Coating composition

Abstract

A coating composition comprising a resin material comprising polyester imide polymer one or more titanate material; and one or more OH reactive cross linking material.

Claims

1. A coating composition comprising a resin material comprising a polyester imide polymer one or more titanate material; and one or more OH reactive cross linking material; wherein the polyester imide polymer is formed from one or more imide containing moiety; wherein the one or more imide containing moiety is formed as a reaction product between one or more isocyanate with one or more cyclic anhydride; wherein the isocyanate is selected from hexamethylene di-isocyanate, tetramethylene di-isocyanate, isophorone di-isocyanate, methylene 4,4′-bis (cyclohexyl isocyanate) or bis-(4-isocyanatocyclohexyl)methane, methylene di phenyl di-isocyanate or bis-(4-isocyanatophenyl)methane, tetramethyl-meta-xylylene di-isocyanate, meta xylylene di -isocyanate, para xylylene di-isocyanate, cyclohexane di-isocyanate, naphthalene di-isocyanate, and trimethyl hexamethylene di-isocyanate.

2. The coating composition according to claim 1, wherein the cyclic anhydride is selected from trimellitic anhydride, pyromellitic di-anhydride, maleic anhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride tetrahydrophthalic anhydride, 1,4,5,-naphthalenetricarboxylic anhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride and hemimellitic anhydride.

3. The coating composition according to claim 1, wherein the imide containing moiety is formed as a reaction product between methylene di-phenyl di-isocyanate and trimellitic anhydride.

4. The coating composition according to claim 1, wherein the imide containing moiety is formed as a reaction product between bis(4-isocyanatocyclohexil)methane and trimellitic anhydride.

5. The coating composition according to claim 1, wherein the polyester imide polymer is formed by reaction of the imide containing moiety with one or more diol, polyol, dicarboxylic acid, di-ester or a component containing one acid (or ester) and one alcohol group.

6. The coating composition according to claim 1, wherein the composition further comprises one or more silane material, preferably wherein the silane material comprises a silane material according to Formula I, or a polysiloxane polymer derived from one or more silane material according to Formula I:
(R.sup.1).sub.nSi(OR.sup.2).sub.m  I wherein each R.sup.1 is independently selected from an optionally substituted linear or branched alkyl group, which may comprise one or more functional groups; each R.sup.2 independently represents H or an alkyl group optionally substituted linear or branched alkyl groups; n=1 to 3; m=1 to 3; and n+m=4, preferably wherein the or each functional group comprises any one or more of the following groups: hydroxyl, epoxy, amino (primary, secondary or tertiary), amido, cyano, isocyano, ethylenic unsaturation (ie one or more carbon—carbon double bonds), carboxylic acid, aldehyde, ketone, C═O, esters (such as C1 to C4 alkyl esters of carboxylic acids), alkyl carboxyl oxy (such as optionally substituted, linear or branched, saturated or unsaturated C1 to C6 alkyl carboxyl oxy, including acryloxy and methacryloxy).

7. The coating composition according to claim 1, wherein the polyester imide polymer is formed from one or more imide containing moiety substituted with i) two or more acid groups, ii) two or more alcohol group or, iii) at least one acid group and at least one alcohol group.

8. The coating composition according to claim 1, wherein the formation of the polyester imide polymer takes place in the presence of a catalyst, preferably wherein the catalyst is selected from tetra n butyl titanate; tetra iso propyl titanate; tetra ethyl hexyl titanate; zinc acetate; di butyl tin oxide; butyl stannoic acid.

9. The coating composition according to claim 1, wherein the polyester imide polymer is a hydroxyl functional polymer.

10. The coating composition according to claim 1, wherein the titanate material comprises an organic titanate material, preferably wherein the titanate material is selected from tetra n-butyl titanate, Ti(O-nC.sub.4H.sub.8).sub.4; tetra iso propyl titanate, Ti(O -CH(CH.sub.2).sub.2).sub.4; or tetra ethyl hexyl titanate, Ti(O-CH.sub.2-CH(C.sub.2H.sub.5)-CH.sub.2-CH.sub.2-CH.sub.2-CH.sub.3).sub.4.

11. The coating composition according to claim 1, wherein the OH reactive cross linking material comprises phenolic material, isocyanate material, amino resin or hydroxyl functional silicone resin material.

12. The coating composition according to claim 1, which further comprises one or more acidic polyester material.

13. The coating composition according to claim 1, which is substantially free of bisphenol A and derivatives or residues thereof, and bisphenol F and derivatives or residues thereof, and/or which is substantially free of N-methyl pyrollidone.

14. The coating composition according to claim 1, wherein the coating composition is a powder coating composition.

15. The coating composition according to claim 1, wherein the coating composition further comprises one or more solvent.

16. A metal substrate, such as aluminium, coated with the coating composition according to claim 1.

17. An aluminium tube coated on at least a portion thereof with the coating composition according to claim 1.

18. A monoblock aerosol can coated on at least a portion thereof, such as an inside portion thereof, with the coating composition according to claim 1.

19. A method of coating a substrate, the method comprising applying the coating composition according to claim 1 to the substrate and curing the same.

Description

EXAMPLES

(1) Reference will now be made, by way of example only to the following non-limiting examples.

(2) Preparation of Polyesterimide Polymer

(3) The polyesterimide resins were prepared according to the following.

Preparative Example 1 (PEI 1)

(4) Formulation

(5) TABLE-US-00001 Amount Component (g) 1. DESMODUR W .sup.1 (Bis(4-isocyanatocyclohexyl)methane) 42.19 2. Trimellitic anhydride 64.8 3. 1,2 Propane diol 71.25 4. Tris hydroxyethylisocyanurate (THEIC) 77.49 5. Isophthalic acid 24.12 6. Terephthalic acid 72.37- 7. TYZOR TnBT .sup.2( Tetra n butyl titanate) 0.4 Foot note .sup.1 Commercially available from Bayer Material Science AG .sup.2 Commercially available from Dorf Ketal

(6) Process Method a) A reaction vessel was prepared with a packed column and interchangeable non packed column leading to a dean stark apparatus and condenser. Nitrogen sparging was applied to the vessel and continued throughout the process. b) Items 1, 2 and 3 were added to the vessel and the non packed column engaged. The mixture was heated with stirring to 80 deg C. and held at temperature for 30 minutes to allow foam to subside. The reaction was then heated to 150 deg C over a period of 1 hour and then held at 150 deg C. for a further 2.5 hours. c) Items 4 to 6 were then added to the vessel and the packed column link to the dean stark apparatus was installed. The reactor was then heated to distillation with a maximum head temperature of 100 deg C. maintained during the process. The reaction temperature reached 200 deg C. after 30 minutes and 220 deg C. after 150 minutes. d) The reactor temperature was maintained at 220 deg C. after 4 hours at temperature samples for acid value and viscosity test were taken at regular intervals. The maximum acid value target for the process was 7 mg KOH/gm, Viscosity was monitored using a cone and plate viscometer at 180 deg C. e) Processing at 220 deg C. continued for a further 1.5 hours with regular samples. f) When the target acid value was reached, (in this process Acid value 6.2 mgKOH/gm and viscosity 49.8 poise @ 180 deg C) the reactor was cooled to 200 deg C. and item 7 was added. g) After mixing for 20 minutes at 200 deg C. the contents of the reactor were discharged onto a cooling sheet and allowed to solidify. The solid material was crushed to a powder and characteristic details measured on a sample are shown in table 1.

Preparative Example 2 (PEI 2)

(7) Formulation

(8) TABLE-US-00002 Amount Component (g) 1. DESMODUR W .sup.1 (Bis(4-isocyanatocyclohexyl)methane) 42.19 2. Trimellitic anhydride 64.8- 3. Ethylene glycol 58.13 4. Tris hydroxyethylisocyanurate (THEIC) 58.11- 5. Trimethylol propane 9.7 6. Isophthalic acid 24.12 7. Terephthalic acid 72.37 8. TYZOR TnBT .sup.2(Tetra n butyl titanate) 0.4 Foot note .sup.1 Commercially available from Bayer Material Science AG .sup.2 Commercially available from Dorf Ketal

(9) Process Method a) A reaction vessel was prepared with a packed column and interchangeable non packed column leading to a dean stark apparatus and condenser. Nitrogen sparging was applied to the vessel and continued throughout the process. b) Items 1, 2 and 3 were added to the vessel and the non packed column engaged. The mixture was heated with stirring to 80 deg C. and held at temperature for 30 minutes to allow foam to subside. The reaction was then heated to 150 deg C. and then held at 150 deg C. for 5 hours. c) Items 4 to 7 were then added to the vessel and the packed column link to the dean stark apparatus was installed. The reactor was then heated to distillation, with a maximum head temperature of 100 deg C. maintained during the process. The reaction temperature reached 190 deg C. after 30 minutes and 220 deg C. after 150 minutes. d) The reactor temperature was maintained at 220 deg c after 3 hours at temperature samples for acid value and viscosity test were taken at regular intervals. The maximum acid value target for the process was 7 mg KOH/gm, viscosity was monitored using a cone and plate viscometer at 180 deg C. e) Processing at 220 deg C. continued for a further 3 hours. When the acid value of the reaction mixture was within 3 mgKOH/gm of the target the temperature of the reaction mixture was increased to 230 deg C. f) When the target acid value was reached, (in this process Acid value 5.4 mgKOH/gm and viscosity 12 poise @ 180 deg C) the reactor was cooled to 180 deg C. and item 8 was added. g) After mixing for 20 minutes at 180 deg C. the contents of the reactor were discharged onto a cooling sheet and allowed to solidify. The solid material was crushed to a powder and characteristic details measure on a sample are shown in table 1

Preparative Example 3 (PEI 3)

(10) Formulation

(11) TABLE-US-00003 Weight Component gm 1. DESMODUR W .sup.1 ( ) 83 2. Trimellitic anhydride 125 3. 1,6 hexane diol 63 4. Neopentyl glycol 22 5. Diethylene glycol 22 6. Tris hydroxyethylisocyanurate (THEIC) 16 7. Isophthalic acid 25 8. TYZOR TnBT .sup.2 (Tetra n butyl titanate) 3.6 Foot note .sup.1 Commercially available from Bayer Material Science AG .sup.2 Commercially available from Dorf Ketal

(12) Process Method a) A reaction vessel was prepared with a packed column and interchangeable non packed column leading to a dean stark apparatus and condenser. Nitrogen sparging was applied to the vessel and continued throughout the process. b) Items 1 and 2 were added to the vessel and the non packed column engaged. The mixture was heated with stirring to 100 deg C. and held at temperature for 30 minutes. c) Items 3 to 7 were then added to the vessel and the packed column link to the dean stark apparatus was installed. The reactor was then heated to distillation, with a maximum head temperature of 100 deg C. maintained during the process. The reaction temperature reached 200 deg C. after 90 minutes and 220 deg C. after 150 minutes. d) The reactor temperature was maintained at 220 deg c and samples for acid value and viscosity test were taken at regular intervals. The maximum acid value target for the process was 9 mg KOH/gm, viscosity was monitored using a cone and plate viscometer at 180 deg C. e) When the acid value of the reaction mixture was within 3 mgKOH/gm of the target the temperature of the reaction mixture was reduced to 200 deg C. f) When the target acid value was reached, (in this process Acid value 8.2 mgKOH/gm and viscosity 58.7 poise @ 180 deg C) the reactor was cooled to 180 deg C. and item 8 was added. g) After mixing for 20 minutes at 180 deg C. the contents of the reactor were discharged onto a cooling sheet and allowed to solidify. The solid material was crushed to a powder and characteristic details measure on a sample are shown in table 1

(13) The preparative examples displayed physical characteristics as shown in Table 1, below.

(14) TABLE-US-00004 TABLE 1 PEI 1 PEI 2 PEI 3 Form solids solids solids melting point [° C.] .sup.(1) 104 93 102 Melt viscosity of the solid 43.5 13.2 71.4 resin [Poise] {CAP 2000+ @180° C. .sup.(2)} acid value [mg KOH/g] .sup.(3) 6.2 5.3 8.1 % imide [by weight of 6.7 7.2 12.8 components] % imide equivalent 18.37 18.37 40.61 Mn daltons .sup.(4) 1757 1103 3010 Mw daltons .sup.(4) 3405 1855 47800 Footnotes .sup.(1) Melting point determined by ball and ring method. .sup.(2) Viscosity determined using a CAP 2000+ viscometer from Brookfield Instruments. Determined at 180 deg C. using spindle 06 at a spindle rotation speed of 400 rpm .sup.(3) Acid value determined by titration with methanolic potassium hydroxide solution. Sample dissolved in Di-methyl formamide with phenolphthalein used as indicator. .sup.(4) Determined using Waters Gel Permeation Chromatography device using a mixed media column with THF eluent at a flow rate of 0.9 ml/min. Molecular weight numbers obtained by reference to polystyrene standards.

(15) Polyester Imide Solutions

(16) Polyester imide solutions were prepared using the polyester imide polymers prepared in the preparative examples listed above, along with a solvent as shown in Table 2, below.

(17) TABLE-US-00005 TABLE 2 Samples PEI 1 soln. PEI 2 soln. PEI 3 soln. PEI 1 75.0 PEI 2 75.0 PEI 3 75.0 Solvent.sup.1 75.0 75.0 75.0 .sup.1The solvent used in Table 2 is a mixture of solvents, as shown in Table 3, below.

(18) TABLE-US-00006 TABLE 3 solvent used in Table 2 Solvent contents Amount (g) benzyl alcohol 680 ethyl lactate 648 propylene carbonate 112 xylene 560

(19) Coatings

(20) Coatings were prepared from the PEI solutions described in Table 3, as detailed in Table below.

(21) TABLE-US-00007 TABLE 4 Coating 1 Coating 2 Coating 3 PEI 1 soln. 100.0 PEI 2 soln. 100.0 PEI 3 soln. 100.0 Benzylalcohol 3.65 3.65 3.65 Ethyl lactate 6.22 6.22 6.22 Propylene Carbonate 12.2 12.2 12.2 Byk-313 0.9 0.9 0.9 Xylene 3.62 3.62 3.62 TEGO WET KL-245 0.16 0.16 0.16 (Evonik) KOMELOL 90 GE 0.73 0.73 0.73 (Melamin) PHENODUR VPR 1785 3.8 3.8 3.8 (Cytec) CYMEL 1123 1.61 1.61 1.61 BYK-4510 ac PE (Byk- 4.38 4.38 4.38 Altana Tyzor TnBT catalyst 4.38 4.38 4.38 (Dorf Ketal) Xylene 4.38 4.38 4.38 Xylene 4.41925 9.9 Benzylalcohol 4.1782 9.36 Ethyl lactate 4.4996 10.08 Propylene Carbonate 2.97295 6.66

(22) The coatings were tested in the following manner with the results as shown in Table 5.

(23) Tests

(24) The viscosity of the coating is measured with a DIN 4 Cup at 23° C.

(25) Coating Application of Uncoated Cans

(26) Coatings were coated on aluminium monobloc can. About 3 grams of the inventive coating formulations 1-3 were filled individually into an aluminium can and then drained 10 minutes where the can was standing up side down with a angle of 45° thereby coating the internal of the can. Subsequently the can was placed into a convection oven to be cured at 240° C. for 5 minutes.

(27) The coated cans were tested for coating thickness, for enamel ratings after the impact test also called falling weight test, solvent resistance, cross cut adhesion and blush and cutting edge adhesion after exposure to boiling water and after sterilisation in water according to the procedures described below.

Test Methods

(28) Test methods include the following:

(29) Coating Thickness

(30) Coating thickness was measured according to a non-destructive measurement of anodic coatings applied onto an aluminium base, using a ISOSCOPE MP30, coating thickness measuring instrument. The uncoated aluminium can was used for calibration after it has been flatted. The thickness of the coating of the coated can was measured on the side wall of the can and on the bottom part. The measured thickness was either the average of 10 measurements or the lowest and highest values and it was reported in microns.

(31) Impact Test

(32) The impact test was carried out according to ASTM D2794.

(33) The bottom part of the coated can was cut at a height of 20 mm and then with the coated side facing down on a Teflon coated fixture. A 1 kg weight is dropped from a 1 meter height to strike an indentation. The test was repeated two times on two individual cans under these conditions. The integrity of the coating was measured using a WACO Enamel Rater Instrument and a 1% salt solution containing 0.1% Diocylnatriumsulfosuccinat and reported in Milliamperes mA.

(34) Solvent Resistance—NMP Test

(35) Flatted parts of coated can were immersed in N-Methyl Pyrrolidone NMP in a glass container closed with a lid at room temperature for 24 hours. The coated parts were removed, washed up into a glass filled with MEK (Methyl Ethyl Ketone) and then dried. A hard rod coated with PTFE was brought into contact with the coating and moved forth-and-back with pressure 10 times over the coated surface. The coatings were checked on their ability to resist the chemical attack by NMP using a visual scale of 1-5 with 5 being the best.

(36) Boiling Water Test

(37) The coated parts of the can were immersed in boiling water at 100° C. for 15 minutes. The parts were removed and dried. The blush appearance was first rated. Blush is a mat whitish appearance of the coating. If the coating does not show any blush, then the rating is no blush; otherwise, it will be rated as very slight blush, slight blush, blush or strong blush. The same coated parts that were immersed in water were also tested in cross-cut adhesion and in cutting edge adhesion.

(38) Cross-Cut Adhesion after Water Exposure

(39) Cross-cut adhesion is measured according to DIN ISO 2409 standard. A crosshatch grid is made in the film using a grid comb and then covered by a tape (grade TESA 4104 clear). Within 60 seconds of application, remove the tape rapidly. The grid area is then checked for removal of coating from the substrate. The adhesion is then scored in accordance with the following scale.

(40) TABLE-US-00008 TABLE 5 GT0 the edges of the cuts are completely smooth; none of the squares of the grid is detached. GT1 small flakes of the coating are detached at intersections; less than 5% of the area is affected. GT2 some flakes of the coating are detached along the edges and/or at intersections of the incisions. The area affected is 5-15% of the grid GT3 The coating has peeled along the edges and on parts of the squares of the grid. The area affected is 15-35% of the grid. GT4 The coating has peeled along the edges of the incisions in large strips and some squares are totally detached. The area affected is 35-65% of the grid. GT5 All degrees of peeling and flecking that can be not classified under GT4.

(41) Cutting Edge Adhesion after Water Exposure

(42) After having being immersed in boiling water and dried, the coated parts of the can are cut in the length of the can from the lowest film thickness to the highest film thickness using a scissor. The cutting edge adhesion of the coating was evaluated according to the level of peeling from the substrate and using a rating 1-5 with 5 being the best.

(43) Sterilization in Water

(44) The coated parts of the can were immersed in water in a pressurizable metal container and placed into a autoclave where it was retorted at 129° C. for 60 minutes. After this, the parts were removed and dried. Immediately upon removal from the retort solution, the coatings were evaluated on their ability to resist blushing. Blush is a mat whitish appearance of the coating. If the coating does not show any blush, then the rating is no blush; otherwise, it will be rated as very slight blush, slight blush, blush or strong blush. The same coated parts that were immersed in water were also tested in cross-cut adhesion and in cutting edge adhesion.

(45) The results of these tests, alongside a comparative example, PPG PAM Coating, are shown in Table 6, below.

(46) The PPG PAM coating is a polyamide imide based coating and is commercially available as PPG 8460.

(47) TABLE-US-00009 TABLE 6 Coating Coating Coating Comparative Samples 1 2 3 example Visco in 24 h/DIN 4 mm 53 44 50 80 (23° C.), sec. appearance wet sample cloudy cloudy clear cloudy Testing on aerosol cans Dry film thickness can 11.0 10.5  9.5  7.5 A/Dom (μm) Enamel rating after impact  9.6  3.1  4.3  3.4 test on bottom part of the can -A, (mA) Enamel rating after impact 13.5  2.4  3.3  1.9 test on bottom part of the can -B, (mA) dry film thickness can  9.0  9.0  9.5  5.5 B/Dom (μm) Solvent resistance - NMP test dry film thickness can A, 10-15 8-14 8-18 6-8 min/max (Fischer) (μm) dry film thickness can B,  8-14 8-15 9-12 5-6 min/max (Fischer) (μm) NMP resistance-24 h-can 3 5 5 5 A, thin/thick film weight NMP resistance-24 h-can 3 5 5 5 B, thin/thick film weight Water boiling test - Adhesion Body-wall can A, GT0 GT0 GT0 GT0 X-hatch test/thin-thick adhesion - cutting 3 3 5 5 edge/min fw-A adhesion - cutting 2 4 5 5 edge/max fw-A Blush-A/high film No No Slight No thickness blush blush blush blush Adhesion Body-wall can B, GT0 GT0 GT0 GT0 Cutcross adhesion test adhesion - cutting 3 2 5 5 edge/min fw-B adhesion - cutting 3 2 5 5 edge/max fw-B Blush-B/high film No No slight No thickness blush blush blush Sterilization in water Blush can A No No Slight No blush blush blush Blush can B No No Slight No blush blush blush blush Cut-cross adhesion can A GT4 GT4 GT0 GT0 Cut-cross adhesion can B GT5 GT5 GT0 GT0 Cutting edge adhesion A 1 1 5 5 Cutting edge adhesion B 2 1 5 5

(48) It has also been found by the present inventors that the addition of a silane containing component surprisingly increases the chemical resistance of the coating composition.

Preparative Example 4 (PEI 4)

(49) Formulation

(50) TABLE-US-00010 Amount Component (g) 1. Desmodur 44 MC.sup.1 (Methylene diphenyl 4,4′diisocyante) 1090 2. Trimellitic anhydride 1670 3. Ethylene glycol 1490 4. Tris hydroxyethylisocyanurate (THEIC) 1990 5. Isophthalic acid 810 6. Terephthalic acid 1860 7. Tyzor TnBT .sup.2(Tetra n butyl titanate) 90 8. benzyl alcohol 2780 9. ethyl lactate 2650 10. propylene carbonate 460 11. xylene 2250 Foot note .sup.1Commercially available from Bayer Material Science AG .sup.2 Commercially available from Dorf Ketal

(51) Process Method a) A reaction vessel was prepared with a packed column and interchangeable non packed column leading to a dean stark apparatus and condenser. Nitrogen sparging was applied to the vessel and continued throughout the process. b) Items 1, 2 and 3 were added to the vessel and the non packed column engaged. The mixture was heated with stirring to 110 deg C. and held at temperature for 30 minutes to allow foam to subside. The reaction was then heated to 150 deg C. over a period of 1 hour and then held at 150-155 deg C. for a further 2.5 hours. c) Items 4 to 6 were then added to the vessel and the packed column link to the dean stark apparatus was installed. The reactor was then heated to distillation, with a maximum head temperature of 100 deg C. maintained during the process. The reaction temperature reached 200 deg C. after 90 minutes and 230 deg C. after 180 minutes. Distillate was removed from the condensor into the collector of the dean stark apparatus. d) The reactor temperature was maintained at 230 deg C. and samples for acid value and viscosity test were taken at regular intervals. The maximum acid value target for the process was 8 mg KOH/gm viscosity was monitored using a cone and plate viscometer at 180 deg C. e) Processing at 230 deg C. continued for a further 4 hours with regular samples. f) When the target acid value was reached (in this process Acid value 6.8 mgKOH/gm and viscosity 216 poise @ 180 deg C) the reactor was cooled to 200 deg C. and item 7 was added. g) After mixing for 20 minutes at 200 deg C. item 11 was added to the reactor and then after further mixing for 30 minutes the contents of the reactor were discharged to a mixing tank containing items 8, 9 and 10. A solution of the material was completed and the characteristics of the polymer solution were a solids content of 50.9% (measured at 150 C for 1 hour on 1 gm samples) and viscosity of 13.9 Poise at 25 deg C. From Gel permeation Chromatography, using polystyrene standards, the Molecular weight of the material was determined as Mn 1940 and Mw 6339.

(52) Using PEI 4, a coating composition, Coating 4, was prepared using the following components in parts by weight.

(53) TABLE-US-00011 Benzyl alcohol 74.00 Propylene carbonate 83.00 Ethyl lactate 41.00 Xylene 30.00 solution PEI4 685.00 Aralink 40-852 (Bitrez) 22.00 Xylene 30.00 BYK-313 3.00 Borchi gol 1376 (OMG Borchers) 2.00 Tyzor tnbt titanate 30.00

(54) The solution of PE14 in this table is a 50.9% solution of the PE14 resin discussed above, prepared as follows.

(55) Coating 4 was then used as a base coating for several further coatings, as shown in the following table. In these coatings, Coating 4, is as described above, whereas Coatings 5 to 10 represent Coating 4, with an additive as detailed in the following table.

(56) TABLE-US-00012 Coating 4 Additive amount (parts by wt) Additive (parts by wt) Coating 4 None None Coating 5 50 1 1.2 Coating 6 50 2 1.5 Coating 7 50 3 1.2 Coating 8 50 4 1.2 Coating 9 50 5 1.2 Coating 10 50 6 1.2 Additives: 1 Geniosil GF 93 (3-Aminopropyltriethoxysilane) 2 Geniosil GF 82 (3-Glycidoxypropyltriethoxysilane) 3 Silquest A-137 (Octyl triethoxysilane) 4 Silquest A-1120 ((N-(Beta-Aminoethyl)-Gamma-Aminopropyl trimethoxysilane) 5 Silquest A-174NT (gamma-Methacryloxypropyl trimethoxysilane) 6 Silquest A-187 (gamma-Glycidoxypropyl trimethoxysilane)

(57) The coatings were then tested for chemical resistance by coating the internal of an aerosol can, then filling the can with a solution as described below and keeping for 2 weeks at 55 C. The cans were then emptied and the crazing/hazing of the coating surface visually inspected and given a rating of 0 to 5, which 5 being perfect (no crazing/hazing observed) and 0 being very bad/very severe crazing/hazing.

(58) The results are shown in the following table.

(59) TABLE-US-00013 Frosting/Crazing Frosting/Crazing with filling 1 with filling 2 Coating 4 2.5 2.5 Coating 5 5 3.5 Coating 6 4.5 3 Coating 7 3.5 3.5 Coating 8 3 3 Coating 9 4 3 Coating 10 3.5 3.5 Filling 1 = Hairspray, pH 6 to 6.5 Filling 2 = self tanning spray, pH 4.5

(60) As can, be seen above, the use of silane in the coatings improves the chemical resistance of the coating, by reducing the frosting/crazing of the coated surface after exposure to chemicals at elevated temperatures.

(61) 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.

(62) 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.

(63) 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.

(64) 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.