Radiation curable composition and curing product thereof, and laminate including the same

Abstract

A radiation curable composition that can provide a curing product not only having excellent transparency and mechanical strength but also excelling in a balance between surface hardness and heat resistance / moisture deformation resistance; and a curing product thereof; and a laminate including a layer of the curing product that is suitable for use as an optical recording medium, etc. There is provided a radiation curable composition comprising a monomer having a radiation curing group, which radiation curable composition is cured to provide a curing product having properties such that (1) the light transmittance at a film thickness of 100+-5 [mu]m and a wavelength of 550 nm is = 80%, (2) with respect to a laminate composed of a polyethylene terephthalate film and, superimposed thereon, a curing product of 100+-5 [mu]m film thickness, the surface hardness is = HB, and (3) with respect to a laminate composed of a polycarbonate disk and, superimposed thereon, a curing product layer of 100+-5 [mu]m thickness, the absolute value of warpage (a mm) measured after being disposed in an environment of 80 DEG C 85% RH for 100 hr, |a|, is = 0.5 mm.

Description

technical field [0001] The present invention relates to a radiation curable composition, a cured product thereof, and a laminate thereof. In detail, it relates to a radiation-curable composition, a cured product thereof, and a layer having the cured product, which can obtain a cured product having excellent transparency and mechanical strength, and a cured product having an excellent balance between surface hardness and heat-resistant and moisture-resistant deformation properties. It is also suitable for laminates for optical recording medium applications and the like. Background technique [0002] Radiation-curable compositions are widely used as various covering materials and adhesive materials, or widely used for optical applications. For example, as a specific example of the optical use of the radiation curable composition, it can be mentioned that the protective film of the information recording layer in the information recording medium, especially the information reco...

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Problems solved by technology

However, according to the research of the present inventors, the surface hardness of this composition is insufficient.

In addition, radiation-curable compositions containing urethane acrylates, alicyclic (meth)acrylates, and ethylenically unsaturated compounds using diols having amide groups are known for their adhesiveness to substrates, low cure shrinkage, It is excellent in mechanical strength and corrosion resistance, and is also excellent in the above-mentioned heat resistance / moisture deformation resistance (Patent Document 4), but according to the research of the present inventors, the reason for the high viscosity of this composition is that the diol of urethane acrylate contains Amide group

[0005] In addition, it is known that as a radiation-curable composition suitable for surface property modification for printing plastic film coating, conventionally, it does not contain inorganic substances such as silica particles. Polyurethane acrylate with polycarbonate polyol skeleton can form excellent curability, good adhesion to various plastic matrix materials, excellent stain resistance, flexibility, wear resistance, scratch resistance, etc. (refer to Patent Document 5), but according to the research of the present inventors, it is judged that this composition has a large curing shrinkage. Therefore, when a cured product layer with a thickness of 50 μm or more is formed on a hard base material, there are cracks or problems with the composition. Delamination of the matrix material, or deformation of the matrix material, etc.

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