37results about How to "Increased curing crosslink density" patented technology

The invention discloses an epoxy adhesive toughened by tertiary-amide modified liquid nitrile butadiene rubber. The adhesive is prepared from the following components in parts by weight: 100 parts of bisphenol-A or bisphenol-F epoxy resin, 8 to 60 parts of amine curing agent and 10 to 70 parts of tertiary-amide modified liquid nitrile butadiene rubber. The curing condition is that all components are uniformly mixed and are cured at a room temperature for 4 to 7 days or are cured at a temperature of 50 DEG C for 1 day. The adhesive has main properties that the tensile strength is 20 to 40 MPa, the elongation at break is 5 percent to 30 percent, the impact strength is 20 to 150 kJ / m2 and high-temperature glass transition temperature is 90 to 120 DEG C. The toughened epoxy adhesive disclosed by the invention has the advantages that excellent mechanical property and excellent toughness are obtained; the curing cross-linking density of the epoxy resin is improved, the high-temperature glass transition temperature of the epoxy adhesive is not reduced, and the high-temperature usage temperature of the adhesive is not reduced while the adhesive is toughened by utilization of the characteristics of catalyzing and curing epoxy functional groups by a tertiary amine group.

The invention discloses a modified urea formaldehyde resin adhesive for veneer sheets and a preparation method thereof. Formaldehyde and urea in low mole ratio are used as raw materials, a polyfunctional reaction enhancer is used as a polycondensation agent instead of the acidic polycondensation agent, and an acid-alkali-acid technique is utilized to synthesize the urea formaldehyde resin, thereby enhancing the molecular branching degree of the urea formaldehyde resin, increasing the molecular weight of the urea formaldehyde resin under the condition of the same viscosity, enhancing the curing crosslinking density of the urea formaldehyde resin, further enhancing the bonding strength and lowering the formaldehyde release amount of the bonded product. The basic process is approximate to the common technique. The method is simple in technique and easy to operate, and does not need to modify the existing equipment.

The invention discloses a modified urea resin adhesive and a preparation method thereof. According to the preparation method, formaldehyde and urea in a low molar ratio are taken as raw materials, and a poly-functionality reaction enhancer is taken as a polycondensation agent to replace an acidic polycondensation condition, and the urea resin is synthesized by use of an acid-alkali-acid process; the molecular branching coefficient of the urea resin is increased, the molecular weight of the urea resin is increased under the same viscosity, and the curing cross-linking density of the urea resin can be increased, and furthermore, the bonding strength is improved and the formaldehyde release amount of the bonded products is reduced. The preparation method of the low-toxicity urea resin adhesive has the advantages that non-traditional melamine-epoxy chloropropane-sodium hydroxide reactants are taken as polycondensation agents and the acid-alkali-acid synthesis process is adopted, the basic procedure is close to the conventional process, the process is simple, the operations are convenient, and the existing equipment does not need to be modified.

The invention relates to a bottom filling glue with high electrical insulation performance, which is composed of the following raw materials: 25-35 parts of self-synthesized diaminodiphenyl sulfone modified epoxy resin, 15-20 parts of low-viscosity epoxy resin, biphenyl ring 25-35 parts of oxygen resin, 0.1-0.4 parts of black pigment, 15-20 parts of curing agent. The underfill adhesive prepared by the invention has the advantages of high volume resistivity, high glass transition temperature, low water absorption, and good electrical insulation performance especially after aging in a humid and hot environment, and is suitable for semiconductor electronic components mounted on various bare chips. encapsulation.

The invention discloses a preparation method for amination polyphenyl ether, which is characterized by including the following steps that low-molecular-weight polyphenyl ether with double hydroxyl is generated through oxidation, coupling and copolymerization of two kinds of phenol, and low-molecular-weight polyphenyl ether resin with double amino is obtained through a process such as nitration. Compared with conventional polyphenyl ether resin, the polyphenyl ether resin with the double amino is more in active groups cross-linked with epoxy, larger in cross-linking degree with epoxy resin, can remarkably improve poly-p-phenylene oxide / epoxy (PPO / EP) compatibility, can increase proportion of the polyphenyl ether resin in a PPO / EP system, and accordingly remarkably improves condensate electrical property of a resin system.

The invention relates to a preparation method of phenolic resin combined honeycomb activated carbon, which can be used for preparing the honeycomb activated carbon by the steps of: mixing dry powder, preparing plastic pug by mixing and kneading through a wet method, vacuum pugging, extrusion molding, drying, curing treatment and secondary heat treatment. Besides the function of bonding and improving the mechanical strength of the activated carbon, the phenolic resin also remarkably improves the heat-resisting property and water resistance of the honeycomb activated carbon; and furthermore, the honeycomb activated carbon is added with porous mineral, thus better effectively improving the mechanical strength and the specific surface area of the honeycomb activated carbon. The preparation method has lower heat treatment temperature and low production energy consumption, and effectively reduces the production cost; and the preparation technique and equipment thereof are simple, and the production investment is lower, so that the cost is further reduced.

The present invention relates to resin composition and its application. Specifically, the present invention relates to a resin composition, which contains: 20 to 35 parts by weight of multifunctional epoxy resin; 8 to 15 parts by weight of isocyanate modified epoxy resin; 5 to 15 parts by weight of difunctional epoxy resin 10 parts by weight; 40-65 parts by weight of polyphenylene ether resin; and 8-16 parts by weight of cyanate resin. The present invention also relates to products of the resin composition, including resin films, adhesive sheets, prepregs, composite materials, laminates and printed circuit boards. Through the combination of different resins, this application realizes the superimposition of product performance, so that the product not only has a good appearance, but also has the comprehensive effects of heat resistance, low dielectric loss and easy processing.