Resin beads, method for producing resin beads, and product using resin beads

Patent metadata

Field	Value
Publication number	US-11926718-B2
Application number	US-202118042739-A
Country	US
Kind code	B2
Filing date	Aug 10, 2021
Priority date	Sep 1, 2020
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

The present invention provides resin beads that can provide various types of products, such as a cosmetic having excellent tactile impression, spreadability on the skin, and transparency, that can be substituted for resin particles composed of a synthetic material derived from petroleum, and that have favorable biodegradability, and the present invention also provides various types of products, such as a cosmetic using the resin beads. The resin beads are formed with a resin containing cellulose as a main component. The resin beads have a cumulative 50% particle size on a volume basis of 50 μm or smaller, a degree of sphericity of 0.7 to 1.0, a degree of surface smoothness of 70 to 100%, a degree of solidity of 50 to 100%, and a biodegradation rate for 5 days, as measured in accordance with JIS K6950:2000 (ISO 14851:1999), of 20% or more, and the content of the cellulose in the resin is 90 to 100% by mass. In addition, the present invention provides a product of any one of a cosmetic, a dermatological preparation, a paint, a shaped article, a film, a coating agent, and a resin composition which contain the resin beads.

First claim

The invention claimed is:

1. A method for producing resin beads formed with a resin comprising cellulose, being a method for producing the resin beads, the method comprising:
mixing an oil phase comprising a cellulose ester and an organic solvent that dissolves the cellulose ester and has a solubility to 100 g of water at 25° C. in a range from 0.1 to 50.0 g with an aqueous phase comprising a dispersion stabilizer, thereby preparing a suspension comprising oil droplets comprising the cellulose ester and the organic solvent;
adding water to the suspension, thereby contracting the oil droplets and forming resin particles; and
treating the resin particles under an acidic condition, or an alkaline condition of a pH in a range of 13 or lower, thereby hydrolyzing at least part of ester bonds in the cellulose ester,
wherein the resin beads have a cumulative 50% particle size on a volume basis in a range of 50 μm or smaller,
a degree of sphericity in a range from 0.7 to 1.0,
a degree of surface smoothness in a range from 70 to 100%,
a degree of solidity in a range from 50 to 100%, and
a biodegradation rate for 5 days, as measured in accordance with JIS K6950:2000 (ISO 14851:1999), in a range of 20% or more, and
a content of the cellulose in the resin beads is in a range from 90 to 100% by mass.

2. The method for producing resin beads according to claim 1 , wherein the water is added to the suspension over a time in a range of 10 minutes or longer.

3. The method for producing resin beads according to claim 1 , wherein a liquid amount of the water to be added to the suspension is in a range of 0.5 times or more based on a liquid amount of the suspension on a mass basis.

4. The method for producing resin beads according to claim 1 , wherein the cellulose ester is at least one material selected from the group consisting of a cellulose organic acid ester and a cellulose phosphoric acid ester.

5. The method for producing resin beads according to claim 1 , wherein the cellulose ester is at least one material selected from the group consisting of cellulose acetate, cellulose propionate, cellulose acetate propionate, cellulose butyrate, and cellulose acetate butyrate.

6. The method for producing resin beads according to claim 1 , wherein the dispersion stabilizer is a water-soluble polymer.

7. The method for producing resin beads according to claim 1 , wherein the resin particles are treated under a temperature condition in a range of 80° C. or lower, thereby hydrolyzing at least part of the ester bonds in the cellulose ester.

Assignees

• Dainichiseika Color Chem

Inventors

• Abe Takashi

Classifications

• C08J3/14 Primary

  by precipitation from solutions {(C08J3/122 takes precedence)} · CPC title

• C08L1/12

  Cellulose acetate · CPC title

• C08L1/14

  Mixed esters, e.g. cellulose acetate-butyrate · CPC title

• C08L1/16

  Esters of inorganic acids · CPC title

• C08J2301/10

  Esters of organic acids · CPC title