JP2894789B2 - Damping thin leaf - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vibration-damping thin leaf that is attached to a vibration generator to reduce vibration and noise. More specifically, the present invention provides a pressure-sensitive adhesive layer in which a specific amount of an acrylic (co) polymer having a specific glass transition point and two types of elastomers having a specific glass transition point are blended, respectively, in a wide temperature range. The present invention relates to a vibration-damping thin leaf having excellent vibration-damping properties.

[Conventional technology]

In recent years, vehicles such as automobiles, railways, aircraft, office equipment,
Vibration and noise of information equipment, electric appliances, building floors, roofs, stairs, walls, and the like have become a problem, and many damping materials have been proposed as countermeasures.

Examples of such a vibration damping material include a composite vibration damping steel sheet having a three-layer structure in which a viscoelastic material is laminated between two steel sheets, an acrylic adhesive, butyl rubber on one surface of a constraining layer such as a metal foil. A two-layer vibration-damping sheet coated with a pressure-sensitive adhesive or the like is known, and the present invention provides an excellent vibration-damping thin leaf body capable of easily exhibiting vibration-damping properties by the latter post-processing. It is the purpose.

With respect to such a two-layered vibration damping sheet, for example, Japanese Patent Application Laid-Open No. 1-69336 discloses "a pressure-sensitive adhesive vibration damping composition layer (A) on a sheet and an adhesively restrained layer. Consists of a two-layer structure with a restraining plate (B),
A vibration-damping pressure-sensitive adhesive sheet in which an uneven pattern is provided on the surface of the layer (A) opposite to the plate (B). (A)
It is recommended that the layer be of a rubber type, an allyl type or a rubber-acryl type.

However, this proposal includes, as its (A) layer,
There is no suggestion to use a pressure-sensitive adhesive layer containing an acrylic (co) polymer and two types of elastomers. Therefore, there is no particular description on the use of such a pressure-sensitive adhesive layer. The effect, that is, even if "the (A) layer does not have a concavo-convex pattern on the surface opposite to the (B) plate" as in this proposal, it has extremely excellent vibration damping properties and can be used in a wide temperature range. Of course, it does not disclose any remarkable effect of maintaining the vibration damping property. Furthermore, as in this proposal, the vibration-damping pressure-sensitive adhesive sheet “having a concavo-convex 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 is It is difficult to handle like normal pressure-sensitive adhesive tape, such as winding in a roll, and there is a problem in storage and transportation.

JP-A-63-69850 discloses that “a) an elastomer having a glass transition point of -40 ° C. or lower (A) 15 to 70% by weight, b) an elastomer having a glass transition point of -40 to 40 ° C. (B) a tackifier resin having a pour point or softening point of -40 to 40 ° C (C) and a plasticizer (D) having a pour point of -40 to 40 ° C; 70% by weight, c) Tackifying resin (E) 15 having a softening point of 60 ° C. or more
A vibration damping material composition comprising: 70 to 70% by weight. Is disclosed.

However, this document does not disclose the use of an acrylic (co) polymer at all, and even if a vibration damping sheet is made using this vibration damping material composition, the pressure-sensitive adhesive The balance of the adhesive strength of the layer, the tack and the cohesive strength is not always sufficient, especially when used at a high temperature, the applied damping sheet may slip down. It has been found that there is a problem that the pressure-sensitive adhesive may protrude from the end face of the sheet when stored at a high temperature.

[Problems to be solved by the invention]

The present inventors have succeeded in producing a vibration-damping thin leaf body that can effectively reduce vibration and noise by post-processing such as attaching to various vibration generators and exhibiting excellent vibration-damping properties. As a result of researching to obtain, as a pressure-sensitive adhesive layer of a vibration-damping thin body, an acrylic (co) polymer having a specific glass transition point and two types of elastomers having a specific glass transition point It has been found that by using a pressure-sensitive adhesive layer in which a specific amount of each is blended, the aforementioned problems of the conventional vibration-damping sheet can be solved at once, and the present invention has been completed. That is, an object of the present invention is to develop a vibration-damping thin leaf having excellent vibration-damping properties in a wide temperature range.

[Means for solving the problem]

According to the present invention, the object is to provide a vibration-damping thin sheet having a pressure-sensitive adhesive layer on at least one surface of a constraining layer,
The pressure-sensitive adhesive layer has the following components (A) to (C): (A) 60 to 90% by weight of an acrylic (co) polymer having a glass transition point of -20 ° C or less; Elastomers below -30 ° C 5-35
(C) an elastomer having a glass transition point of −50 ° C. to 0 ° C. and 5 to 35% by weight of an elastomer other than the above (B), provided that (A), (B) and (C) 100% by weight
The vibration can be solved by a vibration damping thin body comprising:

 Hereinafter, the present invention will be described in detail.

The vibration-damping thin leaf body 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 −20 ° C. or less. It comprises a (co) polymer (A).

As such an acrylic (co) polymer (A),
For example, a acrylate monomer represented by the general formula CH ₂ ＝ CHCOOR ¹ (where R ¹ represents a C ₂ -C ₁₈ linear or branched alkyl group), and a homopolymer glass A monomer (b) having at least one functional group in addition to the radically polymerizable unsaturated group, if necessary, for the monomer (a) having a transition point of −20 ° C. or lower, and Is copolymerizable with these monomers (a) and (b),
And an acrylic copolymer obtained by copolymerizing a monomer (c) other than (b). 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.

As the acrylate monomer of the monomer (a), R ¹ is preferably a C _{2 to} C ₁₈ , preferably a C _{2 to} C ₁₂ linear or branched alkyl group. Specific examples of such a group R ¹ include an ethyl group, an n-propyl group, an n-butyl group, an i-butyl group, an n-hexyl group, an n-octyl group,
Examples thereof include an i-octyl group, a 2-ethylhexyl group, and an i-nonyl group. Specific examples of the monomer (a) include ethyl acrylate, n-propyl acrylate,
n-butyl acrylate, i-butyl acrylate, n
-Hexyl acrylate, n-octyl acrylate,
Examples thereof include i-octyl acrylate, 2-ethylhexyl acrylate, and i-nonyl acrylate.

The amount of the acrylate monomer (a) used is, for example, 5% in the total 100% by weight of the monomers (a) to (c).
An amount of 0% by weight or more, preferably 63 to 99.8% by weight, particularly preferably about 80 to 96.5% by weight is suitable. When the acrylate monomer (a) is used within this range, a good balance of tack, adhesion and cohesion can be achieved.

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

Specific examples of these monomers include carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid, crotonic acid, and citraconic acid (preferably acrylic acid, methacrylic acid, and itaconic acid). Group-containing monomers; acrylamide, methacrylamide,
N-methylolacrylamide, N-methylolmethacrylamide, Nn-butoxymethylacrylamide,
Amide or substituted amide group-containing monomers such as Ni-butoxymethylacrylamide, N, N-dimethylacrylamide, N-methylacrylamide (preferably acrylamide and methacrylamide); aminoethyl acrylate, N, N-dimethyl Aminoethyl acrylate, N, N-diethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate (preferably, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate), etc. An amino group or substituted amino group-containing monomer; 2-hydroxyethyl acrylate,
2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, allyl alcohol, methallyl alcohol (preferably, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl A hydroxyl-containing monomer such as methacrylate); an epoxy-containing monomer such as glycidyl acrylate, glycidyl methacrylate, glycidyl allyl ether, and glycidyl methallyl ether (preferably glycidyl methacrylate); a mercapto group-containing monomer such as vinyl mercaptan and allyl mercaptan Body; and the like. 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 amide group-containing monomer and a hydroxyl group-containing monomer.

The amount of the monomer (b) to be used depends on the amount of the monomer (a) to
For example, 15% by weight or less, preferably 0.2 to 10% by weight, and particularly preferably 1 to 6% by weight in the total 100% by weight of (c).
A small amount can be exemplified. When the amount of the monomer (b) used is not more than the upper limit, the tack of the pressure-sensitive adhesive layer to be formed is preferably not too small. On the other hand, the amount of the monomer (b) is particularly 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, copolymerizable with the monomers (a) and (b),
Examples of the comonomer (c) other than the monomers (a) and (b) include acrylics other than the monomer (a) such as methyl acrylate, t-butyl acrylate, cyclohexyl acrylate, and stearyl acrylate. Acid ester monomers; for example, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, n
-Methacrylate monomers such as octyl methacrylate, i-octyl methacrylate, 2-ethylhexyl methacrylate, i-nonyl methacrylate, n-dodecyl methacrylate, i-dodecyl methacrylate and stearyl methacrylate; for example, vinyl formate, vinyl acetate, propionic acid Vinyl, vinyl esters of saturated fatty acids such as vinyl versatate; for example, α, β-unsaturated dicarboxylic acids such as dibutyl malate, dibutyl fumarate, dibutyl itaconate, dioctyl malate, dioctyl fumarate and dioctyl itaconate;
Linear or branched alkyl esters of C ₁ -C _18; for example, styrene, alpha-methyl styrene, vinyl toluene,
Examples thereof include aromatic vinyl monomers such as ethylvinylbenzene; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile;

The amount of the comonomer (c) used is from the above-mentioned monomers (a) to
The total amount of (c) is generally 50% by weight or less, preferably 36.8% by weight or less, and particularly preferably about 2 to 15% by weight, based on 100% by weight. Since the use of the comonomer (c) can vary depending on the type of the comonomer, the amount of the comonomer cannot be uniquely determined. It is useful to adjust the balance and the like as desired, so that it can be appropriately selected in the above range amount 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. Therefore, when the comonomer (c) is used, it is preferable that the comonomer (c) is appropriately selected and used in the above range.

The glass transition point (hereinafter, sometimes abbreviated as Tg) of the acrylic (co) polymer used in the present invention is -20.
° C or lower, preferably -30 ° C or lower. It is preferable that the Tg is a temperature equal to or lower than the upper limit value, since it has an excellent tack and is easily attached to the vibration generator.

The acrylic (co) polymer has a weight average molecular weight (hereinafter may be abbreviated as ▼) according to the GPC method of 50,000 or more, preferably 20 to 100,000. ▲
If the value of ▼ is equal to or more than the lower limit value, the obtained pressure-sensitive adhesive layer is preferable because the adhesive force and the cohesive force 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 select ▲ of the acrylic (co) polymer appropriately within this range.

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

Measurement of glass transition point In a cylindrical cell made of aluminum foil with a thickness of about 0.05 mm and having an inner diameter of about 5 mm and a depth of about 5 mm, about 10 mg of a 50% by weight organic solvent solution sample of an acrylic (co) polymer was placed. The measurement sample is weighed and dried at 100 ° C. for 2 hours. SSC-5000 differential scanning calorimeter manufactured by Seiko Electronic Industry Co., Ltd. (Differential
Scanning Calorimeter), heating rate from -150 ° C to 1
Measure and determine at 0 ° C / min.

The amount of the acrylic (co) polymer (A) used depends on the amount of the acrylic (co) polymer (A), which is a main component of the pressure-sensitive adhesive layer used in the present invention, and the amount of the glass described below. It is 60 to 90% by weight, preferably 65 to 85% by weight, of the total 100% by weight of the elastomer (B) having a transition point of -30 ° C or lower and the elastomer (C) having a glass transition point of -50 to 0 ° C. If the amount of the acrylic (co) polymer (A) is too small below this lower limit, the tackiness of the resulting pressure-sensitive adhesive layer may decrease, which is not preferable.
Exceeding this upper limit is not preferable because the temperature range exhibiting excellent vibration damping properties may be narrowed.

The method of polymerizing the acrylic (co) polymer (A) is not particularly limited, and known methods such as solution polymerization and emulsion polymerization can be employed. However, the acrylic method of the pressure-sensitive adhesive layer used in the present invention can be used. It is a main component other than the (co) polymer (A). From the viewpoint of ease of blending with the above-mentioned components (B) and (C), the use of solution polymerization is preferred.

Solution polymerization is generally performed by charging a predetermined organic solvent, a monomer, a polymerization initiator, and a chain transfer agent used as necessary in a polymerization tank, and in a nitrogen stream or at the reflux temperature of the organic solvent.
The reaction is carried out 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 in the solution polymerization include aromatic hydrocarbons such as benzene, toluene, xylene, and aromatic naphtha; n-hexane, n-heptane, n-octane, i-octane, and n-decane. Aliphatic or alicyclic hydrocarbons such as dipentene, petroleum spirit, petroleum naphtha, and turpentine oil; ethyl acetate, n-butyl acetate, n-amyl acetate, 3-methoxybutyl acetate, methyl benzoate, cellosolve acetate; Esters such as butyl cellosolve acetate;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, cyclohexanone and 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 Alcohols such as -butyl alcohol, i-butyl alcohol, s-butyl alcohol, t-butyl alcohol; and the like. Each of these organic solvents alone,
Alternatively, two or more kinds can be used in combination.

Among these solvents, organic solvents having a boiling point of 50 to 150 ° C., particularly, 60 to 100 ° C., from the viewpoint of easiness of polymerization operation, high reaction rate, and easy volatilization in forming the pressure-sensitive adhesive layer. It is preferable to use a solvent, 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, t-
Organic peroxides such as butyl peroxybivalate; for example, 2,2'-azobis-i-butyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobis-4-methoxy Azo compounds such as -2,4-dimethylvaleronitrile; and the like can be used alone or in combination. The amount of the polymerization initiator to be used is not particularly limited, but is generally based on 100 parts by weight of the total monomers,
About 0.01 to 1.0 part by weight, preferably about 0.02 to 0.5 part by weight is used.

Further, as the chain transfer agent, for example, cyanoacetic acid; alkyl cyanoacetate esters alkyl group C ₁ -C _8; bromoacetic acid esters alkyl group C ₁ -C _8;; bromoacetate anthracene, phenanthrene, fluorene, 9
Aromatic compounds such as -phenylfluorene; aromatic nitro compounds such as p-nitroaniline, nitrobenzene, dinitrobenzene, p-nitrobenzoic acid, p-nitrophenol, p-nitrotoluene; benzoquinone, 2,3,5,
Benzoquinone derivatives such as 6-tetramethyl-p-benzoquinone; borane derivatives such as tributylborane; carbon tetrabromide, carbon tetrachloride, 1,1,2,2-tetrabromoethane, tribromoethylene, trichloroethylene, bromotrichloro methane, tribromo methane, 3-chloro-1-halogenated hydrocarbons such as propene, chloral, aldehydes such as furaldehyde, alkyl mercaptans C ₁ -C _18; thiophenol, aromatic mercaptans such as toluene mercaptan Mercaptoacetic acid; mercaptoacetic acid
C ₁ -C ₁₀ alkyl esters; C ₁ hydroxamate Le alkyl mercaptans -C _12; Binen, terpenes such Tapinoren; can be exemplified.

The amount used when using the chain transfer agent is not particularly limited, but is preferably about 0.005 to 3.0 per 100 parts by weight of the total monomers.
It is preferably in parts by weight. The polymerization temperature is generally about 30 to
A temperature in the range of 180 ° C, preferably about 60 to 120 ° C, is good.

The (co) polymer solution suitably used in the present invention thus obtained usually contains the acrylic (co) polymer in an amount of from 20 to
It contains 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, together with the acrylic (co) polymer (A), has two elastomers, that is, a glass transition point (Tg) of -30 ° C or lower, preferably Is an elastomer (B) containing -40 ° C or lower and an elastomer (C) having a glass transition point (Tg) of -50 to 0 ° C.

If the Tg of the elastomer (B) exceeds the upper limit and is too high, for example, the temperature control range in a low temperature range such as a range of 0 to 60 ° C. is reduced, and the temperature range in which excellent vibration control performance is obtained is narrowed. There is not preferred.

Examples of such an elastomer (B) include styrene-butadiene block copolymer (SBS), styrene-isoprene block copolymer (SIS), and styrene-
Styrene-based thermoplastic elastomers such as ethylene-butylene block copolymer (SEBS);
R), butadiene rubber (BR), isoprene rubber (IR),
Chloroprene rubber (CR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR),
Examples include isoprene-isobutylene rubber (IIR) and ethylene-propylene rubber (EPM, EPDM).
Of these, SBS, SBS, which have excellent solubility in organic solvents and can be easily blended with the acrylic (co) polymer (A)
The use of IS, IIR, EPDM, etc. is preferred, and the use of SBS is particularly preferred. As such SBS, for example, those having a styrene content of 5 to 60% by weight, particularly 10 to 40% by weight are suitable, and for example, Calyflex TR-1184M, Calyflex TR-1101, Calyflex. KX-65, Kariflex TR-1116 (trade names; both manufactured by Shell Chemical Co., Ltd.)
And other commercially available products can be used.

The amount of the elastomer (B) used depends on the acrylic (co) polymer (A) and the elastomer (B), which are the main components of the pressure-sensitive adhesive layer used in the present invention, and the glass described later. The transition point is 5 to 35% by weight, preferably 7 to 20% by weight, based on 100% by weight of the total of the elastomer (C) having a transition temperature of -50 to 0 ° C. If the amount of the elastomer (B) is too small below the lower limit, the effect of adding the elastomer (B) is less likely to be exhibited, such as a narrower temperature range exhibiting excellent vibration damping properties.
On the other hand, if the amount exceeds the upper limit, the balance between the adhesive force and the cohesive force of the pressure-sensitive adhesive layer tends to deteriorate, which is not preferable.

The elastomer (C) has a glass transition point (Tg)
Is -50 to 0 ° C, preferably -45 to 0 ° C.

If the Tg of the elastomer (C) exceeds the above upper limit and is too high, the adhesive force of the pressure-sensitive adhesive layer is undesirably reduced.
Vibration damping properties in a high temperature region such as 60 ° C. or higher tend to decrease, and the temperature range in which excellent damping properties tend to be narrowed, which is not preferable.

Examples of such an elastomer (C) include ethylene-vinyl acetate copolymer (EVA), ethylene-acrylate copolymer, 1,2-polybutadiene, and the like. The use of EVA is particularly preferred because it is excellent in that it can be easily blended with the acrylic (co) polymer (A). As such an EVA, for example, the ethylene content is 25 to 90% by weight, particularly 30 to 90% by weight.
Those with 60% by weight are suitable, for example, Elvacs 45
Commercial products such as X, Elvacs 40X, Evaflex 150 (trade name; manufactured by Mitsui Dupont Polychemical Co., Ltd.) and Soarex BH (trade name; manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) can be used.

The amount of the elastomer (C) used depends on the acrylic (co) polymer (A) and the elastomer (B), which are the main constituent components of the pressure-sensitive adhesive layer used in the present invention.
And 5 to 35% by weight, preferably 7 to 20% by weight, based on a total of 100% by weight of the elastomer and the elastomer (C). If the amount of the elastomer (C) is too small below this lower limit, the effect of adding the elastomer (C) is less likely to appear, such as a narrow temperature range having excellent vibration damping properties. If the amount is more than the upper limit, the balance between the adhesive force and the cohesive force of the pressure-sensitive adhesive layer tends to deteriorate, which is not preferable.

The pressure-sensitive adhesive layer in the vibration-damping thin body of the present invention is cross-linked with a cross-linking agent such as an organic polyvalent isocyanate compound, an organic polyvalent epoxy compound, an amino resin, and a metal cross-linking agent in order to improve cohesive strength. Is preferred.

As the organic polyvalent isocyanate compound, p-
Aromatic polyisocyanates such as phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, xylene diisocyanate, naphthalene-1,5-diisocyanate; pentamethylene diisocyanate, hexa Methylene diisocyanate, heptamethylene diisocyanate, isophorone diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate,
Aliphatic or alicyclic polyisocyanates such as hydrogenated 2,4-toluylene diisocyanate, hydrogenated 2,6-toluylene diisocyanate, hydrogenated xylene diisocyanate; these aromatic polyisocyanates or aliphatic or alicyclic polyisocyanates Trimers of polyvalent isocyanates; urethane prepolymers which are the reaction products of these aromatic polyisocyanates or aliphatic or alicyclic polyvalent isocyanates with polyhydric alcohols such as pentaerythritol, trimethylolpropane and glycerol; Blocked isocyanates obtained by blocking these polyvalent isocyanates or urethane prepolymers with phenols, oximes and the like;
And the like.

Examples of the organic polyvalent epoxy 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. Other than these, for example, novolak type epoxy resins such as phenol volak type epoxy resin and cresol novolak type epoxy resin; for example, glycidyl ether type epoxy resins such as polyalkylene polyol (neopentyl glycol, glycerol, etc.) polyglycidyl ether and the like For example, tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-
Glycidylamine-based epoxy resins such as m-aminophenol and tetraglycidyl-m-xylenediamine; glycidyl ester-based epoxy resins such as diglycidyl phthalate, diglycidyl hexahydrophthalate, and diglycidyl tetrahydrophthalate; for example, vinylcyclohexene dioxide Cycloaliphatic epoxy resins such as 3,4-epoxycyclohexylmethyl (3,4-epoxycyclohexane) carboxylate and bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; for example, triglycidyl isocyanurate; Examples include heterocyclic epoxy resins such as glycidylglycidoxyalkylhydantoin, and the like. Further, halides of these epoxy resins; polybasic acids or polyester polyols Polyglycidyl ethers of polyester polyols; polyglycidyl esters of polyester polycarboxylic acids; epoxy group-containing resin obtained by reacting a carbon acid can be exemplified various epoxy resins such as.

Examples of the amino resin include a melamine resin, a guanamine resin, a urea resin, a melamine-urea co-condensation resin, a melamine-phenol co-condensation resin, and 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-butylate, ethyl acetoacetate aluminum di-i-propylate, triethanolamine titanium di-i-propylate, ammonium salt of titanium lactate, tetraoctylene glycol titanate Polyalkyl titanate, poly titanium acylate (polymer of titanium tetrabutylate, polymers of titanium oleate), or the like can be exemplified.

Among these crosslinking agents, the use of an organic polyvalent isocyanate compound is preferred for reasons such as the pot life of the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer and the speed of crosslinking.

The amount of the crosslinking agent to be used is generally 0 to 10 parts by weight, preferably about 0.5 to 5 parts by weight, based on 100 parts by weight of the total of the components (A) to (C). When the amount of the crosslinking agent used is not more than the upper limit, the pot life of the pressure-sensitive adhesive composition to be used is preferably long, and when it is not less than 0.5 part by weight, excellent cohesive strength is obtained, so that it is preferable.

The pressure-sensitive adhesive layer in the vibration-damping thin sheet of the present invention may further include, if necessary, for example, coumarone-indene resin, terpene-phenol resin, pt-butylphenol.
Acetylene resin, phenol / form / aldehyde resin, terpene resin, xylene / formaldehyde resin,
A tackifying resin such as 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 as described in the above (A) to
For example, the amount is preferably 0 to 60 parts by weight, particularly preferably about 0 to 40 parts by weight based on 100 parts by weight of the total of the component (C).

In addition to these, the pressure-sensitive adhesive layer of the present invention may be, if necessary, optionally, for example, a phthalate ester such as dioctyl phthalate, a phosphate ester such as tricresyl phosphate, or a plasticizer such as process oil; Organic or inorganic coloring agents such as titanium oxide, carbon black and phthalocyanine blue; inorganic fillers such as clay, talc, calcium carbonate, silica, aluminum hydroxide and glass powder; ultraviolet absorbers; preservatives; Known additives 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 obtained by solution polymerization in an organic solvent having a boiling point of 60 to 100 ° C such as ethyl acetate. Acrylic (co) polymer solution, for example, the (B) component elastomer such as SBS and EVA
The (C) component elastomer is dissolved in an organic solvent such as toluene, and added, and if necessary, a tackifying resin, a plasticizer, a coloring agent, an inorganic filler, and the like are added and mixed.
If necessary, it can be produced by blending a crosslinking agent such as an organic polyvalent isocyanate compound.

The vibration-damping thin body of the present invention is obtained by applying the above-described pressure-sensitive adhesive composition to at least one surface of an appropriate constraining layer selected according to its use, for example, a roll coater, a knife coater, or the like. After applying directly according to the method of above, drying, and heating or leaving it at room temperature for crosslinking as required, the release material is placed on the formed pressure-sensitive adhesive layer, and if necessary, wound up, Alternatively, it can be created by a method such as cutting. 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, and preferably about 20 to 150 μm.

As the constraining layer, 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; Thermoplastic resin film or sheet having a softening point of 60 ° C or more such as vinyl chloride, polyethylene terephthalate, polyamide, thermoplastic polyurethane, petroleum hydrocarbon resin, cumarone resin, rosin derivative, natural resin, natural asfelt; for example, phenol resin Thermosetting resin sheet such as melamine resin, urea resin, epoxy resin, unsaturated polyester resin, urethane resin;
Inorganic sheets such as ceramics; for example, paper such as cardboard and corrugated cardboard can be exemplified. Among these, metal or metal alloy foils, particularly foils such as stainless steel, copper, aluminum, and copper-plated steel sheets, are 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, preferably about 25 to 100 μm.

In the present invention, the "thin leaf" is, for example, a film, a sheet, a tape, a strip,
This is a term representing a shape such as a ribbon shape or a thin plate shape whose dimension in the thickness direction is extremely smaller than the dimension in the length and / or width direction.

[Effect] The vibration-damping thin body of the present invention is, for example, simply affixed to a vibration generator such as an automobile, a railway vehicle, a vehicle such as an aircraft, an information device, an electric product, a floor, a roof, a wall, a stair, etc. The generation of vibration and noise can be suppressed easily and in a wide temperature range.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, it goes without saying that the present invention is not limited to these Examples.

The method for preparing the pressure-sensitive adhesive sheet for testing the vibration-damping thin leaf body of the present invention, the method for measuring the tack, the adhesive force and the cohesive force, and the method for measuring the vibration-damping property are as follows.

(1) Method of preparing pressure-sensitive adhesive sheet for test A pressure-sensitive adhesive composition solution is applied on a 50-μm-thick stainless steel foil so that the thickness of the pressure-sensitive adhesive layer when dried is about 100 μm. After drying at 100 ° C for 10 minutes with a hot-air circulating dryer, the release material is placed on the resulting pressure-sensitive adhesive layer and then crosslinked at 20 ° C and 65% RH for 7 days. A pressure-sensitive adhesive sheet was obtained.

(2) Measurement of tack According to the J.DOW method, the test pressure-sensitive adhesive sheet (test piece length: 100 mm) prepared in (1) above was attached to a slope with a 30 ° inclination angle. Diameter x / 3 from 100mm above slope
Roll a steel ball 2 inches in size and indicate the diameter x of the largest diameter ball that stops on the sample.

(3) Adhesion test SU polished with water-resistant abrasive paper of # 280 specified in JIS R-6253
A test piece cut out from the test pressure-sensitive adhesive sheet prepared in the previous section (1) was placed on a stainless steel plate of S 304 using JIS Z-0237.
After 1 hour, the peel strength (g / 25 mm) is measured under the conditions of 23 ° C., 65% RH, and a peel rate of 300 mm / min.

(4) Measurement of cohesive force A test piece cut out from the test pressure-sensitive adhesive sheet prepared in the preceding section (1) was applied to the same stainless steel plate as used in the preceding section (3), and the adhesion area thereof was 25. × 25 mm ² , and pressed back and forth with a 2 kg roller once.

Apply a static load of 1 kg to the sample in an atmosphere of 80 ° C,
Measure the time until the load falls.

(5) Measurement of vibration damping properties The thickness of the test pressure-sensitive adhesive sheet prepared in
Affixed to a 0.5 mm zinc-treated steel sheet, and using this as a test piece, a loss coefficient (η) at a frequency of 200 Hz is measured at each temperature by a resonance method. The results are shown in FIG.

In the vibration-damping thin body of the present invention, the loss coefficient (η) is preferably 0.04 or more in a temperature range of 0 to 80 ° 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) was added.
97 parts by weight, acrylic acid (AA) 3 parts by weight, azobis-i-
A mixture was prepared by mixing 0.3 parts by weight of butyronitrile (AIBN) and 100 parts by weight of ethyl acetate (EAc). Then, as an initial charge, 25% by weight of this mixture was put into a separable flask, and heated while stirring, and the internal temperature was 80 to 85 ° C.
Polymerization was carried out 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. Further, in order to increase the polymerization rate, the polymerization reaction was performed by refluxing for 120 minutes. Next, 50 parts by weight of toluene was added to the obtained polymerization reaction solution to dilute it, and the solid content was about 40% by weight and the viscosity was 60%.
An acrylic copolymer solution of 00 cps (B-type rotational viscometer, 25 ° C., 10 rpm) was obtained. ▲ ▼ of this copolymer is 550,000, Tg
And -44 ° C.

Reference Example 2 Polymerization was carried out in the same manner as in Reference Example 1, except that instead of using 97 parts by weight of BA, 45 parts by weight of 2-ethylhexyl acrylate (2EHA), 42 parts by weight of ethyl acrylate (EA) and 10 parts by weight of vinyl acetate (VAc) were used. Perform the solids content
An acrylic copolymer solution of 40% by weight and a viscosity of 6000 cps was obtained. ▲ ▼ of this copolymer was 550,000, and Tg was -44 ° C.

Reference Example 3 Polymerization was carried out in the same manner as in Reference Example 1 except that instead of using 97 parts by weight of BA, 65 parts by weight of BA and 32 parts by weight of methyl methacrylate (MMA) were used.
An acrylic copolymer solution having a viscosity of 8000 cps was obtained. ▲ ▼ of this copolymer was 350,000, Tg-10 ° C.

Example 1 To 200 parts by weight (solid content: about 80 parts by weight) of the acrylic copolymer solution obtained in Reference Example 1, Califrex TR1184M (trade name; manufactured by Shell Chemical Co., Ltd.) as a component (B) elastomer; Tg = SBS at -60 ° C] 10 parts by weight of Elvacs 45X as an elastomer of the component (C) [trade name: Mitsui
DuPont Chemical Co., Ltd .; Tg = −38 ° C. EVA] 10 parts by weight dissolved in 30 parts by weight of toluene, and an isocyanate-based crosslinking agent Coronate L (trade name: toluene diisocyanate manufactured by Nippon Polyurethane Co., Ltd.) 2 parts by weight of a urethane prepolymer composed of methylolpropane) were stirred and mixed to obtain a pressure-sensitive adhesive composition solution.

Table 1 shows the measurement results of the composition of the obtained composition, the properties of the pressure-sensitive adhesive, and the vibration damping properties of the obtained thin film.

Example 2 and Comparative Examples 1 and 2 A pressure-sensitive adhesive composition solution was prepared in the same manner as in Example 1 except that the amounts of use of Califrex TR1184M and Elvacs 45X were changed or not used. Table 1 shows the measurement results of the composition of the obtained composition, the properties of the pressure-sensitive adhesive, and the vibration damping properties of the obtained thin film.

Example 3 and Comparative Example 3 In Example 1, instead of using 200 parts by weight of the acrylic copolymer solution of Reference Example 1, Reference Example 2 or Reference Example 3 was used.
A pressure-sensitive adhesive composition solution was obtained in the same manner except that 200 parts by weight of the acrylic copolymer solution was used. Table 1 shows the measurement results of the composition of the obtained composition, the physical properties of the pressure-sensitive adhesive, and the vibration-damping properties of the resulting thin-laminate.

[Brief description of the drawings]

FIG. 1 is a graph showing the results of a vibration damping test of the vibration damping thin leaf of the present invention.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichi Masuhara 7-1 Takatani Shinmachi, Ichikawa-shi, Chiba Nisshin Steel Co., Ltd. (72) Inventor Ryoichi Kato 7-1 Takatani-shinmachi, Ichikawa-shi, Chiba Nisshin Steel Materials Co., Ltd. New Materials Research Laboratories (72) Inventor Hiroshi Enya 7-1 Takamachi Shinmachi, Ichikawa-shi, Chiba Pref. (58) Fields investigated (Int.Cl. ⁶ , DB name) B32B 1/00-35/00 F16F 15/02 C08L 33/00-33/26 C09J 133/04-133 / 16

Claims (4)

(57) [Claims] In a vibration damping thin sheet having a pressure-sensitive adhesive layer on at least one surface of a constraining layer, the pressure-sensitive adhesive layer has the following components (A) to (C): (A) glass transition (B) an elastomer having a glass transition point of -30 ° C or lower;
(C) an elastomer having a glass transition point of −50 ° C. to 0 ° C. and 5 to 35% by weight of an elastomer other than the component (B), provided that the components (A), (B) and ( The total amount of C) is 100% by weight]. 2. The vibration-damping thin sheet according to claim 1, wherein the elastomer of the component (B) is a styrene-butadiene block copolymer. 3. The vibration-damping thin sheet according to claim 1, wherein the elastomer of the component (C) is an ethylene-vinyl acetate copolymer. 4. The vibration-damping thin sheet 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 0 to 80 ° C.