JP2003183596A - Method of manufacturing adhesive tape and adhesive tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an adhesive tape which enables usual adhesion works at room temperature while giving good damping property and adhesive strength at high temperatures. <P>SOLUTION: The manufacturing method of the adhesive tape comprises a first photopolymerization product obtained by photopolymerizing a monomer composition (A) containing 50 wt.% or more of an alkyl (meth)acrylate (the alkyl group having 2-14C atoms) (a1) as the main monomer up to a polymerization rate of 50 wt.% or more, and adding a monomer composition (B) containing 50 wt.% or more of a 2-14C alkyl (meth)acrylate (b1) as the main monomer. This mixed composition is applied on a substrate. Thereafter completing the polymerization of the mixed composition by light irradiation to form an adhesive layer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape manufacturing method and an adhesive tape. The pressure-sensitive adhesive tape of the present invention is used as a pressure-sensitive adhesive tape for vibration damping materials in various fields such as automobile parts, various home appliances, and precision equipment.

[0002]

2. Description of the Related Art Adhesive tapes for vibration damping materials have been used for many vibration countermeasures from automobiles to home electric appliances due to the convenience and high vibration damping performance of the adhesive tapes.

However, the polymer forming the pressure-sensitive adhesive layer of the conventional vibration-damping pressure-sensitive adhesive tape has a loss tangent (hereinafter,
The peak temperature of tan δ) is usually 10 ° C. or less, and it cannot be said that the vibration damping performance in the high temperature region is sufficient. This is because the Tg (glass transition temperature) of, for example, an acrylic polymer used as a base polymer of an adhesive is usually designed to be low in order to maintain and exhibit excellent adhesive properties.

The adhesive can be designed to have a high Tg in order to enhance the vibration damping performance at high temperatures. However, the high T
When designed to be g, the pressure-sensitive adhesive has physical properties having a glass transition region in the vicinity of room temperature at which attachment work and the like are usually performed. Therefore, there is a problem that the elastic modulus of the pressure-sensitive adhesive becomes extremely high, the initial adhesiveness becomes insufficient, and the pressure-sensitive adhesive property cannot be exhibited. There is also a method of treating a viscoelastic material having a high Tg by thermocompression bonding (heat press) or a method of adhering and fixing with an adhesive. However, when these methods are adopted, there is a problem in that a step such as heat treatment needs to be additionally provided and an aging time for adhesive fixation is required, and the work is complicated and uncertain factors increase.

On the other hand, there is a method of using a low Tg pressure-sensitive adhesive in order to obtain appropriate initial adhesiveness. However, the low Tg adhesive has a problem that the adhesive force is insufficient and the adhesive tape or sheet is displaced at a high temperature after bonding. As described above, it is currently difficult to balance the adhesiveness and the cohesive force with the pressure-sensitive adhesive tape.

[0006]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a pressure-sensitive adhesive tape which has a good vibration damping property and a cohesive force at a high temperature and is capable of a normal bonding operation at room temperature, and a method for producing the same. The purpose is to provide.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above technical problems, and as a result, found that an adhesive tape capable of achieving the above object can be obtained by the method for producing an adhesive tape shown below. The present invention has been completed.

That is, according to the present invention, a monomer composition (A) containing 50% by weight or more of a (meth) acrylic acid alkyl ester (a1) having an alkyl group having 2 to 14 carbon atoms as a main monomer has a polymerization rate of The first photopolymer obtained by photopolymerization to 50% by weight or more has 50% by weight of a (meth) acrylic acid alkyl ester (b1) having an alkyl group having 2 to 14 carbon atoms as a main monomer. After coating the mixed composition prepared by adding the above-mentioned monomer composition (B) on a supporting substrate, polymerization of the mixed composition is completed by light irradiation to form a pressure-sensitive adhesive layer. A method for producing an adhesive tape, which is a feature of the present invention.

In the above-mentioned method for producing an adhesive tape of the present invention,
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is formed by first polymerizing the monomer composition (A) at a polymerization rate of 50% by weight.
Polymerization is carried out until the above, then the monomer composition (B) is added thereto, and the second stage polymerization is further carried out to carry out two-stage photopolymerization. In the first-stage polymerization, the polymerization rate of the monomer composition (A) is set to 50% by weight or more, so that the first photopolymerization product in a state where more than half of the monomer composition (A) is a polymer component is added to the monomer. Since the composition (B) is added and the second-stage polymerization is further performed, in the second-stage polymerization, a polymer having a different composition from the polymer component produced in the first-stage polymerization is produced. Can be made. As a result, the finally obtained pressure-sensitive adhesive layer has a structure in which two polymer components are phase-separated into micro or macro. This structure has a so-called IPN (interpenetrating rating).
polymer network) structure, which is preferable in order to improve the vibration damping property. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape thus obtained has good vibration damping property and cohesive force at high temperature,
Also, it has excellent workability at room temperature.

In the pressure-sensitive adhesive tape for damping material, it is generally preferable that the thickness of the pressure-sensitive adhesive layer is large. In the method for producing a pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive layer is formed by photopolymerization of the mixed composition coated on a supporting substrate, so that the thickness of the pressure-sensitive adhesive layer can be easily adjusted. Further, in the pressure-sensitive adhesive prepared by emulsion polymerization or solution polymerization, it is necessary to separately prepare the pressure-sensitive adhesive and form the pressure-sensitive adhesive layer on the supporting substrate, but in the production method of the present invention, the supporting group is formed by photopolymerization. The pressure-sensitive adhesive layer can be directly formed on the material, and the pressure-sensitive adhesive layer can be easily formed.

In the method for producing an adhesive tape, the main monomer (a1) of the monomer composition (A) and the main monomer (b1) of the monomer composition (B) are preferably different monomers.

The main monomer (a) of the monomer composition (A)
By using 1) and the main monomer (b1) of the monomer composition (B) as different monomers, the polymer produced in the first-stage polymerization and the polymer produced in the second-stage polymerization are phase-matched in a micro or macro manner. It is easy to separate and the desired phase structure is easily obtained.

In the above-mentioned method for producing an adhesive tape, it is preferable that the monomer composition (B) contains a compound (c1) containing two or more radical-reactive double bonds in one molecule. .

In the above method for producing an adhesive tape, the monomer composition (A) contains a functional monomer (a2), and the monomer composition (B) reacts with the functional monomer (a2) for crosslinking. It is preferable to contain the agent (c2).

In the method for producing an adhesive tape described above, it is preferable that the monomer composition (B) contains a functional monomer (b2) and a crosslinking agent (c3) that reacts with the functional monomer (b2).

The present invention also relates to the adhesive tape obtained by the above-mentioned manufacturing method.

It is effective to incorporate a cross-linking structure into the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape in order to improve the cohesive force and the adhesive force. For introducing the cross-linking structure into the pressure-sensitive adhesive layer, for example, the above means can be adopted.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing the adhesive tape of the present invention will be described below.

In the method for producing the pressure-sensitive adhesive tape, 50% by weight of a (meth) acrylic acid alkyl ester (a1) having an alkyl group having 2 to 14 carbon atoms as a main monomer.
A monomer composition (A) containing the above and a monomer composition (B) containing 50% by weight or more of a (meth) acrylic acid alkyl ester (b1) having an alkyl group having 2 to 14 carbon atoms as a main monomer, respectively. Prepare. In addition,
The (meth) acrylic acid alkyl ester means an acrylic acid alkyl ester and / or a methacrylic acid alkyl ester, and the following (meth) has the same meaning in the present invention.

(Meth) acrylic acid alkyl ester (a1) having an alkyl group of 2 to 14 carbon atoms, which is used as a main monomer of the monomer compositions (A) and (B),
As the alkyl group (b1), various groups having a linear or branched alkyl group can be used without particular limitation. Examples of the alkyl group include, for example,
Examples thereof include ethyl group, propyl group, butyl group, isoamyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, decyl group, lauryl group and isomyristyl group. These (meth) acrylic acid alkyl esters may be used alone or in combination of two or more. As described above, the main monomers of the monomer compositions (A) and (B) are preferably different monomers, and when two or more main monomers are combined, at least one kind is preferably different monomers.

In the monomer compositions (A) and (B),
The proportion of the main monomers (a1) and (b1) is 50% by weight or more based on the total monomer components contained in the monomer compositions (A) and (B). It is preferably 60% by weight or more, more preferably 70% by weight or more, 80% by weight or more, 90% by weight or more. These main monomers (a1),
When the proportion of (b1) is less than 50% by weight, a pressure-sensitive adhesive layer having good pressure-sensitive adhesive properties cannot be obtained, which is not preferable.

The monomer compositions (A) and (B) may contain a copolymerizable monomer in addition to the main monomers (a1) and (b1). The copolymerizable monomers include (meth) acrylic acid alkyl esters in which the alkyl group such as stearyl (meth) acrylate has 15 or more carbon atoms, methyl (meth) acrylate, vinyl acetate,
Styrene, (meth) acrylonitrile, n-vinylpyrrolidone, (meth) acryloylmorpholine, cyclohexylmaleimide, isopropylmaleimide, (meth) acrylamide, N, N, -dimethyl (meth) acrylamide, N, N, -diethyl (meth ) Acrylamide,
Examples thereof include N, N, -dibutyl (meth) acrylamide, N- (meth) acryloylmorpholine, N- (meth) acryloylpyrrolidone, N-vinylpyrrolidone, itacone imide, and N, N-dimethylaminoethyl (meth) acrylamide.

Further, as the copolymerizable monomer,
Carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, maleic anhydride, crotonic acid, maleic acid, fumaric acid; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth ) Hydroxyalkyl (meth) acrylate such as 4-hydroxybutyl acrylate, hydroxyl group-containing monomer such as glycerin di (meth) acrylate, N-methylol (meth) acrylamide; glycidyl (meth) acrylate,
Functional monomers such as epoxy group-containing monomers such as methylglycidyl methacrylate; amino group-containing monomers such as aminoethyl (meth) acrylate; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate.

In order to improve the cohesive force of the adhesive layer,
It is effective to incorporate a cross-linking structure into the pressure-sensitive adhesive layer, and as a method therefor, for example, (1): two or more radical-reactive double bonds in one molecule in the monomer composition (B) can be used. Including the compound (c1) containing (2):
A cross-linking agent which uses the functional monomer (a2) as a monomer copolymerizable with the main monomer (a1) in the monomer composition (A), and reacts with the functional monomer (a2) in the monomer composition (B). A method of including (c2),
(3): A functional monomer (b) as a monomer copolymerizable with the main monomer (b1) in the monomer composition (B).
A method of using 2) and further including a crosslinking agent (c3) that reacts with the functional monomer (b2), and a method of combining the above methods (1) to (3).

Examples of the compound (c1) containing two or more radical-reactive double bonds in one molecule used in the method (1) include, for example, 1,4-butanediol di (meth) acrylate and 1,6. -Hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, tripropylene glycol di (meth) ) Acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, bisphenol A-ethylene oxide adduct di (meth) acrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol tri (meth) acryl , Trimethylolpropane ethylene oxide-added tri (meth) acrylate, glycerin propylene oxide-added tri (meth) acrylate, trisacryloyloxyethyl phosphate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 3 -Acryloyloxyglycerin monomethacrylate etc. are mentioned. These compounds (c1) can be used alone or in combination of two or more.

The amount of these compounds (c1) used is appropriately adjusted in consideration of the cohesive force of the pressure-sensitive adhesive layer and the like. Compound (c
The amount of 1) used is usually 0.01 to 1 with respect to 100 parts by weight of the total amount of the monomer components in the monomer composition (B).
It is preferable that the amount is about parts by weight. The sufficient crosslinking effect of the compound (c1) improves the cohesive force of the pressure-sensitive adhesive layer,
Compound (c1) for suppressing adhesive residue during re-peeling
It is preferable to adjust the amount used of 0.01 parts by weight or more, more preferably 0.05 parts by weight or more. On the other hand, the compound (c
When the amount of 1) used is large, the cohesive force tends to be too high and the adhesive force tends to be lowered. Therefore, the amount of the compound (c1) used should be adjusted to 10 parts by weight or less, further 5 parts by weight or less. Is preferred.

The amounts of the functional monomers (a2) and (b2) used in the methods (2) and (3) are the adhesive strength of the adhesive layer,
It is adjusted appropriately in consideration of cohesive force and the like. Usually, the functional monomers (a2) and (b2) are used in an amount of 0. 1 of all monomer components contained in the monomer compositions (A) and (B).
It is preferably about 5 to 20% by weight. The amount of the functional monomers (a2) and (b2) used is 0.5% by weight or more, and further 1% by weight in order to improve the adhesive strength of the adhesive layer.
It is preferable to adjust the above. On the other hand, when the amount of the functional monomers (a2) and (b2) used is large, the cohesive force tends to be too high, and the adhesive force tends to decrease. Therefore, the amount of the functional monomers (a2) and (b2) used is 20% by weight or less, more preferably 15% by weight or less.
These functional monomers can be used alone or in combination of two or more.

As the cross-linking agent used in the methods (2) and (3), the cross-linking agents (c2) and (c3) having a functional group capable of reacting with the functional groups of the functional monomers (a2) and (b2) are used. To be The combination of the functional monomer and the cross-linking agent can be appropriately selected, for example, when the functional group of the functional monomer is a carboxyl group, a cross-linking agent having an epoxy group, an isocyanate group, an aziridyl group, a carbodiimide group, etc. is used. When the functional group of the functional monomer is a hydroxyl group, a curing agent having an isocyanate group or a carbodiimide group is used, and when the functional group of the functional monomer is an epoxy group, a crosslinking group having an amino group, a carboxyl group, etc. The agent is used, when the functional group of the functional monomer is an amino group or the like, a crosslinking agent having an epoxy group, a carbodiimide group or the like is used, and when the functional group of the functional monomer is an isocyanate group or the like, a hydroxyl group or a carboxyl group is used. A crosslinking agent having a group, an amino group or the like is used.

Examples of the cross-linking agent include 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl m-xylenediamine, and other epoxy-based cross-linking agents. Agents, isocyanate-based crosslinking agents such as hexamethylene diisocyanate, oil-soluble carbodiimide-based crosslinking agents, and the like can be used.

In the case of the method (2), the amount of the crosslinking agent (c2) used is about 0.01 to 10 parts by weight based on 100 parts by weight of the total amount of the monomer components contained in the monomer composition (A). Preferably. In the case of the method (3), the amount of the cross-linking agent (c3) used is about 0.01 to 10 parts by weight based on 100 parts by weight of the total amount of the monomer components contained in the monomer composition (B). Is preferred.

In any case, the crosslinking agents (c2), (c
In order to improve the cohesive force of the pressure-sensitive adhesive layer by the sufficient crosslinking effect according to 3), the amount of the crosslinking agent used is 0.01 parts by weight or more, more preferably 0.03 parts by weight or more, and particularly 0.05 parts by weight. It is preferable to adjust the amount to more than one part. On the other hand, when the amount of the cross-linking agent used is large, the adhesive force tends to be insufficient due to excessive cross-linking or a decrease in functional groups, so the amount of the cross-linking agent used is 10 parts by weight or less, further 5 parts by weight or less, It is particularly preferable to adjust the amount to 3 parts by weight or less. The amount of crosslinking agent used is
It is preferably 0.03 to 5 parts by weight, more preferably 0.05 to 3 parts by weight.

When the methods (2) and (3) are used in combination, the same functional monomers (a2) and (b2) are used, and the crosslinking agents (c2) and (c3) are also the same. However, it is possible to independently crosslink the monomer composition (A) and the monomer composition (B) by using different kinds of combinations of the functional monomer and the crosslinking agent, It is preferable for forming an IPN structure.

Since the monomer compositions (A) and (B) are subjected to photopolymerization, a photopolymerization initiator is used for photopolymerization. Examples of the photopolymerization initiator include benzoin ethers such as benzoin methyl ether and benzoin isopropyl ether, substituted benzoin ethers such as anizoin methyl ether, 2,2-diethoxyacetophenone and 2,2-dimethoxy-2. -Substituted acetophenones such as phenone acetophenone, 2-methyl-
Substituted α-ketols such as 2-hydroxypropiophenone, 2-naphthalenesulfonyl chlorides, and photoactive oximes such as 1-phenone-1,1-propanedione-2- (ortho-ethoxycarbonyl) oxime. To be The amount of these photopolymerization initiators used is not particularly limited, but it may be 1 for each of the monomer compositions (A) and (B).
0.005 to 1 part by weight, preferably 0.01 to 0. Used in a ratio of 5 parts by weight. If the amount is less than 0.005 parts by weight, a large amount of unreacted monomer remains after photopolymerization, the originally designed adhesive property is difficult to obtain, and problems such as odor are likely to occur. On the other hand, if the amount is more than 1 part by weight, the photopolymerization initiator remains in the pressure-sensitive adhesive layer, which easily causes yellowing. The photopolymerization initiator can be added to the monomer compositions (A) and (B), respectively, or an initiator to be added to the monomer composition (B) can be added to the monomer composition (A). You can also keep it.

Further, the monomer composition (A), (B)
If necessary, various known additives such as a chain transfer agent, a filler, a pigment, a dye, an antiaging agent and a tackifying resin can be added within a range that does not prevent photopolymerization by irradiation with ultraviolet rays. The chain transfer agent is effective in suppressing an excessive increase in viscosity in the polymerization of the first-stage monomer composition (A).

The ratio of the monomer composition (A) to the monomer composition (B) can be appropriately determined depending on the application of the adhesive tape. Usually, the monomer composition (A): monomer composition (B) = 10: 90 to 90:10, preferably 3 based on the total weight ratio of the respective monomer components.
It is 0:70 to 70:30.

In the production of the pressure-sensitive adhesive tape, first, the above-mentioned monomer composition (A) is subjected to the first-stage photopolymerization until the polymerization rate reaches 50% by weight or more to prepare the first photopolymer. Next, the monomer composition (B) is added to the first photopolymerization product to prepare a mixed composition. Then, after coating the mixed composition on a supporting substrate, the second step photopolymerization by light irradiation completes the polymerization of the mixed composition to form a pressure-sensitive adhesive layer to produce a pressure-sensitive adhesive tape. To do.

The higher the polymerization rate of the first photopolymerization product obtained by the first-stage photopolymerization, the clearer the difference in physical properties from the polymer obtained by the second-stage photopolymerization, and the phase separation structure. For the production of The polymerization rate of the first photopolymerization product obtained by the first stage photopolymerization is preferably 60% by weight or more, and more preferably 70% by weight or more. When the polymerization rate of the first photopolymerization product is less than 50% by weight, the monomer composition (A) is
More than half of the monomers in the second stage photopolymerization
Copolymerization with the monomer composition (B) makes it impossible to obtain a characteristic phase separation structure. On the other hand, the polymerization rate of the first photopolymer is 1
00% by weight is desirable, but usually 95% by weight or less. The polymerization rate of the first photopolymerization product is the weighed value (weight before drying) of the sampled polymer and the weighed value after the residual monomer was scattered by placing this in a hot air dryer at 130 ° C. for 2 hours. It is a value obtained from the formula (weight after drying) / (weight after drying) / (weight before drying) × 100 (%) from the weight after drying.

The photopolymerization treatment in both the first and second stages is preferably carried out in an oxygen-free atmosphere substituted with an inert gas such as nitrogen gas. The second-stage photopolymerization can be carried out in a state in which the mixed composition is applied to a supporting base material and then covered with an ultraviolet-transparent release film to block air.

Radiation (ultraviolet rays) in the photopolymerization treatment is
The wavelength range is about 180 to 460 nm, but the wavelength may be longer or shorter than that. Irradiation devices such as a mercury arc, a carbon arc, a low pressure mercury lamp, a medium / high pressure mercury lamp, and a metal halide lamp are used as the ultraviolet ray source. The ultraviolet intensity can be appropriately set by adjusting the distance to the object to be irradiated and the voltage. In consideration of irradiation time (productivity), usually 0.1 to 7 mW / c
It is desirable to use weak light of m ² .

The pressure-sensitive adhesive layer obtained by such a photopolymerization treatment has a sufficiently high molecular weight and can have an appropriate degree of crosslinking by internally crosslinking with a crosslinking agent.
The amount of volatile components such as unreacted monomers contained in this is small. If it is desired to further reduce the volatile component remaining in a trace amount, a heat drying treatment may be performed after the photopolymerization treatment. The heat drying treatment is preferably carried out using a drying oven, especially a hot air circulating drying oven having a far infrared heater. Due to the heating from the inside by the far infrared heater and the diffusion by the circulating hot air from the surface, efficient drying can be performed in a short time. Usually 10 depending on the capacity of the drying oven
The treatment time may be about 10 seconds to several minutes at about 0 to 150 ° C.

The supporting base material on which the mixed composition is applied is appropriately selected depending on the intended use of the adhesive tape. As the supporting substrate, for example, a polyester film, a polyimide film, a plastic film such as a polytetrafluoroethylene film, various metal foils, and a porous material such as nonwoven fabric or paper can be used. In addition, as the supporting base material, a base material subjected to a mold release treatment can also be used. When the pressure-sensitive adhesive layer is formed on the release-treated film, it can be used by transferring it to another supporting substrate after producing the pressure-sensitive adhesive tape. The thickness of the supporting substrate is not particularly limited, but is usually about 25 to 125 μm. Although the thickness of the pressure-sensitive adhesive layer is appropriately set depending on the intended use, it is usually preferably about 20 to 200 μm.

[0042]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples. In each example, parts and% are based on weight.

Example 1 47.5 parts of butyl acrylate, acrylic acid were added to a reactor equipped with a thermometer, a stirrer, a nitrogen introducing tube and a reflux cooling tube.
5 parts, 0.03 part of thioglycol and 0.1 part of 2,2-dimethoxy-2-phenylacetophenone (“Irgacure 651” manufactured by Ciba Specialty Chemicals) were charged, and nitrogen substitution was carried out for 1 hour while stirring. Then, it was exposed to ultraviolet rays and photopolymerized to obtain a first photopolymer (syrup) having a polymerization rate of 73%. To 50 parts of this syrup, 47.5 parts of ethyl acrylate, 2.5 parts of acrylic acid and 0.2 part of trimethylolpropane triacrylate were added and stirred to prepare a mixed composition. This mixed composition was applied on a silicone-treated polyethylene terephthalate film having a thickness of 38 μm to a thickness of 50 μm and irradiated with ultraviolet rays to complete polymerization. Then, it heated at 130 degreeC for 5 minutes, the residual monomer was removed, and the adhesive tape was produced.

Example 2 49 parts of isononyl acrylate and 2 parts of acrylic acid were placed in a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a reflux condenser.
Parts, 0.03 parts of thioglycol and 0.1 parts of 2,2-dimethoxy-2-phenylacetophenone (“Irgacure 651” manufactured by Ciba Specialty Chemicals) were charged, and the atmosphere was replaced with nitrogen for 1 hour while stirring. Then, it was exposed to ultraviolet rays and photopolymerized to obtain a first photopolymer (syrup) having a polymerization rate of 92%. To 51 parts of this syrup, 49 parts of butyl acrylate and 0.1 part of a tetrafunctional epoxy crosslinking agent (“Tetrad C” manufactured by Mitsubishi Gas Chemical Co., Inc.) were added and stirred to prepare a mixed composition. This mixed composition has a thickness of 38 μm.
The coating was applied to the silicone-treated polyethylene terephthalate film in Example 1 to a thickness of 50 μm, and ultraviolet rays were irradiated to complete the polymerization. Then, it heated at 130 degreeC for 5 minutes, the residual monomer was removed, and the adhesive tape was produced.

Example 3 In Example 2, in preparing the mixed composition, trimethylolpropane triacrylate 0. An adhesive tape was produced in the same manner as in Example 2 except that 2 parts were added.

Example 4 48 parts of 2-ethylhexyl acrylate, 2 parts of 2-hydroxyethyl acrylate, 0.0 part of thioglycol were placed in a reactor equipped with a thermometer, a stirrer, a nitrogen introducing tube and a reflux condenser.
3 parts and 0.1 part of 2,2-dimethoxy-2-phenylacetophenone (“Irgacure 651” manufactured by Ciba Specialty Chemicals) were charged, and the atmosphere was replaced with nitrogen for 1 hour while stirring. Then, it was exposed to ultraviolet rays and photopolymerized to obtain a first photopolymer (syrup) having a polymerization rate of 85%. 50 parts of this syrup, 48 parts of ethyl acrylate, 2 parts of acrylic acid
Parts, 3 parts of a trifunctional isocyanate-based cross-linking agent (“Coroneto L” manufactured by Nippon Polyurethane Co., Ltd.) and 0.1 part of a tetra-functional epoxy-based cross-linking agent (“Tetrad C” manufactured by Mitsubishi Gas Chemical Co., Inc.) were added and stirred. A mixed composition was prepared. This mixed composition was applied on a silicone-treated polyethylene terephthalate film having a thickness of 38 μm to a thickness of 50 μm and irradiated with ultraviolet rays to complete polymerization. Then, it heated at 130 degreeC for 5 minutes, the residual monomer was removed, and the adhesive tape was produced.

Comparative Example 1 47.5 parts of butyl acrylate, 47.5 parts of ethyl acrylate, 5 parts of acrylic acid, and 2,2-in a reactor equipped with a thermometer, a stirrer, a nitrogen introducing tube and a reflux cooling tube. 0.1 part of dimethoxy-2-phenylacetophenone (“Irgacure 651” manufactured by Ciba Specialty Chemicals) was charged, and the atmosphere was replaced with nitrogen for 1 hour while stirring. Then, it was exposed to ultraviolet rays and photopolymerized to obtain a syrup having a polymerization rate of 8%. To 100 parts of this syrup, 0.2 part of trimethylolpropane triacrylate was added and stirred to prepare a mixed composition. This mixed composition was applied on a 38 μm thick silicone-treated polyethylene terephthalate film to give a thickness of 5 μm.
The coating was applied to 0 μm and ultraviolet rays were irradiated to complete the polymerization. Then, heat at 130 ° C. for 5 minutes to remove residual monomers,
An adhesive tape was produced.

Comparative Example 2 49 parts of isononyl acrylate, 49 parts of butyl acrylate, 2 parts of acrylic acid and 2,2-dimethoxy- were added to a reactor equipped with a thermometer, a stirrer, a nitrogen introducing tube and a reflux condenser.
0.1 part of 2-phenylacetophenone (“Irgacure 651” manufactured by Ciba Specialty Chemicals) was charged, and the atmosphere was replaced with nitrogen for 1 hour while stirring. Then, it was exposed to ultraviolet rays and photopolymerized to obtain a syrup having a polymerization rate of 11%. To 100 parts of this syrup, 0.1 part of a tetrafunctional epoxy crosslinking agent (“Tetrad C” manufactured by Mitsubishi Gas Chemical Co., Inc.) was added and stirred to prepare a mixed composition. This mixed composition is applied to a thickness of 38
A 50 μm-thick polyethylene terephthalate film was coated on a silicone-treated polyethylene terephthalate film and irradiated with ultraviolet rays to complete polymerization. Then, it heated at 130 degreeC for 5 minutes, the residual monomer was removed, and the adhesive tape was produced.

Comparative Example 3 In Comparative Example 2, a trimethylolpropane triacrylate 0. An adhesive tape was produced in the same manner as in Comparative Example 2 except that 2 parts were added.

Comparative Example 4 48 parts of 2-ethylhexyl acrylate, 48 parts of ethyl acrylate, 2-hydroxyethyl acrylate 2 were placed in a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a reflux condenser.
Parts, 2 parts of acrylic acid and 0.1 part of 2,2-dimethoxy-2-phenylacetophenone (“Irgacure 651” manufactured by Ciba Specialty Chemicals) were charged, and the atmosphere was replaced with nitrogen for 1 hour while stirring. Then, it was exposed to ultraviolet rays and photopolymerized to obtain a syrup having a polymerization rate of 10%. To 100 parts of this syrup, 3 parts of a trifunctional isocyanate cross-linking agent (“Coroneto L” manufactured by Nippon Pourourethane Co., Ltd.) and 4 parts of a tetra-functional epoxy cross-linking agent (“Tetrad C” manufactured by Mitsubishi Gas Chemical Co., Inc.)
0.1 part was added and stirred to prepare a mixed composition. This mixed composition was applied on a silicone-treated polyethylene terephthalate film having a thickness of 38 μm to a thickness of 50 μm and irradiated with ultraviolet rays to complete polymerization. Then 13
The residual monomer was removed by heating at 0 ° C for 5 minutes to prepare an adhesive tape.

The adhesive tapes obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Table 1.

(Measurement of damping property (loss tangent; tan δ))
Approximately 3mm thick by sticking multiple layers of adhesive tape
The test sample of was produced. Using a "dynamic viscoelasticity measuring device ARES" manufactured by Rheometric Co., this sample is
The frequency was 1 Hz, the temperature rising rate was 10 ° C./min, and the measurement was performed using a jig of φ7.9 mm parallel plate. The temperature and value at the peak of tan δ and the value of tan δ at 40 ° C. were obtained.

(Measurement of adhesive strength) Adhesive tape having a thickness of 25 μm
A sample (20 mm × 100 mm) for adhesive strength measurement was prepared by laminating the sample on the polyester film. This is J
SUS30 as an adherend according to IS Z-0237
4 (polished with water-resistant abrasive paper # 280), left for 30 minutes, and then the adhesive strength (N / 20 cm) of 180 ° peeling under the conditions of atmosphere temperature 23 ° C. and peeling speed 300 mm / min. It was measured at.

(Measurement of cohesive force (holding power)) An adhesive tape was attached to a polyester film having a thickness of 25 μm to prepare a sample (10 mm × 100 mm) for measuring cohesive force.
This is adhered to SUS304 (water resistant abrasive paper # 2
It was attached to (polishing at 80) so that the width was 10 mm and the length was 20 mm, a load of 500 g was applied, and the shift distance (mm) after 20 hours at 40 ° C. was measured.

[0055]

[Table 1] From the results shown in Table 1, the pressure-sensitive adhesive layers of Examples 1 to 4 and Comparative Examples 1 to 4 corresponding thereto were formed from the same monomer composition, respectively, but in Example, at 40 ° C. ta
It can be seen that nδ is high and the balance between the adhesive force and the holding force is good. As described above, the pressure-sensitive adhesive tape of the present invention can provide vibration-damping pressure-sensitive adhesive tapes which have good vibration damping properties and cohesive strength at high temperatures and are excellent in workability for bonding at room temperature.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takio Ito             1-2 1-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto             Electric Works Co., Ltd. F-term (reference) 4J004 AA01 AA10 AA17 AB01 AB07                       CC02 FA10 GA01                 4J040 DF041 DF042 DF051 DF052                       EC122 EF181 EF182 FA141                       FA142 FA161 FA162 FA211                       FA212 FA281 FA282 GA02                       HB19 HC16 HC22 JA09 JB08                       JB09 KA13 KA16 LA06 NA16                       NA19 NA22

Claims (6)

[Claims] 1. A monomer composition (A) containing 50% by weight or more of a (meth) acrylic acid alkyl ester (a1) having an alkyl group having 2 to 14 carbon atoms as a main monomer and having a polymerization rate of 50% by weight. The first photopolymer obtained by photopolymerization until the above content contains 50% by weight or more of a (meth) acrylic acid alkyl ester (b1) having an alkyl group having 2 to 14 carbon atoms as a main monomer. The adhesive composition is characterized in that the mixed composition prepared by adding the monomer composition (B) is applied on a supporting substrate, and then the mixed composition is polymerized by light irradiation to form a pressure-sensitive adhesive layer. Adhesive tape manufacturing method. 2. A main monomer (a) of the monomer composition (A).
1) and the main monomer (b1) of the monomer composition (B),
The method for producing an adhesive tape according to claim 1, wherein the monomers are different kinds of monomers. 3. The monomer composition (B) contains 2 in one molecule.
Compound (c1) containing one or more radical-reactive double bonds
The method for producing an adhesive tape according to claim 1 or 2, further comprising: 4. The monomer composition (A) contains a functional monomer (a2), and the monomer composition (B) comprises
Crosslinking agent (c2) that reacts with the functional monomer (a2)
The method for producing an adhesive tape according to any one of claims 1 to 3, further comprising: 5. The monomer composition (B) contains a functional monomer (b2) and a crosslinking agent (c3) which reacts with the functional monomer (b2).
The manufacturing method of the adhesive tape in any one of Claims 1-4. 6. An adhesive tape obtained by the manufacturing method according to claim 1.