290 results about "Inherent viscosity" patented technology

A polyester polymer and method for making the polyester, wherein the polyester is prepared by (1) combining in a reactor a monomer containing a diacid moiety; a monomer comprising a diol moiety; and a monomer containing an isosorbide moiety; with a condensation catalyst suitable for condensing aromatic diacids and diols; and (2) heating the monomers and catalyst to polymerize the monomers to yield a polyester having an inherent viscosity of at least about 0.15 dL/g.

A sheet made of a polyester which includes monomer units of terephthaloyl moieties, ethylene glycol moieties and isosorbide moieties is described. The polyester has an inherent viscosity of at least about 0.35 dL/g when measured as a 1% (weight/volume) solution of said polyester in o-chlorophenol at a temperature of 25 DEG C. The present invention also relates to a method of making the polyester sheet described above and a method of thermoforming the sheet into articles.

An optical article made of a transparent polymer which includes terephthaloyl moieties, optionally, other aromatic diacid moieties; ethylene glycol moieties; isosorbide moieties; and, optionally, one or more other diol moieties, wherein the polymer has an inherent viscosity of at least about 0.35 dL/g as measured on a 1% solution (weight/volume) in o-chlorophenol at 25 DEG C.

Polyester compositions that provide a higher throughput in calendering processes may be prepared from a polyester having crystallization half time of at least 5 minutes, an inherent viscosity of about 0.55 to about 0.75 dL/g, a branching monomer, and a release additive. The polyester compositions show a combination of excellent melt strength with good shear response that permits higher calendering line speeds before melt fracture occurs. Also disclosed are processes for film or sheet by calendering the above compositions and the film or sheet produced therefrom. The polyester compositions, film, or sheet also may include plasticizers and/or flame retardants to increase their flexibility and enable their use in commercial applications requiring flame resistance. The film and sheet have excellent appearance and can be used in a wide range of decorative and packaging applications.

Described are polyester compositions comprising at least one polyester which comprises terephthalic acid residues, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and cyclohexanedimethanol, wherein the inherent viscosity and the Tg of the polyester provides for certain polyester properties. The polyesters may be manufactured into articles such as fibers, films, bottles or sheets.

Described are polyester compositions comprising at least one polyester which comprises terephthalic acid residues, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 1,4-cyclohexanedimethanol, wherein the inherent viscosity and the Tg of the polyester provides for certain polyester properties. The polyesters may be manufactured into articles such as fibers, films, bottles or sheets.

The invention relates to semi-aromatic polyamide and a preparation method thereof. The semi-aromatic polyamide is prepared by: adding aromatic dicarboxylic acids and the fatty diamine with 4-14 carbon atoms to an organic solvent to undergo neutralization reaction to prepare high-purification salt; pre-polymerizing by taking the high-purification salt as the raw material with the existence of water; preparing the semi-aromatic polyamide by the further tackification reaction of the prepolymer. By using high-purification salt, the preparation method can accurately control the molar ratio of dicarboxylic acids and diamine, and avoid the loss of the diamine. By purifying monomers in the salifying process, the preparation method also improves the quality of the semi-aromatic polyamide and obtains the semi-aromatic polyamide with high inherent viscosity, high crystallinity, high melting point and good mechanical performance.

Described as one aspect of the invention are polyester compositions A polyester composition comprising at least one polyester which comprises:

• • (A) a dicarboxylic acid component comprising:
    • i) 70 to 100 mole % of cyclohexanedicarboxylic acid residues or an ester thereof comprising:
      • (a) 80 to 99 mole % trans-cyclohexanedicarboxylic acid residues or an ester thereof; and
      • (b) 1 to 20 mole % cis-cyclohexanedicarboxylic acid residues or an ester thereof;
    • ii) 0 to 30 mole % of aliphatic dicarboxylic acid residues, other than cyclohexanedicarboxylic acid residues, having up to 16 carbon atoms or esters thereof, other than cyclohexanedicarboxylic acid residues; and
    • iii) 0 to 10 mole % of aromatic dicarboxylic acid residues having up to 20 carbon atoms; and
  • (B) a glycol component comprising:
    • i) 5 to 35 mole % of 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and
    • ii) 65 to 95 mole % of 1,4-cyclohexanedimethanol residues, 1,3-cyclohexanedimethanol residues, 1,2-cyclohexanedimethanol residues or esters thereof or mixtures thereof,

wherein the total mole % of said dicarboxylic acid component is equal to 100 mole %;

the total mole % of said glycol component is equal to 100 mole %;

wherein the inherent viscosity of said polyester is from 0.35 to 1.2 dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a concentration of 0.5 g/100 ml at 25° C.; and wherein said polyester has a Tg of from 66 to 120° C. The polyesters may be manufactured into articles.

Disclosed are multicomponent fibers derived from a blend of a sulfopolyester with a water non-dispersible polymer wherein the as-spun denier is less than about 6 and wherein the water dispersible sulfopolyester exhibits a melt viscosity of less than 12,000 poise measured at 240° C. at a strain rate of 1 rad/sec, wherein the sulfopolyester comprising less than about 25 mole % of residues of at least one sulfomonomer, based on the total moles of diacid or diol residues, and wherein said poly(ethylene) terephthalate has an inherent viscosity of less than 0.55 dL/g. The multicomponent fiber is capable of being drawn at a relatively high fiber speed, particularly at least about 2000 m/min, and may be used to produce microdenier fibers. Fibrous articles may be produced from the multicomponent fibers and microdenier fibers. Also disclosed is a process for multicomponent fibers, nonwoven fabrics, and microdenier webs.

A composition including polyalphaolefins that function as drag reducing agents and a process for the preparation of polyalphaolefins that function as drag reducing agents are disclosed. The process includes contacting alpha olefin monomers with a catalyst system, which includes a catalyst and an activator (co-catalyst) in a reactant mixture. The catalyst is a transition metal catalyst, preferably titanium trichloride, and the co-catalyst may include an alkylaluminoxane, alone or in combination, with a dialkylaluminum halide or a halohydrocarbon. The polymerization of the alpha olefin monomers produces a non-crystalline, ultra-high molecular weight polyalphaolefin having an inherent viscosity of at least 10 dL/g. The addition of the alkylaluminoxane during the polymerization process provides for a non-crystalline, ultra-high molecular weight polyalphaolefin and a more uniform molecular weight distribution of the resulting polyalphaolefin, thereby creating a drag reducing agent superior to known drag reducing agents. A process for forming a drag reducing agent comprising a non-crystalline, ultra-high molecular weight polyalphaolefin having an inherent viscosity of about at least 10 dL/g and a process for reducing drag in a conduit are also disclosed.

The present invention is directed to crystalline copolymers of l-lactide and a minor portion of a cyclic monomer, preferably epsi-caprolactone or trimethylene carbonate or both. The present copolymers have a melting temperature of at least 150° C. and a crystallinity of at least 25%. Preferred are high molecular weight copolymers having an inherent viscosity of at least 1.4 dl/g. A variety of surgical constructs may be formed from the present copolymers. Surgical sutures made of mono- or multifilament yarns of the present copolymers will bioabsorb in less than three years and will maintain at least 50% of their initial strength three weeks post-operatively.

The invention discloses parallel composite elastic fiber and a manufacture method thereof. The parallel composite elastic fiber is obtained through false twisting process after parallel composite spinning of valox and polyethylene glycol terephthalate according to a weight ratio of 70/30 to 30/70, wherein the inherent viscosity of the valox is between 0.45 to 0.60 dl/g, and the difference of the inherent viscosity of the valox and the inherent viscosity of the polyethylene glycol terephthalate is between 0.40 and 1.05 dl/g. The elastic extensibility of the elastic fiber of the invention is between 130 and 220 percent, and the elastic recovery rate is higher than 85 percent.

Polyesters whose polycondensation is catalyzed by titanium-containing catalysts and which are susceptible to acetaldehyde formation during polycondensation or subsequent molding operations are prepared with low finished acetaldehyde content and reduced acetaldehyde generation by adding an ammonium or amine salt of an oxyphosphorus-acid. Polyesters, especially polyethylene terephthalate, may be produced with high inherent viscosity in reduced processing time, without the necessity of further polymerization in the solid state.

Described as one aspect of the invention are polyester compositions comprising at least one polyester which comprises: (a) a dicarboxylic acid component comprising: (i) about 90 to about 100 mole % of terephthalic acid residues; (ii) about 0 to about 10 mole % of aromatic and/or aliphatic dicarboxylic acid residues having up to 20 carbon atoms; and (b) a glycol component comprising: (i) about 20 to about 40 mole % 2,2,4,4-tetramethyl-1,3-cyclobutanediol residues; and (ii) about 20 to about 40 mole % cyclohexanedimethanol residues; (iii) ethylene glycol residues, and (iv) less than about 2 mole % of a modifying glycol having from 3 to 16 carbon atoms; wherein the total mole % of the dicarboxylic acid component is 100 mole %, and wherein the total mole % of the glycol component is 100 mole %; and wherein the inherent viscosity of the polyester is from 0.50 to 1.2 dL/g as determined in 60/40 (wt/wt) phenol/tetrachloroethane at a concentration of 0.25 g/50 ml at 25° C. The polyesters may be manufactured into articles.

The present invention is directed to crystalline copolymers of l-lactide and a minor portion of a cyclic monomer, preferably epsi-caprolactone or trimethylene carbonate or both. The present copolymers have a melting temperature of at least 150° C. and a crystallinity of at least 20%. Preferred are high molecular weight copolymers having an inherent viscosity of at least 1.1 dl/g. A variety of surgical constructs may be formed from the present copolymers. Disclosed are coated surgical constructs including sutures made of multifilament yarns of the present copolymers and coated with nitrogenous copolyesters which will bioabsorb in less than three years and will maintain at least 50% of their initial strength three weeks post-operatively.

A liquid crystal device having a plurality of pixel electrodes for transmitting light, a first panel having an activation portion for selectively activating the plurality of pixel electrodes, an orientation layer formed on the activation portion, a light shielding pattern formed on the orientation layer, a second panel having a second orientation layer, a liquid crystal formed between the first and second panels, a polarizing plate or a color filter and a protective film on at least one of the aforementioned surfaces wherein the protective layer includes a cellulose ester selected from the group consisting of cellulose acetate, cellulose formate, cellulose propionate, cellulose butyrate, ethyl cellulose, methyl cellulose and benzyl cellulose having an inherent viscosity of from about 1.0 to less than 2.0 dl/g.

Disclosed are processes for rotational molding of thermoplastic polyesters and for hollow articles produced therefrom. The thermoplastic polyesters have a crystallization half time of at least 10 minutes and an inherent viscosity of 0.55 to 0.70 dL/g. Additional thermoplastic polymers may be used to produce multilayered articles.

This invention relates to a thermoplastic block copolyether ester elastomer and a preparation method thereof, wherein the aromatic dicarboxylic acid and mixing divalent alcohol are reacted at 180-265 DEG C in the mol ratio of 1: 1.2-2.2; the titanium compound, the mixture of titanium compound and zinc compound or the mixture of titanium compound and magnesium compound is used as catalyst; the copolyether ester contains 15-90ppm of titanium element, 10-200ppm of zinc or magnesium, and 300-4000ppm of antioxidant; the obtained matter is reacted under pressure lower than 150Pa to distil out 1,4-butanediol and 1,4-cyclohexanedimethanol; the final temperature of the reaction is at 260-290 DEG C; in terms of total weight of the copolyether ester, the content of the hard segment is 50-92wt%; the inherent viscosity is 0.65-1.85dl/g; the melting point is at 160-220 degrees centigrade; the elongation at break is 500-1400% and the thermal decomposition temperature is 360 to 450 DEG C.

The invention discloses a preparation method of aliphatic polyester amide containing a short polyamide segment, which comprises the following steps: polymerizing cyclic lactam or amino acid with alkamine to prepare a polyamide oligomer; carrying out melt polycondensation on the polyamide oligomer, aliphatic dibasic acids and diatomic alcohols to prepare a polyester amide prepolymer with a carboxyl-terminated and hydroxyl-terminated structure; and carrying out chain extension on the polyester amide prepolymer by using diacyl dilactam or carbonyl dilactam and dioxazoline chain extender to prepare the biodegradable polyester amide containing a short polyamide segment, of which the inherent viscosity is 0.37-0.74 dL/g. The invention has the characteristics of simple method, mild conditions, high efficiency and the like.

Absorbable, essentially non-absorbable, and non-absorbable crystalline, amphiphilic, block/graft copolymeric compositions exhibit an inherent viscosity of at least 0.5 dL/g, a heat of fusion of at least 10 J/g and undergo swelling in the biological environment due to a water up-take of at least 10 percent of original dry mass. These compositions are designed for use in swellable surgical sutures, coatings of medical devices, and carriers for the delivery of bioactive agents.