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EP-4310130-B1 - SILOXANE COMPOUND AND METHOD FOR PRODUCING SAME

EP4310130B1EP 4310130 B1EP4310130 B1EP 4310130B1EP-4310130-B1

Inventors

  • OKAMURA KAORU

Dates

Publication Date
20260506
Application Date
20220316

Claims (18)

  1. A siloxane compound represented by the following formula (1): wherein R 1 is a hydrogen atom or a methyl group, R 2 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, L 1 is a divalent hydrocarbon group having 1 to 5 carbon atoms, L 2 is a divalent hydrocarbon group having 2 to 10 carbon atoms and which may contain an ether bond, and A is a polysiloxane unit represented by the following formula (2) or (3): wherein n is an integer of 1 to 100, a is an integer of 0 to 10, b is an integer of 0 to 10, and c is an integer of 0 to 10, provided that a + b + c is 2 or more, R and R 3 are, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, and the site marked with ** is a binding position to the group L 2 in formula (1).
  2. The siloxane compound according to claim 1, wherein R 1 is a methyl group.
  3. The siloxane compound according to claim 1 or 2, wherein A is represented by said formula (2) and n is an integer of 2 to 20.
  4. The siloxane compound according to claim 1 or 2, wherein A is represented by said formula (3) and a is 1, b is 1 and c is 1.
  5. The siloxane compound according to any one of claims 1 to 4, wherein R and R 3 in said formulae (2) and (3) are, independently of each other, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.
  6. The siloxane compound according to claim 5, wherein R in said formula (2) is a methyl group and R 3 in said formula (2) is a butyl group.
  7. The siloxane compound according to claim 5, wherein R in said formula (3) is a methyl group.
  8. The siloxane compound according to any one of claims 1 to 7, wherein a proportion of the siloxane compound having one specific structure among the structures represented by formula (1) is 95 mass% or more.
  9. A polymer derived by polymerization of the siloxane compound according to any one of claims 1 to 8.
  10. A copolymer derived by polymerization of the siloxane compound according to any one of claims 1 to 8 with other polymerizable monomer(s).
  11. The copolymer according to claim 10, wherein a mass proportion of the repeating units derived from the siloxane compound is 10 mass% or more to 80 mass% or less, relative to the mass of the copolymer.
  12. The copolymer according to claim 10 or 11, wherein at least one of the other polymerizable monomer(s) is a (meth)acrylic monomer other than a siloxane compound, and a total mass proportion of the repeating units derived from the siloxane compound and the repeating units derived from the (meth)acrylic monomer is 50 mass% or more, relative to the mass of the copolymer.
  13. A hydrogel comprising the polymer according to claim 9 or the copolymer according to any one of claims 10 to 12.
  14. A medical material comprising the polymer according to claim 9 or the copolymer according to any one of claims 10 to 12.
  15. A method for preparing the siloxane compound represented by the following formula (1): wherein R 1 is a hydrogen atom or a methyl group, R 2 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, L 1 is a divalent hydrocarbon group having 1 to 5 carbon atoms, L 2 is a divalent hydrocarbon group having 2 to 10 carbon atoms and which may contain an ether bond, and A is a polysiloxane unit represented by the following formula (2) or (3): wherein n is an integer of 1 to 100, a is an integer of 0 to 10, b is an integer of 0 to 10, and c is an integer of 0 to 10, provided that a + b + c is 2 or more, R and R 3 are, independently of each other, a monovalent hydrocarbon group having 1 to 10 carbon atoms, and the site marked with ** is a binding position to the group L 2 in formula (1), wherein the method comprises a step of reacting a siloxane compound having an amino group and represented by the following formula (5): wherein R 2 , L 2 and A are as described above, with a lactone compound having 2 to 6 carbon atoms to obtain a siloxane compound represented by the following formula (4): wherein R 2 , L 1 , L 2 and A are as described above, and a step of reacting the siloxane compound represented by said formula (4) with a (meth)acrylic acid halide to obtain the compound represented by said formula (1).
  16. The method according to claim 15, wherein the lactone compound is selected from the group consisting of α-acetolactone, β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone and ε-caprolactone.
  17. The method according to claim 15 or 16, wherein the (meth)acrylic acid halide is methacrylic acid chloride, acrylic acid chloride, methacrylic acid bromide or acrylic acid bromide.
  18. The method according to any one of claims 15 to 17, wherein a proportion of the siloxane compound having one specific structure among the structures represented by said formula (1) is 95 mass% or more.

Description

TECHNICAL FIELD The present invention relates to a siloxane compound and a method for preparing the same. Specifically, the present invention provides a siloxane compound suitable for medical materials. BACKGROUND ART Conventionally, monomers having siloxanes are known as a compound used for preparing medical materials including ophthalmic devices. For example, 3-[tris(trimethylsiloxy)silyl]propyl methacrylate (TRIS) is widely used as a monomer for medical materials. A polymer obtained by the copolymerization of TRIS with a hydrophilic monomer, such as 2-hydroxyethyl methacrylate, N,N-dimethylacrylamide, and N-vinyl-2-pyrrolidone, has beneficial characteristics such as high oxygen permeability. However, highly hydrophobic siloxane monomers do not have sufficient compatibility with such a hydrophilic monomer and, accordingly, in the preparation of a hydrogel prepared therefrom for medical materials, there is a problem in that phase separation occurs, causing the hydrogel to be cloudy. Therefore, attempts to improve compatibility have been performed by introducing a hydrophilic group in a siloxane monomer molecule. Patent Literatures 1, 2, and 3 disclose a siloxane compound, which is methyl bis(trimethylsiloxy)silyl propyl glycerol methacrylate (SiGMA), having glycerol methacrylate represented by the following formula (a) or (a'). SiGMA is a monomer with a hydroxyl group in the molecule and formed by an addition reaction between methacrylic acid and an epoxy-modified siloxane compound, therefore it expresses satisfactory hydrophilicity. However, with SiGMA, a side reaction in an addition reaction of carboxylic acid with the epoxy-modified siloxane compound cannot be prevented, and there is a problem in that a purity of the intended siloxane compound decreases, thus SiGMA is not desirable as a raw material for medical materials. Patent Literature 4 discloses a siloxane compound having a (meth)acrylamide group. Since the compound has an amide in the molecule, it expresses satisfactory hydrophilicity. Patent Literature 5 discloses self-assembled elastomers with molecularly encoded tissue-like softness, strain-adaptive stiffening and coloration. The disclosed copolymer blocks can be useful in, for example, the formation of polymer networks that replicate biological stress-strain behavior. PRIOR LITERATURES Patent Literature 1: Japanese Patent Application Laid-Open No. Sho 54-55455(1979)Patent Literature 2: Japanese Patent Application Laid-Open No. Sho 56-22325(1981)Patent Literature 3: Japanese Patent Application Laid-Open No. 2004-182724Patent Literature 4: Japanese Patent Application Laid-Open No. Hei 5-17577(1993)Patent Literature 5: US 9,329,306 B2 DISCLOSURE OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION However, most other monomers for medical materials that are polymerized with siloxane compounds have (meth)acrylates. The siloxane compound having a (meth)acrylamide group disclosed in Patent Literature 4 is inferior in terms of reactivity with monomer compounds having (meth)acrylates and causes phase separation during polymerization, which may make the obtained materials nonuniformity. As described above, while a siloxane compound having a hydrophilic group has compatibility with hydrophilic monomers, it has problems with reactivity and purity. Therefore, the siloxane compound not desirable as a raw material of (meth)acrylic resins, particularly a raw material for medical materials. Consequently, providing a material having beneficial hydrophilicity, transparency, and strength is difficult with conventional siloxane compounds. Therefore, demand still exists for compounds and compositions that will overcome these drawbacks. The present invention has been made in view of the above circumstances, and one of the purposes of the present invention is to provide a siloxane compound having an amide bond and a (meth)acrylate group. Further, other purpose of the present invention is to provide a method for preparing a siloxane compound having beneficial purity as a medical material. SOLUTIONS TO THE PROBLEMS As a result of serious examination to solve the above-described problems, the present inventor found that a compound having a siloxane unit and a (meth)acrylate group, and having an amide bond at a linking group portion thereof, has excellent compatibility with other monomers including hydrophilic monomers, and further, has satisfactory reactivity. Further, the present inventor found that the siloxane compound obtained from a siloxane compound having an amino group, a lactone compound, and a (meth)acrylic acid halide has a high purity and, therefore, the siloxane compound is preferred as a raw material of a (meth)acrylic resin serving as medical materials. That is, the present invention provides a siloxane compound represented by the following formula (1): wherein R1 is a hydrogen atom or a methyl group, R2 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, L1 is a divalen