JP4220752B2 - UV absorber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for increasing the absorbance at 350 nm to 400 nm of lignin derived from rice bran .
[0002]
[Prior art]
In recent years, it has been pointed out that the amount of ultraviolet rays falling on the ground is increasing with the destruction of the ozone layer. For this reason, the influence of ultraviolet rays on the human body is increasingly regarded as a problem, and there is concern about an increase in skin diseases such as skin cancer. For this reason, research and development of ultraviolet absorbers have been actively conducted, and various products have been put into practical use so far.
[0003]
For example, although an organic compound having ultraviolet absorbing ability has been synthesized (see Patent Documents 1 to 5), there is almost no absorption ability in the entire ultraviolet wavelength range (UVA and UVB) that falls on the ground. There are many problems in terms. In particular, synthetic organic compounds having a strong ultraviolet-absorbing ability often cause rashes and rashes when applied to the skin. For this reason, it is required to provide a UV absorber that has a high UV absorbing ability and is safe.
[Patent Document 1]
Japanese Patent Laid-Open No. 05-112487 [Patent Document 2]
JP 05-201928 A [Patent Document 3]
JP 05-246946 A [Patent Document 4]
Japanese Patent Laid-Open No. 06-135985 [Patent Document 5]
Japanese Patent Laid-Open No. 2001-200288
[Problems to be solved by the invention]
Taking into account the current state of these prior art, the present invention has an object to provide a safe UV-absorbing material inexpensively by the ultraviolet absorbing ability high Mel. In particular, an object of the present invention is to develop a method for providing an ultraviolet absorbing material useful as an external preparation for skin such as cosmetics.
[0005]
[Means for Solving the Problems]
As a result of various studies to solve the above problems, the present inventors have found that a modified lignin obtained by modifying a lignin contained in a plant by a predetermined method has a good ultraviolet-absorbing ability, and is a raw material. As a result, it was found that if thinned wood, food waste, etc. are used, it can be provided at low cost.
[0006]
Chi words, and (this is referred to herein as "modified lignin") lignin which has been subjected to alkali treatment found that ultraviolet absorber containing are useful. UV absorbers This is preferably the ratio of the minimum absorbance and the maximum absorbance in the region of 280 to 400 nm (minimum absorbance / maximum absorbance) is 0.3 or more, and more preferably 0.8 or more. UV absorbers of this is useful as a skin external preparation.
[0007]
The present invention provides a method for increasing the absorbance of rice bran-derived lignin at 350 nm to 400 nm, which comprises dissolving rice bran-derived lignin in a solvent containing alkali .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the ultraviolet absorbent according to the present invention will be described in detail. In the present specification, “to” means a range including numerical values described before and after that as a minimum value and a maximum value, respectively.
[0009]
In the present invention, lignin derived from rice bran is used. In particular, it can be suitably used in large quantities degreasing rice bran that is discharged as the food industry wastes. Since defatted rice bran is also used for food, it has low toxicity and high safety for the human body.
[0010]
The present invention is characterized in that a treatment for dissolving lignin derived from rice bran in a solvent containing an alkali is performed .
[0011]
Agents for Hair alkali treatment, sodium hydroxide, potassium hydroxide, ammonia, carbonate Natoriuumu, various basic compounds such as sodium borate and the like. Of these, a solution of sodium hydroxide, potassium hydroxide, sodium carbonate, or sodium borate is preferably used in view of safety and ease of post-treatment .
[0012]
Among the modified lignins, alkali-treated lignin obtained by alkali treatment of extracted lignin, alkali-treated lignophenol obtained by alkali treatment of lignophenol in which a phenol compound and lignin are chemically bonded, and the like can be suitably used.
[0013]
The modified lignin obtained by the present invention is characterized by absorbing ultraviolet rays of 280 to 400 nm. Ultraviolet rays reaching the ground are classified into ultraviolet rays in the UV-A region and ultraviolet rays in the UV-B region according to the wavelength. The UV-A region is an ultraviolet ray having a wavelength of about 320 to 400 nm and occupies about 90% of the ultraviolet ray reaching the ground. When exposed to ultraviolet rays in the UV-A region for a long period of time, there is a high risk of causing chronic skin diseases in the deep part of the skin. On the other hand, the UV-B region is an ultraviolet ray having a wavelength of about 280 to 320 nm, and occupies about 10% of the ultraviolet ray reaching the ground. Since the influence on the skin is stronger than that in the UV-A region, the UV-B region often causes freckles and spots.
[0014]
The ultraviolet absorbent containing the modified lignin obtained in the present invention (hereinafter referred to as the ultraviolet absorbent of the present invention) absorbs both ultraviolet rays in the UV-A region and the UV-B region and absorbs ultraviolet rays of 280 to 400 nm. Absorbs relatively evenly. Preferably the ratio of the minimum absorbance and the maximum absorbance in the region of 280~400nm ultraviolet absorbent of the present invention (minimal absorbance / maximum absorbance) is 0.3 or more, more preferably 0.65 or more, 0 More preferably, it is 8 or more. Compared with the ultraviolet absorber containing unmodified lignin, the ultraviolet absorber of the present invention containing modified lignin has particularly high absorption in the region of 350 to 400 nm.
[0015]
The form of the ultraviolet absorber of the present invention is not particularly limited. The ultraviolet absorbent according to the present invention can exhibit ultraviolet absorbing ability in, for example, powder, slurry, or liquid.
[0016]
The ultraviolet absorber of the present invention is effectively used as a skin external preparation.
For example, the ultraviolet absorber of the present invention can be used as a cosmetic or a pharmaceutical product. Specifically, sunscreen oil, sunscreen lotion, sunscreen cream, cream / milky lotion, lotion, perfume, irresistible, cosmetic oil, hair cosmetics, hair dye, paste perfume, powder, pack, foundation, powdered perfume, Can be used as blusher, eyeliner, eye cream, eye shadow, mascara, eyebrow, nail cream, nail polish, lipstick, lip balm, etc. Moreover, the skin external preparation of this invention can also be used as an ointment.
[0017]
Various components other than the ultraviolet absorber can be further added to the external preparation for skin of the present invention. For example, improvement of emollient effect, improvement of feeling of use, reduction of bulk after use, improvement of solubility, improvement of emulsification, improvement of emulsification stability, improvement of compatibility with oil components, reduction of feeling of tension after use, improvement of skin familiarity, skin Improvement of spreading, reduction of stickiness, prevention of rough skin, improvement of skin effect, improvement of skin protection, improvement of skin, normalization of epidermal keratinization, reduction of dry skin such as senile xerosis, dry skin such as cracks and desquamation Condition improvement, wrinkle generation suppression, wrinkle disappearance, wound treatment, pigmentation prevention and improvement, aging prevention, reduction of dandruff and itching, hair loss reduction, scalp disease prevention and treatment, storage stability improvement, flexibility improvement, elasticity improvement, gloss Appropriate ingredients can be added for the purpose of imparting, inhibiting melanin pigment production and preventing sunburn.
[0018]
Examples of components that can be added to the skin external preparation of the present invention include, for example, oil and fat components, phospholipids, UV absorbers, IR absorbers, emulsifiers, surfactants, preservatives, stickers, antioxidants, whitening agents, vitamins , Amino acids, hormones, peptides, bioactive plant extracts, fluorescent materials, pigments, dyes, fragrances, scrub agents, sequestering agents, binders, extenders, thickeners, sugars, nutritional components, pH regulators, chelating agents , Fungicides, keratin improving agents, keratolytic agents, antibiotics, skin permeation enhancers, blood circulation promoters, anti-inflammatory agents, cell activators, anti-inflammatory agents, analgesics, emollients, emollients, wound treatment agents, Metabolism promoters and the like can be appropriately blended depending on the purpose of use.
[0019]
Materials other than these can also be added to the external preparation for skin according to the present invention. About the addition amount and addition method of each component, it can follow the method well-known in this technical field.
Those skilled in the art can easily obtain the ultraviolet absorber of a preferred embodiment of the present invention based on the above general description and the specific disclosure of the examples or by appropriately modifying or modifying them as necessary. Could be manufactured. The amount of the modified lignin is not particularly limited and can be appropriately selected according to the use of the ultraviolet absorber.
[0020]
【Example】
The features of the present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.
[0021]
Example 1: Preparation of ultraviolet absorber 1 of the present invention Extracted from defatted rice bran with dioxane: water = 8: 2, concentrated, dissolved in a small amount of 90% aqueous acetic acid, precipitated by adding excess water, Filtration yielded lignin. 1 mg of the obtained lignin was dissolved in 1 ml of dioxane: 0.2M NaOH = 8: 2 to obtain an ultraviolet absorber 1.
[0023]
Example 2 : Evaluation of UV absorber of the present invention The UV absorber 1 of the UV absorber 1 obtained in Example 1 was evaluated. Specifically, it was evaluated by absorbance using a Hitachi U-2000 ultraviolet-visible spectrophotometer and a quartz cell having an optical path length of 10 mm.
In FIG. 1, the light absorbency in the 280-400 nm area | region of the ultraviolet absorber 1 is shown. For comparison, the absorbance of lignin is also shown. The ultraviolet absorber 1 absorbed ultraviolet rays over the entire range of 280 to 400 nm. In particular, the ultraviolet absorption ability in the wavelength region longer than 340 nm was increased compared to lignin .
[0024]
【The invention's effect】
The ultraviolet absorbent according to the present invention is safe and has high ultraviolet absorbing ability. Moreover, since waste can be manufactured at low cost from raw materials, industrial applicability is also high. Because of such properties, the ultraviolet absorber of the present invention is extremely useful as a skin external preparation including cosmetics and pharmaceuticals.
[Brief description of the drawings]
FIG. 1 is a graph showing the ultraviolet absorption characteristics of an ultraviolet absorber 1 and lignin.

Claims (7)

A method for increasing the absorbance at 350 nm to 400 nm of lignin derived from rice bran, comprising dissolving lignin derived from rice bran in a solvent containing an alkali . The method according to claim 1, wherein the lignin derived from rice bran is lignin obtained by treating an extract from defatted rice bran with an aqueous solution containing an acid. The method of claim 2, wherein the acid is acetic acid. The method according to claim 2 or 3, wherein the extract from the defatted rice bran is an extract extracted from the defatted rice bran with a solvent containing water. The method according to any one of claims 2 to 4, wherein the extract from the defatted rice bran is an extract extracted from the defatted rice bran with a solvent containing dioxane. The method according to any one of claims 1 to 5, wherein the alkali is sodium hydroxide. The method according to claim 1, wherein the alkali-containing solvent contains dioxane.

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