Reflection-preventive pellicle film and process for preparation thereof

Claim 2

A reflection-preventive pellicle film commprising a transparent film of a cellulose derivative and a reflection-preventive layer of polyfluoro(meth)acrylate on one or both of the surfaces of the transparent film, wherein the polyfluoro(meth)acrylate is selected from (1) a polyfluoro(meth)arcylate having a fluorine content of at least 50% by weight and comprising repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 2 is fluoroalkyl optionally containing an intermediate etheric oxygen atom, (2) a polyfluoroacrylate which is a copolymer of (A) trifluoroethyl acrylate and (B) perfluorooctylethyl acrylate having an (A)/(B) molar ratio of from 55/45 to 75/25 and a reduced specific viscosity lower than 1 dl/g, as measured in m-xylene hexafluoride solution at a concentration of 0.1 g/dl at 30 C, (3) a polyfluoro(meth)arcylate which is a copolymer comprising repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 3 is fluoroalkyl, and repeating units derived from at least one monomer of formula wherein R 1 is hydrogen or methyl and Y is a hydrocarbon group containing an intermediate etheric oxygen atom and optionally having a fluroalkyl substituent, (4) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula wherein R' is hydrogen or methyl and R 4 is a linear fluoroalkyl group not containing an etheric oxygen atom, and repeating units derived from at least one monomer of formula wherein R' is a hydrogen or alkyl and R 5 is a linear fluoroalkyl group containing an etheric oxygen atom or a branched fluoroalkyl group optionally containing an etheric oxygen atom, and (5) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula (I) and repeating units derived from at least one monomer of formula: wherein R' is hydrogen or methyl and R 6 is alkyl.

Claim 3

A film according to claim 1, wherein the transparent film is a cellulose propionate film.

Claim 4

A film according to claim 1, wherein the transparent film is nitrocellulose film.

Claim 5

A process for preparing a reflection-preventive pellicle film, which comprises applying a solution of a cellulose derivative to a substrate and rotating the substrate so as to form a transparent film of the cellulose derivative,drying the formed film, dissolving a polyfluoro(meth)acrylate in a solvent capable of dissolving the polyfluoro(meth)acrylate but incapable of dissolving or swelling the cellulose derivative, the polyfluoro-(meth)acrylate being selected from (1) a polyfluoro(meth)arcylate having a fluorine content of at least 50% by weight and comprising repeating units derived from at least one monomer of formula: wherein R' is hydrogen or methyl and R 2 is fluoroalkyl optionally containing an intermediate etheric oxygen atom, (2) a polyfluoroacrylate which is a copolymer of (A) trifluoroethyl acrylate and (B) perfluorooctylethyl acrylate having an (A)/(B) molar ratio of from 55/45 to 75/25 and a reduced specific viscosity lower than 1 dl/g, as measured in m-xylene hexafluoride solution at a concentration of 0.1 g/dl at 30° C, (3) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 3 is fluoroalkyl, and repeating units derived from at least one monomer of formula wherein R 1 is hydrogen or methyl and Y is a hydrocarbon group containing an intermediate etheric oxygen atom and optionally having a fluroalkyl substituent, (4) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula wherein R' is hydrogen or methyl and R 4 is a linear fluoroalkyl group not containing an etheric oxygen atom, and repeating units derived from at least one monomer of formula wherein R 1 is a hydrogen or alkyl and R 5 is a linear fluoroalkyl group containing an etheric oxygen atom or a branched fluoroalkyl group optionally containing an etheric oxygen atom, and (5) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula (I) and repeating units derived from at least one monomer of formula: wherein R I is hydrogen or methyl and R 6 is alkyl, applying the solution to the cellulose derivative film and rotating the film so as to form a reflection-preventive layer thereon.

Claim 6

A process for preparing a reflection-preventive pellicle film, which comprises applying a solution of a cellulose derivative to a substrate and rotating the substrate so as to form a transparent film of the cellulose derivative,drying the formed film, dissolving a polyfluoro(meth)acrylate in a solvent capable of dissolving the polyfluoro(meth)acrylate but incapable of dissolving or swelling the cellulose derivative, the polyfluoro-(meth)acrylate being selected from (1) a polyfluoro(meth)arcylate having a fluorine content of at least 50% by weight and comprising repeating units derived from at least one monomer of formula: wherein R' is hydrogen or methyl and R 2 is fluoroalkyl optionally containing an intermediate etheric oxygen atom, (2) a polyfluoroacrylate which is a copolymer of (A) trifluoroethyl acrylate and (B) perfluorooctylethyl acrylate having an (A)/(B) molar ratio of from 55/45 to 75/25 and a reduced specific viscosity lower than 1 dl/g, as measured in m-xylene hexafluoride solution at a concentration of 0.1 g/dl at 30° C, (3) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 3 is fluoroalkyl, and repeating units derived from at least one monomer of formula wherein R 1 is hydrogen or methyl and Y is a hydrocarbon group containing an intermediate etheric oxygen atom and optionally having a fluroalkyl substituent, (4) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula wherein R' is hydrogen or methyl and R 4 is a linear fluoroalkyl group not containing an etheric oxygen atom, and repeating units derived from at least one monomer of formula wherein R 1 is a hydrogen or alkyl and R 5 is a linear fluoroalkyl group containing an etheric oxygen atom or a branched fluoroalkyl group optionally containing an etheric oxygen atom, and (5) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula (I) and repeating units derived from at least one monomer of formula: wherein R I is hydrogen or methyl and R 6 is alkyl, applying the solution to the cellulose derivative film and rotating the film so as to form a reflection-preventive layer thereon.

Claim 7

A process for the preparation of a reflection-preventive pellicle film having reflection-preventive layers on both surfaces, comprising dissolving a polyfluoro(meth)acrylate in a solvent capable of dissolving the polyfluoro(meth)acrylate but incapable of dissolving or swelling the cellulose derivative, the polyfluoro-(meth)acrylate being selected from (1) a polyfluoro(meth)arcylate having a fluorine content of at least 50% by weight and comprising repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 2 is fluoroalkyl optionally containing an intermediate etheric oxygen atom, (2) a polyfluoroacrylate which is a copolymer of (A) trifluoroethyl acrylate and (B) perfluorooctylethyl acrylate having an (A)/(B) molar ratio of from 55/45 to 75/25 and a reduced specific viscosity lower than 1 dl/g, as measured in m-xylene hexafluoride solution at a concentration of 0.1 g/dl at 30' C, (3) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 3 is fluoroalkyl, and repeating units derived from at least one monomer of formula wherein R 1 is hydrogen or methyl and Y is a hydrocarbon group containing an intermediate etheric oxygen atom and optionally having a fluroalkyl substituent, (4) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula wherein R 1 is hydrogen or methyl and R 4 is a linear fluoroalkyl group not containing an etheric oxygen atom, and repeating units derived from at least one monomer of formula wherein R' is a hydrogen or alkyl and R 5 is a linear fluoroalkyl group containing an etheric oxygen atom or a branched fluoroalkyl group optionally containing an etheric oxygen atom, and (5) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula (I) and repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 6 is alkyl, rotating the substrate so as to form a reflection-preventive layer. drying the reflection-preventive layer, applying a solution of a cellulose derivative to the reflection-preventive layer and rotating the reflection-preventive layer so as to form a film of the cellulose derivative, drying the cellulose derivative film, and applying further polyfluoro(meth)acrylate solution to the cellulose derivative film and rotating the cellulose derivative film as to form a further reflection-preventive layer thereon.

Claim 8

A process for the preparation of a reflection-preventive pellicle film having reflection-preventive layers on both surfaces, comprising dissolving a polyfluoro(meth)acrylate in a solvent capable of dissolving the polyfluoro(meth)acrylate but incapable of dissolving or swelling the cellulose derivative, the polyfluoro-(meth)acrylate being selected from (1) a polyfluoro(meth)arcylate having a fluorine content of at least 50% by weight and comprising repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 2 is fluoroalkyl optionally containing an intermediate etheric oxygen atom, (2) a polyfluoroacrylate which is a copolymer of (A) trifluoroethyl acrylate and (B) perfluorooctylethyl acrylate having an (A)/(B) molar ratio of from 55/45 to 75/25 and a reduced specific viscosity lower than 1 dl/g, as measured in m-xylene hexafluoride solution at a concentration of 0.1 g/dl at 30' C, (3) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 3 is fluoroalkyl, and repeating units derived from at least one monomer of formula wherein R 1 is hydrogen or methyl and Y is a hydrocarbon group containing an intermediate etheric oxygen atom and optionally having a fluroalkyl substituent, (4) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula wherein R 1 is hydrogen or methyl and R 4 is a linear fluoroalkyl group not containing an etheric oxygen atom, and repeating units derived from at least one monomer of formula wherein R' is a hydrogen or alkyl and R 5 is a linear fluoroalkyl group containing an etheric oxygen atom or a branched fluoroalkyl group optionally containing an etheric oxygen atom, and (5) a polyfluoro(meth)acrylate which is a copolymer comprising repeating units derived from at least one monomer of formula (I) and repeating units derived from at least one monomer of formula: wherein R 1 is hydrogen or methyl and R 6 is alkyl, rotating the substrate so as to form a reflection-preventive layer. drying the reflection-preventive layer, applying a solution of a cellulose derivative to the reflection-preventive layer and rotating the reflection-preventive layer so as to form a film of the cellulose derivative, drying the cellulose derivative film, and applying further polyfluoro(meth)acrylate solution to the cellulose derivative film and rotating the cellulose derivative film as to form a further reflection-preventive layer thereon.

Claim 9

A process according to claim 4 or claim 5 for producing a film as defined in any one of claims 1 to 3.

Claim 10

A process according to any one of claims 4 to 6 wherein the solvent for the polyfluoro(meth)acrylate is selected from m-xylene, hexafluoride, benzotrifluoride and pentafluoropropanol.