JP2013199622A - Emulsion composition for heat drying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an emulsion composition for heat drying, which exhibits excellent heat-drying properties and vibration-damping properties, and is applied suitably for various applications such as a vibration-damping material.SOLUTION: An emulsion composition for heat drying comprises a polymer emulsion and starch. A polymer, which forms the polymer emulsion, has a weight-average molecular weight of 20,000-800,000, and the emulsion composition has starch particles dispersed therein.

Description

The present invention relates to an emulsion composition for heat drying. More specifically, an emulsion composition for heating and drying, a thick film coating composition for heating and drying, which is useful as a material for a vibration damping material used to prevent vibration and noise in various structures and maintain silence. And a method for producing a thick film coating composition for heat drying.

The composition for heating and drying is a material used to form a coating film exhibiting various functions on a substrate by heating and drying, and forming a coating film by heating and drying is compatible with industrial production processes. Therefore, it is used in the manufacture of many industrial products. In recent years, damping properties have attracted attention as one of new functions, and are also used for damping materials.
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. On the other hand, when the shape of the place where vibration or sound is generated is complicated, it is difficult to apply these molded products to the place where vibration is generated. Various methods for exerting the effect have been studied. For example, asphalt sheets containing inorganic powder have been used under the floors of automobiles, etc., but since there is a need for heat-sealing, improvement in workability and the like is desired. Various compositions for damping materials and polymers to be formed have been studied.

As described above, coating-type damping materials (paints) have been developed as substitute materials for molded products, and, for example, by coating films formed by spraying or applying by any method to the corresponding locations. Various vibration-damping paints that can obtain a vibration absorbing effect and a sound absorbing 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, an aqueous resin dispersion in which resin particles forming a coating film are dispersed in an aqueous dispersion medium, mica for improving the vibration damping properties of the coating film, and a vibration damping comprising magnesium oxide. A coating composition is disclosed (for example, refer to Patent Document 1). This improves the vibration damping performance of the coating film by blending a large amount of mica, and improves the drying property by blending magnesium oxide. Moreover, a gelling agent is described as an example of another component, and starch is described as an example of the gelling agent.

JP 2009-249505 A (pages 1 to 5)

In recent years, emulsions are being frequently used as heat-drying compositions in consideration of the environment, workability during coating film formation, safety for industrial products, and the like. In a coating material using an emulsion, water is volatilized after application, and emulsion particles (resin particles) are fused to form a coating film. In the case of heat drying (baking), particularly when the film thickness is thick, a film is formed from the surface of the coating film, so-called skinning occurs, and water in the coating film is difficult to escape during drying. In addition, it is difficult for water to escape when trying to form a coating film that can exhibit suitable coating performance for various applications, or when drying by heating at hundreds of degrees Celsius to improve the drying speed. The heat drying property will be reduced. In the case of an emulsion coating film, performance such as water resistance is often required, but the heat drying property tends to decrease as the performance is improved. If the heat drying property is poor, problems such as bubbles are generated during drying. In particular, in applications such as damping materials, it is desirable to form a thick film to make the functions such as damping performance sufficient, but the thicker the film, the more heat drying the emulsion. It becomes difficult to make it good. If a good coating film is not formed such as generation of bubbles, various functions such as vibration damping performance cannot be fully expressed.
For this reason, in an emulsion composition for heat drying that can be suitably applied to vibration damping material applications, etc., heat drying property / thick film drying property (baking property) is one of important performance evaluation indexes.

However, in the technique described in Patent Document 1 described above, it is described that the vibration damping performance and the drying property are improved. However, only the drying property is confirmed in the example. Moreover, in patent document 1, it is said that drying property is good that a drying rate is fast, About the heat drying property / thick film drying property (baking property) at the time of the above-mentioned coating film (especially thick film) formation, It was not recognized as an issue. Therefore, in the composition for heat drying using an emulsion, there is room for improvement in terms of improving heat drying properties and thick film drying properties (baking properties) in order to sufficiently exhibit various performances such as vibration damping properties. there were.
As will be described later, in the present invention, starch is used, and when starch is blended, it is blended in a specific form. In this patent document, starch is an example of an arbitrary blend. Is only described. Moreover, it is not described at all what kind of form the starch was blended. Usually, when starch is blended, it is heated to form an aqueous solution, which is different from the starch form in the present invention.

The present invention has been made in view of the above-mentioned present situation, and the heat drying property of the polymer emulsion is improved, and accordingly, various performances such as vibration damping properties are excellent. Therefore, the present invention is suitable for various applications such as vibration damping materials. It aims at providing the emulsion composition for heat-drying applied to (1).
In addition, the present invention has such an emulsion composition for heat drying as one of the essential components, and is a thick film coating composition for heat drying suitable for forming a thick film coating film, and a coating formed thereby. It aims at providing the manufacturing method of a film and the thick film coating composition for heat-drying.

The inventor has made various studies on the emulsion composition for heat drying, and that the water-based polymer emulsion is excellent in terms of workability and the like, and for the polymer emulsion that can be used as the emulsion composition for heat drying, We paid attention to the fact that starch has the effect of improving characteristics such as bakeability. And in the emulsion composition for heat drying using a water-based polymer emulsion, when the starch as an additive is blended in a solid state (powder) and the starch particles are dispersed, a thick film coating film is formed. It has been found that the heat drying property is improved even when it is formed. In particular, when starch is pre-mixed in an emulsion for vibration damping materials (preferred form is low molecular weight, specific Tg), and starch particles are dispersed in advance in the polymer emulsion, heat drying with a small amount of starch And improved thick film drying (baking). This is because the starch action on the emulsion particles is efficiently exhibited by pre-existing starch around the emulsion particles, and the interaction between the emulsion particles and the starch becomes stronger. Is estimated to have increased.

In conventional heat-drying compositions, starch is blended as a thickener, and it is usual to blend after heating and dissolving the starch to form an aqueous solution. Since the solid (powder) starch particles are dispersed, the starch is preferably blended as it is in a solid or powder form without being converted into an aqueous solution to disperse the starch particles.
Thus, in the composition for heating and drying, it is the first time in the present invention to mix the starch without dissolving it. In the present invention, it is sufficient that the starch particles are in a solid or powdery state, and the surface portion of the particles may be dissolved and hydrated in the emulsion composition.

In addition, a thick film coating composition for heat drying having such a heat drying emulsion composition as one of the essential components has improved heat drying properties when forming a thick film coating film. It is possible to fully exhibit the various functions exhibited by doing this, and in particular, the coating film (damping material) formed using the coating composition for the vibration damping material is remarkably superior. It has also been found that it exhibits damping properties and is extremely useful as a damping material for various structures. In this way, the inventors have arrived at the present invention by conceiving that the above problems can be solved brilliantly.

That is, the present invention is an emulsion composition for heating and drying comprising a polymer emulsion and starch, and the polymer forming the polymer emulsion has a weight average molecular weight of 20,000 to 800,000, and the emulsion composition is The emulsion composition for heat drying, in which starch particles are dispersed.
The present invention is described in detail below.
A combination of two or more preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

The emulsion composition for heat drying of the present invention comprises a polymer emulsion and starch as essential components.
In the present invention, the “polymer emulsion” preferably contains a polymer (hereinafter also referred to as polymer (A)) that forms a polymer emulsion and an aqueous medium.
The polymer (polymer (A)) forming the polymer emulsion may be one kind of polymer or may be composed of two or more kinds of polymers.

The polymer (polymer (A)) forming the polymer emulsion has a weight average molecular weight of 20,000 to 800,000. In order for the polymer to exhibit functionality in various applications, such a molecular weight range is preferable. In particular, in order to exhibit vibration damping properties, it is preferable to change the energy of vibration applied to the polymer to thermal energy due to friction, and the polymer can move when vibration is applied to the polymer. It is necessary to be. 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 (A) 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 polymer (polymer (A)) forming the polymer emulsion preferably has a glass transition temperature of -20 to 40 ° C. When a polymer (A) having such a glass transition temperature is used, the polymer (A) is suitable for application to various applications, and in particular, the damping performance in the practical temperature range of the damping material is effectively reduced. It can be expressed. The glass transition temperature of the polymer (A) is more preferably -15 to 35 ° C, still more preferably -10 to 30 ° C.
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 emulsion composition for heat drying of the present invention is a dispersion of starch particles. In the present specification, the term “starch particles” is particularly used to indicate that starch is dispersed in a solid or powder form.
In the present invention, the state where the starch particles are dispersed may be in a state where the solid (powdered) starch particles are dispersed with respect to the polymer emulsion. In the emulsion composition for heat drying of the present invention, Solid (powder) starch particles are dispersed in a polymer emulsion. In the thick film coating composition for heating and drying described later, the polymer emulsion and solid (powder) starch are contained in the coating composition. It is sufficient that the particles are in a dispersed state. In addition, the dispersion state should just be a state in which it is normally evaluated that the compound is disperse | distributed in the technical field of an emulsion composition or a coating composition.
As described above, in the present invention, when the starch is dispersed, it is not made into an aqueous solution by heating or the like, but is dispersed in the particle state, but the surface portion of the starch particles is dissolved in the emulsion composition to be hydrated. Or the like. Moreover, when dispersing starch, it is preferable not to perform operations such as heating, but as long as the starch remains solid (powdered), operations such as heating are not excluded.

Although it does not specifically limit as starch in this invention, For example, potato starch, corn starch, rice starch, urea phosphate starch, wheat starch etc. are mentioned, Potato starch, corn starch, rice starch etc. are preferable.

The starch preferably has the following gelatinization temperature in order to disperse solid starch particles in the polymer emulsion.
The starch preferably has a gelatinization temperature of 60 ° C. or higher from the viewpoint of storage stability at high temperatures. More preferably, it is 62 degreeC or more, More preferably, it is 63 degreeC or more. The upper limit of the gelatinization temperature is not particularly limited, but is preferably 90 from the viewpoint that the starch is preferably gelatinized when the thick film coating composition for heating and drying described below is heated and dried (baked). ° C or lower, more preferably 80 ° C or lower, still more preferably 75 ° C or lower.
The gelatinization temperature is measured as the temperature when the viscosity rapidly increases and shows the peak viscosity (maximum viscosity) when heated in a warm bath with stirring using a 6% aqueous solution of starch. be able to. Specifically, using a Brabender viscograph (rotation speed 75 rpm), the prepared starch aqueous solution (6%) was heated from 30 ° C. to 93 ° C. at 1.5 ° C./min. Maintain the same temperature for 1 minute, and then lower the temperature to 30 ° C. to obtain a viscosity curve (horizontal axis: temperature, vertical axis: viscosity). From this viscosity curve, the maximum viscosity during gelatinization and its temperature (that is, gelatinization) Viscosity) can be measured.

The starch preferably has an average particle size of 50 μm or less from the viewpoint of dispersibility with respect to the polymer emulsion. More preferably, it is 45 micrometers or less, More preferably, it is 40 micrometers or less. The lower limit of the average particle size is not particularly limited, but is preferably 1 μm or more, more preferably 10 μm or more, and further preferably 20 μm or more from the viewpoint of storage stability.
In addition, the average particle diameter of starch can be measured using a laser diffraction / scattering type particle size distribution measuring apparatus.

In the emulsion composition for heat drying of this invention, it is preferable to contain 12-36 mass parts of starch with respect to 100 mass parts of polymers (polymer (A)) which form a polymer emulsion. If the amount is less than the above range, the heat drying property may not be sufficient. If the amount is more than the above range, starch may precipitate in the composition and storage stability may be deteriorated. The starch content is more preferably 13 to 36 parts by mass, still more preferably 14 to 36 parts by mass, and particularly preferably 18 to 36 parts by mass.

The constituent components of the emulsion composition for heat drying according to the present invention are preferably composed mainly of the above essential components, but other components described later may be included in addition to the above essential components. Preferably, a preservative is included to prevent starch from rotting in the emulsion composition. That is, a heat-drying emulsion composition containing a polymer emulsion, starch and a preservative is one of the preferred embodiments of the present invention.
Examples of the preservative include 2-methyl-4-isothiazolin-3-one (MIT), 1,2-benzisothiazolin-3-one (BIT), and 2-n-octyl-4-isothiazolin-3-one. (OIT). MIT and BIT are preferred.
As a compounding quantity of an antiseptic | preservative, it is preferable to set it as 100-4000 ppm with respect to 100 mass parts of solid content of the emulsion composition for heat-drying, More preferably, it is 200-2000 ppm.
As will be described later, when preparing a thick film paint composition for heat drying using the emulsion composition for heat drying of the present invention, a preservative is blended in the thick film paint composition for heat drying. Starch may be prevented from rotting.

The monomer component that is a raw material of the polymer (polymer (A)) forming the polymer emulsion in the present invention is not particularly limited as long as the effects of the present invention can be exhibited, but the unsaturated carboxylic acid single amount The body is preferably included. 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 the present invention, the polymer (polymer (A)) forming the polymer emulsion may be one kind of polymer as described above, or may be composed of two or more kinds of polymers. Further, the polymer (A) may be composed of two or more kinds of polymers, and they may be combined. In addition, when the polymer (A) is in a form having a core part and a shell part to be described later, the unsaturated carboxylic acid monomer and the other monomer copolymerizable with the unsaturated carboxylic acid monomer are It may be contained in any of the monomer component forming the core part of the emulsion and the monomer component forming the shell part, and may be used in both of them.

The ethylenically unsaturated carboxylic acid monomer is not particularly limited. For example, (meth) acrylic acid, crotonic acid, itaconic acid, citraconic acid, fumaric acid, maleic acid, maleic anhydride, monomethyl fumarate, monoethyl One type or two or more types of unsaturated carboxylic acids such as fumarate, monomethyl maleate, monoethyl maleate, or derivatives thereof may be used. Among these, (meth) acrylic acid monomers such as (meth) acrylic acid are preferable. That is, the polymer (polymer (A)) forming the polymer emulsion is a (meth) acrylic polymer in which at least one of the monomer components is a (meth) acrylic acid monomer, 1 is one of the preferred embodiments of the present invention.

Among the above (meth) acrylic polymers, those obtained by using a monomer component containing a (meth) acrylic acid monomer are preferable. In the (meth) 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 ). A monomer that is a monomer represented by —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). It is preferable that it is obtained using components.
In the present specification, the (meth) acrylic acid monomer has an acryloyl group or a methacryloyl group, or a group in which a hydrogen atom in these groups is replaced with another atom or atomic group, and A monomer having —COOH group, and a (meth) acrylic monomer has an acryloyl group or a methacryloyl group, or a group in which a hydrogen atom in these groups is replaced with another atom or atomic group. And a monomer in the form in which the —COOH group is an ester or a salt, or a derivative of such a monomer.

The monomer component used as the raw material for the (meth) acrylic polymer is 0.1 to 20% by mass of the (meth) acrylic acid monomer with respect to 100% by mass of the total monomer components, and other common components. It preferably contains 99.9 to 80% by mass of a polymerizable ethylenically unsaturated monomer. By including a (meth) acrylic acid monomer, the dispersibility of fillers such as inorganic powders in the heat-drying thick film coating composition described below, which essentially requires the heat-drying emulsion composition of the present invention, This will improve the vibration control performance. 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 monomer component is hardly stably copolymerized. There is a fear. The (meth) acrylic polymer contained in the emulsion composition for heat drying of the present invention has excellent heat drying properties in aqueous vibration damping materials due to the synergistic effect of monomer units formed from these monomers. And vibration damping can be more fully exhibited.
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, unsaturated monomers having nitrogen atoms, and aromatic rings Examples include unsaturated monomers and other monomers copolymerizable with (meth) acrylic acid monomers.

Examples of (meth) acrylic monomers other than the above (meth) acrylic 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 , Iso Cutyl 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, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, diallyl Phthalate, tri Rilcyanurate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, Diethylene glycol diacrylate, diethylene glycol dimethacrylate, allyl acrylate, allyl methacrylate, and the like; these salts and esterified products can be mentioned, and it is preferable to use one or more of these.

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 a raw material of the (meth) acrylic polymer, the (meth) acrylic monomer should contain 20% by mass or more with respect to 100% by mass of all monomer components. Is preferred. More preferably, it is 30 mass% or more.

Examples of the unsaturated monomer having an aromatic ring include divinylbenzene, styrene, α-methylstyrene, vinyltoluene, and ethylvinylbenzene. Styrene is preferred.
That is, the polymer (polymer (A)) forming the polymer emulsion is a styrene (meth) acrylic polymer obtained from a monomer component containing styrene. One.

When the polymer (polymer (A)) forming the polymer emulsion contains a styrene (meth) acrylic polymer, 1 unsaturated monomer having an aromatic ring is added to 100% by mass of all monomer components. It is preferable to contain -50 mass%. More preferably, it is 5-45 mass%, More preferably, it is 10-40 mass%.

Examples of the unsaturated monomer having a nitrogen atom include 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. are mentioned. Acrylonitrile is preferred.

The polymer (polymer (A)) forming the polymer emulsion 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 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 (meth) acrylic polymer may contain an unsaturated monomer having a functional group. Examples of the functional group in the unsaturated monomer having the functional group include an epoxy group, a glycidyl 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. Is mentioned. 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 thereof include glycidyl group-containing unsaturated monomers such as glycidyl (meth) acrylate and acrylic glycidyl ether, and these may be used alone or in combination of two or more.

Examples of the polyfunctional unsaturated monomer include divinylbenzene, ethylene glycol di (meth) acrylate, N-methoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, 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, neopentylglycol Di (meth) acrylate. These may be used alone or in combination of two or more.

One of the preferred forms in the emulsion composition for heat drying is a form of emulsion particles in which at least one of the polymers forming the polymer emulsion has a core part and a shell part. More preferably, the polymer forming the polymer emulsion is in the form of emulsion particles having a core portion and a shell portion. Thereby, the interface between resin can be increased and effects, such as a damping improvement, can be enlarged more.

When the emulsion composition for heat drying 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, and even if they have a homogeneous structure in which they cannot be distinguished from each other Well, it may be a core-shell composite structure or microdomain structure in which they are not completely compatible but heterogeneously formed, but among these structures, the characteristics of the emulsion are sufficiently extracted and stable. In order to prepare an 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. In particular, even in the high temperature range, it exhibits excellent vibration damping properties compared to other forms of composition. As a result, within the practical temperature range, it exhibits vibration suppression performance over a wide range from room temperature to high temperature range. be able to.
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.

When at least one of the polymers forming the polymer emulsion is in the form of emulsion particles having a core part and a shell part, the polymer obtained from the monomer component forming the core part and the monomer forming the shell part The difference in glass transition temperature (Tg) from the polymer obtained from the components is preferably 5 to 60 ° C. Thus, by providing a difference in the glass transition temperature (Tg), for example, when applied to a damping material application, it becomes possible to express higher damping properties under a wide temperature range, and in particular, a practical range. Therefore, the vibration damping property in the 20 to 60 ° C. region is remarkably improved. The difference in glass transition temperature (Tg) is more preferably 5 to 50 ° C, and further preferably 5 to 40 ° C.
Moreover, it is preferable that Tg of the polymer obtained from the total monomer component which combined the monomer component which forms a core part, and the monomer component which forms a 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 (A) contained in the emulsion composition for heat drying of the present invention is present 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 or less, still more preferably 350 nm or less. When the average particle diameter of the emulsion particles is within such a range, the effect of the emulsion composition for heat drying of the present invention is more effectively exhibited. Moreover, the lower limit of the average particle diameter is preferably 110 nm or more, more preferably 120 nm or more.
The average particle size (volume average particle size) can be determined by, for example, diluting the emulsion with distilled water, thoroughly stirring and mixing, then collecting about 10 ml in a glass cell, and measuring the particle size distribution analyzer (Particle) by the dynamic light scattering method. It can be determined by measuring with “NICOMP Model 380” manufactured by Sizing Systems.

In the emulsion composition for heat drying of the present invention, the emulsion particles having the above average particle size have a particle size distribution defined by a value obtained by dividing the standard deviation by the volume average particle size (standard deviation / volume average particle size × 100). However, it is preferable that it is 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 composition for heat drying is affected by such coarse particles. There is a possibility that the product cannot exhibit sufficient heat drying properties.

The emulsion composition for heat drying of the present invention may contain other components as long as it contains a polymer emulsion and starch.
When other components are included, the proportion of the other components is preferably 10% by mass or less, more preferably 5% by mass or less, based on the entire emulsion composition for heat drying. In addition, the other component here means a non-volatile content (solid content) remaining in the coating film even after the emulsion composition for heat drying is applied and heat-dried, and does not include an aqueous medium.
The emulsion composition for heat drying of the present invention preferably has a solid content of 40 to 80% by mass, more preferably 50 to 70% by mass, based on the entire resin.
In addition, solid content here means components other than the aqueous medium contained in the emulsion composition for heat-drying.

Although it does not specifically limit as pH of the emulsion composition for heat drying of this invention, 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 composition for heat drying of this invention, 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 composition for heat drying of the present invention, the monomer component is polymerized by an emulsion polymerization method in the presence of an emulsifier. For example, the polymerization can be carried out by adding a monomer component, a polymerization initiator, and an emulsifier as appropriate in an aqueous medium for polymerization. Moreover, it is preferable to use a polymerization chain transfer agent or the like for molecular weight adjustment.

When the polymer contained in the emulsion composition for heat drying 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 composition for heat drying of the present invention is an emulsion having a core part and a shell part, and after the emulsion forms the core part, the multistage polymerization that forms the shell part The form obtained by the above is also one of the preferred forms 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 composition for heat drying of the present invention.

The amount of the emulsifier used is preferably 0.1 to 10% by mass with respect to 100% by mass of the total amount of compounds having a polymerizable unsaturated bond group. If it is less than 0.1% by mass, the mechanical stability cannot be sufficiently improved and the polymerization stability may not be sufficiently maintained. More preferably, it is 0.5-5 mass%, More preferably, it is 1-3 mass%.

As the emulsifier, one or more of anionic, cationic, nonionic and amphoteric surfactants and a polymeric surfactant can be used.
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; sodium dodecyl sulfate, potassium dodecyl sulfate, ammonium alkyl sulfate Alkyl sulfate salts such as sodium dodecyl polyglycol ether sulfate; sodium sulforicinoate; Alkyl sulfonates such as sodium 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 Examples include salts. These 1 type (s) or 2 or more types can be used.

Examples of commercially available products suitable as the anionic surfactant 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, 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 above anionic surfactants, reactive surfactants, reactive anionic surfactants, sulfosuccinate type reactive anionic surfactants, alkenyl succinate type reactive anionic surfactants, etc. 1 type (s) or 2 or more types 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 surfactant, the following surfactants and the like can be used as the reactive surfactant.
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, and the like. From the viewpoint of stability of emulsion particles generated during emulsion polymerization, for example, heavy It is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, still more preferably 100 parts by weight of the total amount of monomer components used to form the coalesced. 1 to 3 parts by mass.

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 mass or less with respect to 100 parts by mass of the total amount of monomer components used to form the polymer. It is preferable that it is 3 mass parts 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 mass. It is preferable that it is 0.1-2 mass parts with respect to this, More preferably, it is 0.2-1 mass part.

In order to promote emulsion polymerization, the polymerization initiator may 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.
It does not specifically limit as the usage-amount of the said reducing agent, For example, it is preferable that it is 0.05-1 mass part with respect to 100 mass parts of total amounts of the monomer component used in forming a 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, it is preferable to use alkyl mercaptans such as hexyl mercaptan, octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexadecyl mercaptan, and n-tetradecyl mercaptan. The amount of the polymerization chain transfer agent used is, for example, preferably 2.0 parts by mass or less, more preferably 1.0 part by mass or less, with respect to 100 parts by mass of all monomer components.

The emulsion polymerization may be performed in the presence of a chelating agent such as sodium ethylenediaminetetraacetate, a dispersant 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 is preferably 1 to 15 hours, and more preferably 5 to 10 hours, for example.
The addition method of the monomer component, the polymerization initiator, and the like is not particularly limited, and for example, a batch addition method, a continuous addition method, a multistage addition method, or the like can be applied. Moreover, you may combine these addition methods suitably.

In the method for producing a polymer contained in the emulsion composition for heat drying 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, since the water resistance of the coating film formed from the later-described thick film coating composition for heating and drying which requires the emulsion composition for heating and drying is improved, the volatile base that volatilizes when the coating film is heated. Is preferably used. 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 composition for heat drying of the present invention can constitute a thick film coating composition for heat drying together with other components as necessary. The thick film coating composition for heat drying comprising the emulsion composition for heat drying, the pigment, the foaming agent and the thickener as essential components of the present invention is also one aspect of the present invention. Such a thick film coating composition for heat drying, which essentially comprises the emulsion composition for heat drying of the present invention, has excellent heat drying properties, can exhibit various functions, and has particularly excellent vibration damping. It is possible to form a damping material capable of exhibiting the properties.

The heat-drying thick film coating composition preferably contains, for example, 40 to 90% by mass, more preferably 50%, based on a total amount of 100% by mass of the heat-drying thick film coating composition. It is -90 mass%, More preferably, it is 60-90 mass%.
The blending amount of the heat-drying emulsion composition in the heat-drying thick film paint composition is, for example, 100% by mass of the solid content of the heat-drying thick film paint composition, and the solid content of the heat-drying emulsion composition Is preferably set to 10 to 60% by mass, and more preferably 15 to 60% by mass.

The pH of the thick film coating composition for heat drying is preferably 7-11, more preferably 7-9. The pH can be measured by the same method as described above.
The viscosity of the thick film coating composition for heat drying is preferably 50 to 200 Pa · s. With such a viscosity, it is suitable as a thick film coating composition for coating-type heating and drying, which is easy to apply to a substrate and has no dripping. More preferably, it is 60-150 Pa.s.
The viscosity of the thick film coating composition for heat drying can be measured by the same method as the viscosity of the emulsion composition for heat drying described above.

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. As a compounding quantity of the said pigment, it is preferable to set it as 50-700 mass parts with respect to 100 mass parts of solid content of the emulsion composition for heat-drying, More preferably, it is 100-550 mass parts.

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 mass part with respect to 100 mass parts of solid content of the emulsion composition for heat-drying, More preferably, it is 1.0-3.0 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 mass parts by solid content with respect to 100 mass parts of solid content of the emulsion composition for heat-drying, More preferably, it is 0.05-1.5. It is a mass part, More preferably, it is 0.1-1 mass part.

In addition, as other components that can be blended in the thick film coating composition for heat drying of the present invention, for example, a solvent; an aqueous crosslinking agent; a filler; a dispersant; an antifoaming agent; a colorant; Plasticizers; stabilizers; wetting agents; antifoaming agents; anti-aging agents; antifungal agents; ultraviolet absorbers; antistatic agents and the like, and one or more of these can be used.
In addition, the said other component can be mixed with the said emulsion composition for heat drying 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 composition for heat drying in the thick film coating composition for heat drying 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. As a compounding quantity of an aqueous type crosslinking agent, it is preferable to set it as 0.01-20 mass parts by solid content with respect to 100 mass parts of solid content of the emulsion composition for heat drying, for example, More preferably, it is 0.15-15. Part by mass, more preferably 0.5 to 15 parts by mass.
The water-based crosslinking agent may be added to the emulsion composition for heat drying, or may be added at the same time when other components are blended as the thick film coating composition for heat drying. By mixing a crosslinking agent with the emulsion composition for heat drying or the composition, 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; glass Examples of such inorganic fillers include flakes and mica; and fibrous inorganic fillers such as metal oxide whiskers and glass fibers. As a compounding quantity of a filler, it is preferable to set it as 50-700 mass parts with respect to 100 mass parts of solid content of the emulsion composition for heat-drying, More preferably, it is 100-550 mass parts.

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 antifoaming agent include silicon-based antifoaming agents.
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 rust preventive pigment include a metal phosphate, a metal molybdate, and a metal borate.

As the other component, a polyvalent metal compound may be used. In this case, the polyvalent metal compound improves the stability, dispersibility, heat drying properties of the thick film coating composition for heat drying, and the vibration damping properties of the vibration damping material formed from the thick film coating composition for heat drying. Will be. 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. Among them, it is preferable to use in the form of an aqueous dispersion or an emulsified dispersion, and more preferably to use in the form of an emulsified dispersion because dispersibility in the thick film coating composition for heat drying is improved. is there.
Moreover, it is preferable that the usage-amount of a polyvalent metal compound shall be 0.05-5.0 mass parts with respect to 100 mass parts of solid content in the thick film coating composition for heat drying, More preferably, it is 0.00. It is 05-3.5 mass parts.

Moreover, the coating film obtained by apply | coating and drying the thick film coating composition for heat-drying is also one of this invention. The thickness of the coating film is preferably 1 to 5 mm.
The said thick film coating composition for heat-drying can form the coating film used as a damping material by apply | coating to a base material and drying, for example. As a method of applying the thick film coating composition for heat drying to the substrate, for example, it can be applied using a brush, a spatula, an air spray, an airless spray, a mortar gun, a lysine gun or the like.

The coating amount of the heat-drying thick film coating composition may be appropriately set depending on the application, desired performance, etc.For example, in order to exhibit sufficient functions such as vibration damping, The film thickness is preferably 1 mm or more, more preferably 2 mm or more. Moreover, it is preferable to make it the film thickness of the coating film after drying become 5 mm or less from the point of the drying property of a coating film, More preferably, it is 4 mm or less.
It is also preferable that the surface density of the coating film after drying is coated to a 1.0~7.0kg / ^{m 2,} more preferably from 2.0~6.0kg / ^{m 2.} In addition, by using the thick film paint composition for heating and drying of the present invention, it is possible to obtain a coating film that hardly causes expansion and cracks at the time of drying and after drying, and that hardly causes the paint on the inclined surface to slide off. It becomes.
Thus, the coating method of the thick film coating composition for heat drying which coats and dries so that the film thickness of the coating film after drying is 1 to 5 mm, and the surface density of the coating film after drying is The coating method of the thick film coating composition for heat drying which is applied and dried so as to be 2.0 to 6.0 kg / m ² is also one of the preferred embodiments of the present invention.

After applying the above thick film coating composition for heat drying, the condition for drying to form a coating film may be heat drying or room temperature drying. Since the composition is excellent in heat drying property, it is preferable to heat dry from the viewpoint of efficiency. The lower limit of the heat drying temperature is preferably 110 ° C. or higher, and more preferably 120 ° C. or higher. Moreover, as an upper limit of the temperature of heat drying, it is preferable to set it as 210 degrees C or less, More preferably, it is 170 degrees C or less.

Moreover, the manufacturing method of the thick film coating composition for heat-drying consisting of mixing the said polymer emulsion and starch previously, and mix | blending is also one preferable embodiment of this invention.
In the production method, the polymer emulsion and starch are mixed in advance to prepare a heat-drying emulsion composition in which starch particles are dispersed in the polymer emulsion, and this is used as a heat-drying thick film coating composition. Will be blended.
In addition, when components other than the components of the emulsion composition for heat drying are other components, the blending order of the heat drying emulsion composition and the other components is not particularly limited. That is, the heat-drying emulsion composition may be blended in other components, and other components may be mixed in the heat-drying emulsion composition.
When the polymer emulsion and starch are not mixed in advance in the production of the thick film coating composition for heat drying by mixing the polymer emulsion and starch in advance (when the thick film paint composition for heat drying is prepared, Can be obtained with a smaller amount of starch than in other components, etc., with better heat drying properties and thick film drying properties (baking properties).

When the heat-drying thick film coating composition is applied to a damping material, the vibration damping property can be evaluated by measuring the loss factor of the film formed from the heat-drying thick film coating composition. it can.
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 heat-drying thick film paint composition of the present invention, the loss factor of the film formed from the heat-drying thick film paint composition can be measured by a resonance method (3 dB method) using a cantilever method. Is preferred. 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 above loss factor is for heat drying with a cold rolled steel sheet (SPCC-SD: length 250 mm × width 10 mm × thickness 1.6 mm) with a coating film capacity of length 200 mm × width 10 mm × thickness 3.0 mm. It is preferable to measure by applying a thick film coating composition, drying at 95 ° C. for 30 minutes, and baking and drying at 130 ° C. for 60 minutes to form a film. 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. . Moreover, since the practical temperature range of the film formed from the thick film coating composition for heat drying is usually 20 to 60 ° C., the vibration damping performance is evaluated with the sum of the loss coefficients at each temperature of 20 to 60 ° C. The film formed from the heat-drying thick film paint composition may have a total loss coefficient of 0.300 or more, which is the total loss coefficient at 20 ° C., 40 ° C. and 60 ° C. A composition is also one aspect of the present invention. In the case of such a thick film coating composition for heat drying, sufficient damping is exhibited at 20 to 60 ° C. which is a practical temperature range of a film formed from the thick film coating composition for heat drying. It can be said.

Since the emulsion composition for heat drying of the present invention has the above-described configuration, it exhibits excellent heat drying properties and vibration damping properties, and can be suitably used for various applications such as vibration damping materials.

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 mass” and “%” means “% by mass”.

In the following Examples and Comparative Examples, various physical properties of the polymer emulsion were measured and 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”.
Tg values of the respective homopolymers used for calculating the glass transition temperature (Tg) of the polymerizable monomer component by the above 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 (“VISCOMETER TUB-10” manufactured by Toki Sangyo Co., Ltd.), the measurement was performed at 25 ° C. and 20 rpm.

<Average particle size>
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.
<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.

In the following examples and comparative examples, various physical properties of starch were measured and evaluated as follows.
<Maximizing viscosity at the time of gelatinization and gelatinization>
Using a Brabender Viscograph (rotation speed: 75 rpm), the temperature of the prepared starch aqueous solution (6%) was raised from 30 ° C to 93 ° C at 1.5 ° C / min. After reaching 93 ° C, the same temperature was maintained for 30 minutes Subsequently, the temperature was lowered to 30 ° C. to obtain a viscosity curve (horizontal axis: temperature, vertical axis: viscosity). From this viscosity curve, the maximum viscosity at the time of gelatinization and its temperature (that is, gelatinization viscosity) were recorded.
In Table 1 described later, a BU value measured using a Brabender Viscograph and a corresponding converted value to mPa · s (a value obtained by multiplying the BU value by 1.8) are also shown.
<Average particle size>
The average particle size was measured using a laser diffraction / scattering particle size distribution measuring device (Microtrack HRA, manufactured by Lees & Northrup).

Production Example 1
468.3 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, 610 parts of methyl methacrylate, 380 parts of 2-ethylhexyl acrylate, 10 parts of acrylic acid, 2 parts of t-dodecyl mercaptan, Lebenol WZ (trade name, manufactured by Kao Corp., polyoxyethylene) previously adjusted to a 20% aqueous solution were added to the dropping funnel. A monomer emulsion comprising 180.0 parts of alkyl ether sulfate ester salt) 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 monomer emulsion and 40 parts of a 5% potassium persulfate aqueous solution were added to initiate initial polymerization. After 20 minutes, the remaining monomer emulsion was uniformly added dropwise over 180 minutes while maintaining the inside of the reaction system at 80 ° C. The same temperature was maintained for 60 minutes after the completion of dropping. After cooling the resulting reaction solution to room temperature, 5 parts of 25% aqueous ammonia was added, 55% non-volatile content, pH 7.8, viscosity 350 mPa · s, average particle size 270 nm, weight average molecular weight 300,000, Tg 11.7. An emulsion at 0 ° C. was obtained.

Example 1
25 parts of potato starch was added to 100 parts of the emulsion solid content of Production Example 1 and stirred at room temperature for 180 minutes to obtain an emulsion composition A.

Example 2
13 parts of potato starch was added to 100 parts of the emulsion solid content of Production Example 1 and stirred at room temperature for 180 minutes to obtain an emulsion composition B.

Example 3
34 parts of corn starch was added to 100 parts of the emulsion solid content of Production Example 1 and stirred at room temperature for 180 minutes to obtain an emulsion composition C.

Example 4
Eighteen parts of rice starch was added to 100 parts of the emulsion solid content of Production Example 1 and stirred at room temperature for 180 minutes to obtain an emulsion composition D.

Example 5
39 parts of potato starch was added to 100 parts of the emulsion solid content of Production Example 1 and stirred for 180 minutes at room temperature to obtain an emulsion composition E.

Example 6
10 parts of potato starch was added to 100 parts of the emulsion solid content of Production Example 1 and stirred at room temperature for 180 minutes to obtain an emulsion composition F.

Example 7
28 parts of urea phosphate starch was added to 100 parts of the emulsion solid content of Production Example 1 and stirred at room temperature for 180 minutes to obtain an emulsion composition G.

Each emulsion composition obtained in Examples 1 to 7 was blended as follows to obtain a thick film coating composition for heat drying.
Each emulsion composition 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 blowing agent (F-30 ^{* 5} ) 6 parts * 1: Nitto Flour Chemical Co., Ltd. filler * 2: Nippon Shokubai Co., Ltd. polycarboxylic acid type dispersant (active ingredient 44%)
* 3: Nippon Shokubai Co., Ltd. alkali-soluble acrylic thickener (active ingredient 30%)
* 4: Defoaming agent (main component: hydrophobic silicone + mineral oil) manufactured by San Nopco Co., Ltd.
* 5: Matsumoto Yushi Co., Ltd. foaming agent

Comparative Example 1
The emulsion of Production Example 1 was blended as follows to obtain a thick film coating composition for heat drying.
Production Example 1 Emulsion 359 parts Calcium carbonate (NN # 200 ^{* 1} ) 620 parts Dispersant (Aquaric DL-40S ^{* 2} ) 6 parts Thickener (Acryset WR-650 ^{* 3} ) 4 parts Defoamer (Nopco 8034L ^{* 4} ) 1 part foaming agent (F-30 ^{* 5} ) 6 parts potato starch ^{* 6} 25 parts * 1: Nitto Flour Chemical Co., Ltd. filler * 2: Nippon Shokubai Co., Ltd. polycarboxylic acid type dispersant (active ingredient) 44%)
* 3: Nippon Shokubai Co., Ltd. alkali-soluble acrylic thickener (active ingredient 30%)
* 4: Defoaming agent (main component: hydrophobic silicone + mineral oil) manufactured by San Nopco Co., Ltd.
* 5: Foaming agent made by Matsumoto Yushi Co., Ltd. * 6: Made by Hokuren Agricultural Cooperative Federation

Comparative Example 2
A thick film coating composition for heat drying was obtained in the same manner as in Comparative Example 1 except that the amount of potato starch was changed from 25 parts to 13 parts.

Comparative Example 3
A thick film coating composition for heat drying was obtained in the same manner as in Comparative Example 1 except that potato starch was not added.

Using the emulsion compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 3 and the thick film coating composition for heat drying, the storage stability of the emulsion composition and the heat drying time are as follows. The coating film surface state (dried coating film surface state) was evaluated. The results are shown in Table 1.

<Storage stability of emulsion composition>
In a 250 cc PP (polypropylene) container, 200 g of each of the emulsion compositions (Examples 1 to 7) or the emulsion of Production Example 1 (Comparative Examples 1 to 3) is placed for 2 weeks in a thermostatic chamber at 5 ° C. and 50 ° C. The state after storage was evaluated visually. The case where there was no visual change was indicated as ◯, and the case where there was a change was indicated as a specific change.

<Dry coating surface condition>
On the glass plate, the produced thick film coating composition for heat drying was applied so that the coating thickness was 3 mm. Then, it heated for 30 minutes at 150 degreeC using the hot air dryer, and evaluated the surface condition of the obtained dry coating film on the following references | standards.
○: No abnormality △: Surface and interface have small cracks ▽: Surface and interface have slightly large cracks ×: Paint film shape cannot be maintained

As a result of the test of the surface state of the dried coating film, Examples 1 to 7 using the emulsion composition containing starch all showed heat drying properties (baking properties) that could withstand practical use. In particular, in the case of Examples 1 and 3 to 4, there is no abnormality in the coating film after heat drying (after baking), and shows excellent heat drying properties in a thick film having a coating thickness of 3 mm (film thickness after drying). It was found to be suitable as a thick film coating composition for drying. In addition, Examples 1 to 4 in which the starch blending amount is within the preferred range are superior to Examples 5 to 6 in which the starch blending amount is out of the range, as a result of total evaluation of storage stability and heat drying properties. I understood it. Moreover, it turned out that the storage stability in high temperature of Example 7 whose gelatinization temperature is outside a suitable range has fallen a little.
Further, Examples 1 to 7 in which starch was added to the polymer emulsion in advance when the addition of starch was not at the time of coating were heated in comparison with Comparative Examples 1 and 2 in which starch was added during preparation of the thick film coating composition. Superiority was recognized in terms of drying. This is related to the starch addition method, and it is presumed that the dispersibility of the starch in the polymer emulsion was improved. Moreover, the comparative example 3 which does not contain starch in an emulsion composition and a thick film coating composition became remarkably inferior in heat drying property.
In the above-described embodiments, as described above, by using an emulsion composition containing starch, starch particles are dispersed in advance with respect to the polymer emulsion, and by allowing starch to exist around the emulsion particles in advance, the emulsion The action of starch on the particles is efficiently exhibited, and the interaction between the emulsion particles and the starch becomes stronger, so the effect of improving the coating strength is increased. Heat drying and thick film drying with a small amount of starch It is presumed that the property is improved, and such a mechanism of action is considered to be expressed in the same manner in the emulsion composition for heat drying of the present invention.
Therefore, it can be said from the results of the above-described examples and the like that the present invention can be applied in the entire technical scope of the present invention and in various forms disclosed in this specification, and can exhibit advantageous effects.

Claims (5)

An emulsion composition for heating and drying comprising a polymer emulsion and starch,
The polymer forming the polymer emulsion has a weight average molecular weight of 20,000 to 800,000,
The emulsion composition for heat drying, wherein the emulsion composition is a dispersion of starch particles. The emulsion composition for heating and drying according to claim 1, wherein the emulsion composition for heating and drying contains 12 to 36 parts by mass of starch with respect to 100 parts by mass of the polymer forming the polymer emulsion. The starch composition according to claim 1 or 2, wherein the starch has a gelatinization temperature of 60 ° C or higher. The emulsion composition for heat drying according to any one of claims 1 to 3, wherein the starch has an average particle diameter of 50 µm or less. The emulsion composition for heat drying according to any one of claims 1 to 4, wherein the polymer forming the polymer emulsion has a glass transition temperature of -20 to 40 ° C.