329results about How to "Extend curing time" patented technology

The invention discloses a synthetic resin adhesive for an E0/E1 grade flakeboard, which is melamine modified urea-formaldehyde resin; formaldehyde with the concentration of 48 percent in mass percentage is adopted as a raw material; the adhesive comprises the following reaction materials in percentage by mass: 4.0 to 5.0 percent of melamine, 43.0 to 45.0 percent of urea, 48.0 to 51.0 percent of formaldehyde, 1.00 to 1.10 percent of addition agent, 0.20 to 0.22 percent of polyvinyl alcohol and proper acid and alkali; the total molar ratio is between 1.08 and 1.11; and the materials are reacted and synthesized, thereby preparing the adhesive. The high-concentration formaldehyde is adopted as the raw material; the adhesive has excellent bonding strength, proper curing time, good storage stability and the free formaldehyde content of between 0.06 and 0.08 percent; with the adhesive, the E1 and E0 flakeboard with excellent quality can be stably produced; and the adhesive has the advantages of low adhesive application amount, strong process adaptability, rapid curing, etc.

A polyurethane is obtained by continuously reacting a polyurethane prepolymer in an asphalt or asphalt mixture material system under high temperature. The prepolymer is prepared by: adding a polymerization inhibitor, catalyst and isocyanate component in a reaction container, adding a polyol to the reactor while stirring at room temperature under nitrogen, increasing the temperature to 50-80° C., and maintaining the temperature to react for 0.5-6 hours. A polyurethane modified asphalt, a mixture material containing the polyurethane and a polyurethane modified asphalt pavement structure can be prepared. The synthesis condition of the polyurethane is mild, and a secondary reaction with the air and an active hydrogen component in the asphalt can occur during maintenance and formation to further increase the strength of a mixture material. The standard Marshall stability at 60° C. meets the petroleum asphalt requirement, such that a service life of the asphalt pavement can be increased.

A cationically curable composition for dental use containing a cationic polymerization initiator (I) and cationically polymerizable monomers (II), the cationically polymerizable monomers (II) containing an oxetane compound and an epoxy compound or an alkenyl ether compound at a ratio of amounts that satisfy the conditions expressed by the following formula,

(a×A):(b×B)=91:9 to 45:55

wherein A is a mol number of the oxetane compound, “a” is an average number of the oxetane functional group contained in one molecule of the oxetane compound, B is a mol number of the epoxy compound or the alkenyl ether compound, and “b” is an average number of the epoxy functional group contained in one molecule of the epoxy compound or an average number of the alkenyl ether functional group contained in one molecule of the alkenyl ether compound. The composition is not hindered by oxygen from being polymerized, cures quickly even without using a special polymerizable monomer or a particular polymerization initiator, little forms an unpolymerized layer on the surface even when polymerized and cured in a highly humid environment such as in the oral cavity, and is suited as a filling/restorative material for dental use.

The invention discloses fluorinated hyperbranched polyester acrylate and a preparation method thereof. Fluoride-alcohol and hydroxy acrylate are chosen to react with diisocyanate respectively to achieve two semi-additive products, and the two semi-additive products in proper proportions are used to react with hydroxyl-terminated hyperbranched polymer, to achieve hyperbranched polymer fluorine terminated bases with acrylic acid ester base groups and halothane base groups linked to the hyperbranched molecular framework through carbamate base groups as well as acrylic acid modified hyperbranched polymer. The iso-cyan acid radical reaction of the method has high activity, the Fluoro-alcohol conversion rate is high, the raw materials are cheap and easy to obtain, the operation is easy, and capable of facilitating industrial production. The fluoric hyperbranched polyester acrylate achieved by the method can be applied to ultraviolet-light solidification coating, the achieved coating has sound hydrophobic and oleophobic performances, and the industrial application is very broad.

The invention discloses a polyurea adhesive composition and a preparation method thereof. The polyurea adhesive composition is mainly prepared from polyaspartic ester, nanofiller and a curing agent. The polyaspartic ester is prepared by enabling an organic diamine compound and maleate to make a Michael addition reaction; the curing agent is prepared from an organic diisocyanate or polyisocyanate component, and can be a monomer, a polymer, a derivative of isocyanate, a prepolymer or a semi-prepolymer; the nanofiller is selected from nano-silicon dioxide, nano-titanium dioxide and nano-silicon carbide. By utilizing the Michael addition reaction of the organic diamine compound and the maleate, primary amine is transformed into secondary amine on the one hand, and a group having higher steric hindrance is introduced on the other hand, so that the defects that a polyurea material is rapid in reaction time and short in gelation time are overcome; the nanofiller is added into the polyurea adhesive composition, so that the stress shrinkage caused during the curing of an adhesive film is effectively reduced, and the polyurea adhesive composition is high in bonding strength.

The invention relates to a method for preparing a self pore-forming calcium phosphate cement bracket, which comprises the following steps of: 1) uniformly mixing calcium sulfate hemihydrate and tricalcium phosphate cement powder to obtain the mixed cement powder; 2) heating gelatin and NaH2PO4 with stirring in water at the temperature of between 45 and 50 DEG C until the gelatin and the NaH2PO4 are dissolved completely to obtain mixed solution; 3) uniformly mixing the mixed cement powder obtained by the step 1) and the solution obtained by the step 2), adding 25 to 50 percent aqueous solution of glutaraldehyde immediately, injecting the mixed cement powder slurry into a steel mould, then mixing the slurry at room temperature for 60 to 90 seconds, keeping the temperature of the slurry to be 37 DEG C after taking out, and then curing the slurry for 1 to 2 hours under the condition that the humidity is 100 percent to obtain the composite bracket. When the porosity is 71 percent, the average value of the compression strength can be increased to 8.1MPa; the bracket has high porosity and compression strength, and plays a better role in supporting in a human body, and the macropore diameter is between 100 and 300 mu m; and the self pore-forming calcium phosphate cement bracket prepared by the invention can be used as a repairing material of a human hard tissue.

The invention discloses a synthetic resin cementing compound used for an EO-stage fiberboard. The synthetic resin cementing compound consists of melamine modified urea resin and a firming agent and is characterized in that the compositions of reaction material of the urea resin by weight percentage are: 4.0 to 6.0 percent of the melamine, 40.0 to 42.0 percent of urea, 52.0 to 56.0 percent of formaldehyde, and 0.4 to 0.6 percent of an accelerating agent; acid and alkali are appropriate and the total mol ratio is between 0.90 and 0.93; and the cementing compound is obtained by the systemization and reaction of the materials. The cementing compound has good cementation strength, appropriate curing time, and the content of 0.06 to 0.08 percent of free formaldehyde, etc. E1 and the E0-stage fiberboard with good quality can be produced stably and have the advantages of low glue feeding amount, strong adaptability to the hot press molding technology and high curing speed in the hot press molding process, etc., thereby meeting the need of the market on products of high environmental performance fiberboards.

The invention relates to a preparation method of room-temperature regenerated phenolic resin and a recycling technology and application thereof. The preparation method comprises the following steps of according to parts by mass, melting and blending 100 parts of thermoplastic phenolic resin and 18.4 to 55 parts of boric acid compound at the temperature of 60 to 100 DEG C, so as to obtain boron-containing thermoplastic phenolic resin; or, dissolving 100 parts of thermoplastic phenolic resin and 20 to 50 parts of boric acid compound into an organic solvent with low boiling point at the temperature of 40 to 60 DEG C, so as to obtain the boron-containing thermoplastic phenolic resin; curing, so as to obtain the room-temperature regenerated phenolic resin. The preparation method has the advantages that the preparation technology of the resin is simple; the resin is dissolved into the mixing solvent of ethyl alcohol and water at room temperature, so that the resin can be recycled; the resin can be used for preparing the recyclable fiber reinforced boron-containing thermoplastic phenolic resin-based composite material. The prepared boron-containing thermoplastic phenolic resin has the advantages that the function of arylboronic acid ester structure promoting the heat-resistant property of the thermoplastic phenolic resin is fully realized, and the technology of the resin and the mechanical property of the composite material can be simultaneously realized.

The invention discloses a preparation method for an organic silicon resin with high curing activity and high temperature resistance, which comprises the following steps: carrying out hydrolytic polycondensation on two kinds of alkyl alkoxy silane and one kind of metal acid ester to polymerize into a silicone resin polymer with proper molecular weight; and using a low-toxic organic solvent as a diluting agent, and adding a curing agent into the low-toxic organic solvent so as to obtain the organic silicon resin with high curing activity and high temperature resistance which can be used as a coating matrix resin. Compared with the common organic silicon resin, the synthetical organic resin has the advantages of excellent heat resistance, high curing activity, good adhesive force, considerable stability, excellent light stability, and excellent environmental friendliness; the preparation method has simpler synthetic route, easily-obtained raw materials, and low price; and the synthetical silicon resin is a low-cost and high performance resin, and is suitable for large-scale preparation and industrialized production.

The invention relates to a high-fiber-content fiber-reinforced rigid polyurethane foam composite board and a manufacturing method thereof; the high-fiber-content fiber-reinforced rigid polyurethane foam composite board is made from polyurethane resin and reinforcing fibers as base materials, as well as hybrid polyether polyol, a flame retardant, a rigid foam stabilizer, a coupling agent, a catalyst, a foaming agent, an antioxidant, an ultraviolet screening agent, an isocyanate, and reinforcing fibers, wherein the content of the reinforcing fibers is greater than 60%; by means of various techniques such as using low-hydroxyl value low-functionality hybrid polyether polyol and using the coupling agent, the problem that polyurethane resin is insufficiently steeped to reinforcing fibers is solved, the content of the reinforcing fibers is increased, a fiber-reinforced rigid polyurethane foam article higher than 840 kg/m<3> in density and higher than 60% in reinforcing fiber content can be manufactured, the technical blank of fiber-reinforced rigid polyurethane foam composite boards is filled, product specifications and properties are diversified, and the different technical index requirements are met.

The invention discloses a chill-free processing method of a wind-driven generator hub, and the method comprises the following steps: manufacture of a mould, manufacture of a sand mould and moulding by casting, wherein in the manufacture of the sand mould, a completely opened bottom gating system is utilized; an ingate is designed to be disc-shaped; a downgate on an upper sprue is a quantitative ladle stopper sprue gate; the ratio of the components is F(straight):F(transverse):F(internal)=1:(1.5-2):(25-28); a rectangular vent hole is arranged at the highest point at the top face of a casting; the total section area of the rectangular vent hole is greater than that of the ingate; a casting head is arranged on the top face of the casting; the height of the single casting head is greater than 400 mm; no chills are discharged during the manufacture procedure; in the moulding by casting, the casting speed of melted iron entering into a casting cavity is controlled within 0.5-1.0 m/s; the casting time is controlled within 150-210 seconds; and the casting temperature is between 1300 and 1310 DEG C. The chill-free processing method of the wind-driven generator hub disclosed by the invention has the advantages that the method adapts to the large scale production of low-temperature ductile iron castings for large wind-driven generator with quite high requirements, the process is simple, and the production cost is low.

The invention relates to a preparation method of brushite bone cement. The preparation method comprises the following steps: preparing an acidic bone cement solidification liquid by adopting a citric acid solution as a main body and adopting phosphorylated chitosan, hydroxypropyl methyl cellulose and gelatin as modifying agents; fully mixing monohydrate calcium dihydrogen phosphate, beta-tricalcium phosphate and SiO2 to obtain SiO2 modified brushite bone cement solid-phase powder; and mixing the bone cement solid-phase powder with the solidification liquid according to a solid-to-liquid ratio to obtain the brushite bone cement, wherein a solidification product comprises brushite as a main component. By adopting the preparation method disclosed by the invention, the solidification time of the brushite bone cement which adopts a conventional citric acid solution as the solidification liquid can be prolonged to be 6-20 minutes, and the flowability of blended slurry can be increased; and meanwhile, by virtue of complexing action of phosphorylated chitosan, solid-liquid separation of the blended slurry at a certain pressure can be avoided, and the comprehensive performance of the blended slurry can preferably meet the requirements of clinical application.

A powder-liquid dental curable material kit composed of (A) a liquid material and (B) a powder material, wherein the liquid material (A) contains (a1) a radically polymerizable (meth)acrylic monomer, (a2) an organic halogen compound and (a3) a radical chain transfer agent; the powder material (B) contains (b1) non-crosslinked resin particles, (b2) a pyrimidinetrione compound and (b3) an organic metal compound; and (Z) a peroxide is blended in at least one of the liquid material (A) and the powder material (B). This curable material kit is capable of reducing the heat generation during the curing of a curable material which is a mixture of the liquid material (A) and the powder material (B) and is not susceptible to the excessive prolongation of the curing time even when the curable material is cured by a brush-on technique, thereby ensuring an appropriate curing time for both of a brush-on technique and a kneading technique.

The present invention relates to the preparation process of nanometer modified UV cured resin paint. The preparation process includes preparing nanometer oxide through sol-gel process, controlling calcining temperature and adding PVA or gelatin to control the particle size of the nanometer oxide in 20-40 nm; measuring the particle size, crystal form, etc. of the nanometer oxide; surface modifying the nanometer oxide with siloxane or titanate coupling agent; mixing pre-polymerizing glue, active monomer, photosensitive agent, initiator and solvent to form the UV cured resin paint pre-polymer; and adding and ultrasonically dispersing the nanometer oxide to obtain the nanometer modified UV cured resin paint. The nanometer modified UV cured resin paint of the present invention has prolonged curing period, complete curing, homogeneous coating thickness, high coating hardness, high heat resistance, and high wear resistance.

The invention relates to emulsified asphalt modified by carbon nanometer fiber and a preparing method thereof. The nanometer material characteristic of the nanometer carbon fiber and the characteristic of nanometer carbon materials are utilized for modifying emulsified asphalt, high-temperature performance and low-temperature performance of the emulsified asphalt can be improved, pavement materials short in curing time and high in curing strength are obtained, site cold mixing and cold laying can be achieved during construction of fast patching of asphalt road pits and repair of municipal road observation well lids, construction time is short, and the asphalt has a better application effect and has considerable application prospects.