RU2451051C2 - Method of producing siccative for paint material - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: siccative is obtained by fusing 2-ethylhexanoic acid with a mixture of lead oxide (yellow lead) and cobalt hydroxide. Fusion is carried out while feeding said components simultaneously at temperature 110-120°C and molar ratio of cobalt hydroxide, lead oxide and 2-ethylhexanoic acid of 1.0:2.8-10.4:7.4-17.8, respectively. Further, a solvent white alcohol and/or nefras C4 and/or jet engine fuel TS-1 or mixture thereof is then added in amount of 50-58 wt %.

EFFECT: ensuring drying of paint materials based on alkyde, uralkyde and oily film-forming materials.

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Description

The invention relates to the production of paints and varnishes, in particular to methods for producing fused desiccants for paints and varnishes based on alkyd, uralkyd and oil film-forming: oil paints, alkyd varnishes, enamels. As desiccants providing drying of paints and varnishes, salts of transition metals of monocarboxylic acids are used.

A number of methods are known for producing a desiccant by precipitation: saponification of the fatty acid component with an aqueous solution of sodium hydroxide and the subsequent interaction of the resulting water-soluble salt with aqueous solutions of desiccating metals in the presence of an organic solvent (for example, Russian patents Nos. 2182916, 2131446, 2261882, 2266939, Ml. C09F 9 / 00). A common disadvantage of obtaining desiccants by the precipitation method is the presence of a large amount of wastewater, the multi-stage and labor-intensive process, and the loss of solvent during drying.

A known method of producing desiccant by melting at a temperature of 240-260 ° C pre-dehydrated sunflower oil with a mixture of pyrolusite, cobalt oxide and titanium dioxide (Authors. St. USSR 632713, Ml. C09F 9/00, publ. 1977). The disadvantage of this method is the high temperature of the process, as a result of which there is a burning of organic products. The desiccant obtained by this method is characterized by a low metal content and high color, which excludes its use for light and white paints and varnishes.

The closest to the claimed method is a method for producing desiccant by fusion of lead lead and pyrolusite with a fatty acid component, which is used as a high boiling fraction of α-branching of monocarboxylic acids having an acid number of 119-175 mg KOH / g, the process is carried out at 170-200 ° C (Aut St. USSR No. 1261275, Ml. C09F 9/00, publ. 1984).

A significant disadvantage of this process is a high chromaticity of the obtained product (600 mg J _2/100 g in a mixture of linseed oil), which leads to the impossibility of its use in paints light and white tones, and low concentration of metals in the desiccant solution. Deficiency and inconstancy of the composition of monocarboxylic acids, which are production wastes, does not allow to obtain desiccants stable in composition and properties. In addition, the high temperature of the process requires large energy costs in the production of desiccants.

The prototype of the claimed method is a method for producing a light drier by the interaction of zinc oxide or lead with 2-ethylhexanoic acid with two-stage heating to 105 ° C in the first and up to 120 ° C in the second stage in the presence of a reaction accelerator, which is used as an unsaturated low molecular weight co-oligomer, and the subsequent dilution in an organic solvent, which is used as a mixture of white spirit with 25-75% of the mass. distillation of unreacted hydrocarbon polymerization of liquid pyrolysis products. Synthesis of desiccant is carried out at a molar ratio of starting reagents: zinc or lead oxide: 2-ethylhexanoic acid = 1.0: 1.7-2.5 (Russian patent No. 228/308 C2 (D1), MK. C09F 9/00).

A significant disadvantage of this method is its applicability to obtain a single metal desiccant, i.e. desiccant containing one metal (zinc or lead). In the paint and varnish industry, as a rule, mixed desiccants are used, which provide the necessary degree of drying of the paint coatings, for the manufacture of which first several single-metal desiccants are required, and then the mixing of one-metal desiccants in the required proportion. As a result, it becomes necessary to install additional equipment and attract staff. The processability of preparing mixed driers becomes more complicated, and energy costs and production costs increase. In addition, the known method is a two-stage, more complex, the introduction of a reaction accelerator is required. The resulting desiccant has a high viscosity (up to 196-200 ° C), which makes it difficult to use it at low temperatures, especially in winter.

The challenge facing the creators of the invention is the expansion of technological capabilities (i.e. the scope of the desiccant), the possibility of its use for both dark and light (including white) paints, reducing energy costs for the process due to single-stage heating, increasing stability and catalytic activity of the desiccant.

The problem is solved by using 2-ethylhexanoic acid with an acid number of 365-390 mg KOH / g as a fatty acid component, and lead oxide and cobalt hydroxide at the same time as metal-containing compounds. The proposed combination of components and the production method make it possible to carry out the melt process at the same time, in one stage, in contrast to the prototype, and the introduction of two metals at the same time allows to obtain a desiccant with desired properties, which, as shown by tests, provides high durability and stability of the desiccant during drying only oil and alkyd, but also a new class of uralkyd paints and varnishes. This reduces the energy consumption for the process.

The presence of 2-ethylhexanoic acid cobalt salt in the desiccant results in the blue color of the desiccant, which improves the color and, accordingly, the quality of light and especially white paints and varnishes.

The essence of the invention is that in the method of producing desiccant for paints and varnishes by alloying metal oxides or dioxides with a fatty acid component, 2-ethylhexanoic acid with an acid number of 365-390 mg KOH / g is used as a fatty acid component, and a combination of oxide is used as metal-containing compounds lead (lead lead) and cobalt hydroxide (a combination exhibiting a synergistic effect). Moreover, the fusion of all these components is carried out simultaneously (in one stage) and at a lower temperature compared to the prototype.

The method is as follows.

In a reactor equipped with a stirrer and reflux condenser, 2-ethylhexanoic acid is charged; with constant stirring, lead oxide (lead litharge) and cobalt hydroxide are charged in a ratio of 2.5: 1 to 10.5: 1, respectively, see Table 1 ); and gradually increase the temperature to 115 ° C. The reaction mass is maintained at this temperature until the components are completely dissolved (control is carried out visually, according to the transparency of the sample on a glass plate). The optimal range of heating temperatures was determined empirically (see table 2). Carrying out the process at a temperature below 110 ° C slows down the reaction, reduces the metal content and does not allow to obtain a desiccant with high activity; and at temperatures above 120 ° C, energy costs increase without improving the quality of the desiccant.

The obtained concentrated lead-cobalt desiccant is analyzed for metal content, cooled, diluted with organic solvents (for example, white spirit (GOST 3134-78), S-4 nefras (TU 0251-003-78158825-2008) or TS- jet fuel 1 (GOST 10227-86) in an amount of 50-85 wt.% To obtain a desiccant marketable form, 2-ethylhexanoic acid (TU 2431-0353505711-01) is used as the fatty acid component, and lead lithium is used as lead oxide (GOST 5539- 73), as a cobalt-containing component - cobalt hydroxide II (TU 2611-001-4 69133-78-2002) in a ratio of 7.4: 2.8: 1.0 to 17.8: 10.4: 1.0, respectively.

The activity of the obtained desiccant was checked by the drying time of paint coatings to degree 3 at 20 ° C according to the procedure described in GOST 19007-73, on a standard varnish PF-060 (TU 2311-007-98438521-2008), the film hardness - according to GOST 5233- 89 (table 3).

The composition and properties of the samples obtained by the proposed method, in comparison with the properties obtained by the method described in the prototype, are presented in tables 1, 2, 3. The results shown in tables 1, 2, 3, allow us to conclude that the goal .

The technical result from the application of the proposed method is that the desiccants obtained by the proposed method have low color, which allows them to be combined not only with dark, but also with light (even white) paint and varnish materials, and thus expand the technological capabilities of desiccants . The combination of alloyable components (lead oxide and cobalt hydroxide) allows the process of fusion of these components with 2-ethylhexanoic acid at the same time, and at lower temperatures, which saves energy costs for the production of desiccant. Moreover, practice revealed a decrease in drying time and an increase in the hardness of the coating (Table 3), which indicates the high efficiency of the obtained driers.

Thus, the problem to which the invention is directed is solved.

Desiccants obtained by the proposed method were manufactured and tested in the manufacture of coatings in the laboratory of PKF Laurit LLC, as evidenced by testing of lead-cobalt desiccant.

Table 1 A method of producing a desiccant for coatings Components, method parameters The content of components in the compositions,% mass. Prototype No. 1 (known desiccant), sample No. 4 Proposed one 2 3 column mass% 2-ethylhexanoic acid 11.7 18.10 28,20 178.3 46.40 Lead oxide 4.45 10.00 16.49 100.0 26.02 Cobalt hydroxide 1,58 1,58 1,58 - - Solvent 82.27 70.32 53.73 106.0 27.58 Total 100.00 100.00 100.00 384.3 100.00 Fusion temperature, ° C 110-115 115-120 115-120 120

table 2 Process temperature ° C Example No. 2 Successor
reaction rate, h The metal content in the drier,% mass. Color desiccant mg J _2/100 g Activity in varnish PF-060, drying to degree 3, h lead cobalt 90 5 8.5 0.8 330 22 one hundred four 8.7 0.9 340 eighteen 110 3 9.0 1,0 350 fifteen 120 3 9.0 1,0 350 fifteen 130 3 9.0 1,0 370 fifteen

Claims (1)

A method of producing a desiccant for paints and varnishes by reacting 2-ethylhexanoic acid with a mixture of lead oxide and cobalt hydroxide while simultaneously loading and a molar ratio of cobalt hydroxide, lead oxide, 2-ethylhexanoic acid 1.0: 2.8-10.4: 7 , 4-17.8, respectively, and their simultaneous fusion at a temperature of 110-120 ° C followed by the introduction of a solvent: white spirit, and / or nephras C4, and / or fuel for jet engines TS-1, or a mixture thereof in an amount 50-85 wt.%.