CH632001A5 - Process and compositions for the production of mouldings and coatings - Google Patents

Description

632 001

2nd

PATENT CLAIMS

1. Process for the production of moldings or coatings based on polyadducts which are produced at elevated temperature from at least the following components a) and b):

a. 1,2-epoxy compounds with more than one 1,2-epoxy group in the molecule,

b. Urea, characterized in that the urea is of the general formula is present in an amount of 0.05-10% by weight, based on the amount of the 1,2-epoxy compounds.

ch-

ch,

-n-r-n-c— n-

1 I I]

H

Äö

nh

'CH,

ch;

used, in which n = O or a positive integer and R is a divalent hydrocarbon radical free of aromatic rings, which is optionally substituted, or a divalent hydrocarbon radical, the free valences of which both originate from aromatic carbon atoms and which is optionally substituted.

2. The method according to claim 1, characterized in that the 1,2-epoxy compounds and the ureas are used in such amounts that there are 0.6-1.3 equivalents of the hydrogen atoms bound to nitrogen of the ureas per 1 epoxy equivalent.

3. The method according to claim 1, characterized in that in addition to the ureas, epoxy resin hardeners from the group of polyamines, polyamides, aminoamides or polyaminoamides are used, and in that the quantitative ratio between the 1,2-epoxy compounds on the one hand and the ureas and the the above-mentioned additional epoxy resin hardeners, on the other hand, is chosen such that there are 0.6-1.3 equivalents of the hydrogen atoms of nitrogen-bound urea and the above-mentioned additional epoxy resin hardeners per 1 epoxy equivalent.

4. The method according to any one of claims 1 to 3, characterized in that the adduct formation is accelerated by adding hardening catalysts.

5. Storage-stable, thermally curable compositions for performing the method according to claim 1, consisting of a. 1,2-epoxy compounds with more than one 1,2-epoxy group in the molecule,

b. Urea of the general formula

There are storable, thermoplastically processable, thermosetting epoxy resin-hardener combinations which can be prepared by mixing polyureas with two, preferably 10 three or more urea groups in the molecule with 1,2-epoxy compounds. The polyureas used have the framework - [NH-CO-NH-X] -n + 1, where in the formula nêl and X can be the hydrocarbon residue of a diamine or a low molecular weight polyamide 15. X can also have a higher valency than 2, provided that the amount added does not allow crosslinking. These resin-hardener combinations have the advantage that they do not react at normal temperature and are therefore stable in storage. They have thermoplastic properties over a wide temperature range and can be processed in the manner of thermoplastics, e.g. in extruders and injection molding machines. Only when the temperature rises, usually above 150 ° C, do the thermosetting properties predominate.

It is further described that it is possible to use the urine-25 substances with low molecular weights down to the monomer in a mixture with epoxy resins to produce compositions which have a long shelf life and fully cure at high temperatures. The amino groups of the urea component must be at least partially substituted. The invention relates to a process for the production of moldings or coatings based on polyadducts which are produced at elevated temperature from at least the following components a) and b):

a. 1,2-epoxy compounds with more than one 1,2-epoxy group in the molecule,

b. Urea, characterized in that those of the general formula ch-,

ch,

-n-r-n-c-

h h ö

nh

-ch,

ch4

in which n = 0 or a positive integer and R is a divalent hydrocarbon radical free of aromatic rings which is optionally substituted or a divalent hydrocarbon radical whose free valences both originate from aromatic C atoms and which is optionally substituted, and optionally c. Hardening catalysts, where a) and b) are present in such amounts that there are 0.6-1.3 equivalents of the nitrogen-bound hydrogen atoms of the ureas per 1 epoxy equivalent, and component c), if they exist

used, in which n = O or a positive integer and R is a divalent hydrocarbon radical free from aromatic rings, which is optionally substituted, or a divalent hydrocarbon radical whose free valences both originate from aromatic carbon atoms and which optionally is substituted.

The 1,2-epoxy compounds and the ureas can be used in 55 such amounts that there are 0.6-1.3 equivalents of the nitrogen-bound hydrogen atoms of the ureas per 1 epoxy equivalent.

In addition to the ureas, other known epoxy hardeners from the group of polyamines, poly-60 amides, aminoamides or polyaminoamides can also be used in stoichiometrically equivalent amounts.

Another object of the invention are storage-stable, thermally curable compositions for carrying out the process, consisting of a. 1,2-epoxy compounds with more than one 1,2-epoxy group in the molecule,

b. Urea of the general formula

in which n = O or a positive integer and R is a divalent hydrocarbon radical free of aromatic rings which is optionally substituted or a divalent hydrocarbon radical whose free valences both originate from aromatic C atoms and which is optionally substituted, and optionally c. Hardening catalysts, where a) and b) are present in amounts such that there are 0.6-1.3 equivalents of the nitrogen-bound hydrogen atoms of the ureas per 1 epoxy equivalent, and component c), if present, in an amount of 0.05-10% by weight, based on the amount of the 1,2-epoxy compounds, is present.

The use of the above oligoureas with the 2,2,6,6-tetramethylpiperidine ring as end group building block leads to further advantages in addition to the improved shelf life.

For example, when hardening (at higher temperatures) there are certainly no gaseous fission products. Furthermore, the ureas used according to the invention in the cured state give moldings and coatings with excellent heat resistance. The epoxy mixtures containing oligourea according to the invention also show an excellent flow during the production of films. The good UV resistance of the process products is surprising since it is known that TAD derivatives are good UV stabilizers and it must therefore be expected that the hardeners used according to the invention are also subject to rapid degradation under the influence of UV light.

The oligoureas to be used according to the invention can be prepared by known processes e.g. can be produced as follows:

a. by condensation of TAD or TAD-diamine mixtures with carbonic acid derivatives, e.g. with urea, urea derivatives, carbon dioxide, dicarbonic acid esters etc. or b. by adding TAD or TAD-diamine mixtures to diisocyanates.

The following diamines can be mentioned for example:

The aliphatic diamines, such as hexamethylenediamine, do-decamethylenediamine, a diamine-triamine mixture made from dimerized fatty acid via the nitrii with a 95% diamine content, 2-methylhexamethylenediamine, 2,2,4- and 2,4,4-trimethylhexamethylenediamine, the cycloaliphatic diamines, such as 1,3- and 1,4-diaminocyclohexane, 2,2-bis (aminocyclohexyl) propane, l-amino-3-aminomethyl-3,5,5-trimethylcyclohexane and the aromatic diamines, such as m - and p-phenolendiamine, 2,4-diaminotoluene, 4,4'-diaminodiphenylmethane.

The degrees of polymerization of the oligoureas are insignificant in the method according to the invention with regard to the reaction mode.

However, it is fundamentally more advantageous to use oligomers with n è 0-10 in order to keep the kneading work which is converted into heat when mixed with the 1,2-epoxy compounds with hardener as small as possible. Urea with n â 0-2 should be emphasized, since they lead to particularly quick and even cross-linking.

The molding compositions according to the invention can be produced by mixing the above ureas with the 1,2-epoxy compounds which contain more than one epoxy group per molecule. The epoxides are suitable for this purpose multiple

3,632,001

saturated hydrocarbons (vinylcyclohexane, dicyclopentadiene, cyclohexadiene, cyclododecadiene, cyclododecatriene, isoprene, 1,5-hexadiene, butadiene, polybutadienes, divinylbenzenes and the like), epoxy ether of polyhydric alcohols (ethylene, propylene, and glycol glycols) , Gly-cerin, pentaerythritol, sorbitol, polyvinyl alcohol, polyallyl alcohol and the like), epoxy ether of polyhydric phenols (resorcinol, hydrochi-non, bis- (4-hydroxyphenyl) methane, bis- (4-hydroxy-3-methylphenyl) ) methane, bis (4-hydroxy-3,5-dichlorophenyl) methane, K bis (4-hydroxy-3,5-dibromophenyl) methane, bis (4-hydroxy-3,5-difluorophenyl) -methane, l, l-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) -propane, 2,2-bis- (4-hydroxy-3-chlorophenyl) -propane, 2,2-bis- (4-hydroxy-3,5-dichlorophenyl) -propane, bis- (4-hy- 15 hydroxyphenyl) phenyl methane, bis (4-hydroxyphenyl) diphenyl methane, bis (4-hydroxyphenyl) -4'-methylphenyl methane, 1,1-bis (4-hydroxyphenyl) -2,2,2 trichloroethane, B is- (4-hydroxyphenyl) - (4-chlorophenyl) methane, l, l-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) cyclohexylmethane, 20 4,4'- Dihydroxydiphenyl, 2,2'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl sulfone and their hydroxyethyl ether, of phenol-formaldehyde condensation products such as phenol alcohols, phenol aldehyde resins and the like), S- and N-containing epoxides (N, N-diglycidyl-aniline, N, N'-dimethyldiglycidyl-4,4'-diaminodiphe-25 nylmethane, triglycidyl isocyanurate) and epoxides which have been prepared by conventional processes from polyunsaturated carboxylic acids or monounsaturated carboxylic acid esters of unsaturated alcohols, glycidyl esters, Polyglycidyl esters which can be obtained by polymerizing or copolymerizing glycidyl esters of unsaturated acids or other acidic compounds (diglycidyl sulfide, cyclic tri-methylene trisulfone or their derivatives, etc.). Just as well as the pure epoxides above, their mixtures and mixtures with monoepoxides, if appropriate in the presence of solvents or plasticizers,

be implemented according to the present method. For example, the following monoepoxides can be used in a mixture with the aforementioned epoxy compounds: epoxidized monounsaturated hydrocarbons (butylene, 40 cyclohexene, styrene oxide and the like), halogen-containing epoxides, such as e.g. Epichlorohydrin, epoxy ether of monohydric alcohols (methyl, ethyl, butyl, 2-ethylhexyl, dodecyl alcohol, etc.), epoxy ether of monohydric phenols (phenol, cresol and other phenols substituted in ortho * or para position), glycidyl esters of unsaturated 45-saturated carboxylic acids, epoxid Esters of unsaturated alcohols or unsaturated carboxylic acids and the acetals of glycidaldehyde.

To produce the polyadducts according to the invention, part of the ureas 50 to be used according to the invention can also be produced by other known «hardeners», e.g. Polyamines, polyamides, aminoamides and polyaminoamides are replaced in a stoichiometric ratio. However, the use should expediently not exceed 50% of the stoichiometric amount of urea.

55 The polyadducts can be prepared by mixing the ureas with the 1,2-epoxy resins or 1,2-epoxy compounds and shaping by known processes and will be explained further in the examples. Both moldings and coatings can be produced with it. 60 The ureas of the present invention, which can also be described as cyclic diamines, are pronounced heat hardeners, i.e. the actual curing or crosslinking is expediently carried out at temperatures above 140 ° C., preferably between 150-200 ° C.

65 The production of moldings or coatings according to the invention can optionally be carried out by adding accelerating substances, e.g. from the group of mono- or polyhydric phenols, especially aminophe-

632 001

4th

noie, the mono- or polyhydric alcohols or also by compounds such as mercapto compounds, thioethers, di-thioethers or compounds with nitrogen-carbon-sulfur groups or sulfoxide groups. Salts of rhodanhydric acid are also suitable, in particular in the form of complex compounds.

Complex compounds of salts of rhodanhydric acid which can be used are understood to mean complex compounds of these with inorganic or organic components. Such connections include:

NH4SCN, NaSCN, KSCN, Mg (SCN) 2, Ca (SCN) 2, Zn (SCN) 2, Mn (SCN) 2, pyridine • HSCN, quinoline • HSCN, aniline • HSCN, o- and p-toludine • HSCN , Guanidine • HSCN, Cd (SCN) 2 • 4 NH3, Zn (SCN) 2 • 2 N2H4, Mn (SCN) 2 • 2 N2H4.2 KSCN • t (CH2) 6N4], Zn (SCN) 2 • (pyridine ) 4, Mn (C5H5N) 2 • (SCN) 2, NaSCN • (C3H60) and [(NH2) 2CS] 3 • KSCN.

The amount of accelerator added can be varied within a wide range, depending on the reactivity of the amine or epoxy components. As a rule, amounts of accelerator in the range from 0.05 to 10% by weight, preferably 0.5 to 5% by weight, based on the epoxy, are used, but sometimes smaller or larger additives can also be particularly advantageous.

The curing accelerators can be added to the mixture as well as to the epoxide or the amine in the form of solid substance, dispersion or else in solution.

Of course, fillers, dyes, pigments, flexibilizers, solvents and other additives can also be added. It is a particular advantage of the method according to the invention that sufficient time is available for the intensive mixing in of the additives mentioned as a result of the extended processing time.

The mixtures can be prepared by known methods, e.g. by kneading on the friction roller, in kneaders and extruders. In some cases, the mixture in solution is also appropriate.

The substances used according to the invention have great advantages in processing methods which require storage stability at elevated temperatures and in which the viscosity may only increase in a controlled manner during the thermoplastic phase.

The process according to the present invention is illustrated by the following examples:

example 1

a. 312 parts by weight TAD were with 60 Gew.-T. Urea condensed in 2 stages to 1,3-bis- (2,2,6,6-tetramethyl-4-piperidyl) urea, in the 1st stage in 4 h at 150 ° C. about 80% of the expected NH3 were released. In the second stage, the reaction mixture was then heated to 200 ° C. for 1 h, liberating the remaining 20% of NH 3. The reaction product was then heated for a short time (5-10 minutes) at 140 ° C. in vacuo (0.1 torr). The basic urea thus produced had an NH2 content of 5.916 me / g.

b. 10 parts by weight of the urea produced in this way were mixed with 90 parts by weight. of a bisphenol A-based glycidyl ether, the epoxy value of which was 0.102, mixed intensively on a friction roller at 80 ° C. (5 minutes). The gel time of this mixture was 300 seconds at 200 ° C. It also changed after

24 h storage at 50 ° C not. The molded articles produced from this urea / epoxy mixture, which were cured for 10 minutes at 200 ° C., were very hard, transparent and had a smooth surface. They proved to be resistant to organic solvents.

Example 2

20 parts by weight of the urea produced in Example la) were mixed with 80 parts by weight. of a bisphenol-A-ic-based glycidyl ether, the epoxy value of which was also 0.102, intimately mixed at 80 ° C. in a twin-screw extruder.

The kneading resistance of this mixture, measured in the Bra-bender plastograph, was 1.8 kpm at 80 ° C. After 4 weeks of storage at 40 ° C., a value of 1.85 kpm was measured. The molded articles produced from this material by injection molding were very impact-resistant and dimensionally stable after a hardening time of 7 minutes at 200 ° C.

Example 3

20 50 parts by weight of the urea / epoxy mixture prepared in Example lb) were mixed in 50 parts by weight. Isophorone dissolved. The viscosity of this solution was 810 cP at 25 ° C. The viscosity rose to 1020 cP after a storage period of 6 months. The solution was applied to steel sheet; the layer obtained after flash-off was heated to 200 ° C. for 10 minutes. The film went well, was tough and flexible. It was also resistant to acetone. The König pendulum hardness was 218 seconds, the Erichsen depth 112 mm.

30th

Example 4

a. To 222 parts by weight l-Isocyanatomethyl-5-isocyanato-1,3,3-trimethylcyclohexane (IPDI) in 1000 ml acetone were 312 parts by weight within 4 h at 0 ° C. TAD added dropwise. A white fell

35 ser precipitate, which was filtered off and then dried at 80 ° C overnight. The urea thus produced had an NH2 content of 3.740 mA / g.

b. 10 parts by weight of the urea produced in this way were mixed with 90 parts by weight. of a bisphenol A based glycidyl ether, the

40 epoxy value was 0.102, and 0.1 part by weight. Triethylenediamine intimately mixed on a friction roller at 70 ° C.

The kneading resistance of this mixture, measured in the Bra-bender plastograph, was 2.4 kpm at 80 ° C. After 24 h of storage at 50 ° C., a value of 2.5 kpm (at 80 ° C.) was measured.

The moldings produced from this material by injection molding were very impact-resistant and dimensionally stable after a hardening time of 5 minutes at 200 ° C.

50 Example 5

15 parts by weight of the urea produced in Example 4a) were mixed with 85 parts by weight. of a bisphenol A-based glycidyl ether with an epoxy value of 0.22 mixed intensively in a twin-screw extruder at 80 ° C. The glass softening temperature of this mixture was 82 ° C. After storage at 50 ° C. for 24 hours, the glass softening temperature was 82 ° C.

A plate made with this urea / epoxy resin powder by pressing at 200 ° C. for 5 minutes was very hard, transparent and resistant to acetone and methanol.

C.