Radiation curable transparentizing resin systems, methods and products
AssigneeThe Richardson Company
InventorsLouis J. Lombardi, Roy J. Coyne
Life of this patent
Estimating the term…
Abstract
Cellulose materials such as paper and card stocks are provided in a generally transparent or so-called transparentized form while substantially maintaining the initial strength and stiffness of the pretreated stock. A generally opaque stock is treated with a solventless resin system which is cured by actinic radiation in order to thereby transparentize the stock without subjecting it to lengthy and relatively severe wetting conditions.
Claims23
A transparentized cellulosic product comprising:
- a cellulosic stock material having a preselected initial strength and stiffness, said cellulosic stock material having been transparentized in the absence of a solvent by radiation curing of a solventless, radiation-curable resin system while that resin system is within said cellulosic stock material, said stock material having been treated with said resin system to include the resin system within the stock material to an extent sufficient that the stock is transparentized when subjected to actinic radiation, said sufficient extent being limited in order to form a transparentized cellulosic product having a strength and stiffness substantially the same as said initial strength and stiffness, said solventless, radiation-curable resin system including an acrylate monomer, a photosensitizer and an acrylate oligomer, said acrylate oligomer being a diacrylate oligomer derivative of an aliphatic/bisphenol-A diepoxide blend.
A transparentized cellulosic product comprising:
- a cellulosic stock material having a preselected initial strength and stiffness, said cellulosic stock material having been solventlessly transparentized by treating to generally saturate said cellulosic stock material in the absence of a solvent in order in include therewithin a solventless, radiation-curable resin system, and subjecting the resin-saturated cellulosic stock material to a source of actinic radiation to cure the resin system while within the cellulosic stock material for transparentizing the same, said transparentized cellulosic product having a transparentized strength and stiffness substantially the same as said initial strength and stiffness, said solventless, radiation-curable resin system including an acrylate monomer, a photosensitizer and an acrylate oligomer, said acrylate oligomer being a diacrylate oligomer derivative of an aliphatic/bisphenol-A diepoxide blend.
The product of claim 14, wherein said treating includes dipping the stock material within a supply of the solventless resin system.
The product of claim 14, wherein said subjecting with actinic radiation begins within a relatively short period of time after said treating to generally saturate the cellulosic stock material.
The product of claim 16, wherein said relatively short period of time is between about 10 seconds and about a few minutes.
A method for producing transparentized cellulosic material having approximately the same strength and stiffness of the original untransparentized cellulosic stock material comprising:
- selecting a cellulosic stock material;
- treating the stock in the absence of a solvent by including therewithin a solventless, radiation-curable resin system to an extent sufficient that the stock is transparentized when subjected to actinic radiation, said sufficient extent being limited in order to form a transparentized cellulosic product without significantly reducing said original strength and stiffness, said solventless, radiation-curable resin system is formulated by mixing together an acrylate monomer, a photosensitizer, and an acrylate oligomer, said acrylate oligomer being a diacrylate oligomer derivative of an aliphatic/bisphenol-A diepoxide blend;
- and curing the resin-treated cellulosic stock material for transparentizing the same to a generally transparent product having a strength and stiffness approximately the same as said strength and stiffness of the untransparentized cellulosic stock material.
Dependencies are inferred from the claim text.