GB2172602A - Resinous composition for coating use - Google Patents

Abstract

A resinous composition for coating use having improved pigment dispersibility and improved weather resistance, comprising 45 to 95% by weight of amphoteric resin having incorporated therein a hindered amine type photostabilizer and 55 to 5% by weight of amino-formaldehyde resin etherified with a lower monohydric alcohol, or isocyanate compound, the said amphoteric resin being prepared by the ester-ester exchange reaction between the base resin selected from an acidic resin and amphoteric resin having functional group capable of reacting with a crosslinking agent and ester bonding, and a hindered amine type photostabilizer having ester bonding.

Description

1 GB 2 172 602 A 1

SPECIFICATION

Resinous composition for coating use The present invention relates to a resinous composition for coating use having an excellent pigment 5 dispersibility, comprising an amphoteric resin and an amino-formaldehyde resin and/or isocyanate compound.

An amphoteric resin composed of an acidic resinous component as oil-free polyester resin, alkyd resin, acrylic resin and the like, and a basic resinous component as urea resin, melamine resin, polyamide resin, polyurethan resin and their prepolymers and/or a basic compound as hydroxylamines, amino acids, primary 10 or secondary amine compounds and the like do possess in its molecule both of the characteristic acidic and basic groups and therefore, such a resin can exhibit excellent compatibility with a number of resins customarily used for the preparation of coating compositions and good affinity toward various types of pigments. For these reasons, it is being watched with keen interest as general purpose resin.

The combination of amphoteric resin and etherified aminoformaldehyde resin and/or isocyanate 15 compound is characterized by having excellent compatibility with other coating resins, improved coating workability, finishing appearance (gloss, glamorous) and weather resistance, and hence is superior in many points to the aminoalkyd or aminoacrylic resin type paints heretofore used as top coat for automobile bodies and the like.

The present inventors have previously found that a coating -composition comprising an amphoteric resin 20 obtained by the reaction of polyester resin, 10 to 80 mole % of the acid component being composed of saturated alicyclic polycarboxylic acid and 10 to 100 mole % of the carboxyl groups capable of developing resinous acid value being derived from the polycarboxylic acid which will give a titration midpoint potential in non-aqueous potentiometric titration under the state of developing resinous acid value, of more than -350 mV, and basic resin and/or basic compound, and amino-formaldehyde resin etherified with C1 to C4 25 monohydric alcohol can exhibit excellent weather resistance, mechanical properties of the coating, interlaminar adhesion, curability and pigment dispersibility and is especially useful as a top coat for automobile bodies and the like and applied for patent on it. (Japanese Patent Application No. 154210/82).

The disclosed invention aims to, while making the most of the merits possessed by polyester resin as weather resistance, mechanical properties of the coating, interlaminar adhesion and the like, overcome the 30 drawbacks as poor compatibility with amino resin, by the adoption of amphoterization, thereby providing an excellent coating composition for top coat use. Since the resinous composition contains the abovemen tioned amphoteric resin, fairly good results are obtained even in respect of pigment dispersibility, too. Such effect can never be attained with the mere mixture of acidic resin and basic resin and/or basic compound.

However, the subsequent studies revealed that even with the aforesaid resinous composition, when use 35 was made of the so-called hard dispersible pigments having a quinacridone structure as Cinquacia red and the like, no satisfactory results could be obtained, often resulting gloss down, blushing and the like, and that such pigment dispersibility problem was greatly concerned with the kind and amount of basic resin and/or basic compound contained in the amphoteric resin. The present invention has been made during the course of such studies.

A major object of the present invention is, therefore, to provide a resinous composition for coating use, having an exceptionally improved pigment dispersibility. More specifically, the invention aims to provide a resinous composition for coating use which is useful as a top coat for automobile bodies and the like, and capable of showing excellent dispersion stability to hard dispersible pigments liable to cause blushing, gloss down or the like, not to speak of desired coating workability and various other film performances.

The abovesaid objects of the invention can be attained by the following compositions.

(1) A resinous composition for coating use having a greatly improved pigment dispersibility and comprising an amphoteric resin having an acidic resinous component and a basic component of basic resin and/or basic compound, and aminoformladehyde resin etherified with monohydric alcohol having 1 to 4 carbon atoms and/or isocyanate compound, which is characterized by that the basic component of said amphoteric resin consists of basic resin and/or basic compound whose titration midpoint potential in non-aqueous potentiometric titration, under the state incorporated into resin, is less than 450 mV, and the basicity of the amphoteric resin is within the range of 1.0 x 10-2 to 1.0 m mol/g solid.

(2) A resinous composition according to the preceding para. (1) comprising 45 to 95% by weight of said amphoteric resin and 55 to 5% by weight of said amino-formaldehyde resin and/or isocyanate compound. 55 (3) A resinous composition according to anyone of the preceeding paragraphs wherein the acidic resinous component of the amphoteric resin consists of polycarboxylic acid whose titration midpoint potential in non-aqueous potentiometric titration, under the state capable of developing resinous acid value, is more than -350 mV and the acidity of said amphoteric resin is within the range of 2.0 x 10-1 to 3.0 m mol/g solid.

In the present invention, is used as amphoteric resin having both acidic resinous component and basic component of basic resin and/or basic compound. Therefore, the acidic resin may be any of the resins having a functional group capable of reacting with the functional group possessed by basic resin or basic compound, as for example active hydrogen, active alkoxy or the group capable of reacting with the same, as well as an acidic group as, for example, carboxyl, sulfonic group or the like. Examples of such acidic resins 65 2 GB 2 172 602 A 2 are oil-free polyester resin, alkyd resin, acrylic resin and the like.

On the other hand, the basic resin and/or basic compound may be any of the members having both of functional group capable of reacting with the functional group possessed by the acidic resin, as, for example, a group which is reactive with active hydrogen or active alkoxy, or active hydrogen or active alkoxy group, and a basic group as, for example, amino group, imino group and the like. Examples of such members are urea resin, melamine resin, polyamide resin, polyurethan resin, hydroxylamine, aminoacids, primary or secondary amines and the like.

Among the amphoteric resins prepared by the reaction of such acidic resin and basic resin and/or basic compound, the invention intends to use the specific members whose basic components are such basic resins and/or basic compounds as each having a titration midpoint potential in non-aqueous potentiometric 10 titration, under the state incorporated into resin, of less than 450 mV and whose basicity is within the range of 1.0 X 10-2 to 1.0 m mol/g solid.

An amphoteric resin is in general insoluble in water. Therefore, the inventors have developed specific methods for the determination of acidity and basicity of such resin. That is, a test resin is first dissolved in pyridine, a non-aqueous potentiometric titration is carried out with a titer of n-tetrabutylammonium hydroxide, and the resinous acidity is calculated from the molar volume of the titer required for the neutralization thereof. As to the basicity, the test resin is dissolved in acetic acid, a non-aqueous potentiometric titration is carried out with a titer of perchloric acid and the basicity is calculated from the molar volume of the titer required for the neutralization thereof.

The inventors have then studied on the correlation between the pigment dispersibility of the resinous composition and the acidity and basicity of the amphoteric resin to be contained therein.

As a result of a series of studies, the inventors have found that for the dispersion of common pigments fairly good results can be obtained with the amphoteric resins having comparatively wider range of acidity, e.g. 3. 0 to 2.0 x 10-1 m molIg solid and of basicity, e.g. 1.0 to 5 x 10-3 M mol/g solid, and however, for the hard dispersible pigments having quinacridone structure as Cinquacia red and the like, no satisfactory results can be obtained with the aforesaid amphoteric resins, paying regard only to the acidity and basicity thereof, and that in the latter case, the pigment dispersibility is greatly influenced on the types and amounts of the constituting members of the amphoteric resins and especially of the basic components thereof. That is, for obtaining a stable dispersion of such hard dispersible pigment, it is essential to incorporated into an amphoteric resin, a basic resin and/or basic compound having a titration midpoint potential in non-aqueous 30 potentiometric titration under the state incorporated into resin, of less than 450 MVr in an amount corresponding to give the resin a basicity of 1. 0 X 10-2 to 1.0 m molIg solid. It has also been found that the kind of acidic component is not so important providing giving an appropriate acidity to the amphoteric resin.

Examples of basic resins and/or basic compounds each having a titration midpoint potential in non-aqueous potentiometric titration, under the state incorporated into resin, of less than 450 mV are 35 polyethyleneimine, triethanolamine, di-ethanolamine, N-methyl diethanol amine, N,N-dibutylethanol arnine, N,N-diethylethanolamine, N,N-dimethylethanolamine, N,N- diisopropylethanolamine, N-methyl-3-piperidine methanol, 3-pyridine methanol and the like.

The other component of the present resinous composition is an aminoformaldehyde resin and/or isocyanate compound. Examples of such resins and/or compounds are melamine resin, guanamine resin, 40 urea resin and the like, each etherified with monohydric alcohol having 1 to 4 carbon atoms, as methanol and ethanol. Among them, particular preference is given to melamine resin. As the isocyanate compounds, mention is made of aromatic polyisocyanates, alicyclic polyisocyannates, fatty acid modified polyisocyan ates and the like. As to the weight ratio of said amphoteric resin and aminoformaldehyde resin and/or isocyanate compound, it is in general determined in the range of 45 to 95 parts by weight, preferably 60 to 80 parts by weight, of the former and 55 to 5 parts by weight, preferably 40 to 20 parts by weight, of the latter.

However, they may be freely changed according to the intended objects of the composition formulated. Thus obtained resinous composition of the invention is quite useful for the preparation of top coat composition for automobile bodies and the like, because of excellent compatibility with other resin, excellent curability and extra-ordinally improved pigment dispersibility.

Though it is not essential in the invention, it has been found that when the amphoteric resin is composed of particular acidic resinous component based on the polycarboxylic acid showing a titration midpoint potential in non-aqueous potentiometriGtitration, underthe state capable of developing resinous acid value, of more than -35OmV, the amount of said acid being selected so as to give the acidity of 2.OX1 0-2 to 3.0 m mol/g solid, and present basic component, the resinous composition thus obtained can afford by far the best 55 pigment dispersibility, as well as excellent durability, finishing appearance, weather resistance, interlaminar adhesion, impact strength and the like. Thus, in the present invention, is provided a resinous composition having, inter alia, excellent pigment dispersibility for hard dispersible pigments.

However, as a top coat for automobile bodies, it is needless to say that weather resistance is also an important factor among other properties. It has been practiced to add to a resinous composition a photostabilizer which is able to improve the weather resistance thereof. Such an attempt, however, gave only poor results because the photostabilizer heretofore proposed and mechanically mixed in the composition tends to migrate, when the coating is exposed to natural environment, within the coating, easily dissolved out of the system and hence the initial effect cannot be sustained. Recently, a basic compound having both polyalkylpiperidine group and ester bonding has been watched with interests as a 3 GB 2 172 602 A 3 photostabilizer. That is, in Japanese Patent Application Kokai Nos. 14188/77 and 63183/77, there describe a number of hindered amine type (HA type) photostabilizer having polyalkyl piperidine group and ester bonding, and there are many products in the market as, for example, Sanol LS-770, Sanol LS-744, Sanol LS-292, Sanol LS-440 (Ciba Geigy) and the like. Since the photostabilizer disclosed is a basic compound it is expected that the reaction of said photostabilizer with an acidic resin having carboxyl group may give an amphoteric resin. However, it has been recognized that an actual amphoterization can hardly be occured because of the steric hindrance of the functional group developing basicity.

As the results of our extensive studies on the reaction mechanisms involved in the preparation of amphoteric resins from acidic resins and basic resins and/or basic compounds, have been found the fact that 1() an ester-ester exchange reaction is an effective bonding means among other various means relied on the 10 reactions between functional groups possessed by the respective materials as for example addition and condensation reactions.

The abovesaid hindered amine series photostabilizers each have ester bondings in their molecules other than the functional groups developing basicity, and therefore, it would be probable that the said ester exchange reaction be usable for the incorporation of said stabilizer into the resin. In fact, the present 15 inventors have found that by the reaction of acidic resin having ester bondings with HA series photosensitizer having ester bondings, i.e. ester-ester exchange reaction, the aimed amphoteric resin can be advantageously obtained. The inventors also have found that an ester bonding bearing amphoteric resin obtained by the reaction of acidic resin and basic resin and/or basic compound is likewise useful for the ester-ester exchange reaction with ester bonding bearing HA type photostabilizer. On the basis of these 20 findings, the inventors have succeeded in providing a resinous composition having an excellent pigment dispersibility and improved photostability. Thus, in the second aspect of the invention, is provided a resinous composition comprising 45 to 95% by weight of an amphoteric resin having incorporated therein a hindered amine type photostabilizer, obtained by the ester-ester exchange reaction between the base resin selected from acidic resins oramphoteric resins derived from said acidic resins and basic resins and/or basic 25 compounds, having both functional group reactive with a crosslinking agent and ester bonding, and hindered amine type photostabilizer having ester bonding, and 55 to 5% by weight of amino-formaldehyde resin etherified with a lower alcohol and/or isocyanate compound. More specifically, the amphoteric resin used in this second aspect of the invention is characterized by having incorporated therein a hindered amine type photostabilizer. Such resin may be advantageously prepared by the reaction of acidic resin having 30 functional group reactive with a crosslinking agent and ester bonding, with a hindered amine type photostabilizer having ester bonding, e.g. the abovementioned photostabilizer having polyalkylpiperidine group, or by the reaction of amphoteric resin derived from the reaction of acidic resin having functional group reactive with a crosslinking agent and ester bonding and basic resin and/or basic compound, with a hindered amine type photostabilizer having ester bonding, through ester- ester exchange reaction.

As already stated, the hindered amine type photostabilizer is effectively incorporated into the base resin by ester-ester exchange reaction and therefore, differing from the mere blend of such stabilizer and the base resin, can never be flowed out of the system and thus the present resinous composition can afford excellent photostabilization, i.e. weather resistance, besides other desirous properties as pigment dispersibility and the like.

The amphoteric resin to be used in the present invention should have the basicity of 1.0 x 10-2 to 1.0 M mol/g solid and should preferably have the acidity of 2.0 x 10-2 to 3.0 m mol/g solid for the characteristic pigment dispersibility and resin compatibility.

Since the hindered amine type photostabilizer used in the invention is a kind of basic compound, it may take a part of role of the basic component forthe preparation of amphoteric resin. Thus, with respect to the 45 required basicity, the hindered amine type photostabilizer may occupy 100 to 2.0 mole % of the said total basicity. However, this is not an absolute requirement of the invention and the actual amount of hindered amine type photostabilizer may be freely changed depending on the desired effects, application purpose and the like. As the hindered amine type photostabilizer, any of the known compounds may be successfully used, providing having ester bonding therein.

It has already been known that when the amphoteric resin is composed of particular acidic resin, 10 to 80 mole% of the acidic components being saturated alicyclic polycarboxylic acid, a better weather resistance can be expected. And therefore, it may easily be understood that a far better weather resistance could be obtained with the amphoteric resin having as the acidic resinous component a particular type of resin having ester bonding, 10 to 80 mole% of the acid component being saturated alicyclic polycarboxylic acid and as 55 basic component the hindered amine type photostabilizer having ester bonding.

Thus, in the present invention, by the selection of appropriate acidic resinous component and basic component, the so-called tailor made amphoteric resin having desired properties including pigment dispersibility, resin compatibility, weather resistance, mechanical properties and the like may be provided.

As to the details of preparation of such amphoteric resins, reference should be made to Japanese Patent 60 Application No. 154210/82 applied by the same inventors.

The invention shall be now more fully explained in the following Examples. Unless otherwise being stated, all parts and % are by weight.

4 GB 2 172 602 A 4 Example 1 (preparation of amphoteric resin varnish /) Into a reaction tank fitted with heating device, stirrer, refluxing device, water separator, distilling tower and thermometer, were added 133 parts of isophthalic acid, 29.2 parts of adipic acid, 25.1 parts of trimethylolethane, 52.8 parts of neopentylglycol and 56 parts of 1,6hexanediol and the mixture was heated.

Stirring was commenced to start at the stage when the materials charged were dissolved and the tank 5 temperature was raised to 220"C. At this time, from 160 to 220'C, said temperature was raised at a constant speed over 3 hours. The formed condensed water was removed out of the system. When the temperature reached to 220"C, the reaction mixture was maintained at the same temperature for 1 hour, added gradually with 5 parts of xylene as refluxing solvent and after switching to the condensation reaction in the presence of solvent, the reaction was continued. The reaction was overed at the stage of resinous acid value of 8.0 and 10 the mixture was allowed to cool. (Thus obtained acidic resin shall be referred as A). To the reaction mixture, were added at 1400C 3.8 parts of triethanolamine and 0.13 part of FASCAT 4201 (M&T Chemicals Inc.) and an ester exchange reaction was effected at 160'C until the characteristic spot of triethanolamine in TLC (thin layer chromatography) had been disappeared. After cooling, 118.2 parts of xylene and 13.7 parts of cellosolve acetate were added to obtain an amphoteric resinous varnish 1. The characteristics of this varnish 15 are shown in Table 1.

Example 2 (amphoteric resinous varnish 11) To 100 parts of acidic resin A obtained in Example 1, were 1.3 parts of Wmethyl-3-piperidinemethanol and 0.05 part of FASCAT4201 and an ester exchange reaction was carried out at 1MC until the characteristic spot 20 of N-methy]-3-piperidinemethanol in TLC had been disappeared. After cooling, 46.3 parts of xylene and 5.4 parts of Cellosolve acetate were added to obtain an amphoteric resinous varnish 11. The characteristics of this varnish are shown in Table 1.

Example 3 (amphoteric resinous varnish 111) To 100 parts ol acidic resin A obtained in Example 1, were added 0.26 part of N-methyl-3piperidinemelchanol and 0.01 part of FASCAT and the mixture was reacted as in Example 2. After cooling, 45.8 parts of xylene and 5.3 parts of Cellosolve acetate were added to obtain an amphoteric resinous varnish Ill. The characteristics of this varnish are shown in Table 1.

Example 4 (amphoteric resinous varnish IV) To 100 parts of acidic resin A obtained in Example 1, were added 9.1 parts of N-methyl-3piperidinemethanol and 0.1 part of FASCAT4201 and the mixture was reacted as in Example 2. After cooling, 50 parts of xylene and 5.8 parts of Cellosolve acetate were added to obtain an amphoteric resinous varnish IV. The characteristics of this varnish are shown in Table 1.

Example 5 (amphoteric resinous varnish V) 88.6 Parts of coconut oil, 22.1 parts of dehydrated castor oil, 39.9 parts of trimethylolethane and 0.1 part of lithium naphthenate were placed in a reaction tank and the mixture was heated to 2400C. At this temperature, an ester exchange reaction was effected. Then, 38.6 parts of trimethylolethane, 49.9 parts of isophthalic acid, 40 103.7 parts of phthalic anhydride, 31.6 parts of neopentylglycol, and 7 parts of xylene were added, the mixture was heated to 220 to 23M and dehydration reaction was continued until the resinous acid value of 8.0. Thereafter, the reaction mixture was allowed to cool. At the tank temperature of 140"C, 3.8 parts of 3-pyridinemethanol were added and ester exchange reaction was affected at 1600C until the characteristic spot of 3-pyridinemethanol in TI-C had been disappeared. After cooling, 209.5 parts of xylene and 24.1 parts 45 of Cellosolve acetate were added to obtain an amphoteric resinous varnish Y. The characteristics of this varnish are shown in Table 1.

Exampld6 (amphoteric resinous varnish V1) To a reaction tank, were added 40 parts of xylene, 10 parts of Cellosolve acetate, 33.2 parts of methyl 50 methacrylate, 48 parts of ethyl acrylate, 16 parts of 2-hydroxyethyl methacrylate, 1 part of methacrylic acid and 1.8 parts of diethylaminoethyl methacrylate and the mixture was heated to 11 OOC. While maintaining the same temperature, a solution of 40 parts of xylene, 10 parts of Cellosolve acetate, 1 part of azobisisobutyro nitriie and 0.25 part of lauryimercaptane was dropwisely added at a constant speed in 3 hours. Thereafter, the mixture was maintained for 2 hours, added with 2.6 parts of phthalic anhydride and reacted at 1400C until 55 the resinous acid value of 17.0, to obtain an amphoteric resinous varnish VL The characteristics of this varnish are shown in Table 1.

Example 7 (Comparative acidic resinous varnish V11) To 100 parts of acidic resin A obtained in Example 1, were added 45.6 parts of xylene and 5.3 parts of 60 Cellosolve acetate to obtain an acidic resinous varnish VII. The characteristics of this varnish are shown in Table 1.

Example 8 (Comparative amphoteric resinous varnish V/10 To 100 parts of acidic resin A obtained in Example 1, were added 5 parts of melamine resin (n TABLE 1

Example No.

Resin.varnish non-volatile % varnish viscosity 1 acidity(m mol/g soO tit.midpoint poten. of acid component 2 basicity(m mol/g sol) tit.midpoint poten. of basic component 3 1 2 1 65.4 11 64.9 V-W W 0.18 0.18 -31OmV -3110mV 0.11 0.12 387mV 382mV 3 Ill 65.1 V-W 0.18 -31OmV G.02 4 5 1V v 64.7 60.1 W-X U-V 0.18 0.17 -31OmV -290mV 0.83 0.12 382mV 382mV 430mV 6 7 V1 VIl 51.2 65.2 Y-Z v 0.39 0.18 -290mV -31OmV 0.11 38OmV 1 Gardner viscosity 250C 2 Sample was dissolved in pyridine, quantitatively analyzed by means of non-aqueous potentiometric titration with a titer of n-tetrabutylammoniurn hydroxide, and acidity was determined from the molar volume of the titer required neutralization thereof. The potential at the titration midpoint of this titration curve was used as titration midpoint potential of acidic component. 3 Sample was dissolved in acetic acid, quantitative analyzed by means of non- aqueous potentiometric titration with a titer of perchloric acid, and basicity was determined from the molar volume of the titer required for neutralization thereof. The potential at the titration midpoint of this titration curve was used as titration midpoint potential of basic component.

8 Vill 64.8 Y 0.17 -31 OmV 0.15 460mV M UI 0 0 5 C:, =r 2) m K) =r 7r C> 1 0 p+ Cf) CO c) CD a) 3 m 3 0 -0 = m 0 (D 0 =- zt - = 0 0 a).

(D r_ 0 0 =. % (D M c) 0 = " =r -% E CD = - Ln. U) 0 C 0 :3 0 C):1 =r C7 0 1 0) 0 CD (D a) = CL = c) (D 0 < =r (1) 0 X+ (D (n -h CL =. =r -0 cj < 0 ". c 5. (D (n " 0 CL 0 0 2. g C.Z -< CD U):3 < 50) ' US 2. DLE..' (n M -A P. =F (D 0 c) < 5C5 = 5. 0) 3 j -, 0.5 - 0 C:

(D CO.;n:E 0 =r. =r -< 5R 2p 0 =,.: NI j :3 9 =3 W. () CL 0 =r % (D 0._ (D (D a):

- =3 =r - " CD ---1 0 @ C0 =r = c) (D 0:E 0 cr:E c) -0 D) (D W CD 0. 0. 0 F) ' 0 -% C) 0 0 0 0 ' a h 3 C) (D 0 0.

=r -0 - W 0. 0) m -1 m (D =r :3 CD a) CD N) UI 6 GB 2 172 602 A 6 Example 9

Awhite colored dispersion paste was prepared using the amphoteric resinous varnish I obtained in Example 1 and following the receipt shown in the following Table A-1:

TABLE A-1 5 titanium white (Note 1) 60 parts amphoteric resinous varnish 1 27 Solvesso 100 (Note 2) 15 dispersing agent (Note 3) 0.05 10 tota 1 102.05 Thereafter, a white primary color coating composition was prepared by mixing the following:

TABLE A-2 15 white colored dispersion paste 102.05 amphoteric resinous varnish 1 42.0 melamine resin (Note 4) 32.0 n-butanol 5.0 20 triethylamine 0.6 total 181.65 Notell: Titanium R5N manufactured bySakai Kagaku K.K. Note2: mixed solvent by Esso Standard Co. Note& 10% solution of KF-69 manufactured by Shinetsu Silicon K.K. Note4: Super Beckamine 16-508 manufactured by Dainippon Ink K.K.

Thus obtained white primary color coating composition was flow-coated on a glass plate and baked, by using a hot air dryer, at 140'C for 30 minutes. TI value of the white colored dispersion paste and 200 gloss of 30 the baked coating were measured and pigment dispersability was evaluated. The results are shown in Table 2.

Example 10 and 11 An orange colored and a red colored dispersion pastes were prepared with the receipts shown in Table B-1 35 and C-1, and thereafter an orange primary color and a red primary color coating compositions were prepared by mixing the materials shown in Table B-2 and Table C-2, respectively.

TABLE B-1

40 Novaperm orange HL-70 1 35 parts amphoteric resinous varnish 1 27 Solvesso 100 40 dispersing agent 0.05 total 102.05 45 TABLE B-2 orange dispersion paste 102.05 amphoteric resinous varnish 1 42.0 50 melamine resin 32.0 n-butanol 5.0 triethylamine 0.5 total 181.55 55 1 benzimidazolone series, by Hoechst TABLE C-1

Cinquacia red Y-RT 759D 1 35 60 amphoteric resinous varnish 1 27 Solvensso 100 40 dispersing agent 0.05 total 102.05 7 GB 2 172 602 A 7 TABLE C-2 red colored dispersion paste amphoteric resinous varnish 1 melamine resin n-butanol triethylamine 102.05 42.0 32.0 5.0 0.5 total 181.55 1 quinacridone series, by Du Pont Ti values of said orange colored and red colored dispersion pastes and 20' glosses of the baked coatings were evaluated as in Example 9. The test results are shown in Table 2.

Examples 12 to 20 Using amphoteric resinous varnish 11 of Example 2, amphoteric resinous varnish III of Example 3 or amphoteric resinous varnish IV of Example 4 in place of the resinous varnish I in Tables A,Band C in Examples 9 to 11, the respective white primary colored, orange primary colored and red primary colored coating compositions were prepared. TI values of the respective dispersion paste and 200 gloss of the baked coating were measured and pigment dispersibility was evaluated, in each case. The test results are shown in 20 Table 2.

Examples 21 to 23 Using amphoteric resinous varnish V of Example 5 in place of amphoteric resinous varnish I in Tables A,B and C appearing in Examples 9 to 11, but changing the amounts "27" to "29" and "42" to "46", the respective white primary colored, orange primary colored and red primary colored coating compositions were prepared. TI values of thus obtained dispersion pastes and 20'gloss of the baked coatings were measured and the pigment dispersibilities were evaluated. The test results are shown in Table 2.

Examples 24 to 26 Using amphoteric resinous varnish VI of Example 6 in place of amphoteric resinous varnish I in Tables A,B and C appearing in Examples 9 to 11, but changing the amounts "27" to "35,, and"42" to "55", the respective white primary colored, orange primary colored and red primary colored coating compositions were prepared. TI values of thus obtained dispersion pastes and 200 glosses of the baked coatings were measured and pigment dispersibilities were evaluated. The test results are shown in Table 2.

Examples 27 to 32 (Comparative Examples) Using amphoteric resinous varnish VII of Example 7 or amphoteric resinous varnish Vill of Example 8 in place of the resinous varnish I in Tables A, B and C in Examples 9 to 11, the respective white primary colored, ornage primary colored and red primary colored coating compositions. TI values of the obtained dispersion 40 pastes and 20'glosses the the primary colored coating compositions were measured and pigment dispersibilities were evaluated. The results are shown in Table 2.

As is clear from the test results shown in Table 2, the present resinous composition can exhibit far better pigment dispersibility especially to hard dispersible pigments.

TABLE 2

Example 9 10 11 12 13 14 15 16 17 18 19 20 resinous varnish 1 1 1 11 11 11 Ill Ill Ill IV IV IV Primary colour W 0 R W 0 R W 0 R W 0 gloss 84 72 71 89 78 76 82 70 69 86 78 78 TI value 1.2 2.4 3.0 1.1 1.8 2.7 1.2 2.6 3.8 1.1 1.6 2.6 Example 21 22 23 24 25 26 27 28 29 30 31 32 resinous varnish V V V VI Vi VI Vil Vil Vil Vill Vill Vill primary color W 0 R W 0 R W 0 R W 0 R 200gloss 82 68 66 86 70 72 72 15 5< 81 66 51 TI value 1.3 3.0 4.2 1.2 2.8 3.1 1.8 5.4 7.7 1.4 3.2 5.6 viscosity ratio at 6r.p.m. and 60r.p.m., BM type viscometer No. 3 rotor W = white primary color 0 = orange primary color R = red primary color CO G) ca N) -j N) (3) C) N CO 9 GB 2 172 602 A 9 Example 33 (Comparative acidic resin varnish B) Into a reaction tankfitted with heating device, stirrer, refluxing device, water separator, distilling tower and thermometer, were added 52.3 parts of isophthalic acid, 11.5 parts of adipic acid, 9.9. parts of trimethylol propane, 20.8 parts of neopentylglycol and 22.0 parts of 1,6- hexanediol and the mixture was heated. Stirring was commenced to start at the stage when the materials charged were dissolved and the 5 tank temperature was raised to 220'C. At this time, from 160 to 220'C, said temperature was raised at a constant speed over 3 hours. The formed condensed water was removed out of the system. When the temperature reached to 2200C, the reaction mixture was maintained at the same temperature for 1 hour, added gradually with 2 parts of xylene as refluxing solvent and after switching to the condensation reaction in the presence of solvent, the reaction was continued. The reactioned was overed at the stage of resinous 10 acid value of 8.0 and the mixture was allowed to cool. (Thus obtained acidic resin shall be referred as B).

To the reaction mixture, were added 46.5 parts of xylene and 5.4 parts of cellosolve acetate to obtain an acidic resinous varnish B. The characteristics of this varnish are shown in Table 3.

Example 34 (hindered amine type photostabilizer containing amphoteric resin varnish I) To 100 parts of acidic resin B obtained in Example 33,1.5 parts of Sanol LS-292 (hindered amine type photostabilizer having polyalkylpiperadine group and ester bonding, manufactured by Ciba Geigy) and 0.01 part of FASCAT 4201 (M & T Chemicals Inc.) were added and an ester exchange reaction was carried out at 1600C until the characteristic spot of Sanol LS-292 in TLC had been disappeared. After cooling, 49.2 parts of xylene and 5.4 parts of Cellosolve acetate were added to obtain an amphoteric resin varnish 1. The characteristics of this varnish are shown in Table 3.

Example 35 (hindered amine type photostabilizer containing amphoteric resin varnish //j 53.1 Parts of isophthalic acid, 11.7 parts of adipic acid, 12.8 parts of trimethylol propane, 18.7 parts of neopentyl glycol and 19.8 parts of 1,6-hexanediol were reacted byfollowing the procedures of Example 33 25 until the resinous acid value of 20.0 and the reaction mixture was allowed to cool. Next, 9 parts of Sanol LS-292 and 0.05 part of FASCAT 4201 were added and ester exchange reaction was carried out until the characteristic spot of Sanol LS-292 in TLC had been disappeared. After cooling, 52.8 parts of xylene and 5.8 parts of Cellosolve acetate were added to obtain an amphoteric resin varnish 11. The characteristics of this varnish are shown in Table S.

Example 36 (Comparative acidic resin varnish Q 25.5 parts of coconut oil, 6.4 parts of dehydrated castor oil, 43.1 parts of isophthalic acid, 4.2 parts of adipic acid 22.6 parts of trimethylolethane and 9.1 parts of neopentyl glycol were reacted under heating until the resinous acid value of 8.0 and the mixture was allowed to cool. To this, were added 48.5 parts of xylene and 35 5.4 parts of Cellosolve acetate to obtain an acidic resin varnish C. The characteristics of this varnish are shown in Table 3.

Example 37 (hindered amine type photostabilizer containing amphoteric resin varnish III) To 100 parts of the acidic resin C obtained in Example 36,3.0 parts of Sanol LS-292 and 0.02 part of 40 FASCAT 4201 were added and an ester exchange reaction was carried out at 160'C until the characteristic spot of Sanol LS-292 in TLC had been disappeared. After cooling, athe mixture was added with 49.9 parts of xylene and 5.5 parts of Cellosolve acetate to obtain an amphoteric resin varnish Ill. The characteristics of this varnish are shown in Table 3.

Example 38 (comparative acidic resin varnish D) To a reaction tank, were placed in 50 parts of xylene, 35 parts of methyl methacrylate (MMA), 48 parts of ethyl acrylate (EA), 16 parts of 2-hydroxyethyl methacrylate (HEMA) and 1 part of methacrylic acid (MAA) and the temperature was raised to 1 10'C. While maintaining the same temperature, a solution of 50 parts of xylene, 1 part of azobisisobutyro nitrile and 0.25 part of lauryimercaptane was dropwisely added at a constant speed in 3 hours and the mixture was maintained for 2 hours and the reaction was overed. The characteristics of this obtained acidic resin varnish D are shown in Table 3.

Example 39 (hindered amine type photostabilizer containing amphoteric resin varnish IV) To 200 parts of acidic resin varnish D obtained in Example 38,3.0 parts of Sanol LS-292 and 0.05 part of 55 FASCAT 4201 were added and the mixture was reacted at 140'C until the characteristic spot of Sanol LS-292 in TLC had been disappeared to obtain an amphoteric resin varnish IV. The characteristics of this varnish are shown in Table 3.

GB 2 172 602 A TABLE 3 characteristics of resinous varnishes Exam. varnish NV cont varnish acidity basicity name % viscos m mollg solid m mollg solid 5 33 B 65.2 V 0.18 - 34 1 65.0 V 0.18 0.05 11 65.2 T_U 0.45 0.35 36 C 60.0 U 0.19 - 37 111 60.2 U 0.19 0.11 10 38 D 50.1 Y_Z 0.16 - 39 IV 50.7 Y 0.16 0.11 Gardner viscosity 25'C Example 40

A white colored dispersion paste was prepared by using the amphoteric resin varnish I obtained in Example 34 and following the receipt shown in the following Table D-1:

TABLE D-1 20 titanium white (Note 1) 60 parts amphoteric resin varnish 1 27 So ivesso 100 (Note 2) 15 dispersing agent (Note 3) 0.05 25 102.05 Thereafter, a white primary color coating composition was prepared by mixing the following:

TABLE D-2 white colored dispersion paste 102.05 amphotheric resin varnish 1 42.0 melamine resin (Note 4) 32.0 n-butanol 5.0 triethylamine 0.6 181.65 Note 1-Titanium R5N manufactured by Sakai Kagaku K.K. Note 2..mixed solvent by Esso Standard Petroleum Co. Note 3..Silicon KF-69, 10% solution, manufactured by Shinetsu Silicon K.K. Note 4..Super Beckamine 16-508 manufactured by Dainippon Ink. K.K.

Thus obtained white primary color coating composition was flow-coated on a glass plate and baked, by using a hot air dryer, at 1400C for 30 minutes. TI value of the white colored dispersion paste and 20' gloss of the baked coating were measured and pigment dispersibility was evaluated. The results are shown in Table 4.

so Examples 41 and 42 An orange colored and a red colored dispersion pastes were prepared with the recipts shown in Table E-1 and F-1, and thereafter an orange primary color and a red primary color coating compositions were prepared by mixing the materials shown in Table E-2 and Table F-2, respectively.

TABLE E-1

Novaperm orange HL-70 1 35 parts amphoteric resin varnish 1 27 Solvesso 100 40 60 dispersing agent 0.05 102.05 11 GB 2 172 602 A 11 TABLE E-2 orange dispersion paste 102.05 amphoteric resin varnish 1 42.0 melamine resin 32.0 5 n-butanol 5.0 triethylamine 0.5 181.55 1 benzimidazolone series, by Hoechst TABLE F-1

Cinquacia red Y-RT 759D 1 35 parts 15 amphoteric resin varnish 1 27 Solvesso 100 40 dispersing agent 0.05 102.05 20 TABLE F-2 red colored dispersing paste 102.05 amphoteric resin varnish 1 42.0 25 melamine resin 32.0 n-butanol 5.0 triethylamine 0.5 181.55 30 1 quinacridone series, by DuPont TI values of said orange colored and red colored dispersion pastes and 200 glosses of the baked coatings were evaluated as in Example 40. The test results are shown in Table 4.

Examples 43 to 45 Using the amphoteric resin varnish 11 of Example 35 in place of the amphoteric resin varnish I in Tables D, E and F in Examples 40 to 42, white primary colored, orange primary colored and red primary colored coating compositions were prepared. Pigment dispersibilities were evaluated as in Example 40, and the results were 40 shown in Table 4.

Examples 46 to 48 Using the amphoteric resin varnish III of Example 37 in place of amphoteric resin varnish I in Tables D, E and F in Exam. 40 to 42, but changing the amounts "27" to "29" and "42" to "46", white primary colored, 45 orange primary colored and red primary colored coating compositions were prepared. The pigment dispersibilities were evaluated as in Example 40 and the results were shown in Table 4, Examples 49 to 51 Using the amphoteric resin varnish IV of Example 39 in place of amphoteric resin varnish I in Tables D, E 50 and F in Exam. 40 to 42, but changing the amounts "27" to "35" and "42" to "55", white primary colored, orange primary colored and red primary colored coating compositions were prepared and the pigment dispersibilities were evaluated as in Example 40. The results are shown in Table 4.

Examples 52 to 54 (Comparative Examples) Using the acidic resin varnish B of Example 33 in place of amphoteric resin varnish I in Tables D, E and F of Examples 40 to 42, white primary colored, orange primary colored and red primary colored coating compositions were prepared and the pigment dispersibilities were evaluated as in Example 40 The results are shown in Table 4.

Examples 55 to 57 (Comparative Examples) Using the acidic resin varnish C of Example 36 in place of amphoteric resin varnish I in Tables D, E and F of Examples 40 to 42, but changing the amounts "27" to "29" and "42" to "46", white primary colored, orange primary colored and red primary colored coating compositions were prepared and the pigment dispersibilities were evaluated as in Example 40. The results are shown in Table 4.

12 GB 2 172 602 A Examples 58 to 60 (Comparative Examples) Using the acidic resin varnish D of Example 38 in place of amphoteric resin varnish I in Tables D, E and F of Examples 40 to 42, but changing the amounts "27" to "35" and "42" to "55", white primary colored, orange primary colored and red primary colored coating compositions were prepared and the pigment 5 dispersibilities were evaluated as in Example 40. The resiults are shown in Table 4.

Evaluation of pigment dispersibility TABLE 4(A) (polyester base) 12 Exam 40 41 42 43 44 45 52 53 54 10 varnish I I 1 11 11 11 B B B primary color W 0 R W 0 R W 0 R 20'gloss 82 62 56 86 78 73 72 15 5< TI value 1.4 2.8 3.2 1.2 2.2 2.8 1.8 5.4 7.7 15 viscosity ratio at 6r.p.m. and 60r.p.m. BM type viscometer No. 3 rotor W = white primary color 0 = orange primary color R= red primary color From this Table, it is clearthat the coating compositions based on the present resinous compositions show excellent pigment dispersibil ffies, i. e. large 20'gloss and lowT1 value, as compared with those of Comparative Examples.

TABLE 4 (B) (alkyd base) 25 Examles 46 47 48 55 56 57 varnish III III III C C C primary color W 0 R W 0 R 20gloss 90 84 79 76 30 20 30 T1 value 1.3 2.6 2.9 1.6 4.5 6.5 TABLE 4 (C) (acrylic resin base) Example 49 50 51 58 59 60 35 varnish IV IV IV D D D primary color W 0 R W 0 R gloss 78 66 60 68 10 5< TI value 1.3 3.0 3.8 1.8 6.0 8.5 40 From these Tables, it is clear that the present coating can exhibit far better pigment dispersibilities as compared with those of the Comparative Examples. To demonstrate the excellent weather resistance of the present coating compositions, the following resinous varnishes, primary colored coating compositions and mixed colored coating compositions were prepared.

Example 61 (Comparative amphoteric resin varnish E) 52.7 Parts of isophthalic acid, 11.6 parts of adipic acid, 11.3 parts of trimethylolpropane, 19.7 parts of neopentyl glycol and 20.9 parts of 1,6-hexanediol were reacted as in Example 33 until the resinous acid value of 14.0 and the mixture was allowed to cool. Next, 2.4 parts of dibutyl ethanolamine and 0.05 of FASCAT 4201 were added and ester exchange reaction was carried out at 160'to 1700 C until the characteristic spot of 50 dibutylethanolamine in TLC had been disappeared. After cooling, 49.6 parts of xylene and 5.5 parts of Cellosolve acetate were added to obtain an amphoteric resin varnish E. Non-volatile content 64.8%; Gardner viscosity (25'C) U-V; acidity 0.30 m mol/g solid; basicity 0.21 m mol /g solid Example 62 (hindered amine type photostabilizer containing amphoteric resin varnish V) 53.8 Parts of isophthalic acid, 11.8 parts of adipic acid, 15.2 parts of tri methylol propane, 16.9 parts of neopentyl glycol and 18.0 parts of 1,6-hexanediol were reacted as in Example 33 and allowed to cool atthe stage of resinous acid value of 30.0. Next, 2.4 parts of dibutylethanolamine and 0.05 part of FASCAT 4201 were added and reacted as in Example 61 and then 9.6 parts of Sanol LS- 770 (hindered amine type photostabilizer manufactured byCiba Gelgy) were added and ester exchange reaction was effected at 1600C 60 until the characteristic spot of Sanol LS-770 had been disappeared. After cooling, 54.3 parts of xylene and'6.0 parts of Cellosolve acetate were added to obtain an amphoteric resid varnish V, which showed non-volatile content of 64.9%, varnish viscosity of LI, acidity of 0.66 m mollg solid and basicity of 0.63 m mol/g solid.

13 GB 2 172 602 A 13 Examples 63 to 65 Using each primary colored dispersion pastes obtained in Examples 40 to 42, blue dispersion paste (Fastgen blue 700-3 pigment of Dainippon Ink K. K.), red oxide dispersion paste (Tenyo red oxide of Tone Sangyo K.K.) and yellow dispersion paste (Mapico yellow LL-XLO of Titanium Kogyo K.K.), white colored, orange colored and red colored coating compositions were prepared following the receipts of Tables G, H and 1..

TABLE G (white color) white colored dispersion paste 100 parts blue coloured dispersion paste 0.2 amphoteric resin varnish 1 60 parts melamine resin 40 n-butanol 2 triethylamine 0.2 surface conditioner (Note 1) 0.4 192.8 TABLE H (orange color) 20 orange colored dispersion paste 90 parts yellow colored dispersion paste 6 red colored dispersion paste 3 white colored dispersion paste 1 25 amphoteric resin varnish 1 135 melamine resin 74 n-butanol 6 triethylamine 0.6 surface conditioner 0.6 30 316.2 TABLE I (red color) 35 red colored dispersion paste 62 parts red oxide dispersion paste 35 white colored dispersion paste 2 amphoteric resin varnish 1 115 melamine resin 63 40 n-butanol 5 triethylamine 0.5 surface conditioner 0.5 274.0 45 Note 1... Modaflow 50% solution by Monsanto Chem. In each composition, amphoteric resin varnish I/melamine resin is 7/3 (on solid weight ratio) Each of the abovesaid three coating compositions was diluted with a mixed solvent comprising 10 parts of 50 toluene, 20 parts of Solvesso 100, 50 parts of Solvesso 150 (mixed hydrocarbon solvent manufactured by Esso Standard) and 20 parts of butylacetate to adjust the viscosity to 23 sec./No. 4 Fordcup (20OC) and thus obtained top coat paint was applied by spraying onto the test panel of dull steel plate previously treated with zinc phosphate solution, subjected to cationic electrodeposition and applied with an inter coat, and the coated panel was, after kept standing fora defined period of time, baked at 140'C for 30 minutes. Accelerated 55 weather resistance and outdoor exposure test results are shown in Table 5.

Examples 66 to 68 White colored, orange colored and red colored coating compositions were prepared by using the respective primary colored dispersion pastes based on amphoteric resin varnish II and obtained in Examples 60 43 to 45 and following the receipts of Tables G, H and 1. The accelerated weather resistance and outdoor exposure test results are shown in Table 5.

14 GB 2 172 602 A 14 Examples 69 to 74 White colored, orange colored and red colored coating compositions were prepared by using the respective primary colored dispersion pastes based on the amphoteric resin varnishes III and IV obtained in Examples 46 to 48 and 49 to 51 and following the receipts of Table G, H and I (amphoteric resin varnish/melamine resin=7/3). For the respective panel, accelerated weather resistance and outdoor 5 exposure tests were carried out as in Examples 63 to 65 and the test results were shown in Table 5, Examples 75 to 77 White, orange and red primary colored dispersion pastes were prepared by substituting amphoteric resin 1() varnish V obtained in Example 62 for the amphoteric resin varnish I in Tables D, E and F of Examples 40 to 43. 10 Next, white colored, orange colored and red colored coating compositions were prepared by using the abovesaid dispersion pastes and following the receipts of Tables G, H and I of Examples 63 to 65 and the accelerated weather resistance and outdoor exposure tests were carried out. The test results are shown in Table 5.

Examples 78 to 86 (Comparative Examples) Using primary colored dispersion pastes based on acidic resin varnish B obtained in Examples 52 to 54, the dispersion pastes based on acclic resin varnsih C obtained in Examples 55 to 57 and the dispersion pastes based on acidic resin varnish D obtained in Examples 58 to 60 and following the receipts of Tables D, E and F (melamine resin was used so asto give acidic resin varnish/melamine resin=7/3 on solid basis), white coloredr orange colored and red colored coating compositions were prepared. The accelerated weather resistance and outdoor exposure tests were carried out with these coating panels as in Examples 63 to 65 and the test results were shown in Table 5.

Examples 87to 89 (Comparative Examples) The amphoteric resin varnish I in Tables D, E and F of Examples 40 to 42 was replaced by amphoteric resin varnish E obtained in Example 61 and white, orange and red primary colored dispersion pastes were prepared. Next, using these dispersion pastes and following the receipts of Tables G, H and 1, white colored, orange colored and red colored coating compositions were prepared. The accelerated weather resistance and outdoor exposure tests were carried out as in Examples 63 to 65 and the test results were shown in 30 Table 5.

W1 Example resin varnish paint color 60' gloss before test accelerated weather resistance (QUV)l gloss retention % waxing resistance3 outdoor exposure (Okinawa) 2 gloss retention % waxing resistance Example resin varnish paint color 60' gloss before test accelerated weather resistance (QUV) 1 gloss retention % waxing resistance3 outdoor exposure (Okinawa)2 gloss retention % waxing resistance TABLE 5 (accelerated weather resistance & outdoor exposure test results) 63 64 65 66 67 68 75 76 77 1 1 1 11 11 11 V V V B B B W 0 R W 0 R W 0 R W 0 R 94 91 89 94 90 90 95 93 92 92 82 78 A A 88 85 A 69 70 Ill Ill W 0 94 92 83 A 71 Ill R 91 88 89 E E 0 R 78 79 80 87 E W 94 92 90 86 82 84 92 88 88 93 92 90 68 55 50 64 68 63 0 0 0 0 -X X X X 93 0 81 82 c c W 0 93 85 88 92 0 83 c R 0 72 73 IV IV W 0 94 92 0 74 84 IV E R W 92 R 74 78 78 23 20 15 91 87 85 76 73 66 0-A 0-A X X 0 0 A A 82 79 75 38 21 28 93 90 90 73 70 68 0-A 0-A X X 0 0 A A 52 66 59 55 X X A-X X 86 E 0 G) W N) -j N) 0) J0 N) (n 16 GB 2 172 602 A 16 W=whitecolor O=orangecolor R=redcolor crosslinking agent= melamine resin 1... 500 hours'test 2... 24 months'test 3... waxing resistance Asmall amount of automobile wax (Soft 99 manufactured by Nitoh Kagaku K.K. ) was taken on a white linen cloth and the coating was strongly rubbed with the cloth byforefinger (10 cm distance, 10 times back and forth). Thereafter,the remaining waxwas wiped off with a fresh linen cloth and the coating appearance was observed. Waxing resistance was evaluated from the gloss down and scratches in the coating and coloring of the white linen cloth.

0... no gloss down and scratches and no coloring of the cloth...slight gloss down and scratches and some degree of coloring X... heavy gloss down and many scratches, and marked coloring In Table 5, melamine resin was used as crosslinking agent for the respective compositions. In either case of polyester, alkyd and acrylic base resins, the present coating compositions can exhibit excellent weather 15 resistance as clearly known from the outstanding gloss retention and improved waxing resistance as compared with those of the Comparative Examples.

Examples 90 to 92 Using the respective primary color dispersion pastes based on amphoteric resin varnish I of Examples 40 20 to 42, blue colored dispersion paste, red oxide dispersion paste and yellow colored dispersion paste and following the receipts of Tables J,K and L, white colored, orange colored and red colored coating compositions were prepared.

TABLE J (white color) 25 white colored dispersion paste 100 parts blue colored dispersion paste 0.2 amphoteric resin varnish 1 60 Sumidule N 1 24 30 n-butanol 2 dibuty tin dilaurate 0.02 surface conditioner 0.4 186.8 TABLE K (orange color) orange colored dispersion paste 90 yellow colored dispersion paste 6 40 red colored dispersion paste 3 white colored dispersion paste 1 amphoteric resin varnish 1 135 Sumidule N 46 n-butanol 6 45 dibutyl tin dilaurate 0.06 surface conditioner 0.6 288.2 TABLE L (red color) red colored dispersion paste 62 red oxide dispersion paste 35 white colored dispersion paste 2 55 amphoteric resin varnish 1 115 Sumidule N 38 n-butanol 5 clibutyl tin dilaurate 0.06 surface conditioner 0.5 60 258.0 17 GB 2 172 602 A 17 1... aliphatic polyisocyanate 75% Cellosolve acetate/xylene=1/1 manufactured by Sumitomo Bayer Urethane K.K.

In each compositions, OH equivalent/NCO equivalent being 1/1.

The abovesaid three compositions each was diluted with a mixed solvent comprising 10 parts of toluene, 5 parts of Solvesso 100, 50 parts of Solvesso 150 (mixed hydrocarbon solvent) and 20 parts of butylacetate, to adjustthe viscosityto 23 sec./No. 4 Fordcup (200C) and the resulted composition was applied by spraying onto a test panel of dull steel plate previously treated with zinc phosphate, subjected to cationic electrodeposition and applied with an inter coat. After keep standing for a defined period of time, the panel was baked at 100'C for 20 minutes and the accelerated weather resistance and outdoor exposure tests were 10 carried out with the panel. The results are shown in Table 6.

Examples 93 to 98 Using the respective primary colored dispersion pastes based on amphoteric resin varnish 11 of Examples 43 to 45 and primary colored dispersion pastes based on amphoteric resin varnish V of Examples 75 to 77 and following the receipts of Tables J, K and L, white colored, orange colored and red colored coating compositions were prepared. The same procedures as stated in Examples 90 to 92 were repeated and thus obtained accelerated weather resistance and outdoor exposure test results were shown in Table 6.

Examples 99 to 104 (Comparative Examples) Using the primary colored dispersion pastes based on the acidic resin varnish B of Examples 52 to 54 and on the amphoteric resin varnish E of Examples 87 to 89 and following the receipts of Tables J. K and L (with respect to amphoteric resin varnish C, Sumidule N was compounded so as to give OH equivalent/NCO equivalent = 1/1), white colored, orange colored and red colored coating compositions were prepared. The accelerated weather resistance and outdoor exposure tests were carried out as in Examples 90to 92 and the 25 test results were given in Table 6.

From the test results shown in Table 6, it is clear that the present coating composition can exhibit excellent weather resistance (high gloss retention and improved waxing resistance) as compared with those of the Comparative Examples.

TABLE 6 (accelerated weather resistance & outdoor exposure test results) 98 v R 93 90 0 Example resin varnish paint color 600 gloss before test accelerated weather resistance (QUV)l gloss retention % waxing resistance3 outdoor exposure (Okinawa)2 gloss retention % waxing resistance W = white color 0 = orange color R = red color crosslinking agent = isocyanate compound 1 500 hours'test 224 months'test 91 1 1 W 0 94 92 89 86 0 92 93 1 11 R W 89 95 86 93 0 94 95 11 11 0 R 91 90 89 89 0 0 96 97 v v W 0 95 93 93 92 0 99 100 B W 92 84 101 B B 0 R 84 80 78 70 A A 102 103 E E W 0 94 90 82 80 A 104 E R 88 73 A 85 82 92 88 89 92 92 91 82 76 68 80 73 68 0 0 0 0 0 0 A A A A 19 GB 2 172 602 A 19

Claims (5)

CLAIMS 1. A resinous composition for coating use having improved pigment dispersibility and improved weather resistance, comprising 45 to 95% by weight of amphoteric resin having incorporated therein a hindered amine type photostabilizer and 55 to 5% by weight of amino-formaldehyde resin etherified with a lower morlohydric alcohol, or isocyanate compound, the said amphoteric resin being prepared by the ester-ester exchange reaction between the base resin selected from an acidic resin and amphoteric resin having functional group capable of reacting with a crosslinking agent and ester bonding, and a hindered amine type photostabUizer having ester bonding.

1()

2. A resinous composition as claimed in claim 1, wherein the amphoteric resin having incorporated therein a hindered amine type photostabilizer has an acidity of 2.0 x 10-2 to 3.0 m mol/g solid and a basicity of 1.0 X 10-2 to 1.0 m mol/g solid and the basicity based on said hindered amine type photostabilizer occupies 100 to 2.0 mole % of the said total basicity.

3. A resinous composition as claimed in claim 1 or 2, wherein the hindered amine type photostabilizer is a compound having polyalkylpiperidine group.

4. A resinous composition as claimed in claim 1, wherein the acidic resin is a polyester resin, 10 to 80 mole% of the acid component being saturated alicyclic polycarboxylic acid, 10to 100 mole% of the carboxyl groups capable of developing resinous acid value being derived from the polycarboxylic acid whose titration midpoint potential in non-aqueous potentiometric titration under the state of develQping resinous acid value is more than -350 mV.

5. A resinous composition according to claim 1, substantially as described in any of the foregoing Examples.

Printed in the UK for HMSO, D8818935, 8186, 7102. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.