JPS61247750A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To provide a thermosetting resin compsn. which has excellent pigment dispersibility and gives a coating film having excellent resistance to staining corrosion and weather, containing a graft copolymer and an (alkyl-etherified) amino resin. CONSTITUTION:0.5-95 wt% fluororesin (A) having an MW of 1000-200,000 and contg. alkyxyl group or cyclohexyloxy group and carboxyl group ad 0.001-0.055 mol of reactive c-c double bonds per 100g of resin, 0-30 wt% monoethylenically unsaturated monomer (B) contg. a hydroxyl group and 99.5-5 wt% other copolymerizable unsaturated monomer (C) (e.g. alkyl acrylate) are polymerized to obtain a gragt copolymer having a hydroxyl value of 20-150. 95-70 pts. wt. said copolymer and 5-30 pts. wt. alkyl-etherified amino resin are dissolved in a solvent such as toluene.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a thermosetting resin composition having excellent pigment dispersibility and coating film having excellent weather resistance.

(Prior Art) In recent years, in the paint industry, there has been a demand for paints that have excellent weather resistance (therefore, no maintenance of the paint film is required) and are curable at room or low temperatures from the viewpoint of resource and energy conservation. Conventionally, acrylic resins have been commonly used for applications that require weather resistance, but there is a desire for further improvement.

BACKGROUND ART Conventionally, thermosetting resin coatings containing acrylic resins and amino resins are known to have excellent coating properties such as weather resistance and chemical resistance.

However, thermosetting resin paints containing acrylic resins generally have poor compatibility with highly oil-absorbing pigments and have poor pigment dispersibility.

Therefore, in order to improve pigment dispersibility, a method has been used in which an acrylic resin synthesized in the presence of an alkyd resin having unsaturated double bonds is used.

Furthermore, fluorine-containing copolymers containing essential components of fluoroolefins, hydroxyalkyl vinyl ethers, alkyl vinyl ethers, and cyclohexyl vinyl ethers are known.

Furthermore, a graft copolymer obtained by introducing a reactive carbon-carbon double bond into the above-mentioned fluorine-containing copolymer and polymerizing an ethylenically unsaturated monomer in the presence of this is known ( (Japanese Unexamined Patent Publication No. 59-51953).

These are often used in thermosetting resin compositions in combination with amine resins or alkyl etherified amino resins.

(Problems to be Solved by the Invention) Although the resin obtained by synthesizing an acrylic resin in the presence of the above-mentioned alkyd resin has improved pigment dispersibility,
Weather resistance and chemical resistance are inferior to the original performance of acrylic resin. This also applies to combinations with amine resins or alkyl etherified amine resins.

The above fluorine copolymers have excellent weather resistance, but pigment dispersibility and
In addition to poor initial gloss etc., compatibility with amine resins or alkyl etherified amine resins is poor.

Therefore, the above-mentioned graft copolymers have been proposed, and resins having excellent weather resistance, pigment dispersibility, initial gloss, etc. have been obtained. However, this graft copolymer.

It has poor compatibility with the graft component, and even when combined with an amine resin or an alkyl etherified amino resin, its weather resistance, melt resistance, stain resistance, and pigment dispersibility are insufficient.

(Means for solving problems) The present invention is.

(3) Fluorine-containing resin containing 0.001 to 0.055 mol of reactive carbon-carbon double bonds per 100 g of resin and 0.5 to 95.0% by weight of a fluorine-containing resin having an alkoxy group or a cyclohexyloxy group and a carboxyl group fB) A graft compound having a hydroxyl group value of 20 to 150 obtained by blending 0 to 30% by weight of a monoethylenically unsaturated monomer having a hydroxyl group to a total of 100% by weight and carrying out one polymerization. Polymers ([) and amine resins or alkyl etherified amino resins (If
).

The fluorine-containing resin that is the captive component of the present invention is
0.001 to 0 9 reactive carbon-carbon double bonds per g
．． 0.055 mol, preferably 0.005 to 0.031 mol. Less than 0.001 mol, (B) and (C)
When polymerizing with other components, graft polymerization becomes difficult,
If it exceeds 0.055 mol, it will cause polymerization.

Gelation is more likely to occur. Moreover, component (A) has an alkoxy group or a cyclohexyloxy group.

This results in xylene, toluene, and butyl acetate.

It can be made soluble in organic solvents such as methyl isobutyl ketone. Since the carrier component contains fluorine, the coating film obtained from the resin composition according to the present invention has excellent weather resistance.

Furthermore, the component (9) of the present invention has a carboxyl group. Accordingly, the compatibility of the captive component with the graft component can be improved, and the pigment dispersibility of the resin composition according to the present invention can be improved.

The fluorine-rich resin of component (A) has a molecular weight of approximately 10
00 to 200,000 is preferred.

Particularly preferred is about io, ooo to 100,000. If the molecular weight is too low, weather resistance and chemical resistance tend to decrease, while if it is too high, gelation tends to occur during polymerization with components (B) and (C).

The carrier component is a hydroxyl group-containing copolymer (a) mixed with α,β-unsaturated carboxylic acids such as maleic anhydride, acrylic acid, methacrylic acid, acrylic anhydride, methacrylic anhydride, acid chlorides thereof, or their hydroxyl groups. It can be obtained by reacting reactive derivatives.

In this case, the α,β-unsaturated carboxylic acid or its hydroxyl group-reactive derivative is a hydroxyl group-containing copolymer (a) 1
0.001 to 0.055 mol is reacted with respect to 00B.

The above copolymer (a) is chlorotrifluoroethylene,
Nonfluoroolefins such as trifluoroethylene and tetrafluoroethylene, unsaturated acids such as maleic acid, fumaric acid, acrylic acid, and methacrylic acid, and carboxyalkyl vinyl ethers such as carboxyethyl vinyl ether and carboxypropyl vinyl ether, or fluorine-substituted compounds thereof, and carboxyalkyl Ethylenically unsaturated monomers having a carboxyl group such as oxyalkyl vinyl ether or fluorine-substituted compounds thereof, hydroxyethyl vinyl ether, hydroxyclovir vinyl ether,
Hydroxybutyl vinyl ether.

Copolymerization of hydroxyalkyl vinyl ethers such as hydroxyhexyl vinyl ether, alkyl vinyl ethers or cyclohexyl vinyl ethers such as hydroxyethyl vinyl ether, flobil vinyl ether, butyl vinyl ether, hexyl vinyl ether, etc., in which the hydrogen of these alkyl groups or vinyl groups is replaced with fluorine. A copolymer obtained by combining reed, ethylene, and propylene.

It may contain inbutylene, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl n-butyrate, methyl methacrylate, etc. as a copolymer component.

The fluoroolefin preferably has a hydroxyl value of 40 to 60 mole and a hydroxyalkylvinylniteryl hydroxyl value of preferably 0.57 to 250. The ethylenically unsaturated monomer having a carboxyl group preferably has an acid value of 3 to 70, and preferably has an acid value of 0.5 to 20. Particularly preferably, it is used in a range of 1.0 to 10.

If the amount of fluoroolefin is too small, the effect of improving weather resistance will be reduced, and it will be difficult to introduce a large amount in terms of production.

The copolymer (a) has a hydroxyl value of 0.57 to 250.

Preferably it is 3-70. If the hydroxyl value is less than 0.57, the required amount of α,β-unsaturated carboxylic acid or its hydroxyl-reactive derivative will not react completely.

When it exceeds 250, the amount of hydroxyalkyl vinyl ether used increases, and solubility in organic solvents tends to be limited. From the viewpoint of solubility in organic solvents, the hydroxyalkyl vinyl ether is preferably used in an amount of 15 molar or less.

Further, the acid value is 0.5 to 20, preferably 1.0 to 20.
It is 10. When the acid value is less than 0.5, the compatibility with the graft component is poor, and when it is 10 or more, the solubility in organic solvents tends to be limited.

Mata, cyclohekiful vinyl ether, and alkyl vinyl ether are all copolymers (5 to 60% in al).
It is preferable to use it so that it becomes morchi. 9. If the cyclohexyl vinyl ether and alkyl vinyl ether are too small, the copolymer (a) will be difficult to dissolve in the organic bath agent. If it is too large, the amount of fluoroolefin or hydroxyalkyl vinyl ether used will decrease. Further, it is preferable from the viewpoint of characteristics that cyclohexyl vinyl ether and yohyalkyl vinyl ether are used in an amount of 5 to 45 mol each.

Other components are preferably used in the copolymer (a) in a molar proportion of 30 or less.

The CB) component forming the graft component is a hydroxyalkyl acrylate such as 2-hydroxyethyl acrylate, 2-hydroxyalkyl acrylate, or 2-hydroxybutyl acrylate.

Hydroxy alkyl methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxybutyl methacrylate, monoacrylates or monomethacrylates of polyhydric alcohols such as glycerin and trimethylolpropane, N-methylol acrylamide, N-methylol methacrylamide etc.

Component (C) forming the graft component includes alkyl acrylates such as methyl acrylate, ethyl acrylate, inglovir acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, cyclohexyl acrylate, similar alkyl methacrylates, styrene or Havinyltoluene, α-
Substituted styrenes such as methylstyrene and chlorostyrene are preferred, and acrylonitrile, methacrylonitrile, vinyl chloride, vinyl acetate, dialkyl maleate, and the like can also be used. Furthermore, if necessary, acrylamide may be used as component (C).

Unsaturated amides such as methacrylamide, epoxy group-containing unsaturated monomers such as glycidyl methacrylate and glycidyl acrylate, and α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and maleic acid monoester can be used. The unsaturated amide and epoxy group-containing unsaturated monomers are (A), (B) and (C1
It is preferable that the amount of α,β-unsaturated carboxylic acid is used in an amount of 10 Fkcs or less, and 5% by weight or less of the α,β-unsaturated carboxylic acid, based on the total amount of components.

The graft copolymer (I) of the present invention is the above-described carrier component.

It is obtained by polymerizing component (B) and component (C). Within this range, the total amount is 100% by weight. If the content of the pigment is less than 0.5% by weight, the weather resistance and chemical resistance of the coating film will deteriorate, and if it exceeds 95.0% by weight, the pigment dispersibility, drying properties, gloss, and compatibility with other resins will deteriorate. Compatibility decreases. If the content of component (B) exceeds 30% by weight, the viscosity of the resulting graft copolymer will increase and the water resistance of the coating film will be poor. (5) component, (B) component and (C) component are respectively 30-90% by weight, 5-25% by weight and 65-5% by weight.
It is preferable that the total amount is 100% by weight.

In addition, the graft copolymer (1) has a hydroxyl value of 20 to 1.
50. Preferably it is 30-100. Hydroxyl value is 20
If D is less than 150, the crosslinking density will be insufficient even if it is reacted with an amine resin or alkyl etherified amine resin (I) which has few hydroxyl groups, and if D exceeds 150, the water resistance of the coating film will be poor.

During the polymerization of component (3), component (B), and component (C), an organic solvent that does not contain hydroxyl groups such as toluene, xylene, methyl isobutyl ketone, butyl acetate, cellosolve acetate, etc., is used as a reaction solvent or diluted as necessary. It can be used as a solvent, and as a polymerization catalyst, peroxide radical initiators such as benzoyl peroxide and ditertiary butyl peroxide, and azo radical initiators such as azobisinbutyronitrile and azobisvaleronitrile are used. 2. The reaction temperature is approximately 80 to 130° C. 2. The reaction time is 2 to 8 hours.

In the present invention, the amino resin refers to amine compounds such as urea, melamine, benzoguanamine, and acetoguanamine, used alone or in combination of two or more.

It is an amine resin obtained by an addition condensation reaction with formaldehyde, and an alkyl etherified amine resin is an amine resin obtained by adding and condensing the amine resin with methanol or ethanol.

It is obtained by etherification with alcohols such as propatool, n-butanol, and inbutanol.

In the present invention, the graph shows copolymer +11 and amine resin or alkyl etherified amine resin +1).

(Il/(II) is preferably blended in a weight ratio of 9515 to 70/30, particularly 85/15 to
Preferably, the ratio is 75/25. (I
If the amount of component I) is too high or too low, the performance of the coating film tends to deteriorate.

The above components (1) and (If) are used after being dissolved in a suitable organic solvent such as toluene, xylene, methyl isobutyl ketone, butyl acetate, cellosolve acetate, or the like.

The grip == thermosetting resin composition according to the present invention includes titanium white, titanium white,
It can contain inorganic pigments such as cadmium yellow and carbon black, organic pigments such as phthalocyanine pigments and azo pigments, and other additives.

The necessary amounts of inorganic pigments and organic pigments are appropriately determined and used. For example, the amount of organic pigments to be used is about 5 to 9 based on the resin solid content of the thermosetting resin composition according to the present invention.
20% by weight, titanium white about 50-150% by weight, and carbon black about 1-10% by weight.

It is preferable that the pigment and other additives are kneaded with the graft copolymer (1) in advance before use.

(Example) Next, synthesis examples and examples related to the present invention will be shown.

Synthesis Example 1 Fluorine-containing copolymer [hydroxyl value 47. It is a copolymer containing trifluoroethylene, hydroxyalkyl vinyl ether, and alkyl vinyl ether with an acid value of 5°, and contains about 50 mol i of trifluoroethylene in a mixed solvent solution of xylene and methyl isobutyl ketone [solid content 50]. %, viscosity 800CI) S (room temperature), Lumiflon L
100 parts of F-400゜Asahi Glass ■trade name used], 0.25 parts of maleic anhydride, and a portion of xylene were placed in a flask equipped with a stirrer and a reflux condenser, and heated at 50°C for 1 hour, then at 120°C for 2 hours. React to form polymerizable carbon-carbon double bonds per 100g of resin! A fluorine-containing resin having 70.02 moles was synthesized, and a resin solution containing it was obtained.

Synthesis Example 2 (Production of Copolymer) The formulation shown in Table 1, azobisisobutyronitrile 2. ．．
A copolymer was prepared in the following manner using 5 parts of di-t-butyl peroxide and 0.5 parts of di-t-butyl peroxide.

Namely, a resin solution containing the fluorine-containing resin obtained in Synthesis Example 1, 50 parts of a solvent (Turupetz 100, trade name of Esso Petrochemical Co., Ltd.), and 10 parts of n-butanol were placed in a flask, and while keeping the temperature at 120°C, 2- A mixed solution of hydroxyethyl methacrylate, butyl methacrylate, ethyl acrylate, styrene, methacrylic acid, azobisisobutyronitrile and di-t-butyl peroxide was added dropwise over 2 hours, and then kept at the same temperature for another 1 hour. Then, the temperature was raised to 140°C and the mixture was reacted for 4 hours to obtain a graft copolymer. A solvent (Furupetz 100) was added so that the solid content of the obtained copolymer was approximately 50%. Table 1 shows the solid content, viscosity, acid value, and color number of the obtained copolymer solution.

Examples 1 to 4 and Comparative Example 1 75 parts (solid content) of the copolymer solution obtained in Synthesis Example 2.

25 parts (solid content) of isobutyl etherified melamine resin (Melan 28゜Hitachi Chemical Co., Ltd. trade name) and 0.02 part (solid content) of Rehelinking agent (trade name of Ricketts Special Vick Mallinckrodt Co., Ltd.) were mixed. To this, add a solvent [a mixed solvent of the same weight of Tsurupetz 100 and Tsurupetz 150 (both trade names of Esso Petrochemicals)] and dilute it by adding it so that the viscosity is Ford cup ÷ 4 for 25 seconds (20°C). A thermosetting resin composition was obtained. Table 2 shows the results of the accelerated weathering test of the obtained composition. In addition.

The test plate was created as follows.

Creation of test plate Bonderite φ144 treated steel plate (100annx300
Spray coat Primer Surfacer on a dish (0.8 on) and heat for 20 minutes at room temperature and then at 140°C for 20 minutes.
Dried in minutes. Primer surfacer film thickness is 3
It was 0-35μ. Next, undercoat paint [acrylic resin (Hytaloid 2577T).

Hitachi Chemical ■Product name) 80 parts (solid content), Melan 28
(Hitachi Chemical Co., Ltd. trade name) 20 parts (solid content) and aluminum paste 5 parts (solid content) were mixed.

Add a solvent (a mixed solvent consisting of 60 parts of xylene, 20 parts of butyl acetate, 10 parts of butanol, and 10 parts of cellosolve acetate) and heat in a 7-odd kapuna 4 for 18 seconds (at 20°C).
)] was spray-painted to a film thickness of 15 to 20 μm, left at room temperature for 2 minutes, and then the above thermosetting resin composition was spray-painted to a film thickness of 20 to 25 μm. , 20 min at room temperature and 20 min at 140°C.
It dried for a few minutes to obtain a coating film.

Accelerated weathering test method This test plate was tested using a Q-UV accelerated weathering tester (USA).

UV irradiation at 50°C for 4 hours using
Time - Under cycling conditions of 4 hours at 50°C with condensation.

After exposing for a specified time, measure the 60 degree specular reflectance and get 1.
It's knee F.

Table 2 Test results Examples 4 to 6 and Comparative Example 2 A resin solution containing the fluorine-containing resin obtained in Synthesis Example 2.

Isobutyl etherified melamine resin (Melan 28゜Hitachi Chemical ■trade name) and epoxy resin (Eviny) 1
001. 70 parts, 20 parts, and 10 parts of solid content (trade name of Shell Chemical Co., Ltd.) were mixed, and 50 parts of titanium white was mixed therewith.
The mixture was kneaded until it became 0 μm or less to obtain a thermosetting resin composition.

This is bonded to Bonderite Toner 144 treated steel plate (15゜×
70mX O, 8a+m) to a film thickness of 30 to 35 μm, and baked at 150°C for 20 minutes.

A test plate was prepared and tested. The results are shown in Table 3. Table 3 also shows the pigment dispersibility test for the thermosetting resin composition.

The following margin test method (1) Accelerated weathering test method Same as Example 1 (2) Goban test Make cuts with a knife at 1 mm intervals on the coating film, making 10 cuts vertically and horizontally.
Draw 0100 squares so that there are 100 squares.

A peel test was conducted using cellophane tape. Evaluation,
The number of squares that were not peeled off in the peeling test was recorded in the numerator.

(3) Corrosion Resistance Test After cross-cutting the test plate, expose it to salt water spray for 500 hours and perform a cellophane tape peeling test.

It was conducted according to JIS-Z-2351. Evaluation indicates peeling width.

(4) Chemical resistance A 5-thiosulfuric acid aqueous solution was spotted on the coating film of the test plate.

After 24 hours, it was wiped off and the state of the coating film was observed.

The evaluation was as follows.

◎...No whitening O...Slight whitening■...
- Obvious whitening Δ...Significant whitening ×...Paint peeling or close to it (5) Stain resistance Apply magic ink on the coating film of the test board with a red magic pen and keep it warm at 30℃ for 24 hours. Afterwards, the condition was observed with the naked eye after wiping with butanol.

The evaluation was as follows.

◎...No trace O...There is a faint trace @
...Obvious traces Δ...Significant traces × could hardly be wiped away (6) With 100 parts of the thermosetting resin composition obtained above.

After thoroughly mixing 10 parts of the thermosetting resin composition obtained above using 3 parts of carbon black in place of 50 parts of titanium white, spray coating, and then further flow coating on the coating film. The difference in hue between the non-flow-coated area and the flow-coated area was observed.

The evaluation was ◎...No difference ○...Slight difference Δ...Kana difference ×...Pigment separated.

(Effects of the Invention) The thermosetting resin composition according to the present invention has excellent pigment dispersibility, and the coating film thereof has excellent stain resistance, corrosion resistance, and weather resistance (glossy retention).

Claims (1)

[Claims] 1. (A) Reactive carbon-carbon double bond in 100g of resin
0.001 to 0.055 mol per fluorine-containing resin having an alkoxy group or a cyclohexyloxy group and a carboxyl group (B) 0 to 95.0% by weight of a monoethylenically unsaturated monomer having a hydroxyl group
30% by weight and (C) other copolymerizable unsaturated monomers 99.5-5.0
Contains a graft copolymer (I) with a hydroxyl value of 20 to 150 and an amino resin or an alkyl etherified amino resin (II) obtained by blending and polymerizing the total weight % to 100 weight %. A thermosetting resin composition. 2. The fluorine-containing resin of component (A) contains 40 to 60 mol% of fluoroolefin, a carboxyl group-containing ethylenically unsaturated monomer, hydroxyalkyl vinyl ether, and cyclohexyl vinyl ether or alkyl vinyl ether as components, and has a hydroxyl value of 0.57. ~250
and a copolymer having an acid value of 0.5 to 20, the copolymer 1
The thermosetting resin according to claim 1, which is a fluorine-containing resin obtained by reacting 0.001 to 0.055 mol of α,β-unsaturated carboxylic acid or its hydroxyl group-reactive derivative per 00g. resin composition.