JP2012126775A - Emulsion resin composition for damping material and damping material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an emulsion resin composition for a damping material, which exhibits excellent damping property and is suitably used in various structures in which a coated-type damping material is used.SOLUTION: The emulsion resin composition for a damping material includes a polymer obtained by polymerizing monomer components. The emulsion resin composition includes a polymer being a main component and at least one polymer different from the polymer being the main component, wherein the content ratio of the polymer being the main component is 65-99 mass% based on the total mass of the polymers contained in the emulsion resin composition for a damping material.

Description

The present invention relates to an emulsion resin composition for a vibration damping material and a vibration damping material. More specifically, the present invention relates to an emulsion resin composition for a vibration damping material and a vibration damping material useful as a material for a vibration damping material 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. However, even with these conventional products, the vibration damping performance is still not at a sufficiently satisfactory level, and there is a need for a technique that can further exhibit the vibration damping performance.

Under such circumstances, in order to develop a coating-type vibration damping material that exhibits excellent vibration damping properties, the structure of the polymer constituting the vibration damping material, the various components of the vibration damping composition, etc. As one of them, in order to obtain a resin composition having high vibration damping performance and adhesion performance in a wide temperature range from room temperature to a high temperature of about 80 ° C., the glass transition temperature is A resin composition for a damping plate, which contains two different types of polyester resins (A) and (B), wherein the blending ratio of the polyester resins (A) and (B) and the structure of the polyester resin (A) are specified. Is disclosed (for example, see Patent Document 1). In addition, for the purpose of obtaining an emulsion for a vibration damping material that gives high vibration damping properties in a wide temperature range, a specific ratio of two types of acrylic emulsion polymers having different glass transition temperatures and having a specified weight average molecular weight is specified. An emulsion for an aqueous damping material blended in (1) is disclosed (for example, see Patent Document 2).

JP 2004-189817 A (page 1-2) JP 2005-281576 A (page 1-2)

As mentioned above, what mix | blended two types of resin as a resin composition for damping materials is disclosed. However, these are all intended to widen the temperature range in which the damping performance is exhibited, and the damping performance itself is not sufficiently high. As described above, in applications where such vibration damping materials are used, including railway vehicles, ships, airplanes, etc., those that exhibit even better vibration damping properties are required. In order to meet this demand, there was room for improvement in developing a resin composition exhibiting further excellent vibration damping properties.

The present invention has been made in view of the above situation, and provides a resin composition for a vibration damping material that exhibits excellent vibration damping properties and is suitably used in various structures in which a coating-type vibration damping material is used. For the purpose.

As a result of various studies on resin compositions that exhibit excellent vibration damping properties, the present inventor shall include a plurality of different polymers for a resin composition containing a polymer emulsion obtained by polymerizing monomer components. In the case where the resin composition contains only one type of polymer, the content ratio of the polymer as the main component of the plurality of polymers is 65 to 99% by mass with respect to the whole polymer. It has been found that the resin composition exhibits excellent vibration damping properties. The present invention includes a synergistic effect of including two or more different polymers, not including a resin composition having the characteristics of each polymer by including two or more different polymers. As a result, a high level of vibration damping that cannot be exhibited by a resin composition containing only one kind of polymer is exhibited. Furthermore, the present inventor further uses a resin composition having excellent vibration damping properties by using a polymer contained in the resin composition having a glass transition temperature in a specific range or a polymer having a specific structure. As a result, the inventors have arrived at the present invention by conceiving that the above-mentioned problems can be solved brilliantly.

That is, the present invention is an emulsion resin composition for a vibration damping material containing a polymer obtained by polymerizing monomer components, the emulsion resin composition for a vibration damping material comprising a polymer as a main component, and In addition, the content ratio of the polymer as the main component with respect to the entire polymer included in the emulsion resin composition for vibration damping material is 65 to 99% by mass, including at least one polymer different from the polymer as the main component. It is an emulsion resin composition for vibration damping materials.
The present invention is described in detail below.

The reason why the emulsion resin composition for a vibration damping material of the present invention exhibits high vibration damping properties is considered as follows. When vibration propagates to a polymer (also referred to as a resin in this specification) in the vibration damping material, it is converted into thermal energy by friction between the polymers, and vibration damping properties are developed. Therefore, in principle, the greater the friction between the polymers, the more easily the vibration is converted into thermal energy, so that the vibration damping property is further improved. In order to increase the friction between the polymers, it is more effective to use a plurality of different polymers than to use a single polymer. The emulsion resin composition for vibration damping materials of the present invention is mainly used. It is considered that excellent vibration damping properties can be exhibited by including at least one polymer different from the polymer as the component and the polymer as the main component.

The emulsion resin composition for vibration damping material of the present invention comprises a polymer as a main component (hereinafter also referred to as polymer (A)) and a polymer different from the polymer as the main component (in the following). Includes at least one polymer (B)). However, the polymer (B) is different in the composition of the monomer component and the position of the functional group (the functional group is the main chain) as the raw material of the polymer. As long as it is different from the polymer (A) in any of the structural differences such as those in (1) and those in the side chain), glass transition temperature, weight average molecular weight and the like. Preferably, the polymer is different from the polymer (A) in the composition of the monomer component as a raw material and the polymer structure. Thereby, the difference of the mobility of a polymer becomes large between a polymer (A), and the resin composition exhibits the more excellent damping property. The composition of the monomer component is different from the monomer component constituting the polymer (A) and the monomer component constituting the polymer (B). This means that the species are different and / or the constituent ratios of the monomers are different.
The emulsion resin composition for vibration damping material of the present invention may contain at least one type of polymer (B) and may contain two or more types.

In the emulsion resin composition for vibration damping material of the present invention, the content ratio of the polymer (polymer (A)) as a main component with respect to the whole polymer contained in the emulsion resin composition for vibration damping material is 65 to 99% by mass. Although it is, it is preferable that it is 70-99 mass%. With such a content ratio, the effect of containing at least one of the polymer (A) and the polymer (B) is more sufficiently exhibited, and the emulsion resin composition exhibits more excellent vibration damping properties. It becomes. The content ratio of the polymer (A) is more preferably 75 to 99% by mass, and particularly preferably 80 to 99% by mass.
In addition, since the whole polymer which the emulsion resin composition for vibration damping materials is comprised from a polymer (A) and a polymer (B), the content rate of the polymer (A) was remove | excluded from the whole polymer. The remainder is the content ratio of the polymer (B).

In the present invention, the polymer as a main component (polymer (A)) may be one kind of polymer, and there is a difference in polymer mobility from the polymer (B). As long as there are two or more polymers, the total content of the polymers may be 65 to 99% by mass with respect to the entire polymer contained in the emulsion resin composition for vibration damping materials. Good. Further, as will be described later, the polymer (A) may be composed of two or more kinds of polymers, and the polymer (A) may have a composite form, and the polymer (A) has a core part and a shell part. In this case, the polymer (A) may be composed of two types of polymers, one of the two types of polymers forming a core portion and the other forming a shell portion.
In addition, in this invention, when the emulsion resin composition for damping materials contains 3 or more types of polymers, any polymer corresponds to a polymer (A) and any polymer corresponds to a polymer (B). Whether this is true depends on the type and form of the polymer contained in the resin composition and the content of each polymer relative to the entire polymer.

The emulsion resin composition for vibration damping material of the present invention comprises at least a polymer (polymer (A)) as a main component and a polymer (polymer (B)) different from the polymer as the main component. Other components may be included as long as one type is included. When other components are included, the ratio of the other components to the entire emulsion resin composition for vibration damping materials is preferably 10% by mass or less. More preferably, it is 5 mass% or less. In addition, the other component here means a non-volatile content (solid content) remaining in the coating film even after applying a damping material composition including the emulsion resin composition for damping material and drying by heating. An aqueous medium is not included.

The emulsion resin composition for vibration damping material of the present invention preferably has a solid content of 40 to 80% by mass with respect to the entire resin composition. More preferably, it is 50-70 mass%.
In addition, solid content here means components other than the aqueous medium contained in the emulsion resin composition for damping materials.

The polymer (polymer (A)) serving as the main component preferably has a glass transition temperature of -20 to 40 ° C. When a polymer (A) having such a glass transition temperature is used, the vibration damping performance in the practical temperature range of the vibration damping material can be effectively expressed. More preferably, the glass transition temperature of a polymer (A) is -15-35 degreeC, More preferably, it is -10-30 degreeC.
The glass transition temperature (Tg) may be determined based on the knowledge already obtained, and may be controlled by the type and use ratio of the monomer component described later. It can be calculated from the following formula (1).

In the formula, Tg ′ is Tg (absolute temperature) of the polymer. W ₁ ′, W ₂ ′,... Wn ′ are mass fractions of the respective monomers with respect to the total monomer components. T ₁ , T ₂ ,... Tn are glass transition temperatures (absolute temperatures) of homopolymers (homopolymers) composed of the respective monomer components.

The polymer (polymer (A)) serving as the main component preferably has a weight average molecular weight of 20,000 to 400,000. In order for a polymer to exhibit vibration damping properties, it is necessary to change the energy of vibration applied to the polymer to thermal energy due to friction, and it can move when vibration is applied to the polymer. It must be a polymer. When the polymer (A) has such a weight average molecular weight, the polymer can sufficiently move when vibration is applied, and high damping properties can be exhibited. The weight average molecular weight of the polymer as the main component is more preferably 30,000 to 400,000, and still more preferably 40,000 to 400,000.
The weight average molecular weight (Mw) can be determined 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 monomer component used as the raw material of the polymer constituting the emulsion resin composition for vibration damping material in the present invention is not limited as long as it can exert the effects of the present invention. The monomer component is preferably an unsaturated carboxylic acid monomer. More preferably, it comprises an unsaturated carboxylic acid monomer and another monomer copolymerizable with the unsaturated carboxylic acid monomer. The unsaturated carboxylic acid monomer is not particularly limited as long as it is a compound having an unsaturated bond and a carboxyl group in the molecule, but preferably contains an ethylenically unsaturated carboxylic acid monomer.
In addition, when the polymer contained in the emulsion resin composition for vibration damping material of the present invention has a core part and a shell part to be described later, an unsaturated carboxylic acid monomer and an unsaturated carboxylic acid The other monomer copolymerizable with the monomer may be contained in either the monomer component that forms the core part of the emulsion or the monomer component that forms the shell part. It may be used.

The ethylenically unsaturated carboxylic acid monomer is not particularly limited. For example, (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl fumarate, monoethyl fumarate, monomethyl mayate, 1 type, or 2 or more types, such as unsaturated carboxylic acids, such as monoethyl mayate, or its derivative (s) are mentioned.
Among these, (meth) acrylic monomers are preferable.
That is, it is one of the preferred embodiments of the present invention that the main polymer is an acrylic polymer.

In the present invention, the “acrylic polymer” means a polymer in which at least one monomer component is a (meth) acrylic monomer. Among these, it is preferable that it is a thing obtained using the monomer component containing a (meth) acrylic-acid type monomer. The (meth) acrylic acid monomer means (meth) acrylic acid and its salt. That is, in the acrylic polymer of the present invention, at least one of the monomer components is C (R ¹ ₂ ) ═CH—COOR ² or C (R ³ ₂ ) = C (CH ₃ ) —COOR ^4. (R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom, a metal atom, an ammonium group, or an organic amine group). Is preferably obtained.

The monomer component used as the raw material of the acrylic polymer is 0.1 to 20% by mass of a (meth) acrylic acid monomer with respect to 100% by mass of all monomer components, and other copolymerizable components. It is preferable to contain 99.9-80 mass% of ethylenically unsaturated monomers. By containing the (meth) acrylic acid monomer, the dispersibility of the filler such as inorganic powder is improved in the vibration damping composition that essentially requires the emulsion resin composition for vibration damping of the present invention, Damping performance will be further improved. Moreover, it becomes easy to adjust the acid value, Tg, physical properties, etc. of a polymer by including another copolymerizable ethylenically unsaturated monomer. In the monomer component, even if the (meth) acrylic acid monomer is less than 0.1% by mass or more than 20% by mass, the polymer may not be stably copolymerized. . In the acrylic polymer contained in the emulsion resin composition for vibration damping material of the present invention, due to the synergistic effect of the monomer units formed from these monomers, the water-based vibration damping material has excellent heat drying properties. It becomes possible to fully exhibit the vibration damping property.
More preferably, 0.5 to 3% by mass of (meth) acrylic acid monomer and 99.5% of other copolymerizable ethylenically unsaturated monomer are used with respect to 100% by mass of all monomer components. It is comprising -97 mass%.
Other copolymerizable ethylenically unsaturated monomers include (meth) acrylic monomers other than (meth) acrylic acid monomers described later, unsaturated monomers having nitrogen atoms, aromatic rings And other monomers copolymerizable with (meth) acrylic acid monomers.

In the monomer component that is the raw material of the acrylic polymer, examples of the (meth) acrylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, citraconic acid, itaconic acid, maleic acid, maleic anhydride It is preferable to use one or more of fumaric acid and the like.
Examples of (meth) acrylic monomers other than (meth) acrylic acid monomers include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, Butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, pentyl acrylate, pentyl methacrylate, isoamyl acrylate, isoamyl methacrylate, hexyl acrylate, hexyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, octyl acrylate, octyl Methacrylate, a Octyl acrylate, isooctyl methacrylate, nonyl acrylate, nonyl methacrylate, isononyl acrylate, isononyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, hexadecyl acrylate, hexadecyl methacrylate, octadecyl Acrylate, octadecyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, vinyl formate, vinyl acetate, vinyl propionate, 2-hydroxyethyl acrylate, hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, diallyl phthalate, Thoria Rucyanurate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol In addition to diacrylate, diethylene glycol dimethacrylate, allyl acrylate, allyl methacrylate, and the like, it is preferable to use one or more of these salts and esterified products.

The salt is preferably a metal salt, ammonium salt, organic amine salt or the like. Examples of the metal atom forming the metal salt include monovalent metal atoms such as alkali metal atoms such as lithium, sodium and potassium; divalent metal atoms such as alkaline earth metal atoms such as calcium and magnesium; aluminum, Trivalent metal atoms such as iron are suitable, and the organic amine salt is preferably an alkanolamine salt such as an ethanolamine salt, diethanolamine salt, or triethanolamine salt, or a triethylamine salt.

As a monomer component used as the raw material of the acrylic polymer, it is preferable to contain 20% by mass or more of (meth) acrylic monomer with respect to 100% by mass of all monomer components. More preferably, it is 30 mass% or more.

As monomers other than those mentioned above, the monomers contained in the monomer component that is the raw material of the polymer as the main component include aromatic compounds such as divinylbenzene, styrene, α-methylstyrene, vinyltoluene, and ethylvinylbenzene. Examples thereof include unsaturated compounds having a ring. Especially, it is preferable that the unsaturated compound which has an aromatic ring is included, and it is more preferable that styrene is included.
That is, it is also one preferred embodiment of the present invention that the polymer as the main component is an acrylic styrene polymer obtained from a monomer component containing styrene.

When the polymer as the main component is an acrylic styrene polymer, the monomer component as a raw material contains 1 to 50% by mass of a styrene monomer with respect to 100% by mass of the monomer component. Is preferred. More preferably, it is 5 to 45% by mass, and still more preferably 10 to 40% by mass.

As monomers other than those described above, the monomer component that is the raw material of the polymer that is the main component also includes acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, diacetone acrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, Nn-butoxymethyl (meth) acrylamide, Ni-butoxymethyl (meth) acrylamide, etc. Examples thereof include unsaturated compounds. Among these, unsaturated compounds having a nitrogen atom are preferable. Particularly preferred is acrylonitrile.

The polymer as the main component (polymer (A)) is preferably obtained from a monomer component containing a polar group-containing monomer. When the polymer (A) has a polar group, the interaction between the polymers in the damping material becomes larger, and the friction between the polymers becomes larger, so that the damping performance is more fully exhibited. Become.
The content ratio of the polar group-containing monomer is preferably 0.1 to 5% by mass with respect to 100% by mass of the monomer component. More preferably, it is 0.3-4 mass%, More preferably, it is 0.5-3 mass%.

The polar group contained in the polar group-containing monomer is not particularly limited as long as it is generally a polar group in an organic compound, but is selected from the group consisting of a hydroxyl group, a nitrile group, a carboxyl group, an amide group, and a pyrrolidone group. It is preferable that there is at least one. More preferably, it is a nitrile group and / or a carboxyl group.

The monomer component forming the acrylic polymer may further contain an unsaturated monomer having a functional group. Examples of the functional group in the unsaturated monomer having a functional group include an epoxy group, an oxazoline group, a carbodiimide group, an aziridinyl group, an isocyanate group, a methylol group, a vinyl ether group, a cyclocarbonate group, and an alkoxysilane group. . One kind of these functional groups may be present in one molecule of the unsaturated monomer, or two or more kinds thereof may be present.

Examples of the unsaturated monomer having a functional group include divinylbenzene, ethylene glycol di (meth) acrylate, N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, and Nn-butoxymethyl. (Meth) acrylamide, Ni-butoxymethyl (meth) acrylamide, N-methylol (meth) acrylamide, diallyl phthalate, diallyl terephthalate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di ( (Meth) acrylate, tetramethylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl Polyfunctional unsaturated monomers such as Koruji (meth) acrylate; glycidyl (meth) acrylate, glycidyl group-containing unsaturated monomers such as acrylic glycidyl ether. Among these, it is preferable to use an unsaturated monomer (polyfunctional unsaturated monomer) having two or more functional groups. These may be used alone or in combination of two or more.

The emulsion resin composition for a vibration damping material of the present invention preferably contains a polymer having a glass transition temperature of -20 to 40 ° C as a polymer different from the polymer as the main component. Such a polymer can serve as a polymer plasticizer in the resin composition, and can lower the minimum film-forming temperature (MFT) of the polymer as the main component. In addition, since such a polymer is compatible with a polymer as a main component, the use of such a polymer causes turbidity in a coating film formed using the emulsion resin composition for vibration damping materials. Can be suppressed. Therefore, by using such a polymer, the emulsion resin composition for a vibration damping material of the present invention can be more suitably used as a raw material for a coating type vibration damping material composition.
Such a polymer is preferably one that can lower the minimum film-forming temperature of the polymer as the main component by 5 ° C. or more. That is, it is also preferable that the emulsion resin composition for a vibration damping material of the present invention includes a polymer that serves as a polymer plasticizer and lowers the minimum film-forming temperature of the polymer as the main component by 5 ° C. or more. It is one of the embodiments.
The glass transition temperature of the polymer can be determined by the same method as described above.

In the emulsion resin composition for a vibration damping material of the present invention, the difference in glass transition temperature between the polymer (A) and the polymer (B) is preferably 5 to 60 ° C. By providing a difference in the glass transition temperature (Tg) in this way, it becomes possible to express higher vibration damping properties under a wide temperature range, and particularly in the practical range of 20 to 60 ° C. Will be greatly improved. The difference in glass transition temperature (Tg) is more preferably 5 to 50 ° C, and further preferably 5 to 40 ° C. In addition, when two or more types of polymers are included as the polymer (B), the difference in glass transition temperature between at least one of the plurality of types of polymers (B) and the polymer (A) is such as Although it may be in the range, more preferably, the difference in glass transition temperature between all the polymers (B) and the polymer (A) contained in the resin composition is in such a range.
However, as described later, when only one of the polymer (A) and the polymer (B) is an emulsion having a core part and a shell part, the Tg and shell part of the polymer forming the core part In the case where there is a sufficient difference of 10 ° C. or more from the Tg of the polymer that forms the polymer, and thereby high vibration damping properties can be expressed under a wide temperature range, the core-shell emulsion The difference between the Tg of the whole polymer that forms the polymer and the Tg of the other polymer that is not the core-shell emulsion is rather small and is preferably 10 ° C. or less.

The polymer (polymer (B)) different from the polymer as the main component is preferably one having a weight average molecular weight of 500 to 200,000. By using a material having such a weight average molecular weight, the vibration damping property of the resin composition can be further enhanced. More preferably, it is 1000-100,000, More preferably, it is 2000-50,000.
The weight average molecular weight of the polymer can be measured by the same method as described above.

The emulsion resin composition for a vibration damping material of the present invention has an acrylic polymer as a main polymer (polymer (A)) and a polymer different from the main polymer (polymer (B). ) Preferably contains at least one polymer other than the acrylic polymer. Thus, by using an acrylic polymer as the polymer (A) and using a polymer other than the acrylic polymer as the polymer (B), the friction between the polymers is increased and excellent vibration damping properties are obtained. It can be set as the resin composition which exhibits. More preferably, all the polymers (B) contained in the emulsion resin composition for vibration damping materials are polymers other than acrylic polymers.
The polymer other than the acrylic polymer may be one obtained from a monomer component that does not substantially contain an acrylic monomer, and the acrylic monomer is based on the entire monomer component. Any polymer obtained from a monomer component having a body content of 30% by mass or less may be used.

The emulsion resin composition for vibration damping material of the present invention preferably contains at least one resin selected from the group consisting of urethane resin, polyester resin, epoxy resin, vinyl acetate resin, and vinyl chloride resin. . Either the polymer (A) or the polymer (B) may be a resin selected from these groups, but as described above, the polymer (A) is preferably an acrylic polymer. That is, the emulsion resin composition for a vibration damping material of the present invention is more preferably a resin composition containing an acrylic polymer as the polymer (A), and the polymer (B) as a urethane resin, a polyester resin, or an epoxy resin. And at least one resin selected from the group consisting of vinyl acetate resins and vinyl chloride resins.
Here, as the urethane resin, any resin having at least one urethane bond in the structure may be used, but 50% by mass or more of the monomer contained in the monomer component used as the raw material of the urethane resin is urethane bond. Those having a bond formed with other monomers are preferred.
Any polyester resin may be used as long as it has at least one ester bond in the structure, but 50% by mass or more of the monomer contained in the monomer component that is the raw material of the polyester resin is other than the ester bond. Those in which a bond is formed with the monomer are preferred.
In addition, the epoxy resin may be one having at least one epoxy group in the structure, but is bonded to the monomer having an epoxy group contained in the monomer component and the monomer having the epoxy group. A resin obtained from a monomer component having a total ratio of 50% by mass or more based on the whole monomer component is preferable.
The vinyl acetate resin is not particularly limited as long as it has at least one vinyl acetate-derived structure in the structure, but is obtained from the monomer component in which the proportion of vinyl acetate contained in the monomer component is 50% by mass or more. Obtained resins are preferred.
The vinyl chloride resin need only have at least one vinyl chloride-derived structure in the structure, but is obtained from a monomer component in which the proportion of vinyl chloride contained in the monomer component is 50% by mass or more. Obtained resins are preferred.
In addition, urethane resin, polyester resin, epoxy resin, vinyl acetate resin, and vinyl chloride resin are preferably those that do not substantially correspond to an acrylic polymer. It is preferable that it is a thing obtained from the monomer component whose content rate of an acrylic monomer is 30 mass% or less.

In the emulsion resin composition for vibration damping material of the present invention, the presence form of the polymer (A) and the polymer (B) is not particularly limited, but (1) the polymer (A) and the polymer (B ) Separately polymerized and then synthesized (blended), and (2) the polymer (A) and the polymer (B) are included in a series of production steps Examples include a form in which a polymer (A) and a polymer (B) obtained by producing (for example, multistage polymerization) are combined. In order to obtain what contains a polymer (A) and a polymer (B) in a series of manufacturing processes, it can obtain by setting manufacturing conditions, such as a monomer dropping condition, suitably.

In any of the above forms (1) and (2), a form obtained by mixing the polymer (A) and the polymer (B) may be used, and the polymer (B) may be added to the polymer (A). It is good also as a form obtained by making it absorb.
The polymer (A) is obtained by absorbing the polymer (B). After the polymer (A) is synthesized, the polymer (A) is converted into a liquid polymer as the polymer (B). Can be obtained by absorbing. When the polymer (B) is thus absorbed in the polymer (A), a polymer in which the polymer (A) and the polymer (B) are uniformly mixed can be obtained.

Moreover, in the emulsion resin composition for damping materials, the thing of the form which the polymer (A) compounded independently may be sufficient. Similarly, the polymer (B) may be in the form of a composite of the polymer (B) alone.
That is, the emulsion resin composition for vibration damping material of the present invention has the following four forms. When the emulsion resin composition for a vibration damping material of the present invention contains only a non-complexed polymer, it corresponds to the following form (I), and is not composited with the composite polymer. When it contains a polymer, it corresponds to the following form (II) or (III). When it has only one complexed polymer (for example, one emulsion having a core part and a shell part to be described later), it corresponds to the following form (IV).
(I) A form in which an uncomplexed polymer (A) and an uncomplexed polymer (B) are mixed.
(II) A form in which the composite polymer (A) and the non-complex polymer (B) are mixed.
(III) A form in which a non-complexed polymer (A) and a composited polymer (B) are mixed.
(IV) A form in which the polymer (A) and the polymer (B) are combined.

In the emulsion resin composition for a vibration damping material of the present invention, any one of the above (II) to (IV) is preferable. More preferably, it is a form of the above (IV), that is, a form in which the polymer (A) and the polymer (B) are combined. When the polymer (A) and the polymer (B) are in a composite form, the interface between the resins is increased, and the effect of improving the vibration damping properties is further increased. As such a composite form, a form of emulsion particles having a core part and a shell part in which any one of the polymers to be composited forms a core part and the other forms a shell part is preferable. In the case of the form (IV), more preferably, the polymer (polymer (A)) as the main component has a core part, and a polymer (polymer (B)) different from the polymer as the main component. Is present in the form of emulsion particles having a core part and a shell part forming a shell part.
Such an emulsion resin composition for a vibration damping material includes emulsion particles having a core part and a shell part, and the emulsion part having the core part and the shell part has a core part formed by a polymer as a main component. It is one of the preferred embodiments of the present invention that the shell portion is formed of a polymer different from the main polymer.

In the case where the polymer (B) includes at least one resin selected from the group consisting of urethane resin, polyester resin, epoxy resin, vinyl acetate resin, and vinyl chloride resin, the polymer ( A form of emulsion particles having a core part and a shell part in which one of A) and the polymer (B) forms a core part and the other forms a shell part is preferable. More preferably, the polymer (A) exists as a form of emulsion particles having a core part and a polymer (B) having a core part and a shell part in which a shell part is formed.
When producing an emulsion containing at least one resin selected from the group consisting of urethane resin, polyester resin, epoxy resin, vinyl acetate resin, and vinyl chloride resin in either one of the core part or the shell part, At least one resin selected from the group consisting of a urethane resin, a polyester resin, an epoxy resin, a vinyl acetate resin, and a vinyl chloride resin as a monomer component used in the polymerization reaction for forming the core part or the shell part Anything including the above may be used.

When producing an emulsion containing at least one resin selected from the group consisting of a urethane resin, a polyester resin, an epoxy resin, a vinyl acetate resin, and a vinyl chloride resin in either the core part or the shell part For example, when manufacturing the emulsion which contains these resins in a shell part, it is preferable that the content rate of these resins in the monomer component which forms a shell part shall be 1-50 mass%. By including in such a ratio, the effect of including these resins is sufficiently exhibited. More preferably, it is 1-40 mass%. Even in the case of producing an emulsion containing these resins in the core part, it is preferable to produce the core part using a monomer component containing these resins at the same rate as this.
As components other than these resins in the monomer component containing at least one resin selected from the group consisting of urethane resin, polyester resin, epoxy resin, vinyl acetate resin, and vinyl chloride resin, Although not particularly limited, an unsaturated carboxylic acid monomer and an ethylenically unsaturated monomer copolymerizable with the unsaturated carboxylic acid monomer are preferable.

When at least one resin selected from the group consisting of urethane resin, polyester resin, epoxy resin, vinyl acetate resin, and vinyl chloride resin is included in one of the core part and the shell part, Of the entire polymer contained in the emulsion resin composition for vibration materials, all components other than these resins are regarded as the main polymer, urethane resin, polyester resin, epoxy resin, vinyl acetate resin, and vinyl chloride. It can be considered that the polymer resin is a polymer different from the polymer as the main component. That is, when including at least one resin selected from the group consisting of a urethane resin, a polyester resin, an epoxy resin, a vinyl acetate resin, and a vinyl chloride resin, the content ratio of these resins (when two or more resins are included) If the total ratio) is 35 to 1% by mass with respect to the whole polymer contained in the emulsion resin composition for vibration damping material, the polymer forming the core part and the polymer forming the shell part A polymer that forms a core part and a polymer that forms a shell part, both of which are more than 45% by mass and less than 65% by mass with respect to the entire polymer contained in the emulsion resin composition for vibration damping materials, Even when the mass ratio is small, it corresponds to the emulsion resin composition for vibration damping material of the present invention.

When the emulsion resin composition for vibration damping material of the present invention contains emulsion particles having a core part and a shell part, the core part and the shell part are completely compatible with each other and have a homogeneous structure in which they cannot be distinguished. It may be a core-shell composite structure or a microdomain structure in which these are not completely compatible but formed inhomogeneously, but among these structures, the characteristics of the emulsion are sufficiently extracted, In order to produce a stable emulsion, a core / shell composite structure is preferable.
An emulsion having a core-shell composite structure is excellent in vibration damping properties in a wide range within a practical temperature range. Especially in the high temperature range, it exhibits excellent vibration damping performance compared to other forms of vibration damping composition. As a result, within the practical temperature range, the vibration damping performance covers a wide range from room temperature to high temperature range. Can be demonstrated.
In the core / shell composite structure, the surface of the core part is preferably covered with the shell part. In this case, it is preferable that the surface of the core part is completely covered with the shell part, but it may not be completely covered. For example, the core part may be covered in a mesh shape or in some places. The part may be exposed.

Monomer that forms the core portion when the polymer as the main component and at least one polymer different from the polymer as the main component are in the form of emulsion particles having a core portion and a shell portion The difference in glass transition temperature (Tg) between the component and the monomer component forming the shell part is preferably the same as the difference in glass transition temperature between the polymer (A) and the polymer (B) described above. .
Moreover, it is preferable that the total Tg which combined the core part and the shell part is -20-40 degreeC. More preferably, it is -10-30 degreeC.
The emulsion particles having the core part and the shell part can be obtained by using an emulsion polymerization method (multistage polymerization) described later.

The polymer contained in the emulsion resin composition for vibration damping material of the present invention exists in the form of an emulsion, but the average particle diameter of the emulsion particles is preferably 100 to 450 nm.
By using emulsion particles with an average particle size in this range, the basic properties such as heat drying properties and coating properties required for vibration damping materials will be sufficient, and vibration damping properties will be even better. It can be. The upper limit is more preferably 400 nm. More preferably, it is 350 nm. When the average particle diameter of the emulsion particles is within such a range, the effect of the emulsion resin composition for vibration damping material of the present invention is more effectively exhibited.
For example, after the emulsion is diluted with distilled water and sufficiently stirred and mixed, about 10 ml of the average particle size (volume average particle size) is collected in a glass cell, and this is measured by a particle size distribution analyzer (Particle Sizing) by dynamic light scattering. It can be determined by measuring with "NICOMP Model 380" manufactured by Systems.

In the emulsion resin composition for vibration damping material of the present invention, the emulsion particles having the average particle diameter are defined by a value obtained by dividing the standard deviation by the volume average particle diameter (standard deviation / volume average particle diameter × 100). The particle size distribution is preferably 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 possibility that the resin composition cannot exhibit sufficient heat drying properties.

Although it does not specifically limit as pH of the emulsion resin composition for damping materials of this invention, For example, it is preferable that it is 2-10, More preferably, it is 3-9. More preferably, it is 7-8. The pH of the resin composition can be adjusted by adding ammonia water, water-soluble amines, aqueous alkali hydroxide solution, or the like to the resin composition.
In this specification, pH can be measured with a pH meter. For example, it is preferable to measure the value at 25 ° C. using a pH meter (“F-23” manufactured by Horiba, Ltd.).

Although it does not specifically limit as a viscosity of the emulsion resin composition for damping materials of this invention, For example, it is preferable that it is 1-10000 mPa * s, More preferably, it is 5-1000 mPa * s, More preferably, it is 5 ˜500 mPa · s.
The viscosity can be measured using a B-type rotational viscometer under the conditions of 25 ° C. and 20 rpm.

As a method for producing the polymer contained in the emulsion resin composition for vibration damping material of the present invention, the monomer component is polymerized by emulsion polymerization in the presence of an emulsifier. Is not particularly limited, and can be carried out, for example, by appropriately adding a monomer component, a polymerization initiator and an emulsifier to an aqueous medium and polymerizing. Moreover, it is preferable to use a polymerization chain transfer agent or the like for molecular weight adjustment.
As the emulsifier, one or more of anionic, cationic, nonionic and amphoteric surfactants and a polymeric surfactant can be used.

When the polymer contained in the emulsion resin composition for a vibration damping material of the present invention is an emulsion having a core part and a shell part, it is preferably obtained using a usual emulsion polymerization method. Specifically, after the monomer component is emulsion-polymerized in an aqueous medium in the presence of an emulsifier and / or protective colloid to form a core part, the monomer component is further emulsion-polymerized into an emulsion containing the core part. It is preferably obtained by multistage polymerization that forms a shell portion. Thus, the polymer contained in the emulsion resin composition for vibration damping material of the present invention is an emulsion having a core part and a shell part, and after the emulsion forms the core part, the shell part is formed. A form obtained by multistage polymerization is also a preferred form of the present invention.

The aqueous medium is not particularly limited. For example, water, one or two or more mixed solvents that can be mixed with water, and a mixed solvent in which water is a main component in such a solvent. Etc. Among these, water is preferable in consideration of safety and environmental influence when applying the paint containing the emulsion resin composition for vibration damping material of the present invention.

As a usage-amount of the said emulsifier, a lower limit is 0.1-10 mass% with respect to the usage-amount of the compound which has all the polymerizable unsaturated bond groups. If it is less than 0.1% by mass, the mechanical stability may not be sufficiently improved, and the polymerization stability may not be sufficiently maintained. More preferably, it is 0.5-5 mass%, Most preferably, it is 1-3 mass%.

The anionic surfactant is not particularly limited, and examples thereof include polyoxyalkylene alkyl ether sulfate, polyoxyalkylene oleyl ether sulfate sodium salt, polyoxyalkylene alkylphenyl ether sulfate, alkyl diphenyl ether disulfonate, poly Oxyalkylene (mono, di, tri) styryl phenyl ether sulfate, polyoxyalkylene (mono, di, tri) benzyl phenyl ether sulfate, alkenyl succinate; and sodium dodecyl sulfate, potassium dodecyl sulfate, ammonium Alkyl sulfate salts such as alkyl sulfate; sodium dodecyl polyglycol ether sulfate; sodium sulforicinoate; sulfonation Alkyl sulfonates such as raffin salts; alkyl sulfonates such as sodium dodecylbenzene sulfonate and alkali metal sulfates of alkali phenol hydroxyethylene; high alkyl naphthalene sulfonates; naphthalene sulfonic acid formalin condensates; sodium laurate, triethanolamine oleate, tri Fatty acid salts such as ethanolamine abietate; polyoxyalkyl ether sulfate ester; polyoxyethylene carboxylic ester sulfate salt; polyoxyethylene phenyl ether sulfate ester; succinic acid dialkyl ester sulfonate salt; polyoxyethylene alkyl aryl sulfate 1 type (s) or 2 or more types, such as a salt, can be used.

Examples of compounds particularly suitable as the anionic emulsifier include Latemul WX, Latemuru 118B, Perex SS-H, Emulgen A-60, B-66, Lebenol WZ (manufactured by Kao Corporation), New Coal 707SF, New Coal 707SN, Examples include New Call 714SF, New Call 714SN, AB-26S, ABEX-2010, 2020, 2030, DSB (manufactured by Rhodia Nikka Co., Ltd.) and the like.
In addition, surfactants corresponding to these nonionic types can also be used.

As the anionic emulsifier, the reactive emulsifier may be one or two of a reactive anionic surfactant, a sulfosuccinate-type reactive anionic surfactant, an alkenyl succinate-type reactive anionic surfactant, etc. More than seeds can be used.
Commercially available sulfosuccinate-type reactive anionic surfactants include Latemul S-120, S-120A, S-180 and S-180A (all trade names, manufactured by Kao Corporation), Eleminol JS-2 (Products) Name, manufactured by Sanyo Kasei Kogyo Co., Ltd.), ADEKA rear soap SR-10, SR-20, SR-30 (manufactured by ADEKA) and the like.
As a commercial item of an alkenyl succinate type reactive anionic surfactant, Latemul ASK (trade name, manufactured by Kao Corporation) and the like can be mentioned.
Furthermore, (meth) acrylic acid polyoxyethylene sulfonate salt (for example, “Eleminol RS-30” manufactured by Sanyo Chemical Industries, “Antox MS-60” manufactured by Nippon Emulsifier Co., Ltd.), allyloxymethylalkyloxypolyoxy Sulfate ester (salt) having an allyl group such as sulfonate salt of ethylene (for example, “Aqualon KH-10” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), ammonium polyoxyalkylene alkenyl ether sulfate (for example, “Latemul PD-” manufactured by Kao Corporation 104 "etc.) can also be used.

Further, as the anionic emulsifier, the following surfactants and the like can also be used as the reactive emulsifier.
Sulfoalkyl (carbon number 1 to 4) ester salt type surfactant of aliphatic unsaturated carboxylic acid having 3 to 5 carbon atoms, for example, 2-sulfoethyl (meth) acrylate sodium salt, 3-sulfopropyl (meth) acrylate ammonium (Meth) acrylic acid sulfoalkyl ester salt type surfactants such as salts; sulfopropylmaleic acid alkylester sodium salt, sulfopropylmaleic acid polyoxyethylene alkylester ammonium salt, sulfoethylfumaric acid polyoxyethylene alkylester ammonium salt, etc. Aliphatic unsaturated dicarboxylic acid alkyl sulfoalkyl diester salt surfactants.

The nonionic surfactant is not particularly limited. For example, polyoxyethylene alkyl ether; polyoxyethylene alkyl aryl ether; sorbitan aliphatic ester; polyoxyethylene sorbitan aliphatic ester; aliphatic such as monolaurate of glycerol Monoglyceride; polyoxyethyleneoxypropylene copolymer; condensation products of ethylene oxide and aliphatic amines, amides or acids. Also, allyloxymethylalkoxyethylhydroxypolyoxyethylene (for example, “ADEKA rear soap ER-20” manufactured by ADEKA), polyoxyalkylene alkenyl ether (for example, “Latemul PD-420”, “Latemul PD-” manufactured by Kao Corporation) Nonionic surfactants having reactivity such as “430” and the like can also be used. These 1 type (s) or 2 or more types can be used.

The cationic surfactant is not particularly limited, and examples thereof include dialkyldimethylammonium salts, ester-type dialkylammonium salts, amide-type dialkylammonium salts, dialkylimidazolinium salts, and the like. Can be used.

The amphoteric surfactant is not particularly limited, and examples thereof include alkyldimethylaminoacetic acid betaine, alkyldimethylamine oxide, alkylcarboxymethylhydroxyethylimidazolinium betaine, alkylamidopropylbetaine, alkylhydroxysulfobetaine, and the like. 1 type (s) or 2 or more types can be used.

The polymer surfactant is not particularly limited. For example, polyvinyl alcohol and a modified product thereof; (meth) acrylic water-soluble polymer; hydroxyethyl (meth) acrylic water-soluble polymer; hydroxypropyl (meth) acrylic Water-soluble polymers such as polyvinyl pyrrolidone, and one or more of them can be used.

Among the above surfactants, it is preferable to use a non-nonylphenyl type surfactant from the environmental viewpoint.
The amount of the surfactant used may be appropriately set according to the type of surfactant to be used, the type of monomer component, etc. For example, the amount of the monomer component used to form the polymer It is preferable that it is 0.1-10 weight part with respect to 100 weight part of total amounts, More preferably, it is 0.5-5 weight part. More preferably, it is 1 to 3 parts by weight.

Examples of the protective colloid include polyvinyl alcohols such as partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol, and modified polyvinyl alcohol; cellulose derivatives such as hydroxyethyl cellulose, hydroxypropyl cellulose, and carboxymethyl cellulose salt; natural polysaccharides such as guar gum Etc., and one or more of these can be used. The protective colloid may be used alone or in combination with a surfactant.
The use amount of the protective colloid may be appropriately set according to use conditions and the like, for example, 5 parts by weight or less with respect to 100 parts by weight of the total amount of monomer components used to form the polymer. The amount is preferably 3 parts by weight or less.

The polymerization initiator is not particularly limited as long as it is a substance that decomposes by heat and generates radical molecules, but a water-soluble initiator is preferably used. For example, persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate; water-soluble such as 2,2'-azobis (2-amidinopropane) dihydrochloride, 4,4'-azobis (4-cyanopentanoic acid) Thermal decomposition initiators such as hydrogen peroxide; hydrogen peroxide and ascorbic acid, t-butyl hydroperoxide and Rongalite, potassium persulfate and metal salts, redox polymerization of ammonium persulfate and sodium bisulfite, etc. An agent etc. are mentioned, These 1 type (s) or 2 or more types can be used.
The amount of the polymerization initiator used is not particularly limited and may be set as appropriate according to the type of the polymerization initiator. For example, the total amount of monomer components used to form the polymer is 100 parts by weight. It is preferable that it is 0.1-2 weight part with respect to this, More preferably, it is 0.2-1 weight part.

In order to promote emulsion polymerization, the polymerization initiator can be used in combination with a reducing agent as necessary. Examples of the reducing agent include reducing organic compounds such as ascorbic acid, tartaric acid, citric acid, and glucose; for example, reducing inorganic compounds such as sodium thiosulfate, sodium sulfite, sodium bisulfite, and sodium metabisulfite. These 1 type (s) or 2 or more types can be used.
The amount of the reducing agent used is not particularly limited. For example, it is preferably 0.05 to 1 part by weight with respect to 100 parts by weight of the total amount of monomer components used to form the polymer.

The polymerization chain transfer agent is not particularly limited. For example, alkyl mercaptans such as hexyl mercaptan, octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexadecyl mercaptan, n-tetradecyl mercaptan; carbon tetrachloride , Halogenated hydrocarbons such as carbon tetrabromide and ethylene bromide; mercaptocarboxylic acid alkyl esters such as mercaptoacetic acid 2-ethylhexyl ester, mercaptopropionic acid 2-ethylhexyl ester, mercaptopyropionic acid tridecyl ester; mercaptoacetic acid methoxybutyl Mercaptocarboxylic acid alkoxyalkyl ester such as ester, mercaptopropionic acid methoxybutyl ester; carboxylic acid mercaptoal such as octanoic acid 2-mercaptoethyl ester Glycol ester or, alpha-methylstyrene dimer, terpinolene, alpha-terpinene, .gamma.-terpinene, dipentene, anisole, allyl alcohol and the like. These may be used alone or in combination of two or more. Among these, alkyl mercaptans such as hexyl mercaptan, octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexadecyl mercaptan, and n-tetradecyl mercaptan are preferably used. The amount of the polymerization chain transfer agent used is usually 2.0 parts by weight or less, preferably 1.0 part by weight or less, with respect to 100 parts by weight of all monomer components.

The emulsion polymerization may be performed in the presence of a chelating agent such as sodium ethylenediaminetetraacetate, a dispersing agent such as sodium polyacrylate, an inorganic salt, or the like, if necessary. Moreover, as addition methods, such as a monomer component and a polymerization initiator, methods, such as a batch addition method, a continuous addition method, a multistage addition method, are applicable, for example. Moreover, you may combine these addition methods suitably.

Regarding the emulsion polymerization conditions in the above production method, the polymerization temperature is not particularly limited, and is preferably 0 to 100 ° C., and more preferably 40 to 95 ° C., for example. Also, the polymerization time is not particularly limited, and for example, it is preferably 1 to 15 hours, and more preferably 5 to 10 hours.
Moreover, it does not specifically limit as addition methods, such as a monomer component and a polymerization initiator, For example, methods, such as a batch addition method, a continuous addition method, a multistage addition method, are applicable. Moreover, you may combine these addition methods suitably.

In the method for producing a polymer contained in the emulsion resin composition for vibration damping material of the present invention, it is preferable to produce an emulsion by emulsion polymerization and then neutralize the emulsion with a neutralizing agent. As a result, the emulsion is stabilized. The neutralizing agent is not particularly limited, and for example, tertiary amines such as triethanolamine, dimethylethanolamine, diethylethanolamine and morpholine; diglycolamine, aqueous ammonia; sodium hydroxide and the like can be used. These may be used alone or in combination of two or more. Among these, use of a volatile base that volatilizes when the coating film is heated because the water resistance of the coating film formed from the vibration damping composition that requires the emulsion resin composition for damping material is improved. Is preferred. More preferably, an amine having a boiling point of 80 to 360 ° C. is preferably used because heat drying properties are improved and vibration damping properties are improved. As such a neutralizing agent, for example, tertiary amines such as triethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, and diglycolamine are preferable. More preferably, an amine having a boiling point of 130 to 280 ° C is used.
In addition, the said boiling point is a boiling point in a normal pressure.

The emulsion resin composition for vibration damping material of the present invention can constitute a vibration damping material composition together with other components as necessary, and the emulsion resin composition for vibration damping material of the present invention, a pigment, A vibration damping composition containing a foaming agent and a thickener as essential components is also one aspect of the present invention. Such a damping material composition essentially comprising the emulsion resin composition for damping material of the present invention can form a damping material capable of exhibiting excellent damping properties.
Such a vibration damping material obtained using the vibration damping composition of the present invention is also one aspect of the present invention.
As the above-mentioned vibration damping composition, for example, it is preferable that the solid content is 40 to 90 mass%, more preferably 50 to 90 mass, with respect to 100 mass% of the total amount of the vibration damping composition. %, And more preferably 60 to 90% by mass. Moreover, it is preferable to set pH of a damping material compound to 7-11, More preferably, it is 7-9.
As a compounding quantity of the emulsion resin composition for damping materials in the said damping material formulation, solid content of the emulsion resin composition for damping materials is 10 with respect to 100 mass% of solid content of a damping material formulation, for example. It is preferable to set so that it may become-60 mass%, More preferably, it is 15-60 mass%.

The vibration damping composition preferably has a viscosity of 50 to 200 Pa. When the viscosity is such, it is easy to apply to the substrate and is suitable as a coating-type vibration damping composition without dripping. More preferably, it is 60-150 Pa.
The viscosity of the vibration damping composition can be measured by the same method as described above.

As the foaming agent, 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 weight part with respect to 100 weight part of emulsion resin compositions for damping materials. More preferably, it is 1.0 to 3.0 parts by weight.

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 resin composition for damping materials. More preferably, it is 0.05-1.5 weight part, More preferably, it is 0.1-1 weight part.

As said pigment, 1 type (s) or 2 or more types, such as the coloring agent mentioned later and a rust preventive pigment, can be used, for example. The blending amount of the pigment is preferably 50 to 700 parts by weight with respect to 100 parts by weight of the emulsion resin composition for vibration damping materials. More preferably, it is 100-550 weight part.

Other components that can be incorporated into the vibration damping composition of the present invention include, for example, a solvent; a plasticizer; a stabilizer; a wetting agent; an antiseptic; an antifoaming agent; a filler; 1 type or 2 types or more, such as anti-aging agent; antifungal agent; ultraviolet absorber; antistatic agent can be used.
In addition, said other component can be mixed with the said emulsion resin composition 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 the compounding quantity of a solvent so that the solid content density | concentration of the emulsion resin composition for damping materials in a damping material formulation may become the range mentioned above.

Examples of the aqueous crosslinking agent include oxazoline compounds such as Epocross WS-500, WS-700, K-2010, 2020, 2030 (all trade names, manufactured by Nippon Shokubai Co., Ltd.); Adeka Resin EMN-26-60, EM- Epoxy compounds such as 101-50 (Brand name, manufactured by ADEKA); Melamine compounds such as Cymel C-325 (Brand name, manufactured by Mitsui Cytec); Block isocyanate compounds; AZO-50 (Brand name, 50% by mass) Zinc oxide compounds such as zinc oxide aqueous dispersion (manufactured by Nippon Shokubai Co., Ltd.) are preferred. The blending amount of the water-based crosslinking agent is, for example, preferably 0.01 to 20 parts by weight, and more preferably 0.8 parts by weight with respect to 100 parts by weight of the solid content of the emulsion resin composition for vibration damping materials. 15 to 15 parts by weight, more preferably 0.5 to 15 parts by weight, which may be added to the emulsion resin composition for damping material, and at the same time when other components are blended as the damping material composition It may be added.
By mixing a crosslinking agent into the emulsion resin composition or composition for vibration damping materials, the toughness of the resin is improved, and as a result, sufficient high vibration damping properties are exhibited in a high temperature region. Among them, it is preferable to use an oxazoline compound.

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 resin composition for damping materials. More preferably, it is 100-550 weight part.

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.
Examples of the form of the polyvalent metal compound may include a powder, an aqueous dispersion, an emulsion dispersion, and 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 weight part with respect to 100 weight part of solid content in a damping material compound. More preferably, it is 0.05-3.5 weight part.

The said damping material composition forms the coating film used as a damping material, for example by apply | coating to a base material 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 damping material composition may be set as appropriate depending on the application, desired performance, etc., but in order to exhibit sufficient damping properties, the coating film thickness during drying is 1.5 mm or more. It is preferable to do so. More preferably, it is 3.0 mm or more. Moreover, it is preferable to set it as 8.0 mm or less from the point of the drying property of a coating film, More preferably, it is 6.0 mm.
Moreover, it is also preferable to apply so that the surface density of the coating film at the time of drying (after) is 1.0 to 7.0 kg / m ² . More preferably, it is 2.0-6.0 kg / m < ² >. In addition, by using the vibration damping composition of the present invention, it is possible to obtain a coating film that hardly causes expansion and cracks during drying and that does not easily cause the paint on the inclined surface to slide off.
Thus, the coating method of the damping material composition applied so that the film thickness of the coating film during drying is 1.5 to 8.0 mm and dried, and the surface density of the coating film after drying A method for applying a vibration damping composition that is applied so as to be 2.0 to 6.0 kg / m ² and dried is also one of the preferred embodiments of the present invention.

After applying the vibration damping composition, the condition for drying to form a coating film may be heat drying or room temperature drying, but the vibration damping composition in the present invention is heat dried. From the viewpoint of efficiency, it is preferable to heat and dry. The heat drying temperature is preferably 110 ° C. or higher. More preferably, it is 120 ° C. or higher. Moreover, it is preferable to set it as 210 degrees C or less. More preferably, it is 170 degrees C or less.

The damping property of the damping material composition can be evaluated by measuring the loss factor of the film formed from the damping material composition.
The loss factor is usually expressed by η and indicates how much the vibration applied to the damping material is attenuated. The loss factor indicates that the higher the numerical value, the better the damping performance. As a method for measuring the loss factor, a resonance method for measuring near the resonance frequency is generally used, and there are a half width method, an attenuation rate method, and a mechanical impedance method. In the vibration damping composition of the present invention, the loss factor of the film formed from the vibration damping composition is preferably measured by a resonance method using a cantilever method (3 dB method). The measurement using the cantilever method can be performed using, for example, a CF-5200 type FFT analyzer manufactured by Ono Sokki Co., Ltd.
The loss factor is applied on a cold-rolled steel plate (SPCC-SD: length 250 mm × width 10 mm × thickness 1.6 mm) with a coating volume of length 200 mm × width 10 mm × thickness 3.0 mm. After drying at 30 ° C. for 30 minutes, it is preferable to measure by forming a film by baking at 130 ° C. for 60 minutes. For example, the loss factor is preferably measured by measuring the loss factor at each temperature of 20 ° C., 30 ° C., 40 ° C., 50 ° C., and 60 ° C. by the resonance method (3 dB method) and evaluating the peak value therein. . In addition, since the practical temperature range of the film formed from the vibration damping composition is usually 20 to 60 ° C., even if the vibration damping performance is evaluated by the total loss coefficient at each temperature of 20 to 60 ° C. Well, the damping material composition in which the film formed from the damping material composition has a total loss coefficient of 0.300 or more, which is the sum of the loss coefficients at 20 ° C., 40 ° C. and 60 ° C., is also 1 of the present invention. One. In the case of such a damping material composition, it can be said that sufficient damping properties are exhibited at 20 to 60 ° C., which is a practical temperature range of a film formed from the damping material composition.

The emulsion resin composition for a vibration damping material of the present invention has the above-described configuration and exhibits excellent vibration damping properties by including two different polymers. It can be suitably used in various structures in which coating-type damping materials such as ships, aircraft, electrical equipment, building structures, construction equipment, and the like are used.

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.
<Glass transition temperature (Tg)>
It calculated using the following formula (1) from the monomer composition used at each stage.

In addition, Tg calculated from the monomer composition used in all stages was described as “total Tg”.
The Tg values of the respective homopolymers used to calculate the glass transition temperature (Tg) of the polymerizable monomer component by the above calculation formula (1) are shown below.
Methyl methacrylate (MMA): 105 ° C
Styrene (St): 100 ° C
Butyl acrylate (BA): -56 ° C
2-ethylhexyl acrylate (2EHA): -70 ° C
Acrylic acid (AA): 95 ° C

<Nonvolatile content (N.V.)>
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 (“NICOMP 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.

<Vibration suppression test>
The above damping material composition is applied to a cold rolled steel sheet (SPCC, width 15 mm × length 250 mm × thickness 1.5 mm) at a thickness of 3 mm, dried at 150 ° C. for 30 minutes, and then coated on the cold rolled steel sheet. A damping material film having a density of 4.0 kg / m ² was formed. The measurement of damping properties uses the cantilever method (loss coefficient measurement system manufactured by Ono Sokki Co., Ltd.), and the loss coefficient at each temperature (20 ° C, 40 ° C, 60 ° C) is determined by the resonance method (3 dB method). It was measured. In addition, the evaluation of the vibration damping performance was performed based on the total loss coefficient (total of the loss coefficients at 20 ° C., 40 ° C., and 60 ° C.), and the greater the value of the total loss coefficient, the better the vibration damping performance.

Production Example 1
300 parts of deionized water was charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel. Thereafter, the internal temperature was raised to 75 ° C. while stirring under a nitrogen gas stream. On the other hand, 200 parts of styrene, 105 parts of methyl methacrylate, 190 parts of 2-ethylhexyl acrylate, 5 parts of acrylic acid, 2.0 parts of t-dodecyl mercaptan, Levenol WZ (trade name) previously adjusted to a 20% aqueous solution were added to the dropping funnel. (Manufactured by Kao Co., Ltd.) A first stage monomer emulsion consisting of 90.0 parts and 97 parts of deionized water was charged.
Next, while maintaining the internal temperature of the polymerization vessel at 80 ° C., 8 parts of the above monomer emulsion, 5 parts of 5% aqueous potassium persulfate solution and 10 parts of 2% aqueous sodium hydrogensulfite solution were added, Polymerization was started. After 20 minutes, the remaining monomer emulsion was uniformly added dropwise over 120 minutes while maintaining the inside of the reaction system at 80 ° C. At the same time, 50 parts of a 5% aqueous potassium persulfate solution and 50 parts of a 2% aqueous sodium hydrogen sulfite solution were uniformly added dropwise over 120 minutes, and the same temperature was maintained for 60 minutes after completion of the addition. Next, 105 parts of styrene, 100 parts of methyl methacrylate, 290 parts of butyl acrylate, 5 parts of acrylic acid, 2.0 parts of t-dodecyl mercaptan, 90.0 parts of rebenol WZ previously adjusted to a 20% aqueous solution and deionized water in a dropping funnel A second-stage monomer emulsion consisting of 97 parts was charged and added dropwise uniformly over 120 minutes. At the same time, 50 parts of a 5% potassium persulfate aqueous solution and 50 parts of a 2% sodium hydrogen sulfite aqueous solution were uniformly added dropwise over 120 minutes, and the same temperature was maintained for 90 minutes after the addition was completed to complete the polymerization. After cooling the obtained reaction liquid to room temperature, 12 parts of diglycolamine was added, 55% non-volatile content, pH 8.0, viscosity 420 mPa · s, particle size 230 nm, particle size distribution 22%, weight average molecular weight 65,000, Emulsion 1 having a first stage Tg of 10 ° C., a second stage Tg of −10 ° C., and a total Tg of 0 ° C. was obtained.

Production Example 2
300 parts of deionized water was charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel. Thereafter, the internal temperature was raised to 75 ° C. while stirring under a nitrogen gas stream. On the other hand, 305 parts of styrene, 205 parts of methyl methacrylate, 190 parts of 2-ethylhexyl acrylate, 290 parts of butyl acrylate, 10 parts of acrylic acid, 4.0 parts of t-dodecyl mercaptan, and 20% aqueous solution were prepared in advance. A monomer emulsion comprising 180.0 parts of Rebenol WZ (trade name, manufactured by Kao Corporation) and 194 parts of deionized water was charged.
Next, while maintaining the internal temperature of the polymerization vessel at 80 ° C., 8 parts of the above monomer emulsion, 5 parts of 5% aqueous potassium persulfate solution and 10 parts of 2% aqueous sodium hydrogensulfite solution were added, Polymerization was started. After 20 minutes, the remaining monomer emulsion was uniformly added dropwise over 120 minutes while maintaining the inside of the reaction system at 80 ° C. At the same time, 100 parts of a 5% aqueous potassium persulfate solution and 100 parts of a 2% aqueous sodium hydrogen sulfite solution were uniformly added dropwise over 120 minutes. After cooling the obtained reaction liquid to room temperature, 12 parts of diglycolamine was added, 55% non-volatile content, pH 8.0, viscosity 320 mPa · s, particle size 220 nm, particle size distribution 24%, weight average molecular weight 61,000, An emulsion 2 having a Tg of 0 ° C. was obtained.

Example 1
A resin composition A obtained by adding 10 parts of a water-dispersed urethane resin “Superflex 150” (Daiichi Kogyo Seiyaku Co., Ltd., 30% nonvolatile content) to 100 parts of the emulsion of Production Example 1 was obtained.

Example 2
A resin composition B was obtained in which 10 parts of water-dispersed polyester resin “Vylonal MD-1480” (manufactured by Toyobo Co., Ltd., 25% nonvolatile content) was added to 100 parts of the emulsion of Production Example 1.

Example 3
A resin composition C was obtained in which 5 parts of an aqueous polyester resin “Haridip WH-1188” (Harima Kasei Co., Ltd., 65% nonvolatile content) was added to 100 parts of the emulsion of Production Example 1.

Example 4
300 parts of deionized water was charged into a polymerization vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen inlet tube and a dropping funnel. Thereafter, the internal temperature was raised to 75 ° C. while stirring under a nitrogen gas stream. On the other hand, 200 parts of styrene, 105 parts of methyl methacrylate, 190 parts of 2-ethylhexyl acrylate, 5 parts of acrylic acid, 2.0 parts of t-dodecyl mercaptan, Levenol WZ (trade name, Kao) previously adjusted to a 20% aqueous solution were added to the dropping funnel. A first stage monomer emulsion consisting of 90.0 parts) and 97 parts deionized water was charged.
Next, while maintaining the internal temperature of the polymerization vessel at 80 ° C., 8 parts of the above monomer emulsion, 5 parts of 5% aqueous potassium persulfate solution and 10 parts of 2% aqueous sodium hydrogensulfite solution were added, Polymerization was started. After 20 minutes, the remaining monomer emulsion was uniformly added dropwise over 120 minutes while maintaining the inside of the reaction system at 80 ° C.
At the same time, 50 parts of a 5% aqueous potassium persulfate solution and 50 parts of a 2% aqueous sodium hydrogen sulfite solution were uniformly added dropwise over 120 minutes, and the same temperature was maintained for 60 minutes after completion of the addition. Next, 105 parts of styrene, 84 parts of methyl methacrylate, 274 parts of butyl acrylate, 5 parts of acrylic acid, 2.0 parts of t-dodecyl mercaptan, aqueous polyester resin “Haridip WH-1188” (manufactured by Harima Chemical Co., Ltd.) The second stage monomer emulsion consisting of 50 parts of non-volatile content (65%), 90.0 parts of Lebenol WZ previously adjusted to a 20% aqueous solution and 79 parts of deionized water was charged and added dropwise uniformly over 120 minutes. At the same time, 50 parts of a 5% potassium persulfate aqueous solution and 50 parts of a 2% sodium hydrogen sulfite aqueous solution were uniformly added dropwise over 120 minutes, and the same temperature was maintained for 90 minutes after the addition was completed to complete the polymerization. After cooling the obtained reaction liquid to room temperature, 12 parts of diglycolamine was added, 55% non-volatile content, pH 8.5, viscosity 480 mPa · s, particle size 210 nm, particle size distribution 25%, weight average molecular weight 63,000, A resin composition D having a first stage Tg of 10 ° C., a second stage Tg of −10 ° C., and a total Tg of 0 ° C. was obtained.

Example 5
A resin composition E obtained by adding 5 parts of vinyl acetate “Polysol Adhesive-1000J” (produced by Showa Denko KK, 51% nonvolatile content) to 100 parts of the emulsion of Production Example 1 was obtained.

<Preparation of vibration damping composition>
The resin compositions A to E of Examples 1 to 5 and the emulsion 1 or 2 obtained in Production Example 1 or 2 were respectively blended as follows, and a damping material coating film was prepared as a damping material formulation. , Evaluated damping properties. The results are shown in Table 1.
Resin compositions A to E or Emulsion 1 or 2 obtained in Production Example 1 or 2 359 parts Calcium carbonate (NN # 200 ^{* 1} ) 620 parts Dispersant (Aquaric DL-40S ^{* 2} ) 6 parts Thickener (Acry Reset WR-650 ^{* 3} ) 4 parts Antifoam (Nopco 8034L ^{* 4} ) 1 part Foaming Agent (F-30 ^{* 5} ) 6 parts * 1: Nitto Flour Industry Co., Ltd. Filler * 2: Nippon Shokubai Co., Ltd. Manufactured polycarboxylic acid dispersant (active ingredient 44%)
* 3: Nippon Shokubai Co., Ltd. alkali-soluble acrylic thickener (active ingredient 30%)
* 4: Sannopco antifoam (main component: hydrophobic silicone + mineral oil)
* 5: Foaming agent manufactured by Matsumoto Yushi

From the results of Comparative Examples 1 and 2 in Table 1, as the emulsion resin composition, it is better to use the one containing two types of polymers than the one containing only one type of polymer. Was confirmed. In addition, from comparison between Examples 1 to 5 and Comparative Example 1, the resin composition has a core / shell emulsion as a main component and further contains another resin, or another resin as a part of the core / shell emulsion. It was confirmed that the emulsion resin composition is more excellent in vibration damping properties by adopting a form containing.

Claims (8)

An emulsion resin composition for a vibration damping material containing a polymer obtained by polymerizing monomer components,
The emulsion resin composition for a vibration damping material includes at least one polymer that is a main component and a polymer different from the polymer that is the main component,
The emulsion resin composition for damping materials, wherein the content ratio of the polymer as the main component with respect to the entire polymer contained in the emulsion resin composition for damping material is 65 to 99 mass%. The emulsion resin composition for a vibration damping material according to claim 1, wherein the polymer as the main component has a glass transition temperature of -20 to 40 ° C. The emulsion resin composition for vibration damping materials according to claim 2, wherein the polymer as the main component has a weight average molecular weight of 20,000 to 400,000. The emulsion resin composition for a vibration damping material according to claim 2 or 3, wherein the polymer as the main component is an acrylic polymer. The emulsion resin composition for a damping material includes a polymer having a glass transition temperature of -20 to 40 ° C as a polymer different from the polymer as the main component. An emulsion resin composition for a vibration damping material according to claim 1. The emulsion resin composition for a vibration damping material includes at least one resin selected from the group consisting of a urethane resin, a polyester resin, an epoxy resin, a vinyl acetate resin, and a vinyl chloride resin. The emulsion resin composition for vibration damping materials according to any one of claims 1 to 5. An emulsion resin composition for a vibration damping material according to any one of claims 1 to 6, a pigment, a foaming agent, and a thickener as essential components. A damping material obtained using the damping material composition according to claim 7.