Shaped plastic articles having replicated microstructure surfaces

A shaped plastic article, useful for an optical purpose, comprising a shaped, plastic, cast, monolithic layer having a replicated microstructure-bearing surface whose configuration contains a plurality of utilitarian discontinuities which characterizes said optical purpose of said article, said layer comprising 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 mono- or polyvalent 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.degree. K., and wherein each of said moieties of said soft segments has a number average molecular weight of about 500 to 250 and homopolymers thereof have a glass transition temperature below 250.degree. 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.degree. C. to 120.degree. 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.degree. C. for 1 hour as compared to the first order diffraction efficiency before heating.

An article, useful for an optical purpose, comprising a shaped, plastic, optically homogeneous, cast, monolithic layer having a replicated microstructure-bearing surface whose configuration contains a plurality of utilitarian discontinuities which characterize said optical purpose of said article, said layer comprising 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 mono- or polyvalent moieties, wherein said hard segments are represented by one or more of the following formulas:

• ##STR120## where each A is independently --NH-- or --O--,
• each B is ##STR121## where f is an integer of 2 to 5, each R.sup.2 is independently hydrogen or a lower alkyl,
• each R.sup.3 is independently a di-valent carbocyclic-containing radical derived from benzene, naphthalene, cyclohexane, dicyclohexylmethane, diphenylmethane or norbornene, and their lower alkyl-substituted derivatives, by removal of two of their hydrogen atoms,
• each R.sup.4 is independently an alkylene moiety with 2 to 10 carbon atoms, or a cycloalkylene moiety with 6 to 10 carbon atoms,
• each R.sup.5 is independently a phenyl moiety or methyl,
• each R.sup.6 is independently a lower alkyl with 1 to 4 carbon atoms, g is zero or a number up to 5, h is an integer of 1 to 10, h' is zero or an integer of 1 to 10,
• each d, d' and d" is independently zero or 1, with the proviso that if either one of d' or d" is 1, then the other is zero,
• and wherein said soft segments are residues remaining from removal of the active hydrogen atoms of one or more of the following:
• poly(oxyalkylene) polyols, polyester polyols, polyether polyester polyols, polyolefin polyols, poly(alkylacrylate) polyols, and polyamines.

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 ##STR135## where each A is --NH-- or --O--,

• A' is --NH--,
• each R.sup.3 is independently a di-valent carbocyclic-containing radical derived from benzene, naphthalene cyclohexane, dicyclohexylmethane, or diphenylmethane, and their lower alkyl-substituted derivatives, by removal of two of their hydrogen atoms,
• each R.sup.4 is independently an alkylene moiety with 2 or 4 carbon atoms, or a cycloalkylene moiety with 6 to 10 carbon atoms,
• each R.sup.5 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:
• ##STR136## where r' is a number of 1 to 5 and e' is 2 or 3, ##STR137## and where r' is a number of 1 to 5 and s is 2 or 3, and R.sup.9 is oxyalkylene, polyoxyalkylene, or alkanetriyl,
• 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.degree. to 120.degree. 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.degree. C. for 1 hour as compared to the first order diffraction efficiency before heating.

A plastic retroreflective sheet comprising a shaped, plastic, cast, mono-lithic layer having a surface with an array of a plurality of contiguous trihedral or tetrahedral prism elements and comprising optically homogeneous crosslinked polymer composed of (1) 20 to 50 weight percent of a plurality of hard segments represented by the formula ##STR138## where each A is independently --NH-- or --O--,

• A' is --NH--,
• each R.sup.3 is independently a di-valent carbocyclic-containing radical derived from cyclohexane or dicyclohexylmethane, and their lower alkyl-substituted derivatives, by removal of two of their hydrogen atoms,
• each R.sup.4 is independently an alkylene moiety with 2 to 10 carbon atoms, or a cycloalkylene moiety with 6 to 10 carbon atoms,
• d is 1, and
• g is zero or a number up to 5,
• (2) 15 to 45 weight percent of soft segments selected from one of the following formulas ##STR139## where r' is a number of 1 to 10 and e' is 2 or 3, ##STR140## where r' is a number of 1 to 10 and s is 2 or 3 and R.sup.9 is oxyalkylene, polyoxyalkylene or alkanetriyl, ##STR141## where each R.sup.11 is independently hydrogen or methyl,
• R.sup.12 is independently an alkyl of 2 to 10 carbon atoms,
• R.sup.13 is independently --C(O)OCH.sub.3, --CN or phenyl,
• R.sup.14 is --SR.sup.15 H, --SR.sup.15 O--, --SCH.sub.2 C(O)OR.sup.15 H or H, where R.sup.15 is an alkylene having 1 to 12 carbon atoms,
• f is an integer of 2 to 5
• the groups enclosed by the single brackets with subscripts x, y and z are repeating units randomly distributed within the double brackets, the sum of x, y and z being such that the number average molecular weight of the totality of said repeating units is about 500 to 5000, the units enclosed by brackets with subscripts x and y always being present and the units enclosed by the bracket with subscript z being optionally present, said crosslinked polymer having a gel swell within the range of 35 to 200 weight percent, said crosslinked polymer in the form of a diffraction grating having a first order diffraction efficiency which changes less than 5% when heated at 130.degree. C. for 1 hour as compared to the first order diffraction efficiency before heating, said retroreflective sheet having a brightness of at least 600 candles per lumen at 0.2.degree. divergence angle.

A plastic lens element comprising a shaped, plastic, cast, monolithic layer having on its surface a linear Fresnel or echelon pattern, and comprising optically homogeneous crosslinked polymer composed of (1) 20 to 50 weight percent of a plurality of hard segments represented by the formula ##STR142## where each A is independently --NH-- or --O--,

• A' is --NH--
• each R.sup.3 is independently a di-valent carbocyclic-containing radical derived from cyclohexane or dicyclohexylmethane, and their lower alkyl-substituted derivatives, by removal of two of their hydrogen atoms,
• each R.sup.4 is independently an alkylene moiety with 2 to 10 carbon atoms, or a cycloalkylene moiety with 6 to 10 carbon atoms,
• d is 1, and
• g is zero or a number up to 5,
• (2) 15 to 45 weight percent of soft segments selected from one of the following formulas ##STR143## where r' is a number of 1 to 10 and e' is 2 or 3, ##STR144## where r' is a number of 1 to 10 and s is 2 or 3, and R.sup.9 is oxyalkylene, polyoxyalkylene, or alkanetriyl, ##STR145## where each R.sup.11 is independently hydrogen or methyl,
• R.sup.12 is independently an alkyl of 2 to 10 carbon atoms,
• R.sup.13 is independently --C(O)OCH.sub.3, --CN or phenyl,
• R.sup.14 is --SR.sup.15 H, --SR.sup.15 O--, --SCH.sub.2 C(O)OR.sup.15 H or H, where R.sup.15 is an alkylene having 1 to 12 carbon atoms,
• f is an integer of 2 to 5
• the groups enclosed by the single brackets with subscripts x, y and z are repeating units randomly distributed within the double brackets, the sum of x, y and z being such that the number average molecular weight of the totality of said repeating units is about 500 to 5000, the units enclosed by brackets with subscripts x and y always being present and the units enclosed by the bracket with subscript z being optionally present, said crosslinked polymer having a gel swell of 35 to 200% and dynamic shear moduli, over a temperature range of 23.degree. to 120.degree. C., which fall on or within the boundary of A-B-C-D of FIG. 1, said crosslinked polymer in the form of a diffraction grating having a first order diffraction efficiency which changes less than 5% when heated at 130.degree. C. for 1 hour as compared to the first order diffraction efficiency before heating.

A video disc comprising a shaped, plastic, cast, monolithic layer having on its surface information-bearing microstructure in the form of a predetermined array or pattern of spaced-apart depressions and comprising crosslinked polymer composed of (1) 20 to 50 weight percent of a plurality of hard segments represented by the formula ##STR146## where each A is independently --NH-- or --O--,

• A' is --NH--
• each R.sup.3 is independently a di-valent carbocyclic containing radical derived from cyclohexane or dicyclohexylmethane, and their lower alkyl-substituted derivatives, by removal of two of their hydrogen atoms,
• each R.sup.4 is independently an alkylene moiety with 2 to 10 carbon atoms, or a cycloalkylene moiety with 6 to 10 carbon atoms,
• d is 1, and
• g is zero or a number up to 5,
• (2) 15 to 45 weight percent of soft segments represented by the formula:
• ##STR147## where R.sup.9 is a saturated aliphatic radical free of active hydrogen atoms and can contain 1 or 2 non-vicinal catenary oxygen or nitrogen atoms, R.sup.9 having a valence equal to s and 2 to 10 carbon atoms,
• each a, o, p and q is independently zero or 1,
• each e' is independently an integer of 2 to 10,
• each r is independently a number of 1 to 20, and
• each s is independently an integer of 1 to 3, with proviso that
• when q is 1, then s is 2 or 3 and o is zero and either a and p are both zero or both 1, and
• when q is zero, then s and o are 1 and either a and p are both zero or both 1,
• said crosslinked polymer having a gel swell of 35 to 200 weight percent and in the form of a diffraction grating having a first order diffraction efficiency which changes less than 15% when heated at 130.degree. C. for 1 hour as compared to the first order diffraction efficiency before heating.

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 represented by the formula:

• ##STR150## where each .alpha. is independently 1 or 2
• .beta. is zero or a number up to 20 and has an average value up to about 5
• ".gamma." is 2 or 3
• "E" is represented by the formulas:
• ##STR151## where R.sup.1 is a hydrogen atom or methyl,
• each A is independently --NH-- or --O--,
• a, b, c and d are each independently zero or 1, with the provisos that
• (1) at least one of b and d must be 1,
• (2) if b and c are both zero, than a and d must be 1,
• (3) if b and d are both 1, then a and c must be 1, and e is at least 2, and
• (4) if d is 1 and a and b are both zero, then c must be 1,
• e is an integer of 1 to 5, ##STR152## where d is zero or 1,
• e is an integer of 1 to 5, ##STR153## where R.sup.2 is hydrogen or a lower alkyl,
• B is ##STR154## where each f is a integer of 2 to 5, and each d is independently zero or 1,
• "H" is represented by one or more of the formulas:
• ##STR155## where each A is independently --NH-- or --O--,
• each B is ##STR156## where f is an integer of 2 to 5, each R.sup.2 is independently hydrogen or a lower alkyl,
• each R.sup.3 is independently a polyvalent carbocyclic-containing radical derived from benzene, naphthalene, cyclohexane, dicyclohexylmethane, diphenylmethane or norbornene, and their lower alkyl-substituted derivatives, by removal of two or more of their hydrogen atoms,
• each R.sup.4 is independently an alkylene moiety with 2 to 10 carbon atoms, or a cycloalkylene moiety with 6 to 10 carbon atoms,
• each R.sup.5 is independently a phenyl moiety or methyl,
• each R.sup.6 is independently a lower alkyl with 1 to 4 carbon atoms,
• g is zero or a number up to 5,
• h is an integer of 1 to 10,
• h' is zero or an integer of 1 to 10,
• each d, d' and d" is independently zero or 1, with the proviso that if either one of d' or d" is 1, then the other is zero, and
• "S" is the residue remaining after removal of the active hydrogen atoms of one or more of the following:
• poly(oxyalkylene)polyols, polyester polyols, polyether polyester polyols, polyolefin polyols, poly(alkylacrylate)polyols, and polyamines.

A process for making a retroreflective sheet comprising a shaped, plastic, monolithic layer of crosslinked polymer and having a microstructure-bearing surface comprising an array of trihedral or tetrahedral prism elements, said process comprising the steps of filling a metal mold master with a fluid castable, one-part radiation sensitized, crosslinkable, composition comprising an oligomer of the formula:

• ##STR173## where each .alpha. is independently 1 or 2
• .beta. is zero or a number up to 20 and has an average value up to about 5
• .gamma. is 2 or 3
• "E" is ##STR174## "H" is a hard segment of the formula:
• ##STR175## and "S" is a soft segment of the formula:
• ##STR176## said composition further comprising 2-(N-butylcarbamyl)ethyl methacrylate as a diluent monomer, exposing the rsulting cast composition to ultraviolet radiation to cure the same, and removing from said mold master said retroreflective sheet, the latter having a brightness of at least 600 candles per lumen at 0.2.degree. divergence angle, said crosslinked polymer having a gel swell within the range of 35 to 200 weight percent and having dynamic shear moduli, over the temperature range of 23.degree. to 120.degree. 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 at 130.degree. C. for 1 hour as compared to the first order diffraction efficiency before heating.