JPS60106863A - Paint composition having excellent weather resistance and recoatability - Google Patents

Abstract

PURPOSE:To provide the titled paint compsn., by blending a modified hydroxyl group-contg. thermosetting resin, a binder component and a pigment. CONSTITUTION:20-97pts.wt. Polyester resin contg. hydroxyl and carboxyl groups (or an alkyd resin or an acrylic resin) is reacted with 80-3pts.wt. organopolysiloxane resin having a number-average MW of 500-2,000 and the formula [wherein R is a monovalent org. group; R' is H, alkyl, aryl; n, m are each 4 or smaller (n+m=4 or smaller)], such as DC-3037 (a product of Dow Corning). The reaction product is then reacted with an alkyleneimine compd. such as ethyleneimine to obtain a modified resin. 60-90pts.wt. Said modified resin, 40- 10pts.wt. binder component composed of an aminoaldehyde resin and/or an isocyanate compd. and 30-100pts.wt. pigment are blended together.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermosetting coating composition, and more specifically, a thermosetting coating composition comprising a specific silicone-modified and alkylene imine-modified resin,
The present invention relates to a coating composition having excellent weather resistance and toner properties, which contains a binder component consisting of an aminoaldehyde resin and/or an isocyanate compound and a pigment as essential components.

A paint composition containing -C as an essential component and a binder component consisting of a thermosetting resin having a hydroxyl group, an aminoaldehyde resin J3, σ/or an isocyanate 1 or a compound, and a pigment as an essential component, can be baked (punished, three-dimensionalized, and toughened). It is widely used in various fields from the production of coating films.However, coating performance, workability, appearance, etc. vary depending on the resin, and as needs become more diversified, coating performance is being improved even further.
Among other things, improvement in weather resistance is desired.

Resin-based paint compositions made by blending oil-free polyester resin with aminoaldehyde resin, etc. have long been attracting attention because of their excellent weather resistance, mechanical properties of the coating film, and interlayer adhesion, but they do cause repellency. It has not been widely put into practical use because it is easy to coat, gives a scratchy surface, has poor gloss, and has poor compatibility with amino resins. However, recently, by using saturated alicyclic polybasic acid or saturated alicyclic polybasic acid and aromatic polybasic acid as part of the acid component of oil-free polyester resin, paintability,
Improvements in blurring, compatibility with amino resins, gloss, hardenability, etc., or by modifying polyester resins with reactive organopolysiloxane resins, improve weather resistance, scales, and saturated resins. Polyester resin using cyclic polybasic acid is modified with silicone to improve workability (
It was discovered that polyester-based paints could further improve properties such as sagging, sagging, and cissing resistance), gloss, and weather resistance, and polyester paints suddenly attracted attention as top coats for automobile coil coatings and the like.

However, when a polynisder resin is modified with silicone, although its weather resistance is generally improved, it has the disadvantage that the adhesive coating properties deteriorate when the same paint is applied over and over again due to surface tension. Therefore, in order to make full use of the characteristics of polyester resin and to make it widely practical, especially as a top coat, it is essential to improve not only the weather resistance but also the coating properties of the paint, and the various conventional proposals have not answered this question. Ta.

In view of the above, the present inventors conducted extensive research and found that a resin containing hydroxyl and carboxyl groups was modified with silicone.
It was discovered that improvement in weather resistance was achieved by this, and that poor coatability due to silicone modification could be avoided by alkyleneimine modification, and a patent application was filed on the same date as the present application.

That is, in the invention of the same application, a resin having a hydroxyl group and a carboxyl group has the formula % (wherein R is a monovalent organic group bonded to silicon through a carbon-silicon bond; R' is hydrogen; 01 to C20). Alkyl group or aryl group: n and m each have a value of 4 or less, provided that n+
III≦4) number average molecular weight of about 500 to 200
A resin composition has been proposed which is obtained by reacting an organopolysiloxane resin of 0.0 and an alkylene imine compound having at least one alkylene imine ring having 2 to 3 carbon atoms in any order.

The present invention is a rough development of the invention described above.

However, in the present invention, in a coating composition containing as essential components (Δ) a thermosetting resin having a hydroxyl group, (B) a binder component consisting of an aminoaldehyde resin and/or an isocyanate, and (C) a pigment, the component (A) ) is a polyester resin, alkyd resin or acrylic resin having a hydroxyl group and a carboxyl group. Group: R' is hydrogen, Ct-C2o alkyl group or aryl group; 11 and I each have a value of 4 or less, provided that n+m
≦4) Silicone modified with an organopolysiloxane resin having a number average molecular weight of about 500 to 2000, and alkylene imine modified with an alkylene imine compound having at least one alkylene imine ring having 2 to 3 carbon atoms. It is a resin, and the content ratio of component (A) and component (B) is 60 to 90:40 to 10% by weight (solid content), and the pigment content m is 3 to 100 Pl-IR. A coating composition is provided.

The thermosetting resin used as component (A>) in the present invention is obtained by modifying a base resin consisting of a polyester resin, an alkyd resin, or an acrylic resin having hydroxyl groups and carboxyl groups with silicone and alkyleneimine in any order. It is a resin.

When modifying silicone, a reactive organopolysiloxane resin is reacted with the base resin.
No. 56-157462, where R is a monovalent organic group bonded to silicon through a carbon-silicon bond; R' is hydrogen; an alkyl group or aryl group having a Ct~020; m is a value of 4 or less, and n+m
organopolysiloxane resins with a number average molecular weight of about 500 to 2000 are preferred;
It is more desirable to have two or more reactive groups such as hydroxyl groups and alkoxy groups represented by the following in the molecule, and silicone modification is performed by dehydration of these functional groups and the hydroxyl functional group of the base resin, IB2 water alcohol reaction, etc. It is.

Examples of the resin include Z-6018 (7-6188 (D
ow Corning products, including 5ylkyd
50. DC-3037 (Dow Corning product), KR-216, KR-218, KSP-'j
(Shin-Etsu Silicone product), TSR-160, TSR
-165 (Tokyo Shibaura Electric Products), 5H-5050, 5H
Various products such as -6018 and SI-1-6188 (products of Toshi Silicone Co., Ltd.) are commercially available, and any of them can be suitably used. Base resin usually has a solid content weight ratio of 20 to 97.
parts of the above reactive organoborisiloxane resin 80~
If the latter is less than 3 parts by weight, the expected improvement in weather resistance will not be observed, and if it exceeds 80 parts by weight, the compatibility between the base resin and the organopolysiloxane resin will deteriorate and it will be difficult for the two to react. This is not desirable.

The weather resistance of any of the above-mentioned base resins can be significantly improved by silicone modification. However, since silicone modification tends to lower the surface tension, it also has the disadvantage that when the same paint is applied over and over again, the paint does not adhere sufficiently, resulting in poor recoatability. Therefore, the resin used in the present invention has at least 1 alkyleneimine ring having 2 to 3 carbon atoms.
A compound having X>1 causes alkyleneimine modification and effectively prevents poor recoatability due to silicone modification.

In the alkylene imine modification, for example, an alkylene imine compound represented by the following formula is preferably used.

■ 5 Here, R1, Rz, R3, R4 and R5 are each hydrogen, alkyl having 20 or less carbon atoms such as methyl, ethyl, propyl, etc.; aryl such as phenyl; alkaryl such as tolyl, xylyl; aralkyl such as benzyl, phenethyl,
R6 is hydrogen or alkyl usually having 6 or less carbon atoms, and jl is an integer of 0 or 1.

Incidentally, the above group may include a substituent that does not adversely affect the basic properties of the imine during the reaction. Examples of such substituents -C include carbonyl, cyano, halogen, amino, hydroxyl, alkoxy, carbalkoxy and di]-lyl. For example, cyanoalkyl,
haloalkyl, aminoalkyl, carbalkoxyalkyl and aryl, alkaryl and aralkyl with similar substituents.

[Some compounds cannot be obtained due to steric harm or interaction. For this reason, R1 to R6 often contain -b of hydrogen, and specific compounds are shown below.

Ethyleneimine, 1.2-propyleneimine, 1.3-
Propyleneimine, 1,2-dodecyleneimine, 1,1
-dimedylethyleneimine, phenylethyleneimine,
Triethyleneimine, benzylethyleneimine, 1.2
-Diphenylethyleneimine, 2-hydroxyethylethyleneimine, aminoethylethyleneimine, 2-methylpropyleneimine, 3-chloropropylethyleneimine, p-chlorophenylethyleneimine, methoxyethylethyleneimine, carboethoxyethylethyleneimine, N-ethyl Ethyleneimine, N-butylethyleneimine, N-(2-aminoethyl)ethyleneimine, N-
(2-hydroxyethyl)ethyleneimine, N-”(cyanoethyl)ethyleneimine, N-phenylethyleneimine, N-t-ethylethyleneimine, N-(p-chlorophenyl)ethyleneimine, N-(2-carboethyleneimine) ethoxy-1-ethyl)ethyleneimine.

Particularly preferred imines from the viewpoint of availability and effectiveness are ethyleneimine, 1,2-propyleneimine, and N-(2-
Hydroxyethyl) ethyleneimine.

In addition to the above preferred alkylene imine compounds, alkylene imine compounds other than those of the general formulas above can also be used. For example, ethylene-1,2-bisaziridine and 1,2.41-lis(2-1-aziridinylethyl)
Satisfactory results can also be obtained using alkylene imines containing one or more alkylene imine rings, such as trimeresol. In this invention, the term alkylene imine compound includes all the above-mentioned alkylene imines, including substituted ones.

In the present invention, it is necessary that the alkylene imine compound is reacted in an amount corresponding to the resin acid value of the base resin from 0.1 to 50. In other words, when (molecular weight of the alkylene imine compound)/(number of alkylene imino groups contained in one molecule of the alkylene imine compound)=M, 2X10-'M to i X 10-1M with respect to the base resin
It is necessary to react wt% of the alkylene imine compound. This is because if the above lower limit is not met, the effect of alkyleneimine modification cannot be sufficiently obtained, and if the amount exceeds the resin acid value of 50, yellowing will occur when formed into a film, significantly reducing the film performance. This is because it has been recognized that, in some cases, curing may be insufficient when compounded with a crosslinking agent or a crosslinking agent.

For both silicone modification and alkyleneimine modification of the base resin, the raw resin and reactant are mixed in the presence or absence of an appropriate solvent and heated at 200°C or lower, preferably at 150°C.
This can be easily achieved by simply heating, and the order of such denaturation can be arbitrarily selected.

In the present invention, in J3, a crosslinking agent consisting of an aminoaldehyde resin and/or an isocyanate compound is used as component (B).

Examples of the aminoaldehyde resin include melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiroguanamine, etc. as the amine component, and most of the aminoaldehyde resins commonly used in Method 1 can be used. Among them, melamine formaldehyde resin is most preferred from the viewpoint of weather resistance. Conventional curing catalysts can also be added to these aminoaldehyde resins to lower the curing temperature. Examples of the isocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate 1-, isophorone diisocyanate,
Polyisocyanates such as methylene bis(4-Schiffhexyl isocyanate) and such polyisocyanates made into blocked polyisocyanates using conventional blocking agents such as aliphatic or aromatic monoalcohols, phenol, oxime, caprolactam. For example, Takenate B-815N (Takeda Pharmaceutical Akane Products), Takenate B-84ON (Takeda Kuwa Products 0)
Wood products), AddLICt B 1065 (Vcba Chcm
IC (Germany)), ADDITOL VX, L-80 (Hoechst Japan (I Wood Products), etc. When using these block type polyisocyanates, release of the blocking agent is encouraged as necessary, and one catalyst is removed. It may be used by adding it.

The above aminoaldehyde resin and polyisocyanate may each be used alone, or both may be used in one.

The binder component of the coating composition of the present invention is the silicone-modified alkyleneimine-modified resin (A)/aminoaldehyde resin 33 J: and/or polyisocyanate (B).
) is required to be within the range of 90/10 to 60/4.0. This is because if the proportion of the crosslinking agent component (B) is less than this range, curing will be insufficient.
This is because weather resistance, coating film hardness, solvent resistance, etc. are reduced, and if too much is used, the coating film becomes dull.

Pigments are usually organic or non-organic used in paints.
The number of pigments is 100 P l-I R or less used in degrees. When the pigment concentration exceeds 100 Pl-IR, an adverse effect on weather resistance is observed.

The paint of the present invention is made into a paint using the above-mentioned binder components and pigments by a conventional method, and a surface conditioner, ultraviolet inhibitor, antisettling agent, antioxidant, wetting agent, diluent, and other optional paint additives are added. I can do it this year. The coating composition of the present invention can be used as an intermediate coat, top coat, etc. in ordinary coating methods such as brush printing, spray painting, and dipping. It is useful as a top coat for textiles, etc.

Synthesis Example 1 Hexahydro anophthalic acid 19
．． 4 parts of trimethylolpropane, 22.6 parts of trimethylolpropane, 26.5 parts of neopentyl glycol, and 30.1 parts of 1,6-hexanediol were charged and heated. When the raw materials are melted and stirring becomes possible, stirring is started and the temperature is raised to 210°C. 2
The temperature was raised at a constant rate from 10°C to 230'C over 2 hours, and the condensed water produced was distilled out of the system. 230°
Once it reaches C, keep the temperature constant and increase the resin acid value to 1.0.
Cool it down. After cooling, 83.1 parts of isophthalic acid was added and the temperature was raised to 190°C again. From 190℃ to 210℃3
The temperature is raised at a constant rate over time, and the condensed water produced is distilled out of the system. When the temperature reached 210'C, 3.2 parts of Kijirole was added to the reaction tank, and the condensation was switched to the presence of a solvent.
Cool and cover with resin acid number 20.0. 2 pheasant rolls after cooling
Oil-free polyester resin varnish A (referred to as base resin A) was obtained by adding 9.3 parts and 75.9 parts of Seconvex Solve Arretate.

Subsequently, 28.7 parts of reactive silicone resin DC-3037 (manufactured by Dow Corning) and -UTBT as a condensation catalyst were added.
-100 (Tetrabutyl titanate manufactured by Nippon Soda) 0
．． Add 38 parts, heat and stir. Keep the reaction temperature constant at 140°C, and when the amount of methanol flowing out reaches 75% of the theoretical methanol level (the amount of methanol removed when the methoxy group of the reactive silicone resin reacts with the hydroxyl group of the 100% polyester resin). Cool and finally N-(2-
hydroxyethyl) ethyleneimine (mutual chemical engineering 0 wooden
Add 0.9 part (product name + 1EEI) (resin consumed by reaction, acid value corresponds to 3.0), heat and stir at 80'C for 1 hour, and then cool. After cooling, 5.8 parts of pheasant roll,
13.6 parts of cellosolve acetate was added to obtain alkyleneimine modified silicone polyester resin varnish 1.

This varnish has a non-volatile content of 60.5% and a varnish viscosity [R-3 (
The cardner viscosity was 25° C.) and the resin acid value was 15.0.

Synthesis Example 2 The same base resin as in Synthesis Example 1 was used, and silicon modification (I) was carried out in exactly the same manner as in Synthesis Example 1. Finally] -1EEI to 3
．． Alkyleneimine-modified silicone polyester resin varnish 2 was obtained in the same manner by adding 0 parts (resin acid value consumed by reaction corresponds to 10.0). The special values of this varnish are shown in Table 1.

Synthesis Example 3 A synthetic reaction was carried out in the same manner as in Synthesis Example 1 using the composition shown in Table 1, and the resin was cooled to a resin acid value of 60.0 (this is referred to as base resin B). After cooling, silicone modification and alkyleneimine modification were performed in the same manner as in Synthesis Example 1 to obtain alkyleneimine modified silicone polyester resin varnish 3. The characteristic values of this varnish are shown in Table 1.

Synthesis Example 4 Coconut oil is transesterified using the composition shown in Table 1 in a conventional manner, and after IC, a condensation reaction is carried out in the same manner as in Synthesis Example 1, and the resin is cooled to a resin acid value of 20.0 (this is referred to as base resin C). ). After cooling, silicone modification and alkyleneimine modification were performed in the same manner as in Synthesis Example 1 to obtain alkyleneimine modified silicone alkyd resin varnish 4. The special values of this varnish are shown in Table 1.

Synthesis example 5.

Silicon modification was carried out under the same conditions as in Synthesis Example 1, using A as the base resin and KR-213 (manufactured by Shin-Etsu Silicone) as the reactive silicone resin.

Next, as an alkylene imine compound, ■tyrenimine (
The reaction was carried out using Nippon Shokubai Kagaku (manufactured by I) under the same conditions as in Synthesis Example 1 to obtain alkyleneimine modified polynisder resin varnish 5. The characteristic values of this varnish are shown in Table 1.

Synthesis Example 6.7 A condensation reaction was carried out in the same manner as in Synthesis Example 1 according to the composition shown in Table 1, and the resins were cooled to acid values of 2Q, 0, and 40.0, respectively (this was referred to as the base resin E). After cooling, DC-303'7 corresponding to base resin/reactive silicone resin (solid differentiation) 9515.40/60 was added to perform silicon modification under the same conditions as in Synthesis Example 1. Subsequently, alkyleneimine modification was carried out in the same manner as in Synthesis Example 1 to obtain alkyleneimine modified polyester resin varnish 6.7. The characteristic values of these varnishes are shown in Table 1.

Synthesis Example 8 45 parts of quijirole and 50 parts of cellosolve acetate in a reaction tank
After heating the hot stones to 130℃,
ST) 15 parts, n-butyl methacrylate (n-BMA)
42.2 parts, lauryl methacrylate (LMA) 16.6
part, 2-hydroxyethyl methacrylate (21-IE
MΔ) 23.2 parts, methacrylic acid (MAA) 3.0 parts, t-butylperoxy 2-ethylhexanoate 2.
0 parts of lauryl mercaptan and 0.3 parts of lauryl mercaptan were added dropwise at the same rate over 3 hours, kept warm for 30 minutes, and then added 1.0 parts of 1-butyl peroxy 2-, ethylhexanoate and 5 parts of Kijirol. The mixed solution was added dropwise at a constant speed for 30 minutes, and after the completion of the dropping, it was kept for 2R and then cooled (this is referred to as base resin F). After cooling, 6 parts of DC-303717 was added, and the reaction product was thinly coated on a glass plate while methanol was distilled out of the system at 140°C, and forced drying (130°C x 20
minute).

Both before and after drying, the reaction is continued until the resins are completely compatible and become transparent. When the resin becomes transparent, it is cooled. After cooling, followed by I-IE E I 1 .

1 part was added, heated and stirred at 80°C for 1 hour, and then cooled. After cooling, 34.2 parts of Kijirole was added to obtain alkyleneimine-modified silicone acrylic resin varnish 8. The special values of this varnish are shown in Table 1.

Synthesis Example 9 Using the base resin A of Synthesis Example 1, silicone modification was also performed in Synthesis Example 1.
In exactly the same manner as above, silicone polyester resin varnish '9 was obtained. The characteristic values of this varnish are shown in Table 1.

Synthesis Example 10 Using the base resin C of Synthesis Example 4, silicone modification was performed in Synthesis Example 1.
A silicone alkyd resin varnish 10 was obtained in exactly the same manner as above. The characteristic values of this varnish are shown in Table 1.

Synthesis Example 11 Using the base resin F of Synthesis Example 8, silicone modification was performed in Synthesis Example 8.
Do exactly the same thing as silicon ac 1 nor resin varnish 11
I got it. The number of temples of this varnish is shown in Table 1.

Synthesis Example 12 Table 1 shows the A-yl obtained during the production stage of Synthesis Example 1.

(Margin below) (Continued from Table 1) Example 1 Using the alkyleneimine-modified silicone polyester resin varnish 1 obtained in Synthesis Example 1 and melamine resin as a hardening agent, a blue paint was prepared based on the formulation shown in Table 2. It was created.

The resulting paint was diluted with a diluting solvent of Tsurupetz 150 (manufactured by Esso Standard Oil, mixed solvent)/Kijirol/butyl acetate/methyl isobutylene chloride-50/20/15/15 to a viscosity of 23 seconds () A-docup N004.20°C. )
diluted to The diluted paint was sprayed onto a 5PC-1 dull steel plate treated with zinc monophosphate and coated with an intermediate coat, and after being left for a certain period of time, it was baked at 140°C for 30 minutes. The test results of the obtained coating film are shown in Table 2.

Examples 2 to 8, Comparative Examples 1 to 4 Using the various resin varnishes obtained in Synthesis Examples 2 to 12, the second
A blue paint was prepared based on the formulation in the table, diluted and spray coated in the same manner as in Example 1. The results of each test are shown in Table 2.

(Note 1) Made by Mitsui Toatsu Kagaku Ω Sai) Melamine resin, non-volatile content 60% (Note 2) Ishibei Sangyo C Wood White Pigment (Note 3) Dainippon Ink 1 Wooden Blue Pigment (Note 4) Esso Standard Oil (Ha )) Mixed solvent (Note 5) Shin-Etsu Chemical @ Surface conditioning agent (Note (3)) Evaluate the appearance of the burnt surface using the following criteria: 1i1 [i L
is.

◎: Very good ○: Good △: Very good ×: Poor (Note 7) Determined based on the highest hardness until no scratches occur at all with a Mitsubishi Uni-pencil.

(Note 8) An additional 16 coated plates were prepared in each example and comparative example.
Overbake at 0°C for 30 minutes, then spray coat each barley with coating A'to, and bake at 120'C for 30 minutes (the same top coat will be overcoated). After that, cross cut 2111+111'lJ with a razor.
A peel test was performed using t-tape to remove the scratches, and a coating film of 2 cm
Evaluate using the following basis r%1 based on the number of peeled pieces in each direction.

◎: Not peeled off at all (very good) O: 1 to 10 pieces (good) △: 11 to 30 pieces (good texture) ×: 31 or more... (poor) Examples 9 to 13, Comparative Example 5 ~8 Using the various resin varnishes obtained in Synthesis Examples 2.4.6 to 12 and an isocyanate compound as a curing agent, four sizes of blue color were prepared based on the formulations in Table 3, and diluted in the same manner as in Example 1. It was spray painted. The results of each test are shown in Table 3 J0 (The following is a blank space) (Note 9) Manufactured by Sumitomo Bayer Urethane 01, aliphatic polyisocyanate, non-volatile content 75% (Note 10) Mon V To C Wooden surface conditioner Table 2, 3
From the results in the table, it is clear that the curing agent is melamine resin and isocyanate.
1. It is clear that by combining both compounds with an alkyleneimine-modified resin, weather resistance is maintained while the adhesion is significantly improved.

Claims (1)

[Claims] (1) In a coating composition containing (Δ) a thermosetting resin having a hydroxyl group, (B) a binder component consisting of an aminoaldehyde resin and/or an isocyanate 1-compound, and (C) a pigment as essential components, the component ( A) is a polyester resin, alkyd resin or acrylic resin containing hydroxyl groups and carboxyl groups, with the formula % formula % (wherein R is bonded to silicon through a carbon-silicon bond (ru-
Valid organic group; R' is hydrogen, C1-C20 alkyl group or aryl group; 11 and m each have a value of 4 or less, provided that 11→
−…≦4) Number average molecular weight of approximately 500 to 2000
Weather resistance and recoatability characterized by being a resin obtained by silicone modification with an organopolysiloxane resin and alkylene imine modification with an alkylene imine compound having at least one alkylene imine ring having 2 to 3 carbon atoms. Excellent paint composition.