Shaped plastic articles having replicated microstructure surfaces
First Claim
1. An article comprising a shaped, plastic, optically homogeneous, cast, monolithic layer having a replicated microstructure-bearing surface having a plurality of utilitarian discontinuities and comprising a crosslinked polymer composed of (1) a plurality of hard segments of mono- or polyvalent moieties containing one or more carbocyclic and/or heterocyclic groups, and (2) a plurality of soft segments of polyvalent polysiloxane moieties.
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Abstract
An article comprising a shaped, plastic layer or body comprising crosslinked polymer with hard and soft segments or moieties and having a microstructure-bearing surface is prepared by a process comprising filling a mold master, bearing or encoded with the microstructure to be replicated, with a fluid, castable, one-part, preferably solvent-free, radiation addition-polymerizable, crosslinkable, synthetic, organic oligomeric composition (or precursors thereof) having "hard" segments and "soft" polysiloxane segments, exposing the resulting case composition to radiation, preferably actinic radiation such as ultraviolet radiation, and thereby forming said article, e.g., a retroreflective cube-corner sheeting, Fresnel lens or video disc.
295 Citations
37 Claims
- 1. An article comprising a shaped, plastic, optically homogeneous, cast, monolithic layer having a replicated microstructure-bearing surface having a plurality of utilitarian discontinuities and comprising a crosslinked polymer composed of (1) a plurality of hard segments of mono- or polyvalent moieties containing one or more carbocyclic and/or heterocyclic groups, and (2) a plurality of soft segments of polyvalent polysiloxane moieties.
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8. A shaped plastic article comprising a shaped, plastic, optically homogeneous, cast, monolithic layer having a replicated microstructure-bearing surface having a plurality of utilitarian discontinuities and consisting essentially of crosslinked polymer composed of (1) a plurality of hard segments of mono- or polyvalent moieties containing one or more carbocyclic and/or heterocyclic groups and difunctional linking groups with hydrogen bonding capability, and (2) a plurality of soft segments of polyvalent polysiloxane moieties, wherein each of said moieties of said hard segments, when their valences are satisfied by protons, has at least one major transition temperature above 250°
- K., and wherein each of said moieties of said soft segments has a number average molecular weight of about 500 to 5000 and homopolymers thereof have a glass transition temperature below 250°
K., said crosslinked polymer having a gel swell within the range of 35 to 200 weight percent, 10 to 80 weight percent of said hard segments and 10 to 60 weight percent of said soft segments, and dynamic shear moduli, over the temperature range of 23°
C. to 120°
C., which fall on or within the boundary of A-B-C-D of FIG. 1, and wherein a diffraction grating of said crosslinked polymer has a first order diffraction efficiency which changes less than 15% when heated to 130°
C. for 1 hour as compared to the first order diffraction efficiency before heating. - View Dependent Claims (37)
- K., and wherein each of said moieties of said soft segments has a number average molecular weight of about 500 to 5000 and homopolymers thereof have a glass transition temperature below 250°
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21. A plastic diffraction grating comprising a shaped, plastic, monolithic layer having a diffraction grating-bearing surface and comprising crosslinked polymer composed of
(1) 20 to 50 weight percent of a plurality of hard segments selected from those represented by one or both of the formulas: - ##STR58## where each A is independently --NH-- or --O--, A'"'"' is --NH--,
each R3 is independently a di-valent carbocyclic-containing radical derived from benzene, napthalene cyclohexane, dicyclohexylmethane, or diphenylmethane, and their lower alkyl-substituted derivatives, by removal of two of their hydrogen atoms, each R4 is independently an alkylene moiety with 2 or 4 carbon atoms, or a cycloalkylene moiety with 6 to 10 carbon atoms, each R5 is phenyl, each d is independently zero or 1 g is zero or a number having an average of 1 to 3, and h'"'"' is zero or an integer of 1 to 10, (2) 15 to 45 weight percent of a plurality of soft segments selected from those represented by one or more of the formulas;
##STR59## where b'"'"' is a number of 6 to 35, and R is a linear or branched alkylene group having 1 to 12 carbon atoms or a polyoxyalkylene group having 4 to 80 carbon atoms and 1 to 40 oxygen atoms, and ##STR60## where the groups enclosed by the single brackets with subscripts b'"'"' and c'"'"' are repeating units randomly distributed within the double bracket, b'"'"' being a number of 6 to 35 and c'"'"' being 2 or 3, and R is alkylene as defined above, said crosslinked polymer having a gel swell within the range of 35 to 200 weight %, and dynamic shear moduli, over a temperature range of 23°
to 120°
C., which fall on or within the boundary of A-B-C-D of FIG. 1, and wherein the first order diffraction efficiency of said grating changes less than 5% when heated at 130°
C. for 1 hour as compared to the first order diffraction efficiency before heating.
- ##STR58## where each A is independently --NH-- or --O--, A'"'"' is --NH--,
- 22. A process for making a shaped plastic article comprising a shaped, plastic, monolithic layer having a microstructure-bearing surface and comprising crosslinked, polymer, comprising the steps of filling a mold master with a fluid, castable, one-part radiation addition-polymerizable, crosslinkable, oligomeric composition or precursors thereof, said oligomeric composition comprising one or more oligomers having (1) one or more like or different hard segments each comprising a mono- or poly-valent moiety containing one or more carbocyclic and/or heterocyclic groups, (2) one or more like or different soft segments each comprising poly-valent polysiloxane moiety, and (3) one or more like or different monovalent moieties containing a radiation sensitive, addition polymerizable, functional group selected from the group consisting of acrylyl, methacrylyl, allyl, and vic-epoxy, exposing the resulting cast oligomeric composition, or precursors thereof, to radiation, and recovering said shaped plastic article.
Specification