JPH0730290B2 - Curable resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coating material for plastics.

[Prior Art] Conventionally, as a coating material for plastics, a two-pack type resin composition using a hydroxyl group-containing polyurethane and an aliphatic polyisocyanate as a cross-linking agent (for example, Japanese Patent Publication No. 61-54061).
No.) or a hydroxyl group and / or carboxyl group-containing acrylic resin, and a chelate cross-linking resin composition using a metal chelate compound as a cross-linking agent (for example, JP-A-5-
No. 45340) is generally known.

[Problems to be Solved by the Invention] The above two-pack type resin composition reacts rapidly when a hydroxyl group-containing polyurethane and an aliphatic polyisocyanate are mixed, and therefore, it is necessary to use immediately after mixing, resulting in poor storage stability. There is a problem that workability is restricted. Further, the above-mentioned chelate-crosslinking resin composition of acrylic resin has a problem in physical properties such as a hard coating film and no elasticity.

[Means for Solving the Problems] The present inventors arrived at the present invention as a result of diligent studies of a curable resin composition having excellent strength and elongation properties of a coating film, good storage stability, and not restricted in workability. did.

That is, according to the present invention, a polyurethane resin (A) having a hydroxyl group and / or a carboxyl group, an organometallic coordination compound (C), and optionally a polyacrylic resin (B)
And a plastic molded article obtained by applying the coating agent.

Examples of the polyurethane resin (A) used in the present invention include those obtained from an active hydrogen compound and an organic polyisocyanate and having substantially no free isocyanate group.

Examples of active hydrogen-containing compounds include high molecular weight polyols, low molecular weight polyols and polyamines.

Polyether polyols (low molecular weight polyols (ethylene glycol, propylene glycol, 1.3- or 1.4-butanediol, 3-
Methylpentanediol, 1.6-hexanediol,
Bifunctional polyols such as neopentyl glycol, diethylene glycol, cyclohexylene glycol; trifunctional or higher functional polyols such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose; lactic acid, tartaric acid, citric acid, salicylic acid, dimethylolpropion A monoalcohol such as methanol, ethanol, propanol, butanol, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate can be partially used in combination with a hydroxycarboxylic acid such as an acid. ), Polyphenols (bisphenols such as bisphenol A), and amines (alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine; aliphatic polyamines such as ethylenediamine, hexamethylenediamine, isophoronediamine, diethylenetriamine. Alkylene oxides of aromatic diamines such as tolylenediamine, diphenylmethanediamine, etc. [One or more kinds of alkylene oxides having 2 to 4 carbon atoms such as ethylene oxide, propylene oxide, butylene oxide (random and / or block)]
Addition product, ring-opening polymer of alkylene oxide (polytetramethylene ether glycol, etc.), polyester polyol [polycarboxylic acid (aliphatic polycarboxylic acid such as adipic acid, succinic acid, sebacic acid, azelaic acid, fumaric acid, maleic acid An acid and a dimerized linoleic acid; an aromatic polycarboxylic acid such as phthalic acid, isophthalic acid and terephthalic acid) and a low molecular weight polyol or polyether polyol (the low molecular weight polyol, triethylene glycol to polyethylene glycol, etc.) are terminated with a hydroxyl group. Is a polyester polyol,
Lactone polyester (polycaprolactone diol, etc.), polycarbonate diol, etc.], polybutadiene polyol, hydrogenated polybutadiene polyol, acrylic polyol, polymer polyol [polyol (polyether polyol, polyester polyol, etc.), vinyl monomer (acrylonitrile, styrene, etc.) Polymerized polyol] and the like, and mixtures of two or more thereof.

Among the polymer polyols, preferred are polyether polyols and polyester polyols.

The OH equivalent of the polymer polyol is usually 200 to 3000, preferably 250 to 2000.

As the low molecular weight polyol, the same low molecular weight polyol as described in the section of the polyether polyol can be mentioned. Preferred low molecular weight polyols are ethylene glycol, 1.4 butanediol and dimethylolpropionic acid.

As polyamines, aliphatic polyamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, diethylenetriamine, etc.), alicyclic polyamines [4.4'-diaminodicyclohexylmethane (hydrogenated MB
A), 1.4-diaminocyclohexane, 4.4'-diaminomethyldicyclohexylmethane, isophoronediamine, etc.], aliphatic diamine having an aromatic ring (xylylenediamine, tetramethylxylylenediamine, etc.), aromatic polyamine (diphenylmethanediamine, dichlorodiphenylmethane) Diamine, tolylenediamine, diethyltolylenediamine, benzidine, phenylenediamine, etc.), alkanolamine (mono- or di-ethanolamine, propanolamine, N-hydroxyethylethylenediamine, etc.), polyalkylene oxide polyamine [of the active hydrogen-containing compound One or more kinds of alkylene oxides having 2 to 4 carbon atoms such as ethylene oxide, propylene oxide, butylene oxide (random and / or Is a block), an alkylene oxide ring-opening polymer (polytetramethylene ether glycol, etc.), or a compound having a structure in which the terminal OH group of a polyether polyol is substituted with an amino group, such as polyoxyethylene ether diamine and polyoxy Propylene ether diamine] and the like, and mixtures of two or more thereof.

Preferred of the polyamines are hexamethylenediamine, isophoronediamine and 4.4'-diaminodicyclohexylmethane.

These active hydrogen-containing compounds are used alone or in combination with the high-molecular polyol and the low-molecular polyol and / or polyamine.

The weight ratio of the high molecular weight polyol to the low molecular weight polyol and / or the polyamine is usually 1: 0 to 1: 5, preferably 1 :.
It is 0 to 1: 3. The average active hydrogen (OH, NH ₂ , NH) equivalent of the active hydrogen-containing compound (total) is usually 70 to 2000, preferably 1
00 to 1300.

The average number of functional groups of the active hydrogen compound is usually 2 to 3, preferably 2 to 2.5.

As the organic polyisocyanate, an aliphatic polyisocyanate having 2 to 12 carbon atoms (excluding carbons in the NCO group), for example, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1.61.1- Undecane triisocyanate, 2,2.4-trimethylhexane diisocyanate, lysine diisocyanate, 2.6
-Diisocyanate methyl caproate, bis (2-isocyanateethyl) fumarate, bis (2-isocyanateethyl) carbonate, 2-isocyanateethyl-2,6-diisocyanate hexanoate, etc .; alicyclic poly having 4 to 15 carbon atoms Isocyanates such as isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylhexylene diisocyanate (hydrogenated TDI), bis (2-isocyanatoethyl) 4-
Cyclohexene-1,2-dicarboxylate, etc .; Aroaliphatic polyisocyanates having 8 to 12 carbon atoms, such as xylylene diisocyanate, tetramethylxylylene diisocyanate, diethylbenzene diisocyanate; HDI water-modified product, IPDI and HDI trimerization Aromatic polyisocyanates having 6 to 20 carbon atoms such as tolylene diisocyanate (TDI), crude TDI, diphenylmethane diisocyanate (MDI) polyphenylmethane polyisocyanate (PAPI; crude MDI), naphthylene diisocyanate, and the like; Modified products of isocyanate (carbodiimide group, uretdione group, uretoimine group, burette group and / or isocyanurate group-containing modified product, etc.) can be used. Of these, preferred are HDI, IPDI, hydrogenated MDI and tetramethylxylylene diisocyanate.

In producing the polyurethane resin (A), the ratio of active hydrogen-containing compound and organic polyisocyanate can be variously changed, but NCO and active hydrogen groups (OH, NH ₂ , NH, etc.)
The equivalent ratio with is usually 1: 1.01 to 1: 2, preferably 1: 1.02 to 1:
It is 1.5. In producing a polyurethane resin, an active hydrogen-containing compound and an organic polyisocyanate may be produced by reacting them all at once, or a stepwise reaction method [a part of the active hydrogen-containing compound (for example, a polymer polyol) and an organic polyisocyanate] Method for producing by reacting polyisocyanate to form NCO-terminated prepolymer and then reacting the rest of active hydrogen-containing compound (for example, low molecular weight polyol and / or polyamine), reacting active hydrogen compound and part of organic polyisocyanate A method of producing by reacting the rest of the organic polyisocyanate after forming an active hydrogen group terminal (OH, NH ₂ , NH, etc.) prepolymer by
And the like] may be used.

The polyurethane-forming reaction is usually 40-140 ° C, preferably 6
It is carried out at 0 to 120 ° C. (when polyamine is reacted, it is usually carried out at a temperature of 80 ° C. or lower, preferably 0 to 70 ° C.)

The reaction may be carried out in a solvent (for example, dimethylformamide, dioxane, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, cellosolve acetate, etc.), and the solvent may be added during or after the reaction.

Hydroxyl group content of polyurethane resin (A) and /
Alternatively, the carboxy content is usually 0.02 to 3.3 meq / g, preferably 0.04 to 2.5 meq / g. If it is less than 0.02 meq / g, the cross-linking effect will be poor and the solvent resistance of the coating film will be poor, and if it exceeds 3.3 meq / g, the coating film will be hard and brittle and the strength and elongation properties will be poor. The molecular weight of the polyurethane resin (A) is usually 3000 or more, preferably 50.
It is 100 to 100,000.

Polyurethane having a hydroxyl group is usually obtained by reacting a polyol and a polyisocyanate at an excess ratio of the hydroxyl group.

Polyurethane having a hydroxyl group and a carboxyl group is usually obtained by reacting a polyol, a hydroxycarboxylic acid compound (for example, dimethylolpropionic acid), and a polyisocyanate at a ratio in which the hydroxyl group and the carboxyl group are in excess.

Polyurethanes having carboxyl groups usually produce urethane prepolymers having terminal isocyanate groups from polyols, hydroxycarboxylic acid compounds and polyisocyanates, and then monoalcohols (eg methanol, n-butanol etc.) and / or monoamines (eg n- Butylamine, di-n-butylamine, etc.).

As the organometallic coordination compound (C), an organoaluminum coordination compound such as aluminum trisacetylacetonate and aluminum triisopropoxide, an organozirconium coordination compound such as zirconium tetrakisacetylacetonate and diisopropoxyzirconium bisacetylacetonate. , An organic titanium coordination compound such as titanium tetrakis acetylacetonate and diisopropoxy titanium bisacetylacetonate. Of these, preferred are organoaluminum coordination compounds and organozirconium coordination compounds that do not cause discoloration of the coating film.

As the acrylic resin (B), one of the following ethylenically unsaturated monomers (a), or (a) and another (b)
At least two types of polymers of (c), (d), (e), and (f) are included.

(B) (meth) acrylic acid and its derivatives: (meth) acrylonitrile; (meth) acrylic acid and salts thereof; alkyl (meth) acrylates such as methyl (meth) acrylate and n-butyl (meth) acrylate. The carbon number of the group is usually 1 to 20, preferably 1 to 1.
2) ester; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ε
-(Meth) acrylic acid hydroxyalkyl (wherein the alkyl group has 2 to 4 carbon atoms) esters such as caprolactone-2-hydroxyethyl (meth) acrylate and lactone adducts thereof; aminoalkyl (meth) such as dimethylaminoethyl methacrylate Acrylate; (meth)
Acrylic amide, glycidyl (meth) acrylate, etc. (B) Aromatic vinyl hydrocarbon monomer: Styrene, α-methylstyrene, etc. (C) Vinyl ester monomer: Vinyl acetate, etc. (D) Vinyl ether monomer : Vinyl methyl ether, etc. (e) Vinyl halide monomer: Vinyl chloride, vinylidene chloride, etc. (f) Olefin hydrocarbon monomer: Ethylene, propylene, butadiene, isobutylene, isoprene, 1,4-pentadiene, etc. Of these, preferred are (a) or (a) and (b) and / or (c).

The polyurethane resin (A) and the acrylic resin (B) may be compounded after polymerization, or the polymerizable monomer may be polymerized in the polyurethane resin (A). The active hydrogen compound and the organic polyisocyanate may be polymerized in the resin (B).

If necessary, the plastic coating composition of the present invention may contain an auxiliary compounding agent.

For example, coloring agents such as dyes and pigments for decorative coloring, inorganic fillers, organic modifiers, various stabilizers for improving light resistance and heat deterioration, plasticizers, surfactants, antifoaming agents. , And other additives.

Examples of dyes include direct dyes, acid dyes, basic dyes, reactive dyes, and metal complex dyes.

Examples of the pigment include carbon black, titanium oxide, chromium oxide, zinc oxide, iron oxide, mica, dark blue and other inorganic pigments and coupling azo type, condensed azo type anthraquinone type, perylene type, quinacridone type thioindigo type, dioxazine type, Examples include phthalocyanine-based organic pigments.

Examples of the inorganic filler include calcium carbonate, silica, talc, glass fiber and the like.

Examples of the organic modifier include fluororesin powder, silicone resin powder, polyamide resin powder, urethane resin powder and the like.

As stabilizers, hindered phenols, hydrazines, phosphorus, benzophenones, benzotriazoles,
Examples include oxalic acid anilide type and hindered amine type.

Examples of the plasticizer include dibutyl phthalate and dioctyl phthalate.

Examples of the surfactant (foaming agent etc.) include silicone type foam stabilizers such as siloxane oxyalkylene block copolymers.

Examples of the defoaming agent include silicone-based defoaming agents.

Other additives include flame retardants, thixotropic agents, antistatic agents,
Examples include germicides. These auxiliary agents may be added to (A) or any of (A) and (B),
It may be before, during, or after the production of (A) and (B).

The addition amount of the organometallic coordination compound (C) in the present invention is usually 1 to 15%, preferably 2 to 12% with respect to the polyurethane resin (A) or the polyurethane resin (A) and the polyacrylic resin (B). is there. If it is less than 1%, the crosslinking effect is poor and the solvent resistance is poor. If it exceeds 15%, unreacted substances are deposited on the surface of the coating film, resulting in poor appearance.

The solid content ratio of the polyurethane resin (A) and the polyacrylic resin (B) is usually 1: 0 to 1: 1.5, preferably 1: 0 to 1: 1. If it exceeds 1: 1.5, the coating film has no elasticity, becomes hard and brittle, and has poor strength and elongation properties.

The amount of the auxiliary compounding agent added is usually 0 to 50%, preferably 0 to 20% of the dye based on the polyurethane resin (A) or the polyurethane resin (A) and the polyacrylic resin (B). Pigment, inorganic filler And the organic modifier is usually 0-170%,
Preferably 0-150%, stabilizers usually 0-20%, preferably 0.1-3%, plasticizers usually 0-100%, preferably 0.
~ 50%, surfactants and other additives usually 0-20
%, Preferably 0-10%.

The coating agent of the present invention may be a mixture of (A), (B), (C) and other components only by ordinary stirring, or a dispersion mixer (ball mill, kneader, sand grinder,
It can also be obtained by dispersing and mixing using a roll mill, a flat stone mill, etc. The order of mixing may be any order.

The coating agent of the present invention includes cloth (woven fabric and non-woven fabric such as natural fiber, chemical fiber, and synthetic fiber), rubber (natural rubber, chloroprene rubber, isoprene rubber, styrene / butadiene rubber, etc.), plastic (polyethylene, polypropylene, It can be applied to polystyrene, ABS resin, vinyl chloride resin, polycarbonate, polyacetal, polyester, polyamide, polyurethane, modified PPO, acrylic resin, epoxy resin, phenol resin, melamine resin, etc.). Particularly preferred for plastic substrates.

The coating amount of the coating agent of the present invention is usually 1 to 1000 g / m ² , and preferably 5 to 500 mg / m ² . Examples of the application method of the coating agent of the present invention include ordinary methods such as brush coating, iron coating, roll coating, flow coating, spray coating and dipping.

The coating composition of the present invention can be cured at room temperature or by heating. Usually at room temperature or below 200 ° C, preferably 40-120
℃. The curing time is 1 to 5 days at room temperature and short when heated, for example, 20 to 120 minutes at 60 to 120 ° C.

The coating agent of the present invention is used as a seat, an interior coating agent, and an exterior coating agent for vehicles such as automobiles, motorcycles, and trains, and ships such as ships, motor boats, and yachts, and an exterior coating agent and interior coating agent for buildings such as houses and buildings. TV, refrigerator,
It is useful as a paint for home appliances such as stereos, videos, washing machines, and office automation equipment.

[Examples] The present invention will be described below with reference to practical examples, but the present invention is not limited thereto. Parts in the examples and comparative examples represent parts by weight.

The raw materials used in the examples and comparative examples are as follows.

(1) Polymer polyol PCL; polycaprolactone diol (molecular weight 2000) PBG; polytetramethylene glycol (molecular weight 1000) (2) low molecular polyol BD; 1.4-butanediol DEG; diethylene glycol TMP; trimethylolpropane DMPM; di Methylolpropionic acid (3) Amine compound HMDA; Dicyclohexylmethanediamine DEA; Diethanolamine DBA; Di-n-butylamine (4) Polyisocyanate IPDI; Isophorone diisocyanate Sumidule N-75;
Addition product of 1 mol water and 3 mol HDI [Sumitomo Bayer Urethane Co., Ltd.] (5) Solvent TOL; Toluene MIBK; Methyl isobutyl ketone IPA; Isopropyl alcohol DOX; 1.4 Dioxane BAc; Butyl acetate (6) Catalyst DTD; Dibutyltin Dilaurate AIBN; Azobisisobutyronitrile (7) Ethylenically unsaturated monomer 2-EHMA; 2-Ethylhexyl methacrylate n-BA; n-Butyl acrylate MMA; Methyl methacrylate 2-EHA; 2-Ethylhexyl acrylate HEA; 2 -Hydroxyethyl acrylate St; Styrene (8) Organic metal coordination compound Al-AA; Aluminum trisacetylacetonate Zr-AA; Zirconium tetrakisacetylacetonate (9) OH group- and COOH group-containing polyurethane resin (A-1), (A-2); A four-necked flask was charged with the raw materials shown in Table 1 and placed under a nitrogen atmosphere at 100 ° C. Obtained by reacting 12 hours, the solid shown in Yes Table 11 with an OH group and COOH group-containing polyurethane resin component, having a viscosity, the OH content and COOH content.

(A-3); A high-molecular polyol, a low-molecular polyol and a polyisocyanate were charged into a four-necked flask and reacted at 100 ° C for 10 hours under a nitrogen atmosphere to produce an NCO-terminated prepolymer, and then a solvent was added to dilute it. After that, OH obtained by reacting by adding an amine compound at room temperature
Group and COOH group-containing polyurethane resin having the solid content, viscosity, OH content and COOH content shown in Table 2.

(10) Polyurethane resin (D) containing no OH group and COOH group; OH group and OH group obtained by charging a four-necked flask with the raw materials shown in Table 1 and reacting at 100 ° C. for 12 hours in a nitrogen atmosphere. It is a polyurethane resin containing no COOH group and has the solid content and viscosity shown in Table 1.

(11) Acrylic resins (B-1) and (B-2); In a four-necked four-necked flask equipped with a stirrer, a reflux condenser, and a nitrogen blowing tube dropping device, half the amount of toluene of the raw materials shown in Table 3 and Butyl acetate was charged, and a mixture of half the amount of the ethylenically unsaturated monomer and the catalyst shown in Table 2 was added dropwise over 3 hours into a flask whose temperature was maintained at 100 ° C while blowing nitrogen at a rate of 10 ml / min. Then, a polymerization reaction was performed. One hour after the completion of the dropping, a mixed solution of the rest of the catalyst and the rest of the toluene was added dropwise over 3 hours for aging to complete the reaction. It has the solid content, viscosity and Tg shown in Table 3.

Examples 1 to 3 and Comparative Example 1 100 parts of (A-1) to (A-3) and (D) shown in Table 1 were mixed with a solution prepared by dissolving 1 part of A1-AA in 19 parts of IPA and 19 parts of DOX. The coating composition of the present invention was obtained. This coating agent was applied onto a polypropylene plate so that the film thickness after drying was 50 μm, and dried at 80 ° C. for 30 minutes to obtain a colorless and transparent elastic film. Table 4 shows the strength and elongation properties and solvent resistance of the film.
And shown in Table 5.

(Solvent resistance test) The film was immersed in each solvent for 60 minutes at room temperature, and the degree of dissolution and swelling was observed.

⊚: Shape is maintained with almost no swelling.

◯: Swelled to some extent, but retained its shape.

Δ: Semi-dissolved and does not retain its shape.

X: completely dissolved.

Examples 4 to 6 and Comparative Example 2 (A-1) and (B- shown in Table 1, Table 2 and Table 3
1) and (B-2) in the same manner as in Examples 1 to 3
AA was added to obtain the coating composition of the present invention. This coating agent was applied in the same manner as in Examples 1 to 3, and the strength and elongation properties of the obtained film are shown in Table 6.

Examples 7 to 9 and Comparative Example 3 (A-1) and (A-2) shown in Table 1 and Table 2.
Al-AA, Zr-AA and Sumidule N-75 were blended with to obtain a coating composition of the present invention. Table 7 shows the solution stability of this coating agent.

[Advantages of the Invention] The coating agent of the present invention exhibits excellent strength and elongation physical properties and solvent resistance as compared with conventional ones, and further, the solution stability is stable for a long period of time, and the work life is not restricted by working time. It is remarkably excellent in terms of efficiency and economy.

Because of the above effects, the coating agent of the present invention is useful as a paint, coating agent, primer, adhesive, sealing agent, etc. for various plastic surfaces. In particular, it is suitable as a coating material for plastic base materials because it has good low-temperature curability, flexibility, solvent resistance, light resistance, and heat resistance.

Claims (6)

[Claims] 1. A coating agent for plastics comprising a polyurethane resin (A) having a hydroxyl group and / or a carboxyl group, an organometallic coordination compound (C) and optionally an acrylic resin (B). 2. The amount of (C) is (A) or (A) and (B)
The coating composition according to claim 1, which is 1 to 15% based on the weight of the solid content. 3. (C) is an organoaluminum compound and /
The coating agent according to claim 1 or 2, which is a zirconium compound. 4. The coating agent according to claim 1, wherein (A) is a polyurethane resin obtained by reacting an aliphatic polyisocyanate, a high-molecular polyol, a low-molecular polyol and / or a polyamine. . 5. The coating agent according to claim 1, wherein the number average molecular weight of (A) is at least 3000. 6. A plastic molded product obtained by coating with the coating agent according to claim 1.