CS237708B1 - Powder based on acrylic derivatives - Google Patents

Abstract

The invention relates to powder paints based on homopolymers and copolymers of acrylic acid ether compounds, which can be used for the production of dry powder paints and protective coatings in automotive manufacturing, in electrical and lighting technology, in the production of medical devices. The subject of the invention is a powder paint based on acrylic derivatives as a binder and pigment, characterized in that it contains oligourethane methacrylate as a binder with an oligomeric block distance corresponding to the general formula 1. The invention relates to powder paints based on acrylic derivatives as a binder and pigment, characterized in that it contains oligourethane methacrylate with an oligomeric block distance corresponding to the general formula 1. The invention relates to powder paints based on acrylic derivatives as a binder and a polymer CH3 CH„ = C-CO-CH3-CH;,-O-C-N-H-R-H-N-C-O-CH,-CH?-O-C-C 2 II 2 2 II II 2 2 II 0 0 o o where R is - (CH2)6- and the general formula 11 ch2 i (I) -(CHo)x-OC-N-H-CH,-CH,-0-CH,-CH„-H-N-C0-(CH,)(II) 2 6 i 2 2 2 2 ji O Ó with an admixture of triphenyl phosphate, whereby the ratio of the individual components in the mixture is 70 to 80 wt. % oligourethane methacrylate of the general formula I, 12 to 9 wt. % oligourethane methacrylate of the general formula II, 2 to 1 wt. % triphenyl phosphate and 16 to .0 wt. % pigment. The paint according to the invention can be used where it is necessary to increase protection resistance

Description

The subject of the invention is a powder paint based on acrylic derivatives as a binder and pigment, characterized in that it contains oligourethane methacrylate as a binder with an oligomeric block distance corresponding to the general formula 1. These advantages are particularly useful for the surface protection of mechanical equipment operating in the weather, in mechanical engineering, the automotive industry, in electrical engineering and lighting technology, in the production of medical devices and elsewhere.

CH

CH„ = C-CO-CH ₃ -CH;,-OCNHRHNCO-CH,-CH _? -OCC ² II ^{2 2} II II ^{2 2} II

0 oo where R is - (CH ₂ ) ₆ and the general formula 11 ch ₂ i (I)

-(CH _o )x-OC-NH-CH,-CH,-O-CH,-CH„-HN-C0-(CH,)(II) ^{2 6} i ^{2 2 2 2} ji

O Ó with an admixture of triphenyl phosphate, the ratio of the individual components in the mixture being 70 to % by weight of oligourethane methacrylate of general formula I, 12 to 9 % by weight of oligourethane methacrylate of general formula II, up to 1 % by weight of triphenyl phosphate and 16 to .0 % by weight of pigment.

The paint according to the invention can be used where it is necessary to increase the resistance of protective coatings.

The invention relates to powder paints based on homopolymers and copolymers of acrylic acid ether compounds, which can be used for the production of dry paints and protective coatings in automotive manufacturing, electrical and lighting technology, and in the production of medical devices.

A powder composition for coatings is known comprising a product formed by the reaction of acrylic rubber (containing hydroxyl functional groups) with an oxyalkylate diisocyanate and a vinyl monomer (US Pat. No. 3,660,143).

A composition for a coating comprising an acrylic resin and an organic diisocyanate is known (Great Britain Pat. 1,253,572).

Furthermore, a powder mixture for coatings is known which contains an acrylic resin and an organic diisocyanate with one blocked diisocyanate group, used as a stiffening agent (US Pat. 3,659,008).

The disadvantage of these compositions is that, firstly, all these compositions contain toxic components - diisocyanates, and secondly, the coatings obtained on the basis of these systems have unsatisfactory physico-mechanical properties, such as low adhesion, brittleness, etc.

The closest to the proposed one is acrylic powder paint, with a binder based on acrylic copolymers containing carboxyl and glycidyl groups in a ratio of 1:1.7 with pigment content (Kozlov L. V., Drezels S. S., Smechov F. M., Alekaandrova N. A.: Creation of acrylic copolymers - binders for powder paints. Coating materials and their use, 1975, No. 5, pp. 15 to 17; Plyplina A. 1., Smechov F. H., Amfiteatrova T. A. et al.: Development of recipes for acrylic powder paints. Coating materials and their use, 1976, No. 1, pp. 9 to II).

The disadvantage of this paint, chosen as a prototype, is the high curing temperature (180 to 200 °C); coatings based on it are characterized by insufficient adhesion, high internal stress, low strength, and unsatisfactory decorative qualities.

Currently, polyether paints of various colors are produced industrially, used to obtain coatings for various purposes.

Ready-made polyether paints are complex compositions. In addition to the basic binder - polyether, they contain hardeners, pigments, fillers and substances that improve processing - wetting and spreading of the paints.

Curing of coatings based on polymer paints occurs at high temperatures (180 to 200 °C). The coatings have unsatisfactory physical and mechanical parameters - the internal stress in them is 4 MPa, their adhesion to metal is 8 to 9 MPa, the tensile strength is 27 to 30 MPa. When the coating is cured in a thick layer, deterioration of decorative properties is observed - craters and bubbles are formed.

The aim of the present invention is to create a powder paint, ensuring the curing of the coating at a lower temperature (110 °C), having high adhesion and strength, low internal stress, good gloss.

These shortcomings are eliminated by the powder paint according to the invention. The subject of the invention is a powder paint based on acrylate derivatives as a binder and pigment, characterized in that it contains oligourethane methacrylate as a binder, with an oligomeric block length corresponding to the general formula I

CH, CH,

I ³ 1 ³

CH, = C-C0-CH,-CH ₉ -0-CNHRHNC-0-CH,-CH ₉ -0-CC = CH, ² 1 ^{2 2} ! i ^{2 2} i (I) (II) where R j· -(CH ₂ ) ₆ and formulas II

-(ch ₂ ) ₆ -oc-nh-ch ₂ -ch ₂ -o-ch ₂ -ch ₂ -hn-co-(ch ₂ ) ₆ O os admixture*triphenyl phosphate, whereby the ratio of the individual components in the mixture is 70 to 80 wt. % oligourethane methacrylate of the general formula I, 12 to 9 wt. % oligourethane methacrylate of the formula II, 2 to 1 wt. % triphenyl phosphate and 16 to 10 wt. % pigment.

Thermal crosslinking of oligomers results in minimal internal stress and thus significantly increases the resistance of the protective coating to destruction during changes in thermal and atmospheric conditions (machines working in the weather). The absence of plasticizers prevents their migration to the surface, thereby reducing the aging of the coating and ensuring its hygiene for application in medicine.

In the following, the invention is described in detail and illustrated by examples of embodiments, without being limited thereto.

The binder is based on crystalline oligourethane methacrylates with different oligomeric block lengths, obtained by the method of interfacial condensation of the chloroformate component with the amine component in a water-organic solvent environment (Berlin A. A., Verlamova N. V., Kefeli I. <Ja. et al.: USSR Pat. 445 316; Method for the production of compounds with urethane groups). Their selection as a binder is conditioned by the fact that oligourethane methacrylates are oligomers capable of polymerization, the thermal curing of which, unlike oligoetheracrylates of other types, is not inhibited by oxygen in the air and proceeds without the introduction of the initiation system directly on the substrate and ends with the formation of a crosslinked polymer.

Oligurethane methacrylates are white crystalline substances with a melting point of 70 to 75 °C.

These compounds are highly structurally regular, contain terminal groups and regularly alternating polar urethane groups that participate in intermolecular and adhesive bonds. The presence of oligomers in the composition, differing in the length of the oligomeric block, determines the obtaining of coatings that have high parameters of physical-mechanical and utility characteristics.

The addition of triphenyl phosphate ensures uniform spreading of the melt on the surface of the substrate.

The application of the present powder paint can be carried out by methods known for powder compositions.

Examples of powder paint compositions according to the invention are given below.

Example 1

The compositions are prepared by mixing oligomers of general formula I, formula II, triphenyl phosphate and pigment. The mixture of dry components is thoroughly mixed in a ball mill for 30 minutes. In this way, a white paint was prepared.

Composition of white paint in weight percent:

1. oligourethane methacrylate of formula I

2. olgourethanmethacrylate of formula 11

3. triphenyl phosphate

4. titanium dioxide

5. barite

6. ultramarine »

% % 5 %

10.95 # 0.05 »

The prepared powder paint is applied by pneumatic spraying to the degreased metal substrates to be protected and cured in an oven at 110 °C for 20 minutes.

Example 2

A light blue dye was prepared using the same procedure as in Appendix I.

Composition of light blue paint in weight percent:

1· oligourethane methacrylate of formula 1 75 % 2. oligourethane methacrylate of formula 11 10 % 3. triphenyl phosphate 1.5 % 4. titanium dioxide 3 % 5. barite 5.5 % 6. ultramarine 5.0 % Example 3 gray color, composition in weight percent: 1. oligourethane methacrylate of formula X 77 % 2. oligourethane methacrylate of formula XX 10 % 3. triphenyl phosphate 1.2% 4. titanium dioxide 2.6% 5· barite 8.0 % 6. diesel soot 0.2 % Example 4 Red paint, composition in weight percent: 1. oligourethane methacrylate of formula I 80 % 2. oligourethane methacrylate of formula 11 9 % 3. triphenyl phosphate 1 % 4. titanium dioxide 2 % 5. barite 5 % 6. yellow lead molybdenum 3 %

The properties of the coatings obtained based on the above mixture examples are summarized in Table 1. Coating thickness 100 µm.

As is evident from the data given in Table I, coatings based on the presented powder paints are characterized by high physical and mechanical parameters. Compared to the prototype, they have high adhesion, strength (3 times), lower internal stresses (1.5 to 2 times), better impact strength and gloss.

Features Prototype Proposed mixtures 1 2 3 4 internal stress, UPa 4.0 1.5 1.7 ’,8 2.0 strength, MPa 24 70 72 74 76 adhesion 8 20 21 20 22 hardness on a pendulum 0.8 0.87 0.90 0.93 0.97 impact strength 2 4 4.5 4.7 5 gloss 64 74 73 72 75

The advantage of the paint according to the invention in comparison with the polyether paints available to date is in the simplification of the powder composition by eliminating hardeners and some auxiliary substances, in the reduction of the curing temperature of the coatings by using molecularly homogeneous polymerizable oligomers of low molecular weight, and in the high physical-mechanical and decorative properties of the obtained coatings.

Claims (1)

BACKGROUND AND INVENTION Powder paint based on acrylic derivatives as binder and pigment, characterized in that it contains oligourethane methacrylate with an oligomeric block length corresponding to the general formula 1 as binder CH CU ch ₂ = -CO-CH ₂ -CH ₂ -OCNHHHNC · 0-CH _"about -CH -0-CC ^{2 2} CH (I) wherein R is - (CH ₂ ) ₆ and of Formula II - (ch ₂ ) ₆ -oc-nh-ch ₂ -ch ₂ -o-ch ₂ -ch ₂ -hn-co- (ch ₂ ) ₆ (II) % With the addition of triphenyl phosphate, the ratio of the individual components in the mixture being 70 to 80 wt. % of oligourethane methacrylate of formula I, 12 to 9 wt. % of oligourethane methacrylate of formula II, 2 to 1 wt. % of triphenylphosphate and 16 to 10 wt. pigment.