1967 results about "Intrinsic viscosity" patented technology

A polypropylene resin composition, which is light weighing, has very high values for the stiffness and heat resistance and is superior in the scratch-proof property with better moldability upon molding and which can be injection-molded into formed articles without occurrence of cracking, comprising 5-25% by weight of a higher molecular weight polypropylene (A) having an intrinsic viscosity [eta], determined in decalin at 135° C., in the range from 6 to 11 dl/g and 95-75% by weight of a lower molecular weight polypropylene (B) having an intrinsic viscosity [eta], determined in decalin at 135° C., in the range from 0.6 to 1.6 dl/g, wherein the said resin composition has the following charactristic features <<1>> and <<2>>, namely,<<1>> an isotactic pentad fraction (mmmm-fraction), determined by 13C-NMR, of at least 96.5% and<<2>> a molecular weight distribution value expressed by Mw/Mn (weight-average molecular weight/number-average molecular weight), determined by gel permeation chromatography (GPC), of at least 8.

Polypropylene composition comprising (a) a high melt strength polypropylene having a melt flow rate MFR 2 (230 °C) of equal or below 15 g/l 0min and a branching index g' of below 1.0, (b) a first heterophasic propylene copolymer comprising €¢ a polypropylene having a melt flow rate MFR 2 (230 °C) in the range of 50 to 500 g/10min and an elastomeric propylene copolymer having a propylene content in the range of 50 to 80 wt.-% and €¢ an intrinsic viscosity (IV) of equal or more than 2.5 dl/g, (c) a second heterophasic propylene copolymer comprising €¢ a random propylene copolymer having a melt flow rate MFR 2 (230 °C) in the range of 1 to 40 g/10min, a branching index g' of 1.0, and a comonomer content of more than 0.5 wt.-%,and €¢ an elastomeric propylene copolymer having a propylene content in the range of 50 to 80 wt.-%, and an intrinsic viscosity (IV) of equal or below 2.4 dl/g, (d) a polyethylene plastomer having an ethylene content of at least 50 wt.-%, and (e) a mineral filler (F).

Photographically useful materials are disclosed comprising a hyperbranched polymer segment and multiple pendant photographically useful groups. Such materials may be prepared by forming an active hyperbranched polymer segment with multiple functionalized end group sites, and reacting the active hyperbranched polymer segment with an active compound comprising a photographically useful group to form a hyperbranched polymer ended with photographically useful groups. The hyperbranched segment may comprise any kind of polymer segment with hyperbranched architecture, and the active end groups may comprise any kind of reactive site. The active hyperbranched polymer may comprise any kind of other functional groups which are located in either backbone or the ends. The hyperbranched polymers containing photographically useful groups obtained in accordance with the invention are particularly advantageous in that they enable polymer structures comprising components exhibiting different photographically useful properties, while maintaining relatively low intrinsic viscosities compared to non-hyperbranched polymers containing photographically useful groups of similar chemical compositions. Additionally, the hyperbranched polymers are advantageous with respect to dendrimer type polymers in that a wide variety of hyperbranched polymer compositions may be synthesized in accordance with commercially acceptable processes.

The present invention provides a propylene/1-butene random copolymer (PBR) having excellent flexibility, impact resistance, heat resistance and low-temperature heat-seal properties, a polypropylene composition containg the copolymer, a sheet, film or stretched film comprising the composition and a composite film having a layer of the composition. The propylene/1-butene random copolymer contains 60 to 90 mol % of propylene units and 10 to 40 mol % of 1-butene units and has a triad isotacticity of not less than 85% and not more than 97.5%, a molecular weight distribution (Mw/Mn) of from 1 to 3, an intrinsic viscosity of from 0.1 to 12 dl/g, a melting point (Tm) of from 40 to 120° C., and satisfies the following relation

146 exp(−0.022M)≧Tm≧125 exp(−0.032M)

wherein Tm represents a melting point and M (mol %) represents a content of 1-butene constituent units.

The invention, further, provides a transition metal compound useful as an olefin polymerization catalyst and an olefin polymerization catalyst containing the transition metal compound. The transition metal compound is represented by the following formula (2a):

wherein each of R¹ and R³ is hydrogen, R² and R⁴ are selected from a hydrocarbon group and silicon-containing group, R⁵ to R¹³ are selected from hydrogen, a hydrocarbon group and silicon-containing group, and adjacent substituent groups R⁵ to R¹² may be linked to form a ring. R¹⁴ is an aryl group, and R¹³ and R¹⁴ may be linked to form a ring. M is a Group 4 transition metal, Y is a carbon atom, Q is halogen, etc, and j is an integer of 1 to 4.

A thermoplastic composition comprises poly(arylene ether) having an initial intrinsic viscosity greater than 0.25 dl/g as measured in chloroform at 25° C.; a polyolefin having a melt temperature greater than or equal to 120° C. and a melt flow rate of 0.3 to 15; a first block copolymer having a aryl alkylene content greater than or equal to 50 weight percent based on the total weight of the first block copolymer; a second block copolymer having an aryl alkylene content less than 50 weight percent based on the total weight of the second block copolymer; and a flame retardant, wherein the poly(arylene ether) is present in an amount greater than the amount of polyolefin. The composition is useful in the production of covered wire.

The present invention is a method of preparing a high molecular weight copolyester bottle resin that has excellent melt processing characteristics. The method includes the steps of reacting a diacid or diester component and a diol component to form modified polyethylene terephthalate, wherein diol component is present in excess of stoichiometric proportions. Together, the diacid or diester component and the diol component must include at least 7 percent comonomer. The remainder of the diacid component is terephthalic acid or dimethyl terephthalate and the remainder of the diol component is ethylene glycol. The modified polyethylene terephthalate is copolymerized in the melt phase to an intrinsic viscosity of between about 0.25 dl/g and 0.40 dl/g to thereby form a copolyester prepolymer. Thereafter the copolyester prepolymer is polymerized in the solid phase to form a high molecular weight bottle resin that has an intrinsic viscosity of at least about 0.70 dl/g, and a solid phase density of less than 1.413 g/cc.

The invention relates to semi-aromatic high-temperature resistant nylon and its preparation method. The preparation method provided by the invention comprises the following steps of: by weight, adding 75-95 parts of nylon salt, 0.2-0.8 part of an end-capping reagent, 0.1-0.6 part of a catalyst, 0.5-1 part of an antioxidant, 0.1-0.5 part of a lubricant and 30-50 parts of deionized water into a stirred polymerization autoclave, synthesizing a high-temperature resistant nylon prepolymer in a high-pressure stirred tank reactor, and carrying out melting extrusion on the prepolymer through a double screw extruder twice. According to the invention, devolatilization efficiency is raised, tackifying time is shortened, and simultaneously the high-viscosity polymer in the reaction vessel can be smoothly discharged. By different extrusion temperatures, high-temperature degradation of the prepolymer is prevented. Intrinsic viscosity of the high-temperature resistant nylon prepared by the method is higher than that of a polymer prepared by a present method. Therefore, the obtained nylon in the invention has better mechanical properties.

The present invention provides a polypropylene-based resin composition which is light weighing, has a very high values of stiffness and heat resistance, exhibits superior scratchproof property and is superior in the processibility with better flowability upon molding thereof, especially that can favorably be used for injection molding. The polypropylene-based resin composition according to the present invention is constituted predominantly of polypropylene and has the following characteristic features A and B:A: a melt flow rate (MFR), determined at 230° C. under a load of 2.16 kg, in the range of 5-50 g/10 min. andB: a content of a high molecular weight polypropylene having an intrinsic viscosity [eta] of 9-13 dl/g in the range of 15-30% by weight.

Methods to produce thermoforms from P4HB homopolymer and blends thereof have been developed. These thermoforms are produced from films and sheets including P4HB, wherein the intrinsic viscosity of the P4HB is less than 3.5 dl/g, but greater than 0.35 dl/g, and the thermoforms are produced at a temperature equal to or greater than the softening point of P4HB, and more preferably at a temperature higher than the melting point of P4HB. A preferred embodiment includes a P4HB thermoform wherein a film or sheet including a P4HB polymer is thermoformed at a temperature between its melting point and 150° C. In a particularly preferred embodiment the thermoform is a laminate made from a P4HB film and a P4HB mesh.

Airbag cushions manufactured from polyester yarn having certain levels of intrinsic viscosity (IV) and certain specific carboxyl end group (“CEG”) levels perform unexpectedly well in high temperature and high humidity environments for airbag cushion applications. This specification identifies certain polyester yarns and characteristics of such polyester yams that are necessary to achieve unexpectedly good performance in such high humidity and high temperature applications. A polymeric polyester yarn for airbags, said yarn having a high degree of tenacity even after a long period of exposure to high temperature and high humidity conditions is disclosed. In one aspect of the invention, a polyester yarn having CEG of less than about 60 equivalents/10⁶ gram, and more preferably less than about 30 equivalents/10⁶ grams, is particularly useful. In another embodiment, a polyester yarn having an IV value of at least about 0.6 performs exhibits superior properties.

Provided is a method for producing a polyester film, including: subjecting a polyester raw material resin, which contains a titanium compound and has an intrinsic viscosity of from 0.71 to 1.00, to melt extrusion using a twin-screw extruder which includes a cylinder; two screws disposed inside the cylinder; and a kneading disk unit disposed in at least a portion of a region extending from a 10%-position to a 65%-position of screw length with respect to an upstream end of the screws in a resin extrusion direction as a starting point, at a maximum shear rate generated inside the twin-screw extruder of from 10 sec⁻¹ to 2000 sec⁻¹;

• • forming an unstretched film by cooling and solidifying the melt extruded polyester resin on a cast roll; subjecting the unstretched film to biaxial stretching in a longitudinal direction and a lateral direction; and heat fixing the stretched film formed by biaxial stretching.

A propylene random copolymer and a film laminate thereof is described having excellent blocking resistance and transparency and substantially maintaining favorable low-temperature heat-sealing properties after corona discharge treatment. The propylene random copolymer of the invention includes a propylene component and an alpha-olefin component having 4 to 10 carbon atoms, wherein the content of the alpha-olefin component is in the range of about 6% to about 40% by weight, the intrinsic viscosity [eta] measured in tetralin at 135° C. is not lower than about 0.45 dl/g and not higher than about 5.0 dl/g, and the melting point (Tm) measured by a differential scanning calorimeter and the content of 20° C. xylene soluble fraction (CSX) fulfill a relationship of

The invention relates to low melting point copolyester and a preparation method thereof. The low melting point copolyester is made from the following monomers followed by the esterification reaction and the polycondensation reaction: (a) terephthalic acid (PTA) and isophthalic acid (IPA), (b) 1, 4- butanediol (BDO) and (c) polyethylene glycol 600 to 6000 (PEG); wherein, in the a component, the feeding mass ratio of the terephthalic acid and the isophthalic acid is between 80 to 20 : 20 to 80; in the c component, the feeding weight ratio of polyethylene glycol is 1 to 30 percent based on the a; the molar ratio of the a and the b is 1:1.5 to 2.3. The preparation method comprises an esterifcation stage and a polycondensation stage. The copolyester has the characteristics of low melting point, good crystallization property, high intrinsic viscosity and difficult adhesion of particles, and is suitable for spinning the filament, the staple fibers and the non-woven fabrics.

A method of increasing the intrinsic viscosity of polyester by means of solid state polymerization, wherein a polyester plastics melt is granulated and after granulation is conveyed into a thermal treatment container (13) for thermal treatment therein, the granules being produced slightly below their melting temperature and being fed into the thermal treatment container (13) immediately after granulation so as to utilize the residual heat in the granules, as well as an arrangement for increasing the intrinsic viscosity of polyester by means of solid state polymerization with a granulating and a thermal treatment unit, with an unheated, thermally insulated container (13) or a container (13) having wall heating means (15) being provided as the thermal treatment unit, which is directly connected to the granulating unit via a conveying device (11, 36, 37).

The invention relates to a preparation method of polybutylene terephthalate/adipate butanediol copolyester, which utilizes a titanium compound and an antimony compound as the composite catalyst, the mole ratio of terephthalic acid to adipate is 3:7-8:2, the ratio of the total mole of the terephthalic acid and the adipate to the mole of 1,4-butanediol is 1:1.0-1.8, esterification is carried out at normal pressure and the temperature of 150-220 DEG C, the pressure is reduced to high vacuum 10-150 Pa for the reaction, the final temperature for the reaction is 265-280 DEG C, and inert gas is utilized to recover the pressure to be normal to obtain the copolyester. The reaction time is shortened, the production amount of tetrahydrofuran is small, the intrinsic viscosity of copolyester chips is 0.90-1.32 dL/g, the hue b value of the product is between 0 and 8, the L value is between 68 and 85, and the product of the polybutylene terephthalate/adipate butanediol copolyester can be used in the fields of various soft package plastic products.

High-quality pectins may be extracted from pectin-containing plant materials with microwave energy under pressure. The pectins are characterized by increased molecular weight, size and intrinsic viscosity when compared to pectin extracted by conventional heating techniques.

The invention provides a propylene random block copolymer (A) that has a melt flow rate from 0.1 to 100 g/10 min and a melting point from 100 to 155° C. and includes 90 to 60% by weight of a portion insoluble (D_insol) in n-decane at room temperature and 10 to 40% by weight of a portion soluble (D_sol) in n-decane at room temperature, wherein the D_insol satisfies the following requirements (1) through (3) and the D_sol satisfies the following requirements (4) through (6). The invention further provides molded articles such as sheets, films, injection molded articles, hollow molded articles, injection blow molded articles and fibers, which are formed of the propylene random block copolymer (A) or a propylene resin composition containing the propylene random block copolymer (A). (1) The molecular weight distribution (Mw/Mn) obtained by GPC of the D_insol is from 1.0 to 3.5, (2) the content of skeletons derived from ethylene in the D_insol is from 0.5 to 13% by mole, (3) the total amount of 2,1- and 1,3-propylene units in the D_insol is 0.2% by mole or less, (4) the molecular weight distribution (Mw/Mn) obtained by GPC of the D_sol is from 1.0 to 3.5, (5) the intrinsic viscosity [η] in decalin at 135° C. of the D_sol is from 1.5 to 4 dl/g and (6) the content of skeletons derived from ethylene in the D_sol is from 15 to 35% by mole.

A magnetic recording medium comprising a non-magnetic support and at least one magnetic layer containing a ferromagnetic powder and a binder, wherein the non-magnetic support has an intrinsic viscosity of from 0.46 to 0.58 dl/g and a refractive index in a direction of a depth within a range from 1.490 to 1.500.

A glass run channel comprising a glass run channel body composed of a bottom wall and side walls extending from two opposite edges of the bottom wall, the glass run channel body having a substantially U-shaped section and provided with a groove, and tonguelike draining parts protruding from vicinities of distal edges of the side walls toward the bottom wall of the glass run channel body so as to become proximate to each other. Each of the tonguelike draining parts has a window glass contact part composed of a surface to be brought into contact with a window glass, which comprises a layer of a thermoplastic elastomer and a layer of an ultrahigh molecular weight polyolefin composition. The layer of ultrahigh molecular weight polyolefin composition is arranged so as to contact a window glass. The ultrahigh molecular weight polyolefin composition comprises at least a polyolefin (composition) having a specified intrinsic viscosity and an olefinic thermoplastic elastomer. The glass run channel is excellent in the durability, tight contactability with a window glass exhibited when the window glass is held closed and supple slide exhibited when a window glass is closed or opened and, even when twisted or bent, is free from a creasing of the ultrahigh molecular weight polyolefin composition layer.