JPH05163461A - Resin composition for coating and method for coating - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing a specific phenolic hydroxyl group-containing polyester-based resin and a urethane prepolymer, having a long shelf life, directly curable in the presence of a tertiary amine and providing films excellent in hardness, flexibility, etc. CONSTITUTION:The objective composition containing (A) a phenolic hydroxyl group-containing polyester-based resin prepared from 1-30wt.% isopropenylphenol and/or isopropenylphenol dimer and 70-99wt.% unsaturated polyester and (B) a urethane prepolymer. The blending ratio of the components (A)/(B) is preferably 0.5-2 equiv. ratio. Furthermore, the component (A) is obtained by a well- known radical polymerization method; however, a radical polymerization initiator is used in an amount of preferably 0.05-10wt.%. The reaction temperature is preferably 60-150 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating resin composition, and more specifically, it has a fast-curing property and contains a polyester resin containing a phenolic hydroxyl group and a urethane prepolymer and has a pot life. TECHNICAL FIELD The present invention relates to a long-lasting resin composition for urethane coatings and a coating method thereof.

[0002]

2. Description of the Related Art Urethane paints have urethane bonds in the resulting coating film, and the coating film has hardness, flexibility, abrasion resistance,
It is used in various fields because it has excellent physical properties such as chemical resistance.

[0003]

However, as the polyester resin used in the conventional coating material, one generally containing a primary or secondary hydroxyl group is used. The primary or secondary hydroxyl group does not have sufficient reactivity with isocyanate, and a catalyst such as amine was required to increase the reactivity. When such a catalyst is used, there is a drawback that the pot life of the coating material becomes extremely short. Therefore, a coating material which has a long pot life and is quickly cured has been desired.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a polyester containing a phenolic hydroxyl group obtained by reacting isopropenylphenol and / or isopropenylphenol dimer. The present invention has been completed by finding that a resin composition containing a base resin and a urethane prepolymer has a long pot life and is cured immediately by the presence of a tertiary amine. That is, the present invention relates to a polyester resin (A) containing a phenolic hydroxyl group obtained from 1 to 30% by weight of isopropenylphenol and / or isopropenylphenol dimer and 70 to 99% by weight of an unsaturated polyester, and a urethane prepolymer ( The present invention relates to a coating resin composition containing B). Furthermore, when applying a paint comprising the above resin composition, a tertiary amine vapor or atomized tertiary amine should be contained in the spray air and mixed with the paint, or contacted with the tertiary amine vapor after coating. Relates to a coating method.

The present invention will be described in detail below. As the polyester resin (A) containing a phenolic hydroxyl group used in the present invention, the amount of isopropenylphenol and / or isopropenylphenol dimer used is 1 to 30%, and other unsaturated polyester 70 to 99% by weight.
The polyester resin obtained from the above is suitable. Preferably, a polyester resin obtained by using 5 to 20% by weight of isopropenylphenol and / or isopropenylphenol dimer and 80 to 95% by weight of other unsaturated polyester is suitable. When the amount of the isopropenylphenol dimer used is 1% by weight or less, the curability decreases, and when it is 30% or more, the adhesion tends to decrease, which is not preferable. The unsaturated polyester used in the present invention includes, as a carboxylic acid component, an unsaturated dicarboxylic acid such as maleic anhydride, maleic acid, fumaric acid and itaconic acid, terephthalic acid, isophthalic acid, phthalic anhydride, naphthalenedicarboxylic acid, and amber. Saturated polycarboxylic acids such as acids, glutaric acid, adipic acid, azelaic acid, 1,10-decanedicarboxylic acid, cyclohexanedicarboxylic acid, trimellitic acid, and alcohol esters thereof can be used. As the alcohol component, for example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol,
1,4-butanediol, 1,5-pentanediol, 1,6
-Hexanediol, 1,10-decanediol, 3-methyl-pentanediol, 2,2'-diethyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, neopentyl glycol, trimethylolethane , Trimethylolpropane, glycerin, pentaerythritol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct and the like can be used. it can.

According to the present invention, linseed oil, tung oil,
Of course, safflower oil, dehydrated castor oil, cottonseed oil, coconut oil and its fatty acids can be used. The unsaturated polyester used in the present invention can be obtained by a usual transesterification reaction or a direct esterification reaction of one or more kinds of the above-mentioned carboxylic acid component and one or more kinds of the above-mentioned alcohol component. The production of the polyester resin (A) containing a phenolic hydroxyl group used in the present invention is carried out by a known radical polymerization method using the unsaturated polyester and isopropenylphenol and / or isopropenylphenol dimer. The method is not particularly limited. Examples of the radical initiator include organic peroxides such as benzoyl peroxide and dibutyl peroxide, and azobis compounds such as azobisisobutyronitrile. The amount of the radical initiator used is suitably 0.05 to 10% by weight, particularly preferably 0.1 to 5% by weight, based on the reaction mixture. Reaction temperature is 30-180 C, especially 60-150 C
Is preferred. The reaction is usually carried out under normal pressure,
It can also be carried out under pressure or under reduced pressure. As the urethane prepolymer (B) used in the present invention, various urethane prepolymers derived from known polyisocyanates can be used. For example, tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, diphenyl-methane- Examples thereof include isocyanurate derivatives derived from diisocyanates such as 4,4′-diisocyanate, biuret modified products, adduct products, and urethane modified products modified with the following various polyols.

Examples of polyols used for the above modification include, for example, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, trimethylene glycol, 1,3- and 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-hexylene glycol, 1,10-decanediol, neopentyl glycol, 1,2-cyclohexanediol, 2-butene-
1,4-diol, 3-cyclohexane-1,1-dimethanol, 4-methyl-3-cyclohexane-1,1-dimethanol, 3-methylene-1,5-pentanediol,
(2-Hydroxyethoxy) -1-propanol-4-
(2-hydroethoxy) -1-butanol, 5- (2-
(Hydroxypropoxy) -2-octanol, 3-allyloxy-1,5-pentanediol, 2-allyloxymethyl-2-1,3-pentanediol, [(4,4-pentyloxy) -methyl] -1,3- Propanediol, 3-(o-
Propenylphenoxy) -1,2-propanediol, 2,
2'-diisopropylidene bis (P-phenyleneoxy)
Diethanol, glycerin, 1,2,6-hexanetriol, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, 3- (2-hydroethoxy) -1,2-
Propanediol, pentaerythritol, sorbit,
Polyhydric hydroxy compounds such as sucrose, lactic acid, α-methyl glucoside, α-hydroxyalkyl glucoside, novolac resin, phosphoric acid, benzene phosphoric acid, polyphosphoric acid (eg tripolyphosphoric acid and tetrapolyphosphoric acid), phenol-aniline -Formaldehyde ternary condensation product,
Aniline-formaldehyde condensation product, ethylenediamine, diethylenetriamine, triethylenetetramine, methylenebisorthochloraniline, 4,4'- and 2,
Polyamines such as 4'-diphenylmethanediamine, 2,4-tolylenediamine, 2,6-tolylenediamine, alkanolamines such as triethanolamine and diethanolamine, ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide, etc. Or a polytetramethylene ether glycol obtained by adding one or more of the above. Also, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3- and 1,4-butanediol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, decamethylene glycol, Glycerin, trimethylolpropane, pentaerythritol,
One or more compounds having at least two hydroxyl groups such as sorbit, and malonic acid, maleic acid, succinic acid, adipic acid, tartaric acid, pimelic acid, sebacic acid, oxalic acid, phthalic acid, terephthalic acid, Ring-opening polymers of cyclic ester such as polyester polyol or polycaprolactone obtained from one or more compounds having at least two carboxyl groups such as trimellitic acid and hemimellitic acid are also used. Furthermore,
39-24737, Japanese Examined Sho 41-3473, Japanese Examined Sho 42-22108, Japanese Examined Sho
44-8230, JP-B-47-47597, JP-B-47-47999, JP-A-48
-34991, JP-A-51-50398, JP-A-51-70286, JP-A-52-1
1249, JP-A-53-4092, JP-A-53-13700, JP-A-54-6426
4, JP-A-53-78297, JP-A-54-13700, JP-A-55-5988
The so-called polymer polyol composition obtained by graft-polymerizing an ethylenically unsaturated compound in the polyether polyol and / or the polyether polyol described in the above etc. is used. Suitable ethylenically unsaturated compounds for preparing such compositions include, for example, acrylonitrile,
Styrene etc. Furthermore, 1,2-polybutadiene polyol, polybutadiene polyol such as 1,4-polybutadiene polyol, or polyester polyol resin,
Acrylic polyol resin and the like can also be used. In addition, these derivatives may be used in any mixture.

When the above-mentioned resin composition for paints is made into paint, additives such as diluent solvents, pigments typified by calcium carbonate and titanium oxide, various coupling agents, leveling agents and the like may be used as a matter of course. .. Further, a polyester resin (A) containing a phenolic hydroxyl group and a polyol resin such as an acrylic polyol resin, an epoxy polyol resin, a polyester polyol resin or a glycol can be used in combination. Here, the compounding ratio of the phenol group-containing resin (A) having a hydroxyl group and the urethane prepolymer (B) having an isocyanate group is the equivalent ratio (B
/ A) is preferably in the range of 0.5 to 2.0. If the equivalence ratio is higher than 2.0, the film becomes hard and bending properties and adhesion are deteriorated. On the other hand, if the equivalence ratio is lower than 0.5, the moisture resistance decreases. A coating made of such a resin composition for coating has a pot life of one day or more, but if a tertiary amine is present, it will be rapidly cured regardless of the type of urethane prepolymer, so a special coating method is required. Become.

The tertiary amine used in the present invention may be any known tertiary amine, but is preferably trimethylamine, triethylamine, dimethylethylamine, methyldiethanolamine, dimethylethanolamine, diethylethanolamine, triethanolamine, Diethylethanolamine, triethanolamine, N-methylmorpholine, N-ethylmorpholine and the like can be mentioned. In general, a vapor injection cure (V
IC) system, a tertiary amine mist is contained in the spray air, mist injection cure (MIC) system, the object to be coated is passed through a chamber filled with tertiary amine vapor and brought into contact with the tertiary amine vapor, The paint can be used only by the coating method called vapor cure method. Also, after applying this paint in advance,
The coating film can be cured by blowing air containing a tertiary amine generated by the VIC method or the MIC method onto the coated object. The resin composition containing the phenolic hydroxyl group-containing polyester resin and the urethane prepolymer of the present invention has a long pot life as compared with a conventional resin composition for coatings of this type, and is cured immediately by the presence of a tertiary amine. To do. Further, since the coating film has excellent physical properties such as hardness, flexibility, abrasion resistance and chemical resistance, it can be used in various fields.

[0010]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Parts in the examples indicate parts by weight. (Preparation Example of Unsaturated Polyester Resin) Production Example 1 222 parts of phthalic anhydride, 292 parts of adipic acid, and 111 parts of maleic anhydride were placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser with a stack din, and a nitrogen inlet tube. Department,
Neopentyl glycol 260 parts, 1,3-butanediol
270 parts and 27 parts of trimethylolpropane were charged, and dehydration reaction was carried out by heating to 150 C to 230 ° C in a nitrogen stream, and an unsaturated polyester resin (A-0) having a hydroxyl value of 80 (mgKOH / g) and a molecular weight of 3000 was prepared. Obtained. Production Example 2 The raw materials shown in Table 1 were placed in a four-necked flask equipped with a stirrer, a thermometer, a condenser and a nitrogen introducing tube, and the temperature was 110 ° C.
The temperature was raised to 0. Then azobisisobutyronitrile 0.3
And 1 hour later, azobisisobutyronitrile 0.
After adding 3 parts and holding for 2 hours, 22 parts of toluene and 22 parts of butyl acetate were added to obtain a polyester resin (A-1) containing a phenolic hydroxyl group having a solid content of about 70%. Production Examples 3 to 5 Phenolic hydroxyl group-containing polyester resins (A-2) to (A-5) were obtained in the same manner as in Production Example 2. (Adjustment of base paint)

Examples 1 to 4 Base paints were formulated as follows. Synthesized resin (A-1) 100 parts Titanium oxide; Taipaque CR-90 [manufactured by Ishihara Sangyo Co., Ltd.] 98 parts Thinner (xylene: toluene: butyl acetate: methyl isobutyl ketone = 2: 1: 1: 1) 40 parts With the above formulation, the pigment was dispersed for 1 hour with a paint shaker. The curing agent is Orestar P75 [Mitsui Toatsu Chemicals
Co., Ltd .: Tolylene diisocyanate, trimethylolpropane adduct, non-volatile content 78%, isocyanate group content 13.5%] are blended so that the equivalent ratio (NCO / OH) is 1, and the above thinner is used. It was diluted and the viscosity was adjusted to 14 seconds / 20 ° C. with a Ford cup # 4 to obtain a paint.
Table 2 shows an example of blending the polyester resin. The concentration of the tertiary amine generated by the VIC method in the atomizing air is 0.5
% With the air spray gun,
It was coated on a zinc phosphate-treated plate to a dry film thickness of 40 μm. In all the following Examples and Comparative Examples, dimethylethanolamine was used as the tertiary amine. The results are shown in Table-3. Example 5 The coating material prepared in Example 2 was coated with an air spray gun, and then air containing a tertiary amine vapor generated by the VIC method was sprayed on the coated article to cure the coating film.

Comparative Example 1 A coating material was obtained in the same manner as in Example 1 except that the polyester resin (A-1) used in Example 1 was replaced with (A-0). Comparative Example 2 A coating material was obtained in the same manner as in Example 1 except that the polyester resin (A-1) used in Example 1 was replaced with (A-5). Comparative Example 3 A coating material was obtained in the same manner as in Example 2 except that the urethane prepolymer having an isocyanate group and the polyester resin (A-2) used in Example 2 had an equivalent ratio of 0.4. It was Comparative Example 4 A coating material was obtained in the same manner as in Example 2 except that the urethane prepolymer having an isocyanate group and the polyester resin (A-2) used in Example 2 had an equivalent ratio of 2.5. It was Comparative Example 5 The paint prepared in Example 2 was applied by a normal air spray containing no tertiary amine. These paints were sprayed onto a zinc phosphide-treated plate in the same manner as in the Example by a VIC system (excluding Comparative Example 5) so that the dry coating film had a thickness of 40 μm. The results are shown in Table-3.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

[Table 3]

[0016]

The resin composition containing the phenolic hydroxyl group-containing polyester resin and the urethane prepolymer of the present invention has a long pot life and is cured immediately due to the presence of the tertiary amine. Is clear from.

Claims (4)

[Claims] 1. A polyester resin (A) containing a phenolic hydroxyl group obtained from 1 to 30% by weight of isopropenylphenol and / or isopropenylphenol dimer and 70 to 99% by weight of an unsaturated polyester, and a urethane prepolymer ( A resin composition for coating, which comprises B). 2. The coating composition according to claim 1, wherein the compounding ratio of the polyester resin (A) containing a phenolic hydroxyl group and the urethane prepolymer (B) is in an equivalent ratio (B / A) of 0.5 to 2.0. Resin composition. 3. When applying a paint comprising the resin composition for paints according to claim 1 or 2, is a tertiary amine vapor or atomized tertiary amine contained in the spray air and mixed with the paint? Or a coating method characterized by contacting with tertiary amine vapor after coating. 4. The coating method according to claim 3, wherein the tertiary amine is trimethylamine, triethylamine, dimethylethylamine, methyldiethanolamine, dimethylethanolamine, diethylethanolamine, triethanolamine, N-methylmorpholine, N-ethylmorpholine. ..