Process for producing printing substrate capable of laser sculpture

A process for producing a laser engravable printing substrate, comprising the steps of:

• forming a photosensitive resin composition layer on a cylindrical support or a sheeted support;
• and applying light to the formed photosensitive resin composition layer to form a cured photosensitive resin layer, and then adjusting a thickness of the cured photosensitive resin layer and shaping a surface of the cured photosensitive resin layer, wherein the light applied to the photosensitive resin composition layer includes light having a wavelength of 200 nm or more and 450 nm or less, and an illuminance of light at a surface of the photosensitive resin composition layer is 20 mW/cm2 or more when measured using a UV meter (trade mark “UV-M02” manufactured by ORC Manufacturing Co., Ltd.) and a filter (trade mark “UV-35-APR Filter” manufactured by ORC Manufacturing Co., Ltd.), and 3 mW/cm2 or more when measured using the UV meter and a filter (trade mark “UV-25 Filter” manufactured by ORC Manufacturing Co., Ltd.).

A laser engravable printing substrate, characterized in that in measurement of dynamic viscoelasticity of a photo-cured photosensitive resin using a non-resonant forced stretch vibration apparatus, a loss tangent (tan δ) defined by a ratio of a loss elastic modulus (E″) to a storage elastic modulus (E′) has a peak in a measurement temperature range of −100° C. or more and 20° C. or less, and when tan δ has a peak in a temperature range of −50° C. or more and 20° C. or less, the value of tan δ at the peak temperature is 0.87 or more and 1.5 or less, and when tan δ has a peak in a temperature range of −100° C. or more and less than −50° C., the value of tan δ at the peak temperature is 0.7 or more and 1.5 or less.