CS259164B1 - Composition for conducting flowing materials,glues and cements - Google Patents

Abstract

The solution relates to the construction industry and engineering. The technical problem is solved compositions for the production of semiconducting to conductive liquids, adhesives and sealants. ' The essence of the solution is a composition consisting of from 68 to 90 parts of epoxy resin; to 42 parts of 2-ethylenehexyl ticrylate, 10 to 10%; 50 parts of active fillers and 1 to 20 parts conductive carbon black. The solution will be used where static charge discharge is desirable; \ tor. \ t protection from stray currents.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to epoxy-acrylic resin based adhesives and sealants compositions.

In modern technology and technology, we often face serious problems related to the formation and discharge of electrostatic charges, which arise in various ways, most often by rubbing limes of low specific conductivity. The charge values are considerably higher, and high-temperature sparks of several hundred to 1000 volts are generated during the discharge. Such discharges are not only physiologically unpleasant, but can also cause ignition of vapors of flammable liquids, dust and the like. Modern electronic devices are very sensitive to the presence of electrostatic fields, which in many cases can seriously damage them. The second serious problem is stray currents of different character and intensity, usually occurring in the vicinity of electrical machines and wires. Stray currents can often be the source of malfunctions in sensitive devices such as computers, electronic controller sensors and the like, but can cause / cause serious health hazards to sensitive persons. Efforts are therefore being made to prevent the formation of electrostatic fields or harmless discharge of charges and stray currents to the ground. There are many known solutions, but none of them guarantees the desired effect in full. In recent years, a relatively good effect has been achieved by using conductive plastics, adhesives and sealants containing 40 to 70% graphite or plastics containing powdery or scaly metals, in particular silver, copper or gold. The binder component of such compositions is most often polyester, polyurethane or epoxy resins, alkyd condensates and the like. The high content of graphite necessary to achieve the required level of conductivity or electrostatic conductivity not only causes a serious deterioration of the processing conditions for the preparation and application of plastics, adhesives and sealants, but cured materials significantly deteriorate the mechanical parameters chemical resistance, adhesion and cohesion, and the like. For this reason, a solution is sought which allows to reduce the amount of substances affecting the conductivity in order not to further deteriorate the utility properties. In the preparation of compositions for conductive floors of adhesive and sealant, good conductivity is achieved only when using a disintegrated copper which, like graphite, significantly worsens the mechanical parameters of the cured materials. The application of ionogenic compounds, in particular quaternary ammonium, sulfonium and phosphonium compounds, also does not solve the situation, since these substances are easily calculated and washed off from the cured materials, so that the effect of semiconductivity is only temporary. The state of the art does not know any other effective solution to said technical problem.

Through extensive experimental work, we have found compositions for epoxy resin based adhesives and sealants having fully satisfactory mechanical and electrical parameters. The compositions according to the invention for the molds, adhesives and sealants consist by weight. 68 to 90 parts of a diane epoxy resin having a mean epoxy functionality of 2.0 and an average molecular weight of 340 to 60 to 42 parts of 2-ethylhexyl acrylate to 50 parts of active fillers 1 to 20 parts of electro conductive carbon black.

The compositions of the invention are cured with aminoamide resins, cycloaliphatic diamines and some aliphatic diamines such as hexamethylenediamine, trimethylhexamethylenediamine and the like. In some cases, the condensation products of phenolic compounds with aldehydes and aromatic or other polyamines may also be used.

Tidal compositions, adhesives and sealants are usually stabilized with 50-300 ppm hydroquinone and pigmented as necessary with colored pigments such as iron oxides, stunning, natural ochers, colored clays, phthalocyanine pigments, zinc white, titanium white, lithopone and the like. If necessary, surface tension, flow and other Theological properties are adjusted by the addition of substances such as methyl silicone oils, fluorocarbons, melamine- or urea-formaldehyde condensates, low molecular weight acrylate polymers, etc. The conductive carbon black having a high structure ( high degree of chaining), large surface area and low oxygen content. Experimentally it has been found that the carbon blacks are Cezacarb EC (Chemical Plant Záluží), acetylene carbon black P 1250 and retort carbon black SAF, PEP, HAF or ISAP. Other types of carbon black did not provide the desired conductivity effect. Depending on the type and quantity, a throughput resistance of 1 to 500 kohm.cm is achieved in hardened tumbling materials, adhesives and sealants, which is sufficient for the vast majority of technical applications. .

Active fillers reduce material costs and improve a number of physico-mechanical parameters of cured materials, especially tensile and compressive strength, reduce abrasion, flammability, etc. As active fillers are used mainly peel-type PVC, boron-type aluminosilicate kieselguhr, ground quartz glass silica), silica gel and the like.

Compositions for electro-conductive materials, adhesives and sealants provide easy to handle and process low-sedimentation materials which, after curing, have very good mechanical and electrical parameters, in addition to good climatic resistance. A significant advantage is that the compositions of the invention are not toxic even in the uncured state and do not endanger their environment. EXAMPLE 1 1 g of a dianionic epoxy resin having a mean molecular weight of 342 and an average epoxy functionality of 2.0 is mixed with 2-ethylhexyl acrylate, 50 ppm hydroquinone, and homogeneously added 50 g of ground quartz glass and 20 g of ISAP. The composition creates a thixotropic sealant. Prior to use, 10 g of the mixture was mixed with. and 100 grams of an amino-amide resin of equivalent weight 171 is mixed into the mastic bottom and allowed to cure. The cured sealant has tensile strength 43.5 MPa,, elongation 19.8%, the impact strength of 22.8 kJ / m, the electric resistance of 5.8 · P * kohm.cm _by Kud, for comparison in the same composition, we replace carbon black graphite CR12 has cured putty only 22.4 MPa, elongation 8.9%, impact strength 11.7 kJ / m and el, resistance 899 kohm.cm.

Example 2

68 g of a diane epoxy resin having an average molecular weight of 666 and an average epoxy functionality of 2.0 is mixed at 125 DEG with 42 g of 2-ethylhexyl acrylate and 250 ppm of hydroquinone. To the homogeneous cooled mixture was added 10g of Neralite 702 (peel type PVC), 1.5g of conductive carbon black Chezacarb EC and 0.5g of salicylic acid. The homogeneous composition is cured by the addition of 25.7 g of the Laromin C 260 cycloaliphatic diamine. The cured mass is an epoxy rubber having a tensile strength of 8.9 MPa, an elongation of 78% and an electrical resistance of 488 kohm. cm. If the carbon black in the composition was replaced by CR12 graphite, el. the resistance of 1.2 x 10 ^ kohm.cm ^ is insufficient.

Claims (1)

Composition for electro-conductive epoxy resins, adhesives and sealants, characterized in that it consists of 68 to 90 parts of a dian epoxy resin having a mean molecular weight of 340 to 670 and an average epoxy functionality of 2.0, 10 to 42 parts of 2-ethylhexyl acrylate, 10 to 50 parts active fillers and 1 to 20 parts electro conductive carbon black.