DE1494417C - Binder for air and oven drying paints - Google Patents

Description

Around 60 to 70% of all paints currently on the market contain natural binders drying oils or the stand oils made from them. The most effective ingredients in these oils are mainly glycerine esters of linoleic, linoleic, oil-castor and eleostearic acid. About the relatively slow drying and the durability to improve against chemicals, the oils are modified with natural or synthetic resins, e.g. B. with Rosin, dammar and copal, with glyptal, phenol, maleate and coumarone resins, with urethanes and epoxies. In the case of film layers with a thickness of around 200 μ, the risk of shrinkage is already very high large.

In addition to these disadvantages and the saponifiability due to their nature as an ester, the oils have the further disadvantage that their composition can fluctuate very widely. They differ depending on their place of origin, e.g. B. by the content of free acid, of which the compatibility of the paint with basic pigments, such as zinc oxide or red lead, depends, so that sometimes special measures are required to neutralize an excessively high acid content of the oils. By forming Salts of the metals present in the pigment or siccative with the free acids tend to form fog and thus loss of gloss. Furthermore, one can know about the shelf life of such paints make no sure statements.

Efforts have therefore been made to replace the natural oils with artificially produced compounds. It is known, for example, to produce polymers from compounds with conjugated double bonds which are suitable as binders for air-drying and oven-drying paints. Such processes are described, for example, in German patent specification 1133 894 and Belgian patent specification 605 225. In particular, 1,4-trans and 1,2-polymers from 1,3-butadiene and 1,2- from 1,3-isoprene have been obtained. , 3,4- and 1,4-cis- or -trans-polymers produced. The polymers have become of no importance for the production of air-drying paints. They are usually so highly viscous. that the paints produced therefrom have a significantly poorer filling capacity than paints based on natural oils. In addition, the paints made from these binders dry much more slowly in the air than those made with naturally derived oils, e.g. B. linseed oil. Therefore they can be used almost exclusively as cans paints that need to be baked at temperatures above 150 ^0C.

According to the invention, the disadvantages of the type shown are overcome if certain low-viscosity 1,4-cis-polybutadienes are used as paint binders.
It has already been proposed to use mixed catalysts from soluble nickel compounds and aluminum sesquichlorides in a molar ratio of 1: 4 to produce liquid polybutadienes and to use them as coating agents, among other things (German patent specification 1,186,631).

In addition, it has now been found that it is particularly advantageous if 1,4-cis-polybutadienes a viscosity of 30 to 3OOOO cP / 20 ° C in 50 to 100% form, with the exception of the 100% 1,4-cis-polybutadienes produced according to patent 1,186,631, can be used as binders in air- and oven-drying paints.

Preferably, such 1,4-cis-polybutadienes are used which have a viscosity of 00OcP 200-10 / 20 ⁰ C. The binders preferably contain 75 to <100% of 1,4-cis-polybutadienes.

The polybutadienes to be used according to the invention can, in addition to the process of German Patent specification 1 186 631 also after the French patent specification 1 310 146 and the German Auslegeschrift 1 139 647 can be obtained. The paints produced with these polybutadienes surprisingly dry considerably better in the air than, for example, a linseed oil level oil of the same viscosity Paints.

The oxidative cross-linking of the cis-polybutadiene chains takes place so easily that both the dust drying, drying level 1 according to DIN 53 150, and the Thorough drying of the paints according to the invention is much faster than with the same composition Paints with linseed oil as a binder. In contrast to trans products, polyisoprene and linseed oil, the reactivity of the 1,4-cis-polybutadienes is so great that they can be used at elevated temperatures gel like wood oil. Dry films made of low-viscosity 1,4-cis-polybutadiene in a layer thickness of 200 μ in contrast to linseed oil layers of the same thickness without shrinking. Due to the lack of saponifiable Esters are essential to the gloss, chemical resistance, and water resistance of films improved. The pigment compatibility of 1,4-cis-polybutadienes is excellent, since they do not Contain acid or ester groups. There is a risk of thickening of the paints when adding basic ones Pigments do not. As a result, there is no risk of thickening when storing paints, 1,4-cis-polybutadienes, which are low-viscosity as binders contain. Since the polymerization of butadiene to 1,4-cis polymers is very uniform can be guided, can also be used in the opposite

set to the natural oils the composition of the Keep the binder practically constant. The color number! of 1,4-ds-polybutadiene is practically 0. In comparison to a coating of a paint according to de

Invention with a pigment volume concentration of 15% titanium dioxide RN a coating appears Linseed oil base yellowish.

By introducing reactive groups into the 1,4-cis-polybutadiene molecule, e.g. B. in that a Part of the double bonds of the polymer is epoxidized in a manner known per se, can be added to the binder confer beneficial properties, e.g. B. improved adhesive strength and better wettability. It It is generally sufficient to epoxidize about 1 to 50%, preferably 5 to 20%, of the double bonds. the

Epoxy group is very reactive and provides good contact, e.g. B. on metal, wood and paper. It is also possible to use the 1,4-cis-polybutadienes in an to modify in a known manner by adding 1 to 50%, preferably 5 to 20%, of that present in the polybutadiene Double bonds by means of Diels-Alder addition with conjugated dienes, e.g. B. with hexachlorocyclopentadiene. In this case receives depending on the amount of added hexachlorocyclopentadiene in a known manner to a greater or lesser extent self-extinguishing films.

Table 1

composition V IaIlUMIaI Middle Siccative tempera DIN 53150 Shrink Gelatin Rp i- cP / 20C (as naphthenate, door Drying level 1 foresight DCl Mole related to ability in game Polybutadiene 711 Weight Binder, ⁰ C (Hours) no Seconds Polybutadiene 1880 6 500 20th 140 no at ⁰ C 1 Polybutadiene 3991 11000 20th 140 no 430/340 2 Polybutadiene 711 17,000 - 20th 140 after 408/340 3 6 500 - 20th 36 24 hours 380/340 4th Polybutadiene 1880 0.1Co no 430/340 Polybutadiene 3991 11000 20th 24 no 5 Polybutadiene 1880 17,000 0.1Co 20th 24 no 408/340 6th 11000 0.1Co 50 3 380/340 7th Polybutadiene epoxide 413 1.0 lead no 408/340 Polybutadiene epoxide 413 11500 Manganese IV
Q. 1 20th 150 no 8th Polybutadiene epoxide 413 11500 y . χ 20th 36 no - 9 Polybutadiene adduct 3568 11500 0.1 Co 80 0.5 no - 10 - · 0.1 Co 20th 6.5 - 11th 1.5 lead 1.5 manganese 1.3 Co

Note: All films in 200 μ layer thickness on glass.

Together
settlement viscosity
cP / 20 ° C Middle
Mole Table : > Tempe
rature DIN 53150
Dry
step 1 Shrink Gelatin
foresight
ability in
Seconds Ver
equal
example Weight Siccative
(as naphthenate,
related to
Binder, ⁰ C (Hours) at ⁰ C linseed oil 831 - 20th 720 after 36 hours - 1 Wood oil 295 - 20th 60 after 1 hour 682/290 2 linseed oil 831 - - 20th 60 after 48 hours - 3 Wood oil 295 - 0.1Co 20th 12th after 0.5 hours 682/290 4th Polybutadiene 41142 40,000 0.1Co 20th 280 after 36 hours - 5 Polybutadiene 41 142 40,000 -. 20th 90 after 35 hours - 6th linseed oil 831 0.1 Co 50 24 after 12 hours 7th 1.0 lead Manganese i.V. Polybutadiene - 9: 1 20th 140 no - 8th 1.0 lead Manganese i.V. Polyisoprene - - 9: 1 20th 720 no - 9 1.0 lead Manganese i.V. 9: 1

Note: All films in 200 μ layer thickness on glass.

In the examples 1 to 11 compiled in Tables 1 and 2 (Table 1) and the comparative examples The polybutadienes consist of 1 to 9 (Table 2)

1. from 80% 1,4-cis and 20% 1,4-trans polybutadiene (Examples 1, 2, 3, 4, 5, 6 and 7),

2. from an epoxidized 100% 1,4-cis-polybutadiene with 11.7% oxygen, corresponding to an epoxidation of about 50% of the double bonds (Examples 8, 9 and 10),

3. from 22% 1,4-cis- and 78% 1,4-trans-polybutadiene (Comparative Examples 5 and 6) and

4. made of 24% 1,2-polybutadiene, 39% 1,4-cis and 37% 1,4-trans-polybutadiene (Comparative Example 8).

The polyisoprene used for Comparative Example 9 consists of 75% 1,4-cis and 25% 3,4-cis poly isoprene.

The polybutadiene adduct used for Example 11 is a Diels-Alder adduct of hexachlorocyclopentadiene and a 100% 1,4-cis polybutadiene. Its chlorine content is 24.35 ⁰ I ₀ .

All the polymers were prepared by polymerizing the monomers using known processes.

The natural oils used for Comparative Examples 1, 2, 3, 4 and 7 are normal commercial goods.

Comparative Examples 5 and 6 show how much the difference in the case of a predominant proportion of trans-polybutadiene the drying time increases in the polymer. It is noticeable that according to Comparative Example 9 paints with Dry polyisoprene 2V2 times worse than even that predominantly products containing trans-polybutadiene.

Example 12

Binders off
90% according to example 3 and
10% according to examples,

35 siccativates with
0.5% co-naphthenate and
2.0% Pb-naphthenate, calculated on the binder,

pigmented with titanium dioxide rutile, pigment volume concentration: 15%

Thinner: white spirit,

Viscosity in 4 mm Ford cup at 20 ⁰ C: 130S <

announce,, * _{,. ^> JL} . . ·. _v

Viscosity at shear rate D (l / sec) 9445: 4.4Po

Solid content: 91 percent by weight, layer thickness: 200 μ wet,

Dust drying DIN 53150, drying level:

9 hours,

Grip after approx. 24 hours, degree of gloss according to Lange: 95%, Shrinking: no,

Color: pure white.

Comparative example 10

Binding agent linseed oil stand oil 8.3 poises according to comparative example 1,

Desiccation and pigmentation as in Example 12,

Thinner: white spirit, viscosity in 4 mm Ford cup at 2O ⁰ C:

130 seconds,

Viscosity at shear rate D (l / sec) 9445: 5.5Po;

Solid content: 94 percent by weight, layer thickness: 200 μ wet,

Dust drying DIN 53150, drying level I 20 hours,

Grip strength after about 240 hours, degree of gloss according to L a η g e: 80%, haze formation Shrinkage: after 24 hours, color: yellowish.

Claims (3)

Patent claims: 1. Use of 1,4-cis-polybutadienes with a viscosity of 30 to 30,000 ocP ^ O ⁰ C in 50 to 100 ° / ₀ iger form, with the exception of the 100%, according to patent 1 186 631 produced 1,4- cis-polybutadienes, as binders in air- and oven-drying paints. 2. Use of 1,4-cis-polybutadienes with a viscosity of 200 to 10,000 cP / 20 ° C according to claim 1. 3. Use of 1,4-cis-polybutadienes with a viscosity of 30 to 3OOOOcP / 20 ° C in 50 to 100% form in which 1 to 50% of the existing double bonds are epoxidized or by means of Diels-Alder addition implemented with conjugated dienes are used as binders in air- and oven-drying paints.