JP2008063436A - (meth)acrylic ester copolymer, coating resin composition, coating, and coating film, and method for producing (meth)acrylic ester copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a (meth)acrylic ester copolymer capable of forming a coating film having gloss feeling and smoothness, excellent in low tackiness, alcohol resistance and water resistance, good in balance between appearance and hardness, and giving high adhesiveness to any materials. <P>SOLUTION: The (meth)acrylic ester copolymer (A) is composed of 30-60 mass% of monomer units each derived from a specific alkyl (meth)acrylate (a), 8-25 mass% of monomer units each derived from a specific alkyl (meth)acrylate (b), 3-15 mass% of monomer units each derived from a specific (meth)acrylic ester (c), 19-35 mass% of monomer units each derived from a specific (meth)acrylic ester (d), and 0-35 mass% of monomer units each derived from an unsaturated compound (e) copolymerizable with each of the compounds (a) to (d). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a (meth) acrylic acid ester copolymer, a coating resin composition, a coating material, and a coating film formed using the same, which are suitably used for molding a coating film on metal, plastic and wood surfaces. .

  Conventionally, (meth) acrylic acid ester copolymers, which are copolymers of (meth) acrylic acid, (meth) acrylic acid esters, and derivatives thereof, have excellent weather resistance, flexibility, strength, adhesiveness, and the like. Therefore, it is widely used in applications such as paints, inks, adhesives, and synthetic leather. In particular, in the application of paints, (meth) acrylic acid ester copolymers having various compositions suitable for each required performance are used for various materials in the fields of automobiles, home appliances, building materials and the like.

  In coatings containing (meth) acrylic acid ester copolymers used for home appliances, (meth) acrylic acid ester copolymer is used to satisfy the requirements for hardness, alcohol resistance, etc. The molecular weight of the coalescence and the glass transition temperature (Tg) are set high. However, in recent years, it has been strongly demanded that the coating film have an appearance such as glossiness and smoothness and low adhesiveness that does not leave a trace of the packing material when the product is packaged. When the molecular weight and Tg of the (meth) acrylic acid ester copolymer are reduced in order to improve the gloss and smoothness of the coating film, the hardness, alcohol resistance, and drying properties decrease.

  Moreover, in order to raise the intensity | strength of a coating film, although the method of increasing the quantity of the hydroxyl group introduce | transduced into a (meth) acrylic acid ester copolymer is used, the coating film obtained by this method raises the hardness. However, it is not satisfactory for the reduction of the tack. In addition, a method for improving the resistance to scratches of a coating film by using a reaction product obtained by addition reaction of ε-caprolactone to hydroxyalkyl (meth) acrylate has been reported (Patent Document 1). ). The coating film obtained using these reactants has excellent low tack. However, in such a coating film, the water resistance and alcohol resistance are remarkably impaired by the polyester structure of the side chain of the (meth) acrylic acid ester copolymer, and further, the hydroxyl value is high and the backbone skeleton is soluble. Due to the low value, the adhesion to materials such as plastics is poor.

  In addition, in order to give a product a high appearance, a coating layer formed by two layers composed of a base layer that includes aluminum, pigments, and the like that bears design properties and a clear layer that exhibits gloss and smoothness is used. However, due to the complexity of the process and cost reduction, there is an increasing demand for paints that can obtain these characteristics by single-layer coating. In order to obtain a coating film with gloss and smoothness equivalent to that of the clear layer, it is essential to lower the molecular weight of the (meth) acrylic acid ester copolymer and lower the viscosity of the resin. In order to compensate for the decrease in film strength, a method for increasing the degree of crosslinking has been studied. However, if the (meth) acrylic acid ester copolymer has a high degree of cross-linking, the cross-linking shrinkage is strong and the adhesion of the coating film to the substrate is reduced.

Furthermore, in order to express gloss in the coating film, when a large amount of (meth) acrylic acid ester monomer or aromatic vinyl monomer having a high refractive index is used in the (meth) acrylic acid ester copolymer Inadequate adhesion to ABS, polycarbonate, etc.
JP-A-2-305873

  The object of the present invention is to provide a coating film having glossiness, smoothness, low adhesiveness, leaving no trace of packing by packing materials, etc., excellent in alcohol resistance and water resistance, and having a good balance between appearance and hardness. It is to provide a (meth) acrylic acid ester copolymer that can be provided, a resin composition using the same, a paint, and a coating film.

  In addition, the object of the present invention is glossy, smooth, has low adhesion, does not leave a packing mark due to packing materials, etc., has excellent alcohol resistance and water resistance, and has a good balance between appearance and hardness, It is providing the manufacturing method of the (meth) acrylic acid ester copolymer which gives the coating film which has the outstanding adhesiveness with respect to any raw material.

  The gist of the present invention is the formula (1).

(In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 3 carbon atoms.) A monomer unit derived from an alkyl (meth) acrylate (a) 30-60% by mass, formula (2)

(In the formula, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group having 8 to 22 carbon atoms.) A monomer unit derived from alkyl (meth) acrylate (b) 8-25% by mass, formula (3)

(In the formula, R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents a hydroxyalkyl group having 4 or more carbon atoms.) A monomer unit derived from a (meth) acrylic acid ester (c) 3 to 15% by mass, formula (4)

(In the formula, R ⁷ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 25.) Monomer unit 19 derived from (meth) acrylic acid ester (d) represented by (35)% by weight and (meth) acrylic acid ester copolymer containing 0 to 35% by weight of monomer units derived from unsaturated compound (e) copolymerizable with (a) to (d) Regarding A).

  Moreover, this invention relates to the resin composition for coating materials containing the said (meth) acrylic acid ester copolymer (A) and an isocyanate compound (B).

  Moreover, this invention relates to the coating material obtained using the coating material containing this resin composition for coating materials, and this coating material.

  Further, the present invention provides the formula (1)

(Wherein, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 3 carbon atoms) (meth) acrylic acid alkyl (a) 30 to 60% by mass, a formula (2)

(Wherein R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group having 8 to 22 carbon atoms) (meth) acrylate alkyl (b) represented by 8 to 25% by mass, formula (3)

(Wherein R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents a hydroxyalkyl group having 4 or more carbon atoms) (meth) acrylic acid ester (c) 3 to 15% by mass, formula (4)

(Wherein R ⁷ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 25). (Meth) acrylic acid ester (d) 19 to 35% by mass, and (Meth) acryl which polymerizes unsaturated compound (e) 0-35 mass% (however, the total amount of (a)-(e) is 100 mass%) copolymerizable with (d) from (a) The present invention relates to a method for producing an acid ester copolymer (A) solution.

  The (meth) acrylic acid ester copolymer of the present invention, and a resin composition for paints and paints using the same have glossiness, smoothness, low adhesiveness, and leave no packing marks due to packing materials, etc. Gives a coating film that is excellent in alcohol resistance and water resistance and has a good balance between appearance and hardness.

  In the present invention, the notation of (meth) acrylic acid ester means acrylic acid ester or methacrylic acid ester. Similarly, the notation of (meth) acryl in alkyl (meth) acrylate or the like means acryl or methacryl.

  The (meth) acrylic acid ester copolymer (A) of the present invention is a monomer unit derived from an alkyl (meth) acrylate (a) represented by the formula (1), an alkyl (meth) acrylate (b ) Derived monomer units, (meth) acrylic acid ester (c) derived monomer units, (meth) acrylic acid ester (d) derived monomer units, and other, if necessary It contains monomer units derived from the copolymerizable unsaturated compound (e).

The monomer unit derived from the alkyl (meth) acrylate (a) represented by the formula (1) contained in the (meth) acrylic acid ester copolymer (A) is a (meth) acrylic acid ester copolymer. While improving the hardness of the coating film obtained using (A), the adhesiveness to materials with low adhesiveness, such as a plastic, is improved. In formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl (meth) acrylate (a) represented by the formula (1) include methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate. These can be used alone or in combination of two or more.

  The monomer unit derived from the alkyl acrylate (a) is contained in the range of 30 to 60% by mass in the (meth) acrylic acid ester copolymer (A). If the content of the monomer unit derived from the alkyl acrylate (a) is 30% by mass or more, the hardness of the coating film obtained using the (meth) acrylic acid ester copolymer (A) is improved. At the same time, the adhesion to a material having low adhesion such as plastic can be improved. When the content of the monomer unit derived from the alkyl acrylate (a) is 60% by mass or less, the surface smoothness of the coating film is improved and the low adhesiveness is excellent. The content of the monomer unit derived from the alkyl acrylate (a) in the (meth) acrylate copolymer (A) is preferably 30 to 55% by mass, more preferably 33 to 51% by mass. % Range.

The monomer unit derived from the alkyl (meth) acrylate (b) represented by the formula (2) contained in the (meth) acrylic acid ester copolymer (A) has surface smoothness and low adhesion to the coating film. Imparts properties and elasticity, and improves alcohol resistance and the like. If the carbon number of the alkyl group represented by R ⁴ in Formula (2) is 8 or more, the glass transition temperature of the (meth) acrylic acid ester copolymer (A) is kept low, and sufficient elasticity is obtained in the coating film. In addition, low tack and alcohol resistance are improved. On the other hand, if the carbon number of the alkyl group represented by R ⁴ in Formula (2) is 22 or less, the solubility parameter does not become too high, and the coating film has excellent adhesion even to a low adhesion substrate. give. Specific examples of the alkyl (meth) acrylate (b) represented by the formula (2) include 2-ethylhexyl (meth) acrylate, n-lauryl (meth) acrylate, and n- (meth) acrylate. Examples thereof include alkyl (meth) acrylates such as stearyl and dodecyl (meth) acrylate, cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate, and the like. These can be used alone or in combination of two or more.

  The monomer unit derived from the alkyl acrylate (b) is contained in the range of 8 to 25% by mass in the (meth) acrylic acid ester copolymer (A). If the content of the monomer unit derived from the alkyl acrylate (b) is 8% by mass or more, the coating film is provided with smoothness, low tackiness and water resistance, and if it is 25% by mass or less, the coating is applied. The film hardness is improved and the adhesion to the substrate is improved. The content of the monomer unit derived from the alkyl acrylate (b) is preferably 13 to 21% by mass, more preferably 14 to 21% by mass.

  The monomer unit derived from the (meth) acrylic acid ester (c) represented by the formula (3) contained in the (meth) acrylic acid ester copolymer (A) forms a crosslink in the coating film. Improves hardness development speed and flexibility immediately after curing to impart hardness. Specific examples of the (meth) acrylic acid ester (c) represented by the formula (3) include 4-hydroxybutyl (meth) acrylate and 6-hydroxyhexyl (meth) acrylate. These can be used alone or in combination of two or more.

  The monomer unit derived from the acrylic ester (c) is contained in the range of 3 to 15% by mass in the (meth) acrylic ester copolymer (A). If the content of the monomer unit derived from the acrylate ester (c) is 3% by mass or more, while improving the hardness of the coating film, it is possible to improve the hardness expression speed and flexibility immediately after curing, If it is 25 mass% or less, the hardness of a coating film and the adhesiveness to a base material will be improved. The content of the monomer unit derived from the acrylate ester (c) is preferably 5 to 10% by mass, more preferably 8 to 10% by mass.

  The monomer unit derived from the (meth) acrylic acid ester (d) represented by the formula (4) contained in the (meth) acrylic acid ester copolymer (A) gives the coating film elasticity and external addition. It is a component that gives a function of restoring deformation due to. The ester group of the (meth) acrylic acid ester (d) represented by the formula (4) includes a ring-opened product of ε-caprolactone and a polymer thereof, and the degree of polymerization of the ring-opened product of ε-caprolactone is 2 to 2. 25. If the number of ring-opening ε-caprolactone in the ester group is 1 or more, water resistance is imparted to the coating film, and if it is 25 or less, elasticity and low tackiness are imparted to the coating film. As the (meth) acrylic acid ester (d) represented by the formula (4), as a product of Daicel Chemical Industries, Plaxel FA-1 (1 mol of ε-caprolactone is added to 1 mol of 2-hydroxyethyl acrylate) Monomer), Plaxel FA-4 (a monomer obtained by adding 4 mol of ε-caprolactone to 1 mol of 2-hydroxyethyl acrylate), Plaxel FA-10L (ε-caprolactone to 1 mol of 2-hydroxyethyl acrylate) Monomer with 10 mol added), Plaxel FM-1 (monomer with 1 mol of ε-caprolactone added to 1 mol of 2-hydroxyethyl methacrylate), Plaxel FM-2 (1 mol of 2-hydroxyethyl methacrylate) A monomer obtained by adding 2 mol of ε-caprolactone to 1), Plaxel FM-3 (2-hydroxyethyl methacrylate 1 mol) Monomer having 3 mol of ε-caprolactone added to the monomer), Plaxel FM-4 (monomer having 4 mol of ε-caprolactone added to 1 mol of 2-hydroxyethyl methacrylate), Plaxel FM-5 (methacrylic acid 2 -Monomer obtained by adding 5 mol of ε-caprolactone to 1 mol of hydroxyethyl). These can be used alone or in combination of two or more.

  The monomer unit derived from the acrylate ester (d) is contained in the range of 19 to 35% by mass in the (meth) acrylate ester copolymer (A). If the content of the monomer unit derived from the acrylate ester (d) is 19% by mass or more, the elasticity of the coating film and low adhesiveness are improved, and if it is 35% by mass or less, the hardness of the coating film, Improves adhesion to the substrate. The content of the monomer unit derived from the acrylate ester (d) is preferably 20 to 34% by mass, and more preferably 19 to 33% by mass.

  The monomer units derived from the unsaturated compound (e) copolymerizable with (a) to (d) contained in the (meth) acrylic acid ester copolymer (A) are the above (a) to (d). In order to impart, for example, weather resistance, aesthetics, water resistance, and other physical performances to the coating film, it can be appropriately selected and contained. As such an unsaturated compound (e), alkyl (meth) acrylates such as n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, N-phenyl Maleimide derivatives such as maleimide, N-cyclohexylmaleimide, N-butylmaleimide, hydroxyalkyl groups such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate Polymerizable monomer having acrolein, acrolein, diacetone acrylamide, formyl styrene, vinyl alkyl ketone, (meth) acrylamide pivalin aldehyde, diacetone (meth) acrylate, acetonyl acrylate, 2-hydroxypropyl acrylate Acetyl acetate, ace Acetoxyethyl (meth) acrylate, butanediol-1,4-acrylate-acetyl acetate, vinyl monomer having aldehyde group or carbonyl group of acrylamide methylanisaldehyde, (meth) acrylamide, crotonamide, N-methylolacrylamide, etc. Amide group-containing vinyl monomers, allyl glycidyl ether, epoxy group-containing vinyl monomers such as glycidyl (meth) acrylate, aromatic vinyl monomers such as styrene and α-methylstyrene, vinyl chloride, chloride Vinyl derivatives such as vinylidene, vinyl acetate, isopropenyl acetate, divinylbenzene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylo Monomers having two or more unsaturated double bonds such as rupropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, nitrile group-containing vinyl monomers such as acrylonitrile, Examples thereof include olefinic monomers such as butadiene. These can be used alone or in combination of two or more.

  In addition, the monomer unit derived from the unsaturated compound (e) is preferably a monomer unit containing an amino group or an acid group in consideration of improving curability, pigment dispersibility, adhesion, and the like. As an amino group containing monomer, the (meth) acrylic acid ester unit which has a C1-C20 aminoalkyl group can be mentioned, for example. Specific examples of the (meth) acrylic acid ester having an aminoalkyl group having 1 to 20 carbon atoms include aminomethyl (meth) acrylate, N-methylaminomethyl (meth) acrylate, and (meth) acrylic. Examples thereof include acid N, N-diethylaminoethyl and the like. Examples of the acid group-containing monomer include (meth) acrylic acid, 2- (meth) acryloxyethyl hexahydrophthalic acid, 2- (meth) acryloxypropylhexahydrophthalic acid, 2- (meth) acryloxyethyl tetrahydro Phthalic acid, 2- (meth) acryloxypropyltetrahydrophthalelic acid, 5-methyl-2- (meth) acryloxyethyl hexahydrophthalic acid, 2- (meth) acryloxyethylphthalic acid, 2- (meth) acrylic acid Carboxyl group-containing vinyl compounds such as loxypropyl phthalic acid, 2- (meth) acryloxyethyl oxalic acid, 2- (meth) acryloxypropyl oxalic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, sorbic acid, etc. , Carboxylic anhydrides such as maleic anhydride and itaconic anhydride, tertiary butyl acrylamide Sulfonic acid, vinyl monomers having a phosphoric acid group (Kyoeisha Chemical Co., Light Ester P-1M, etc.) and the like can be exemplified. Among these, a carboxyl group-containing vinyl compound and a vinyl monomer having a phosphoric acid group are preferable from the viewpoint of water resistance, adhesion, yellowing, and the like. These can be used alone or in combination of two or more.

  The (meth) acrylic acid ester copolymer (A) preferably has a theoretical glass transition temperature (Tg) in the range of −10 to 40 ° C. When Tg is −10 ° C. or higher, it has hardness and alcohol resistance, and when it is 40 ° C. or lower, it has elasticity associated with low adhesion.

  The method for producing the (meth) acrylic acid ester copolymer (A) of the present invention has the formula (1)

(Wherein, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 3 carbon atoms) (meth) acrylic acid alkyl (a) 30 to 60% by mass, a formula (2)

(Wherein R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group having 8 to 22 carbon atoms) (meth) acrylate alkyl (b) represented by 8 to 25% by mass, formula (3)

(Wherein R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents a hydroxyalkyl group having 4 or more carbon atoms) (meth) acrylic acid ester (c) 3 to 15% by mass, formula (4)

(Wherein R ⁷ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 25). (Meth) acrylic acid ester (d) 19 to 35% by mass, and (A) to (d) copolymerizable unsaturated compound (e) 0 to 35% by mass (however, the total amount of (a) to (e) is 100% by mass) is polymerized.

  The polymerization method may be any of a polymerization method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, and a non-aqueous dispersion polymerization method. Solution polymerization is suitable because of ease of time. Moreover, the method of obtaining the said (meth) acrylic acid ester copolymer by high temperature pressurization polymerization which superposes | polymerizes by pressurization can reduce a polymerization initiator, shorten reaction time, etc., and is economical.

  Solvents that can be used when employing such a solution polymerization method include, for example, toluene, xylene and other high boiling aromatic solvents, ester solvents such as ethyl acetate, butyl acetate and cellosolve acetate, methyl ethyl ketone, and methyl isobutyl ketone. And ketone solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, and isobutyl alcohol. These can be used alone or in combination of two or more. As a usage-amount of a solvent, although the range of 40-1000 mass% is preferable with respect to 100 mass% of monomer components, when using a polymerization liquid as a coating material, it is 50-100 mass% from handling property, transportation cost, etc. Within the range is particularly preferred. Moreover, as a polymerization initiator, a well-known radical polymerization initiator can be utilized and an organic peroxide, an azo compound, etc. can be used. Examples of the organic peroxide include t-butylperoxy 2-ethylhexanoate, benzoyl peroxide, dicumyl peroxide, dibutyl peroxide, and the like. Examples of the azo compound include 2, Examples include 2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), and the like. These can be used alone or in combination of two or more. Moreover, a chain transfer agent can also be used as needed. Examples of the chain transfer agent include 2-mercaptoethanol, n-dodecyl mercaptan, t-dodecyl mercaptan, α-methylstyrene dimer and the like, and these may be used alone or in combination of two or more. it can.

  The reaction temperature in solution polymerization can be in the range of room temperature to 200 ° C, and preferably in the range of 40 to 170 ° C. When the temperature is from room temperature to 200 ° C. or less, the polymerization can be efficiently performed with a high yield.

  The resin composition for coatings of the present invention comprises a hydroxyl group in the (meth) acrylic acid ester copolymer (A) and a crosslinkable isocyanate compound (B). The isocyanate compound (B) may be any as long as it contains two or more isocyanate groups in the molecule. Examples of the isocyanate compound (B) include aromatic, aliphatic and alicyclic isocyanate compounds, and any of urethane adducts, burettes, isocyanates and the like may be used. Specific examples of the isocyanate compound (B) include isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, 1,5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-dibenzyl isocyanate, and dialkyldiphenylmethane isocyanate. Tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethyl Hexamethylene diisocyanate, tolidine diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate Over DOO, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate. Further, it is also possible to use a buret body or isocyanurate body, which is a trimer of hexamethylene diisocyanate, or an isocyanate compound mainly composed of an adduct of hexamethylene diisocyanate to trimethylolpropane. Specific examples include Coronate HX, Coronate HK, Coronate HL, Sumidur N-75 and Sumidur N-3200 manufactured by Sumitomo Bayer Urethane Co., Ltd. Moreover, the block body which isocyanate reproduces | regenerates by heating etc. can also be used. These can be used alone or in combination of two or more.

  As content in the resin composition of an isocyanate compound (B), the equivalent ratio OH / NCO of the hydroxyl group (OH) of a (meth) acrylic acid ester copolymer (A) and an isocyanate group (NCO) is 10 /. A range of 1 to 0.1 / 1 is preferred. When the ratio of OH / NCO is 10/1 or less, the drying property is good in coating film molding, and the hardness of the coating film becomes high. When the ratio of OH / NCO is 0.1 / 1 or more, the solvent resistance and water resistance are excellent. As content of an isocyanate compound (B), More preferably, OH / NCO is the range of 5 / 1-0.3 / 1, More preferably, OH / NCO is 3 / 1-0.5 / 1. It is a range.

  The coating resin composition may contain other polymers. As the other polymer, a polymer compatible with the (meth) acrylic acid ester copolymer (A) is preferable. For example, polyacrylic resins such as a copolymer of styrene and alkyl acrylate, polyester resins, polyurethane resins, polyether resins, polyamide resins, alkyd resins, and the like can be given. These can be used alone or in combination of two or more. These other polymers can be used as long as the effects of the acrylic ester copolymer (A) are not impaired. The acrylic ester copolymer (A) and the other polymer are preferably used in a mass ratio of 10/90 to 100/0.

  The coating resin composition may contain a catalyst for promoting the urethanization reaction between the hydroxyl group of the (meth) acrylic acid ester copolymer (A) and the isocyanate group of the isocyanate compound (B). Examples of the catalyst include di-n-butyltin dilaurate, dimethyltin bis (methyl maleate), dimethyltin (ethyl maleate), dimethyltin (butyl maleate), dibutyltin (butyl maleate), and dibutyltin (dodecylbenzenesulfonate). ) And the like. These can be used alone or in combination of two or more.

  In addition, the coating resin composition may contain additives, solvents, and the like. Specific examples include aluminum pastes, fillers, plasticizers, pigment dispersion stabilizers, UV absorbers, UV stabilizers, antioxidants, crosslinked resin particles as rheology control agents, inorganic pigments, and organic pigments. it can. Examples of inorganic pigments include titanium white and carbon black. Examples of organic pigments include phthalocyanine pigments and azo pigments. As a method for containing these inorganic pigments and organic pigments, a normal pigment dispersion method can be used.

  Furthermore, the resin composition for coatings may contain a solvent for adjusting the viscosity. The diluent can be appropriately selected in consideration of the evaporation rate, drying property, and the like. Specifically, the same solvents as those exemplified as the solvent that can be used in the solution polymerization method of the (meth) acrylic acid ester copolymer (A) can be exemplified.

  As a manufacturing method of the resin composition for coating materials, the method of stirring and mixing a (meth) acrylic acid ester copolymer (A) and an isocyanate compound (B) in the said ratio can be mentioned.

  The coating material of this invention contains the said resin composition for coating materials. The paint resin composition can be used as a paint as it is, but paint additives such as glittering materials, fillers, plasticizers, pigment dispersants, thickeners, antifoaming agents, leveling agents and the like are added appropriately. Paints can be prepared.

  The coating material can be used for molding each layer of a coating film comprising a pigment-containing base layer having excellent design properties and a clear layer provided on the base layer and imparting gloss and smoothness. Moreover, it can contain a pigment and can be used for shaping | molding of the film of the 1 layer structure which has the glossiness and smoothness of a surface. As the pigment, organic pigments and inorganic pigments such as aluminum, titanium oxide, iron oxide, aluminum flakes, titanium coat mica and the like can be used. When using aluminum flakes as a pigment, the range of 0.001-50 mass% is preferable with respect to 100 mass% of the total amount of a resin component.

  As a manufacturing method of a coating material, it can be based on the method which adds and stirs and mixes another polymer, an additive, and a solvent as needed to the resin composition for coating materials, and can also adjust temperature. When the (meth) acrylic acid ester copolymer (A) is produced by the solution polymerization method, the reaction system can be applied as it is.

  As a method of forming a coating film using the coating material of the present invention, it is applied to a substrate, and the hydroxyl group of the (meth) acrylic acid ester copolymer (A) and the isocyanate group of the isocyanate compound (B) are combined. And a method of forming crosslinks.

  Examples of the base material include metals, plastics, and wood. Specifically, metals such as iron, stainless steel and aluminum; olefin polymers such as polycarbonate, polypropylene and polyethylene; plastics such as polymethyl methacrylate, ABS polymer and polystyrene; glass, slate plate, concrete, calcium silicate, etc. Silicate-based, gypsum-based, asbestos-based or ceramic-based inorganic materials; woods, papers, fibers, FRP, and the like.

  Examples of the coating method include spray coating, brush coating, dip coating, roll coating, and flow coating. The temperature and time for crosslinking the coating film are the kind of (meth) acrylic acid ester copolymer (A), the content, the kind of isocyanate compound (B), the content, the kind of catalyst, the content, the crosslinking accelerating catalyst. It can be appropriately selected depending on the presence, type, content, and the like. For example, the temperature can be in the range of room temperature to 200 ° C., and the time can be in the range of 3 seconds to 1 week.

  The coating film thus obtained can be applied to a wide range of uses such as for large structures, for automobiles, for automobile repairs, for plastic molded products, and for woodwork such as furniture.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the technical scope of this invention is not limited to these Examples. Here, “parts” and “%” in Examples and Comparative Examples are based on mass.

[Example 1]
[Acrylic resin composition: Preparation of (meth) acrylic acid ester copolymer (A-1)]
A four-necked flask equipped with a cooler, a thermometer, a dropping funnel and a stirrer was used, and 33 parts of toluene and 17 parts of butyl acetate were charged into the flask and heated to 110 ° C.

  Subsequently, in the blending ratio shown in Table 1, alkyl (meth) acrylate (a), alkyl (meth) acrylate (b), (meth) acrylate ester (c), (meth) acrylate ester (d), And the monomer mixture which consists of unsaturated monomer (e) which can copolymerize, and the mixture which melt | dissolved the polymerization initiator uniformly were dripped over 4 hours, keeping the temperature in a flask at the same temperature. Further, 2 parts of butyl acetate was charged into the flask and held for 30 minutes, and 0.05 part of AIBN was charged four times at 30-minute intervals into the flask at the same temperature and held for 1 hour. Toluene was added so that solid content might be 60%, it was made to cool, and the (meth) acrylic acid ester copolymer (A-1) was obtained.

[Evaluation of (meth) acrylic acid ester copolymer (A-1)]
The acid value, weight average molecular weight (Mw), number average molecular weight (Mn), theoretical glass transition temperature (Tg), and theoretical hydroxyl value of the obtained (meth) acrylic acid ester copolymer (A-1) are as follows. I asked for it. The results are shown in Table 1.

  The acid value was determined by measuring the mass of potassium hydroxide required to neutralize 1 g of the (meth) acrylic acid ester copolymer (A-1) and determining the acid value (mgKOH / g).

  The weight average molecular weight (Mw) and number average molecular weight (Mn) were adjusted to a solution concentration of 0.4% with (meth) acrylic acid ester copolymer (A-1) with tetrahydrofuran, and then a column made by TOSO. (GE4000HXL and G2000HXL) were injected into a gel permeation chromatography device manufactured by TOSO, and 100 μl of the injection amount was injected. The flow rate was 1 ml / min (eluent tetrahydrofuran), and the column temperature was 40 ° C. Measured with reference to.

  The theoretical glass transition temperature (Tg) is determined using the Fox equation based on the glass transition temperature (Tg) of each monomer.

Fox formula: 1 / (Tg + 273.14) = Σ (wn / (Tgn + 273.14))
(Wn = mass fraction of monomer n, Tgn = Tg of homopolymer of monomer n).

[Examples 2 to 8, Comparative Examples 1 to 6]
(Meth) acrylic acid ester copolymers (A-2) to (A-8) (Synthesis Examples 2 to 8) and (meth) acrylic acid in the same manner as in Example 1 except that the blending ratios shown in Table 1 were used. Ester copolymers (A-9) to (A-14) (Synthesis Comparative Examples 1 to 6) were prepared, and the acid value, weight average molecular weight (Mw) of the obtained (meth) acrylic acid ester copolymer, The number average molecular weight (Mn), theoretical glass transition temperature (Tg), and theoretical hydroxyl value were determined. The results are shown in Table 1. The names of the abbreviations in Table 1 are shown in Table 2.

[Example 9]
[Preparation of resin composition for paint (B-1)]
Hydroxyl group in (meth) acrylate copolymer (A-1) with respect to 100 parts of (meth) acrylate copolymer (A-1) (solid content 60%) obtained in Example 1 above. And Duranate TPA-100 (Hexamethylene diisocyanate manufactured by Asahi Kasei Kogyo Co., Ltd., isocyanate content = 23.1% by mass) so that the equivalent ratio of isocyanate groups in the compound is OH / NCO = 1 / 1.1. After mixing, prepare for 12 seconds in Ford Cup # 4 with a mixed solvent consisting of toluene / xylene / supersol # 1500 / MEK = 30/30/30/10 (mass ratio) A resin composition (B-1) was obtained.

[Formation of coating film]
An ABS base material (Mitsubishi Rayon Co., Ltd., Diapet ABS3001M, plate thickness 3 mm, size: 9 × 5 cm) was wiped and degreased with gauze impregnated with isopropyl alcohol, and this surface was dried using a paint spray gun. The coating composition (B-1) was sprayed so that the coating film was 20 μm, and dried at 80 ° C. for 30 minutes to form a coating film.

[Evaluation of coating film]
About the obtained coating film, the following method evaluated. The results are shown in Table 3.

[Adhesiveness]
The coating film was cut with 100 squares at intervals of 1 mm with a cutter knife, and tested by peeling the cell tape.
○: No peeling ×: There is peeling even with 1 square.

[Low adhesion]
A polyolefin foam sheet or gauze was placed on the coating, 500 g / cm ² was applied, and the coating was allowed to stand for 24 hours in an atmosphere of 40 ° C. and 95% RH, and the state of the coating was visually observed. (Double-circle): There is no change of the coating-film surface and it is excellent.
○: The gloss on the surface of the coating film is slightly lowered but good.
Δ: A mark remains on the surface of the coating film, which is slightly poor and cannot be used.
X: The coating film surface is deformed and cannot be used.

[hardness]
The paint film was allowed to stand for 1 day after drying, and a pencil scratch test was performed according to JIS K 5400.

[Glossy]
The surface gloss value of the test paper for evaluation was measured at a measurement angle of 60 ° C. using a variable angle gloss meter VG-2000 manufactured by Nippon Denshoku Industries Co., Ltd.

[Alcohol resistance]
While the gauze soaked with ethanol was pressed against the surface of the coating film, the coating film was rubbed back and forth 50 times from one end to the other end, and changes in the coating film were visually evaluated according to the following criteria.
(Double-circle): There is no change in a coating film and it is excellent.
○: The coating film is slightly whitened and is good.
(Triangle | delta): A coating film whitens and is a little bad, and cannot endure use.
X: The coating film is affected by ethanol and cannot be used.

[Examples 10 to 16, Comparative Examples 7 to 12]
A paint as in Example 9 except that (meth) acrylic acid ester copolymers (A-2) to (A-14) were used instead of (meth) acrylic acid ester copolymer (A-1). (B-2) to (B-8) (Examples 10 to 16) and paints (B-9) to (B-14) (Comparative Examples 7 to 12) were obtained. The obtained coating materials (B-2) to (B-14) were evaluated in the same manner as in Example 9. The results are shown in Table 3.

  From the results, the coating film obtained using any of the (meth) acrylic acid ester copolymers (A-1) to (A-8) of Examples 1 to 8 has good gloss and gloss. Moreover, it is clear that it is excellent in the adhesiveness with respect to a base material, and is excellent in the hardness and low adhesiveness of the coating film calculated | required in household electrical appliances.

  On the other hand, the coating films obtained using the acrylic acid ester copolymers (A-9) to (A-14) of Comparative Examples 1 to 6 have characteristics such as smoothness, gloss and hardness, and low adhesion. It is clear that a coating film satisfying all of the above cannot be obtained.

Claims (5)

Formula (1)

(In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 3 carbon atoms.) A monomer unit derived from an alkyl (meth) acrylate (a) 30-60% by mass, formula (2)

(In the formula, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group having 8 to 22 carbon atoms.) A monomer unit derived from alkyl (meth) acrylate (b) 8-25% by mass, formula (3)

(In the formula, R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents a hydroxyalkyl group having 4 or more carbon atoms.) A monomer unit derived from a (meth) acrylic acid ester (c) 3 to 15% by mass, formula (4)

(In the formula, R ⁷ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 25.) Monomer unit 19 derived from (meth) acrylic acid ester (d) represented by ~ 35 mass%, and 0 to 35 mass% of monomer units derived from the unsaturated compound (e) copolymerizable with (a) to (d) (provided that the total amount of (a) to (e) is (Meth) acrylic acid ester copolymer (A) containing 100% by mass).   The resin composition for coating materials containing the (meth) acrylic acid ester copolymer (A) and isocyanate compound (B) of Claim 1.   The coating material containing the resin composition for coating materials of Claim 2.   The coating film obtained using the coating material of Claim 3. Formula (1)

(Wherein, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 3 carbon atoms) (meth) acrylic acid alkyl (a) 30 to 60% by mass, a formula (2)

(Wherein R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group having 8 to 22 carbon atoms) (meth) acrylate alkyl (b) represented by 8 to 25% by mass, formula (3)

(Wherein R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents a hydroxyalkyl group having 4 or more carbon atoms) (meth) acrylic acid ester (c) 3 to 15% by mass, formula (4)

(Wherein R ⁷ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 25). (Meth) acrylic acid ester (d) 19 to 35% by mass, and (Meth) acryl which polymerizes unsaturated compound (e) 0-35 mass% (however, the total amount of (a)-(e) is 100 mass%) copolymerizable with (d) from (a) The manufacturing method of an acid ester copolymer (A) solution.