CA2074104A1 - Copolymer solutions based on addition products of .alpha.,.beta.-unsaturated carboxylic acid with glycidyl esters and copolymerisable .alpha.,.bete.-unsaturated montomers - Google Patents
Copolymer solutions based on addition products of .alpha.,.beta.-unsaturated carboxylic acid with glycidyl esters and copolymerisable .alpha.,.bete.-unsaturated montomersInfo
- Publication number
- CA2074104A1 CA2074104A1 CA002074104A CA2074104A CA2074104A1 CA 2074104 A1 CA2074104 A1 CA 2074104A1 CA 002074104 A CA002074104 A CA 002074104A CA 2074104 A CA2074104 A CA 2074104A CA 2074104 A1 CA2074104 A1 CA 2074104A1
- Authority
- CA
- Canada
- Prior art keywords
- weight
- alpha
- copolymer
- component
- methacrylate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
- C08F283/12—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polysiloxanes
- C08F283/122—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polysiloxanes on to saturated polysiloxanes containing hydrolysable groups, e.g. alkoxy-, thio-, hydroxy-
-
- 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
- C09D151/00—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
- C09D151/08—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers grafted on to macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- C09D151/085—Coating compositions based on graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers grafted on to macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds on to polysiloxanes
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/10—Esters
- C08F220/26—Esters containing oxygen in addition to the carboxy oxygen
- C08F220/32—Esters containing oxygen in addition to the carboxy oxygen containing epoxy radicals
- C08F220/325—Esters containing oxygen in addition to the carboxy oxygen containing epoxy radicals containing glycidyl radical, e.g. glycidyl (meth)acrylate
Abstract
Abstract:
Copolymer solutions based on addition products of .alpha.,.beta.-unsaturated carboxylic acids with qlycidyl esters and copolymerisable .alpha.,.beta.-unsaturated monomers The invention relates to copolymer solutions of the abovementioned type with a remarkably high as-copolymerised solids content of about 80% by weight and which can be processed with polyisocyanates into high solids two-component coatings having a good processing viscosity. The copolymers contain a methoxy-functional polysiloxane as copolymerised units. The copolymers can be processed with amino resins into binders for baking finishes which used as improved clear coatings for automotive topcoating produce paint films which possess excellent abrasion resistance in car washes.
Copolymer solutions based on addition products of .alpha.,.beta.-unsaturated carboxylic acids with qlycidyl esters and copolymerisable .alpha.,.beta.-unsaturated monomers The invention relates to copolymer solutions of the abovementioned type with a remarkably high as-copolymerised solids content of about 80% by weight and which can be processed with polyisocyanates into high solids two-component coatings having a good processing viscosity. The copolymers contain a methoxy-functional polysiloxane as copolymerised units. The copolymers can be processed with amino resins into binders for baking finishes which used as improved clear coatings for automotive topcoating produce paint films which possess excellent abrasion resistance in car washes.
Description
2~7~10~
Copolymer solutions based on addition products of ~,B-unsaturated car~oYvlic acid ~7ith qlycidyl esters and copolymerisable ~ B-unsaturated monomers The invention relate6 to copolymer solutions based on addition products of ~ unsaturated carboxylic acid with glycidyl esters and copolymerisable ~ unsaturated monomers with and without hydroxyl groups. It also relates to the preparation of such hydroxyl-containing copolymers and to the use thereof in clear or pigmented coatings.
Hydroxyl-containing copolymers based on (meth)-acrylates and reaction products of acrylic acid and glycidyl esters of ~-alkylalkanemonocarboxylic acids and/or ~ dialkylalkanemonocarboxylic acids which can be processed together with organic polyisocyanates to form coatings are known. DE-B-l 668 510 describes copolymers of addition products of ~ ethylenically unsaturated carboxylic acids with glycidyl esters and copolymerisable ~ unsaturated monomers with and without hydroxyl groups. DE-C-2 603 259 di~closes two-component coatings containing specific binders. The~e binders are copolymers based on styrene, methyl methacrylate, acrylic acid and glycidyl esters of ~-alkylalkanemonocarboxylic acids and/or ~ dialkylalkanemonocarboxylic acids obtained by heating with simultaneous esterification and polymerisa-tion in inert solvents in the presence o~ polymerisation initiators with or without chain terminators.
The solids contents of prior art copolymer solutions on termination of the simultaneous esterifica-tion and copolymerisation is not more than 55% by weightor, according to page 4 of DE-A-3 740 774 (component A), about 65% by weight, although the objective of the latter reference was a particularly high solids content.
The object of the invention is 5 l. To provide copolymer solutions which have a signi~i-cantly higher solids content, 2. To provide processes for preparing the novel copoly-mer solutions, . , . . .
.
- 2 - 2~7~4 3. The binders obtainable from the novel copolymer solutions shall when used with difunctional and/or higher polyisocyanates have an increased solids content for the same viscosity. This means that the two-component coating~ prepared from the copolymer solutions or the binder of the invention can be applied quickly, for example ~y omitting one or more spraying operations. Furthermore, because of the higher solids content of the re~dy-prepared two-component coatings less organic solvent shall be emitted into the environment.
Copolymer solutions based on addition products of ~,B-unsaturated car~oYvlic acid ~7ith qlycidyl esters and copolymerisable ~ B-unsaturated monomers The invention relate6 to copolymer solutions based on addition products of ~ unsaturated carboxylic acid with glycidyl esters and copolymerisable ~ unsaturated monomers with and without hydroxyl groups. It also relates to the preparation of such hydroxyl-containing copolymers and to the use thereof in clear or pigmented coatings.
Hydroxyl-containing copolymers based on (meth)-acrylates and reaction products of acrylic acid and glycidyl esters of ~-alkylalkanemonocarboxylic acids and/or ~ dialkylalkanemonocarboxylic acids which can be processed together with organic polyisocyanates to form coatings are known. DE-B-l 668 510 describes copolymers of addition products of ~ ethylenically unsaturated carboxylic acids with glycidyl esters and copolymerisable ~ unsaturated monomers with and without hydroxyl groups. DE-C-2 603 259 di~closes two-component coatings containing specific binders. The~e binders are copolymers based on styrene, methyl methacrylate, acrylic acid and glycidyl esters of ~-alkylalkanemonocarboxylic acids and/or ~ dialkylalkanemonocarboxylic acids obtained by heating with simultaneous esterification and polymerisa-tion in inert solvents in the presence o~ polymerisation initiators with or without chain terminators.
The solids contents of prior art copolymer solutions on termination of the simultaneous esterifica-tion and copolymerisation is not more than 55% by weightor, according to page 4 of DE-A-3 740 774 (component A), about 65% by weight, although the objective of the latter reference was a particularly high solids content.
The object of the invention is 5 l. To provide copolymer solutions which have a signi~i-cantly higher solids content, 2. To provide processes for preparing the novel copoly-mer solutions, . , . . .
.
- 2 - 2~7~4 3. The binders obtainable from the novel copolymer solutions shall when used with difunctional and/or higher polyisocyanates have an increased solids content for the same viscosity. This means that the two-component coating~ prepared from the copolymer solutions or the binder of the invention can be applied quickly, for example ~y omitting one or more spraying operations. Furthermore, because of the higher solids content of the re~dy-prepared two-component coatings less organic solvent shall be emitted into the environment.
4. The copol~mer solutions or binders, when combined with aliphatic polyisocyanates, shall produce air-and oven-drying high-solids two-component finishes lS of high mechanical, chemical, weathering and ultra violet radiation resistance.
5. The provision of copolymer solutions or binders or clear or pigmented coatings with an increased solids content that lead to coatings of high gloss, good build, good flow, less environmental pollution and improved processing reliability.
6. The copolymer solutions or binders shall be proces-sible into two-component coatin~s highly suitable for use not only as automotive original equipment coatings but also as automotive re~inish coatin~s.
7. The binders mentioned earlier under point 3 shall result in improved clear coatings for automotive topcoating by producing paint films with excellent abrasion resistance in car washes.
8. The novel polymer solutions shall also be combinable with amino resins to form binders which are pro-ce~sed to form baking finishes with or without pigments. It shall also be possible to add polyiso-cyanates to the copolymer-amino resin combina~ion.
Again, the foregoing binders are suitable ~or improved clear baking finishes ~or automotive topcoating which provide paint films with excellent abrasion resistance in car washes.
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.
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It has been found that this object is achieved by providing a copolymer solution which contains a hydroxyl-containing copolymer based on addition products of e,~-unsaturated carboxylic acid with glycidyl esters and copolymerisable Q,~-unsaturated monomers with and without hydroxyl groups, said copolymer being characterised in that it consists essentially of a hydroxyl-containing copolymer obtainable from a) 10 to 30% by weight of glycidyl esters of e~alkyl~
alkanemonocarboxylic acids and/or e,e~dialkylalkane~
monocarboxylic acids, b) 5 to 12% by weight of methacrylic acid, c) 10 to 27% by weight of hydroxyalkyl methacrylate having 1 to 6 carbon atoms in the hydroxylalkyl radical, d) lO to 38% by weight of styrene, e) 1 to 5% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387~
f) 3 to 20% by weight of alkyl methacrylate having 1 to 8 carbon atoms in the alkyl radical, g) 9 to 20% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
An advantageous embodiment of the copolymer is obtainable fro~:
a) 17 to 25% by weight of glycidyl esters of ~-alkyl-alkanemonocarboxylic acids and/or e~e~dialkylalkane monocarboxylic acids, b) 7 to 12% by weight of methacrylic acid, c) 15 to 26% by weight of 2 hydroxyethyl methacrylate, d) 17 to 28% by weight of styrene, : . . , -: ~ . .
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.
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. .
_ 4 _ 207~4 e) 1 to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 5 to 15% by weight of methyl methacrylate, S g) 12 to 17% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
A preferred embodiment of the copolymer is obtainable from:
a) 18 to 24% by weight of glycidyl esters of ~-alkyl-alkanemonocarboxylic acids and/or ~,~-dialkylalkane-monocarboxylic acids, b) 6 to 12% by weight of methacrylic acid, c) 17 to 22~ by weight of 2 hydroxyethyl methacrylate, d) 20 to 28~ by weight of styrene, e) l to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 8 to 12% by weight of methyl methacrylate, g) 12 to 17% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
Another preferred embodiment of the copolymer solution is obtainable from:
a~ 8 to 22% by weight of glycidyl ester~ of ~-alkyl-alkanemonocarboxylic acids and/or ~ dialkylalkane-monocarboxylic acids, b) 7 to IO% by weight of methaorylic acid, c) 19 to 22% by weight of 2-hydroxyethyl methacrylate, d) 20 to 2~% by weight of styrene, e) 1 to 3% by weight o~ polypropylene glycol mono-methacrylate~having an average , : . . ,:
.
5- ~7~10~
molecular weight of 350 to 387, f) 9 to 11% by weight of methyl methacrylate, g) 13 to 17% by weight of solvent-free, r~active, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
The most preferred embodiment of the above-mentioned copolymer solutions is characterised in that, after its preparation, it consists of A) 15.0-25.0% by weight, preferably 15 to 20~ by weight, of customary inert paint sol-vents, preferably with boiling points of 150 to 2D0~C, and B) 75.0-85.0% by weight, preferably 85 to 80% by weight, of hydroxyl-containing copolymers.
It has been ~ound that such a copolymer solution, when used with difunctional and/or higher polyisocyanates produces, compared with the prior art, an increased solids content for the same viscosity or a reduced vis-cosity for the same solids content. What is more, it has coating advantages, such as improved glo5s~ build, flow, processing reliability as well as the high solids con-tent, and also better environmental properties.
The copol~mer solution of the invention isprepared by solution polymerisation. This involves an addition reaction between components a and b with a simultaneous condensation with component g by elimination of methanol, which is removed in the reflux of the boiling reaction mixture. This process comprises intro-ducing the solvents and the glycidyl esters of ~-alkyl-alkanemonocarboxylic acid~ andlor ~ dialkylalkane-monocarboxylic acids into the reaction ves~el as initial charge, heating to the boilj and continuously adding the mixture or mixtures of monomers, optionally carboxy~epoxy catalysts and initiator continuou~ly over about 12-20 hours. On completion o~ the metered addition the . . .
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.
20741 D~
polymerisation temperature is maintained for a further 2 to 5 hours - with or without the addition of further polymerisation initiator - until conversion is virtually complete. The polymerisation is carried out at tempera-tures between 140 and 195C, preferably at 160 to 190C, the reaction being initiated at about 180 to 190C. The temperature decreases in the course o~ the simultaneou~
copolymerisation, addition and condensation.
In a preferred embodiment, illustrated by the Examples, a mixture of inert solvents is introduced as initial charge and heated to the boil under reflux, the inert solvents having been selected in such a way that the reflux temperature is about 188C. Following initia-tion of the copolymerisation and towards the end of the metered addition time, the boiling temperature of the copolymer solution decreases to about 170C to about 140C. The metered addition i9 then followed by holding the temperature at 170C to about 140C until conversion is virtually complete and the desired solids content (about 80% in the Examples~ has been obtained.
The polymerisation reaction is initiated with known polymerisation initiators. Suitable initiators are ~or example peroxides which decompose thermally into free radicals by a 1st order reaction. Initiator type and amount are chosen in such a way that a very constant supply of free radicals is present at the polymerisation - temperature during the metered addition phase.
Preferred initiators for the polymerisation are:
dialkyl peroxides, such as di-tert-butyl peroxide, dicumyl peroxide; hydroperoxides, such as cumene hydro-peroxide, tert-butyl hydroperoxide; peresters, such as tert-butyl perbenzoate, tert-butyl per-3,5,5-trimethyl-hexanoate, tert-butyl per-2-ethylhexanoate.
The polymerisation initiators, iA particular tert-butyl per-2-ethylhexanoate, are pre~erably added in an amount o~ 2 to 6% by weight, based on the weight of monomer used.
_ 7 ~ 0 The molecular welght may be regulated using chain trans~er agents~ Examples are mercap~ans, thioglycolic esters and chlorohydrocarbons, preference being given to dodecylmercaptan.
Suitable solvents ~or the solution polymerisation are customary inert paint solvents alone, preferably mixed, with boiling points of 150C to 200C, preferably 154C to 200C. The preferr~d organic solvents are those which later are also used in the ready-prepared coatings.
Examples of such solvents are: glycol ethers, such as ethylene glycol dimethyl ~her; glycol ~ther esters, such as ethylglycol acekate, butylglycol acetate, 3-methoxy-n-butyl acetate, butyldiglycol acetate, methoxypropyl acetate; ethoxypropyl acetate, esters, such as butyl acetate, isobutyl acetate, amyl acetate; and ketones, such as methyl ~thyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, isophorone, aromatic hydrocarbons, such as xylene. Shellsol A (registered trade mark for aromatic hydrocarbon mixtures) and ali-~0 phatic hydrocarbons can likewise be used cut with theabovementioned solvents. Preference i9 given to using a mixture of butyl glycol acetate, Shellsol A and ethoxy-propyl acetate in a weight ratio of 1:2:2.
Component a) for preparing the hydroxyl-containing copolymer solutions of the invention comprises glycidyl esters of ~-alkylalkanemonocarboxylic acids and/or ~,~-dialkylalkanemonocarboxylic acids. The gly-cidyl esters preferably have the empirical formula Cl3H2403 individually or together.
Since the glycidyl radical in the glycidyl ester of such ~-alkylalkanemonocarboxylic acids and/or ~ di alkylalkanemonocarboxylic acids has the empirical formula C3~50 ~ the ~ alkylalkanemonocarboxylic acids and ~ di-alkylalkanemonocarboxylic acid~ are isomer mixtures of those monocarhoxylic acids which contain a C10 chain.
These acids are preferably very highly substituted at the ~-disposed carbon atom and fully saturated; examples thereo~ are described in Deutsche Farbenzeikschrift, ' - ' :' ' " ' ' .
2 ~
No. 10/volume 16, page 435.
Suitable hydroxyalkyl methacrylates having 1 to 6 carbon atoms in the hydroxyalkyl radical are hydroxy-methyl methacrylate, 2-hydroxyethyl methacrylate, 5 2-hydroxypropyl methacrylate, 4-butanediol monometh-acrylate, 5-pentanediol monomethacrylate, cyclohexanediol monomethacrylate and 4~dihydroxymethylcyclohexane mono-methacrylate, alone or mixed, preference being given to using 2-hydroxyethyl methacrylate.
The Yolvent-free, reactive, methoxy-functional polysiloxan~ component g with a narrow molecular weight distribution, a low average molecular weight and a very low proportion of volatiles is Silicone Intermediate SY 231 from Wacker-Chemie Gmb~, 8000 Munich 22.
lS Suitable carboxy-epoxy catalysts based on an alkali metal compound are all sodium, lithium, potassium, rubidium and caesium compounds - alo~e or mixed - which are soluble in the reaction mixture of methacrylic acid~
monoglycidyl compound and vinyl compounds or at least dissolve therein in the course of the metered addition and/or in the course of the reaction b tch being main-tained at the reaction temperature for the purpose of esterification by addition with simultaneous copoly-merisation, although the alkali metal compound used should be free of constituents which may have an unfavourable effect in the`course of the copolymerisation o~ the addition product, which is an ester.
It is po3sible to use for example the carbonates, bicarbonates, formatec, iodides, bromides, fluorides and hydroxides of the aforementioned alkali metals. On a ~actory scale it is best to use lithium hydroxide and potassium hydroxide, alone or mixed. Of these, potassium hydroxide is particularly advantageous on a factory scale on account o~ its low cost and excellent catalytic properties. The alkali metal compound or hydroxide or mixture is advantageously dissolved in the methacrylic acid to be e~teri~ied. However, it is al50 possible first to convert the alkali metal compound, e.g. alkali metal , ~ :
Again, the foregoing binders are suitable ~or improved clear baking finishes ~or automotive topcoating which provide paint films with excellent abrasion resistance in car washes.
. . :
.
.
: ' .
.
` ' ' ' '.: ' ; ,, 3- 2~7~0~
It has been found that this object is achieved by providing a copolymer solution which contains a hydroxyl-containing copolymer based on addition products of e,~-unsaturated carboxylic acid with glycidyl esters and copolymerisable Q,~-unsaturated monomers with and without hydroxyl groups, said copolymer being characterised in that it consists essentially of a hydroxyl-containing copolymer obtainable from a) 10 to 30% by weight of glycidyl esters of e~alkyl~
alkanemonocarboxylic acids and/or e,e~dialkylalkane~
monocarboxylic acids, b) 5 to 12% by weight of methacrylic acid, c) 10 to 27% by weight of hydroxyalkyl methacrylate having 1 to 6 carbon atoms in the hydroxylalkyl radical, d) lO to 38% by weight of styrene, e) 1 to 5% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387~
f) 3 to 20% by weight of alkyl methacrylate having 1 to 8 carbon atoms in the alkyl radical, g) 9 to 20% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
An advantageous embodiment of the copolymer is obtainable fro~:
a) 17 to 25% by weight of glycidyl esters of ~-alkyl-alkanemonocarboxylic acids and/or e~e~dialkylalkane monocarboxylic acids, b) 7 to 12% by weight of methacrylic acid, c) 15 to 26% by weight of 2 hydroxyethyl methacrylate, d) 17 to 28% by weight of styrene, : . . , -: ~ . .
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.
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_ 4 _ 207~4 e) 1 to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 5 to 15% by weight of methyl methacrylate, S g) 12 to 17% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
A preferred embodiment of the copolymer is obtainable from:
a) 18 to 24% by weight of glycidyl esters of ~-alkyl-alkanemonocarboxylic acids and/or ~,~-dialkylalkane-monocarboxylic acids, b) 6 to 12% by weight of methacrylic acid, c) 17 to 22~ by weight of 2 hydroxyethyl methacrylate, d) 20 to 28~ by weight of styrene, e) l to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 8 to 12% by weight of methyl methacrylate, g) 12 to 17% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
Another preferred embodiment of the copolymer solution is obtainable from:
a~ 8 to 22% by weight of glycidyl ester~ of ~-alkyl-alkanemonocarboxylic acids and/or ~ dialkylalkane-monocarboxylic acids, b) 7 to IO% by weight of methaorylic acid, c) 19 to 22% by weight of 2-hydroxyethyl methacrylate, d) 20 to 2~% by weight of styrene, e) 1 to 3% by weight o~ polypropylene glycol mono-methacrylate~having an average , : . . ,:
.
5- ~7~10~
molecular weight of 350 to 387, f) 9 to 11% by weight of methyl methacrylate, g) 13 to 17% by weight of solvent-free, r~active, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
The most preferred embodiment of the above-mentioned copolymer solutions is characterised in that, after its preparation, it consists of A) 15.0-25.0% by weight, preferably 15 to 20~ by weight, of customary inert paint sol-vents, preferably with boiling points of 150 to 2D0~C, and B) 75.0-85.0% by weight, preferably 85 to 80% by weight, of hydroxyl-containing copolymers.
It has been ~ound that such a copolymer solution, when used with difunctional and/or higher polyisocyanates produces, compared with the prior art, an increased solids content for the same viscosity or a reduced vis-cosity for the same solids content. What is more, it has coating advantages, such as improved glo5s~ build, flow, processing reliability as well as the high solids con-tent, and also better environmental properties.
The copol~mer solution of the invention isprepared by solution polymerisation. This involves an addition reaction between components a and b with a simultaneous condensation with component g by elimination of methanol, which is removed in the reflux of the boiling reaction mixture. This process comprises intro-ducing the solvents and the glycidyl esters of ~-alkyl-alkanemonocarboxylic acid~ andlor ~ dialkylalkane-monocarboxylic acids into the reaction ves~el as initial charge, heating to the boilj and continuously adding the mixture or mixtures of monomers, optionally carboxy~epoxy catalysts and initiator continuou~ly over about 12-20 hours. On completion o~ the metered addition the . . .
- .:
.
20741 D~
polymerisation temperature is maintained for a further 2 to 5 hours - with or without the addition of further polymerisation initiator - until conversion is virtually complete. The polymerisation is carried out at tempera-tures between 140 and 195C, preferably at 160 to 190C, the reaction being initiated at about 180 to 190C. The temperature decreases in the course o~ the simultaneou~
copolymerisation, addition and condensation.
In a preferred embodiment, illustrated by the Examples, a mixture of inert solvents is introduced as initial charge and heated to the boil under reflux, the inert solvents having been selected in such a way that the reflux temperature is about 188C. Following initia-tion of the copolymerisation and towards the end of the metered addition time, the boiling temperature of the copolymer solution decreases to about 170C to about 140C. The metered addition i9 then followed by holding the temperature at 170C to about 140C until conversion is virtually complete and the desired solids content (about 80% in the Examples~ has been obtained.
The polymerisation reaction is initiated with known polymerisation initiators. Suitable initiators are ~or example peroxides which decompose thermally into free radicals by a 1st order reaction. Initiator type and amount are chosen in such a way that a very constant supply of free radicals is present at the polymerisation - temperature during the metered addition phase.
Preferred initiators for the polymerisation are:
dialkyl peroxides, such as di-tert-butyl peroxide, dicumyl peroxide; hydroperoxides, such as cumene hydro-peroxide, tert-butyl hydroperoxide; peresters, such as tert-butyl perbenzoate, tert-butyl per-3,5,5-trimethyl-hexanoate, tert-butyl per-2-ethylhexanoate.
The polymerisation initiators, iA particular tert-butyl per-2-ethylhexanoate, are pre~erably added in an amount o~ 2 to 6% by weight, based on the weight of monomer used.
_ 7 ~ 0 The molecular welght may be regulated using chain trans~er agents~ Examples are mercap~ans, thioglycolic esters and chlorohydrocarbons, preference being given to dodecylmercaptan.
Suitable solvents ~or the solution polymerisation are customary inert paint solvents alone, preferably mixed, with boiling points of 150C to 200C, preferably 154C to 200C. The preferr~d organic solvents are those which later are also used in the ready-prepared coatings.
Examples of such solvents are: glycol ethers, such as ethylene glycol dimethyl ~her; glycol ~ther esters, such as ethylglycol acekate, butylglycol acetate, 3-methoxy-n-butyl acetate, butyldiglycol acetate, methoxypropyl acetate; ethoxypropyl acetate, esters, such as butyl acetate, isobutyl acetate, amyl acetate; and ketones, such as methyl ~thyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, isophorone, aromatic hydrocarbons, such as xylene. Shellsol A (registered trade mark for aromatic hydrocarbon mixtures) and ali-~0 phatic hydrocarbons can likewise be used cut with theabovementioned solvents. Preference i9 given to using a mixture of butyl glycol acetate, Shellsol A and ethoxy-propyl acetate in a weight ratio of 1:2:2.
Component a) for preparing the hydroxyl-containing copolymer solutions of the invention comprises glycidyl esters of ~-alkylalkanemonocarboxylic acids and/or ~,~-dialkylalkanemonocarboxylic acids. The gly-cidyl esters preferably have the empirical formula Cl3H2403 individually or together.
Since the glycidyl radical in the glycidyl ester of such ~-alkylalkanemonocarboxylic acids and/or ~ di alkylalkanemonocarboxylic acids has the empirical formula C3~50 ~ the ~ alkylalkanemonocarboxylic acids and ~ di-alkylalkanemonocarboxylic acid~ are isomer mixtures of those monocarhoxylic acids which contain a C10 chain.
These acids are preferably very highly substituted at the ~-disposed carbon atom and fully saturated; examples thereo~ are described in Deutsche Farbenzeikschrift, ' - ' :' ' " ' ' .
2 ~
No. 10/volume 16, page 435.
Suitable hydroxyalkyl methacrylates having 1 to 6 carbon atoms in the hydroxyalkyl radical are hydroxy-methyl methacrylate, 2-hydroxyethyl methacrylate, 5 2-hydroxypropyl methacrylate, 4-butanediol monometh-acrylate, 5-pentanediol monomethacrylate, cyclohexanediol monomethacrylate and 4~dihydroxymethylcyclohexane mono-methacrylate, alone or mixed, preference being given to using 2-hydroxyethyl methacrylate.
The Yolvent-free, reactive, methoxy-functional polysiloxan~ component g with a narrow molecular weight distribution, a low average molecular weight and a very low proportion of volatiles is Silicone Intermediate SY 231 from Wacker-Chemie Gmb~, 8000 Munich 22.
lS Suitable carboxy-epoxy catalysts based on an alkali metal compound are all sodium, lithium, potassium, rubidium and caesium compounds - alo~e or mixed - which are soluble in the reaction mixture of methacrylic acid~
monoglycidyl compound and vinyl compounds or at least dissolve therein in the course of the metered addition and/or in the course of the reaction b tch being main-tained at the reaction temperature for the purpose of esterification by addition with simultaneous copoly-merisation, although the alkali metal compound used should be free of constituents which may have an unfavourable effect in the`course of the copolymerisation o~ the addition product, which is an ester.
It is po3sible to use for example the carbonates, bicarbonates, formatec, iodides, bromides, fluorides and hydroxides of the aforementioned alkali metals. On a ~actory scale it is best to use lithium hydroxide and potassium hydroxide, alone or mixed. Of these, potassium hydroxide is particularly advantageous on a factory scale on account o~ its low cost and excellent catalytic properties. The alkali metal compound or hydroxide or mixture is advantageously dissolved in the methacrylic acid to be e~teri~ied. However, it is al50 possible first to convert the alkali metal compound, e.g. alkali metal , ~ :
- 9 207~
hydroxide, carbonate or bicarbonate, and the methacrylic acid into the alkali metal salt thereof and then to dissolve the alkali metal salt of methacrylic acid as catalyst in the reaction mixture, if necessary by heating in the course of the addition reaction.
It is in general sufficient to add from about 0.001% by weight to about 0.5~ by weight of alkali metal compound of the a~orementioned kind, based on the weight of the ester-forming components, for the addition reac-tion. However, preference is given to an addition ofabout 0.001~ by weight to about 0.3~ by weight of alkali metal compound.
The most preferred addition range extends from about 0.005~ by weight to 0.1% by weight of an alkali metal compound, in which case the alkali metal compounds used are very particularly advantageously potassium and lithium compounds.
Special studies have shown that, if an alkali metal caxhoxy-epoxy catalyst, preferably an alkali metal hydxoxide, carbonate or bicarbonate~ is used in preparing the copolymer solution, the coating compositions obtain-able therefrom with polyisocyanates have special, unforeseeable properties. For instance, such two-component coating compositions have a longer pot life and the coatings produced therefrom have a better ageing resistance as regards the loæs in elasticity.
The copolymer solutions according to the inven-tion can be processed into clear or pigmented coating compositions. For this they are admixed in solvents with a customary coatings polyisocyanate in the presence or absence of customary coatings additives and auxiliaries.
Preferably, 60.0 to 80.0~ by weight of the hydroxyl-containing copolymer B is admixed with 20 to 40% by weight of a difunctional and/or higher polyisocyanate as component C; the percentages of components B and C always add up to 100%.
The polyisocyanates C uiable for crosslinking the copolymer B according to the invention are typical :
, ' " ; '~' ' ,.. .
: , ; ' ' lo- 2~7~
coatings polyisocyanates.
The proportion of polyisocyanate crosslinker is chosen in such a way that from 0.5 to 1.5 isocyanate groups are added per hydroxyl group of the binder mix-ture. Excess isocyanate groups can react with moistureand contribute to the crosslinking.
It is possible to use aliphatic, cycloaliphatic and aromatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisccyanate, 4,4~-diisocyanatodicyclohexyl-methane, toluylene 2,4-diisocyanate, o-, m- and p-xylylene diisocyanate, 4,4'-diisocyanatodiphenyl-methane; blocked polyisocyanates, such as polyisocyanates blocked with acidic CH, NH or OH compounds; and also, for example, polyisocyanates with biuret, allophanate~
urethane or isocyanurate groups. Examples of such poly-isocyanates are a biuret formed from 3 mol of hexamethylene diisocyanate with 1 mol of water and having an NCO content of about 22% (corresponding to the commer-cial product Desmodur N BAYER AG, registered trade mark);a polyisocyanate with isocyanate groups, prepared by trimerisation of 3 mol of hexamethyler.e diisocyanate and having an NCO content of about 21.5% (corresponding to the commercial product ~esmodur N 3390 ~AYER AG, registered trade mark) or polyisocyanates with urethane groups, which are reaction products of 3 mol of toluylene diisocyanate and 1 mol of trimethylolpropane and have an NCO content o~ about 17.5% (corresponding to the commer-cial product Desmodur L BAYER AG, registered trade mark).
Preference is given to using Desmodur N and Desmodur N 3390, BAYER AG, registered trade mark.
As mentioned earlier, coating compositions prepared from components ~ and C can be transparent or pigmented. Transparent coating compositions find use for example as clear coatings in a two-layer coating composed of a pigment-containing basecoat and a transparent topcoat, applied wet-on-wet and subsequently cured either in air or in baking stoves. The~e clear coating 20~0~
compositions may, in addition to customary solven-ts for controlling the spray viscosity, also contain customary flow control agents and light stabilisers but also other customary coatings additives.
The aforementioned transparent or pigmented coat-ing compositions may contain as further hardeners from 1 to 10% by weight o reactive amino resins customary for coatings.
To prepàre pigmented coating compositions, the individual constituents are mixed with one another and conventionally homogenised or ground. ~ possible pro-cedure is for example first to mix some of the copolymer solution with the pigments to be included and customary coatings auxiliaries and solvents and then to subject the mixture to milling.
The mill base is then completed with the remain-ing copolymer solution.
The coating compositions obtained from the hydroxyl-containing copolymer solution according to the invention have the considerable advantage of a high solids content coupled with a relatively low viscosity.
Their flow-out properties are excellent and they lead to paint films of excellent gloss and outstanding build. The paint films obtained are very rapidly assemblyproof and abhesive to adhesive tape, permitting for example multiple coating. The coa~ing compositions obtainable from the copolymer solutions according to the invention are thu~ particularly suitable for use in the automotive industry for coating motor car bodies, but also suitable in the re~iniæhing sector for the rapid repair of, for example, acoident damage.
The copolymer solutions of the invention can be combined with amino resins to form binders which are suita~le for baking finishes. Suitable amino reæins are the known reaction products o~ aldehydes, in particulax formaldehyde, with substances carrying a plurality of amino or amido groups, for example melamine, urea, N,N'-ethyleneurea, dicyandiamide or benzoguanamine, ' ~ , . . :; : . .
,: . .
12 - 20~4~
obtained by etherification with alcohols, in particular with n-butanol or isobutanol, in particular melamine-formaldehyde condensates, for example a melamine-formaldehyde condensate which has been etherified with isobutanol in an average molar ratio of 1 melamine-6-formaldehyde to 3 mol of isobutanol. For instance, a baking clearcoat finish can consist of50to60~ by weight of customary coatings solvents, of25to44% by weight of copolymers of the invention,19to4 ~ by weight of an amino resin, as well as customary baking finish additives.
Embodiments of the invention will now be more particularly described by way of example.
Preparation of copolymer solution A 4-1 three-necked flask equipped with a stirrer, a contact thermometer, a spherical condenser with a reflux trap for methanol and any other ellmination products, and 2 dropping funnels is charged with con-stituent I in accordance with the quantitative data given below in the table and the contents are heated with stirring and under switched-on reflux cooling to about 180 to 190C. Constituent II (monomer mixture and XOH as carboxy-epoxy catalyst and optionally a chain transfer agent) and constituent II~ (solvent-initiator mixture) are metered in continuously from dropping funnels 1 and 2 in the course of 16 hours. The temperature decreases from 188C towards the end of the addition time to about 160 to about 165C. On completion of the metered addition a temperature of about 160 to 167C is maintained for 3 hours, during which if necessary further polymerisation initiator is added after one hour, so that conversion is virtually complete~
`
.
. ' ' . ' ' , ' .
, ~ 13 - 207~10~
Table (weights in grams) .
Copolymer 1 Copolymer 2 Copolymer 3 Constituent I ButYlqlvcol_acetate 100 100 100 Ethoxvpropvl acetate 160 160 160 Mixture of aromatic hydrocarbons (Shellsol A, regis-tered trade mark) 200 200 200 Glycidyl ester (Cardura E 10, regis-tered trade mark) 400 _ 400 400 II MethacrYlic acid . 182 182 182 2-Hydroxyethyl methacrYlate 420 478 536 Stvrene 478 360 247 Polypropylene glycol monomethacrvlate* 20 20 21 MethYl methacrvlate 200 _ 160 _ 114 Potassium hydrox;de 0.1 0.1 0.1 Silicone Intermediate SY 231 _ _ _ _ _ 300 400 500 III Ethoxvpro~Yl acetate 40 40 40 tert-Butyl per-2-ethvlhexanoate 80 _ 80 80 Parameters:
Solids content (%): 80 80 80 Viscosity~ DIN 4 cup after dilution with butyl acetate to 60%
by wei~ht sollds 60-90 sec. 81-86 sect70-100 sec.
35 Acid number~ (based on resin solids?: 16.4-19.3 .18.9-20 20.6 OH number~ (based on resin solids), _ _ _ 125-17Q 156 150 _ _ ~ Average molecular weight from 350 to 387 .
~ Range of variation obtained in numerous repeats of the reaction. :~
.
- 1~ 2~10~
First studies have shown that the copolymer solution can be prepared under the stated conditions ~ven in the absence of carboxy-epoxy catalysts.
Preparation of clear coating from copolymer solution 1 In a clean, dry vessel 800 g of bu-tyl acetate, 850 g of xylene, 1050 g of a mixture of aromatic hydro-carbons tShellsol A trade mark), 150 g of light stabiliser (trade name Tinuvin~ 1130), 100 g of light stabiliser (trade name Tinuvin~ 292), 50 g of 5% strength dibutyltin dilaurate solution in xylene as accelerator and 200 g of flow-control agent (trade name Byk~ 300 10%
strength in xylene) are thoroughly mixed. Then 6800 g of copolymer solution 1 (previously adjusted from 80% by weight solids to 75~ by weight solids with butyl acetate) are add~d and thoroughly mixed in. Then 3000 g of the coatings polyisocyanate Desmodur~ N 3390, 80% solution in 1:1 xylene/butyl acetate, are added to the batch and thoroughly mixed in, and the viscosity of the mixture is immediately determined in a DIN 4 cup~ The batch is diluted with 1:1 Shellsol~ A/butyl acetate to a spray application viscosity corresponding to an efflux time of 21 seconds.
The solids content of the aforementioned clear coating is 54.8~ by weight. This represents a distinct improvement over the prior art solids content of only 50.2% by weight. Further tests o the clear coating have shown that it has improved performance characteristics.
Applied to test panels and, a~ter flash-off, heated at 80C for 45 minlltes, it produced a pendulum hardness of 120 seconds and heated at 130C for 30 minutes after flash-off it produced a pendulum hardness of 157 seconds.
The measurement was carried out after standing for one hour for the purpose of cooling.
Preparation of a white coating from copolymer solution 1:
In a clean, dry vessel 550 g of Shellsol~ A, 665 g of butyl acetate 98/100, 200 g of antisettling agent consisting of Bentone~ 38.10% strength in xylene and 4~
Anti-Terra~ U, 50 g of dibutyltin dilaurate 1% strength by .
.
- ~
,' ' .
' .
- 15 - 2~1Q~
weight in xylene, 2500 g of copolymer solutlon 1 (diluted as indicated earlier to a solids content of 75% by weight) and 375 g of wetting agent (trade name Byk~ 160 30% strength) are thoroughly mixed, and 2900 g of the white pigment titanium dioxide 2160 are gradually added with stirring and the mixture is then bead milled for 30 minutes with a bead ratio of 1:1. The batch are then admixed with 15Q0 g of copol~mer solution 1, previously adjusted to 75% by weight solids, 200 g of flow control agent (Byk~ 344 10% strength by weight in xylene), 300 g of deaerating agent (Byketol~ OK) and 760 g of n-butyl acetate and thoroughly mixed. To this batch are added 1800 g of dilution Bd 1316 as solvent followed with thorough stirring by 1800 g of the coatings polyiso-cyanate Desmodur~N 3390 90% strength. The solids content of the aforementioned white coating is 63% by weight.
This fact reveals that the coatings which contain the copolymer solution according to the invention can be applied within a shorter period (e.g. omission of spray-ing operationS) and that the paint film produced none-thsless has satisfactory performance characteristics and, by virtue of the spraying being shortened, less organic solvent is emitted into the environment. The aforemen-tioned dilution Bd 1316 is obtained by mixing 2500 g of ethoxypropyl acetate, 2500 g of n-~utyl acetate, 500 g of butoxyl (- 3-methoxy-1-butyl acetate), 2500 g of xylene and 2000 g of Shellsol~ A.
The pot life of the aforementioned white coating, measured as the DIN 4 cup efflux time, was:
measured immediately following preparation 21 second~
after 2 hours 27 "
after 4 hours 39 "
after 6 hours 58 "
after 8 hours 120 "
Steel panels coated with commercial primer were overcoated after one day with the aforementioned white coating and cured at 80C for 60 minutes. The properties . '' '' ` ' ' ' ~
. .
. . - . ' " ` ' " .
.
- 16 2~7~0~
were measured after 24 hours:
primer 24 ~m coating 44 ~m gloss ~ 60 93% measured to DIN 67530 and ISO 2813 Konig pendulum hardness 108/~ measured to DIN 53157 or ISO 1522 Buchholz hardness 87 measured to DIN 53153 or IS0 2815 Erichsen indentation7.5 mm measured to DIN 53156 or ISO 1520 adhesion (cross hatch test) Gt 0 measured to DIN 53151 or IS0 ~409 resistance 15 test 5' xylene pass 5' four-star petrol unleaded pass Resistance tests with xylene and unleaded four-star petrol A cotton wool swab soaked with xylene or unleaded four-star petrol was placed on the baked film of the white coating in the covered state and left for 5 minutes. After the cotton wool swab had b~en removed and the test liquid wiped away, the dry tested film was assessed. For a film to pass, as in the present case, it must not show any changes.
Evaluation of aforementioned test results:
Despite the high solids content of the in-test coating, the measured values show that the gloss, the Konig pendulum hardness, the Buchholz hardness, the Erichsen indentation, the cross hatch and the petrol resistance tests all produced values which correspond to tho~e of very good commercial products, which, however~
have the disadvantage that the coatings have only a lower solid~ content. Any person skilled in the art knows that as the sol~ds content of a coating increase~ ît is very difficult to achieve the requixed high quality features at all, so that the test results demon~trate surprising ` ' ~ . ~' - ' :`
:' ~ ~ '` . ' ' `
.
2~7~0~
properties.
Preparation of a clear coating from copolymer solution 2 In a clean, dry ves~el 800 g of n-butyl ac~tate, 850 g o~ xylene, 1050 g of a mixture of aromatic hydro-carbons (Shellsol A trade mark), 150 g of light stabi-liser (trade name Tinuvin~ 1130), 100 g of light stabiliser (trade name Tinuvin3 292), 50 g of a 5%
strength dibutyltin dilaurate solution in xylene as accelerator and 200 g of flow control agent (trade name Byk~ 300 10~ strength in xylene) are thoroughly mixed.
Then 6800 g of copolymer solution 2 (previously adjusted from 80% by weight solids to 75% by weight solids with butyl acetate) are added and thoroughly mixed in. Then 3000 g of coatings polyisocyanzte/Desmodur~ N 3390 dis-solved in 80% strength in 1:1 xylene/butyl acetate are added to the batch and ~horoughly mixed in and the viscosity is determined at once in a DIN 4 cup. By diluting with a l:l Shellsol~ A/butyl acetate mixture the batch is adjusted to a spray application viscosity corresponding to an efflux time of 21 seconds.
The solids content of the aforementioned clear coating is 54.7% by weight. This represents a distinct improvement over the prior art solids content of only 50.2% by weight. Further tests on the clear coating have shown that it has Lmproved performance characteristics.
Preparation o~ a white coating from copolymer solution 2:
In a clean, dry vessel 5S0 g of Shellsol0 A, 665 g o~ n-butyl acetate, 2nO g of an antisettling agent comprising Bentone~ 38 10~ strength in xylene and 4% o~
Anti Terra0 U, 50 g of dibutyltin dilaurate 1% strength by weight in xylene, 2500 g o~ copolymer ~olution 2 (diluted to a solids content of 75% by weight as indicated above) and 375 g o~ a wetting agent ttrade name Byk~ 160 30%
strength) are thoroughly mixed, and 2900 g of the white pigment titanium dioxide 2160 are gradually added with ~tirring, and the mixture i~ introduced into a bead mill and bead milled for 30 minute~ with a bead ratio of 1:1.
The batch i~ then admixed with 1500 g of copolymer ~.
- 18 - 20 7~ 1 Q4 solution 2 (adjusted to 75% solids), 200 g of a ~low control agent (Byk3 344 10% strength by weight in xylene), 300 g o~ a deaerating agent (Byketol~ OK) and 760 g of butyl acetate and ~horoughly mixed. To this batch are added 1800 g of dilution Bd 1316 as solvent followed with thorough stirring by 1800 g of coating polyisocyanate Desmodur~ N 3390 90% strength. The solids content of the aforementioned white coating is 63.5~ by weight. This fact shows that coatings which contain the copolymer solution of the invention can be applied within a shorter time (for example through omission of spraying opera-tions) and that the paint film produced nonetheless has satisfactory performance characteristics and less organic solvent is emitted into the environment by virtue of the shortening of the spraying operation.
The pot life of the aforementioned white coating, measured as efflux time from the DIN 4 cup, was:
measured immediately following preparation 21 seaonds after 2 hours 33 a~ter 4 hours 54 "
after 6 hours 120 Steel panels coated with ~ommercial primer were overcoated after one day with the aforementioned white coating and cured at 80C for 60 minutes. The properties were measured after 24 hours:
primer 22-26 ~m coating 44-51 ~m gloss ~ 60 93~measured to DIN 67530 or ISO 2813 Xonig pendulum hardness 114~ measured to DIN 53157 or ISO 1522 Buchholz hardnes~ 87measured to DIN 53153 or ISO 2815 Erichsen indentation6.8 mm measured to DIN 53156 or ISO 1520 adhesion (cross hatch test) Gt 0 measured to DIN 53151 or ISO 2409 , .
- 19 - ~07~
resistance test 5~ xylene pass 5~ fo~r-star petrol unleaded pass The aforementioned test results likewise show the surprising properties of th~ films compared from the white coating based on copolymer solution 2, as demon-strated earlier at length with the films of white coating based on copolymer solution 1.
Preparation of an amino resin clear coating from copoly-mer solution 1:
In a clean, dry vessel 400 g of aromatic hydro-carbons (Shellsol A trade mark~, 35 g of light sta~ er (trade name Tinuvin~ 1130), 35 g of light stabiliser (trade name Tinuvin~ R 292) and 200 g of a flow control agent (trade name Byk~ 300 10% strength in xylene) are thoroughly mixed. Then 5600 g of copolymer solution 1 (previously adjusted from 80% by weight solids to 75% by weight solids with butyl acetate) are added and thorough-ly mixed in. Then 373 g of melamine resin BE 683 are added to the batch and thoroughly mixed in and the viscosity is determined at once in a DIN 4 cup. By diluting with a mixture of 30 g of xylene, 20 g of n-butanol and 35 g of Solvesso~ 150 and 5 g of ethoxy-propyl acetate the batch is adjusted to a spray applica-tion viscosity corresponding to an efflux time of 21 seconds.
The solids content of the aforementioned clear coating is 43.6% by weight. This represents a distinct improvement over the prior art solids content of only 40%
by weight. Further tests on the clear coating have shown that it has improved performance characteristics. Applied to test panels and, after drying, baked at 130C for 30 minutes, the clear coating resulted in a pendulum hardne~s of 128 seconds.
Preparation of an amino re~in clear coating ~rom copolymer solution 1:
- , ~
`
, ~
, - 20 - 2~7~Q~
In a clean, dry vessel 400 g of aromatic hydro-carbons (Shellsol A trade mark), 35 g of ligh~ stabiliser (trade name Tinuvin3 1130), 35 g of light stabiliser (trade name Tinuvin~ R 292) and 200 g of a flow control 5 agent (trade name Byk0 300 10~ strength in xylene) are thoroughly mixed. Then 6530 g of copolymer solution 1 (previously adjusted from 80% by weight solids to 75~ by weight solids with butyl acetate) are added and thorough-ly mixed in. Then 280 g of melamine resin BE 683 are added to the batch and thoroughly mixed in and the viscosity is determined at once in a DIN 4 Cupt By diluting with a mixture of 30 g of xylene, 20 g of n~butanol and 35 g of Solvesso~ 150 and 5 g of ethoxy-propyl acetate the batch is adjusted to the spray vi~cosity corresponding to an efflux time of 21 seconds.
The solids content of the af orementioned clear coating is 43.5% by weight. This represents a distinct improvement over the prior art solids content of only 40%
by weight. Further tests on the clear coating have shown that it has improved performance charactexistics. Applied to test panels and, after drying, baked at 130C for 30 minutes, the clear coating resulted in a pendulum hardness of 12 seconds.
The description, the examples, the coatings and the experimentally determined data all show that the above-stated objects of the invention are indeed achieved.
The preparation of the copolymer solutions and of the coatings involved the u~e of commercial products which will now be more particularly described:
Shellsol~ A s~arts to boil at 166C and has an aromatics content of 98~ by volume.
Tinuvin~ 1130 is a liquid W absorber ~ased on a hydroxyphenylbenzotriazole derivative. It is the reaction product of the following 2 components and has an average molecular weight of MW > 600:
., , . , ~ -~ ' :
.. , ".... .
::
, .
207~
. ~
~o ~N~ ~'` ~ HO (C~ CH~ 0~ ~,H
CH2 CH1 COOCH3 n = 6.7 Methyl 3-[3-(2H-benzo- Polyethylene glycol 300 triazol-2-yl)-5-tert-butyl-4-hydro~yphenyl~propionate ~ TINUVIN 1130 Tinuvin~ 292 is a liquid light stabiliser, developed ~or the light stabilisation of industrial coatings. Tinuvin0 292 i~ a member of the class of the sterically hindered amines (HALS). It has the advantage of not being sensitive to acid-catalysed systems which are used as automotive refinishes with low baking temperatures.
BYK0-300 is an additive for increasing the scratch and mar resistanc~ and it is based on a 50% strength solution of a specific, ~oating-compatible polysiloxane copolymer. It is manufactured by Byk-Chemie GmbH in D-4230 Wesel.
BYK~-344 is an additive for increasing the scratch and mar resistance, and it is a 50% strength solution of a specific, modified, coating-compatible siloxane copolymer.
Density at 20C (DIN 51757) 0-93-0-95 g/cm3 Refractive index ~DIN 53491) 1.463-1.468 Nonvolatiles (ASTM D1644~) 48-50%
25 Solvent 4:1 xylene/isobutanol Flashpoint (DIN/ISO 3679) 23C
Appearance clear or slightly cloudy liquid Manufacturer: BYX-Chemie Gmb~
BYKETOL~-OK is a flow control additive based on a mixture of high boiling aromatics, ketones and esters.
Den ity at 20C (DIN 51757) 0.8~-0.87 g/cm3 Refractive index (DIN 53491) 1.468-1.474 .,,. .... , ... :
. ' :
~7~1Q4 Flashpoint (DIN/ISO 3679) 42C
Appearance clear or slightly cloudy liquid Manufacturer: BYK-Chemie GmbH
Silicone Intermediate SY 231 is a solvent~free, reactive, methoxy-functional polysiloxane having a narrow molecular weight distribution, a low average molecular weight and a very low volatiles content. Silicone Inter mediate SY 231 is a clear, slightly yellowish liquid having an alkoxy equivalent of 222, a total silicone content (all methoxy groups replaced by Si~O-Si bonds) of 89% by weight, a viscosity at 25C of 100-150 mm2/s, a density at 25C of 1.14 g/ml, a refractive index at 25C
of 1.500-1.505, and a volatiles content (5 g/1 h/150C) of 2~ ~y weight.
Manufacturer: Wacker-Chemie GmbH, 8000 Munich 22.
BE 683 A is an n-butylated melamine resin having a relatively high solids content of 75% + 2, dissolved in n-butanol. Its acid number (mg of KOH/g) is 0~1 max. The viscosity (poise at 25C) is between 30 and 60. The white spirit tolerance ~ml/5 g) is between 28 and 60. Its viscosity allows transport in tank vessels. It has a wide compatibility range, a high reactivity and good flow properties. 5 Manufacturer: BIP Chemicals Ltdo Popes Lane Oldbury, Warley West Midlands - . . , , , ~
hydroxide, carbonate or bicarbonate, and the methacrylic acid into the alkali metal salt thereof and then to dissolve the alkali metal salt of methacrylic acid as catalyst in the reaction mixture, if necessary by heating in the course of the addition reaction.
It is in general sufficient to add from about 0.001% by weight to about 0.5~ by weight of alkali metal compound of the a~orementioned kind, based on the weight of the ester-forming components, for the addition reac-tion. However, preference is given to an addition ofabout 0.001~ by weight to about 0.3~ by weight of alkali metal compound.
The most preferred addition range extends from about 0.005~ by weight to 0.1% by weight of an alkali metal compound, in which case the alkali metal compounds used are very particularly advantageously potassium and lithium compounds.
Special studies have shown that, if an alkali metal caxhoxy-epoxy catalyst, preferably an alkali metal hydxoxide, carbonate or bicarbonate~ is used in preparing the copolymer solution, the coating compositions obtain-able therefrom with polyisocyanates have special, unforeseeable properties. For instance, such two-component coating compositions have a longer pot life and the coatings produced therefrom have a better ageing resistance as regards the loæs in elasticity.
The copolymer solutions according to the inven-tion can be processed into clear or pigmented coating compositions. For this they are admixed in solvents with a customary coatings polyisocyanate in the presence or absence of customary coatings additives and auxiliaries.
Preferably, 60.0 to 80.0~ by weight of the hydroxyl-containing copolymer B is admixed with 20 to 40% by weight of a difunctional and/or higher polyisocyanate as component C; the percentages of components B and C always add up to 100%.
The polyisocyanates C uiable for crosslinking the copolymer B according to the invention are typical :
, ' " ; '~' ' ,.. .
: , ; ' ' lo- 2~7~
coatings polyisocyanates.
The proportion of polyisocyanate crosslinker is chosen in such a way that from 0.5 to 1.5 isocyanate groups are added per hydroxyl group of the binder mix-ture. Excess isocyanate groups can react with moistureand contribute to the crosslinking.
It is possible to use aliphatic, cycloaliphatic and aromatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisccyanate, 4,4~-diisocyanatodicyclohexyl-methane, toluylene 2,4-diisocyanate, o-, m- and p-xylylene diisocyanate, 4,4'-diisocyanatodiphenyl-methane; blocked polyisocyanates, such as polyisocyanates blocked with acidic CH, NH or OH compounds; and also, for example, polyisocyanates with biuret, allophanate~
urethane or isocyanurate groups. Examples of such poly-isocyanates are a biuret formed from 3 mol of hexamethylene diisocyanate with 1 mol of water and having an NCO content of about 22% (corresponding to the commer-cial product Desmodur N BAYER AG, registered trade mark);a polyisocyanate with isocyanate groups, prepared by trimerisation of 3 mol of hexamethyler.e diisocyanate and having an NCO content of about 21.5% (corresponding to the commercial product ~esmodur N 3390 ~AYER AG, registered trade mark) or polyisocyanates with urethane groups, which are reaction products of 3 mol of toluylene diisocyanate and 1 mol of trimethylolpropane and have an NCO content o~ about 17.5% (corresponding to the commer-cial product Desmodur L BAYER AG, registered trade mark).
Preference is given to using Desmodur N and Desmodur N 3390, BAYER AG, registered trade mark.
As mentioned earlier, coating compositions prepared from components ~ and C can be transparent or pigmented. Transparent coating compositions find use for example as clear coatings in a two-layer coating composed of a pigment-containing basecoat and a transparent topcoat, applied wet-on-wet and subsequently cured either in air or in baking stoves. The~e clear coating 20~0~
compositions may, in addition to customary solven-ts for controlling the spray viscosity, also contain customary flow control agents and light stabilisers but also other customary coatings additives.
The aforementioned transparent or pigmented coat-ing compositions may contain as further hardeners from 1 to 10% by weight o reactive amino resins customary for coatings.
To prepàre pigmented coating compositions, the individual constituents are mixed with one another and conventionally homogenised or ground. ~ possible pro-cedure is for example first to mix some of the copolymer solution with the pigments to be included and customary coatings auxiliaries and solvents and then to subject the mixture to milling.
The mill base is then completed with the remain-ing copolymer solution.
The coating compositions obtained from the hydroxyl-containing copolymer solution according to the invention have the considerable advantage of a high solids content coupled with a relatively low viscosity.
Their flow-out properties are excellent and they lead to paint films of excellent gloss and outstanding build. The paint films obtained are very rapidly assemblyproof and abhesive to adhesive tape, permitting for example multiple coating. The coa~ing compositions obtainable from the copolymer solutions according to the invention are thu~ particularly suitable for use in the automotive industry for coating motor car bodies, but also suitable in the re~iniæhing sector for the rapid repair of, for example, acoident damage.
The copolymer solutions of the invention can be combined with amino resins to form binders which are suita~le for baking finishes. Suitable amino reæins are the known reaction products o~ aldehydes, in particulax formaldehyde, with substances carrying a plurality of amino or amido groups, for example melamine, urea, N,N'-ethyleneurea, dicyandiamide or benzoguanamine, ' ~ , . . :; : . .
,: . .
12 - 20~4~
obtained by etherification with alcohols, in particular with n-butanol or isobutanol, in particular melamine-formaldehyde condensates, for example a melamine-formaldehyde condensate which has been etherified with isobutanol in an average molar ratio of 1 melamine-6-formaldehyde to 3 mol of isobutanol. For instance, a baking clearcoat finish can consist of50to60~ by weight of customary coatings solvents, of25to44% by weight of copolymers of the invention,19to4 ~ by weight of an amino resin, as well as customary baking finish additives.
Embodiments of the invention will now be more particularly described by way of example.
Preparation of copolymer solution A 4-1 three-necked flask equipped with a stirrer, a contact thermometer, a spherical condenser with a reflux trap for methanol and any other ellmination products, and 2 dropping funnels is charged with con-stituent I in accordance with the quantitative data given below in the table and the contents are heated with stirring and under switched-on reflux cooling to about 180 to 190C. Constituent II (monomer mixture and XOH as carboxy-epoxy catalyst and optionally a chain transfer agent) and constituent II~ (solvent-initiator mixture) are metered in continuously from dropping funnels 1 and 2 in the course of 16 hours. The temperature decreases from 188C towards the end of the addition time to about 160 to about 165C. On completion of the metered addition a temperature of about 160 to 167C is maintained for 3 hours, during which if necessary further polymerisation initiator is added after one hour, so that conversion is virtually complete~
`
.
. ' ' . ' ' , ' .
, ~ 13 - 207~10~
Table (weights in grams) .
Copolymer 1 Copolymer 2 Copolymer 3 Constituent I ButYlqlvcol_acetate 100 100 100 Ethoxvpropvl acetate 160 160 160 Mixture of aromatic hydrocarbons (Shellsol A, regis-tered trade mark) 200 200 200 Glycidyl ester (Cardura E 10, regis-tered trade mark) 400 _ 400 400 II MethacrYlic acid . 182 182 182 2-Hydroxyethyl methacrYlate 420 478 536 Stvrene 478 360 247 Polypropylene glycol monomethacrvlate* 20 20 21 MethYl methacrvlate 200 _ 160 _ 114 Potassium hydrox;de 0.1 0.1 0.1 Silicone Intermediate SY 231 _ _ _ _ _ 300 400 500 III Ethoxvpro~Yl acetate 40 40 40 tert-Butyl per-2-ethvlhexanoate 80 _ 80 80 Parameters:
Solids content (%): 80 80 80 Viscosity~ DIN 4 cup after dilution with butyl acetate to 60%
by wei~ht sollds 60-90 sec. 81-86 sect70-100 sec.
35 Acid number~ (based on resin solids?: 16.4-19.3 .18.9-20 20.6 OH number~ (based on resin solids), _ _ _ 125-17Q 156 150 _ _ ~ Average molecular weight from 350 to 387 .
~ Range of variation obtained in numerous repeats of the reaction. :~
.
- 1~ 2~10~
First studies have shown that the copolymer solution can be prepared under the stated conditions ~ven in the absence of carboxy-epoxy catalysts.
Preparation of clear coating from copolymer solution 1 In a clean, dry vessel 800 g of bu-tyl acetate, 850 g of xylene, 1050 g of a mixture of aromatic hydro-carbons tShellsol A trade mark), 150 g of light stabiliser (trade name Tinuvin~ 1130), 100 g of light stabiliser (trade name Tinuvin~ 292), 50 g of 5% strength dibutyltin dilaurate solution in xylene as accelerator and 200 g of flow-control agent (trade name Byk~ 300 10%
strength in xylene) are thoroughly mixed. Then 6800 g of copolymer solution 1 (previously adjusted from 80% by weight solids to 75~ by weight solids with butyl acetate) are add~d and thoroughly mixed in. Then 3000 g of the coatings polyisocyanate Desmodur~ N 3390, 80% solution in 1:1 xylene/butyl acetate, are added to the batch and thoroughly mixed in, and the viscosity of the mixture is immediately determined in a DIN 4 cup~ The batch is diluted with 1:1 Shellsol~ A/butyl acetate to a spray application viscosity corresponding to an efflux time of 21 seconds.
The solids content of the aforementioned clear coating is 54.8~ by weight. This represents a distinct improvement over the prior art solids content of only 50.2% by weight. Further tests o the clear coating have shown that it has improved performance characteristics.
Applied to test panels and, a~ter flash-off, heated at 80C for 45 minlltes, it produced a pendulum hardness of 120 seconds and heated at 130C for 30 minutes after flash-off it produced a pendulum hardness of 157 seconds.
The measurement was carried out after standing for one hour for the purpose of cooling.
Preparation of a white coating from copolymer solution 1:
In a clean, dry vessel 550 g of Shellsol~ A, 665 g of butyl acetate 98/100, 200 g of antisettling agent consisting of Bentone~ 38.10% strength in xylene and 4~
Anti-Terra~ U, 50 g of dibutyltin dilaurate 1% strength by .
.
- ~
,' ' .
' .
- 15 - 2~1Q~
weight in xylene, 2500 g of copolymer solutlon 1 (diluted as indicated earlier to a solids content of 75% by weight) and 375 g of wetting agent (trade name Byk~ 160 30% strength) are thoroughly mixed, and 2900 g of the white pigment titanium dioxide 2160 are gradually added with stirring and the mixture is then bead milled for 30 minutes with a bead ratio of 1:1. The batch are then admixed with 15Q0 g of copol~mer solution 1, previously adjusted to 75% by weight solids, 200 g of flow control agent (Byk~ 344 10% strength by weight in xylene), 300 g of deaerating agent (Byketol~ OK) and 760 g of n-butyl acetate and thoroughly mixed. To this batch are added 1800 g of dilution Bd 1316 as solvent followed with thorough stirring by 1800 g of the coatings polyiso-cyanate Desmodur~N 3390 90% strength. The solids content of the aforementioned white coating is 63% by weight.
This fact reveals that the coatings which contain the copolymer solution according to the invention can be applied within a shorter period (e.g. omission of spray-ing operationS) and that the paint film produced none-thsless has satisfactory performance characteristics and, by virtue of the spraying being shortened, less organic solvent is emitted into the environment. The aforemen-tioned dilution Bd 1316 is obtained by mixing 2500 g of ethoxypropyl acetate, 2500 g of n-~utyl acetate, 500 g of butoxyl (- 3-methoxy-1-butyl acetate), 2500 g of xylene and 2000 g of Shellsol~ A.
The pot life of the aforementioned white coating, measured as the DIN 4 cup efflux time, was:
measured immediately following preparation 21 second~
after 2 hours 27 "
after 4 hours 39 "
after 6 hours 58 "
after 8 hours 120 "
Steel panels coated with commercial primer were overcoated after one day with the aforementioned white coating and cured at 80C for 60 minutes. The properties . '' '' ` ' ' ' ~
. .
. . - . ' " ` ' " .
.
- 16 2~7~0~
were measured after 24 hours:
primer 24 ~m coating 44 ~m gloss ~ 60 93% measured to DIN 67530 and ISO 2813 Konig pendulum hardness 108/~ measured to DIN 53157 or ISO 1522 Buchholz hardness 87 measured to DIN 53153 or IS0 2815 Erichsen indentation7.5 mm measured to DIN 53156 or ISO 1520 adhesion (cross hatch test) Gt 0 measured to DIN 53151 or IS0 ~409 resistance 15 test 5' xylene pass 5' four-star petrol unleaded pass Resistance tests with xylene and unleaded four-star petrol A cotton wool swab soaked with xylene or unleaded four-star petrol was placed on the baked film of the white coating in the covered state and left for 5 minutes. After the cotton wool swab had b~en removed and the test liquid wiped away, the dry tested film was assessed. For a film to pass, as in the present case, it must not show any changes.
Evaluation of aforementioned test results:
Despite the high solids content of the in-test coating, the measured values show that the gloss, the Konig pendulum hardness, the Buchholz hardness, the Erichsen indentation, the cross hatch and the petrol resistance tests all produced values which correspond to tho~e of very good commercial products, which, however~
have the disadvantage that the coatings have only a lower solid~ content. Any person skilled in the art knows that as the sol~ds content of a coating increase~ ît is very difficult to achieve the requixed high quality features at all, so that the test results demon~trate surprising ` ' ~ . ~' - ' :`
:' ~ ~ '` . ' ' `
.
2~7~0~
properties.
Preparation of a clear coating from copolymer solution 2 In a clean, dry ves~el 800 g of n-butyl ac~tate, 850 g o~ xylene, 1050 g of a mixture of aromatic hydro-carbons (Shellsol A trade mark), 150 g of light stabi-liser (trade name Tinuvin~ 1130), 100 g of light stabiliser (trade name Tinuvin3 292), 50 g of a 5%
strength dibutyltin dilaurate solution in xylene as accelerator and 200 g of flow control agent (trade name Byk~ 300 10~ strength in xylene) are thoroughly mixed.
Then 6800 g of copolymer solution 2 (previously adjusted from 80% by weight solids to 75% by weight solids with butyl acetate) are added and thoroughly mixed in. Then 3000 g of coatings polyisocyanzte/Desmodur~ N 3390 dis-solved in 80% strength in 1:1 xylene/butyl acetate are added to the batch and ~horoughly mixed in and the viscosity is determined at once in a DIN 4 cup. By diluting with a l:l Shellsol~ A/butyl acetate mixture the batch is adjusted to a spray application viscosity corresponding to an efflux time of 21 seconds.
The solids content of the aforementioned clear coating is 54.7% by weight. This represents a distinct improvement over the prior art solids content of only 50.2% by weight. Further tests on the clear coating have shown that it has Lmproved performance characteristics.
Preparation o~ a white coating from copolymer solution 2:
In a clean, dry vessel 5S0 g of Shellsol0 A, 665 g o~ n-butyl acetate, 2nO g of an antisettling agent comprising Bentone~ 38 10~ strength in xylene and 4% o~
Anti Terra0 U, 50 g of dibutyltin dilaurate 1% strength by weight in xylene, 2500 g o~ copolymer ~olution 2 (diluted to a solids content of 75% by weight as indicated above) and 375 g o~ a wetting agent ttrade name Byk~ 160 30%
strength) are thoroughly mixed, and 2900 g of the white pigment titanium dioxide 2160 are gradually added with ~tirring, and the mixture i~ introduced into a bead mill and bead milled for 30 minute~ with a bead ratio of 1:1.
The batch i~ then admixed with 1500 g of copolymer ~.
- 18 - 20 7~ 1 Q4 solution 2 (adjusted to 75% solids), 200 g of a ~low control agent (Byk3 344 10% strength by weight in xylene), 300 g o~ a deaerating agent (Byketol~ OK) and 760 g of butyl acetate and ~horoughly mixed. To this batch are added 1800 g of dilution Bd 1316 as solvent followed with thorough stirring by 1800 g of coating polyisocyanate Desmodur~ N 3390 90% strength. The solids content of the aforementioned white coating is 63.5~ by weight. This fact shows that coatings which contain the copolymer solution of the invention can be applied within a shorter time (for example through omission of spraying opera-tions) and that the paint film produced nonetheless has satisfactory performance characteristics and less organic solvent is emitted into the environment by virtue of the shortening of the spraying operation.
The pot life of the aforementioned white coating, measured as efflux time from the DIN 4 cup, was:
measured immediately following preparation 21 seaonds after 2 hours 33 a~ter 4 hours 54 "
after 6 hours 120 Steel panels coated with ~ommercial primer were overcoated after one day with the aforementioned white coating and cured at 80C for 60 minutes. The properties were measured after 24 hours:
primer 22-26 ~m coating 44-51 ~m gloss ~ 60 93~measured to DIN 67530 or ISO 2813 Xonig pendulum hardness 114~ measured to DIN 53157 or ISO 1522 Buchholz hardnes~ 87measured to DIN 53153 or ISO 2815 Erichsen indentation6.8 mm measured to DIN 53156 or ISO 1520 adhesion (cross hatch test) Gt 0 measured to DIN 53151 or ISO 2409 , .
- 19 - ~07~
resistance test 5~ xylene pass 5~ fo~r-star petrol unleaded pass The aforementioned test results likewise show the surprising properties of th~ films compared from the white coating based on copolymer solution 2, as demon-strated earlier at length with the films of white coating based on copolymer solution 1.
Preparation of an amino resin clear coating from copoly-mer solution 1:
In a clean, dry vessel 400 g of aromatic hydro-carbons (Shellsol A trade mark~, 35 g of light sta~ er (trade name Tinuvin~ 1130), 35 g of light stabiliser (trade name Tinuvin~ R 292) and 200 g of a flow control agent (trade name Byk~ 300 10% strength in xylene) are thoroughly mixed. Then 5600 g of copolymer solution 1 (previously adjusted from 80% by weight solids to 75% by weight solids with butyl acetate) are added and thorough-ly mixed in. Then 373 g of melamine resin BE 683 are added to the batch and thoroughly mixed in and the viscosity is determined at once in a DIN 4 cup. By diluting with a mixture of 30 g of xylene, 20 g of n-butanol and 35 g of Solvesso~ 150 and 5 g of ethoxy-propyl acetate the batch is adjusted to a spray applica-tion viscosity corresponding to an efflux time of 21 seconds.
The solids content of the aforementioned clear coating is 43.6% by weight. This represents a distinct improvement over the prior art solids content of only 40%
by weight. Further tests on the clear coating have shown that it has improved performance characteristics. Applied to test panels and, after drying, baked at 130C for 30 minutes, the clear coating resulted in a pendulum hardne~s of 128 seconds.
Preparation of an amino re~in clear coating ~rom copolymer solution 1:
- , ~
`
, ~
, - 20 - 2~7~Q~
In a clean, dry vessel 400 g of aromatic hydro-carbons (Shellsol A trade mark), 35 g of ligh~ stabiliser (trade name Tinuvin3 1130), 35 g of light stabiliser (trade name Tinuvin~ R 292) and 200 g of a flow control 5 agent (trade name Byk0 300 10~ strength in xylene) are thoroughly mixed. Then 6530 g of copolymer solution 1 (previously adjusted from 80% by weight solids to 75~ by weight solids with butyl acetate) are added and thorough-ly mixed in. Then 280 g of melamine resin BE 683 are added to the batch and thoroughly mixed in and the viscosity is determined at once in a DIN 4 Cupt By diluting with a mixture of 30 g of xylene, 20 g of n~butanol and 35 g of Solvesso~ 150 and 5 g of ethoxy-propyl acetate the batch is adjusted to the spray vi~cosity corresponding to an efflux time of 21 seconds.
The solids content of the af orementioned clear coating is 43.5% by weight. This represents a distinct improvement over the prior art solids content of only 40%
by weight. Further tests on the clear coating have shown that it has improved performance charactexistics. Applied to test panels and, after drying, baked at 130C for 30 minutes, the clear coating resulted in a pendulum hardness of 12 seconds.
The description, the examples, the coatings and the experimentally determined data all show that the above-stated objects of the invention are indeed achieved.
The preparation of the copolymer solutions and of the coatings involved the u~e of commercial products which will now be more particularly described:
Shellsol~ A s~arts to boil at 166C and has an aromatics content of 98~ by volume.
Tinuvin~ 1130 is a liquid W absorber ~ased on a hydroxyphenylbenzotriazole derivative. It is the reaction product of the following 2 components and has an average molecular weight of MW > 600:
., , . , ~ -~ ' :
.. , ".... .
::
, .
207~
. ~
~o ~N~ ~'` ~ HO (C~ CH~ 0~ ~,H
CH2 CH1 COOCH3 n = 6.7 Methyl 3-[3-(2H-benzo- Polyethylene glycol 300 triazol-2-yl)-5-tert-butyl-4-hydro~yphenyl~propionate ~ TINUVIN 1130 Tinuvin~ 292 is a liquid light stabiliser, developed ~or the light stabilisation of industrial coatings. Tinuvin0 292 i~ a member of the class of the sterically hindered amines (HALS). It has the advantage of not being sensitive to acid-catalysed systems which are used as automotive refinishes with low baking temperatures.
BYK0-300 is an additive for increasing the scratch and mar resistanc~ and it is based on a 50% strength solution of a specific, ~oating-compatible polysiloxane copolymer. It is manufactured by Byk-Chemie GmbH in D-4230 Wesel.
BYK~-344 is an additive for increasing the scratch and mar resistance, and it is a 50% strength solution of a specific, modified, coating-compatible siloxane copolymer.
Density at 20C (DIN 51757) 0-93-0-95 g/cm3 Refractive index ~DIN 53491) 1.463-1.468 Nonvolatiles (ASTM D1644~) 48-50%
25 Solvent 4:1 xylene/isobutanol Flashpoint (DIN/ISO 3679) 23C
Appearance clear or slightly cloudy liquid Manufacturer: BYX-Chemie Gmb~
BYKETOL~-OK is a flow control additive based on a mixture of high boiling aromatics, ketones and esters.
Den ity at 20C (DIN 51757) 0.8~-0.87 g/cm3 Refractive index (DIN 53491) 1.468-1.474 .,,. .... , ... :
. ' :
~7~1Q4 Flashpoint (DIN/ISO 3679) 42C
Appearance clear or slightly cloudy liquid Manufacturer: BYK-Chemie GmbH
Silicone Intermediate SY 231 is a solvent~free, reactive, methoxy-functional polysiloxane having a narrow molecular weight distribution, a low average molecular weight and a very low volatiles content. Silicone Inter mediate SY 231 is a clear, slightly yellowish liquid having an alkoxy equivalent of 222, a total silicone content (all methoxy groups replaced by Si~O-Si bonds) of 89% by weight, a viscosity at 25C of 100-150 mm2/s, a density at 25C of 1.14 g/ml, a refractive index at 25C
of 1.500-1.505, and a volatiles content (5 g/1 h/150C) of 2~ ~y weight.
Manufacturer: Wacker-Chemie GmbH, 8000 Munich 22.
BE 683 A is an n-butylated melamine resin having a relatively high solids content of 75% + 2, dissolved in n-butanol. Its acid number (mg of KOH/g) is 0~1 max. The viscosity (poise at 25C) is between 30 and 60. The white spirit tolerance ~ml/5 g) is between 28 and 60. Its viscosity allows transport in tank vessels. It has a wide compatibility range, a high reactivity and good flow properties. 5 Manufacturer: BIP Chemicals Ltdo Popes Lane Oldbury, Warley West Midlands - . . , , , ~
Claims (15)
1. Copolymer solution containing inert organic solvents and copolymers based on addition products of .alpha.,.beta. - unsaturated carboxylic acid with glycidyl esters and copolymerisable .alpha.,.beta. -unsaturated monomers with and without hydroxyl groups, characterised in that the copolymer solution has the components A) 15.0-50.0% by weight of inert organic solvents customary in the paints industry, B) 50.0-85.0% by weight of hydroxyl-containing copolymers obtained by simultaneous addition, condensation and polymerization in inert organic solvents or mixtures thereof with a boiling range between 160°C and 200°C
by heating under reflex in the presence of poly-merisation initiators, optionally chain transfer agents, optionally carboxy-epoxy catalyst , of a) 10 to 30% by weight of glycidyl esters of .alpha.-alkyl-alkanemonocarboxylic acids and/or .alpha.,.alpha.-dialkylalkane-monocarboxylic acids, b) 5 to 12% by weight of methacrylic acid, c) 10 to 27% by weight of hydroxyalkyl methacrylate having 1 to 6 carbon atoms in the hydroxyalkyl radical, d) 10 to 38% by weight of styrene, e) 1 to 5% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 3 to 20% by weight of alkyl methacrylate having 1 to 8 carbon atoms in the alkyl radical, g) 9 to 20% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
by heating under reflex in the presence of poly-merisation initiators, optionally chain transfer agents, optionally carboxy-epoxy catalyst , of a) 10 to 30% by weight of glycidyl esters of .alpha.-alkyl-alkanemonocarboxylic acids and/or .alpha.,.alpha.-dialkylalkane-monocarboxylic acids, b) 5 to 12% by weight of methacrylic acid, c) 10 to 27% by weight of hydroxyalkyl methacrylate having 1 to 6 carbon atoms in the hydroxyalkyl radical, d) 10 to 38% by weight of styrene, e) 1 to 5% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 3 to 20% by weight of alkyl methacrylate having 1 to 8 carbon atoms in the alkyl radical, g) 9 to 20% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
2. Copolymer solution according to Claim 1, charac terised in that component B comprises a copolymer pre-pared from mixtures consisting of a) 17 to 25% by weight of glycidyl esters of .alpha.-alkyl-alkanemonocarboxylic acids and/or .alpha.,.alpha. -dialkylalkane-monocarboxylic acids, b) 7 to 12% by weight of methacrylic acid, c) 15 to 26% by weight of 2-hydroxyethyl methacrylate, d) 17 to 28% by weight of styrene, e) 1 to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 5 to 15% by weight of methyl methacrylate, g) 12 to 17% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentage3 of components a, b, c, d, e, f and g always adding up to 100% by weight.
3. Copolymer solution according to Claim 1, characterised in that component B comprises a copolymer prepared from a mixture consisting of:
a) 18 to 24% by weight of glycidyl esters of .alpha.-alkyl-alkanemonocarboxylic acids and/or .alpha.,.alpha. -dialkylalkane-monocarboxylic acids, b) 6 to 12% by weight of methacrylic acid, c) 17 to 22% by weight of hydroxyalkyl methacrylate having 1 to 6 carbon atoms in the hydroxyalkyl radical, d) 20 to 28% by weight of styrene, e) 1 to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 8 to 12% by weight of methyl methacrylate, g) 12 to 27% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100 % by weight.
a) 18 to 24% by weight of glycidyl esters of .alpha.-alkyl-alkanemonocarboxylic acids and/or .alpha.,.alpha. -dialkylalkane-monocarboxylic acids, b) 6 to 12% by weight of methacrylic acid, c) 17 to 22% by weight of hydroxyalkyl methacrylate having 1 to 6 carbon atoms in the hydroxyalkyl radical, d) 20 to 28% by weight of styrene, e) 1 to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 8 to 12% by weight of methyl methacrylate, g) 12 to 27% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100 % by weight.
4. Copolymer solution according to Claim 1, characterised in that component B comprises a copolymer prepared from mixtures consisting of:
a) 8 to 22% by weight of glycidyl esters of .alpha.-a1kyl-alkanemonocarboxylic acids and/or .alpha., .alpha.-dialkylalkane-monocarboxylic acids, b) 7 to 10% by weight of methacrylic acid, c) 19 to 22% by weight of 2-hydroxyethyl methacrylate, d) 2 0 to 28 % by weight of styrene, e) 1 to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 9 to 11% by weight of methyl methacrylate, g) 13 to 17% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
a) 8 to 22% by weight of glycidyl esters of .alpha.-a1kyl-alkanemonocarboxylic acids and/or .alpha., .alpha.-dialkylalkane-monocarboxylic acids, b) 7 to 10% by weight of methacrylic acid, c) 19 to 22% by weight of 2-hydroxyethyl methacrylate, d) 2 0 to 28 % by weight of styrene, e) 1 to 3% by weight of polypropylene glycol mono-methacrylate having an average molecular weight of 350 to 387, f) 9 to 11% by weight of methyl methacrylate, g) 13 to 17% by weight of solvent-free, reactive, methoxy-functional polysiloxane, the percentages of components a, b, c, d, e, f and g always adding up to 100% by weight.
5. Copolymer solution according to any one of Claims 1 to 4, characterised in that, after its preparation, it consists of A) 15.0-25.0% by weight, preferably 15 to 20% by weight, of customary inert organic paint solvents and B) 75.0-85.0% by weight of hydroxyl-containing copolymers .
6. Copolymer solution according to any one of Claims 1 to 5, characterised in that as carboxy-epoxy catalyst there is present 0.001% by weight to 0.5% by weight of at least one alkali metal compound, based on the weight of the ester-forming components.
7. Two-component coatings containing as binder a copolymer solution according to any one of Claims 1 to 6 and as hardener a difunctional or higher polyisocyanate.
8. Two-component coatings according to Claim 7 containing 60 to 80% by weight of copolymer as binder and 20 to 40% by weight of di- and/or higher po]yisocyanate as hardener.
9. Two-component coatings according to Claim 7 or 8 containing 1 to 10% by weight of reactive amino resins as additional hardeners.
10. Baking finishes containing as binder a copolymer solution according to any one of Claims 1 to 6 and as hardener at least one reactive amino resin.
11. Baking finishes according to Claim 10 containing 60 to 90% by weight of copolymer as binder and 10 to 40%
by weight of reactive amino resin.
by weight of reactive amino resin.
12. Process for preparing the hydroxyl-containing copolymer solutions according to any one of Claims 1 to 6, characterised by heating a mixture consisting of component A and the monomers of component B, the boiling point of component A being such that, after the reaction has ended, the copolymers are present in component A with the desired solids content, as initial charge into which the necessary monomers a, b, c, d, e, f and component g, polymerisation initiators, optionally chain transfer agents, optionally carboxy-epoxy catalysts are gradually introduced at the polymerisation temperature at the rate of the polymerisation and the simultaneous addition and condensation and on completion of the metered addition if necessary maintained at the polymerisation temperature until the reaction has ended.
13. Process according to Claim 9, characterised in that component A has a boiling range between 180°C and 200°C and is kept as initial charge at the reflux tem-perature and the metered addition is effected at a uniform rate over 12 to 20 hours and on completion of the metered addition the batch is maintained at the reflex temperature until the copolymerisation has ended, although the reflux temperature may drop to about 140°C.
14. Process according to either of Claims 9 and 10, characterised is that component A is used in an amount of
15 to 25% by weight, preferably 15 to 20% by weight.
15. Process according to any one of Claims 9 to 11, characterised in that as carboxy-epoxy catalyst there is used 0.001% by weight to 0.5% by weight of at least one alkali metal compound, based on the weight of the ester forming components.
15. Process according to any one of Claims 9 to 11, characterised in that as carboxy-epoxy catalyst there is used 0.001% by weight to 0.5% by weight of at least one alkali metal compound, based on the weight of the ester forming components.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4124167.3 | 1991-07-20 | ||
| DE4124167A DE4124167A1 (en) | 1991-07-20 | 1991-07-20 | COPOLYMERIZATION SOLUTIONS BASED ON ADDITIONAL PRODUCTS (ALPHA), (BETA) -IN-ACID CARBOXYLIC ACID WITH GLYCIDYL REPELLERS, AND THEREOF MIXED POLYMERIZABLE (ALPHA), (BETA) -UNITENATE-SUBSTITUTED MONOMERERS |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2074104A1 true CA2074104A1 (en) | 1993-01-21 |
Family
ID=6436674
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002074104A Abandoned CA2074104A1 (en) | 1991-07-20 | 1992-07-17 | Copolymer solutions based on addition products of .alpha.,.beta.-unsaturated carboxylic acid with glycidyl esters and copolymerisable .alpha.,.bete.-unsaturated montomers |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0528169B1 (en) |
| AT (1) | ATE185354T1 (en) |
| AU (1) | AU651901B2 (en) |
| CA (1) | CA2074104A1 (en) |
| DE (2) | DE4124167A1 (en) |
| ES (1) | ES2139581T3 (en) |
| NZ (1) | NZ243485A (en) |
| ZA (1) | ZA925121B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5663265A (en) * | 1994-05-02 | 1997-09-02 | Hoechst Aktiengesellschaft | Copolymers containing hydroxyl and carboxyl groups by reacting glycidyl esters and carboxyl monomers |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19519807A1 (en) * | 1995-05-31 | 1997-02-13 | Basf Lacke & Farben | Coating compositions based on a hydroxyl-containing polyacrylate resin and its use in processes for producing a multicoat paint system |
| DE19535603A1 (en) * | 1995-09-25 | 1997-03-27 | Basf Lacke & Farben | 3-component coating agent with high solvent resistance and high bond strength |
| ATE183530T1 (en) | 1996-02-29 | 1999-09-15 | Synthopol Chemie Dr Koch | NEW POLYESTER POLYOLS AND THEIR USE AS POLYOL COMPONENTS IN TWO-COMPONENT POLYURETHANE PAINTS |
| US7288616B2 (en) | 2002-01-18 | 2007-10-30 | Lubrizol Advanced Materials, Inc. | Multi-purpose polymers, methods and compositions |
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| US3850772A (en) * | 1967-08-16 | 1974-11-26 | Desoto Inc | Electrodeposition of organopolysiloxane-containing coatings to provide improved gloss and weather resistance |
| DE2603259C3 (en) * | 1976-01-29 | 1982-10-21 | Hoechst Ag, 6000 Frankfurt | Process for the production of copolymers containing hydroxyl groups |
| DE2618809C2 (en) * | 1976-04-29 | 1983-06-30 | Hoechst Ag, 6230 Frankfurt | Process for the production of copolymers which are soluble in organic solvents and their use in reactive lacquers |
| AT350685B (en) * | 1977-12-27 | 1979-06-11 | Vianova Kunstharz Ag | PROCESS FOR THE PRODUCTION OF WATER-SOLUBLE POLYSILOXANE-MODIFIED PAINT BINDERS |
| DE2851615C2 (en) * | 1978-11-29 | 1990-05-31 | Synthopol Chemie Dr. rer. pol. Koch & Co, 2150 Buxtehude | Process for the preparation of copolymers containing hydroxyl groups which are soluble in organic solvents and their use |
| BE885473A (en) * | 1979-06-05 | 1981-01-16 | Gen Electric | PROCESS FOR THE PREPARATION OF POLYDIMETHYLSILOXANES WITH METHOXY TERMINATIONS |
| DE3412534A1 (en) * | 1984-04-04 | 1985-10-17 | Basf Farben + Fasern Ag, 2000 Hamburg | BY ACID-CURABLE COATING AGENTS AND METHOD FOR THE PRODUCTION THEREOF |
| US4589999A (en) * | 1984-12-28 | 1986-05-20 | E. I. Du Pont De Nemours And Company | Electrically conductive coating composition of a glycidyl acrylic polymer and a reactive polysiloxane |
| DE3702542A1 (en) * | 1987-01-29 | 1988-08-11 | Bayer Ag | GRAFT POLYMERISATE MADE OF (METH) ACRYLIC ACID DERIVATIVES AND SILICONE RESINS |
| DE3740774A1 (en) * | 1987-12-02 | 1989-06-15 | Herberts Gmbh | BINDER, METHOD FOR THE PRODUCTION THEREOF AND THEIR USE IN CLEAR OR PIGMENTED CONTAINERS |
| EP0329260B1 (en) * | 1988-02-19 | 1995-06-21 | Nippon Paint Co., Ltd. | Resinous composition for coating use |
| DE59105478D1 (en) * | 1990-01-20 | 1995-06-22 | Synthopol Chemie Dr Koch | Copolymer solutions based on addition products of alpha, beta-unsaturated carboxylic acid with glycidyl esters and thus copolymerizable alpha, beta-unsaturated monomers. |
-
1991
- 1991-07-20 DE DE4124167A patent/DE4124167A1/en not_active Withdrawn
-
1992
- 1992-07-09 ZA ZA925121A patent/ZA925121B/en unknown
- 1992-07-09 NZ NZ243485A patent/NZ243485A/en not_active IP Right Cessation
- 1992-07-13 EP EP92111872A patent/EP0528169B1/en not_active Expired - Lifetime
- 1992-07-13 ES ES92111872T patent/ES2139581T3/en not_active Expired - Lifetime
- 1992-07-13 DE DE59209754T patent/DE59209754D1/en not_active Expired - Fee Related
- 1992-07-13 AT AT92111872T patent/ATE185354T1/en not_active IP Right Cessation
- 1992-07-14 AU AU19684/92A patent/AU651901B2/en not_active Ceased
- 1992-07-17 CA CA002074104A patent/CA2074104A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5663265A (en) * | 1994-05-02 | 1997-09-02 | Hoechst Aktiengesellschaft | Copolymers containing hydroxyl and carboxyl groups by reacting glycidyl esters and carboxyl monomers |
Also Published As
| Publication number | Publication date |
|---|---|
| DE4124167A1 (en) | 1993-01-21 |
| NZ243485A (en) | 1994-06-27 |
| EP0528169A3 (en) | 1994-11-30 |
| ZA925121B (en) | 1993-03-31 |
| EP0528169A2 (en) | 1993-02-24 |
| DE59209754D1 (en) | 1999-11-11 |
| AU651901B2 (en) | 1994-08-04 |
| EP0528169B1 (en) | 1999-10-06 |
| ES2139581T3 (en) | 2000-02-16 |
| ATE185354T1 (en) | 1999-10-15 |
| AU1968492A (en) | 1993-01-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |