CS262495B1 - Solvent-borne acrylic paints - Google Patents

Abstract

The materials contain acrylic binders, which enable optimal properties of both the paint materials themselves and the coatings prepared from them to be achieved. The acrylic binder is a copolymer of lower alkyl esters of acrylic and/or methacrylic acid, optionally with functional acrylic monomers and other specified unsaturated monomers. The acrylic polymer has a controlled molecular structure due to the use of radical polymerization with time-controlled addition of monomers during its preparation and is a mixture of two to three polymers obtained by polymerization of different mixtures of monomers in individual polymerization stages.

Description

The invention relates to solvent acrylic coating compositions based on solution acrylic binders, optionally with the addition of other types of binders, pigments, fillers, solvents and additives.

Find acrylic paints! increasingly widespread use in a wide variety of industries. The reason for the great interest in acrylic paints is their very good properties, especially in terms of weather resistance, resistance to water, chemicals and yellowing. This is because acrylic polymers in their molecules do not have such unsaturated groups that could undergo oxidation and thus affect the degradation of the polymer chains. Another degradation mechanism, which is oxidation at the tertiary carbon atom, especially in the acrylic acid derivative segments, is very difficult and therefore unlikely. Acrylic binders are the most commonly used coatings for topcoats. High-quality paints are also expected to have a high hardness of the coatings while maintaining sufficient resistance to impact, bending and trenching, short drying time and adhesion to various substrates. Most coatings produced meet these requirements only partially.

This problem is successfully solved by the present invention, which relates to solvent-based acrylic paints consisting of 3 to 50 wt. 5 parts to 70 wt. parts of other lacquer binders, in particular polyester and aldehyde resins, rosin esters and cellulose derivatives, up to 70 wt. parts and / or fillers and up to 8 wt. parts of additives, in particular from the group consisting of flow agents, matting agents, antifoams, desiccants and emollients. It is an object of the present invention to provide such coating compositions as an acrylic binder with at least one controlled-state acrylic polymer prepared from 30 to 100% by weight. parts of alkyl esters of acrylic and / or methacrylic acid having a number of carbon atoms in the alkyl group of 1 to 12 and optionally up to 40 wt. parts of functional acrylic monomers selected from the group consisting of acrylic and methacrylic acid, their amides optionally substituted on nitrogen by methylol or alkyl or alkoxymethyl groups having a carbon number of 1 to 5, hydroxyalkyl esters of acrylic and methacrylic acid having a number of carbon atoms in hydroxyalkyl group 2 to 4, glycidyl acrylate and glycidyl methacrylate, and up to 100 wt. parts of monoethylenically unsaturated monomers from the group consisting of styrene, its alkyl derivatives having a number of carbon atoms in the alkyl substituent of 1 to 4 vinyl acetate. Regulated molecular structure acrylic polymer means a polymer having a number average molecular weight of 3,000 to 60,000 and a weight to number average molecular weight ratio of 2 to 6 while maintaining random distribution of monomer segments, prepared by free-radical polymerization with time-controlled continuous or sequential addition of monomer mixture. with a polymerization initiator into the solvents of the resulting polymer at their boiling point for 1 to 6 hours and subsequent completion of the polymerization at this temperature within 2 to 12 hours. Controlled molecular structure acrylic polymers are also blends of two to three polymers prepared by phased radical polymerization in two or three-phase continuous or sequential dosing of one to three different blends of polymerization initiator monomers into the solvents of the resulting polymers at their boiling point for 20 minutes to 4 hours. without a time delay or with a time interval of up to 3 hours between the individual phases of dosing.

The paints according to the invention contain acrylic binders which, by means of a suitable molecular weight and advantageous distribution of segments in the polymer chain, make it possible to achieve optimum properties of the paints and coatings prepared therefrom. These coatings have a very good resistance to accelerated and normal weathering, in a corrosive environment, and excellent resistance to chemical agents and UV radiation after drying at normal temperature or drying. By suitable composition of acrylic binder and the ratio of other components of the paint, coat films with excellent adhesion to various substrates, sufficient hardness? desired elasticity.

The most important component of said solvent acrylic paints is an acrylic binder, which is a copolymer prepared by copolymerization of 30 to 100 parts by weight, parts of alkyl esters of acrylic and / or methacrylic acid having a number of carbon atoms in the alkyl group of 1 to 3 parts. parts of functional acrylic monomers from the group consisting of acrylic and methacrylic acid, their amides which may be substituted on the nitrogen by methylol or alkyl or alkoxymethyl groups having a carbon number of 1 to 5, hydroxyalkyl esters of acrylic and methacrylic acid having a number of carbon atoms in hydroxyalkyl groups 2 to 4, glycidyl acrylate and glycidyl methacrylate; and up to 100 wt. parts of monoethylenically unsaturated monomers from the group consisting of: styrene, its C1-C4 alkyl substituents and vinyl acetate. Of the acrylic and methacrylic esters, esters derived from aliphatic alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-methylbutanol, 2-pentanol, 3-pentanol, n-hexanol are particularly used. , 1-methylpentanol, 3-methylpentanol, 2-ethylbutanol, 2-methylpentanol, n-heptanol, 1-methylhexanol, 2-methylhexanol, 3-methylhexanol, 3-heptanol, n-octanol, isooctanol, 2-ethylhexanol, 3,5 , 5-trimethylhexanol, n-decanol or dodecanol.

Of the functional group nomoners, acrylic and methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate and the corresponding methacrylates, as well as monomers containing amide groups, in particular acrylamide, methyl acrylamide, N-methoxymethyl-, are used. acrylamide, N-butoxymethylacrylamide, N-isobutoxymethylacrylamide, Ν, Ν-dimethylacrylamide, N-tert-butyl acrylamide,,, Ν-butyl acrylamide and similar methacrylic acid derived compounds.

Among the functional monomers containing an oxyran group, glycidyl acrylate and glycidyl methacrylate are most suitable. Further comonomers of the acrylic copolymers may optionally also be styrene and its alkyl derivatives having a number of carbon atoms in the 1-4 alkyl substituent, such as alpha-methylstyrene, beta-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene and tert-butylstyrene, as well as vinyl acetate.

Other types of lacquer binders can be added to these acrylic copolymers, derivatives derived from natural macromolecular and low molecular weight substances, as well as other types of synthetic binders. Natural macromolecular and low molecular weight substances include, for example, cellulose nitrate, propionate and acetobutyrate, chlorinated rubber, adducts and esters of rosin, vegetable oils, and binders derived from drying or semi-drying vegetable oils. Suitable synthetic binders are aldehyde resins, such as melamine-formaldehyde, phenol-formaldehyde, urea-formaldehyde, guanamine-formaldehyde and ketone-formaldehyde; polyisocyanates and silicone resins.

Inorganic and organic pigments such as titanium and zinc white, green and red ferric, molybdate and cadmium, zinc, iron and chrome yellow or orange, ultramarine, chrome and phthalocyanine, manganese violet, permanent and chrome transducer, ferric and carbon black. Metal effect coatings are obtained using pearl and metal pigments. Anti-corrosion pigments such as lead, zinc chromate, zinc phosphate and metallic pigments, especially zinc dust, may be added to the primer. Finely ground or precipitated fillers may also be added to these pigments. Calcium carbonate (precipitated, limestone, chalk), calcium sulphate (precipitated, limestone, colloidal silica, kaolin, diatomite, talc, slate and glass flour, graphite, asbestos and mica etc.) are used.

The organic solvents used are alcohols, esters, ethers, ether-alcohols, ether-esters, ketones, acyclic, aromatic, aliphatic and chlorinated hydrocarbons.

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Other additives may also be added, such as agents affecting either the preparation of the properties of the paints themselves, such as desperation, sedimentation, swimming and flotation of pigments and fillers, foaming, flow, skin formation or the like, or formation. coating film, eg drying, mechanical resistance, adhesion, gloss, flammability, water or radiation resistance, electrical conductivity, etc. These are usually silicone resins, low molecular weight acrylic copolymers, surfactants, mineral oils, metal soaps, high boiling aromatic hydrocarbons, ketones, esters, oximes, phenol derivatives, quaternary amine salts of fatty acids, silica, polyethylene, polypropylene, polyamides or stearates of zinc, aluminum, magnesium and calcium.

262495 4

The coating compositions of the present invention are prepared by known techniques using various types of dispersing devices. The products obtained are applied by conventional application techniques, in particular on metal and wood substrates.

Examples

The invention is further exemplified by using acrylic binders, the composition of which is expressed in parts by weight.

Acrylic binder

Starting monomer AND (B) C D E F butyl acrylate 45.0 47.0 45.0 - 50.0 43.0 2-hydroxyethyl- methacrylate - - - - 8.0 - acrylic acid 2,0 - 2,0 - 2.5 3.0 styrene 45.5 16.0 18.0 - 39.5 40.0 N-isobutoxymethyl- acrylamide - - - - - 14.0 methyl methacrylate 8.0 35.0 35.0 10.0 - - butyl methacrylate - - - 80.0 - - methacrylic acid - 2,0 - - - -

Acrylic binder A - precipitation of polymers having a number average molecular weight of 6,000 to 8,000 and 12,000 to 20,000, a viscosity of 1,400 to 2,200 mPa · s at 25 ° C, a nonvolatile content of 49 to 50% by weight.

Acrylic binder B - blend of 2 polymers with a number average molecular weight of 12,000 to 20,000, a viscosity at 25 ° C of 1.7 to 3.2 Pa.s, a nonvolatile content of 50 to 54% by weight.

Acrylic binder C τ

- random distribution of monomer segments, number average molecular weight

000 to 36 000, a polydispersity of about 2.9, a viscosity at 25 ° C and a content of non-volatile components of 50 + 2 wt. is about 3.5 Pa.s.

Acrylic binder D - random distribution of monomer segments, number average mol. weight 6 000 to

000, a polydispersity of about 3.6, a viscosity at 25 [deg.] C. of 2.00 to 400 Pa.s, a content of nonvolatile components of 49 to 51 wt.

Acrylic binder E - blend of 2 polymers, number average molecular weight 10 000, viscosity at 25 ° C 400 to 1000 mPa.s, content of nonvolatile components 49 to 52% by weight.

Acrylic binder P-random distribution of monomer segments, numbered average molecular weight 15,000, ratio of weight to number average molecular weight 5.6, viscosity at 25 ° C is 1.0 to 2.0 Pa.s, content of non-volatile components 47 to 50 wt.

Example 1

Acrylic lacquer

acrylic binder 19.4 wt. part nitrocellulose (type E, low viscosity) 14.9 wt. part ethyl acetate 13.6 wt. part butyl acetate 31.8 wt. part butanol 4.9 wt. part toluene 1.3 wt. part petrol 3.6 wt. part rosin esters 4.9 wt. part dioctyl phthalate 3.3 wt. part acetone 2.3 wt. part

Drying at 23 ° C for 24 h gives a coating with a pendulum hardness of 63% at a coating thickness of 20 to 30 µm. drying to step 1 in 10 minutes, to step 5 in 85 minutes.

Example 2

Matt acrylic lacquer acrylic binder 17.6 wt. part nitrolellulose (type E, low viscosity) 14.7 wt. part ethyl acetate 11.8 wt. part butyl acetate 30.3 wt. part ethyl alcohol 5.0 wt. part toluene 2.5 wt. part petrol 3.6 wt. part rosin esters 4,5 wt. part dibutyl phthalate 2.3 wt. 'díl Castor oil 4,5 wt. part acetone 2.3 wt. part matting agent (modified silica) 0.9 wt. part

Drying for 24 hours at 23 ° C at a coating thickness _of 20-30 .mu.m gave a coating with a pendulum hardness of 56%, drying to a degree of 1 to 8 minutes, to a degree of from 5 to 75 minutes.

Example 3

Red acrylic enamel

acrylic binder 19.1 wt. part nitrocellulose (type E, low viscosity) 4.1 wt. part rutile titanium white 11.2 wt. part organic red 4.0 wt. part ethyl glycol 15.2 wt. part xylene 10.1 wt. part butanol 6.6 wt. part butyl acetate 28.7 wt. part dioctyl phthalate 0.7 wt. part Drainage agent (modified silicone resin) 0.3 wt. part

Drying for 24 h at 23 ° C gives a coating with a pendulum hardness of 35%, a punch resistance of 90 cm, a 9 mm digging resistance and a bending resistance of 3 mm at a coating thickness of 30 to 40 µm, drying to degree 1 in 15 minutes, degree 5 to 40 minutes.

Example 4

White acrylic enamel

acrylic binder D 7.0 wt. part alkyd resins (pentaerythritol type modified with linseed oil) 46.7 wt. part desiccant (mixture of calcium, cobalt and lead octoates) 3.1 wt. part rutile titanium white 32.0 wt. part white spirit 8.7 wt. part butanol 2.1 wt. part flow agent (polysiloxane copolymer) 0.4 wt. part

Drying for 30 days at 23 ° C gives a coating with a pendulum hardness of 27%, a 90 cm impact resistance, a 9 mm digging resistance and a 3 mm bending resistance, drying to degree 1 in 70 minutes to degree 30 5 in 5 days.

Example 5

Acrylic repair enamel yellow

acrylic binder 30.6 wt. part melamine formaldehyde resin (medium etherified) 5.2 wt. part melamine formaldehyde resin (above etherified) 5.2 wt. part nitrocellulose (type E, low viscous) 4.8 wt. part chrome Yellow 22.3 wt. part butanol 12.5 wt. part butylglycol 3.2 wt. part xylene 20.1 wt. part butyl acetate 5.6 wt. part antifoam (without silicone resin) 0.3 wt. part flowing agent (modified polysiloxane copolymer) 0.2 wt. part

Drying for 24 h at 23 ° C gives a coating with a pendulum hardness of 25%, a 35 cm impact resistance, a 8.5 mm digging resistance and a 3 mm bending resistance, drying to degree 1 in 30 minutes at a coating thickness of 30 to 40 µm. , to degree 5 in 3 days.

Example 6

White enamel acrylic enamel

acrylic binder 16.9 wt. part nitrocellulose (type E, low viscous) 4.0 wt. part titanium white anatas 9.6 wt. part zinc white 9.8 wt. part ethyl glycol 14.6 wt. part xylene 18.1 wt. part butanol 2.5 wt. part butyl acetate 22.1 wt. part dibutyl phthalate 0.7 wt. part matting agent (modified silica) 1.3 wt. part Drainage agent (modified silicone resin) 0.4 wt. part

Drying for 24 h at 23 ° C gives a coating with a pendulum hardness of 32-40, a impact strength of 85 cm, an excavation resistance of 8 mm, a bending resistance of 3 mm, and a drying step of 1 to 15 minutes at a coating thickness of 30 to 40 µm. Grade 5 in 40 minutes.

Example 7

Repair acrylic enamel black matt

acrylic binder F 34.1 wt. part xylene 35.4 wt. part butanol 14.4 wt. part butyl acetate 5.4 wt. part nitrocellulose (type E, low-viscosity) 4.9 wt. part soot 2.8 wt. part matting agent (modified silica) 4,5 wt. part dispersant (high molecular weight polycarboxylic acid) 0.6 wt. part defoamer (anhydrous emulsion of modified polysiloxane copolymers) 0.4 wt. part flowing agent (higher aromatics, ketones, esters) 0.3 wt. part

Drying for 24 h at 23 ° C gives a coating with a pendulum hardness of 31%, a impact resistance of 30 cm, a digging resistance of 7.7 mm, a bending resistance of 5 mm, drying to degree 1 in 60 minutes at a coating thickness of 30 to 40 µm. , to degree 5 in 24 hours.

Example

Acrylic paint base

acrylic binder 10.4 wt. part nitrocellulose (type E, medium viscosity) 3.0 wt. part rosin esters 1.2 wt. part alkyd resin (glycerol type modified with castor oil) 7.0 wt. part litopon 23.5 wt. part spar 5.9 wt. part dioctyl phthalate 1.8 wt. part xylene 12.0 wt. part isobutanol 7.7 wt. part isobutyl acetate 10.0 wt. part petrol 7.0 wt. part butyl acetate 10.5 wt. part

Drying for 24 h at 23 ° C gives a coating of 8% pendulum hardness, a punch resistance of 60 cm, a 9 mm digging resistance and a 3 mm bending resistance at a coating thickness of 30 to 40 jum, a 1 to 15 minute drying step 5 in 60 minutes.

Example 9

Acrylic paint for facades

acrylic binder D limestone titanium white 15.5 wt. 36.9 wt. part 17.5 wt. part white spirit 22.9 wt. part butanol 7.2 wt. part

Drying for 30 days at 23 ° C gives a coating with a pendulum hardness of 20.8% at a coating thickness of 40 to 50 µm, drying to degree 1 in 90 minutes, degree 5 in 5 days.

Example 10

Acrylic impregnant acrylic binder A butylate acetate xylene white spirit butanol

30.0 wt. 30.0 wt. 20.9 wt. 10.0 wt. 10.0 wt. part

Dry to degree 1 in 30 minutes.

Claims (3)

Solvent-based acrylic paints consisting of 3 to 50 parts by weight of an acrylic binder, 5 to 70 parts by weight of organic solvents and optionally up to 60 parts by weight of other lacquer binders, in particular polyester and aldehyde resins, rosin esters and cellulose derivatives, up to 70 parts by weight of pigments and / or fillers and up to 8 parts by weight of additives, in particular from the group consisting of flow agents, minters, defoamers, desiccants and emollients characterized in that they comprise as an acrylic binder at least an acrylic polymer having a controlled molecular structure, prepared from 30 to 100 parts by weight of alkyl esters of acrylic and / or methacrylic acid having a carbon number in the alkyl group of 1 to 12, and optionally up to 40 parts by weight acrylic monomers from the group consisting of acrylic and methacrylic acid, the amides of which are optionally substituted on the nitrogen by methylol or alkyl or alkoxymethyl groups having a carbon number of 1 to 5, hydroxyalkyl esters of acrylic acid and methacrylates and from up to 100 parts by weight of monoethylenically unsaturated monomers from the group consisting of styrene, its C1-C4 alkyl substituents and vinyl acetate. 2. Solvent-based acrylic paints according to claim 1, characterized in that the controlled-structure acrylic polymer is a polymer having a number average molecular weight of 3,000 to -60,000 and a weight to number average molecular weight ratio of 2 to 5,000. 6 while maintaining random distribution of monomer segments, prepared by free-radical polymerization with time-controlled continuous or sequential addition of a mixture of monomers with a polymerization initiator to the resulting polymer solvents at their boiling point for 1 to 6 hours and subsequent polymerization at this temperature within 2 to 12 hours. 3. Solvent-based acrylic paints according to claim 1, characterized in that the controlled-structure acrylic polymers are mixtures of two to three polymers prepared by phased radical polymerization in two or three-phase continuous or sequential dosing of one to three different monomer initiator mixtures. into the solvents of the resulting polymers at their boiling point for 20 minutes to 4 hours without a time delay or with a time interval of individual phases of dosing of up to 3 hours.