48results about How to "Low in acetaldehyde" patented technology

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.

The present invention provides a catalyst for polyester production capable of producing a polyester with high catalytic activity, a process for producing a polyester using the catalyst and a polyester produced thereby. The catalyst comprises a solid titanium compound obtained by dehydro-drying a hydrolyzate obtained by hydrolysis of a titanium halide and which has a molar ratio (OH / Ti) of a hydroxyl group (OH) to titanium (Ti) exceeding 0.09 and less than 4. In the process, the polyester is obtained by polycondensing an aromatic dicarboxylic acid, or an ester-forming derivative thereof, and an aliphatic diol, or ester-forming derivative thereof, in the presence of the catalyst. The resulting polyester has excellent transparency and tint, a titanium content of 1 to 100 ppm, a magnesium content of 1 to 200 ppm and a magnesium to titanium weight ratio of not less than 0.01.

The invention relates to a low-VOC (volatile organic compound) polypropylene material as well as a preparation method and an application thereof. The polypropylene material is prepared from raw materials in percentage by weight as follows: 15-95% of polypropylene, 0-25% of an elastomer, 5-50% of mineral filler, 0.1-2% of a dispersing agent, 0.05-1% of a lubricant, 0.05-1% of an acid acceptor, 0.1-2% of an antioxidant, 0.1-1% of a weather resistance agent and 0.2-2% of a molecular sieve, wherein the acid acceptor is a compound of stearate and a metal oxide, and the dispersing agent is purified water, acetone or a mixture of the purified water and the acetone. The prepared low-VOC polypropylene material has the characteristics of low VOC and low acetaldehyde, does not produce acetaldehyde during injection molding, can be applied to injection molding of automotive interior parts and can meet the VOC requirement.

The invention belongs to the field of chemical industry and provides a method for inhibiting the polymerization of acetaldehyde in the production process of polyvinyl alcohol and vinyl acetate. The method is to add a polymerization inhibitor to prevent the self-polymerization of acetaldehyde in the process of acetaldehyde refining and recycling, and adjust the pH value of the acetaldehyde aqueous solution in the range of 4.5 to 5.6 in the process of acetaldehyde refining and recycling; The agent is a mixture of acetic acid and sodium acetate, wherein the mass ratio of acetic acid to sodium acetate is 0.02-0.4:1, and the concentration of the polymerization inhibitor added is 25ppm-2000ppm. The method of the invention has the advantages of good polymerization inhibition effect, low cost, can significantly improve the quality of refined vinyl acetate and the recovery rate of acetaldehyde, the polymerization inhibitor is not easy to decompose, and has stable properties and the like.

Polyester compositions having desirable injection molding properties and that retain good crystallization rates and natural stretch ratio characteristics are described. These polyesters are suitable for the manufacture of beverage containers, bulk continuous filaments, and other articles that can benefit from such improved properties.

There is provided a method (200) for decreasing acetaldehyde level in a molded article. The method (200) of decreasing acetaldehyde content in a molded article to be produced comprises introducing (202) into a feed throat (120) of an injection unit (100) a PET material to be plasticized, the PET material having been dried in a pre-treatment chamber (130); and introducing (204) into the feed throat (120) an un-treated agent (136) configured to increase moisture level of the PET material to be plasticized. In some embodiments of the present invention, the un-treated agent (136) is also configured to provide additional lubrication to the plasticizing screw (106).

The invention relates to a production method of high-viscosity polyester resin with relatively low acetaldehyde content. The invention focuses on the whole process of polyester production from liquid phase polymerization to solid phase polycondensation, and proposes targeted improvement measures and specific technical solutions for reducing AA: adjust the production formula in the liquid phase polymerization stage, add additives containing cobalt, sodium, and phosphorus, The reaction speed is accelerated, the degradation speed is slowed down, and the degradation by-products are significantly reduced. The AA content in the obtained low-viscosity chips is below 100-120ppm; in the SSP stage, through process optimization, the adjustment of the viscosity increase range of the resin during preheating and reaction process is realized. , which is more conducive to the removal of acetaldehyde. On the premise of ensuring other quality indicators, the AA content in the product is lower than 1.0ppm, which can meet the requirements of food packaging under the most stringent conditions. The technical scheme has reliable process and stable operation, and is especially suitable for producing polyester resin for mineral water packaging by adopting conventional SSP process.