Lithium silicate glass ceramics and glass with hexavalent metal oxide
FIELD: ceramic industry.
SUBSTANCE: invention relates to lithium silicate glass ceramic and glass, which are crystallized at low temperatures and are especially suitable as dental materials, in particular, for dental restoration. Lithium silicate glass ceramics contains hexavalent metal oxide, selected from MoO3, WO3 and mixtures thereof, in amount of 0.1–8.4 wt%, from 12.0 to 20.0 wt% of Li2O and wherein including from 0 to less than 0.5 wt% of K2O. For production of glass ceramics with lithium disilicate as main crystalline phase initial glass with germs is subjected to thermal treatment at temperature of 520–750 °C.
EFFECT: technical result of invention is production of glass ceramic with improved mechanical and optical properties.
22 cl, 1 tbl, 9 ex
SUBSTANCE: present invention relates to medicine, particularly 5-100 mcm microbeads for radiotherapy, which are made from aluminosilicate glass having high content of Y2O3. The microbeads made from yttrium-aluminosilicate glass for radiotherapy with diameter from 5 to 100 mcm contain Y2O3, Al2O3 and SiO2, with the following ratio of components, mol %: Y2O3 - 17-22; Al2O3 - 19-25; SiO2 - 53-64.
EFFECT: obtaining articles which do not contain glass crystallisation products and foreign inclusions.
2 cl, 11 ex, 8 dwg
SUBSTANCE: glass contains SiO2, Al2O3, B2O3, SrO and SnO2 at the following component ratio, mass %: SiO2 - 50.0-55.0; Al2O3 - 10.0-15.0; B2O3-5.0-10.0; SrO - 15.0-25.0; SnO2 - 5.0-10.0.
EFFECT: glass softening temperature rise.
SUBSTANCE: invention pertains to compounds of heat-absorbing glass, used in construction. The glass consists of the following components with the given percentage mass ratios: SiO2 50.0-55.0; Al2O3 1.5-3.0; CaO 6.0-7.2; MgO 5.5-6.3, Na2O 13.0-17.0; Fe2O3 0.4-0.75; C 0.05-0.1; Li2O 0.5-1.0; B2O3 15.5-17.2.
EFFECT: lower melting temperature of the glass.
FIELD: composition of glass; manufacture of floor tiles, pipes, ejector bodies for aeration systems and abrasive material pneumatic transport.
SUBSTANCE: proposed glass contains the following components, mass-%: SiO2, 50.0-58.0; Al2O3, 15.0-20.0; CaO, 5.0-7.0; MgO, 5.0-7.0; Fe2O3, 1.0-2.0; MnO, 5.0-7.0;S-2, 0.1-0.2; Na2O and/or K2O, 1.9-3.8; B2O3, 5.0-7.0.
EFFECT: enhanced resistance of glass to attrition.
SUBSTANCE: invention relates to production of pyroelectric materials widely used in modern engineering. The glassceramic pyroelectric material contains oxides of lanthanum, boron, germanium, samarium and silicon, with the following ratio of components in mol %: La2O3 - 15-22.5, Sm2O3 - 2.5-10, SiO2 - 30-40, GeO2 - 10-20, B2O3 - the rest. The method of producing glassceramic pyroelectric material involves melting a mixture in a platinum crucible, pressing the melt, making glass sheets, crystallisation and polarisation of the sheets. Crystallisation is carried out temperature 900-1000°C in a temperature gradient field for 6-8 hours with extraction of solid solutions of the formula La(1-X)SmxBGeySi(1-y)O5, where x=0.1-0.4, y=0.2-0.4. The heat treated specimen then undergoes polarisation in a constant electric field with field strength of 1-8 kV/mm at temperature not higher than 350°C. The glassceramic textured pyroelectric material is characterised by pyroelectric coefficient γ (6.0 nC/cm2K), which, combined with a low value of ε (approximately 9), provides high pyroelectric efficiency.
EFFECT: obtaining cheap glassceramic pyroelectric material with high pyroelectric efficiency and high electric resistance.
2 cl, 1 tbl, 1 dwg, 1 ex
SUBSTANCE: decorative facing material contains the following components, wt %: ground glass 66.0-70.0; ground tuff or ground natural volcanic slag 15.0-17.0; ground blast furnace slag 15.0-17.0.
EFFECT: increased strength of decorative facing material.
SUBSTANCE: invention relates to production of pyroelectric materials widely used in modern technology (devices for remote thermal control of production processes, thermal monitoring of the environment, electronic control of the mode of operation of internal combustion engines, fire alarms etc). The method of producing glassceramic pyroelectric material involves melting a mixture of the following composition in mol %: La2O3 23-27, B2O3 23-27, SiO2 15-35, GeO2 15-35. Glass is crystallised at 925-1000°C in a field with temperature gradient of 50-100°C/mm for 4-8 hours. The material has low dielectric loss (0.001) and high electrical resistance.
EFFECT: invention enables to obtain glassceramic pyroelectric material with high pyroelectric coefficient in the region of room temperature due to reduction of the ferroelectric phase transition temperature of LaBGeO5.
SUBSTANCE: invention relates to glass-ceramic materials and glass for making said materials, designed for making electronic engineering products, mainly phase changers, controlled array modules having low dielectric loss in the microwave range, coupled with relatively high permittivity. The glass-ceramic material for microwave engineering based on SiO2, Al2O3, MgO, TiO2, where glass for making the said material contains the following in wt %: SiO2 35.5-38.5; Al2O3 22.8-25.5; MgO 20-22.7; TiO2 16.2-18.8, undergoes thermal treatment under the following conditions: heating to 1170-1240°C at a rate of 80-300°C/hour, maintaining this temperature for 4-7 hours, cooling to room temperature at a rate of 80-200°C/hour.
EFFECT: obtaining predefined permittivity and loss angle tangent values kept within defined limits.
SUBSTANCE: invention relates to composition of decorative facing material and can be applied in construction. Decorative facing material contains mass%: glass of 0.5-2.0 mm fraction 37.0-43.0, tuf of 0.5-2.0 mm fraction 47.0-55.0, kaolin 5.0-8.0, lime 2.0-3.0.
EFFECT: increase of strength of decorative facing material.
FIELD: composition of decorative facing materials; construction engineering.
SUBSTANCE: proposed decorative facing material contains the following components, mass-%: tuff, 75.0-78.0; sodium fluosilicate, 4.0-5.0; soda ash, 4.0-5.0; wollastonite, 12.0-14.0; caustic magnesite, 1.0-2.0.
EFFECT: enhanced strength of decorative facing material.
SUBSTANCE: invention discloses a composite adhesive for attaching composite filler materials to hard dental tissue, characterised by that the starting adhesive used is a polymer composition containing 10-47.5 wt % urethane di(meth)acrylate, 2.5-40 wt % esters of aromatic tri- or tetracarboxylic acids with methacryloyloxy groups of corresponding anhydrides, 25-75 wt % volatile, water-miscible solvent, 0.01-2.5 wt % photoinitiator, which is mixed with multilayer carbon nanotubes in solid to liquid weight ratio of 1:0.0005; dispersion is carried out under ultrasound action with frequency of 20000 Hz for 30 s.
EFFECT: obtaining an adhesive whose components penetrate dentinal canals and cracks formed when preparing a tooth, and increasing adhesion of the filler material to hard dental tissue.
SUBSTANCE: what is used is an oral composition containing a polyguanidine compound expressed by formula (I) and orally acceptable carrier. There are also presented: a method for the target delivery of the composition into the oral cavity, a method for inhibition of the development and prevention of dental caries, a method for the treatment of caries lesions.
EFFECT: group of invention provides the antimicrobial, anti-caries action.
19 cl, 3 dwg, 1 tbl, 2 ex
SUBSTANCE: invention relates to dentistry, namely to root bonding systems for filling canals and carious cavities. Claimed bioactive root bonding system contains dentine conditioner, primer and adhesive. Primer contains amino-acids: histidine - 0.01%-0.2%, lysine - 0.05%-0.4%, arginine - 0.2%-1.6% from total weight quantity of primer. Material has good affinity to dentine, easily penetrates into dentinal canals, suppresses pathogenic microflora.
EFFECT: complex composition of primer preserves collagen fibres in hybrid layer of dentine, forms chemical-mechanical bond of wet dentine with bonging-resins, completely isolates prepared dentine.
21 cl, 1 ex
SUBSTANCE: invention relates to medicine, namely to therapeutic dentistry and deals with medications for deep fluorination of teeth, intended for prevention and treatment of dental caries. Composition for prevention and treatment of dental caries contains sodium fluoride, acrylate-methacrylate copolymer, ethyl alcohol and water with definite component ratio. Used is acrylate-methacrylate copolymer, selected from copolymer of n-butyl acrylate, 2-hydroxyethyl methacrylate and acrylic acid, copolymer of n-butyl acrylate, n-butyl methacrylate, hydroxypropyl methacrylate and acrylic acid and copolymer of 2-ethylhexyl acrylate, 2-hydroxyethyl metacrylate and methacrylic acid, and possessing, due to the method of its obtaining, properties, which ensure migration of fluoride-ions from film to tooth enamel and their penetration into dental tissues.
EFFECT: small thickness and absence of refraction of the film, obtained in drying fluorine-containing lacquer, makes its presence on teeth surface imperceptible for patients themselves and invisible for other people, which increases patient's life quality considerably.
1 tbl, 3 ex
SUBSTANCE: invention relates to polymerised dental material and method of itsmanufacturing. Polymerised dental material contains filler, which includes in organic connecting substance partially aggregated nanosize filler and other inorganic and/or organic filler, selected from group, which consists of milled filler, which has average size of particles from 0.2 mcm to 50 mcm, and spherical filler, which has average size of particles from 0.1 mcm to 50 mcm. Method of obtaining material includes stages of organic modifying of partially aggregated nanosize filler, including of said nanosize filler with modified surface in organic connecting agent, and then including of said other inorganic and/or organic filler in organic connecting agent.
EFFECT: dental material by invention includes economic aggregated fillers, such as silicon dioxide, obtained by pyrolysis, and has advantages of materials, based on nanosize fillers, in particularl mechanical properties.
25 cl, 2 dwg, 4 tbl, 6 ex