DD257442A1 - SOLVENT ARMS, AIR AND FORCED DRYING ALKYLD RESIN FUELS - Google Patents

Abstract

Low-solvent, air-dried and forced-drying alkyd resin paints based on special novel air-drying alkyd resins which contain carboxyl-functionalized, oligomeric dicyclopentadiene copolymers condensed as polycarboxylic acid. The application is predominantly as primers, pre-, topcoats and clearcoats in the industrial sector or as a consumer good.

Description

Characteristic of the known technical solutions

Air-drying paints based on alkyd resins, which cure at room temperature by oxidation in the air, are known.

In applying these paints, a considerable amount of solvents must be used to ensure processability (see Comparative Example 1 in Table 4). After applying the paint, the solvent evaporates and thus pollutes the atmosphere. A reduction of the solvent content in the alkyd resin paints would not only lead to a reduced environmental impact, but there are next to an improvement in occupational health and safety of the painters employed also economic benefits by cost savings in valuable chemical raw materials.

It is also known to obtain low-viscosity, high-solids resins and paints with the usual alkyd resin raw materials, but these do not achieve the properties of conventional paints (see Comparative Example 2 in Table 4). From DE-OS 2618629 it is known that modified air-drying alkyd resins with improved drying and hardness properties by reacting polycarboxylic acid, polyhydric alcohols and monocarboxylic acids having at least 7 carbon atoms with a copolymer of dicyclopentadiene or its alkyl derivatives and olefinically unsaturated carboxylic acids or derivatives thereof or can be prepared with olefinically unsaturated alcohols as the acid or alcohol component. The copolymers used in this case have low acid numbers up to a maximum of 200 mg KOH / g and are: condensed together with or partially instead of other mono- and polycarboxylic acids and polyhydric alcohols in the alkyd resin. The paints made from these binders have the disadvantage of requiring even larger amounts of solvent compared to unmodified alkyd resins, especially when aliphatic hydrocarbons are used as solvents (see Comparative Example 3 in Table 4).

Object of the invention

The aim of the invention is to significantly reduce the solvent requirement for adjusting the processing viscosity of air-dried and forced-drying alkyd resin paints without adversely affecting the coating properties of the resulting films.

Explanation of the essence of the invention

The invention is based on the object air-dried and forced-drying alkyd resin paints which at the same time have good application properties, in particular good drying and curing behavior, to be developed on the basis of special novel alkyd resins.

Surprisingly, it has been found that this object can be achieved by using as binder an alkyd resin which contains 10 to 50% by mass, preferably 15 to 40% by mass, of a carboxyl-functionalized, oligomeric dicyclopentadiene copolymer as polycarboxylic acid.

Coatings based on these alkyd resins require substantially less solvent for adjusting the processing viscosity, the properties, in particular the drying and hardening behavior, having good to very good values.

The novel alkyd resins are synthesized by known methods. In addition to the usual raw materials such as oils or their fatty acids, polyalcohols and optionally other monocarboxylic acids, they always contain carboxyl-functionalized, oligomeric dicyclopentadiene copolymers as polycarboxylic acids. In addition, minor amounts of other known polycarboxylic acids can be used.

The copolymers used to prepare the alkyd resins are prepared by thermal polymerization known per se at temperatures> 423K of dicyclopentadiene and its alkyl derivatives or technical dicyclopentadiene fractions with a minimum content of 80Ma .-% dicyclopentadiene including its alkyl derivatives or codimers of cyclopentadiene with other dienes and α, β ethylenically unsaturated dicarboxylic acids or their anhydrides or mixtures thereof with olefinically unsaturated monocarboxylic acids. Particularly suitable are maleic acid, fumaric acid, acrylic and

Methacrylic acid. The molecular weights of these copolymers are generally below 1 000 g / mol, their acid number is in the range of> 200 to 350 mg KOH / g. Their functionality is in the range of about 2 to 5, preferably 2.5 to 4.

These alkyd resins have a fatty acid content of about 40 to 75, preferably 50 to 70 wt .-%, their acid number is less than 20, preferably less than 15 mg KOH / g. At a solids content of at least 80% by mass, they have a viscosity of

maximum 600OmPa · s.

To prepare the paints according to the invention, these alkyd resins can be used alone or else mixtures thereof

become.

The paints according to the invention are prepared by known processes and, in addition to dryers, stabilizers and solvents, optionally also contain pigments, extenders, dyes, leveling agents and the like. a. They can be processed as primers, precursors, topcoats and clearcoats according to the usual application methods. The paints can be dried at room temperature or forced at temperatures up to 353 K.

embodiments

For the preparation of the invention and the comparative paints alkyd resins were used, whose

Composition is shown in Table 1.

Table 2 contains the characteristics of the alkyd resins obtained according to Table 1.

The characteristic of the carboxyl-functionalized, oligomeric dicyclopentadiene copolymers used for the preparation of the alkyd resins of the paints according to the invention is shown in Table 3.

From the alkyd resins 1 to 3 and from the comparative alkyd resins 4 to 6 in Tables 1 and 2, white pigmented paints were prepared and tested in terms of performance. The composition of the paints was in all cases as follows: 100 parts by mass of alkyd resin, calculated as solid resin, 84 parts by mass of titanium dioxide (R), 7.85 parts by mass of dry mixture of cobalt, Pb and octoates and 2 Bulk Parts "Skin Contraceptive (50%).

For application, the paints were adjusted with white spirit to a processing viscosity of 80 ± 2s flow time (4 mm to TGL 14301 sheet 1) and applied by brushing on the appropriate support material (glass and steel sheet) so that after drying a layer thickness of 35 microns has been.

The performance results are summarized in Table 4.

Table 1

raw material

Alkyd resin according to the invention 1 2

Composition in% by mass

Comparative alkyd resin 3 4 (1) 5 (2)

pentaerythritol 10.0 3.4 - 14.2 glycerol - 3.0 - - trimethylolpropane - - 7.9 - 1,3-butanediol - - 5.6 - phthalic anhydride 8.1 - - 24.3 maleic anhydride - - - 1.0 tall oil fatty acid - - - - linseed oil 32.5 67.0 - - soybean oil 32.0 - 46.8 60.5 dicyclopentadiene copolymers 17.4 26.6 39.7 -

10.8

15.6

73.6

(1) long oil commercial soy alkyd

(2) fat linseed oil alkyd for low-solvent paints

(3) according to Example 1 DE-OS 2618629

Table 2

characteristic value Alkyd resin according to the invention 5.9 2 7.0 3 Vergleichsalkydharz 8.3 5 4.0 6 1 4 acid number 85.3 94.2 12.5 60.3 89.5 11.8 mg KOH / g solid 4050 5 050 79.8 1200 826 60.1 % Spirit / xylene Test report / Spirit / viscosity Butanol9: 1 5 630 Butanol9: 1 Butanol9: 1 6820 mPa.s Spirit / Testben- solvent Butanol9: 1 zin / buta nol9: 1

Table 3

characteristics

Alkyd resin according to invention 2

functionality 3.0 3.9 3.1 Molar mass g / mol 475 744 600 Acid number mg KOH / g , 351 294 287 acid component fumaric acid maleic fumaric acid

Table 4

test values

Paint according to the invention

1 2 3

Comparative paint 1 2

Festkorperg eh a It at 82.0 86.3 76.5 60.0 83.0 56.4 Processing viscosity (%) Drying after TGL 14301.3 (h) 2 2.75 1.5 2 5 1.5 Drying grade 1 16 12 10 16 40 9 Drying grade 4 Pendelhärtenach TGL29771 (s) 30.8 39.2 65.0 30.2 21.0 70.0 8 days after degree of dryness 4 Shine after TGL107-06104.1 106 102 115 100 102 115 (%) Erichsentiefung after TGL14302 / 03 9.7 10.0 9.2 9.5 10.4 9.0 (Mm) Cross-hatch characteristic after 1 1 1 1 1 1 TGL14302 / 05

Claims (1)

Low-solvent, air-dried and forced-drying alkyd resin paints based on special alkyd resins and solvents, driers, stabilizers and optionally other components, such as pigments, extenders, dyes and conventional paint auxiliaries, characterized in that the specific alkyd resin 10 to 50 wt .-%, preferably 15 to 40 wt .-%, of a carboxyl-functionalized, oligomeric dicyclopentadiene copolymer as polycarboxylic acid. Field of application of the invention The invention relates to low-solvent, air-dried and forced-drying alkyd resin paints, which have a high solids content at processing viscosity and can be used in industrial coatings and as consumer goods.