JP2865741B2 - Organic solvent-based thermosetting composition - Google Patents

Description

The present invention relates to an organic solvent-based thermosetting composition.

[Conventional technology and its problems] Conventionally, as a curable composition, a composition in which a crosslinking agent such as polyisocyanate or melamine is blended with a hydroxyl group-containing compound is known. However, when a polysocyanate is used, there is a drawback that the weather resistance of the obtained film is insufficient and yellowing easily occurs. Also,
The pot life of the composition is short and there is also the problem of the toxicity of polysocyanates.

On the other hand, when melamine is used, baking at a high temperature of about 140 ° C. or more is required, and the resulting film has insufficient acid resistance.

On the other hand, the present applicant has disclosed a one-part, non-toxic, low-temperature curable composition, for example, a vinyl polymer containing an alkoxysilane such as methacryloxypropyltrimethoxysilane in JP-A-60-67553. A composition in which an aluminum chelate compound is blended is proposed. However, in the above composition, since only silanol groups generated by hydrolysis of alkoxysilane are cross-linking functional groups, a large amount of water is required for curing, and curing is also caused by a large amount of by-products such as alcohol generated during the hydrolysis. There are drawbacks in that the physical properties of the product are not sufficient, and when the product is cured only with moisture in the air, it hardens from the surface because it cures from the surface, so that the inside of the product is hardly cured, and the cured product is apt to be pinched.

JP-A-53-111336 discloses a compound containing an epoxy group and / or a silanol group and / or a siloxane group (provided that both the epoxy group and the silanol and / or siloxane group are in the same molecule or in each case). In different molecules), silica fine particles and an aluminum chelate compound. However, in the above composition, as the compound having an epoxy group and a silanol and / or siloxane group, a compound having these groups in substantially the same molecule is used. Specifically, a γ-glycidoxyalkylalkoxy is used. A hydrolyzate of silane is used, but in this case, the reaction between the hydrolysates or the reaction between the hydrolyzate and the silica fine particles proceeds during storage, and the viscosity increases and gelation occurs, which is not practical. . Also, a mixture of a compound containing an epoxy group and a compound containing a silanol and / or siloxane group is shown. However, these compounds are separated during storage, the system thickens, and the like. There is a problem that the transparency of the film is also reduced.

The silica fine particles used in the composition of the present invention have an average particle diameter of about 0.001 μm to 0.1 μm having a silanol group on the particle surface.
Can be used. If the average particle size is larger than about 0.1 μm, the cured product may become cloudy or sedimentation stability may be reduced, while if the average particle size is smaller than about 0.001 μm, the viscosity of the composition increases. It is not preferable because handling becomes difficult. Dry silica powder can be used as the silica fine particles, but in the present invention, it is preferable to use colloidal silica dispersed in an organic solvent, particularly an organic solvent other than water. As an organic solvent other than water, any organic solvent can be used without particular limitation as long as it can stably disperse silica. Preferred specific examples include methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, sec-butyl alcohol,
tert-butyl alcohol, n-pentyl alcohol, n
C _1-6 monohydric alcohols such as heptyl alcohol; ethylene glycol, diethylene glycol,
Polyhydric alcohols such as propylene glycol and dipropylene glycol; ethers such as ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; amides such as N, N-dimethylformamide A nitrile such as acetonitrile; Organic solvents other than those described above, for example, aromatic hydrocarbons, esters, ketones, and the like can also be used in combination.

The alicyclic polyepoxy compound used in the composition of the present invention is a compound containing two or more, preferably two to 400 on average, alicyclic epoxy groups in one molecule. If the number of alicyclic epoxy groups is less than two on average, the curability is reduced, and as a result, the appearance (such as cracking), water resistance, chemical resistance, and the like of the coating are reduced.

In addition, the alicyclic polyepoxy compound is about 150 to 200,00
It may have a number average molecular weight of 0, preferably about 150-80,000. If the molecular weight is more than 200,000, the viscosity of the composition becomes high and handling becomes difficult.

Specific examples of the alicyclic polyepoxy compound include a compound (1) represented by the following formula: A compound (2) containing an alicyclic epoxy group and a functional group (an alicyclic epoxy group and an inert group such as a hydroxyl group and an epoxy group) (the compound (1), ) And a low-molecular or high-molecular-weight compound containing an average of two or more functional groups (such as a carboxyl group, an isocyanate group, and an amino group) that react complementarily with the functional group of the compound (2) (hexamethylene diisocyanate, Polyisocyanate compounds such as polydiisocyanate and tolylene diisocyanate; polybasic acid compounds such as phthalic acid and adipic acid; carboxylic acids such as acrylic resins and polyester resins; and isocyanate group-containing resins). And the like.

Other alicyclic polyepoxy compounds other than those described above include, for example, homopolymers of the following alicyclic epoxy group-containing polymerizable unsaturated monomers or these unsaturated monomers and α, β-ethylenically unsaturated monomers. Copolymers with the body can also be used.

Polymerizable unsaturated group Having a monomer In each formula, R ¹ is a hydrogen atom or a methyl group, and R ² is C _1-8 2
A monovalent hydrocarbon group, R ³ is a C _1-20 divalent hydrocarbon group, R ⁴
_{Represents a} C _1-4 alkyl group or a hydrogen atom. w represents 0 and an integer of 1 to 10.

Examples of the divalent hydrocarbon group described above, for example _{-CH 2 -, - CH 2 CH} 2 -, - CH 2 -CH 2 -CH 2 -, And the like. R ¹ , R ² , R ³ and R ⁴ may be the same or different.

Specific examples represented by the general formulas (1) to (12) include:
For example Polymerizable unsaturated group Unsaturated monomer having In each formula, R ¹ , R ² and R ⁴ have the same meaning as described above.

Specific examples of the compounds represented by the general formulas (13) to (15) include, for example, Polymerizable unsaturated group Having a monomer In each formula, R ¹ and R ² have the same meaning as described above.

Specific examples of the compounds represented by the general formulas (16) and (17) include, for example, And the like.

Polymerizable unsaturated group Having a monomer In each formula, R ¹ , R ² , R ³ , R ⁴ and w have the same meaning as described above.

Specific examples of the compounds represented by the general formulas (18) to (22) include, for example, Can be mentioned.

Monomer having polymerizable unsaturated group (CH ₂ CHCHCH ₂ O-) In each formula, R ¹ and R ² have the same meaning as described above.

Specific examples of the compounds represented by the general formulas (23) to (25) include, for example, Can be mentioned.

Unsaturated monomer having a polymerizable unsaturated group (CH ₂ = CHO-) In each formula, R ¹ and R ² have the same meaning as described above.

Specific examples of the compounds represented by the general formulas (26) and (27) include, for example, Can be mentioned.

Unsaturated monomer having polymerizable unsaturated group (CH ₂ ＝ CH-) In each formula, R ² has the same meaning as described above.

Specific examples of the compounds represented by the general formulas (28) and (29) include, for example, Can be mentioned.

Polymerizable unsaturated group Unsaturated monomer having In each formula, R ¹ , R ² and R ³ have the same meaning as described above.

Specific examples of the compounds represented by the general formulas (30) to (33) include, for example, Specific examples of the α, β-ethylenically unsaturated monomer include: (a) esters of acrylic acid or methacrylic acid: for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, Acrylic or methacrylic acid such as hexyl acrylate, octyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate, lauryl methacrylate C1-C18 alkyl esters of acrylic acid such as methoxybutyl acrylate, methoxybutyl methacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, ethoxybutyl acrylate and ethoxybutyl methacrylate Or alkoxyalkyl esters having 2 to 18 carbon atoms methacrylate; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate of (meth) hydroxyalkyl esters and the (meth) acrylic acid C _{2 to 8} Acrylic acid Hydroxyl-containing unsaturated monomers such as adducts of _C2-8 hydroxyalkyl esters with lactones such as ε-caprolactone and γ-valerolactone; carbons of acrylic acid or methacrylic acid such as allyl acrylate and allyl methacrylate Alkenyl esters of the formulas 2 to 8; alkenyloxyalkyl esters of acrylic acid or methacrylic acid having 3 to 18 carbon atoms, such as allyloxyethyl acrylate and allyloxy methacrylate.

(B) Vinyl aromatic compounds: for example, styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene.

(C) polyolefin-based compound: for example, butadiene,
Isoprene, chloroprene.

(D) Others: acrylonitrile, methacrylonitrile, methyl isopropenyl ketone, vinyl acetate, veova monomer (shell chemical product), vinyl propionate,
Examples thereof include vinyl pivalate, acrylic acid, methacrylic acid, perfluorobutylethyl methacrylate, perfluoroisononylethyl methacrylate, perfluorooctylethyl methacrylate, glycidyl acrylate, and glycidyl methacrylate.

In the composition of the present invention, the composition may contain at least one other functional group such as an aliphatic epoxy group, a hydroxyl group, and a carboxyl group. Among these, a hydroxyl group is particularly preferable since the curability of the coating film is improved. As a method of including the other functional group in the composition, as the alicyclic polyepoxy compound, an alicyclic polyepoxy compound having another functional group is used, or a compound having another functional group is added. Can be contained. Examples of the alicyclic polyepoxy compound having another functional group include, for example, an alicyclic epoxy group-containing polymerizable unsaturated monomer, the hydroxyl group-containing unsaturated monomer, glycidyl (meth) acrylate, and (meth)
A copolymer obtained by copolymerizing at least one monomer selected from acrylic acid and, if necessary, an α, β-ethylenically unsaturated monomer other than those described above can be used. Examples of the compound having another functional group include at least one selected from a hydroxyl group-containing unsaturated monomer, glycidyl (meth) acrylate, and (meth) acrylic acid.
Homopolymers or copolymers obtained by copolymerizing these monomers with α, β-ethylenically unsaturated monomers other than the above, if necessary; containing hydroxyl groups and / or carboxyl groups Resins such as polyester-based, silicon-based, and polyether-based resins; and low molecular weight compounds such as ethylene glycol. If the content of other functional groups is too large, the performance of the coating such as water resistance and chemical resistance may be reduced. Therefore, the amount of other functional groups is about 5 mol per 1 kg of the solid content of the curable composition. It is necessary to hold down below.

In the composition of the present invention, when the alicyclic polyepoxy compound contains a silanol group and / or a siloxane group in the alicyclic polyepoxy compound or a compound containing a silanol group and / or a siloxane group is added, the storage stability of the composition is improved. This is not preferred because the properties, chemical resistance and heat resistance of the coating are reduced.

As the metal chelate compound used in the composition of the present invention, an aluminum chelate compound, a titanium chelate compound, and a zirconium chelate compound are preferable. Among these chelate compounds, a chelate compound containing a compound capable of forming a keto-enol tautomer as a ligand forming a stable chelate ring is preferable.

Compounds that can form keto-enol tautomers include β-diketones (such as acetylacetone), acetoacetates (such as methyl acetoacetate), malonic esters (such as ethyl malonate), and β-diketones (such as ethyl malonate). Ketones having a hydroxyl group (such as diacetone alcohol), aldehydes having a hydroxyl group at the β-position (such as salicylaldehyde), and esters having a hydroxyl group at the β-position (methyl salicylate) can be used. In particular, acetoacetic esters,
Suitable results are obtained with β-diketones.

The aluminum chelate compound is suitably prepared by mixing the compound capable of constituting the keto-enol tautomer in a molar ratio of usually about 3 mol or less with respect to 1 mol of the aluminum alkoxide, and optionally heating the mixture. can do. Particularly preferred aluminum chelate compounds include, for example, tris (ethylacetoacetate) aluminum, tris (n-propylacetoacetate) aluminum, tris (isopropylacetoacetate) aluminum, tris (n-butylacetoacetate) aluminum, isopropoxybis ( Ethyl acetoacetate) aluminum, diisopropoxyethyl acetoacetate aluminum, tris (acetylacetonato) aluminum, tris (propionylacetonato) aluminum, diisopropoxypropionylacetonatoaluminum, acetylacetonatobis (propionylacetonato) aluminum, Monoethyl acetoacetate bis (acetylacetonato) aluminum and the like can be mentioned.

The titanium chelate compound is suitably prepared by mixing the compound capable of constituting the above keto-enol tautomer in a molar ratio of usually about 4 mol or less with respect to 1 mol of the titanium alkoxide, and optionally heating the mixture. can do. Particularly preferred titanium chelate compounds include, for example, diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetonato) titanium and the like.

The zirconium chelate compound is preferably prepared by mixing the compound capable of forming the keto-enol tautomer in an amount of usually about 4 mol or less with respect to 1 mol of the zirconium alkoxide, and heating as necessary. can do. Particularly preferred zirconium chelate compounds include, for example, zirconium chelate compounds such as tetrakis (acetylacetonato) zirconium, tetrakis (n-propylacetoacetate) zirconium, tetrakis (acetylacetonato) zirconium, and tetrakis (ethylacetoacetate) zirconium. be able to.

Any one of these aluminum chelate compound, zirconium chelate compound and titanium chelate compound may be used, or two or more thereof may be used in combination.

The mixing ratio of the metal chelate compound is suitably about 0.01 to 30 parts by weight with respect to the total of 100 parts by weight of the solid content of the silica fine particles and the alicyclic polyepoxy compound. If the amount is less than this range, the crosslinking reaction curability tends to decrease, and if it is more than this range, it tends to remain in the cured product and reduce water resistance, which is not preferable. The preferred compounding amount is 0.1 to 10 parts by weight, and the more preferable compounding amount is 1 to 5 parts by weight.

The mixing ratio of the silica fine particles and the alicyclic polyepoxy compound is 5 to 85% by weight, preferably 30 to 75% by weight, based on the total solid content of both components. ~ 15% by weight, preferably 70 ~ 25
% By weight. If the amount of the silica fine particles is less than 5% by weight (more than 95% by weight of the alicyclic polyepoxy compound), the curability, the hardness, the chemical resistance and the like are inferior. (Less than 15% by weight of the compound) and poor curability, film appearance (crackling, transparency, etc.).

The composition of the present invention, if necessary, an inorganic pigment, an organic pigment,
Various additives can be blended.

The composition of the present invention can be used in a form dissolved or dispersed in an organic solvent. Preferred organic solvents include, for example, aromatic hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; dioxane; and ethers such as ethylene glycol diethyl ether. And a solvent such as an alcoholic solvent such as butanol and propanol. These solvents can be used alone or in a suitable mixture. The concentration of the composition is not uniform depending on the purpose of use, but may be generally about 10 to 70% by weight.

The composition of the present invention can be suitably used, for example, as paints, adhesives, inks and the like.

The coating method when the composition of the present invention is used as a coating material is not particularly limited, and can be applied by a general coating method such as spray coating, roll coating, brush coating, and the like.

The composition of the present invention can be easily cross-linked and cured at a low temperature of about 140 ° C. or less.
It can be sufficiently cured in about 30 minutes to about 30 minutes, and about 20 minutes to 5 hours at about 60 ° C to 100 ° C.

EXAMPLES Next, the present invention will be described in detail with reference to examples. In the Examples and Comparative Examples, “parts” and “%” are based on weight.

Production Example of Resin Solution A 1,000 parts of butyl acetate was charged into a reaction vessel and heated to 100 ° C. Subsequently, the following mixture isocyanate ethyl methacrylate 155 parts n-butyl acrylate 695 parts styrene 150 parts azobisisobutyronitrile 5 parts was added dropwise over 3 hours, and the mixture was aged at the same temperature for 3 hours to obtain a resin. A solution with 50% solids was obtained.

Next, 2,000 parts of the resin solution, A mixture of 356 parts and 356 parts of methyl isobutyl ketone was added to 100 parts.
The reaction was carried out at 4 ° C. for 4 hours to obtain a resin solution A having a solid content of 50%.
The resin had a number average molecular weight of about 50,000 and an average of about 37 alicyclic epoxy groups per molecule.

Production Example of Resin Solution B 1,000 parts of butyl acetate was charged into a reaction vessel and heated to 100 ° C. Subsequently, the following mixture 3,4 epoxycyclohexylmethyl methacrylate 200 parts 2-hydroxyethyl acrylate 50 parts n-butyl acrylate 500 parts styrene 250 parts t-butyl peroxyoctoate 30 parts described below was added dropwise over 3 hours. The mixture was further aged at the same temperature for 3 hours to obtain a resin solution B having a solid content of 50%. The resin had a number average molecular weight of about 15,000 and about 15 alicyclic epoxy groups per molecule.

Production Example of Resin Solution C Solid content was prepared in the same manner as in Production Example of Resin Solution B, except that the mixture was replaced with 1,000 parts of 3,4 epoxycyclohexylmethyl methacrylate and 5 parts of benzoyl peroxide. A 50% resin solution C was obtained. The resin had a number average molecular weight of about 40,000 and about 204 alicyclic epoxy groups per molecule.

Production Example of Resin Solution D Resin solution D having a solid content of 50% was prepared in the same manner as in Production Example of Resin Solution C, except that 3,4 epoxycyclohexylmethyl methacrylate was completely replaced with glycidyl methacrylate. Obtained. The resin has a number average molecular weight of about 40,000, and a number of alicyclic epoxy groups of about 28 per molecule.
There was one.

Production Example of Resin Solution E 248 parts of γ-glycidoxypropylmethyldiethoxysilane were charged into a reaction vessel, and a 0.05N hydrochloric acid aqueous solution was added thereto.
36 parts were added and reacted to obtain a resin solution E having a resin solid content of 61%.
I got

Examples 1 to 4 The compositions of the examples were obtained by blending the raw materials and the proportions shown in the table.

Comparative Examples 1 to 4 The raw materials and the proportions shown in the table were blended to obtain compositions of Comparative Examples.

(* 1) ERL-4221: Union Carbide product, trade name, solid content 100%,
Alicyclic diepoxy compound, (* 2) Silica sol IPA-ST: Nissan Chemical Co., product name, solid content 30%, i-propanol dispersion colloidal silica average particle diameter 0.01 μm to 0.02
μm silica sol NBA-ST: same product, solid content 20%, n-butanol dispersion colloidal silica, average particle size 0.01 μm to 0.02 μm (* 3) Storage stability: Stored at 30 ° C. The storage period in which abnormalities such as sedimentation, thickening, and gelation occurred were examined.

(* 4) Preparation of test plate: The composition was applied on a mild steel plate so as to have a dry film thickness of 25 to 30 µm, and dried under the conditions described in the table.

Coating appearance: The coating was examined for abnormalities (white turbidity, cracking, discoloration, transparency, etc.).

Pencil hardness: Performed according to JISK-5400.

Acid resistance: 5% sulfuric acid (5 cc) was placed and dried at 60 ° C. for 1 hour, and the change in the film appearance (same as above) was compared with the initial one.

Hot water resistance: After immersion in hot water at 90 ° C. for 10 hours, changes in the film appearance (same as above) were compared with those of the initial one.

Heat resistance: After heating at 160 ° C. for 10 hours, changes in the film appearance (as described above) were compared with those of the initial one.

[Effects of the Invention] The invention composition has the above-mentioned composition, and thus has excellent long-term storage stability, and exhibits the effect of excellent appearance, chemical resistance, heat resistance, and the like of the formed film. is there.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08L 63/00-63/10 C08K 3/36 C08G 59/20 C08G 59/68

Claims (1)

(57) [Claims] 1. A composition comprising (a) colloidal silica dispersed in an organic solvent, (b) an alicyclic polyepoxy compound and (c) a metal chelate compound as essential components, and (a) and (b) components. (A) component 5
85% by weight and 95 to 15% by weight of component (b), and component (c) is the total solid content of component (a) and component (b).
An organic solvent-based thermosetting composition, which is contained in an amount of 0.01 to 30 parts by weight per 100 parts by weight.