DE2505368C2 - - Google Patents

Description

Cold-curable mixtures of epoxy resins and amines or Polyamides containing amino groups have long been found in the Construction industry as paints, coverings, mortar, glue, injection agents and use for impregnation.

The hardening time of these mixtures, that is, the time required for full Development of usage properties is required is temperature dependent. In general, the hardening reaction proceeds Temperatures below about 8 ° C so slowly that these mixtures can no longer be used.

It has already been suggested that such curable mixtures be compounds add that accelerate the hardening reaction.

The disadvantage of this is that the accelerators involved in the curing reaction not be consumed, the performance characteristics of the hardened Mixtures, e.g. B. the surface hardness, the resistance to the action of water and chemicals and the mechanical Strength, adversely affect, which is why they are only available in limited quantities can be added - the possible uses of the accelerator containing curable mixtures is thus at temperatures above limited by about 5 ° C - and that most accelerators are toxic are soluble compounds, which is why accelerator-containing epoxy resins generally not used in swimming pool or drinking water construction can be.  

At temperatures between 5 and 10 ° C so-called highly reactive Epoxy resins used, but not at temperatures above 10 ° C. can be used more because their processing time for one proper application is too short.

It has now been found that using episulfide compounds on average more than one

in the Molecule with stoichiometric amounts of amines, preferably with aliphatic or cycloaliphatic amines, forming quickly Cure resilient products without adding heat to this mixture must become.

It has also been found that episulfide compounds cure dependent on epoxy resins by amine hardeners at low temperatures accelerate strongly from their dosage.

It is known from US Pat. No. 3,378,522, episulfide compounds with an average of more than one episulfide group in the molecule with a polyamine quickly and at depth Harden temperatures; however, it was surprising that a Addition of these episulfide compounds to slow-curing Epoxy compounds act as accelerators.

The episulfide compounds or mixtures used according to the invention of episulfide compounds can e.g. B. after that of K. Dachlauer and L. Jackel found and patented in 1934 (DE-PS 6 36 708) from epoxy compounds by reaction with thiocyanates, Sodium thiosulfate, thiourea or by reducing chloropolysulfides made with Al amalgam (FR-PS 14 28 686) will.

The episulfide groups of the episulfide compounds which can be used according to the invention can optionally by heteroatoms, in particular Oxygen, or functional groups, such as ester, urea, Urethane or amide groups aliphatic, cycloaliphatic, if appropriate substituted aryl or optionally substituted arylalkyl Remnants connected.

The polyamines used to cure the episulfide resins are preferred cycloaliphatic and aliphatic polyamines or mixtures thereof Amines with amines with aryl or substituted arylalkyl radicals.  

The increased reactivity compared to the corresponding epoxy compounds of episulfide compounds is known and is used e.g. B. from P. Sigwalt in "Ring-Opening Polymerization", Marcel Dekker Verlag, New York, 1969, p. 191 treated in an overview. Behaviour of polyepisulfide compounds versus nucleophilic reaction partners is z. B. from P. Penczek et al. in "Plastics and rubber", 20 (3), 176 (1973). These authors have a. detected, that polyepisulfides with catalytic amounts of nucleophilic reactants at temperatures of 24 ° C and 80 ° C gel faster than that corresponding epoxy resins. The hardening of polyepisulfide compounds due to nucleophilic reactants in heat is the subject of the US PS 33 78 522, (R. W. Martin, 1968).

Based on our own investigations, it can be assumed that the Episulfide compounds used according to the invention the course of the Modify the reaction between an epoxy resin and a polyamine. Kinetic studies have shown that polyepisulfide compounds first react with polyamines and that the reaction products formed in this reaction either with other polyepisulfide molecules or react with polyepoxide molecules, this reaction is faster than the reaction between one Polyepoxide compound and a polyamine.

It is thus possible to previously use any amine hardener e.g. B. an aliphatic or a cycloaliphatic amine or a mixture of these amines to mix in such a way that the stoichiometric conditions are maintained remain, and the episulfide compound before application to the system add in a dosage such that a curable mixture is obtained, the appropriate at a certain temperature Has processing time or curing time. That way it is possible to determine the degree of hardening acceleration via the dosage the episulfide compound in a wide temperature range, for. B. between -30 ° and + 10 ° C to control.  

The episulfide resins used according to the invention are characterized in that gel and cure with amines at 20 ° C within one minute.

The preferred amines for curing these episulfide compounds are aliphatic or cycloaliphatic amines, alone or in Mixture with another polyamine or polyaminoamide e.g. B. with aryl or arylalkyl radicals can be used.

Since the episulfide compounds which can be used according to the invention even during the hardening reaction are consumed, arise from them and one Amine hardener insoluble products, so that the used according to the invention quickly curing resins or resin mixtures also the legal regulations in terms of toxicity.

The episulfide compounds used according to the invention or their mixtures with Epoxy resin have a low viscosity, which causes mixing the components are relieved at low temperatures.

The episulfide compounds used according to the invention or their mixtures with Epoxy resins can be used with or without additives such as fillers, pigments, Plasticizers, extenders and auxiliaries such as surface-active Agents, leveling agents, wetting agents, matting agents, e.g. B. as a paint, coating, covering, adhesive, mortar or injection agent be used.

They are particularly suitable for processing with a so-called Two-component system, which contains the resin component and the hardener component promotes separately, e.g. B. in the spraying process, reinforcing Materials such as fabrics or fibers can be used.  

example 1

Table 1 shows the accelerating influence of the invention Combination of episulfide compound and ethylene amine on the Hardening of a bisphenol A type epoxy resin by an amine hardener. The mixing ratio resin: hardener is 4: 1 parts by weight, the amine hardener contains 10 wt .-% triethylenetetramine (TETA) and the resin component the amounts given in Tab. 1 episulfide compound with a Episulfide value of 0.78.

Table 1

Example 2

Table 2 shows the influence of the dosage of the episulfide compound from Tab. 1 to the curing speed of the too resin-hardener mixture used for Tab. 1. The amine hardener contains 10% by weight of TETA.

Table 2

Example 3

Table 3 shows the influence of the dosage of the ethylene amine (DETA) on the curing rate of those used in Table 1 Epoxy resin-amine hardener mixture, the epoxy resin component 10% by weight episulfide compound with an "episulfide value" of 0.60 and the hardener component contains the amounts of DETA specified in Table 3.  

Table 3

Example 4

Table 4 shows the development of the Brinell hardness at one Temperature of 10 ° C and -5 ° C for an unaccelerated and a accelerated resin-hardener mixture. There are 100 g of mixture of an aliphatic epoxy resin and an amine hardener in the ratio 3: 1 made, the accelerated resin component 25 wt .-% episulfide compound of Tab. 1 and the accelerated resin component Contains 15 wt .-% TETA.

Table 4

Example 5

Table 5 shows the influence of the episulfide compound in Table 1 on the viscosity of an epoxy resin and the possibility of Addition of an episulfide compound used according to the invention to an epoxy resin to gradually reduce its viscosity. The viscosities were measured at 20 ° ± 1 ° C with a rheomat. The epoxy resin is of the bisphenol A type.

Table 5

Claims (7)

1. Fast-curing synthetic resin that cures even at low temperatures without heating, characterized in that the resin component is an episulfide compound with an average of more than one contains one amine hardener and one epoxy resin per molecule. 2. Synthetic resin according to claim 1, characterized characterized in that it is an episulfide compound or a Mixture of episulfide compounds with an episulfide value between 0.2 and 0.9, preferably between 0.5 and 0.9 contains. 3. Synthetic resin according to claim 1, characterized characterized in that it contains at least one of the contained amount Episulfide compound equivalent amount of an aliphatic or cycloaliphatic amine, preferably diethylene triamine, Triethylene tetramine or tetraethylene pentamine or mixtures of such compounds. 4. Synthetic resin according to claim 1, characterized in that it is an episulfide compound or a mixture of episulfide compounds whose are linked by divalent aliphatic, divalent cycloaliphatic, optionally substituted arylene or optionally substituted arylene or optionally substituted arylene alkylene radicals which are optionally interrupted by heteroatoms or functional groups. 5. Use of the synthetic resin according to claim 1 for Manufacture of paints, coatings and coverings, as Glue, mortar or injection agent and for impregnation. 6. Use according to claim 5 in construction or container construction. 7. Use according to claim 5, characterized in that one the components using a two-component system in the Spraying process applied.