GB2055378A

GB2055378A - Modified epoxy resin

Info

Publication number: GB2055378A
Application number: GB7925168A
Authority: GB
Original assignee: Nippon Paint Co Ltd
Current assignee: Nippon Paint Co Ltd
Priority date: 1979-07-19
Filing date: 1979-07-19
Publication date: 1981-03-04
Also published as: GB2055378B

Abstract

A reaction product of an epoxy group-containing compound with a carboxyl group-containing butadiene/acrylonitrile copolymer is simultaneously or separately reacted with an amino group-containing compound and a fully or a partially blocked isocyanato group- containing compound. A composition comprising the resultant resin, or a composition comprising (1) a product obtained by reacting a reaction product of an epoxy group-containing compound butadiene/acrylonitrile copolymer with an amino group-containing compound and (2) a fully or partially blocked isocyanato group-containing compound is useful for cathodical electrodeposition.

Description

SPECIFICATION Resins for electrocoating compositions the compositions and their uses in electrocoating.

The present invention relates to an electrocoating composition.

Various kinds of cationic resins for practical application have already been developed as vehicles for cationic electrocoating compositions. In particular, the cationic resin described in Japanese Patent Publication (Unexamined) No. 18746/1977 and Japanese Patent Publication No. 103135/1976, are stated to produce electrocoated films with a very high corrosion-resistance and solvent-resistance. However, even the coating films formed by the latter resin are still not entirely satisfactory in respect of their adhesion test or Ericksen test values.

The present invention provides a vehicle resin which yields a coating film exhibiting excellent properties as regards the adhesion and Ericksen texts whilst the other desirable characteristics of the above vehicles for electrode-position coating compositions and cationic electrocoating compositions are retained.

It should be noted therefore that the vehicle resin for electrocoating compositions of the present invention provides a specific improvement of the vehicle described in Japanese Patent Publication (Unexamined) No.

18746/1977. Thus, we have found in accordance with the present invention that the use of a butadienelacrylonitrile copolymer as a component of a vehicle resin provides outstanding effects in turnover, impact resistance, selectivity for surface treatment, and so in addition to the above-mentioned desirable properties of the previously proposed resin.

The present invention provides a resin useful for electrocoating, which is obtained by reacting a reaction product (A) of an epoxy group-containing compound with a carboxyl group-containing butadienel acrylonitrile copolymer, in the ratio of 1 epoxy equivalent of the former to 0.2 to 0.7 equivalent of the free carboxyl group of the latter, simultaneously or separately with an amino group-containing compound and a fully or partially blocked isocyanato group-containing compound, and compositions comprising such resins.

The present invention also provides an electrocoating composition comprising (1) a reaction product obtained by reacting a reaction product (A) of an epoxy group-containing compound and a carboxyl group-containing butadienelacrylonitrile copolymer, in the ratio of 1 epoxy equivalent of the former to 0.2 to 0.7 equivalent of the free carboxyl group of the latter, with an amino group-containing compound, and (2) a fully or partially blocked isocyanato group-containing compound.

Furthermore, the present invention provides a process for cathodically electrodepositing the latter coating compositions.

In accordance with the present invention, the "epoxy group-containing compound" may be either a monomer or a polymer. Epoxy compounds prepared e.g. from a polyglycidyl ether of a polyphenol or bisphenol A, novolac resins or like phenol resins, are commercially available. 1,2-epoxy-containing compounds are typical useful marking materials. Epoxy group-containing compounds with an epoxy equivalent of from about 300 to 1000 are particularly preferred.

These epoxy group-containing compounds may themselves possess groups with an active hydrogen atom such as hydroxyl groups, or they may e.g. be partially etherified with alcohols such as polypropylene glycol or polyethylene glycol or various other diols, or with caprolactam. Alternatively, they may be partially esterified with various carboxylic acids, dimer-acids, adipic acid, sebacic acid, or the like.

By the "carboxyl group containing butadiene/acrylonitrile copolymer" is meant a copolymer which has acrylonitrile and butadiene moieties in the main chain and has a carboxyl group derived by partial oxidation.

Preferred copolymers are those containing from 8 to 30% by weight of the acrylonitrile moiety and from 70 to 92% by weight of the butadiene moiety, with from 1.5 to 2.5 free carboxyl groups per molcule. The number average molecular weight of the copolymer is from 1000 to 4000, preferably from 2000 to 3500.

The carboxyl groups of the carboxyl group-containing butadiene/acrylonitrile copolymer may be partially esterified. They may also be partially copolymerized with other polymerizable monomers such as methacrylonitrile, acrylates, methacrylates, styrene, chloroprene, isoprene and the like.

The isocyanato group-containing compounds to be used in accordance with the present invention are derived from organic polyisocyanates, preferably organic diisocyanates. The isocyanato group may be fully blocked or partially blocked. As regards the organic polyisocyanates, any polyisocyanates which have hitherto been used as vehicle components for electrocoating composition may be used. These include, for example, aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aliphatic-aromatic diisocyanates, nuclear-substituted aromatic diisocyanates (e.g. dianisidine diisocyanate), polyfunctional isocyanates (e.g. triisocyanates or tetraisocyanates and polymerized polyisocyanates (e.g. toluene diisocyanate dimers or trimers).

The blocking agent for the organic polyisocyanates is exemplified by aliphatic alcohols (e.g. aliphatic alcohols having 1 to 10 carbon atoms), aromatic alkyl alcohols (e.g. phenyl carbinol), ether bond-containing alcohols (e.g. cellosolves - Registered Trade Mark), phenol and oximes (e.g. methylethylketoxime). The isocyanates blocked by oximes and phenols are particularly preferred because they are reactive at relatively low temperatures. Blocking agents of high molecular weight and of relatively non-volatile character may be used in small amounts.

The amino group-containing compounds may be any of primary amines, secondary amines, tertiary amines, polyamines or alkanolamines.

Preferred amines include ethylenediamine, diethylenetriamine, dimethylcyclohexylamine, dimethylethanolamine, methyldiethanolamine, dimethylamino-2-prnpanol, diethylamino-ethoxyethanol, di-npropanolamine, and the like. Particularly preferred are ethylene diamine and methylethanolamine.

Where a tertiary amine which does not have an active hydrogen is used, the amine is first converted to its acid amine salt by acidifying with a suitable acid such as e.g. boric a-cid, phosphoric acid, sulfuric acid, acetic acid or lactic acid.

In preparing the resin of the present invention, firstly, the epoxy group-containing compound is reacted with the carboxyl group-containing butadiene/acrylonitrile copolymer [hereinafter the reaction product under this process is referred to as reaction product (A)]. In this case, the reaction between the epoxy group-containing compound and the butadiene/acrylonitrile copolymer is carried out in the ratio of 1 epoxy equivalent of the epoxy group of the former to 0.2 to 0.7 equivalent of the carboxyl group of the latter.

The reaction product (A) may be reacted with the amino group-containing compound and the partially blocked isocyanato group-containing compound, or the isocyanato group-containing compound may be simply mixed with the product (A) before or after the latter is reacted with the amino group-containing compound.

The reaction of the reaction product (A) with the amino group-containing compound and the partially blocked isocyanato group-containing compound may be carried out simultaneously or separately. Thus, any of the following four methods may be adopted: (1) previously reacting an amino group-containing compound with the reaction product (A), and reacting therewith the isocyanate group-containing compound; (2) reacting an isocyanato group-containing compound with the reaction product (A), and reacting therewith an amino group-containing compound; (3) reacting simultaneously the reaction product (A), the isocyanato group-containing compound, and the amino group-containing compound; and (4) reacting in advance the isocyanato group-containing compound and the amino group-containing compound, and causing the reaction product (A) to react therewith.

In practice a person skilled in the art will choose the appropriate one of the above methods.

The reaction may be carried out at the temperature at which the blocked isocyanate is stable and the reaction between the amino group-containing compound and the epoxy-group of the reaction product (A) is effected. Whereas the temperature at which the blocked isocyanate is stable may differ greatly depending on the kind of blocking agent used, in general, a blocking agent which is stable at 70"C to 200"C may be used, and the reaction between the epoxy group and the amino group-containing compound may be carried out at the temperature at which the blocked isocyanate is stable. In the process of the foregoing (1), the reaction product (A) is reacted previously with the amino group-containing compound, so that the use of blocking agents in a more extensive range becomes feasible.

Where the amino group-containing compound has no active hydrogen or where the reaction product [the reaction product under this process is hereinafter referred to as reaction product (B)] between the isocyanato group-containing compound and the amino group-containing compound in the foregoing method (4) does not have an active hydrogen attributed to the amino group-containing compound or moiety, the latter may be so processed that the amino group-containing compound or reaction product (B) acidified with a suitable acid is reacted with the epoxy group of the reaction product (A). In this way, a quaternary ammonium group-containing resin may be obtained.

In the present invention, the typical embodiment is a method of employing a fully blocked isocyanato group-containing compound. In such a method, a partially blocked isocyanato group-containing compound may be used, in which case the reaction progresses gradually.

The fully or partially blocked isocyanato group-containing compound may be mixed before the reaction between the reaction product (A) and the amino group-containing compound, or it may be mixed before the preparation of the electrodeposition bath.

Blocked isocyanates may be used in an amount sufficient to induce such a state that, when the electrocoated film is baked, an isocyanato group reacts with a hydroxyl group or aminor group in the resin to give a cured film. Generally, the fully or partially blocked isocyanato group-containing compound is used in an amount of from about 5 to 50% by weight relative to said resin.

The amount of amino group-containing compound to be used is obtained by calculation so as to make it approximately equivalent to the epoxy group.

The resins obtained by the process of the present invention may be modified with other resin components or blended with other resins, depending on the end uses.

The cationic resin of the present invention may be partially acidified with an organic acid such as acetic acid or lactic acid or an inorganic acid such as boric acid, phosphoric acid, sulfuric acid or hydrochloric acid, either alone or in combination, so as to assit in its solution or dispersion in water. Organic acids are preferred.

In order to obtain a composition for cathodic electrodeposition, the resin is suitably mixed with a pigment or solvent. Other desired additives such as antioxidizing agents or surfactants may be added.

The present invention is hereafter illustrated with following examples, which, however, are not to be construed as limiting the invention to their details.

Example 1 Parts Ingredient by weight EPON10021 416 Hicar-CTBN 1300-13(2) 104 toluene diisocyanate blocked with 2-ethylhexanol (70% solution) 250 reaction product of diethylene triamine and MIBK (methyl isobutyl ketone) 31.2 methylethanolamine 25.5 n-hexylcellosolve 42.3 water 1032 acetic acid 14 (1)Trade Mark (Reaction product between epichlorohydrin and bis-phenol A; epoxy equivalent about 630; commercialized by the Shell Chemical Company).

(2)Trade Mark (Polycarboxybutadiene acrylonitrile copolymer having an average molecular weight number of 3400, an average carboxyl group number of 1.9 and a proportion by weight of an acrylonitrile moiety of 27%; available from the B.F. Goodrich Chemical Co, U.S.A.).

The starting material EPON 1002 and Hicar-CTBN 1300-13 are heated at 130-150"C for about 2 hours, toluene diisocyanate blocked with 2-ethylhexanol is added thereto, and the resulting mixture is then reacted under heat at 1 10"C. The reaction product of diethylene triamine and MIBK and the methyl ethanolamine are added, and the mixture, kept at 120"C is then incorporated into the n-hexylcellosolve. Water and acetic acid are mixed with the product to give a resinous varnish having a 36% (by weight) solid component.

On the other hand, a pigment paste is prepared from the following charge.

Ingredient Parts Solids by weight toluene diisocyanate semi-blocked with 2 ethylhexanol (in MIBK) 320 304 dimethylethanolamine 87.2 87.2 aqueous solution of lactic acid 117.6 88.2 butyl cellosolve 39.2 By the use of an appropriate reaction vessel, the toluene diisocyanate semi-blocked with 2-ethylhexanol is added to the di methyl ethanolamine at room temperature. The mixture reacts exothermically. It is at 800C for 1 hour. The lactic acid is then charged, and the butyl cellosolve is added. The reaction mixture is stirred at 65"C for 1 hour to yield the desired quaternizing agent.

A dissolved vehicle containing the reaction product between the epoxy group-containing organic compound and the above block isocyanato group-containing organic amine is prepared from the following charge: Parts Ingredient by weight Solids EPON 829 (3) 710.0 681.2 Bisphenol A 289.6 289.6 toluene diisocyanate semi-blocked with 2 ethylhexanol (methyi isobutyl ketone) 406.4 286.1 the above quaternizing agent 496.3 421.9 deionized water 71.2 butylcellosolve 56.76 '3'EPON 829: Trade Mark (Reaction product between epichlorohydrin and bisphenol A; epoxy equivalent about 193-203; commercialized by the Shell Chemical Company).

The EPON 829 and Bisphenol A are charged into a suitable reactor and are heated under a nitrogen atmosphere to 150-160"C. It is an initial exothermic reaction. The reaction mixture is subjected to thermal reaction at 150-160"C for about 1 hour. Then, after cooling to 120"C, the mixture is admixed with toluene diisocyanate semi-blocked with 2-ethylhexanol. The reaction mixture is kept at 110-1200C for about 1 hour, after which it is admixed with butyl cellosolve.

Thereafter, the mixture is cooled to 85-950C, homogenized, admixed with water, and further with the quaternizing agent. The temperature of the reaction mixture is kept at 80-85"C until the acid value comes to 1.

By the use of this resin vehicle, a pigment paste is prepared under the following charge.

Parts Ingredient by weight vehicle 2087 Aluminium silicate 1853 zinc silicate 318 carbon black 256 strontium chromate 159 The above components are charged into an attritor, and dispersed for about 11-12 hours to Hegman No.

6-7. Deionized water is added to the mixture to make it up to the desired concentration. The formed paste has excellent thermal stability and does not cause separation or precipitation even after storage at 120"C for 1 week.

The above resinous varnish (1555 parts by weight), pigment paste (297 parts by weight), and water (1749 parts by weight) were mixed to make an elctrodeposition bath, which was applied by cathodic electrodeposition to a zinc phosphate treated steel panel and a bare steel panel. The results are shown in Table 1 below. The coating showed a good appearance even when the composition was applied by electrodeposition to a zinc phosphate treated steel panel having unevenness of treatment.

Example 2 A resinous varnish is prepared under the following charge.

Parts Ingredient by weight EPON 1001 (4) 370 Hicar-CTBN 1300-13 92 polycaprolactam diol 88 toluene diisocyanate blocked with 2-ethylhexanol (70% solution) 233 reaction product of di ethylene triamine and MIBK 31.2 methylethanolamine 25.5 n-hexyl cellosolve 42.3 water 1032 acetic acid 14 (4)Trade Mark (Reaction product between epichlorohydrin and bisphenol A; epoxy equivalent about 450 to 500; commercialized by the Shell Chemical Company).

The EPON 1001 and Hicar-CTBN were heated at 130-1 50C and the product was subjected to reaction with polycaprolactam diol. The epoxy equivalent was 1394. Hereafter, in the same manner as in Example 1, a resinous varnish was obtained, and elelctrocoating was carried out under the same conditions as described in Example 1.

Comparative Example In the following charge, a resinous varnish was prepared.

Parts Ingredient by weight EPON 1001 291 polycaprolactam diol 105 toluene diisocyanate blocked with 2-ethylhexanol (70% solution) 250 reaction product of di ethylene triamine and MIBK 29 methylethanolamine 23 n-hexyl cellosolve 40 water 1052 acetic acid 16 The EPON 1001 and polycaprolactam diol were heated at about 1300C, after which toluene diisocyanate blocked with 2-ethylhexanol was added thereto, and the mixture was heated at 110 C. Subsequent treatments were made in the same manner as in Example 1 to obtain a resinous varnish, with which electrodeposition coating was carried out underthe same conditions as in Example 1. The results are shown in Table 1, as follows.

Table 1.

Item Example 1 Example 2 Rupture voltage (V) 350 370 coating voltage (V) 150 200 Film thickness ( ) 20 20 Salt spray resistance # # # # Ericksen (mm) 6.4 6.4 Impact Surface 50 < 50 < resistance (cm) Reverse 50 < 50 < surface Moisture-resistance (after top coating) 100/100 100/100 Appearance # #

Table 1 (continued)

Item Comparative Example Rupture voltage(V) 350 coating voltage (V) 150 Film thickness ( ) 20 Salt spray # Bare steel Panel resistance 360 H Zinc phosphate tr eated steel panel Go eated steel panel Ericksen (mm) | 2.5 Impact re- Surface 50 S istance (cm) 1/2" x 500 g Reverse surface 10 > tIoisture-rQ- sistance (after 20/100 Zinc phosphate trtop coating) eated steel panel 50 C x 2408 Appearance Zing phosphate tr- DC eated steel panel having unevenness of treatment

Claims

1. A resin obtained by reacting a reaction product (A) of an epoxy group-containing compound with a carboxyl group-containing butadiene/acrylonitrile copolymer in the ratio of 1 eopoxy equivalent of the former to from 0.2 to 0.7 equivalent of the free carboxyl group of the latter, simultaneously or separately with an amino group-containing compound and a partially blocked isocyanato group-containing compound.

2. The resin according to Claim 1, wherein the epoxy group-containing compound is a 1,2-epoxy group-containing compound having an epoxy equivalent of from 300 to 1000.

3. The resin according to Claim 1 or 2, wherein the carboxyl group-containing butadiene/acrylonitrile copolymer contains 8 to 30% by weight of an acrylonitrile moiety, has an average carboxyl group number of from 1.5 to 2.5 in a molecule and a number average molcular weight of 1000 to 4000, said carboxyl group being optionally partially esterified.

4. The resin according to any of Claims 1 to 3 obtained by first reacting an isocyanato group-containing compound with the reaction ,product (A), and then reacting an amino group-containing compound therewith.

5. The resin according to any of Claims 1 to 3 obtained by first reacting an amino group-containing compound with the reaction product (A) and then reacting an isocyanate group-containing compound therewith.

6. The resin according to any of Claims 1 to 5, wherein the amino group-containing compound contains an active hydrogen.

7. The resin according to any of Claims 1 to 5, wherein the amino group-containing compound, in the case of not having an active hydrogen atom, is used as an acid salt.

8. The resin according to any of Claims 1 to 3, obtained by reacting the reaction product (A) with a reaction product (B) of an isocyanato group-containing compound and an amino group-containing compound.

9. The resin according to Claim 8, wherein the reaction product (B), in the case of not having an active hydrogen attributed to the amino group-containing compound, is used as an acid salt.

10. An electrocoating composition which comprises a resin obtained by reacting a reaction product (A) of an epoxy group-containing compound with a carboxyl group-containing butadienefacrylonftdle copolymer in the ratio of 1 epoxy equivalent of the former to from 0.2 to 0.7 equivalent of the free carboxyl group of the latter, simultaneously or separately with an amino group-containing compound and a partially blocked isocyanato group-containing compound.

11. The composition according to Claim 10, wherein the epoxy group-containing compound is a 1,2-epoxy group-containing compound having an epoxy equivalent of from 300 to 1000.

12. The composition according to Claim 10 or 11, wherein the carboxyl group-containing butadiene acrylonitrile copolymer contains from 8 to 30% by weight of an acrylonitrile moiety and has an average charboxyl group number of from 1.5 to 2.5 in a molecule and a number average molecular weight of from 1000 to 4000, said carboxyl group being optionally partially esterified.

13. The composition according to any of Claims 10 to 12, wherein the resin is that obtained by first reacting an isocyanato group-containing compound with the reaction product (A) and then reacting an amino group-containing compound therewith.

14. The composition according to any of Claims 10 to 12, wherein the resin is that obtained by first reacting an amino group-containing compound with the reaction product (A) and then reacting an isocyanato group-containing compound therewith.

15. The composition according to any of Claims 10 to 14, wherein the amino group-containing compound contains an active hydrogen.

16. The composition according to any of Claims 10 to 14, wherein the amino group-containing compound, in the case of not having an active hydrogen, is used as an acid salt.

17. The composition according to any of Claims 10 to 12, wherein the resin is that obtained by reacting the reaction product (A) with a reaction product (B) of an isocyanato group-containing compound and an amino group-containing compound.

18. The composition according to Claim 17, wherein the reaction product (B), in the case of not having an active hydrogen attributed to the amino group-containing compound, is used as an acid salt.

19. An electrocoating composition which comprises: (1) a reaction product obtained by reacting a reaction product (A) of an epoxy group-containing compound and a carboxyl group-containing butadiene/ acrylonitrile copolymer, in the ratio of 1 epoxy equivalent of the former to from 0.2 to 0.7 equivalent of the free carboxyl group of the latter, with an amino group-containing compound; and (2) a fully or partially blocked isocyanato group-containing compound.

20. The composition according to Claim 19, wherein the epoxy group-containing compound is a 1,2-epoxy group-containing compound having from 300 to 1000 epoxy equivalents.

21. The composition according to Claim 19 or 20, wherein the carboxyl group-containing butadiene acrylonitrile co-polymer contains from 8 to 30% by weight of acrylonitrile moiety, has an average carboxyl group number of from 1.5 to 2.5 and a number average molecular weight of from 1000 to 4000 per molecule, said carboxyl group being optionally partially esterified.

22. The composition according to any of Claims 19 to 21 obtained by blending the fully blocked isocyanato group-containing compound with the reaction product (A) andiorthe amino group-containing compound before the reaction of the reaction product (A) with the amino group-containing compound.

23. A method of coating a conductive substrate serving as a cathode, which method comprises passing an electric current between an anode and said cathode in electrical contact with a water-dispersed composition comprising a resin obtained by reacting a reaction product (A) of an epoxy group-containing compound with a carboxyl group-containing butadieneiacrylonitrile copolymer, in the ratio of 1 epoxy equivalent of the former to from 0.2 to 0.7 equivalent of the free carboxyl group of the latter, with, simultaneously or separately, an amino group-containing compound and a partially blocked isocyanato group-containing compound.

24. The method according to Claim 23, wherein the epoxy group-containing compound is a 1,2-epoxy group-containing compound having an epoxy equivalent of about 300 to 1000.

25. The method according to Claim 23 or 24, wherein the carboxyl group-containing butadiene acrylonitrile copolymer contains from 8 to 30% by weight of an acrylonitrile moiety, has an average carboxyl group number of from 1.5 to 2.5 per molcule and a number average molecular weight of from 1000 to 4000, said carboxyl group being optionally partially esterified.

26. The method according to any of Claims 23 to 25, wherein the resin is that obtained by first reacting an isocyanato group-containing compound with the reaction product (A), and then reacting an amino group-containing compound therewith.

27. The method according tio any of Claims 23, to 25, wherein the resin is that obtained by first reacting an amino group-containing compound with the reaction product (A), and then reacting an isocyanato group-containing compound therewith.

28. The method according to any of Claims 23 to 24, wherein the amino group-containing compound contains an active hydrogen.

29. The method according to any of Claims 23 to 27, wherein the amino group-containing compound, in the case of not having an active hydrogen, is used as an acid salt.

30. The method according to any of Claims 23 to 25, wherein the resin is that obtained by reacting the reaction product (A) with a reaction product (B) of an isocyanato group-containing compound and an amino group-containing compound.

31. The method according to Claim 30, wherein the reaction product (B), in the case of not having an active hydrogen attributed to the amino group-containing compound, is used as an acid salt.

32. A method of coating a conductive substrate serving as a cathode which method comprises passing an electric current between an anode and said cathode in electrical contact with a water-dispersed composition comprising (1) a reaction product obtained by reacting a reaction product (A) of an epoxy group-containing compound and a carboxyl group-containing butadiene/acrylonitrile copolymer in the ratio of 1 epoxy equivalent of the former to from 0.2 to 0.7 equivalent of the free carboxyl group of the latter, with an amino group-containing compound, and (2) a fully or partially blocked isocyanato group-containing compound.

33. The method according to Claim 32, wherein the epoxy group-containing compound is 1,2-epoxy group-containing compound having about 300 to 1000 epoxy equivalents.

34. The method according to Claims 32 or 33 wherein the carboxyl group-containing butadiene/ acrylonitrile copolymer contains from 8 to 30% by weight of acrylonitrile moiety, has an average carboxyl group number of from 1.5 to 2.5 and a number average molecular weight of from 1000 to 4000 per molecule, said carboxyl group being optionally partially esterfied.

35. The method according to any of Claims 32 to 34, wherein the composition is obtained by blending the fully blocked isocyanato group-containing compound with the reaction product (A) and/or the amino group-containing compound before the reaction of the reaction product (A) with the amino group-containing compound.

36. A method according to Claim 1 substantially as herein described with reference to any of the specific Examples.

37. A composition according to Claim 10, substantially as herein described with reference to any of the specific Examples.

38. A composition according to Claim 19 substantially as herein described with reference to any of the specific Examples.

39. A method according to claim 23 substantially as herein described with reference to any of the specific Examples.

40. A method according to Claim 32 substantially as herein described with reference to any of the specific Examples.

41. A substrate electrocoated with the composition of any of Claims 10 to 22 or Claim 37 or Claim 38.

42. A substrate electrocoated by a method as claimed in any of Claims 23 to 38 or Claim 39 or Claim 40.