CS197984B1 - Self-vulcanizing sealing binder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber-based self-vulcanizing sealant composition for sealing external joints of peripheral walls of large-scale concrete and reinforced concrete panels in construction and for the repair of joints of panel buildings.

With the development of sludge construction, the requirements for the quality of sealing and repair materials increase. Joint seals must absorb and transfer mechanical, chemical and thermal stresses and are exposed to adverse weather conditions.

The plastic sealants hitherto produced, which serve to seal joints in panel construction, have so far shown relatively less aging resistance and the ability to withstand mechanical stress and damage. The use of ethylene-propylene terpolymer (EPDM) as the basic rubber component fulfills the maximum life expectancy of the sealant. The disadvantage of these sealants due to the high saturation of EPDM is the difficulty of their vulcanization at normal temperature.

From relatively little extensive patent literature, e.g. Netherlands 7301 910-0 / 1972, cure systems based on quinoids and halogenated sulfonamides are known. With these systems, EPDM-based sealants can be vulcanized at normal temperature, but they are unavailable in Czechoslovakia and the individual components are very expensive. The problem is solved by the subject of the invention, which is a self-curing sealant for sealing the external

197 984

197,984 gaps in concrete and reinforced concrete in the construction industry, characterized in that it consists of 3.5 to 15 weight percent of an ethylene-propylene terpolymer containing as a third component ethylidene-norhomen, 3 to 15 weight percent of aaphthal, 20 to 50 weight percent mineral oil, 20 to 60 weight percent of mineral fillers,

0.01 to 0.6% by weight of sulfur, 0.02 to 1.5% by weight of zinc oxide, 0.01 to 1.5% by weight of the diatylthiocarhamic acid derivative, 0.01 to 0.5% by weight of stearic acid, 01 to 0.5 weight percent of 2-mercaptobenzthiazole or derivatives thereof and 0.01 to 0.5 weight percent of henzothiazyldiaulfide or derivatives thereof.

The sulfur vulcanization system is very cheap at high efficiency and in addition all components are ejected in Czechoslovakia. For the sulfur vulcanization system, EPM containing ethylidan-norbomen, as the third component, rubbers characterized by accelerated vulcanization, are suitable.

With EPIM containing, for example, 1,4-hexadiene naphthalicyclopentadiene as the third component, satisfactory results were not achieved due to the diene component which causes the slow rate of vulcanization.

In order to achieve the maximum mechanical properties of the EPM-based self-vulcanizing sealant according to the invention, unlike the vulcanizing systems commonly used, slow and very fast types of blowers are not required. The vulcanization is effected by the action of ultra-urea distyldithiocarbamic acid derivatives, optionally in combination with fast mercaptobenzthioazole or benzothiazyl disulphide accelerators.

The sealant can be manufactured as a two-component, tsn., That in production! it already contains all vulcanizing agents and vulcanization activators, accelerators and adds just prior to application.

Advantageously, EPM-based sealants can be manufactured as a single component, all vulcanizing agents, activators and vulcanization accelerators already present in the sealant during manufacture. The putty slowly cures when exposed to temperatures above 25 ° C, the rate of vulcanization at ambient temperature and the number of vulcanization activators and accelerators. With a suitable combination of additives, sealants can be prepared that can be stored at temperatures below 25 ° C for 6 or more months. Similar sealants, such as those based on chloroprene rubber, are subject to self-vulcanization under these conditions and thus to deterioration. The sealant cures at temperatures above 25 ° C depending on the content and type of accelerators and ambient temperature. After standing for 4 to 6 months at temperatures above 25 ° C, the sealant vulcanizes to its final state (mechanical properties, such as strength, ductility, no longer change). The sealant cured to room temperature to the final stage is characterized by viscoelastic behavior, good adhesion to the substrate, high mechanical properties and is resistant to mechanical damage. The tensile strength of the sealant after complete vulcanization ranges from 0.15 MPa to 1.5 MPa, elongation 280%. etc.

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Example recipe 1 wt. Percent ethylene-propylene terpolymer containing, as a third component, ethylidene-norbomen and oeinek 12 Calcium carbonate 40 Mineral oil 32 Asphalt 5 Stearic acid 0.1 Zinc magnesium 0.5 Zinc ethylphenyldithiocarbamidate 0.2 A 0.2

It is a formulation of a recipe suitable for the production of one-component self-curing sealants at normal temperature. All components are already included in the production of the sealant.

Example of recipe 2 wt. percent ethylene-propylene copolymer 5 oeinek 10 calcium carbonate 40 mineral softener 37 asphalt 6 stearic acid 0.1 zinc oxide 0.5

Zinc 2-mercaptobenzthiazole 0.3 Zinc diethyldithiocarbamidate 0.6 Zinc ethylphenyldithiocarbamidate 0.3 Sulfur 0.2

It is a formulation of a recipe suitable for the production of two-component self-curing sealants at normal temperature. Sulfur, zinc oxide and stearic acid are added at the time of manufacture, vulcanization accelerators - 2-mercaptobenzthiazole and zinc diethyldithiocarbamidate are added before application. The sealant is characterized by a high rate of vulcanization

Claims (1)

SUBJECT OF THE INVENTION Self-vulcanizing sealant for sealing external perimeter walls of concrete and reinforced concrete components in construction, characterized in that it consists of 3 to 15 weight percent of an ethylene-propylene terpolymer containing as a third component ethylidene-norbomen, 3 to 15 weight percent of asphalt, 20 to 50 weight percent 20 to 60 weight percent of mineral fillers, 0.01 to 0.6 weight percent of sulfur, 0.02 to 1.5 weight percent of zinc oxide, 0.01 to 1.5 weight percent of a diethyldithiocarbamic acid derivative, 0.01 to 0.5% by weight of stearic acid, 0.01 to 0.5% by weight of 2-mercaptoxysthiasol or derivatives thereof, and 0.01 to 0.5% by weight of benzothiazyl disulfide or derivatives thereof.