6results about How to "Guaranteed crosslink density" patented technology

The invention relates to the field of waterproof sealing materials, and discloses a composite high-weather-resistance rubber waterstop which is composed of an outer layer, a middle layer and an inner layer. The outer layer contains 3%-8% of nano titanium dioxide, 2%-5% of nano zinc oxide, 50%-70% of a rubber matrix and 1%-3% of an ultraviolet light absorber, and the total proportion of the outer layer is 10%-20%. The middle layer is composed of 70%-85% of EPDM, 5%-10% of carbon fiber and 5%-10% of plasticizer, and the total proportion of the middle layer is 60%-75%. The inner layer is a dynamic covalent bond rubber material and contains 5%-10% of a vulcanizing agent and 1%-3% of an antioxidant, the rubber material accounts for 80%-90%, and the inner layer accounts for 15%-25% in total. Through a multi-layer composite structure, a dynamic covalent bond self-repairing material and an optimized vulcanization process, the comprehensive performance of the water-stop belt is remarkably improved, and particularly the durability and the service life of the water-stop belt in a long-term exposure environment are improved.

The invention belongs to the technical field of IC packaging materials, and relates to a hyperbranched active ester curing agent containing double bonds and a layer-adding film containing the active ester curing agent. The structural formula of the hyperbranched active ester curing agent containing the double bonds is as shown in a formula I: # imgabs0 # formula I; the double-bond-containing hyperbranched active ester curing agent contains more branched structures, has better flowability, can improve the film-forming property of the curing agent, and provides more active ester equivalent; meanwhile, through the free radical polymerization reaction of double bonds, the crosslinking density is further increased, and after the combined action with the crosslinking reaction of the non-hyperbranched active ester curing agent and the epoxy resin, the glass-transition temperature of the layer-adding film can be increased, the thermal expansion coefficient of the layer-adding film can be reduced, and the thermodynamic property of the layer-adding film can be improved; in addition, the hyperbranched rigid skeleton structure can introduce nanoscale micropores into a curing system, so that the dielectric property of the layer-adding film is improved.

The invention relates to intrinsic flame-retardant bio-based epoxy resin and a synthesis method thereof.The intrinsic flame-retardant bio-based epoxy resin takes magnolol as a main raw material, and the molecular structure contains biphenyl units and ester bonds, so that the intrinsic flame-retardant bio-based epoxy resin has excellent flame retardance and thermal performance. The synthesis method comprises the following three steps: firstly, reacting magnolol with halogenated alkane to generate a precursor; secondly, reacting the precursor with acyl chloride to generate an intermediate; finally, oxidizing the intermediate to generate the target epoxy resin. The method does not need to add a large amount of flame retardant, and avoids negative influence on the performance of the epoxy resin. The synthesized epoxy resin shows excellent flame retardance and heat resistance, has high carbon residue rate, glass transition temperature and thermal decomposition temperature, and has the flame retardant level reaching V-0 level which is superior to that of general epoxy resin.

This invention relates to the field of rubber materials technology. It provides a high-strength, low dynamic ratio EPDM rubber material and its preparation method. The raw materials for the EPDM rubber material, by weight, include: 140-200 parts of EPDM raw rubber, 70-80 parts of filler, 5-40 parts of plasticizer, 2.0-3.0 parts of antioxidant, 1.0-3.0 parts of processing aid, 0.3-0.8 parts of vulcanizing agent, 3.0-4.0 parts of accelerator, 4-6 parts of zinc oxide, and 1.0-2.0 parts of stearic acid. The EPDM raw rubber is oil-extended EPDM rubber, with an oil content of 40-100 parts. This invention provides a high-strength, low dynamic ratio EPDM rubber material with high strength and low dynamic ratio, significantly improving the NVH performance and service life of the product. It can meet the functional requirements of current new energy vehicles for vibration damping rubber products, such as vibration reduction, noise reduction, high load-bearing capacity, and high durability.

The invention discloses polyester resin for indoor powder coating as well as preparation and application thereof, and belongs to the technical field of polyester resin. The polyester resin comprises the following raw material components in percentage by mass: 32.0-45.0% of linear aliphatic dihydric alcohol with a side group; 1.0 to 2.5 percent of a branching agent; 0 to 1.5 percent of aliphatic cyclic dihydric alcohol; 45 to 58 percent of aromatic polybasic acid; 0 to 1.5 percent of alicyclic polybasic acid; 1.0-6.0% of an end-capping reagent A saturated long straight chain single fatty acid; 4.0 to 8.0 percent of end-capping reagent B isophthalic acid; 1.0-3.0% of an auxiliary agent A hydroxyl acrylic resin; 0.03 to 0.5 percent of an auxiliary agent B; and 0.05 to 0.15% of an esterification catalyst. According to the polyester resin for the indoor powder coating, a main chain structure, a branched structure and an end-capping structure of the polyester resin are improved, and the hydroxyl acrylic resin is added, so that the polyester resin can be cured with a TGIC (or HAA) curing agent, a cured coating film has the advantages of excellent leveling property, excellent boiling resistance, fine surface and the like, and can replace a polyester / epoxy powder coating system; therefore, the residues of bisphenol A and trimellitic anhydride in the powder coating are avoided.

This application relates to a special material for thermally conductive and pressure-resistant polyolefin pipes and its preparation method. The special material comprises a polyethylene resin blend matrix, pretreated filler, maleic anhydride-grafted polyethylene, polyvinyl chloride / polyethyl methacrylate (PVC / PEMA) polymer, carbon fiber, and stabilizer. The preparation method includes adding the polyethylene resin blend matrix, PVC / PEMA polymer, maleic anhydride-grafted polyethylene, pretreated filler, carbon fiber, antioxidant, and zinc stearate into a high-speed mixer and mixing them. Then, the mixture is blended with vinyltrimethoxysilane and dicumyl peroxide using a twin-screw extruder at 195°C and 280 rpm, and granulated to obtain the special material for thermally conductive and pressure-resistant polyolefin pipes. The resulting special material has both high thermal conductivity and pressure resistance, making it suitable for manufacturing polyolefin pipes. It solves the problems of poor thermal conductivity and insufficient pressure resistance of polyolefin pipes and can be applied to geothermal, underfloor heating, and chemical fluid transportation systems.