JP-7855866-B2 - Cellulose particles

Inventors

• 八百 健二
• 内藤 亜侑
• 吉田 和世
• 岩舘 侑子
• 大木 正啓
• 田口 哲也
• 濱野 弘一
• 石塚 孝宏
• 吉川 英昭

Assignees

• 富士フイルムビジネスイノベーション株式会社

Dates

Publication Date

20260511

Application Date

20220208

Claims (11)

1. It is mainly composed of cellulose, Cellulose particles having an ultrasonic desorption rate of 50% or less when hydrophobized silica particles are attached, The aforementioned mother particles mainly composed of cellulose, A coating layer that covers the aforementioned mother particles, comprising at least one selected from the group consisting of polyamine compounds, waxes, linear saturated fatty acids, hydroxy fatty acids, and amino acid compounds, It has, The coating layer comprises a first coating layer that coats the mother particles and contains at least one selected from the group consisting of the polyamine compound, the linear saturated fatty acid, the hydroxy fatty acid, and the amino acid compound, and a second coating layer that coats the first coating layer and contains wax. The second coating layer further contains a polyvalent metal salt, The aforementioned polyvalent metal salt is a compound composed of a metal ion with two or more valencies and an anion. Cellulose particles.
2. The cellulose particle according to claim 1 , wherein the polyamine compound is at least one selected from the group consisting of polyethyleneimine and polylysine.
3. The cellulose particles according to claim 1 or claim 2 , wherein the wax is carnauba wax.
4. Cellulose particles according to any one of claims 1 to 3 , wherein at least one external additive selected from the group consisting of silicon-containing compound particles and metal soap particles is added externally.
5. The cellulose particles according to claim 4 , wherein the silicon-containing compound particles are silica particles.
6. Cellulose particles according to any one of claims 1 to 5 , wherein the volume-average particle diameter is 3 μm or more and less than 10 μm.
7. Cellulose particles according to any one of claims 1 to 6 , wherein the large diameter side particle size distribution index GSDv is 1.0 or more and 1.7 or less.
8. Cellulose particles according to any one of claims 1 to 7 , wherein the sphericity is 0.90 or higher.
9. The cellulose particles according to any one of claims 1 to 8 , wherein the number-average molecular weight of the cellulose is 37,000 or more.
10. The cellulose particles according to claim 9 , wherein the number-average molecular weight of the cellulose is 45,000 or more.
11. Cellulose particles according to any one of claims 1 to 10 , wherein the surface smoothness is 80% or more.

Description

This invention relates to cellulose particles. Patent Document 1 proposes "an oily solid cosmetic composition characterized by containing surface-treated spherical cellulose powder having an average particle size of 1.0 to 30.0 μm." Patent Document 2 proposes "resin beads formed from a resin mainly composed of cellulose, wherein the cumulative 50% particle diameter by volume is 50 μm or less, the sphericity is 0.7 to 1.0, the surface smoothness is 70 to 100%, the solidity is 50 to 100%, the 5-day biodegradation rate measured in accordance with JIS K6950:2000 (ISO 14851:1999) is 20% or more, and the cellulose content in the resin is 90 to 100% by mass." Japanese Patent Publication No. 2020-132616Patent No. 6872068 The following describes an example embodiment of the present invention. These descriptions and examples are illustrative and do not limit the scope of the invention. In numerical ranges described stepwise within this specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described stepwise. Furthermore, in numerical ranges described within this specification, the upper or lower limit of that range may be replaced with the values shown in the examples. Each component may contain multiple types of the relevant substance. When referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, unless otherwise specified, it refers to the total amount of those multiple substances present in the composition. <Cellulose particles> The cellulose particles according to this embodiment are mainly composed of cellulose, and when hydrophobically treated silica particles are attached to them, the ultrasonic desorption rate of the silica particles is 50% or less. The cellulose particles according to this embodiment exhibit excellent biodegradability and are resistant to aggregation due to the above-described structure. The reason for this is presumed to be as follows: Cellulose-containing particles (hereinafter referred to as cellulose particles) have the advantage of being highly biodegradable due to their cellulose content. However, because cellulose particles tend to aggregate, their applications have sometimes been limited. The aggregation of cellulose particles is thought to be due to the presence of hydroxyl groups on the surface of the cellulose particles, which then form hydrogen bonds. In contrast, the cellulose particles according to this embodiment are mainly composed of cellulose, and when hydrophobically treated silica particles are attached to them, the ultrasonic desorption rate of the silica particles is 50% or less. The fact that the ultrasonic desorption rate of the silica particles described above is 50% or less suggests that the surface of the cellulose particles tends to be highly hydrophobic. This is thought to be because the amount of hydroxyl groups contained in the cellulose on the surface of the cellulose particles is small. Therefore, hydrogen bonds are less likely to form on the hydroxyl groups present on the surface of the cellulose particles. Based on the above, it is presumed that the cellulose particles according to this embodiment, with the above configuration, exhibit excellent biodegradability and are less prone to aggregation. (cellulose) The cellulose particles according to this embodiment are mainly composed of cellulose. Here, "primarily composed of cellulose" means that the cellulose content relative to the cellulose particles is 90% by mass or more. The number-average molecular weight of cellulose is preferably 37,000 or more, and more preferably 45,000 or more. The upper limit of the number-average molecular weight of cellulose is not particularly limited, but it may be, for example, 100,000 or less. By setting the number-average molecular weight of cellulose to 37,000 or higher, it becomes easier to form cellulose particles that are highly biodegradable and less prone to aggregation. The reason for this is presumed to be as follows: By setting the number-average molecular weight of cellulose to 37,000 or higher, the number of terminal hydroxyl groups per unit volume of particles decreases, suppressing intramolecular and extramolecular hydrogen bonding, which makes cellulose particles less likely to aggregate. Regarding biodegradation, the suppression of cellulose particle aggregation increases the specific surface area, improving biodegradability. Based on the above, it is presumed that the material is more likely to form cellulose particles that are highly biodegradable and less prone to aggregation. The number-average molecular weight of cellulose is measured using gel permeation chromatography (differential refractometer Optilab T-rEX / Wyatt Technology, multi-angle light scattering detector DAWN HELEOS II / Wyatt Technology, one TSKgel α-M and one α-3000 column / Tosoh Corporation) with dimethylacetamide (with