JPS61247751A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. which has excellent pigment dispersibility and gives a coating film having excellent weather resistance, containing a graft copolymer and an amino resin or an alkyl-etherfied amino resin. CONSTITUTION:50-99.5 wt% fluororesin (a) having an MW of 1000-200,000 and contg. alkyxy group or cyclohexyloxy group and 0.001-0.025 mol of reactive C-C double bonds per 100g of resin, 0-30 wt% monoethylenically unsaturated monomer (h) contg. a hydroxyl group and 0.5-50 wt% other copolymerizable unsaturated monomer (c) (e.g. alkyl acrylate) are copolymerized to obtain a graft copolymer (A) having a hydroxyl value of 20-150. 95-70 wt% component A is blended with 5-30 wt% amino resin or alkyl-etherified amino resin, and the mixture is dissolved in a solvent.

Description

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

(Conventional technology) In recent years, in the paint industry, there has been a demand for paints that have excellent weather resistance (therefore, no maintenance is required for the paint film) and that cure at room or low temperatures, from the perspective of saving resources and energy. . Conventionally, acrylic resins have been commonly used for applications that require weather resistance, but there is a desire for further improvement.

Conventionally, thermosetting resin paints containing acrylic resins and amino resins (including alkyl etherified ones) 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 fluoroolefins, hydroxyalkyl vinyl ethers, alkyl vinyl ethers, and cyclohexyl vinyl ethers as essential components are known, and are known to have excellent weather resistance themselves.

Furthermore, a thermosetting resin composition for paints containing a graft copolymer obtained by polymerizing an ethylenically unsaturated monomer in the presence of 0.5 to 50% by weight of the fluorine-containing copolymer and an amino resin. is known (Japanese Unexamined Patent Publication No. 59-51953).

(Problems to be Solved by the Invention) The acrylic resin synthesized in the presence of the above-mentioned alkyd resin has good pigment dispersibility, but its weather resistance and chemical resistance are inferior to the original performance of acrylic resin. It's inferior.

On the other hand, the above fluorine-containing copolymers have excellent weather resistance, but
Poor compatibility with amino resins, pigment dispersibility, gloss, etc.

However, when combined with an amino resin, there is a problem in that long-term weather resistance is insufficient.

(Means for Solving the Problems) The present invention is characterized in that the reactive carbon-carbon double bond is
．． Fluorine-containing resin having 1 to 0.025 mole of OO and 7 alkoxy groups or cyclohexyloxy groups More than 50% by weight and not more than 99.5% by weight (B) 0 to 30% by weight of a monoethylenically unsaturated monomer having a hydroxyl group and 0 other copolymerizable unsaturated monomers 0.5% by weight or more 5
Contains a graft copolymer (I) obtained by blending and polymerizing less than 0% by weight so that the total becomes 100% by weight and having a hydroxyl value of 20 to 150, and an amino resin or an alkyl etherified amino resin. The present invention relates to a thermosetting resin composition.

The fluorine-containing resin that is the captive component of the present invention is
g, the reactive carbon-carbon double bond is 0,0 O1~
It has 0.025 mol, preferably 0.003 to 0.015 mol. If the amount is less than 0.0 moles, graft polymerization will be difficult when polymerized and cured together with component (2) and (Q), and if the amount is less than 0.
If the amount exceeds 0.025 mol, gelation tends to occur during polymerization. Further, the fluorine-containing resin has an alkoxy group or a cyclohexyloxy group. For this, xylene, toluene.

It can be made soluble in organic solvents such as butyl acetate and methyl isobutyl ketone. Furthermore, by containing fluorine, the coating film obtained from the resin composition according to the present invention has excellent weather resistance.

The molecular weight of the fluorine-containing resin is approximately 1000.
~200,000 is preferred, especially about 10
,000 to 100,000 is preferred. 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 when polymerizing with component (I) and component (Q).

■The component fluorine-containing resin is a copolymer (a) having a hydroxyl group, and alpha, beta-unsaturated carboxylic acid such as maleic anhydride, acrylic acid, methacrylic acid, acrylic anhydride, methacrylic anhydride, and their acid chlorides. It can be obtained by reacting an acid or its hydroxyl group with a reactive derivative.

In this case, the α,β-unsaturated carboxylic acid or its hydroxyl group-reactive derivative is a copolymer (a) having a hydroxyl group.
0.001 to 0.025 mol is reacted per 100 g.

The above copolymer (a) is chlorotrifluoroethylene,
Fluoroolefins such as trifluoroethylene and tetrafluoroethylene, hydroxyethyl vinyl ether,
hydroxyalkyl vinyl ethers and ethyl vinyl ethers such as hydroxyalkyl vinyl ether, hydroxybutyl vinyl ether, hydroxyhexyl vinyl ether;

Propyl vinyl ether, phthyl vinyl ether.

A copolymer obtained by copolymerizing alkyl vinyl ether or cyclohexyl vinyl ether, such as hexyl vinyl ether, which has the hydrogen of these alkyl groups or vinyl groups replaced with fluorine. Vinylidene, vinyl acetate.

It may also contain n-vinyl butyrate, methyl methacrylate, etc. as a copolymerization component.

The fluoroolefins are 40 to 60 mol% and
:l-11-cyfurkyl vinyl ether has a hydroxyl value of 0
．． It is preferably used so that it becomes 57-100, especially 3-70. If the amount of fluoroolefin is too small, the effect of improving weather resistance will be reduced, and if it is introduced in a large amount, it will be difficult to manufacture.

The copolymer (a) has a hydroxyl value of 0.57 to 100,
Preferably it is 3-70. If the hydroxyl value is less than 0.57, it will be difficult for α, β-, β-carboxylic acid or its hydroxyl-reactive derivative to react completely, and if it exceeds 100, the amount of hydroxyalkyl vinyl ether used will increase, so organic solvents The solubility in these substances tends to be limited. From the viewpoint of solubility in organic solvents, the hydroxyalkyl vinyl ether is preferably used in an amount of 15 mol % or less.

In addition, cyclohexyl vinyl ether and alkyl vinyl ether contain 5 to 60% in total in the copolymer (a).
It is preferable to use it in mol%. If the amount of cyclohexyl vinyl ether and alkyl vinyl ether is too small, the copolymer (a) will be difficult to dissolve in an organic solvent, and if it is too large, the amount of fluoroolefin or hydroxyalkyl vinyl ether used will be reduced. Moreover, it is preferable from the viewpoint of characteristics that cyclohexyl vinyl ether and alkyl vinyl ether are used in an amount of 5 to 45 mol %, respectively.

Other components are preferably used in the copolymer (a) in an amount of 30 mol% or less.

03) Components include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate, and hydroxyalkyl acrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxybutyl methacrylate. Monoacrylate or monomethacrylate of polyhydric alcohols such as methacrylate, glycerin, trimethylolpropane,
Examples include N-methylol acrylamide and N.-methylol methacrylamide.

0 components include alkyl acrylates such as methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and cyclohexyl acrylate, similar alkyl methacrylates, styrene or vinyltoluene, and α-methylstyrene. Substituted styrene such as , chlorostyrene and the like are preferred, and in addition, acrylonitrile, methacrylonitrile, vinyl chloride, vinyl acetate, dialkyl maleate gel and the like can be used. Furthermore, if necessary, as zero components, unsaturated amides such as acrylamide and methacrylamide, epoxy group-containing unsaturated monomers such as glycidyl methacrylate and glycidyl acrylate, α such as acrylic acid, methacrylic acid, and maleic acid monoester, β-, β-carboxylic acids can be used. The unsaturated amide and epoxy group-containing unsaturated monomers are (b), (Bl and (
It is preferably used in an amount of 10% by weight or less, and an amount of α,β-unsaturated unsaturated norboxic acid, based on the total amount of component Q.

The graft copolymer (I) of the present invention is obtained by polymerizing the above-mentioned prisoner component, component (2) and component (0).
) component is more than 50% by weight and 99.5% by weight or less, ■ component is 0 to 30% by weight, and 0 component is 0.5% by weight or more 50
Within the range of less than 1% by weight, the total amount is 130% by weight. If the (4) component is less than 50.0% by weight, the weather resistance, chemical resistance, etc. of the coating film will be insufficient;
If it exceeds 5% by weight, pigment dispersibility, gloss, hardness, etc. will decrease. (2) If the amount of the component exceeds 30% by weight, the resulting graft copolymer will have a high viscosity and the water resistance of the coating film will still be poor. The prison component, (g) component and 0 component are each 60~
It is preferable to use 95% by weight, 25-5% by weight and 35-5% by weight to make a total of 100% by weight.

In the present invention, the graft copolymer exhibits sufficient pigment dispersibility even if the graft component is a small amount.

In addition, the graft copolymer (I) has a hydroxyl value of 20 to 1.
50, preferably 30-100. Hydroxyl value is 20
If it is less than 150, the crosslinking density will be insufficient even if it is reacted with amino resin or alkyl etherified amino resin (2), which has few hydroxyl groups, and if it exceeds 150, the water resistance of the coating film will be poor.

(4) When polymerizing component (B) and component 0, toluene, xylene, methyl isobutyl ketone,
Organic solvents that do not contain hydroxyl groups, such as butyl acetate and cellosolve acetate, can be used as reaction solvents or diluting solvents, and as polymerization catalysts, peroxide-based radical initiators such as benzoyl peroxide and ditertiary butyl peroxide, and azobis Azo radical initiators such as isobutyronitrile and azobisvaleronitrile are used, and the reaction temperature is approximately 8.
0-130r, reaction time is 2-8 hours.

In the present invention, the amino resin is an amino resin obtained by addition-condensation reaction with formaldehyde of amino compounds such as urea, melamine, benzoguanamine, acetoguanamine, etc. alone or in combination with formaldehyde. Amino resin refers to the amino resin being mixed with methanol or ethanol.

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

In the present invention, graft copolymer (I) and amino resin or alkyl etherified amino resin (ID is (I)
/(ID is preferably blended in a weight ratio of 9515 to 70/30, particularly 85/15 to 75/2
It is preferable to use it so that it becomes 5. (If the ID component is too large or too small, the performance of the coating film tends to deteriorate.

In addition, the above-mentioned component (I) and (ID component) 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 thermosetting resin composition according to the present invention can contain inorganic pigments such as titanium white, cadmium yellow, and carbon black, organic pigments such as phthalocyanine pigments and azo pigments, and other additives.

The inorganic pigment and the organic pigment are used by appropriately determining the necessary amount, but to illustrate the amount of the organic pigment used, the amount of the organic pigment is about 5 to 50% relative to 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.

The pigment and other additives are preferably kneaded with the graft copolymer (I) in advance before use.

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

Synthesis Example 1 Xylene-methylisophthyl, a fluorine-containing copolymer having a hydroxyl group [hydroxyl value 52, a copolymer of trifluoroethylene, hydroxyalkyl vinyl ether, and alkyl vinyl ether, containing about 50 mol% of trifluoroethylene] Ketone mixed solvent solution [solid content 5
0%, Lumiflon LF-200D, Asahi Insulator Co., Ltd. trade name used] TooLm water 0.3 parts of maleic acid and 0.3 parts of xylene were charged into a flask equipped with a stirrer and a reflux condenser, and heated at 50C for 1 hour. React at 120 tr for 2 hours to form polymerizable carbon-carbon double bonds per 100 g of resin.
A fluorine-containing resin containing O,006 moles was synthesized, and a resin solution containing it was poured into a barrel.

Synthesis Example 2 (Production of copolymer) Blend shown in Table 1, azobisisobutyronitrile 2.5
1 part and 0.5 part of di-t-butyl peroxide, a copolymer was produced in the following manner.

That is, a resin solution containing the fluorine-containing resin obtained in Synthesis Example 1 and a solvent (Turupetz 100, trade name of Esso Petrochemicals) n-butanol were placed in a flask, and while keeping the temperature at 120C, 2-human loxyethyl methacrylate was added. , butyl methacrylate, ethyl acrylate, styrene, methacrylic acid, azobisin butyronitrile, and di-1-butyl peroxide were added dropwise over 2 hours, and then reacted at the same temperature for 4 hours to obtain a graft copolymer. Obtained union. A solvent (Tsurpetz 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 1-2 and Comparative Examples 1-3 Fluorine-containing resin used in Synthesis Example 1, Lumiflon LF20
0D or 75 parts (solid content) of the copolymer solution obtained in Synthesis Example 2, isobutyl etherified melamine resin (Melan 28,
25 parts (solid content) of Hitachi Chemical Co., Ltd. (product name) and 0.02 parts (solid content) of a leveling agent (product name of Kettle Special Bick Mallinckrodt Co., Ltd.), and to this were mixed solvents [Tsurupez 100 and Tsurpez 150 (both are trade names of Esso Petrochemical Co., Ltd.) of the same weight mixed solvent] and the viscosity is Ford cup ≠ 4, for 25 seconds ((B0C)
A thermosetting resin composition was obtained. Table 2 shows the accelerated weathering test results of the obtained composition.

In addition, the test plate was created as follows.

Preparation of test plate Bonderitena 144 treated steel plate (I00mm x 300+
mX O, 8 mm) was spray coated with Primer Surfacer and dried at room temperature for 20 minutes and then at 140C for 20 minutes. The film thickness of Primer Surf Acer is 30-3
It was 5μ. Next, undercoat paint [acrylic resin (Hytaloid 2577T).

Hitachi Chemical Co., Ltd. trade 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, and a solvent (xylene 60 parts of butyl acetate, 20 parts of butyl acetate, 10 parts of butanol, and 10 parts of cellosolve acetate (mixed solvent) and adjusted to 18 seconds (B0r) with a Ford cup +4] to a film thickness of 15 to 20 μm. After spray painting and leaving at room temperature for 2 minutes, the above thermosetting resin composition was spray-painted to a film thickness of 20 to 25 μm, and the coating was dried at room temperature for 20 minutes and at 140C for 20 minutes to form a coating film. Obtained.

Accelerated weathering test, test method This test plate was tested using a Q-UV accelerated weathering tester (USA, Q-
After exposing the sample for a predetermined time under the cycle of ultraviolet irradiation at 50C for 4 hours and dew condensation at 50C for 4 hours, the 60 degree specular reflectance was measured.

Examples 3-4 and Comparative Examples 4-6 Fluorine-containing resin Lumiflon LF200 used in Synthesis Example 1
D or a resin solution containing a fluorine-containing resin obtained in Synthesis Example 2,
Inbutyl etherified melamine resin (Melan 28, trade name of Hitachi Chemical Co., Ltd.) and epoxy resin (Epicote 1001, trade name of Shell Chemical Co., Ltd.) were mixed in a solid content of 70 parts, 20 parts, and 10 parts, respectively. Mix Titanium White 50 and use three rolls to measure the particle size of 1 on the particle gauge.
The mixture was kneaded until it became 0 parts m or less to obtain a thermosetting resin composition.

This was prepared using Bonderite Toner 144 treated steel plate (I5°, m
x 70 rtrm x 0.8 mm) with a film thickness of 3
A test plate was prepared by coating to a thickness of 0 to 35 μm and baking at 15°C for 20 minutes, and tested. This result is shown in Table 3.
Shown below. Table 3 also shows the pigment dispersibility test for the thermosetting resin composition.

Test method (I) Accelerated weathering test method Same as Example 1 (B) Column cut test Make cuts with a knife at 1 mm intervals on the coating film, making 10 cuts vertically and horizontally.
We made 0100 squares so that there were 0,100 squares, and then performed a peeling test using cellophane tape. For evaluation, the number of squares that were not peeled off in the peeling test was recorded in the numerator.

(8) 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. JIS-Z-
It was carried out according to 2351.

Evaluation indicates peeling width.

(4) Chemical resistance A 5% sulfuric acid aqueous solution was spotted on the coating film of the test plate, and after 24 hours, it was wiped off and the condition of the coating film was observed. The evaluation was as follows.

◎...No whitening O...Slight whitening@・
...Obvious whitening Δ...Kana whitening ×...Paint peeling or close to it (5) Stain resistance Apply magic ink on the paint film of the test board with a red magic pen, and store at 30C for 24 hours. After keeping warm, the condition was observed with the naked eye after wiping with butanol. The evaluation was as follows.

◎...No trace O...Slight trace ■
...Obviously there are traces Δ...Kanasi traces ×・
(6) Thermosetting resin composition obtained by using 100 parts of the thermosetting resin composition obtained above and 3 parts of carbon black in place of 50 parts of titanium white above. After thoroughly mixing 10 parts of the mixture, spray painting was performed. Evaluation: ◎...No difference ○...Slight difference observed.

Δ...Kana is different ×...Pigment is separated.

〔Effect of the invention〕

Claims (1)

[Claims] 1. (A) Reactive carbon-carbon double bond in 100g of resin
Fluorine-containing resin 5 having 0.001 to 0.025 mol per unit and an alkoxy group or a cyclohexyloxy group
More than 0% by weight and not more than 99.5% by weight (B) Monoethylenically unsaturated monomer having hydroxyl group 0 -
30% by weight and (C) 0.5% by weight or more and less than 50% by weight of other copolymerizable unsaturated monomers so that the total amount is 100% by weight, and is obtained by polymerizing, and the hydroxyl value is A thermosetting resin composition comprising a graft copolymer (I) having a molecular weight of 20 to 150 and an amino resin or an alkyl etherified amino resin (II). 2. The fluorine-containing resin of component (A) contains 40 to 60 mol% of fluoroolefin, hydroxyalkyl vinyl ether and cyclohexyl vinyl ether or alkyl vinyl ether as components, and has a hydroxyl value of 0.57.
A fluorine-containing resin obtained by reacting a copolymer having a molecular weight of 100 to 100 with 0.001 to 0.025 mol of an α,β-unsaturated carboxylic acid or a derivative reactive with its hydroxyl group per 100 g of the copolymer. The thermosetting resin composition according to claim 1.