CH632285A5 - Process for the preparation of cured epoxy resins - Google Patents

Description

The invention relates to a method for producing hardened epoxy resins with high adhesive strength.

Epoxy resins form a large class of polymeric materials that include a wide range of properties. The resins are characterized by epoxy groups which can be cured by reaction with certain catalysts or hardeners to give cured epoxy resin compositions with certain desired properties. Such a class of hardeners are the amines. The amines most frequently used as hardeners are aliphatic amines, such as diethylene triamine, triethylene tetramine and the like, and / or polyoxyalkylene polyamines, such as polyoxypropylene diamines and triamines.

Epoxy resins with improved mechanical properties are obtained by using polyoxyalkylene polyamines, in particular polyoxyalkylene diamines, as hardeners. It is common to use a co-hardener as described in US Pat. No. 3,549,592 in such epoxy resin compositions.

It is known to form oligomers from aliphatic or aromatic amines and 2-basic acids or anhydrides (see US Pat. No. 3,732,189). Furthermore, diamines were reacted with maleimides or anhydrides to give elastomers (US Pat

2 818 405). Heat-curing base materials have also been produced from epoxides and certain N-containing compounds with terminal carboxyl groups (see US Pat. No. 3,984,373).

Various ureas and substituted ureas are also known as epoxy hardeners or co-hardeners. In this context, reference is made to U.S. Patents 3,294,749,2,713,569.

3,386,956 and 3,386,955.2 855,372 and 3,639,338. The urea compounds disclosed in these patents are suitable as hardeners and as hardening accelerators.

The invention has for its object to provide a method for producing hardened epoxy resins, which leads to hardened products with significantly improved adhesive strength and shear strength. The object is achieved according to the invention in that a vicinal polyepoxide with an epoxy equivalent weight of more than 1.8 and a polyamine as hardener with an additive of the general formula (I)

[R-NH- (CH-CH-0) m-Z- (0-CH-CH) nNH] 2-X (I)

65 il II

Y H H Y

7. The method according to any one of claims 1 to 5, characterized in that:

3,632,285

X A or B, where A = CO or a residue of a difunkyoxipropylenediamine, is placed in a suitable reaction vessel.

tional isocyanate with two -N = CO groups and B the rest ben. Then 1 mol of urea or maleic anhydride is added. Thereafter, the mixture is gradually heated, with the addition of urea

-HN-C H2-CO at 180 to 200 ° C and the temperature as long as possible-

I is; 5 until ammonia evolution stops. If you paint

CH2-CO has added acid anhydride is heated to 140 to 170 ° C until the azeotropic water removal is complete. The

Z is an alkylene radical with 2 to 5 carbon atoms; The reaction mixture is then at 120 to 150 ° C or 170 to

Y H, methyl or ethyl, 190 ° C (the latter in the case of polyether succinimide production)

m and n are numbers such that the molecular weight of the ad and 1.33 mbar is stripped and a viscous liquid is obtained,

ditivs is about 4000 to 4500; and in the 2nd stage, the viscous liquid of stage 1

R H, a straight-chain or branched alkyl radical with 1 a polyoxypropylene diamine having a molecular weight of 200

up to 10 carbon atoms, a monocyclic aryl, alkaryl or up to 250 in a ratio of 5: 1 to 1: 5. This

Aralkyl radical with 6 to 12 carbon atoms, a straight-chain or mixed, if desired, a commercially available

branched alkenyl or alkadienyl radical with 2 to 10 carbon atoms 1S accelerator are added.

or an aminoalkylamine radical of the formula The mixture from stage 2 is mixed in stage 3 with a suitable -NH (CH2) pNH2, in which p is 2 or 3, and the mixture of a diglycidyl ether of 4,4'-isopropylidene-bisphenol is hardened becomes. added so that the amine equivalents are equal to the epoxy. The additives added according to the invention can be equivalent. The epoxy resin and the hardener mixture are drawn as polyoxyalkylenes with terminal ami 20 are carefully mixed; about 3 drops of a nogroup and, if in the general formula I is X A, liquid silicone are added in order to avoid the formation of bubbles and a ureylene bridge or, if X B is, a succinimide cavities. The resulting assembly bridge. In the following, for the sake of brevity, the term polyting will be used after 2 to 5 minutes of degassing under vacuum ether-ureylene or polyether-succinimide. applied to the substrates to be glued or poured in for the use of these compounds as additives in 25 men. The resins are cured at room temperature epoxy resin compositions to cured products with, and preferably post cured at 80 to 125 ° C. The hardness leads to improved shear strength and adhesive strength, products have improved shear strength, flexural strength and rapid, especially since compounds of a similar type but with lower elongation, elongation at break and, in particular, improved adhesive molecular weight do not bring this effect. Invention 3111 substrate.

According to resins hardened with the additives, the compositions which contain vicinal polyepoxides are 30

Castings, seals and particularly suitable as an adhesive. and which are cured with amine are organic materials

Generally speaking, the adhesive strength (adhesive property) Ken with an average of more than 1.8 reactive 1,2-epoxy group

of amine-hardened epoxy resins by adding a polyether pen i111 molecule. These polyepoxides can be monomeric or with terminal amino groups and ureylene or succin polymers, saturated or unsaturated aliphatic, cycloaliphatic

imide bridges and a molecular weight of 4000 to 4500 35 table, aromatic or heterocyclic compounds, which significantly improves. According to one aspect of the invention, in addition to the epoxy groups, other substituents, such as terminal amino groups, are primary, according to another se-hydroxyl, ether residues, aromatic halogen and the like. can wear.

Preferred are a diglycidyl ether of 4,4'-isopropyl. Preferred polyepoxides are those of glycidyl ethers, herp-pylidenebisphenol, an amount sufficient for curing of 40% by epoxidation of the corresponding allyl ether or hardener carrying primary amino groups, which is essentially known per se by reacting a molar excess of a polyoxypropylene polyamine with a molecular weight shot of epichlorohydrin with an aromatic polyhydric compound of about 200 to 500, a piperazine alkanolamine - hydroxyl compound, for example Isopropylidene bisphenol, novolak, retarder and a lot of the sorzine to be used according to the invention, etc. The epoxy derivatives of methylene and isopropyl additive are mixed together and hardened. 45 den-bisphenol are preferred. A polyepoxide, an amine hardener, a method suitable for polyethers which are suitable for the invention include the resin-type amino groups with terminal groups and a ureylene or sucrose epoxy polyether, which are formed by reacting an epihalogeno-cinimide bridge and , if desired, an accelerator, such as epichlorohydrin, can be mixed with either a polyhydric compound and obtained by conventional methods hardened phenol or a polyhydric alcohol. Cured products with a surprising 50 examples are then obtained: 4,4'-isopropylidene-bisphenol, 2,4'-dihy high adhesive strength. droxidiphenylethylmethane, 3,3'-dihydroxidiphenyl-diethylme- According to one embodiment of the invention, a di-than, 3,4'-dihydroxidiphenylmethylpropylmethane, 2,3'-di-glycidyl ether of 4,4'-isopropylidene-bisphenol with a droxidiphenylethylphenylmethane, 4,4'-dihydroxidiphenylpro-sufficient amount of a hardener and the additive according to the invention monopolyphenylmethane, 4,4'-dihydroxidiphenylbutylphenylmethane, additive, namely a polyether-ureylene or 55 2,2'-dihydroxidiphenylditolylmethane, 4,4'- Dihydroxidiphenyl succinimide with terminal amino groups and a Moltolylmethylmethan and the like. Other polyvalent molecular weight of about 4,000, mixed with one another and haemnoie, which in particular reacted with an epihalohydrin. The preferred polyether-ureylene can be made by reaction, e.g. Resorcinol, hydroquinone, substituted from about 2 moles of polyoxypropylene diamine of a molecular hydroquinone, e.g. Methylhydroquinone, and the like.

weight of about 2000 with one mole of urea and the poly 60 Among the polyhydric alcohols with an epihalo

ether-succinimide by reacting 2 moles of the polyoxypropenhydrin to form the resinous epoxy polyethers, pylenediamines with about one mole of maleic anhydride are used to produce compounds such as ethylene glycol, propylene glycols, butylene glycol. A polyoxypropylene polyamine of a molecular glycol, pentanediols, bis (4-hydroxicyclohexyl) dimethyl methane,

Weights from 200 to 500 can be added as a co-hardener. 1,4-dimethylol-benzene, glycerin, 1,2,6-hexanetriol, trimethyl

The hardened epoxy resins are preferably made of 65 lolpropane, mannitol, sorbitol, erythritol, pentaerythritol, their di-

wise in 3 stages: In the 1st stage the additive is manufactured. mers, trimers and higher polymers e.g. Polyethylene glycol

For this purpose, about 2.0 moles of a polyoxypropylene polyamine, glycols, polypropylene glycols, triglycerol, dipentaerythritol and a molecular weight of about 2000, which essentially consists of the like, polyallyl alcohol, polyhydroxy-thioether, such as 2,2'-,

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3,3'-tetrahydroxide dipropyl sulfide and the like, mercapto alcohols such as monothioglycerin, dithioglycerin and the like, partial esters of polyhydric alcohols such as monostearin, pentaerythritol monoacetate and the like and halogenated polyhydric alcohols such as the monochlorohydrins of glycerol and glycerol, sorbitol.

Another class of polymeric polyepoxides which can be cured with amine and are suitable for the process according to the invention are the epoxy novolak resins which are obtained by reaction, preferably in the presence of a basic catalyst, e.g. Sodium or potassium hydroxide, an epi-halohydrin such as epichlorohydrin, with the resinous condensation product of an aldehyde, e.g. Formaldehyde, and either a monohydric phenol, e.g. Phenol itself or a phenol with several hydroxyl groups can be obtained. Further details on the nature and manufacture of epoxy novolak resins can be found in the Handbook of Epoxy Resins by Lee Henry and Neville, McGraw Hill Book Co., 1967.

It is obvious to the person skilled in the art that other polyepoxide compositions can also be used for the process according to the invention.

The additives to be used according to the invention can generally be described as polyoxyalkylene-containing materials with a single ureylene bridge or a succinimide bridge, terminal amino groups and a molecular weight of 4,000 to 4,500. The additives fall under the general formula I.

Average of 12-20. The preferred polyoxyalkylene diamines are those in which Y is a methyl radical, n 16-18 and Z are a 1,2-propylene radical. These polyoxyalkylene polyamines can be prepared by known methods, such as those e.g. in U.S. Patent Nos. 3,236,895 and 3,654,370.

The polyether-ureylenes can be prepared by reacting a polyoxyalkylene polyamine with alkylene radicals having 2-4 C atoms, with urea, a ureylene-forming compound or organic bifunctional isocyanates. Urea is preferred. When urea is used as the reactant, the reaction proceeds to form ammonia and the terminal primary amino group of the polyoxyalkylene polyamine is converted to an ureido group. The functionality of the polyoxialkylene polyamine depends on the number of terminal primary amino groups. Since urea itself is bifunctional, each molecule of urea can react with 2 terminal amino groups of the polyoxyalkylene polyamine.

20 Although urea is the preferred reactant, other urea-forming compounds can also be used to provide the bridging residue -C—. Since that

II

O

25 Polyoxialkylenpolyamin already contains terminal primary amino groups, compounds such as carbonyldi-imidazole, phosgene or diphenyl carbonate as O

[RNH (CH-CH-0) m-Z- (0-CH-CH) nNH] 2-X II II

Y

(1) 30

H

H Y

in which the individual symbols have the meaning given above. When R is a branched 35 or straight-chain alkyl radical, R preferably has 1-6 C atoms; if it is a monocyclic aryl, alkaryl or aralkyl radical, 6-8 C atoms; or if it is a branched or straight-chain alkenyl or alkadienyl radical, 3-8 C atoms.

The additives according to general formula I are very particularly preferred, in which R is an alkyl radical with 1-4 C atoms or an amino-1,2-propylamine radical, in particular hydrogen, Y is a methyl radical, Z is a 1,2- Propylene and m and n are equal numbers from 16-19; m and n are of course average values. The preferred polyetherureylenes are those in which 45 X = CO.

The polyether-ureylene with terminal primary amino groups can be prepared by reacting a ureylene-forming compound with a polyoxyalkylenediamine having a molecular weight of 1800 to 2200 at 100 to 200 ° C., the molar ratio of ureylene-forming compound to polyoxyalkylenediamine being approximately Is 1: 2.

The polyether succinimides with terminal primary amino groups can be prepared in two steps by reacting maleic anhydride with a polyoxyalkylenediamine having a molecular weight from 1800 to 2200. First, the reactants at lower temperature, i.e. Room temperature, mixed and then the crude product heated to 120-180 ° C, the water being removed with one mole of maleic anhydride. 60

The diamines which are suitable for the preparation of the additives are polyoxyalkylenediamines of the general formula IV

[H, N- (CH-CH-0) "] 2-Z I I Y H

(IV)

65

in which: Y is hydrogen, methyl or ethyl; Z is a hydrocarbon alkylene radical with 2-5 C atoms and n one

-C supplier can be used for the formation of ureylene bridges without ammonia elimination.

Another class of polyetherureylene can be obtained by reacting polyoxyalkylene polyamines with a bifunctional organic isocyanate, e.g. prepared by phosgenation of the condensation product of aniline and formaldehyde. Suitable compounds are 4,4'-diphenylmethane diisocyanate or its isomers, such as 2,4'-diphenylmethane diisocyanate, and mixtures of these isomers.

The polyether succinimides can be prepared by reacting a polyoxyalkylene polyamine with alkylene radicals having 2-4 C atoms with maleic anhydride. The reaction proceeds with the liberation of water and a terminal primary amino group of the polyoxyalkylene polyamine converts to a succinimide group. The maleic anhydride has a bifunctional function, linking the ethylenic unsaturation to the terminal amino group of another polyoxyalkylenediamine.

According to a further embodiment of the invention, polyether ureylenes or succinimides with terminal secondary amino groups are used. These compounds are preferably obtained by reductive amination of the compounds having terminal primary amino groups.

The reductive amination of primary amines with aldehydes and ketones on standard hydrogenation / dehydrogenation catalysts is known and need not be explained in more detail here. Another method of making compounds with secondary amino groups involves the use of organo-halogen compounds. This method is not preferred because there are too many side reactions.

According to a further embodiment, polyether ureylenes or succinimides with terminal amino-alkylamine residues can be prepared by cyanoalkylation of polyethers with terminal primary amino groups and subsequent hydrogenation of the cyanoalkylated compounds. The preparation of cyanoalkylated adducts is described in U.S. Patent 3,666,788. The hydrogenation is carried out according to the conventional method on a standard hydrogenation / dehydration catalyst.

5 632 285

The polyether-ureides and -succinimides with terminal addition of certain amine-containing compounds as curing primary amine groups can be described alone as amino hardeners for accelerating epoxy resin compositions. Thus, these compounds perform both the function of and many of the accelerators known in the process

Amine hardener as well as that of an additive, by means of which the according to the invention can be used. Examples of this

Adhesive strength is increased from. According to the invention, however, 5 are salts of phenols, salicylic acid, amine salts of fatty acid — apart from these additives with terminal primary amines, as described in US Pat. No. 2,681,901, and tertiary amino groups, the polyepoxides are also a polyamine as hardener as described in U.S. Patent No. 2,839,480. Given a preferred one. Accelerator is disclosed in U.S. Patent No. 3,875,072. It is a

All amines customary in the weight oxides for curing vicinal ep mixture of piperazine and an alkanolamine can be used as the amine hardener. General ic ratio of about 1: 8 to 1: 1.

are such hardeners with at least 2 reactive amino groups. According to the invention, the adhesive strength of the known ones is suitable. Examples of such amines are alkylene polyamines, amine-cured epoxy resins by adding a polyether such as diethylene triamine, triethylene tetramine and the like; Ureylens or -Succinimids with terminal amino groups

Oxialkylene polyamines, such as polyoxypropylene di- and triamine and a molecular weight of about 4,000 to 4,500, and diamine derivatives of ethylene glycol, such as 1,13-diamino-15 The amount of additive required to increase the adhesive strength-4.7 , 10-trioxatrideecane. is somewhat empirical and depends on the resin, the use

Aromatic amines are also suitable as hardeners. The use of an amine hardener and the use of an accelerator are examples of alkylene bridges polyphenylers. In general, the polyether with terminal amines, phenylenediamines and polycyclic or condensed nogroups, if it is to serve as a hardener / additive, becomes roughly aromatic-ring systems with primary amino groups. Also 20 chiometric amounts used.

the corresponding cycloaliphatic compounds can be used in conjunction with other known amine hardeners. the additive preferably in amounts of about 5-40 parts by weight,

Also suitable are polyamide hardeners, such as the condensate based on 100 parts by weight. Resin. The exact quantity of polyamines and polycarboxylic acids. As an additive that is required, the condensation product of a polyamine and 25 che can be easily determined empirically, without further experimentation, due to the fact that a resin blends a dimerized fatty acid disclosed in U.S. Patent 2,379,413 contains a sufficient amount of the additive. Undergoes changes that become even more visible when hardened

Of the amine hardeners that become the hardening of vicinal ep- The hardenable resin adopts an opaque milky-white oxide resin, the polyoxyalkylene amines will take on the appearance, which becomes even stronger when hardened and leads to the following general formula II: 30 product with a glossy white appearance. This change in optical absorption increases the beauty of castings [H2N- (CH-CHO) „] r-Z (II) and makes the use of white pigments or fillers

I I superfluous fabrics.

Y H The ratio of additive and hardener to resin can be

35 easily determine on an equivalence basis. The equivalence determination in which Y H, methyl or ethyl, Z is a hydrocarbon residue with mung is also intended to include the functional groups of the accelerator 2 to 5 carbon atoms, which forms 2 to 4 external ether bridges. The required amount can be calculated n is a number from 1 to 15 and r is a number from 2 to 4. by adding the number of equivalents on a weight basis Most preferred are the polyoxypropylene diamines, where, per replaceable HN groups in the amine hardener, the additive in the formula II, Y is methyl, n is a number from 1 to 10, Z is a 1.2- * 0 and when used the accelerator. Based on this propylene residue and r 2 is. The preparation of these compounds is generally described as a blend of a poly-is described in U.S. Patent Nos. 3,236,895 and 3,654,370. oxialkylenediamine hardener, additive and accelerator in

It is very particularly preferred to use a polyoxypropylene diamine of 10% excess over the stoichiometric amount required, based on the resin, of about 230%. According to a

Another preferred class of polyoxyalkylene polyamides, the adhesive properties of an epoxy resin composition known from the general formula III below can be given epoxy equivalence over 1.8 by adding polyoxypropylene-ureylene or sucrose.

cinimide with terminal amino groups, obtained by Kon-Z - [(OC H-C H) n -NH (CH2) y -NH2] r (III) condensation of one mole of urea or one mole of maleic acid

I I 50 reanhydride with 2 moles of a polyoxypropylene diamine of a mole

H Y molecular weight increased from 2000. Preferred resin compositions are polyglyzidyl ethers of polyphenols which, by means of an in the Y, Z, n and r, have the same meaning as in formula II, an amount of a poly-

have and y is 2 or 3. These poly (aminoalkylamino) polyoxyalkylene polyamines with a molecular weight of 200 to 500 ether are the hydrogenation products of the cyanoalkylated ads and an accelerator combination of piperazine and a product of a polyoxyalkylene polyamine as described above. The alkanolamine cured in a weight ratio of 1: 8 to 1: 1. The preparation of these adducts is described in US Pat. No. 3,666,788. Preferred known compositions, the ben. The hydrogenated cyanoethylated polyoxy adhesive strength by the additives propylene triamine added according to the invention are preferred. can be increased are disclosed in U.S. Patent 3,943,104.

If desired, the epoxy resin compositions can contain a vicina-gen also contain an accelerator, the amine curing les polyepoxide an epoxy equivalent weight over 1.8, a sufficient amount of the amine curing agent, especially at room temperature to cure, an amount of the nigt. Such acceleration is with some application additive and possibly an accelerator. Although all ken are advantageous, in particular if an epoxy resin is applied as an adhesive in epoxy resins specified herein for use in a combustible environment according to the invention, which increases the temperature, those which are based on aliphatic curing temperatures become unsuitable, if not dangerous - bindings based, preferably not used alone. That would do loan. In the hand presence of resins cited above, the polyglyzidyl ether of polyvalent book of epoxy resins is on pages 7 to 14, the use of phenols in amounts above 50, preferably 80% by weight.

632 285 6

contain, in particular resins that 100% polyglizidyl see 0 and 45 ° C) harden themselves. Post-curing with increased

ether of polyhydric phenols, improve the temperature up to about 135 ° C has proven to be beneficial,

desired properties of the hardened products, in particular according to a preferred embodiment of the invention, the adhesive strength. become a diglyzidyl ether of 4,4'-isopropylidene-bisphenol,

In the same way, all amine hardeners can also be used in an amount sufficient to harden a primary amino

methods according to the invention are used. It is, however, a group-containing hardener, which was essentially found from a resin containing hardeners in which, unlike polyoxypropylene diamine, a molecular weight of about 200

in the additives used according to the invention, which consists of ami to 250, an accelerator composed of piperazine and triethyl

long aliphatic or oxyalkylene chains of anolamine in a weight ratio of 3: 7 and an additive with end

separated from each other, viscous and difficult to process are 10 permanent amino groups and a molecular weight of about

and harden in the presence of the additive to products that are not mixed and hardened.

have the desired high adhesive strength. The reason for this - according to a preferred embodiment, poly-for is not exactly known, but it is assumed that this glycidyl ether of polyhydric phenols is incorporated by incorporation into the compatibility of the constituents with a polyoxyalkylene polyamine having a molecular weight of 230. For example, Resins which are mixed with polyoxypropylene diamine in an up to stoichiometric amount, about 5 to 30 parts by weight. nes molecular weight of 400 in the presence of the additive of an additive to be used according to the invention and 1 to 5 have been cured, no significant improvement in the% by weight, based on 100 parts by weight. Resin, an accelerator strength. mixture of piperazine and triethanolamine (3: 7) hardened. The

Because of the greater economy and better hand hardening takes place at room temperature and you get pro

Availability amines are preferred whose molecular products with improved adhesive strength.

weight is less than about 500. Preferred amine hardeners are poly-. It is of course also possible to use other conventional additives, amines, with an amine equivalent weight of 20-150, in particular in the composition before hardening. So 20-70. Examples of such hardeners are polyoxypropylene - e.g. be useful in certain cases, small

diamines with a molecular weight in the range of 200 to 300 genes of other polyalkylene amine CO catalysts, as further described and polyoxypropylene polyamines with a molecular weight in the foregoing, or hardeners together with various ranges from 400 to 700. other accelerators and known curing systems.

Unsuitable amine hardeners can be added quickly by a specialist.

determine, since these hardeners do not have any effective optical improvements. In addition, common pigments can be added,

bring. Fillers, flame retardants and the like, which

The amine-hardened resins with improved adhesive strength so that their constituents are compatible with the composition, so

can be produced in the usual way. Because an amine resin like natural and synthetic resins.

ter is used in addition to the additive, although if not preferred, the solvents known for poly-the mixture with the polyepoxide composition in the epoxide can also be used, such as toluene, amine equivalent weight of the mixture, corresponding amount of benzene, xylene, dioxane, ethylene glycol. Monomethyl ether and combined. In general, the number of equivalents 35 is the same. The polyepoxy resins containing the additives, the amino groups 0.8 to 1.2 times the number of epoxies, can be used wherever polyep equivalents in the curable epoxy resin composition, where oxides have been used up to now. A special feature of the stoichiometric amount is preferred. If a population is such that they become opaque after hardening and are used more quickly, amounts generally have a smooth white glossy surface, which is particularly from 1 to about 10 parts by weight, based on 100 parts by weight. Resin. is advantageous for moldings and castings. The exact amount of ingredients obtained depends primarily on compositions used for impregnation, surface purpose, for which the cured resin is intended. coating, for encapsulation, laminating and especially as

It is preferable to mix the additive first with the metal / metal adhesive.

Hardener or the hardener-accelerator mixture before it is The invention is now explained using examples,

incorporated into the resin. The ingredients that make up the curable 45-

Form material, can intimately with the usual- Example 1

mixed together and in the presence of conventional defoamers. Preparation of an ad-guest in the process according to the invention, small amounts of silicone oil being added to polyether-ureylenes to be used with terminal amines in order to negate the formation of bubbles and cavities.

avoid. 50 In a suitable reaction vessel using a stirrer

If an accelerator is used, such an one was provided, 28.5 kg (0.032 mol) of a polyoxy, which was the mixture of piperazine and alkanolamine in propylene diamine (POPPA) (molecular weight 2000 and 1.0 weight ratio of 1: Is 8 to 1: 1. It is preferably added in milliequivalents (meq. Primary amine / g) and 0.45 lcg (0.016 of an amount of 1 to 5 parts by weight per 100 parts resin-mole) urea. The mixture was placed with nitrogen. The accelerator is flushed with a polyoxyalkylene diamine 55 and stirred under a blanket of nitrogen while mixing gradually and more slowly, reducing to 10-50 parts by weight. Accelerator 100 was heated to 183 ° C. This mixing temperature was parts by weight. of the hardener come. maintained until ammonia evolution ceased. The

Polyoxyalkylenediamines of the type which resulted in a crude reaction product at 150 ° C. were used as co-hardeners

described earlier, which stripped an amine equivalent of 20 to 70 and 1.33 mbar and obtained a viscous liquid,

preferably have 40 to 70, preferred. It was found what- 60 This product was then filtered through a filter cloth. The ratio of polyether-ureylene or succinimide analysis showed: 1.57% N, 0.53 meq total amine / g, 0.52 meq to amine (-Co) hardener from about 5: 1 to about 1: 5 epoxy resins with primary amine / g, 0.10% water.

significantly improved properties, e.g. Give shear strength, flexural strength, elongation at break and in particular adhesive strength example 2. 65 Production of a polyether sucrose which can be used as an additive

The mixture of epoxy resin, polyoxyalkylene polyamine, ad cinimids with terminal amino groups.

ditive and accelerator combination of piperazine and AI- In a suitable, clean, dry reaction vessel, the kanolamine is generally left at room temperature (between stirrer, thermometer, reflux condenser and Dean-Stark-

7

632 285

Trap was provided, 750 g (0.39 mol) of POPPA 2000, 18.4 g (0.183 mol) of maleic anhydride and 50 g of benzene were added. This mixture was heated under reflux (vessel temperature 146 to 167 ° C.) for about 2 1/2 hours until the azeotropic removal of the water (2.3 g of water) had ended. Then the benzene was removed from the crude reaction mixture until the vessel temperature was 205 ° C. The remaining reaction product was then stripped at 180 ° C. and 3.99 mbar and a viscous residue was obtained, the analysis of which showed: 0.64 meq total amine / g, 0.43 meq primary amine / g, 0.009 meq acidity / g . IR analysis showed the presence of a succinimide group.

To demonstrate the benefits of the polyether additives, various epoxy resin compositions were cured using the diglyzidyl ether of 4,4'-isopropylidene bisphenol with various known amine hardeners. Where appropriate, an accelerator was also added. Three drops of silicone oil were added to each batch to avoid the formation of bubbles and voids. After degassing under vacuum, the compositions were cured under the specified conditions. The cured products were subjected to the ASTM tests listed below.

ASTM D 256 ASTM D-790-66 ASTM D-638-64 T ASTM D-648-56 ASTM 2240-64 T ASTM D-903

Impact strength according to Izod Flexural strength and modulus of elasticity Tensile strength and elongation at break Heat deformation temperature Hardness and / or Shore D hardness Peel strength

example

3rd

4th

5

Parts by weight

Epoxy

(Eq. 190)

100

100

100

Harder ''

30th

29

30th

Accelerator 2)

10th

10th

10th

Polyether urea 3)

-

29

14

Tensile shear strength, bar 4)

Curing conditions

24 hours

98

112

161

48 h

70

154

231

72 h

98

168

210

96 h

98

217

259

7 days

105

227

273

72 h, 30 days5 '

112

203

238

72 h, 30 days6 '

126

245

266

Polyoxipropylidenediamine, MW 230 2) Piperazine-triethanolamine mixture (30:70)

3 'Product of Example I 41 Hardened at room temp.

5 5 'Submerged in water for the specified time after hardening

6) After hardening, the samples were placed in a weathering apparatus for the specified time; Cycle: full light, 18 min. Water spray / 2h.

io This example shows the improved bond strengths of the epoxy resin compositions when amounts of the polyether ureylene with terminal amino groups have been added to the polyoxypropylene diamine hardener.

15 Example 6-9

In these examples, epoxy resins were prepared in which glycidyl ether of 4,4'-isopropylidene bisphenol with a polyoxypropylene diamine having a molecular weight of 230 and an equivalent weight of 58, to which the specified amounts of the polyether succinimide of Example 2 had been added, were cured. The resulting resins were used to bond aluminum to aluminum and the resulting bonds were subjected to ASTM tests. The data, which should only be used for comparison purposes, are summarized in Ta-25 table 2.

Table II

Examples

The tensile shear strength according to ASTM D-1002-64 was determined on bonds. All substrates were aluminum plates (No. 2024-T-3 alloy, 16 gage), degreased, then etched with chromic acid and only then glued.

Example 3-5

In these examples, epoxy resins were prepared in which glycidyl ether of 4,4'-isopropylidene bisphenol was cured with a polyoxypropylene diamine having a molecular weight of 230 and an equivalent weight of 58 to which the indicated amounts of polyether urylene of Example 1 had been added. The resulting resins were used to bond aluminum to aluminum and the resulting bonds were subjected to ASTM tests. The data, which are intended for comparison purposes only, are summarized in Table 1.

Table I

100

100

100

100

30th

30th

30th

30th

10th

10th

10th

10th

0

75

14

29

87

270

288

232

1.37

1.82

4.18

6.91

30 composition (parts by weight)

Epoxy (eq. 190)

35 hardener accelerator polyether succinimide 2 '

Tensile shear strength, bar3 '

Peel strength kg / cm

40

^ Piperazine-triethanolamine mixture 2 'Product of Example 2

3 'curing conditions: room temperature, 7 days. These examples show the improved adhesive strengths of the 45 epoxy resin compositions when amounts of the polyether succinimide with terminal amino groups have been added to the polyoxypropylene diamine hardener.

Examples 10-13

so In these examples, the polyether-ureylene from Example I was added in different amounts of amine hardener systems. In these 4 examples a polyoxypropylene diamine with a molecular weight of 400 and an amine equivalent of 105 was used. The results are shown in Table 3.

Table III

Examples

composition

(W / part)

10th

11

12

13

Epoxy resin, (eq. 190)

100

100

100

100

Harder

28

49

54

55

Polyether-ureylene ^

250

49

13

0

Tensile shear strength, bar 2 '

21st

133

238

273

Product of Example 1 2> Hardened: 2 h at 80 ° C, 3 h at 125 ° C

632 285

These examples show that this additive is less effective in improving adhesive strength when used in resins whose polyether polyamine hardener has an equivalent weight above 70.

Example 14

This example shows the use of the additive according to Example II in connection with various amine hardeners. The composition is shown in Table 4.

Examples

18 19

20th

23

100 100

100

100

10 10

10th

10th

5

10th

20th

57 83

129

111

Table IV

Composition (parts by weight)

Example 14

Epoxy doctor (eq. 190) 100

Hardener 57

Additive 11 24

Accelerator 25 10

Appearance of the casting after hardening

24 h, room temperature 3 h, 125 ° C

Opaque, white Opaque, white r> Product of Example 1 2) Piperazine-triethanolamine mixture The opaque appearance of the castings after curing indicates improved adhesive properties.

Examples 15-17 In these examples, the polyether urea with terminal amino groups from Example 1 was added to an epoxy resin system containing a polyamidopolyamine (VERSAMID140) as a hardener. The properties of the cured products are shown in Table 5. These examples show the improvement in adhesive strength that the additive brings over the polyamidopolyamine alone.

Table V

Table VI

Composition (parts by weight)

5 epoxy resin, (eq. 190) triethylenetetramine polyether-ureylene, 15

Tensile shear strength, bar; OK with curing conditions

Product of Example 1 2) Hardened at room temp.

Example 24

In this example, a polyether-ureylene with terminal amino groups but lower molecular weight was used to demonstrate the surprising effect of the higher molecular weight material.

First, a material was prepared as in Example 1 to obtain a polyoxyalkylene material with ureylene bridges and terminal di-primary amino groups and a molecular weight of about 800.

This material was then incorporated into the resin as used in Example 4 2s. The resulting resin was poured into separate containers. One half was hardened at room temperature, the other half at elevated temperature. The results are shown in Table VII.

30th

Table VII

Composition (parts by weight)

Example 24

35

Epoxy resin, (eq. 190) additive

composition

Examples

(Parts by weight)

15

16

17th

Epoxy resin, (eq. 190)

100

100

100

Harder

40

40

40

Polyether-UreylenX)

-

5

10th

Accelerator 2)

10th

10th

10th

Tensile shear strength, bar

with curing conditions 3)

96

132

218

Product of example 1

2) Piperazine-alkanolamine mixture (30:70)

3) Hardened at room temperature

Examples 18-23

In these examples, the additive according to the invention from Example 1 was added to an epoxy resin system which was cured with triethylene tetramine at room temperature. For comparison, the same system was hardened under the same conditions, but without the addition of additives. The composition and properties of the cured resins are summarized in Table VI. The resins that contain the additive show significantly better adhesive properties.

100 14

Hardener 28

Appearance of the castings after curing for 24 h at room temperature clear 3 h at 125 ° C clear

40 The above example shows the lack of adhesive properties in the absence of the optical improvement.

Example 25

In this example, the additive from Example 1 was used in various

45 different quantities incorporated into an amine-hardened system. In the following experiment, a polyoxypropylene diamine with a molecular weight of 400 and an amine equivalent in about 70 was used. The results are shown in Table VIII.

50

Table VIII

Composition (parts by weight)

Example 25

55 epoxy resin, (eq. 190) 100 hardener 40

Polyether-ureylene2) 10 Appearance of the casting after hardening

24 h at room temp. opaque, white so 3 h at 125 ° C opaque, white

Polyoxypropylenetriamine 2) Product of Example 1

C.

Claims (8)

632 285 2nd PATENT CLAIMS 1. Process for the preparation of hardened epoxy resins with high adhesive strength, characterized in that a vicinal polyepoxide with an epoxy equivalent weight above 1.8 and a polyamine as hardener with an additive of the general formula 5 characterized in that a polyoxialkylene polyamine of the general formula III [NH2-NH (CH2) y - (CH-CHO) n] r-Z (III) [R-NH- (CH-CH-0) m-Z- (0-CH-CH) nNH] 2-X (I) Y H H Y 10th in which mean: X A or B, where A = CO or a residue of a difunctional isocyanate with two -N = CO groups and B the rest -HN-CH2-CO I> N- is ch2-co; Z is an alkylene radical with 2 to 5 carbon atoms; Y is H, methyl or ethyl; m and n are numbers such that the molecular weight of the additive is 4000 to 4500; and RH, a straight-chain or branched alkyl radical with 1 25 to 10 carbon atoms, a monocyclic aryl, alkaryl or aralkyl radical with 6 to 12 carbon atoms, a straight-chain or branched alkenyl or alkadienyl radical with 2 to 10 carbon atoms or a Aminoalkylamine radical of the formula -NH (CH2) pNH2, in which p is 2 or 3, are mixed and the mixture is hardened. 2. The method according to claim 1, characterized in that that in the mixture an additive of the general formula I, in which R is hydrogen, an alkyl radical having 1 to 4 carbon atoms or an amino-1,2-propylamine radical; Y is methyl and Z is 1,2-propylene 35 and m is n and a number from 16 to 19 is used. 3. The method according to any one of claims 1 or 2, characterized in that a curing accelerator or a mixture of accelerators, in particular an accelerator with at least 40 at least three reactive amino hydrogen atoms is used. 4. The method according to claim 3, characterized in that a polyepoxide, which consists of more than 80 wt .-% of a polyglycidyl ether of a polyhydric phenol; a polyoxyalkylene polyamine in an amount such that there are 0.8 to 1.2 amino equivalents per 1 epoxy equivalent; and a mixture of piperazine and an alkanolamine in a weight ratio of 1: 8 to 1: 1 are used as accelerators. 5. The method according to any one of claims 1 to 4, characterized in that a polyglycidyl ether of a 50 polyhydric phenol is used as the polyepoxide and a polyoxialkylene polyamine of an amine equivalent weight of 20 to 70 is used as the hardener. 6. The method according to any one of claims 1 to 5, characterized in that a polyoxialkylene polyamine of 55 general formula II Y H is used in which Y, Z, n and r have the same meaning as in formula II of claim 6 and y is 2 or 3. 8. The method according to any one of claims 3 to 7, characterized in that a diglycidyl ether of 4,4'-isopropylidene-bisphenol polyepoxide, a polyoxypropylene diamine having a molecular weight of 200 to 250, as an accelerator a mixture of piperazine and triethanolamine in a weight ratio of 3: 7 and an additive with a molecular weight of 4000 is used. 9. The method according to any one of claims 3 to 8, characterized in that the hardener is used in an amount so that for 1 epoxy equivalent of the polyepoxide is 1 amine equivalent, the accelerator in an amount of 1 to 5 parts by weight per 100 parts by weight of polyepoxide and the additive is used in an amount of 5 to 40 parts by weight per 100 parts by weight of polyepoxide. [H2N- (CH-CHO) n] r-Z (II) I I Y H is used, in which mean: Y H, methyl or ethyl Z is a hydrocarbon radical with 2 to 5 carbon atoms, which 2 to 4 external ether bridges form n a number from 1 to 15 and r a number from 2 to 4.