JP2009024104A - (meth)acrylic coating and damping material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damping material having excellent damping performance and blocking resistance. <P>SOLUTION: This coating comprises (A) an amorphous polyester of 10-50 parts by mass the glass transition temperature of which is ≥40°C, and (B) a (meth)acrylic monomer of 90-50 parts by mass in which a monomer represented by general formula (1) (wherein R<SB>1</SB>is hydrogen or a methyl group, *R<SB>2</SB>is * (CH<SB>2</SB>CH<SB>2</SB>O)<SB>n</SB>, n is 1-4, and R<SB>3</SB>is a 1-4C alkyl group) occupies 5-80 mol% based on the total (meth)acrylic monomer. The damping material coated with the coating is also disclosed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a paint exhibiting excellent vibration damping properties and a vibration damping material coated with the paint.

  In recent years, vibrations and noises from buildings such as automobiles, railroads, airplanes and other transportation, office equipment, information equipment, electrical equipment, and other equipment, building floors, roofs, and walls have become a problem. Damping materials have been proposed as means for solving such problems. The damping material refers to a material that converts solid vibration energy into heat energy and reduces solid vibration.

  The damping material is a non-restraining type damping material formed by laminating a viscoelastic material (also referred to as a viscoelastic material) on a vibrating body, and a restraining type obtained by further laminating a restraining material on the viscoelastic material. Damping materials are known. The damping material in which the vibrating body is a steel plate is also referred to as a damping steel plate.

  Patent Document 1 discloses a block copolymer of a vinyl aromatic compound and a conjugated diene compound, which is modified by grafting an unsaturated carboxylic acid on both surfaces of a resin layer A having a glass transition temperature of −20 ° C. or higher. A constrained vibration-damping steel sheet is disclosed in which a vibration-damping film composed of three layers in which the olefin-based resin layer B is disposed is disposed between two steel sheets. However, such a constrained vibration-damping steel sheet is obtained by forming a vibration-damping film and then press-molding it with the steel sheet, so that the manufacturing process is complicated.

  On the other hand, since the unconstrained vibration damping material does not have a constraining layer, it can be manufactured more easily than the constrained vibration damping material. Moreover, since it does not have a constrained layer, it has attracted attention because it has the advantage of being easily processed into a desired shape. For example, Patent Document 2 discloses an unconstrained vibration damping material using a pressure-sensitive adhesive layer obtained by crosslinking an acrylic polymer having a specific glass transition point and molecular weight with a specific crosslinking agent. . Such an unconstrained damping material is obtained by applying a viscoelastic material capable of exhibiting damping properties to a vibrating body and solidifying the coating film to form a coating film (also referred to as coating). . That is, since it can be manufactured in the same manner as a so-called precoated steel sheet, it is excellent in productivity.

However, since the unconstrained vibration damping material has excellent vibration damping performance, it is necessary to increase the thickness of the viscoelastic material to some extent (100 μm or more). For this reason, it is necessary to apply the coating material exhibiting vibration damping properties a plurality of times, and this causes a problem of a decrease in productivity. Further, when a thick coating film is formed by one-time coating without recoating, a so-called “boiled” defect occurs in which the solvent contained in the coating cannot evaporate and the coating film foams.
Further, when the vibration-free body coated with the viscoelastic material is wound and stored, the unconstrained vibration damping material adheres (blocks) the viscoelastic materials or the viscoelastic material and the vibration body. There was a problem.
JP 2000-238193 A JP-A-6-210800

  As a method of “increasing the thickness of the viscoelastic material” in the unconstrained vibration damping material, a method of painting a vinyl chloride sol paint on a vibrating body is conceivable. The vinyl chloride sol paint is a paint obtained by kneading vinyl chloride resin particles having a small particle diameter with a plasticizer, a stabilizer, a pigment and the like. Since the vinyl chloride sol paint does not contain a solvent, the above-mentioned problem does not occur. Therefore, a coating film having a thickness of 100 μm or more can be formed on the vibrating body by a single coating. However, with the passage of time, the plasticizer bleeds out from the coating film, so there is a problem that the vibration damping characteristics are unstable. Furthermore, the vinyl chloride sol coating film has a glass transition temperature of −34 ° C., low heat resistance, and low blocking resistance.

It is known that damping materials are generally excellent in damping properties when the glass transition temperature of the viscoelastic material is in the vicinity of room temperature. However, when the glass transition temperature of the viscoelastic material is close to room temperature, the blocking problem becomes significant as described above.
Accordingly, an object of the present invention is to provide a vibration damping material, particularly an unconstrained vibration damping material, which has excellent vibration damping properties and is difficult to block (excellent blocking resistance).

  As a result of intensive studies, the inventors have found that the above problems can be solved by using an acrylic paint containing a specific amorphous polyester and a specific (meth) acrylic monomer, and have completed the present invention.

式（１）においてＲ_１は水素原子またはメチル基を表す。
^＊Ｒ_２は、^＊（ＣＨ_２ＣＨ_２Ｏ）_ｎであり、ｎは１〜４である。Ｒ_３は炭素数が１〜４のアルキル基である。
［２］前記一般式（１）で表される化合物の含有量が、前記（Ａ）の非晶性ポリエステル１００質量部に対して、１０〜３００質量部である［１］に記載の（メタ）アクリル塗料。
［３］（Ｂ）（メタ）アクリル系モノマーが下記一般式（２）、（３）または（４）の化合物を含む［１］または［２］に記載の（メタ）アクリル塗料。

式（２）において、Ｒ_１は水素原子またはメチル基を表す。
Ｒ_４は炭素数が１〜１５の炭化水素基を表す。

式（３）において、Ｒ_１は水素原子またはメチル基を示す。
Ｒ_５は炭素数が１〜１２のアルキレン基を示す。

式（４）において、Ｒ_１は水素原子またはメチル基を示す。
Ｒ_６は炭素数が１〜１０のアルキレン基を示す。
［４］前記（Ａ）と（Ｂ）の合計１００質量部に対し０．１〜２０質量部のポリイソシアネートをさらに含む［１］〜［３］いずれかに記載の（メタ）アクリル塗料。 That is, the said subject is solved by the following acrylic paints of this invention.
[1] A (meth) acrylic paint comprising (A) 10 to 50 parts by mass of an amorphous polyester having a glass transition temperature of 40 ° C. or higher, and (B) 90 to 50 parts by mass of a (meth) acrylic monomer. ,
The (meth) acrylic monomer of (B) contains a compound represented by the following general formula (1), and the compound is 5 to 80 mol% in the total (meth) acrylic monomer. .

In the formula (1), R ₁ represents a hydrogen atom or a methyl group.
^* R ₂ ^is _{* (CH 2 CH 2 O)} n, n is 1-4. R ₃ is an alkyl group having 1 to 4 carbon atoms.
[2] The content of the compound represented by the general formula (1) is 10 to 300 parts by mass with respect to 100 parts by mass of the amorphous polyester (A). ) Acrylic paint.
[3] The (meth) acrylic paint according to [1] or [2], wherein the (B) (meth) acrylic monomer includes a compound of the following general formula (2), (3) or (4).

In the formula (2), R ₁ represents a hydrogen atom or a methyl group.
R ₄ represents a hydrocarbon group having 1 to 15 carbon atoms.

In the formula (3), R ₁ represents a hydrogen atom or a methyl group.
R ₅ represents an alkylene group having 1 to 12 carbon atoms.

In the formula (4), R ₁ represents a hydrogen atom or a methyl group.
R ₆ represents an alkylene group having 1 to 10 carbon atoms.
[4] The (meth) acrylic paint according to any one of [1] to [3], further comprising 0.1 to 20 parts by mass of polyisocyanate with respect to 100 parts by mass in total of (A) and (B).

Moreover, the said subject is solved by the damping material which has the coating film formed by polymerizing the acrylic paint of the following this invention, and the manufacturing method of the said damping material.
[5] A control having a coating film formed by polymerizing the (B) (meth) acrylic monomer contained in the (meth) acrylic paint according to any one of [1] to [4] on the surface of the vibrator. Vibration material.
[6] The coating film has a layer a mainly composed of the (A) polyester resin and a layer b mainly composed of the polymer of the (B) (meth) acrylic monomer. The vibration damping material according to [5], wherein the interface of b exists in a thickness of 1 to 50% from the surface layer of the coating film, and the layer b is in contact with the vibrating body.
[7] A step of applying the (meth) acrylic paint according to any one of [1] to [4] to a vibrating body, and a step of polymerizing (B) (meth) acrylic monomer contained in the coating film. A method for manufacturing a damping material.

  According to the present invention, it is possible to provide an unconstrained vibration damping material having excellent vibration damping properties and excellent blocking resistance.

1. (Meth) acrylic paint of the present invention The (meth) acrylic paint of the present invention is
(A) 10 to 50 parts by mass of a specific amorphous polyester,
(B) It is characterized by including 90-50 mass parts of (meth) acrylic-type monomers containing a specific compound.
In the present invention, “(meth) acryl” means “acryl or methacryl”. That is, the “(meth) acrylic paint” is a paint containing an acrylate monomer and a methacrylate monomer. In the present invention, “(meth) acryl” may be simply referred to as “acryl”.

(A) Amorphous polyester Polyester is a general term for polymers having an ester bond in the main chain. The polyester used in the present invention is an amorphous polyester in which polymer chains do not form crystals. The amorphous polyester becomes a matrix (vehicle) of the paint of the present invention together with a polymer of an acrylic monomer described later. Accordingly, the amorphous polyester is preferably dissolved in the acrylic monomer. In general, an amorphous polymer is more compatible with other compounds than crystalline. Therefore, in this invention, amorphous polyester is employ | adopted as polyester.

  Polyester can be obtained by polycondensation reaction of polybasic acid and polyhydric alcohol. By selecting a polybasic acid and a polyhydric alcohol as raw materials, the polyester can be made amorphous. Polyesters made from compounds with low symmetry are likely to be amorphous.

The molecular weight of the amorphous polyester is not particularly limited, but the number average molecular weight is preferably 1000 to 40000. In the present invention, “to” includes numerical values at both ends thereof. The number average molecular weight is measured from a standard polystyrene calibration curve by gel permeation chromatography (GPC). If the molecular weight is too high, the solubility in acrylic monomers is reduced, and if the molecular weight is too low, the coating film performance is reduced. When the number average molecular weight of the amorphous polyester is within the above range, the balance between the two is excellent.
The molecular weight of the amorphous polyester can be adjusted by adjusting the feed ratio of polybasic acid and polyhydric alcohol as raw materials, reaction time, and the like.

The glass transition temperature (Tg) of the amorphous polyester of the present invention is 40 ° C. or higher. The acrylic paint of the present invention is applied to a vibrating body, and the acrylic monomer in the coating film is polymerized to form a coating film. The coating film becomes a viscoelastic material that converts vibration energy into heat energy. As described later, the coating film thus obtained has a layer (also referred to as “polyester-rich layer”) containing an amorphous polyester resin as a main component in the coating surface layer portion (air interface side). Therefore, it is preferable that the polyester rich layer has a Tg of 40 ° C. or higher because the damping material having the coating film is difficult to block.
However, if the Tg of the amorphous polyester is too high, the compatibility with the (meth) acrylic monomer is lowered. For this reason, it is preferable that Tg of amorphous polyester is 40-85 degreeC. Tg is measured by a differential scanning calorimeter (DSC).
Tg can be adjusted by selecting a polybasic acid and a polyhydric alcohol as raw materials. In general, when an aromatic compound is used, Tg is improved.

The amorphous polyester preferably has a specific gravity at 30 ° C. of 1.3 or less. When the specific gravity of the amorphous polyester is lowered, the polymer chain packing is loosened, so that the acrylic monomer easily enters between the polymer chains of the amorphous polyester and the compatibility with the acrylic monomer is improved. is there.
Specific gravity can be adjusted by selecting a polybasic acid and a polyhydric alcohol as raw materials. When a polyhydric alcohol having a side chain is used as a raw material, the steric hindrance increases, so the specific gravity of the amorphous polyester decreases.

The hydroxyl value of the amorphous polyester is preferably 2 to 200 mgKOH / g, and more preferably 4 to 80 mgKOH / g. The acid value of the amorphous polyester is preferably 2 to 40 mgKOH / g, and more preferably 5 to 50 mgKOH / g.
When the hydroxyl value is greater than 200 mgKOH / g or the acid value is greater than 80 mgKOH / g, the water resistance of the coating film is poor. On the other hand, when the hydroxyl value is less than 2 mgKOH / g, when a crosslinking agent is used in forming the coating film as described later, the number of reaction sites with the crosslinking agent is reduced, so that the coating film strength is lowered. Further, when the acid value is less than 2 mgKOH / g, the adhesion between the coating film and the vibrating body is lowered, and thus the coating film may be peeled off from the vibrating body when processing such as bending is performed on the vibration damping material.

  Examples of the polybasic acid used in the amorphous polyester of the present invention include divalent carboxylic acids and trivalent or higher polyvalent carboxylic acids. Examples of divalent carboxylic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, sodium sulfoisophthalate; succinic acid, adipic acid, azelaic acid, 1,10- Aliphatic carboxylic acids such as decanedicarboxylic acid and dimer acid are included. Examples of the polyvalent carboxylic acid include aromatic carboxylic acids such as trimellitic acid and pyromellitic acid; and hydroxycarboxylic acids such as ε-caprolactone and lactide.

Examples of the polyhydric alcohol used in the amorphous polyester of the present invention include dihydric alcohols and polyhydric alcohols having 3 or more hydroxyl groups in one molecule.
Examples of dihydric alcohols include ethylene glycol, diethylene glycol, tritylene glycol, trimethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2- Butanediol, 3-methyl-1,2-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyltriethylene glycol 3-methyl-1,5-pentanediol, 3-methyl-4,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexane Diol, 1,4-hexanediol, 2,5-hexanediol, neopentyl glycol, etc. Glycols; polylactone diols obtained by adding lactones such as ε-caprolactone to these glycols; polyester diols such as bis (hydroxyethyl) terephthalate; 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, spiroglycol, Alicyclic dihydric alcohols such as dihydroxymethyl tricyclodecane are included.

  Examples of the polyhydric alcohol include glycerin, trimethylolpropane, trimethylolethane, diglycerin, triglycerin, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, sorbitol, mannitol.

Amorphous polyester may be used alone or in combination of two or more. When using 2 or more types of polyester, it is preferable that the polyhydric alcohol component of polyester is common.
Preferable examples of the amorphous polyester used in the present invention include Toyobo Co., Ltd., Byron GK810 and Byron GK640.

(B) (Meth) acrylic monomer A (meth) acrylic monomer is a polymerizable compound having an acroyl group or a methacryloyl group in the molecule. As described above, the (meth) acrylic monomer is also called “acrylic monomer”. The acrylic monomer of this invention contains the compound represented by following General formula (1), and the said compound is 5-80 mol% in all the acrylic monomers.

In the formula (1), R ₁ represents a hydrogen atom or a methyl group.
^* R ₂ ^is _{* (CH 2 CH 2 O)} n, n is 1-4. * Indicates the direction of _{R 2.} That is, the carbon atom of R ₂ is bonded to the oxygen atom of acrylic acid.
The compound of formula (1) is also called (poly) ethylene glycol (meth) acrylate. Moreover, the compound of Formula (1) may be called "ether acrylate." In the present invention, n is preferably 2.
R ₃ is an alkyl group having 1 to 4 carbon atoms, and may be a branched alkyl group. In the present invention, an ethyl group is preferable.

  Examples of the ether acrylate represented by the formula (1) include methoxyethylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxytetraethylene glycol (meth) acrylate, ethoxy Ethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, ethoxytriethylene glycol (meth) acrylate, and ethoxytetraethylene glycol (meth) acrylate are included.

  The acrylic paint of the present invention can form a coating film by polymerizing an acrylic monomer. When the ether acrylate is present in a specific amount, the amorphous polyester (A) contained in the paint is concentrated on the coating surface layer (air interface side). This phenomenon is inferred as follows. In the paint containing the amorphous polyester and the acrylic monomer, when the polymerization of the acrylic monomer proceeds, the compatibility with the amorphous polyester is lowered, and the amorphous polyester is pushed out to the surface layer side. On the other hand, since ether-based acrylate and polyester have very high compatibility, if the content of ether-based acrylate is too large, phase separation from the polyester is difficult to occur. However, the mechanism is not limited to the above.

On the other hand, when the addition amount of the ether acrylate is too small, it is difficult to dissolve the amorphous polyester in the acrylic monomer, and it is difficult to obtain a uniform paint. Even if the addition amount of ether acrylate is reduced, a uniform coating can be obtained if the addition amount of amorphous polyester is reduced. However, if the amount of amorphous polyester is reduced, workability as a damping material is reduced. Is damaged.
As mentioned above, it is preferable that the said ether-type acrylate is 5-80 mol% in all the acryl-type monomers. Furthermore, it is preferable that the said ether-type acrylate is 10-300 mass parts with respect to 100 mass parts of amorphous polyester.

The acrylic monomer of the present invention preferably contains a compound of the following general formula (2).

In the formula (2), R ₁ represents a hydrogen atom or a methyl group.
R ₄ is a hydrocarbon group having 1 to 15 carbon atoms. R ₄ may be an alkyl group, a branched alkyl group, or an aryl group. Among them, R ₄ is preferably a 10-15 alkyl group. The compound of formula (2) may be referred to as “monoacrylate”.

  Examples of monoacrylates represented by formula (2) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate (Meth) acrylic acid alkyl esters such as 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; cyclohexyl ( (Meth) acrylic acid esters of alicyclic alcohols such as (meth) acrylate; aryl aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate are included.

The acrylic monomer of the present invention preferably contains a compound of the following general formula (3).

In Formula (3), R ₁ is a hydrogen atom or a methyl group.
R ₅ is an alkylene group having 1 to 12 carbon atoms, and may be a branched alkylene group. Especially, it is preferable that it is a C5-C7 alkylene group. The compound of the formula (3) is a bifunctional acrylate, and a crosslinked structure can be introduced into a polymer of an acrylic monomer (also referred to as an acrylic polymer). When the acrylic polymer has a crosslinked structure, the strength and heat resistance of the coating film are improved. The compound of formula (3) may be referred to as “diacrylate”.

  Examples of diacrylates represented by formula (3) include ethylene glycol di (meth) acrylate, 1,5-pentanediol di (meth) acrylate, and 3-methyl-1,5-pentanediol di (meth) acrylate. 1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,8-octanediol di (meth) acrylate, and the like.

The acrylic monomer of the present invention preferably contains a compound of the following general formula (4).

In the formula (4), R ₁ is a hydrogen atom or a methyl group.
R ₆ is an alkylene group having 1 to 10 carbon atoms, and may be a branched alkylene group. R ₆ is preferably a 2-6 alkylene group, more preferably a butylene group. Since the compound of the formula (4) has a hydroxyl group, it may be called “hydroxy acrylate”. Since the hydroxyl group reacts with various compounds, various performances can be imparted to the acrylic polymer.

  Examples of the hydroxy acrylate represented by the formula (4) include 2-hydroxymethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. 1,4-cyclohexanedimethanol mono (meth) acrylate.

  The composition ratio of the above-mentioned monomer is not limited as long as the ether-based acrylate of the formula (1) is 5 to 80 mol% of the whole monomer. However, in order to adjust the polymerizability at the time of coating and the Tg of the resulting coating film to a desired value, ether acrylate 5 to 80 mol%, monoacrylate 0 to 40 mol%, diacrylate 15 to 55 mol%, hydroxyacrylate In the range of 3 to 20 mol%, the total is preferably selected to be 100 mol%.

  In the coating material of the present invention, the composition ratio of the amorphous polyester as the component (A) and the acrylic monomer as the component (B) is 10 to 50 parts by mass: 90 to 50 parts by mass. Among them, it is preferable that (A) :( B) = “20-50 parts by mass”: “80-50 parts by mass” because the performance of the coating film is excellent.

(C) Other additives The paint of the present invention may contain a thermal radical polymerization initiator (also referred to as a thermal polymerization initiator). Examples of the thermal radical polymerization initiator include a peroxide-based initiator and an azo-based initiator. Of these, peroxide thermal polymerization initiators are preferred. A thermal polymerization initiator may be used independently and may use 2 or more types together. Further, a decomposition accelerator such as cobalt naphthenate or dimethylaniline may be used in combination.
The addition amount of the thermal polymerization initiator is preferably 0.1 to 5 parts by mass, and 0.3 to 3 parts by mass with respect to 100 parts by mass of the total amount of (A) amorphous polyester and (B) acrylic monomer. More preferably, it is a part. When the blending amount of the thermal polymerization initiator is small, the polymerization takes time, and the volatile content of the monomer increases at the time of coating, so that the coating property is lowered. On the other hand, if the blending amount of the thermal polymerization initiator is excessive, a large amount of bubbles are generated during the reaction, and coating film defects such as peeling and rough skin are likely to occur. From the above, the addition amount of the thermal polymerization initiator is preferably within the above range.

  Examples of peroxide thermal polymerization initiators include isobutyl peroxide, cumyl peroxyneodecanate, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t-butyl peroxyneodecanate, 3, 5,5-trimethylhexanol peroxide, lauryl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanate, t-hexylperoxy-2-ethylhexanate, benzoyl peroxide, t-Butylperoxymaleic acid, t-butylperoxybenzoate are included. Among these, a thermal polymerization initiator having a 1-minute half-life temperature of 100 to 170 ° C. is preferable. The 1 minute half-life temperature is the temperature at which the thermal polymerization initiator concentration becomes half the original when a thermal polymerization initiator is subjected to a thermal decomposition reaction at a constant temperature under an inert gas for 1 minute.

The coating material of the present invention may contain a crosslinking agent for crosslinking the acrylic monomer. Examples of the crosslinking agent include a polyisocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, a metal chelate crosslinking agent, a melamine resin crosslinking agent, and a silane coupling agent. These may be used alone or in combination of two or more.
The addition amount of the crosslinking agent is preferably 0.1 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass in total of (A) and (B). By adding a crosslinking agent, the strength and heat resistance of the coating film are improved.

In the polyisocyanate crosslinking agent, the isocyanate group reacts with a hydroxyl group contained in the acrylic monomer to form a crosslinked structure.
Examples of polyisocyanate crosslinking agents include tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. Isocyanate; Isocyanate compound obtained by addition reaction of these isocyanates with trimethylolpropane, etc .; Isocyanurate product; Bullet type compound; Urethane obtained by addition reaction of isocyanate and polyether polyol polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. Prepolymeric isocyanates are included.

  Among these, a block type isocyanate crosslinking agent that does not react with a hydroxyl group at room temperature is preferable. This is because the storage stability of the paint is excellent. The block type isocyanate includes an oxime type and an active methylene type. Among them, the active methylene type is preferable.

  Examples of the epoxy-based crosslinking agent include ethylene glycol glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N , N ′, N′-tetraglycidyl-m-xylylenediamine, N, N, N ′, N′-tetraglycidylaminophenylmethane, triglycidyl isocyanurate, m-N, N-diglycidylaminophenylglycidyl ether, N, N-diglycidyl toluidine and N, N-diglycidyl aniline are included.

  Examples of aziridine-based crosslinking agents include trimethylolpropane tri-β-aziridinylpropionate, trimethylolpropane tri-β- (2-methylaziridine) propionate, tetramethylolmethanetri-β-aziridinylpropionate. Nate is included.

  Examples of the metal chelate-based cross-linking agent include aluminum isopropylate diisopropoxybisacetylacetone titanate and aluminum triethylacetoacetate.

  Examples of the melamine resin-based crosslinking agent include methylated melamine resin, butylated melamine resin, benzoguanamine resin and the like.

  Examples of the silane coupling agent-based crosslinking agent include glycidoxypropyltrimethoxysilane, aminopropyltrimethoxysilane, and chloropropyltrimethoxysilane.

  The paint of the present invention may contain a plasticizer. A plasticizer is an additive used to improve the flexibility of a coating film. The plasticizer used in the present invention is preferably an ester compound having three or more ester bonds in one molecule. Examples of such plasticizers include trimellitic acid derivatives, fatty acid derivatives such as pentaerythritol fatty acid esters, phosphoric acid derivatives, and polyester plasticizers. A plasticizer may be used independently and may be used in combination of 2 or more type. It is preferable that the compounding quantity of a plasticizer is 20 mass parts or less with respect to 100 mass parts of total amounts of (A) and (B). This is because the effect of the plasticizer can be expressed without causing stickiness or the like on the coating film.

The paint of the present invention may contain a pigment. Examples of pigments include extender pigments, inorganic / organic color pigments, and rust preventive pigments. Examples of extender pigments include calcium carbonate, clay, talc, and barium sulfate. Examples of inorganic color pigments include titanium oxide, zinc sulfide, lead white, yellow iron oxide, chromium oxide, zinc white, carbon black, molybdenum red, permanent red, bengara, ocher, chrome green, bitumen, ultramarine, aluminum powder, Copper alloy powder is included. Examples of the organic coloring pigment include Hansa Yellow, phthalocyanine green, phthalocyanine blue, flavanthrone yellow, indanthrene blue and the like. The pigment is selected to exhibit the desired performance. A pigment may be used independently and may be used in combination of 2 or more type.
It is preferable that the compounding quantity of a pigment shall be 0.1-100 mass parts with respect to 100 mass parts of total amounts of (A) and (B).

  In addition to the above, the coating material of the present invention may contain a filler, an antioxidant, a flame retardant, an ultraviolet absorber and the like.

(D) Manufacturing method of the coating material of this invention The coating material of this invention can be manufactured by a well-known method. For example, it can be obtained by (B) a step of dissolving (A) an amorphous polyester in an acrylic monomer to obtain a resin composition, and (C) a step of mixing various additives as necessary with the resin composition. The means for mixing is not particularly limited, but it is preferable to use a triple roll or the like.
The coating material thus produced preferably has a viscosity of 0.1 to 40 Pa · s, and more preferably 0.5 to 10 Pa · s.

2. Damping material using the coating material of the present invention The damping material coated with the coating material is obtained by applying the coating material of the present invention to the vibrating body and polymerizing the monomer contained in the coating material. The vibrator is a material to which a paint is applied and is also called a vibrator. Examples of the vibrator include a metal material, a ceramic material, and a polymer material. Among these, a metal material is preferable, and a steel plate is more preferable. The shape of the vibrator is not particularly limited, but is preferably “plate” or “foil”. Although the coating film of the present invention is formed on the surface of the vibrating body, when the undercoating or the like is applied to the vibrating body, the coating film of the present invention may be provided on the surface coated with the undercoating.
In the present invention, a film before polymerization obtained by applying a paint to a vibrating body is referred to as “coating film”, and a film obtained by polymerizing monomers in the film is referred to as “coating film”.

  The coating film in the vibration damping material of the present invention comprises a layer a (also referred to as a polyester rich layer a) mainly composed of an amorphous polyester resin and a layer b (mainly composed of an acrylic monomer polymer (acrylic polymer)). Two layers (also referred to as acrylic rich layer b), and these layers are adjacent to each other. The interface between the layer a and the layer b exists in a thickness of 1 to 50% from the coating surface layer, and the layer b is in contact with the vibrating body. The interface between the layer a and the layer b is preferably present at a thickness of 5 to 30% from the coating surface layer. “The layer b is in contact with the vibrating body” includes that the layer b is in contact with the undercoating or the like when the vibrating body is undercoated. These layers can be easily recognized by observing the cross section of the coating film with a microscope or the like.

  The polyester rich layer a is a layer mainly composed of (A) amorphous polyester, and preferably refers to a layer having an amorphous polyester content of 80% by mass or more. (A) When the content of the amorphous polyester is 80% by mass or less, the content of the acrylic polymer having a low Tg that serves as a viscoelastic layer contained in the polyester rich layer a is increased, and the blocking resistance is poor. Sometimes. The content of (A) amorphous polyester in the polyester rich layer a is determined by a pyrolysis gas chromatograph mass spectrometer (GC-MS). Specifically, it is obtained as follows. First, a standard curve is prepared by analyzing a mixture of amorphous polyester and acrylic polymer at various blending ratios by GC-MS. Next, the polyester rich layer a collected from the coating film is analyzed by GC-MS, and the obtained main peak is analyzed based on the calibration curve to obtain the amorphous polyester / acrylic polymer ratio.

  The acrylic rich layer b is a layer containing (B) a polymer of an acrylic monomer as a main component, and preferably a layer having an acrylic polymer content of 80% by mass or more. When the content of the acrylic polymer is 80% by mass or less, amorphous polyester having a high Tg may be present in the acrylic rich layer b, which may be inferior in vibration damping properties. The content of the acrylic polymer is determined by the analysis method described above.

The glass transition temperature (Tg) of the acrylic polymer in the present invention is preferably -40 to 30 ° C. This is because if the Tg of the acrylic polymer is within this range, the damping property of the damping material is excellent as described later.
The Tg of the polymer is obtained by calculation using the following Fox formula. The Fox equation is a method for calculating the Tg of a copolymer composed of x parts by mass of monomer M and y parts by mass of monomer N. When Tg of the homopolymer of M is X (K) and Tg of the homopolymer of N is Y (K), the Tg of the copolymer is represented by the following formula.

  FIG. 1 is a cross-sectional view showing an example of the vibration damping material of the present invention. In FIG. 1, 1 is a polyester-rich layer a, 2 is an acrylic-rich layer b, 3 is a vibrating body, 4 is an interface between the layers a and b, and 5 is an undercoat layer. As described above, the interface of 4 is preferably present at 1 to 50% from the surface layer of the coating film, and more preferably at a thickness of 5 to 30%.

  Although the acrylic rich layer b of the coating film of the present invention contains a small amount of amorphous polyester, the Tg is substantially the same as the Tg of the acrylic polymer and is -40 to 30 ° C. Therefore, it is easy to convert the energy of the given vibration into heat energy, and excellent vibration damping can be expressed.

  The vibration damping property is preferably based on JIS G0602: 1993, and a vibration damping characteristic test is performed by a cantilever method using a sample (damping material) obtained by coating a steel sheet with the paint of the present invention. The loss factor η is obtained from the attenuation curve obtained in the test. The loss coefficient η of the vibration damping material of the present invention is preferably 0.015 or more and more preferably 0.020 or more with respect to vibration of 100 to 400 Hz.

  Although the polyester rich layer a which is the outermost layer of the vibration damping material of the present invention used in the present invention contains a small amount of acrylic polymer, Tg substantially coincides with Tg of amorphous polyester and is 40 ° C. or higher. For this reason, the vibration damping material of the present invention has no stickiness of the coating film and is excellent in blocking resistance.

  The polyester-rich layer a in the vibration damping material of the present invention contains a small amount of an acrylic polymer, and the acrylic-rich layer b also contains amorphous polyester, so that the adhesion between the layer a and the layer b is good. However, it is preferable that the paint of the present invention contains the polyisocyanate because the adhesiveness between the two is further increased. Since polyisocyanate can react with the hydroxyl group of (A) the amorphous polyester and the hydroxyl group contained in (B) the acrylic monomer, it is presumed that the adhesion between layer a and layer b can be enhanced.

The total thickness of the coating film of the present invention is preferably 40 to 400 μm, and more preferably 100 to 300 μm. When the thickness of the coating film is within this range, the damping material of the damping material having the coating film is excellent, and a good coating film can be obtained without undergoing polymerization shrinkage at the time of coating.
The coating film of this invention may provide a protective film etc. further on the said coating film.

3. Production method of vibration damping material of the present invention The vibration damping material of the present invention can be produced arbitrarily as long as the effects of the invention are not impaired, and the preferred production method will be described below.
The vibration damping material of the present invention is preferably obtained by applying the paint of the present invention. Specifically, it is manufactured through a process of applying an acrylic paint to a vibrating body to form a coating film (application process), a process of heating and polymerizing the coating film to obtain a coating film (baking process). Is preferred.
Examples of the method for applying the paint to the vibrating body include roll coating, curtain coating, die coating, and knife coating. The coating amount of the paint is adjusted so as to obtain a desired film thickness, and is preferably 40 μm or more. This is because the resulting damping material is excellent in damping characteristics. However, when the coating film is polymerized in the air, the film thickness is preferably 100 μm or more. This is because when the film thickness is less than 100 μm, radicals are easily deactivated by oxygen in the air.

  Next, the vibrating body coated with the paint is heated to polymerize the monomer in the coating film. When 2% by mass or more, preferably 5 to 10% by mass, of the unpolymerized (meth) acrylic monomer is volatilized in this baking step, a coating film having excellent surface coating strength and scratch resistance is obtained. The baking temperature is preferably 120 to 250 ° C. The baking time is preferably 30 to 600 seconds.

  The vibration damping material of the present invention is preferably a so-called “one coat and one bake” in which the coating process is performed once, and the baking process is performed once. It is because it is excellent in productivity. As described above, in the coating material of the present invention, the amorphous polyester component moves to the coating surface layer portion in the baking step to form the polyester rich layer a. Since the Tg is 40 ° C. or higher, the layer improves the blocking resistance of the vibration damping material. Therefore, when the acrylic paint of the present invention is used, a vibration damping material having excellent vibration damping properties and blocking resistance can be obtained with one coat.

  In the vibration damping material of the present invention, the vibrator may be undercoated before the acrylic paint is applied. The undercoating can be performed, for example, by applying and baking to a vibrating body that has been chemically treated with an acrylic-modified epoxy resin paint. The undercoat coating film thus obtained is preferred because of its good adhesion to the paint of the present invention. The undercoat paint may contain a rust preventive pigment. It is preferable that a rust preventive pigment shall be 10-30 mass parts with respect to 100 mass parts of resin of undercoat.

The following were used for the amorphous polyester.
Byron GK810 (manufactured by Toyobo Co., Ltd.): Tg measured by DSC was 46 ° C., hydroxyl value was 19 mgKOH / g, specific gravity at 30 ° C. was 1.17, and number average molecular weight measured by GPC was 6000.
Byron GK640 (manufactured by Toyobo Co., Ltd.): Tg measured by DSC was 79 ° C., hydroxyl value was 5 mg KOH / g, specific gravity at 30 ° C. was 1.28, and number average molecular weight measured by GPC was 18000.

The following were used as acrylic monomers.
Ethoxydiethylene glycol acrylate (ECA): Compound of formula (1) Lauryl acrylate (LA): Compound of formula (2) 3-Methyl-1,5-pentanediol diacrylate (MPDA): Compound of formula (3) 4-hydroxybutyl Acrylate (4HBA): Compound of formula (4)

[Preparation of paints 1-4]
Paint 1
Byron GK810 (50 parts by mass), 4HBA (10 parts by mass), MPDA (20 parts by mass) and ECA (50 parts by mass) were mixed to obtain a resin composition in which an amorphous polyester was dissolved in an acrylic monomer. 14.9 parts by mass of an isocyanate crosslinking agent (Asahi Kasei Chemicals Co., Ltd., K6000) with respect to 100 parts by mass of the resin composition, an organic peroxide (Nippon Yushi Co., Ltd., Perocta O) 2 as a thermal radical polymerization initiator .5 parts by mass was mixed and kneaded using three rolls to prepare paint 1.

Paint 2
Byron GK810 50 parts by weight, LA 30 parts by weight, 4HBA 2 parts by weight, MPDA 40 parts by weight, ECA 8 parts by weight are mixed to obtain a resin composition in which an amorphous polyester is dissolved in an acrylic monomer. It was. 10.8 parts by mass of an isocyanate crosslinking agent (Asahi Kasei Chemicals Co., Ltd., K6000) with respect to 100 parts by mass of the resin composition, an organic peroxide (Nippon Yushi Co., Ltd., Perocta O) 2 as a thermal radical polymerization initiator .5 parts by mass was mixed and kneaded using a three roll to prepare paint 2.

Paint 3
Paint 3 was prepared in the same manner as Paint 1 except that 20 parts by weight of Byron GK640 and 9.1 parts by weight of an isocyanate crosslinking agent (K6000, manufactured by Asahi Kasei Chemicals Co., Ltd.) were added as an amorphous polyester instead of Byron GK810. .

Paint 4
Paint 4 was prepared in the same manner as Paint 2 except that 20 parts by weight of Byron GK640 and 2.6 parts by weight of an isocyanate crosslinking agent (K6000, manufactured by Asahi Kasei Chemicals Corporation) were added as an amorphous polyester instead of Byron GK810. .

[Preparation of comparative paint]
Paint 5
Byron GK810 50 parts by mass, LA 30 parts by mass, 4HBA 7 parts by mass, MPDA 40 parts by mass and ECA 3 parts by mass are mixed to obtain a resin composition in which an amorphous polyester is dissolved in an acrylic monomer. It was. 13.4 parts by mass of an isocyanate crosslinking agent (Asahi Kasei Chemicals Co., Ltd., K6000) and 100% by mass of the resin composition as an organic peroxide (Nippon Yushi Co., Ltd., Perocta O) 2 .5 parts by mass were mixed and kneaded using a three roll to prepare paint 5.
Table 1 shows the composition of each paint.

[Example 1] Preparation and Evaluation of Damping Material A 5% Al-Zn plated steel sheet having a thickness of 0.35 mm was prepared as a vibrating body, and Ni substitution treatment was performed by a conventional method. The steel sheet was further subjected to coating-type chromate treatment. The thus obtained chemical conversion treatment vibrator was roll-coated with an acrylic-modified epoxy resin and heated under the conditions of 220 ° C. × 100 seconds to form an undercoat film having a dry film thickness of 5 μm.

  On the undercoat coating film, the coating material 1 was applied by knife coating and heated at 150 ° C. for 90 seconds to prepare a vibration damping material on which a coating film having a thickness of 200 μm was formed. When the cross section of the coating film of the obtained vibration damping material was observed with an optical microscope, the coating film had a two-layer structure, with a 30 μm polyester rich layer a on the surface layer side and a 170 μm acrylic rich layer b on the vibrating body side. It was confirmed.

The obtained vibration damping material was evaluated as follows. The results are shown in Table 2.
1) Loss coefficient η
The damping material was cut into a shape of 220 mm × 15 mm to prepare a sample.
Using a vibration damping characteristic tester (Ono Sokki Co., Ltd., Graduo DS-2000), a vibration damping curve was measured based on JIS G0602: 1993. Η was obtained from the obtained curve by the half-width method.

2) Damping characteristics after heating at 80 ° C. Samples having the same shape as in 1) above were prepared. The sample was placed in a thermostat (Toyo Seiki Seisakusho: Gear type aging tester) maintained at a temperature of 80 ° C., taken out after 100 hours, and cooled to room temperature. Using this sample, the loss factor was determined in the same manner as in 1) above. From the obtained values, the vibration damping characteristics after heating at 80 ° C. were evaluated according to the following criteria.
What hardly decreased compared to the value before heating: ○ (Good)
Reduced compared to the value before heating: x (defect)

3) Blocking resistance after heating at 80 ° C. The damping material was cut into a 50 mm × 50 mm shape and heated at 80 ° C. for 100 hours in the same manner as in 2) above. Ten or more of the samples were laminated on a horizontal and smooth surface plate with the coating surface facing upward, a load of 10 kg / cm ² was added at room temperature, and the sample was allowed to stand for 24 hours. Subsequently, blocking resistance was evaluated according to the following criteria.
No abnormalities: ○ (Good)
Sample adhered to sample vibration material laminated on top: × (defect)

4) Tg of acrylic polymer
The calculation was performed based on the aforementioned calculation formula.

[Example 2]
A vibration damping material having a coating film with a thickness of 200 μm was obtained using paint 2 in the same manner as in Example 1. When the cross section of the obtained coating film was observed with an optical microscope, it was confirmed that the coating film had a two-layer structure, and a 50 μm polyester rich layer a on the surface layer side and a 150 μm acrylic rich layer b on the vibrating body side were present. . The obtained vibration damping material was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Examples 3 and 4]
A damping material having a coating film with a thickness of 200 μm was obtained using paints 3 and 4 in the same manner as in Example 1. When the cross section of the obtained coating film was observed with an optical microscope, the coating film had a two-layer structure, and the coating film of Example 3 using the coating material 3 had a polyester rich layer a of 20 μm on the surface layer side and the vibration body side. It was confirmed that an acrylic rich layer b of 180 μm was present.
In addition, it was confirmed that the coating film of Example 4 using the paint 4 also had a two-layer structure, and a 40 μm polyester rich layer a on the surface layer side and a 160 μm acrylic rich layer b on the vibrating body side were present.
The obtained vibration damping material was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Examples 5 and 6]
A damping material having a coating film with a thickness of 110 μm was obtained using paints 1 and 2 in the same manner as in Example 1. When the cross section of the obtained coating film was observed with an optical microscope, the coating film of Example 5 using the coating material 1 had a two-layer structure, a 20 μm polyester rich layer a on the surface layer side, and a 90 μm acrylic rich layer on the vibrating body side. It was confirmed that b was present.
It was confirmed that the coating film of Example 6 using the paint 2 also had a two-layer structure, and the 30 μm polyester rich layer a was present on the surface layer side and the 80 μm acrylic rich layer b was present on the vibrating body side.
The obtained vibration damping material was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 1]
A pre-coated steel plate having a coating film made of a polyester resin-based paint having a thickness of 20 μm was prepared on a steel plate having a thickness of 0.35 mm, and processed into the same shape as that of the vibration damping material of Example 1. Next, in the same manner as in Example 1, loss coefficient η, vibration damping characteristics after heating at 80 ° C., and blocking resistance after heating at 80 ° C. were evaluated. The results are shown in Table 3.

[Comparative Example 2]
A steel plate having a coating film made of a vinyl chloride sol paint having a thickness of 200 μm on a steel plate having a thickness of 0.35 mm was prepared and processed into the same shape as the vibration damping material of Example 1. Next, in the same manner as in Example 1, loss coefficient η, vibration damping characteristics after heating at 80 ° C., and blocking resistance after heating at 80 ° C. were evaluated. The results are shown in Table 3.

[Comparative Example 3]
Except for using the paint 5 in place of the polyester resin paint, an attempt was made to obtain a vibration damping material in the same manner as in Example 1. However, the paint 5 did not become a uniform paint, so that a coating film could be formed. could not.

  As shown in Table 2, the vibration damping material obtained by applying the acrylic paint of the present invention has excellent vibration damping properties and blocking resistance.

  The vibration damping material coated with the paint of the present invention has excellent vibration damping properties. Therefore, the vibration damping material of the present invention is suitable for applications that require vibration damping such as automobiles and electrical products.

Sectional drawing which shows an example of the damping material of this invention

Explanation of symbols

1 Polyester rich layer a
2 Acrylic rich layer b
3 Vibrating body 4 Interface between layer a and layer b 5 Undercoat layer

Claims (7)

(A) 10 to 50 parts by mass of an amorphous polyester having a glass transition temperature of 40 ° C. or higher, and (B) a (meth) acrylic paint containing 90 to 50 parts by mass of a (meth) acrylic monomer,
The (meth) acrylic monomer of (B) contains a compound represented by the following general formula (1), and the compound is 5 to 80 mol% in the total (meth) acrylic monomer. .

In the formula (1), R ₁ represents a hydrogen atom or a methyl group.
^* R ₂ ^is _{* (CH 2 CH 2 O)} n, n is 1-4. R ₃ is an alkyl group having 1 to 4 carbon atoms.   The (meth) acrylic paint according to claim 1, wherein the content of the compound represented by the general formula (1) is 10 to 300 parts by mass with respect to 100 parts by mass of the amorphous polyester (A). . The (meth) acrylic paint according to claim 1, wherein the (B) (meth) acrylic monomer contains a compound of the following general formula (2), (3) or (4).

In the formula (2), R ₁ represents a hydrogen atom or a methyl group.
R ₄ represents a hydrocarbon group having 1 to 15 carbon atoms.

In the formula (3), R ₁ represents a hydrogen atom or a methyl group.
R ₅ represents an alkylene group having 1 to 12 carbon atoms.

In the formula (4), R ₁ represents a hydrogen atom or a methyl group.
R ₆ represents an alkylene group having 1 to 10 carbon atoms.   The (meth) acrylic paint according to claim 1, further comprising 0.1 to 20 parts by mass of polyisocyanate with respect to 100 parts by mass in total of (A) and (B).   The vibration damping material which has the coating film formed by superposing | polymerizing the said (B) (meth) acrylic-type monomer contained in the (meth) acrylic coating material of Claim 1 on a vibrating body surface.   The coating film has a layer a mainly composed of the (A) polyester resin and a layer b mainly composed of the polymer of the (B) (meth) acrylic monomer, and an interface between the layer a and the layer b. Exists in a thickness of 1 to 50% from the surface layer of the coating film, and the layer b is in contact with the vibrating body.   The manufacturing method of the damping material including the process of apply | coating the (meth) acrylic coating material of Claim 1 to a vibrating body, and the process of polymerizing the (B) (meth) acrylic-type monomer contained in the said coating film.

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