CS277594B6 - Materials based on epoxy bitumens - Google Patents

Abstract

masses on the basis epoxy resins suitable for sealants, concretes, adhesives, laminates and cast floorings, which ones Is a possible cured at temperatures Come point frost and Is a possible their apply and on the slightly wet documents, after remain from 60 until 90 weight parts EPO xidovej bitumen palmar and / or novolac type molecular weight 340 until 700. 0.1 until 40 weight parts 2-ethylhexyl acrylate and 10 until 65 weight parts hardener The prepared sausage Venet reaction 1 until 1.5 mole dipropyléntri- amine, 0.7 until 1.2 mole formaldehyde and 1 mole cresol.

Description

The invention relates to epoxy-based compositions for use mainly in construction.

Epoxy resins in the uncured state (except for high molecular weight ones) have only limited use. They form semi-solid to solid thermoplastics which are wettable, soluble in a variety of organic solvents and therefore unusable for normal applications. Only after curing and creating a three-dimensional network do they acquire excellent properties with a wide range of application applications. Chemicals are used for curing, which are divided into three groups according to the chemistry of the reaction with the epoxy group. The first group includes substances with so-called active hydrogen atoms, i.e. substances which react additionally by protonation of the epoxy ring. These include, for example, polyamines, polycarboxylic acids, aminoamides, dicyandiamide, and the like. The second group consists of substances which do not actively contain hydrogen atoms, but react first with hydroxyl groups and only then react with epoxides by the mechanism as substances in the first group. This includes mainly dicarboxylic anhydrides resp. polycarboxylic acids and polyisocyanates. The third group includes substances which cure epoxy resins by the mechanism of ionic polymerization, e.g. complex compounds derived from boron trifluoride, tertiary amines and the like. .

One of the most important and in practice the most used hardeners are amino compounds, which can be aliphatic and aromatic, cyclic and linear, monomeric and polymeric and modified, but also unmodified. The most important of these are aliphatic and cycloaliphatic amines. The properties of the resins formed by them depend on the particular type of hardener, the method of curing, the curing temperature and the possible addition of a curing accelerator.

The use of amines, resp. their derivatives for curing epoxy resins, as well as their preparation is the subject of a large number of older and newer patents, e.g. Belgian Patent Nos. 861056 and 867589, Japanese Patent Nos. 51082400, 51098732 and 52021093, German Patent No. 2611019 and U.S. Pat. 4007160 and 4503171.

U.S. Patent No. 4,503,174 addresses the reactivity of the system at low temperatures using isophoronediamine, bicyclic amidines, free phenol, and combines it with alkaline copolymers.

For some applications, eg in construction, it is necessary for curing to take place at low temperatures and at a sufficient speed. These conditions trigger rapidly reactive boron trifluoride complexes. However, these are sensitive to alkaline environments, which can even stop the reaction. This fact limits the use in construction.

This problem is eliminated by the present invention, which comprises 60 to 90 parts by weight of a palm and / or novolak type epoxy resin having a molecular weight of 340 to 700, 0.1 to 40 parts by weight of 2-ethylhexyl acrylate, 10-65 parts by weight of a hardener prepared by reaction 1. to 1.5 moles of dipropylenetriamine, 0.7 to 1.2 moles of formaldehyde and 1 mole of cresol.

CS 277594. B6 2

The compositions according to the invention excel in that they can be used on wet substrates, the reaction takes place even at low temperatures and also in an alkaline environment. Cured epoxy systems achieve very good properties.

Examples of embodiments of the present invention

Example 1 parts by weight of a palm-type epoxy resin having a molecular weight of 400 with 1 part by weight of 2-ethylhexyl acrylate are mixed with 50 parts by weight of a hardener prepared by reacting 1 mole of dipropylenetriamine (131.2 g), 1 mole of formaldehyde (30.03 g) in the form 38% aqueous solution at 70 ° C for one hour, freed of condensation water as well as water from a formaldehyde solution reacted with 1 mole of cresol (108.13 g).

The reaction mixture has a pot life of 10 minutes at 20 ° C and is suitable for bonding cement kiln bricks.

Example 2

The procedure of Example 1 is followed, 25 parts by weight of 2-ethylhexyl acrylate are used instead of 1 part by weight of 2-ethylhexyl acrylate and the amount of hardener is increased to 60 parts by weight.

The reaction mixture is suitable for sealing joints.

Claims (1)

Materials based on epoxy resins, used especially in the construction industry, suitable for sealants, plastic concretes, adhesives, cast floors, laminates, grouts and others applied to slightly wet substrates and at low temperatures up to minus 5 ° C, characterized in that they consist of 60 to 90 parts by weight of epoxy resin, palm and / or novolak type molecular weight 340 to 700, 0.1 to 40 parts by weight of 2-ethylhexyl acrylate, 10 to 65 parts by weight of hardener prepared by reacting 1 to 1.5 moles of dipropylenetriamine, 0.7 up to 1.2 moles of formaldehyde and 1 mole of cresol.