CS259462B1 - Air-drying coating composition - Google Patents

Abstract

The solution relates to the field of paints and solves the technical problem of paints with a reduced content of siccativating ingredients. The essence of the solution is rhodanocobaltic diccativity more complex than the known types of cobalt siccatives. The solution can be used in production and use paints and inks.

Description

The present invention relates to an air-drying coating composition comprising dessicants.

Air-drying coatings are still widely used in many industries and households, especially in protecting various materials from the corrosive effects of external atmospheric agents. Most commonly used are paints based on polymerized or isomerized drying oils, alkyd resins, epoxy ester resins and the like.

The quality of the coating film is determined not only by the type and composition of the coating itself, but also by the speed and perfection of the drying of the applied film, which in turn affects the amount and type of the desiccant. The most serious component of the desiccant are the salts of bivalent monobasic cobalt, most commonly the cobalt salts of organic acids (octoates, naphthenates, resinates, etc.). In recent years, the availability of cobalt on the world market has been getting worse and its prices have reached considerable heights.

Given the continued depletion of cobalt ore deposits, no significant improvement can be expected in the future. For this reason, as well as for health and environmental concerns, replacement of cobalt desiccant agents is being sought intensively, but the results achieved are not yet very encouraging. So far, no significant success has been achieved in attempts to tackle cobalt desiccant agents.

Based on extensive experimental work, we have now found air-drying coatings based on resin, oil-resins or oil polycondensates, containing, optionally, fillers, pigments, solvents and other substances, sicified by the rhodanocobalt complex or its solutions.

where:

Q / R ^{1 (} COO / ₂ CoSCN) m] nZ r! Yippee. an aliphatic or cycloaliphatic radical of up to 35 carbons is an aliphatic radical of 1 to 4 carbons

Z is R OCí ^CHjOH and / or butanol or isobutanol

M is Na, K or NH 2 n-2, in an amount corresponding to 0.001 to 0.1 µ cobalt in the dry matter of the paint or of a mixture of this complex with Pb, Ca, Zn or Mn octoates, naphthenates or resinates in an amount corresponding to 0.001 to 0 , 5% metal in the dry matter of the paint.

Compared to the prior art, the coating compositions of the present invention can produce coating films of comparable quality, at a comparable film drying and drying rate, even at half the amount of cobalt in the dry matter of the coating composition. In some cases, very good coating film performance has been achieved even with only a third of the commonly used amount of cobalt dessicants. By reducing the cobalt content of the coating composition according to the invention, not only is the saving of the raw material deficient, but also the aging of the dried film films is improved.

The rhodanocobalt complex is used in the coating compositions of the invention in the form of solutions in a mixture of aliphatic and aromatic or cyclanic solvents. (White spirit, aromatol, etc.) and butanol, isobutanol, diacetone alcohol, toluene, xylene, ketones and the like. The ratio of these components in the solution must be solved to avoid premature precipitation of the binder paint with the siccativating component of the rhodanocobalt complex, which must not be separated from the drying material during the gradual evaporation of the individual solvent components.

Therefore, each coating composition according to the invention has a different solvent composition necessary for optimum drying.

Paints are usually supplemented with substances preventing or retarding the formation of crusts (ketoximes), substances improving the surface properties of materials (silicone oils, fluorinated oils, etc.) and other properties with fillers, pigments and the like. Some types of paints can also be used as transparent, especially when protecting the wood surface.

Example 1

By mixing a 5% cobalt octoate solution in white spirit, a mixture of n-butanol and ethylene glycol monoethyl ether and potassium rhodanide in a Co-octoate: KSCN = lsl molar ratio, a desiccant solution is prepared containing 1% cobalt in the dry matter.

Alkyd resin PL 65 (60% white spirit) prepared by polycondensation of linseed oil, phthalic anhydride and pentaerythrite is mixed with 0.1% methylethylketoxime and 1% lead octoate solution in white spirit and the corresponding rhodanocobalt complex solution in an amount corresponding to the content of the respective of metal in the dry matter according to the table.

Table

Drying time

Drying speed (pendulum,%)

26 ° C (days) 0.03% Co ^and 0.02% Co ³ 0.01% Co ^a 0.03% Co 0.3% Pb 0.3% Pb 0.2% Pb 0.1% Pb standard 1 7.9 5.9 4.9 5.6 3 9.5 8.5 6.3 7.9 10 24.4 13.4 10.8 13.6 3h / 105 ° C 51.6 48.4 30.4 48.7

b a - rhodanocobaltate complex, b - Co-octoate

The results show that rhodanocobalt complex sicatisation is substantially more effective with the same metal content in the dry matter than the existing sicativation and a good sieving result can be achieved even with a reduced cobalt content in the form of rhodanocobalt complex.

Example 2

By mixing a 5% solution of cobalt naphthenate in white spirit or aromatol BTA 50, ethylene glycol monobutyl ether and sodium rhodanide in a Co-naphthenate: NaSCN = 1: 1 molar ratio, a desiccant solution containing 2% cobalt in dry matter is prepared.

Epoxiester 1/16 RS 40-50X is prepared by esterifying Epoxy 1/16 with a mixture of soybean oil and DEDICO acids. The 50% xylene solution of this epoxiester is siccated with different amounts of rhodanocobalt complex and cobalt naphthenate in a standard manner.

The coatings are applied to the glass with a 0.12 mm slot ruler and the drying speed is monitored according to ČSN 67 3053. The results are shown in the table.

Table

Drying speed (h) pendulum film hardness (%)

Sikativace AND ^B 1 ^B 5 1 day 10 days 3h, 100 ° C stand. naphthenate Co diccative (0.028% Co) 1 5 25 8.9 22.8 48.9 siccative according to the invention (0.014% Co) 1 5 25 14.2 35.5 52.2 siccative according to the invention (0.007% Co) 1.5 5 30 7.9 24.7 50.6 The results show that at reduce the dry matter to a third The amount of hitherto used (in the form of Co-naphthenate) can be used to desiccate the rhodanocobalt complex. cobalt

Example 3

The air-drying primer is prepared by mixing and homogenizing the following substances:

parts by weight of coalkyd resin RS 55 / S25 parts by weight of ferric red parts by weight of barium sulfate

12.6 parts by weight of white spirit 0.6 parts by weight of the desiccating complex of Example 1, containing 1% Co 1.2 parts by weight of lead octoate containing 10% Pb in dry matter 0.6 parts by weight of manganese octoate containing 2% Mn v dry matter

Stage A dries the coat after 2.5 hours, stage stad _χ is reached in 7 hours and stage Bg in 27 hours.

After 1 day the film hardness (pendulum,%) reached 5.9 after 10 days 29.0 and after 3 hours at 105 ° C the hardness was 54.1.

Claims (1)

OBJECT OF THE INVENTION Air-drying paint based on oily, oil-resins or resinous polycondensates or fillers, pigments and solvents, characterized by being dicatified by a rhodanocobalt complex Q / R ¹ COO / ₂ CoSCN) n Z wherein R ¹ is an aliphatic or cycloaliphatic radical having the number of carbons in the molecule 6-35, R ² is an aliphatic radical of carbon number 1 to 4, Z is R ² OCH ₂ CH ₂ OH and / or or butanol or isobutanol, M is Na, K or NH ₄ , n ^ 2, in an amount corresponding to 0.001 to 0.1% cobalt in the dry matter of the paint or mixtures of this complex with Pb, Ca, Zn or Mn octoates, naphthenates or resinates in an amount corresponding to 0.001 to 0.5% metal in the dry matter of the paint. Sevarography, n. P., MOST