POLYHYDROXYALKYLAMIDE MATERIALS FOR USE AS CROSSLINKERS

Abstract

A polyhydroxyalkylamide material having the formula (I), wherein Z represents a polymer or an alkylene, alkenylene, alkynylene or arylene group; Z′ represents a bivalent organic linking group; m is 0 or 1; X represents a bivalent organic bridging group; R represents a hydroxyalkylamide group; and n is at least 2. The present invention extends to coatings compositions containing the polyhydroxyalkylamide material and articles coated with coatings derived from said coated compositions.

Claims

1. A polyhydroxyalkylamide material having the formula (I): ##STR00035## wherein Z represents a polymer or an alkylene, alkenylene, alkynylene or arylene group; Z′ represents a bivalent organic linking group; m is 0 or 1; X represents a bivalent organic bridging group; R represents a hydroxyalkylamide group; and n is at least 2.

2. A polyhydroxyalkylamide material according to claim 1, wherein the polymer is an acrylic polymer derived from monomers having ethylenic unsaturation.

3. A polyhydroxyalkylamide material according to claim 2, wherein the monomers having ethylenic unsaturation comprise glycidyl methacrylate.

4. A polyhydroxyalkylamide material according to claim 2, wherein Z′ is substituted by an oxygen atom and a carbonyl group such that the polyhydroxyalkylamide material is represented by the formula (II): ##STR00036## wherein Z represents an acrylic polymer derived from monomers having ethylenic unsaturation; Z″ represents an alkylene, alkenylene, alkynylene, aralkylene or arylene group; X represents a bivalent organic bridging group; and n is at least 2.

5. A polyhydroxyalkylamide material according to claim 1, wherein Z is derived from a material having one or more epoxy group(s).

6. A polyhydroxyalkylamide material according to claim 1, wherein R is according to formula (IV): ##STR00037## such that the polyhydroxyalkylamide material is represented by the formula (V): ##STR00038## wherein Z represents a polymer or an alkylene, alkenylene, alkynylene or arylene group; Z′ represents a bivalent organic linking group; m is 0 or 1; X represents a bivalent organic bridging group; R.sup.9 represents hydrogen, an alkyl, alkenyl, alkynyl or aryl group, or —Y—OH; each Y independently represents an alkylene, alkenylene, alkynylene or arylene linking group; and n is at least 2.

7. A polyhydroxyalkylamide material according to claim 6, wherein R.sup.9 is hydrogen or methyl and Y is ethylene.

8. A polyhydroxyalkylamide material according to claim 6, wherein when R.sup.9 is a methyl group and X is an alkylene group, R.sup.9 together with one or more atom(s) of X forms a cyclic group such that the polyhydroxyalkylamide material is represented by the formula (VII): ##STR00039## wherein Z represents a polymer or an alkylene, alkenylene, alkynylene or arylene group; Z′ represents a bivalent organic linking group; m is 0 or 1; R.sup.11 is the bivalent radical of R.sup.9 and represents a methylene group; X′ is a fragment of X and represents —CR.sup.11—, wherein R.sup.11 represents hydrogen or a C.sub.1 to C.sub.9 alkyl group; X″ is the remaining fragment of X and represents a C.sub.0 to C.sub.8 alkylene group; and n is at least 2.

9. A coating composition, the coating composition comprising: a) a film-forming resin; and b) a polyhydroxyalkylamide material having the formula (I): ##STR00040## wherein Z represents polymer or an alkylene, alkenylene, alkynylene or arylene group; Z′ represents a bivalent organic linking group; m is 0 or 1; X represents a bivalent organic bridging group; R represents a hydroxyalkylamide group; and n is at least 2.

10. A coating composition according to claim 9, wherein the film-forming resin comprises a solution polymerised acrylic resin and an emulsion polymerised acrylic resin.

11. A coating composition according to claim 9, wherein the coating composition comprises a further crosslinking material, the further crosslinking material comprising a phenolic resin.

12. A substrate at least partially coated with a coating, the coating being derived from a coating composition, the coating composition comprising: a) a film-forming resin; and b) a polyhydroxyalkylamide material having the formula (I): ##STR00041## wherein Z represents a polymer or an alkylene, alkenylene, alkynylene or arylene group; Z′ represents a bivalent organic linking group; m is 0 or 1; X represents a bivalent organic bridging group; R represents a hydroxyalkylamide group; and n is at least 2.

13. A package coated on at least a portion thereof with a coating, the coating being derived from a coating composition, the coating composition comprising: a) a film-forming resin; and b) a polyhydroxyalkylamide material having the formula (I): ##STR00042## wherein Z represents a polymer or an alkylene, alkenylene, alkynylene or arylene group; Z′ represents a bivalent organic linking group; m is 0 or 1; X represents a bivalent organic bridging group; R represents a hydroxyalkylamide group; and n is at least 2.

14. A method of preparing a polyhydroxyalkylamide material having the formula (I): ##STR00043## wherein Z represents a polymer or an alkylene, alkenylene, alkynylene or arylene group; Z′ represents a bivalent organic linking group; m is 0 or 1; X represents a bivalent organic bridging group; R represents a hydroxyalkylamide group; and n is at least 2, the method comprising: reacting an acrylic pre-polymer derived from monomers having ethylenic unsaturation, said acrylic pre-polymer having at least two epoxy group(s), and/or a diepoxide with the reaction product of a diacid and an alkanolamine.

15. A coating composition, the coating composition comprising a polyhydroxyalkylamide material having the formula (I): ##STR00044## wherein Z represents a polymer derived from monomers having ethylenic unsaturation, and wherein Z has acid functionality; Z′ represents a bivalent organic linking group; m is 0 or 1; X represents a bivalent organic bridging group; R represents a hydroxyalkylamide group; and n is at least 2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0321] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings and the examples in which:

[0322] FIG. 1 shows a .sup.1H NMR spectrum relating to the examples discussed herein.

[0323] FIGS. 2 and 3 show .sup.13C NMR spectra relating to the examples discussed herein.

EXAMPLES

Polyhydroxyalkylamide Materials

[0324] Polyhydroxyalkylamide (polyHAA) examples 1 to 5 were prepared as follows.

Polyhydroxyalkylamide (polyHAA) Example 1

(A) Synthesis of Acrylic Pre-Polymer 1

[0325] Acrylic pre-polymer 1 was prepared according to the formulation in Table 1 and by the following method. All amounts are given in parts by weight (pbw) unless otherwise specified.

[0326] The polymerisation was carried out in a reactor equipped with heating, stirring and a water-cooled reflux condenser. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. Components 1 and 2 were charged to the reactor and heated to reflux at a temperature of 150 to 160° C. with stirring. A monomer mixture containing components 3, 4, 5 and 6 and an initiator mixture comprising components 7 and 8 were prepared separately and added to a monomer tank and an initiator tank, respectively. The monomer mixture (components 3, 4, 5, and 6) was added to the reactor at a temperature of 140° C. over a period of 150 minutes. The initiator mixture (components 7 and 8) was also added to the reactor at the same temperature but over a period of 180 mins, with the beginning of the initiator mixture charge starting 5 minutes after the monomer mixture had begun being charged to the reactor. At the end of the initiator feed, the reactor was held for 30 mins before components 9 and 10 were added over a period of 30 minutes. The reactor was then held for 60 minutes at reflux at 150° C. After this time, the reactor (containing the reaction mixture) was allowed to cool by removing the heat.

[0327] When the reaction mixture was below 100° C., component 5 was added to the reactor. The resultant acrylic pre-polymer was then removed from the reactor when hot. The resultant acrylic pre-polymer was 62% weight solids and had a Tg of 26.4° C.

TABLE-US-00001 TABLE 1 Formulation of acrylic pre-polymer 1 Acrylic Pre-polymer 1 Component Amount/pbw 1 Butyl cellosolve 314.30 2 n-butyl alcohol 83.80 3 Glycidyl methacrylate 500.00 4 Methyl methacrylate 100.10 5 Butyl acrylate 100.00 6 Butyl methacrylate 300.10 7 t-butyl peroxy-3,5,5-trimethylhexanoate 66.67 8 Butyl cellosolve 66.70 9 t-butyl peroxy-3,5,5-trimethylhexanoate 5.00 10 Butyl cellosolve 10.00 11 n-butyl alcohol 83.80 Total 1629.97

(B) Reaction of Itaconic Acid and Ethanolamine

[0328] The reaction was carried out in a 500 mL flask equipped with a condenser and thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 130.1 grams (g) itaconic acid in 260.2 g deionised water was charged to the flask at room temperature. Then, 58.03 g ethanolamine was added to the flask over a period of 30 minutes (in order to keep the reaction temperature below 50° C.). After the ethanolamine had been added, the flask was heated to reflux at 100° C. The reaction mixture was held at reflux until an amine equivalent weight (MEQ) of <0.20 was achieved. The flask (containing the reaction mixture) was allowed to cool before the product was poured out.

[0329] The resultant product had an acid value of about 125 mg KOH/g.

(C) Synthesis of Polyhydroxyalkylamide (polyHAA) 1

[0330] The reaction was carried out in a 500 mL flask equipped with a condenser thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 106 g of the acrylic pre-polymer made in step (A), 0.11 g tetrabutyl ammonium bromide and 64.14 g of the reaction product of itaconic acid and ethanolamine made in step (B) were added to the flask and heated to 100° C. The flask (containing the reaction mixture) was held at 100° C. until the acid value was measured to be below 10 mg KOH/g. Then, 53 g n-butanol was added before the product was poured out through a cone.

[0331] The resultant polyhydroxyalkylamide material was 62% by weight solids. The polyhydroxyalkylamide material had a Tg of 26.4° C.

Polyhydroxyalkylamide (polyHAA) Example 2

(A) Acrylic Pre-Polymer 2

[0332] Acrylic pre-polymer 2 was prepared according to the formulation in Table 2 and by the following method. All amounts are given in parts by weight (pbw) unless otherwise specified.

[0333] The polymerisation was carried out in a 3 L equipped with heating, cooling, stirring and a water-cooled reflux condenser. A sparge of nitrogen was applied to the flask to provide an inert atmosphere. Components 1 and 2 were charged to the flask and heated to a temperature of 144° C. with stirring. A monomer mixture containing components 3, 4, 5 and 6 and an initiator mixture comprising components 7 and 8 were prepared separately and added to a monomer tank and an initiator feed line, respectively. The initiator mixture (components 7 and 8) was added to the flask over a period of 180 mins. The monomer mixture (components 3, 4, 5 and 6) was also added to the flask but over a period of 150 minutes, with the beginning of the monomer mixture charge starting 5 minutes after the initiator mixture had begun being charged to the flask. At the end of the monomer/initiator feeds, the reactor was cooled to a temperature of 130° C. and was held at this temperature for 30 mins. After this time. components 9 and 10 were added over a period of 30 minutes. The reactor was then held for 60 minutes at 130° C. with stirring. Then, component 11 was added before the flask (containing the reaction mixture) was allowed to cool to 40° C. by removing the heat.

[0334] The resultant acrylic pre-polymer was 61% weight solids and had Mw of 6,457 Da.

TABLE-US-00002 TABLE 2 Formulation of acrylic pre-polymer 2 Acrylic Pre-polymer 2 Component Amount/pbw 1 Butyl cellosolve 314.30 2 n-Butyl alcohol 83.980 3 Glycidyl methacrylate 500.00 4 Methyl methacrylate 100.00 5 Butyl acrylate 100.00 6 Butyl methacrylate 300.00 7 Luperox 270 .sup.1 66.70 8 Butyl cellosolve 66.70 9 Luperox270 5.00 10 Butyl cellosolve 10.00 11 n-Butyl alcohol 83.80 Total 1630.48 .sup.1 peroxyester polymer initiator (available from Arkema)

(B) Reaction of Succinic Anhydride and N-Methyl Ethanolamine

[0335] The reaction was carried out in a 3000 mL flask equipped with a condenser, additional funnel and thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 751.10 grams (g) N-methyl ethanolamine and 1000 g acetone were charged to the flask at room temperature. Then, the reaction mixture was slowly cooled to 0° C. Once the reaction mixture had reached this temperature, 1000.70 g succinic anhydride was added to the flask over a period of 60 minutes (in order to keep the reaction temperature below 20° C.). After the succinic anhydride had been added, the flask was slowly warmed to room temperature. The solvent (acetone) was then removed by vacuum distillation. The product was then poured out.

(C) Synthesis of Polyhydroxyalkylamide (polyHAA) 2

[0336] The reaction was carried out in a 1000 mL flask equipped with a condenser, additional funnel and thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 0.06 g of the reaction product of succinic anhydride and N-methyl ethanolamine made in step (B), 100.2 g n-butyl alcohol and 41.56 g tetrabutylammonium bromide were added to the flask and heated to 95° C. with stirring. Then, 115.62 g of the acrylic pre-polymer made in step (A) was added to the flask dropwise over a period of 2 hours (in order to keep the reaction temperature below 100° C.). The flask (containing the reaction mixture) was held at 100° C. until the acid value was measured to be below 10 mg KOH/g. After, the addition of the acrylic pre-polymer made in step (A), the reaction mixture was held at a temperature of 95° C. for about 16 hours until a stable acid value of 17 mg KOH/g was achieved. The flask (containing the reaction mixture) was then cooled to 40° C.

[0337] The resultant polyhydroxyalkylamide material was 42.44% by weight solids and had an Mw of 6,616 Da.

Polyhydroxyalkylamide (polyHAA) Example 3

(A) Reaction of Succinic Anhydride and N-Methyl Ethanolamine

[0338] The reaction was carried out in a 500 mL flask equipped with a condenser, additional funnel and thermocouple in a cooling bath. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 50.04 grams (g) succinic anhydride in 105.07 g methanol was charged to the flask at room temperature. Then, the reaction mixture was slowly cooled to 0° C. Once the reaction mixture had reached this temperature, 37.56 g N-methyl ethanolamine was added to the flask over a period of 30 minutes (in order to keep the reaction temperature below 5° C.). After the N-methyl ethanolamine had been added, the flask was slowly warmed to room temperature. The reaction mixture was held at room temperature until a stable amine equivalent weight (MEQ) of 0.570 was achieved. The product was then poured out.

(B) Synthesis of Polyhydroxyalkylamide (polyHAA) 3

[0339] The reaction was carried out in a 1000 mL flask equipped with a condenser and thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 57.26 g of the reaction product of succinic anhydride and N-methyl ethanolamine prepared in step (A) and 59.80 g CELLOXIDE 2021 P (available from DAICEL U.S.A.) were added to the flask and heated to reflux at 80° C. with stirring. The reaction mixture was held at reflux for about 6 hours until an acid value of less than 5 mg KOH/g was reached (AV was 3.52 mg KOH/g). The flask (containing the reaction mixture) was then cooled to 40° C. before the product was poured out.

[0340] The resultant polyhydroxyalkylamide material was 57.44% by weight solids and had an Mw of 413 Da. The resultant polyhydroxyalkylamide material had a theoretical hydroxyalkylamide equivalent weight on solids of 547 g/equivalent.

Polyhydroxyalkylamide (polyHAA) Example 4

(A) Synthesis of Acrylic Pre-Polymer 3

[0341] An acrylic pre-polymer comprising 50% glycidyl methacrylate, 18% butyl methacrylate, 12% methyl methacrylate, 10% butyl acrylate and 10% hydroxyethyl methacrylate was prepared according to the formulation in Table 3 and by the following method. All amounts are given in parts by weight (pbw) unless otherwise specified.

[0342] The polymerisation was carried out in a 3 L flask equipped with heating, stirring and a water-cooled reflux condenser. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. Components 1 and 2 were charged to the reactor and heated to 144° C. with stirring. A monomer mixture containing components 3, 4, 5, 6 and 7 and an initiator mixture comprising components 8 and 9 were prepared separately. The initiator mixture (components 8 and 9) was added to the flask over a period of 180 mins. The monomer mixture (components 3, 4, 5, 6 and 7) was also added to the flask but over a period of 150 minutes, with the beginning of the monomer mixture charge starting 5 minutes after the initiator mixture had begun being charged to the flask. At the end of the initiator feed, the flask was cooled to 130° C. and held for 30 mins. Then, and still at a temperature of 130° C., components 10 and 11 were added to the flask over a period of 30 minutes with stirring. The flask was then held for 60 minutes at 130° C. After this time, component 12 was added to the flask before the flask (containing the reaction mixture) was allowed to cool to 40° C. by removing the heat. The product was then removed from the flask.

[0343] The resultant acrylic pre-polymer was 64.95% weight solids and had an Mw of 6018 Da.

TABLE-US-00003 TABLE 3 Formulation of acrylic pre-polymer 3 Acrylic Pre-polymer 3 Component Amount/pbw 1 Butyl cellosolve 305.30 2 n-butyl alcohol 83.90 3 Glycidyl methacrylate 500.00 4 Methyl methacrylate 220.20 5 Butyl acrylate 100.20 6 Butyl methacrylate 180.20 7 Hydroxyethyl methacrylate 100.00 8 Luperox 270 .sup.1 66.70 9 Butyl cellosolve 66.70 10 Luperox 270 10.00 11 Butyl cellosolve 20.00 12 n-butyl alcohol 84.00 Total 1737.20 .sup.1 peroxyester polymer initiator (available from Arkema)

(B) Reaction of Itaconic Acid and Ethanolamine

[0344] The reaction was carried out in a 500 mL flask equipped with a condenser and thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 260.2 grams (g) itaconic acid, 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) and 86.73 g deionised water were charged to the flask at room temperature. Then, the reaction mixture was slowly heated to 60° C. Once the reaction mixture had reached this temperature, 116.05 g ethanolamine was added to the flask over a period of 30 minutes. After the ethanolamine had been added, the reaction mixture was heated to reflux and held for approximately 15 hours until the amine equivalent weight (MEQ) was less than 0.2 (MEQ was 0.157). The reaction mixture was then cooled to 40° C. before the product was poured out.

(C) Synthesis of Polyhydroxyalkylamide (polyHAA) 4

[0345] The reaction was carried out in a 1000 mL flask equipped with a condenser and thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 500.00 g of acrylic pre-polymer 3 and 125.28 g of the reaction product of itaconic acid and ethanolamine produced in step (B) were added to the flask and heated to 100° C. with stirring. The reaction mixture was held at 100° C. for about 6 hours until an acid value of less than 2 mg KOH/g was reached (AV was 1.39 mg KOH/g). Then, 250.00 g n-butyl alcohol was added to the flask. The flask (containing the reaction mixture) was cooled to 40° C. before the product was poured out.

[0346] The resultant polyhydroxyalkylamide material was 49.3% weight solids. The polyhydroxyalkylamide material had an Mw of 6,414 Da and a hydroxyalkylamide equivalent weight of 773 g/equivalent.

Polyhydroxyalkylamide (polyHAA) Example 5

[0347] A polyhydroxyalkylamide material having multiple amide groups per hydroxyalkylamide group, R, and wherein the chain contained N-containing cyclic groups was prepared as follows.

(A) Acrylic Pre-Polymer

[0348] Acrylic pre-polymer 3 as described above in step (A) of the synthesis of polyhydroxyalkylamide (polyHAA) Example 4 was used in the synthesis of polyHAA 5.

(B) Reaction of Itaconic Acid and Ethanolamine

[0349] The reaction was carried out in a 1000 mL flask equipped with a condenser and thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 390.30 grams (g) itaconic acid and 130.10 g methyl isobutyl ketone (MIBK) was charged to the flask at room temperature. Then, 183.24 g ethanolamine was added to the flask dropwise over a period of 10 minutes. After the ethanolamine had been added, the reaction mixture was heated to reflux at 130° C. The reaction mixture was held at reflux for approximately 5 hours until an amine equivalent weight (MEQ) of less than 0.1 was achieved (MEQ was 0.081). Then, 2.53 g butyl stannoic acid and 1.56 g triphenyl phosphite was added to the flask and the reaction mixture was held at 130° C. until an acid value of about 40-50 mg KOH/g was reached (AV was 40.65 mg KOH/g). The resultant product was a solid and had a Mw of 819 Da.

(C) Synthesis of Polyhydroxyalkylamide (polyHAA) 5

[0350] The reaction was carried out in a 1000 mL flask equipped with a condenser and thermocouple. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. 125.00 g of acrylic pre-polymer 3, 275.98 g of the reaction product of itaconic acid and ethanolamine produced in step (B) and 0.28 g tetrabutylammonium bromide were added to the flask and heated to 100° C. with stirring. The reaction mixture was held at 100° C. for about 6 hours until an acid value of less than 5 mg KOH/g was reached (AV was 3.65 mg KOH/g). Then, 125.00 g n-butyl alcohol was added to the flask. The flask (containing the reaction mixture) was cooled to 40° C. before the product was poured out.

[0351] The resultant polyhydroxyalkylamide material was 70.79% weight solids.

COATING COMPOSITION EXAMPLES

[0352] Coating compositions comprising, among others, an acrylic latex, a solution acrylic and a polyhydroxyalkylamide (polyHAA) material were prepared as follows.

Latex Acrylic Example 1

[0353] Latex acrylic example 1 was prepared according to the formulation in Table 4 and by the following method. All amounts are given in parts by weight (pbw) unless otherwise specified.

[0354] The polymerisation was carried out in a reactor equipped with heating, cooling, stirring and a water-cooled reflux condenser. A sparge of nitrogen was applied to the reactor to provide an inert atmosphere. Components 1 and 2 were charged to the reactor and heated to 85° C. with stirring at a speed of 275 rpm. A monomer mixture containing components 5 to 10 and an initiator mixture containing components 3 and 4 were prepared separately and added to a monomer tank and initiator tank, respectively. The initiator mixture (components 3 and 4) was then fed to the reactor dropwise over a period of 20 minutes. At the end of the initiator feed, the reactor was held for 5 minutes. Then, the monomer mixture (components 5 to 10) was charged to the reactor at 80° C. over 240 minutes at a rate of 4.42 g/minute. At the same time as the monomer mixture (components 5 to 10), a pre-mix of components 11 and 12 was added to the reactor over 240 minutes at a rate of 0.4125 g/minute.

[0355] At the end of the monomer feed, the reactor was held for 60 minutes at 85° C. After this time, the reactor was allowed to cool to below 50° C. by removing the heat. Once the reactor was cooled, a pre-mix of components 13 and 14 were added over a period of 30 minutes. The reactor was then held for 10 minutes before the resultant emulsion polymerised acrylic latex material was removed from the reactor.

TABLE-US-00004 TABLE 4 Formulation of Latex Acrylic Example 1 Latex Acrylic Example 1 Component Amount/pbw 1 Deionised water 1491.60 2 Sodium bicarbonate 4.31 3 Deionised water 167.34 4 Ammonium persulfate 2.20 5 Butyl methacrylate 273.00 6 Methyl methacrylate 274.20 7 Butyl acrylate 295.80 8 Acrylic acid 52.80 9 Methacrylic acid 152.50 10 Benzoin 10.50 11 Hydrogen peroxide (35% solution) 9.00 12 Deionised water 89.90 13 Dimethylethanolamine 57.30 14 Deionised water 684.43 Total 3564.88

Solution Acrylic Example 1

[0356] Solution acrylic example 1 was prepared according to the formulation in Table 5 and by the following method. All amounts are given in parts by weight (pbw) unless otherwise specified.

[0357] The polymerisation was carried out in a 5 L flask equipped with heating, cooling, stirring and a water-cooled reflux condenser. A sparge of nitrogen was applied to the flask to provide an inert atmosphere. Components 1 and 2 were charged to the flask and heated to reflux at a temperature of 135° C. with stirring. A monomer mixture containing components 5, 6 and 7 and an initiator mixture comprising components 3 and 4 were prepared separately. The monomer mixture (components 5, 6 and 7) and initiator mixture (components 3 and 4) were then fed to the flask via a feed funnel at 135° C. over a period of 180 minutes. At the end of the monomer/initiator feed, component 8 was added as wash for the feed funnel and the flask was maintained at reflux at 135° C. for an additional 60 minutes. A chase feed of initiator containing components 9 and 10 was then added to the flask over 20 minutes. The flask was then held for 60 minutes at reflux at 135° C. After this time, the flask (containing the reaction mixture) was allowed to cool to below 110° C. by removing the heat before component 11 was added. Then, a pre-mix of components 12 and 13 was added over a period of 10 minutes. After this time, the flask (containing the reaction mixture) was allowed to cool to below 40° C. by removing the heat.

[0358] The resultant solution polymerised acrylic material was then removed from the flask.

TABLE-US-00005 TABLE 5 Formulation of Solution Acrylic Example 1 Solution Acrylic Example 1 Component Amount/pbw 1 Ethylene Glycol n-butyl ether 407.2 2 n-butyl alcohol 186.9 3 t-butyl peroxy-3,5,5-trimethylhexanoate 4.0 4 Ethylene Glycol n-butyl ether 40.0 5 Butyl acrylate 350.0 6 Butyl methacrylate 440.0 7 Acrylic acid 210.0 8 Ethylene Glycol n-butyl ether 7.5 9 t-butyl peroxy-3,5,5-trimethylhexanoate 8.5 10 Ethylene Glycol n-butyl ether 12.9 11 n-butyl alcohol 186.9 12 Dimethylethanolamine 130.1 13 Deionised water 93.5 Total 2077.5

Coating Examples 1 to 4

[0359] Coating composition examples 1 to 4 were prepared according to the formulations in Table 6.

TABLE-US-00006 TABLE 6 Formulation of Coating Examples 1 to 4 Coating Coating Coating Coating Example 1 Example 2 Example 3 Example 4 Component Wet/g Solid/g Wet/g Solid/g Wet/g Solid/g Wet/g Solid/g Latex acrylic 270.1 84.0 270.1 84.0 270.1 84.0 270.1 84.0 example 1 .sup.1 Solution acrylic 19.0 10.0 19.0 10.0 19.0 10.0 19.0 10.0 example 1 .sup.2 polyHAA example 3 .sup.3 10.4 6.0 — — 5.2 3.0 — — polyHAA example 4 .sup.4 — — 12.2 6.0 — — 6.1 3.0 CURAPHEN 40-804 — — — — 4.0 3.0 4.0 3.0 W75 .sup.5 Deionised water 220.0 — 223.6 — 213.7 — 220.2 — n-butyl alcohol 25.5 — 25.5 — 25.2 — 25.5 — Ethylene glycol 9.7 — 9.7 — 9.7 — 9.7 — n-butyl ether Amyl alcohol 10.0 — 10.0 — 10.0 — 10.0 — Dimethylethanolamine 2.0 — 2.0 — 2.0 — 2.0 — Total 566.7 100 572.1 100 559.2 100 566.6 100 .sup.1 31.1% solids .sup.2 52.5% solids .sup.3 57.4% solids .sup.4 49.3% solids .sup.5 74% phenolic resin in deionised water (available from BITREZ Ltd)

Comparative Coating Example 1

[0360] Comparative coating example 1 is a commercial inside spray available from PPG Industries containing a latex acrylic and a phenolic crosslinker.

[0361] The properties of the coatings were then tested by the following methods. The results are shown in Table 7.

[0362] Test panel preparation: Coated panels were prepared by coating flat aluminium cans using a bar coater. The dry film weight for the coating layer was 5 to 6 g/m.sup.2 (gsm). After application, the coated panels were baked in a box oven for 1 minute 45 seconds at 215° C.

[0363] Wedge Bend Test: A 10 cm×4 cm coated panel was bent on a 6 mm steel rod to form a U-shaped strip 10 cm long and 2 cm wide. The U-shaped strip was then placed onto a metal block with a built in tapered recess. A 2 kg weight was dropped onto the recessed block containing the U-shaped strip from a height of 60 cm in order to from a wedge. The test piece was then immersed in a copper sulphate (CuSO.sub.4) solution acidified with hydrochloric acid (HCl) for 2 minutes, followed by rinsing with tap water. The sample was then carefully dried by blotting any residual water with tissue paper. The length of coating without any fracture was measured. The result was quoted in mm passed. The wedge bends were tested in triplicate and the average value was quoted.

[0364] MEK Double rubs: The number of reciprocating rubs required to remove the coating composition from coated test panels was measured using a two pound ball hammer with gauze soaked in methyl ethyl ketone (MEK) covering the end of the hammer.

[0365] Processing in various simulants: Coated panels cut into 10 cm×5 cm panels were placed in a container containing one of 5% acetic acid, deionised water or 1% Joy solution such that the panel was submerged in the solution. The container was then placed in an autoclave and processed according to the parameters in Table 5 (i.e. 30 minutes at 100° C., 45 minutes at 82° C. or 10 minutes at 82° C. for 5% acetic acid, deionised water or 1% Joy solution, respectively). After this time, the panels were assessed by the following methods:

[0366] Adhesion: The processed panels were tested for coating adhesion to the aluminium substrate using a BYK Cross-Cut Tester Kit #5127 (commercially available from BYK-Gardner GmbH) in accordance with ASTM D3359. The cutter spacing was 1.5 mm and Scotch 610 tape was used. The results were rated on a scale of 0 to 5. Grade 0 corresponds to good adhesion with no removal of coating (0% loss), grade 1 corresponds to a coating loss of <5%, grade 2 corresponds to a coating loss of 5 to 15%, grade 3 corresponds to a coating loss of 16 to 5%, grade 4 corresponds to a coating loss of 36 to 65% and grade 5 corresponds to a coating loss of >65%.

TABLE-US-00007 TABLE 7 Test Results Comparative Coating Coating Coating Coating Coating Example 1 Example 2 Example 3 Example 4 Example 1 Wedge 51 49 50 49 65 Bend Test MEK 2 2 20 10 100 Double Rubs 5% acetic acid, 30 mins, 100° C. Adhesion 0 2 0 0 3 Deionised water, 45 mins, 82° C. Adhesion 0 0 0 0 0 1% Joy Detergent, 10 mins, 82° C. Adhesion 0 0 0 0 0

[0367] The results show that coating compositions containing the polyhydroxyalkylamide materials of the invention perform as well, or better, than the coatings of the comparative examples.

Solubility

[0368] The solubility of PRIMID XL 552 and PRIMID QM 1260 (each available from EMS Chemie) in solvents was tested according to the following method:

[0369] Solubility: a solvent mixture of n-butyl alcohol and ethylene glycol n-butyl ether was prepared in accordance with Table 8. Then, 0.5 g of the PRIMID crosslinker according to Table 8 was added. Solid pieces of the PRIMID crosslinker were broken up via mechanical mixing and sonication, as required. The mixture was stirred for at least 30 minutes with gentle heating (<80 C). Then, the mixture was cooled to room temperature. The solubility was assessed visually by inspecting for undissolved solids or haziness. If soluble, the process was repeated with 0.5 g additions of PRIMID crosslinker until insoluble concentration was found.

[0370] The results are shown in Table 8.

TABLE-US-00008 TABLE 8 Solubility Results PRIMID XL 552 PRIMID QM 1260 Primid (g) 0.5 0.5 0.5 0.5 n-butyl alcohol (g) 4.8 4.2 4.8 4.2 Ethylene glycol n- butyl ether (g) 1.2 1.8 1.2 1.8 % total solids 7.69% 7.69% 7.69% 7.69% BuOH-BC ratio 4:1 7:3 4:1 7:3 Solubility? Insoluble Insoluble Insoluble Insoluble

[0371] The results show that the known small molecule (poly)hydroxyalkylamide crosslinkers are insoluble in, at least, the organic solvents used in coating examples 1 to 4. The polyhydroxyalkylamide materials of the invention are soluble in these solvents, as shown by the fact that the polyhydroxyalkylamide materials of the invention are synthesised in these solvents. For example, the acrylic pre-polymers are synthesised in, and contain, n-butyl alcohol and ethylene glycol n-butyl ether (i.e. butyl cellosolve). Also, n-butyl alcohol is used as a solvent in the synthesis of the polyhydroxyalkylamide materials.

Hydrolytic Stability Examples 1 to 4

[0372] The hydrolytic stability of polyhydroxyalkylamide materials in a coating composition was tested according to the following method.

Latex Acrylic Examples 2 to 5

[0373] Latex acrylic examples 2 to 5 were prepared according to the formulations in Table 9 and by the following method. All amounts are given in parts by weight (pbw) unless otherwise specified.

[0374] The polymerisation was carried out in a reactor equipped with heating, cooling, stirring and a water-cooled reflux condenser. A blanket of nitrogen was applied to the reactor to provide an inert atmosphere. Components 1 and 2 were charged to the reactor and heated to 80° C. with stirring at a speed of 275 rpm. A monomer mixture containing components 5 to 9 and an initiator mixture containing components 3 and 4 were prepared separately and added to a monomer tank and initiator tank, respectively. The initiator mixture (components 3 and 4) was then fed to the reactor dropwise over a period of 20 minutes. At the end of the initiator feed, the reactor was held for 5 minutes. Then, the first 10 wt % of the monomer mixture (components 5 to 9) was charged to the reactor at 80° C. over 60 minutes, followed by 20 wt % of the monomer mixture (components 5 to 9) over the next 60 minutes, and finally the remaining 70 wt % of the monomer mixture (components 5 to 9) over 120 minutes.

[0375] At the end of the monomer feed, the reactor was held for 60 minutes at 80° C. After this time, the reactor was allowed to cool to below 50° C. by removing the heat. Once the reactor was cooled, a pre-mix of components 10 and 11 were added over a period of 30 minutes. The reactor was then held for 10 minutes before the resultant emulsion polymerised acrylic latex material was removed from the reactor.

TABLE-US-00009 TABLE 9 Formulation of Acrylic Latex Examples 2 to 5 Acrylic Acrylic Acrylic Acrylic Latex Latex Latex Latex Exam- Example 2 Example 3 Example 4 ple 5 Component Amount/pbw 1 Deionised water 4565.60 4437.49 633.59 570.13 2 Sodium bicarbonate 6.53 2.86 0.41 0.81 3 Deionised water 985.60 862.40 123.30 123.20 4 Ammonium persulfate 12.32 10.78 1.54 1.54 5 Butyl methacrylate 1120.00 980.00 140.00 262.50 6 Methyl methacrylate 560.20 612.60 87.50 0.00 7 Butyl acrylate 840.00 735.00 105.00 17.50 8 Acrylic acid 280.00 122.70 17.50 35.00 9 2-ethylhexyl acrylate — — — 35.00 10 Deionised water 1212.90 530.30 76.20 152.32 11 Dimethylethanolamine 86.60 37.90 5.44 10.90 Total 9669.75 8332.03 1190.48 1208.90

Coating Examples 2 to 5

[0376] Latex acrylic examples 2 to 5 were then formulated into coating examples 2 to 5 as follows: 308.92 g of the latex acrylic according to Table 9, 26.67 g of the polyhydroxyalkylamide material according to Table 9, 2.5 g phosphoric acid in dimethylethanolamine (DMEA), 25.5 g n-butyl alcohol, 10 g amyl alcohol, 10 g butyl cellosolve and 8.57 g of a 50% solution of DMEA in deionised water.

[0377] The hydrolytic stability of the polyhydroxyalkylamide materials in coating examples 2 to 5 was then tested according to the following methods:

[0378] Test panel preparation: coated panels were prepared by coating flat aluminium cans using a bar coater. The dry film weight for the coating layer was 5 to 6 g/m.sup.2 (gsm). After application, the coated panels were baked in a box oven for 1 minute 45 seconds at 215° C.

[0379] Hydrolytic stability: the coated panels were placed in a container containing 20% ethanol or 3% acetic acid (‘extraction solvents’) according to Table 8 such that the panel was submerged in the solution. The container was then placed in an autoclave and processed according to the parameters in Table 8. After this time, the extraction solvents were assessed by gradient elution LC-MS/MS quantitation suitable for detecting hydroxylamines in the low ng/mL range. The extraction solvents of examples 1 and 2 and comparative examples 1, 2 and 3 were diluted 500-fold for analysis, whereas the extraction solvents for examples 3 and 4 were undiluted.

[0380] The results are shown in Table 10.

Hydrolytic Stability Comparative Examples 1 to 3

[0381] The method described above for hydrolytic stability examples 1 to 4 was repeated with the exception that PRIMID XL 552 or PRIMID QM 1260 (each available from EMS Chemie) was used instead of the polyhydroxyalkylamide materials of the invention, in accordance with Table 9.

[0382] The results are shown in Table 10.

TABLE-US-00010 TABLE 10 Hydrolytic Stability Test Results Amount of Hydrolytic Acrylic Amine after Stability Latex Extraction Extraction / Example Example (poly)HAA Conditions (μg/6 dm.sup.2) Example 1 Example 4 polyHAA 20% Ethanol 41.5 Example 2 1 hour Example 2 Example 5 polyHAA 100° C. 37.5 Example 2 Example 3 Example 4 polyHAA <30.0 Example 1 Example 4 Example 5 polyHAA <30.0 Example 1 Comparative Example 1 PRIMID XL 552 3% Acetic 2,364 example 1 acid 2 hours Comparative Example 1 PRIMID XL 552 121° C. 1,212 example 2 (purified) Comparative Example 2 PRIMID QM 240 example 3 1260

[0383] The results show that the polyhydroxyalkylamide materials of the invention are more hydrolytically stable than those of the comparative examples. This is because less free amine is present in the extraction solvents for the inventive examples compared to the comparative examples.

Electrodeposition

[0384] The ability of the polyhydroxyalkylamide materials of the invention to be applied to a substrate by electrodeposition was tested according to the following method.

Anionic Acrylic Resin 1

[0385] Anionic acrylic resin 1 was prepared according to the formulation in Table 11 and by the following method. All amounts are given in parts by weight (pbw) unless otherwise specified.

[0386] The reaction was carried out in a 5000 mL flask equipped with a condenser, distillation apparatus, and thermocouple. A blanket of nitrogen was applied to the reactor to provide an inert atmosphere. Component 1 was charged to the flask at room temperature. The reaction mixture was then heated to reflux with a temperature set-point of 120° C. The monomer mixture (components 2, 3, 4, 5, 6, and 7), the initiator mixture (components 8 and 9), and AMPS monomer mixture (components 10, 11, and 12) were all fed into the flask separately and simultaneously over a period of 180 minutes while continuing to heat the reaction mixture at reflux. Upon the completion of the three feeds, the reaction mixture was held at reflux for 30 minutes. Then, half of the second initiator mixture (components 13 and 14) was fed over 10 minutes. The reaction mixture was then held at reflux for 60 minutes. Then, the remaining portion of the second initiator mixture (components 13 and 14) was fed over 10 minutes. The reaction mixture was then held at reflux for 60 minutes. After this time, the reaction mixture was cooled to 115° C. Vacuum was gradually applied and increased as needed to collect 644.4 g of collected distillate. Vacuum was then broken and replaced with a blanket of nitrogen. The reaction mixture was then equilibrated to 90° C. before component 15 was fed into the flask over 20 minutes. Then, a mixture of components 16 and 17 was fed into the flask over 30 minutes at 90° C. The reaction mixture was then held at 90° C. for 30 minutes to complete the reaction.

[0387] The resultant anionic acrylic resin dispersion was 87.4% weight solids and had an Mw of 15,454 Da.

TABLE-US-00011 TABLE 11 Formulation of Anionic Acrylic Resin 1 Anionic Acrylic Resin 1 Component Amount/pbw 1 n-Butyl alcohol 333.2 2 Methacrylic acid 239.4 3 Styrene 848.8 4 Butyl acrylate 848.8 5 2-Hydroxyethyl acrylate 228.5 6 Tertiary dodecyl mercaptan 70.6 7 n-Butyl alcohol 5.1 8 n-Butyl alcohol 113.8 9 t-Butylperbenzoate 26.2 10 n-Butyl alcohol 200.6 11 AMPS 2401 monomer.sup.1 10.9 12 Diisopropanolamine 7.3 13 N-Butyl alcohol 25.5 14 t-Butylperbenzoate 5.9 15 Deionized water 205.7 16 Dimethylthanolamine 110.2 17 Deionized water 17.1 Total 2653.2 .sup.1Sulfonic acid acrylic monomer (available from Lubrizol)

Electrodeposition Example 1

[0388] A coating composition for electrodeposition example 1 was prepared according to the formulation in Table 12. The coating was then tested according to the following method.

[0389] Test Panel Preparation: aluminium “Q” panels (0.0245 inch thickness) were cut into 4 inch by 4 inch squares for electrodeposition. The panels were immersed 7 centimetres into the electrodeposition baths and connected to the anode of the direct current source. The power source was programed to raise the voltage over the first 30 seconds of electrodeposition and then to hold the voltage at the chose value for the duration of the electrodeposition process. The coating composition was electrodeposited according to the conditions in Table 12. After electrodeposition the voltage was disengaged, the panels were rinsed vigorously with deionized water and allowed to air dry overnight. Panels with the electrodeposited coating thereon are referred to as the ‘panel’ samples in the accompanying Figures.

[0390] NMR Analysis: the composition of the deposited coating was analysed by .sup.1H-NMR and .sup.13C-NMR. The air-dried panels were washed with THF-D.sub.8 or CDCl.sub.3 (as appropriate) and then dried under a stream of nitrogen to concentrate the sample. The resulting spectra were compared to the .sup.1H-NMR and .sup.13C-NMR spectra of air-dried samples of the electrodeposition bath mixtures (referred to as ‘bath’ samples in the accompanying figures).

Electrodeposition Comparative Examples 1 and 2

[0391] The method described above for electrodeposition example 1 was repeated with the exception that the coating compositions and electrodeposition conditions according to Table 12 were used instead of the coating composition and electrodeposition conditions of electrodeposition example 1.

Electrodeposition Comparative Example 3

[0392] Electrodeposition comparative example 3 was prepared in order to identify the carbon peaks in the NMR spectrum that correspond to the HAA functionality. Electrodeposition example 3 was the reaction product of itaconic acid and ethanolamine prepared in step (B) of the synthesis of polyhydroxyalkylamide (polyHAA) example 4 dissolved in the same deuterated solvent as used in electrodeposition example 1.

TABLE-US-00012 TABLE 12 Formulation of Coatings for Electrodeposition Example 1 and Comparative Examples 1 and 2 Electrodeposition  Electrodeposition Electrodeposition Example 1  Comparative Example 1  Comparative Example 2 Component Wet/g Solid/g Wet/g Solid/g Wet/g Solid/g Anionic acrylic 67.1 58.6 115.8 101.2092 108.0 94.4 resin 1 .sup.1 polyHAA Example 4 .sup.2 80.1 39.5 — — — — PRIMID XL 552 .sup.3 — — — — 15.2 15.2 Ethylene Glycol — — 12 — 11.2 — n-butyl ether n-Butyl alcohol — — 28 — 26.1 — Isopropanol 8.4 — — — — — Deionized water 910 — 910 — 863.9 — Total 1065.6 98.1 1065.8 101.2 1024.4 109.6 Deposition Conditions Deposition time (s) 180 60 180 Voltage (V) 250 50 250 Bath temperature (° F.) 107 95 107 .sup.1 87.4% solids .sup.2 49.3% solids .sup.3 100% solids (available from EMS)

[0393] The results for electrodeposition example 1 and electrodeposition comparative examples 1 to 3 are shown in FIGS. 1 to 3.

[0394] The results show that PRIMID XL 552 was not coated out onto the steel panel (see FIG. 3). As shown in FIG. 3, PRIMID XL 552, which can be observed in the bath sample, was not observed on the panel sample. This is because analysis of the .sup.13C-NMR spectrum of the coating composition from electrodeposition comparative example 2 revealed no peaks associated with the HAA functionality, indicating that PRIMID XL-552 did not electrodeposit with anionic acrylic resin 1 (see FIG. 3).

[0395] The results also confirmed the incorporation of polyhydroxyalkylamide (polyHAA) example 4 onto the panel. In FIG. 1, it can be seen that electrodeposition example 1 contained more acrylic components (from polyhydroxyalkylamide (polyHAA) example 4) than the comparative examples. In addition, as shown in FIG. 2, .sup.13C NMR showed distinctive peaks corresponding to the amide carbonyl carbon and methylene carbons of the 2-hydroxyethyl substituents of polyhydroxyalkylamide (polyHAA) example 4. This demonstrated that polyhydroxyalkylamide (polyHAA) example 4 deposited onto the panel along with anionic acrylic resin 1 in electrodeposition example 1.

[0396] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0397] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0398] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0399] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.