JPH07228852A - Adhesive composition and tackifying processed product - Google Patents

Abstract

PURPOSE:To produce a pressure-sensitive adhesive composition which shows high heat resistance and excellent adhesion at low temperatures and processed adhesion products. CONSTITUTION:The pressure-sensitive adhesive composition comprises 100 pts.wt. of an acrylic copolymer resulting from copoly-merization of 60 to 100wt.% of an alkyl (meth)acrylate where the alkyl group has 2 to 18 carbon atoms and 0 to 40wt.% of a vinyl monomer copolymerizable with the alkyl (meth) acrylate, 5 to 20 pts.wt. of a rosin tackifying resin containing 1.5 or more hydroxyl groups every molecule on the average and 0.5 to 20 pts.wt. of a thermosetting alkylphenol resin. And another pressure-sensitive adhesive composition comprises 100 pts.wt. of an acryllc copolymer resulting from copoly-merization of 60 to 100wt.% of an alkyl (meth)acrylate where the alkyl group has 2 to 18 carbon atoms and 0 to 40wt.% of a vinyl monomer copolymerizable with the alkyl (meth)acrylate, 5 to 20 pts.wt. of a rosin tackifying resin containing 1.5 or more hydroxyl groups every molecule on the average and 5 to 20 pts.wt. of a polymer rosin tackifier softening above 135 deg.C, and a processed adhesion product which has a pressure-sensitive adhesive layer of at least one of the compositions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive processed product used for building materials, home electric appliances, automobile cushioning materials, gap tapes and the like, and an adhesive composition used for an adhesive layer of the adhesive processed product.

[0002]

2. Description of the Related Art An adhesive composition is used in an adhesive layer of an adhesive tape (double-sided tape, foam tape, etc.) or an adhesive sheet used for building materials, home electric appliances, cushioning materials for automobiles, gap tapes and the like. For the pressure-sensitive adhesive layer of such a pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet, a solvent-based pressure-sensitive adhesive composition mainly composed of an acrylic resin having excellent light resistance, durability, heat resistance, cold resistance, water resistance, etc. is used. There is.

In recent years, as the use of adhesive processed products such as adhesive tapes has expanded, there has been an increasing demand for an adhesive layer having higher heat resistance and excellent other physical properties such as cold resistance. Kaihei 4-114079). As a means for increasing the heat resistance of the pressure-sensitive adhesive layer, a method of using a large amount of a polar monomer or a monomer having a high cohesive force, a method of increasing the amount of a curing agent, etc. are known. However, when these means are used, even if the heat resistance is improved, the tackiness at low temperature,
Since there is a problem that physical properties such as adhesive strength to olefin and initial tack are deteriorated, it is difficult to obtain an adhesive composition having high heat resistance and excellent adhesiveness at low temperature by these means. Is.

[0004]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an adhesive composition and an adhesive processed product which have high heat resistance and excellent adhesiveness at low temperatures.

[0005]

The gist of the present invention is that when the pressure-sensitive adhesive composition is constituted, the alkyl group has 2 carbon atoms.
To (meth) acrylic acid alkyl ester 60 to 1
100 parts by weight of an acrylic copolymer obtained by copolymerizing 0% to 40% by weight of the vinyl-based monomer copolymerizable with the (meth) acrylic acid alkyl ester and 0 to 40% by weight, and an average of hydroxyl groups in one molecule is 1. 5 to 20 parts by weight of a rosin-based tackifying resin containing 5 or more and 0.5 to 10 parts by weight of a thermosetting alkylphenol resin are used.

The acrylic copolymer according to the present invention is obtained by copolymerizing a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms with a vinyl monomer. Examples of the (meth) acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms include ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and (meth) acrylic acid. Examples include lauryl and the like.

The vinyl-based monomer according to the present invention may be any one that can be copolymerized with the above-mentioned alkyl ester, and examples thereof include carboxylic acids having an ethylenic double bond such as (meth) acrylic acid, itaconic acid and crotonic acid. Acrylic acid esters having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; functional group-containing monomers such as (meth) acrylamide, acrylonitrile, N-vinylpyrrolidone and maleic anhydride; Examples thereof include methyl (meth) acrylate, vinyl acetate, styrene, fluorine acrylate, isononyl (meth) acrylate and the like.

The mixing ratio of the alkyl ester and the vinyl monomer is in the range of 0 to 40% by weight of the vinyl monomer with respect to 60 to 100% by weight of the alkyl ester. If the proportion of the vinyl-based monomer is higher than this range, the adhesive force and tack are lowered, so the range is limited to the above range. The alkyl ester is preferably 60 to 97% by weight and the vinyl monomer is 3 to 40% by weight.

The pressure-sensitive adhesive composition according to the present invention contains a rosin-based tackifying resin containing an average of 1.5 or more hydroxyl groups in one molecule in an amount of 5 to 100 parts by weight of the acrylic copolymer.
Contains 20 parts by weight. If the amount of the rosin-based tackifying resin is less than 5 parts by weight, the heat resistance will decrease, and if it exceeds 20 parts by weight, the cold resistance will decrease, so the amount is limited to the above range. It is preferably 5 to 15 parts by weight.

Examples of the rosin-based tackifying resin containing an average of 1.5 or more hydroxyl groups in one molecule include hydrogenated rosin ester, disproportionated rosin ester, polymerized rosin ester, and polyester diol having a rosin skeleton at the end. Etc.

The pressure-sensitive adhesive composition according to the present invention contains 0.5 to 10 parts by weight of a thermosetting alkylphenol resin.
If the content of the thermosetting alkylphenol resin is less than 0.5 parts by weight, the heat resistance will decrease, and if it exceeds 10 parts by weight, the cold resistance will decrease, so the content is limited to the above range. It is preferably 0.5 to 5 parts by weight.

The above-mentioned thermosetting alkylphenol resin is
It is not particularly limited, and examples thereof include condensation polymers of various alkylphenols such as pt-butylphenol and formaldehyde.

The pressure-sensitive adhesive composition according to the present invention comprises a rosin-modified phenol resin,
Tackifying resins such as coumarone-indene resins, rosin esters, hydrogenated rosin esters, terpene phenol resins and petroleum resins may be blended.

Further, a curing agent may be added in order to improve heat resistance. As such a curing agent, for example, an isocyanate compound, an epoxy compound, an organometallic complex,
Examples thereof include aziridine compounds. Isocyanate compounds are preferred. In this case, the mixing ratio of the isocyanate compound is preferably in the range of 0.5 to 15 parts by weight with respect to 100 parts by weight of the monomer so as not to impair the adhesive property of the adhesive composition. Further, if necessary, a thickener, a thixotropic agent, a filler, a filler, a pigment, a rust preventive agent, etc. may be added.

The gist of the second aspect of the present invention is to provide a pressure-sensitive adhesive composition in which 60 to 100% by weight of a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms is used together with the (meth) acrylic acid alkyl ester. 100 parts by weight of an acrylic copolymer obtained by copolymerizing 0 to 40% by weight of a polymerizable vinyl monomer, 5 to 20 parts by weight of a rosin-based tackifying resin containing an average of 1.5 or more hydroxyl groups in one molecule. Parts, and 5 to 20 parts by weight of a polymerized rosin-based tackifying resin having a softening point of 135 ° C. or higher.

The pressure-sensitive adhesive composition according to the present invention contains a rosin-based tackifying resin containing an average of 1.5 or more hydroxyl groups in one molecule in an amount of 5 to 5 parts by weight with respect to 100 parts by weight of the acrylic copolymer.
Contains 20 parts by weight. If the amount of the hydroxyl group-containing rosin-based tackifying resin is less than 5 parts by weight, the heat resistance will decrease, and if it exceeds 20 parts by weight, the cold resistance will decrease, so the content is limited to the above range.

Furthermore, the pressure-sensitive adhesive composition according to the present invention contains 5 to 20 parts by weight of a polymerized rosin-based tackifying resin having a softening point of 135 ° C. or higher. If the content of the polymerized rosin-based tackifying resin having a softening point of 135 ° C. or more is less than 5 parts by weight, the heat resistance is lowered, and if it exceeds 20 parts by weight, the cold resistance is lowered, so that the content is limited to the above range.

The gist of the present invention 3 is to provide an adhesive processed product, an adhesive layer comprising at least one of the adhesive composition according to claim 1 and the adhesive composition according to claim 2, and at least one of the substrates. It has to be configured as having on the surface. Examples of the base material include various non-woven fabrics (rayon-based, cellulosic-based, etc.), various films or foams such as polyethylene, polyester, cellophane, polypropylene and polystyrene; foamed polyethylene, urethane foam or various rubber foams such as neoprene. Etc. The shape of the adhesive processed product is not particularly limited, and examples thereof include tapes or sheets including double-sided tape.

[0019]

In the pressure-sensitive adhesive composition of the present invention, the use of the reactive tackifying resin as the tackifying resin improves the heat resistance, and at the same time, imparts the heat resistance to the tackifying resin (especially alkylphenol resin or polymerized rosin resin). resin)
Since the amount of is relatively small, the elastic modulus at low temperature is lower than that of a system containing a conventional tackifying resin, and the adhesiveness at low temperature is also improved.

[0020]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Example 1 In a four-necked flask equipped with a cooling tube, at the ratio shown in Table 1,
A monomer was charged, then 81.8 parts by weight of ethyl acetate was charged, the temperature was raised and refluxed for 30 minutes, 0.1 parts by weight of benzol peroxide as a polymerization initiator was added dropwise, and the reaction was carried out for 7 hours. Thereafter, 0.1 part by weight of benzol peroxide was further added dropwise and the reaction was carried out for 3 hours. Then
To this, 40.4 parts by weight of toluene was added and cooled to obtain a transparent and viscous acrylic copolymer solution.

The above acrylic copolymer solution and the tackifying resin were mixed at the ratio shown in Table 1, and an isocyanate compound was further added as a curing agent and mixed to obtain an acrylic pressure sensitive adhesive composition.

The above-mentioned pressure-sensitive adhesive composition was coated on a release paper with a doctor blade at 145 μm (wet) and dried for 2 minutes at 80 ° C. in a dryer. Next, thickness 10mm, specific gravity 0.02
The ether-based urethane foam sheet of was pressure-bonded with a roll to obtain a urethane foam tape. This urethane foam tape was cured for 10 days in a thermostatic chamber at a temperature of 20 ° C. and a humidity of 65% RH.

Examples 2 to 12 Adhesive compositions were prepared in the same manner as in Example 1 except that the monomer composition of the acrylic copolymer and the composition of the tackifying resin were changed to the proportions shown in Tables 1 and 3. A urethane foam tape was prepared and obtained in the same manner as in Example 1.

Comparative Examples 1 to 12 Adhesive compositions were prepared in the same manner as in Example 1 except that the monomer composition of the acrylic copolymer and the composition of the tackifying resin were changed to the ratios shown in Tables 2 and 4. A urethane foam tape was prepared and obtained in the same manner as in Example 1.

The above urethane foam tape was evaluated by the following methods, and the results are shown in Tables 1 to 4. Heat resistance (heat resistance) A urethane foam tape with a width of 50 mm and a length of 120 mm is attached to a stainless steel plate (SUS-304), and 2K is used.
The g roll was reciprocated once to bond. Temperature 20 ℃, humidity 6
After curing at 5% RH for 17 hours, leave it in a gear oven at 80 ° C for 20 minutes, and then set the tape side down 1
A static load of 00 g was applied (angle is 90 ° with respect to the stainless steel plate). The tape was left for 1 hour, and the time (minutes) until the tape dropped from the steel plate or the distance (mm) peeled from the steel plate was measured. Adhesion at low temperature (SUS adhesion) Width 25 mm, length 20 on stainless steel plate at 5 ° C atmosphere
A 0 mm urethane foam tape was attached, and a 2 Kg roll was reciprocated once for adhesion. After leaving for 20 minutes under the same conditions, 90 ° peel strength (g / 25mm) with a tensile tester
Was measured. The pulling speed was 300 mm / min. Adhesive strength to olefin (PP adhesive strength) A urethane foam tape was adhered to a PP (polypropylene) plate in the same manner as the above SUS adhesive strength, and 90 ° in the same manner.
The peel strength (g / 25 mm) was measured. Initial tack (probe tack) A urethane foam tape having a width of 25 mm and a length of 100 mm was attached to a stainless steel plate with a rubber paste, with the adhesive surface facing upward. Probe (bottom area 1 cm ² , stainless steel weighing 10 g) The bottom surface was adhered to the glue surface for 3 seconds, and then the pulling speed was 200.
The strength (g / 25 mm) when pulled up at mm / min was measured.

The terms used in each of Tables 1 to 4 are as follows. In the acrylic copolymer composition, A represents maleic anhydride and B represents acrylamide. D in the polymerized rosin-based tackifying resin is a polymerized rosin ester resin having a softening point of 135 ° C. (Pencel D-135, manufactured by Arakawa Chemical Industry Co., Ltd.), and E is a polymerized rosin ester resin having a softening point of 160 ° C. (Pencel D-160, Arakawa Chemical Industry Co., Ltd.) are shown respectively. F in the tackifying resin composition is a disproportionated rosin ester resin (super ester A115, having a softening point of 115 ° C.).
Arakawa Chemical Industry Co., Ltd.), G is a disproportionated rosin ester resin with a softening point of 125 ° C. (Super Ester A125, manufactured by Arakawa Chemical Industry Co., Ltd.), and H is a terpene phenol resin with a softening point of 145 ° C. (YS Polystar S145, Yasuhara). Yuki Kogyo Co., Ltd.), Hitanol is an alkylphenol resin with a softening point of 100 ° C. (Hitanol 643KN, manufactured by Hitachi Chemical Co., Ltd.),
KE is a rosin polyol having two hydroxyl groups in one molecule with a softening point of 86 ° C. (KE-601, manufactured by Arakawa Chemical Industry Co., Ltd.)
CRW is a rosin polyol having three hydroxyl groups in one molecule with a softening point of 68 ° C. (CRW-238, manufactured by Arakawa Chemical Industry Co., Ltd.). Hardener Coronate L-55
(Active ingredient 55%) (manufactured by Nippon Polyurethane Industry Co., Ltd.) represents an isocyanate compound.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

[Table 4]

[0031]

EFFECTS OF THE INVENTION According to the present invention, a pressure-sensitive adhesive composition and a pressure-sensitive adhesive processed product having good heat resistance and excellent adhesiveness at low temperatures can be obtained.

Claims (3)

[Claims] 1. A (meth) acrylic acid alkyl ester having an alkyl group with 2 to 18 carbon atoms in an amount of 60 to 100% by weight.
And 100 parts by weight of an acrylic copolymer obtained by copolymerizing 0 to 40% by weight of a vinyl-based monomer copolymerizable with the (meth) acrylic acid alkyl ester, and an average of 1.5 hydroxyl groups in one molecule. Rosin-based tackifying resin containing 5 or more
˜20 parts by weight and 0.5 to 10 parts by weight of thermosetting alkylphenol resin. 2. A (meth) acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms in an amount of 60 to 100% by weight.
And 100 parts by weight of an acrylic copolymer obtained by copolymerizing 0 to 40% by weight of a vinyl-based monomer copolymerizable with the (meth) acrylic acid alkyl ester, and an average of 1.5 hydroxyl groups in one molecule. Rosin-based tackifying resin containing 5 or more
To 20 parts by weight and 5 to 20 parts by weight of a polymerized rosin-based tackifying resin having a softening point of 135 ° C. or higher. 3. A pressure-sensitive adhesive process, comprising a pressure-sensitive adhesive layer comprising at least one of the pressure-sensitive adhesive composition according to claim 1 and the pressure-sensitive adhesive composition according to claim 2, on at least one surface of a base material. Goods.