JP3016670B2 - Damping thin leaf - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-damping thin sheet which is attached to a vibration generator to reduce vibration and noise, and more particularly, to a specific thin sheet obtained by copolymerizing a specific monomer. Acrylic copolymer having a glass transition temperature or lower, and the proportion of a low molecular weight copolymer component having a molecular weight of 100,000 or less contained in the copolymer, an acrylic copolymer having a specific amount or less is a specific amount. The present invention relates to a vibration-damping thin sheet excellent in solvent resistance and heat resistance having a pressure-sensitive adhesive layer crosslinked by a crosslinking agent.

[0002]

2. Description of the Related Art In recent years, vehicles such as automobiles, railways, and aircraft, office equipment, information equipment, electrical products, floors and roofs of buildings,
Vibration and noise of stairs, walls and the like have become a problem, and many damping materials have been proposed as measures to solve such problems.

As such a vibration damping material, a composite vibration damping steel sheet having a three-layer structure in which a material having viscoelasticity is laminated between two steel sheets, an acrylic-based adhesive on one side of a constraining layer such as a metal foil, or the like. Damping sheet having a two-layer structure coated with an adhesive, a butyl rubber-based pressure-sensitive adhesive, etc. is known, and the present invention provides an excellent vibration damping thin leaf body that can easily exhibit the vibration damping property by the latter post-processing. Is to be provided.

With respect to such a two-layered vibration damping sheet, for example, Japanese Patent Application Laid-Open No. 1-69336 discloses that a pressure-sensitive adhesive vibration damping composition layer (A) on a sheet is bonded to the layer. Consisting of a two-layer structure with a restraining plate (B), the above (A) layer (B)
A vibration-damping pressure-sensitive adhesive sheet having a concavo-convex pattern on the surface opposite to the plate is disclosed, and it is recommended to use a rubber-based, acrylic-based, or rubber-acrylic-based material for the (A) layer.

However, in this proposal, the pressure-sensitive adhesive vibration damping composition layer (A) contains a specific acrylic copolymer in which the content of a specific low molecular weight copolymer component is not more than a specific amount. There is no description or suggestion of using a pressure-sensitive adhesive layer formed by crosslinking with a glycidylamine compound.Therefore, a special effect by using such a pressure-sensitive adhesive layer, That is,
Of course, it does not disclose any outstanding effects such as extremely excellent vibration damping properties and excellent solvent resistance and heat resistance. And like this proposal,
The vibration-damping pressure-sensitive adhesive sheet having an uneven pattern on the surface of the (A) layer opposite to the plate (B) is complicated to manufacture, and the obtained vibration-damping pressure-sensitive adhesive sheet can be formed in a normal feeling such as being wound into a roll. It is difficult to handle like a pressure-sensitive adhesive tape, and there is a problem in storage and transportation.

[0006] Also, JP-A-63-69850 discloses a) -40
Elastomer (A) having a glass transition point of not more than 15 ° C. 15 to 70
% By weight, b) an elastomer (B) having a glass transition point of -40 to 40 ° C, a tackifying resin (C) having a pour point or softening point of -40 to 40 ° C, and a pour point of -40 to 40 ° C. A damping material comprising 15 to 70% by weight of at least one selected from the group of plasticizers (D) and c) a tackifying resin having a softening point of 60 ° C. or more (E) 15 to 70% by weight. A composition is disclosed.

[0007] However, in the second proposal, there is no description about the use of an acrylic copolymer.
Also, even when a vibration damping sheet is prepared using this vibration damping material composition, the balance of the adhesive force, tack and cohesive force of the pressure-sensitive adhesive layer is not always sufficient, and especially when used at a high temperature, the sheet is adhered. There is a problem that the damping sheet may slip down, and the pressure-sensitive adhesive may protrude from the end face of the sheet when the damping sheet wound in a roll is stored at a high temperature as described below. It turned out to be.

[0008]

SUMMARY OF THE INVENTION The inventors of the present invention have been able to effectively reduce vibration and noise by post-processing such as sticking to various vibration generators, and exhibit excellent vibration damping properties. As a result of research to obtain a vibration-damping thin body that can be treated, an acrylic polymer having a specific glass transition point or a specific monomer reaction with each other was used as the pressure-sensitive adhesive layer of the vibration-damping thin body. Acrylic copolymer having a specific glass transition point obtained by copolymerizing monomers having a sex ratio, wherein the low molecular weight copolymer component having a molecular weight of 100,000 or less contained in the copolymer By using a pressure-sensitive adhesive layer in which the copolymer is cross-linked by a specific cross-linking agent, the above-described problem that the conventional vibration-damping sheet has We found that it could be solved at once, and completed the present invention Accordingly, an object of the present invention is to develop a vibration-damping thin leaf excellent in solvent resistance and heat resistance.

[0009]

According to the present invention, there is provided a vibration-damping thin sheet having a pressure-sensitive adhesive layer on at least one surface of a constraining layer, wherein the pressure-sensitive adhesive layer has a single weight. At least one acrylic monomer (a) having a glass transition point of -20 ° C or lower and at least one monomer having at least one functional group in addition to a radically polymerizable unsaturated group (b) And, if necessary, the monomers (a) and (b)
Other than the comonomer (c) (wherein, the monomer (a) has a mutual monomer reactivity ratio and the monomer (a) and the monomer (b), and the comonomer The monomer reactivity ratio with (c) shall be in the range of 0.25 to 4.0) .The acrylic copolymer having a glass transition point of −5 ° C. or lower obtained by copolymerizing Acrylic copolymer (A) in which the weight average molecular weight of the copolymer is 150,000 to 1.5 million and the proportion of copolymer components having a molecular weight of 100,000 or less contained in the copolymer is 15% by weight or less. And
The copolymer (A) can be solved by a damping thin leaf which is obtained by crosslinking with a polyglycidylamine compound (B).

Hereinafter, the present invention will be described in more detail. The vibration-damping thin sheet of the present invention has a pressure-sensitive adhesive layer on at least one surface of the constraining layer, and the pressure-sensitive adhesive layer first has an acrylic glass transition point of -5 ° C or less. The copolymer (A) contains an acrylic monomer (a) having a homopolymer having a glass transition point of −20 ° C. or lower, and a radical polymerizable unsaturated polymer. A monomer (b) having at least one functional group in addition to the group, and a comonomer (c) other than the monomers (a) and (b), if necessary, are copolymerized. It becomes.

As the acrylic monomer (a), the following general formula (1):

CH ₂ ＣＨCH—COOR ¹ (I)

(Wherein, R ¹ represents a linear or branched alkyl group having 2 to 18 carbon atoms)

And a monomer (a) having a glass transition point of a homopolymer of -20 ° C. or lower. When such an acrylic copolymer is used, the obtained pressure-sensitive adhesive layer has a suitable tack, and the constraining layer in the vibration-damping thin sheet of the present invention and the vibration generator which is the object of use thereof It is preferable because it has an excellent balance between adhesion and cohesion.

In selecting the acrylic monomer (a) and the monomer (b), and the optional comonomer (c), the monomers (a) The reactivity ratio, and the monomer reactivity ratio of the monomer (a) to the monomer (b) and the comonomer (c) are all in the range of 0.25 to 4.0, preferably 0.3 to 3.0. It is necessary to be. If the monomer reactivity ratio of these monomers exceeds the upper limit of the above range, and is too large or too small, heat resistance and solvent resistance may be undesirably reduced.

As the acrylic monomer (a), R ¹ is preferably a linear or branched alkyl group having 2 to 18 carbon atoms, preferably 2 to 12 carbon atoms. Specific examples of such a group R ¹ include an ethyl group, an n-propyl group, an n-butyl group,
i-butyl group, n-hexyl group, n-octyl group, i-octyl group, 2-ethylhexyl group, i-nonyl group, and the like.Examples of the monomer (a) include ethyl acrylate. , N-propyl acrylate, n-butyl acrylate, i-butyl acrylate, n-hexyl acrylate,
n-octyl acrylate, i-octyl acrylate, 2-
Acrylic ester monomers such as ethylhexyl acrylate and i-nonyl acrylate can be exemplified.

The amount of the acrylic monomer (a) to be used is, for example, 50 parts by weight or more, preferably 63 to 100 parts by weight, per 100 parts by weight of the total of the monomers (a), (b) and (c). An amount of 99.8 parts by weight, particularly preferably about 80 to 96.5 parts by weight, is suitable. By setting the acrylic monomer (a) to this amount range,
A good balance of tack, adhesion and cohesion can be achieved.

The monomer having at least one functional group in addition to the radically polymerizable unsaturated group of the monomer (b) includes a functional group such as a carboxyl group,
Examples include monomers having an amide group or a substituted amide group, an amino group or a substituted amino group, a hydroxyl group, an epoxy group, or a mercapto group.In the present invention, among these monomers (b), One or more monomers can be appropriately selected and used.

Specific examples of these monomers include acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, citraconic acid and the like, preferably acrylic acid, methacrylic acid, itaconic acid. Carboxyl group-containing monomers such as: acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, Nn-butoxymethylacrylamide, Ni-butoxymethylacrylamide, N, N-dimethylacrylamide, N-methylacrylamide, etc. Preferably, an amide group or a substituted amide group-containing monomer such as acrylamide and methacrylamide;

Aminoethyl acrylate, N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate and the like, preferably N, N-dimethyl Aminoethyl methacrylate,
An amino- or substituted amino-group-containing monomer such as N, N-diethylaminoethyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, allyl alcohol, methallyl alcohol and the like, preferably, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, hydroxyl group-containing such as 2-hydroxypropyl methacrylate Monomer;

Epoxy group-containing monomers such as glycidyl acrylate, glycidyl methacrylate, glycidyl allyl ether and glycidyl methallyl ether, preferably glycidyl methacrylate; and mercapto group-containing monomers such as vinyl mercaptan and allyl mercaptan. it can. Among these monomers (b), it is particularly preferable to use at least one monomer selected from the group consisting of a carboxy group-containing monomer, an amino group-containing monomer and a hydroxyl group-containing monomer.

The amount of the monomer (b) used is
For example, 25 parts by weight or less, preferably 0.2 to 20 parts by weight, particularly preferably 1 to 10 parts by weight per 100 parts by weight of the total of (a) to (c)
An amount of about parts by weight can be exemplified. When the amount of the monomer (b) is equal to or less than the upper limit, the tack of the pressure-sensitive adhesive layer to be formed is preferably not too small, and the amount is particularly preferably 0.5% by weight or more. This is preferable because a good balance between the adhesive force and the cohesive force of the pressure-sensitive adhesive layer formed can be achieved.

Further, the comonomer (c) may be, for example, an acrylate monomer other than the acrylic monomer (a) such as methyl acrylate, t-butyl acrylate, cyclohexyl acrylate, stearyl acrylate, etc. For example, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, i-octyl methacrylate, 2-ethylhexyl methacrylate, i-nonyl Methacrylate monomers such as methacrylate, n-dodecyl methacrylate, i-dodecyl methacrylate and stearyl methacrylate;

For example, saturated fatty acid vinyl ester monomers such as vinyl formate, vinyl acetate, vinyl propionate and "vinyl versatate" (trade name); for example, dibutyl malate, dibutyl fumarate, dibutyl itaconate, dioctyl malate , Dioctyl fumarate, dioctyl itaconate, etc., linear or branched alkyl esters of α, β-unsaturated dicarboxylic acids having 1 to 18 carbon atoms; for example, styrene, α-methylstyrene, vinyltoluene, ethylvinylbenzene, etc. Aromatic vinyl monomers; for example, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile;

The amount of the comonomer (c) to be used is
In general, 50 parts by weight or less, preferably 36.8 parts by weight or less, particularly preferably 2 to 2 parts by weight, per 100 parts by weight of the total of (a) and (b)
An amount of about 15 parts by weight is preferred. Since the use of the comonomer (c) can vary depending on the type of the comonomer, the amount of use is not uniquely determined. It is useful to adjust the balance and the like as desired, so that the above range amount can be appropriately selected so as to meet such purpose. When the amount of the comonomer (c) used is equal to or less than the upper limit of the above range, the pressure-sensitive adhesiveness does not become too low, and an appropriate balance between the adhesive force and the pressure-sensitive adhesiveness is maintained. So the comonomer
When (c) is used, it is preferable to select and use the amount in the above range appropriately.

The glass transition point (hereinafter sometimes abbreviated as Tg) of the acrylic copolymer used in the present invention must be -5 ° C. or lower, and is -20 ° C. or lower. Is preferred. If the Tg exceeds this upper limit and is too high, the tack of the resulting pressure-sensitive adhesive layer becomes insufficient, making it difficult to adhere to the vibration generator, which is not preferred.

In the acrylic copolymer used in the present invention, the proportion of the copolymer component having a molecular weight of 100,000 or less must be 15% by weight or less, and 10% by weight or less. It is preferred that If the proportion of the copolymer component exceeds 15% by weight, the heat resistance and solvent resistance of the resulting pressure-sensitive adhesive layer tend to decrease, which is not preferable.

The acrylic copolymer used in the present invention preferably has a weight average molecular weight (hereinafter sometimes abbreviated as Mw) of 150,000 to 1.5 million, particularly preferably 25 to 1,000,000. . When the value of Mw is equal to or more than the lower limit, the adhesive force and the cohesive force of the obtained pressure-sensitive adhesive layer have a good balance. When applying the pressure-sensitive adhesive composition solution at the time of forming, a suitable coating viscosity can be obtained without significantly lowering the solid content of the composition solution, so that the composition is dried and cured in a relatively short time to obtain a pressure-sensitive adhesive. Since the adhesive layer can be formed and the amount of the organic solvent volatilized does not become too large, it is preferable from the viewpoint of cost and environmental health. Therefore, it is preferable to appropriately select the Mw of the acrylic copolymer within this range. The “molecular weight” and “weight average molecular weight” of the copolymer referred to in the present invention both refer to values measured by the GPC method.

In the present invention, the glass transition point (Tg) of the acrylic copolymer is a value measured by the following method.

Measurement of glass transition point: In a cylindrical cell made of aluminum foil having a thickness of about 0.05 mm and having an inner diameter of about 5 mm and a depth of about 5 mm, a sample of an organic solvent solution of about 50% by weight of an acrylic copolymer was prepared. 10 mg is weighed and dried at 100 ° C for 2 hours to be used as a measurement sample. "SSC-5000" manufactured by Seiko Electronic Industry Co., Ltd.
Differential Scanning Calorimeter
) And determine the temperature from -150 ° C at a rate of 10 ° C / min.

The method of polymerizing the acrylic copolymer used in the present invention is not particularly limited, and may be a solution polymerization,
Known methods such as emulsion polymerization can be employed, but solution polymerization is preferred from the viewpoint of excellent heat resistance and solvent resistance of the resulting pressure-sensitive adhesive layer.

In the solution polymerization, generally, a predetermined organic solvent, a monomer, a polymerization initiator, and a chain transfer agent used as required are charged into a polymerization tank, and the polymerization is carried out in a nitrogen stream or at the reflux temperature of the organic solvent. The reaction is performed by heating for several hours while stirring. In this case, at least a part of the organic solvent, the monomer, the polymerization initiator and / or the chain transfer agent may be sequentially added.

Examples of the organic solvent used for the solution polymerization include aromatic hydrocarbons such as benzene, toluene, xylene and aromatic naphtha; for example, n-hexane, n-hexane and the like.
Aliphatic or alicyclic hydrocarbons such as heptane, n-octane, i-octane, n-decane, dipentene, petroleum spirit, petroleum naphtha, and turpentine oil; for example, ethyl acetate, n-butyl acetate, n- Esters such as amyl acetate, 3-methoxybutyl acetate, methyl benzoate, cellosolve acetate, butyl cellosolve acetate;

For example, acetone, methyl ethyl ketone,
Ketones such as methyl isobutyl ketone, isophorone, cyclohexanone, methyl cyclohexanone;
Glycol ethers such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, i-butyl alcohol, s-butyl alcohol, t-butyl alcohol And the like. These organic solvents can be used alone or in combination of two or more.

Among these solvents, the easiness of the polymerization operation,
From the viewpoint of the reaction speed, the ease of volatilization in forming the pressure-sensitive adhesive layer, and the like, the boiling point is 50 to 150 ° C, and particularly, the boiling point is 60 to
It is preferable to use an organic solvent at 100 ° C., and particularly preferable to use an organic solvent such as n-hexane, ethyl acetate, acetone, methyl ethyl ketone, methyl alcohol, and n-propyl alcohol.

Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, caproyl peroxide, di-i-propylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate and t-butylperoxy. Organic peroxides such as bivalate; for example, 2,2'-azobis-i-butyronitrile, 2,2 '
Azo compounds such as -azobis-2,4-dimethylvaleronitrile and 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile can be used alone or in combination. The amount of the polymerization initiator used is not particularly limited, but is generally about 0.01 to 1.0 part by weight, preferably about 0.02 to 0.5 part by weight, based on 100 parts by weight of the total amount of the monomers.

The chain transfer agent includes, for example,
Cyanoacetic acid; alkyl esters of cyanoacetic acid having an alkyl group having 1 to 8 carbon atoms; bromoacetic acid;
Aromatic compounds such as anthracene, phenanthrene, fluorene and 9-phenylfluorene; p-nitroaniline, nitrobenzene, dinitrobenzene, p-nitrobenzoic acid, p-nitrophenol, p-nitrophenol
Aromatic nitro compounds such as nitrotoluene; benzoquinone derivatives such as benzoquinone and 2,3,5,6-tetramethyl-p-benzoquinone; borane derivatives such as tributylborane;

Halogenated carbons such as carbon tetrabromide, carbon tetrachloride, 1,1,2,2-tetrabromoethane, tribromoethylene, trichloroethylene, bromotrichloromethane, tribromomethane and 3-chloro-1-propene Hydrogens; aldehydes such as chloral and furaldehyde; C1-18
Aromatic mercaptans such as thiophenol and toluene mercaptan; mercaptoacetic acid; alkyl esters of mercaptoacetic acid having 1 to 10 carbon atoms; hydroxyalkyl mercaptans having 1 to 12 carbon atoms; binene, terpinolene and the like. Terpenes and the like can be mentioned.

The amount of the chain transfer agent used is not particularly limited, but is preferably about 100 parts by weight of the total monomer.
It is preferably 0.005 to 3.0 parts by weight. The polymerization temperature is
Generally, the range is about 30 to 180 ° C, preferably about 60 to 120 ° C.

As described above, in the acrylic copolymer (A) used in the present invention, the proportion of the copolymer component having a molecular weight of 100,000 or less needs to be 15% by weight or less.
As a method of obtaining such an acrylic copolymer (A), for example, a copolymer solution obtained by solution polymerization,
A so-called reprecipitation method, in which a poor solvent for the copolymer is added to remove the low molecular weight copolymer component which is a soluble portion, may be used.

The copolymer solution preferably used in the present invention thus obtained usually contains the above-mentioned acrylic copolymer in 20 parts.
About 90% by weight, preferably about 25 to 60% by weight.

The pressure-sensitive adhesive layer in the vibration-damping thin sheet of the present invention is formed by crosslinking with a polyglycidylamine compound (B) in order to improve cohesion, heat resistance and solvent resistance. .

Examples of the polyglycidylamine compound (B) include, for example, N, N-diglycidylaniline, N, N-diglycidyltoluidine, mN, N-diglycidylaminophenylglycidyl ether, pN, N-diglycidyl Aminophenyl glycidyl ether, N, N, N ', N'-tetraglycidyl
-4,4'-methylenebisbenzeneamine, triglycidyl isocyanurate, N, N, N ', N'-tetraglycidylethylenediamine, N, N, N', N'-tetraglycidyldiaminodiphenylmethane, N, N, N ', N'-Tetraglycidyl-m-xylenediamine, N, N, N', N ', N'-pentaglycidyldiethylenetriamine, 1,3-bis (N, N-dicrysidylaminomethyl) cyclohexane, etc. Can be.

The amount of the polyglycidylamine compound (B) to be used is generally 0.05 to 5 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total amount of the acrylic copolymer (A).
It is about 1 to 2 parts by weight. If the amount of the cross-linking agent is less than or equal to the upper limit, the pot life of the pressure-sensitive adhesive composition used is preferably long, and if the amount is equal to or greater than the lower limit, excellent cohesion, heat resistance and solvent resistance are obtained. This is preferable because a pressure-sensitive adhesive layer can be obtained.

The pressure-sensitive adhesive layer of the vibration-damping thin sheet of the present invention may comprise, if necessary, an organic polyisocyanate compound or an organic polyepoxy as a crosslinking agent in addition to the polyglycidylamine compound (B). Compounds, amino resins, metal crosslinking agents and the like can be used in combination.

As the above-mentioned organic polyvalent isocyanate compound, for example, p-phenylene diisocyanate, 4,4'-
Aromatic polyisocyanates such as diphenylmethane diisocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, xylene diisocyanate, naphthalene-1,5-diisocyanate; for example, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate , Isophorone diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated 2,4-toluylene diisocyanate,
Aliphatic or alicyclic polyisocyanates such as hydrogenated 2,6-toluylene diisocyanate and hydrogenated xylene diisocyanate;

Trimers of these aromatic polyisocyanates or aliphatic or alicyclic polyisocyanates; these aromatic polyisocyanates or aliphatic or alicyclic polyisocyanates, and pentaerythritol, trimethylolpropane, glycerol Urethane prepolymers which are reaction products with polyhydric alcohols such as, for example; blocked isocyanates obtained by blocking these polyvalent isocyanates or urethane prepolymers with phenols, oximes and the like.

Examples of the organic polyepoxy compound include bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin and hydrogenated bisphenol A type epoxy resin. it can. Other than these, for example, novolak-type epoxy resins such as phenol novolak-type epoxy resin and cresol novolak-type epoxy resin; for example, polyalkylene polyol (neopentyl glycol, glycerol, etc.)
Glycidyl ether-based epoxy resins such as polyglycidyl ether;

For example, tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, tetraglycidyl
glycidylamine epoxy resins such as -m-xylenediamine; glycidyl ester epoxy resins such as diglycidyl phthalate, diglycidyl hexahydrophthalate, diglycidyl tetrahydrophthalate;
For example, cycloaliphatic epoxy resins such as vinylcyclohexene dioxide, 3,4-epoxycyclohexylmethyl (3,4-epoxycyclohexane) carboxylate, and bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; , Triglycidyl isocyanurate, glycidyl glycidoxyalkylhydantoin and the like can be exemplified heterocyclic epoxy resin and the like,

Further, a halide of the epoxy resin; an epoxy group-containing resin obtained by reacting the epoxy resin with a polybasic acid or a polyester polycarboxylic acid;
Various epoxy resins such as polyglycidyl ester of polyester polycarboxylic acid and polyglycidyl ether of polyester polyol can be exemplified.

As the amino resin, a melamine resin,
A guanamine resin, a urea resin, a melamine-urea co-condensation resin, a melamine-phenol co-condensation resin and the like can be exemplified. Further, as the metal crosslinking agent, for example, aluminum trisacetylacetonate, aluminum tri-i
-Propylate, aluminum tri-s-butyrate, titanium tetra-i-propylate, titanium tetra-2
-Ethylhexylate, antimony butyrate, zirconium-s-butyrate, zirconium diethoxy-t-butyrate, hafnium-t-butyrate, ethyl acetoacetate aluminum di-i-propylate, triethanolamine titanium di-i-propylate, titanium Examples thereof include ammonium lactate, tetraoctylene glycol titanate, polyalkyl titanate, polytitanium acylate (polymer of titanium tetrabutyrate, polymer of titanium oleate) and the like.

The amount of the cross-linking agent used is generally 0% based on 100 parts by weight of the total amount of the acrylic copolymer (A).
About 10 parts by weight, preferably 0 to 5 parts by weight.

The pressure-sensitive adhesive layer in the vibration-damping thin sheet of the present invention may further comprise, if necessary, for example, coumarone-indene resin, terpene-phenol resin, pt-butylphenol-acetylene resin, phenol-formaldehyde resin, terpene Resin, a tackifying resin such as a xylene / formaldehyde resin, a petroleum hydrocarbon resin, a hydrogenated hydrocarbon resin, a rosin derivative, and a turpentine resin can be added. The addition amount of these resins is preferably, for example, about 0 to 10 parts by weight based on 100 parts by weight of the total of the acrylic copolymer (A) component.

In the pressure-sensitive adhesive layer of the present invention, in addition to the above-mentioned components, if necessary, for example, a phthalic acid ester such as dioctyl phthalate, a phosphate ester such as tricresyl phosphate, a process, etc. Plasticizers such as oils; organic or inorganic colorants such as titanium oxide, carbon black, phthalocyanine blue; inorganic fillers such as clay, talc, calcium carbonate, silica, aluminum hydroxide, glass powder; A known additive such as an antiseptic may be added.

As described above, the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer used in the present invention is preferably prepared by solution polymerization in an organic solvent having a boiling point of 60 to 120 ° C., such as ethyl acetate. To the obtained copolymer solution, a poor solvent for the copolymer is added to extract and purify a low molecular weight copolymer component having a molecular weight of 100,000 or less, which is a soluble portion, and the content thereof is reduced.
15% by weight or less of an acrylic copolymer solution, to which a polyglycidylamine compound (B) was added, and further, if necessary, a tackifying resin, a plasticizer, a coloring agent, an inorganic filler, etc. were added. It can be manufactured by mixing.

In the vibration-damping thin body of the present invention, the pressure-sensitive adhesive composition as described above is applied to at least one surface of an appropriate constraining layer selected according to its use, for example, by using a roll coater.
Apply directly according to a generally known method such as a knife coater, etc., dry, and heat or leave at room temperature as necessary to crosslink, place a release material on the formed pressure-sensitive adhesive layer, It can be created by a method such as winding or cutting as appropriate. Alternatively, the pressure-sensitive adhesive composition can be applied to a release material by a similar method, dried, and then bonded to a constraining layer. The thickness of the pressure-sensitive adhesive layer is generally about 10 to 200 μm, preferably about 20 to 15 μm.
It is good to be about 0 μm.

The constraining layer may be, for example, a metal or metal alloy foil such as iron, steel, aluminum, nickel, chromium, cobalt, stainless steel, zinc-treated steel sheet, copper-plated steel sheet, copper, brass, etc. Polystyrene, vinyl chloride, polyethylene terephthalate,
Polyamide, thermoplastic polyurethane, petroleum hydrocarbon resin, cumarone resin, rosin derivative, natural resin, thermoplastic resin film or sheet having a softening point of 60 ° C or higher such as natural asphalt; for example, phenol resin, melamine resin, urea resin, Thermosetting resin sheets such as epoxy resin, unsaturated polyester resin, and urethane resin; for example, inorganic sheets such as glass and ceramic;
Examples include paper such as cardboard and cardboard.
Of these, the use of metal or metal alloy foils, particularly foils such as stainless steel, copper, aluminum, and copper-plated steel sheets, is preferred for reasons such as robustness and good electromagnetic wave shielding properties.

The thickness of the constraining layer is generally about 10 to 200 μm.
m, preferably about 25 to 100 μm.

The term "thin leaf" used in the present invention refers to, for example, a film, sheet, tape, strip, ribbon, thin plate, or the like in comparison with the dimension in the length and / or width direction. It refers to a shape whose dimension in the thickness direction is extremely small.

[0060]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but it goes without saying that the present invention is not limited to these Examples. The method for preparing a pressure-sensitive adhesive sheet for testing a vibration-damping thin leaf of the present invention, and the methods for measuring tack, adhesion, cohesion, heat resistance, solvent resistance, and vibration-damping properties are as follows.

(1) Method for preparing pressure-sensitive adhesive sheet for test A pressure-sensitive adhesive composition solution was placed on a stainless steel foil having a thickness of 50 μm and the thickness of the pressure-sensitive adhesive layer when dried was about 100 μm. And dried with a hot air circulating drier at 100 ° C. for 10 minutes. Then, a release material is placed on the resulting pressure-sensitive adhesive layer. After cross-linking for one day, a pressure-sensitive adhesive sheet for test was obtained.

(2) Measurement of tack According to the DOW method, the test pressure-sensitive adhesive sheet (test piece length 100 mm) created in paragraph (1) above was stuck on a slope with a slope angle of 30 °, and the diameter was measured 100 mm above the slope of the test piece. x /
Roll a steel ball 32 inches in size and indicate the diameter x of the largest ball that stops on the sample.

(3) Measurement of adhesive strength SUS 3 polished with water-resistant abrasive paper of # 280 specified in JIS R-6253
A specimen cut out from the test pressure-sensitive adhesive sheet prepared in the previous section (1) was pressed on the stainless steel sheet No. 04 according to the method of JIS Z-0237, and after 1 hour, 23 ° C, 65% RH, peeling rate 300m
Measure the peel strength (g / 25mm) under the condition of m / min.

(4) Measurement of cohesive force A test piece cut out from the test pressure-sensitive adhesive sheet prepared in the previous section (1) was applied to the same stainless steel plate as used in the previous section (3), and the affixed area was Paste to 25 × 25mm2, 2
A kg roller was pressed back and forth once. A 1 kg static load is applied to the sample in an atmosphere at 80 ° C., and the time until the load drops is measured.

(5) Measurement of heat resistance After the test piece was crimped under the predetermined conditions in the previous section (3),
Leave at 23 ° C. for 1 hour and heat on a hot plate heated to 300 ° C. for 5 seconds. Then leave at 23 ° C for 30 minutes,
The peel strength (g / 25 mm) is measured under the conditions of ° C., 65% RH, and a peel speed of 300 mm / min.

(6) Measurement of solvent resistance 20 mm × 30 mm from the test pressure-sensitive adhesive sheet prepared in the previous section (1)
mm-cut test piece on a 50μ thick stainless steel foil
Attach in the same manner as in (1), and after 1 hour, perform ultrasonic cleaning in 50 ml of trichlorethylene for 1 minute. The amount of the melted copolymer is measured with an ultraviolet spectrophotometer, and evaluated according to the following criteria.

○ ・ ・ ・ less than 200ppm △ ・ ・ ・ ・ ・ ・ 200ppm or more and less than 500ppm × ・ ・ ・ ・ ・ ・ 500ppm or more

(7) Measurement of Vibration Suppression The pressure-sensitive adhesive sheet for test prepared in the preceding section (1) was
The test piece was used as a test piece, and the loss factor (η) at a frequency of 200 Hz was measured at 20 ° C and 40 ° C using the resonance method.
And at each temperature of 60 ° C.

Reference Example 1 In a separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a sequential dropping device, butyl acrylate (BA) 90
Parts by weight, acrylic acid (AA) 10 parts by weight, azobis-i-butyronitrile (AIBN) 0.3 part by weight, ethyl acetate (EA
c) 100 parts by weight were mixed to prepare a mixture. And
As an initial charge, 25% by weight of this mixture was placed in a separable flask, heated with stirring, and polymerized at an internal temperature of 80 to 85 ° C under reflux for 40 minutes. Next, while maintaining the internal temperature at 80 to 85 ° C., the remaining 75% by weight of the mixture was successively dropped over about 60 minutes. After maintaining the reflux temperature for another 120 minutes, toluene 50
A part by weight was added and diluted to obtain an acrylic copolymer solution having a solid content of about 34% by weight. Heptane 30 is added to 100 parts by weight of this solution.
After repeating the extraction and purification operation 5 times by adding 0 parts by weight and removing the supernatant in which a part of the low molecular weight copolymer was dissolved,
Toluene was added again for dilution, and the solid content was 30% by weight and the viscosity was 90%.
An acrylic copolymer solution of 00 cps (B-type rotational viscometer, 25 ° C., 10 RPM) was obtained. The average weight average molecular weight Mw of this copolymer was 720,000, the content of low molecular weight copolymer having a molecular weight of 100,000 or less was 8% by weight, and Tg was -45 ° C.

Reference Example 2 An acrylic copolymer solution was prepared in the same manner as in Reference Example 1 except that 85 parts by weight of BA and 15 parts by weight of AA were used instead of 90 parts by weight of BA and 10 parts by weight of AA. I got Table 1 shows the composition and monomer reactivity ratio of this copolymer, the appearance of the resulting solution, the viscosity and solids, and the values of Mw, low molecular weight copolymer content and Tg.

Comparative Reference Example 1 The procedure of Reference Example 1 was repeated except that the extraction and purification procedure was not carried out.
s was obtained as an acrylic copolymer solution. Table 1 shows the composition and monomer reactivity ratio of this copolymer, appearance of the resulting solution, viscosity and solid content, and values of Mw, low molecular weight copolymer content and Tg.

Comparative Reference Example 2 In Comparative Reference Example 1, instead of 90 parts by weight of BA and 10 parts by weight of AA, 64 parts by weight of 2-ethylhexyl acrylate (EHA), 33 parts by weight of vinyl acetate (VAc) and 3 parts by weight of AA were used. An acrylic copolymer solution having a solid content of about 35% by weight and a viscosity of 5000 cps was obtained in the same manner as in Reference Example 1 except for using the same. Table 1 shows the composition and monomer reactivity ratio of this copolymer, the appearance of the resulting solution, viscosity and solids, and values of Mw, low molecular weight copolymer content and Tg.

[0073]

[Table 1]

Example 1 A polyglycidylamine compound "Tetrad C" (trade name: Mitsubishi Gas Chemical Co., Ltd.) was used for 100 parts by weight (solid content: about 30 parts by weight) of the acrylic copolymer solution obtained in Reference Example 1. stock)
1,3-bis (N, N-diglycidylaminomethyl) cyclohexane] 0.1 part by weight (about 0.33 part by weight with respect to 100 parts by weight of acrylic copolymer) by stirring and mixing A solution was obtained. The composition of the obtained composition, the physical properties of the pressure-sensitive adhesive, and the vibration-damping properties of the resulting thin-laminate were measured, and the results are shown in Table 2.

Example 2 In Example 1, 100 parts by weight of the acrylic copolymer solution obtained in Reference Example 2 was used instead of 100 parts by weight of the acrylic copolymer solution obtained in Reference Example 1. A pressure-sensitive adhesive composition solution was prepared in the same manner as in Example 1 except for the above. Table 2 shows the measurement results of the composition of the obtained composition, the physical properties of the pressure-sensitive adhesive, and the damping properties of the obtained thin sheet.

Comparative Example 1 In Example 1, instead of 0.1 parts by weight of the polyglycidylamine-based compound “Tetrad C”, an isocyanate-based crosslinking agent “Coronate L” [trade name; manufactured by Nippon Polyurethane Co., Ltd .; Urethane prepolymer comprising trimethylolpropane] A pressure-sensitive adhesive composition solution was prepared in the same manner as in Example 1 except that 1.0 part by weight (about 2.5 parts by weight based on 100 parts by weight of the acrylic copolymer) was used. Obtained. Table 2 shows the measurement results of the composition of the obtained composition, the physical properties of the pressure-sensitive adhesive, and the damping properties of the obtained thin sheet.

Comparative Examples 2 and 3 In Example 1, 100 parts by weight of the acrylic copolymer solution obtained in Reference Example 1 was replaced with the acrylic copolymer obtained in Comparative Reference Example 1 or Comparative Example 2. A pressure-sensitive adhesive composition solution was obtained in the same manner as in Example 1, except that 100 parts by weight of the combined solution was used. Table 2 shows the measurement results of the composition of the obtained composition, the physical properties of the pressure-sensitive adhesive, and the damping properties of the obtained thin sheet.

[0078]

[Table 2]

[0079]

As is clear from the results of the above embodiments, the damping thin sheet of the present invention is, for example, a vehicle such as an automobile, a railroad vehicle, an aircraft, an information device, an electric product, a floor of a building, and a roof. It can easily suppress the generation of vibration and noise simply by being attached to a vibration generator such as a wall or a stair, and has excellent performance in solvent resistance and heat resistance.

Continuing on the front page (72) Inventor Nobuyuki Tsuchiya 7-1 Takaya Shinmachi, Ichikawa-shi, Chiba Nisshin Steel Co., Ltd. Steel Co., Ltd. Steel Coating Research Laboratories (72) Inventor Kazuchika Iino 7-1 Takaya Shinmachi, Ichikawa-shi, Chiba Nissin Steel Co., Ltd. Steel Research Laboratory Coating & Coating Research Department (72) Inventor Kazuhito Tsubaki 7-1 Ichikawa City, Chiba Prefecture Takaya Shinmachi Co., Ltd. Nisshin Steel Co., Ltd. Steel Research Laboratory Coating & Coating Research Department (72) Inventor Kenji Koshiishi 7-1 Takatani-Shimmachi, Ichikawa-shi, Chiba Pref. Nisshin Steel Co., Ltd. Steel Co., Ltd. Steel Co., Ltd. Coating Coating Research Department (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 F16F 15/00 -15/32 C09J 7/00-7/04

Claims (2)

(57) [Claims] 1. A vibration-damping thin sheet having a pressure-sensitive adhesive layer on at least one surface of a constraining layer, wherein the pressure-sensitive adhesive layer has at least one type of glass transition point of a homopolymer of −20 ° C. or less. An acrylic monomer (a) and at least one monomer (b) having at least one functional group in addition to the radically polymerizable unsaturated group, and if necessary, the monomer (a)
And at least one comonomer other than (b) (c) (wherein the monomer (a)
(a) and the monomer (b) and the comonomer (c) each having a monomer reactivity ratio in the range of 0.25 to 4.0]. Acrylic copolymer having a glass transition point of -5 ° C or lower] (A), wherein the copolymer has a weight average molecular weight of 150,000 to 1.5 million and a molecular weight of 10% contained in the copolymer.
And an acrylic copolymer (A) having a proportion of not more than 15% by weight or less, and the acrylic copolymer (A) is crosslinked with a polyglycidylamine compound (B). A vibration-damping thin body characterized by being formed by: 2. The vibration-damping thin body according to claim 1, wherein the pressure-sensitive adhesive layer has a loss coefficient at a frequency of 200 Hz of 0.04 or more in a temperature range of 20 to 60 ° C.