US-12616240-B2 - Double-layer seamless capsule containing water-soluble composition

Abstract

The present invention addresses the problem of providing a double-layer seamless soft capsule having a water-soluble composition as its fill, and by preparing a capsule shell from an ultraviolet-curing resin composition, a double-layer seamless capsule is made which consists of a capsule shell and a water-soluble composition as a fill and where volatility of the fill due to permeation through the shell is low.

Inventors

• Shoji Tachikawa
• Miku Sasaki
• Sergio Ishiba
• Tsubasa MOCHIZUKI
• Taisuke Sano

Assignees

• FUJI CAPSULE CO., LTD.

Dates

Publication Date

20260505

Application Date

20210326

Priority Date

20200327

Claims (8)

1. 1 . A cigarette filter comprising: a double-layer seamless capsule consisting of a capsule shell and water or a water-soluble composition as a fill, wherein the capsule shell is prepared by curing an ultraviolet-curing resin composition, the ultraviolet-curing resin composition is an acrylic resin composition or a silicone resin composition, the acrylic resin composition comprising an acrylic oligomer, an acrylic monomer, an acrylic acid and a photopolymerization initiator, a viscosity of the ultraviolet-curing resin composition is 20 to 2000 mPa·s, and wherein the seamless capsule has a mass decrease of less than 5% after stored at 20° C. for 60 days.
2. 2 . The cigarette filter according to claim 1 , wherein the water-soluble composition comprises water, a water-soluble flavor, a water-soluble alcohol, glycerol, or propylene glycol.
3. 3 . The cigarette filter according to claim 1 , wherein a shell thickness of the thinnest part of the capsule shell, as measured using a three-dimensional X-ray microscope, is 100 μm or more.
4. 4 . The cigarette filter according to claim 1 , wherein the seamless capsule has a diameter of 1 to 6 mm.
5. 5 . A method for making a cigarette filter, comprising the double-layer seamless capsule according to claim 1 , wherein the double-layer seamless capsule is prepared by a method comprising the following steps (a) to (c): (a) a step of providing water or a water-soluble composition as the fill; (b) a step of providing an ultraviolet-curing resin composition as a capsule-shell solution, wherein the ultraviolet-curing resin composition is an acrylic resin composition or a silicone resin composition, the acrylic resin composition comprising an acrylic oligomer, an acrylic monomer, an acrylic acid and a photopolymerization initiator, wherein a viscosity of the ultraviolet-curing resin composition is 20 to 2000 mPa·s; and (c) a step of discharging, into a forming liquid, the capsule-shell solution from an outer nozzle and the water or the water-soluble composition from an inner nozzle by use of a concentric double nozzle to form a double-layer droplet, and irradiating the double-layer droplet with ultraviolet rays to cure the capsule-shell solution and thereby give a capsule shell, and the method for making the cigarette filter comprises a step of enclosing the double-layer seamless capsule in a cigarette filter.
6. 6 . The method according to claim 5 , wherein the water-soluble composition comprises water, a water-soluble flavor, a water-soluble alcohol, glycerol, or propylene glycol.
7. 7 . The method according to claim 5 , wherein a shell thickness of the thinnest part of the capsule shell, as measured using a three-dimensional X-ray microscope, is 100 μm or more.
8. 8 . The method according to claim 5 , wherein the seamless capsule has a diameter of 1 to 6 mm.

Description

TECHNICAL FIELD The present invention relates to a double-layer seamless capsule consisting of a capsule shell provided from an ultraviolet-curing resin composition and a water-soluble composition as a fill. The capsule of the present invention can have a water-soluble flavor or the like as the fill. BACKGROUND ART A dropping method (also called an in-liquid gelling method) utilized for the production of seamless capsules is a capsule production method utilizing liquid-liquid (filling solution-shell solution, shell solution-cooled oil liquid) interfacial tension or gas-liquid (air-shell solution) surface tension. Conventionally, a production method including discharging, into a cooled oil liquid, a water-soluble composition for a shell (for example, aqueous solution of gelatin) and a hydrophobic filling solution from an outer nozzle and an inner nozzle of a concentric double nozzle, respectively, to form concentric double droplets, then cooling an outer droplet (shell solution) to allow it to gel and thereby performing encapsulation is widely carried out. In this production method, there is a problem that when the composition for a shell, which is used as the shell, is water-soluble, the capsule fill is limited to oils and fats, an oil and fat solution of an oil-soluble substance, or the like, which have interfacial tension with the composition for a shell, and a water-soluble component cannot be encapsulated. Then, an encapsulation method by dispersing a water-soluble component in an oily liquid (see for example, patent document 1) or by emulsifying it therein (see for example, patent documents 2 and 3) has been developed. Moreover, as a capsule to be enclosed in a filter part of a cigarette, a capsule having a shell composed of at least one hydrophilic colloid selected from gellan gum, agar, an alginate, carrageenan, pectin, gum arabic, ghatti gum, pullulan gum, mannan gum and modified starch, singly, or a mixture of these or a mixture thereof with gelatin, and a core of a substance or a product which is lipophilic or partially soluble in ethanol, or an oil/water/oil type emulsion has been proposed (see for example, patent document 4). On the other hand, as a capsule whose fill is a hydrophilic substance, a seamless capsule consisting of a fill and a shell for coating the fill, wherein the fill is a hydrophilic substance, and a lower fatty acid ester of sucrose is interposed between the fill and the shell has been proposed (see for example, patent document 5). However, in such a capsule, isolation of the shell from a component contained in the core is insufficient, and it is only possible to temporarily prevent direct contact of the component contained in the core with the capsule shell. PRIOR ART DOCUMENTS Patent Documents Patent Document 1: Japanese unexamined Patent Application Publication No. 1-186815Patent Document 2: Japanese unexamined Patent Application Publication No. 11-342329Patent Document 3: Japanese unexamined Patent Application Publication No. 9-327501Patent Document 4: Japanese unexamined Patent Application Publication No. 2014-166188Patent Document 5: Japanese unexamined Patent Application Publication No. 3-52639 SUMMARY OF THE INVENTION Object to be Solved by the Invention It is an object of the present invention to provide a double-layer seamless capsule containing a water-soluble composition. Means to Solve the Object The present inventors have studied various shell compositions in the case where water or a water-soluble composition such as a water-soluble flavor is used as a capsule fill, and they have confirmed that by preparing a capsule shell from an ultraviolet-curing resin composition, volatility due to permeation of the fill through the shell is decreased, and therefore, volatilization of the aroma component is reduced, and they have completed the present invention. The present invention can also be applied to a seamless capsule of three or more layers. That is to say, the present invention is as follows. [1] A double-layer seamless capsule consisting of a capsule shell provided from an ultraviolet-curing resin composition and water or a water-soluble composition as a fill.[2] The seamless capsule according to “1”, wherein a viscosity of the ultraviolet-curing resin composition is 20 to 2000 mPa·s.[3] The seamless capsule according to “1” or “2”, wherein the ultraviolet-curing resin composition is an acrylic resin composition, an epoxy-based resin composition or a silicone resin composition.[4] The seamless capsule according to any one of “1” to “3”, wherein the acrylic resin composition comprises an acrylic oligomer, an acrylic monomer and a photopolymerization initiator.[5] The seamless capsule according to any one of “1” to “4”, wherein the water-soluble composition comprises water, a water-soluble flavor, a water-soluble alcohol, glycerol or propylene glycol.[6] The seamless capsule according to any one of “1” to “5”, wherein a shell thickness of the thinnest part of the cap