RU2213757C2 - Coating powder composite - Google Patents

Abstract

FIELD: paint and varnish materials. SUBSTANCE: coating powder material contains film- -forming agent as a binding agent prepared on the base of diethylene glycol, phthalic anhydride and laproxides taken in the ratio (in equivalents) = (1.0 : 1.0 : 1.0) (1.0 : 1.0 :1.2); titanium dioxide as pigment; silicon dioxide and dolomite as filling agents; mixture of the following components as surface-active substances: sodium polyphosphate as dispersing agent, OP- 7 as emulsifying and wetting agent; polyvinyl alcohol as stabilizing agent; acremos 402 as thickening agent; stearic acid heptyl ester as stabilizing agent. The combination of components taken in the definite ratio allows obtaining and preparing amount of "dry" dye in this moment that shows good hardiness and transportability being without polluting environment. Invention is designated for preparing protective-decorative coatings for nonmetallic backings in building and in homes, for internal painting buildings and constructions on brick, concrete, plastered, wood and other porous surfaces. EFFECT: valuable properties of composite. 1 tbl

Description

 The invention relates to paints and varnishes, in particular to redispersible powder compositions intended for the preparation of protective and decorative coatings on non-metallic substrates, as well as for the internal painting of buildings and structures on brick, concrete, plaster, wood and other porous surfaces.

A known powder composition comprising a thermoplastic polyester and a means for improving filling; as a thermoplastic polyester contains a copolyester of 1,4-butanediol or a mixture thereof with aliphatic C ₂ -C ₆ diols and tere- and / or isophthalic acid or a mixture thereof with C ₆ -C ₁₀ aliphatic dicarboxylic acids having a melting point of 150-200 ^o C, weight. %
[Germany, ed. certificate 605548, class C 09 D 5/00, 1978]:
Copolyester - 95-99.9
Means for improving filling - 0.1-5
However, this composition is not capable of redispersion and is used only in the form of a powder, and coatings can be formed only at high temperatures (180-200 ^o C).

Known for the closest in technical essence and selected for the prototype powder paint containing as a binder polyester resin, with the following components, wt.% [USSR, ed. certificate 734238, class C 09 D 5/03, 1980]:
Saturated Polyester Resin - 60-80
Thermoset Acrylic Copolymer - 0.4-6.0
Hardener - 3-10
Surfactant - 0.2-3.0
Pigments and Fillers - Else
However, this paint has a number of disadvantages:
a sufficiently high temperature (about 200 ^o C) is required to form a coating;
need special expensive equipment for coating;
dusting occurs during coating, which degrades the environment in the workshop and adversely affects the health of workers.

 Also, a paint of this nature does not have the ability to redisperse, which excludes the possibility of its use as a dry mixture in construction.

The objective of the invention is to provide a dry paint capable of redispersible in water immediately before use (i.e., redispersible powder paint), coatings based on which can be formed at low temperatures (<15 ^o C). The term “redispersible” emphasizes the special and important property of a synthetic resin: the ability of a dried dispersion to re-disperse in water.

In this case:
there is no need to transport water (transportation and storage are cheaper);
simple and cheaper packaging - paper bags (packaging recycling is simplified);
storage and transportation are possible even in extremely difficult climatic conditions (for example, in cold weather) without compromising the quality of the paint;
simplicity of paint preparation at the construction site by mixing the dry mixture in water (the possibility of preparing paint in the quantity necessary for work);
no special equipment for application is required - paint is applied to the surface with rollers or a brush;
due to the low temperature of coating formation, such paints are applicable for various construction works, for example, for decorating walls and ceilings on brick, concrete, plaster, wood and other porous surfaces [G. Lutz. Powder polymers for the modification of dry building paints. LKM and their application, 1997, 2, p. 26-27].

The object of the invention is achieved in that the powder coating composition contains a film-forming, pigments, fillers, surfactants, characterized in that it contains a film-forming, obtained on the basis of diethylene glycol, phthalic anhydride and low molecular weight laproxides, taken in the ratio (in equivalents) 1.0: 1.0: 1.0-1.0: 1.0: 1.2; titanium dioxide as a pigment; as fillers - silicon dioxide and dolomite; as surface-active substances - a mixture of components: as a dispersant - sodium polyphosphate, as an emulsifier and wetting agent - OP-7, as a stabilizer - polyvinyl alcohol, as a thickener - acramos 402, as a stabilizer - heptyl ester of stearic acid, in the following ratio of components (wt.%):
The specified film-forming - 15-25
Titanium Dioxide - 14.06-23.44
Silicon Dioxide - 5.63-9.37
Dolomite - 35.94-60.94
Sodium Polyphosphate - 0.38-0.63
OP-7 - 1.5-2.5
Polyvinyl alcohol - 0.19-0.31
Akramos 402 - 1.5-2.5
Stearic acid heptyl ester - 0.19-0.31
Laproxides are low molecular weight oligomers with terminal epoxy groups obtained by the interaction of laprols (polyethers obtained by anionic polymerization of propylene oxide) with epichlorohydrin.

 As laproxides, for example, laproxides of grades 603 and 703 can be used.

The film-forming is synthesized in two stages as follows: in the first stage, diethylene glycol is placed in a four-necked flask equipped with a thermometer, an inert gas supply tube and a reflux condenser and includes a stirrer, an inert gas purge system and heating. Then, in three doses, phthalic anhydride is charged, and each portion of phthalic anhydride is charged after the previous portion has been dissolved. The synthesis is carried out at a temperature of 100 ^o C. the Degree of completion of the reaction is evaluated by the change in acid number. The synthesis of the first stage is stopped when the initial acid number is halved.

In the second stage, laproxide is added to the four-necked flask to the acid obtained in the first stage. Turn on the stirrer, inert gas purge system and raise the temperature to 130 ^o C. The degree of completion of the reaction is controlled by a change in acid number. The synthesis is stopped when the degree of completion of the reaction is close to that calculated according to the Carozers equation. The characteristics of the film-forming are shown in table 1.

 The preparation of "dry" paint is illustrated by the following example.

 Example 1. The resulting solution formed during the synthesis of the oligomer is checked for the content of the basic substance (dry residue) and diluted, if necessary, to a 30% concentration.

The disolver is loaded (in wt.%):
The specified film-forming - 20
Titanium dioxide - 18.75
Silicon Dioxide - 7.5
Dolomite - 48.75
Sodium Polyphosphate - 0.50
OP-7 - 2.0
Polyvinyl alcohol - 0.25
Akramos 402 - 2.0
Stearic acid heptyl ester - 0.25
Dispersion is carried out to achieve a degree of dispersion of 38-40 microns, which is controlled by the wedge method. After dispersion, the solvent is removed from the obtained product and the dry mixture is crushed.

 The resulting powder is the desired form of "dry" paint.

 A ready-to-use paint material is obtained by adding water to the powder in a powder: water ratio of 1: 1-3: 4 (by weight) and thoroughly mixing first for 60 s, and then after a ten-minute break for another 5 minutes.

 The material was applied (with a brush, roller, paint sprayer) on glass, wood, concrete and plaster substrates. After curing, the resulting coatings were evaluated by their appearance, adhesion, and washability.

 Examples 2-6 are similar to example 1. The test results of samples of compositions of various compositions are given in table.2.

 As can be seen from the above examples, coatings obtained on the basis of the proposed compositions have satisfactory adhesion and hardness compared with the compositions obtained by the prototype.

 The powder form of "dry" paint makes it possible to prepare such an amount as is required at the moment. In addition, this paint is very practical due to the fact that in powder form it does not freeze and frost does not affect the quality of the paint at all. When dry, it does not deteriorate and is immediately ready for use after mixing with water. Also, the paint does not pollute the environment, since it does not contain any preservatives or toxic solvents.

 In addition to the positive qualities of the paint listed above, it is necessary to mention its practical packaging (paper bags), as water is added only before use, which is very convenient and beneficial during transportation.

Claims (1)

The powder coating composition contains a film-forming, pigments, fillers, surfactants, characterized in that as a binder it contains a film-forming, obtained on the basis of diethylene glycol, phthalic anhydride and low molecular weight laproxides, taken in the ratio (in equivalents) of 1.0: 1 , 0: 1.0 - 1.0: 1.0: 1.2, titanium dioxide as a pigment, silicon dioxide and dolomite as fillers, a mixture of components as surfactants, polyphosphate as a dispersant sodium as e ulgatora and wetting agent - OP-7, as a stabilizer - polyvinyl alcohol as a thickener - akremos 402, as a stabilizer - heptyl ester of stearic acid with the following ratio of components, wt.%:
The specified film-forming - 15 - 25
Titanium Dioxide - 14.06 - 23.44
Silicon Dioxide - 5.63 - 9.37
Dolomite - 35.94 - 60.94
Sodium Polyphosphate - 0.38 - 0.63
OP-7 - 1.5 - 2.5
Polyvinyl alcohol - 0.19 - 0.31
Akramos 402 - 1.5 - 2.5
Stearic acid heptyl ester - 0.19 - 0.31 and

Images