JP2002167423A - Curable resin composition using low-lactone modified hydroxyalkyl (meth)acrylic ester composition and coating material therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable coating material composition whereby a coating film which long potlife, improved workability, high level balance of acid resistance and excoriation resistance and excellent flexibility and adhesion in recoating is obtained even if it has an isocyanate curable property. SOLUTION: The curable resin composition contains, as essential components, (A) 0.5-80 pts.wt. curable oligomer of obtained by using a low-lactone modified hydroxyalkyl (meth)acrylic ester composition wherein the ratio of a monomer having 2 or more lactone chains (n>=2) is less than 50% and which is obtained by the formula [wherein R, R1, R2 and R3 are independently H or methyl group; (j) is an integer of 2-6; R4 and R5 of each xn pieces are independently H or a 1-12C alkyl group; (x) is 4-7; (n) is 0 or an integer of 1 or above; the average value of (n) in the composition is 0.3 or more and less than 1.0] and (B) 0.5-50 pts.wt. polyisocyanate compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an acrylic polyol resin (A) obtained by using a lactone-modified hydroxyalkyl (meth) acrylate composition having two or more lactone chains reduced (A). A curable resin composition containing 80 parts by weight and 0.5 to 50 parts by weight of a polyisocyanate compound (B) as essential components (however, the total of (A) and (B) does not exceed 100 parts by weight); The present invention relates to a method for producing crosslinked particles obtained from a curable resin composition, a method for producing urethane-urea / ethylene-based resin composite type crosslinked particles, and a paint comprising each crosslinked particle as an essential film-forming component.

[0002]

2. Description of the Related Art In recent years, the importance of acrylic paints in the field of coating has increased. The reason for this is that it has characteristics superior to other alkyd resins, polyester resins and epoxy resins in weather resistance, chemical resistance, stain resistance and the like. So cars, home appliances, metals,
Acrylic coatings have been used in various fields such as building materials. In automotive coatings, the durability of the coatings, particularly rainfall due to acid rain, and spot scratches caused by car wash brushes and sand particles flying during running are regarded as problems. For example, a clear coat of an overcoat of an automobile body or the like is often made of an acrylic resin / melamine resin. However, it has been revealed that the melamine resin causes a decrease in acid resistance, and a new melamine resin-free resin is not included. A cross-linking type coating material has been proposed (JP-A-63-221123).
JP-A-63-108048). But,
These paints have problems that the price is higher than the melamine-based thermosetting paint and that the adhesion to the melamine-based thermoset paint is poor.

[0003] Among acrylic resins, acrylic polyols obtained by copolymerizing a monomer having a hydroxyl group have been applied to a room temperature curing or baking curing coating compounded with a crosslinking agent capable of reacting with a hydroxyl group, for example, a polyisocyanate or a melamine resin. The acrylic monomer having a hydroxyl group is indispensable for imparting adhesion to a coating film and gasoline resistance. As such a monomer having a hydroxyl group, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and the like have been conventionally used. However, since the hydroxyl groups of the acrylic polyol obtained by copolymerizing these monomers are located very close to the main chain of the rigid acrylic resin skeleton, the reactivity with the crosslinking agent is not sufficient. For these purposes, 4-hydroxybutyl acrylate has been proposed, but its reactivity is still not sufficient.

As a solution to such a problem, abrasion resistance has heretofore been evaluated, for example, by using hydroxyalkyl acrylate or hydroxyalkyl methacrylate obtained by addition reaction of ε-caprolactone, and copolymerizing the monomer with the monomer. It is known to apply a clear coat using an ε-caprolactone-modified acrylic resin obtained by the treatment and a melamine curing agent (JP-A-64-66274). There is known an application in which a clear coat using a reaction of a carboxylic acid and an epoxy in combination with an acrylic resin and a melamine curing agent is applied (Japanese Patent Application Laid-Open No. 4-114069).

However, in the former technique, the lactone-modified (meth) acrylate has a wide lactone chain distribution and a large lactone chain number (n), so that the curing reactivity and flexibility are improved, but the hardness and the hardness are improved. The problem that acid resistance etc. falls may arise. For example, when a hydroxyalkyl acrylate or hydroxyalkyl methacrylate obtained by addition reaction of ε-caprolactone having a large number of lactone chains is used as a raw material for an automotive topcoat, the hydroxyl value per unit weight of the product is reduced. In order to adjust the hydroxyl value, it is necessary to use a large amount, which may impair other requirements such as gloss and acid resistance other than scratch resistance. Also, in order to adjust the hydroxyl value without charging a large amount of lactone-modified hydroxyalkyl methacrylate, adjustment may be made with hydroxyethyl methacrylate or hydroxyethyl acrylate. N with good balance between properties and hardness
= 1 ratio of lactone single chain hydroxyalkyl (meth) acrylic ester is reduced.

[0006] In the latter technique, a coating film excellent in acid resistance can be obtained, but the scratch resistance is insufficient. In addition, it is known that raising the glass transition temperature of the cured coating film of the clear coat of the outermost layer is an effective method to obtain a higher acid resistance. There has been a problem that undesirable situations such as a decrease in not only scratch resistance but also bending resistance and adhesion during recoating are caused.

On the other hand, isocyanate curability shows excellent acid resistance, adhesion, water resistance, and hardness, but the pot life is shorter than melamine paint, and the cross-linking of the resin is insufficient, and the scratch resistance of the coating film is poor. There is a problem of low. JP 5
No. 148313 discloses a highly corrosion-resistant metal coating film that has various characteristics such as economy and workability and can satisfy corrosion resistance without impairing aesthetics.
A paint has been proposed in which specific crosslinked particles which do not cause any problem in corrosion resistance or the like even when a conventional melamine resin curing agent is used are used as a main resin of a film-forming resin component. Regarding scratch resistance, modified hydroxy (meth)
Although it can be improved by using acrylate or the like (PCL F or the like), existing PCL F with a long lactone chain length
In some cases the improvement is inadequate.

[0008]

The problem to be solved by the present invention is that it has a sufficient pot life while taking advantage of the excellent acid resistance, adhesion, water resistance and hardness excellent in isocyanate curability, and has an abrasion resistance. It is an object of the present invention to provide a curable coating composition which has solved the above problems.

[0009]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the reaction molar ratio of hydroxyalkyl (meth) acrylate and lactone monomer (the former number of moles / the latter number of moles). Two or more lactone chains (n ≧
0.5 to 80 parts by weight of an acrylic polyol resin (A) and a polyisocyanate compound (B) obtained using a lactone-modified hydroxyalkyl (meth) acrylate composition in which the proportion of the monomer in 2) is reduced. 5-50
The present inventors have found that a curable resin composition containing not less than part by weight as an essential component satisfies the above requirements, and have completed the present invention.

That is, the first aspect of the present invention is that the general formula (1)
Acrylic polyol obtained by using a low lactone-modified hydroxyalkyl (meth) acrylate composition having a proportion of lactone two or more chains (n ≧ 2) less than 50% (GPC area%) Resin (A) 0.5-8
0 parts by weight and polyisocyanate compound (B) 0.5
A curable resin composition containing ５０50 parts by weight as an essential component (provided that the total of (A) and (B) does not exceed 100 parts by weight).

Embedded image Wherein R, R ¹ , R ² and R ³ are independently hydrogen or a methyl group, j is an integer of 2 to 6, and xn R ⁴ and R ⁵ are independently hydrogen. Or 1 to 12 carbon atoms
Wherein x is 4-7 and n is 0
Or an integer of 1 or more, and the average value of n in the composition is 0.1.
3 or more and less than 1.0. A second aspect of the present invention is that the acrylic polyol resin (A) is obtained by adding a low lactone-modified hydroxyalkyl (meth) acrylate composition to a carboxyl group-containing vinyl monomer and another vinyl monomer. The curable resin composition according to the first aspect of the present invention, which is a vinyl copolymer having a carboxyl group and a crosslinkable functional group, obtained by reacting A third aspect of the present invention is that the acrylic polyol resin (A) is a low lactone-modified hydroxyalkyl (meth)
The hydroxyl group-containing resin obtained by polymerizing the acrylic ester composition is reacted with (meth) acrylic anhydride, and then the obtained reaction product is converted into a carboxyl group-containing vinyl monomer and other The curable resin composition according to the first aspect of the present invention, which is a vinyl copolymer having a carboxyl group and a crosslinkable functional group obtained by reacting with a vinyl monomer. A fourth aspect of the present invention is that the acrylic polyol resin (A) comprises, as the hydroxyl group-containing resin, the hydroxyl group-containing resin according to the third aspect of the present invention,
The first aspect of the present invention, which is obtained using one or more resins selected from the group consisting of a hydroxyl group-containing urethane resin, a hydroxyl group-containing epoxy resin, a hydroxyl group-containing cellulose derivative, and a hydroxyl group-containing polyester resin. The present invention provides a curable resin composition. A fifth aspect of the present invention is that the acrylic polyol resin (A) is obtained by using the hydroxyl group-containing resin and the hydroxyl group-containing urethane resin according to the third aspect of the present invention as the hydroxyl group-containing resin. A curable resin composition according to the first aspect is provided. A sixth aspect of the present invention provides the curable resin composition according to the first aspect, wherein the polyisocyanate compound (B) contains an epoxy resin in the polyisocyanate compound. A seventh aspect of the present invention provides the curable resin composition according to any one of the first to sixth aspects, wherein the hydroxyalkyl (meth) acrylate is a hydroxyethyl (meth) acrylate. The eighth aspect of the present invention is that (i) a mixture of an acrylic polyol resin (A) and a polyisocyanate compound (B) is dispersed in an aqueous medium and crosslinked, and (ii) at least low crosslinked particles are obtained. A urethane-urea / ethylene resin composite type obtained by polymerizing a polymerizable ethylenically unsaturated compound containing a lactone-modified hydroxyalkyl (meth) acrylate composition in water in which crosslinked urethane-urea particles are dispersed. A coating material characterized by containing any of the crosslinked particles as a film-forming resin component. A ninth aspect of the present invention is to provide a film-forming resin component,
The particle diameter is 1 μm or less, and the average molecular weight between crosslinks is 30.
The paint according to the eighth aspect of the present invention, which comprises more than 50% by weight of crosslinked particles in the range of 0 to 2,000. A tenth aspect of the present invention provides the paint according to the eighth or ninth aspect, wherein the crosslinked particles have a film forming temperature of 100 ° C or less. An eleventh aspect of the present invention provides the paint according to any one of the eighth to tenth aspects, wherein the content of the crosslinked particles in the film-forming resin component is 70% by weight or more. According to a twelfth aspect of the present invention, there is provided the paint according to any one of the eighth to eleventh aspects of the present invention, wherein the coating film-forming resin component contains a cross-linking agent together with cross-linking particles in an amount of 1 to 25% by weight. I do. According to a thirteenth aspect of the present invention, as the above-mentioned film-forming resin component, a reactive group-containing film-forming resin other than the crosslinked particles is further contained.
12. A paint according to any one of the above items 12. First of the present invention
4 provides the paint according to any one of the eighth to thirteenth aspects of the present invention, wherein the crosslinked particles include a pigment.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Low lactone modification in which the proportion of a monomer having two or more lactone chains (n ≧ 2) represented by the general formula (1) used in the present invention is less than 50% (GPC area%) The hydroxyalkyl (meth) acrylate composition is used for producing a polylactone-modified hydroxyalkyl (meth) acrylate by ring-opening polymerization of hydroxyalkyl (meth) acrylate with lactone. And a lactone monomer in a reaction molar ratio greater than 1. More specifically, in an atmosphere containing oxygen, the lactone and the hydroxyalkyl (meth) acrylate are reacted with less than 1000 ppm of a catalyst and less than 1% by weight to prevent polymerization of the hydroxyalkyl (meth) acrylate. In the presence of the agent,
It comprises a composition obtained by reacting at a temperature of about 80 to about 140 ° C.

In obtaining the above composition used in the present invention, the lactone is charged to a hydroxyalkyl (meth) acrylate such as hydroxyethyl acrylate (HEA) or hydroxyethyl methacrylate (HEMA) in order to reduce the lactone chain. 1 molar ratio
Perform the reaction at less than Catalysts that can be used in the present invention are various organic and inorganic metal compounds, and preferred catalysts include stannous chloride, monobutyltin tris-2-ethylhexanate, stannous octoate, and dibutyltin dilaurate. And tin-based compounds. Thus, a caprolactone-modified hydroxyalkyl (meth) acrylate composition having reduced lactone chains can be produced. While reducing the lactone chain, unreacted H
EA and HEMA will remain, but HEA and HEMA will remain.
EMA is often used alone, and if it is 50% by weight or less, a mixed monomer is often acceptable.

Conventionally, ring-opening polymerization of ε-caprolactone to a substance having a hydroxyl group is performed by adding a titanium-based catalyst such as tetrabutyl titanate, tetraethyl titanate, tetrapropyl titanate or the like at 130 to 230 ° C. Although ring-opening polymerization is performed, even if an attempt is made to add ε-caprolactone to a (meth) acrylic acid ester having a hydroxyl group at a temperature condition of 130 ° C. or higher, the (meth) acrylic acid ester itself causes thermal polymerization, It is difficult to obtain the desired product. At a temperature lower than 130 ° C., the polymerization of (meth) acrylate itself can be prevented, but the ring-opening reaction rate of ε-caprolactone is extremely slow.

[0014] Titanium-based catalysts have relatively high activity and can obtain the desired product. However, since this catalyst is extremely active at the same time as a transesterification catalyst, the transesterification reaction proceeds during the reaction, The polyhydric alcohol comes off from 2 moles of the alkyl (meth) acrylate to produce hydroxyalkyl di (meth) acrylate as a by-product.
Since such di (meth) acrylate has a high boiling point,
Difficult to separate from target. When the target product containing these by-products is radically copolymerized with another (meth) acrylic acid ester in a solvent, the resin undergoes three-dimensional cross-linking, resulting in a remarkable increase in viscosity or further gelation. It will arrive. For this reason, it is necessary to use a catalyst which has a strong catalytic activity, allows the reaction to proceed sufficiently with a low temperature of 80 to 130 ° C. and a small amount of the catalyst, and has a small amount of di (meth) acrylate by-produced by the transesterification reaction. desirable. As the catalyst used in the present invention, stannous halide, monobutyltin tris-2-ethylhexanate, stannous octoate, dibutyltin dilaurate and the like can be used. Among these, the use of monobutyltin tris-2-ethylhexanate can further reduce coloration, and can reduce the transesterification reaction, thereby increasing the catalyst concentration and reducing the reaction time. Excellent and more preferred. When using this catalyst,
It is 1 to 1000 ppm, preferably 10 to 500 ppm.

The hydroxyalkyl (meth) acrylate usable in the production of the composition includes 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate,
Examples thereof include 1,4-butylene glycol monomethacrylate and 1,4-butylene glycol monoacrylate.

The lactone is used in an amount of from 0.3 to less than 1.0 mol, preferably from 0.35 to less than 1, more preferably from 0.5 to 0.75 mol, per mol of the hydroxyalkyl (meth) acrylate. Let it. When the reaction amount of lactone is large, the number of lactone chains increases, and when used as a coating material, the curing reactivity and flexibility are improved, but the hardness and acid resistance of the cured product are reduced. On the other hand, if it is smaller than 0.3, the scratch resistance becomes poor. However, in practice, when 1 mole of lactone is reacted with 1 mole of hydroxyalkyl (meth) acrylate, the rate of ring-opening reaction of lactone to the hydroxyl group of hydroxyalkyl (meth) acrylate and the product Since the rate of ring-opening reaction of the lactone to the caprolactone terminal hydroxyl group hardly changes, the reactant is
It is a compound represented by the formula (1).

The above reaction composition is statistically distributed from the unreacted material of n = 0 to the polycaprolactone of n = 1, 2, 3, 4, 5,... Here, n is preferably 2 or less, and the average value of n in the composition is from 0.3 to 1.
Preferably it is less than zero. However, since it is industrially difficult to separate and purify these, in order to reduce the production amount of those having two or more chains, the reaction amount of ε-caprolactone per mole of hydroxyalkyl (meth) acrylate is less than 1. To be reduced. As the lactone, ε-caprolactone, trimethylcaprolactone,
δ-Valerolactone, γ-butyrolactone or mixtures thereof can be used.

The reaction temperature is 80-150 ° C., preferably 1
00-140 ° C. If the temperature is lower than 80 ° C, the reaction is slow,
If the temperature is higher than 150 ° C., thermal polymerization of the (meth) acrylic compound occurs during the reaction, and there is a risk of gelation. It is preferable to add a polymerization inhibitor to the reaction system. As the polymerization inhibitor, hydroquinone, hydroquinone monomethyl ether, phenothiazine and the like are used in an amount of 0.01 to 1%, preferably 0.03 to 0.5%. When an inert gas such as nitrogen is passed through the reaction system, radical polymerization is likely to occur. Therefore, passing a gas at all or passing air or the like helps to prevent thermal polymerization of a reactant.

The low lactone-modified hydroxyalkyl (meth) acrylate composition produced by the above production method according to the present invention has a residual lactone content of 0 to 10%.
% By weight, the content of residual hydroxyalkyl (meth) acrylate is 20% by weight to 50% by weight, the content of di (meth) acrylate by-product is 2% by weight or less, The content of by-products obtained from addition, (meth) acrylic polymerization, transesterification or other side reactions is 10% by weight or less, the content of the catalyst is less than 1000 ppm, and the content of the polymerization inhibitor is 1% by weight. % Or less.

The low lactone-modified (meth) acrylic acid ester composition used in the present invention has excellent reactivity with a crosslinking agent, alone or by copolymerizing with another radical polymerizable monomer. Acrylic polyol resin with high flexibility (sometimes simply referred to as (meth) acrylic resin)
And can be applied as a material for the curable resin composition for paints of the present invention.

The acrylic polyol resin (A) according to the present invention comprises a low lactone-modified hydroxyalkyl (meth)
A vinyl copolymer having a carboxyl group and a crosslinkable functional group obtained by reacting a carboxyl group-containing vinyl monomer with another vinyl monomer in an acrylate ester composition. Examples of the carboxyl group-containing vinyl monomer used in the present invention include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, (anhydride) maleic acid or fumaric acid, if only typical ones are exemplified. Α, β-ethylenically unsaturated carboxylic acids such as itaconic acid, itaconic anhydride and citraconic acid.

Examples of other vinyl monomers include isocyanate group-containing unsaturated monomers, active hydrogen-containing polymerizable monomers and other polymerizable unsaturated monomers, and the following are exemplified. You. As (meth) acrylates,
For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2- (meth) acrylate Ethylhexyl, octyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate,
C1-C20 alkyl or cyclic alkyl esters of (meth) acrylic acid such as stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, and adamantyl (meth) acrylate;
(Meth) acrylates such as benzyl (meth) acrylate; and 2 carbon atoms of (meth) acrylic acid such as methoxybutyl (meth) acrylate, methoxyethyl (meth) acrylate, and ethoxybutyl (meth) acrylate 8 to 8; viscose 3F (trade name, manufactured by Osaka Organic Chemical Co., Ltd., having the same meaning as described below);
MF, 8F, 8MF, 8MF, perfluorocyclohexyl (meth) acrylate, N-2-propylperfluorooctanesulfonamidoethyl (meth) acrylate, vinyl fluoride-containing monomers such as vinyl fluoride and vinylidene fluoride N, N'-diethylaminoethyl (meth) acrylate, N, N'-diethylaminoethyl (meth) acrylate, N, N'-diethylaminoethyl (meth) acrylate, N, N'-diethyl (meth) acrylate
Nitrogen-containing vinyl monomers such as acrylamide; vinyl ether monomers such as vinyl ethyl ether and vinyl butyl ether; and glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, aryl glycidyl ether, Alkyl ethers such as methylol acrylamide, (meth)
Acrylamide, (meth) acrylic chloride, vinyl chloride, vinylidene chloride, (meth) acrylonitrile,
aromatic vinyl monomers such as γ-methacryloxyalkyltrimethoxysilane, styrene, α-methylstyrene and vinyltoluene; (meth) acrolein, butadiene,
Examples include isoprene and methyl isopropenyl ketone, and these may be used alone or as a mixture of two or more.

Examples of the active hydrogen-containing polymerizable monomer include the following hydroxyl group-containing (meth) acrylates and amino group-containing (meth) acrylates, and these can be used in combination. Examples of the hydroxyl group-containing (meth) acrylate include hydroxyethyl (meth) acrylate, hydroxypropyl (meth)
Acrylic acid ester, hydroxybutyl acrylate,
(Meth) such as 2,3-dihydroxypropyl acrylate and 2-hydroxy-3-ethoxyethyl acrylate
2-hydroxy-3-phenoxyethyl acrylate, such as a hydroxyalkyl ester of acrylic acid having 2 to 8 carbon atoms, and an equimolar addition product of acrylic acid or methacrylic acid and glycol (2 to 20 carbon atoms);
(Manufactured by Daicel Chemical Industries, Ltd., trade name, the same applies hereinafter), F
M-2, FM-3, FM-4, FM-5, FA-1, F
And caprolactone-modified (meth) acrylates such as A-2, FA-3, FA-4, and FA-5.
These may be used alone or in combination of two or more. Examples of the amino group-containing (meth) acrylate include (meth) acrylic acid aminoalkyl esters such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; and (meth) acrylamide. And these can be used as a mixture.

Examples of the isocyanate group-containing monomer include isocyanate ethyl (meth) acrylate, isocyanate propyl (meth) acrylate, isocyanate butyl (meth) acrylate, isocyanate hexyl (meth) acrylate, m -Isopropenyl-α, α'-dimethylbenzyl isocyanate, m-ethylenyl-α, α'-dimethylbenzyl isocyanate, and the like. Examples thereof include unsaturated compounds obtained by adding a polyisocyanate compound such as methylene diisocyanate, and these can be used as a mixture. The other vinyl monomers described above can be used as a mixture, and are selected and used according to desired physical properties.

The acrylic polyol resin used in the present invention is produced by radical polymerization in the presence of a radical polymerization initiator by a known solution polymerization method. Examples of the radical polymerization initiator include benzoyl peroxide, t-butyl hydroperoxide, cumyl hydroperoxide, cumene hydroperoxide, t-butylperoxybenzoate, t-butylperoxy-2-ethylhexanoate and the like. And azo-based initiators such as azobisisobutyronitrile and azobisdimethylvaleronitrile. Solvents used for solution polymerization include, for example, aromatic hydrocarbons such as benzene, toluene, and xylene; esters such as ethyl acetate, propyl acetate, butyl acetate, and cellosolve acetate; ethers such as dioxane and ethylene glycol dibutyl ether; , Methyl ethyl ketone, methyl isobutyl ketone, and other ketone solvents, and these can be used alone or as a mixture of two or more.

As the reactor used for the above polymerization, a reactor equipped with a stirrer, a reflux condenser with a drying tube, and a twin-screw extruder are preferably used. The polymerization temperature and the polymerization time are determined based on the types, charge ratios, and catalysts of the low-lactone-modified hydroxyalkyl (meth) acrylic acid composition of the present invention, the carboxyl group-containing vinyl monomer and the other vinyl monomers, and the like. Depends on the type and amount of the
There is no particular limitation, and it is appropriately determined according to the intended use of the curable oligomer or (co) polymer acrylic resin, physical properties of the coating film required for the paint, and the like. Such a polymerization reaction is carried out at a temperature of about 60 to 150 ° C. in the organic solvent using the ordinary radical polymerization initiator.

The acrylic polyol resin used in the present invention can be easily designed in molecular weight, composition and structure, and needs to have corrosion resistance because of its excellent weather resistance. Gives novel crosslinked fine particles that can be applied to a wide range of applications.

The hydroxyl group content in the hydroxy group-containing resin used in the present invention is desirably 10 or more in terms of hydroxyl value. This is because copolymerization with various polymerizable monomers including a group-containing polymerizable monomer becomes insufficient, and in many cases, the water dispersibility eventually decreases. In addition, the reaction with the polyisocyanate compound (B) (hydrophobic crosslinking agent) becomes insufficient, and as a result, the crosslinking density is reduced and sufficient corrosion resistance cannot be obtained.

On the other hand, the copolymer serving as a hydrophobic part may contain an acid component. In this case, the acid value is preferably up to 10. If such an acid component is contained in an acid value of more than 10, the hydrophilicity will inevitably increase, the core-shell structure will be destroyed, and the stability after the inclusion of the hydrophobic crosslinking agent will decrease.

The acrylic polyol resin (A) used in the present invention has a number average molecular weight of 3,000 to 10
A range of 0000 is appropriate. Preferably, 3,
A range of 000 to 50,000 is appropriate. If the number average molecular weight is less than 3,000, the polyisocyanate compound (B) (hydrophobic crosslinking agent) cannot be stably incorporated into the particles, and various factors such as sufficient water resistance and coating film appearance are required. It is not preferable because the physical properties of the coating film may not be obtained. On the other hand, when the number average molecular weight is 1
If it is larger than 000, it is not preferred because gelation or thickening at the time of phase inversion emulsification is inevitably caused, and it becomes difficult to form a good aqueous dispersion.

The content of the carboxyl group-containing vinyl monomer serving as a hydrophilic segment is required to have an acid value of 10 as a minimum amount for the resin to self-emulsify. Here, a carboxyl group is used as the hydrophilic segment, but since it does not have sufficient hydrophilicity in a carboxylic acid state, it is usually preferable to increase the hydrophilicity by forming an amine salt.

Even if the content of carboxyl groups is large, the resin does not exhibit self-emulsifiability if the amount of carboxylate neutralized with amine is small. In other words, even if the neutralization ratio by the amine is too high, the resin becomes water-dispersible if the neutralization ratio is lowered, even if it becomes water-soluble. However, preferably, the composition should be designed so that even if the contained carboxyl group is neutralized by 100%, the composition does not become water-soluble.

Further, since the carboxyl group itself has a high polarity, if the content exceeds 60% by weight, the corrosion resistance is adversely affected, which is not preferable. Considering the reaction with the crosslinking agent, the content of the low lactone-modified hydroxyalkyl (meth) acrylic acid composition of the present invention is also required to be an amount which becomes 10 or more as the hydroxyl value of the obtained vinyl copolymer. .

However, in the case where the content of the low lactone-modified hydroxyalkyl (meth) acrylic acid composition of the present invention exceeds 300 as the hydroxyl value, the corrosion resistance is adversely affected. Not preferred.

The acrylic polyol resin (A) according to the present invention comprises a low lactone-modified hydroxyalkyl (meth)
The hydroxyl group-containing resin obtained by polymerizing the acrylate composition is reacted with (meth) acrylic anhydride, and then the obtained reaction product is mixed with the carboxyl group-containing vinyl monomer and the other And a vinyl copolymer having a carboxyl group and a crosslinkable functional group obtained by reacting with a vinyl monomer.

The acrylic polyol resin (A) according to the present invention comprises, as a hydroxyl group-containing resin, the hydroxyl group-containing resin, a hydroxyl group-containing urethane resin, a hydroxyl group-containing epoxy resin, a hydroxyl group-containing cellulose derivative and a hydroxyl group-containing resin. It may be obtained using at least one resin selected from the group consisting of polyester resins.

In this case, as the hydroxyl group-containing resin, a hydrophobic resin having no self-water dispersibility should be used. In such hydrophobic non-self-dispersing resin,
It is possible to easily introduce a vinyl group by reacting a specific acid anhydride called (meth) acrylic anhydride.

This type of copolymer forms core-shell type particles having different hydrophobic portions and hydrophilic portions. Therefore, polyisocyanate compound (B) (hydrophobic crosslinking agent)
The dispersion stability after the incorporation of is the point where extremely excellent crosslinked particles are formed.

In addition, this type of copolymer has a high degree of neutralization of carboxyl groups, even after the phase inversion emulsification.
Since it has a shell structure, it does not become a water-soluble resin. In other words, it can be said that the resin system has an excellent ability to take in a hydrophobic substance such as a hydrophobic crosslinking agent.

Further, according to such a production method, the hydroxyl group-containing resin is not limited to a radical polymerization type resin, and it is also possible to use a condensation type resin in combination. There is an advantage that a suitable resin can be selected and used in accordance with various required corrosion resistance grades or applications. In addition, it can be said that there is no method for easily producing crosslinked particles using various condensation resins. The use of such novel crosslinked particles makes it possible for the first time to provide a new and useful paint having excellent corrosion resistance.

Incidentally, it is also possible to copolymerize the hydroxyl group-containing resin with a glycidyl group. Such a glycidyl group is contained in the core portion of the particle after the phase inversion emulsification, and is isolated from the carboxyl group contained in the shell portion of the adjacent particle. Thus, the glycidyl group is contained in the hydroxyl group-containing vinyl resin. In the case where is copolymerized, very good crosslinked particles having excellent dispersion stability (specifically, no gelation over time) can be obtained.

Some of the glycidyl groups react with carboxyl groups contained in the polyisocyanate compound (B) (hydrophobic crosslinking agent) after the particles are formed, or with the carboxyl groups contained in the core copolymer. , Which can increase the crosslink density. The glycidyl group remaining in the core also serves as a functional group for self-crosslinking the crosslinked particles during baking.

In the aqueous system, a high molecular weight type epoxy resin can be used in combination, and according to such a method, a low molecular weight epoxy resin such as "Epicoat 1001" (a product of Dainippon Ink and Chemicals, Inc.) can be used. Epoxy resins are also available. However, as an application, a field that does not require weather resistance is desirable.

Examples of the aromatic epoxy resin used include:
For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin and the like can be mentioned. Of these epoxy resins, those having an epoxy equivalent of 400 or more are desirably used, and those having an epoxy equivalent of 4,000 or more are also preferably used.

The epoxy equivalent in the range of 400 to 4,000 is, for example, “Epicoat 1001, 1004, 1007 or 1009” manufactured by Shell Co., The Netherlands, or Dainippon Ink and Chemicals, Inc.
"Epiclon 4055, 7055 or 90"
55 "and the like. Further, when the epoxy equivalent is 4,
000 or more, for example, Ciel
"Epicoat 1010 or 1100L" or Phenoxy resin manufactured by Union Carbide Co., USA, "P
KHA ”,“ PKHC ”,“ PKHH ”or“ PK
HJ ".

As the epoxy resin, various modified epoxy resins such as fatty acid-modified epoxy resin, phenol-based compound-modified epoxy resin or alcohol-based compound-modified epoxy resin can be used in addition to the above-mentioned ones.

The fatty acids used for these modifications include various vegetable oil fatty acids, such as soybean oil fatty acid or castor oil fatty acid; and various organic acids, such as benzoic acid or acetic acid. Examples of the compound include bisphenol A, phenol, and cresol. Examples of the alcohol compound include methanol, butanol, and benzene alcohol. These modifiers and aromatic epoxy resins can be used in the absence of a catalyst or in the presence of a suitable reaction catalyst such as tertiary amine or quaternary ammonium.
By heating to about 0 to 170 ° C., the respective modified epoxy resins as described above are obtained.

Of course, each of these groups of epoxy resins may be used alone, or a plurality of the epoxy resins in each group or a plurality of the two or more groups (combined use) may be used.

Further, a hydroxyl group-containing cellulose derivative can be used in combination. Such cellulose derivatives are a resin system excellent in oil resistance and solvent resistance, among others, and in such a point, crosslinked fine particles having characteristics different from those of the above-mentioned hydroxyl group-containing vinyl resin can be obtained.
However, it should be noted that cellulose derivatives have low hydrolysis resistance and heat yellowing resistance when used in an aqueous system, and their use may be limited in some cases.

The hydroxyl group-containing cellulose derivative is generally used for coatings, and examples thereof include an ester-modified hydroxyl group-containing cellulose derivative and an ether-modified hydroxyl group-containing cellulose derivative.

First, particularly representative examples of the above-mentioned ester-modified hydroxyl group-containing cellulose derivatives are given below.
Cellulose propionate, cellulose butyrate, cellulose phosphate or cellulose sulfate.

In addition, only typical representative examples of the above-mentioned ether-modified hydroxyl-containing cellulose derivatives include methyl cellulose, ethyl cellulose, and methyl cellulose.
Butylcellulose, benzylcellulose, carboxymethylcellulose, carboxyethylcellulose, aminoethylcellulose, oxyethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose or hydroxypropylmethylcellulose.

Among these hydroxyl group-containing cellulose derivatives, it is particularly desirable to use cellulose acetate butyrate (hereinafter referred to as CAB) obtained by further butyl esterifying a partially acetylated product of cellulose.

The number average molecular weight of the hydroxyl group-containing cellulose derivative used in the present invention is from 3,000 to 3
It is preferably in the range of 00000, 5,000 to 15
The range of 000 is particularly preferred. Further, as the content of hydroxyl groups in the hydroxyl group-containing cellulose derivative,
0.4% by weight or more is desirable. When the content of the hydroxyl group is less than 0.4% by weight, the (meth) acryloyl group that can be introduced into the hydroxyl group-containing cellulose derivative is inevitably reduced, so that the grafting rate is reduced, and the carboxyl group-containing modified polymer is consequently reduced. It is not preferable because self-emulsification tends to be difficult.

If only typical examples of commercially available products of the hydroxyl group-containing cellulose derivative are exemplified,
"CAB" series, "CAP" series or "CA" series manufactured by Eastman Kodak Company, USA.

A hydroxyl group-containing urethane resin can also be used in combination. By using the urethane resin, characteristics such as elasticity and flexibility due to the urethane resin can be obtained, and a corrosion-resistant coating film that is strong against impact can be obtained.

Such a hydroxyl group-containing polyurethane resin has, for example, an active hydrogen atom (active hydrogen group) in the molecule.
In the presence or absence of an organic solvent containing no, aliphatic and / or alicyclic diisocyanate, alkyl diol or polyether diol or polyester diol, or a mixture thereof, if necessary,
It is obtained by polymerizing a low molecular weight polyhydroxyl compound by a one-shot or multi-stage method at a OH / NCO variable ratio within a range of 1.1 to 1.9.

Here, if the OH / NCO equivalent ratio is less than 1.1, the hydroxyl value will inevitably become very small, and the introduction of vinyl groups will be insufficient, and eventually the carboxyl group-containing polymerizable monomer described later Copolymerization tends to be insufficient, and as a result, the water dispersibility is often reduced. On the other hand, if it is larger than 1.9, a low-molecular-weight one is inevitably formed, and various properties such as physical properties of the coating film are deteriorated.

The aliphatic diisocyanate and the alicyclic diisocyanate used in the production of such a hydroxyl group-containing polyurethane resin have a carbon number such as hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate or lysine diisocyanate. Aliphatic diisocyanates of 2 to 12 and the like are particularly typical examples of 1,4-cyclohexane diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate), 4 to 1 carbon atoms such as 4'-dicyclohexylmethane diisocyanate, methylcyclohexylene diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate
The alicyclic diisocyanates of No. 8 are particularly typical, and furthermore, modified products of these various diisocyanates (modified products containing carbodiimide, uretdione or uretoimine), or mixtures of two or more thereof Is mentioned.

Of these, preferred are alicyclic diisocyanates, especially 1,4-cyclohexane diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane or 4,4'-dicyclohexyl. Methane diisocyanate is exemplified. Here, when an aromatic diisocyanate is used, the coating film is liable to yellow during baking and curing, and the coating film is easily discolored by the influence of ultraviolet rays.

If only typical representative examples of polyether diols are given, ethylene oxide,
Such as propylene oxide or butylene oxide,
Various alkylene oxides; compounds obtained by polymerizing or copolymerizing various heterocyclic ethers such as tetrahydrofuran; or polyethylene glycol, polypropylene glycol, polyethylene-propylene glycol, polytetramethylene ether glycol, polyhexamethylene Ether glycol and the like.

As typical examples of polyester diols, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, poly-3-methylpentyl adipate, polyethylene / butylene adipate, Dicarboxylic acids such as adipic acid, succinic acid, sebacic acid, maleic acid, fumaric acid, and phthalic acid, such as polyneopentyl / hexyl adipate, and ethylene glycol, propylene glycol, and 1,4-butanediol , 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, compounds obtained by condensation polymerization with glycols represented by bishydroxymethylcyclohexane and the like; or poly Caprolactone diol, poly -3
Polylactone diols typified by -methylvalerolactone diol; polycarbonate diols; or a mixture of two or more of these.

As typical examples of the alkyl diol, fatty acid esters of glycerin are exemplified.

If only low-molecular-weight polyhydroxyl compounds are particularly typical ones, the number-average molecular weight is less than 500. , Glycols and their low alkylene oxide low molecular adducts (molecular weight = less than 500); various trihydric alcohols represented by glycerin or trimethylolpropane and their low alkylene oxide low molecular adducts (molecular weight) = Less than 500); or a mixture of two or more of these.

The amount of the low molecular weight polyhydroxyl compound is usually in the range of 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on the above-mentioned polyether diol or polyester diol. Within the range is appropriate.

The polyether diols and / or polyester diols used for preparing the urethane resin described above have a number average molecular weight of 500 to 500.
5,000, preferably 1,000
Those in the range of 3,000 to 3,000 are used. If the number average molecular weight is less than 500, it becomes inevitably a hard urethane resin, and it is difficult to obtain a resin having desired coating film properties. The molecular weight is also higher, resulting in a lower hydroxyl number and consequently insufficient vinyl modification.

Further, as will be described later, the compatibility of various polymerizable monomers including various carboxyl group-containing polymerizable monomers with copolymers, adhesion to coatings (substrates), etc. It is a matter of course that a carboxyl group may be introduced for the purpose of improving the molecular weight. Specifically, for example, it is introduced by reacting various dimethylolalkanoic acids such as dimethylolpropionic acid. However, the introduction of a hydrophilic group such as a carboxyl group increases the hydrophilicity of the urethane resin, and thus reduces the water resistance of the coating film. Better.

Similarly, a polyester-based resin can be used in combination as a hydroxyl group-containing resin. However, if the molecular weight is small, a problem arises in hydrolysis resistance in an aqueous system.
On the other hand, if the molecular weight is large, the modification is inevitably insufficient, and the cross-linking density cannot be increased due to the insufficient cross-linking functional group amount. Therefore, there is a tendency that the solvent resistance is poor.

The various hydroxyl group-containing resins listed above can be mixed with (meth) acrylic anhydride in an inert organic solvent in the absence of a catalyst at a relatively low temperature of about 60 to 80 ° C. By reacting with stirring for about 1 to 6 hours, a vinyl group can be introduced into the resin.

The reaction (esterification) at this time is performed by using, for example, a Fourier transform infrared photometer (FI-IR).
(Meth) acrylic anhydride, a specific acid anhydride absorption is no longer recognized or a low constant value is read in order to perform the reaction. You can do it.
Note that, of course, the confirmation means is not limited to this.

As the inert organic solvent used in the synthesis of the hydroxyl group-containing resin and the reaction with the anhydride used in the present invention, only typical examples of the inert organic solvent are exemplified, and acetone, methyl ethyl ketone, methyl Various ketones, such as isobutyl ketone, ethyl propyl ketone, and ethyl butyl ketone; esters; and aromatic hydrocarbons, are preferably used.

The modification amount of the anhydrous (meth) acrylic compound is such that the amount of the modified (meth) acrylic acid is 0.5 to 30% with respect to the hydroxyl equivalent contained in 100 g of various hydroxyl group-containing resins. ) Acrylic acid is reacted. If the amount of modification is less than 0.5%, the introduction of vinyl groups becomes insufficient, and the copolymerization with monomers to be subsequently copolymerized becomes insufficient, and the water dispersibility decreases. On the other hand, if it is more than 30%, it is not preferable because it is subsequently copolymerized to have a high molecular weight and gelation easily occurs.

The vinyl group-modified hydroxyl group-containing resin thus obtained is reacted with various vinyl monomers having a carboxyl group-containing vinyl monomer as an essential component to obtain the desired acrylic polyol resin (A ) Is obtained.

When the acrylic polyol resin (A) is obtained, a blend of two or more vinyl group-modified hydroxyl group-containing resins is also possible. For example, in the case of a hydroxyl group-containing resin, a glycidyl group-containing copolymer and the low lactone-modified hydroxyalkyl (meth) acrylate composition according to the present invention can be used alone or in a copolymer. It is also possible to control the crosslink density by blending with a copolymer that does not contain it.

In this case, the cross-linking agent and the glycidyl group respectively correspond to IPN (Interpenetrati).
ng polymer network (interpenetrating polymer network) shows better corrosion resistance because of the formation of a crosslinked structure. Also, by blending a hydroxyl group-containing resin with a hydroxyl group-containing urethane resin, it is possible to effectively bring out the flexibility of the urethane resin and the establishment of a vinyl copolymer. In this case, even if different kinds of resins are copolymerized at the same time, they are partially connected by a chemical bond, so that the compatibility is improved and the coating film is hardly clouded.

The polymerizable monomers to be (co) polymerized with the vinyl group-modified hydroxyl group-containing resin include:
Basically, a type in which at least 10% by weight of a carboxyl group-containing vinyl monomer is contained in all polymerizable monomers is used. When the use amount of the carboxyl group-containing vinyl monomer is less than 10% by weight,
This is not preferable because the dispersion stability of the resin in the aqueous medium tends to deteriorate. For example, examples of the carboxyl group-containing vinyl monomer and other vinyl monomers include those described above. By the way, as the reaction ratio of the vinyl-modified hydroxyl group-containing resin described above and the polymerizable monomer containing various carboxyl groups,
The weight ratio of the former resin to the latter monomer is from 20:80 to
A range of 90:10 is appropriate.

It is not preferable that the proportion of the resin to be used with the vinyl-modified hydroxyl group-containing resin is less than 20% by weight because various properties of the resin cannot be utilized in some cases. 90% by weight
If it is larger than this, the number of carboxyl groups will inevitably decrease, and the resulting resin will have insufficient self-dispersibility, and in many cases will not be able to disperse in an aqueous medium, which is not preferable.

The polymerization reaction between various polymerizable monomers including the above-mentioned carboxyl group-containing vinyl monomer and the vinyl-modified hydroxyl group-containing resin is carried out in an inert organic solvent.
It is carried out at a temperature of about 60 to 150 ° C. using various known and commonly used radical polymerization initiators such as azobisisobutyronitrile or benzoyl peroxide.

In carrying out this reaction, various organic ketones such as acetone, methyl ethyl ketone or diisobutyl ketone; And aromatic hydrocarbons. Further, various ester solvents such as ethyl acetate or butyl acetate can also be used.

The method for producing the crosslinked particles in the present invention is to mix the above-mentioned various acrylic polyol resins (A) (self-dispersible resin) with the polyisocyanate compound (B) (hydrophobic crosslinker). After that, a hydrophobic cross-linking agent is encapsulated in the particles by emulsifying phase inversion in an aqueous medium, and then the cross-linking is accelerated in the particles to obtain the desired cross-linked particles. It is.

The polyisocyanate compound (B) used in the present invention is an aromatic, aliphatic or alicyclic polyisocyanate. The aromatic polyisocyanate has 6 to 30 carbon atoms. The aliphatic polyisocyanate preferably has 4 to 30 carbon atoms, and the alicyclic polyisocyanate preferably has 8 to 30 carbon atoms. For example, 2,4-naphthalenediisocyanate,
1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4'-diphenylene diisocyanate, 4,4'-dibenzyl Diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate such as 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, P-xylylene diisocyanate and m-xylylene diisocyanate Xylylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,
6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene-1,6-diisocyanate,
2,4,4-trimethylhexamethylene-1,6-diisocyanate, lysine diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, 4,4'-diisocyanate dicyclohexane, dicyclohexylmethane-4,4'-diisocyanate, , 3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane-2,4 (or 2,
6) -Methylcyclohexane diisocyanate such as diisocyanate, or a polyhydric alcohol such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, polycaprolactone polyol, trimethylolethane, or trimethylolpropane, or an isocyanate group. Polyester resin having a reactive functional group (including oil-modified type), acrylic resin, etc., adduct with water, etc., biuret, polymer reacted with isocyanate, or 2-hydroxypropyl (meth) acrylate -Vinyl monomers having isocyanate groups and copolymerizable unsaturated groups, such as hexamethylene diisocyanate equimolar adducts and isocyanate ethyl (meth) acrylate Is an essential component or a copolymer as disclosed in JP-A-61-72013, or is blocked with a blocking agent such as lower monohydric alcohol, phenols, methyl ethyl ketoxime or lactam. Are typical examples. One of these diisocyanates may be used, or two or more thereof may be used in combination.

From the viewpoint of the color tone of the coating film obtained by using the curable resin composition of the present invention, the polyisocyanate compound to be used is preferably a non-yellowing type polyisocyanate. Disclosed. Aliphatic polyisocyanates such as 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, and lysine diisocyanate One drop: isophorone diisocyanate, methylcyclohexane-2,4 (or 2,6)
Diisocyanate, dicyclohexylmethane-4,
Examples include alicyclic polyisocyanates such as 4′-diisocyanate and 1,3-bis (isocyanatomethyl) cyclohexane, and the above-mentioned derivatives (including adducts). Among them, 1,6-hexamethylene diisocyanate (hereinafter referred to as H
MDI), isophorone diisocyanate (hereinafter I)
PDI) and their derivatives (including adducts).

The polyisocyanate compound has a problem that it is inferior in storage stability because it reacts with the polyols at the base even at room temperature, and is complicated in handling and unfavorable in terms of safety and hygiene. Is preferably a block type. Block-type polyisocyanate (hereinafter sometimes also referred to as hyperbranched block polyisocyanate) can be obtained simply by reacting the polyisocyanate with a polyhydric alcohol, but more preferably after reacting a diisocyanate with a polyhydric alcohol,
It is obtained by cyclic trimerization of isocyanate, in other words, isocyanuration.

The polyhydric alcohol in this case is preferably a trihydric or higher alcohol. Examples of the low molecular weight polyhydric alcohol include trimethylolpropane, glycerin, 1,1,7-trimethylolheptane, 1,2,7
-Trimethylol heptane, pentaerythritol and the like. Examples of the high molecular weight polyhydric alcohol include aliphatic hydrocarbon polyols, polyether polyols, polyester polyols, and epoxy resins having a plurality of hydroxyl groups at terminals.

The aliphatic hydrocarbon polyols include, for example, terminal hydroxylated polybutadiene and hydrogenated products thereof. Examples of the polyether polyols include, for example, polyether polyols obtained by adding an alkylene oxide such as ethylene oxide and propylene oxide alone or a mixture thereof to a polyhydric alcohol such as glycerin and propylene glycol alone or as a mixture, and polytetraols. Methylene glycols, further obtained by polymerizing acrylamide and the like with polyethers obtained by reacting polyfunctional compounds such as ethylenediamine and ethanolamines with alkylene oxide,
So-called polymer polyols and the like are included.

As the polyester polyols, polyester polyol resins obtained by a condensation reaction of a polybasic acid alone or a mixture with a polyhydric alcohol alone or a mixture and, for example, ε-caprolactone are ring-opened using a polyhydric alcohol. And polycaprolactones obtained by polymerization. Examples of the polybasic acid include (phthalic anhydride), terephthalic acid, isophthalic acid,
Tetrahydro (anhydride) phthalic acid, hexahydro (anhydride)
Phthalic acid, 4-methylhexahydro (anhydride) phthalic acid,
3-methylhexahydro (anhydride) phthalic acid, 3-methyltetrahydro (anhydride) phthalic acid, (anhydride) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) hetic acid, (anhydride) hymic acid, adipic acid, Sebacic acid, azelaic acid, succinic acid (anhydride), maleic anhydride, fumaric acid,
Examples include itaconic acid, dimer acid, dimethyl isophthalate, dimethyl terephthalate, and the like. The polyhydric alcohol is a compound having two or more alcoholic or phenolic hydroxyl groups in one molecule. Specifically, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,6
-Hexanediol, pentanediol, cyclohexanone dimethanol, propylene glycol, butylene glycol, butylene diglycol, trimethylolethane, trimethylolpropane, glycerin, neopentylglycol, sorbitol, tris (2-hydroxyethyl) isocyanurate, diethanolamine, diethanolamine Examples include isopropanolamine, bisphenol A, bisphenol F, and the like.

Examples of epoxy resins include novolak type, β-methyl epichloro type, cyclic oxirane type, glycidyl ether type, glycol ether type, epoxy type of aliphatic unsaturated compound, epoxidized fatty acid ester type,
Epoxy resins of polycarboxylic acid ester type, aminoglycidyl type, halogenated type, resorcinol type and the like can be mentioned.

Preferred among these polyols are the above-mentioned low molecular weight polyhydric alcohols and polyether polyols having 3 to 8 hydroxyl groups in one molecule, aliphatic hydrocarbon polyols and polyester polyols. Particularly preferred are It is a polyester polyol. These may be used alone or in combination of two or more. Aliphatic / alicyclic diisocyanate and polyhydric alcohol are 50 to 200
C., preferably at 50 to 150.degree. At this time, a solvent may be used, but a solvent inert to the isocyanate is preferably used. As such an inert organic solvent, for example, hexane, heptane, octane and other aliphatic hydrocarbons, benzene, toluene, xylene and other aromatics, esters, ketones and the like, or a mixed solvent is used. Can be Since these solvents may contain water, they are preferably dehydrated as necessary. This reaction can be performed after the isocyanuration reaction, but is preferably performed before the isocyanuration reaction.

A catalyst is usually used for the isocyanurate-forming reaction. In general, the catalyst used here is preferably a basic one, and examples thereof include quaternary ammonium salts, their organic weak acid salts, alkyl metal salts of alkyl carboxylic acids, metal alcoholates, and compounds containing an aminosilyl group. The catalyst concentration is usually selected from the range of 210 ppm to 1.0% based on the isocyanate compound.

The reaction may or may not use a solvent. If a solvent is used, a solvent inert to the isocyanate groups should be used. The reaction temperature is usually 20 to
160 ° C, preferably 40 to 130 ° C. The end point of the reaction depends on the polyhydric alcohol used, but the yield is generally 3
0% or more. When the reaction reaches the target yield, the reaction is stopped by deactivating the catalyst with, for example, sulfonic acid, phosphoric acid, phosphate ester, or the like.

The viscosity at 25 ° C. of the hyperbranched polyisocyanate having an isocyanurate structure by removing unreacted diisocyanate and solvent is preferably 0.5 to 300 Pas. If the viscosity exceeds 300 Pas, the appearance of the coating film may be adversely affected.

Examples of the blocking agent used for obtaining a highly branched blocked polyisocyanate include phenol, cresol, xylenol, ethylphenol,
butylphenol such as o-isopropylphenol and p-tert-butylphenol, p-tert-octylphenol, nonylphenol, dinonylphenol, styrenated phenol, oxybenzoic acid ester,
Thymol, p-naphthol, p-nitrophenol, p
-Phenols such as chlorophenol; alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, butyl cellosolve, methyl carbitol, benzyl alcohol, phenyl cellosolve, furfuryl alcohol, cyclohexanol; dimethyl malonate, malon Active methylene systems such as diethyl acid, methyl acetoacetate, ethyl acetoacetate, and acetylacetone; mercaptan systems such as butyl mercaptan, thiophenol, tert-dodecyl mercaptan; amine systems such as diphenylamine, phenylnaphthylamine, aniline, carbazole; acetanilide;
Acid amides such as acetanisidide, acetate amide and benzamide; ε-caprolactam, δ-valerolactam, γ
Lactams such as butyrolactam and β-propiolactam; acid imides such as succinimide and maleic imide; imidazoles such as imidazole, 2-methylimidazole and 2-ethylimidazole; urea, thiourea;
Urea such as ethylene urea; carbamic acid salt such as phenyl N-phenylcarbamate and 2-oxazolidone: imine such as ethylene imine and polyethylene imine; formaldoxime, acetoaldoxime, acetoxime, methyl ethyl ketoxime, methyl isobutyl Oximes such as ketoxime and cyclohexanone oxime; bisulfites such as sodium bisulfite and potassium bisulfite, and the like may be used alone or as a mixture. Of these, preferred are phenols, lactams, alcohols and oximes, especially nonylphenol, styrenated phenol, oxybenzoic acid esters, acetoxime, methylethylketoxime,
ε-caprolactam is preferred. Low temperature baking (140
C. or lower) is particularly preferable.

By reacting the above-mentioned blocking agent with a highly branched polyisocyanate, a highly branched blocked polyisocyanate can be obtained. The reaction between the isocyanate and the blocking agent can be performed with or without the presence of a solvent.
When a solvent is used, it is necessary to use a solvent inert to isocyanate groups.

At the time of the blocking reaction, an organic metal salt such as tin, zinc and lead, and a tertiary amine may be used as a catalyst. The reaction can be generally performed at -20 to 150 ° C, but preferably at 0 to 100 ° C. If the temperature is higher than 100 ° C., a side reaction may occur.

The blocked polyisocyanate used in the present invention has an average number of blocked isocyanate functional groups per molecule of 4.5 to 10, preferably 5 to 8.

The average number of blocked isocyanate functional groups of the blocked polyisocyanate is the number of blocked isocyanate functional groups statistically possessed by one molecule of the blocked polyisocyanate, and is calculated from the number average molecular weight of the polyisocyanate before blocking and the isocyanate concentration (%). It can be calculated by the following equation (1).

[0097]

(Equation 1)

Particularly representative examples of the polyisocyanate compound used as the hydrophobic crosslinked particles described above include:
Various toluene diisocyanate (TDI) polyisocyanates represented by trimethylolpropane (TMP) adduct prepolymer; various hexamethylene diisocyanate (HMDI) polyisocyanates represented by TMP adduct prepolymer HMDI polyisocyanates as burette type or HMDI polyisocyanates as isocyanurate prepolymer; isophorone diisocyanate (IPDI) prepolymers as isocyanurate prepolymer; TMP adduct prepolymer Various types of xylylene diisocyanate (XDI) -based polyisocyanates as represented;
Alternatively, 4,4′-diphenylmethane diisocyanate (MDI) polyisocyanates and the like.

An epoxy resin can be used in combination as the hydrophobic crosslinked particles. In particular, to exemplify only typical examples, "Epicoat 828 or 1001" which is of bisphenol A type manufactured by Yuka Shell Co., Ltd .; Epoxidized polybutadiene manufactured by Adeka Argus Co., Ltd .; Dow Chemical's phenol novolak epoxy resin "DEN431, 438, X
D-7818 or XD-7855 "or" DE
R331 ";or" ECN268, 2 which is a cresol novolak type epoxy resin manufactured by Asahi Kasei Chemical Corporation.
73, 280, 285 or 299 "; or polyfunctional glycidylamines or polyfunctional glycidyl ethers. Further, as this type of epoxy compound, glycidyl group-containing copolymers obtained by copolymerizing glycidyl (meth) acrylate can also be used.

In the present invention, the urethane bond formed by using the polyisocyanate compound has, in particular, excellent properties such as chemical resistance, hydrolysis resistance and various physical properties as compared with other ether bonds and ester bonds. Aspects of the present invention are particularly desirable because they can be extracted.

The acrylic polyol resin (A) and the polyisocyanate compound (B) according to the present invention constitute the main components of the curable resin composition of the present invention, and are used as a raw material for a coating. The equivalent ratio of the isocyanate group or the blocked isocyanate group in the polyisocyanate to the hydroxyl group in the hydroxyl group-containing resin is determined by the required physical properties of the coating film. The mixing ratio of the acrylic polyol resin (A) and the polyisocyanate compound (B) obtained by using the low lactone-modified hydroxyalkyl (meth) acrylate composition in the present invention is determined from the viewpoint of coating film performance.
It is preferable to mix them so that /NCO=1/0.5 to 1 / 1.5 (equivalent ratio). Especially, OH / NCO = 1 / 0.7-1
/1.2 (equivalent ratio). OH1
If the NCO is less than 0.5 equivalent to the equivalent, predetermined film properties such as extensibility, weather resistance, solvent resistance, and stain resistance are not obtained. If the NCO is more than 1.5 equivalent, the coating properties are not obtained. However, it is not preferable in that it is easy to fire at a high temperature and the price of paint becomes high.

The curable resin composition of the present invention comprises an acrylic polyol resin (A) 2 obtained by using a low lactone-modified hydroxyalkyl (meth) acrylate composition.
0 to 80 parts by weight and polyisocyanate compound (B)
It contains 5 to 50 parts by weight as an essential component. However,
The sum of (A) and (B) does not exceed 100 parts by weight. When the amount of the acrylic polyol resin (A) is less than 20 parts by weight, the amount of the hydrophilic portion which is responsible for water dispersibility is insufficient, and the water dispersion stability is reduced. When the amount exceeds 90 parts by weight, workability and water dispersibility deteriorate, Not preferred. If the amount of the polyisocyanate compound (B) is less than 5 parts by weight, curing will be insufficient, while if it exceeds 50 parts by weight, the cured coating film will be too hard or brittle, which is not preferable. The usage ratio of the acrylic polyol resin (A) to the polyisocyanate compound (B) is 60 to 90% by weight of the polyisocyanate compound (B) based on 40 to 90% by weight of the acrylic polyol resin (A). When the use ratio of the acrylic polyol resin (A) is less than 40% by weight, the self-condensation reaction between the polyisocyanate compounds increases, and the coating film becomes brittle. For example, it is suitable as a paint for a polyolefin resin molded article. Not. On the other hand, when the use ratio of the acrylic polyol resin (A) is more than 10% by weight, the crosslinking becomes insufficient, and the solvent resistance and the weather resistance decrease. The preferred usage ratio of the acrylic polyol resin (A) is 60 to 80% by weight, and therefore, the preferred usage ratio of the polyisocyanate compound (B) is 20 to 40% by weight. If the amount of the polyisocyanate compound (B) is less than 20% by weight, curing will be insufficient, and the intermolecular crosslink density will inevitably decrease. As a result, the characteristics using the crosslinked particles cannot be sufficiently exhibited. easy. On the other hand, if it exceeds 40% by weight, the cured coating film becomes too hard, and phase inversion emulsification becomes difficult, or
Either case is not preferable because it often becomes impossible at all.

The present invention basically relates to a method in which a mixture of an acrylic polyol resin (A) having a carboxyl group and a crosslinkable functional group and a polyisocyanate compound (B) (hydrophobic crosslinking agent) is used in an aqueous medium. A process for producing crosslinked particles, comprising dispersing and crosslinking in water, or a polymer comprising at least a low lactone-modified hydroxyalkyl (meth) acrylate composition in water in which crosslinked urethane-urea particles are dispersed. It is intended to provide a method for producing urethane-urea / ethylene resin composite type crosslinked particles obtained by polymerizing a water-soluble ethylenically unsaturated compound. In addition, various crosslinked particles thus obtained are required. Another object of the present invention is to provide a paint which is contained as a film-forming resin component.

Here, the specific crosslinked particles used in the present invention are, first, an acrylic polyol resin (A) having a carboxyl group and a crosslinkable functional group, a polyisocyanate compound (B) (hydrophobic crosslinker) and Mixture of
It is obtained by dispersing in an aqueous medium and crosslinking.

That is, the above-mentioned acrylic polyol resin (A) used in producing specific crosslinked particles is obtained by reacting a carboxyl group as a hydrophilic segment with a polyisocyanate compound (B) (hydrophobic crosslinker). A so-called self-water dispersible resin having a crosslinkable functional group that can be combined with a non-continuous O / W by emulsifying phase inversion by adding water to the organic continuous phase (O). It refers to a resin that forms a phase.

In this regard, the water-soluble resin basically has different characteristics. Further, such a self-water-dispersible resin is accompanied by a physicochemical phenomenon called phase inversion emulsification from an organic phase to an aqueous phase, and has the ability to form O / W particles in an aqueous medium, At that time, a hydrophobic substance can be incorporated into the particles.

The present invention utilizes such characteristics of the self-water dispersible resin to perform phase inversion emulsification of the polyisocyanate compound (B) (hydrophobic crosslinking agent) together with the self-water dispersible resin into an aqueous medium. By incorporating the cross-linking agent (B) into the particles, and then, by allowing the cross-linking reaction to proceed,
An object of the present invention is to provide a highly crosslinked particle which has not existed before. Further, a coating containing such crosslinked particles as an essential component gives a very excellent corrosion-resistant coating film.

If the acrylic polyol resin (A) is a water-soluble resin, the particles are formed with a hydrophobic crosslinking agent as a nucleus, so that the stability in an aqueous medium becomes insufficient and the crosslinking reaction proceeds. It becomes easy to gel on the way. Alternatively, it tends to gel over time.

The crosslinked particles obtained by the production method of the present invention are obtained by mixing the acrylic polyol resin (A) (self-dispersible resin) and the polyisocyanate compound (B) (hydrophobic crosslinking agent), The substance is added and dispersed in the aqueous medium.

As the basic raw material used here, volatile tertiary amines are desirably used. On the other hand, the inorganic basic compound remains in the coating film to deteriorate the water resistance. It is not preferable because of the tendency. As the above-mentioned amines, only typical ones are exemplified. Various alkylamines such as trimethylamine or triethylamine; various alcoholamines such as dimethylaminoethanol, diethanolamine or aminomethylpyropanol Or various cyclic amines such as morpholine.

Next, after dispersing in an aqueous medium, the solvent is removed if necessary. First, when the polyisocyanate compound is contained, the mixture is heated at 50 to 60 ° C. for about 1 hour. In the case of containing the epoxy resin together, the heating is performed at about 80 ° C. for about 1 to 2 hours to promote the crosslinking,
Thereafter, dehydration is performed to obtain a crosslinked particle-containing aqueous dispersion having a desired solid content.

In the present invention, the following types of urethane / acrylic resin composite type crosslinked particles can also be used. That is, 1) first, an aqueous dispersion of crosslinked urethane particles is separately prepared, and 2)
In the aqueous dispersion, the low-polymerizable vinyl monomer according to the present invention is dropped and polymerized in the presence of a radical initiator (a polymerization method called so-called seed polymerization). It is of the type that can be obtained.

Here, there are roughly three methods for obtaining an aqueous dispersion of crosslinked urethane particles. Those skilled in the art are all well known in the art, and therefore will only be briefly described. After emulsification in the presence of a water-soluble resin for use, a polyamine or the like as a cross-linking agent is added to cross-link the terminal isocyanate groups, thus obtaining the desired cross-linked particles.

As a second method, an anionic, cationic or nonionic hydrophilic group is pendant in a polyisocyanate prepolymer molecule having an isocyanate group at a molecular terminal, whereby In this method, the prepolymer is self-emulsified without using an auxiliary agent such as an emulsifier, and then, as described above, a polyamine or the like as a cross-linking agent is added to form cross-linked particles.

As a third method, the same prepolymer as in the above-mentioned second method and a hydrophobic polyisocyanate compound are mixed, and then these are phase-inverted and emulsified in an aqueous medium, and the particles are mixed. After encapsulating this hydrophobic polyisocyanate compound, polyamines or the like as a cross-linking agent are added to form cross-linked particles.

Of these, in both the second and third methods, it goes without saying that auxiliary agents may be used in combination. However, considering the later, there is no such combination. It has never passed. For this reason, in the present invention, it is desirable to use an aqueous dispersion of crosslinked urethane particles obtained by the second or third method without using so-called auxiliary agents such as an emulsifier. I can say that there are many.

In the step of polymerizing a polymerizable vinyl monomer such as the low lactone-modified hydroxyalkyl (meth) methacrylate ester composition of the present invention using the aqueous dispersion of crosslinked urethane particles as a seed, The essential part is that a crosslinked urethane aqueous dispersion is used as a seed body, and, of course, a conventionally known method can be used as it is as a polymerization method of a vinyl monomer.

As the radical initiator, any of water-soluble and oil-soluble radical initiators can be used. Among them, the use of a water-soluble radical initiator is simpler and more convenient. This can be said to be desirable in that it can also contribute to the dispersion stability of the obtained composite resin aqueous dispersion.

The weight ratio of the solid content of the crosslinked urethane resin (GU) to the polymerizable vinyl monomer (VM) is 0/1.
Although the range of 00 <GU / VM <100/0 is possible, if the use of auxiliary agents such as emulsifiers is completely absent, the gel density (crosslink density) of the gel / urethane used In general, the range of 20/80 <GU / VM <100/0 is appropriate, though it depends on the dispersion stability.

However, the main purpose of the composite is to form the crosslinked urethane resin (GU) and the polymer based on the polymerizable vinyl monomer (VM) such that both resins have the characteristics of both resins. Therefore, in order to express the various properties of both resins to a certain extent, in any case, 10/90 <GU /
VM <90/10, preferably 25/75
A range of <GU / VM <75/25 is appropriate and particularly recommended.

The polymerizable vinyl monomer may be added dropwise to the seed system maintained under the reaction temperature condition, or the polymerizable vinyl monomer may be swelled and absorbed in the seed particles in advance. This may be dropped into a system maintained under the reaction temperature conditions. Since the main purpose of such dropping is to control the heat of reaction involved in the polymerization, the dropping method is not particularly limited.

In the thus obtained crosslinked urethane resin / vinyl resin composite type aqueous dispersion, when a polyfunctional vinyl monomer is used in combination, the network of both resins becomes
It is in the form of a so-called IPN that is entangled with each other, and has even more excellent solvent resistance, chemical resistance, high tension, and the like.

In the present invention, a coating film excellent in corrosion resistance and the like is formed from a coating material containing crosslinked particles having the above-mentioned properties as an essential film-forming resin component. The present inventors will call this a gel particle film formation method. That is, the present invention
Liquid paint (liquid paint) on the surface to be coated, for example, metal surface
Is applied and dried to form a corrosion-resistant metal coating film or a corrosion-resistant decorative metal coating film. As a liquid coating agent, the above-mentioned crosslinked particles having a particle size of 1 micron (μm) or less are indispensable. As the film-forming resin component, a coating agent containing more than 50% by weight is used.
An object of the present invention is to provide a method of forming a corrosion-resistant metal coating film, that is, a method of forming a film by performing a heat treatment at a temperature of about 350 ° C. for a required time for a required time, that is, a method of forming a gel particle. .

That is, the gel particle film forming method is as follows.
Depending on the design level of the crosslinked particles, the crosslinked particles can crosslink each other to form a continuous film, or a crosslinker can be used in combination to crosslink particles / particles to form a continuous film. In addition, what is possible, furthermore, in the conventional film forming method as a cross-linking agent, even if a melamine resin-based curing agent is used in combination, there are some disadvantages and, consequently, some problems. Have been found not to occur, and the present invention has been completed.

In short, the main component of the film-forming resin is formed by cross-linked particles which are formed of strong bonds to various chemicals such as acids and alkalis, and are also cross-linked to solvents to such an extent that they do not easily swell. By being a component, the cross-linking that connects the particles is formed when a melamine resin-based curing agent is used, even if the bond is weak in chemical resistance, such as a methylene ether bond, the bond is formed by the cross-linked particles. It is presumed that the protection from the four sides makes it less susceptible to direct attack by chemicals, and, as a result, has the advantage of suppressing the occurrence of problems such as decomposition.

Furthermore, it should be noted that the crosslinked particles are truly unique monomolecular compounds having a gelled (crosslinked) macromolecular weight. Roughly speaking, the molecular weight of a monomolecular compound particle having a size of 1 μm is
Will be at least 300,000,000.

Needless to say, the conventional film-forming resin used in the form of a paint is at the level of a so-called prepolymer, and although its molecular weight can be said to be high, it is at most about 100,000. Things.

The gel forming method according to the present invention is based on the fact that starting from macromolecular weight crosslinked particles in comparison with the number of chemical bonds required to form a crosslinked gel film having a sufficiently high molecular weight by forming a crosslinked film. In the membrane method, it is sufficient that the number of occurrences of chemical bonds is as small as one digit, that is, the number of occurrences of one chemical per 300 million forms a continuous cross-linked gel coating, and therefore, the formation of a coating formed. The molecular weight will reach tremendous levels.

In other words, this type of gel particle film forming method starting from a macromolecule requires substantially fewer chemical bonds during film formation than the conventional method. It will be good.

This means that, for example, temperature, time, or the amount of catalyst used as a condition necessary to induce a chemical bond is reduced or shortened altogether. In particular, when a cross-linking agent is used in combination, the amount used can be further reduced. This is also one of the major features of the present invention.

In the composition of the liquid coating composition (liquid coating composition) according to the present invention, the crosslinked particles should contain more than 50% by weight as a film-forming resin component (film-forming resin component). It is desirable. Even if the content is less than 50% by weight, a certain effect is exhibited, but of course, it cannot be said to be sufficient. Preferably,
70% by weight or more.

In order to obtain a glossy and smooth coating surface,
It is absolutely necessary that the particle size is 1 μm or less, and it can be said that the smaller the particle size, the more preferable. Also, having a specific chemical bond of urethane bond, the resulting coating film is hard and tough,
It is desirable because it is tough.

By providing so-called active atomic groups (polar groups) such as hydroxyl groups, carboxyl groups or glycidyl groups or urethane bonds in the particles, respectively,
A continuous film can be formed here by causing the gel particles to self-crosslink or to form a crosslink between the particles in combination with a curing agent (crosslinking agent).

The crosslinking reaction is usually induced under forced heating and is completed. Although it depends on the type of the reactive active group (reactive polar group) involved in the cross-linking reaction, it is necessary that the temperature be 100 ° C. or higher, preferably 120 ° C. or higher in order to perform the treatment within an appropriate time. Necessary both.

If the reactive active group (reactive polar group) is any of various unsaturated bonds such as a vinyl bond, irradiation with ultraviolet rays, electron beams or the like also causes irradiation with a so-called radiation. Heating is not necessary, but heating is desirable in order to promote close fusion of particles and facilitate reaction.

When a curing agent is used in combination, various compounds such as a melamine resin, a phenol resin and a polyisocyanate compound can be used as the curing agent.
The use of a melamine resin is desirable in order to obtain a light-colored coating film through heating or exposure.

For example, in the case of a water-based paint, a water-soluble or water-dispersible melamine resin can be mentioned. Of those, only typical ones are exemplified.
"MW12LF" [product of Sanwa Chemical Co., Ltd.], "Nikarac MW-30" [Nippon Carbide Chemical Industry Co., Ltd.]
Products) or various kinds of hexamethoxymethyl melamines such as "Sumimar M-100C" (manufactured by Sumitomo Chemical Co., Ltd.) and various kinds of products such as "Sumimar M-40W" or "Sumimar M-30W" (ibid.). And methoxymethylmelamine having a free methylol group.

A water / methanol mixed solvent (weight ratio =
35/65) is 20% by weight or less.
A so-called hydrophobic melamine resin may be used in the form of a melamine resin dispersed in a water-soluble resin or a dispersant, but hexamethoxy melamine resin is preferred.

The amount of the curing agent used is appropriately in the range of 1 to 25% by weight, preferably in the range of 3 to 15% by weight, based on the amount of the crosslinked particles. A thermoplastic resin having a reactive active group (reactive polar group) can be used in combination as a film-forming resin component other than the cross-linking particles and the curing agent represented by the above-described melamine resin. An appropriate amount of the active group-containing thermoplastic resin is 30% by weight or less, preferably 20% by weight or less in the film-forming resin component.

As the amount of use other than the hardener component increases, the inherent properties of the gel film are impaired, and the effect of exhibiting the desired property of high corrosion resistance is impaired.

When the average molecular weight between crosslinks of the various crosslinked particles described above is in the range of 300 to 2,000,
The coating of the present invention containing the crosslinked particles as an essential component has more preferable corrosion resistance. By the way, the average molecular weight between crosslinks referred to here is a weighted average obtained by calculating the average molecular weight per functional group involved in crosslink in each of the compounded resins (including the hydrophobic crosslinker). This is indicated by the value of

The film forming temperature of the crosslinked particles at this time is desirably 100 ° C. or less. Even when various solvents are used as a film forming aid, the film forming temperature is still 100 ° C.
Unless a higher heat is applied, if the crosslinked particles do not form a film, it is one of the objects of the present invention, from the point where it becomes difficult to obtain a coating film excellent in corrosion resistance, on the composition, or The film forming temperature should be designed to be 100 ° C. or less from the viewpoints of, for example, the crosslinking density.

When the average molecular weight between crosslinks is less than 300, that is, when the crosslink density in the particles is extremely high, it necessarily affects the film forming temperature and causes fusion between particles or film formation. (Film formation) becomes difficult,
It is not preferable because various properties as a coating film are impaired.
On the other hand, if the average molecular weight between crosslinks is too large exceeding 3,000, that is, if the crosslink density in the particles is low, the particles will inevitably swell with respect to the solvent, and thus the solvent resistance will decrease. This is also not preferred.

In the paint of the present invention, of course, a pigment can be included in the crosslinked particles which are an essential component of the paint. By enclosing the pigment in the crosslinkable particles, the present invention eliminates all the drawbacks, such as the dispersibility and color separation of the pigment, which have been a problem so far. It has the merit that it is also released from.

In particular, in the case of an aqueous system, there is no good dispersant, and a method is employed in which a pigment is dispersed in a water-soluble resin, and a pigment in such a form is added and encapsulated. On the other hand, according to the present invention, the pigment can be encapsulated in the crosslinked particle as it is, if desired, and by doing so, the influence of the surface state of various pigments can be canceled. In addition, since the pigment is covered with particles having a cross-linked structure, the pigment may be separated from a place where the particles do not swell or dissolve due to solvents contained therein. There is also the advantage of showing excellent dispersibility and stability.

As a specific production method, the above-mentioned acrylic polyol resin (A) (self-water dispersible resin) and a pigment can be mixed with a known general method, for example, by using various devices such as a three-roll mill and a paint conditioner. A mill base is prepared by kneading, and then the above-mentioned polyisocyanate compound (B) (hydrophobic crosslinking agent) is mixed therein, and then amines are added thereto.
Disperse in aqueous medium. Thereafter, by promoting the crosslinking, a desired aqueous dispersion in which the pigment is encapsulated in the crosslinked particles is obtained, which is generally performed by such means and steps. Thus, the desired aqueous dispersion containing the pigment is obtained.

Such a method is particularly effective when a self-water-dispersible resin is used to form particles by phase inversion emulsification, and known methods such as emulsion polymerization or non-aqueous polymerization (non-aqueous dispersion It is very difficult to encapsulate such a pigment by using a method such as polymerization.

Here, only typical examples of the pigments to be used are given as examples of titanium dioxide (for example, Taipaque CR-95 (titanium oxide pigment manufactured by Ciba Geigy)), iron oxide, red iron oxide, Lead molybdate,
Various inorganic pigments, such as chromium oxide, chromate or carbon black; or phthalocyanine pigments such as phthalocyanine blue, phthalocyanine green, carbazole violet, anthrapyrimidine yellow, flavanthrone yellow, isoindoline. Various organic pigments such as yellow, induthrone blue or quinacridone violet, quinacridone red, azo pigments and anthraquinone pigments.

Although the crosslinked particles described above are aqueous, compared to so-called nonaqueous crosslinked particles obtained by a method such as non-aqueous polymerization (non-aqueous dispersion polymerization), the present invention is not limited thereto. The crosslinked particles dealt with in the present invention have a wide range of application in composition and are easy to manufacture.

The crosslinked particles of the present invention can be easily transferred into various polar organic solvents such as butanol and methyl ethyl ketone. In this case, the carboxylate can be returned to the carboxylic acid form by reverse neutralization, and the transfer is further facilitated.

Thus, in the present invention, it is also possible to use the water-based crosslinked particles in a solvent system. However, slightly, the dispersion stability, from the place where the tendency to be inferior to the aqueous system is recognized, from the method for producing the crosslinked particles of the present invention and paint obtained using the crosslinked particles,
Rather, it can even be said that it is suitable for use in water systems.

The coating material according to the present invention is obtained by dissolving or dispersing the resin in water with the above-mentioned curable resin composition as a main component, and if necessary, has conventionally been used in the field of coating materials. Various additives, such as ultraviolet absorbers, light stabilizers, antioxidants, coloring pigments,
Extender pigment, metallic pigment, aluminum powder, pearl mica powder, anti-sagging or anti-settling agent, leveling agent,
Dispersants, defoamers, antistatic agents, curing catalysts, flow regulators,
A two-part paint or a one-part paint composition can be prepared by appropriately blending known and commonly used additives such as cellulose acetate butyrate and thinner in a usual amount. Also,
Compatible resins or polymer compounds such as epoxy resins and polyester resins may be used in combination as long as the effects of the present invention are not reduced. The paint thus obtained can be applied by a known and commonly used method such as spray paint, roller paint, brush paint and the like. It goes without saying that the resin composition for a paint of the present invention can be used as a clear paint without using a pigment or as an enamel paint using a pigment.

The acid resistance of the paint according to the present invention is remarkably superior to that of a conventional paint composed of a polyol and a melamine resin even when another polyol resin or a crosslinking agent (for example, a melamine resin) is used in combination. Acid resistance without any problem can be realized. In the paint according to the present invention, when other polyol resins and melamine resins are used in combination, the content of the curable resin composition of the present invention is 10% by weight or more, preferably 25% by weight or more in the total resin solid content thereof. The melamine resin content is preferably 30% by weight or less, and more preferably 20% by weight or less. When the amount of the curable resin composition of the present invention is less than 10% by weight or the amount of the melamine resin is more than 30% by weight, the acid resistance cannot be improved, which is not preferable.

Among the curable resin compositions of the present invention, in particular, an ultraviolet absorber / hindered amine light stabilizing agent is used to further improve weather resistance such as maintaining gloss during exposure and maintaining high extensibility. It is preferable to use a mixture consisting of the agent = 40 to 60/60 to 40 (solid content ratio) in the range of 0 to 10% by weight based on the solid content of the acrylic polyol resin (A). At that time, if the addition amount is 10 wt% or more, the paint price becomes high, and at the low temperature, it precipitates as crystals,
It is not preferable because the water resistance is lowered and the resin solution is colored. Although the mixing ratio of the ultraviolet absorber and the hindered amine-based light stabilizer is effective to some extent even outside the above-mentioned mixing ratio, the above-mentioned mixing ratio shows the most excellent effectiveness.

Known UV absorbers can be used. Representative examples thereof include benzotriazole UV absorbers such as Tinuvin 900, Tinuvin 384, and Tinuvin P (all manufactured by Ciba Geigy). , Sand bar 3206
Oxalic acid anilide-based ultraviolet absorbers (made of sand) or the like can be preferably used. These may be added in predetermined amounts at the end of the acrylic polyol copolymerization reaction or at the time of coating. On the other hand, T-17, T-37, T-3
8 (all manufactured by Adeka Argus Chemical Co., Ltd.) and an organic group having an ultraviolet absorbing ability such as an O-hydroxybenzophenone group and a copolymerizable ethylene such as a (meth) acrylic acid group. In the case of a reactive ultraviolet absorber having a functional unsaturated group in the same molecule, it is preferable to introduce a predetermined amount by simultaneously copolymerizing and introducing a predetermined amount in the step of synthesizing the acrylic polyol resin (A).

Examples of the hindered amine-based light stabilizers include piperidine-based ones usually referred to as HALS (hals), and typical examples thereof include 4-benzoyloxy-2,
2,6,6-tetramethylpiperidine, bis- (2,2,6,
6-tetramethyl-4-piperidine) sebacate or tinuvin 144, 292, 765 (all products of Ciba-Geigy), MARK LA-57, 62, 63, 67, 68 (= Adeka Argus Chemical Co., Ltd. ) Products), Sanol LS29
Hindered amine light stabilizers such as 2 (manufactured by Sankyo) and Sand Bar 3058 (manufactured by Sando) can be preferably used. These are acrylic polyol resins (A)
May be added in a predetermined amount at the end of the copolymerization reaction or at the time of coating, and has a light stabilizing function such as MARK LA-82, 87 and T-41 (all manufactured by Adeka Argus Chemical Co., Ltd.). In the case of a hindered amine compound having a copolymerizable ethylenically unsaturated group such as an organic group and a (meth) acrylic acid group, a predetermined amount is simultaneously copolymerized and introduced in the synthesis step of the acrylic polyol resin (A). Just fine.

In order to further increase the effectiveness, “Sumilyzer BHT” (manufactured by Sumitomo Chemical Co., Ltd.), if desired,
"Seanox BCS" (Shiraishi Calcium Co., Ltd. product),
Well-known and common oxidations such as "Irganox 1010 or 1076" (product of Ciba-Gaiky), "Nokriza-TNP" (product of Ouchi Shinko Co., Ltd.) or "Antioxidant KB" (product of Bayer AG, West Germany) An inhibitor may be used in combination.

Examples of the curing catalyst include organic acids such as phosphoric acid ester, dodecylbenzenesulfonic acid and paratoluenesulfonic acid and amine salts thereof, and organic tin compounds such as dibutyltin dilaurate and dibutyltin maleate and chelate compounds thereof. Can be

As extenders, for example, kaolin,
Examples include talc, silica, mica, barium sulfate, calcium carbonate and the like. As the anti-sagging agent or the anti-settling agent, for example, bentonite, castor oil wax, amide wax, microgel (for example, MG100S (manufactured by Dainippon Ink)), aluminum acetate and the like can be preferably used.

As the leveling agent, for example, KF69, Kp
Silicon-based surfactants such as 321 and Kp301 (above, manufactured by Shin-Etsu Chemical), silicon-based surfactants such as Modaflow (a surface conditioner manufactured by Mitsubishi Monsanto), BYK301 and 358 (manufactured by Big Chemie Japan), and diamond aids AD9001 (manufactured by Mitsubishi Rayon) or the like can be preferably used.

As the dispersant, for example, Anti-Terra U
Alternatively, Anti-Terra P and Disperbyk-101 (all manufactured by Big Chemie Japan) and the like can be preferably used. As the antifoaming agent, for example, BYK-0 (manufactured by BYK Japan) can be preferably used.

As the thinner, conventionally known aromatic compounds, alcohols, ketones, ester compounds, and mixtures thereof can be used. As the antistatic agent, for example, Esocard C25 (manufactured by Lion Armor) or the like can be preferably used.

In preparing the coating composition of the present invention, the acrylic polyol resin (A), the polyisocyanate compound (B) and, if necessary, additives such as a curing agent and a pigment are mixed, and the mixture is mixed with a sand grind mill or the like. The curable resin composition for a paint is prepared by uniformly dispersing the composition with a dispersing machine such as a ball mill or an attritor.

The curable resin composition of the present invention (paint composition)
First, a known degreasing and cleaning treatment, for example, degreasing and cleaning with an organic solvent such as 1,1,1-trichloroethane, alkali degreasing, acid cleaning, solvent wipe, etc. Also, if necessary, in order to further improve the adhesion of the paint to the object to be coated, for example,
After applying a primer such as Primac N0.1500 (manufactured by Nippon Oil & Fat), the coating composition of the present invention is directly applied by air atomization coating, airless coating, or the like.
0 minutes, preferably after setting for 1 to 20 minutes, 90 to 140 ° C,
Heat curing (baking) is preferably performed at a low temperature of 100 to 120 ° C. The clear paint may be applied wet-on-wet to the base coat paint constituting the lower layer.
In the present invention, with the above configuration, it is possible to heat and cure at a low temperature of 140 ° C. or less, so that a polyolefin-based resin molded article can be coated with a coating having excellent coating properties without damaging the molded article. it can.

When a primer is applied, its thickness is generally 3 to 20 μm, preferably, as a thickness after drying.
5 to 15 μm. Further, the film thickness of the clear paint, as a film thickness after drying, generally 15 to 45 μm, preferably 20 to 35 μm
It is. Examples of a coating method using the coating composition of the present invention include a two-coat one-bake type, a three-coat two-bake type, and the like. Here, the two-coat one-bake type is one of the methods for applying a top coat, in which a base coat paint containing a large amount of pigment and / or metal powder is first applied, and then a transparent clear paint is applied thereon. Alternatively, it is a coating method in which a top coat, which is a color clear paint containing less pigment, is applied and baked at a time. In the case of the above-mentioned two-coat one-bake-type coating method, an ordinary coating composition can be used as the base coat coating, and the coating composition of the present invention can be used for the top coat. 3 coat 2 bake type, apply paint containing blended materials, dyes and / or metal powders, bake, apply a base coat further blended pigments, dyes and / or metal powders, and then This is a coating method in which a transparent clear paint or a top coat which is a color clear paint having a small amount of pigments or dyes is applied thereon and baked at a time.

[0166]

Next, the present invention will be described more specifically with reference examples, examples, and comparative examples, but the present invention is not limited to only these examples. In the following examples, all parts and percentages are by weight unless otherwise specified. Reference Example 1 In a four-necked flask equipped with an air inlet tube, a thermometer, a cooling tube, and a stirrer, 2446 parts of 2-hydroxyethyl methacrylate (2-HEMA) and ε-caprolactone (ε) were placed.
-CL) (1610 parts), 1.99 parts of hydroquinone monomethyl ether (HQME) as a polymerization inhibitor, and 0.199 parts of stannous chloride (SnCl2) as a reaction catalyst were reacted at 100 ° C for 23 hours while passing air. The conversion of ε-caprolactone is 99.4%, and the hue of the reaction product is 2
0 (APHA). When the obtained lactone-modified 2-hydroxyethyl methacrylate composition was copolymerized with another monomer, a good acrylic polyol resin was obtained.

Reference Example 2 In a four-necked flask equipped with an air inlet tube, a thermometer, a cooling tube, and a stirrer, 2446 parts of 2-hydroxyethyl methacrylate (2-HEMA) and ε-caprolactone (ε
-CL) (1610 parts), 1.99 parts of hydroquinone monomethyl ether (HQME) as a polymerization inhibitor, and 0.795 parts of monobutyltin tris-2-ethylhexate as a reaction catalyst.
The reaction was performed for 5 hours. The conversion of ε-caprolactone is 9
The hue of the reaction was 9.4%, 20 (APHA).
When the obtained lactone-modified 2-hydroxyethyl methacrylate was copolymerized with another monomer, a good acrylic polyol resin was obtained (see Reference Example 5).

Reference Example 3 In a four-necked flask equipped with an air inlet tube, a thermometer, a cooling tube, and a stirrer, 2446 parts of 2-hydroxyethyl methacrylate (2-HEMA) and ε-caprolactone (ε
-CL) 1073 parts, 1.72 parts of hydroquinone monomethyl ether (HQME) as a polymerization inhibitor, and 0.690 parts of monobutyltin tris-2-ethylhexanate as a reaction catalyst, and react at 100 ° C for 7 hours while passing air. Was. The conversion of ε-caprolactone is 99.6.
%, The hue of the reaction was 30 (APHA). When the obtained lactone-modified 2-hydroxyethyl methacrylate was copolymerized with another monomer, a good acrylic polyol resin was obtained (see Reference Example 6).

Reference Example 4 In the same apparatus as in Reference Example 1, 504 parts of 2-hydroxyethyl acrylate (2-HEMA), 248 parts of ε-caprolactone, 0.368 part of hydroquinone monomethyl ether as a polymerization inhibitor, monobutyltin tris -2
-Ethylhexanate (0.148 parts) was charged and reacted at 100 ° C. for 7 hours while passing air through the reaction.
(APHA). When the obtained composition was copolymerized in the same manner as in Reference Example 5, a good acrylic polyol resin was obtained.

Reference Comparative Example 1 In the same apparatus as in Reference Example 1, 2446 parts of 2-hydroxyethyl methacrylate and 2146 of ε-caprolactone were added.
Parts, 2.25 parts of hydroquinone monomethyl ether as a polymerization inhibitor, and monobutyltin tris-2- as a catalyst
0.900 parts of ethyl hexanate was added and reacted at 100 ° C. for 8 hours while passing air. The conversion of ε-caprolactone was 99.0%, and the hue of the reaction product was 25 (APH
A). When the obtained lactone-modified 2-hydroxyethyl methacrylate composition was copolymerized with another monomer, an excellent acrylic polyol resin was obtained (see Reference Comparative Example 7).

REFERENCE COMPARATIVE EXAMPLE 2 In the same apparatus as in Reference Example 1, 799 parts of 2-hydroxyethyl methacrylate, 701 parts of ε-caprolactone,
0.735 parts of hydroquinone monomethyl ether and 0.147 parts of tetrabutyl titanate (TBT) were added, and the mixture was reacted at 100 ° C. for 64 hours while passing air.
-The conversion of caprolactone was 99.6% and the hue of the reaction product was 50 (APHA). When the obtained composition was copolymerized in the same manner as in Reference Example 1, the composition thickened during the reaction and eventually gelled, and an acrylic polyol resin could not be obtained.

Reference Comparative Example 3 1816 parts of 2-hydroxyethyl methacrylate and ε-caprolactone 3184 were added to the same apparatus as in Reference Example 1.
Parts, 2.50 parts of hydroquinone monomethyl ether, 1.00 of monobutyltin tris-2-ethylhexanate
The reaction was carried out at 100 ° C. for 8.5 hours while passing air, and the reaction rate of ε-caprolactone was 99.2.
%, The hue of the reaction was 25 (APHA). When the obtained lactone-modified 2-hydroxyethyl methacrylate composition was copolymerized with another monomer, a good acrylic polyol resin was obtained (see Reference Comparative Examples 9 and 10).

REFERENCE COMPARATIVE EXAMPLE 4 1816 parts of 2-hydroxyethyl methacrylate and ε-caprolactone 4776 were added to the same apparatus as in Reference Example 1.
Parts, 3.30 parts of hydroquinone monomethyl ether, 1.32 monobutyltin tris-2-ethylhexanate
The reaction was carried out at 100 ° C. for 8 hours while passing air, and the reaction rate of ε-caprolactone was 99.2%,
The hue of the reaction was 25 (APHA). When the obtained lactone-modified 2-hydroxyethyl methacrylate composition was copolymerized with another monomer, a good acrylic polyol resin was obtained (see Reference Comparative Example 11).

Reference Comparative Example 5 1816 parts of 2-hydroxyethyl methacrylate and ε-caprolactone 6364 were added to the same apparatus as in Reference Example 1.
Parts, hydroquinone monomethyl ether 4.10 parts, monobutyltin tris-2-ethylhexanate 1.64
The reaction was carried out at 100 ° C. for 8.5 hours while passing air, and the reaction rate of ε-caprolactone was 99.2.
%, The hue of the reaction was 30 (APHA). When the obtained lactone-modified 2-hydroxyethyl methacrylate composition was copolymerized with another monomer, a good acrylic polyol resin was obtained.

Note that ε in the above reference example and reference comparative example was used.
-The theoretical molar number of addition of caprolactone is as follows. Reference Example 1: n = 0.75, Reference Example 2: n = 0.75, Reference Example 3: n = 0.50, Reference Example 4: n = 0.50, Reference Comparative Example 1: n = 1, Reference Comparative Example 2: n = 1, Reference Comparative Example 3: n = 2, Reference Comparative Example 4: n = 3, Reference Comparative Example 5: n
= 4 FM = 0 for n = 0.50, FM0.75 for n = 0.75, FM1 for n = 1, FM2 for n = 2, FM3 for n = 3, FM with n = 4
Notated as 4 etc. GCP of the composition actually obtained above
The chain distribution of ε-caprolactone from Table 1 is shown in Table 1 and FIG. % Indicates GPC area%.

[0176]

[Table 1]

Tables 2 and 3 summarize the reaction compositions, reaction conditions, and properties of the reactants of Reference Examples 1 to 4 and Reference Comparative Examples 1 to 5.

[0178]

[Table 2]

[0179]

[Table 3]

Reference Example 5 50 parts of butyl acetate, 50 parts of toluene were placed in a four-necked flask equipped with a thermometer, a reflux condenser, a nitrogen gas inlet, and a stirrer.
Ditertiary butyl peroxide (DTBPO) 1.0
The mixture was heated to 115 ° C., and when the temperature reached 115 ° C., 17.3 parts of styrene, 17.3 parts of butyl methacrylate, 17.3 parts of butyl acrylate,
2.0 parts of methacrylic acid, 46 parts of the ε-caprolactone-modified 2-hydroxyethyl methacrylate composition synthesized in Reference Example 2, 0 parts of 2-hydroxyethyl methacrylate, and 1.0 part of azobisisobutyronitrile 3
The mixture was added dropwise over a period of time, and the reaction was continued for another 4 hours to obtain a good acrylic polyol resin transparent solution (a-1). The raw material composition and the properties of the resin solution are shown in Tables 4 and 5, respectively. Table 6 and FIG. 2 show the relationship between the ε-caprolactone / HEMA charge ratio and the ε-caprolactone chain distribution ratio.

Reference Example 6 and Reference Comparative Examples 6 to 11 Monomers and HEMA of the ε-caprolactone-modified acrylate composition obtained in Reference Examples 3 and Reference Comparative Examples 1 to 4
Was polymerized in the same apparatus and under the same blending conditions as in Reference Example 5, and a good acrylic polyol resin transparent solution could be obtained from the monomers obtained in Reference Example 3 and Reference Comparative Examples 3 and 4. In the case of the monomer obtained in Comparative Example 2, the reaction solution became thickened and gelled during the polymerization, and a resin solution could not be obtained. Tables 4 and 5 show the raw material composition and the properties of the resin solution of each Reference Example and Reference Comparative Example, respectively.
Table 6 and FIG. 2 show the relationship between the ε-caprolactone / HEMA charge ratio and the ε-caprolactone chain distribution ratio.

[0182]

[Table 4]

[0183]

[Table 5]

[0184]

[Table 6]

In the polymerization of the acrylic polyol resin,
The resulting hydroxyl number (OHV) is set to 120 and the Tg
Are set to 0 to 10 ° C., in Reference Examples 5, 6, and Reference Comparative Examples 7, 8, 10, and 11, in which Reference Examples 5 and 6 are each a single adduct of ε-caprolactone (n = 1). It can be seen that the ratio is high and the ratio of the adduct of two or more chains of ε-caprolactone, which lowers the hardness of the melamine cured product of the acrylic polyol resin, is low.

Reference Example 7 [Preparation Example of Copolymer (A-1)] In a four-necked flask purged with nitrogen gas, 294 parts of methyl ethyl ketone was charged and kept at 75 ° C. with stirring. Then, 36.9 parts of methacrylic acid, 90.0 parts of styrene, 42.6 parts of butyl acrylate, Reference Example 1
Ε-caprolactone-modified acrylic monomer 4 obtained in
A mixture consisting of 0.5 part, 90.0 parts of lauryl methacrylate and 6.0 parts of perbutyl O [tert-butyl peroxy-2-ethylhexanoate manufactured by NOF Corporation] was added for 2 hours. And let it drip. Further, the reaction was carried out at the same temperature for 5 hours to obtain a nonvolatile content of 50.0% by weight.
%, The acid value is 80, and the hydroxyl value is 58 (unit: mg
-KOH / g, the same applies hereinafter) to obtain a copolymer (A-1).

Reference Example 8 [Preparation Example of Copolymer (A-2)] 870 of methyl ethyl ketone was placed in a reaction vessel purged with nitrogen.
And heated to 80 ° C. with stirring. further,
207 parts of styrene, 150 parts of lauryl methacrylate
Parts, 72 parts of the ε-caprolactone-modified acrylic monomer obtained in Reference Example 3, 3 parts of methacrylic acid, 168 parts of butyl methacrylate, and 30 parts of “perbutyl O” were dropped over 4 hours. After that, stirring was continued for 4 hours to continue the polymerization reaction, thereby obtaining a hydroxyl group-containing resin having a number average molecular weight of 26,000 and a nonvolatile content of 40%. Then
To the above polymer solution, 6.8 parts of methacrylic anhydride was added, and stirring was continued at 80 ° C. for 4 hours to obtain a vinyl-modified hydroxyl group-containing resin (B-1). After a while
In a container similar to the above-mentioned reaction container, 1 of this resin (B-1) was added.
75 parts were charged, and the temperature was raised to 80 ° C. with stirring. 9.2 parts of methacrylic acid, 7.6 parts of styrene, 7.5 parts of lauryl methacrylate, 3.4 parts of butyl acrylate, 2.3 parts of 2-hydroxyethyl methacrylate, and “perbutyl O” A mixture consisting of 4.5 parts and 20 parts of methyl ethyl ketone was added dropwise over 4 hours to continue the polymerization. Thereafter, stirring was continued for 2 hours to obtain a vinyl copolymer (A-2). Non-volatile content is 4
It was 5.6%.

Reference Example 9 [Preparation Example of Copolymer (A-3)] 870 of methyl ethyl ketone was placed in a reaction vessel purged with nitrogen.
The temperature was raised to 80 ° C. while stirring. There,
180 parts of styrene, 150 parts of lauryl methacrylate
Part, butyl acrylate 78 parts, ε obtained in Reference Example 3
-72 parts of caprolactone-modified acrylic monomer, 120 parts of glycidyl methacrylate and "perbutyl O"
Was added dropwise over 4 hours to continue the polymerization. Further, stirring was continued for 4 hours to obtain a resin having a number average molecular weight of 20,000 and a nonvolatile content of 40% and having both a glycidyl group and a hydroxyl group. Next, 6.8 parts of methacrylic anhydride was added to the polymer solution, and stirring was continued at 60 ° C. for 6 hours.
0.5 part of water was added. As a result, the vinyl-modified hydroxyl group-containing resin (B
-2) was obtained. Thereafter, 300 parts of the resin (B-2) was charged into the same container as above, and the temperature was raised to 80 ° C. with stirring. Then 39.2 parts of methacrylic acid, 27.0 parts of styrene, 45.0 parts of lauryl methacrylate,
41.0 parts of butyl acrylate, 27.8 parts of 2-hydroxyethyl methacrylate, 2 parts of “perbutyl O”
A mixture of 7.0 parts and 40.0 parts of methyl ethyl ketone was added dropwise over 4 hours to carry out polymerization. Thereafter, stirring was continued for 2 hours to obtain a vinyl copolymer (A-3). The nonvolatile content was 54.8%.

Reference Example 10 [Preparation Example of Copolymer (A-4)] The resin (B-1) obtained in Reference Example 8 and the resin (B-1) obtained in Reference Example 10 were each added in 150 parts. B-2) was charged to a reaction vessel purged with nitrogen, and stirred at 80 ° C.
Temperature. Then, 39.2 parts of methacrylic acid, 27.0 parts of styrene, and 45.0 parts of lauryl methacrylate.
Parts, 41.0 parts of butyl acrylate, 2-methacrylic acid 2-
A mixed solution consisting of 27.8 parts of hydroxyethyl, 27.0 parts of “perbutyl O” and 40.0 parts of methyl ethyl ketone was added dropwise over 4 hours to carry out polymerization. After that, stirring was continued for 2 hours to obtain a vinyl copolymer (A-4). The nonvolatile content was 54.8%.

Reference Example 11 [Preparation Example of Copolymer (A-5)] 62.5 parts of polycaprolactone diol having a number average molecular weight of 1,250 and "AOGX 68" [manufactured by Daicel Chemical Industries, Ltd.] Chain olefin glycol; hydroxyl value = 290], 167.8 parts, and 1-isocyanato-3-
111 parts of isocyanatomethyl-3,5,5-trimethylcyclohexane (IPDI) were charged into a reaction vessel, heated to 110 ° C. with stirring under a nitrogen atmosphere, and maintained at the same temperature for 60 minutes. After that, raise the temperature to 80
° C., 33.5 parts of dimethylolpropionic acid,
160.6 parts of ethyl acetate and 0.06 parts of tin octenoate
Five parts were charged and the reaction was allowed to continue at 75 ° C. for 7 hours. After the completion of the reaction, a hydroxyl group-containing urethane resin having a nonvolatile content of 50% was obtained by adding 214.2 parts of ethyl acetate. In the above resin solution,
2.6 parts of methacrylic anhydride was charged, and stirring was continued at 75 ° C. for 4 hours under a nitrogen atmosphere to obtain a vinyl-modified hydroxyl group-containing resin (B-3). Next, in a similar reaction vessel purged with nitrogen, the resin (B-
100 parts of 3) was charged, and the temperature was raised to 75 ° C. with stirring. 15.4 parts of methacrylic acid, 23.3 of styrene
Parts, 22.4 parts of isobutyl methacrylate, 5.5 parts of 2-hydroxyethyl methacrylate, and 50.1 parts of the ε-caprolactone-modified acrylic monomer obtained in Reference Example 3.
And 9.3 parts of "Nipper BW" [benzoyl peroxide manufactured by NOF Corporation] and 11 parts of ethyl acetate.
A mixture consisting of 6.7 parts was added dropwise over 4 hours to carry out a polymerization reaction. After that, by continuing stirring for 4 hours, the vinyl copolymer (A-5)
I got The nonvolatile content was 48.6%.

Reference Comparative Example 12 [Vinyl copolymer (RA
Preparation Example of -1)] In Reference Example 7, the ε-caprolactone-modified acrylic monomer obtained in Reference Comparative Example 1 was used instead of 40.5 parts of the ε-caprolactone-modified acrylic monomer obtained in Reference Example 1. Similarly, the non-volatile content is 50.0%,
A vinyl copolymer having an acid value of 80 and a hydroxyl value of 58 was obtained.

Reference Comparative Example 13 [Vinyl copolymer (RA
Preparation Example of -2)] In Reference Example 11, “Placcel” was used instead of the ε-caprolactone-modified acrylic monomer obtained in Reference Example 3.
FM3 "[lactone-modified hydroxyethyl methacrylate, manufactured by Daicel Chemical Industries, Ltd.]. A vinyl copolymer having a nonvolatile content of 50.0%, an acid value of 80 and a hydroxyl value of 58 was obtained. A polymer was obtained.

Example 1 A vinyl copolymer as an acrylic polyol resin (A-
200 parts of 1) and "Barnock 980" [a polyisocyanate manufactured by Dainippon Chemical Co., Ltd .;
5.6%], 100 parts of methyl ethyl ketone.
Parts and 5.0 parts of triethylamine were mixed, and 300 parts of distilled water was gradually added to a well-stirred reaction vessel. On the way, just before the phase inversion of the system, 0.02 parts of dibutyltin dilaurate was added.
0 parts were added. Then, the solvent was distilled off under reduced pressure, and then heating was continued at 60 ° C. for 1 hour to promote the crosslinking inside the particles. Then, a part of water was distilled off under reduced pressure, and the non-volatile content was 31.0%.
Thus, an aqueous dispersion of crosslinked particles was obtained. Thereafter, a part of the aqueous dispersion of the crosslinked particles was taken and added to a 100-fold amount of tetrahydrofuran. In addition, when this aqueous dispersion was kept at 50 ° C. for 20 days and the change with time was observed, no change was observed in the dispersion stability. However, ethylene glycol monobutyl ether is added to the aqueous dispersion at a solid content of 2%.
After 20 days at 50 ° C. with the addition of 0%, a tendency of the system to thicken was observed. The average molecular weight between crosslinks of the crosslinked particles thus obtained was designed to be 570. Further, by adding a solvent in an amount corresponding to 20% of the solid content, the film-forming temperature became lower than room temperature.

Example 2 A vinyl copolymer (A-
21) copy of 29.3 and 3 of "Barnock 980"
9.7 parts, 100 parts of methyl ethyl ketone and 10.8 parts of triethylamine were changed to use,
When the same procedure as in Example 1 was carried out, the thus-obtained aqueous dispersion of crosslinked particles had a nonvolatile content of 31.6% and a good dispersion state. Next, a part of the aqueous dispersion of the crosslinked particles was taken and added to 100 times the amount of tetrahydrofuran.
It was cloudy without dissolving transparently. Also, this aqueous dispersion is
When the composition was kept at 50 ° C. for 20 days and the change with time was observed, no change in dispersion stability was observed. Similarly, when ethylene glycol monobutyl ether was added in an amount corresponding to 20% based on the solid content of the aqueous dispersion, no change was observed in the viscosity characteristics even after aging at 50 ° C. for 20 days. . The average molecular weight between crosslinks of the crosslinked particles was designed to be 630. Further, by adding a solvent in an amount corresponding to 20% of the solid content, the film-forming temperature became lower than room temperature.

Example 3 A vinyl copolymer (A-
32.5) and 2 in "Barnock 980"
6.5 parts, 150 parts of methyl ethyl ketone and 15.3 parts of triethylamine, except that
When the same procedure as in Example 1 was carried out, the thus-obtained aqueous dispersion of crosslinked particles had a nonvolatile content of 30.5% and a good dispersion state. Next, a part of the aqueous dispersion of the crosslinked particles was taken and added to 100 times the amount of tetrahydrofuran.
It was cloudy without dissolving transparently. Also, this aqueous dispersion is
When the composition was kept at 50 ° C. for 20 days and observed over time, no change was observed in the dispersion stability. Similarly, when ethylene glycol monobutyl ether was added in an amount corresponding to 20% based on the solid content of the aqueous dispersion, the viscosity characteristics still changed even after 20 days at 50 ° C. Did not. The average molecular weight between cross-links of the cross-linked particles only slightly changes through the reaction of the glycidyl group.
It was designed in the range of 0 to 680. Also, by adding a solvent equivalent to 20% of the solid content,
The film forming temperature was below room temperature.

Example 4 Acrylic polyol resin, a vinyl copolymer (A-
4) 182.5 copies and “Barnock 980” 2
6.5 parts, 150 parts of methyl ethyl ketone and 15.3 parts of triethylamine, except that
When the same procedure as in Example 1 was carried out, the aqueous dispersion of crosslinked particles thus obtained had a nonvolatile content of 32.3% and a good dispersion state. Next, a part of the aqueous dispersion of the crosslinked particles was taken and added to 100 times the amount of tetrahydrofuran.
It was cloudy without dissolving transparently. Also, this aqueous dispersion is
When the composition was kept at 50 ° C. for 20 days and the change over time was observed, no change was observed in the dispersion stability.
Similarly, ethylene glycol monobutyl ether was added in an amount corresponding to 20% with respect to the solid content of this aqueous dispersion, but even after 20 days at 50 ° C., there was still a change in viscosity characteristics. I couldn't. In addition, the average molecular weight between crosslinks of the crosslinked particles is only slightly changed through the reaction of the glycidyl group.
It was designed in the range of 0 to 680. Also, by adding a solvent equivalent to 20% of the solid content,
The film forming temperature was below room temperature.

Example 5 A vinyl copolymer as an acrylic polyol resin (A-
55.8) and 3 of "Barnock 980"
9.7 parts, 150 parts of methyl ethyl ketone and 10.8 parts of triethylamine were changed to use,
When the same procedure as in Example 1 was carried out, the aqueous dispersion of crosslinked particles thus obtained had a nonvolatile content of 35.3% and a good dispersion state. Next, a part of the aqueous dispersion of the crosslinked particles was taken and added to 100 times the amount of tetrahydrofuran.
It was cloudy without dissolving transparently. Also, this aqueous dispersion is
When the sample was kept at 50 ° C. for 20 days and the change over time was observed, no change was observed in the dispersion stability. Similarly, ethylene glycol monobutyl ether was added in an amount corresponding to 20% with respect to the solid content of the aqueous dispersion, but after 20 days at 50 ° C., the viscosity characteristics still remained as: No changes were observed. The average molecular weight between crosslinks of the crosslinked particles was designed to be 630. Further, by adding a solvent in an amount corresponding to 20% of the solid content, the film-forming temperature became lower than room temperature.

Example 6 In a four-necked flask purged with nitrogen, "UNICEF PT-2" was added.
00 "[Polytetramethylene glycol manufactured by NOF Corporation; Mn = 2,000] and 55.5 parts of isophorone diisocyanate were charged at 120 ° C.
After performing the reaction for 0 minutes, 0.05 parts of tin octenoate was added, and the reaction was further performed at the same temperature for 60 minutes. 182.5 parts of dimethylolpropionic acid
When 3.5 parts were charged and the reaction was carried out at 80 ° C. for 6 hours, a urethane having a nonvolatile content of 65%, an acid value of 41.4 and an isocyanate group content of 3.0% was obtained. -A prepolymer was obtained. Thereafter, 200 parts of this resin, 51.6 parts of "Barnock 980", 100 parts of methyl ethyl ketone and 5.0 parts of triethylamine were combined, mixed well, and gradually stirred, while continuing to stir. , 600 parts of distilled water and then an aqueous solution of 12 parts of diethylenetriamine in 100 parts of distilled water, and then keeping the system under reduced pressure at 60-70 ° C.
Solvent and a part of water were distilled off to obtain a non-volatile content of 31.0%.
% Of an aqueous dispersion of crosslinked particles was obtained. Next, 194 parts of the aqueous dispersion of crosslinked particles thus obtained, 407 parts of distilled water and 12 parts of toluene were added to a nitrogen-substituted four-necked flask, and the temperature was raised to 80 ° C. Thereafter, a solution obtained by mixing 4 parts of allyl methacrylate, 13 parts of methyl methacrylate, 13 parts of butyl methacrylate, and a solution obtained by mixing the ε-caprolactone-modified acrylic monomer obtained in Reference Example 4 with 0.15 part of ammonium persulfate And 20 parts of an aqueous solution of distilled water were added dropwise over 4 hours to carry out polymerization. Thereafter, stirring was continued at the same temperature for 2 hours. Next, the solvent and a part of water were distilled off under reduced pressure to obtain acrylic / urethane composite crosslinked particles having a nonvolatile content of 32.7%. Next, a part of the aqueous dispersion of the crosslinked particles is taken, and 1
When it was added to a 00-fold amount of tetrahydrofuran, it did not dissolve transparently and became cloudy. Further, this aqueous dispersion was heated at 50 ° C. for 20 minutes.
As a result of observing the change over time while keeping the mixture for a period of days, no change was observed in the dispersion stability. Similarly, ethylene glycol monobutyl ether was added in an amount corresponding to 20% based on the solid content of the aqueous dispersion.
Even after 20 days at ℃, no change was observed in the viscosity characteristics. The average molecular weight between crosslinks of the crosslinked particles was designed to be 500. further,
By adding a solvent in an amount corresponding to 20% of the solid content, the film formation temperature was reduced to room temperature or lower.

Comparative Example 1 Example 1 was repeated, except that the vinyl copolymer (RA-1) was used instead of the vinyl copolymer (A-1).
The same was done.

Comparative Example 2 The procedure of Example 1 was repeated, except that the vinyl copolymer (RA-2) was used instead of the vinyl copolymer (A-5).
The same was done.

Comparative Example 3 The procedure of Example 6 was repeated, except that the vinyl copolymer (RA-1) was used instead of the ε-caprolactone-modified acrylic monomer obtained in Reference Example 4. Was.

COMPARATIVE EXAMPLES 4 AND 5 As a result of a conventional film forming method, a commercially available baking-curable paint having a constitution of acrylic resin / melamine resin and a commercial coating of a constitution comprising acrylic resin / polyisocyanate resin were used. And a room temperature-curable coating material, both of which are resin compositions for automotive topcoats.

Application Examples 1 to 6 and Comparative Application Examples 1 to 4 Next, each of the crosslinked particles obtained in each of the Examples and Comparative Examples was used alone or as a cross-linking agent, “MW
12LF "[melamine resin manufactured by Sanwa Chemical Co., Ltd .; non-volatile content = 75.6%], on a metal plate, on a white base, or on an electrodeposition coated plate, respectively. By spray coating to form a film.

Next, various physical properties were evaluated for each coating.

Each evaluation was performed in the following manner. [Boiling water resistance] The state of the coated surface after immersing the test coated plate in boiling water for 60 minutes was visually evaluated and determined. …: No abnormality was observed at all △: Softening or whitening was slightly observed ×: Softening or whitening was observed significantly [Stain resistance] Marked with red or black oil-based magic on test coated plate , And left standing for 60 minutes, and the state of contamination after wiping with alcohol was visually evaluated and determined. …: A state in which scarcely remains. △: A state in which scarcely remains. ×: A state in which scarcely remains. [Impact resistance] Using a DuPont impact tester, a strike radius of 1
/ 2 inch, when dropped under a load of 1 kg, the maximum height (cm) at which the coating surface did not crack was indicated. [Tipping resistance] Using a stepping stone tester (manufactured by Suga Test Instruments Co., Ltd.), a coated test plate was vertically mounted on the sample holder of the tester, and 50 g of No. 7 crushed stone was pressed with the pressure of the tester. At a pressure of 4 kg / cm ² , and the crushed stones collide with the test plate at right angles. Thereafter, the test plate was washed with water and dried, and the state of the coating film and the scratches raised by the tipping was evaluated and evaluated according to the following criteria. The test plate was placed in a thermostat cooled to −25 ° C. for 20 minutes or more, and immediately after being taken out, a tipping test was performed by the above method. ◎ …… Peeling or lifting of the coating film is not observed. ……… Peeling or lifting of the coating film is slightly observed. × ……… The coating film is remarkably peeled or raised. cut in, with a cutter knife, approximately in the middle of the specimen, the parallel lines of each vertical and horizontal eleven orthogonal, pulling at intervals of 1 mm, so that it is 100 squares in 1 cm ^2, in a grid pattern , And a sticky cellophane tape was stuck on the coated surface, and the coated painted surface after rapidly peeling it off was visually evaluated and judged. …: No peeling of the coating film was observed at all △:… Peeling of the coating film was slightly observed ×: …… Peeling of the coating film was noticeably observed [Glossy] Specular reflectance of 60-degree specular photometer The evaluation was determined by [Solvent resistance] The felt was impregnated with xylene or acetone, and a load of 1 kg was applied by a rubbing device to form
It was indicated by the gloss retention of the coated surface after rubbing was performed 0 times. [Acid resistance] A 10% sulfuric acid aqueous solution was spotted on the coated surface, and after holding at 60 ° C. for 30 minutes, the degree of blistering or damage of the coating film was visually evaluated and evaluated in 10 steps. . [Alkali resistance] The coated plate was immersed in a 5% aqueous KOH solution at room temperature for 100 hours, and the degree of damage to the coating film was visually evaluated and determined. [Hardness] Evaluation was made by pencil hardness. [Weather resistance] The coated plate was indicated by a gloss retention after a 1,000-hour weather resistance acceleration test was performed by "Sunshine Weatherometer" manufactured by Suga Test Instruments Co., Ltd. [Pot life] Performed according to JIS K5400 (1999) 4.9.

From the above Examples and Comparative Examples, when those having a small proportion of these two or more ε-caprolactone adducts are used, for example, as a coating material for a top coat for automobiles, good workability and hardness of the coating film are obtained. It is clear that a coating film having a well-balanced finish appearance, weather resistance, acid resistance, stain resistance, gloss, flexibility and scratch resistance can be produced.

[0207]

The curable coating composition using the lactone-modified monomer having a reduced lactone chain according to the present invention has good workability and high acid resistance and abrasion resistance even if it is curable with polyisocyanate. And a coating film which is excellent in bending resistance and recoat adhesion. In the case of a coating composition using a conventional film-forming resin, which was a cause of poor acid resistance, even when using a melamine resin hardener, if the coating of the present invention is used, any This has the great advantage of not causing the problem described above.

[Brief description of the drawings]

FIG. 1 shows ε in Reference Examples 1 to 4 and Reference Comparative Examples 1 to 5.
-Shows the chain distribution of caprolactone.

FIG. 2 shows ε in Reference Examples 5 to 6 and Reference Comparative Examples 7 to 11.
The relationship between the caprolactone / HEMA charge ratio and the ε-caprolactone chain distribution ratio is shown.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J034 BA03 DA01 DA05 DB03 DB05 DK02 DP03 DP06 DP18 GA24 GA33 GA36 HA01 HA02 HB08 HC03 HC12 HC13 HC16 HC34 HC35 HD02 RA07 4J038 CP111 DG191 DG261 KA03 KA08 MA02 MA08 MA10 NA04 NA11 NA12 PC

Claims (14)

[Claims] 1. A low lactone-modified hydroxyalkyl (meth) represented by the general formula (1) wherein the proportion of a monomer having two or more lactone chains (n ≧ 2) is less than 50% (GPC area%).
A curable resin composition containing, as essential components, 0.5 to 80 parts by weight of an acrylic polyol resin (A) and 0.5 to 50 parts by weight of a polyisocyanate compound (B) obtained using the acrylic acid ester composition (however, , (A) and (B) do not exceed 100 parts by weight). Embedded image Wherein R, R ¹ , R ² and R ³ are independently hydrogen or a methyl group, j is an integer of 2 to 6, and xn R ⁴ and R ⁵ are independently hydrogen. Or 1 to 12 carbon atoms
Wherein x is 4-7 and n is 0
Or an integer of 1 or more, and the average value of n in the composition is 0.1.
3 or more and less than 1.0. ) 2. An acrylic polyol resin (A) comprising a low lactone-modified hydroxyalkyl (meth) acrylic acid ester composition, a carboxyl group-containing vinyl monomer,
The curable resin composition according to claim 1, wherein the curable resin composition is a vinyl copolymer having a carboxyl group and a crosslinkable functional group obtained by reacting with another vinyl monomer. 3. An acrylic polyol resin (A) reacts a hydroxyl group-containing resin obtained by polymerizing a low lactone-modified hydroxyalkyl (meth) acrylate composition with (meth) acrylic anhydride, And a vinyl copolymer having a carboxyl group and a crosslinkable functional group obtained by reacting the resulting reaction product with a carboxyl group-containing vinyl monomer and another vinyl monomer. Item 2. The curable resin composition according to Item 1. 4. The acrylic polyol resin (A) as a hydroxyl group-containing resin, wherein the hydroxyl group-containing resin according to claim 3, a hydroxyl group-containing urethane resin, a hydroxyl group-containing epoxy resin, a hydroxyl group-containing cellulose derivative and a hydroxyl group The curable resin composition according to claim 1, wherein the curable resin composition is obtained by using at least one resin selected from the group consisting of a polyester resin. 5. The curable resin according to claim 1, wherein the acrylic polyol resin (A) is obtained by using the hydroxyl group-containing resin and the hydroxyl group-containing urethane resin according to claim 3 as the hydroxyl group-containing resin. Composition. 6. The curable resin composition according to claim 1, wherein the polyisocyanate compound (B) contains an epoxy resin in the polyisocyanate compound. 7. The curable resin composition according to claim 1, wherein the hydroxyalkyl (meth) acrylate is a hydroxyethyl (meth) acrylate. 8. A crosslinked particle obtained by dispersing (i) a mixture of an acrylic polyol resin (A) and a polyisocyanate compound (B) in an aqueous medium and crosslinking the mixture, or (i)
i) Urethane-urea / ethylene obtained by polymerizing a polymerizable ethylenically unsaturated compound containing at least a low lactone-modified hydroxyalkyl (meth) acrylate composition in water in which crosslinked urethane-urea particles are dispersed. A paint comprising any one of resin-based crosslinked particles as a film-forming resin component. 9. A film-forming resin component having a particle diameter of 1
μm or less, and the average molecular weight between crosslinks is 300 to 2.0.
9. The paint according to claim 8, comprising more than 50% by weight of crosslinked particles in the range of 00. 10. The paint according to claim 8, wherein the crosslinked particles have a film forming temperature of 100 ° C. or less. 11. The paint according to claim 8, wherein the content of the crosslinked particles in the film forming resin component is 70% by weight or more. 12. The film-forming resin component as described above,
The paint according to any one of claims 8 to 11, wherein the paint contains a crosslinker in an amount of 1 to 25% by weight together with the crosslinked particles. 13. The film-forming resin component as described above,
The coating according to any one of claims 8 to 12, further comprising a reactive group-containing film-forming resin other than the crosslinked particles. 14. The paint according to claim 8, wherein the crosslinked particles contain a pigment.