EP0227337A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for manufacturing photochromic articles
Assignee: Pilkington Group Ltd
•
Filing: 1986-12-01
•
Granted: —
•
Expires: 2006-12-01
Abstract
Abstract A direct casting process for manufacturing a shaped synthetic plastic article, such as an ophthalmic lens, which has photochromic properties, the process comprising incorporating a photochromic spiro-oxazine compound into a mixture comprising a highly reactive polyfunctional monomer and a low amount of a polymerisation catalyst, and curing the composition in a mould to form the shaped synthetic plastic article.
Inventors
- 👤 William Ramsey Maltman
- 👤 Ian Michael Threlfall
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 05:55
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/16; G; G03; G03C; G03C1/00; G03C1/685; C08F; C08F2/00; C08F2/44
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
106 words
A direct casting process for manufacturing a shaped synthetic plastic article having photochromic properties, which process comprises incorporating a photochromic spiro-oxazine compound into a mixture comprising a polyfunctional monomer and a polymerisation catalyst; introducing the resultant polymerisable composition into a mould, and curing the composition to form the shaped synthetic plastic article, characterised in that the polyfunctional monomer is a highly reactive monomer, and in that the amount of the polymerisation catalyst is 0.01 to 1% by weight, based on the volume of the monomer, and the amount of the photochromic spiro-oxazine compound is 0.05 to 5% by weight, based on the volume of the monomer.
Claim 2
Dependent Claim
106 words
A direct casting process for manufacturing a shaped synthetic plastic article having photochromic properties, which process comprises incorporating a photochromic spiro-oxazine compound into a mixture comprising a polyfunctional monomer and a polymerisation catalyst; introducing the resultant polymerisable composition into a mould, and curing the composition to form the shaped synthetic plastic article, characterised in that the polyfunctional monomer is a highly reactive monomer, and in that the amount of the polymerisation catalyst is 0.01 to 1% by weight, based on the volume of the monomer, and the amount of the photochromic spiro-oxazine compound is 0.05 to 5% by weight, based on the volume of the monomer.
Claim 3
Dependent Claim
19 words
A process according to Claim 1, wherein the mixture is cured at temperatures ranging from room temperature to 100°C.
Claim 4
Dependent Claim
15 words
A process according to Claim 2, wherein the temperature range is from 40° to 80°C.
Claim 5
Dependent Claim
20 words
A process according to Claim 1, 2 or 3, wherein the curing is performed over a period of 5 hours.
Claim 6
Dependent Claim
21 words
A process according to any one of the preceding claims, wherein the amount of the spiro-oxazine compound is 0.3% by weight.
Claim 7
Dependent Claim
106 words
A process according to any one of the preceding claims, wherein the spiro-oxazine compound is a compound of general formula (I): in which X represents -CH= or -N=, each of R₁ and R₂ independently represents a lower alkyl group, or R₁ and R₂ together represent an alicyclic ring, R₃ represents a lower alkyl group, each of R₄ and R₇ independently represents a hydrogen atom or a lower alkyl group, each of R₅ and R₆ independently represents a hydrogen or halogen atom, a lower alkyl group which optionally may be fluorinated, or a lower alkoxy group, and R₉ʹ represents a hydrogen atom or a lower alkoxy group.
Claim 8
Dependent Claim
48 words
A process according to Claim 6, wherein each of R₁, R₂ and R₃ independently represents a methyl group, each of R₄ and R₇ independently represents a methyl group, and each of R₅ and R₆ independently represents a methyl, trifluoromethyl or methoxy group, and R₉ʹ represents a methoxy group.
Claim 9
Dependent Claim
29 words
A process according to any one of the preceding claims, wherein the polyfunctional monomer is a methacrylate or acrylate of a linear or branched aliphatic or aromatic liquid polyol.
Claim 10
Dependent Claim
23 words
A process according to claim 8, wherein the polyfunctional monomer is triethylene glycol dimethacrylate, ethylene glycol dimethacrylate, 1,3-butyleneglycol dimethacrylate, or trimethylol propane trimethacrylate.
Claim 11
Dependent Claim
30 words
A process according to any one of the preceding claims, wherein up to 30% by weight, based on the volume of the polyfunctional monomer, of a monofunctional comonomer is added.
Claim 12
Dependent Claim
20 words
A process according to any one of the preceding claims, wherein the shaped synthetic plastic article is an ophthalmic lens.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.