Substrate for UV transmittance evaluation of cosmetics and evaluation method
An object is to develop a measurement method, and a measurement substrate, for measuring SPF or other value in a single measurement, instead of having to measure it on many substrates as has been the case to date. As a solution, a substrate for UV transmittance evaluation, including a base material that allows UV rays in a range of 290 to 400 nm to transmit through, and a layer provided on one side thereof that contains at least one type of compound other than cellulose triacetate that has a sugar skeleton but is not a salt, is provided.
1. A substrate for UV transmittance evaluation, comprising a base material that allows UV rays in a range of 290 to 400 nm to transmit through, and a layer provided on one side thereof that contains at least one compound, other than cellulose triacetate, which has a sugar skeleton but is not a salt,
wherein a surface of the layer has a contact angle change property which is defined as a change in contact angle with distilled water 5 minutes after dripping the water onto the layer that contains at least one compound, other than cellulose triacetate, which has a sugar skeleton but is not a salt, said change being at least 15 degrees as compared with a contact angle immediately after the dripping of the water.
2. The substrate for UV transmittance evaluation according to claim 1 , wherein the base material that allows UV rays in a range of 290 to 400 nm to transmit through is a quartz plate.
3. The substrate for UV transmittance evaluation according to claim 2 , wherein the compound that has a sugar skeleton but is not a salt is at least one type selected from mannose, galactose, xylose, glucose, maltose, lactose, sucrose, trehalose, fructose, cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, maltotriose, raffinose, inulin, oligosaccharide, glucan, agar, α-cyclodextrin, maltodextrin, cornstarch, powdered arrowroot, tapioca starch, potato starch, flour starch, hydroxyethyl starch, hydroxypropyl starch, Tamarind gum, xanthan gum, native gellan gum, and gellan gum.
4. A measurement method for SPF value, comprising steps A and B below:
A. coating a cosmetic preparation on the layer provided on the one side of the substrate for UV transmittance evaluation according to claim 2 ; and
B. measuring an UV absorption spectrum that transmits through a coated substrate for UV transmittance evaluation, to obtain a transmittance and also obtain an SPF value.
5. The substrate for UV transmittance evaluation according to claim 1 , wherein the compound that has a sugar skeleton but is not a salt is at least one type selected from mannose, galactose, xylose, glucose, maltose, lactose, sucrose, trehalose, fructose, cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, maltotriose, raffinose, inulin, oligosaccharide, glucan, agar, α-cyclodextrin, maltodextrin, cornstarch, powdered arrowroot, tapioca starch, potato starch, flour starch, hydroxyethyl starch, hydroxypropyl starch, Tamarind gum, xanthan gum, native gellan gum, and gellan gum.
6. A measurement method for SPF value, comprising steps A and B below:
A. coating a cosmetic preparation on the layer provided on the one side of the substrate for UV transmittance evaluation according to claim 4 ; and
B. measuring an UV absorption spectrum that transmits through a coated substrate for UV transmittance evaluation, to obtain a transmittance and also obtain an SPF value.
7. A measurement method for SPF value, comprising steps A and B below:
A. coating a cosmetic preparation on the layer provided on the one side of the substrate for UV transmittance evaluation according to claim 1 ; and
B. measuring an UV absorption spectrum that transmits through a coated substrate for UV transmittance evaluation, to obtain a transmittance and also obtain an SPF value.
8. A measurement method for SPF value, comprising steps A and B below:
A. coating a cosmetic preparation on the layer provided on the one side of the substrate for UV transmittance evaluation according to claim 3 ; and
B. measuring an UV absorption spectrum that transmits through a coated substrate for UV transmittance evaluation, to obtain a transmittance and also obtain an SPF value.