Composition to create heat-resistant welded insulating coatings for electrical steels
The invention relates to the field of electrical engineering, in particular to compositions for the manufacture of coatings for electrical steels for magnetic circuits of electrical machines and devices. The composition is prepared by adding an aqueous solution of polyvinyl alcohol at a temperature of 65-80oWith phosphoric acid, urea, ethanol, surfactants, with prolonged stirring, cooled to room temperature, add a pre-prepared alkali-alumino-Boro-silicate glass in the form of an aqueous suspension of chromium oxide (III). The composition is thoroughly mixed to achieve homogeneity and put on a strip of electrical steel, removing excess rubber roller. The drying is effected at 500-600oC for 30-60 C. a Significant predominance of inorganic components in the composition allows to obtain a uniform thickness of the heat-resistant coating with a high coefficient of electrical resistance, enabling welding package isolated steel plates coated on the side surface, which is the technical result of the proposed technical solution. table 1. Isophasic steels for magnetic circuits of electrical machines and devices.The aim of the invention is to provide a composition based on polyvinyl alcohol to obtain a heat-resistant coating for electrical steel having good insulating properties and allows to weld the outer edges of the packages insulated steel plates coated.Known insulating compositions for the manufacture of coatings for electrical steels on the basis of phosphoric acid, butadiene-styrene latex,-butyrolactam or valerolactam, fraction of fatty alcohols C7-C12and water. The quality of the coverage provided by the introduction of faction fatty alcohols (Ed. mon. The USSR 1568081). Known mixture for insulation coating containing a latex of ethylene-propylene rubber, cellulose ether, neionogennye emulsifier, wax and stabilizer that protects from aging (Patent GDR 274512). The disadvantage of these compositions is their heterogeneity due to the insolubility of inorganic components in the water, leading to rapid stratification. The consequence of this is the non-uniformity of coating thickness and low-tech application process: the formation of traffic jams in transportation systems to the s deprived of compositions based on water-soluble polymers, in particular, polyvinyl alcohol (PVA). The use of PVA to obtain coatings can increase their dielectric properties and stampability.The closest prototype is a composition to create a thermally stable insulating coatings for electrical steels on the basis of polyvinyl alcohol, phosphoric acid, urea, thiourea, boric anhydride, ethyl alcohol, glycerine, phthalic anhydride, surfactants (surface-active substance which is a mixture of mono - and diesters of phosphoric acid with polyfluorinated alcohol) and water (Patent RF 2161341).The disadvantage of this composition is the limited thermal stability (only when heated in an inert atmosphere), as well as a low coefficient of resistivity isolation and poor weldability (impossibility of implementing welding package steel plates coated on the side surface). All these drawbacks the composition of the prototype associated with a high proportion of organic components in its composition.The proposed composition contains, along with PVA, phosphoric acid, urea, ethanol, surfactants and water g/l alumino-Boro-silicate glass and chromium oxide (III).Composition photosporno acid, urea, ethanol, surfactants, prolonged stirring, cooling to room temperature, add pre-cooked alumino-Boro-silicate glass in the form of an aqueous suspension of chromium oxide (III). The composition is thoroughly mixed to achieve homogeneity and put on a strip of electrical steel, removing excess rubber roller. The drying is performed at a temperature of 500-600oC for 30-60 sec.Study of thermal stability of the coating, measuring resistance and testing the adhesion of coatings to metal produced according to GOST 21427-83. Coating thickness was measured on the device Deltascope. The drag coefficient was measured on the instrument CIS/C-2550 Interlaminar resistivity testr. Heat treatment of samples for testing thermal stability of the coatings produced in the atmosphere of nitrogen-hydrogen 95:5 and in the air. Properties of the obtained coatings was compared to the coating properties of the prototype (Patent RF 2161341). The weldability was evaluated by the possibility of obtaining monolithic (without shell) of the weld.Formulations of the compositions and properties of the resulting insulating coating is shown in the table.Example: To 800 ml heated to 80-85oWith deionized water were added 50 g of PVA and pen and slowly added to 15 g of orthophosphoric acid, 6 g CR2About3and 70 g alumino-Boro-silicate glass, crushed and pre-mixed with 30 g of deionized water. After stirring for 2 h to the resulting composition was added water up to a volume of 1 l and continued stirring. Applying the composition on a steel strip produced directly from the working tank with continuous stirring. The drying is carried out at a temperature of 540-560oC for 30-60 C. After drying, the measured thickness and the resistivity of the coating was subjected to heat treatment and re-measured the resistivity, and also investigated the strength of adhesion of the coating to the metal. Produced welding package steel plates coated on the side surface of the MIG (MiG welding in inert gas) and investigated g/l the quality of the weld.
ClaimsComposition to create heat-resistant welded insulating coatings for electrical steels on the basis of polyvinyl alcohol, phosphoric acid, urea, ethanol, surfactants and water, characterized in that it further comprises alumino-Boro-silicate glass and the ACS is the 15 - 22Urea 3 - 8Ethyl alcohol 50 - 80Surfactant 5 - 8Alkali-alumino-Boro-silicate glass 70 - 90Oxide chromium (III) 5 - 6
FIELD: electronic engineering; gas panel manufacture.
SUBSTANCE: protective coating that can be used for manufacturing contact members of gas-panel strip conductors is formed on both sides of polyamide and applied by stenciling method using for the purpose dielectric composition resistant to 20-30% alkali solutions at temperature of 65 - 85oC that incorporates in its composition ethyl cellulose in the amount of maximum 9 parts by weight and organic solvent in the amount of minimum 91 parts by weight with boiling temperature of ≥ 190oC, minimal amount of ethyl cellulose and maximal amount of organic solvent being, respectively, 7.5 and 92.5 parts by weight.
EFFECT: improved rheological and protective properties of coating using proposed composition.
1 cl, 1 ex
FIELD: marking materials.
SUBSTANCE: invention relates to pigmentation and compositions for use in laser marking, in particular UV absorbing pigment at least partly covered with synergist having general formula [Rm(SiOn)]pR'q wherein m=1-3, n=1-3, p is a number equal to at least 1, q=0-3, and at least one of R or R' represents substituent. When pyrolized, pigment forms black material appropriate to form label. Such pigments are suitable for fluoropolymers serving to insulate wire conductors and cables.
EFFECT: expanded marking possibilities.
20 cl, 6 tbl, 38 ex
FIELD: electrical engineering.
SUBSTANCE: proposed insulating material that can be effectively used to insulate conductors for various industries, including radio engineering, cable industry, microelectronics, and the like, has multilayer structure of N thin-film layers, where N > 1; all layers are made of separate piled films produced from same material and by same method, having actually equal thickness d < 25 μm.
EFFECT: facilitated manufacture, reduced cost of materials used, enhanced electric and mechanical strength.
1 cl, 1 dwg, 2 tbl
SUBSTANCE: invention is attributed to the field of electric engineering specifically to epoxide thin filling compounds used for electric insulating and reinforcing by means of embedding of high-voltage power supply units, transformers, electric circuitry, uncased and cased electric couplers, for sealing and protecting elements of radio-electronic devices against moisture and mechanical impacts. Composition for filling compound with moderate initial viscosity contains 30-36 wt-p. of epoxide diane resin, 12-20 wt-p. of threeglycid polyoxypropylene triol ether, 10-12 wt-p. of monoglycid n-butanol ether, 18-22 mass-p. of low-polymeric polyamid resin and 7-10 wt-p. of aliphatic amine.
EFFECT: creation of electric insulating filling compound composition keeping resiliency not less than for an hour, having high specific volume, high value of surface electric resistance and increased elasticity.
SUBSTANCE: there is disclosed insulating coating composition, containing bitumen in amount 90-100 wt fractions, fluorocarbon polymer 32 LN in amount 10-15 wt fractions, butyl acetate in amount 40-45 wt fractions, acetone in amount 40-45 wt fractions and mica in amount 2-3 wt fractions.
EFFECT: improved insulating properties, mechanical strength and chemical stability.
1 tbl, 1 ex
SUBSTANCE: invention relates to a polyolefin composition with improved dielectric strength of insulation, to a wire or cable, in particular to a cable of middle, high or superhigh voltage, which includes such composition, as well as to application of such composition for production of wire or cable, in particular a cable of medium, high and superhigh voltage. Polyolefin composition contains polyolefin (A) and benzyl derivative (B) of a certain structure. Benzyl derivative (B) is used in the polyolefin composition as an additive for stabilisation of dielectric strength.
EFFECT: additive provides considerable improvement of dielectric strength, possesses good solubility in a polyolefin matrix and low predisposition to migration, and also possesses compatibility with respect to all other components of the polyolefin composition, in particular with cross-linking agents.
21 cl, 6 tbl, 5 ex
SUBSTANCE: coating comprises an adhesive sublayer of a thermoplastic adhesive and a functional layer of a nanostructured composite material based on polyethylene. The composite material of the functional layer has a polyethylene matrix and montmorillonite particles dispersed in the matrix in amount of 0.1-2 wt %.
EFFECT: improved physical and mechanical properties of the coating.
12 cl, 2 ex
SUBSTANCE: compound casting method for electrical goods includes mixing of components with receipt of the compound and casting of the electrical goods with the compound. At that before casting an electrical good is heated at temperature of 50-55°C and residual pressure of 10-15 mm hg at least during 3 hours. The compound is received by mixing of predried components in the following ratio, g: styrene - 50, castor oil - 38, product 102T - 12, benzoyl peroxide paste - 1. The paste made by mixing of predried benzoyl peroxide with dibutyl phthalate is used as the benzoyl peroxide paste. At that before casting the compound is vacuumised additionally at temperature of 15-35°C and residual pressure of 10-15 mm hg at least during 3-5 minutes. The pretreated electrical goods and compound are heated in the same furnace at temperature of 70°C during 1 hour. Then the heated electrical goods are casted step by step with the hot compound by the free casting method initially to ѕ of the electrical good height or volume with further vacuum degassing of the casted electrical goods at temperature of 15-35°C and residual pressure of 10-15 mm hg during 15-20 minutes with further casting of the electrical good with the same compound up to the required level. The multistage polymerisation of the compound is carried out. At that the casted electrical goods are held in the furnace heated up to 70°C during 4 hours at first, then they are casted with the same compound and its polymerisation takes place again at temperature of 70°C during 4 hours.
EFFECT: non-availability of defects in the form of cracks and air bubbles in the compound mass thus ensuring high quality of the casted electrical goods, and namely increasing their electric strength and reducing quantity of wastes.
FIELD: electrical engineering.
SUBSTANCE: method of production of power cable including conductor and ply of polymer coat. This method comprises the steps whereat polypropylene matrix is mixed with dielectric fluid to obtain polymer mix. Hydrodynamic pressure of said mix is increased. Polymer mix is filtered. Said polymer mix is forced through extrusion head to get coat ply on conductor and cable is cooled.
EFFECT: decreased amount of contaminants, process with sufficient rate.
13 cl, 3 dwg
SUBSTANCE: proposed material represents a glass fibre and is manufactured using glass cloth impregnated with a mixture of epoxy-diane resin, 4,4'-diaminodiphenyl sulphone, nickel acetylacetonate and spherical particles of butadiene-nitrile-styrole-carboxylate copolymer, where the copolymer particle size is from 10-8 to 10-7 m, at the following ratios, parts by weight: epoxy-diane resin: 100, the said polymer 5-20, 4,4'-diaminodiphenyl sulphone 20, glass cloth 170, nickel acetylacetonate 1.
EFFECT: glass fibre resistance to multiple bends.
1 tbl, 3 ex