Method of duplicating plastics information carriers

Claim 1

The method of manufacturing a plastic information carrier containing an information track having detail of such fineness as to be suitable for reading by an optical beam or similar reading means, said fineness being as small as in the order of a micron or less, comprising: (a) directly applying to a metal surface of a rigid, substantially flat die, which surface contains the negative of the desired information track, a thin layer of a thickness of 0.2-300 microns of a light-curable polymerizable liquid having a viscosity of from 1 to 100 cP and comprising low molecular weight acrylic monomers or a mixture of low molecular weight acrylic monomers and acrylic oligomers, which liquid contains 25-70% by weight of saturated hydrocarbon and/or phenyl groups, has an average functionality in regard to unsaturatedness of between 2.1 and 6, is at least substantially aprotic and consists for at least 95% of monomers having a maximum average molecular weight of about 400; (b) applying to the exposed surface of said thin layer of polymerizable liquid a thin light-pervious plastic substrate; (c) exposing said thin layer of polymerizable liquid to light radiation through said substrate for a time sufficient to cause said thin layer of polymerizable liquid to cure to a solid state adhering to said substrate thereby producing a laminate of said substrate and said cured layer containing the desired optically readable information track readily removable from said die without effect on said laminate or said die; and (d) removing said laminate from said die.

Claim 2

The method of manufacturing a plastic information carrier containing an information track having detail of such fineness as to be suitable for reading by an optical beam or similar reading means, said fineness being as small as in the order of a micron or less, comprising: (a) directly applying to a metal surface of a rigid, substantially flat die, which surface contains the negative of the desired information track, a thin layer of a thickness of 0.2-300 microns of a light-curable polymerizable liquid having a viscosity of from 1 to 100 cP and comprising low molecular weight acrylic monomers or a mixture of low molecular weight acrylic monomers and acrylic oligomers, which liquid contains 25-70% by weight of saturated hydrocarbon and/or phenyl groups, has an average functionality in regard to unsaturatedness of between 2.1 and 6, is at least substantially aprotic and consists for at least 95% of monomers having a maximum average molecular weight of about 400; (b) applying to the exposed surface of said thin layer of polymerizable liquid a thin light-pervious plastic substrate; (c) exposing said thin layer of polymerizable liquid to light radiation through said substrate for a time sufficient to cause said thin layer of polymerizable liquid to cure to a solid state adhering to said substrate thereby producing a laminate of said substrate and said cured layer containing the desired optically readable information track readily removable from said die without effect on said laminate or said die; and (d) removing said laminate from said die.

Claim 14

A method of manufacturing a plastic information carrier containing on a major surface an information track optically readable through the carrier, comprising the steps: (a) bringing into contact relationship with a metal surface of a rigid substantially flat die, a thin layer of a thickness of 0.2-300 microns of a light radiation-curable polymerizable liquid having a viscosity of from 1 to 100 cP and comprising low molecular weight acrylic monomers and/or acrylic oligomers which on an average contains 25-70% by weight of saturated hydrocarbon radicals and/or phenyl groups, and which liquid has an average molecular weight of approximately 400 or less, and which liquid has an average functionality as regards unsaturatedness in the range of 2.1 to 6, and which liquid is substantially aprotic, said polymerizable liquid containing less than 5% by weight of polymers, having the properties that will cause it, when cured, to be substantially stress-free and to adhere to a contacting plastic substrate but to be removable without damage from the die metal surface, and also having the property that it will fill when liquid and stably retain when cured any fine surface structure present on the die surface; (b) said die metal surface to which the polymerizable liquid is contacted is substantially flat and contains a fine surface structure pattern having surface level differences less than 1 micron in size and constituting the negative of the said information track to be replicated on the information carrier; (c) providing in contact relationship with the exposed surface of said thin layer of polymerizable liquid while still in the liquid state, which exposed surface is remote from the surface in contact with the die, a thin light radiation-pervious plastic substrate to whose contacting surface said polymerizable liquid adheres when cured; (d) exposing said thin layer of polymerizable liquid while in contact with the die to curing light radiation through said contacted substrate for a time sufficient to cause said thin layer of polymerizable liquid to cure to a solid layer adhering to said substrate but removable without damage from said die metal surface thereby producing a laminate of said substrate and said cured layer whose major surface contacting the die contains a replica of the fine surface structure pattern present on the die metal surface; (e) removing said laminate from said die; and (f) applying over the exposed cured layer surface containing the fine surface pattern a thin light-reflective layer thereby to form the plastic information carrier containing the optically-readable information track.

Claim 15

A method of manufacturing a plastic information carrier containing on a major surface an information track optically readable through the carrier, comprising the steps: (a) bringing into contact relationship with a metal surface of a rigid substantially flat die, a thin layer of a thickness of 0.2-300 microns of a light radiation-curable polymerizable liquid having a viscosity of from 1 to 100 cP and comprising low molecular weight acrylic monomers and/or acrylic oligomers which on an average contains 25-70% by weight of saturated hydrocarbon radicals and/or phenyl groups, and which liquid has an average molecular weight of approximately 400 or less, and which liquid has an average functionality as regards unsaturatedness in the range of 2.1 to 6, and which liquid is substantially aprotic, said polymerizable liquid containing less than 5% by weight of polymers, having the properties that will cause it, when cured, to be substantially stress-free and to adhere to a contacting plastic substrate but to be removable without damage from the die metal surface, and also having the property that it will fill when liquid and stably retain when cured any fine surface structure present on the die surface; (b) said die metal surface to which the polymerizable liquid is contacted is substantially flat and contains a fine surface structure pattern having surface level differences less than 1 micron in size and constituting the negative of the said information track to be replicated on the information carrier; (c) providing in contact relationship with the exposed surface of said thin layer of polymerizable liquid while still in the liquid state, which exposed surface is remote from the surface in contact with the die, a thin light radiation-pervious plastic substrate to whose contacting surface said polymerizable liquid adheres when cured; (d) exposing said thin layer of polymerizable liquid while in contact with the die to curing light radiation through said contacted substrate for a time sufficient to cause said thin layer of polymerizable liquid to cure to a solid layer adhering to said substrate but removable without damage from said die metal surface thereby producing a laminate of said substrate and said cured layer whose major surface contacting the die contains a replica of the fine surface structure pattern present on the die metal surface; (e) removing said laminate from said die; and (f) applying over the exposed cured layer surface containing the fine surface pattern a thin light-reflective layer thereby to form the plastic information carrier containing the optically-readable information track.