CA2041148A1 - Aqueous, clear, coating composition containing emulsion copolymers and coated substrates prepared therefrom - Google Patents
Aqueous, clear, coating composition containing emulsion copolymers and coated substrates prepared therefromInfo
- Publication number
- CA2041148A1 CA2041148A1 CA002041148A CA2041148A CA2041148A1 CA 2041148 A1 CA2041148 A1 CA 2041148A1 CA 002041148 A CA002041148 A CA 002041148A CA 2041148 A CA2041148 A CA 2041148A CA 2041148 A1 CA2041148 A1 CA 2041148A1
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- weight
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Classifications
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
- C09D133/04—Homopolymers or copolymers of esters
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
- C09D133/04—Homopolymers or copolymers of esters
- C09D133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
- C09D133/062—Copolymers with monomers not covered by C09D133/06
- C09D133/066—Copolymers with monomers not covered by C09D133/06 containing -OH groups
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
- C08L61/20—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Wood Science & Technology (AREA)
- Organic Chemistry (AREA)
- Paints Or Removers (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
Abstract
Mo3554 LeA 27,59I
AQUEOUS, CLEAR, COATING COMPOSITION
CONTAINING EMULSION COPOlYMERS AND
COATED SUBSTRATES PREPARED THEREFROM
ABSTRACT OF THE DISCLOSURE
The present invention relates to aqueous, clear, coating compositions containing A) 60 to 90% by weight, based on the total weight of components A) and B), of an emulsion copolymer which is the reaction product of a) 0 to 50% by weight of styrene, .alpha.-methyl-styrene or a mixture of these monomers, b) 0 to 50% by weight of methyl methacrylate, c) 10 to 45% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, d) 5 to 30% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl- or 2-, 3- or 4-hydroxybutyl-(meth)-acrylate or any mixture of these monomers, e) 1 to 15% by weight of acrylic acid, methacrylic acid or any mixture of these acids and f) 0 to 15% by weight of other comonomers, wherein i) 0 to 50% of the carboxyl groups are neutralized with an aliphatic amine or with ammonia, ii) the percentages a) - f) adding up to 100, based on the total weight of a) - f) and iii) the combined weight of monomers a) and b) being 10 - 70% by weight, based on the total weight of monomers a) - f), B) 0to100% by weight, based on the total weight of components A) and B), of a melamine resin and C) water.
The present invention also relates to coated substrates, particularly coated motor vehicle substrates, prepared from these aqueous, clear, coating compositions.
Mo3554
AQUEOUS, CLEAR, COATING COMPOSITION
CONTAINING EMULSION COPOlYMERS AND
COATED SUBSTRATES PREPARED THEREFROM
ABSTRACT OF THE DISCLOSURE
The present invention relates to aqueous, clear, coating compositions containing A) 60 to 90% by weight, based on the total weight of components A) and B), of an emulsion copolymer which is the reaction product of a) 0 to 50% by weight of styrene, .alpha.-methyl-styrene or a mixture of these monomers, b) 0 to 50% by weight of methyl methacrylate, c) 10 to 45% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, d) 5 to 30% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl- or 2-, 3- or 4-hydroxybutyl-(meth)-acrylate or any mixture of these monomers, e) 1 to 15% by weight of acrylic acid, methacrylic acid or any mixture of these acids and f) 0 to 15% by weight of other comonomers, wherein i) 0 to 50% of the carboxyl groups are neutralized with an aliphatic amine or with ammonia, ii) the percentages a) - f) adding up to 100, based on the total weight of a) - f) and iii) the combined weight of monomers a) and b) being 10 - 70% by weight, based on the total weight of monomers a) - f), B) 0to100% by weight, based on the total weight of components A) and B), of a melamine resin and C) water.
The present invention also relates to coated substrates, particularly coated motor vehicle substrates, prepared from these aqueous, clear, coating compositions.
Mo3554
Description
Mo3554 - LeA 27,591 AQUEOUS, CLEAR, COATING COMPOSITION
CONTAINING EMULSION COPOLYMERS AND
COATED SUBSTRATES PREPARED THEREFROM
BACKGROUND OF THE INVENTION
S Field of the Invention This invention relates to aqueous, clear, coating compositions containing mixtures of certain emulsion copolymers and melamine resins as the binder and their use for preparing coated substrates, particularly the uppermost top coat for motor vehicle bodies.
Description of the Invention The preparation of coatings for motor vehicles may be carried out by any of various processes conventionally used industrially. Although the primer is generally applied in the aqueous phase by electro dip priming, both water dilutable and organically dissolved systems may be used as fillers and base coat;ngs (base coa~). Water dilutable coating systems are preferred for reasons of safety in work and environmental protection as well as for saving raw materials, but at present there are various technical problems in achieving a build up of motor vehicle coatings from the aqueous phase. In particular, there is no technically useful solut;on to the problem of applying the aqueous clear coating (clear coat) as the fourth layer over base coats (metallic or pigmented) so that a complete build up of coatings from the aqueous phase has not previously been achieved.
Although numerous publications deal with the preparation of aqueous binders based on copolymers of olefinically unsaturated compounds, the present invention for the first time provides an aqueous clear coating which satisfies all of the requirements of an aqueous clear coat for coating motor vehicles in serîes.
US-PS 3,611,827 (Ashland Oil) relates to a process for the preparation of a water dispersible acrylic coating 35376TWR201~
compound which is not an emulsion polymer. In the opinion of the authors of DE-OS 2,357,152, th;s product does not satisfy the requirements of manufacturers of passenger cars and trucks for a first class aqueous coating.
DE-OS 2,357,152 (US-PS 4,164,488) describes ~queous, heat hardening acrylic coating compositions which are said to be the first aqueous systems to provide suitable coatings for motor vehicles. The special suitability of this product is said to be particularly apparent when it is used as a pigmented coating binder but the specification does not describe the particular use or suitability of this product as a clear coating. It is evident from the description that the products prepared according to DE-OS 2,357,152 are solution polymers.
A partial solubility of the completed polymer in watPr is achieved by special measures in providing the composition. It is stated that due to a COOH:OH group ratio of from 1:0.2 to 1:1.8, about 30 to 50% by weight of the polymer is in a dispersed form while the remaining 50 to 70% are soluble and present in a dissolved form in the aqueous medium.
US-PS 3,862,071 describes similar systems of partially soluble, partially dispersed polymers containing at least 0.25% by weight of a dispersed aluminum bronze. This application also shows that thermosetting motor vehicle coatings based on acrylic resins cross-linked with amino resins provide particularly useful results if partially water-soluble polymers are used.
This principle is applied in DE-PS 2,918,067 to a combination of special emulsion polymers. These aqueous coating systems are also cross-linked with amino resins but the products are unsatisfactory in various respects, e.g., the hardness of the films in sp;te of the high stoving temperature, the resistance to solvents or the adherence to the underlying surface. It is clear from the description that the polymer amino resin mixtures according to the invention are to be used Mo3554 , , , . . . ....
" : ~ ,, ;
,. :
, in particular for the preparation of pigmented coatings and there is no indication that the mixtures are particularly suitable for clear coats, let alone clear coats for motor vehicles.
Aqueous coating systems based on acrylate emulsion polymers and melamine resins are described in DE-OS 2,531,802.
These products are said to be superior, for example, to the products of US-PS 3,862,071 (see above~. The acrylic polymers of DE-OS 2,531,802, however, only differ from those of US-PS
3,862,071 in that the dispersed component is prepared by the emulsion polymerization technique and the binder mixture contains a lower percentage of water-soluble acrylic copolymers; the product according to DE-OS 2,531,802 does not dispense with such a soluble component.
i~ European Patent Application EP-A-0,253,251 mentions clear coatings based on acrylic resins with aminoplasts as second component. In the presence of solubili~ing or dispersing carboxylate groups, these coatings may be applied as aqueous systems. Since these products must be capable of developing deep drawable coatings if applied from tins, no functional groups such as hydroxyl groups are used in the acrylic polymers, i.e., the copolymers contain no hydroxyalkyl acrylates or methacrylates as monomer units.
In EP-A-0,029,597, the teaching oF DE-O~ ~,357,152 by the same applicant is varied. While otherwise similar polymers are used, UV stabilizers are used in add;tion for the purpose of improving the resistance to weathering, e.g., in clear coatings. In addition, the patent application also states that for obtaining good coating properties the products are required to contain considerable proportions of acrylic polymers dissolved in water in addition to 50% of d;spersed components.
The Applicant also emphasizes that the product must not contain external emulsifiers.
Numerous technical instructions for the preparation of optimum aqueous acrylic coating compositions, all pointing Mo3554 ,: - , in the same direction, may be found in the article by Y.Nakayama, T.Watanabe and I.Toyomoto (Kansai Paint) "High Performance Coatings from Blends of Emulsions and Water-Soluble Resins" in the Journal of Coatings Technology, V01.569 No.716, September 1984, page 73 et seq. The article emphasizes the necessity of mixing aqueous, dispersible acrylic polymers with water-soluble acrylic polymers and points out the harmfulness of surface-active additives such as emulsifiers (surfactants) for the water resistance and adherence to the underlying surface in the presence of high moisture contents. So-called soap-free acrylic emulsions are therefore recommended and produced.
The disadvantage of aqueous emulsion polymers prepared with low molecular weight emulsifiers is also particularly mentioned in EP-A-0,001,489. The presence of the emulsifiers required for stabilizing the polymer dispersion considerably reduces, for example, the resistance of the coating films to the influences of moisture and weather. For overcoming these technical disadvantages, the preparation of so-called "sterically stabilized" dispersion polymers is described in EP-A-0,001,489. In the application the polymers are not prepared in an aqueous phase or aqueous emulsion, but rather are converted into an aqueous dispersion only after completion of the various steps of polymerizatibn which are to be carried out in non-aqueous solvents.
This idea is also present in EP-B-0,038,127.
Pseudoplastic or thixotropic microgel emulsions based on acrylate copolymers cross-linked with amino resins are described for the aqueous metallic base coat in EP-B-0,038,127.
Various possibilities are described in EP-B-0,038,127 for the acrylate binders for the clear coats applied over the metallic coating:
1) Solution polymers in non-aqueous solvents (Examples 1, 2, 4, 5) Mo3554 , . , . .~ , , .
CONTAINING EMULSION COPOLYMERS AND
COATED SUBSTRATES PREPARED THEREFROM
BACKGROUND OF THE INVENTION
S Field of the Invention This invention relates to aqueous, clear, coating compositions containing mixtures of certain emulsion copolymers and melamine resins as the binder and their use for preparing coated substrates, particularly the uppermost top coat for motor vehicle bodies.
Description of the Invention The preparation of coatings for motor vehicles may be carried out by any of various processes conventionally used industrially. Although the primer is generally applied in the aqueous phase by electro dip priming, both water dilutable and organically dissolved systems may be used as fillers and base coat;ngs (base coa~). Water dilutable coating systems are preferred for reasons of safety in work and environmental protection as well as for saving raw materials, but at present there are various technical problems in achieving a build up of motor vehicle coatings from the aqueous phase. In particular, there is no technically useful solut;on to the problem of applying the aqueous clear coating (clear coat) as the fourth layer over base coats (metallic or pigmented) so that a complete build up of coatings from the aqueous phase has not previously been achieved.
Although numerous publications deal with the preparation of aqueous binders based on copolymers of olefinically unsaturated compounds, the present invention for the first time provides an aqueous clear coating which satisfies all of the requirements of an aqueous clear coat for coating motor vehicles in serîes.
US-PS 3,611,827 (Ashland Oil) relates to a process for the preparation of a water dispersible acrylic coating 35376TWR201~
compound which is not an emulsion polymer. In the opinion of the authors of DE-OS 2,357,152, th;s product does not satisfy the requirements of manufacturers of passenger cars and trucks for a first class aqueous coating.
DE-OS 2,357,152 (US-PS 4,164,488) describes ~queous, heat hardening acrylic coating compositions which are said to be the first aqueous systems to provide suitable coatings for motor vehicles. The special suitability of this product is said to be particularly apparent when it is used as a pigmented coating binder but the specification does not describe the particular use or suitability of this product as a clear coating. It is evident from the description that the products prepared according to DE-OS 2,357,152 are solution polymers.
A partial solubility of the completed polymer in watPr is achieved by special measures in providing the composition. It is stated that due to a COOH:OH group ratio of from 1:0.2 to 1:1.8, about 30 to 50% by weight of the polymer is in a dispersed form while the remaining 50 to 70% are soluble and present in a dissolved form in the aqueous medium.
US-PS 3,862,071 describes similar systems of partially soluble, partially dispersed polymers containing at least 0.25% by weight of a dispersed aluminum bronze. This application also shows that thermosetting motor vehicle coatings based on acrylic resins cross-linked with amino resins provide particularly useful results if partially water-soluble polymers are used.
This principle is applied in DE-PS 2,918,067 to a combination of special emulsion polymers. These aqueous coating systems are also cross-linked with amino resins but the products are unsatisfactory in various respects, e.g., the hardness of the films in sp;te of the high stoving temperature, the resistance to solvents or the adherence to the underlying surface. It is clear from the description that the polymer amino resin mixtures according to the invention are to be used Mo3554 , , , . . . ....
" : ~ ,, ;
,. :
, in particular for the preparation of pigmented coatings and there is no indication that the mixtures are particularly suitable for clear coats, let alone clear coats for motor vehicles.
Aqueous coating systems based on acrylate emulsion polymers and melamine resins are described in DE-OS 2,531,802.
These products are said to be superior, for example, to the products of US-PS 3,862,071 (see above~. The acrylic polymers of DE-OS 2,531,802, however, only differ from those of US-PS
3,862,071 in that the dispersed component is prepared by the emulsion polymerization technique and the binder mixture contains a lower percentage of water-soluble acrylic copolymers; the product according to DE-OS 2,531,802 does not dispense with such a soluble component.
i~ European Patent Application EP-A-0,253,251 mentions clear coatings based on acrylic resins with aminoplasts as second component. In the presence of solubili~ing or dispersing carboxylate groups, these coatings may be applied as aqueous systems. Since these products must be capable of developing deep drawable coatings if applied from tins, no functional groups such as hydroxyl groups are used in the acrylic polymers, i.e., the copolymers contain no hydroxyalkyl acrylates or methacrylates as monomer units.
In EP-A-0,029,597, the teaching oF DE-O~ ~,357,152 by the same applicant is varied. While otherwise similar polymers are used, UV stabilizers are used in add;tion for the purpose of improving the resistance to weathering, e.g., in clear coatings. In addition, the patent application also states that for obtaining good coating properties the products are required to contain considerable proportions of acrylic polymers dissolved in water in addition to 50% of d;spersed components.
The Applicant also emphasizes that the product must not contain external emulsifiers.
Numerous technical instructions for the preparation of optimum aqueous acrylic coating compositions, all pointing Mo3554 ,: - , in the same direction, may be found in the article by Y.Nakayama, T.Watanabe and I.Toyomoto (Kansai Paint) "High Performance Coatings from Blends of Emulsions and Water-Soluble Resins" in the Journal of Coatings Technology, V01.569 No.716, September 1984, page 73 et seq. The article emphasizes the necessity of mixing aqueous, dispersible acrylic polymers with water-soluble acrylic polymers and points out the harmfulness of surface-active additives such as emulsifiers (surfactants) for the water resistance and adherence to the underlying surface in the presence of high moisture contents. So-called soap-free acrylic emulsions are therefore recommended and produced.
The disadvantage of aqueous emulsion polymers prepared with low molecular weight emulsifiers is also particularly mentioned in EP-A-0,001,489. The presence of the emulsifiers required for stabilizing the polymer dispersion considerably reduces, for example, the resistance of the coating films to the influences of moisture and weather. For overcoming these technical disadvantages, the preparation of so-called "sterically stabilized" dispersion polymers is described in EP-A-0,001,489. In the application the polymers are not prepared in an aqueous phase or aqueous emulsion, but rather are converted into an aqueous dispersion only after completion of the various steps of polymerizatibn which are to be carried out in non-aqueous solvents.
This idea is also present in EP-B-0,038,127.
Pseudoplastic or thixotropic microgel emulsions based on acrylate copolymers cross-linked with amino resins are described for the aqueous metallic base coat in EP-B-0,038,127.
Various possibilities are described in EP-B-0,038,127 for the acrylate binders for the clear coats applied over the metallic coating:
1) Solution polymers in non-aqueous solvents (Examples 1, 2, 4, 5) Mo3554 , . , . .~ , , .
2) Solution polymers prepared in non-aqueous, water miscible solvents such as isopropanol and subsequently converted into an aqueous solution (Example 3) 3) Aqueous dispersion polymers (no Example, column 14, lines 22-29).
The use of an acrylic polymer prepared by the emulsion polymerization technique is also suggested as a possib;lity for the clear coat if it is to be applied from the aqueous phase (column 14, lines 30-32, no Example). No details are gi~en as to the technical procedures which would be necessary for preparing a workable clear coating (additives, cross-linking agents and auxiliary agents used). Further, the examples of practical applica~ion give no indication that aqueous emulsion polymers, which are not in the form of 1, microgels, are particularly useful.
The acrylate solution described in EP-B-0,038,127 is prepared by a two-stage and therefore complicated manufacturing process and is not an emulsion polymer. In view of the numerous doubts raised inter alia in EP-A-0,001,489 by the same applicant against the use of emulsifiers in emulsion polymers and against systems which are dispersed in water alone, without the presence of substantial quant;ties of dissolved polymers, it may be inferred from EP-B-0,038,127 in conjunction with the remainder of the art that no technically useful aqueous clear coat for motor vehicles comparable to the clear coatings according to the invention may be obtained.
It is known from DE-OS 3,803,522 that water dispersible acrylic polymers used in combination with special hydrophobic melamine resins having molecular weights of at least 500 as cross-linking agents can be worked up to produce pigmented coating systems, in particular systems containing metallic pigments. According to the teachings of ~E-OS
3,802,522, these systems are particularly suitable for use as the lower layer of two coats to be applied wet-on-wet. There is no indication as to the suitability of the coating systems for Mo3554 . .
.
.
J
clPar coats. Instead, the pigment is specif;cally claimed as integral component of the coating composition. The only clear coats mentioned ;n DE-OS 3,803,522 are products d;ssolved in organic solvents.
The binder systems of DE-OS 3,803,522 (acryl;c copolymer + hydrophobic, h;gh molecular weight melamine resin) g;ve poor gloss values in clear coat;ngs when the pigment ;s omitted and do not satisfy practical processing requ;rements due to the technical complication of incorporating the hydrophob;c melam;ne resin into the aqueous system. Thus, there is no indication that a useful clear coat system could be obtained according to DE-OS 3,803,522.
EP-A-0,287,144 describes acrylic polymers prepared by at least two stages of emuls;on polymerization and having a special composition adapted exclusively to their use as metallic base coats. Apart from the complicated method of preparation, the specification contains no indication of the use of the products as clear coats.
DE-OS 3,734,755 descr;bes polyacrylate emulsions and dispersions as temporary surface protection with a reduced tendency to corrode. No teaching ~or the preparation of aqueous clear coats can be derived from these non-crosslinked coatings which are readily removed again from the substrate.
Water-soluble acrylic stoving coatings are described in DE-OS 2,840,574. These products are solution polymers for metal effect coatings but due to the insufficient metallic effect and the complicated method of preparation, they have not become established industrially. These products are unsuitable for use as aqueous clear coats due to the unfavorable rheological properties of the aqueous solutions, which must be compensated for by the addition of considerable quantities of organic auxiliary solvents, which is undesirable from an environmental point of view. These products are also unsuitable due to the hydrophilic character of the binder system, which is a disadvantage, for example for wet-on-wet Mo3554 .: , ~ , : ,; ,- ,, , . ~ , ; . , ~ -, ,, , , ~
,, :
, , application on an aqueous base coat7 because of ~he faults produced in the film and the li~itation of the products to special~ selected cross-linker resins.
Summarizing, it is found that technically useful aqueous clear coatings for motor vehicles have not prevlously been described. Accordingly, it is an object of the present invent;on to provide aqueous clear coating compositions which overcome the deficiencies of the prior art.
This object may be achieved in accordance with the present invention as described hereinafter.
SUMMARY OF THE INVENTION
The present ;nvention relates to aqueous, clear, coating compositions containing A) 60 to 90% by weight, based on the total weight of components A) and B), of an emulsion copolymer which is the reaction product of a) O to 50% by weight of styrene, ~-methyl-styrene or a mixture of these monomers, b) O to 50% by weight of methyl methacrylate7 c) 10 to 45% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, d) 5 to 30% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl- or 2-, 3- or 4-hydroxybutyl-(meth)acrylate or any mixture of these monomers, e) 1 to 15% by weight of acrylic acid, methacrylic acid or any mixture of these acids and f~ O to 15% by weight of other comonomers, wherein i ) O to 100, preferably 0 to 80 and most preferably 0 to 50% of ~e carboxyl 3Q groups are neutralized with an aliphatic amine or with ammon~
ii) the percentages a) - f) adding up to 100, based on the total weight of a) - f) and iii) the combined weight of monomers a) and b) being 10 - 70% by we;ght, based on the total weight of monomers a) - f), Mo3554 B3 10 to 40% by weight, basPd on the total weight of components A) and B), of a melamine resin and C) water.
The present invention also relates to coated substrates, particularly coated motor vehicle substrates, prepared from these aqueous, clear, coating compositions.
DETAILED DESCRIPTION OF THE INYENTION
Based on the weight of components A) and B), the aqueous, clear, coating compositions according to the invention contain 60 to 90% by weight, preferably 65 to 85% by weight of component A) and 10 to 40% by weight, preferably 15 to 35% by weight of component B).
The mixture of components A) and B) ;s the primary binder component according to the present inven~ion. Component C) may include, in addition to water, known auxil;ary agents and additives such as additional cross-linking agents, auxiliary rheological agents, wetting agents, catalysts, organic solvents and light protect;ve agents.
Component A), which is essential for the invention, is based on an emuls;on copolymer of the above-mentioned monomers a) to f). Monomer c) includes methyl acrylate, ethyl acrylate, n-butyl acrylate, n-hexyl acrylate and n-octyl acrylate. Optional monomer f) includes vinyl toluene; alkyl methacrylates having from 2 to 18 carbon atoms in the alkyl group; alkyl acrylates having 9 to 18 carbon atoms in the alkyl group; N-vinylpyrrolidone; vinyl-alkyl-ketones having 1 to 4 carbon atoms; vinyl-alkyl-carboxylates having 1 to 18 carbon atoms in the alkyl group; alkyl esters of maleic, fumaric or itaconic acid in each case having 1 to 4 carbon atoms in the alkyl group; vinyl sulphonic acid salts and mixtures thereof.
Particularly preferred emulsion copolymers A) are based on the reaction product of a) 0 to 40, most preferably 20 to 40% by weight of s~yrene b) 5 to S0, most preferably 5 to 20% by weight of me~yl methaclylate, Mo3554 .
;
- : ,:
, ~ . ~ ,, , c) 25 to 40% by weight of at least one alkyl acrylate having 4 to 8 carbon atoms in the alkyl group, d) 12 to 20% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl-methacrylate or mixtures of these monomers, e~ 2 to 10% by weight of methacrylio acid and f) O to 15% by weight of other comonomers wherein the combined weight of monomers a) and b) being 35 -50, pre~erably 35 - 45% by weight, based on the total weight of monomers a) - f).
Preferably, monomers d) and e~ are used in an amount which corresponds to an equivalent ratio of carboxyl groups to hydroxyl groups of 1:1.5 to 1:4.5, more preferably 1:1.9 to 1:4.5.
The preparation of emulsion polymer A) may be carried out by the conventional emulsion polymerization process as described e.g. in Houben-Weyl, Methoden der Organischen Chemie, Supplements to the 4th Edition, Volume E 20/Part 1, pages 218-313. The known polymerization auxiliaries are used when the emulsion polymers are prepared in an aqueous medium.
20 . The quantity of water is generally calculated to result in aqueous polymer emulsion having solids contents of 20 to 60% by weight, preferably 35 to 50% by weight.
The emulsion polymers thus prepared and present as aqueous emulsions are combined with the other components to produce the clear coating compositions of the present invent;on.
The cross linking agents B) are melamine resins which may be unetherified or partially or completely etherified with saturated alcohols containing 1 to 4 carbon atoms. Preferred melamine resins are fully methyl etherified melamine resins as described, for example, in FR-PS 943,411 sr in 7he Chemistry of Organic Filmformers by D.H.Solomon, John Wiley & Sons, Inc., New York, 1967, pages 235r240.
It is in many cases advisable to use acid catalysts to ensure adequate cross-linking of the cvating films. The Mo3554 ; ~ :
'' nature and concentration of these catalysts will depend on the stoving conditions and the nature of the melamine resins.
Suitable acid catalysts include alkyl benzene sulphonic acids such as toluene sulphonic ac;ds and dialkylnaphthalene mono-and disulphonic ac;ds which may be free or blocked w;th amines.
Commercially available thickeners such as those based on polyacrylates or polyurethanes are frequently used to ;mprove the rheological properties. These properties may in addition be influenced by varying the pH either by the nature and concentration of the neutralization amines added or by the addition of auxiliary solvents.
Although the emulsion polymers are stable in storage due to the presence of the external emulsifiers generally used duling emulsion polymerization, up to 100, preferably up to 80% and most preferably up to 50% of the carboxyl ,groups in the copolymers may b~ n~u~cralized using ammonia aliphatic amines as neutralizing agents. Examples of aliphatic amines include triethylamine, ethanolamine, dimethylethanolamine and triethanolamine.
Examples of suitable auxiliary solvents, which may optionally be used in quantities of up to 10% by weight, based on the total quantity of coating composition, include monohydric and polyhydric alcohols, hydrocarbons, ethers, esters and ketones, e.g., ethyl or butyl glycol and their acetates, ethyl and butyl diglycol, ethylene glycol ~5 dimethylether and methoxy propanol.
The other auxiliary agents and additives pre~iously ment;oned may also be used in the preparation of the clear, ready-for-use coating compositions. The clear coating compositions have a solids content of 25 to 50% by weight, preferably 30 to 45% by weight, and a viscosity of 15 to 60 sec, preferably 18 to 40 sec (DIN 4 cup/25~C).
The coating may be applied by known methods employed in coating technology, preferably by spraying wlth a flow cup gun. The coatin~ may be applied wet^on-wet (after brief pauses for ventilation) or on pre-dried base coating containing Mo3554 ,. . .
, ~ , solvent. It is particularly environmentally desirable for the entire coatings bu;ld-up to apply the clear coat;ng composition according to the invention to a layer of an aqueous base coat.
This application may be carried out either wet-on-wet (after brief intervals for ventilation) or on a pre-dried aqueous base coat.
The substrates coated with the clear coating composition are generally ventilated at a temperature of 10 to 50~C, preferably 25 to 40C, for a short ~ime after application and then stoved at about 100 to 160C, preferably 120 to 140C, for a period of about 10 to 60, preferably 20 to 30 minutes.
For relatively thick coatings, it is in many cases advisable also to carry out an intermediate drying at 8QC to reduce blistering. The stoved coatings thus obtained are distinguished by excellent optical and mechanical properties comb;ned with good solvent resistance.
In the examples which follow, all the parts and percentages are by weight unless otherwise specified.
ExamPles of preparation of aaueous emulsion polvmers to be used accordinq to the invention AcrYlate dispersion 1 The following components were reacted by the known emulsion polymerization at 800 in a glass reactor with stirrer:
613.50 parts of deionized water, 3.90 parts of polyethoxylated 3-benzyl-4-hydroxy-biphenyl (about 10 moles of ethylene oxide per mole of hydroxy compound) (Emulsifier 1) 0.75 parts of sodium-di-sec.-butyl-naphthalene sulphonate (Emulsifier 2), 1.25 parts of ammon~um peroxydisulphate, 117.00 parts of styrene, 53.00 parts of methyl methacrylate, 35- 141.00 parts of butyl acrylate, Mo3554 72.00 parts of hydroxyethylmethacryla~, 25.00 parts of methacryl;c acid and 7.40 parts of dodecylmercaptan.
When polymerization had been terminated, a post-polymerization was carried out at 80C by the addition of 0.25 parts of ammonium peroxydisulphate~ and the product was then partially neutralized with 3.26 parts of dimethylethanolamine.
The emulsion was still perfect and free from ground settlement after ~ year's storage at 23C.
AcrYlate disDersion 2 Sam2 as acrylate d;spersion 1 but neutralized with 1.63 parts of dimethylethanolamine.
Acrylate dispersion 3 Same as acrylate dispsrs;on 1 but neutral;zed with 1~ 6.52 parts of dimethylethanolamine.
Acrylate disDersion_4 Same as acrylate dispersion 1 but neutralized with 5.47 parts of triethanolamine.
AcrYlate dispers;on 5 Same as acrylate dispersion 1 but neutralized with 3.67 parts of triethylamine.
Acrvlate disDersion 6 Same as acrylate dispersion 1 but neutralized w;th 1.75 parts of 33% aqueous ammonia.
AcrYlate disDersion 7 The following components were reacted using the method set forth for acrylate dispers;on 1:
613.80 parts of deionized water, 3.90 parts of Emulsifier 1, 0.75 parts of Emulsifier 2, 1.25 parts of ammonium peroxydisulphate, 117.00 parts of styrene, 63.00 parts of methyl methacrylate, 141.00 parts of butyl acrylate, 72.00 parts of hydroxyethylmethacryla~, Mo3554 ~J.~
11.10 parts of methacrylic acid and 7.40 parts of dodecylmercaptan.
When polymerizat;on had been term;nated, a post-polymerization was carried out at 800 by the addition of 0.25 5parts of ammonium peroxydisulphate and the product was then partially neutrali7ed with 3.26 parts of dimethylethanolamine.
Acrylate dis~ersion 8 The following components were reacted using the method set forth for acrylate dispersion 1:
~614.50 parts of deionised water 3.90parts of Emulsifier 1, 0.75 parts of Emulsifier 2, 1.63 parts of ammonium peroxydisulphate, 117.00 parts of styrene, 1553.00 parts of methyl methacrylate, 141.00 parts of butyl acrylate, 72.00 parts of hydroxyethyl methacrylate, 21.00 parts of methacrylic acid and 9.62 parts of dodecylmercaptan.
20When polymerization had been terminated, a post-polymerization was carried out by the addition of 0.325 parts of ammonium peroxydisulp~ate at 80C and the product was then partially neutralized with 3.26 parts of dimethylethanolamine.
Acrylate dispers;on 9 25The following components were reacted us;ng the method set forth for acrylate dispersion 1:
613.00 parts of deionized water, 3.90 parts of Emulsifier 1, 0.75 parts of Emulsifier 2, 300.63 parts of ammon~um peroxydisulphate, 117.00 parts of styrene, 53.00 parts of methyl methacrylate, 141.00 parts of butyl acrylate, 72.00 parts of hydkoxyethylmethacrylate, 3521.00 parts of methacrylic acid and Mo3554 .
, : , ~14-3.70 parts of dodecylmercaptan.
When polymer kation had been terminated, a post-polymerization was carried out by the addition of 0.125 parts of ammonium peroxydisulphate at 80C and the product was then partially neutralized with 3.26 parts of dimethylethanolam;ne.
AcrYlate dispersions 10-14 The components summarized in Table 1 below were reacted using the method set forth for acrylate dispersion l;
the number in Table 1 represent parts.
Table 1 11 12 13 14 Acrylate dispersions 1247.01251.01246.0 1251.0 1250.0 de;onized water 7.8 7.8 7.8 7.8 7.8 Emulsifier 1 1.5 1.5 1.5 1.5 1.5 Emulsifier 2 2.5 2.5 ~.5 2.5 2.5 ammonium peroxy-disulphate 105.0105.0 105.0 339.0 105.0 styrene 234.0281.0 247.0 - 247.0 methyl methacrylate 283.0283.0 272.0 283.0 72.0 butyl acrylate 144.0 97.0 141.0 144.0 - hydroxyethyl methacrylate - - - -141.0 hydroxypropyl methacrylate 47.0 43.0 47.0 43.0 43.0 methacrylic acid 14.8 14.8 14.~ 14.8 14.8 dodecylmercaptan _ Commercial mixture of 2- and 3-hydroxypropyl-methacrylate Mo3554 .
, .
Post-polymerization was carried out in all cases by the addition of 0.5 parts of ammonium peroxydisulphate at 80C
after termination of the polymerization and the product was then partially neutralized with 6.5 parts of ~imethylethanolam;ne.
PreDaration of an aqueous clear coatinq The formulations used to prepare aqueous clear coat;ng compositions are set forth in Table 2.
Table 2 Formulations of the clear coating compositions Formulation No. 1 2 3 4 5 6 7 Melamine resin 1* 11.0 11.0 Melamine resin 2* 10.2 10.2 10.2 10.2 10.5 Levelling agent 1* 1.2 1.2 1.2 1.2 1.2 1.2 1.2 Levelling agent 2* 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Butyl glycol 3.9 4.0 4.1 4.1 4.1 1, Ethyl diglycol/
butyl diglycol 3.2 3.3 Acid catalyst 1* 0.3 Acid catalyst 2* 0.8 0.8 0.8 0.8 Light protective agent 1* 1.8 1.8 1.8 1.8 1.7 1.7 1.8 Light protective agent 2* 1.8 1.8 Light protective agent 3* 1.& 1.8 1.7 1.7 1.8 Dimethylethanolamine, 10% in water 6.1 6.0 5.g 5.~ 5.8 5.8 6.0 Wetting auxiliary* 1.2 1.2 1.2 1.2 1.2 1.2 1.2 deionized water 6.8 8.1 8.1 9.2 9.9 9.5 7.8 Acrylate dispersion 1 60.6 60.2 Acrylate dispersion 6 - 59.5 59.1 Acrylate dispersion 8 57.8 Acrylate dispersion 9 58.3 59.7 Th;ckener* 5.0 4.9 4.9 4.9 5.0 4.9 5.0 Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 ========================================================= ===========
Outflow v;s~os;ty 2~ 20 1~ 17 19 26 26 in sec (DIN 4 cup, 25C~
Mo3554 f~. ' 3 i~
Melamine resin 1: Cymel 327 (Cyanamid Int., Wayne, N.J. 90% solids content in i-propanol Melamine resin 2: Cymel 303 (Cyanamid Int., Wayne, N.J.) 98% solids content in water Levelling agent 1: Additol XW 395 (Hoechst AG, Frankfurt/M, BRD) 50% in butyl ~lycol Levelling agent 2: Resiflow W 50 (Worlee-Chem;e GmbH, Hamburg, BRD) 50% in butyl glycol/isopropanol 4:1 Wetting auxiliary: Fluorotensid FT 929 (Bayer AG, Leverkusen, BRD~ 10% in water/ethanol 8:1 Acid catalyst 1: Nacure 2501 (King Industries Inc., Norwalk CT) 25% in isopropanol Acid catalyst 2: Nacure 1051 (King Industries Inc., Norwalk CT) 50% ;n butyl glycol Light protective agent 1: Tinuvin 1130 (Ciba-Geigy Marienberg 6mbH, Lautertal, BRD~ 20% ;n ethyl diglycol/butyl diglycol 1:1 Light protective agent 2: Tinuvin 292 (Ciba-Geigy Marienberg GmbH, Lautertal, BRD) 20% in ethyl diglycol/butyl diglycol 1:1 0 Light protective agent 3: Tinuvin 440 (Ciba-Geigy Marienberg GmbH, Lautertal, BRD) 20% in butyl glycol Thickener: Viscalex HV 30 (Allied Colloids GmbH, Hamburg, BRD) 5% in water 25 The indiv;dual components were successively stirred in at a uniform rate and homogenized with a dissolver.
Application of the aqueous clear coatinq A steel sheet which had been prepared with an electro dip primer (KTL), filler and base coat (aqueous or containing solvent) was coated with the clear coating.
Mo3554 ,~ . , - ~ , A temperature of 20-25C and relativQ humid;ty of 40 to 70% was maintained during the application of this coating. The outflow rate from the flow cup gun was 300-~00 ml/min, depending upon the viscosity of the formulation. The spray gun was fitted with a 1.2 mm no~zle and operated at a pressure of 3.5-5.0 bar.
The coating was applied in three stages with a brief interruption for ventilation after the first spraying stage.
DrYing of the clear coatings The coated steel sheets were ventilated at 40C for 1 to 5 minutes, pre-dried at 80C and stoved at 140C for 20 minutes. Increasing the duration of the ventilating phases provided a marked reduction in the formation of blisters. The clear coating film obtained had a layer thickness of 35-60 ~m.
Testinq of the clear coatinq films The lacquered substrates were first assessed optically after the stoving process. The Erichsen cupping (DIN
IS0 1520) was then determined as a measure of the elasticity, the pendulum hardness (DIN 53157) was determined as a measure oF the hardness of the film and the degree of gloss was determined (at an angle of 20 and at 60). The ease with which the films were attacked by the solvent action of toluene, butyl acetate, methoxypropyl acetate and acetone was then tested by placing a wad of cotton wool impregnated with solvent for 1 minute directly on the coating surface and the results were assessed optically and mechanically. The best result was denoted by 0 (unchanged surface) and the worst by 5 (coating film became detached). The res;stance of the films to solvents and water was then tested by exposing the films to the action of the solvents (ethanol, xylene/10 minutes) and water (for 24 h) and then assessing the result as described above for the test for solvent action.
The detailed test results for the clear coating formulations according to the invention are summarized in Table 3.
Mo3554 , , .
Table 3: Test results nf clear coating formulations Formulation No. 1 2 3 4 5 6 7 Layer thickness (~m) 50 40 45 50 40 50 45 Formation of film 0 0 0 0 1 0 Gloss according to Lange 20~ 88 89 ~7 94 95 96 96 Erichsen cupping (DIN IS0 1520) (mm) 7.0 5-5 5.0 5.5 7.0 6.0 7.0 Pendulum hardness according to Konig (DIN 53157) (s)180 169 187 184 171 171 185 Action of sol-vent (1 min) (Tol/BuAc/
MPA/Ac) 0000 0000 0000 0000 0000 0000 0000 Resistance to xylene (10 min) 0 0 0 Resistance to ethanol (10 min) 0 0 0 0 1 0 Resistance to water (24 h) 0 0 0 0 0 0 0 Practical tests carried out on clear coating fiims showed no differences when applied to base coats containing solvent and aqueous base coats. The adh~rence of the clear coating film was good on both substrates.
Although the invention has been described in detail in the foregoing for the purpose of illustration9 it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
Mo3554 .
. ~ ... .
, . . - ~ -. ' ~ ~- ,
The use of an acrylic polymer prepared by the emulsion polymerization technique is also suggested as a possib;lity for the clear coat if it is to be applied from the aqueous phase (column 14, lines 30-32, no Example). No details are gi~en as to the technical procedures which would be necessary for preparing a workable clear coating (additives, cross-linking agents and auxiliary agents used). Further, the examples of practical applica~ion give no indication that aqueous emulsion polymers, which are not in the form of 1, microgels, are particularly useful.
The acrylate solution described in EP-B-0,038,127 is prepared by a two-stage and therefore complicated manufacturing process and is not an emulsion polymer. In view of the numerous doubts raised inter alia in EP-A-0,001,489 by the same applicant against the use of emulsifiers in emulsion polymers and against systems which are dispersed in water alone, without the presence of substantial quant;ties of dissolved polymers, it may be inferred from EP-B-0,038,127 in conjunction with the remainder of the art that no technically useful aqueous clear coat for motor vehicles comparable to the clear coatings according to the invention may be obtained.
It is known from DE-OS 3,803,522 that water dispersible acrylic polymers used in combination with special hydrophobic melamine resins having molecular weights of at least 500 as cross-linking agents can be worked up to produce pigmented coating systems, in particular systems containing metallic pigments. According to the teachings of ~E-OS
3,802,522, these systems are particularly suitable for use as the lower layer of two coats to be applied wet-on-wet. There is no indication as to the suitability of the coating systems for Mo3554 . .
.
.
J
clPar coats. Instead, the pigment is specif;cally claimed as integral component of the coating composition. The only clear coats mentioned ;n DE-OS 3,803,522 are products d;ssolved in organic solvents.
The binder systems of DE-OS 3,803,522 (acryl;c copolymer + hydrophobic, h;gh molecular weight melamine resin) g;ve poor gloss values in clear coat;ngs when the pigment ;s omitted and do not satisfy practical processing requ;rements due to the technical complication of incorporating the hydrophob;c melam;ne resin into the aqueous system. Thus, there is no indication that a useful clear coat system could be obtained according to DE-OS 3,803,522.
EP-A-0,287,144 describes acrylic polymers prepared by at least two stages of emuls;on polymerization and having a special composition adapted exclusively to their use as metallic base coats. Apart from the complicated method of preparation, the specification contains no indication of the use of the products as clear coats.
DE-OS 3,734,755 descr;bes polyacrylate emulsions and dispersions as temporary surface protection with a reduced tendency to corrode. No teaching ~or the preparation of aqueous clear coats can be derived from these non-crosslinked coatings which are readily removed again from the substrate.
Water-soluble acrylic stoving coatings are described in DE-OS 2,840,574. These products are solution polymers for metal effect coatings but due to the insufficient metallic effect and the complicated method of preparation, they have not become established industrially. These products are unsuitable for use as aqueous clear coats due to the unfavorable rheological properties of the aqueous solutions, which must be compensated for by the addition of considerable quantities of organic auxiliary solvents, which is undesirable from an environmental point of view. These products are also unsuitable due to the hydrophilic character of the binder system, which is a disadvantage, for example for wet-on-wet Mo3554 .: , ~ , : ,; ,- ,, , . ~ , ; . , ~ -, ,, , , ~
,, :
, , application on an aqueous base coat7 because of ~he faults produced in the film and the li~itation of the products to special~ selected cross-linker resins.
Summarizing, it is found that technically useful aqueous clear coatings for motor vehicles have not prevlously been described. Accordingly, it is an object of the present invent;on to provide aqueous clear coating compositions which overcome the deficiencies of the prior art.
This object may be achieved in accordance with the present invention as described hereinafter.
SUMMARY OF THE INVENTION
The present ;nvention relates to aqueous, clear, coating compositions containing A) 60 to 90% by weight, based on the total weight of components A) and B), of an emulsion copolymer which is the reaction product of a) O to 50% by weight of styrene, ~-methyl-styrene or a mixture of these monomers, b) O to 50% by weight of methyl methacrylate7 c) 10 to 45% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, d) 5 to 30% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl- or 2-, 3- or 4-hydroxybutyl-(meth)acrylate or any mixture of these monomers, e) 1 to 15% by weight of acrylic acid, methacrylic acid or any mixture of these acids and f~ O to 15% by weight of other comonomers, wherein i ) O to 100, preferably 0 to 80 and most preferably 0 to 50% of ~e carboxyl 3Q groups are neutralized with an aliphatic amine or with ammon~
ii) the percentages a) - f) adding up to 100, based on the total weight of a) - f) and iii) the combined weight of monomers a) and b) being 10 - 70% by we;ght, based on the total weight of monomers a) - f), Mo3554 B3 10 to 40% by weight, basPd on the total weight of components A) and B), of a melamine resin and C) water.
The present invention also relates to coated substrates, particularly coated motor vehicle substrates, prepared from these aqueous, clear, coating compositions.
DETAILED DESCRIPTION OF THE INYENTION
Based on the weight of components A) and B), the aqueous, clear, coating compositions according to the invention contain 60 to 90% by weight, preferably 65 to 85% by weight of component A) and 10 to 40% by weight, preferably 15 to 35% by weight of component B).
The mixture of components A) and B) ;s the primary binder component according to the present inven~ion. Component C) may include, in addition to water, known auxil;ary agents and additives such as additional cross-linking agents, auxiliary rheological agents, wetting agents, catalysts, organic solvents and light protect;ve agents.
Component A), which is essential for the invention, is based on an emuls;on copolymer of the above-mentioned monomers a) to f). Monomer c) includes methyl acrylate, ethyl acrylate, n-butyl acrylate, n-hexyl acrylate and n-octyl acrylate. Optional monomer f) includes vinyl toluene; alkyl methacrylates having from 2 to 18 carbon atoms in the alkyl group; alkyl acrylates having 9 to 18 carbon atoms in the alkyl group; N-vinylpyrrolidone; vinyl-alkyl-ketones having 1 to 4 carbon atoms; vinyl-alkyl-carboxylates having 1 to 18 carbon atoms in the alkyl group; alkyl esters of maleic, fumaric or itaconic acid in each case having 1 to 4 carbon atoms in the alkyl group; vinyl sulphonic acid salts and mixtures thereof.
Particularly preferred emulsion copolymers A) are based on the reaction product of a) 0 to 40, most preferably 20 to 40% by weight of s~yrene b) 5 to S0, most preferably 5 to 20% by weight of me~yl methaclylate, Mo3554 .
;
- : ,:
, ~ . ~ ,, , c) 25 to 40% by weight of at least one alkyl acrylate having 4 to 8 carbon atoms in the alkyl group, d) 12 to 20% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl-methacrylate or mixtures of these monomers, e~ 2 to 10% by weight of methacrylio acid and f) O to 15% by weight of other comonomers wherein the combined weight of monomers a) and b) being 35 -50, pre~erably 35 - 45% by weight, based on the total weight of monomers a) - f).
Preferably, monomers d) and e~ are used in an amount which corresponds to an equivalent ratio of carboxyl groups to hydroxyl groups of 1:1.5 to 1:4.5, more preferably 1:1.9 to 1:4.5.
The preparation of emulsion polymer A) may be carried out by the conventional emulsion polymerization process as described e.g. in Houben-Weyl, Methoden der Organischen Chemie, Supplements to the 4th Edition, Volume E 20/Part 1, pages 218-313. The known polymerization auxiliaries are used when the emulsion polymers are prepared in an aqueous medium.
20 . The quantity of water is generally calculated to result in aqueous polymer emulsion having solids contents of 20 to 60% by weight, preferably 35 to 50% by weight.
The emulsion polymers thus prepared and present as aqueous emulsions are combined with the other components to produce the clear coating compositions of the present invent;on.
The cross linking agents B) are melamine resins which may be unetherified or partially or completely etherified with saturated alcohols containing 1 to 4 carbon atoms. Preferred melamine resins are fully methyl etherified melamine resins as described, for example, in FR-PS 943,411 sr in 7he Chemistry of Organic Filmformers by D.H.Solomon, John Wiley & Sons, Inc., New York, 1967, pages 235r240.
It is in many cases advisable to use acid catalysts to ensure adequate cross-linking of the cvating films. The Mo3554 ; ~ :
'' nature and concentration of these catalysts will depend on the stoving conditions and the nature of the melamine resins.
Suitable acid catalysts include alkyl benzene sulphonic acids such as toluene sulphonic ac;ds and dialkylnaphthalene mono-and disulphonic ac;ds which may be free or blocked w;th amines.
Commercially available thickeners such as those based on polyacrylates or polyurethanes are frequently used to ;mprove the rheological properties. These properties may in addition be influenced by varying the pH either by the nature and concentration of the neutralization amines added or by the addition of auxiliary solvents.
Although the emulsion polymers are stable in storage due to the presence of the external emulsifiers generally used duling emulsion polymerization, up to 100, preferably up to 80% and most preferably up to 50% of the carboxyl ,groups in the copolymers may b~ n~u~cralized using ammonia aliphatic amines as neutralizing agents. Examples of aliphatic amines include triethylamine, ethanolamine, dimethylethanolamine and triethanolamine.
Examples of suitable auxiliary solvents, which may optionally be used in quantities of up to 10% by weight, based on the total quantity of coating composition, include monohydric and polyhydric alcohols, hydrocarbons, ethers, esters and ketones, e.g., ethyl or butyl glycol and their acetates, ethyl and butyl diglycol, ethylene glycol ~5 dimethylether and methoxy propanol.
The other auxiliary agents and additives pre~iously ment;oned may also be used in the preparation of the clear, ready-for-use coating compositions. The clear coating compositions have a solids content of 25 to 50% by weight, preferably 30 to 45% by weight, and a viscosity of 15 to 60 sec, preferably 18 to 40 sec (DIN 4 cup/25~C).
The coating may be applied by known methods employed in coating technology, preferably by spraying wlth a flow cup gun. The coatin~ may be applied wet^on-wet (after brief pauses for ventilation) or on pre-dried base coating containing Mo3554 ,. . .
, ~ , solvent. It is particularly environmentally desirable for the entire coatings bu;ld-up to apply the clear coat;ng composition according to the invention to a layer of an aqueous base coat.
This application may be carried out either wet-on-wet (after brief intervals for ventilation) or on a pre-dried aqueous base coat.
The substrates coated with the clear coating composition are generally ventilated at a temperature of 10 to 50~C, preferably 25 to 40C, for a short ~ime after application and then stoved at about 100 to 160C, preferably 120 to 140C, for a period of about 10 to 60, preferably 20 to 30 minutes.
For relatively thick coatings, it is in many cases advisable also to carry out an intermediate drying at 8QC to reduce blistering. The stoved coatings thus obtained are distinguished by excellent optical and mechanical properties comb;ned with good solvent resistance.
In the examples which follow, all the parts and percentages are by weight unless otherwise specified.
ExamPles of preparation of aaueous emulsion polvmers to be used accordinq to the invention AcrYlate dispersion 1 The following components were reacted by the known emulsion polymerization at 800 in a glass reactor with stirrer:
613.50 parts of deionized water, 3.90 parts of polyethoxylated 3-benzyl-4-hydroxy-biphenyl (about 10 moles of ethylene oxide per mole of hydroxy compound) (Emulsifier 1) 0.75 parts of sodium-di-sec.-butyl-naphthalene sulphonate (Emulsifier 2), 1.25 parts of ammon~um peroxydisulphate, 117.00 parts of styrene, 53.00 parts of methyl methacrylate, 35- 141.00 parts of butyl acrylate, Mo3554 72.00 parts of hydroxyethylmethacryla~, 25.00 parts of methacryl;c acid and 7.40 parts of dodecylmercaptan.
When polymerization had been terminated, a post-polymerization was carried out at 80C by the addition of 0.25 parts of ammonium peroxydisulphate~ and the product was then partially neutralized with 3.26 parts of dimethylethanolamine.
The emulsion was still perfect and free from ground settlement after ~ year's storage at 23C.
AcrYlate disDersion 2 Sam2 as acrylate d;spersion 1 but neutralized with 1.63 parts of dimethylethanolamine.
Acrylate dispersion 3 Same as acrylate dispsrs;on 1 but neutral;zed with 1~ 6.52 parts of dimethylethanolamine.
Acrylate disDersion_4 Same as acrylate dispersion 1 but neutralized with 5.47 parts of triethanolamine.
AcrYlate dispers;on 5 Same as acrylate dispersion 1 but neutralized with 3.67 parts of triethylamine.
Acrvlate disDersion 6 Same as acrylate dispersion 1 but neutralized w;th 1.75 parts of 33% aqueous ammonia.
AcrYlate disDersion 7 The following components were reacted using the method set forth for acrylate dispers;on 1:
613.80 parts of deionized water, 3.90 parts of Emulsifier 1, 0.75 parts of Emulsifier 2, 1.25 parts of ammonium peroxydisulphate, 117.00 parts of styrene, 63.00 parts of methyl methacrylate, 141.00 parts of butyl acrylate, 72.00 parts of hydroxyethylmethacryla~, Mo3554 ~J.~
11.10 parts of methacrylic acid and 7.40 parts of dodecylmercaptan.
When polymerizat;on had been term;nated, a post-polymerization was carried out at 800 by the addition of 0.25 5parts of ammonium peroxydisulphate and the product was then partially neutrali7ed with 3.26 parts of dimethylethanolamine.
Acrylate dis~ersion 8 The following components were reacted using the method set forth for acrylate dispersion 1:
~614.50 parts of deionised water 3.90parts of Emulsifier 1, 0.75 parts of Emulsifier 2, 1.63 parts of ammonium peroxydisulphate, 117.00 parts of styrene, 1553.00 parts of methyl methacrylate, 141.00 parts of butyl acrylate, 72.00 parts of hydroxyethyl methacrylate, 21.00 parts of methacrylic acid and 9.62 parts of dodecylmercaptan.
20When polymerization had been terminated, a post-polymerization was carried out by the addition of 0.325 parts of ammonium peroxydisulp~ate at 80C and the product was then partially neutralized with 3.26 parts of dimethylethanolamine.
Acrylate dispers;on 9 25The following components were reacted us;ng the method set forth for acrylate dispersion 1:
613.00 parts of deionized water, 3.90 parts of Emulsifier 1, 0.75 parts of Emulsifier 2, 300.63 parts of ammon~um peroxydisulphate, 117.00 parts of styrene, 53.00 parts of methyl methacrylate, 141.00 parts of butyl acrylate, 72.00 parts of hydkoxyethylmethacrylate, 3521.00 parts of methacrylic acid and Mo3554 .
, : , ~14-3.70 parts of dodecylmercaptan.
When polymer kation had been terminated, a post-polymerization was carried out by the addition of 0.125 parts of ammonium peroxydisulphate at 80C and the product was then partially neutralized with 3.26 parts of dimethylethanolam;ne.
AcrYlate dispersions 10-14 The components summarized in Table 1 below were reacted using the method set forth for acrylate dispersion l;
the number in Table 1 represent parts.
Table 1 11 12 13 14 Acrylate dispersions 1247.01251.01246.0 1251.0 1250.0 de;onized water 7.8 7.8 7.8 7.8 7.8 Emulsifier 1 1.5 1.5 1.5 1.5 1.5 Emulsifier 2 2.5 2.5 ~.5 2.5 2.5 ammonium peroxy-disulphate 105.0105.0 105.0 339.0 105.0 styrene 234.0281.0 247.0 - 247.0 methyl methacrylate 283.0283.0 272.0 283.0 72.0 butyl acrylate 144.0 97.0 141.0 144.0 - hydroxyethyl methacrylate - - - -141.0 hydroxypropyl methacrylate 47.0 43.0 47.0 43.0 43.0 methacrylic acid 14.8 14.8 14.~ 14.8 14.8 dodecylmercaptan _ Commercial mixture of 2- and 3-hydroxypropyl-methacrylate Mo3554 .
, .
Post-polymerization was carried out in all cases by the addition of 0.5 parts of ammonium peroxydisulphate at 80C
after termination of the polymerization and the product was then partially neutralized with 6.5 parts of ~imethylethanolam;ne.
PreDaration of an aqueous clear coatinq The formulations used to prepare aqueous clear coat;ng compositions are set forth in Table 2.
Table 2 Formulations of the clear coating compositions Formulation No. 1 2 3 4 5 6 7 Melamine resin 1* 11.0 11.0 Melamine resin 2* 10.2 10.2 10.2 10.2 10.5 Levelling agent 1* 1.2 1.2 1.2 1.2 1.2 1.2 1.2 Levelling agent 2* 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Butyl glycol 3.9 4.0 4.1 4.1 4.1 1, Ethyl diglycol/
butyl diglycol 3.2 3.3 Acid catalyst 1* 0.3 Acid catalyst 2* 0.8 0.8 0.8 0.8 Light protective agent 1* 1.8 1.8 1.8 1.8 1.7 1.7 1.8 Light protective agent 2* 1.8 1.8 Light protective agent 3* 1.& 1.8 1.7 1.7 1.8 Dimethylethanolamine, 10% in water 6.1 6.0 5.g 5.~ 5.8 5.8 6.0 Wetting auxiliary* 1.2 1.2 1.2 1.2 1.2 1.2 1.2 deionized water 6.8 8.1 8.1 9.2 9.9 9.5 7.8 Acrylate dispersion 1 60.6 60.2 Acrylate dispersion 6 - 59.5 59.1 Acrylate dispersion 8 57.8 Acrylate dispersion 9 58.3 59.7 Th;ckener* 5.0 4.9 4.9 4.9 5.0 4.9 5.0 Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 ========================================================= ===========
Outflow v;s~os;ty 2~ 20 1~ 17 19 26 26 in sec (DIN 4 cup, 25C~
Mo3554 f~. ' 3 i~
Melamine resin 1: Cymel 327 (Cyanamid Int., Wayne, N.J. 90% solids content in i-propanol Melamine resin 2: Cymel 303 (Cyanamid Int., Wayne, N.J.) 98% solids content in water Levelling agent 1: Additol XW 395 (Hoechst AG, Frankfurt/M, BRD) 50% in butyl ~lycol Levelling agent 2: Resiflow W 50 (Worlee-Chem;e GmbH, Hamburg, BRD) 50% in butyl glycol/isopropanol 4:1 Wetting auxiliary: Fluorotensid FT 929 (Bayer AG, Leverkusen, BRD~ 10% in water/ethanol 8:1 Acid catalyst 1: Nacure 2501 (King Industries Inc., Norwalk CT) 25% in isopropanol Acid catalyst 2: Nacure 1051 (King Industries Inc., Norwalk CT) 50% ;n butyl glycol Light protective agent 1: Tinuvin 1130 (Ciba-Geigy Marienberg 6mbH, Lautertal, BRD~ 20% ;n ethyl diglycol/butyl diglycol 1:1 Light protective agent 2: Tinuvin 292 (Ciba-Geigy Marienberg GmbH, Lautertal, BRD) 20% in ethyl diglycol/butyl diglycol 1:1 0 Light protective agent 3: Tinuvin 440 (Ciba-Geigy Marienberg GmbH, Lautertal, BRD) 20% in butyl glycol Thickener: Viscalex HV 30 (Allied Colloids GmbH, Hamburg, BRD) 5% in water 25 The indiv;dual components were successively stirred in at a uniform rate and homogenized with a dissolver.
Application of the aqueous clear coatinq A steel sheet which had been prepared with an electro dip primer (KTL), filler and base coat (aqueous or containing solvent) was coated with the clear coating.
Mo3554 ,~ . , - ~ , A temperature of 20-25C and relativQ humid;ty of 40 to 70% was maintained during the application of this coating. The outflow rate from the flow cup gun was 300-~00 ml/min, depending upon the viscosity of the formulation. The spray gun was fitted with a 1.2 mm no~zle and operated at a pressure of 3.5-5.0 bar.
The coating was applied in three stages with a brief interruption for ventilation after the first spraying stage.
DrYing of the clear coatings The coated steel sheets were ventilated at 40C for 1 to 5 minutes, pre-dried at 80C and stoved at 140C for 20 minutes. Increasing the duration of the ventilating phases provided a marked reduction in the formation of blisters. The clear coating film obtained had a layer thickness of 35-60 ~m.
Testinq of the clear coatinq films The lacquered substrates were first assessed optically after the stoving process. The Erichsen cupping (DIN
IS0 1520) was then determined as a measure of the elasticity, the pendulum hardness (DIN 53157) was determined as a measure oF the hardness of the film and the degree of gloss was determined (at an angle of 20 and at 60). The ease with which the films were attacked by the solvent action of toluene, butyl acetate, methoxypropyl acetate and acetone was then tested by placing a wad of cotton wool impregnated with solvent for 1 minute directly on the coating surface and the results were assessed optically and mechanically. The best result was denoted by 0 (unchanged surface) and the worst by 5 (coating film became detached). The res;stance of the films to solvents and water was then tested by exposing the films to the action of the solvents (ethanol, xylene/10 minutes) and water (for 24 h) and then assessing the result as described above for the test for solvent action.
The detailed test results for the clear coating formulations according to the invention are summarized in Table 3.
Mo3554 , , .
Table 3: Test results nf clear coating formulations Formulation No. 1 2 3 4 5 6 7 Layer thickness (~m) 50 40 45 50 40 50 45 Formation of film 0 0 0 0 1 0 Gloss according to Lange 20~ 88 89 ~7 94 95 96 96 Erichsen cupping (DIN IS0 1520) (mm) 7.0 5-5 5.0 5.5 7.0 6.0 7.0 Pendulum hardness according to Konig (DIN 53157) (s)180 169 187 184 171 171 185 Action of sol-vent (1 min) (Tol/BuAc/
MPA/Ac) 0000 0000 0000 0000 0000 0000 0000 Resistance to xylene (10 min) 0 0 0 Resistance to ethanol (10 min) 0 0 0 0 1 0 Resistance to water (24 h) 0 0 0 0 0 0 0 Practical tests carried out on clear coating fiims showed no differences when applied to base coats containing solvent and aqueous base coats. The adh~rence of the clear coating film was good on both substrates.
Although the invention has been described in detail in the foregoing for the purpose of illustration9 it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
Mo3554 .
. ~ ... .
, . . - ~ -. ' ~ ~- ,
Claims (24)
1. An aqueous, clear, coating composition comprising A) 60 to 90% by weight, based on the total weight of components A) and B), of an emulsion copolymer which comprises the reaction product of a) 0 to 50% by weight of styrene, .alpha.-methyl-styrene or a mixture of these monomers, b) 0 to 50% by weight of methyl methacrylate, c) 10 to 45% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, d) 5 to 30% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl-, 2-, 3- or 4-hydroxybutyl-(meth)-acrylate or mixtures of these monomers, e) 1 to 15% by weight of acrylic acid, methacrylic acid or any mixture of these acids and f) 0 to 15% by weight of other comonomers, wherein i) 0 to 100% of the carboxyl groups are neutralized with an aliphatic amine or with ammonia, ii) the percentages a) - f) add up to 100, based on the total weight of a) - f) and iii) the combined weight of monomers a) and b) are 10 to 70% by weight, based on the total weight of monomers a) - f), B) 10 to 40% by weight, based on the total weight of components A) and B), of a melamine resin and C) water.
2. The composition of Claim 1 wherein said copolymer comprises the reaction product of a) 0 to 40% by weight styrene, b) 5 to 50% by weight of methyl methacrylate, c) 25 to 40% by weight of at least one alkyl acrylate having 4 to 8 carbon atoms in the alkyl group.
Mo3554 d) 12 to 20% by weight of hydroxyethyl methacrylatel 2 or 3- hydroxypropyl methacrylate or a mixture of these monomers, e) 2 to 10% by weight of methacrylic acid and f) 0 to 15% by weight of other comonomers, wherein the combined weight of monomers a) and b) are 35 to 50% by weight,based on the total weight of monomers a) - f).
Mo3554 d) 12 to 20% by weight of hydroxyethyl methacrylatel 2 or 3- hydroxypropyl methacrylate or a mixture of these monomers, e) 2 to 10% by weight of methacrylic acid and f) 0 to 15% by weight of other comonomers, wherein the combined weight of monomers a) and b) are 35 to 50% by weight,based on the total weight of monomers a) - f).
3. The composition of Claim 1 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.5 to 1:4.5.
4. The composition of Claim 2 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.5 to 1:4.5.
5. The composition of Claim 1 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.9 to l:4.5.
6. The composition of claim 2 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.9 to 1:4.5.
7. A clear coating prepared from an aqueous, clear, coating composition comprising A) 60 to 90% by weight, based on the total weight of components A) and B), of an emulsion copolymer which comprises the reaction produce of a) 0 to 50% by weight of styrene, .alpha.-methyl-styrene or a mixture of these monomers, b) 0 to 50% by weight of methyl methacrylate, c) 10 to 45% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, Mo3554 d) 5 to 30% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl-, 2-, 3- or 4-hydroxybutyl-(meth)-acrylate or mixtures of these monomers, e) 1 to 15% by weight of acrylic acid, methacrylic acid or any mixture of these acids and f) 0 to 15% by weight of other comonomers, wherein i) 0 to 80% of the carboxyl groups are neutralized with an aliphatlc amine or with ammonia, ii) the percentages a) - f) add up to l00, based on the total weight of a) - f) and iii) the combined weight of monomers a) and b) are 10 to 70% by weight, based on the total weight of monomers a) - f), B) 10 to 40% by weight, based on the total weight of components A) and B), of a melamine resin and C) water.
8. The coating of Claim 7 wherein said copolymer comprises the reaction product of a) 0 to 40% by weight of styrene, b) 5 to 50% by weight of methyl methacrylate, c) 25 to 40% by weight of at least one alkyl acrylate having 4 to 8 carbon atoms in the alkyl group, d) 12 to 20% by weight of hydroxyethyl methacrylate, 2-or 3- hydroxypropyl methacrylate or a mixture of these monomers, e) 2 to 10% by weight of methacrylic acid and f) 0 to 15% by weight of other comonomers, wherein the combined weight of monomers a) and b) are 35 to 50% by weight, based on the total weight of monomers a) - f).
9. The coating of Claim 7 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.5 to 1:4.5.
Mo3554
Mo3554
10. The coating of Claim 8 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.5 to 1:4.5.
11. The coating of Claim 7 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.9 to 1:4.5.
12. The coating of Claim 8 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.9 to 1:4.5.
13. An aqueous, clear, coating composition comprising A) 60 to 90% by weight, based on the total weight of components A) and B), of an emulsion copolymer which comprises the reaction product of a) 0 to 50% by weight of styrene, .alpha.-methyl-styrene or a mixture of these monomers, b) 0 to 50% by weight of methyl methacrylate, c) 10 to 45% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, d) 5 to 30% by weight of hydroxyethy1-, 2- or 3-hydroxypropyl-, 2-, 3- or 4-hydroxybutyl-(meth)acrylate or mixtures of these monomers, e) 1 to 15% by weight of acrylic acid, methacrylic acid or any mixture of these acids and f) 0 to 15% by weight of other comonomers, wherein i) 0 to 50% of the carboxyl groups are neutralized with an aliphatic amine or with ammonia, ii) the percentages a) - f) add up to 100, based on the total weight of a) - f) and iii) the combined weight of monomers a) and b) are 10 to 70% by weight, based on the total weight of monomers a) - f), Mo3554 B) 10 to 40% by weight, based on the total weight of components A) and B), of a melamine resin and C) water.
14. The composition of Claim 13 wherein said copolymer comprises the reaction product of a) 20 to 40% by weight of styrene, b) 5 to 20% by weight of methyl methacrylate, c) 25 to 40% by weight of at least one alkyl acrylate having 4 to 8 carbon atoms in the alkyl group, d) 12 to 20% by weight of hydroxyethyl methacrylate, 2-or 3-hydroxypropyl methacrylate or a mixture of these monomers, e) 2 to 10% by weight of methacrylic acid and f) 0 to 15% by weight of other comonomers, wherein the combined weight of monomers a) and b) are 35 to 45%
by weight, based on the total weight of monomers a) - f).
by weight, based on the total weight of monomers a) - f).
15. The composition of Claim 13 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.5 to 1:4.5.
16. The composition of Claim 14 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.5 to 1:4.5.
17. The composition of Claim 13 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.9 to 1:4.5.
18. The composition of Claim 14 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.9 to 1:4.5.
19. A clear coating prepared from an aqueous, clear, coating composition comprising Mo3554 A) 60 to 90% by weight, based on the total weight of components A) and B), of an emulsion copolymer which comprises the reaction product of a) 0 to 50% by weight of styrene, .alpha.-methyl-styrene or a mixture of these monomers, b) 0 to 50% by weight of methyl methacrylate, c) 10 to 45% by weight of at least one alkyl acrylate having 1 to 8 carbon atoms in the alkyl group, d) 5 to 30% by weight of hydroxyethyl-, 2- or 3-hydroxypropyl-, 2-, 3- or 4-hydroxybutyl-(meth)acrylate or mixtures or these monomers, e) 1 to 15% by weight of acrylic acid methacrylic acid or any mixture of these acids and f) 0 to 15% by weight of other comonomers, wherein i) 0 to 50% of the carboxyl groups are neutralized with an aliphatic amine or with ammonia, ii) the percentages a) - f) add up to 100, based on the total weight of a) - f) and iii) the combined weight of monomers a) and b) are 10 to 70% by weight, based on the total weight of monomers a) - f), B) 10 to 40% by weight, based on the total weight of components A) and B), of a melamine resin and C) water.
20. The coating of Claim 19 wherein said copolymer comprises the reaction product of a) 20 to 40% by weight of styrene, b) 5 to 20% by weight of methyl methacrylate, c) 25 to 40% by weight of at least one alkyl acrylate having 4 to 8 carbon atoms in the alkyl group, d) 12 to 20% by weight of hydroxyethyl methacrylate, 2-or 3-hydroxypropyl methacrylate or a mixture of these monomers, e) 2 to 10% by weight of methacrylic acid and Mo3554 f) 0 to 15% by weight of other comonomers, wherein the combined weight of monomers a) and b) are 35 to 45%
by weight, based on the total weight of monomers a) - f)
by weight, based on the total weight of monomers a) - f)
21. The coating of Claim 19 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.5 to 1:4.5.
22. The coating of Claim 20 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.5 1:4.5.
23. The coating of Claim 19 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.9 to 1:4.5.
24. The coating of Claim 20 wherein components Ad) and Ae) are present in amounts which provide an equivalent ratio of carboxyl groups to hydroxyl groups in the copolymer of 1:1.9 to 1:4.5.
Mo3554
Mo3554
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4013710A DE4013710A1 (en) | 1990-04-28 | 1990-04-28 | USE OF EMULSION SCOPOLYMERISES IN CLEAR VARNISHES AND A WAESSER CLEAR LACQUER |
| DEP4013710.4 | 1990-04-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2041148A1 true CA2041148A1 (en) | 1991-10-29 |
Family
ID=6405344
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002041148A Abandoned CA2041148A1 (en) | 1990-04-28 | 1991-04-24 | Aqueous, clear, coating composition containing emulsion copolymers and coated substrates prepared therefrom |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0455028A1 (en) |
| JP (1) | JPH04227775A (en) |
| KR (1) | KR910018500A (en) |
| CA (1) | CA2041148A1 (en) |
| DE (1) | DE4013710A1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4216536A1 (en) * | 1992-05-19 | 1993-11-25 | Bayer Ag | Water-thinnable polyester polyols and their use |
| AU5006593A (en) * | 1992-09-03 | 1994-03-29 | Dow Chemical Company, The | Polymer latex composition and coating formulation made therefrom |
| CN1042641C (en) * | 1992-09-16 | 1999-03-24 | 上海宝山钢铁总厂 | Method for production of color antistatic permeable adhesive |
| CN1038761C (en) * | 1993-05-31 | 1998-06-17 | 大连市风彩涂料厂 | Water-proof paint |
| IL113600A0 (en) * | 1994-05-19 | 1995-08-31 | Du Pont | Aqueous coatings comprising self-stabilized lattices |
| WO1995032229A1 (en) * | 1994-05-19 | 1995-11-30 | E.I. Du Pont De Nemours And Company | Coatings comprising self-stabilized lattices prepared in an aqueous carrier |
| DE19540725A1 (en) * | 1995-11-02 | 1997-05-07 | Basf Ag | Aqueous polymer dispersions as binders for oil-resistant, abrasion-resistant floor paints |
| KR20000046303A (en) * | 1998-12-31 | 2000-07-25 | 김충세 | Anionic electro-deposition paint composition based on water soluble acrylate |
| KR100356396B1 (en) * | 1999-11-30 | 2002-10-19 | 주식회사 디피아이 | Resin composition for a thermosetting paint composition |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA980475A (en) * | 1971-04-02 | 1975-12-23 | Richard Martorano | Metal decorating and aqueous coating composition comprising copolymer and aminoplast |
| CA1059674A (en) * | 1974-01-17 | 1979-07-31 | William H. Brendley (Jr.) | Rheologically modified metal decorating and aqueous coating composition comprising water-soluble copolymer and aminoplast |
| DE2514741A1 (en) * | 1974-04-05 | 1975-10-09 | Fuji Photo Film Co Ltd | Aqueous coating |
| US4139514A (en) * | 1977-06-29 | 1979-02-13 | Union Carbide Corporation | Aqueous vehicles |
-
1990
- 1990-04-28 DE DE4013710A patent/DE4013710A1/en not_active Withdrawn
-
1991
- 1991-04-13 EP EP91105918A patent/EP0455028A1/en not_active Withdrawn
- 1991-04-22 JP JP3116541A patent/JPH04227775A/en active Pending
- 1991-04-24 CA CA002041148A patent/CA2041148A1/en not_active Abandoned
- 1991-04-25 KR KR1019910006651A patent/KR910018500A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| KR910018500A (en) | 1991-11-30 |
| DE4013710A1 (en) | 1991-10-31 |
| EP0455028A1 (en) | 1991-11-06 |
| JPH04227775A (en) | 1992-08-17 |
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