Preparation Methods of Light Stabilizers (Patent Technologies)

Benzophenone-type light stabilizer for information-recording materials: This light stabilizer can inhibit the UV photo-oxidative fading of dyes, laser materials, and information-recording materials; by adding this light stabilizer, the weatherability and resistance to photo-oxidative fading of dyes, laser materials, and information-recording materials are improved. The composition of this light stabilizer is made up of a series of derivatives formed by introducing a benzophenone functional group with UV-absorbing function and a nickel sulfonate with UV-quenching function, as well as a series of compounds and mixtures formed by combining the benzophenone molecular functional group with phenols and their derivatives that provide anti-photo-oxidative stabilization. Weathering test results show that this light stabilizer has a significant effect on improving the resistance of dyes, laser materials, and information-recording materials to UV photo-oxidative fading. 
  P3395 — Preparation method of polyester for light stabilizers: The corresponding linear hydroxy-piperidinol and linear dibasic acid ester are used as monomer raw materials and subjected to polycondensation in the presence of an organic titanate catalyst. The polycondensation is carried out in two stages—atmospheric-pressure polycondensation and reduced-pressure polycondensation—with atmospheric-pressure polycondensation for 1–5 hours, reduced-pressure polycondensation for 3–7 hours, a vacuum of 0.094–0.1 MPa, and a reaction temperature of 140–200℃. An antioxidant, tris(2,4-di-tert-butylphenyl) phosphite, is added to the polycondensation system at 0.1–2.0 wt% of the total raw materials. In structural formula I, R is ethylene or propylene, R1 is a C3–C5 linear carbon chain, R2 is methyl or ethyl, and n is a positive integer from 20 to 50. 
  Light stabilizer for dyes and their information-recording materials: Belongs to the technical field of preventing UV photo-oxidative fading of dyes, laser materials, and information-recording materials. Its background technology derives from information technology and laser technology. By adding this light stabilizer, the weatherability and resistance to photo-oxidative fading of dyes, laser materials, and information-recording materials are improved. The composition of this light stabilizer consists of benzotriazole and its derivatives of the chemical formula: 2-(N’-N*’hydroxyphenyl) N-N* hydroxybenzotriazole and 1-R, N-N*R* benzotriazole. Examples include 2-(2’,4’-dihydroxyphenyl)-5,6-dihydroxybenzotriazole and 1,6-dihydroxybenzotriazole. Weathering test results show that this light stabilizer has an obvious effect on improving the resistance of dyes, laser materials, and information-recording materials to UV photo-oxidative fading.    Preparation method of 2,2,6,6-tetramethyl-4-piperidamine intermediates for light stabilizers: Specifically, a method for preparing intermediates of hindered-amine light stabilizers by reacting 2,2,6,6-tetramethyl-4-piperidone with amine compounds. The 2,2,6,6-tetramethyl-4-piperidamine intermediates are prepared by a three-step method, mainly completed through pre-mixing, dehydration, and hydrogenation. This further reduces by-products, yields high product yield and purity, simplifies post-treatment, and gives the product excellent storage stability. After six months of storage, the product's color still meets the standard. 

Preparation method of polymeric light stabilizers with self-synergistic effect: A method for preparing polymeric light stabilizers with self-synergistic effect that have both hindered-amine (HA) and o-hydroxybenzophenone (HBP) groups on the side chains. It is prepared by free-radical polymerization of olefinic unsaturated monomers each containing a 2,2,6,6-tetramethylpiperidine (hindered amine—HA) or 2-hydroxybenzophenone (HBP) light-stabilizing group. Polymer light-stabilization tests show that the polymeric light stabilizer prepared by this invention exhibits an obvious synergistic effect. The prepared self-synergistic polymeric light stabilizer is a brand-new type of light-stabilization additive.