Binaphthyl Monomer Structure for Low-Oligomer Optical Resins
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Solution Overview
Problem
Binaphthyl-derived monomers used in the production of thermoplastic resins like polycarbonates form significant amounts of undesirable cyclic oligomers, leading to reduced mechanical strength and optical properties, which are difficult to remove efficiently.
Innovation Solution
The use of binaphthyl compounds with specific structural modifications, such as formula (I), reduces the formation of cyclic oligomers, resulting in resins with higher molecular weight and refractive index, and improved mechanical and optical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If binaphthyl-derived monomers are used to produce thermoplastic resins, then the resins achieve high refractive index and suitable glass transition temperature, but significant amounts of cyclic oligomers form which reduce mechanical strength and worsen product properties
Solution Approach 1:
The patent modifies the binaphthyl monomer structure by changing the linker unit parameters - specifically using rigid aromatic linkers (phenylene, naphthalene, anthracene groups) instead of flexible aliphatic linkers, and optimizing linker length and position. These parameter changes in the monomer structure prevent cyclic oligomer formation while maintaining the desired glass transition temperature and mechanical strength of the resulting thermoplastic resin
2Temperature
If binaphthyl-derived monomers are used to produce thermoplastic resins, then the resins achieve high refractive index, but cyclic oligomers form which reduce optical properties and mechanical strength
Solution Approach 1:
The patent introduces rigid aromatic linker units with specific structural parameters into the binaphthyl monomer. These parameter changes in the molecular structure increase the refractive index of the resin while the rigid structure prevents cyclic oligomer formation, thereby maintaining optical properties such as transparency and low birefringence
3Reliability
If binaphthyl-derived monomers are used in thermoplastic resin production, then the resins achieve desired optical properties, but cyclic oligomers form which are difficult to remove and require high amounts of comonomers
Solution Approach 1:
The patent modifies the monomer structure by incorporating rigid aromatic linkers with optimized parameters, which fundamentally changes the polymerization behavior to prevent cyclic oligomer formation. This structural parameter change eliminates the need for complex purification processes and high comonomer additions, simplifying the overall manufacturing process while maintaining optical properties
4Ease of manufacture
If binaphthyl-derived monomers with flexible linker units are used, then the monomers are suitable for polymerization, but cyclic oligomers form due to the flexible and short linker units
Solution Approach 1:
The patent changes the key parameter of the linker unit from flexible aliphatic to rigid aromatic structure. This parameter change maintains polymerization suitability because the linker still connects the binaphthyl units effectively, while the rigidity and extended length of the aromatic linker prevent the monomers from forming cyclic structures during polymerization
Data Source
AI summary
The present invention relates to binaphthyl compounds of the formula {I) that are suitable as monomers for preparing thermoplastic resins, such as polycarbonate resins, which have beneficial optical and mechanical properties and can be used for producing optical devices, where X1 and X2 are independently selected from —CH2OH and —C(O)ORX, where Rx is selected from the group consisting of hydrogen, phenyl, benzyl and C1-C4-alkyl: A1 and A2 are independently e.g. mono- or polycyclic arylene having from 6 to 26 carbon atoms as ring members or mono- or polycyclic hetarylene having a total of 5 to 26 atoms, which are ring members: R1 and R2 are independently selected from the group consisting of halogen, C2-C3-alkynyl, CN, R, OR, CHsR′3-s, NR2, C(O)R and CH═CHR″, it being possible that R1 and R2 are identical or different if p+q>1, where s on each occurrence is 0, 1 or 2; p and q are independently 0, 1 or 2.