DE2748705C2 - Additives for amine curable epoxy resin compositions - Google Patents

Description

in which:

X A or B,

where A —C = O or a radical of a difunctional isocyanate with two —N = C = O groups and is B the rest

-HN-CH ₂ -CO

N -
CH ₂ -CO

is;

Z is an alkylene radical having 2 to 5 carbon atoms;

Y H. Methyl or Ethyl:

/ n and η such numbers that the molecular weight of the additive is 4000 to 4500: and R H. is a straight-chain or branched alkyl radical with I to IOC atoms, a monocyclic aryl, alkaryl or aralkyl radical with 6 to 12 carbon atoms, a straight-chain or branched alkenyl or aikadienyl radical with 2 to. 10 carbon atoms or an aminoalkyiamine radical of the formula

-NH (CH ₂ ) ,, NH ₂ .

in which ρ is 2 or 3.
35

2. Additive according to claim 1, characterized in that in dor general formula I of claim 1 R, H, an alkyl having 1 to 4 carbon atoms or aminopropylamine; Y is methyl and Z is 1,2-propylene and m is π and is a number from 16 to 19.

3. Use of the additive according to claim 1 or 2 for 1 setting of cured epoxy resins.

The invention relates to additives for amine-curable epoxy resin compositions and their additives Use for the production of cured epoxy resins with improved adhesive strength.

Epoxy resins are a large class of polymeric materials that encompass a wide range of properties. the Resins are characterized by epoxy groups that react with certain catalysts or hardeners are curable into cured epoxy resin compositions having certain desired properties. The amines are one such class of hardeners. The amines most frequently used as hardeners are aliphatic Amines, such as diethyleneamine. Triethyl tetramine and / or poly (alkyl) alkyl polyamines such as polyoxypropylenediamines and triamines.

Epoxy resins with improved mechanical properties are made by using polyoxyalkylene polyamines, in particular polyoxialkylenediamines obtained as hardeners. It is common in such epoxy resin compositions additional hardeners, as described in US-PS 35 49 592, to use.

It is known from aliphatic or aromatic amines and / or white-basic acids or anhydrides

To form oligomers, see US-PS 37 32 189. Furthermore, diamines with maleimides or anhydrides were too

Implemented elastomers, see US-PS 28 18 405. Even thermosetting raw materials are made of epoxides and bc-

W) correct N-containing compounds with terminal carboxyl groups have been prepared, see US-PS 84 373.

Also known as epoxy hardeners or additional hardeners are various ureas and substituted ones Ureas. In this context, reference is made to US patents 32 94 749, 27 13 569, 33 86 956, 33 86 955, 55 372 and 36 39 338 are referred to. The urea compounds disclosed in these patents are as b5 hardener and hardening accelerator suitable.

The invention is based on the object of creating an additive for epoxy resins curable with amine that can cured products with significantly improved bond strength and shear strength.

The task is crfindiingsgemaß closed by an additive for amine-curable epoxy resin / composite

tongues, which is characterized by the general formula I.

r-nh- (ch-ch-o \ -z- (o-ch-ch \ nh -x

h L Ui].

in which:

X A or B,

where A = CO or a radical of a difunctional isocyanate with two - N = ■ · C = O groups and B the rest

-HN-CH ₂ -CO

N— is

CH ₂ -CO

Z is an alkylene group having 2 to 5 carbon atoms;

Y H, methyl otk-r ethyl;

m and η are numbers such that the molecular weight of the additive is 4,000 to 4,500; and

R is hydrogen, a straight-chain or branched alkyl radical with 1 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 an aminoalkylamine radical of the formula

-NH (CH ₂ ) p NH ₂ ,
in which ρ is 2 or 3.

The additives according to the invention can be referred to as polyoxyalkylenes with terminal amino groups and, if IX = A in the general formula, with an ureyl bridge. or when X = B. with a succinimide bridge. For the sake of brevity, the term polyether-ureylene or polyether-succinimide is used for the sake of brevity second hand.

It was surprisingly found. iden. that the incorporation of these compounds as additives in epoxy resin js compositions results in cured products with improved shear strength and bond strength. links similar type with lower molecular weight do not bring this effect. The with the invention Additive hardened resins are used as overriding, casting, seals and especially as adhesives suitable.

The adhesive strength (Klcbe property) of amine-hardened epoxy resins is made effective by adding an Amount of a polyether according to the invention with terminal amino groups and ureylene or succinimide bridges and a molecular weight of 4,000 to 4,500 is greatly improved. The terminal amino groups can be primary or secondary.

Preference is given to diglycidyl ethers of 4,4'-isopropylidene bisphenol. an amount sufficient to harden a primary amino group-bearing hardener consisting essentially of a polyoxypropylene polyamine with a molecular weight of about 200 to 500, a pipcrazine alkanolamine accelerator and a effective amount of the additive according to the invention mixed together and cured.

A polyepoxide, an amine hardener, a polyether with terminal amino groups and a ureylene or succinimide bridge and, if desired, an accelerator carefully mixed according to conventional methods Methods to be hardened. Cured products with surprisingly high adhesive strength are then obtained.

According to one embodiment of the invention, a diglycidyl ether of 4,4'-isopropylidene-bisphenol with an effective amount of a hardener and the inventive additive, namely a polyether ureylene or succinimides with terminal amino groups and a molecular weight of 4000 mixed with one another and hardened. The preferred polyether-ureylene can be obtained by reacting 2 moles of polyoxypropylenediamine a molecular weight of 2000 with one mole of urea, and the polyether succinimide by reaction 2 moles of the polyoxypropylene diamine can be prepared with one mole of maleic anhydride. A Polyoxypropylene polyamine having a molecular weight of 200 to 500 can be added as an additional hardener will.

The cured epoxy resins are preferably produced in 3 stages: In the 1st stage, the additive is produced. To this end, 2.0 mol of a polyoxypropylenepolyamine with a molecular weight of 2000, which is w) essentially polyoxypropylenediamine, are placed in a suitable reaction vessel. Then I mol of urea or maleic anhydride are added. The mixture is then gradually heated, with the addition of urea to 180 to 200 ° C. and the temperature is maintained until the evolution of ammonia ceases. If one has added maleic anhydride is heated to 140 to 170 ⁰ C steps until the azeotropc Wasscrentfernung terminated. The reaction mixture is then stripped at 120 to 150 "C or 170 to 190" C (the latter in the case of the polyether-succinimide synthesis at 1.33 mbar and a viscous liquid wedge is obtained.

In the 2nd stage, the viscous liquid of stage I is treated with a polyoxypropylenediamine of one molecular weight from 200 to 250 mixed in a ratio of 5: I to I: 5. If desired, an im

Commercially available accelerators can be added.

A suitable amount of a diglycidyl ether of 4,4'-isopropylidenebisphenol is added to the mixture of stage 2 in stage 3 added so that the amine equivalents are equal to the epoxy equivalents. The epoxy resin and the Hardener mix are mixed carefully; about 3 drops of a liquid silicone are added, to avoid the formation of bubbles and voids. The resulting composition is after 2 to Vacuum degassing for 5 minutes applied to the substrates to be bonded or in molds poured. The resins are cured at room temperature and preferably post-cured at 80 to 125 ° C. The cured products have improved shear strength, flexural strength, elongation at break and in particular improved adhesion to the substrate.

ο In the uncommon are the compositions which contain vicinalc polyepoxides and which are cured with amine organic materials with an average of at least 1.8 reactive 1,2-epoxy groups in the molecule. These polyepoxides can be monomeric or polymeric, saturated or unsaturated aliphatic, cycloaliphatic, be aromatic or heterocyclic compounds which, in addition to the epoxy groups, seek others Substituents such as hydroxyl, ether residues. aromatic halogen and the like. Preferred polyepoxides are those of glycidyl ethers, prepared by epoxidizing the corresponding Allyl ether or in a manner known per se by reacting a molar excess of epichlorohydrin with an aromatic polyhydroxy compound. / "B. Isopropylidene-bisphenol, novolak or resorcinol. The epoxy derivatives of methylene and isopropylidene bisphenol are preferred. To the for the invention Process suitable polyepoxides include the resinous epoxy polyethers. which are produced by the conversion of an epihalohydrin, like epichlorohydrin. with either a polyhydric phenol or a polyhydric alcohol can be obtained. Examples are: 4.4'-Isopropylidcn-bisphenol. 2.4'-dihydrate «jiphenylethylmelhan, 33'-Dihydroxidiphenyl-diethylmeιhan. S.-T-Dihydroxidiphenyimethyipropyimeihan, 2, γ-Dihydroxiuipheny'iäthylphenylmethan. 4,4'-Dihydroxiaiphenylpropylphc-nylmethane, 4,4'-Dihydroxidiphenylbutylbutylenephenylmethan, 2.2'-Dihydroxidiphenylditolylmethane and 4.4'-Dihydroxidiphcnγllolylmethylπlethan. Other polyhydric phenols, which can be reacted in particular with an epihalohydrin are, for. B. resorcinol. Hydroquinone and substituted hydroquinones, e.g. B. methyl hydroquinone.

Among the polyhydric alcohols that combine with an epihalohydrin to form the resinous epoxy polyethers Lead include compounds like ethylene glycol. Propylene glycols, butylene glycols, pentanediols, bis (4-hydroxicyclohexyl) dimethyl methane, 1,4-dimethylol-benzene, glycerine, 1,2,6-hexanetriol, trimethylolpropane, mannitol, Sorbitol, erythritol. Pentaerythritol, their öimcren.Trimeren and higher polymers, e.g. B. polyethylene glycols, polypropylene glycols, Triglycerin and dipentaerythritol, polyallyl alcohol, polyhydroxy thioether, such as 2,2'-, 3,3'-tetrahydroxidipropyl sulfide, Mercapto alcohols such as monothioglycerin and dithioglycerin. Partial esters of polyvalent ones Alcohols such as monostearin and pentaerythritol monoacetate and halogenated polyhydric alcohols such as Monochlorohydrins of glycerin, sorbitol and pentaerythritol.

Another class of polymeric polyepoxides. which can be cured with amine and for the inventive Processes are suitable are the epoxy novolak resins. by implementation, preferably in Presence of a basic catalyst, e.g. B. sodium or potassium hydroxide, an epihalohydrin. how Epichlorohydrin, with the resinous condensation product of an aldehyde, / .. B. formaldehyde, and either a monohydric phenol. e.g. phenol itself or a phenol with several hydroxyl groups turn around. Further details on the nature and formation of F.poxi-Novokikharzcn can be found in the Handbook of Epoxy Resons by Lee and Neville. McGraw Hill Book Co .. I9b7.

For the person skilled in the art, it goes without saying that other polyepoxide compositions are also used can be.

The additives according to the invention can generally be used as polyoxyalkylene-containing materials with a ureylene bridge or a succinimkl bridge. terminal amino groups and a molecular weight of 4000 to 4500 are described. In the general formula I of the additives according to the invention, R preferably has when it denotes a branched or straight-chain alkyl radical. 1 to 6 carbon atoms; when it is a monocyclic aryl, alkaryl or aralkyl radical. b to 8 carbon atoms: or if it is a branched or straight-chain alkenyl or alkadienyl resl. 3 to 8 carbon atoms.

The additives according to the general formula I in which R is an alkyl radical having 1 to 4 carbon atoms or an amino-1,2-propyl;! Minrcst are very particularly preferred. in particular hydrogen, Y is a methyl radical. Z is a 1,2-propyne residue and m and η are the same numbers from 16 to 19 ;;;) and η are of course average values. The preferred polyether acrylics are those in which X = C = O.

The polyether Ureylcnc with terminal primary amino groups are prepared by reacting a compound having a Ureylenbildenden Polyoxialkylcndiainin a molecular weight of 1800 and 2200 at 100 to 200 ⁰ C, wherein the molar ratio of IJreylen-bildendcr connection to Polyoxialkylendiamin I: 2.

The polyether succinimides with terminal primary amino groups are made by reacting maleic anhydride with a Polyoxialkylcndiainin a molecular weight of 1800 to 2200 in 2 stages hcrgcwi represents. First, the reactants are run at a lower temperature, i.e. H. Room temperature, mixed and then that Crude product obtained from 120 to 180 "C / .l. The water being removed with one mole of maleic anhydride.

The diamines which are suitable for the production of the additives are l \> lyoxialkylenedian> ii) e of the general Formula IV:

H ₂ N- / CH-CH-O

Y H

-Z

in which: Y is hydrogen, methyl or ethyl; Z is a hydrocarbon radical with 2 to 5 carbon atoms and π has an average value of 12 to 20. The preferred polyoxyalkylenediamines are those in which Y is a methyl radical. η 16 to 18 and Z is a 1,2-propyl radical. These polyoxyalkylene polyamines can be prepared by known methods, as they /. B. in the US-PiHentschriften i2 2b 895 and 36 54 370 are described. <-,,

The polyether-ureylenes can be obtained by reacting a polyoxyalkylene polyamine with alkylene radicals with 2 up to 4 carbon atoms, with urea, a ureylene-forming compound or organic bifunctional isocyanates getting produced. Hanistoff is preferred. If urea is used as Reaktani, the Reaction with evolution of ammonia and the terminal primary amino group of the polyoxialkylenepolyamine is transformed into a ureido gnippe. The functionality of the polyoxyalkylene polyamine depends on the number of terminal primary amino groups. Since urea itself is bifunctional, any molecule can Urea react with 2 terminal amino groups of the polyoxialkylenepolyamine.

Although urea is the preferred Rcaktuni. Other urea bicarbonate compounds can also be used the bridging remainder

- C - Il ο

to deliver. Since the polyoxyalkylenepolyamine already contains terminal primary amino groups, compounds can such as carbonyldiimidazole, phosgene or diphenyl carbonate as a -C supplier for the formation of urcylene bridges can be used without splitting off ammonia.

Another class of Polyäther-Urcylenes is made by reacting Polyoxialkylenpolyaminen with a bifunctional organic isocyanate. z. B. prepared by phosgenation of the condensation product of aniline and formaldehyde. Suitable compounds are 4,4'-diphenyl methane diisocyanate or its isomers, such as 2,4'-diphenyl methylene isocyanate and mixtures of these isomers.

The polyether succinimides are produced by reacting a polyoxyalkylene polyamine with alkylene radicals with 2 to 4 carbon atoms with maleic anhydride. The reaction v. runs down, releasing water, and a terminal primary amino group of the polyoxialkylenepolyamine converts to a succinimide group. The maleic anhydride has a bifunctional effect. the ethylene unsaturation with the terminal amino group linking pe of another polyoxyalkylenediamine.

Polyether-ureylenes or -succinimides with terminal secondary amino groups are preferred obtained by reductive amination of the compounds with terminal primary amino groups.

The reductive animation of primary amines with aldehydes and ketones on standard hydrogenation / dehydrogenation catalysts is known and does not need to be explained in more detail here. Another method for i> the production of compounds with secondary amino groups includes the use of organo-halogenvcrbindun ^tf cr! a. This method is not used before / u ***; ^w cil / uvio! Ncbcnrciiktioncn take place.

Polyether-ureylenes or -succinimides with terminal aminoalkylamine residues can be obtained by cyanoalkylation of polyethers with terminal primary amino groups and subsequent hydrogenation of the cyanoaikyliertcn Make connections. The preparation of cyanoalkylated adducts is described in US Pat. No. 3,666,788 described. The hydrogenation takes place according to a conventional method on a standard hydrogenation / dehydrogenation Catalyst.

The polyether ureals and succinimides with terminal primary amino groups can be used alone as amine hardeners act. So these compounds exercise both the function of an amine hardener and that of an additive, which increases the adhesive strength. However, it is preferred to have these additives besides terminal primary amino groups the epoxy resin compositions nor a common amine hardener <

admit it. C.

All amines customary for curing vicinal epoxides can be used as amine hardeners. I.

In general, hardeners with at least 2 reactive amino groups are suitable. Examples of such amines s

are alkylenepolyamines such as diethylenetrianine and triethylenetetramine; Oxyalkylene polyamines. like Polyoxipropy- 50 '■>

len-di- and -triamir; and diamino derivatives of ethylene glycol such as I, U-diamino ^ J.lO-trioxatridecane.

In addition, aromatic amines are suitable as hardeners. Examples of this are those having alkylene bridges Polyphenylamines. Phenylenediamines and polycyclic or condensed aromatic ring systems with primary Amino groups. The corresponding cycloaliphatic compounds can also be used.

Polyamide hardeners, such as the condensation products of polyamines and polycarboxylic acids, are also suitable. The condensation product of a polyamine and a dimerized acidic acid is disclosed as an example in US-PS 23 79 413. used.

Of the amine hardeners that are suitable for hardening vicinal epoxy resins, according to the invention the polyoxialkyleneamines of the general formula II below are preferred:

H ₂ N-

—Z

in the YH, Methy! or ethyl, Z is a hydrocarbon radical with 2 to 5 carbon atoms which forms 2 to 4 external ether bridges, η is a number from 1 to 15 and a pure number from 2 to 4. Most preferred are the polyoxypropylenediamines, where in the formula II Y is methyl, 7? is a number from 1 to 10, Z is 1,2-propylene and rl . The preparation of these compounds is described in US Patents 3,236,895 and 3,654,370.

A polyoxypropylenediamine with a molecular weight of 230 is very particularly preferred.

Another preferred class of polyoxyalkylene polyamines can be represented by the following general Formula Hl can be reproduced:

/ OCH - H

—Z

in which Y, Z, π and r have the same meaning as in formula II and ρ is 2 or 3. This poly (aminoalkylami- jj.j

no) polyethers are the hydrogenation products of the cyanoalkylicrten adduct of a polyoxialkylenepolyamine such as ßj

described above. The preparation of these adducts is described in US Pat. No. 3,666,788. Preferred are \ |,

the hydrogenated cyanoethylated polyoxypropyl triamines. ^

If desired, the epoxy resin compositions can also contain an accelerator which

Amine curing of the epoxy resin is accelerated, especially at room temperature. Such acceleration is at jj

Advantageous for some applications, especially when an epoxy resin is applied as an adhesive in a flammable environment, because increased hardening temperatures are unsuitable, if not dangerous would do. In the Handbook of Epoxy Resins already quoted above, on pages 7 to 14 the; | Aminhaliiger use of certain compounds as described lläriungsbeschleunigcr for Epoxiharzzusammenset-% / Ungen. £

Many accelerators are known which are used together with the additives according to the invention M can. Examples are salts of phenols. Salicylic acid. Amine salts of fatty acids as described in U.S. Patent J 26 81 901, and tertiary amines, as described in US Pat. No. 28, W480. The one in the | 'j is preferred U.S. Patent 3,875,072 disclosed accelerators. It is a mixture of piperazine and an alkanolamine in the;! Weight ratio from 1: 8 to -1: 1. ■ ,:

: s The adhesive strength of the known amine-cured epoxy resins is f by adding an effective amount of a polyether increases {Ureylens invention or -Succinimids having terminal amino groups and a molecular weight fi 4000-4500.. The amount of additive that is needed. to increase the adhesive strength, jfj is to be determined empirically and depends on the resin, the use of an amine hardener and the use § <! an accelerator. In general, the amine-terminated polyether is used as a hardener / jj! J

To serve as an additive, used in an approximately stoehiometric amount. ? - ■

In connection with other known amine hardeners, the additive according to the invention is preferably used in? |

Quantities of 5-40 parts by weight, based on 100 parts by weight of resin, are used. Whether alone or with an amine; |

Harder used, the exact amount of additive that is required can be easily g

determined empirically due to the fact that a resin mixture containing an effective amount of the additive -M

contains changes that become even more noticeable when hardened. The curable resin occupies a £; opaque milky-white appearance, which becomes even stronger on curing and results in a product with a glossy % white appearance. This change in optical absorption enhances the beauty of castings and eliminates the need for white pigments or fillers.

The ratio of additive and hardener to resin can easily be determined on an equivalence basis. The equivalence determination should also include the functional groups of the accelerator. The required amount can be calculated by adding the number of equivalents on a weight basis per replaceable HN group in the amine hardener. the additive and. if used, the accelerator. Based on this calculation, a mixture of a polyoxyalkylenedianiine hardener, additive and accelerator in 10% excess the required sioichiometric amount, based on the resin, is used. According to a preferred embodiment the adhesive properties of a known epoxy resin composition of an epoxy equivalent are used over 1.8 by adding an effective amount of a polyoxypropylene ureylene or succinimide with terminal ends Amino groups obtained by condensation of one mole of urea or one mole of maleic anhydride with 2 moles of a polyoxypropylenediamine having a molecular weight of 2000. Preferred resin compositions are polyglycidyl ethers of polyphenols. by incorporating a sufficient for hardening Amount of a polyoxyalkylene polyamine of molecular weight from 200 to 500 and an accelerator combination are hardened from piperazine and an alkanolamine in a Gcwichlsrelatio of 1: 8 to 1: 1. Preferred known compositions whose adhesive strength is increased by the additives according to the invention are disclosed in US Pat. No. 3,943,104.

The curable epoxy resin compositions contain a vicinal polyepoxide of epoxy equivalent weight above 1.8, an amount of amine hardener sufficient to cure, an effective amount of that of the present invention Additive and an accelerator. Although all epoxy resins specified herein are suitable for this process are, those based on aliphatic compounds are preferably not used alone. the Presence of resins containing polyglycidyl ethers of polyhydric phenols in amounts above 50, preferably 80% by weight, in particular resins, which are 100% polyglycidyl ethers of polyhydric phenols

on exist, improve the desired properties of the cured products, in particular the adhesive strength.

In the same way, all amine hardeners can be used in the process according to the invention. It is

but it has been found that Har / .e with hard, in which, unlike the additives according to the invention, the amino groups are separated from one another by long aliphatic or oxyalkylene moieties, are viscous and heavy are to be processed and cure in the presence of the additive according to the invention to form products that do not

hi desired high! iaftfcstigketi have. The exact reason for this is not known, but it is believed that this is related to the compatibility of the ingredients. So show z. B. Resins with Polyoxypropylenediamine having a molecular weight of 400 in the absence of otherwise effective amounts of the invention Additive cured does not provide a significant improvement in bond strength.

Because of the greater economy and better handleability, such amines are preferred, their Molecular weight is below 500. Preferred amine hardeners are polyamines having an amine equivalent weight of 20 to 150, in particular 20 to 70. Examples of such hardeners are polyoxypropylenediamine of one molecular weight in the range from 200 to 300 and polyoxypropylene polydiamines having a molecular weight in the range of 400 up to 700. ■ -,

Unsuitable amine hardeners can be quickly identified by a person skilled in the art, since these hardeners are not effective bring visual improvement.

The amine-attached resins with improved adhesive strength are produced in a conventional manner. When a Amine hardener is used in addition to the additive, the mixture with the polyepoxy composition in the amine equivalent weight of the mixture together in an amount corresponding to the amine equivalent weight of the mixture. In general, the Number of equivalents of amino groups 0.8 to 1.2 times the number of epoxy equivalents in the curable Epoxy resin composition, with a stoichiometric amount being preferred. If an accelerator is used, amounts of 1 to 10 parts by weight, based on 100 parts by weight of resin, are generally sufficient. The exact amount of the ingredients depends primarily on the purpose for which the cured resin is being used is determined.

When the additive of the present invention is used alone, it is mixed into the uncured resin. If a hardener is also used, it is preferable to mix the additive first with the hardener or the hardener-accelerator mixture. before working it into the resin. The ingredients that make the curable Forming material are intimately mixed with one another according to the usual methods and in the presence more usual Defoamer degassed by adding small amounts of silicone oil to prevent the formation of bubbles and voids men to avoid.

If an accelerator is used, it is preferred that the mixture of piperazine and Is alkanolamine in a weight ratio of 1: 8 to 1: 1. It is preferably used in an amount from 1 to 5 parts by weight per 100 parts of resin incorporated. The accelerator is hardened with a polyoxyalkylenediamine mixed, with 100 parts by weight of the hardener for every 10 to 50 parts by weight of accelerator. : =>

As already said, it can be sufficient to use the additive according to the invention as the only hardener. Preferably but it is used in conjunction with a common amine hardener for epoxy resins, as described above are listed. Polyoxialkylenedianiine of the type described above, which have an amine equivalent from 20 to 70, preferably from 40 to 70, are preferred as additional hardeners. It has been found that ratios of polyether ureylene or succinimide to amine hardener, possibly including additional hardener from 5: 1 to 1: 5 epoxy resins with considerably improved properties, e.g. B. Shear strength wedge, flexural strength, Give elongation at break and especially adhesive strength.

The mixture of epoxy resin, polyoxyalkylene polyamine, additive and accelerator combination of piperazine and alkanolamine is generally allowed to cure itself at room temperature (between 0 and 45 ° C.). One Post-curing at elevated temperatures of up to 135 ° C has proven to be beneficial.

According to a preferred embodiment of the invention, a diglycidyl ether of 4,4'-isopropylidon-bisphenol is used. an amount sufficient to cure a primary amino group-containing hardener which consists essentially of a polyoxypropylenediamine having a molecular weight of 200 to 250, one Accelerator of piperazine and triethanolamine in a weight ratio of 3: 7 and an effective amount of one Additive with terminal amino groups and a molecular weight of 4000 mixed and cured.

According to a preferred embodiment, polyglycidyl ethers of polyhydric phenols are through Incorporation of a polyoxyethylene polyamine with a molecular weight of 230 in one up to stoichiometric Amount, 5 to 30 parts by weight of an additive according to the invention and 1 to 5% by weight, based on 100 parts by weight Resin, an accelerator mixture of piperazine and triethanolamine (3: 7) hardened. The hardening takes place at Room temperature instead of, and one obtains products with improved adhesive strength.

Other conventional additives can of course also be incorporated into the composition prior to curing will. So it can be B. in certain cases it may be useful to use small amounts of other polyalkyleneamines than additional hardeners, as described above, or hardeners together with various other accelerators and to add known curing systems.

It is also possible to add the usual pigments, fillers and flame retardants that are compatible with the other components of the composition are compatible, as well as natural and synthetic resins.

Although not preferred, the solvents known for polyepoxides can also be used, such as toluene, benzene, xylene, dioxane and ethylene glycol monomethyl ether. The polyepoxy resins which the invention Containing additives can be used wherever polyepoxides have been used up to now Has. A particular feature of the compositions is that after curing they become opaque and one have a smooth white glossy surface, which is particularly advantageous for moldings and castings. the Compositions obtained according to the invention can be used for impregnation, surface coating, for Encapsulate, laminate and mostly used as an adhesive for metal / metal.

B is ρ ie I 1 _M

Production of a polyether-ureylene with terminal amino groups according to the invention

Into a suitable reaction vessel equipped with a stirrer. 28.5 kg (0.032 Mo!) of a polyoxypropylenediamine (POPPA) (molecular weight 2000 and 1.0 milliequivaient (meq.) primary amine / g) and b => 0.45 kg (0.016 mol) urea were added. The mixture was purged with nitrogen and placed under a nitrogen blanket

kc stirred while gradually heating to 183 ° C. This mixing temperature was maintained until the

Ammonia evolution ceased. The resulting crude reaction product was then stirred at 15O ⁰ C and I

Stripped i, 33 mbar and obtained a viscous liquid. This product was then through a Filie.tuch filtered. The analysis showed: 1.57% N, 0.53 meq total amine / g, 0.52 mcq primary amine / g, 0.10% water.

Example 2

Production of a polyether suecinimicl according to the invention with terminal amino groups

In a suitable, clean, dry reaction vessel equipped with a stirrer, thermometer, reflux tank and Dean-Stark-Fallc was given away, 750 g (0.39 mol) ΙΌΡΡΑ 2000, 18.4 g (0.183 mol) maleic anhydride

ίο and given 50 g of benzene. This mixture was heated under reflux (vessel temperature 146 to 167 ° C.) for about 2 ¹ A ₁ or until the azeotropic removal of the water (2.3 g of water) was complete. Then, the benzene from the crude Reakiionsgcmisch removed was until the Gefäßtempcrattir ⁿ 205 C. The remaining reaction product was then stripped at 180 ° C. and 3.99 nibar and a viscous residue was obtained, the analysis of which showed: 0.64 meq total amine / g, 0.43 mcc | primary amine / g, 0.009 meq acidity / g The IR analysis showed the presence of a succinimide group.

In order to show the advantages of the polyether additives according to the invention / ti, various epoxy resin compositions using the diglycidyl ether of 4,4'-Isopropyliclcnbisphnols with various known amine hardeners. An accelerator was also added where appropriate. Three Drops of silicone oil were added to each batch to avoid the formation of bubbles and voids.

;> (> After degassing under vacuum wutucii the ZusiuniuciiSci / .iiMguM linier the specified conditions hardened. The cured products were subjected to the ASTM tests listed below:

ASTM D 256 Izod impact strength

ASTM D-790-66 Flexural Strength and Young's Modulus

ASTM D-638-64 T Tensile Strength and Elongation at Break

ASTM D-648-56 Thermal Deformation Temperature

ASTM 2240-64 T hardness and / or Shore D hardness

ASTM D-903 Peel Strength

The tensile strength according to ASTM D-1002-64 was determined on bonds. All substrates were Aluminum plates (No. 2024-T-3 alloy, 406 μm), degreased, then etched with chromic acid and only then glued.

Application examples 1–3

In these examples, epoxy resins were prepared in which glycidyl ethers of 4,4'-isopropylidenebisphenol with a polyoxypropylenediamine having a molecular weight of 230 and an equivalent weight of 58 to which the specified amounts of Polyülher-Ureylen of the example! had been added, were cured. The resulting resins have been used to bond aluminum to aluminum, and the resulting Bondings subject to ASTM-Tcsts. The data, which should only be used for comparison purposes, are in Table I compiled.

Table I.

Composition (parts by weight) Application examples

Epoxy (eq. 190) 100 100 100

so hardener ¹ ) 30 29 30

Accelerator ² ) 10 10 10

Polyether-ureylene ³ ) - 29 14 Tensile shear strength, bar
Curing conditions ⁴ )

24 h 98 112 161

48 h 70 154 231

72 h 98 168 210

96 h 98 217 259

7 days 105 227 273

"O 72 hours, 30 days ⁵ ) 112 203 238

72 hours, 30 days ⁶ ) 126 245 266

') Polyoxipropyüdendianiin. MG 230.
² ) Piperazine-triethanolamine mixture (30:70).
^! ) Product of Example I.
^b5 ') Cured at room temperature.

') Immersed in water for the specified time after hardening.

") After hardening, the specimens were placed in a weathering apparatus for the specified time: 2-Sümdcn cycle: full Light. Spray with water for 18 min.

This example! shows the improved adhesive strengths of the epoxy resin compositions. if quantities of the Polyether-ureylenes with terminal amino groups have been added to the polyoxypropylenediamine hardener are.

Application Examples 4-7

In these examples, epoxy resins were prepared in which glycidyl ethers of 4,4'-l.sopropylidenebisphenol with a polyoxypropylenediamine having a molecular weight of 230 and an equivalent weight of 58, those the specified amounts of polyether succinimide of Example 2 had been added, were cured. the The resulting resins have been used to bond aluminum to aluminum, and the resulting Displacements subjected to ASTM tests. The data, which are only intended for comparison purposes, are in Table II compiled

Table II

Composition (parts by weight) Application examples 5 b 7th 4th 100 100 100 Epoxy (eq. 190) 100 30th 30th 30th Harder 30th 10 10 10 Accelerator ¹ ) 10 75 14th 29 Polyether succinimide ² ) 0 270 288 232 Tensile strength, bar ³ ) 87 1.82 4.18 6.91 Peel strength kg / cm U7

') Piperazine-triethanolamine-Gemiseh (30:70).

² J product of example 2.

-) Curing conditions: room temperature. 7 days.

These examples demonstrate the improved bond strengths of the epoxy resin compositions. if quantities of the polyether succinimide with terminal amino groups added to the polyoxypropylenediamine hardener have been.

Application examples 8-11

In these examples, the polyether-ureylene from Example 1 was used in various amounts of amine hardener systems admitted. In these 4 examples, a polyoxypropylenediamine having a molecular weight of 400 was used and an amine equivalent of 105 is used. The results are shown in Table III.

Table u

Composition (wt. TIc.)

Application example
8 9

10

Epoxy resin (Aq. 190) hardener

Polyether Ureylon ¹ ) Tensile seer strength, bar

100 100 100 100 28 49 54 55 250 49 13th -0- 21 133 238 273

') Product of Example 1.

- ') hardness: 2 h at 80 ⁰ C.3 h at I25 "C.

These examples show that this additive is less effective in improving oil strength. if it is used in a resin whose polyether-polyamide-hardener has an equivalent weight of over 70.

Application example 12

This example shows the use of the additive according to Example 2 in connection with various amine hardeners. The composition is shown in Table IV.

27 48 705 APPLICATION EXAMPLE 12 Table IV 100 Composition (parts by weight) 57 Epoxy resin (eq. 190) 24 Harder 10 Additive ¹ ) Accelerator ² ) opaque, white Appearance of the casting after Hardening opaque, white 24 h, room temperature 3h.l25 ° C

') Product of the example

² ) Piperazine-triethanolamine mixture po: 70).

The opaque appearance of the castings after curing indicates improved adhesive properties.

Application examples 13-15

In these examples, the amino-terminated polyether-ureylene from Example 1 was one Epoxy resin system added, which contained a polyamido polyamine (VERSAMiD 140) as a hardener. The properties Table V shows the cured products. These examples show the improvement in Adhesion strength that the additive brings to the polyamido polyamine alone.

Table V Composition (wt. TIc.)

Application games 13th

14th

15th

Epoxy resin (Aq. 190) 100 Harder 40 Polyether-ureylene ') - Accelerator ² ) 10 Tensile shear strength, bar under hardening conditions') 96 ') Product of Example 1. ² ) Piperazine-alkanolamine mixture (30:70). ^J ) Cured at room temperature.

100

40

10

132

100 40 10 10

218

Application examples 16-19

In these examples, the additive according to the invention from Example I was added to an epoxy resin system.

45 which was cured with Triälhylenieiramin at room temperature. For comparison, the same system was used below the same conditions but without the additive / usat /. hardened. The composition and properties of the

cured resins are summarized in Table VI. The har / e. which contain the additive show clearly

better adhesion properties.

Table Vl Composition (wt. TIc)

Application areas Ib 17

18th

Epoxy resin (eq. 190) triethylenetetramine polyether-ureylene ¹ ) Z-ug shear strength, bar under curing conditions ² )

') Product of the example ■') Hardened by Kaumicmp.

100 10

57

100

10

83

100
10
10

129

Application example 20

In this example, a polyether-ureylene terminated with amino groups but with lower molecular weight used, the surprising effect of the material of higher molecular weight increases significantly do.

First, a material was prepared as in Example 1 to be a polyoxyalkylene material with Lireylene 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 Application Example 2. That resulting resin was poured into separate containers. One half was at room temperature, the other half hardened at elevated temperature. The results can be found in Table VH. 5

Table VII

Composition (wt. TIc.) Application example 20

Epoxy resin (Aq. 190) 100

Additive 14

Hardener 28
Appearance of the castings after hardening

Clear for 24 h at room temperature 15

Clear for 3 h at 125 ° C

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

Application example 21

In this example, the additive from Example I was used in various amounts in an amine-hardened system incorporated. In the following experiment, a polyoxypropylenediamine with a molecular weight of 400 and of an amine equivalent in about 70 is used. The results are shown in Table VI II. 25th

Table VIII

Composition (parts by weight) Application example 21

- ^

Epoxy resin (Aq. 190) 100

Hardener ¹ ) 40

Polyether UreyJen ² ) 10
Appearance of the Gieöling

after hardening 35

24 h at room temp. opaque, white

3hbeil25 ° C opaque, white

') Polyoxypropylene diamine.

² ) Product of Example I. 40

Claims (1)

Patent claims: 1. Additive for epoxy resin compositions curable with amine, characterized by the general formula I.
5 IR_NH- / CH-CH-O \ -Z-fO-CH-CH \ nh1-X Μ LI α η L