Classifications

• • 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
  • C09D125/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Coating compositions based on derivatives of such polymers
  • C09D125/02—Homopolymers or copolymers of hydrocarbons
• • 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
  • C08F212/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring
  • C08F212/02—Monomers containing only one unsaturated aliphatic radical
  • C08F212/04—Monomers containing only one unsaturated aliphatic radical containing one ring
  • C08F212/06—Hydrocarbons
  • C08F212/12—Monomers containing a branched unsaturated aliphatic radical or a ring substituted by an alkyl radical
• • 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
  • C08F8/00—Chemical modification by after-treatment
  • C08F8/14—Esterification
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
  • C09D133/04—Homopolymers or copolymers of esters
  • C09D133/14—Homopolymers or copolymers of esters of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
• • 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
  • C08F2810/00—Chemical modification of a polymer
  • C08F2810/30—Chemical modification of a polymer leading to the formation or introduction of aliphatic or alicyclic unsaturated groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
  • C08L61/20—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen

Definitions

• the invention relates to a process for the preparation of an acrylate copolymer by polymerization of a monomer mixture consisting of 35-60 mole % of styrene and/or ⁇ -methyl styrene, 20-60 mole % of acrylic acid and/or methacrylic acid and 0-30 mole % of one or more other monovinyl compounds at a temperature of 60 to 200 C in the presence of a radical initiator, after which the resulting reaction product is brought into reaction with a glycidyl ester of a carboxylic acid of the general formula where R represents an alkyl group having 4 to 10 carbon atoms.
• a compound of the type indicated above is known from British Patent Specification 1 009 217, in which however exclusively high molecular weight acrylate copolymers are described. It is of course possible to make use of chain length regulating compounds such as dodecyl mercaptan, but they have the disadvantage that the resulting products give out a strong smell.
• the present invention has for its object to provide low molecular weight acrylate copolymers which do not at all or hardly give out any smell and are excellently suitable for use in liquid coating compositions having a high solids content.
• the process according to the invention is characterized in that the polymerization of the monomeric compounds is carried out in the presence of a 2 to 8 carbon atoms-containing nercaptomonocarboxylic acid and/or mercaptodicarboxylic acid as chain length regulator in an amount of 0.02 to 0.25 moles per mole of the monomeric compounds.
• chain length regulators may be mentioned mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, mercaptovaleric acid, 2-mercaptobenzoic acid, mercaptosuccinic acid, mercaptoisophthalic acid.
• mercaptoacetic acid 2-mercaptopropionic acid
• 3-mercaptopropionic acid 2-mercaptovaleric acid
• 2-mercaptobenzoic acid mercaptosuccinic acid
• mercaptoisophthalic acid mercaptoisophthalic acid.
• mercaptomonocarboxylic acid and/or mercaptodicarboxylic acid containing 2 to 6 carbon atoms more particularly a mercaptopropionic acid.
• the chain length regulator is preferably used in an amount of 0.05 to 0.20 moles per mole of the monomeric compounds.
• the monomer mixture to be polymerized may be built up from 35-60 mole % of styrene and/or ⁇ -methyl styrene and 20-60 mole % of acrylic acid and/or methacrylic acid as well as from not more than 30 mole % of one or more other monovinyl compounds, for instance: acrylonitrile, vinyl chloride and vinyl acetate.
• a monovinyl compound should preferably be a monoacrylic or a monomethacrylic ester of an alcohol having 1-12 carbon atoms and 1-3 hydroxyl groups.
• acrylate monomer examples may be mentioned methyl acrylate, methyl methacrylate, ethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, butyl acrylate, hydroxybutyl acrylate, 2-ethylhexyl acrylate, hydroxyoctyl acrylate, dodecyl methacrylate, trimethylol propane monoacrylate, 2-hydroxy-3-chloropropyl acrylate.
• mixtures of 2 or more acrylate comonomers may be used.
• an organic solvent in an amount of 10-40 parts by weight per 100 parts by weight of the monomeric compounds if the acrylate copolymer to be prepared is also made up of styrene; if use is made of ⁇ -methyl styrene, then generally no use will be made of a solvent.
• suitable organic solvents include esters, such as ethyl acetate, butyl acetate and ethyl glycol acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone and hydrocarbons such as petroleum ether, toluene and xylene.
• radical initiators may be mentioned dibenzoyl peroxide,dicumyl peroxide,methylethyl ketone peroxid cumene hydroperoxide, tert. butyloxy-2-ethyl hexanoate, tert.butyl perbenzoate, tert.butylcumyl peroxide, di-tert.butylperoxy-3,3,5-trimethyl cyclohexane, 1,3-bis (tert.butyl)peroxyisopropyl benzene and azobisisobutyro nitrile. It is also possible to use mixtures of the above-envisaged radical initiators.
• the radical initiator is generally used in an amount of 0.05-5% by weight, and preferably of 0.1-3% by weight, based on the total amount.of monomer.
• the reaction product obtained by polymerization of the monomer mixture is subsequently brought into reaction with a glycidyl ester of a carboxylic acid of the general formula where R represents an alkyl group having 4 to 10 carbon atoms. It is preferred that in the general formula for the glycidyl ester R should be a branched alkyl group having 4 carbon atoms or 8-10 carbon atoms.
• suitable carboxylic acids of which the glycidyl ester according to the invention may be used include 1,1-dimethyl-1-ethane carboxylic acid, 1,1-dimethyl-1-propane carboxylic acid, 1-methyl-1-ethyl-1-propane carboxylic acid, 1-pentane carboxylic acid, 3-methyl-1-butane carboxylic acid, 1-hexane carboxylic acid, 1-heptane carboxylic acid, 1,1-dimethyl-l-hexane carboxylic acid, 1-octane carboxylic acid, decanoic acids such as 1,1-dimethyl-l-heptane carboxylic acid, nonane carboxylic acid and isononane carboxylic acid and 1,1-dimethyl-1-octane carboxylic acid.
• glycidyl ester of pivalic acid or the one of 1,1-dimethylheptane-1-carboxylic acid.
• the reaction with the glycidyl ester usually takes en masse" or in the presence of an organic solvent at a temperature between 60° and 200°C.
• a suitable catalyst for instance an acid catalyst, such as p-toluene sulphonic acid and sulphuric acid, or a basic compound, such as ammonia and an amine, and ammonium and phosphonium compounds, for instance tetramethyl ammonium chloride, benzyltrimethyl ammonium methoxide and triphenylbenzyl phosphonium chloride, and compounds such as zinc chloride and zinc acetyl acetonate.
• an acid catalyst such as p-toluene sulphonic acid and sulphuric acid
• a basic compound such as ammonia and an amine
• ammonium and phosphonium compounds for instance tetramethyl ammonium chloride, benzyltrimethyl ammonium methoxide and triphenylbenzyl phosphonium chloride, and compounds such as zinc chloride and zinc acetyl acetonate.
• the consecutive reaction with the glycidyl ester has the advantage that traces of the mercapto compound used in the preceding reaction can be rendered innocuous in an effective manner, so that an odourless product is obtained.
• the acrylate copolymer has a number average molecular weight in the range of 400 to 2000, and preferably in the range of 600 to 1500. This means that on an average 2-10 monomer units are present in 1 molecule of the acrylate copolymer.
• the acrylate copolymer described hereinbefore may conceivably be built up from 35-60 mole % of styrene and/or ⁇ -methyl styrene, and from 20-60 mole % of a compound having the general formula wherein R 1 is a hydrogen atom or a methyl group and R 2 represents an alkyl group containing 4-10 carbon atoms, and from 0-30 mole % of one or more other monovinyl compounds, and the number average molecular weight of the acrylate copolymer is in the range of 400 to 2000. It is preferred that in the general formula R 1 should represent a hydrogen atom and R 2 a branched alkyl group having 4 or 8-10 carbon atoms.
• the invention also relates to a liquid coating composition havingca solids content of at least 60% by weight and preferably at leaste 70% by weight, based on the above-described acrylate copolymer and a curing agent for the acrylate copolymer.
• the solids content is determined in accordance with ASTM-method D 1644-59 after heating for 1 hour at 105°C.
• an N-methylol groups and/or N-methylol ether groups - containing aminoplast which is obtained by reaction of an aldehyde, for instance formaldehyde with an amino groups- or amido groups-containing compound such as melamine, urea, N, N'-ethylene urea, dicyandiamide and benzoguanamine; for the preparation of these compounds see, for instance, Houben-Weyl, Methoden der organischen Chemie, Volume 14/2, p. 319-371 (1963).
• the above described compounds should entirely or partly be etherified with alcohols having 1 to 6 carbon atoms, for instance methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, amyl alcohol, hexanol or mixtures of the above-envisaged alcohols.
• Use is made particularly of a methylol melamine having 4 to 6 methylol groups per molecule of melamine, at least 3 methylol groups being etherified with methanol, ethanol, propanol or butanol, and preferably with methanol, or a condensation product of formaldehyde and N,N'-ethylene diurea etherified with butanol.
• the curing agent is generally used in such an amount that the molar ratio of the hydroxyl groups present in the coating composition to the reactive groups of the curing agent is in the range of approximately 0.7 to 1.5, and preferably in the range of 0.8 to 1.3.
• the coating composition may further contain usual adjuvants and additives, for instance pigment dispersing agents, anti-sagging agents or other means of influencing the rheological properties pigments, dyes and accelerators for the curing reaction, for instance acid compounds such as p-toluene sulphonic acid or blocked products thereof.
• the coating composition may further contain one or more organic solvents, such as esters, for instance ethyl acetate, butyl acatate and ethylglycol acetate, ketones, for instance methylethyl. ketone and methylisobutyl ketone and hydrocarbons, for instance getroleum ether, toluene and xylene.
• the organic solvent is present a in the ready-for-use coating composition in an amount of 10-40 parts by weight per 100 parts by weight of the composition.
• water may be used as a solvent if carboxyl groups of the copolymer are neutralized with a basic compound, such as an alkali metal or ammonium hydroxide or an amine.
• the ready-for use coating composition generally has a viscosity not higher than 20 poises, and preferably from 0.5 to 10 poises.
• the coating composition maybe applied to the substrate in any convenient manner, for instance by roller coating, spraying, brushing, sprinkling, flow coating, dipping or elctrostatic spraying.
• the coating composition may further be cured or baked in the usual manner, for instance at ambient temperature or at the usual temperatures of, for instance, between 100° and 160°C, while being kept in a baking oven for 20 to 60 minutes.
• the coating composition according to the invention Upon being cured the coating composition according to the invention will form a coating having a high gloss and excellent durability. It particularly has generally a remarkably high resistance to, for instance, S0 2 (Kesternich test) and organic solvents and ultraviolet light (Weather-O-meter test). Especially the resistance to S0 2 is surprising, considering the usually poor resistance to it of high molecular polyacrylates.
• the Persoz hardness was measured and the values obtained expressed in seconds. An acceptable minimum value for the hardness is about 200 seconds.
• the flexibility was determined with a "falling-weight" coating tester ( E richsen type 304) in accordance with ASTM D 2794-69, using a weight of 0.908 kg, measuring 15.9 mm in diameter and having a dropping opening or 16.3 mm, the value obtained being expressed in kg.cm. In conformity with this method the values were determined both for the coated side and the back of the test panel (Bonder 120). An acceptable minimum for the flexibility is about 10 kg.cm.
• the gloss was determined at angles of 60° and 20 0 (ASTM D-523). A gloss value at 60° of over 90 is high. A gloss value at 20 of over 80 is also to be considered high. The values for the measured properties are given in Table 1.
• the spraying compositions described in the examples all had a viscosity at 20°C of 24 seconds (Ford cup No. 4).
• the solids content of the coating compositions used in the examples was 69-76% by weight.
• the coating (after baking) had a layer thickness of 40 ⁇ m.
• the pigment dispersion used in the examples was prepared by intermixing 24 parts by weight of titanium dioxide, 1.5 parts by weight of a pigment dispersing agent (a polyacrylate having a high molecular weight), 7.5 parts by weight of hexamethoxymethyl melamine and 3.0 parts by weight of xylene, and grinding the resulting mixture in-a Red-Devil shaking machine and subsequently filtering it off.
• reaction product obtained was mixed with 0.25 grammes of triphenyl benzyl phosphonium chloride, after which over a period of 1 hour 125 grammes of the glycidyl ester of 1,1-dimethyl-
• Example 4 The same procedure was used in Example 4, except that the 3-mercaptopropionic acid was used in an amount of 8.5 grammes (0.08 moles) and the dicumyl peroxide in an amount of 1.0 gramme, and the phosphonium chloride and the glycidyl ester were used in amounts of 0.3 grammes and 138 grammes, respectively. Upon conclusion of the polymerization reaction it was found that all of the monomer had been converted.
• the acrylate copolymer prepared had an acid number lower than 0.1 and a number average molecular weight of 1200.
• Example 4 The procedure of Example 4 was repeated, with the exception that instead of 28.8 grammes (0.4 moles) of acrylic acid there was used a mixture of 21.6 grammes (0.3 moles) of acrylic acid and 12.8 grammes (0.1 mole) of n-butyl acrylate, and the glycidyl ester was used in an amount of 128 grammes. Upon conclusion of the polymerization reaction it was found that all of the monomer had been converted.
• the acrylate copolymer prepared had an acid number of 5.0.and a number average molecular weight of 700.
• Example 4 The procedure of Example 4 was repeated, but in such a way that instead of 28.8 grammes (0.4 moles) of acrylic acid there was used a mixture of 14.4 grammes (0.2 moles) of acrylic acid and 25.6 grammes (0.2 moles) of butyl acrylate, and the phosphonium chloride and the glycidyl ester were employed in amounts of 0.3 grammes and 100 grammes, respectively. Upon conclusion of the polymerization reaction it was found that all of the monomer had been converted.
• the acrylate copolymer formed had an acid number of 3.9 and a number average molecular weight of 750. '
• the acrylate copolymer prepared had an acid number of 0.7 and a number average molecular weight of 900.
• Example 10 The proceedure of Example 10 was repeated, but in such a way that instead of 3-mercaptopropionic acid there was used mercaptosuccinic acid in a corresponding amount (24.0 grammes; 0.16 moles), and the xylene was used in an amount of 74 grammes, and further the phosphonium chloride and the glycidyl ester were used in amounts of 0.40 grammes and 200 grammes, respectively. Upon conclusion of the polymerization reaction it was found that all of the monomer had been converted.
• the acrylate copolymer prepared had an acid number of 0.2 and a number average molecular weight of 1200.
• Example 10 The same procedure was used as in Example 10, except that instead of 3-mercaptopropionic acid there was used 2-mercaptoethanol in a corresponding amount(12.5 grammes; 0.16 moles) and the xylene was added in an amount of 53 grammes, and the phosphonium chloride and the glycidyl ester were used in amounts of 0.3 grammes and 125 grammes, respectively Upon conclusion of the polymerization it was found that all of the mono mer had been converted.
• 2-mercaptoethanol in a corresponding amount(12.5 grammes; 0.16 moles)
• the xylene was added in an amount of 53 grammes
• the phosphonium chloride and the glycidyl ester were used in amounts of 0.3 grammes and 125 grammes, respectively
• the acrylate copolymer prepared had an acid number of 0.1 and a number average molecular weight of 800.
• Example 10 The same procedure was employed as in Example 10, except that instead of 3 - mercaptopropionic acid there was used 2-mercaptobenzoic acid in a corresponding amount (24.6 grammes; 0.16 moles) and the xylene was used in an amount of 65 grammes. Upon conclusion of the polymerization it was found that all of the monomer had been converted. There was obtaine an 80% weight solution of the acrylate copolymer in xylene. The acrylate copolymer prepared had an acid number of 0.1 and a number average molecular weight of 1000.
• the coating composition obtained was applied to a steel panel treated with zinc phosphate (Bonder 120) and cured for 30 minutes at a temperature of 130°C.
• the properties of the baked coating are mentioned in the Tables 1 and 2.
• Example 15 The same procedure was used as in Example 15, with the exception that use was made of the acrylate polymer prepared according to Example 2 and not the one prepared according to Example 1, and the solvent mixture was employed in an amount of only 14 grammes.
• the properties of the baked coating are mentioned in the Tables 1 and 2.
• Example 15 The same procedure was used as in Example 15, with the exception that use was made of 23 grammes of the acrylate copolymer according to Example 3 instead of 25 grammes of the acrylate copolymer according to Example 1, and the hexamethoxymethyl melamine and the solvent mixture were used in amounts of 3 grammes and 10 grammes, respectively.
• the properties of the baked coating are mentioned in the Tables 1 and 2.
• Example 17 The same procedure was employed as in Example 17, with the exception that use was made of the acrylate copolymer according to Example 4 instead of the one according to Example 3.
• the properties of the baked coating are listed in the Tables 1 and 2.
• Example 15 The same procedure was used as in Example 15, with the exception that use was made of the acrylate copolymer according to Example 5 instead of the one according to Example 1.
• the properties of the baked coating are mentioned in Table 1.
• Example 15 The same procedure was used as in Example 15, with the exception that use was made of the acrylate copolymer according to Example 6 instead of the one according to Example 1.
• the properties of the baked coating are mentioned in Table 1.
• Example 15 The same procedure was used as in Example 15, with the exception that use was made of the acrylate copolymer according to Example 7 instead o the one according to Example 1.
• the properties of the baked coating are listed in Table 1.
• the resulting coating composition was applied to a steel panel "treated with zinc phosphate (Bonder 120) and cured for 30 minutes at a d'teniperature of 130°C.
• the properties of the baked coating are mentioned in Table 1.
• Example 22 The procedure of Example 22 was repeated in such a way that instead of the solution of the acrylate copolymer according to Example 8 there was employed the 80% by weight solution in xylene of the acrylate copolymer.prepared in accordance with the proceedures used in the respective Examples 9(23), 10(24), 11(25), 12(26), 13(27) and 14(28).
• the properties of the baked coatings are listed in Table 1.

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• 1977
  • 1977-07-23 NL NL7708218A patent/NL7708218A/xx not_active Application Discontinuation
• 1978
  • 1978-07-13 EP EP78200096A patent/EP0000601B1/fr not_active Expired
  • 1978-07-13 DE DE7878200096T patent/DE2860978D1/de not_active Expired
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  • 1978-07-21 US US05/926,616 patent/US4245074A/en not_active Expired - Lifetime
  • 1978-07-22 ES ES471977A patent/ES471977A1/es not_active Expired
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