571results about How to "Reduce yellowing" patented technology

The present invention is directed to novel organometallic complexes as catalysts for the reaction of compounds with isocyanate and hydroxyl functional groups to form urethane and / or polyurethane and the process employing such catalysts. More particularly, the present invention is directed to novel complexes of zinc(II) with substituted amidines. These novel catalysts are useful for the production of urethanes and polyurethanes which are important in many industrial applications.

The invention relates to an organic silicon encapsulating material for a high-power LED and a preparation method thereof. The organic silicon encapsulating material is prepared by mixing a component A containing vinyl polysiloxanes, a silicone resin component B, a component C containing hydrogen polysiloxane, a platinum catalyst component D, a component E of catalytic inhibitor of acetylene alcohols and a tackifier component F. The obtained encapsulating silicon rubber with different refractive indexes of level 1.4, level 1.5 and the like can be used for the encapsulation of various high-power LEDs and the encapsulation of other optical application. The organic silicon rubber encapsulating material for the high-power LED takes the silicone resin component B as a filling material, which not only enables that the silicone rubber has high transparency, high strength and high light transmittance, but also improves the temperature resistance, the yellowing resistance, and the durability of the high light transmittance of high-power LED products. The organic silicon rubber encapsulating material for the high-power LED can be prepared into two encapsulating forms of a single component and bi-component, which improves the adaptability and the encapsulating efficiency for encapsulating equipment and process procedures, and has the characteristics of reduced cost and convenient use.

Disclosed herein is a light module comprising a substrate, at least one light-emitting element on the substrate, a sealing cap on the substrate and covering the light-emitting elements, and a fluid in the space formed among the sealing cap, the light-emitting elements, and the substrate, such that heat dissipation is fast and yellowing of the encapsulating material is retarded.

The invention discloses a preparation method of hyper-branched polyether amide block silicone. The preparation method comprises the following steps: preparing polyether / epoxy block silicone oil and preparing hyper-branched polyether amide block silicone. According to the preparation method, hyper-branched polymers and linear polyether amino block silicone are combined together to develop a new silicone softening agent with a newly modified silicone chemical structure; the synthesized hyper-branched material has a reticular structure which not only strengthens cohesive force between fibers, but also strengthens cohesive force between yarns; the invention is high in molecular weight, low in viscosity, rich in hydrophilic groups and capable of endowing soft, well-rounded and washable touch on fabrics; the problem of easy demulsification of traditional amino-modified silicone oil is solved; the product has self-emulsifying performance in water and is good in emulsion stability; the hyper-branched polyether amide block silicone is reduced in yellowing performance and enhanced in hydrophilicity; fabrics made accordingly has good hydrophilicity and low yellowing performance; and the hyper-branched polyether amide block silicone combines with the fabrics in a form of chemical bonds, so that the wash resistances is enhanced and the soft effect of amino silicone oil is achieved.

The present invention is directed to novel organometallic complexes as catalysts for the reaction of compounds with isocyanate and hydroxyl functional groups to form urethane and / or polyurethane and the process employing such catalysts. More particularly, the present invention is directed to novel complexes of zinc(II) with substituted amidines. These novel catalysts are useful for the production of urethanes and polyurethanes which are important in many industrial applications.

The invention discloses a preparation method of a polyurethane trimer curing agent of a low free isocyanate monomer, comprising the following steps of: under the protection of nitrogen, firstly putting an isocyanate monomer and an esters solvent into a reaction container to evenly stir, wherein the temperature is kept at 50-90DEG C; dropwise adding diamine into the reaction container under the condition of stirring, wherein the dropwise adding time is 1-1.5 hours; and after dropwise adding, adding a catalyst of which the mass is 0.1-0.5% of that of the isocyanate monomer once, continuing stirring and reacting at the temperature of 70-100DEG C for 3-6hours, when the NCO base content is 20%-25%, immediately adding the polymerization inhibitor of which the mass is 0.1-1% of that of the isocyanate monomer, keeping the temperature for 1-2hours, and discharging in a cooling way. The polyurethane trimer curing agent prepared by the preparation method can be better compatible with the resin, can be quickly solidified under normal temperature, and has the advantages of being higher in mechanical strength, modulus, adhesion, etc.

The invention relates application of low-viscosity light-cured resin in 3D (three-dimensional) printing materials. The low-viscosity light-cured resin is (branched) polyether acrylate or heterocyclic amine modified (branched) polyether acrylate. A 3D printing material prepared from the low-viscosity light-cured resin is of low viscosity and high curing speed, is low in curing shrinkage, low in yellowing property, moderate in rigidity and flexibility, high in forming speed and high in product dimensional precision, is free of curing incompleteness, edge warping and the like, and is very suitable for being applied to 3D printing materials based on the SLA (stereolithography) or 3DP (three-dimensional printing) technology.

The invention provides a method for improving the physical and mechanical properties of oxidation-degummed ramie. The method comprises the following steps of: preparing a degumming solution by using caustic soda, an oxidant, a surfactant, a fiber expanding agent, an oxidant stabilizer and water; mixing raw ramie and the degumming solution, heating, and boiling off to sufficiently remove colloid; and then cooling, adding a reduction softener, maintaining the temperature, oiling and drying after washing with clear water, and opening and carding to obtain textile ramie fiber subjected to reduction modification. According to the method disclosed by the invention, the defects of the prior art are overcome; and the reduction softener is added to raffinate obtained after oxidation-degumming, oxycellulose produced in the degumming process is reduced and softened, so that the physical and mechanical properties, such as strength, length, elongation and softness of the fiber are improved, the working procedures are simplified, and pollution and environmental pressure are lightened.

The invention relates to the field of a textile finishing agent, and particularly relates to a method for preparing a super-smooth hydrophilic quaternary ammonium salt-modified organic silicon copolymer. The method comprises the following steps: synthesizing a cationic modified polyether amine intermediate by using aliphatic polyether diamine and an alkylating agent under the action of an acid catalyst; carrying out addition polymerization of amino and an epoxy group on the cationic modified polyether amine intermediate and terminated epoxy polyether silicone oil in the presence of an organic solvent, then adding a glacial acetic acid, and synthesizing ternary block silicon oil. The super-smooth hydrophilic quaternary ammonium salt modified organic silicon copolymer prepared by the method provides excellent hydrophilic performance to cotton fabric, and has an outstanding smooth effect, and the smoothness can achieve the level of common amino silicon oil, and is superior to that of most of ternary block silicon oil. The super-smooth hydrophilic quaternary ammonium salt modified organic silicon copolymer has certain antibacterial and antistatic functions by improvement of the cationization degree, meanwhile, the problem that amino is easy to yellow in a high-temperature condition can be effectively solved, and the processed fabric is small in yellowing, and applicable to finishing of white or light fabric.

The invention discloses a long-acting antibacterial agent, a long-acting antibacterial agent with an instant effect and a preparation method of the long-acting antibacterial agent, and relates to thetechnical field of coating antibacterial agents. The long-acting antibacterial agent mainly comprises nano silver, carrier particles and hydrophilic polymers / a mixture of hydrophilic polymers and hydrophilic inorganic matters, and the long-acting antibacterial agent with the instant effect comprises nano silver, silver salts, other metal salts, carrier particles, hydrophilic polymers / a mixture ofhydrophilic polymers and hydrophilic inorganic matters and a cross-linking agent. By the invention, the problems that a coating film prepared by an existing antibacterial agent is not washable and poor in long-acting property, yellowing of antibacterial active component Ag ions is easily caused, an organic antibacterial agent is harmful to human bodies, pollutes the environment and the like are solved. In addition, hydrophilic polymers or a mixture of the hydrophilic polymers and hydrophilic oligomers or inorganic matters wrap the surface of the antibacterial agent, the releasing speed of silver ions is controlled, and silver simple substances can be promoted to ionize silver ions to resist bacteria.

A white thermosetting silicone resin composition for molding an optical semiconductor case and a case for an optical semiconductor such as LED are provided. The composition comprises (A) a thermosetting organopolysiloxane, (B) a white pigment, (C) an inorganic filler (excluding the white pigment), (D) a condensation catalyst, and (E) a coupling agent represented by the following formula: R3dSi(OR2)e wherein R3 represents an organic group containing a mercapto group, a glycidyl group, or an amino group, R2 represents a C1-4 organic group, d represents 1 or 2, and e represents 2 or 3; wherein content of the white pigment (B) is 1 to 50% by weight in the entire composition, and total content of the white pigment (B) and the inorganic filler (C) is 70 to 93% by weight in the entire composition. When cured, it has excellent whiteness, consistency, and resistance to heat, light, yellowing, and warping.

The invention includes a method of conditioning fabrics, comprising contacting fabric with a liquid composition comprising an amino-functional silicone and a quaternary ammonium, and drying said fabric at 200 degrees F. or greater. The invention includes a method of conditioning fabrics, comprising washing fabric in a detergent having a wash pH of greater than 10, contacting fabric with a liquid composition comprising an amino-functional silicone and a quaternary ammonium, and drying said fabric at less than 200 degrees F. The invention further provides a method of conditioning fabrics wherein softness, anti-static, and anti-wrinkle properties are imparted to the fabric wherein the conditioned fabric resists yellowing in industrial and institutional conditions wherein the wash pH is greater than 9 and / or the fabric temperature is 200 degrees Fahrenheit or greater.