CS244608B1 - Binder, in particular for paints and inks and method for its preparation - Google Patents

Abstract

The invention relates to a new binder for paints, printing inks and other technical coatings and a method of its production. The essence of the invention lies in the fact that the binder consists of 90 to 99.5% by weight of general compounds and 0.5 to 10% by weight of aliphatic and/or aromatic monocarboxylic acids with a carbon number of 6 to 24 and/or their derivatives. In the formula R denotes a polyalcohol residue with 2 to 6 hydroxyl groups and an average molecular weight of 62 to 6,000, R2 denotes a residue of the above-specified aliphatic and aromatic acid residue, x is 0 to 6 and y is 0 to 6. The binder is prepared by subjecting the polyalcohols, aliphatic and aromatic acids or their derivatives to mutual reaction in a molecular. ratio of 1.0:0.2 to n 1.0:1.5 to 4.0. at a temperature of 180 to 260 °C, a pressure of 0.02 to 0.1 MPa, in an inert gas environment and/or an azeotropic organic solvent and optionally in the presence of a catalyst, with constant removal of reaction by-products, until the acid number of the reaction product is below 30 mg KOH/g.

Description

The subject of the invention is a binder component of coatings, printing inks and other technical compositions consisting mainly of mixtures of esters based on polyalcohols, monocarboxylic aliphatic and aromatic acids.

The properties of known macromolecular substances used in the field of plastics and coatings are constantly being modified and improved in technical practice. This is achieved by means of modification processes, in which macromolecules of the substance or modifying compounds either chemically react or form physical mixtures with them.

These compositions of macromolecular substances with low- and high-molecular modifying aluminum ions are easy to prepare and process. Due to their composition, they exhibit excellent physical, mechanical and chemical properties, such as increased flexibility, toughness, thermal and color stability, resistance to chemicals, water and aging, wear resistance, gloss, etc.

In order to achieve these properties, the modifying compounds must meet a number of requirements. In particular, they must be compatible and miscible with a wide range and selection of macromolecular substances. They also need to be well soluble in the additives used, such as organic solvents and plasticizers.

These requirements are usually not met by macromolecule modifying compounds. The problem is that modifying compounds require high boiling points, low volatility, and relatively low viscosity.

In the compositions, they should not react with the catalysts or other additives present and adversely affect the curing rate and properties of the final products. They should not be released spontaneously from them or be extracted by oils or solvents. These negative properties then prevail <zaoe in low-molecular modifying compounds.

These problems are solved by the present invention, the subject of which is a binder, especially for coatings and printing inks, including a method of their preparation, meeting the stated requirements for modifying compounds and improving the properties of modified macromolecular substances.

The essence of the invention lies in the fact that the binder consists of 90 to 99.5% by weight of compounds of the general formula

and 0.5 to 10 wt. % of aliphatic and/or aromatic monocarboxylic acids and having a number of carbon atoms of 6 to 24 and/or their derivatives. In the above formula R denotes a polyalkylene radical with 2 to 6 hydroxyl groups and an average molecular weight of 62 to 6,000, Rj is the radical of the above aliphatic and Rj is an aromatic acid, x is 0 to 6 and y is 0 to 6.

The essence of the method for preparing the binder consists in the fact that the above-specified polyols, monocarboxylic aliphatic acids or monocarboxylic aromatic acids or derivatives of these acids are subjected to a mutual reaction in a molar ratio of 1.0:0.2 to 1.0:1.5 to 4.0 at a temperature of 180 to 260 °C, a pressure of 0.02 to 0.1 MPa, in an inert gas environment and/or an esotropi organic solvent and optionally in the presence of a catalyst, in particular from a group of oxides or salts of zinc, cobalt, lead and calcium, with constant removal of reaction by-products up to

until the acid number of the reaction product is below 30 mg KOH/g.

The binder prepared according to the present invention has several advantages over known modifying compounds. In particular, it is soluble in common organic solvents and very miscible with a significant number of macromolecular substances.

Furthermore, it is liquid and low-viscosity, has excellent dispersing, plasticizing and flexibilizing effects. It is added to coatings, printing inks and other technical compositions. The reactive component chemically bonds with them during oxypolymerization curing and improves their properties.

The prepared composition is easily pigmented, has improved flow properties and after processing has improved physical and mechanical properties. The mentioned properties of the binder component can be varied in a wide range by the composition of the starting components and the choice of the technological production process.

Polyalcohols with 2 to 6 hydroxyl groups and an average molecular weight of 62 to 6,000 are suitable for the synthesis of the binder component according to the present invention. They include glycals (ethylene glycol, propyl glycol, butylene glycol, neopentyl glycol, diethylene glycol, diprylene glycol, triethylene glycol and other polyalkylene glycols), cyclic diols (1, 2- and 1,4-cyclohexanedial, 1,4-bis(hydroxymethyl)cyclohexane), hydrogenated or alkylene-oxidized bisphenols (2,2-bis(4-hydroxycyclohexyl)propane, 2,2-bis(4-hydroxyethoxyphenyl)propane, 2,2-bis(4-hydroxypropoxyphenyl)propane), trihydric alcohols (glycerol, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, 2,3,4-pentanetriol, 1,2,3-trihydroxybutone, 1,2,6-hexanetriol, tris(2-hydroxyethyl)isocyanurate), Tetravalent to Hexavalent (pehtaerythritol, dipentaerythritol, arylitol, mannitol, etc.).

The polyalcohols mentioned are then used individually or in mixtures with each other, in molar ratios to monocarboxylic aliphatic and aromatic acids or their derivatives: 1.0:0.2 to 1.0:1.5 to 4.0.

Of the monocarboxylic aliphatic acids, the most important are those obtained from natural oils: drying (linseed, wood, safflower, rapeseed, oiticica, perillum, castor, fish), semi-drying (sowing, tallow, cotton, sunflower) and non-drying (coconut, castor, olive, peanut).

These acids are mixtures of saturated and/or unsaturated monocarboxylic fatty acids. Of the saturated acids, caproic, caprylic, lauric, myristic, palmitic, stearic, arachidic, behenic and lignosic acids are important.

Unsaturated acids are represented by oleic, linoleic, linolenic, α- and β-eleostearic, erucic, ricinoleic and 9,11-ricinoleic acids. In addition to these acids, saturated synthetic aliphatic acids (non-acids, Koch acids), 2-ethylhexanoic, pelargonic and others are also used.

The starting point is the individual acids mentioned, their mixtures, various fractions or their functional derivatives. Of these, esters of aliphatic monocarboxylic acids with monohydric alcohols (especially methyl esters) or polyhydric alcohols (especially glycerides) are mainly considered.

Monocarboxylic aromatic acids are represented mainly by benzoic acid or its substituted or functional derivatives. These include in particular p-tert-butylbenzoic acid, m- and p-hydroxybenzoic acid and halogen derivatives.

A part of the mentioned aliphatic β/or aromatic acids or their derivatives remains free in the final product, in an amount of not more than 10% by weight.

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In preparing the binder component according to the present invention, the general procedure is as follows: the batch process takes place in a stirred reactor equipped with a jacket for heating and cooling, an agitator and, optionally, a device for measuring viscosity or conductivity.

In continuous flow, the reaction mixture passes continuously through a system of reactors arranged in series or in a cascade. The starting materials, i.e. one or more polyols, a mixture of monocarboxylic aliphatic and aromatic acids or their derivatives, are introduced into the heated reactor with effective mixing.

The esterification takes place at temperatures of 100 to 260 °C in the presence of a catalyst or without it, and either in the melt of the reaction components or preferably in the presence of 2 to 10% by weight of the azeotrope solvent, xylene.

such as aromatic and chlorinated hydrocarbons, especially

In this case, the esterification process removes the reaction mixture continuously in the form of azeotrope with the resolvent, which is returned to the reactor. If methyl esters or other alkyl esters of monocarboxylic acids are used as the starting material, then their alkylation with alkyl alcohol occurs, which is accelerated by the addition of a catalyst.

It mainly uses salts of divalent metals, such as zinc, cobalt, lead and calcium acetate. In the alcoholysis of triglycerides, i.e. natural drying, semi-drying or non-drying oils, polyalcohols, catalysts from the group of alkaline earth oxides (mainly lead and calcium oxide) or alkali metal hydroxides are added.

Alcoholyses take place at temperatures of 100 to 260°C, optimally at 200 to 240°C, in an inert atmosphere of carbon dioxide or nitrogen. By blowing them under the surface of the reaction mixture, the released methanol or other low molecular weight alcohol is removed.

After the alcoholysis of triglycerides, which can also be carried out in the presence of an azeotropic solvent, the esterification of the obtained glycerides with other monocarboxylic acids follows at a temperature of 180 to 260 °C.

The synthesis takes place under atmospheric pressure, then reduced towards the end (down to 0.02 MPa), when residues of by-products, possibly the organic solvent present or even a part of the unreacted components are removed from the reaction mixture.

The course of the reactions is monitored by determining the acid number, hydroxyl number or even by measuring viscosity and conductivity. The final product has an acid number below 30 mg KOH/g and a hydroxyl number below 100 mg KOH/g.

It forms a liquid, low-viscosity composition soluble in common organic solvents and miscible with various macromolecular substances.

The main proportion, i.e. 90 to 99.5% by weight of the binder component prepared according to the present invention, consists of a mixture of simple and mixed esters and hydroxyesters. The initial unreacted or additionally added aliphatic and/or aromatic monocarboxylic acids or their derivatives are present in an amount of 0.5 to 10% by weight.

It can be assumed that the representation of individual esters and hydroxyesters varies mainly depending on the composition of the starting materials and the synthesis conditions. For example, during the esterification of glycerol (Q)/1/ with 9,12-linoleic acid (L)/2/ and benzoic acid (B)/3/, theoretically 9 esters can be formed, if the configuration of the hydroxyesters (4-12) is not distinguished.

When replacing glycerol with pentaerythritol, as many as 14 ester compounds may be present.

In technical practice, when esterifying two or more polyalcohols with mixtures of aliphatic saturated and unsaturated monocarboxylic acids and saturated aromatic monocarboxylic acids and saturated aromatic monocarboxylic acids or their derivatives, even more complex compositions of esters and hydroxyesters are obtained. These cannot be precisely identified and determined even by current modern physicochemical methods, such as gel permeation chromatography and infrared spectroscopy.

CHg-CH-CHg 0 CH ₃ -(CHg) ₄ -CH=CH-CH ₂ -CH=CH-(CHg) _? -&-0H* 0 II C-OH 1 OH OH OH /1/ /2/ /3/ L - - L L B - G - B 1 B L - G - L 1 B B - G - B L - 1 L G - OH 1 L /4/ /5/ /6/ /7/ /8/ OH - a - OH J B - O - OH I OH - G - OH 1 L - G - B | 1 L 1 B 1 B OH /9/ /10/ /11/ /12/

The binder component prepared according to this invention is particularly suitable as an additive to solvent and water-based coatings and printing inks, especially oil, alkyd, polyester, polyurethane, acrylic and nitrocellulose.

It can also be added to various technical compositions such as adhesives, marking sealants and other materials. Depending on its composition, it is mainly used as a modifying component, plasticizer, flexibilizer and dispersant.

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 mentioned are intended as units of mass. The analytical methods were carried out according to the monograph P. Rybnikář, Z. Ditrych, Z. Kláeel, 0. Ordplt: Analýza a skúšení plastických hmot, SNTL, Prague, 1965.

Example 1

At a temperature of 180 to 235 °C, 84 g (0.90 gmol) of glycerol, 600 g (0.10 gmol) of polyethylene glycol with an average molecular weight of 6,000, 142 g (0.5 gmol) of aliphatic monocarboxylic acids obtained by cleavage from linseed oil (composition determined by gas chromatography: acids 7.1 95, C ₁₈ saturated 4.9 95, C, ₈ with one double bond 20.3%, C, ₈ with two double bonds 16.9%, C ₁₈ with three double bonds 50.1 95) are reacted under nitrogen supply with 356 g (2 gmol) of p-tert-butylbenzoic acid.

The esterification is completed when the acid number reaches 12.3 mg KOH.g ^-1 . At this stage, 90-95 wt. of mixed esters and hydroxyesters and 10-95 wt. of unreacted monocarboxylic acids are present in the mixture.

The prepared product, in the form of its ammonium salt, serves as an emulsifier for alkyd water dispersion paints. Compared to other known emulsifiers, it has the advantage of being incorporated into the resulting macromolecules during the drying of the paints.

Therefore, it does not migrate to the surface of the coatings and their properties do not deteriorate.

Example 2

At a temperature of 190 to 250 °C, 133 g (1.0 gmol) of technical pentaerythritol containing 90 mol. % monopentaerythritol and 10 mol. % dipentaerythritol are reacted with 8,280.6 g (2.3 gmol) of benzoic acid and 284 g (1.0 gmol) of monocarboxylic aliphatic acids obtained by the cleavage of soybean oil. (composition determined by gas chromatography method:

11.1%, C, _and 4.4%, C _)g with one double bond 23.1%, C _1g with two double bonds 51.8%, C _1g with three double bonds 6.5%).

The esterification carried out with the addition of 3 wt. % xylene as an azeotropic agent is completed at an acid number of 3 mg KOH.g ^-1 , at which 99 wt. % mixed esters or hydroxyesters and 1 wt. % starting monocarboxylic acids are present in the mixture.

The prepared product serves as a plasticizer for baking coatings based on alkyd-melamine resins.

Example 3

140 g (0.95 gmol) of monopentaerythritol is reacted at a temperature of 180 to 240 °C,

3.2 g (0.05 gmol) of ethylene glycol, 451.4 g (3.7 gmol) of benzoic acid and 28.5 g (0.1 gmol) of monocarboxylic aliphatic acids obtained by the cleavage of rapeseed oil (acid content determined by gas chromatography: - 5.4%, C^g - 2.2%, C,gs with one double bond 48.1%, 0,θ with two double bonds 26.1%, Ο^θ with three double bonds 9.0%, C ₂₀ with one double bond 1.3%, C ₂₂ - 0.1%, C ₂₂ with one double bond 6.9% and C ₂ ^ 0.1%) until the acid number drops to 5 mg KOH.g ^-1 , at which the product contains 1.5% by weight. of the starting acids and the remainder corresponds to mixed esters.

The product serves as a binder for pigment pastes for tinting two-component epoxy coatings.

Attached

At a temperature of 180 to 200 °C, a mixture of 19 g (0.25 gmol) is reacted in the first stage

1,2-propylene glycol, 15.5 g (0.25 gmol) ethylene glycol, 174 g (1.1 gmol) pelargonic acid and 61 g (0.5 gmol) benzoic acid until the acid number of the reaction product drops below 150 mg KOH.g ^-1 .

After cooling the reaction mixture to 150 °C, 680 g (0.5 gmol) of monopentaerythritol is added and at a temperature of 200 to 240 °C it is esterified to an acid number of 29 mg KOH.g ^-1 . At this stage, the reaction product contains 90 wt. % mixed esters or hydroxyesters and 10 wt. % unreacted acids.

The product serves as a plasticizing component of baking types of alkyd-melamine, or nitrocellulose or nitrocombination coatings.

Example 5

At a temperature of 240 °C, a reaction is allowed to take place between 305 g of linseed oil (containing 1.04 gmol of carboxylic acid glycerides) and 182 g (1.28 gmol) of monopentaerythritol under the catalysis of 0.05 g of PbO (0.015% by weight of the oil content).

After reaching reaction equilibrium, which occurs in 2.5 h, the reaction mixture is cooled to 120 °C and 90 g (0.61 gmol) of phthalic anhydride and 423 g (3.47 gmol) of benzoic acid are added and the reaction mixture is esterified at a temperature of 230 to 245 °C initially under a pressure of 0.1 MPa.

The reaction is terminated at a pressure of 0.02 MPa and after reaching an acid number of 5 mg KOH.g ^-1 . In tom7

At this stage, 98 of the 85 incoming carboxyl groups are esterified.

The reaction product is preferably used as a binder for tinting pastes.

Claims (2)

Binder, in particular for paints and inks, characterized in that it consists of 90 to 99.5% by weight. of the compounds of formula (I)! and 0.5 to 10 85 wt. aliphatic and / or aromatic monocarboxylic acids having a number of carbon atoms of 6 to 24 and / or derivatives thereof, wherein in the general formula R denotes the residue of a polyalcohol having 2 to 6 hydroxyl groups and an average mol. of a weight of 62 to 6,000 R 1 is the residue of said aliphatic and R _{2 is an} aromatic acid residue, x is 0 to 6 and y is 0 to 6. 2. A process for preparing a binder according to claim 1, characterized in that: characterized in that the polyalcohels, monocarbexyl aliphatic acids and monocarboxylic aromatic acids or derivatives thereof are subjected to a molar ratio of 1.0: 0.2 to 1.0: 1.5 to 4.0 to react with each other at a temperature of 1Θ0 to 260 ° C at a pressure of 0.02 to 0.1 MPa, in an inert gas and / or azeotropic organic solvent, and optionally in the presence of a catalyst, in particular from the group of oxides and salts of zinc, cobalt, lead and calcium, continuously evacuating by-products. of the reaction product below 30 mg KOH / g.