FR2510130A1 - COATING COMPOSITIONS CONTAINING A CATALYST PARTICULARLY FOR THE REFECTION OF MOTOR VEHICLES - Google Patents

Abstract

COATING COMPOSITIONS CONTAINING A CATALYST, IN PARTICULAR FOR THE REFECTION OF AUTOMOBILES. THEY ARE ESSENTIALLY CONSTITUTED BY A) FILM-GENERATED COMPONENTS OF POLYEPOXIDE RESIN AND VINYL ADDITIONAL INTERPOLYMERS CONTAINING AN AMINE, B) A SOLUBLE SALT OF A METAL FROM GROUPIIA AS A CATALYST AND C) AN ORGANIC SOLVENT.

Description

The present invention relates to coating compositions based on

  Organic solvents The invention relates more particularly to coating compositions

  especially interesting for the repair of automobiles.

  During the original equipment, cars are

  painted in the usual way with several layers of paint.

  The paint provides the automobile with aesthetic and protective features Although the paints provide long-lasting protection, it is time to

  The time needed to repaint a car.

  Usually, however, the repainting of automobiles is done in workshops where high curing temperatures are not available and the equipment used

  for the application of paint does not equate to the equi-

  of car manufacturers A coating composition

  automotive refinishing will have to dry quickly at a low curing temperature and at the same time provide the expected qualities of a paint,

  example durability, good appearance and good adhesion The characteristics

  characteristics required for an automotive paint are the following: resistance to organic solvents, resistance to petrol, resistance to moisture and resistance to gritning In the prior art, there are

  numerous compositions for the repair of motor vehicles

  These compositions of the prior art can be improved, and coating compositions having all the desired qualities of automotive refinishing paint have now been discovered.

in a short time.

  In this description all percentages,

  parts and ratios are by weight unless otherwise indicated. According to the invention, the organic solvent-based coating compositions intended in particular for the repair of automobiles consist essentially of a) film-forming constituents of polyepoxide resin and of an amine-containing vinyl addition interpolymer and b) in one embodiment. Catalyst The polyepoxide resins have a

  1,2-epoxy functionality greater than 1 and a molecular weight

  less than about 6000 in one embodiment

  polyepoxide resins are preferably polyglycol ethers.

  saturated polyphenol diols, polyglycidyl ethers of polyalcohols or polyglycidyl ethers of nitrogen-containing cyclic compounds. The addition interpolymer can be derived from ethylenically unsaturated carboxylic acid monomers.

  and other copolymerically ethylenically unsaturated monomers

  From about 5% to about 100% of the pendant carboxyl groups are iminated with an alkyleneimine, or polyamines having aliphatic amine groups on the polycarboxyl group-containing substances. The catalyst is a soluble salt of Group IIA of the Periodic Table of Elements. . The present invention relates to organic solvent-based coating compositions. The compositions consist essentially of a) a polyepoxide resin

  and addition interpolymers and b) catalysts.

  The following paragraphs describe in more detail the essential components and their formulation in

the coating compositions.

  The polyepoxide resin has a 1,2-epoxy functionality greater than 1 and a molecular weight of less than about 6,000.

  molecular weight less than about 4000 A class of poly-

  epoxides are constituted by the polygly-

  Polyalcohols alcohols can be ethylene glycol, diethylene glycol, triethylene glycol,

  1,2-propyleneglycol, 1,4-butyleneglycol, 1,5-pentane-

  diol, 1,2,6-hexanetriol and glycerol.

  Another class of useful polyepoxides is polyglycidyl ethers of saturated polyphenols. These products are commercially available or can be made from the reaction product of a

  biphenyl and an epihalohydrin with hydrogen

  Examples of biphenyl compounds are bis- (4-hydroxyphenyl) methane, namely bisphenol F, 1,1-bis- (4-hydroxyphenyl) ethane, 2,2-bis- ( 4-hydroxyphenyl) propane, namely bisphenol A

  and 1,1-bis- (4-hydroxyphenyl) butane 2,2-bis-

  (4-hydroxyphenyl) propane Suitable epihalohydrins are epichlorohydrin and epibromohydrin Suitable catalysts for the reaction of the diphenyl compound with epihalohydrin are tertiary amines, hydroxides

  quaternary ammonium, quaternary ammonium halides

  In general, the reaction of the diphenyl compound with epihalohydrin is carried out at elevated temperatures, for example between about 60.degree. C. and about 200.degree. C.. The removal of the hydrogen halide is, as a rule, strong alkalis such as anhydrous sodium hydroxide or concentrated sodium hydroxide solution. The reaction products described above are manufactured according to the process described in the patent. US 3,336,241 to which one skilled in the art can refer to

if needed.

  Other polyepoxide resins used include polyglycidyl ethers of nitrogen-containing aromatic compounds. Such resins are commercially available or can be obtained by reaction of an N-heterocyclic compound and an epihalohydrin. Suitable N-heterocyclic compounds are 2,4-imidazolidinedione (hydantoin); 5-methyl-2,4-imidazolidinedione; the 5.5

  dimethyl-4-imidazolidinedione; 5-methyl-ethyl

  2,4-imidazolidinedione; 5-ethyl-5-amyl-2,4-imidazolidine

  dione; 5-isopropyl-2,4-imidazolidinedione and 5,5-

  pentamethylene-2-imidazolidinedione epichlorohydrin and

  epibromohydrin are examples of common epihalohydrins

  US Pat. Nos. 3,365,471, 3,391,097, 3,450,711, 3,503,979 and GB 1,172,916 comprise

  additional illustrations of this class of poly-

  epoxides These patents are incorporated by reference.

  A class of a vinyl addition interpolymer

  containing an amine is derived from a carboxylic acid monomer

  ethylenically unsaturated xyl and at least one copolymerizable ethylenically unsaturated monomer Examples of the ethylenically unsaturated carboxylic acids are the acid

  acrylic and methacrylic acid The ethylenic monomers

  copolymerizable unsaturated compounds include alkyl acrylates, for example methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and t-butyl acrylate; alkyl methacrylates, for example methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and isobutyl methacrylate and styrene, for example

  styrene, alpha methyl styrene and substituted halo styrenes

  you are. The interpolymer is made from about 5% to about 30%, preferably from about 10% to

  about 25% of the ethylenic carboxylic acid-based monomer

  neatly unsaturated and from about 70% to about 95%, preferably from about 75% to about 90% of the

  copolymerizable ethylenically unsaturated monomers.

  Usually, the monomer mixture described above is polymerized in a solvent medium and in the presence of a suitable catalyst. The reaction is usually carried out under stirring at controlled high temperatures. Various modifications commonly employed in such solution polymerization reactions can be used. that an addition

  of the monomer mixture during the polymer

  fractional addition of catalysts, polymeric

  inert atmosphere and polymeric

  continuously or discontinuously.

  Typically, an organic solvent is included in the reaction mixture for ease of handling. Many different solvents can be used, including alcohols such as propanol, butanol and other lower alcohols, ketones such as methyl ethyl ketone; aromatic hydrocarbons such as xylene and toluene and esters such as butyl acetate mixtures of

  Solvents can also be used.

  The interpolymers described above are iminated by reaction of the interpolymer with an alkyleneimine in an amount sufficient to imine about 5 mol% to about 100 mol% of the pendant carboxyl groups. The imination rate expressed in moles is from Preferably it is found that the above imination rates are important for obtaining a coating composition rapidly curing at low temperature. High imination rates, for example 200 mol%, provide a composition having a reduced response to polymerization as well as physical properties

lower.

  The alkyleneimines used for the imination reaction include ethyleneimine, 1,2-propyleneimine,

  1,3-propyleneimine, 11-dimethylethyleneimine, phenyl

  ethyleneimine, tolylethyleneimine, benzylethyleneimine, 1,2-diphenylethyleneimine, hydroxyethylethyleneimine, aminoethylethyleneimine, 2-methylpropyleneimine, pchlorophenylethyleneimine, methoxyethylethyleneimine, N-ethylethylenimine and N-butylethyleneimine.

  preferred alkyleneimines are ethyleneimine and 1,2-

Propyleneimine.

  Another class of vinyl addition interpolymers containing amines is obtained by reacting a polyamine containing aliphatic amine groups and at least one

  ether group with a polycarboxylic material

  Polymers are described in copending US patent application filed November 27, 1979 for Amidation Reaction Products of Polyamines and Polycarboxyl Containing Materials and Coating C omitions Containing Samel (which is mentioned

  here for reference) The skeleton of the substances containing

  Polycarboxyl groups include acrylics,

polyesters and polyamides.

  acrylic polymers as described above can be used as a backbone. Saturated polyester resins having pendant carboxyl groups

  can also form the skeleton of the resins of the invention.

  The saturated polyesters are derived from polycarboxylic acids.

  saturated acids, preferably dicarboxylic acids and polyhydric alcohol mixtures having a functionality

  average greater than 2 For the purposes of this description,

  aromatic polycarboxylic acids having unsaturation only in the aromatic ring are considered as saturated since aromatic double bonds do not react by addition. Examples of such acids are phthalic acid, isophthalic acid, adipic acid, azelaic acid, sebacic acid and their anhydrides when they exist The polyalcohols commonly used are ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butylene glycol, glycerol,

  trimethylolpropane, pentaerythritol and sorbitol.

  Other useful substances containing polycarboxyl groups belong to the class of polyamide-based resins Polyamide resins are obtained by condensation of a diamine with a dicarboxylic acid They are characterized by recurrent amide groups, CONH-,

  as an integral part of the main polymer chain.

  Examples of diamines used for the preparation of

  polyamide resins are ethylenediamine, diethylene-

  triamine and hexamethylenediamine The dicarboxylic acids used in the reaction are those listed above in connection with the production of polyester resins, the preferred acids being adipic acid, sebacic acid,

  succinic acid, glutaric acid and azelaic acid.

  The ratio of diamine to dicarboxylic acid equivalents in polyamide resins ranges from about 1.5: 1 to

  about 1: 2 We use techniques known for the elaboration

resins.

  The carboxyl content of the preferred polycarboxyl group-containing materials is from about 0.5 milliequivalents to about 12 milliequivalents.

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  The preferred carboxyl content is from about 1 milliequivalent to about 1 milligram per gram.

  milliequivalents of carboxyl per gram.

  The ungelled amidation products of the invention are prepared by reaction of the materials described above,

  containing pendant carboxyl groups, with a poly-

  amine containing aliphatic amine groups and at least one ether linkage A class of polyamines has the formula: H 2 N (C n Ra H 2 na O) x R 'NH 2 where N is between 2 and 6, a between O and 2, R is H, CH 3 or C 2 H 5, x is from 1 to 60 and R 'is an alkylene group having 2 to 6 carbon atoms. The number x is preferably from 1 to 40. Examples of suitable polyamines are The following:

H 2 N C 2 H 40 C 2 H 4 NH 2

H 2 N (C 2 H 40) 16C 2H 4 NH 2

H 2 N (C 2 H 40) 25 C 2 H 4 NH 2

  23 H 2 N CH (CH 3) CH 20 1 3 CH 2 CH (CH 3) -NH 2 H 2 N 1 CH (CH 3) CH 203 6 CH 2 CH (CH 3) NH 2

  H 2 N LCH (CH 3) CH 20 J 33 CH 2 CH (CH 3) NH 2

H 2 N (C 4 H 80) 3 C 4 H 8 NH 2

  H 2 N (C 3 H 60) 3 CH 2 C (CH 3) 2 CH 2 C 3 H 6 NH 2

H 2 N C 3 H 60 C 4 H -C 3 H 6 NH 2

  Another class of polyamines useful in the present case corresponds to the formula: ## STR2 ## where Z is N between 2 and 4, a between O and 2, R is H, CH 3 or C 2 H 5, x is from 1 to 60, y is 2 or 3 and Z is alkyl, aryl or alkylaryl. Preferably, x is from 1 to 40 and the alkyl and alkylaryl groups contain from about 1 to about 20 carbon atoms A specific example of such a polyamine is:

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  Embedded image CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 3 CH 2 CH 3 CH 2 CH 3 CH 2 CH 3 CH 2 CH 3 CH 2 CH 3 Other polyamines useful in the reaction described above are the polyamines resulting from the ring-opening reaction of a polyepoxide containing ether groups with ammonia. These non-gelled reaction products are referred to as the polyamines. name of epoxy resins defunctionalized with ammonia A suitable class of polyepoxides is polyglycidyl ethers of polyphenols, such as bisphenol-A They are obtained by etherification of a polyphenol with epichlorohydrin in the presence of an alkali The phenolic compound may be the

  1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl)

  nyl) isobutane, 2,2-bis (4-hydroxytertiobutylphenyl)

  propane, bis (2-hydroxynaphthyl) methane, 1,5-dihydroxy-

  naphthalene and 1,1-bis (4-hydroxy-3-allylphenyl) ethane.

  Another class of useful polyepoxides is obtained in the same way from suitable polyphenol resins.

  also the similar polyglycidyl ethers of polyal-

  cools derived from polyalcohols such as ethylene glycol,

  diethylene glycol, triethylene glycol, 1,2-propyl-

  ethylene glycol, 1,4-butylene glycol, 1,5-pentanediol,

  1,2,6-hexanetriol, glycerol and 2,2-bis (4-hydroxy-

  cyclohexyl) propane The polyepoxide resins described above are reacted with ammonia This reaction involves a simple ring opening reaction during which the resulting ungelled product

  is the amine terminated product of the polyepoxide resin.

  The ammonia used can be an aqueous solution or anhydrous ammonia. It is desirable for almost all the 1,2-epoxy groups of the polyepoxide resin to react with ammonia. The reaction can be carried out with a molar excess of ammonia relative to the epoxy groups. Ammonium excesses of up to 10: 1 or more can be used, the unreacted excess ammonia being subsequently removed. The reaction of the polyepoxide resin with the ammonia takes place in a temperature range preferably between about 301 ° C. and about 1000 ° C. The duration of the reaction varies according to the temperature used, but is generally between

  approximately 2 and 5 hours The above conditions are necessary

  to minimize a subsequent reaction of the primary amine produced with the epoxy groups to form

  a highly polymerized or gelled product.

  The ratio of equivalents of the above materials containing pendant carboxyl groups and polyamines is important for obtaining an ungelled product. The equivalent ratio of polyamine to polymer containing

  carboxyl ranges from about 3: 1 to about 1: 4, preferably

  from about 1.5: 1 to about 1: 1.5. The temperatures and reaction times may vary considerably; however, it is preferred to use a temperature of from about 250 ° C to about 2500 ° C, preferably from about 85 ° C to about 1950 ° C with a reaction time of from about 0.1 hour to about 48 hours, preferably between about 0.5

hour and about 8 hours.

  The resulting reaction product is an ungelled amidation polymer which is storage stable for long periods of time. The ungelled amidation product contains primary amine groups, secondary amine groups or a mixture thereof. The amidation products have an acid number of at least 5, preferably from about 10 to about 500, more preferably from about 15 to about 300 and amine equivalent values of about 100. to about 5000, preferably from 200 to about 2000 Products may

  be kept for at least one year at 50% C.

  The coating compositions of the invention contain

  the polyepoxide resins described above and the

  vinyl addition interpolymers containing an amine.

  The coating compositions are based on organic solvents, the film former consisting essentially of the polyepoxide resin and the addition interpolymer

  in a ratio of about 1:19 to about 19: 1, preferably

  in a ratio of about 1: 5 to about 5: 1.

  The content of organic solvent in the compositions is up to about 90% and is preferably from about 0% to about 80%. Suitable solvents include alkanes, toluene, xylene, naphthas, white spirits, monoalkyl ethers of alkylene glycol, for example ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether and propylene glycol monobutyl ether; monoalkyl ethers of dialkylenegycol, for example

  diethylene glycol monoethyl ether and monobutyl ether

  dipropylene glycol tyline; lower alcohols, for example ethanol, isopropanol and butanol; esters,

  for example butyl acetate, ethyl acetate, acetal

  ethylene glycol monoethyl ether and mixtures thereof.

  The soluble salt of a Group II A metal catalyst is included in the compositions from about 0.1 part to about 5 parts, preferably from about 1 part to about 3 parts per 100 parts of the film forming constituents. Higher doses of catalyst can be used but are generally not used since there is no increased catalytic effect. The characteristics of the films obtained from the compositions using the higher doses can be impaired, for example the resistance to moisture. the film decreases with high doses of catalyst Examples of suitable catalysts are magnesium nitrate, calcium nitrate, strontium nitrate, barium nitrate, magnesium chloride, calcium chloride, strontium fluoride and Barium chloride Magnesium nitrate and calcium nitrate are preferred with a clear preference for magnesium nitrate. It is stated that the Group II A metal nitrate or halide catalyst is particularly suitable for use with the film forming components of the

  low temperature curing coating composition.

  Various other common additives are incorporated, in particular

  pigments, dyes, fillers, antioxidants, agents affecting the flowability, surfactants, thickeners and

other formulation additives.

  The compositions are preferably applied to automobile bodies. However, they can be used for coating other substrates such as wood, cement and plastics. In general, the compositions are applied by spraying, although other conventional methods are used. , such as

  the brush, the roller, the soaked, the coating by

  roller coating can be used.

  The compositions of the invention can be cured at the air temperature in about 36 hours. However, high temperatures can be used as needed.

  to accelerate the curing time.

  The composition is a polymeric composition in two

  packaging, the polyepoxide constituting a packaging, the

  addition polymer forming a second package and the

  catalyst in one or the other package.

  The following examples illustrate the invention, but

without limiting it.

EXAMPLE 1

  The following compositions are formulated to

  take out the benefits of hardening times achieved at

  using the compositions of the invention.

  Constituents l%) ABCDEF Diglycidyl ether of 2,2-bis (4-hydroxycyclohexyl) propane (1) 8.3 8.3 8.3 8.3 8.3 8.3 Addition interpolymer (2) 15.5 15, 15.5 15.5 15.5 15.5 Pigment (non-leafing aluminum flake) 1.0 1.0 1.0 1.0 1.0 1.0

Ethyl monoethyl ether

  glycol 15.2 15.2 15.2 15.2 15.2 15.2 Naphtha 40.0 40.0 40.0 40.0 40.0 40.2 Toluene 9.0 9.0 9.0 9, 0 9.0 9.0

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  Constituents (%) ABCDEF Xylene 10.8 10.8 10.8 10.8 10.8 10.8 Magnesium nitrate 0.2 Calcium nitrate 0.2 __ __ __ Magnesium chloride 0, 2 Calcium chloride 0, 2 Magnesium bromide 0.2 (1) Available from Shell Chem Co under reference

HR 151

  (2) The interpolymer is derived from 53.3% methacrylate

  butyl, 26.7% styrene and 20% methacrylate.

  Crylic Propylene imine is used to imine% molar carboxyl groups The interpolymer has an acid number of 29 and an equivalent weight

amine of 515.

  The compositions are applied separately to metal plates to form dry films of 45 to 53.5 microns. The coatings are then checked to determine the times required to obtain a tack-free surface that does not mark the adhesive strip. to this last criterion is that or the application and the removal of an adhesive tape does not leave

  no mark) The pencil hardness, the resistance to the essen-

  This and the double rubs with toluene performed on the coatings are also determined after different curing time intervals. The gasoline resistance is measured by soaking the coated plate in gasoline for 3 minutes and then visually evaluating the loss. Gloss and softening of the coating on a scale of 1 to 4, with the number 1 representing the maximum strength The results of the tests are given in the table below Composition ABCDEF Free of adhesive (min) 50 40 40 40 40 45 No mark at the adhesive tape (h) 24 24 24 24 24 48

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  Composition Pencil hardness (24 hours hardening (168 hours hardening) Gasoline resistance (48 hours curing) (168 hours curing) Double rubbing with

toluene (168 hours hardening)

ment)

A B C D E F

2 B 2 B 2 B 2 B 3 B 4 B

H H H H H F

1 1 i 1 3 3 1 1 i 1 1 1

30 35 30 20 15

  The above results show that the compositions of the invention, namely the A-E compositions, achieve faster than the control at the stage evaluated by the second test above, while being comparable or better for all.

the other tests.

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Claims (12)

  1 essentially concentrated coating composition   formed by film-forming components, a catalyst and   an organic solvent, characterized in that a) the constitution   The film-forming inhibitor is (i) a polyepoxide having a 1,2 epoxy functionality greater than 1 and a molecular weight of less than about 6,000 and (ii) an amine-containing vinyl addition interpolymer, the weight ratio of (i)   to (ii) from 1:19 to about 19: 1 and that   is a soluble salt of a Group II A metal, the level of catalyst being between about 0.1 part and   about 5 parts per 100 parts of the film-forming components.   Coating composition according to Claim 1, characterized in that the polyepoxide is chosen from polyglycidyl ethers of saturated polyphenols, polyglycidyl ethers of polyaleols and polyglycidyl ethers.   cyclic compounds containing nitrogen and mixtures thereof.   Coating composition according to one of the claims   1 Qu 2, characterized in that the amine-containing vinyl interpolymer is formed from about% to about 30% of an ethylenically unsaturated carboxylic acid monomer and from about 70% to about 95%   of at least one ethylenically unsaturated copolymer-   sand selected from alkyl acrylates, alkyl methacrylates, styrenes and mixtures thereof, and from about 100 to about 100 mol% of the carboxyl groups   pendents of the interpolymer are iminated with an alkylene   mine. Coating composition according to claim 3,   characterized in that the carboxylic acid-based monomer   ethylenically unsaturated acid is acrylic acid,   methacrylic acid or a mixture thereof.   Coating composition according to one of Claims 3 or 4, characterized in that the alkyl acrylates and the alkyl methacrylates contain 1 to 20 carbon atoms. carbon in the alkyl groups.   Coating composition according to any one of   claims 1 to 5, characterized in that   The polymer is comprised of from about 10% to about 25% of an ethylenically unsaturated carboxylic acid monomer and from about 75% to about 90% of copolymerizable ethylenically unsaturated monomers. Coating composition according to any one of   Claims 3 to 6, characterized in that the alkylene   imine is propyleneimine, ethyleneimine or a mixture thereof and about 50% molar to about 95%   carboxy groups are iminated.   Coating composition according to any one of   Claims 1 to 7, characterized in that   amine-containing polymer is an ungelled reaction product of a polyamine containing aliphatic amine groups and at least one ether group with a substance   containing carboxyl groups.   Coating composition according to claim 8, characterized in that the polyamine has the formula: H 2 N (C n Ra H 2 na 0) x R 'NH 2 in which N is between 2 and 6, a between O and 2 , R is H, CH 3 or C 2 H 5, x is from 1 to 60 and R '   is an alkylene group having 2 to 6 carbon atoms.   Coating composition according to the   8, characterized in that the polyamine is a   epoxy resin defunctionalized with ammonia.   11 Coating composition according to any one   Claims 8 to 10, characterized in that the subs-   containing polycarboxyl groups is an acrylic resin, a polyester resin, a polyamide resin, or their mixtures.   Coating composition according to any one of   Claims 1 to 11, characterized in that the resin   of polyepoxide is a polyglycidyl ether of saturated polyphenols, a polyglycidyl ether of polyalcoholsjou an ether   polyglycidique of a cyclic compound containing nitrogen.   Coating composition according to any one of   Claims 1 to 12, characterized in that the content   in organic solvent the composition lies between about 60% and about 80%.   Coating composition according to any one of   Claims 1 to 13, characterized in that the   catalyst is magnesium nitrate, nitrate calcium or a mixture thereof.   Coating composition according to any one   Claims 1 to 14, characterized in that the   polyepoxide ratio to interpolymer addition is between about 1: 5 and about 5: 1.   Coating composition according to any one of   Claims 1 to 15, characterized in that the   composition is a two-package polymeric composition, the polyepoxide constituting a package, the addition interpolymer forming a second package and the catalyst   in one or the other packaging.   17Automatic bodies or parts thereof coated with paint from the composition   according to any one of claims 1 to 16.