431 results about "Polyvinyl acetate" patented technology

The invention discloses a cement-based aerogel heat preservation and heat insulation coating material for concrete and a spraying construction process of the cement-based aerogel heat preservation and heat insulation coating material, and belongs to the technical field of concrete materials. The coating material is prepared from powder, composite emulsion and water, and the powder is prepared by mixing superfine sand, cement, modified silicon dioxide-carbon nanotube composite aerogel powder, hollow glass beads, nanofibers, graphene nanosheets, an ultraviolet light absorber, a water reducing agent and a defoaming agent. The composite emulsion is composed of an acrylate copolymer emulsion, a polyvinyl acetate-ethylene emulsion, a temperature-sensitive polymer emulsion and a coalescing agent. Based on the multi-stage pore network and multi-component emulsion optimization design and multi-component synergistic effect, the material has good fluidity after being mixed, and has low heat conductivity coefficient, high strength and high toughness after being hardened; the construction technology of high-pressure water flushing and layered spraying is provided, and the method has the advantages of being efficient in construction, stable in quality and the like and can be applied to heat preservation and heat insulation of a concrete structure in a severe environment.

To provide a label which improves recyclability of an adherent after the label is adhered, and is capable of adjusting peeling of a dummy adhesive layer and an intermediate substrate.SOLUTION: A label comprises a surface substrate, an intermediate substrate and an adhesive layer. In the label, between the surface substrate and the intermediate substrate, a first thermally curable resin layer and a second thermally curable resin layer are disposed in this order. The second thermally curable resin layer and the intermediate substrate can be peeled, and the intermediate substrate is a paper substrate. An adhesive agent constituting the adhesive layer is a re-moistened adhesive agent containing at least one selected from a group consisting of a polyvinyl alcohol-based adhesive agent, a starch-based adhesive agent, a cellulose-based adhesive agent and a polyvinyl acetate-based adhesive agent.SELECTED DRAWING: None

The invention discloses a perovskite solar cell, a preparation method thereof, a cell module and a laminated cell. The perovskite solar cell comprises a composite hole transport layer and a perovskite light absorption layer, the perovskite light absorption layer is located on one side of the composite hole transport layer, and the composite hole transport layer comprises polyvinyl acetate and an SAM material. Therefore, the polyvinyl acetate is of a cross-linked network structure and can play a role in stabilizing the SAM material and inhibiting the SAM material from diffusing to the perovskite light absorption layer, so that the stability of the self-assembled monomolecular layer is improved, and the stability of the perovskite solar cell is improved; in the perovskite solar cell, carbonyl oxygen in polyvinyl acetate can be coordinated with uncoordinated metal ions in the perovskite light absorption layer to realize passivation of a bottom interface of the perovskite light absorption layer, so that interface recombination is reduced, and the performance of the perovskite solar cell is improved.

To provide solid electrolyte materials which are stable when in contact with aqueous electrolytes but retain conductivity and flexibility.SOLUTION: A solid electrolyte comprises a first polymer which is a polyvinyl acetal or polyvinyl acetate, and / or a copolymer having vinyl acetal and / or vinyl acetate units, doped with a sodium or lithium salt.SELECTED DRAWING: None

A chewing gum includes a body and a coating. The body includes a gum base polymer, an oil, an active ingredient, an insoluble cellulosic material, and a buffer system. The gum base polymer includes polyvinyl acetate (PVA) in an amount ranging from 35 weight percent to 55 weight percent of the body. The oil includes medium chain triglycerides in an amount ranging from 3 weight percent to 11 weight of the body. The buffer system is present in an amount ranging from 0.1 weight percent to 8 weight percent of the body. The coating is at least partially surrounding the body.

The invention relates to the technical field of plastic films, and provides a degradable plastic film and a preparation method thereof.The mode that microorganisms are placed between an inner layer film and an outer layer film in advance is adopted, auxiliary degradation of the degradable plastic film after use is achieved, the meeting and matching links of the degradable plastic film and the microorganisms in the external environment are reduced, and the degradation efficiency of the degradable plastic film is improved. The degradable plastic film is good in degradation environment matching performance and shorter in degradation period and comprises an inner-layer film and an outer-layer film, the inner-layer film and the outer-layer film are formed in a heating and rolling mode, a plurality of film-closing-free areas are arranged between the inner-layer film and the outer-layer film, microbial carriers are arranged in the multiple film-closing-free areas, and the microbial carriers are arranged between the inner-layer film and the outer-layer film. The inner layer film and the outer layer film are both formed by casting matrix plastic, and the matrix plastic is prepared from the following raw materials in parts by weight: 55 to 68 parts of polyvinyl chloride, 40 to 50 parts of polylactic acid, 22 to 28 parts of polyvinyl acetate, 15 to 20 parts of plant straw, 7 to 10 parts of ionic compound, 11 to 14 parts of flexibilizer, 14 to 20 parts of coupling agent and 13 to 16 parts of strength additive.

The invention provides a method for preparing a high-performance PVA / PBAT (polyvinyl alcohol / poly (butyleneadipate-co-terephthalate)) composite film by blow molding, which comprises the following steps: carrying out swelling plastification modification on polyvinyl alcohol by using an environment-friendly plasticizer to obtain modified polyvinyl alcohol; the preparation method comprises the following steps: modifying polyvinyl alcohol, blending the modified polyvinyl alcohol with a certain proportion of PBAT, carrying out screw extrusion granulation to prepare composite granules, and carrying out extrusion blow molding film formation to prepare the PVA / PBAT composite film. According to the method disclosed by the invention, the specific environment-friendly plasticizer is selected, so that the PBAT is well dispersed in a PVA matrix, the phase domain size of a dispersed phase is less than 1 mu m in a breakthrough manner, and the PVA / PBAT composite film with good mechanical properties is successfully prepared for the first time. The prepared PVA / PBAT composite film has good water resistance and blocking resistance, the application scene of the PVA film in the packaging field can be widened, and the PVA / PBAT composite film has good commercial application prospects.

In some embodiments of the present disclosure, a solid dispersion is provided, comprising: lurasidone or its pharmaceutically acceptable salt and a carrier. The material of the carrier comprises polyvinyl acetate phthalate (PVAP), polyvinyl alcohol (PVA), cellulose acetate phthalate (CAP), mesoporous silica, hydroxypropyl methycellulose (HPMC), polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, acrylic resin, hydroxypropyl cellulose (HPC), povidone, copovidone, ethyl cellulose, polyoxyethylene glycol, hypromellose acetate succinate (HPMCAS), hypromellose phthalate (HPMCP), or a combination thereof.

The invention discloses biomass polyvinyl alcohol and a preparation method thereof, and relates to the technical field of polyvinyl alcohol, the method comprises the following steps: adding initial biomass vinyl acetate into a rectifying tower for continuous rectification to obtain refined biomass vinyl acetate; the method comprises the following steps: adding refined biomass vinyl acetate, a methanol solution and an initiator into a polymerization kettle, stirring for reaction, transferring into a rectifying tower for rectification after the reaction is finished, obtaining a biomass polyvinyl acetate methanol solution from the kettle, uniformly mixing the biomass polyvinyl acetate methanol solution and an alkali methanol solution, performing alcoholysis reaction, crushing, extruding and drying, thereby obtaining the biomass polyvinyl acetate. Biomass polyvinyl alcohol is obtained; by using the biomass vinyl acetate as the raw material, the bio-based content in the polyvinyl alcohol can be increased, the biodegradability of the polyvinyl alcohol is further improved, and the polyvinyl alcohol has the advantages of sustainable development, low energy consumption, environmental protection and high quality, can meet the national requirements of ecological priority and green low-carbon development road, and expands the application field of the polyvinyl alcohol.

The invention discloses a sunscald-preventing protective agent for fruits. The sunscald-preventing protective agent is prepared from the following raw materials in parts by mass: 1 to 20 parts of monodisperse calcium carbonate filter cake, 0.01 to 0.9 part of ethyoxyl modified polytrisiloxane, 0.01 to 0.8 part of polyvinyl acetate emulsion, 0.01 to 0.8 part of glycerol, 0.01 to 0.8 part of enzyme and 10 to 180 parts of water. The raw materials are mixed in two steps according to a certain sequence, stirred and dispersed to obtain the novel fruit anti-sunburn protective agent, and the novel fruit anti-sunburn protective agent can be used for fruit anti-sunburn planting after being diluted with water until the solid content of calcium carbonate is 2-6%. The sunburn-preventing protective agent is safe and non-toxic, can be sprayed on fruit surfaces or fruit tree leaf surfaces during use, can remarkably avoid the risk that fruits and fruit trees are burnt by strong sunlight, improves the disease resistance and stress resistance of the fruit trees, and reduces the occurrence probability of sunburn spots, sunburn fruits and diseased fruits. The anti-sunburn protective agent for the fruits has no great influence on transmission of visible light, does not influence normal photosynthesis of fruit trees, and can obviously improve the yield and quality of the fruits when being used for fruit planting compared with other sunshade modes.

The invention discloses a seed coating containing an arbuscular mycorrhizal inoculant. The seed coating is prepared from the following components in parts by weight: 25 to 35 parts of the arbuscular mycorrhizal inoculant, 35 to 45 parts of a soil conditioner, 15 to 20 parts of talcum powder and 15 to 20 parts of polyvinyl acetate. The invention further provides a preparation method of the seed coating containing the arbuscular mycorrhizal inoculant and application of the seed coating to reduction of soil heavy metal pollution, increase of disease resistance and stress resistance of crops and promotion of crop growth. The seed coating containing the arbuscular mycorrhizal inoculant wraps the surfaces of plant seeds, provides good nutritional ingredients for growth and development of the seeds, and is beneficial to improving the germination rate of the seeds under heavy metal cadmium stress, reducing soil heavy metal cadmium pollution, improving soil quality, increasing soil fertility and improving disease resistance and stress resistance of crops; growth of seedlings is promoted, and crop quality and yield are improved.

A kit for preparing a cured article may include first and second casting compositions configured to form a curable composition, and an additive delivery composition for introducing an additive into the curable composition. The additive delivery composition includes a liquid carrier and at least one additive. The liquid carrier may include one or more of polyvinyl acetate, polyvinyl alcohol, or polyacrylate. A mold assembly for preparing a cured article may include a first mold body defining a first mold chamber and a groove surrounding the first mold chamber. The mold assembly further includes a second mold body defining a second mold chamber and a tongue surrounding the second mold chamber. The tongue is receivable into the groove to secure the first and second mold bodies. The first and second mold chambers together define a mold volume configured to receive and shape the curable composition.

The invention relates to the technical field of chemical control of brontispa longissima and discloses a pesticide preparation for controlling brontispa longissima and a preparation method and application thereof.The pesticide preparation is composed of active ingredients, auxiliaries and deionized water, and the auxiliaries comprise a polymeric dispersant and a high-molecular polymer emulsion; the polymeric dispersant comprises polymeric polycarboxylate, a modified polyacrylic acid copolymer and sodium salt of a maleic acid / olefin copolymer; the high-molecular polymer emulsion comprises a pure acrylic emulsion, a styrene-acrylic emulsion, a silicone-acrylic emulsion, a fluoroacrylic emulsion, a vinyl acetate-acrylic emulsion, a polyvinyl acetate emulsion, a polystyrene emulsion, a styrene-maleic acid copolymer emulsion, a polyethylene wax emulsion, a vinyl acetate-ethylene copolymer emulsion and a polyurethane emulsion. The special pesticide suitable for flying prevention is provided for flying prevention and control of the brontispa longissima, unmanned aerial vehicle plant protection is achieved for preventing and controlling the brontispa longissima of tall tree species such as coconut trees and areca trees, and the defects of an existing brontispa longissima prevention and control method are overcome through the flying prevention advantage.

The invention relates to the technical field of pharmacy, and discloses a carbidopa-levodopa sustained release tablet and a preparation method thereof.The carbidopa-levodopa sustained release tablet is prepared from, by mass, 65.4%-68.0% of levodopa, 17.0%-18.5% of carbidopa, 0.1%-0.5% of an adhesive, 0.1%-0.5% of a lubricant and 0.1%-0.5% of a coloring agent. And the mass percentage of the sustained-release material is 8.0%-9.0%. According to the carbidopa-levodopa sustained-release tablet and the preparation method thereof, polyvinyl acetate-crotonic acid copolymer is selected as a sustained-release material, hydroxypropyl cellulose is selected as an adhesive, the defects existing in the prior art are overcome, the carbidopa-levodopa sustained-release tablet can well control slow release of carbidopa and levodopa, and the sustained-release effect is good. According to the present invention, the release curve is highly consistent with the release curve of the original development agent, such that the safety and the effectiveness of the medication can be significantly improved, the wet granulation process is adopted, the addition mode of the adhesive is adjusted, the granulation process problem that the granulation is not easily performed when the active component content is large is solved, the preparation process is simple, and the industrial production is easy.

The invention provides a CIS chip grinding protection liquid and a preparation method and application thereof. The CIS chip grinding protection liquid comprises the following components in parts by weight: 15-25 parts of silane modified polyvinyl acetate; 50 to 100 parts of a diluent; 0.5 to 6 parts of an anti-gel auxiliary agent; the anti-gel auxiliary agent is a high-boiling-point alcohol. The silane modified polyvinyl acetate is one or more of 3-amino propyl triethoxy silane modified polyvinyl acetate, 3-chloropropyl triethoxy silane modified polyvinyl acetate, methyl triethoxy silane modified polyvinyl acetate and 3-(diethoxy ethyl) amino propyl triethoxy silane modified polyvinyl acetate. According to the CIS chip grinding protection liquid, a layer of protection film can be formed on the surface of a wafer to ensure that the wafer is not damaged by external force in the grinding process, the yield of the CIS chip is further improved, and the CIS chip grinding protection liquid has good application prospects and industrial popularization value in the field of semiconductor processing.

The present disclosure relates to a separator for an electrochemical device and an electrochemical device including the same, and more specifically, to a separator for an electrochemical device, the present invention relates to a separator for an electrochemical device and an electrochemical device comprising the same, and more particularly, to a separator for an electrochemical device capable of improving heat resistance and reducing resistance of a battery by providing an adhesive layer containing a polyvinyl acetate-based resin on a coating layer, and an electrochemical device comprising the same.

The invention discloses a laying method of a back contact cell string, and belongs to the field of laying of cell strings of photovoltaic modules, and the method comprises a scheme I. The scheme I comprises the following steps: before thermal welding of back contact cells, the back surfaces of adjacent cells are pasted and interconnected through composite material small strips; the two sides of the composite material strip are coated with fluorine-containing film layers to resist ultraviolet attenuation, the fluorine-containing film layers on the bonding face of the composite material strip are covered with an EVA (polyethylene-polyvinyl acetate copolymer) adhesive film, and when the temperature of 125 DEG C is applied to the composite material strip, the EVA adhesive film is melted and crosslinked. According to the laying method of the back contact battery string, three technical schemes are provided, the first scheme can fix the sheet spacing and prevent welding warping and sheet spacing fluctuation caused during lamination, the second scheme can fix the sheet spacing and prevent sheet spacing fluctuation caused during lamination, and the third scheme can flatten warped batteries and the battery string. And the phenomenon of sheet combination in the laminating process can be effectively avoided, and the reject ratio is greatly reduced.

The invention relates to a flame-retardant water diversion adhesive for a fireproof wet curtain, which comprises the following raw material components in percentage by weight: 55-93% of polyvinyl acetate emulsion and the balance of flame-retardant filler, the flame-retardant filler is magnesium hydroxide and / or expanded graphite; in the flame-retardant filler, the content of the magnesium hydroxide is 15-30%, and the content of the expanded graphite is not higher than 15%; or, the content of the expanded graphite is 7-15%, and the content of the magnesium hydroxide is not higher than 30%. According to the invention, the polyvinyl acetate emulsion is taken as a matrix, and the flame-retardant inorganic filler magnesium hydroxide and / or expanded graphite are compounded in a specific proportion, so that the obtained flame-retardant water diversion glue has lasting and excellent adhesive property and flame-retardant property in a long-term water immersion environment, and can be matched with wet curtains made of various materials for use.

The application discloses a kind of hydrolysis-resistant acetylacetamide modified polyvinyl alcohol and preparation method thereof, and the preparation method comprises the following steps: double vinyl ketone and first and alcohol amine compound are reacted to generate N-(hydroxyalkyl) acetylacetamide intermediate;Then trichloro cyanogen and N-(hydroxyalkyl) acetylacetamide intermediate are reacted to generate 3,5-bis[acetylacetamide alkoxyl] monochloro s-triazine;Finally, 3,5-bis[acetylacetamide alkoxyl] monochloro s-triazine is reacted with PVA in polar solvent to generate AAM-PVA.The AAM-PVA prepared in the application can be used as a protective colloid for polyvinyl acetate emulsion polymerization, and the prepared emulsion adhesive has obvious improvement in water resistance, tensile strength and stability;The raw materials of the application are cheap and easy to obtain, the preparation process is simple, the reaction conditions are mild, and there is no waste water and waste gas emission.

The present disclosure relates to cementing fluids including a latex and a cement. In an exemplary embodiments, the latex includes a first polymer and a second polymer; the first polymer includes at least about 80 mol % polyvinyl acetate; the second polymer has a general structure in which x is an overall molar ratio of styrene, y is an overall molar ratio of butadiene, and z is an overall molar ratio of carboxylic acid; a sum of x, y, and z is represented as s; styrene (x) is about 20% to about 30% of s; butadiene (y) is about 70% to about 80% of s; and carboxylic acid (z) is 0% to about 2% of s.

The invention discloses a fluralan chewable tablet as well as a preparation method and application thereof, and belongs to the field of pharmaceutical preparations. The flurala chewable tablet disclosed by the invention comprises the following components in parts by weight: 30-60 parts of flurala self-micelle solid dispersion; 20 to 60 parts of a filling agent; 1-15 parts of a disintegrating agent; 1-5 parts of a lubricant; 1-5 parts of a flavoring agent; the fluralan self-micelle solid dispersion is prepared from the following components in parts by weight: 5-15 parts of fluralan, 1-5 parts of an emulsifier, 1-5 parts of a crosslinking agent, 1-5 parts of a crosslinking agent and the balance of water. 25 to 35 parts of a polyethylene caprolactam-polyvinyl acetate-polyethylene glycol grafted copolymer; 1 to 6 parts of a DSPE-PEG material modified by an RRRRRRRR peptide; and 1 to 6 parts of an ATS peptide modified DSPE-PEG material. The chewable tablet disclosed by the invention has the advantages of high drug dissolution rate, high oral bioavailability, half-life period of longfluralana and the like.

The invention discloses a composite fiberboard and a preparation method thereof, and belongs to the technical field of artificial boards. Comprising the following raw materials in parts by weight: 34-45 parts of wood fiber, 17-26 parts of composite resin, 7-13 parts of hydroxymethyl cellulose, 5-9 parts of aluminate cement, 4-8 parts of talcum powder, 11-16 parts of polyvinyl alcohol, 9-14 parts of polyvinyl acetate emulsion, 7-11 parts of urea-formaldehyde resin adhesive, 5-9 parts of polyacrylate and 1.2-2.5 parts of a composite coupling agent. According to the composite fiberboard, the water resistance of the composite fiberboard can be improved, and the problem that harmful substances containing formaldehyde and the like are released is solved.

The invention relates to a humidity-adjustable anti-condensation coating which comprises the following components in parts by weight: 10-25 parts of expanded microspheres, 15-40 parts of an emulsion, 0-5 parts of rutile titanium dioxide, 1.7-5.9 parts of an auxiliary agent and the balance of water, wherein the total amount is 100 parts; the expanded microspheres are prepared by heating and expanding unexpanded microspheres at 60-80 DEG C; the emulsion is elastic acrylic emulsion and / or polyvinyl acetate emulsion. The expanded microspheres and the polymer emulsion are compounded, other porous or heat insulation materials are not needed, the formed coating can absorb a large amount of water vapor under high humidity and release the water vapor under low humidity, wall surface dew formation and mildew caused by too high environment humidity are avoided, the coating has an ultra-low heat conductivity coefficient, and the coating can be widely applied to wall surface decoration. The moisture condensation condition caused by the fact that the wall surface temperature is lower than the water vapor dew point is effectively avoided, and the excellent moisture adjusting, heat preservation and moisture condensation preventing capacities are achieved. Besides, gas is sealed in the expanded microspheres, and when external force acts on the coating, the shell of the expanded microspheres is made of the flexible polymer, so that structural damage can be reduced and the anti-condensation effect of the coating can be maintained when the expanded microspheres are subjected to the external force.

The invention discloses a solubility-resistant fluoride-free aqueous film-forming foam extinguishing agent and a preparation method thereof, and relates to the technical field of extinguishing agents. The invention discloses a soluble-resistant fluoride-free aqueous film-forming foam extinguishing agent. The cleaning agent is prepared from the following raw materials in parts by weight: 8 to 12 parts of a compound surfactant, 15 to 20 parts of modified polyvinyl acetate, 3 to 5 parts of modified xanthan gum, 5 to 8 parts of ethylene glycol butyl ether, 4 to 6 parts of propylene glycol, 0.5 to 1 part of benzotriazole, 0.3 to 0.6 part of triethanolamine, 0.2 to 0.4 part of disodium ethylene diamine tetraacetate, 0.8 to 1.2 parts of hydroxyethyl cellulose, 0.1 to 0.3 part of polyether modified silicone oil and 0.05 to 0.1 part of isothiazolinone. 6-9 parts of ammonium dihydrogen phosphate and the balance of deionized water. According to the anti-dissolution fluoride-free aqueous film-forming foam extinguishing agent, fluoride-free components are more environmentally friendly, and the requirement for green development is met; the compound surfactant has a synergistic effect with the modified polyvinyl acetate and the modified xanthan gum, so that the fire extinguishing efficiency and the solubility resistance are improved; the process is clear, parameters are clear, the product stability is good through ultrasonic dispersion and high-pressure homogenization treatment, the performance is optimized through multiple additives, and the application scene is wide.

The invention discloses a high-permeability grouting material for treating leakage water diseases and a preparation method of the high-permeability grouting material, and belongs to the technical field of energy-saving and environment-friendly building materials. According to the material, 525 type sulphoaluminate cement, fly ash, isophorone diisocyanate, polyvinyl acetate and a nano modifier are used as main raw materials, and the fluidity, permeability and solidified body performance of the grouting material are remarkably improved by optimizing the formula proportion and the preparation process. The nano modifier enhances the compactness and interface bonding force of the slurry through efficient dispersion and cross-linking reaction, the porosity is effectively reduced, and the impermeability and compressive strength are improved. The preparation method comprises the steps of raw material weighing and pretreatment, mixing reaction, temperature-controlled stirring and the like, and the performance stability and construction adaptability of the slurry are ensured. The material provided by the invention has the advantages of low viscosity, high permeability, rapid curing, high strength and good environmental adaptability, can be widely applied to underground engineering leakage water treatment, and has the remarkable advantages of convenience in construction, environmental protection, economy and the like.

The solid dispersion comprises from 20% by weight to 40% by weight of etradient and from 60% by weight to 80% by weight of a polymer selected from the group consisting of HPMCAS, PVPPA, CAP, HPMC E3, HPMCP, PVP, and a polyethylene caprolactam-polyvinyl acetate-PEG graft copolymer. A process for preparing the composition by spray drying. The composition is useful for the treatment of cancer.

This invention encompasses a composite material based on cow dung as a craft product and its manufacturing process. With the global issue of environmental pollution increasingly impacting social aspects of society, this invention addresses one such issue through the processing of waste materials and community-based production methods. Using ethnographic and participatory design approaches, cow dung waste is initially transformed into various functional products that align with the daily activities of the local community. In subsequent production stages, the development of these products into crafts is expected to significantly address waste, environmental, and social issues in Indonesia, considering the characteristics of its communities. Furthermore, this invention aims to contribute to the structured development of craft production from the smallest community groups to broader scopes. The vision for this cow dung waste production is intended as an effort to empower grassroots businesses that are local, sustainable, and closely related to the daily problems of the residents. This composite material consists of cow dung, an adhesive mixture of polyvinyl acetate and water, a filler material of calcium carbonate, pigments both organic and inorganic, and clove and pine oils.

A method of manufacturing sugar cane polyvinyl alcohol wherein sugar cane bagasse is processed into polyvinyl alcohol. Processing raw materials including sugar cane bagasse and deionized water. Enzymatically hydrolyzing and using saccharification on the sugar cane bagasse to obtain sugar cane bagasse enzymatic hydrolysate. Fermenting the sugar cane bagasse solution. Distilling the fermented sugar cane bagasse solution to obtain ethanol solution and lignin solution. Transferring the distilled solutions to an ethylene plant area to obtain a polymer grade ethylene product. Transferring the polymer grade ethylene product to an acetic acid evaporator to generate vinyl acetate. Introducing the vinyl acetate into an autoclave with methanol solution wherein said solutions undergo a reflux reaction process. Ethyl acetate is then dissolved in methanol to prepare a polyvinyl acetate solution which undergoes alcoholysis wherein the product is then washed and deionized, yielding polyvinyl alcohol.

The anti-crack leveling gypsum comprises 25% of desulfurized gypsum, 11% of cement, 5% of graphite, 11% of rubber particles, 11% of cellosilk, 10% of molybdenum disulfide, 12% of a polyvinyl acetate emulsion, 5% of calcium lignosulphonate, 3% of a cementing agent and 7% of a conditioning agent. According to the invention, the multi-stage compounded gypsum particles are utilized, so that cracking is avoided after leveling of thick gypsum batch.

The application belongs to the technical field of drug dissolution and dispersion, and particularly relates to a bunazosin water-based solution preparation and a preparation method. The bunazosin water-based solution preparation provided by the application comprises the following components: bunazosin, gamma-cyclodextrin, lecithin, polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, aspartame and water. The above components are mixed to be homogeneous to prepare an oral solution which is uniform, clear and can be stored for a long time. The scheme of the application further enriches the dosage form of bunazosin, improves the convenience of taking bunazosin, and is expected to help improve the oral bioavailability and absorption efficiency of bunazosin. The scheme of the application also provides a reference direction for the mechanism research on the dissolution and dispersion behavior of the insoluble bunazosin macromolecule in a water medium.