An optical recording medium has a substrate, a recording layer having a bare portion at the end face, and a protecting layer The bare portion of the recording layer and the vicinity thereof are resinified so as to be substantially incapable of optical recording

Optical recording medium and production thereof

A composite tack-free film having a film substrate with opposing surfaces, bearing on at least one of said surfaces a highly crosslinked, film-forming acrylate composition containing from about 25 to about 78 of at least one lower alkyl (meth)acrylate ester and from about 10 to about 60 percent vinyl acetate and at least about 1 percent of a polar monomer, wherein the acrylate composition is capable of attaching temporarily to polyimide film surface to provide a substantially air-tight seal and being cleanly removable from said polyimide film surface leaving no visible residue, even after being subjected to elevated temperatures.

Circuit protection film

PROBLEM TO BE SOLVED: To provide an active energy ray-curable composition which can be favorably adhered to an acrylic substrate.SOLUTION: The provided active energy ray-curable composition includes active energy ray-polymerizable compounds and a photopolymerization initiator, whereas at least 85 mol% of a (meth)acryloyl group-containing polyfunctional (meth)acrylate having an acrylic equivalent of 78-145 is included as one active energy ray-polymerizable compound with respect to all active energy ray-polymerizable compounds, whereas the ester group concentration with respect to the entirety of the active energy ray-polymerizable compounds is at least 7.4 mmol/g; a cured product of the same is also provided.

Active energy ray-curable composition and cured product

PURPOSE:To obtain the subject composition, composed of a specific (meth)acrylic acid ester monomer or oligomer and a low-boiling solvent therefor, having a high hardness without causing cracks, etc., by bending etc. CONSTITUTION:The objective composition composed of (A) an acrylic or methacrylic acid ester monomer or oligomer having =3 (preferably >=5) acrylic functionality and (B) a low-boiling solvent such as ethanol, toluene, ethyl acetate, methyl cellosolve, acetone, methyl isobutyl ketone, methyl ethyl ketone, ethyl cellosolve or isopropyl alcohol. The aforementioned composition is applied to the surface of a substrate such as an optical card or flexible disk and then cured by exposure to ionizing radiation.

Hotta Takeshi

Papers

Composition for forming surface protective film