CS230800B1 - Water-dilutable alkyd dispersion binder - Google Patents

Abstract

The invention relates to a water-dilutable dispersion binder based on alkyd resins, which is useful primarily for the production of paints. The essence of the invention lies in the fact that the binder consists of 300 and 600 parts by weight of salts prepared from nitrogen bases and alkyd resins modified with mono- * carboxylic acids with 6 to 24 carbon atoms, 300 to 700 parts by weight of water, 2 to 35 parts by weight of surfactants, 1 to 15 parts by weight of a mixture of surfactants consisting of 2 to 78% by weight of fluorine-containing surfactants, 8 to 81% by weight of phosphorus-containing surfactants and 10 to 70% by weight of polyacrylic surfactants, and optionally up to 200% by weight of parts of additives from the group of organic solvents, spreading agents, defoamers, additional surfactants, nitrogen bases and viscosity regulators.

Description

The invention relates to a stable water-dilutable alkyd dispersion binder, which is particularly suitable for the preparation of dispersion coatings.

Water-based binders have recently become increasingly important because they significantly solve current problems with paints. First of all, they replace scarce and expensive organic solvents, thereby also eliminating air pollution during the production and especially during the processing of paints. At the same time, they significantly reduce the risk of fire and explosion.

In addition to the well-known and widely used water-based binders based on polymer dispersions, such as vinyl acetate, acrylate, styrene acrylate and styrene butadiene, alkyd dispersion binders are also used to a limited extent (J. Šňupárek ml·, L. Formánek: Water Dispersions of Synthetic Polymers, SNTL, Prague 1979). The first alkyd dispersions were produced by dispersing common alkyd resins in an aqueous ammonia solution of casein (German Pat. No. 551 681 and 552 624, French Pat. No. 1 188 139). The dispersions obtained were not very stable and provided coatings that were very sensitive to moisture and to the effects of mold. Improvements were achieved by using other protective colloids, such as cellulose ethers and polyvinyl alcohol (NDR Pat. No. 23,007, US Pat. Nos. 2,272,057 and 2,308,474), and especially by adding nonionic emulsifiers, namely ethylhexoxidized nonylphenol (European Pat. No. 2,253, French Pat. No. 1,478,892, German Pat. No. 2,754,141, US Pat. No. 3,440,193). However, the protective colloids and emulsifiers mentioned were used in

230,800 in high concentrations, thus adversely affecting the resistance of coatings to water, atmospheric influences and sometimes even the drying speed.

The above-mentioned shortcomings are eliminated by the present invention, the subject of which is a water-dilutable alkyd dispersion binder based on oil alkyds, drying agents, surfactants and optionally MS-type additives. The essence of the invention lies in the fact that the dispersion binder consists of 300 to 600 parts by weight of salts prepared from nitrogen-based and alkyd resins modified with monocarboxylic acids with 6 to 24 carbon atoms, 300 to 700 parts by weight of water, 2 to 35 parts by weight of drying agents, in particular octoates and naphthenates of cobalt, lead, manganese, zinc, zirconium, calcium and barium, and 1 to 15 parts by weight of a mixture of surfactants consisting of 2 to 78% by weight of fluorine-containing surfactants, 8 to 82% by weight of phosphorus-containing surfactants and 10 to 70% by weight of polyacrylic surfactants. The dispersion binder optionally further contains up to 200 parts by weight of additives from the group comprising organic solvents, spreading agents, defoamers, additional surfactants, nitrogen bases and viscosity regulators.

The water-soluble alkyd dispersion binder has some advantages compared to known alkyd dispersion binders. For example, it is stable for a long time at normal storage temperatures, for at least one year. If the dispersion system stratifies, this is not a phase separation, but only a sedimentation distribution according to the particle size of the dispersion that is reversible by stirring. The excellent stability of the alkyd dispersion binder is mainly due to the special composition of the surfactant mixtures used, which exhibit strong synergistic dispersion effects. Therefore, they can be added in very small amounts, which favorably affects the final properties of the alkyd dispersion binder and the films formed from it. It is also advantageous that special types of alkyds are not required to prepare the dispersion binder, but can be based on common types of alkyd resins that are otherwise applicable in solvents.

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The basic film-forming component of the water-dilutable alkyd dispersion binder according to this invention are alkyd resins. They are known condensation products of polyalcohols (glycerol, pentaerythritol, trimethylolethane, trimethylolpropane) with polycarboxylic acids or their anhydrides (phthalic anhydride, tetrahydrophthalic anhydride, isophthalic and adipic acid, maleic anhydride, trimellitic anhydride). They are modified with natural drying oils (wood, linseed, oiticica, perillic, castor, fish, safflower), semi-drying (soybean, tallow, sunflower, cotton) and non-drying (coconut, olive, castor, peanut) or their fatty acids, fractionated fatty acids or even synthetic fatty acids. These modifying components are aliphatic monocarboxylic _acids containing 6 to 24 carbon atoms. The oil length of the alkyds used ranges from 40 to 70% by weight. From the point of view of the stability of alkyd dispersions, it is advantageous to also add aromatic monocarboxylic acids, especially benzoic acid and its derivatives (toluic, p-tert-butylbenzoic, salicylic).

The alkyd resins mentioned above with an acid number of 5 to 25 mg KOH/g are neutralized with volatile inorganic and/or organic nitrogenous bases. Ammonia and primary, secondary and tertiary monoamines or polyamines, e.g. ethylamine, diethylamine, triethylamine, tripropylamine, monoethanolamine, diethanolamine, triethanolamine and N-dimethylethanolamine, are most commonly used. Nitrogenous bases are usually added in an amount of 0.1 to 3% by weight, thereby forming partially water-dispersible ammonium or amine salts of alkyds.

According to the invention, a surfactant mixture is added to the dispersion of the alkyd salts in an amount of 1 to 15 parts by weight, which corresponds to 300 to 600 parts by weight of alkyd salts. The surfactant mixture consists primarily of 2 to 78% by weight of fluorine-containing surfactants.

These are derivatives of fluorocarbons, mainly salts of fluorinated alkylcarboxylic and alkylsulfonic acids, as well as

230 800 fluorinated alkyl alkanols and alkyl alkyl amines, optionally ethylene oxidized. Depending on the surface-active groups present, anionic, cationic or nonionic types are used. Very effective anionic surfactants are water-soluble alkaline salts, e.g. potassium salts of heptadecafluoro-1-octanesulfonic acid or N-ethyl-1- {\heptadecafluorooctyl)sulfonyl lj aminoacetic acid.

The second component of the surfactant mixture consists of 8 to 82% by weight of surfactants containing phosphorus. The main importance is given to water-soluble salts of monoesters and diesters of phosphoric acid and monohydric aliphatic alcohols with 11 to 18 carbon atoms (lauryl alcohol, cetyl alcohol, stearyl alcohol). These alcohols can also be alkoxylated (ethoxylated) to varying degrees and can contain 1 to 12 ethoxyl groups. The same inorganic and/or organic nitrogen bases mentioned in the formation of alkyd resin salts or alkali metal hydroxides are used to neutralize alkyl phosphates.

The third component of the surfactant mixture is 10 to 70 wt. % polyacrylic surfactants. These are linear homopolymers of (meth)acrylic acid or its amides and especially their copolymers with (meth)acrylic esters, styrene, vinyl acetate and other vinyl or allyl monomers. Carboxylic polymers are neutralized with the above-mentioned inorganic and/or organic nitrogen bases or alkali metal hydroxides. Water-soluble acrylic polymers or their salts are excellent thickeners, the effectiveness of which increases with increasing relative molecular weight and content of carboxyl groups.

Another essential component of the water-dilutable alkyd dispersion binder according to this invention are drying agents (siccatives), which catalytically accelerate the drying of the binder in air. The most commonly used are salts of divalent metals of organic acids with a higher molecular weight. These are in particular octoates, oleates, resinates and naphthenates of cobalt, lead, manganese, zinc, zirconium, calcium and barium. They are added in an amount of 2 to 35 parts by weight per 300 to 600 parts by weight of the indicated

230 800 salts of alkyd resins. They are usually used in the form of solutions of drying agent mixtures in xylene or glycol ethers. The stability of drying agent solutions in an aqueous medium can be increased by the addition of benzoic acid.

The optionally present additives of the water-dilutable alkyd dispersion binder according to this invention include up to 200 parts by weight of other additives that positively affect its properties. These are organic solvents and spreading agents (xylene, white spirit, alcohols, glycol ethers; glycol ether esters), defoamers (silicones, higher aliphatic alcohols, mixtures of esters and hydrocarbons), additional surfactants (non-ionic emulsifiers of the type of ethoxylated alkylphenols, aliphatic alcohols, acids and others), viscosity regulators (cellulose ethers, polyvinyl alcohol, polyvinyl pyrrolidone, etc.) and the aforementioned inorganic and/or organic bases, which are contained in either the oil or aqueous base of the dispersion, depending on the purpose.

Water forms the dispersion medium in which the alkyd resin salt and other additives are dispersed. Softened, demineralized or deionized water is usually used for dispersion. It should not contain polyvalent metal ions, which can otherwise form insoluble salts with alkyds or even surfactants and thus cause coagulation of the dispersion. According to the present invention, 300 to 700 parts by weight of water are added to 300 to 600 parts by weight of alkyd resin salts.

The water-dilutable alkyd dispersion binder according to the invention can be prepared by all known methods using conventional dispersing devices, e.g. so-called dissolvers. This results in dispersion binders with a particle size of not more than 10 μm, which are suitable primarily for the production of dispersion coatings, as well as printing and marking inks and for various other applications.

The subject of the invention is further illustrated by examples of embodiments, which, however, do not limit its scope in any way. The parts and percentages given are considered as units by weight.

Characteristics of the surfactants used:

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Fluorine-containing surfactants:

type A: potassium salt of heptadecafluoro-1-octoanesulfonic acid type B: potassium salt of trifluoroacetic acid type C: potassium salt of N-ethyl-K ^T -£(]eptadecafluorooctyl)sulfonylaminoacetic acid

Phosphorus-containing surfactants:

type I: triethylamine salt and technical mixtures of monoesters and diesters of phosphoric acid with triethoxylated lauryl alcohol type II: potassium salt of monoesters of phosphoric acid with a mixture of aliphatic monohydric alcohols containing 10 to 18 carbon atoms

Polyacrylic surfactants:

type A: salt of triethylamine and copolymer of methacrylic acid, ethyl acrylate, styrene and diallyl phthalate type B: salt of triethylamine and copolymer of methacrylic acid, ethyl acrylate and 2-hydroxyethyl acrylate

Example 1

Water-based alkyd dispersion binder based on long linseed oil alkyd components parts by weight

Salt of triethylamine and linseed oil modified alkyd with oil length 65 (acid number of starting alkyd 15 mg KOH/g) 300

Condensed water 685

Dryers 3

230,600 of which: cobalt naphthenate 1 part lead naphthenate 2 parts

Mixture of surfactants, of which: fluorine-containing surfactant A 5% phosphorus-containing surfactant I 75% polyacrylate surfactant type A 20%

Nitrogen base (triethylamine) for pH adjustment Xylene

Total

000

Properties: particle size 2 to 6 µm, pH 8.5, shelf life 1 year without phase separation.

Example 2

Water-based alkyd dispersion binder based on medium-length alkyd modified with linseed and soybean oil and benzoic acid.

Components mass parts

Mixed salt of triethylamine and triethanolamine (mass ratio 3:1) and alkyds modified with linseed and soybean oil and benzoic acid with an oil content of 58 (acid number)

ti starting alkyd 10 mg KOH/g) 450 Demineralized water 515 Dries 12 of which: cobalt(II) octoate 1.3 parts ‘lead octoate’ 7.3 parts zinc octoate 3.4 parts

Smws surfactants

230,800 of which: fluorine-containing surfactant type B 2% fluorine-containing surfactant type C 8% phosphorus-containing surfactant type II 50% polyacrylate surfactant type B 40% Nitrogenous base (triethylamine) for pH adjustment 2

Xylene 2

Ethylene glycol monobutyl ether 10

Additional surfactant - ethoxylated nonylphenol (HLB 10.5) 1

Defoamer 1 of which: mineral spirits 0.95 parts ethyl alcohol 0.05 parts

Total 1,000

Properties: dispersion particle size 2 to 4 µm (occasionally 6 µm), pH 9.0, stability 13 months without phase separation.

Example 3

Water-based alkyd dispersion binder based on a mixture of short and long alkyd.

Ingredients of materials · parts

Salt of tripropylamine and a mixture of alkyd modified with soybean oil acids and p.tert.butylbenzoic acid with an oil length of 40 (acid number of the starting alkyd 25 mg KOH/g) and linseed oil alkyd with an oil length of 65 (acid number of the starting alkyd 8 mg KOH/g) in a mass ratio of 1 : 3

520

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Surface water (filtered) 432

Drying agents 14 of which: manganese naphthenate 6 parts barium naphthenate 3 parts lead naphthenate 5 parts

Mixture of surfactants 15 of which: fluorine-containing surfactant type C 35% phosphorus-containing surfactant type I 30% polyacrylate surfactant 3 35%

Nitric acid base (36% ammonium hydroxide) for pH adjustment 2

Spill control agent - poly-2-ethylhexyl acrylate (0n3OOO) 1 Additional surfactant ethoxylated nonylphenol (HLB 11.5) 1

Xylene 15

Total

000

Properties: dispersion particle size 2 to 5 μm (occasionally 8 μm), pH 9.3, dispersion can be stored without phase separation for more than 1 year.

Example 4

Water-soluble alkyd dispersion binder based on mixtures of short castor and safflower alkyd.

Components mass parts

Salt of tripropylamine and a mixture of acid-modified dehydrated castor oil alkyd with an oil length of 40 (acid number of the starting alkyd 20 mg'KOH/g) and acid-modified safflower oil alkyd with an oil length of 45 (acid number of the starting alkyd 15 mg KOH/g) in a weight ratio of 1 : 3

480

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Demineralized water 475 Dries 12 of which: zirconium naphthenate 2 parts cobalt naphthenate 6 parts lead naphthenate 4 parts Tensile mixture 13 of which: fluorine-containing surfactant type C 80% phosphorus containing surfactant type II 10 % polyacrylate surfactant type A 10 % Nitrogenous base (tripropylamine) for pH adjustment 2 Xylene 15 White spirit 2 Additional surfactant - ethoxylated nonylphenol (HLB 11.0) 1 C e 1 k e m 1,000

Properties: dispersion particle size 2 to 4 μm, pH 9.0, stable up to 1 year without phase separation.

Claims (1)

Water-based alkyd dispersion binder based on oil. alkyd, desiccant, surfactant and optionally other additives, characterized in that it consists of 300 to 600 wt. parts by weight of salts prepared from nitrogen bases and alkyd resins modified with monocarboxylic acids having 6 to 24 carbon atoms, 300 to 700 wt. 2 to 35 wt. 1 to 15 wt. % of a surfactant mixture comprising 2 to 78 wt. surfactants containing fluorine, 8 to 82 wt. % surfactants containing phosphorus and 10 to 70 wt. % polyacrylic surfactants, and optionally up to 200 wt. parts of ingredients from the group consisting of organic solvents, flow agents, defoamers, additional surfactants, nitrogen bases and viscosity regulators.