An aromatic polysulfone resin having a yellowness index of 50 or higher and a weight average molecular weight of 25,000 to 45,000 is provided.

A method for purifying polybutylene terephthalate (PBT) includes: providing or receiving initial PBT, in which oligomers and tetrahydrofuran are present; dissolving the initial PBT in hexafluoroisopropanol (HFIP) to form a solution, in which the oligomers are also dissolved in the HFIP; and contacting the solution with compressed CO.sub.2 at a temperature and a pressure, thereby precipitating the purified PBT, resulting from a large portion of the oligomers are still dissolved in the HFIP, in the operation the temperature is in a range of 20 C. to 35 C., and the pressure is in a range of 900 psi to 1400 psi. A device for purifying PBT is also provided.

The present invention concerns an organopolysiloxane (A) able to be obtained by the reaction, at a temperature of between 10 C. and 75 C., betweenat least one compound (C) chosen from the organic compounds comprising at least one alkene or alkyne functional group, at least one of the substituents of which is an acid functional group and the organic compounds comprising at least one acid functional group and at least one alkene or alkyne functional group, at least one of the substituents of which is an electron-withdrawing group; andat least one organopolysiloxane (B) chosen from the organopolysiloxanes comprising siloxyl units (I.1) and (I.2) of the following formulae: (I) The present invention also concerns compositions comprising said organopolysiloxanes (A) and the uses thereof.

[00001]$\left(I\right)$$\begin{array}{cc}{Y}_a.Math.Z_b^1.Math.{\mathrm{SiO}}_{\frac{4-\left(a+b\right)}{2}};& \left(I.Math.\mathrm{.1}\right)\\ Z_c^2.Math.{\mathrm{SiO}}_{\frac{4-c}{2}}& \left(I.Math.\mathrm{.2}\right)\end{array}$

The present invention relates to vinyl-based thermoplastic resin composition having excellent thermal stability, which comprises a metal complex agent, and a first vinyl-based monomer and a second vinyl-based monomer having different iron ion concentration from each other, a method for manufacturing thereof, and vinyl-based thermoplastic resin manufactured therefrom. The accompanying vinyl-based thermoplastic resin composition can enhance thermal stability, and the vinyl-based thermoplastic resin manufactured from the composition may have excellent thermal stability. Thus, it can be easily applied to industries requiring thereof, in particular, industries of vinyl-based thermoplastic resin and its mold processed goods.

The present invention concerns a method for processing and detoxification of a material, especially a thermoplastic material, and for removal of contaminants or impurities from this material, wherein the material is heated under vacuum in at least one receiving tank, mixed and possibly comminuted, and wherein a rinsing medium is introduced into the receiving tank beneath the material level, conducted through at least a partial region of the material, and the rinsing medium enriched or saturated with contaminants is brought out from the receiving tank once more. According to the invention, the quantity of rinsing medium introduced into the receiving tank is less than 0.1 liter per hour per kilogram of material or material throughput per hour, while at the same time the vacuum in the receiving tank is kept constantly below 100 mbar.

In a method and an apparatus for increasing the intrinsic viscosity of a polycondensate melt at negative pressure, the melt enters a chamber, in which a negative pressure of less than 20 mbar prevails, through a perforated plate or a screen having openings with a diameter of less than 0.5 mm. The melt passes through this chamber in free fall in thin threads and remains in a reservoir beneath the chamber for at least one minute. The melt is moved constantly in the reservoir, and discharged from the reservoir, by a helical mixing and discharge part.

The filter for gel shearing and particle filtration of molten polymer has a first layer of metal fibers of an average equivalent diameter between 8 and 65 m. The cross-section of the metal fibers has two neighboring straight sides with an included angle of less than 90 and one or more irregularly shaped curved sides. The metal fibers have an average length of at least 6 mm. The metal fibers are bonded to each other by metal bonds; where the metal of the metal fibers of the first layer is the bonding agent forming the metal bonds. The filter has a second layer of metal fibers. The average equivalent diameter of the metal fibers of the second layer is smaller than the average equivalent diameter of the metal fibers of the first layer.

Polycarbonate based polyurethane prepolymers having a low amount of free isocyanate monomer with excellent handling and processing properties are prepared and used in the preparation of cast polyurethane polymers with excellent performance and handling properties.

The invention relates to a method for eliminating metal ions from a viscous organic solution, the viscosity of which at 20 C. is between 1 and 1000 cP. This method comprises the steps consisting in placing a macroporous ion-exchange resin in a column, said resin comprising at least one acid resin of carboxylic type, based on a copolymer having active groups in carboxylic form (CO.sub.2H), then in continuously passing said viscous organic solution over said ion-exchange resin.

The filter for gel shearing and particle filtration of molten polymer has a first layer of metal fibers of an average equivalent diameter between 8 and 65 m. The cross-section of the metal fibers has two neighboring straight sides with an included angle of less than 90 and one or more irregularly shaped curved sides. The metal fibers have an average length of at least 6 mm. The metal fibers are bonded to each other by metal bonds; where the metal of the metal fibers of the first layer is the bonding agent forming the metal bonds. The filter has a second layer of metal fibers. The average equivalent diameter of the metal fibers of the second layer is smaller than the average equivalent diameter of the metal fibers of the first layer.