44results about How to "Avoid self-polymerization" patented technology

This case involves a one-component PU adhesive for microfiber leather and its preparation method. The preparation method includes: putting polyester polyol into a reaction bottle and heating it to melt, then adding antioxidant BHT and phosphoric acid, stirring evenly and then adding The molten isocyanate is reacted at 110°C. During the reaction, an organic solvent is added for dilution until the viscosity of the system reaches 8-120,000 cps / °C; another organic solvent is added to the reaction bottle to adjust the solid content of the system to 40%, and then continue to stir for 1h before wrapping. The single-component PU adhesive for microfiber leather prepared in this case has the advantages of simple process and convenient operation; the prepared PU adhesive has a low softening point, good hydrolysis resistance, heat resistance and mildew resistance, and is suitable for dry pasting. When this PU adhesive is used for superfiber veneer, there will be no fogging phenomenon.

The present invention provides a depolymerization process of dicyclopentadiene. With dicyclopentadiene as a raw material, a diluent and a polymerization inhibitor are added to the raw material and mixed uniformly, and then subjected to depolymerization rectification separation in a reactive distillation tower after still standing for 30-60 minutes, under controlled conditions as follows: a tower bottom temperature of 240-270 DEG C, a tower top temperature of 40-45 DEG C, a tower top pressure of 12-17 KPaG, a reflux ratio of 6-10, and a feed rate of 8-15 mL / min; and cyclopentadiene is collectedat the top of the tower. The depolymerization process provided by the present invention, by adding a diluent and a polymerization inhibitor which are scientifically proportioned and controlling reaction conditions, realizes effective inhibition of the occurrence of self-polymerization and side reactions during pyrolysis, and inhibits the occurrence of coking simultaneously, thus improving the yield and purity of cyclopentadiene.

The invention relates to a method for preparing environment-friendly PVC plasticizer, including the following steps: epoxy vegetable-oil acrylic acid is modified; dehydration is conducted; and the compound compatible to epoxy vegetable-oil is prepared. The achieved plasticizer does not contain phthalate, and can completely substitute phthalate and serve as plasticizer during the process of PVC contour matching.

The invention belongs to the technical field of casting auxiliary materials, in particular to a fructose-modified furan resin for casting and a preparation method thereof. The chemical composition of the raw materials used in the furan resin is calculated in parts by mass, specifically 30-40 parts of fructose, 130-180 parts of furfuryl alcohol, 15-20 parts of tetraethylammonium bromide, 0.2-0.4 parts of chromium trichloride, liquid urea-formaldehyde 5-20 parts of resin, 30-40 parts of water and 1-2 parts of formic acid; the water content of the liquid urea-formaldehyde resin is less than 30%. The present invention uses the water-furfuryl alcohol system as the fructose hydrolysis solvent, so that the hydrolyzed product can be directly used in the subsequent production of furan resin, replacing furfuryl alcohol, effectively reducing the preparation cost of furan resin; by adding catalyst trichlorination to the reaction system Chromium can effectively avoid the self-polymerization reaction of furfuryl alcohol in the first step of the reaction, and improve the reaction efficiency; the present invention can greatly improve the conversion rate of fructose by introducing tetraethylammonium bromide as a phase transfer agent; Production Process.

The invention provides a continuous production process and a continuous production device of emulsion type polymer and its application. The emulsion is prepared first, then the emulsion and the oxidant are mixed and transported to the tubular continuous reactor, and the reducing agent is separately input at the same time, which can prevent early polymerization. The invented tubular continuous reactor has internal stirring and back-mixing effects, and is suitable for the continuous production process of high-viscosity emulsion system. The process uses a pump to transport the emulsion from the bottom of the tubular continuous reactor to the reactor. The compound oxidant is added, the reducing agent is added at the bottom of the reactor, and then the liquid is gradually pumped to the reactor pipeline by the pump, and the material is discharged from the top of the reactor to avoid early polymerization, ensure the continuous polymerization, and improve the stability of the product.