JP5599966B2 - Emulsion composition for damping material - Google Patents

Description

The present invention relates to an emulsion composition for a vibration damping material. More specifically, the present invention relates to an emulsion composition for a damping material that is useful as a material for a damping material that is used to prevent vibration and noise in various structures and maintain silence.

The damping material is for keeping vibration and noise in various structures and keeping quiet, for example, in addition to being used under the indoor floor of an automobile, a railway vehicle, a ship, an aircraft, an electrical device, Widely used in building structures and construction equipment. As a material used for such a damping material, conventionally, a molded product such as a plate-shaped molded body or a sheet-shaped molded body made of a material having vibration absorption performance and sound absorption performance has been used. If the shape of the sound generation location is complicated, it is difficult to apply these molded products to the vibration generation location. Various methods have been studied. That is, for example, asphalt sheets containing inorganic powder have been used under the interior floor of automobiles, etc. However, since there is a need to heat-seal, improvement in workability and the like is desired, and vibration suppression is desired. Various damping material compositions and polymers forming the material have been studied.

Thus, as an alternative material for such molded products, coating-type damping materials (paints) have been developed. For example, a coating film formed by spraying or spraying a corresponding portion by an arbitrary method. Thus, various vibration-damping paints that can obtain a vibration absorption effect and a sound absorption effect have been proposed. Specifically, for example, as a water-based vibration-damping paint with improved coating film hardness obtained by blending a synthetic resin powder with a color developing agent such as asphalt, rubber, synthetic resin, and the like suitable for indoor use in automobiles, Anti-vibration coatings in which activated carbon is dispersed as a filler in a resin emulsion have been developed.

A conventional damping material, which is a copolymer emulsion for damping material or chipping-resistant material obtained by copolymerization of a monomer mixture containing an acrylic monomer as an essential component. A copolymer emulsion for vibration damping materials or chipping resistant materials, which essentially contains an unsaturated monomer having the above functional group, is disclosed (for example, see Patent Document 1). Further, an emulsion for vibration damping materials comprising an emulsion obtained by polymerizing a monomer component essentially containing an unsaturated carboxylic acid monomer and a crosslinking agent is disclosed. (For example, refer to Patent Document 2).
Such a vibration-damping coating material is required to have excellent vibration-damping properties and coating film strength, as well as excellent heat drying properties. There is a need for damping materials that can be realized.
JP 2003-155391 A (page 1-2) Japanese Patent Laying-Open No. 2003-193025 (page 1-2)

The present invention has been made in view of the above-described situation, and has a high strength, exhibits excellent vibration damping properties, and can form a coating film having excellent heat drying properties. The object is to provide an emulsion composition.

The present inventor has made various studies on the emulsion composition for a vibration damping material having excellent strength, vibration damping properties, and heat drying properties. As a result, the emulsion particles obtained by emulsion polymerization of the monomer component are hydrophobic. When the curable monomer and / or oligomer and the polymerization initiator are included, the curable monomer and / or oligomer in the emulsion particles are polymerized to form a crosslinked product, thereby forming this crosslinked product and an emulsion. Since the polymer that forms the base forms an IPN structure (interpenetrating network structure), and in this emulsion, the polymer that forms the emulsion itself does not crosslink. Damping performance is not impaired, and the resin has excellent strength due to the formation of the IPN structure. It is found to be the thing. Further, in this dispersion of emulsion, it has been found that the solid content concentration can be made higher than that of an emulsion composition conventionally used for damping materials, and this emulsion is water having a water content of 40% by mass or less. When a dispersion is used, it is possible to heat and dry with less heat when forming the coating film, and in a shorter time than before, it can form a coating film with a good surface condition that can exhibit vibration damping and high strength at a high level. It has been found that the composition is more excellent in heat drying property. Further, this emulsion composition has good coating film disintegration resistance without being slipped off even when the coating film is applied to a vertical surface and dried by heat drying using a high temperature. As a result, the inventors have found that the above problem can be solved brilliantly, and have reached the present invention.

That is, the present invention is a emulsion composition comprising emulsion particles obtained by emulsion polymerization of a monomer component, the emulsion particles, the curable monomer and / or oligomer and a polymerization initiator in the emulsion particles The above-mentioned emulsion composition for damping material is an emulsion composition for damping material which is an aqueous dispersion of the above emulsion particles having a water content of 40% by mass or less.
The present invention is described in detail below.

The emulsion composition for vibration damping material of the present invention is an aqueous dispersion of emulsion particles containing a curable monomer and / or oligomer and a polymerization initiator, and has a water content of 40% by mass or less. The aqueous dispersion of emulsion particles may further contain other components.
In addition, the emulsion may be any of those containing either or both of a curable monomer and an oligomer, and each of the emulsion, the curable monomer and / or oligomer, and the polymerization initiator may be one kind. Two or more types may be used.

The water dispersion of the emulsion particles has a water content of 40% by mass or less, and as a result, the emulsion composition for a vibration damping material of the present invention is more effective than an emulsion used for a conventional vibration damping material. Can be heat-dried in a short time, for example, when used as a paint for automobiles, in an automobile paint line, the conventional baking is performed twice, in addition to the two-baking line in which baking is performed twice. It is possible to deal with a bake line.
Moreover, in the emulsion in the present invention, it is possible to make an aqueous dispersion having a smaller water content. The water content of the aqueous dispersion of emulsion particles is preferably 30% by mass or less. More preferably, it is 25 mass% or less. When the water content is low, the amount of heat required in the coating drying process is small, and a good coating film can be formed in a shorter heating time.

As a form in which the curable monomer and / or oligomer and the polymerization initiator are included in the emulsion particles, for example, (1) the prepared emulsion particles absorb the curable monomer and / or oligomer and the polymerization initiator. (2) A form in which a curable monomer and / or oligomer and a polymerization initiator are sucked during preparation of emulsion particles may be mentioned, and a form in which these are combined may be used. Preferably, a form in which the prepared emulsion particles are allowed to absorb a curable monomer and / or oligomer and a polymerization initiator is essential.
Thus, when it is set as the form which contained the curable monomer and / or oligomer, and the polymerization initiator in the emulsion particle | grains, as a curable monomer and / or oligomer, and a polymerization initiator, it osmose | permeates in an emulsion particle | grain. It is preferable to use those having the property of

As said curable monomer and oligomer, what is hardened | cured or superposed | polymerized by light, a heat | fever, and an electron beam should just be used. Further, the curable monomer and / or oligomer may be hydrophilic or hydrophobic as long as it can be present in the emulsion particles.
In the case of the present invention, the curable monomer and / or oligomer is preferably a compound that can be absorbed during the preparation of the emulsion particles.

Preferred forms of the curable monomer and / or oligomer include (1) UV curable hydrophilic monomer, thermosetting hydrophilic monomer or electron beam curable monomer, (2) UV curable hydrophobic monomer, and thermosetting. Hydrophobic monomer or electron beam curable hydrophobic monomer, (3) UV curable hydrophilic oligomer, thermosetting hydrophilic oligomer or electron beam curable hydrophilic oligomer, (4) UV curable hydrophobic oligomer, thermosetting It is a hydrophobic oligomer or an electron beam curable hydrophobic oligomer. More preferably, it is a hydrophobic monomer and / or a hydrophobic oligomer because it is easily impregnated in the emulsion particles. The curable monomer is preferably a polyfunctional monomer having two or more functional groups having curing reactivity. Thereby, the coating film formed with an emulsion composition becomes more tough, and can improve the physical properties of the coating film. That is, the emulsion composition is preferably cured or polymerized with at least one of ultraviolet light, heat, and electron beam. It is more preferable to perform heating as necessary after ultraviolet irradiation or electron beam irradiation.

Examples of the curable monomer and / or oligomer include 1,6-hexanediol di (meth) acrylate, ethoxylated glycerin tri (meth) acrylate, triallyl isocyanurate, polyfunctional (meth) acrylate having a polyethylene glycol chain, Examples include 1,3-butylene glycol di (meth) acrylate and 1,4-butanediol di (meth) acrylate.

The curable monomer is preferably a polyfunctional (meth) acrylate.
As the polyfunctional (meth) acrylate having a polyethylene glycol chain, polyalkylene glycol (meth) acrylate represented by the following general formula (1) is suitable.

In the formula, R represents H or CH ₃ . n = 1 to 6, m = 1 to 50, more preferably integers of n = 1 to 6 and m = 2 to 30.
In addition, polyethylene glycol diacrylate (trade name “SARTOMER SR-344”, manufactured by Sakai Kogyo Co., Ltd.), tripropylene glycol acrylate (trade name “Aronix M-200”, manufactured by Toagosei Co., Ltd.), and the like are also suitable. Furthermore, 2- (2′-vinyloxyethoxyethyl) acrylate represented by the following general formula (2) is also suitable.

R: H or CH ₃ , n = 2 to 6, more preferably an integer of n = 2.

Examples of other curable monomers and / or oligomers include the compounds exemplified in the following (A) and (B). These can be used in combination with the preferred curable monomers and / or oligomers described above.
(A) Urethane (meth) acrylate, polyfunctional (meth) acrylate, (meth) acrylic ester polymer or copolymer side chain (meth) acryloyl group-containing acrylic resin (hereinafter simply referred to as (meth) acrylic resin) ) Polyfunctional radically polymerizable compounds such as epoxy (meth) acrylate and polyester (meth) acrylate, for example, di (meth) acrylate such as 1,4-butanediol di (meth) acrylate and bisphenol A di (meth) acrylate (Meth) acrylates; tri (meth) acrylates such as trimethylolpropane tri (meth) acrylate, pentaerythritol monohydroxytri (meth) acrylate, trimethylolpropane triethoxytri (meth) acrylate; pentaerythritol tetra (meth) Acrylate Di - tetra (meth) acrylates such as trimethylolpropane tetra (meth) acrylate; penta (meth) acrylates such as pentaerythritol penta / hexa (meth) acrylate, dipentaerythritol (monohydroxy) penta (meth) acrylate.
(B) Polyolefin compounds that are oligomers and monomers having at least two polymerizable unsaturated double bonds, such as butadiene, isoprene, chloroprene, divinylbenzene, diallyl phthalate, and the like.

In the emulsion composition for vibration damping material of the present invention, the curable monomer and / or oligomer is selected from the group consisting of polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, and polypropylene glycol diacrylate among the above-mentioned ones. It is preferable that it is at least one kind. Among the various compounds described above, these compounds exhibit more excellent curability, and when they are used, more excellent vibration damping properties are exhibited.

Examples of the polymerization initiator contained in the emulsion of the present invention include benzophenone, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, and oxy-phenyl. -Acetic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester, oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy] -ethyl ester, 1-hydroxy-cyclohexyl-phenyl Ketones, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) 2-hydroxy-2 -Methylpropan-1-one, 2-methyl-1- [4- (methyl E) phenyl] 2-morpholinopropan-1-one, 2-morpholinopropan-1-one, iodonium, (4-methylphenyl [4- (2-methylpropyl) phenyl])-hexafluorophosphate, diethylthioxanthone, Photopolymerization initiators such as isopropylthioxanthone; 2,2′-azobis- (2-methylbutyronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4′- Oil-soluble initiators such as dimethylvaleronitrile), benzoyl peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxy-2-ethylhexanoate, Persulfates such as potassium persulfate, ammonium persulfate and sodium persulfate, water-soluble peroxides such as hydrogen peroxide, , 2'-azobis (2-amidinopropane) thermal polymerization initiator such as a water-soluble azo compounds such as dihydrochloride salt. Among these, only 1 type may be used and 2 or more types may be used together. Of these, oil-soluble initiators are preferred. More preferred is 2,2'-azobis- (2-methylbutyronitrile).

The amount of the polymerization initiator in the emulsion particles of the present invention is preferably 0.5 to 10% by mass with respect to 100% by mass of the curable monomer and / or oligomer. More preferably, it is 1-10 mass%. If it is less than 0.5% by weight, the polymerization rate becomes slow and unreacted monomer tends to remain. On the other hand, if it exceeds 10% by weight, a coating defect is caused by the remaining initiator and physical properties are lowered. It can be a cause.

The emulsion in the emulsion composition for vibration damping material of the present invention preferably has a glass transition temperature (Tg) of -20 to 30 ° C. When Tg is in such a range, high vibration damping properties can be expressed in a practical temperature range (20 to 60 ° C.). More preferably, it is -20-20 degreeC.

The emulsion preferably has a particle size of 50 to 500 nm. When the particle diameter of the emulsion is in such a range, the stability is good. More preferably, it is 100 to 400 nm.
For example, after the emulsion is diluted with distilled water and sufficiently stirred and mixed, about 10 ml is collected in a glass cell, and the average particle size is measured by a particle size distribution analyzer (Particulate Sizing Systems “NICOM P” by dynamic light scattering method). It can be determined by measuring with Model 380 ").

The emulsion particles having the above average particle diameter preferably have a particle size distribution defined by a value obtained by dividing the standard deviation by the volume average particle diameter (standard deviation / volume average particle diameter × 100) of 40% or less. More preferably, it is 30% or less. When the particle size distribution exceeds 40%, the width of the particle size distribution of the emulsion particles becomes very wide, and some of the particles contain coarse particles. Therefore, the emulsion for damping material is affected by such coarse particles. There is a risk that the stability of the composition becomes poor and precipitates are generated.

The emulsion preferably has a weight average molecular weight of 20,000 to 500,000. If it is less than 20,000, the vibration damping property may not be sufficient, and the resulting emulsion composition for vibration damping material may not have sufficient stability in the state where the paint is blended. If it exceeds 500,000, for example, when two or more kinds of acrylic copolymers are used, the compatibility is not sufficient, so that the balance of vibration damping properties cannot be kept sufficiently, particularly in the range of 30 to 40 ° C. There is a possibility that the vibration damping property cannot be improved, and there is a possibility that the film-forming property at a low temperature in the state of being blended in the paint may not be sufficient. More preferably, it is 25000-400000, More preferably, it is 30000-300000.
The weight average molecular weight can be determined, for example, by GPC (gel permeation chromatography) measurement under the following measurement conditions.
Measuring instrument: HLC-8120GPC (trade name, manufactured by Tosoh Corporation)
Molecular weight column: TSK-GEL GMHXL-L and TSK-GELG5000HXL (both manufactured by Tosoh Corporation) are connected in series. Eluent: Tetrahydrofuran (THF)
Standard material for calibration curve: Polystyrene (manufactured by Tosoh Corporation)
Measurement method: The measurement object is dissolved in THF so that the solid content is about 0.2% by mass, and the molecular weight is measured using an object obtained by filtration through a filter as a measurement sample.

The pH of the emulsion composition for vibration damping material of the present invention is not particularly limited, but is preferably 2 to 10, for example. More preferably, it is 3-9. The pH of the emulsion can be adjusted by adding ammonia water, water-soluble amines, alkaline hydroxide aqueous solution, and the like to the emulsion.
The pH can be measured with a pH meter (“F-23” manufactured by Horiba, Ltd.) or the like.

The viscosity of the emulsion composition for a vibration damping material of the present invention is not particularly limited, but is preferably, for example, 10 to 10000 mPa · s, and more preferably 50 to 5000 mPa · s.
The viscosity can be measured using a B-type rotational viscometer under the conditions of 25 ° C. and 20 rpm.

The emulsion which is an essential component of the emulsion composition for vibration damping material of the present invention may be any emulsion produced by ordinary emulsion polymerization. For example, the monomer in the micelle formed in water by the emulsifier and the monomer (monomer) component containing another monomer as needed may be polymerized by the polymerization initiator.
In the emulsion composition for vibration damping material, the difference between Tg of the emulsion produced by emulsion polymerization and MFT (minimum film forming temperature) indicated by the emulsion composition for vibration damping material is preferably 10 to 100 ° C. Here, MFT is preferably obtained by a measurement method described later. The Tg of the emulsion is preferably a calculated Tg. The calculation Tg (glass transition temperature) is obtained by the following Fox equation. In addition, when calculating calculation Tg, MFT below 0 degreeC shall be handled as 0 degreeC.
Fox formula: 1 / Tg = Σ (Wn / Tgn) / 100
Here, Wn represents the weight% of monomer n, and Tgn represents the Tg (absolute temperature) of a homopolymer composed of monomer n. In addition, about the polymerizable monomer component containing polyethyleneglycol diacrylate, Tg calculated except these was made into the glass transition temperature of this polymer monomer component.

The emulsion particles are preferably acrylic emulsion particles containing 35% by mass or more of styrene with respect to 100% by mass of all monomer components. When the emulsion particles are acrylic emulsion particles , the compatibility between the polymers is excellent and high vibration damping properties can be expressed. As will be described later, the emulsion particles have sufficient curability and particle stability by containing 35% by mass or more of styrene with respect to the total monomer components. The acrylic emulsion particles are obtained from a monomer component containing a (meth) acrylic acid derivative (hereinafter referred to as an acrylic monomer) such as (meth) acrylic acid or (meth) acrylic acid ester. As long as it is emulsion particles and the monomer component contains an acrylic monomer, it may contain other monomers.

As the acrylic monomer, the following compounds are suitable. These can use 1 type (s) or 2 or more types.
(Meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, tridecyl ( C1-C20 alkyl (meth) acrylates such as meth) acrylate; C4 such as cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, etc. -20 cycloalkyl (meth) acrylate; aralkyl (meth) acrylate having 3 to 20 carbon atoms such as allyl (meth) acrylate and benzyl (meth) acrylate; epoxy group-containing vinyl such as glycidyl (meth) acrylate System monomer.

2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, epsilon-caprolactone adducts to hydroxyalkyl (meth) acrylate, PlacelFA-1, PlacelFA-4, Hydroxyl-containing acrylic monomers such as Placel FM-1, Placel FM-4 (manufactured by Daicel Chemical Industries), (meth) acryloxy polyoxyalkylene; acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, Α, β-ethylenically unsaturated carboxylic acid or unsaturated carboxylic acid anhydride such as itaconic anhydride, crotonic acid, fumaric acid, citraconic acid; (meth) acryloxyethyl phosphate, (meth) acryloxyethylsulfonic acid, etc. Contains acidic groups ) Acrylate; unsaturated carboxylic acids, acid group-containing (meth) acrylate salts (alkali metal salts, ammonium salts, amine salts, etc.).

Half ester of unsaturated carboxylic anhydride such as maleic anhydride and linear or branched alcohol having 1 to 20 carbon atoms; including urethane bond which is a reaction product of isocyanate group-containing compound and hydroalkyl (meth) acrylate Urethane (meth) acrylate compounds; containing (meth) acrylate groups such as γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane (Meth) acrylic acid group-containing silicone macromers such as organopolyoxysiloxane; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) Basic unsaturated monomers such as acrylamide.

Unsaturated sulfonic acids such as 2-sulfonic acid ethyl (meth) acrylate and salts thereof; caprolactone modified product of (meth) acrylic acid; t-butylaminoethyl (meth) acrylate, t-butylaminopropyl (meth) acrylate, (Meth) acrylates having amino groups such as lysinylethyl (meth) acrylate, pyrrolidinyl (meth) acrylate, piperidinylethyl (meth) acrylate; (meth) acrylamide, N-monomethyl (meth) acrylamide, N-monoethyl (Meth) acrylamide, N, N′-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxy (meth) acrylamide, N-dimethylaminoethyl (meth) acrylamide, N-diethylaminoethyl (meth) acrylic De, N- dimethylaminopropyl (meth) acrylamide, N- diethylaminopropyl (meth) (meth) acrylamides such as acrylamide.

Polyethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, triacyl cyanute, etc. A monomer having two or more polymerizable unsaturated bonds: 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6 6-tetramethylpiperidine, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-1-methoxy-2,2,6,6-tetramethyl Piperidine, 4-cyano-4- (meth) acryloyloxy-2,2,6,6-tetrame Piperidine series such as lupiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotoylamino-2,2,6,6-tetramethylpiperidine A polymerizable monomer having a photostable group such as polymerization.

Benzophenone-based polymerizable monomers such as 2-hydroxy-4- [3- (meth) acryloyloxy-2-hydroxypropoxy] benzophenone; 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl]- 2H-benzotriazole, 2- [hydroxy-5- (methacryloyloxymethyl) phenyl] -2H-1,2,3-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxymethyl) phenyl]- Benzotriazole-based polymerizable monomers such as 5-cyano-2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -5-t-butyl-2H-benzotriazole, etc. A polymerizable monomer having an ultraviolet absorbing group.

As said acryl-type monomer, C1-C20 alkyl (meth) acrylate and C4-C20 cycloalkyl (meth) acrylate are preferable from viewpoints, such as water resistance and a weather resistance. More preferred are alkyl (meth) acrylates having 4 to 10 carbon atoms and cycloalkyl (meth) acrylates having 6 to 10 carbon atoms, and still more preferred are alkyl (meth) acrylates having 4 to 6 carbon atoms and 6 carbon atoms. ~ 8 cycloalkyl (meth) acrylates. Further, a polymerizable monomer having a photostable group and / or a polymerizable monomer having an ultraviolet absorbing group is preferable.
That is, as a preferable embodiment of the emulsion in the present invention, at least one kind of a cycloalkyl (meth) acrylate having 4 to 20 carbon atoms and a polymerizable monomer having a photostable group and / or an ultraviolet absorbing group is essential. The form formed from the monomer component to be mentioned. That is, it may be in a form formed from a monomer component essentially comprising only a cycloalkyl (meth) acrylate having 4 to 20 carbon atoms, and only a polymerizable monomer having a photostable group and / or an ultraviolet absorbing group. The form formed from the essential monomer component may be sufficient.
In addition, although these alkyl (meth) acrylates and cycloalkyl (meth) acrylates may be used in combination with the acrylic monomers described above, they are selected from the group consisting of alkyl (meth) acrylates and cycloalkyl (meth) acrylates. It is most preferable to use one or more selected, and further two or more selected.

As the usage-amount of the said alkyl (meth) acrylate and / or cycloalkyl (meth) acrylate, it is preferable to set it as 5 to 60 weight% with respect to the total usage-amount of all the monomers, for example, 10-50 weight % Is more preferable, and 20 to 40% by weight is still more preferable. Moreover, when using the monomer which has a photostable group, it is preferable to set it as 0.1-10 weight% with respect to the total usage-amount of all the monomers, and 0.5-5 weight% is more preferable. .

Other monomers other than acrylic monomer the monomer component comprises, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl fumarate, monoethyl fumarate, Monomechiruma oleate, Monoechiruma-oleate Unsaturated carboxylic acids or derivatives thereof such as styrene, divinylbenzene and the like. Among these monomers, styrene is preferable as the other monomer, and the preferable use amount thereof is 30% by mass or more, and more preferably 35% by mass or more with respect to 100% by mass of all monomer components. When the content is 30% by mass or less, the hydrophobicity of the particles decreases, so that the absorption of the curable monomer and the polymerization initiator decreases, which may result in insufficient curing. In addition, the emulsion particles upon absorption of the curable monomer are likely to expand, and the stability of the particles may be reduced.

In the present invention, the monomer component contains 0.1 to 20% by mass of an ethylenically unsaturated carboxylic acid monomer and 99.9 to 80% by mass of another copolymerizable ethylenically unsaturated monomer. Preferably it comprises. By including an ethylenically unsaturated carboxylic acid monomer, the dispersibility of fillers such as inorganic powders is improved in the vibration damping composition that requires the emulsion for vibration damping material of the present invention. Will be improved. Moreover, it becomes easy to adjust the acid value, Tg, physical properties, etc. of an emulsion by including the other copolymerizable ethylenically unsaturated monomer. In the monomer component, even if the ethylenically unsaturated carboxylic acid monomer is less than 0.1% by mass or exceeds 20% by mass, the emulsion may not be stably copolymerized.
In the emulsion of the present invention, the synergistic effect of the monomer units formed from these monomers makes it possible to more fully exhibit excellent heat drying properties and vibration damping properties in the aqueous vibration damping material. .
In addition, the said mass ratio is a mass ratio with respect to 100 mass% of all the monomer components.

The ethylenically unsaturated carboxylic acid monomer is not particularly limited, but among the compounds contained in the monomer components described above, (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl fumarate, monoethyl fumarate, Monomechiruma oleate, include unsaturated carboxylic acids or derivatives thereof such as Monoechiruma oleate. Other copolymerizable ethylenically unsaturated monomers include those other than (meth) acrylic acid among the acrylic monomers described above.

In this invention, it is preferable that the monomer component which forms an emulsion contains 1 or more types of polymerizable monomers whose glass transition temperature of a homopolymer is 0 degrees C or less. More preferably, two or more types are included. As the polymerizable monomer having a glass transition temperature of the homopolymer of 0 ° C. or lower, butyl acrylate or 2-ethylhexyl acrylate is preferable.
That is, in this invention, it is preferable that the monomer component which forms the particle | grains of the emulsion formed by emulsion-polymerizing a monomer component is what comprises butyl acrylate and / or 2-ethylhexyl acrylate. When the monomer component comprises butyl acrylate and / or 2-ethylhexyl acrylate, vibration damping properties in a wide temperature range are improved.
More preferably, the monomer component contains butyl acrylate and 2-ethylhexyl acrylate.

When the said monomer component contains butyl acrylate, it is preferable that content of butyl acrylate is 10-60 mass% with respect to 100 mass% of monomer components which form an emulsion. More preferably, it is 20-50 mass%.
When the monomer component contains 2-ethylhexyl acrylate, the content of 2-ethylhexyl acrylate is 5 to 55% by mass with respect to 100% by mass of the monomer component forming the acrylic copolymer. Is preferred. More preferably, it is 10-50 mass%.
Moreover, when it includes both butyl acrylate and 2-ethylhexyl acrylate, the total content of butyl acrylate and 2-ethylhexyl acrylate is 20-60 with respect to 100% by mass of the monomer component forming the acrylic copolymer. It is preferable that it is mass%. More preferably, it is 30-50 mass%.

The emulsion in the present invention is obtained by emulsion polymerization of monomers. Examples of the emulsifier used for emulsion polymerization include an anionic emulsifier, a nonionic emulsifier, a cationic emulsifier, an amphoteric emulsifier, and a polymer emulsifier. Can be used.
Examples of the anionic emulsifier include alkyl sulfonate salts such as ammonium dodecyl sulfonate and sodium dodecyl sulfonate; alkyl aryl sulfonate salts such as ammonium dodecyl benzene sulfonate and sodium dodecyl naphthalene sulfonate; Polyoxyethylene alkyl sulfonate salt (eg, Daiten Kogyo Seiyaku Co., Ltd., Hytenol 18E); Polyoxyethylene alkyl aryl sulfonate salt (eg, Daiichi Kogyo Seiyaku Co., Ltd., Hytenol N) Dialkylsulfosuccinate; aryl sulfonic acid formalin condensate; fatty acid salts such as ammonium laurate and sodium stearate;

Examples of the nonionic emulsifier include polyoxyethylene alkyl ether (eg, Sanyo Kasei Kogyo Co., Ltd., Naroacti-N-200); polyoxyethylene alkyl ether (eg, Sanyo Kasei Kogyo Co., Ltd., Nonipol). -200 etc.); condensate of polyethylene glycol and polypropylene glycol; sorbitan fatty acid ester; polyoxyethylene sorbitan fatty acid ester: fatty acid monoglyceride; polyamide; condensation product of ethylene oxide and aliphatic amine;
Examples of the cationic emulsifier include alkyl ammonium salts such as dodecyl ammonium chloride;

Examples of the amphoteric emulsifier include betaine ester type emulsifiers.
Examples of the polymer emulsifier include poly (meth) acrylates such as sodium such as polyacryl; polyvinyl alcohol; polyvinyl pyrrolidone; polyhydroxyalkyl (meth) acrylate such as polyhydroxyethyl acrylate; or a polymer thereof. A copolymer having one or more of the monomers to be copolymerized as a copolymerization component; and the like.

As the type of the emulsifier, when emphasizing water resistance, it is preferable to use an emulsifier having a polymerizable group. Examples of the anionic emulsifier having a polymerizable group include bis (polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate salts (for example, Antox MS-60 manufactured by Nippon Emulsifier Co., Ltd.), propenyl-alkylsulfosuccinic acid. Ester salt, (meth) acrylic acid polyoxyethylene sulfonate salt, (meth) acrylic acid polyoxyethylene sulfonate salt (for example, Sanyo Kasei Kogyo Co., Ltd., Eleminol RS-30), polyoxyethylene alkyl Propenyl phenyl ether sulfonate salt (for example, Aqualon HS-10 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Sulfonate salt of allyloxymethylalkyloxypolyoxyethylene (for example, Aqualon manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) KH-10 etc.), allyloxymethi Nonylphenoxyethyl hydroxypolyoxyethylene sulfonate salt (for example, manufactured by Asahi Denka Kogyo Co., Ltd., Adecalia Soap SE-10, etc.), allyloxymethylalkoxyethyl hydroxypolyoxyethylene sulfate salt (for example, Asahi Denka Kogyo Co., Ltd.) And sulfuric acid esters (salts) having an allyl group, such as Adekaria Soap-SR-10N). Examples of the nonionic emulsifier having a polymerizable group include polyoxyethylene alkylpropenyl phenyl ether (for example, Aqualon RN-20 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), allyloxymethylnonylphenoxyethylhydroxypolyoxyethylene ( For example, Asahi Denka Kogyo Co., Ltd., Adeka Soap NE-10, etc.), allyloxymethylalkoxyethyl hydroxypolyoxyethylene (for example, Asahi Denka Kogyo Co., Ltd., Adeka Soap ER-10, etc.) and the like can be mentioned. It is done.
The said emulsifier may use only 1 type and may use 2 or more types together.

It does not specifically limit as the usage-amount of the said emulsifier, For example, Preferably it is 0.5-5 weight% with respect to the total usage-amount of a monomer, More preferably, it is 1-3 weight%. If the amount used is too large, the water resistance of the coating film may be lowered. On the other hand, if the amount is too small, the polymerization stability is lowered.

The initiator for the emulsion polymerization is not particularly limited, and examples thereof include azo compounds such as 2,2′-azobis (2-diaminopropane) hydrochloride; persulfates such as potassium persulfate; An oxide etc. are mentioned. In addition, a polymerization initiator may use only 1 type and may use 2 or more types together.

The usage-amount of the said polymerization initiator is not specifically limited, Preferably, it is good to set it as 0.05 to 1 weight% with respect to the total usage-amount of all the monomer components, More preferably, it is 0.1-0. It should be 5% by weight. If it is less than 0.05% by weight, the polymerization rate becomes slow and unreacted monomer tends to remain, whereas if it exceeds 1% by weight, the water resistance of the formed coating film tends to decrease. . The polymerization initiator is preferably added in an amount of 40 to 100% by weight based on the total amount used in the initial polymerization in order to make the resulting resin particles fine.

The method for adding the polymerization initiator is not particularly limited, and may be any method such as batch charging, split charging, and continuous dropping. Furthermore, in order to accelerate the completion of the polymerization, a part of the polymerization initiator may be added before and after the completion of the dropping of the monomer component in the final stage.
In the emulsion polymerization, for the purpose of promoting the decomposition of the polymerization initiator, for example, a reducing agent such as sodium bisulfite or a transition metal salt such as ferrous sulfate may be added.

As the aqueous medium that can be used in the emulsion polymerization step, water is suitable. For example, a hydrophilic solvent such as a lower alcohol such as methanol can be used in combination.
Examples of additives that can be used in the emulsion polymerization include known additives such as pH buffering agents (for example, compounds having a thiol group such as t-dodecyl mercaptan).

The polymerization temperature in the emulsion polymerization is not particularly limited, and is preferably 0 to 100 ° C, more preferably 40 to 95 ° C. The polymerization time is not particularly limited and may be set as appropriate according to the progress of the reaction. For example, the polymerization time is preferably in the range of 2 to 8 hours. The atmosphere during the polymerization is generally performed in a nitrogen atmosphere in order to increase the efficiency of the photopolymerization initiator.

The emulsion composition for a vibration damping material of the present invention can constitute a vibration damping material composition together with other components such as a pigment, a foaming agent, and a thickener as necessary. As described above, the emulsion composition for a vibration damping material of the present invention has a lower water content than the conventional emulsion composition for a vibration damping material. The damping material composition using can also have a low water content and a high solid content concentration. Such an emulsion composition for a vibration damping material of the present invention, a vibration damping composition containing pigments, foaming agents, and thickeners as essential components, and having a solid content concentration of 100% by weight of the vibration damping composition The damping material blend of 70 to 90% by mass is also one aspect of the present invention.
It should be noted that the solid content of the vibration damping composition does not volatilize when the vibration damping composition such as an emulsion polymer obtained from the monomer component described above or other components described below is applied and dried by heating. It is the ingredient that remains in.

In the emulsion composition for damping material or damping composition of the present invention, when the emulsion or curable monomer and / or oligomer is cured by UV irradiation, the curing method is the start of photopolymerization to be used. Depending on the conditions such as the agent, the type of light source that generates ultraviolet light, and the distance between the light source and the coating surface, for example, ultraviolet light with a wavelength of 1,000 to 8,000 angstroms is usually irradiated for several seconds, at most several tens of seconds The method of doing can be mentioned.
When used by being cured by electron beam irradiation, mention is made of, for example, a method of irradiating an electron beam at an acceleration voltage of usually 50 to 1000 kev, preferably 100 to 300 kev so that the absorption line is about 1 to 20 Mrad. Can do. The electron beam irradiation may be performed in the air, but is preferably performed in an inert gas such as nitrogen. The absorbed dose can be irradiated until the polymerizable double bond remaining in the coating does not affect the physical properties of the coating. After ultraviolet irradiation or electron beam irradiation, heating may be performed as necessary to further advance the curing.
When cured by heat and used, a method of drying for 0.5 to 10 minutes with a dryer at 50 to 180 ° C. can be mentioned. You may use together the method of preheating a base material before the said drying process, or setting at room temperature for 1 to 10 minutes. As the dryer, a commonly used one such as a jet oven or a hot air dryer can be used.
Moreover, when hardening with an electron beam, since heat or a photoinitiator is not required, the obtained coating film can improve coating film performance, such as a weather resistance and water resistance.

By mixing the foaming agent, the vibration damping composition of the present invention exhibits effects such as formation of a uniform foam structure of the vibration damping material and thickening, resulting in sufficient heat drying properties and high Damping will be manifested.

The foaming agent is not particularly limited, and for example, a low-boiling hydrocarbon encapsulated heated expansion capsule, an organic foaming agent, an inorganic foaming agent, and the like are suitable, and one or more of these can be used. Examples of the heated expansion capsule include Matsumoto Microsphere F-30, F-50 (manufactured by Matsumoto Yushi Co., Ltd.); EXPANSELL WU642, WU551, WU461, DU551, DU401 (manufactured by Nippon Expandcel). Examples of the organic foaming agent include azodicarbonamide, azobisisobutyronitrile, N, N-dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazine, p-oxybis (benzenesulfohydrazide), and the like. Examples of the foaming agent include sodium bicarbonate, ammonium carbonate, silicon hydride and the like.
As a compounding quantity of the said foaming agent, it is preferable to set it as 0.5-5.0 mass% with respect to 100 mass% of emulsion for damping materials. More preferably, it is 1.0-3.0 mass%.

It is preferable that the vibration damping composition of the present invention also contains an inorganic pigment, whereby it is possible to more sufficiently confirm the above-described expression of heat drying properties and high vibration damping properties. It becomes.
It does not specifically limit as said inorganic pigment, For example, 1 type (s) or 2 or more types, such as an inorganic coloring agent mentioned later and an inorganic rust preventive pigment, can be used.
As a compounding quantity of the said inorganic pigment, it is preferable to set it as 50-700 mass% with respect to 100 mass% of emulsion for damping materials. More preferably, it is 100-550 mass% part.

Examples of the thickener include polyvinyl alcohol, cellulose derivatives, polycarboxylic acid resins, and the like. As a compounding quantity of a thickener, it is preferable to set it as 0.01-2 weight part by solid content with respect to 100 weight part of solid content of the emulsion for vibration damping materials. More preferably, it is 0.05-1.5 weight part, More preferably, it is 0.1-1 weight part.
Examples of the filler include inorganic fillers such as calcium carbonate, kaolin, silica, talc, barium sulfate, alumina, iron oxide, titanium oxide, glass talk, magnesium carbonate, aluminum hydroxide, talc, diatomaceous earth, and clay; Examples of the inorganic filler include glass flakes and mica; and fibrous inorganic fillers such as metal oxide whiskers and glass fibers. As a compounding quantity of an inorganic filler, it is preferable to set it as 50-700 weight part with respect to 100 weight part of solid content of the emulsion for vibration damping materials. More preferably, it is 100-550 weight part.

Other components included in the vibration damping composition of the present invention include, for example, solvents; plasticizers; stabilizers; wetting agents; preservatives; antifoaming agents; One or more of a coloring agent, a dispersant, an antifoaming agent, an anti-aging agent, an antifungal agent, an ultraviolet absorber, and an antistatic agent can be used. Among these, it is preferable to include a filler.
In addition, the said other component can be mixed with the said emulsion for damping materials etc. using a butterfly mixer, a planetary mixer, a spiral mixer, a kneader, a dissolver etc., for example.

Examples of the solvent include ethylene glycol, butyl cellosolve, butyl carbitol, butyl carbitol acetate, and the like. What is necessary is just to set suitably as a compounding quantity of a solvent so that the solid content density | concentration of the emulsion for damping materials in a damping material formulation may become the range mentioned above.

Examples of the colorant include organic or inorganic colorants such as titanium oxide, carbon black, dial, hansa yellow, benzine yellow, phthalocyanine blue, and quinacridone red.
Examples of the dispersant include inorganic dispersants such as sodium hexametaphosphate and sodium tripolyphosphate, and organic dispersants such as polycarboxylic acid-based dispersants.
Examples of the rust preventive pigment include a metal phosphate, a metal molybdate, and a metal borate.
Examples of the antifoaming agent include silicon-based antifoaming agents.

As the other component, a polyvalent metal compound may be further used. In this case, the polyvalent metal compound improves the stability, dispersibility, heat drying property, and damping property of the damping material formed from the damping material formulation. It does not specifically limit as a polyvalent metal compound, For example, zinc oxide, zinc chloride, zinc sulfate etc. are mentioned, These 1 type (s) or 2 or more types can be used.
The form of the polyvalent metal compound is not particularly limited, and may be, for example, a powder, an aqueous dispersion, an emulsion dispersion, or the like. Especially, since the dispersibility in a damping material formulation improves, it is preferable to use it with the form of an aqueous dispersion or an emulsion dispersion, More preferably, it is used with the form of an emulsion dispersion. Moreover, it is preferable that the usage-amount of a polyvalent metal compound shall be 0.05-5.0 mass% with respect to 100 mass% of solid content in a damping material compound. More preferably, it is 0.05-3.5 mass%.

The vibration damping composition of the present invention can form, for example, a coating film that becomes a vibration damping material by applying to a substrate and drying. The substrate is not particularly limited. Moreover, as a method of apply | coating a damping material compound to a base material, it can apply | coat using a brush, a spatula, an air spray, an airless spray, a mortar gun, a lysing gun etc., for example.
The coating amount of the vibration damping composition may be appropriately set depending on the application, desired performance, and the like, but it is preferable that the film thickness of the coating film during drying is 0.5 to 8 mm. More preferably, it is 3-6 mm.
Since the vibration damping composition of the present invention is excellent in heat drying property, even if a thick coating film having a film thickness of 3 to 6 mm is formed, expansion and cracking hardly occur during drying, and an inclined surface It is possible to obtain a good coating film that hardly causes the paint to slip off. Such a vibration damping material obtained by applying the vibration damping composition of the present invention so that the film thickness after heating and drying is 3 to 6 mm is also one aspect of the present invention.

It is also preferable to apply the vibration damping composition so that the surface weight of the coating film when dried (after) is 1.0 to 7.0 kg / m ² . More preferably, it is 2.0-6.0 kg / m < ² >.
Also by this, it is possible to obtain a good coating film which hardly causes expansion and cracks during drying and hardly causes the paint on the inclined surface to slide off.
The coating method of the damping material composition to be coated and dried so that the film thickness of the coating film at the time of drying is 3 to 6 mm, and the surface weight of the coating film after drying is 2.0. A method of applying a vibration damping composition that is applied to ˜6.0 kg / m ² and dried is also one of the preferred embodiments of the present invention.

The emulsion composition for a vibration damping material of the present invention includes an emulsion that exhibits high resin strength and exhibits high vibration damping properties, and also has excellent heat drying properties, and is therefore suitable for use as a vibration damping material. Since it is not only a composition that can be used, but also an aqueous resin composition, it is preferable from the viewpoint of environmental problems.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

In the following examples, various physical properties and the like were evaluated as follows.
<Nonvolatile content (NV)>
About 1 g of the obtained aqueous resin dispersion was weighed, and after 110 hours at 110 ° C. with a hot air drier, the remaining amount after drying was regarded as a non-volatile content, and the ratio to the mass before drying was expressed in mass%.
<PH>
The value at 25 ° C. was measured with a pH meter (“F-23” manufactured by Horiba, Ltd.).
<Viscosity>
Using a B-type rotational viscometer, the measurement was performed at 25 ° C. and 20 rpm.

<Average particle size, particle size distribution>
The volume average particle diameter was measured using a particle size distribution measuring apparatus (“NICOM P Model 380” manufactured by Particle Sizing Systems) by a dynamic light scattering method.
Further, a value obtained by dividing the standard deviation by the volume average particle diameter (standard deviation / volume average particle diameter × 100) was calculated as the particle size distribution.

<Weight average molecular weight>
It measured by GPC (gel permeation chromatography) on the following measurement conditions.
Measuring instrument: HLC-8120GPC (trade name, manufactured by Tosoh Corporation)
Molecular weight column: TSK-GEL GMHXL-L and TSK-GELG5000HXL (both manufactured by Tosoh Corporation) are connected in series. Eluent: Tetrahydrofuran (THF)
Standard material for calibration curve: Polystyrene (manufactured by Tosoh Corporation)
Measurement method: The molecular weight was measured using a measurement sample dissolved in THF so that the solid content was about 0.2% by mass and filtered through a filter.

(Production Example 1)
A polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel was charged with 339 parts of deionized water. Thereafter, the internal temperature was raised to 75 ° C. while stirring under a nitrogen gas stream. On the other hand, 400 parts of styrene, 105 parts of methyl methacrylate, 135.0 parts of 2-ethylhexyl acrylate, 350 parts of butyl acrylate, 10.0 parts of acrylic acid, 4.0 parts of t-dodecyl mercaptan, 20 parts in advance. A monomer emulsion consisting of 180.0 parts of Newcor 707SF (trade name, polyoxyethylene polycyclic phenyl ether ammonium sulfate: manufactured by Nippon Emulsifier Co., Ltd.) and 164.0 parts of deionized water prepared in a% aqueous solution was charged. Next, while maintaining the internal temperature of the polymerization vessel at 75 ° C., 27.0 parts of the monomer emulsion, 5 parts of 5% aqueous potassium persulfate solution and 10 parts of 2% aqueous sodium hydrogensulfite solution were added. The initial polymerization was started. After 40 minutes, the remaining monomer emulsion was uniformly added dropwise over 210 minutes while maintaining the inside of the reaction system at 80 ° C. At the same time, 95 parts of a 5% aqueous potassium persulfate solution and 90 parts of a 2% aqueous sodium hydrogen sulfite solution were uniformly added dropwise over 210 minutes.
After cooling the resulting reaction liquid to room temperature, 16.7 parts of 2-dimethylethanolamine was added, and the non-volatile content was 54.9%, pH 8.1, viscosity 460 mPa · s, particle size 230 nm (particle size distribution 24%), Acrylic emulsion particles having a weight average molecular weight of 49000 were obtained.

(Production Example 2)
400 parts of monomer styrene, 105 parts of methyl methacrylate, 135 parts of 2-ethylhexyl acrylate, 350 parts of butyl acrylate, 10 parts of acrylic acid, 350 parts of styrene and 155 parts of methyl methacrylate charged in the dropping funnel in Production Example 1 , Except that 135 parts of 2-ethylhexyl acrylate, 350 parts of butyl acrylate and 10 parts of acrylic acid were used, the same operation as in Production Example 1 was performed, the non-volatile content was 55.0%, the pH was 7.9 parts, the viscosity was 250 mPa · s, Acrylic emulsion particles having a particle size of 215 nm (particle size distribution 22%) and a weight average molecular weight of 42,000 were obtained.

(Production Example 3)
400 parts of monomer styrene, 105 parts of methyl methacrylate, 135 parts of 2-ethylhexyl acrylate, 350 parts of butyl acrylate, 10 parts of acrylic acid, 250 parts of styrene, 255 parts of methyl methacrylate charged into the dropping funnel in Production Example 1 The same operation as in Production Example 1 was conducted except that 135 parts of 2-ethylhexyl acrylate, 350 parts of butyl acrylate, and 10 parts of acrylic acid were used, and the non-volatile content was 55.0%, pH 8.0, viscosity 290 mPa · s, particles Acrylic emulsion particles having a diameter of 238 nm (particle size distribution: 25%) and a weight average molecular weight of 48,000 were obtained.

(Production Example 4)
Monomer styrene 400 parts, methyl methacrylate 105 parts, 2-ethylhexyl acrylate 135 parts, butyl acrylate 350 parts, acrylic acid 10 parts, styrene 505 parts, 2-ethylhexyl charged into the dropping funnel in Production Example 1 The same operation as in Production Example 1 was performed except that 135 parts of acrylate, 350 parts of butyl acrylate, and 10 parts of acrylic acid were used. The nonvolatile content was 55.0%, pH 7.8, viscosity 180 mPa · s, particle size 205 nm (particle size distribution 21 %), And acrylic emulsion particles having a weight average molecular weight of 40,000 were obtained.

Example 1
To 100 parts of the emulsion particles obtained in Production Example 1, 20 parts of polyethylene glycol diacrylate (trade name, Sartomer SR-344: manufactured by Sartomer) as a curable monomer and 2,2′-azobis- ( 1 part of 2-methylbutyronitrile (trade name, ABN-E: manufactured by Nippon Hydrazine Kogyo Co., Ltd.) was mixed to obtain emulsion type polymer particles 1.

(Examples 2 to 6)
About Examples 2-6, except having used what shows a curable monomer or a curable oligomer in Table 1, the same operation was repeated and the emulsion type polymer particles 2-6 were obtained.

(Example 7)
To 100 parts of the emulsion particles obtained in Production Example 1, 40 parts of polyethylene glycol diacrylate (trade name, Sartomer SR-344: manufactured by Sartomer) as a curable monomer and 2,2′-azobis- ( 1 part of 2-methylbutyronitrile (trade name, ABN-E: manufactured by Nippon Hydrazine Kogyo Co., Ltd.) was mixed to obtain emulsion type polymer particles 7.

(Example 8)
In 100 parts of the emulsion particles obtained in Production Example 2, 20 parts of polyethylene glycol diacrylate (trade name, Sartomer SR-344: manufactured by Sartomer) as a curable monomer and 2,2′azobis- (2 as a polymerization initiator) -Methylbutyronitrile) (trade name, ABN-E: manufactured by Nippon Hydrazine Kogyo Co., Ltd.) 1 part was mixed to obtain emulsion-type polymer particles 8.

Example 9
To 100 parts of the emulsion particles obtained in Production Example 3, 20 parts of polyethylene glycol diacrylate (trade name, Sartomer SR-344: manufactured by Sartomer) as a curable monomer and 2,2′azobis- (2 as a polymerization initiator) -Methylbutyronitrile) (trade name, ABN-E: manufactured by Nippon Hydrazine Kogyo Co., Ltd.) 1 part was mixed to obtain emulsion type polymer particles 9.

(Example 10)
To 100 parts of the emulsion particles obtained in Production Example 4, 20 parts of polyethylene glycol diacrylate (trade name, Sartomer SR-344: manufactured by Sartomer) as a curable monomer and 2,2′azobis- (2 as a polymerization initiator) -Methylbutyronitrile) (trade name, ABN-E: manufactured by Nippon Hydrazine Kogyo Co., Ltd.) 1 part was mixed to obtain emulsion type polymer particles 10.

(Comparative Example 1)
To 100 parts of the acrylic emulsion particles obtained in Production Example 1, 3 parts of an aqueous zinc oxide dispersion (trade name, Acryset EMN-AZO-50: manufactured by Nippon Shokubai Co., Ltd.) as an interparticle crosslinking agent was added and stirred. Emulsion-type polymer particles 11 were obtained.

(Comparative Example 2)
In addition to the monomers used in Production Example 1 (methyl methacrylate 505 parts, 2-ethylhexyl acrylate 135.0 parts, butyl acrylate 350 parts, acrylic acid 10.0 parts), trimethylolpropane trimethacrylate as a polyfunctional monomer Emulsion-type polymer particles 12 were obtained in the same manner except that 0.5 part was added.

(Comparative Example 3)
To 100 parts of the emulsion particles obtained in Production Example 1, 10 parts of polyethylene glycol diacrylate (trade name, Sartomer SR-344: manufactured by Sartomer) as a curable monomer and 2,2′-azobis- ( 1 part of 2-methylbutyronitrile (trade name, ABN-E: manufactured by Nippon Hydrazine Kogyo Co., Ltd.) was mixed to obtain emulsion type polymer particles 13.

(Comparative Example 4)
In Production Example 1, the same operation was repeated except that 339 parts of deionized water initially charged in the reactor was changed to 123 parts, the nonvolatile content was 62.0%, pH 8.3, viscosity 2800 mPa · s, particle size 210 nm (particle size Emulsion type polymer particles 14 having a distribution of 26%) and a weight average molecular weight of 52,000 were obtained.

(Preparation of damping material composition)
The emulsion type polymer particles obtained in Examples 1 to 10 and Comparative Examples 1 to 4 were blended as follows, and as a vibration damping composition, mechanical stability, dry coating surface condition, coating disintegration resistance, And the damping property was evaluated according to the following method. The results are shown in Table 2.
Emulsion-type polymer particles 359 parts Calcium carbonate NN # 200 * ¹ 620 parts Dispersant Aquaric DL-40S ^{* 2} 6 parts Thickener Acryset WR-650 ^{* 3} 4 parts Antifoam Nopco 8034L ^{* 4} 1 part Foaming agent F- 30 ^{* 5} 6 parts * 1: Filler * 2 manufactured by Nitto Flour & Chemical Co., Ltd. Polycarboxylic acid type dispersant manufactured by Nippon Shokubai Co., Ltd. (active ingredient 44%)
* 3: Nippon Shokubai Co., Ltd. alkali-soluble acrylic thickener (active ingredient 30%)
* 4: Defoaming agent manufactured by San Nopco Co., Ltd. (main component: hydrophobic silicone + mineral oil)
* 5: Foaming agent manufactured by Matsumoto Yushi

<Machine stability>
After adding 30 g of pure water to 100 g of the vibration damping composition, thoroughly stirring and mixing, and filtering through a 100 mesh wire netting, 70 g of that was used with a Marlon test stability tester (manufactured by Kumagaya Riki Kogyo Co., Ltd.). A mechanical stability test was conducted. (According to JIS K6828: 1996, scale scale 10 kg, disc rotation speed 1000 min-1, rotation time 5 minutes, test temperature 25 ° C.) After completion of the test, the vibration damping composition was immediately filtered through a 100 mesh wire mesh, 110 Dry in an oven at 1 ° C for 1 hour. The aggregation rate was calculated by the following formula and evaluated.
Aggregation rate (%) = (mass of wire mesh after drying (g) −mass of wire mesh before drying (g)) / 70 (g) × 100
Evaluation criteria A: Less than 0.0001% B: 0.001 or more, less than 0.0001% Δ: 0.01 or more, less than 0.001% X: 0.1 or more, less than 0.01%

<Coating film disintegration resistance test>
To the 0.8 * 70 * 150 steel plate (ED steel plate) electrodeposited using the cationic electrodeposition paint Electron “KG-400” manufactured by Kansai Paint Co., Ltd. Then, the coated surface was immediately made vertical and baked at 120 ° C. for 30 minutes, and the obtained coating film was visually observed to evaluate the coating film disintegration property.
Length of paint collapsed from the upper end of the evaluation standard application surface (mm)
: Omm
○: 1-2 mm
Δ: 3 to 5 mm
×: 6 mm or more

<Vibration suppression test I>
The damping material composition was applied to a cold rolled steel plate (SPCC, 15 mm width × 250 mm length × thickness 1.5 mm) with a thickness of 3 mm, dried at 150 ° C. for 30 minutes, and the surface density on the cold rolled steel plate A damping material film of 4.0 Kg / m ² was formed. The vibration damping property was evaluated using the cantilever method (loss coefficient measurement system manufactured by Ono Sokki Co., Ltd.).
Evaluation criteria (relative evaluation)
◎: Very good vibration damping ○: Good vibration damping △: Bad vibration damping <Damping test II>
In the vibration damping test I, the same operation was performed except that the heat drying condition was changed to 150 ° C. for 15 minutes, and the vibration damping performance was evaluated.
Evaluation criteria (relative evaluation)
◎: Very good vibration suppression ○: Good vibration suppression △: Poor vibration control ×: Impossible to measure

Claims (6)

An emulsion composition for a vibration damping material containing emulsion particles obtained by emulsion polymerization of a monomer component,
The emulsion particles contain curable monomers and / or oligomers and a polymerization initiator in the emulsion particles,
The curable monomer and / or oligomer includes 1,6-hexanediol di (meth) acrylate, ethoxylated glycerin tri (meth) acrylate, triallyl isocyanurate, polyfunctional (meth) acrylate having a polyethylene glycol chain, Is at least one selected from the group consisting of 3-butylene glycol di (meth) acrylate and 1,4-butanediol di (meth) acrylate,
The emulsion particles contain 0.1 to 20% by mass of an ethylenically unsaturated carboxylic acid monomer and 99% of other copolymerizable ethylenically unsaturated monomer with respect to 100% by mass of all monomer components. .9 to 80% by mass, obtained by emulsion polymerization of a monomer component containing 30% by mass or more of styrene with respect to 100% by mass of the total monomer component,
The ethylenically unsaturated carboxylic acid monomer is a group consisting of (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl fumarate, monoethyl fumarate, monomethyl maleate, monoethyl maleate At least one selected from
The other copolymerizable ethylenically unsaturated monomers are styrene, C1-C20 alkyl (meth) acrylate, C4-C20 cycloalkyl (meth) acrylate, C3-C20 aralkyl. (Meth) acrylate, glycidyl (meth) acrylate, hydroxyl group-containing acrylic monomer, acidic group-containing (meth) acrylate, salt of acidic group-containing (meth) acrylate, unsaturated carboxylic acid anhydride and 1 to 20 carbon atoms Half ester with linear or branched alcohol, urethane (meth) acrylate compound containing urethane bond, (meth) acrylic acid group-containing silicone macromer, caprolactone modified product of (meth) acrylic acid, (meth) acrylate having amino group , (Meth) acrylamide, piperidine polymerizable monomer, benzophenone polymerizable monomer Body, at least one selected from the group consisting of benzotriazole-based polymerizable monomer,
The emulsion composition for a vibration damping material is an aqueous dispersion of the emulsion particles having a water content of 40% by mass or less. The emulsion particles are acrylic emulsion particles obtained by emulsion polymerization of a monomer component containing 35% by mass or more of styrene with respect to 100% by mass of all monomer components. The emulsion composition for vibration damping materials described in 1. The curable monomer and / or oligomer is at least one selected from the group consisting of polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, and polypropylene glycol diacrylate. The emulsion composition for vibration damping materials described in 1. An emulsion composition for a vibration damping material according to any one of claims 1 to 3, a pigment, a foaming agent, and a vibration damping composition comprising a thickener as essential components,
A damping material composition, wherein the solid content concentration is 70 to 90% by mass in 100% by mass of the damping material composition. A vibration damping material obtained by applying the vibration damping composition according to claim 4 so that the film thickness after heating and drying is 3 to 6 mm. The monomer component contains 5 to 60% by weight of alkyl (meth) acrylate and / or cycloalkyl (meth) acrylate based on the total of all monomers. The emulsion composition for vibration damping materials in any one.