GB1581982A - Hardenable bituminous compositions for coatings and adhesive bonds - Google Patents

Description

(54) HARDENABLE BITUMINOUS COMPOSITIONS FOR COATINGS AND ADHESIVE BONDS (71) We, SCHERING AKTIENGESELLSCHAFT, a body corporate organised according to the laws of the Federal Republic of Germany, of Berlin and Bergkamen, Federal Republic of Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to compositions for coatings and adhesive bonds based on combinations of epoxy resins and bitumen.

Epoxy resin/hardener mixtures with coal tar have long been used for coating concrete, metals and other materials as protection against water. Such combinations are particularly important in hydraulic steelwork and bridge construction.

Because of the preponderant proportion of aromatic hydrocarbons in coal tar, the latter is entirely compatible with epoxy resins based on aromatic bisphenols.

Bituminous substances, which occur in the processing of crude oil, are also used in covering and coating compositions, but it is very difficult to combine them with epoxy resins. Because of the preponderant proportion of aliphatic hydrocarbon in bitumens, compatibility is achieved with the conventional amine hardener/epoxy resin mixtures, based on reaction products of bisphenol-A and epichlorohydrin, only when very small quantities of bitumen are added. Examples of the narrow range of compatibility are given, inter alia, in French Patent Specification 2 093 201.

Many experiments have therefore been carried out to increase the compatibility of the epoxy resin component, above all of aromatic epoxy resins, with the aliphatic bitumen. This has been achieved, on the one hand, by reducing the aromaticity of the epoxy resin as described in French Patent Specification 2 093 201 and German Patent Specification 2 125 866. On the other hand, the use of aromatic bisphenols can be abandoned in favour of aliphatic epoxy resins, e.g. glycidyl esters based on dimerised fatty acids, as has been described in British Patent Specification 883 522 and French Patent Specification 2 053 400.

However, these processes require relatively expensive epoxy resin raw materials and are suitable only for special fields of application.

A further method to achieve compatibility of the bitumen-containing resin reaction mixture is by a special hardener mixture. In this manner such combinations as are described, for example, in British Patent Specifications 949 717 and 950 298 and in Belgian Patent Specifications 618 790 and 765 466 and German Patent Specification 1154 032 have been possible.

However, a common feature of the last-mentioned comninations based on special hardener mixtures is narrow range of compatibility, which results in limited application in various fields and limited possibilities of influencing the duromer properties.

There is therefore a need to extend the areas of compatibility of mixtures of bitumen and epoxy resins based on phenols and thus to generalise their applicability.

We have found that there is good compatibility between distillation, high vacuum or blown bitumen and an epoxy resin/hardener mixture comprising a) an epoxy component comprising i) one or more aromatic glycidyl compounds having at least two glycidyl groups, and, if desired, (ii) one or more monofunctional glycidyl compounds, (b) (i) one or more polyaminoamides and/or polyaminoimidazolines and (ii) one or more amines having from 2 to 18 carbon atoms and containing aliphatic and/or cycloaliphatic hydrocarbon radicals and one or more amino groups, and/or one or more Mannich bases, the amount of component (bii), calculated on the weight of (bi) and (bii), being from 10 to 80% by weight, the amount of components (bi) and (bii) being from 0.8 to 1.2 equivalents per equivalent of the epoxide component, and component (b) having on average at least 2 active amine hydrogen atoms per molecule, and (c) one or more alkyl-substituted phenols, the amount of component (c), calculated on the weight of (b) and (c), being from 5 to 40% by weight.

The proportion of bitumen in the mixture of bitumen and components (a), (b) and (c) may be up to 60% by weight, and is preferably from 20 to 60% by weight.

Accordingly, the present invention provides a hardenable composition which comprises the components (a), (b) and (c) listed above and (d) distillation, high vacuum or blown bitumen or two or more such bitumens, in an amount of up to 60%by weight, calculated on the total weight of components (a), (b), (c) and (d).

There is good compatibility between the bitumen in this proportion and the hardener components of the above epoxy resin/hardener mixture and some or all of the bitumen may therefore be added to the components (b) or to (b) and (c) or to all of the components together. Thus, the composition of the present invention may be made up in two or more parts. For example, the epoxy component (a) may be one constituent and the other components (b), (c) and (d) may be mixed together as the other constituent, or components (a) and (c) may be one constituent and components (b) and (d) the other constituent.

The polyglycidyl component (ai) preferably comprises one or more aromatic polyglycidyl ethers having an average epoxide value in the range of from 0.2 to 0.6, and, if desired, up to 25 % by weight of one or more aliphatic and/or cycloaliphatic polyglycidyl ethers, calculated on the total glycidyl ether component.

The term epoxide value used herein denotes the fractional number of epoxy equivalents contained in 100 grams of component.

The monoglycidyl component (aii) is preferably up to 15 % by weight of the polyglycidyl ether component and preferably comprises a low-viscosity monoglycidyl ether of an alcohol or a phenol.

The polyaminoamide/polyaminoimidazoline component (bi) preferably has an average amine number in the range of from 50 to 650.

The mono-/polyamine component (bii) preferably also has an average amine number in the range of from 50 to 650.

(As will be understood, the term "poly" used in referring to components (a) and (b) is used in a'broad sense and includes diglycidyl and diamine compounds respectively.) The alkyl-substituted phenol component (c) preferably has one or more straight-chained or branched alkyl radicals each having from 4 to 12 carbon atoms, more especially one such alkyl radical. This component may be mixed, for example, with component (a) and/or component (b).

The composition may, if desired, contain up to 30% by weight, calculated on the bitumen, of mineral oil.

One or more conventional additives may, if desired, be present in the composition of the present invention.

More especially.the present invention provides a hardenable coating or adhesive composition, which comprises (a) an aromatic polyglycidyl ether having an epoxide value of from 0.2 to 0.6 and, if desired, up to 15% by weight, calculated on polyglycidyl ether, of a low-viscosity monoglycidyl ether, (b) i. a polyaminoamide having an amine number in the range of from 50 to 650 and ii. a mono- or polyamine having 2 to 18 carbon atoms and containing aliphatic and/or cycloaliphatic moieties in an amount of from 10 to 80% by weight, calculated on the mixture (bi) and (bii), (bi) and (bii) being used in an amount of from 0.8 to 1.2 equivalents per equivalent of the epoxide component (a), and component (b) having on average at least 2 active amine hydrogen atoms per molecule, (c) an alkylphenol wherein the alkyl radical is straight-chained or branched and has from 4 to 12 carbon atoms, in an amount of from 5 to 40%by weight, calculated on the weight of (b) and (c), and (d) from 20 to 60% by weight, calculated on the total weight of binder (a), (b), (c) and (d), of distillation or high vacuum bitumen and/or blown bitumen which may if desired be diluted to the extent of up to 30% by weight, calculated on bitumen constituent (d), with mineral oil, and, if desired, (e) one or more additves, e.g. a filler, pigment, dyestuff, solvent, diluent, accelerator, wetting agent or fibrous material or mixture of two or more such additives.

A polyepoxide used as component (ai) has more than one epoxide group per molecule and is derived, on the one hand, from a polyhydric phenol, especially a bisphenol, or from a novolak. A comprehensive list of suitable di- or polyphenols is given in the manual "Epoxidverbindungen und Epoxidharze" by A.M. Paquin, Springer Verlag, Berlin, 1958.

A mixture of the epoxy resins may also be used. The epoxide values of the preferred aromatic polyglycidyl ethers based on bisphenol A are in the range of from 0.2 to 0.6, especially from 0.4 to 0.55. If necessary in order to achieve a particular effect, a small proportion, up to 25% by weight of the epoxide component, of a low-viscosity aliphatic or cycloaliphatic epoxide compound having two or more epoxide groups may be used concomitantly. It is also possible to use a mixture of the above epoxy resin(s) with one or more reactive diluents, i.e. in particular with one or more reactive diluents, i.e. in particular with one or more monoglycidyl ethers of alcohols or phenols, The proportion of reactive diluent depends on the particular requirements, but it should not greatly exceed a quantity of 15 % by weight, calculated on the di- or polyglycidyl compound.

Suitable as one of the hardener components are liquid aliphatic and cycloaliphatic amine compounds which are capable of forming polyadducts at room temperature and have at least two, preferably three or more, reactive amine hydrogen atoms, as described in the "Handbook of Epoxy Resins", Lee & Neville, 1967 Chapters 7 and 10. This component is used in an amount of 10 to 80%by weight, calculated on total amine component. Equally, phenol/formaldehyde/amine condensation products (so-called Mannich bases) may, if desired, be used instead or concomitantly. The amount of Mannich base alone or together with the amine (bii) is in the range of 10 to 80% of (b).

The other hardener component consists of polyaminoamide and/or polyaminoimidazoline, produced from a dimerised fatty acid or from monocarboxylic acid having up to 22 carbon atoms, preferably 8 to 18 carbon atoms, and an excess of an aliphatic polyamine, e.g. diethylenetriamine, triethylenetetramine, dipropylenetriamine or a mixture thereof, or an adduct thereof with a small quantity of an epoxide.

The term "dimerised fatty acid" refers generally to polymerised acids obtained from fatty acids. The term "fatty acid" includes unsaturated natural and synthetic monobasic aliphatic acids having from 12 to 22 carbon atoms, preferably 18 carbon atoms. These fatty acids may be polymerised by known processes (cf. German Offenlegungsschrift 1 443 938, German Offenlegungsschrift 1 443 968, German Patent Specification 2 118 702 and German Patent Specification 1 280 852). Typical polymeric fatty acids obtainable commercially have approximately the following composition: monomeric acids 5 - 15 % by weight dimeric acids 60 - 80 % by weight trimeric or higher polymeric acids 10 - 35 %by weight.

The content of dimeric acid can be increased to 100% by weight by distillation processes.

A process for the production of such polyaminoamides and polyaminoimidazolines is described in US Patent Specifications 2 450 940 and 2 695 908 and also in German Patent Specification 1 520 918.

The above-mentioned hardeners preferably have amine numbers in the range of from 50 to 650, more especially from 200 to 450, and are used in amounts of from 0.8 to 1.2 equivalents per equivalent of epoxide.

The average functionality, i.e. number of active amine hydrogen atoms per molecule, should be at least 2, preferably at least 3, in order to obtain duromer properties.

The types of bitumen suitable for combination with the epoxy resins and hardeners described may be obtained from the residue of crude oil processing by distillation under normal pressure, by blowing or by high vacuum distillation. The distillation bitumens are preferred since they are easier to process because of their favourable consistency. Especially suitable types of bitumen are those having a penetration at 250C of from 320 to 50.

To improve the compatibility of a bitumen of lower penetration within this range it is advantageously diluted with a high-boiling mineral oil (boiling point above 200 C), preferably 10 to 30% by weight, calculated on the bitumen. Diesel oil having a boiling range of from 275 to 350"C is especially suitable.

According to requirements, the bitumen, bitumen mixture or their dilutions may be added either immediately to the hardener components or not until all the components are finally mixed together.

Preferred alkyl-substituted phenols to be used concomitantly according to the invention in quantities of 5 to 40% by weight, calculated on the hardener components (bi), (bii) and (6), are those having alkyl radicals with 4 to 12 carbon atoms, for example butyl-, hexyl-, octyl-, nonyl- and dodecylphenol.

Using the epoxy resin/hardener combination specified it is possible to increase the bitumen content of the binder system to up to 60% by weight, calculated on the mixture of the reaction resin and the bitumen, without impairing the final properties necessary for the various applications.

The composition of the present invention may, if desired, contain one or more conventional auxiliaries, for example a filler, pigment, dyestuff, accelerator, solvent, diluent, wetting agent or inorganic or organic fibrous material or mixture of two or more such additives, as necessary for the various fields of application.

The bitumen-containing composition of the invention may be used as a paint, e.g. for protection against corrosion, as coating or adhesive agent, e.g. for bituminised felt, or as highly-filled epoxy resin floor finish or, e.g., for footpaths and road surfaces.

The following Examples illustrate the invention: Examples The following components were used: a. Epoxy resin based on diphenylolpropane and epichlorohydrin having an epoxide equivalent weight of 185 and a viscosity of 8 Pa.s/25 C. (Epoxide value 0.54) Hardener bi. Polyaminoamides polyaminoamide I: condensation product of tall oil fatty acid (TFA) and triethylenetetramine (TETA). polyaminoamide II: low-molecular condensation product of dimerised tall oil fatty acid (DFA) and TETA. polyaminoamide III: high-molecular condensation product of DFA and TETA. bii. Amines Polyamine A: alkylmonoamine Polyamine B: cycloaliphatic diamine.

Some data for these hardeners is shown in the following Table: Table 1 Hardener NH-equivalent Amine Viscosity weight number pa.s/25 C 1 95 360 0.6 II 95 395 2.2 III 240 220 50 (at 40"C) A 63 255 0.02 B 60 470 0.1 c. Phenol component Technically pure grades of phenol, t-butylphenol and nonylphenol were used as phenol constituents. d. Bitumen 1. Distillation bitumen B 200 B 45 B 200 (diesel oil) 80/20 2. High-vacuum bitumen HVB 85/95 HVB 85/95 (diesel oil) 80/20 3. Blown bitumen bitumen 85/40 Some data for these bitumens is given in the following Table: Table 2 Bitumen Penetration Softening point OC 25"C, 1/10 mm (ring and ball) B200 172 42 B 45 37 57 HVB85/95 7 89 85/40 42 85 The epoxy resin was used as one constituent of the compositions and the second constituent was mixed together from the remaining ingredients, partly with the use of heat. After adding the epoxy resin the whole was mixed thoroughly and the homogeneity of the resin reaction composition was assessed. A film up to 0.1 mm thick was applied to glass plates and a layer of approximately 6 mm to sheet metal covers. These films and layers were left to harden in the atmosphere of the laboratory for 7 days at 230 C. The uniformity of distribution of the bitumen in the film on the glass plate was then assessed optically. The layer on the sheet metal was exposed and the shore hardness D was determined on the upper side and underside. The difference in the hardnesses was a measure for the homogeneity of the duromer: the greater the difference the more inhomogeneous the body.

Test combinations and the properties determined are shown in Table 3. Examples 1 - 6 are within the present invention. Examples 7 and 8 are comparison Examples.

Table 3 Composition Comparison examples 1 2 3 4 5 6 7 8 EP resin quantity (g) 47.4 47.4 47.4 50.7 50.7 50.7 54.4 51.4 polyaminoamide I II I III III III I I quantity (g) 9.2 5.7 5.7 37.5 37.5 37.5 4.5 15 polyamine B A A B B A A B quantity (g) 9.2 11.4 11.4 7.5 7.5 7.5 14.3 7.5 phenol Nonyl t-Butyl Nonyl t-Butyl Nonyl t-Butyl - phenol quantity (g) 14.2 10.7 10.7 22.5 22.5 22.5 - 25 bitumen B 200-D B 200 B 45 85/95 85/95-D 85/40 B 45 85/95-D quantity (g) 20 24.8 24.8 118.2 50.7 50.7 26.8 98.9 % by weight 20 24.8 24.8 50 30 30 26.8 50 homogeneity of the reaction resin + + + + + + + homogeneity of the film 1 1 2 1 2 2 3 4 Shore D above 77 82 64 62 69 68 8 36 below 77 82 69 60 70 68 71 55 + @ homogeneous 1 homogeneously distributed 3 bituminous particles - : inhomogeneous 2 very small bituminous particles 4 large bituminous particles

Claims (26)

WHAT, WE CLAIM IS:

1. A hardenable composition which comprises (a) an epoxy component comprising (i) one or more aromatic glycidyl compounds having at least two glycidyl groups, and, if desired, ii one or more monofunctional glycidyl compounds, b an amine component having on average at least two active amine hydrogen atoms per molecule and comprising (i) one or more polyaminoamides and/or polyaminoimidazolines and (ii) one or more amines having from 2 to 18 carbon atoms and containing aliphatic and/or cycloaliphatic hydrocarbon radicals and one or more amino groups, and/or one or more Mannich bases, the amount of component (bii), calculated on the weight of (bi) and (bii), being from 10 to 80% by weight, the amount of components (bi) and (bii) being from 0.8 to 1.2 equivalents per equivalent of the epoxide component, (c) one or more alkyl-substituted phenols, the amount of component (c), calculated on the weight of (b) and (c), being from 5 to 40% by weight, and (d) distillation bitumen, high vacuum bitumen or blown bitumen or two or more such bitumens, in an amount of up to 60% by weight, calculated on the total weight of components (a), (b), (c) and (d).

2. A composition as claimed in claim 1, wherein component (ai) comprises one or more aromatic polyglycidyl ethers having an average epoxide value (as hereinbefore defined) in the range of from 0.2 to 0.6.

3. A composition as claimed in claim 2, wherein the average epoxide value is from 0.4 to 0.55.

4. A composition as claimed in any one of claims 1 to 3, wherein the aromatic polyglycidyl ether or ethers are derived from bisphenol A.

5. A composition as claimed in any one of claims 1 to 4, wherein component (ai) includes up to 25 % by weight of one or more non-aromatic polyglycidyl ethers, calculated on the total of component (a).

6. A composition as claimed in any one of claims 1 to 5, wherein component (a) includes up to 15 % by weight of one or more monoglycidyl ethers, calculated on the polyglycidyl ether component (ai).

7. A composition as claimed in any one of claims 1 to 6, wherein component (bi) has an average amine number in the range of from 50 to 650.

8. A composition as claimed in claim 7, wherein the average amine number is from 200 to 450.

9. A composition as claimed in any one of claims 1 to 8, wherein component (bii) has an average amine number as specified in claim 7 or claim 8.

10. A composition as claimed in any one of claims 1 to 9, wherein component (c) comprises one or more alkylphenols having an alkyl radical of from 4 to 12 carbon atoms.

11. A composition as claimed in any one of claims 1 to 10, which contains at least 20% of bitumen, calculated on the total weight of components (a), (b), (c) and (d).

12. A composition as claimed in any one of claims 1 to 11, which contains distillation bitumen.

13. A composition as claimed in any one of claims 1 to 12, wherein the bitumen has a penetration at 25"C in the range of from 320 to 50.

14. A composition as claimed in any one of claims 1 to 13, which contains up to 30% by weight of mineral oil, calculated on the weight of the bitumen.

15. A composition as claimed in claim 14, wherein the amount of mineral oil is from 10 to 30%, calculated on the weight of bitumen.

16. A composition as claimed in claim 14 or claim 15, wherein the mineral oil is diesel oil having a boiling range of from 275 to 3500C.

17. A composition as claimed in any one od claims 1 to 16, which contains a filler, pigment, dyestuff, solvent, diluent, accelerator, wetting agent or fibrous material or two or more such additives.

18. A hardenable composition which comprises (a) one or more aromatic polyglycidyl ethers having an average epoxide value (as hereinbefore defined) of from 0.2 to 0.6 and, if desired, up to 15% by weight, calculated on polyglycidyl ether, of one or more monoglycidyl ethers, (b) 1. one or more polyaminoamides having an average amine number in the range of from 50 to 650 and 2. a mono- or polyamine having 2 to 18 carbon atoms and containing aliphatic and/or cycloaliphatic moieties or two or more such amines, in an amount of from 10 to 80% by weight, calculated on the mixture (bl) and (b2), (bl) and (b2) being used in an amount of from 0.8 to 1.2 equivalents per equivalent of the epoxide component (a), and component (b) having on average at least 2 active amine hydrogen atoms per molecule, (c) an alkylphenol wherein the alkyl radical is straight-chained or branched and has from 4 to 12 carbon atoms, or two or more such alkylphenols, in an amount of from 5 to 40% by weight, calculated on the weight of (b) and (c), and (d) from 20 to 60% by weight, calculated on the total weight of binder (a), (b), (c) and (d), of distillation or high vacuum bitumen and/or blown bitumen which may if desired be diluted to the extent of up to 30% by weight, calculated on bitumen constituent (d), with mineral oil, and, if desired, (e) a filler, pigment, dyestuff, solvent, diluent, accelerator, wetting agents or fibrous material of two or more such additives.

19. A composition as claimed in claim 1, substantially as described in any one of the Examples 1 to 6 herein.

20. A composition as claimed in any one of claims 1 to 19, which is made up in discrete parts, components (a) and (b) being in separate parts and component (d) being in the same part as component (b).

21. A composition as claimed in claim 20, wherein the epoxy component (a) is in one part and the remaining components are in the other part.

22. A composition as claimed in any one of claims 1 to 19, which has undergone hardening.

23. A process for coating a substrate or for combining two substrates, which comprises applying a composition as claimed in any one of claims 1 to 21 to the substrate or substrates and allowing it to harden in contact with the substrate or substrates.

24. A process as claimed in claim 23, wherein the substrate or substrates are metal or glass.

25. An article which has been treated by a process as claimed in claim 23 or claim 24.

26. A footpath or road which incorporates a composition as claimed in claim 22.