DE1939792A1 - Stoving enamels based on hot-curing acrylic or alkyd resins with 2,9-dichloroquinacridone as a color pigment - Google Patents

Description

EGG. Du PONT DE NEMOURS AND GOPlPANI, Wilmington ,. Delaware, USA

"concerning : . -

Stoving enamels based on hot-tempered aoryl or AlkyZdharzen with 2,9-Dichlorehinacridon as even bpi gm en to

The invention relates to colored with quinacridones Stoving enamels and relates to automotive finishes, which contain a heat-curing acrylic or alkyd carrier colored with 2,9-dichloroquinacridone is. '

Quinacridone dyes are well known and find "" ~ 1 "" "" ΓΞΖ. widely used for all types of paints. Their use for the coloring of thermosetting Acrylic and alkyd varnishes in the area of bluish red, however, were the result of poor flow properties Paint weights limited .. That's' for this application

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hitherto preferred quincacridone, the 2,9-dimethylquinaoridone, has a very desirable hue; but varnishes colored with it show a very high viscosity, so that you cannot use the paint in the usual way can apply to get a good finish. The dried paint film from one? such unusual viscous paint shows such a low gloss that it is unsuitable for many areas of application. This disadvantage is particularly important in the final painting of motor vehicles.

The compound 2,9-dichloroquinacridone has long been known * in US Pat. No. 5,157,659 of November 17, 1964 four polymorphic forms that are suitable as colorants for paints are shown. However, so far, there is no known indication of using the 2,9-dichloroquinacridone in a hot-curing acrylic or alkyd resin, a motor vehicle finish with good flow properties to manufacture.

The present invention provides an automotive finish comprising a thermosetting acrylic or alkyd resin is colored with 2,9-dichloroquinacridone. Such lacquers with one that is customary for motor vehicle finishes Dye content have good flow properties. One Color layer from this varnish has the excellent resistance and color properties as they are for quinacridone dyes typical are, and can be, in contrast to lacquers of a very similar color to those with other quinacridone dyes can be easily applied with the usual methods and results in final finishes of

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as high quality as is required for motor vehicles. With "thermosetting acrylic or alkyl resin" is meant one in which the polymeric chain is derived from acrylic (CH ₂ = CHR) or alkyd (maleic or phthalic anhydride and polyhydric alcohol) and which is crosslinked in the color layer will*

All 2,9-dichloroquinacridone dyes give with hot-curing acrylic or alkyd base paints of low viscosity. Dyes with a relative large particle size show a slightly lower viscosity than those with smaller particles, but the viscosities are in any case lower than that of / with 2,9-dimethylquinacridone colored paints. The influence on the flow properties does not depend on the type of synthesis Compound or from the comminution of the particles. The raw dye can be synthesized in any known manner and using any of the usual procedures for that. Further Prepared for use, e.g. by salt grinding, salt solvent grinding, grinding with borax, trituration with Acid and similar processes.

The binder of the paint according to the invention can be any be a thermosetting acrylic or alkyd resin, which with a suitable amount of a heat effective crosslinking agent Λ-is mixed. To the suitable acrylic resin monomers include methacrylic acid, hydroxyethyl methacrylate, vinyl isocyanate, acrylamide and others, which together with suitable, in the heat-acting crosslinking agents such as epoxy and polyhydroxy compounds, polyamines and others are used.

* appropriate

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Both phthalic and maleic alkyd resins are used as a resin component together with one of the usual urine-formaldehyde or melamine-formaldehyde crosslinking agents "So are among others the alkyd resins from" - phthalic acid-glycerine, phthalic acid-pentaerythritol-tree resin ester, Maleic acid anhydride glycerine and maleic pentaerythritol tree resin residues as binders in the paint compositions of the present invention g-ee-ignet. Sometimes a catalyst can be used to reduce that Accelerate crosslinking reaction. While applying a resin with a suitable separate crosslinking agent is preferred, systems in which the resin itself can be crosslinked in the heat can also be used or used without a catalyst. If a mixture a resin and a crosslinking agent is used, the most favorable ratio of these substances is different and depends on the particular combination used away. Generally, the resin / crosslinking agent ratio will range from 80/20 to about 60/40.

Any of the previously common for hot-curing acrylic paints used solvent can be used as a solvent component for the carrier. The most common Usable solvents are toluene, xylene, aromatic petroleum fractions and alcohols. Relatively low-boiling hydrocarbon fractions and xylene mixtures v / earth preferred.

The concentration of binder used in the Paint mass can be very different and depends on the The nature of the components and the viscosity required for processing. When used for power

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vehicles is a portion of the binder in the area from about 18 to 25% by weight, based on the total weight of the mass, favorably with the dye making up about 2 to about 6% by weight of the mass.

λ.
The following. Examples are intended to illustrate the "invention. Unless otherwise stated, all" parts "given in the examples mean parts by weight.

example 1

15 parts of a washed, crude 2,9-dichloroquinacridone dye, which has been prepared according to Example 13 of US Pat. No. 2,821,529, are placed in a container of approximately 1 liter containing 1500 parts of 1.2? 1/2 inch steel balls, 150 parts steel pins, 135 parts hydrous aluminum sulfate (Al ₂ (SO ₄ ) ^. 15H ₂ O) and 4.0 parts tetrachlorethylene, 72 hours by rotating at 120 rpm on one The powder is separated from the balls and pins and added to a solution of 79 parts of 96% sulfuric acid in 2000 parts of water The mixture is then filtered off. The filter cake is washed free of acid and sulfate with water, then dried and pulverized. As a comparison, 2,9-dimethylquinacridone is produced and processed in the same way

12 parts of each of these dyes are used in an acrylic support dispersed by placing it in a glass jar of about 0.5 1 content with 30 parts of a solution

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a thermosetting acrylic resin containing 50 % hydroxyl-substituted methyl methacrylate, 144 parts of a solvent composed of 3% xylene and 25 % ' petroleum hydrocarbon solvent'("Solvesso150" from Enjay Chemical Co) and 400 parts of size 3 steel shot, 2 mm (1/8 inch) should be rubbed in. After rubbing for 48/5 hours by rotating the closed vessel at almost 70 % of the critical speed, a further 48.0 parts of the solution of the thermosetting acrylic resin and 35j.0 parts of the xylene-Solvesso solvent mixture are added and the vessel is closed again and another 20 to Shaken for 30 minutes. A further 34.0 parts of the resin solution and 40.0 parts of a melamine-formaldehyde solution "containing 60 % non-volatile components" are then added as crosslinking agents and the material is carefully mixed. The resulting paint, after being separated from the steel shot, has a dye; Binder ratio of -0.15 "and contains 3.5% by weight of dye and 21% by weight of binder, based on the total solids content. The ratio of the resin to the crosslinking agent is 70:30. with the aid of a Brookfield SynchrQ-Lectric viscometer of Brookfield Engineering Laboratories, Sharon, Mass, USA, with a # 2 spindle examples about 29 ⁰ C (84 ° F) _{-durchgeführt,%;..,} were give the consistency in Values for the resistance generated by a rotating spindle in the material to be examined. The numerical values increase with increasing viscosity. The outflow times of the paint from a Ford cup viscometer Ur, 4 are also determined.

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. viscosity .12. Rpm 3 OK RPM 60 rpm Outflow
Time sample 6 rpm 57
6th 66
12th 76
18th (Sec.) 2,9-dimethyl
quinacridone
2,9-dichloro
quinacridone 53
3. 26th
16

An application of the paint on clear plastic

colored shows that with 2,9-dichloroquinacriaon / in shade j-transparency and color intensity is similar to that of 2,9-dimethylquinachridone. A metallic finish that goes through Addition of an aluminum flake dispersion to the lacquer colored with ■ 2,9-dichiorquinacridone in the usual way can be made and has an aluminum: color ratio such as 10:90, giving a bluish-red metallic Color layer with excellent "two-color" effect, the "two-color" effect is known in the art as one Change of color 'known with the change of the angle of view and creates desired highlights on curved Surfaces, such as on fenders and other curved parts of the motor vehicle. The one with 2,9-dichloroquinacridone colored varnish has excellent flow properties, which make it particularly suitable for car finishing.

At s ρ i el 2

Crude 2,9-dichloroquinacridone, which was prepared as described in Example 1, is obtained by recrystallization

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Purified sulfuric acid. Then it is ground, washed, dried and coated in the thermosetting acrylic varnish of the Example 1 in the manner indicated in Example 1 dispersed. The viscosity determinations of the resulting Paints and the corresponding paints, those with 2,9-dimethylquinacridone in equal proportions are colored give the following. Values (measured with a Brookfield Viscometer using a Spindle No. 2):.

Rpm 6 12 30 60

2,9-dimethyl

quinacridone 37.5 4-2.0 49.0 57.5

2,9-dichloro

quinacridone 1.0 2.5 5.0 8.0 -

The advantage in the viscosity of that with 2,9-dichloroquinacridone colored paint, based on the corresponding colored with 2,9-dimethylquinacridone, which has a similar color is clearly visible.

Similar advantages v / ground for that with 2,9-dichloroquinacridone colored system compared to the corresponding colored with 2,9-dimethylquinacridone, if one uses hot-curing alkyd varnishes, which in the usual way by grinding the dyes with a Melamine modified alkyd carrier formed from maleic anhydride and glycerine in a ball mill manufactured vnirden.

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Example 5

Crude S ^ -Dichlorquinacridone prepared as in Example 1 is prepared, is triturated with acid, in which it is added to concentrated sulfuric acid and then, the acid solution with vigorous stirring is poured into water, leaving a dye slurry arises. Me suspension '"is filtered off * and the Dye press cake carefully washed and dried. A coating composition is prepared in that the dye is dispersed in the varnish of Example 1 Paint has favorable flow properties for automotive coatings compared to that on the 2,9-dimethylquinacridone prepared in the same way ent-./ holding mass. - "". "■

PATENT CLAIMS:

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Claims (1)

DR.ING. F.WUESTHOFF S UONCHKM 90 DIPL. ING. G. PULS - 4 QOOIQ ¹ ) 'SCBWEIGEHSTRASS * S DR. ING. D. BEHRENS * «ι.« Ο »4» μΑι »« ... «. PATENT Attorneys' ηοηοτητιη AO 1A-36 608 Claims 1o stoving enamels based on hot-curing acrylic P or alkyd resins as binders, which with a Ciiinacridon- pigment dyed are characterized by _f .. 2,9-dichloroquinacridone as Parbpigment · 2β stoving enamel according to claim 1, characterized in that g e k e η η -. indicates that it contains crosslinking agents for the binder in question ... 3 * stoving enamel according to claim 1 or 2, characterized in that the pigment part is approximately 2 to about 6 wt .- ^ of the paint is · > 4 · Stoving enamel according to claims 1 to 3, characterized in that g e k e η η shows that the proportion of binding agent is 18 to 25 Grew * ~? £ of the varnish is. XX44 009811/0967