JPH1030078A - Adhesive composition and coating using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an adhesive composition used by mixing in a desired ratio, comprising a specific polymer different in adhesive strength, capable of exhibiting adhesive strength on multilevel according to mixing ratio, having good melting characteristic, excellent in coating property and suitable for hot melt type adhesives, etc. SOLUTION: This adhesive composition is used after mixing at a desired ratio and comprises (A) an adhesive polymer and (B) an adhesive polymer having an adhesive strength different from the component A and these components A and B is composed of a block copolymer represented by formula I [A is a vinylic (co)polymer; B is a (co)polymer comprising a (meth)acrylic acid 1-12C alkyl ester; (a) is 1-10], formula II [(b) is (a)], formula III [(c) is (a)], formula IV [X is a compound residue capable of bonding plural copolymers (A-B); (m) is 3-30] or formula V [T is a compound residue capable of bonding A to B; (o) and (p) are each >=1 and (o+p) is (m)] or a random (co)polymer comprising M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an adhesive composition and a method for applying the same.

[0002]

2. Description of the Related Art Adhesive compositions are widely used as pressure-sensitive adhesive tapes, pressure-sensitive adhesives, hot melt adhesives and the like.
Such adhesive compositions tend to have higher required performance as their applications expand. As the adhesive composition, a rubber-based adhesive composition is conventionally known. However, the rubber-based adhesive composition cannot exhibit sufficient performance in terms of cohesive strength, weather resistance, and the like, and it is difficult to meet advanced performance requirements. Therefore, an acrylic adhesive composition composed of a (meth) acrylate random copolymer excellent in cohesive strength, weather resistance, oil resistance, etc., compared to a rubber adhesive composition, has been developed and used for various purposes. Have been.

[0003] However, such a copolymer having a random structure, even when two kinds of random copolymers having different adhesive strengths are kneaded at an arbitrary ratio, only one of the performances appears strongly. Cannot be obtained. Therefore, when an adhesive composition having an intermediate performance is required, a new adhesive composition must be developed each time.

[0004] Therefore, it is necessary to have various kinds of adhesive compositions corresponding to various adherends, various uses, and the like. Also,
There are many setups required for changing the type of production line,
Poor production efficiency.

In recent years, the problem of environmental pollution caused by an adhesive using a solvent such as a (meth) acrylic random copolymer has been taken up strictly. Further, from the viewpoint of energy saving and resource saving, the use of a solvent is also considered. The use as a hot-melt adhesive composition that is not used has been highlighted.

JP-A-6-41501 discloses a method in which an adhesive composition comprising a (meth) acrylate random copolymer is used as a hot-melt adhesive composition. According to this, the (meth) acrylic acid ester-based random copolymer is made into a bulk state, and is heated and melted to form a hot melt.

However, such a (meth) acrylate random copolymer has inherently poor melting properties and is not suitable for use as a hot-melt adhesive composition. For example, there have been problems in coatability to a base material when producing an adhesive tape, and coatability to an adherend when used as an adhesive.

[0008]

DISCLOSURE OF THE INVENTION In view of the above, the present invention has been made in view of the above circumstances. An object of the present invention is to provide an adhesive composition suitable as an adhesive and a coating method using the same.

[0009]

The adhesive composition of the present invention comprises an adhesive composition comprising the polymer (I) and a polymer (II) having an adhesive strength different from that of the polymer (I). Wherein the polymer (I) and the polymer (II) are represented by the general formula (AB) aA, the general formula (B)
-A) b-B, general formula (AB) c, general formula (AB)
1 selected from the group consisting of a block copolymer represented by mX and a general formula Ao-T-Bp, and a random (co) polymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms. It is a polymer of at least one kind.

(In the formula, A represents a vinyl polymer or a vinyl copolymer. B represents a polymer or copolymer comprising an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms. a, b, and c are the same or different and are 1 to 1;
Represents an integer of 0. X represents a compound residue capable of binding a plurality of copolymers (AB), and T represents a compound residue capable of binding A and B. m represents an integer of 3 to 30, o and p are the same or different and represent one or more integers, and o + p = 3 to 30. Hereinafter, the present invention will be described in detail.

The adhesive composition according to the first aspect of the present invention comprises a polymer (I) and a polymer (II) having an adhesive strength different from that of the polymer (I).

The polymer (I) and the polymer (II) have different adhesive strengths. The difference in adhesive strength means that the polymer (I) has a high level of adhesive strength, and the polymer (II) may have a low level of adhesive strength. The polymer (II) may have a low level of adhesive strength, and the polymer (II) may have a high level of adhesive strength.

The adhesive composition of the present invention comprises the above polymer (I)
And the polymer (II) in an appropriate ratio to obtain an adhesive composition exhibiting adhesive performance according to the type and application of the adherend within the range of the adhesive strength of each polymer. be able to.

The polymer (I) and the polymer (II) are represented by the general formula (AB) aA and the general formula (BA) b-
B, a block copolymer represented by the general formula (AB) c, the general formula (AB) mX, and the general formula Ao-T-Bp,
And 1 selected from the group of random (co) polymers consisting of alkyl (meth) acrylates having 1 to 12 carbon atoms
Or more polymers.

The formula (AB) aA and the formula (B-
A) bB, general formula (AB) c, general formula (AB) m
Each of the block copolymers represented by -X and the general formula Ao-T-Bp has a vinyl polymer or a vinyl copolymer as a block represented by A.

The vinyl-based polymer and the vinyl-based monomer constituting the vinyl-based copolymer are not particularly restricted but include, for example, styrene, methyl methacrylate, ethyl methacrylate, α-methylstyrene, o-methylstyrene and p-methylstyrene. Methylstyrene, acrylonitrile, vinyl acetate and the like can be mentioned. Of these, styrene and methyl methacrylate are preferred from the viewpoint of improving cohesion. A vinyl polymer can be obtained by using these alone, and a vinyl copolymer can be obtained by using two or more thereof in combination.

T of vinyl polymer and vinyl copolymer
g (measured according to the measuring method prescribed in JIS K 7121) is preferably 20 ° C. or higher. When the temperature is lower than 20 ° C., the cohesive strength is insufficient, and the heat resistance is poor.

In the vinyl polymer or vinyl copolymer as the block represented by A, a vinyl monomer may be copolymerized with a polar monomer in order to improve the balance between tackiness and adhesiveness. it can. The polar monomer is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, acrylamide, and 2-hydroxyethyl methacrylate.

In any of the block copolymers represented by the above general formula, the amount of the polar monomer added is preferably 15 parts by weight or less.

The vinyl polymer and the vinyl copolymer preferably have a weight average molecular weight of 500 to 300,000. 500
If it is less than 3, the function as a block will not be exhibited, and if it exceeds 300,000, the adhesion to a low-polarity adherend will decrease.

The block represented by B has a polymer or copolymer of an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms.

The alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group is one in which the alkyl group has 1 carbon atom.
No particular limitation is imposed on the alkyl (meth) acrylate of Nos. 1 to 12, such as ethyl (meth) acrylate,
Butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, i
-Nonyl (meth) acrylate and the like. When these are used alone, the alkyl group has 1 carbon atom.
A polymer comprising an alkyl (meth) acrylate having from 1 to 12 carbon atoms can be obtained by using two or more kinds in combination. it can.

The Tg (measured according to the measuring method prescribed in JIS K 7121) of a polymer or copolymer comprising an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms is preferably 0 ° C. or lower. If the temperature exceeds 0 ° C., the tackiness becomes insufficient, and the low-temperature adhesiveness is reduced.

The polymer comprising an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms as a B block has an alkyl group having 1 to 12 carbon atoms in order to improve the balance between tackiness and adhesiveness. 12 alkyl (meth)
A polar monomer can be copolymerized with the acrylate. Examples of the polar monomer include those similar to those exemplified for the vinyl polymer or vinyl copolymer.

When a polar monomer is copolymerized with the above polymer, the amount of the polar monomer is preferably 15 parts by weight or less based on 100 parts by weight of the alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group. . If the amount exceeds 15 parts by weight, tackiness is reduced and low-temperature adhesiveness is reduced.

The polymer or copolymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group preferably has a weight average molecular weight of 9500 to 1,000,000. If it is less than 9500, the cohesive strength will be insufficient, and if it exceeds 1,000,000, the viscosity will increase and the coatability will deteriorate.

In any of the block copolymers represented by the above general formulas, the content of the vinyl polymer or the vinyl copolymer is preferably from 1 to 40% by weight. If it is less than 1% by weight, the cohesive force of the adhesive composition will be insufficient, and
If the content is more than 10% by weight, the tack becomes insufficient and the adhesiveness becomes poor. More preferably, it is 3 to 30% by weight.

In each of the block copolymers represented by the general formulas, the block represented by A and the block represented by B are substantially different from each other. For example, when the block represented by A is a copolymer composed of two or more types of monomers, and the block represented by B is a polymer composed of one type of monomer, one block represented by A is used. When the block represented by B is a copolymer composed of two or more monomers, the block represented by A and the block represented by B are both two or more monomers. When the constituent monomers are different, the block represented by A and the block represented by B are both composed of one kind of monomer, and the constituent monomers are different. Can be

The general formula (AB) aA, the general formula (B-
A) In the block copolymer represented by bB or the general formula (AB) c, a, b and c are the same or different and are 1 to 1
It is an integer of 0. If it exceeds 10, the viscosity increases and the coatability to the base material deteriorates, so that it is limited to the above range. Preferably it is 1-8.

Formula (AB) mX, Formula Ao-T
In the block copolymer represented by -Bp, as the compound residue X capable of binding a plurality of copolymers (AB), for example, the copolymer (AB) may be anionic polymerized. When obtained by living polymerization of, a polyfunctional initiator having three or more halogen-containing groups in one molecule, such as tetrachlorosilane or trichloromethylbenzene, tetrachloromethylbenzene, pentachloromethylbenzene, hexachloromethylbenzene, and the like. . By adding the compound residue X as a polymerization terminator for the copolymer (AB), an (AB) mx block copolymer can be obtained.

Examples of the compound residue T capable of binding A and B include, for example, an initiator [2,2-Bis (4,4-d) having three or more peroxide groups in one molecule.
it-butyloxycyclohexy
l) propane (manufactured by NOF Corporation, trade name "Pertetra A")] or t-Butylperoxy A
llyl Carbonate (trade name "Peromer AC", manufactured by NOF Corporation) or t-Butylpero
xy Methacryl Carbonate or t-Butylperoxy Acryl Car
A copolymer obtained by copolymerizing a vinyl group-containing peroxide such as boronate with the constituent monomer of the block A or the block B may be used.

The weight average molecular weight of the polymer (I) and the polymer (II) is preferably 10,000 to 2,000,000. If it is less than 10,000, the cohesive strength is insufficient, and if it exceeds 2,000,000, the viscosity increases and the coatability deteriorates. More preferably, it is 100,000 to 1,000,000.

In the present invention, the structure of the block copolymer represented by each general formula is not particularly limited, and may be, for example, any of a linear structure, a star structure, and a comb structure. However, it is not preferable to use a macromonomer to obtain a comb structure.

The reason for this is derived from the process of producing the macromonomer, and the following three points are pointed out as problems. (1) Since a dimer exists as a side reaction product in the macromonomer itself, if the blending amount of the macromonomer is reduced in order to suppress the gel generated in the polymerization step, the intended performance is inevitably increased. I can't get it. (2) When the molecular weight of the macromonomer is increased to tens of thousands or more in order to obtain a comb-shaped copolymer having a high molecular weight branch, introduction of a terminal reactive group necessary for addition polymerization becomes difficult, and a large amount of by-products is produced. The desired physical properties cannot be obtained due to the unreacted oligomer. (3) Since macromonomers are generally synthesized by anionic polymerization, the types of monomers that can be used are limited. Particularly, since only a small amount of a polar group can be introduced, there is a disadvantage that the degree of freedom in designing is reduced.

In the case where these block copolymers have a star structure, a vinyl polymer or a vinyl copolymer is inside, and an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms. A polymer or copolymer consisting of an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms may be a structure in which a polymer or a copolymer comprising an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms is provided on the inside. The structure in which the polymer or the vinyl copolymer is on the outside may be used.

The method for synthesizing each of the block copolymers represented by the general formulas is not particularly limited. For example, a living polymerization method, a method using an initiator having a starting point having a different reactivity, or a method in one molecule. A method using an initiator having a reactive group and an initiation point, an ultraviolet polymerization method, and the like can be employed.

The method of using an initiator having a reactive group and an initiation point in one molecule is not particularly limited. For example, an initiator (D) having at least one peroxide group and one vinyl group in one molecule may be used. The method used can be adopted. In the method using an initiator (D) having at least one peroxide group and one vinyl group in one molecule, the number of carbon atoms of the vinyl monomer or the alkyl group is 1 to 3 depending on the initiator different from the initiator (D). 12 alkyl (meth)
After copolymerizing the acrylate and the vinyl group portion of the initiator (D), and polymerizing the block represented by A or the block represented by B, the other block is formed by the peroxide group of the initiator (D). By polymerizing the constituent monomers, the block represented by A or the block represented by B can be polymerized.

According to the above living polymerization method, for example, a vinyl monomer or an alkyl (meth) alkyl group having 1 to 12 carbon atoms can be prepared by using a living polymerizable initiator.
When either one of the acrylates is polymerized and the polymerization of the block represented by A or the block represented by B is completed, a monomer constituting another polymer or copolymer is added, and the terminal of the growing chain is added. Then, a polymerization reaction is further performed to polymerize the block represented by B or the block represented by A.

The living polymerization method is not particularly limited.
For example, a method using an iniferter such as N, N, N ', N'-tetraethyllithium disulfide, benzyl-N, N-diethyldithiocarbamate, p-xylenebis (N, N-diethyldithiocarbamate) as an initiator; A method using a lanthanoid compound as an initiator; an anionic polymerization method using an alkyl lithium or the like as an initiator; a group transfer method using a silyl ketene acetal or the like as an initiator; a method using aluminum porphyrin as an initiator; a metal-free living anion method; Known methods such as a radical method can be employed.

The method of using an initiator having a starting point having a different reactivity is not particularly limited. For example, a method of using an initiator having at least two peroxide groups having different radical generation temperatures and a method of using a different radical generation mechanism. A method using an initiator having at least two peroxide groups can be employed.

The method using an initiator having at least two peroxide groups having different radical generation temperatures is as follows.
From the starting point on the low temperature side, the polymerization of either the vinyl monomer or the alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group is started, and the polymerization of the block represented by A or the block represented by B is started. After the start, the polymerization of the block represented by B or the block represented by A can be performed by starting the polymerization of the monomer constituting another polymer or copolymer from the starting point on the high temperature side. it can.

According to the above-mentioned method using an initiator having at least two peroxide groups having different radical generating mechanisms, for example, a radical is generated using a reducing agent at one of the starting points to form a vinyl monomer or an alkyl group. Initiates the polymerization of any one of the alkyl (meth) acrylates having 1 to 12 carbon atoms and forms a block represented by A or B
After the polymerization of the block represented by is started, the temperature is increased to start the polymerization of the monomer constituting another polymer or copolymer from the other starting point, and the block represented by B or A Can be polymerized.

Specifically, the alkyl group has 1 to 1 carbon atoms.
2 is reacted with a radical polymerization initiator having two or more peroxide groups in one molecule by heating at a set temperature level of 1 to obtain an alkyl group having 1 to 12 carbon atoms. A polymer composed of an alkyl (meth) acrylate or a copolymer composed of an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms is polymerized, and then a vinyl monomer is added, and the temperature is set to be higher than the above temperature level 1. The block copolymer represented by the general formula (AB) c can be synthesized by performing a heating reaction at the specified temperature level 2.

According to the ultraviolet polymerization method, for example, an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms or the vinyl monomer is mixed with N, N-diethyldithiocarbamate, and the inside of the reaction vessel is mixed. After purging with nitrogen, UV irradiation is performed with an ultraviolet (UV) lamp, and a polymer or copolymer of an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms, or a vinyl polymer or vinyl copolymer is used. The polymer is polymerized, and then a vinyl-based monomer or an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms is added, followed by UV irradiation to obtain a vinyl-based polymer or a vinyl-based copolymer, or an alkyl group. Is obtained by polymerizing a polymer or copolymer comprising an alkyl (meth) acrylate having 1 to 12 carbon atoms, B) block copolymer represented by a-A, or the general formula (B-A) block copolymer represented by b-B can be synthesized.

Other methods include, for example, a vinyl polymer having an azo group, a vinyl copolymer having an azo group, or an alkyl group having 1 to 12 carbon atoms. A polymer comprising an alkyl (meth) acrylate having an azo group or a copolymer comprising an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms and a polymer having an azo group, A method of polymerizing a monomer constituting another polymer or copolymer with the azo group as a starting point;

After preliminarily polymerizing a vinyl polymer or vinyl copolymer and a polymer or copolymer composed of an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms by ordinary radical polymerization or the like. By mixing these and irradiating ultraviolet rays, electron beams, radiation, etc.,
A method of block-bonding a vinyl polymer or a vinyl copolymer with a polymer or copolymer composed of an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms may be employed.

The random (co) polymer includes a vinyl polymer, a vinyl copolymer, and an alkyl group having 1 to 1 carbon atoms.
And at least one homopolymer selected from the group consisting of polymers or copolymers comprising 2 alkyl (meth) acrylates. The method for producing the random (co) polymer is not particularly limited, and examples thereof include a radical polymerization method such as a known photopolymerization method or solution polymerization method.

The above polymer or random (co) polymer preferably has a weight average molecular weight of 10,000 to 2,000,000. If it is less than 10,000, the cohesive strength will be insufficient, and if it exceeds 2,000,000, the viscosity will increase and the coatability will deteriorate.

In the adhesive composition of the present invention, the polymer (I) and the polymer (II) are each composed of a block copolymer represented by each of the above general formulas and an alkyl (meta) having 1 to 12 carbon atoms. ) One or more polymers selected from the group consisting of random (co) polymers composed of acrylates, and are appropriately selected from these in accordance with the adhesive performance.

In the adhesive composition of the present invention, the content of the block copolymer in the polymer (I) and the polymer (II) is 20 to 95% by weight, and the alkyl (meth) having 1 to 12 carbon atoms. The content of the random (co) polymer composed of acrylate is preferably 80 to 5% by weight.

The adhesive composition of the present invention may contain a tackifier resin, a filler, an antioxidant, an ultraviolet absorber, a metal carboxylate, and the like, if necessary.

The tackifying resin is not particularly restricted but includes, for example, C5 (hydrogenated) petroleum resins and C9 (hydrogenated) petroleum resins.
Petroleum resin, (hydrogenated) rosin resin, (hydrogenated) rosin ester resin, (hydrogenated) terpene resin, (hydrogenated) terpene phenolic resin, (hydrogenated) coumarone indene resin, disproportionated rosin resin, uneven Rosin ester resin, polymerized rosin resin, polymerized rosin ester resin, and the like. These may be used alone or in combination of two or more.

The filler is not particularly restricted but includes, for example, calcium carbonate, titanium oxide, mica, talc and the like.

The antioxidant is not particularly limited.
For example, a phenol type, an amine type and the like can be mentioned.

The ultraviolet absorber is not particularly restricted but includes, for example, benzotriazoles.

The metal carboxylate is not particularly restricted but includes, for example, sodium stearate, magnesium stearate, calcium stearate, zinc stearate, barium stearate, sodium palmitate and the like.

The adhesive composition of the present invention comprises a polymer (I)
And the polymer (II) having a different adhesive strength are kneaded at an appropriate ratio, whereby the adhesive strength is precisely controlled within the adhesive strength of each. This is because the block represented by A and the block represented by B in each polymer form a domain, and these domains are not completely compatible with each other. It is thought that this is because

The adhesive composition of the present invention can be suitably used, for example, as an adhesive; a paint; a coating; a pressure-sensitive adhesive layer such as a pressure-sensitive adhesive tape or a pressure-sensitive adhesive label; It is particularly preferably used as a pressure-sensitive adhesive layer of a pressure-sensitive adhesive tape or a pressure-sensitive adhesive label.

According to a second aspect of the present invention, there is provided a coating method of applying the adhesive composition according to the first aspect to a substrate or an adherend using an applicator. ) And the polymer (II) were supplied and mixed in a mixing device provided with a supply path capable of independently supplying the mixture at a speed corresponding to the use speed in coating at a preset ratio. Thereafter, the mixture is transported from the mixing device to the applicator. The mixing device is not particularly limited, and examples thereof include a tank having a stirring device and a kneader-type kneader.

The above-mentioned ratios are determined based on the polymer (I) and the polymer (II).
Thus, it can be set in advance so that a desired adhesive strength can be obtained.

The supply of the adhesive composition is performed at a speed corresponding to the use speed in coating. That is, the adhesive composition is supplied from the applicator to the mixing device according to the use speed of the adhesive composition used. Therefore, a constant amount of the adhesive composition is always present in the mixing device, and the coating operation can be performed smoothly.

The polymer (I) and the copolymer (II) are sequentially transported from a mixing device to an applicator, and are applied to a substrate or an adherend.

The method of coating with an applicator is not particularly limited, and for example, a method such as solvent coating or hot melt coating can be adopted.

As a method of solvent coating, for example, a method of dissolving the adhesive composition of the present invention in a solvent, coating the adhesive composition on a substrate for an adhesive tape, an adhesive sheet, or the like, and then drying the solvent can be mentioned. .

Examples of the hot melt coating method include a method of integrally producing the adhesive composition of the present invention together with a base film resin or, if necessary, a primer resin by a multilayer coextrusion molding method. Can be According to the multilayer coextrusion molding method, the base film, the adhesive composition of the present invention, and the primer resin are each plasticized by a separate extruder, and a multilayer coextrusion mold such as an inflation method or a T-die method is used. And can be laminated by co-extrusion in a hot-melt system.

As the hot-melt coating, a hot-melt coating method can be adopted. According to the hot melt coating method,
If necessary, a primer layer is previously formed on one surface of the substrate film by an appropriate method, and hot-melt coating can be performed on the primer layer by a hot melt coater.

When the adhesive composition of the present invention is applied to an adherend and used for an adhesive, the adhesive composition of the present invention is applied to the adherend in the same manner as in the case of producing an adhesive tape or the like. A method of solvent coating, a method of hot melt coating, and the like can be employed.

According to the coating method of the present invention, the polymer (I) and the polymer (II) having different adhesive strengths are mixed immediately before coating on a substrate or an adherend, and a desired adhesive property is obtained. Can be prepared. Therefore, by controlling the respective supply rates of the polymer (I) and the polymer (II) to the mixing device, an adhesive composition having an adhesive performance according to the type, application, etc. of the substrate or the adherend. Can be prepared. For this reason, it is not necessary to have various kinds of adhesive compositions, and the number of setups required for changing the type of the production line is small, and the production efficiency is improved.

[0069]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Synthesis of Polymer (I) Ethyl acrylate and N, N-diethyldithiocarbamate were mixed, and the inside of the reaction vessel was purged with nitrogen.
UV irradiation was performed with an ultraviolet (UV) lamp to obtain a polymer block of ethyl acrylate. Next, methyl methacrylate was added thereto, and the mixture was further polymerized by UV irradiation, whereby an ABA type block copolymer (1) in which the A block was a methyl methacrylate polymer and the B block was an ethyl acrylate polymer was synthesized. . The content of the A block was 10% by weight, and the weight average molecular weight was 200,000.

The cohesive strength and adhesive strength of the adhesive composition comprising 100% by weight of the obtained block copolymer (1) were evaluated by the following methods. The results are shown in Table 1.

Evaluation method Cohesive force The obtained adhesive composition was cut into a cube having a side of 5 mm to form a test piece, and the obtained test piece was stuck on an aluminum plate held vertically and left in an oven at 80 ° C for 12 hours. Thereafter, the sagging length of the test piece was measured and defined as the cohesive strength.

2. Adhesive strength Polyethylene plate with clean surface (thickness: 1.5mm, width:
20 mm) in a thickness of 1 mm and an area of 10 × 20 mm, and then the shear adhesive strength was measured at a measurement temperature of 23 ° C. to obtain an adhesive strength.

Preparation of pressure-sensitive adhesive tape The block copolymer (1) was supplied at a constant rate of 1 kg / min as a solid content to a tank provided in the middle of the transport route to the coating section, and stirred to obtain an adhesive composition. The product was transported to the coating section, and the surface after corona discharge treatment of a 38 μm-thick polyethylene terephthalate film (Tetron film SC, manufactured by Teijin Limited) having been subjected to one-sided corona discharge treatment was dried to a thickness of 10 μm by a general solvent coating method. Was applied to obtain an adhesive tape. The peeling force, the holding force, and the coating property of the obtained pressure-sensitive adhesive tape were evaluated by the following methods. The results are shown in Table 1.

Evaluation method Peeling force According to JIS Z 0237, 2 kg of a pressure-sensitive adhesive tape (width 25 mm) that had passed for one day on a stainless steel plate polished with a water-resistant abrasive paper No. 280 at 23 ° C.
And then left at 23 ° C. for 1 hour, and measured a load when peeled at a measuring temperature of 23 ° C., a pulling speed of 300 mm / min, and a peeling angle of 180 ° as a peeling force. After the peel test, the presence or absence of adhesive residue of the adhesive on the surface of the stainless steel plate was evaluated. The evaluation criteria were as follows. ：: No adhesive residue. Δ: A small amount of glue remains. ×: Glue remaining. If there is glue residue, the degree is indicated by comments such as small and large.

2. Retention force According to JIS Z 0237, width 20 mm, length 1
The adhesive tape cut into 00 mm was bonded to a stainless steel plate polished with a No. 280 water-resistant abrasive paper at a bonding length of 20 mm using a 2 kg pressure roller at 23 ° C., and then pressed at 40 ° C. in an atmosphere. Leave the adhesive tape hanging downward in a constant temperature dryer at 80 ° C. so that the adhesive tape hangs down, apply a load of 1 kg to the lower end of the adhesive tape, and allow the adhesive tape to fall off the stainless steel plate. The time was measured.

3. Coatability The smoothness of the adhesive surface of the prepared adhesive tape was visually judged. The evaluation criteria were as follows. ：: Excellent in smoothness. ×: Poor smoothness.

Example 2 Synthesis of Polymer (II) Ethyl acrylate, acrylic acid, and N, N-diethyldithiocarbamate were mixed, and the inside of the reaction vessel was purged with nitrogen, and then the mixture was irradiated with an ultraviolet (UV) lamp. UV irradiation gave a copolymer block of ethyl acrylate and acrylic acid. Subsequently, methyl methacrylate was added, and the mixture was further polymerized by UV irradiation, and an ABA type block copolymer (2) in which the A block was a methyl methacrylate polymer and the B block was an ethyl acrylate / acrylic acid copolymer. ) Was synthesized. The content of the A block was 30% by weight, the content of acrylic acid in the B block was 5% by weight, and the weight average molecular weight was 200,000.

Preparation of Adhesive Composition A 70% by weight block copolymer (1) and a 30% by weight block copolymer (2) are placed in a tank provided in the middle of the transport route to the coating section. As described above, both solid contents were supplied at a constant rate of 1 kg / min by separate routes and stirred to obtain an adhesive composition, which was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Preparation of pressure-sensitive adhesive tape A pressure-sensitive adhesive tape was obtained and evaluated in the same manner as in Example 1 except that the obtained adhesive composition was used. The results are shown in Table 1.

Example 3 Block copolymer (1)
0% by weight and the adhesive composition in the same manner as in Example 1 except that the amount of the block copolymer (2) was 70% by weight, and
An adhesive tape was obtained and evaluated. The results are shown in Table 1.

Example 4 The block copolymer (2) was replaced with 1
An adhesive composition and a pressure-sensitive adhesive tape were obtained and evaluated in the same manner as in Example 1 except that the content was set to 00% by weight.

Example 5 Preparation of Adhesive Composition In a kneader-type kneader, both solid contents were adjusted to 70% by weight of the block copolymer (1) and 30% by weight of the block copolymer (2). At a constant rate of 1 kg / min, an antioxidant (Irganox 10) was added to 100 parts by weight of the block copolymer (1) and the block copolymer (2) in total.
10, Ciba-Geigy) 1 part by weight, 15
The mixture was kneaded under a nitrogen atmosphere at a temperature of 0 ° C. to prepare an adhesive composition. The obtained adhesive composition was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Preparation of Adhesive Tape The obtained adhesive composition was applied to a hot melt coater (YUR).
IROLL, manufactured by MACHINE Co., Ltd.) at a mold temperature of 180 ° C. by a hot melt coating method on a corona discharge-treated surface of a 38 μm-thick polyethylene terephthalate film (Tetron film SC, manufactured by Teijin Limited) having a one-sided corona discharge treatment. Work was performed to obtain an adhesive tape. The obtained adhesive tape was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 6) Block copolymer (1) was added to 3
An adhesive composition and a pressure-sensitive adhesive tape were obtained and evaluated in the same manner as in Example 5 except that 0% by weight and 70% by weight of the block copolymer (2) were used. The results are shown in Table 1.

(Comparative Example 1) Ethyl acrylate, acrylic acid, and lauryl mercaptan were mixed in a solvent, and benzoyl peroxide was added thereto, followed by polymerization to obtain the same weight average molecular weight as the block copolymer (I). The adhesive composition and the pressure-sensitive adhesive tape were obtained and evaluated in the same manner as in Example 1, except that the random copolymer (1) having the following was used as 100% by weight. The results are shown in Table 1.

(Comparative Example 2) Random copolymer (1)
A random copolymer having the same weight average molecular weight as that of the block copolymer (2) was prepared by preparing the same as the random copolymer (1) with 0% by weight and the same monomer blend as the block copolymer (2). An adhesive composition and a pressure-sensitive adhesive tape were prepared and evaluated in the same manner as in Example 1 except that the content was changed to% by weight. The results are shown in Table 1.

Comparative Example 3 An adhesive composition and a pressure-sensitive adhesive tape were obtained and evaluated in the same manner as in Example 1 except that the amount of the random copolymer was changed to 100% by weight. The results are shown in Table 1.

Comparative Example 4 Random copolymer (1)
An adhesive composition and a pressure-sensitive adhesive tape were obtained and evaluated in the same manner as in Example 1, except that 0% by weight and 30% by weight of the random copolymer (2) were used. The results are shown in Table 1.

[0090]

[Table 1]

[0091]

According to the adhesive composition of the present invention, within the range of the adhesive strength of each polymer, an adhesive composition exhibiting an adhesive performance according to the type and application of the adherend is obtained. be able to. Further, the adhesive composition of the present invention can exhibit a multi-level adhesive strength, has good melting properties and excellent coating properties, and can be suitably used as a hot melt adhesive. In addition, according to the coating method of the present invention, it is not necessary to hold various types of adhesive compositions, but only by holding the minimum necessary number of types of adhesive compositions. A suitable adhesive composition can be prepared. For this reason,
This leads to reduction of the inventory space, the type switching process in the production line, and the like, thereby improving the production efficiency.
Further, since it is composed of a block copolymer and a random (co) polymer, it has good heat melting properties and can be suitably used as a hot melt adhesive composition.
Environmental protection and reduction of steps can be achieved.

Claims (2)

[Claims] 1. An adhesive composition comprising a polymer (I), and a polymer (I) having an adhesive strength different from that of the polymer (I).
(I) wherein the polymer (I) and the polymer (II) are represented by the general formula (AB) a-
A, a block copolymer represented by a general formula (BA) bB, a general formula (AB) c, a general formula (AB) mX, and a general formula Ao-T-Bp, And random (co) composed of an alkyl (meth) acrylate having 1 to 12 carbon atoms
An adhesive composition comprising at least one polymer selected from the group consisting of polymers. (In the formula, A represents a vinyl polymer or a vinyl copolymer. B represents a polymer or copolymer composed of an alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group. A, b , C are the same or different and represent an integer of 1 to 10. X is a compound residue capable of binding a plurality of copolymers (AB);
Represents a compound residue capable of binding A and B.
m represents an integer of 3 to 30, o and p are the same or different and represent one or more integers, and o + p = 3 to 30. ) 2. A coating method for applying the adhesive composition according to claim 1 to a substrate using an applicator, wherein the polymer (I) and the polymer (II) are each independently formed. In a mixing device with a supply path that can be supplied,
A coating method, comprising: supplying at a preset amount ratio at a speed corresponding to a use speed in coating, mixing, and transporting the mixed product to the applicator from the mixing device.