Ultraviolet-curable polysiloxane and preparation method and application thereof

Abstract

The invention discloses ultraviolet-curable polysiloxane and a preparation method and application thereof. According to the ultraviolet-curable polysiloxane, Si-O-Si is taken as a main chain, and a branched chain contains an aromatic group, a photocuring group and a symmetrical episulfide group modified organosilicon material. The ultraviolet-curable polysiloxane disclosed by the invention not only has high refractive index and light transmittance, does not have pungent smell and has good compatibility with organosilicon polymers, but also has good elongation at break, excellent storage stability and mechanical properties. Meanwhile, the polysiloxane has a photoactive group, and can further react to obtain a polysiloxane material with high refractive index and mechanical property, the luminous efficiency of the polysiloxane material is improved, a heat packaging process commonly applied at present is changed, the industrial efficiency is improved, and the ultraviolet-curable polysiloxane can be widely applied to the fields of flexible optical fibers, optical lenses, optical coatings, flexible display screens and the like with high requirements on optical materials.

Description

technical field [0001] The invention relates to the technical field of functional polymer materials, and more particularly relates to a polysiloxane curable by ultraviolet light and its preparation method and application. Background technique [0002] With the rapid development and application of optical materials, the current optical material products are developing in the direction of high refractive index, high light transmittance and high reliability, especially in the application fields of optical lenses, optical glass, optical plastics and optical fiber materials, which require The material has a higher refractive index, even as high as 1.7 or more, and it also needs to have good mechanical properties and easy processing properties. At present, the method of increasing the refractive index of polymer materials is mainly to introduce groups with high refractive index and small molecular volume. There are mainly the following methods: (1) introducing aromatic compounds o...

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Problems solved by technology

The main problems of introducing sulfur into polysiloxane in the above form are that the product is easy to yellow, the introduction is difficult, the reaction conditions are harsh, the effect of increasing the refractive index is not obvious, and the smell is strong

On the other hand, currently commercially available optical silicone materials mainly increase the refractive index by introducing aromatic structures or polycyclic aromatic mechanisms, but the mechanical properties of the materials are often poor, which limits the improvement of the refractive index, thereby limiting Its application in high-end fields such as optical lenses, lens materials, optical instruments, LEDs, and flexible optical fibers

Among them, the most important application is high-power LED silicone encapsulation. The commercially available high-fold silicone encapsulant generally needs several hours of thermal curing above 100°C, which greatly reduces production efficiency and increases production cost. Generally, the refractive index of sub-LED encapsulation glue can only reach 1.54, the viscosity is high, the colloid itself and the colloid and phosphor are mixed unevenly, mechanical degassing is required, the steps are cumbersome, and it is difficult to meet the needs of a fast and fully automatic production line

At present, there are relatively few researches on high-refractive index sulfur-containing polysiloxanes that can be cured by ultraviolet light. Industrial application, and in the preparation process of organosilicon system in the form of sulfur heterocycle, the stability of sulfur heterocycle is poor, it is easy to open the ring during the reaction process, forming a linear thioether segment, thereby increasing the sulfur content The irritating smell of polymer

Moreover, it is introduced into the organosilicon system in the form of an episulfide structure (such as a sulfone group, etc.). The asymmetric episulfide structure not only has a large odor, but it is also difficult to introduce the episulfide structure into the organosilicon system. Not high, poor transparency, easy to yellow, poor storage stability, poor compatibility with polysiloxane

At present, the modified polysiloxane of sulfur heterocycle is mainly prepared by ultra-low temperature Grignard reaction method, which requires high experimental conditions, huge investment, difficulty in industrial production, and many unstable factors. Sulfur atoms are introduced into the organosilicon system. tougher

Prior art CN106317898A discloses a photocurable silicone elastomer and its preparation method and application. This technology mainly improves the mechanical properties, hardness and Refractive index, but the refractive index is difficult to exceed 1.55, it is difficult to use optical materials with high optical performance requirements, and there is no improvement in the odor control, storage stability and compatibility of materials. does not provide a good solution

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