molecular weight of 200 to 100.
It is an aromatic hydrocarbon formaldehyde compound having a weight average molecular weight of 300 to 900. When the weight average molecular weight is less than 300, the obtained pressure-sensitive adhesive composition has poor holding power, and when the weight average molecular weight exceeds 1,000, the obtained pressure-sensitive adhesive composition has poor initial adhesion and tack. Examples thereof include toluene formaldehyde resin and xylene formaldehyde resin.

Among these tackifiers used in the present invention, the rosin derivative is superior to other compounds in terms of physical properties such as initial adhesive strength, adhesive strength, holding power and corrugated board sealing property. It is preferable because

One or more of these tackifiers may be added to the copolymer as it is, or may be added to the polymerization system together with the above-mentioned monomer when the copolymer is synthesized. Further, the emulsified tackifier may be added to the copolymer emulsion obtained by the aqueous emulsion polymerization method.

A specific example of the rosin derivative used in the present invention is Harcoline D, trade name, manufactured by Rika Hercules Co., Ltd.
(Hydrogenated rosin methyl ester resin solid content: 100
%), Trade name G-971 manufactured by Chukyo Yushi Co., Ltd. (emulsified product of hydrogenated rosin methyl ester resin), trade name SN-OX-1125 manufactured by San Nopco Co., Ltd. (emulsified product of hydrogenated rosin methyl ester resin) Solid content:
50%) and the like.

A specific example of the terpene resin used in the present invention is YS resin L, manufactured by Yasuhara Chemical Co., Ltd.
P505-1 (aromatic modified terpene resin, weight average molecular weight: 250, solid content: 100%) and YP-90LL
(Terpene phenol resin weight average molecular weight: 255, solid content: 100%) and the like.

Specific examples of the aromatic hydrocarbon formaldehyde resin used in the present invention include Generalite 6010 (toluene formaldehyde resin, weight average molecular weight: 410, solid content: 10) manufactured by General Petrochemical Industry Co., Ltd.
0%), Genelite 6015 (toluene formaldehyde resin, weight average molecular weight: 540, solid content: 100)
%), Genelite 3030 (xylene formaldehyde resin weight average molecular weight: 700 solid content: 100%) and Genelite 3100 (xylene formaldehyde resin weight average molecular weight: 920 solid content: 100%), and Mitsubishi Gas Chemical Co., Ltd. trade name Nikanol H (xylene formaldehyde resin weight average molecular weight: 480 solid content: 100%) and nikanol HH (xylene formaldehyde resin weight average molecular weight: 550 solid content:
100%) and the like.

The amount of the tackifier used is such that the copolymer 10
The amount is 0.5 to 30 parts by weight, preferably 1 to 25 parts by weight, and more preferably 3 to 16 parts by weight per 0 parts by weight. If it is less than 0.5 parts by weight, the initial adhesive strength and tack to the non-polar adherend are poor, while if it exceeds 30 parts by weight, the holding power and the corrugated board sealing property are deteriorated and the original function as an adhesive may be impaired. There is.

The pressure-sensitive adhesive composition of the present invention obtained by the above method or the like is applied to the surface of a substrate sheet made of paper, polyethylene, polypropylene, polyester or the like so that the thickness after drying is 20 to 50 μm. Thus, it can be processed into an adhesive sheet, and the obtained adhesive sheet can be used for applications such as an adhesive tape, an adhesive label or an adhesive poster.

[0028]

The pressure-sensitive adhesive composition of the present invention is particularly excellent in initial adhesive, tack, and cardboard sealing property. The reason for this is not clear, but since the tackifier added to the composition has a low softening point, the wetting of the copolymer containing (meth) acrylic acid ester as a main component to the surface of the adherend is well performed. However, it is presumed that the contact area is increased.

[0029]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples. In the following examples, parts mean parts by weight, and% means% by weight. The adhesive strength, holding power, tackiness, initial adhesive strength, and corrugated board sealing property were measured by the following methods.

Adhesive strength: Thickness of kraft paper after drying is 4
The pressure-sensitive adhesive composition is applied so as to have a thickness of 0 μm, and dried at 120 ° C. for 2 minutes to prepare a pressure-sensitive adhesive sheet. A stainless steel plate is used as an adherend, and JIS is used under the conditions of 23 ° C. and 65% RH.
It measured according to the 180 degree peeling strength of Z-0237.

Holding power: An adhesive sheet similar to that used in the adhesive strength test was prepared and laminated on a stainless steel plate with a size of 25 × 25 mm.
A load of 1 kg was applied at ℃, and the time until peeling off was measured. When held for 3 hours, the deviation width was measured.

Tack: A pressure-sensitive adhesive sheet similar to that used in the pressure-sensitive adhesive strength test was prepared and measured at 23 ° C. in an atmosphere of 65% RH in accordance with the ball rolling method of JISZ-0237.

Initial adhesive strength: An adhesive sheet similar to that used in the adhesive strength test was prepared, and a polyethylene plate was used as an adherend.
Under a condition of 5% RH, a roller having a load of 200 g was used to bond 50 × 100 mm, and 90-degree peel strength was measured at a peeling speed of 500 mm / min.

Cardboard sealing property: thickness after drying is 40 μ
The kraft paper was coated with the adhesive composition so that the kraft paper had a width of m, and a kraft tape having a width of 5 cm and a length of 50 cm was prepared. 25 cm x
A double-sided cardboard box of 25 cm x 25 cm and K-liner finish, with double-sided double-sided seams and adhesive tape so that the length of the mimi is 5 cm. 4 were produced. 2 each of the obtained test cardboard boxes, 65% RH at 23 ℃,
Leave the tape at 0 ° C in an atmosphere of 30% RH for 1 week, and measure the number of tapes peeled off and opened (there are 8 observation points per test because 2 boxes of corrugated board are used for 1 test). did.

Example 1 A 3 liter flask equipped with a stirrer, a thermometer, a condenser and two dropping funnels was charged with 30 parts of water and heated to 80 ° C. 2-ethylhexyl acrylate (hereinafter "H
A ". ) 84 parts, n-butyl acrylate (hereinafter "BA") 10 parts, acrylonitrile (hereinafter "AN") 4 parts, acrylic acid (hereinafter "AA").
Called. 2) A monomer mixture consisting of 2 parts was used, to which 2 parts of sodium lauryl sulfate and 19 parts of water were added and emulsified. The emulsion thus obtained and 8 parts of a 5% aqueous solution of ammonium persulfate were continuously added dropwise from the dropping funnel to the flask over 4 hours to carry out polymerization.

A thickener was added to the obtained copolymer emulsion to have a viscosity of 10,000 cps. To this, G-971 (trade name, manufactured by Chukyo Yushi Co., Ltd., solid content: 50%), which is an emulsified product of hydrogenated rosin methyl ester resin as a tackifier, was added to 15 parts per 100 parts of the solid content of the copolymer emulsion ( 7.5% solids of tackifier
Part) was added to obtain an adhesive composition. The adhesive property of the obtained composition is shown in Table 1, and the corrugated board sealing property is shown in Table 2.

Examples 2 to 7 HA 88 parts, methacrylonitrile (hereinafter referred to as "MAN") 4 parts, methacrylic acid (hereinafter referred to as "MAA") 3 parts, vinyl acetate (hereinafter referred to as "VAc"). )
To a monomer mixture consisting of 4 parts and 1 part of styrene (hereinafter referred to as "St"), 4 parts of sodium polyoxyethylene nonylphenyl ether sulfate and 30 parts of water were added and emulsified, followed by the same method as in Example 1. Polymerized.

The copolymer emulsion obtained was used in Example 1.
SN-O which is an emulsified product of hydrogenated rosin methyl ester resin as a tackifier after thickening in the same manner as
X-1125 (trade name, manufactured by San Nopco Ltd.) Solid content:
50%) was added in an amount shown below per 100 parts of solid content of the copolymer emulsion to obtain each pressure-sensitive adhesive composition of Examples 2 to 7.

Example 2: 1.4 parts (0.7 parts by solid content of tackifier) Example 3: 3 parts (1.5 parts by weight) Example 4:10 parts (5 parts by weight) Example 5:30 parts (15 same parts) Example 6:40 parts (20 same parts) Example 7:54 parts (27 same parts) The physical properties of the obtained composition are shown in Tables 1 and 2.

Example 8 90 parts HA, 4 parts methyl acrylate, 3.5 parts MAN,
To a monomer mixture consisting of 1.5 parts of AA and 1 part of glycidyl methacrylate, sodium dodecylbenzene sulfate 2
And 20 parts of water were added and emulsified, followed by polymerization in the same manner as in Example 1. The copolymer emulsion thus obtained was used in Example 1.
Thickened in the same manner as described above, and has a weight average molecular weight of 25 as a tackifier.
0 aromatic modified terpene resin YS resin LP505-1
(Yasuhara Chemical Co., Ltd. product name solid content: 100
%) Was added to 8 parts per 100 parts of the solid content of the copolymer emulsion to obtain a pressure-sensitive adhesive composition. The physical properties are shown in Tables 1 and 2.

Example 9 88.5 parts BA, 10 parts methyl methacrylate and MA
3 parts of sodium polyoxyethylene octylphenyl ether sulfate and 28 parts of water were added to a monomer mixture consisting of 1.5 parts of A to emulsify, and polymerization was carried out in the same manner as in Example 1. The obtained copolymer emulsion was thickened in the same manner as in Example 1, and then a toluene formaldehyde resin having a weight average molecular weight of 540, Genelite 601 was used as a tackifier.
5 (manufactured by General Petrochemical Industry Co., Ltd.) Solid content:
100%) was added to 5 parts per 100 parts of the solid content of the copolymer emulsion to obtain a pressure-sensitive adhesive composition. The physical properties are shown in Tables 1 and 2.

Example 10 HA 50 parts, BA 38.5 parts, St 8 parts and AA3.
5 parts of sodium dodecylbenzene sulfonate and 32 parts of water were added to the monomer mixture consisting of 5 and emulsified, followed by polymerization in the same manner as in Example 1. The obtained copolymer emulsion was thickened in the same manner as in Example 1, and then, as a tackifier, Xylene formaldehyde resin having a weight average molecular weight of 920, Generalite 3100 (trade name, manufactured by General Petrochemical Industry Co., Ltd., solid content: 100). %) Was added to 5 parts per 100 parts of the solid content of the copolymer emulsion to obtain a pressure-sensitive adhesive composition. The physical properties are shown in Tables 1 and 2.

Example 11 85 parts HA, 10 parts BA, 3 parts AN, 1.5 parts MAA,
N-methylol acrylamide 0.5 part, n-dodecyl mercaptan 0.06 part, polyoxyethylene 2-ethylhexyl ether sulfosuccinate disodium 5
Parts, 1.5 parts of Hercoline D (trade name of Rika Hercules Co., Ltd., solid content: 100%), which is a hydrogenated methyl ester of liquid rosin at room temperature as a tackifier, and 19 parts of water are mixed and emulsified. Polymerization was carried out in the same manner as in 1. The obtained copolymer emulsion was thickened in the same manner as in Example 1 to obtain a pressure-sensitive adhesive composition. The physical properties are shown in Tables 1 and 2.

Example 12 To a monomer mixture consisting of 65 parts HA, 6 parts BA, 2 parts 2-hydroxyethyl acrylate, 24 parts ethyl acrylate and 3 parts AA, 5 parts sodium polyoxyethylene tridecyl ether sulfate and 25 parts water. Emulsify
Polymerization was carried out in the same manner as in Example 1. The obtained copolymer emulsion was thickened in the same manner as in Example 1, and 20 parts of the above-mentioned G-971 as a tackifier was added to 100 parts of the solid content of the copolymer emulsion (10 parts of the tackifier was used as the solid content). Part)
An adhesive composition was obtained by adding. The physical properties are shown in Tables 1 and 2.

Example 13 86.8 parts HA, 6 parts BA, acrylamide (hereinafter referred to as "A
MD)), 6 parts of VAc and 0.2 part of AA, 3 parts of sodium polyoctylphenoxyethoxyethyl ether sulfate and 20 parts of water were added to emulsify, and polymerization was carried out in the same manner as in Example 1. did. The obtained copolymer emulsion was thickened in the same manner as in Example 1, and 20 parts by weight of the above-mentioned G-971 as a tackifier was added per 100 parts by weight of the solid content of the copolymer emulsion (in the solid content of the tackifier. 10 parts) was added to obtain an adhesive composition. The physical properties are shown in Tables 1 and 2.

Example 14 To a monomer mixture consisting of 79 parts of HA, 6 parts of BA, 1 part of AMD, 6 parts of VAc and 8 parts of AA, 3 parts of sodium polyoctylphenoxyethoxyethyl ether sulfate and 20 parts of water were added and emulsified. Polymerization was carried out in the same manner as in. The obtained copolymer emulsion was thickened in the same manner as in Example 1, and 20 parts by weight of the above-mentioned G-971 as a tackifier was added per 100 parts by weight of the solid content of the copolymer emulsion (in the solid content of the tackifier. 10 parts) was added to obtain an adhesive composition. The physical properties are shown in Tables 1 and 2.

[0047]

[Table 1]

[0048]

[Table 2]

Comparative Examples 1 and 2 Using the copolymer emulsion synthesized in Example 1,
The tackifiers shown below were added per 100 parts of the solid content of the copolymer emulsion in the amounts shown below to obtain pressure-sensitive adhesive compositions of Comparative Examples 1 and 2. Comparative Example 1: Super Ester E-720 (manufactured by Arakawa Chemical Co., Ltd., trade name: disproportionated rosin glycerin ester resin emulsified product, solid content: 50%): 12 parts (tackifier solid content: 6 parts) Comparative Example 2: Generalite 3150 (trade name, manufactured by General Petrochemical Co., Ltd., weight average molecular weight: 1050, solid content: 100%): 6 parts

Comparative Example 3 Example 11 was repeated except that Hercoline D was not used.
Polymerization was carried out in the same manner as above, and the obtained copolymer emulsion was thickened in the same manner as in Example 1 to obtain a pressure-sensitive adhesive composition.

Comparative Example 4 In place of Hercoline D, terpene resin YS resin PX-1250 having a weight average molecular weight of 800 (trade name, manufactured by Yasuhara Chemical Co., Ltd., solid content: 100%) was used in an amount of 1.5 parts. Polymerization was performed in the same manner as in 11, and the obtained copolymer emulsion was thickened in the same manner as in Example 1 to obtain a pressure-sensitive adhesive composition. Physical properties of the pressure-sensitive adhesive compositions of Comparative Examples 1 to 4 are shown in Tables 3 and 4.

[0052]

[Table 3]

[0053]

[Table 4]

[0054]

The pressure-sensitive adhesive composition of the present invention is excellent in initial adhesive force, adhesive force, cohesive force and tack to various adherends, and particularly excellent in initial adhesive force to nonpolar adherends.
It also has excellent sealing properties for corrugated board in a wide temperature range. Therefore, the present pressure-sensitive adhesive composition can be widely used not only for pressure-sensitive adhesive tapes but also for pressure-sensitive adhesive labels and pressure-sensitive adhesive sheets.

Claims (1)

[Claims] 1. (a) Acrylic acid alkyl ester and / or methacrylic acid alkyl ester monomer unit having an alkyl group having 4 to 12 carbon atoms, (b) α, β-
70 to 98.9% by weight of (a) based on the total amount of all the monomer units, which is composed of unsaturated carboxylic acid monomer units and (c) other vinyl monomer units. ) Is 0.1 to 10% by weight and (c) is 1 to 29.9% by weight.
1 to 10 carbon atoms per 100 parts by weight of the copolymer consisting of
A rosin-based derivative esterified with a monohydric alcohol having an alkyl group of 200 to 500 in weight average molecular weight
Terpene resin or weight average molecular weight of 200 to 10
A pressure-sensitive adhesive composition comprising 0.5 to 30 parts by weight of at least one compound of 00 aromatic hydrocarbon formaldehyde resin.