39results about How to "Moderate molecular weight distribution" patented technology

The invention discloses a high-slump-retaining coagulation-retarding type polycarboxylate water reducing agent and a preparation method and application thereof. The water reducing agent is prepared from, by molar part, 10-30 parts of small-molecule unsaturated carboxylic acid, 3-8 parts of ester of small-molecule unsaturated carboxylic acid, 1-5 parts of salt of small-molecule unsaturated carboxylic acid, 2-6 parts of polyethylene glycol diacrylate, 1-5 parts of an unsaturated polyether macromonomer, 8-20 parts of an acrylamide monomer, an initiator and a chain transferring agent, wherein theacrylamide monomer is a group consisting of three monomers including acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and 2-acryloylamino-2-phenylethanesulfonic acid (AMSS). The molecular structure of the water reducing agent is designed according to the construction demands for workability and slump retaining performance, and the high-slump-retaining coagulation-retarding type polycarboxylate water reducing agent with excellent comprehensive performance is finally obtained. During construction, a high water reducing rate can be achieved by applying a low dosage of the water reducing agent, the construction can be guaranteed, the slump retaining performance is excellent, the slump is basically not changed within 3 hours, and the water reducing agent has wide applicabilityin concrete construction.

The invention discloses an olefin polymerization catalyst, which consists of two electron-donating compounds, including a polycyclic 1,4-diester compound shown as a general formula (I) and a phthalic acid ester compound and can be used for effectively solving the problems of poor hydrogen regulation sensitivity, over-narrow molecular weight distribution of a product and the like of a catalyst caused by separate use of an electron-donating compound. The average particle size of the obtained catalyst is 5-100 microns, and the specific surface area is more than 100 m<2>/g. The catalyst is approximately spherical, has high comprehensive performance, and can be well suitable for the requirements of slurry, gas-phase and mass propylene polymerization processes. The molecular weight distribution of an obtained polymerization product is appropriate.

The invention relates to a non-bridge mono/bi-nuclear metallocene compound and a relative application olefin polymerization catalyst technical field. The compound contains 1-(4-methyl)-phenyl-2, 3, 4, 5-tetramethyl cyclopentadienyl-(2, 4, 6-tertiary butyl phenoxy)-titanium chloride, and (3, 3', 5, 5'-quattuor isopropyl-4, 4'-biphenyl oxygen)-bi-[1-(4-methyl)-phenyl-2, 3, 4, 5-tetramethyl cyclopentadienyl-titanium dichloride] or the like. The metallocene compound can be used as main catalyst, while alkyl aluminum is used as promoter, or organic boron compound and alkyl aluminum are assembled into a promoter system, to catalyze and synthesize high-molecular-weight atactic polypropylene with improved catalysis activity and polymer molecular weight, which can catalyze the polymerization of vinyl and alpha-olefin, to obtain the polymer with suitable molecular weight in narrow distribution and high co-monomer content.

The invention discloses a preparation method of high-molecular sodium polyacrylate for water-absorbent resin. The preparation method includes the steps: (1) preparing sodium acrylate water solution; (2) emulsification; (3) polymerization reaction; (4) purification. The preparation method of the high-molecular sodium polyacrylate for the water-absorbent resin is simple and convenient to operate and easy to implement, the cost of raw materials is reduced is reduced by reversed emulsion polymerization, yield and purity of reactants are improved, and the obtained polyacrylic resin is transparent in appearance, stable in performance, moderate in molecular weight distribution and excellent in water absorptivity.

The invention relates to a supported non-metallocene catalyst and its preparation method and use. The supported non-metallocene catalyst has the characteristics of simple and feasible processes and obvious comonomer effects. A polyolefin product prepared by the supported non-metallocene catalyst is especially suitable as a raw material which can be directly used for preparing chlorinated polyolefin.

The invention belongs to the technical field of petroleum resin, and particularly relates to a preparation method of light-color modified petroleum resin with low softening point. The preparation method of the light-color modified petroleum resin with low softening point comprises the following steps of pretreating the byproduct of C5 fraction twice to remove cyclopentadiene and dicyclopentadiene,so as to obtain a mixture which has lower content of cyclopentadiene and contains multiple types of diolefin, monoolefine and alkene, wherein the C5 fraction byproduct is produced in the petroleum cracking process for preparing the ethylene; selecting one or multiple of aromatic vinyl monomers as a polymer modifying agent, selecting a compound catalyst, enabling the olefin in the C5 fraction andthe aromatic vinyl monomers to generate polymerizing reaction under the certain polymerizing condition, effectively controlling the heat of the polymerizing reaction, and slowly performing the reaction, so as to prepare the light-color modified petroleum resin with low softening point with the advantages of stable quality, excellent property and moderate molecular weight.

The invention provides a solid catalyst component used for olefin polymerization. The solid catalyst component includes Mg, Ti, halogen and at least two electron donor; one electron donor is 2-substituted amino-phenyl ester compound A selected from a general formula (I), and the other electron donor is selected from a Lewis alkali compound B containing one or more electronegative groups. A catalyst containing the solid catalyst component and an application of the catalyst in olefin polymerization, especially in propylene polymerization, are also disclosed. The catalyst has high activity; highisotacticity and wide molecular weight distribution polypropylene can be obtained; high isotacticity polypropylene can also be obtained without external electron donors; high activity can still be maintained when Al/Ti and Al/Si are reduced or polymerization time is prolonged during polymerization; and the solid catalyst component is suitable for manufacturing low ash polymers.

The invention relates to a polymeric hindered amine light stabilizer HA-88 and a preparation method of a polymeric hindered amine light stabilizer HA-88 intermediate. The method is characterized in that firstly, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine is reacted with cyanuric chloride; after the reaction is finished, the obtained reaction liquid is dropwise added into an N,N'-bis(3-aminopropyl) ethylenediamine solution; after the dropwise adding is completed, alkali metal hydroxide or salt is added as a catalyst; reaction is performed in a backflow state. The mild reaction conditions areused; by using different feeding methods and sequences, the molecular weight distribution of the intermediate can be obviously improved; the disubstituted substance content of N,N'-bis(3-aminopropyl)ethylenediamine is obviously increased; the condition of mixed ingredients of the product synthesized by the existing process is greatly reduced; the intermediate can be directly applied to HA-88 synthesis without post treatment; the dispersion index of the prepared HA-88 is relatively low; the molecular weight distribution is proper; the product quality is high; the application effect is prominent.

The invention relates to a synthesis method of a bimodal-distribution ethylene-propylene-nonconjugated diene random copolymer, which comprises the following steps: introducing a gas mixture of ethylene, propylene and hydrogen into a reaction kettle, adding a primary catalyst, a cocatalyst and an activating agent, and adding the non-conjugated diene for polymerization at 25-45 DEG C under the pressure of 0.3-0.6 MPa. The propylene/ethylene mol ratio is 1-6; the hydrogen accounts for 0.05-0.5 mol% in the comonomer; the addition amount of the non-conjugated diene in every 1000mL of hexane is 2-10mL; the acidic-phosphate modified vanadium compound is used as the primary catalyst, the halogenated alkyl aluminum is used as the cocatalyst, and the mol ratio of Al in the cocatalyst to V in the primary catalyst is (1-100)/1; the activating agent is ethyl trichloroacetate, and the mol ratio of the activating agent and the vanadium compound is (1-10)/1; and the copolymer has high Mooney viscosity and moderate molecular weight distribution, and is used in processing rubber of automobile seals.

The invention relates to a preparation method and application of a compounded carrier supported olefin polymerization catalyst. The method is characterized in that a compounded carrier formed by a magnesium compound and a porous carrier is treated through a silicon-containing compound and a chemical treating agent containing group IVB (titanium, zirconium and hafnium) metal halides, and filtering, washing and drying are then carried out to obtain the compounded carrier supported olefin polymerization catalyst. The catalyst exhibits a high polymerization activity when used for olefin polymerization, and an obtained polymer achieves a high bulk density, uniform particle distribution, as well as moderate molecular weight distribution. The catalyst is particularly suitable for the manufacture of ultra-high molecular weight polyethylene.

The invention provides a silicofluoride mixed glue. The invention mainly comprises silicofluoride, white carbon black, scale control agent, heat stabilizer, curing agent and so on. The vulcanised silicofluoride mixed glue possesses properties of high hot strength, good low and high temperature resistance, perfect solvent resistance and oil resistance. The invention also discloses the method for manufacturing silicofluoride mixed glue.

The invention discloses a solid catalyst component for producing polymers. The solid catalyst component comprises magnesium, titanium, halogen and internal electron donor compounds, and the internal electron compounds comprise a first internal electron donor compound as shown in a general formula (I) and a second internal electron donor compound as shown in a general formula (II). The invention also provides a catalyst system comprising the solid catalyst component. When the catalyst component provided by the invention is used for propylene polymerization reaction, polymerization activity is high, stereospecificity is good, hydrogen regulation sensitivity is good, and the molecular weight distribution of the obtained polymers is moderate.

The invention discloses a catalyst combination that includes silanolate compound and F contained organo-silicon low molecular polymer that is selected from methyl fluoride silicone oil, hydroxyl silicone oil, and vinyl silicone oil. The weight rate of the silanolate compound and the Fl contained organo-silicon is from 1:1 to 50:1. The invention also discloses the method to make Fl contained silanol by using the catalyst compound.

An olefin polymerization catalyst, containing the following ingredients:(1) solid catalyst with general formula of TiAlmMgpClq(OR)s(MgCl2)t*n(THF), wherein R is an alkyl from C2-C4, m is 0-2, p is 0-10, q is 4-10, s is 3-14, t is 0.5-1.5 and n is 2-13; and (2) auxiliary catalyst of alkyl aluminum selected from alkyl aluminum or modified alkyl aluminum. The Moore ratio of aluminium in the auxiliary catalyst to titanium in the solid catalyst is 150-1000:1. The raw materials for preparing olefin polymerization catalyst are cheap and easy to get, the preparation process is simple, and the olefin polymerization catalyst can be applied in olefin polymerization to get polyolefines in appropriate molecular weight range.

The invention relates to an ethylene polymer and a preparation method thereof. The ethylene polymer has an average particle size of 50-3000 [mu] m, a bulk density of 0.28-0.55 g/cm < 3 >, a true density of 0.930-0.980 g/cm < 3 >, a melt index of 0.01-2500 g/10 min under a load of 2.16 Kg at 190 DEG C, a crystallinity of 30-90%, a melting point of 105-147 DEG C, a comonomer molar insertion rate of 0.01-5 mol%, a weight-average molecular weight of 20,000-400,000 g/mol, and a molecular weight distribution of 1.8-10. In the preparation method, an alkane solvent with a boiling point of 5-55 DEG C or a mixed alkane solvent with saturated vapor pressure of 20-150KPa at 20 DEG C is used as a polymerization solvent, and under the condition that the molar ratio of hydrogen to ethylene is (0.01-20): 1, preferably (0.015-10): 1, and the molar ratio of hydrogen to a comonomer is (8-30): 1, preferably (10-25): 1, the polymerization reaction is carried out for 1-2 hours under the existence of a polyethylene catalytic system. A raw material comprising ethylene, hydrogen and a comonomer is subjected to kettle slurry polymerization to produce an ethylene polymer.