JP7275777B2 - paint composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coating composition, and more particularly to a one-component acrylic urethane coating.

Conventionally, a two-liquid type acrylic urethane resin that utilizes an OH/NCO reaction between an acrylic polyol resin having weather resistance and glossiness and a polyurethane resin having flexibility and toughness is known. It is used as a resin composition for
A typical example of a topcoat resin composition composed of a two-component acrylic urethane resin is a two-component mixed composition in which a hydroxyl group-containing acrylic resin and a polyisocyanate or an isocyanate group-terminated polyurethane prepolymer are mixed during use. It has been known.

However, this two-liquid type acrylic urethane paint requires the painter to mix it accurately in a specified ratio at the painting site and stir it sufficiently. There is a big problem in terms of workability.

Attempts have also been made to improve the weather resistance of coating films by introducing a Si-containing component into a two-liquid type acrylic urethane coating composition. Specifically, acrylic components having hydroxyl groups and silyl groups are used. It has been proposed to separately mix a vinyl copolymer containing a silyl group.
For example, Patent Document 1 describes an acrylic copolymer of a vinyl monomer having a hydrolyzable silyl group and a vinyl monomer having a hydroxyl group, an organic solvent having an aromatic content of 50% by mass or less, and a curable resin composition for a topcoat comprising a polyfunctional isocyanate compound.
Further, Patent Document 2 discloses a curable resin composition for paint containing a hydroxyl group-containing acrylic resin component, a vinyl copolymer component having a hydrolyzable silyl group, a polyfunctional isocyanate compound component, and a weak solvent. It is

However, if the amount of Si component increases due to the introduction of silyl groups, the coating film becomes hard and easily cracked.
Furthermore, two-liquid type acrylic urethane paints cure by a urethane bond-forming reaction, but this urethane bond-forming reaction is greatly dependent on the environment. NCO turns into urea, and cross-linking with the acrylic component does not proceed sufficiently. Moreover, as a result of hardening of the coating film due to the formation of urea, there is also a problem that the coating film becomes easily cracked.
As described above, the two-liquid type acrylic urethane paint is greatly affected by the natural environment during use, and it is very difficult to always obtain a paint film with the same performance.

From this point of view, the present inventors have proposed a vinyl-based polyurethane prepolymer having ethylenically unsaturated double bond groups at both ends and a vinyl monomer having a (meth)acrylic acid ester and a reactive silyl group. A one-liquid type coating composition containing an acrylic urethane copolymer obtained by reacting a compound has already been found (Patent Document 3), but there is room for further improvement in terms of the flexibility of the coating film.

JP-A-2000-297242 JP-A-2002-129097 JP 2004-217795 A

The present invention has been made in view of such circumstances, and is a one-liquid solution that provides a coating film with good weather resistance and flexibility and that can exhibit good coating film performance without being affected by the environment. The object is to provide a mold coating composition.

As a result of extensive studies to achieve the above object, the present inventors have found that a predetermined proportion of a predetermined acrylic urethane copolymer resin that does not contain an alkoxysilyl group and a predetermined resin that contains an alkoxysilyl group, and To provide a one-liquid type coating composition having a silicon atom content within a predetermined range, capable of exhibiting good coating film performance without being affected by the environment, and providing a coating film with good weather resistance and flexibility. He found the headline and completed the present invention.

（式中、Ｒ¹は、それぞれ独立して、炭素数１～１０のアルキル基を表し、Ｒ²は、それぞれ独立して、水素原子、炭素数１～１０のアルキル基、炭素数６～１０のアリール基、または炭素数７～１０のアラルキル基を表し、Ｒ³は、水素原子またはメチル基を表し、ａは、０～２の整数を表す。）
４． 前記アルコキシシリル基を有するポリウレタンプレポリマーが、ポリイソシアネートと、ポリオールと、イソシアネート基と反応し得る官能基を有するアルコキシシラン化合物とのウレタン化反応物である１または２の１液型塗料組成物
を提供する。 That is, the present invention
1. (a) One or two types containing a linear polyurethane prepolymer having an ethylenically unsaturated double bond group at one end and a weight average molecular weight of 3,000 to 50,000 and a (meth)acrylic acid ester an acrylic urethane copolymer resin obtained by reacting the above vinyl-based compound and having a mass ratio of the vinyl-based compound to the polyurethane prepolymer of 85/15 to 25/75;
(b) an alkoxysilyl group-containing urethane copolymer resin obtained by reacting the polyurethane prepolymer with a vinyl compound having an alkoxysilyl group, an acrylic resin having an alkoxysilyl group, a polyurethane prepolymer having an alkoxysilyl group, and an alkoxysilyl group; and (c) an organic solvent,
The component (b) is contained in an amount of 1 to 100 parts by mass (solid content) per 100 parts by mass (solid content) of the component (a), and the silicon derived from the component (b) is added to the component (a). and 0.1 to 10% by mass of the total solid content of the component (b), a one-component coating composition,
2. The vinyl compound containing the (meth)acrylic acid ester is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, (meth)acryl Acid t-butyl, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, (meth) ) 2-ethylhexyl acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, undecyl (meth)acrylate, isobornyl (meth)acrylate, lauryl (meth)acrylate, (meth)acrylic 1. A one-liquid paint composition which is one or more selected from stearyl acid and N,N-dimethylaminoethyl (meth)acrylate,
3. The one-component coating composition of 1 or 2, wherein the vinyl compound having an alkoxysilyl group is a compound represented by the following formula (3);

(In the formula, each R ¹ independently represents an alkyl group having 1 to 10 carbon atoms, each R ² independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkyl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms, R ³ represents a hydrogen atom or a methyl group, and a represents an integer of 0 to 2.)
4. 1 or 2, wherein the polyurethane prepolymer having an alkoxysilyl group is a urethanized reaction product of a polyisocyanate, a polyol, and an alkoxysilane compound having a functional group capable of reacting with an isocyanate group; offer.

According to the present invention, it is possible to provide a one-liquid type coating composition that provides a coating film with good weather resistance and flexibility and that can exhibit good coating film performance regardless of the environment.
One-liquid type coating compositions having such properties are, for example, metals, ceramics, glass, cement, mortar, ceramic moldings, plastics, wood, paper, fibers, iron parts, etc. Buildings, household appliances, It is suitable as a topcoat paint for industrial equipment, and particularly suitable as a topcoat paint for urethane waterproof materials.

The present invention will be described in more detail below.
The one-component coating composition according to the present invention comprises (a) a linear polyurethane prepolymer having an ethylenically unsaturated double bond group at one end and having a weight average molecular weight of 3,000 to 50,000; An acrylic urethane compound obtained by reacting one or more vinyl compounds containing meth)acrylic acid ester, wherein the vinyl compound and the polyurethane prepolymer have a mass ratio of 85/15 to 25/75. polymeric resin,
(b) Alkoxy obtained by reacting a linear polyurethane prepolymer having an ethylenically unsaturated double bond group at one end and a weight average molecular weight of 3,000 to 50,000 with a vinyl compound having an alkoxysilyl group. At least one selected from a silyl group-containing urethane copolymer resin, an acrylic resin having an alkoxysilyl group, a polyurethane prepolymer having an alkoxysilyl group, and an organopolysiloxane having an alkoxysilyl group, and (c) an organic solvent, Component b) is contained in an amount of 1 to 100 parts by mass (solid content) per 100 parts by mass (solid content) of component (a), and the silicon derived from component (b) is contained in components (a) and (b). It is characterized by containing 0.1 to 10% by mass in the total solid content of.

(1) Component (a) Having an ethylenically unsaturated double bond group at one end, which is a raw material for the silicon-free acrylic urethane copolymer resin of component (a), and having a weight average molecular weight of 3,000 to 50, 000 linear polyurethane prepolymer can be obtained by urethanizing a polyisocyanate, a (meth)acrylate containing one hydroxyl group, a polyol, and a monool.

As the polyisocyanate, it can be appropriately selected from conventionally known various polyisocyanates and used. Aliphatic isocyanates; alicyclic diisocyanates such as isophorone diisocyanate, norbornane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylene diisocyanate; 2,4-tolylene diisocyanate , 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4' -diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene aromatic isocyanates such as diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3′-dimethoxydiphenyl-4,4′-diisocyanate; xylylene-1,4-diisocyanate, xylylene-1, Araliphatic diisocyanates such as 3-diisocyanate may be mentioned, and these may be used alone or in combination of two or more.
Among these, aliphatic isocyanates and alicyclic diisocyanates are preferred, and hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate and norbornane diisocyanate are particularly preferred.

Specific examples of (meth)acrylates having one hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 3-hydroxybutyl (meth)acrylate. , 4-hydroxybutyl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate and other hydroxyl group-containing monofunctional (meth) acrylate; glycerin di (meth) acrylate, 2-hydroxy-3-acryloyloxy Hydroxyl group-containing bifunctional (meth) acrylates such as propyl methacrylate; hydroxyl group-containing trifunctional (meth) acrylates such as pentaerythritol triacrylate, etc., and these may be used singly or in combination of two or more. good.
Commercially available products can be used as the (meth)acrylate, and specific examples thereof include Miramer M340 (pentaerythritol triacrylate) manufactured by Bigen Specialty Chemical Co., Ltd., and NK Ester A manufactured by Shin-Nakamura Chemical Co., Ltd. -TMM-3LM-N, Aronix M306 manufactured by Toagosei Co., Ltd., and the like.

Examples of polyols include long-chain polyols such as polyester diols, polyester amide diols, polyether diols, polyester-polyether diols, and polycarbonate diols.
Specific examples of polyester polyols include dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, dimer acid, terephthalic acid, isophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, acid esters or acid anhydrides thereof. and ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,5-pentane glycol, 1,6-hexane glycol, 3-methyl-1,5-pentane Glycol, neopentyl glycol, 1,8-octane glycol, 1,9-nonanediol, diethylene glycol, cyclohexane-1,4-diol, cyclohexane-1,4-dimethanol, dimer acid diol, trimethylolpropane, glycerin, hexane Polyester polyols obtained by dehydration condensation reaction with glycols such as triol, quadrol, or ethylene oxide or propylene oxide adducts of bisphenol A alone or mixtures thereof, ε-caprolactone, alkyl-substituted ε-caprolactone, δ-valerolactone, Examples include polyester polyols obtained by ring-opening polymerization of cyclic ester (ie, lactone) monomers such as alkyl-substituted δ-valerolactone.

Specific examples of monools include methanol, ethanol, propanol, 1-butanol, 2-butanol, 1-pentanol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2 -ethyl-1-butanol, 1-heptanol, 1-octanol, 2-octanol, 2-ethylhexanol, 3,5-dimethyl-1-hexanol, 2,2,4-trimethyl-1-pentanol, 1-nonanol , 2,6-dimethyl-4-heptanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol , 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptatricontanol, 1-oleyl alcohol, 2-octyldodecanol and other aliphatic monoalcohols; phenol, cresol, xylenol, Polyalkylene glycol monoalkyl/aryl ether which is an oxyalkylene adduct initiated by a compound containing a phenolic hydroxyl group such as nonylphenol; monocarboxylic acid ester of polyalkylene glycol; dehydration condensate of castor oil fatty acid and monool; These may be used singly or in combination of two or more.

Specific examples of polyesteramide polyols include the dicarboxylic acids exemplified in the above polyester polyols, their acid esters or acid anhydrides, and diamines such as hexamethylenediamine, xylenediamine, isophoronediamine, monoethanolamine, isopropanoltriamine, triamines or A polyesteramide polyol obtained by a dehydration condensation reaction with an aminoalcohol alone or a mixture thereof may be mentioned.
Specific examples of polyether polyols include polyethylene glycol, polypropylene ether polyol, polytetramethylene ether polyol and the like.
Specific examples of polyether-ester polyols include those produced from the above polyether polyols and the above dicarboxylic acids or acid anhydrides.
Specific examples of polycarbonate polyols include 1,4-butylene glycol, 1,5-pentane glycol, hexane glycol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, diethyl carbonate, diphenyl Examples thereof include reaction products with carbonates such as carbonates.

Furthermore, urea resins, melamine resins, epoxy resins, polyester resins, acrylic resins, polyvinyl alcohols and the like can also be used as long-chain polyols or parts thereof as long as they contain two or more active hydrogen groups.
The above long-chain polyols may be used singly or in combination of two or more.

The molecular weight or weight-average molecular weight of these long-chain polyols is not particularly limited, but it is recommended that the flexibility of the resulting coating film is increased and that the coating film exhibits abrasion resistance, heat resistance, and solvent resistance. Taking into consideration, 350 to 8,000 is preferable.

Moreover, as a polyol, you may use a short chain glycol together with the said long chain polyol.
Specific examples of short-chain glycols include ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,5-pentane glycol, 1,6-hexane glycol, 3-methyl -1,5-pentane glycol, neopentyl glycol, 1,8-octane glycol, 1,9-nonanediol, diethylene glycol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, dimer acid diol, trimethylol Examples include propane, glycerin, hexanetriol, quadrol, ethylene oxide or propylene oxide adducts of bisphenol A, and the like, and these may be used alone or in combination of two or more.

The ratio of the long-chain diol and the short-chain glycol used is not particularly limited, but the weight ratio of long-chain diol/short-chain glycol=100/0 to 70/30 is preferable, and 100/0 to 80/ 20 is more preferred.

A chain extender can also be used as necessary when producing the linear polyurethane prepolymer.
Examples of chain extenders include hydrazine; alicyclic diamines such as ethylenediamine and hexamethylenediamine; aromatic diamines such as toluenediamine and diaminodiphenylmethane; alicyclic diamines such as isophoronediamine; Examples include polyether polyamines, and these may be used singly or in combination of two or more.

The conditions for the urethanization reaction are not particularly limited. For example, a polyisocyanate, a (meth)acrylate having one hydroxyl group, and a polyol are reacted at 20 to 150° C. in the presence of a urethanization catalyst. method.
The urethanization catalyst can be appropriately selected from known catalysts such as dibutyltin dilaurate and dioctyltin dilaurate.

The charge ratio of polyisocyanate, (meth)acrylate having one hydroxyl group, polyol, and monool is such that the NCO disappears and the (meth)acrylate-derived ethylenically unsaturated double bond group is at one end. However, as long as a linear polyurethane prepolymer having a predetermined molecular weight can be obtained, there is no particular limitation. Preferably 2 to 50 parts by weight, polyol is usually 150 to 500 parts by weight, preferably 200 to 450 parts by weight, monool is usually 0.5 to 50 parts by weight, preferably 1 to 30 parts by weight.

In the urethanization reaction, an organic solvent that does not affect the reaction may be used. Specific examples thereof include aliphatic hydrocarbons such as n-hexane and octane; cyclohexane and alicyclic hydrocarbons such as methylcyclohexane. ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, butyl acetate, and isobutyl acetate; ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3- glycol ether esters such as methoxybutyl acetate and ethyl-3-ethoxypropionate; ethers such as diethyl ether, tetrahydrofuran and dioxane; methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, methylene iodide, halogenated hydrocarbons such as dichloroethane; polar aprotic solvents such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, and hexamethylphosphonylamide; They can be used in combination.

The linear polyurethane prepolymer used in the present invention has a weight average molecular weight of 3,000 to 50,000, preferably 5,000 to 48,000, more preferably 7,000 to 46,000. In addition, the weight average molecular weight in the present invention is a polystyrene conversion value obtained by gel permeation chromatography (eluent THF) for any polymer.

The (meth)acrylic acid ester compound to be reacted with the linear polyurethane prepolymer is not particularly limited as long as it does not contain a silicon atom, and specific examples thereof include methyl (meth)acrylate, ( meth)ethyl acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate , cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, n-(meth)acrylate -decyl, undecyl (meth)acrylate, isobornyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, etc., which are It may be used individually by 1 type, or may be used in combination of 2 or more types.
Although the above-described (meth)acrylate having one hydroxyl group can also be used, the (meth)acrylic acid ester compound to be reacted with the linear polyurethane prepolymer preferably contains no hydroxyl group.

In the present invention, in addition to (meth)acrylic esters, aromatic hydrocarbon-based vinyl compounds such as styrene, α-methylstyrene, chlorostyrene, 4-hydroxystyrene, and vinyltoluene; maleic acid, fumaric acid, Although unsaturated carboxylic acids such as itaconic acid and (meth)acrylic acid may be used in combination, it is preferable to use only (meth)acrylic acid esters as vinyl compounds.

In the present invention, from the viewpoint of the balance between weather resistance and flexibility of the coating film to be obtained, the quantitative ratio of the linear polyurethane prepolymer and the vinyl compound is vinyl compound/urethane prepolymer=85/15 to 25/. 75 (mass ratio), preferably 80/20 to 30/70.

The reaction between the linear polyurethane prepolymer and the vinyl compound is carried out using a radical polymerization initiator in the presence of a suitable organic solvent.
Any organic solvent may be used as long as it does not adversely affect the reaction. Examples include aliphatic or alicyclic hydrocarbons such as n-hexane, n-heptane, n-octane, cyclohexane, and cyclopentane; toluene, Aromatic hydrocarbons such as xylene, ethylbenzene, low-boiling aromatic naphtha, high-boiling aromatic naphtha; ethyl acetate, n-butyl acetate, n-amyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol Esters such as monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate; methanol, ethanol, i-propanol, n-butanol , i-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, propylene glycol mono-n-propyl ether, diethylene glycol monobutyl ether and other alcohols; acetone, methyl ethyl ketone, methyl ketones such as isobutyl ketone, methyl n-amyl ketone, cyclohexanone; ethers such as dimethoxyethane, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether; N-methylpyrrolidone, dimethylformamide, dimethyl Acetamide, ethylene carbonate and the like can be mentioned. These may be used alone or in combination of two or more.

The radical polymerization initiator can be appropriately selected from known ones, such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), azobisiso valeronitrile, benzoyl peroxide, t-butyl peroxide, cumene hydroperoxide and the like. These may be used alone or in combination of two or more. The amount of the radical polymerization initiator to be used is preferably 0.1 to 5% by mass with respect to the total mass of the vinyl compound.
The reaction temperature is usually about 60 to 120°C. The reaction time is usually about 6 to 12 hours.

(2) Component (b) The component (b) is (b-1) an alkoxysilyl group-containing urethane copolymer resin obtained by reacting a vinyl compound having an alkoxysilyl group with the linear polyurethane prepolymer described above, ( At least one selected from (b-2) an acrylic resin having an alkoxysilyl group, (b-3) a polyurethane prepolymer having an alkoxysilyl group, and (b-4) an organopolysiloxane having an alkoxysilyl group.

(b-1) Alkoxysilyl Group-Containing Urethane Copolymer Resin An alkoxysilyl group that is a raw material for the alkoxysilyl group-containing urethane copolymer resin and that is copolymerized with the linear polyurethane prepolymer that is also the raw material for component (a) described above. is any vinyl compound having a group represented by the following formula (1).

In formula (1), each R ¹ independently represents an alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, and each R ² independently represents a hydrogen atom or 1 to 5 carbon atoms. 10, preferably an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms, a is 0 to 2, preferably 0 or 1, more preferably Represents an integer of 0.
The alkyl group having 1 to 10 carbon atoms may be linear, branched or cyclic, and specific examples include methyl, ethyl, n-propyl, i-propyl, cyclopropyl, n-butyl, isobutyl, s- Butyl, t-butyl, cyclobutyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl groups and the like.
Specific examples of aryl groups having 6 to 10 carbon atoms include phenyl, α-naphthyl and β-naphthyl groups.
Specific examples of aralkyl groups having 7 to 10 carbon atoms include benzyl and phenylethyl groups.

Examples of vinyl compounds having a group represented by the above formula (1) include those represented by the following formulas (2) to (6), and a reactive silyl group bonded to a carbon atom with a urethane bond or a siloxane bond. (Meth)acrylates having a terminal through a terminal are exemplified. Among these, excellent copolymerizability and polymerization stability with a linear polyurethane prepolymer, and curability and storage stability of the resulting coating composition are obtained. From this point of view, the compound represented by the general formula (3) is suitable. Incidentally, the vinyl compound having a group represented by formula (1) may be used singly or in combination of two or more.

（式中、Ｒ¹、Ｒ²およびａは、上記と同じ意味を表す。Ｒ³は、水素原子またはメチル基を表し、ｎは、１～１３の整数を表し、ｍは、１～１４の整数を表し、ｐは、１～２１の整数を表す。）

(In the formula, R ¹ , R ² and a have the same meanings as above; R ³ represents a hydrogen atom or a methyl group; n represents an integer of 1 to 13; m represents an integer of 1 to 14; represents an integer, and p represents an integer from 1 to 21.)

Specific examples of the vinyl compound having a group represented by the above formula (1), which are suitably used in the present invention, include those represented by the following formulas, but are not limited thereto.

（式中、ｎは、上記と同じ意味を表す。）

(Wherein, n has the same meaning as above.)

Also in this case, in addition to the vinyl compound having the alkoxysilyl group, the above-described (meth)acrylate having one hydroxyl group; the above-described silicon-free (meth)acrylic acid ester compound; styrene, α-methyl Aromatic hydrocarbon-based vinyl compounds such as styrene, chlorostyrene, 4-hydroxystyrene, and vinyltoluene; In particular, it is preferable to use a (meth)acrylic ester compound containing no silicon atom in combination with a vinyl compound having an alkoxysilyl group.

The reaction between the linear polyurethane prepolymer described in detail in component (a) and the vinyl compound having an alkoxysilyl group is carried out by It can be carried out under the same conditions as the reaction with
The amount ratio of the linear polyurethane prepolymer and all the vinyl compounds including the vinyl compound having an alkoxysilyl group is not particularly limited. From the viewpoint of water resistance, the total vinyl compound/urethane prepolymer = 85/15 to 25/75 (mass ratio) is preferable, 80/20 to 30/70 is more preferable, and 70/30 to 40/60 is even more preferable. preferable.

(b-2) Acrylic resin having an alkoxysilyl group As the acrylic resin having an alkoxysilyl group, a homopolymer of a (meth)acrylate group-containing alkoxysilane compound, or this, (meth)acrylic acid, and the above-described hydroxyl group A (meth)acrylate having one alkoxysilyl group and a copolymer with other (meth)acrylic compounds such as the acrylic acid ester compound having no alkoxysilyl group can be used.
In this case, the (meth)acrylate group-containing alkoxysilane compound can be appropriately selected from known compounds and used, but the compound represented by the above formula (3) is preferable.
Specific examples thereof include (meth)acryloxydialkoxysilanes such as 3-methacryloxypropylmethyldiethoxysilane and 3-acryloxypropylmethyldimethoxysilane; 3-acryloxypropyltrimethoxysilane and 3-methacryloxysilane; Examples include (meth)acryloxytrialkoxysilanes such as propyltriethoxysilane and 3-methacryloxypropyltripropoxysilane, and these may be used alone or in combination of two or more.
The alkoxysilyl group may be a (partial) hydrolysis condensate.
As the condensate of the (meth)acrylate group-containing alkoxysilane compound, a commercially available product can be used, and specific examples include KR-513 (Si content 14.0% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.) X-40-2655A (Si content 16.8% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

When the (meth)acrylate group-containing alkoxysilane compound and other (meth)acrylic compound are copolymerized, the ratio of use thereof is not particularly limited, but the weather resistance and flexibility of the resulting coating film are improved. From the viewpoint of balance and water resistance, (meth)acrylate group-containing alkoxysilane compound / other (meth)acrylic compound = 5/95 to 90/10 (mass ratio) is preferable, and 10/90 to 80/20 is preferable. More preferably 10/90 to 50/50, even more preferably 10/90 to 30/70.

The polymerization reaction of the acrylic compound containing the (meth)acrylate group-containing alkoxysilane compound is carried out under the same conditions as the reaction between the linear polyurethane prepolymer and the vinyl compound containing the (meth)acrylic acid ester. be able to.

(b-3) Polyurethane prepolymer having alkoxysilyl group Polyurethane prepolymer having alkoxysilyl group is obtained by urethanization reaction of polyisocyanate, polyol, and alkoxysilane compound having functional group capable of reacting with isocyanate group. be able to. Examples of the polyisocyanate and polyol include the same compounds as those exemplified for the component (a) above.
Specific examples of the alkoxysilane compound having a functional group capable of reacting with an isocyanate group include a mercapto group-containing alkoxysilane compound, an amino group-containing alkoxysilane compound, a hydroxyl group-containing alkoxysilane compound, and the like. or two or more of them may be used in combination.

Specific examples of the mercapto group-containing alkoxysilane compound include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane and the like. You may use it in combination of 2 or more types.
Specific examples of amino group-containing alkoxysilanes include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3 -aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyl Dimethoxysilane and the like can be mentioned, and these may be used singly or in combination of two or more.
The hydroxyl group-containing alkoxysilanes include 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane and the like, and these are used alone. You may use it in combination of 2 or more types.

The charging ratio of the polyisocyanate, the polyol, and the alkoxysilane compound having a functional group capable of reacting with the isocyanate group is not particularly limited as long as the desired polyurethane prepolymer can be obtained by eliminating the NCO. In the present invention, with respect to 100 parts by mass of the polyisocyanate, the polyol is usually 100 to 800 parts by mass, preferably 300 to 700 parts by mass, and the alkoxysilane compound having a functional group capable of reacting with the isocyanate group is usually 50 to 150 parts by mass. , preferably 60 to 100 parts by mass.
As the conditions for the urethanization reaction in this case, the same conditions as those for the component (a) can be employed. For example, a method of reacting each component at 20 to 150° C. in the presence of the above-mentioned urethanization catalyst can be mentioned.

The weight average molecular weight of the polyurethane prepolymer having alkoxysilyl groups is not particularly limited, but is preferably 3,000 to 50,000, more preferably 5,000 to 40,000.

(b-4) Organopolysiloxane having an alkoxysilyl group The organopolysiloxane having an alkoxysilyl group used in the present invention is a tetraalkylsilicate such as tetramethylsilicate (tetramethoxysilane), tetraethylsilicate (tetraethoxysilane); Alkyltrialkoxysilanes such as trimethoxysilane, methyltriethoxysilane and methyltriisopropoxysilane; aryltrialkoxysilanes such as phenyltrimethoxysilane and phenyltriethoxysilane; and organopolysiloxane obtained by partial hydrolytic condensation, and these may be used singly or in combination of two or more.

In addition, in the present invention, commercially available organopolysiloxanes can also be used. Specific examples thereof include KR-510 (Si content 20.5% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), KR-213 ( Si content 17.7% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), KR-217 (Si content 11.6% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), KR-500 (Si content 29.4% by mass, Shin-Etsu Chemical Co., Ltd.), KC-89S (Si content 27.5% by mass, Shin-Etsu Chemical Co., Ltd.), X-40-9225 (Si content 31.3% by mass, Shin-Etsu Chemical Co., Ltd. ), X-40-9246 (Si content 33.6% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), X-40-9250 (Si content 34.1% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), KR -401N (Si content 26.1% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), X-40-9227 (Si content 27.5% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), X-40-9247 (Si Content 21.5% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), KR-9218 (Si content 18.7% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), X-40-2308 (Si content 23.8% by mass , manufactured by Shin-Etsu Chemical Co., Ltd.), X-40-9238 (Si content 21% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.

Each of the alkoxycysyl group-containing components (b-1) to (b-2) above may be used alone or in combination of two or more of (b-1) to (b-4). may
In particular, it is preferable to use (b-4) in combination with each of (b-1) to (b-3) in consideration of exhibiting good coating film performance without being influenced by the environment. .
When used in combination, the proportion of (b-4) in component (b) is preferably 0.1 to 50% by mass, preferably 0.5 to 25% by mass, and more preferably 1 to 10% by mass.

(3) Component (c) Examples of the organic solvent of component (c) include aromatic hydrocarbon solvents such as toluene and xylene; ester solvents such as ethyl acetate, n-butyl acetate and n-amyl acetate; Ketone solvents such as isobutyl ketone; alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane; petroleum hydrocarbon solvents such as mineral spirits; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether Acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, glycol ether ester solvents and the like. These solvents may be used alone or in combination of two or more.

(4) Optional components The one-liquid paint composition of the present invention contains pigment components that are commonly used in paints, such as titanium oxide, ultramarine blue, Prussian blue, zinc white, red iron oxide, and yellow lead, as long as they do not impair the effects of the present invention. , lead white, carbon black, transparent iron oxide, inorganic pigments such as aluminum powder, azo pigments, triphenylmethane pigments, quinoline pigments, anthraquinone pigments, phthalocyanine pigments and other organic pigments; diluent; Additives such as ultraviolet absorbers; light stabilizers; anti-sagging agents; leveling agents;

The one-package coating composition of the present invention can be prepared by appropriately orienting the above components in any order.
In the one-liquid type coating composition of the present invention, the content of component (b) is such that the resulting coating film has a good balance between weather resistance and flexibility, and exhibits good coating performance regardless of the environment. Therefore, it is 1 to 100 parts by mass (solid content) per 100 parts by mass (solid content) of component (a), preferably 1 to 90 parts by mass.
In addition, from the viewpoint of further improving the water resistance of the coating film, the content of silicon derived from component (b) in the one-component coating composition of the present invention is the total of component (a) and component (b). 0.1 to 10% by mass, preferably 0.12 to 9.9% by mass, in the solid content.
There are no particular restrictions on the amount of solvent used as the component (c), but the amount is preferably such that the total solid content in the composition is about 10 to 70% by mass. As the solvent, the solvent used for synthesizing the component (a) or the component (b) may be used as it is, or may be added at the time of preparation of the composition, if necessary.

The one-component coating composition of the present invention may be applied to an object to be coated by a conventional method using immersion, spraying, brushing, rollers, etc., usually at room temperature as it is or at 30° C. or higher. Bake and harden.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following, "parts" means "parts by mass" and "%" means "% by mass". Moreover, the used apparatus is as follows.
(1) Viscosity device: Viscometer DV-E manufactured by Brookfield
(2) Weight average molecular weight device: High-speed GPC device HLC-8320GPC manufactured by Tosoh Corporation
Column: Two connected columns of TSK-GEL SUPER MULTIPORE HZ manufactured by Tosoh Corporation Temperature: 40 ° C.
Detector: Differential refractometer Eluent: THF
Column flow rate: 0.35 ml/min

[Synthesis Example 1] Production of acrylic urethane copolymer resin (1) Synthesis of linear polyurethane prepolymer 500 parts of propylene glycol monomethyl ether acetate was placed in a reactor equipped with a stirrer, thermometer, cooling pipe and nitrogen gas introduction pipe. , isophorone diisocyanate (manufactured by Sumika Covestro Urethane Co., Ltd., Dismodur I) 126.4 parts, polytetramethylene ether glycol having a molecular weight of 1,000 (manufactured by Hodogaya Chemical Co., Ltd., PTG-1000SN) 142.2 177.2 parts of polycaprolactone diol (PLAXEL L212AL, molecular weight 1250, manufactured by Daicel Corporation), 37.0 parts of 2-hydroxyethyl methacrylate, 17.2 parts of isopropanol, and 0.05 part of dibutyltin dilaurate as a catalyst were charged. , under a nitrogen atmosphere at 80° C. for 12 hours or longer. After confirming that the infrared absorption spectrum at 2250 cm ⁻¹ indicating the isocyanate group had disappeared, the ethylenically unsaturated double bond group with a solid content of 50%, a viscosity of 180 mPa·s (25°C) and a weight average molecular weight of 8,000 was removed. A linear polyurethane prepolymer solution having terminal ends was obtained.

(2) Synthesis of acrylic urethane copolymer resin 187.4 parts of the linear polyurethane prepolymer solution obtained above was added to a reactor equipped with a stirring device, a thermometer, a cooling pipe, a nitrogen gas inlet pipe, and a dropping device. 362.1 parts of propylene glycol monomethyl ether acetate, 226.3 parts of methyl methacrylate, 64.8 parts of 2-ethylhexyl acrylate, 36.2 parts of cyclohexyl methacrylate, and 34.8 parts of α-methylstyrene dimer were charged and heated to 105°C while stirring. The temperature was raised to A mixture of 11.9 parts of 2,2′-azobis(2-methylbutyronitrile) and 76.5 parts of propylene glycol monomethyl ether acetate was added dropwise thereto over 4 hours. After completion of dropping, reaction was carried out at the same temperature for 3 hours to obtain an acrylic urethane copolymer resin A having a solid content of 46.8% and a viscosity of 520 mPa·s (25°C).

[Synthesis Examples 2 to 12] Production of acrylic urethane copolymer resins Acrylic urethane copolymer resins B to L were obtained by reacting under the same conditions as in Synthesis Example 1, except that the composition and blending amount were changed to those shown in Table 1 below. .

[Synthesis Example 13] Production of alkoxysilyl group-containing acrylic urethane copolymer resin An alkoxysilyl group-containing acrylic urethane copolymer resin was produced by reacting under the same conditions as in Synthesis Example 1, except that the composition and blending amount were changed to those shown in Table 1 below. got an A.

[Synthesis Example 14] Production of alkoxysilyl group-containing acrylic resin 467.7 parts of propylene glycol monomethyl ether acetate was charged into a reactor equipped with a stirring device, a thermometer, a cooling pipe, a nitrogen gas inlet pipe, and a dropping device, and the mixture was stirred. The temperature was raised to 105°C. There, 281.2 parts of methyl methacrylate, 81.0 parts of 2-ethylhexyl acrylate, 45.3 parts of cyclohexyl methacrylate, 45.3 parts of 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503) part, 14.9 parts of 2,2'-azobis(2-methylbutyronitrile), and 64.6 parts of propylene glycol monomethyl ether acetate was added dropwise over 4 hours. After completion of the dropwise addition, the mixture was reacted at the same temperature for 3 hours to obtain an alkoxysilyl group-containing acrylic resin A having a solid content of 46.8% and a viscosity of 800 mPa·s (25°C).

[Synthesis Example 15] Synthesis Example of Alkoxysilyl Group-Containing Polyurethane Prepolymer Into a reactor equipped with a stirrer, a thermometer, a condenser tube and a nitrogen gas introduction tube, 500 parts of propylene glycol monomethyl ether acetate, isophorone diisocyanate (Sumika Covestro Urethane Co., Ltd., Dismodur I) 78.4 parts, polytetramethylene ether glycol (Hodogaya Chemical Co., Ltd., PTG-2000SN, molecular weight 2,000) 176.2 parts, polycaprolactone diol (manufactured by ) Daicel, Praxel L220AL, molecular weight 2,000) 176.2 parts, 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-803) 69.2 parts, dibutyl tin dilaurate 0.05 as a catalyst were charged and reacted at 80° C. for 16 hours or more under nitrogen atmosphere. After confirming that the infrared absorption spectrum at 2250 cm ⁻¹ indicating the isocyanate group had disappeared, an alkoxysilyl group-containing polyurethane prepolymer A having a solid content of 50%, a viscosity of 300 mPa·s (25° C.) and a weight average molecular weight of 13,000 was obtained. rice field.

(2) 1-component paint composition [Example 1]
Propylene glycol monomethyl ether acetate 343 parts, acrylic urethane copolymer resin A427.0 parts obtained in Synthesis Example 1, alkoxysilyl group-containing acrylic urethane copolymer resin A110.0 parts obtained in Synthesis Example 13, titanium oxide (Ishihara 120.0 parts of PFC-105 (manufactured by Sangyo Co., Ltd.) and 1000 parts of glass beads were placed in a mixing vessel and dispersed for 1 hour using a paint shaker to obtain a coating composition.

[Examples 2 to 22, Comparative Examples 1 to 13]
A coating composition was obtained in the same manner as in Example 1, except that the composition was changed to that shown in Tables 2 and 3 below.

The coating compositions prepared in the above examples and comparative examples were evaluated as follows. The results are also shown in Table 4.
(1) Accelerated weather resistance An accelerated weather resistance test was performed using a super accelerated weather resistance tester (eye super UV tester manufactured by Iwasaki Electric Co., Ltd.). The test piece was prepared by spraying the coating composition on a flexible board of 50 x 50 x 4 mm so that the dry coating thickness was 50 μm, and drying for 7 days under the conditions of 23 ° C. and 50% RH. bottom. The test conditions were a wavelength of 295 to 450 nm, an ultraviolet irradiation intensity of 100 mW/cm ² , a black panel temperature of 63° C., 50% RH, and 125 cycles (1000 hours) of 4 hours of irradiation and 4 hours of dew condensation per cycle. After completion of the test, the gloss retention relative to the initial 60-degree specular gloss value of the coating film was obtained and evaluated in the following three stages.
○: Gloss retention rate of 60% or more △: Gloss retention rate of 30% or more and less than 60% ×: Gloss retention rate of less than 30% (2) Extensibility Extensibility is measured by a tensile tester (Shimadzu Corporation Autograph AG- 5000C), the elongation rate until breakage was measured at a tensile speed of 200 mm/min, and evaluated in the following three stages. For the test piece, the coating composition was spray-coated on a polypropylene test plate so that the dry film thickness was 50 μm, and dried for 7 days at 23° C. and 50% RH to form a coating film. Next, the coating film was peeled off from the test plate and punched out using a No. 2 dumbbell.
○: Elongation rate of 60% or more △: Elongation rate of 30% or more and less than 60% ×: Elongation rate of less than 30% The state of the coating film was visually observed, and the degree of gloss loss and whitening of the coating film was evaluated according to the following three grades. The test piece was prepared by spraying the coating composition on a flexible board of 150 x 70 x 4 mm so that the dry coating thickness was 50 μm, and drying for 7 days under the conditions of 23 ° C. and 50% RH. bottom.
○: No change in the coating film △: Slight loss of gloss and whitening in the coating film ×: Loss of gloss and whitening in the coating film (4) Initial water resistance Initial water resistance is 23 ° C., Under the conditions of 50% RH, about 2 ml of water was dropped on the test piece, and after 24 hours, the state of the coating film was visually observed immediately after wiping it off, and the degree of gloss loss and whitening of the coating film was evaluated in the following three stages. evaluated with The test piece was prepared by spraying the coating composition on a flexible board of 150 x 70 x 4 mm so that the dry coating thickness was 50 μm, and drying for 16 hours under the conditions of 23 ° C. and 50% RH. bottom.
○: No change in the coating film △: Slight loss of gloss and whitening observed in the coating film ×: Loss of gloss and whitening observed in the coating film

As shown in Table 4, the films formed from the compositions prepared in each example are excellent in accelerated weather resistance, extensibility, water resistance and initial water resistance.

Claims (4)

(a) One or two types containing a linear polyurethane prepolymer having an ethylenically unsaturated double bond group at one end and a weight average molecular weight of 3,000 to 50,000 and a (meth)acrylic acid ester an acrylic urethane copolymer resin containing no silicon atoms, obtained by reacting the above vinyl-based compound and having a mass ratio of the vinyl-based compound to the polyurethane prepolymer of 85/15 to 25/75;
(b) an alkoxysilyl group-containing urethane copolymer resin obtained by reacting the polyurethane prepolymer with a vinyl compound having an alkoxysilyl group, an acrylic resin having an alkoxysilyl group, a polyurethane prepolymer having an alkoxysilyl group, and an alkoxysilyl group; and (c) an organic solvent,
The component (b) is contained in an amount of 1 to 100 parts by mass (solid content) per 100 parts by mass (solid content) of the component (a), and the silicon derived from the component (b) is added to the component (a). and the component (b) in an amount of 0.1 to 10% by mass in the total solid content. The vinyl compound containing the (meth)acrylic acid ester is methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, (meth)acryl Acid t-butyl, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, (meth) ) 2-ethylhexyl acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, undecyl (meth)acrylate, isobornyl (meth)acrylate, lauryl (meth)acrylate, (meth)acrylic 2. The one-liquid coating composition according to claim 1, which is one or more selected from stearyl acid and N,N-dimethylaminoethyl (meth)acrylate. 3. The one-component coating composition according to claim 1 or 2, wherein the vinyl compound having an alkoxysilyl group is a compound represented by the following formula (3).

(In the formula, each R ¹ independently represents an alkyl group having 1 to 10 carbon atoms, each R ² independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkyl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms, R ³ represents a hydrogen atom or a methyl group, and a represents an integer of 0 to 2.) 3. The one-component paint according to claim 1 or 2, wherein the polyurethane prepolymer having alkoxysilyl groups is a urethanized reaction product of polyisocyanate, polyol, and an alkoxysilane compound having a functional group capable of reacting with isocyanate groups. Composition.