Plastic and nonmetallic article shaping or treating: processes – Formation of solid particulate material directly from molten... – By extrusion spraying or gravity fall through orifice
Reexamination Certificate
2002-09-25
2004-04-13
Sergent, Rabon (Department: 1711)
Plastic and nonmetallic article shaping or treating: processes
Formation of solid particulate material directly from molten...
By extrusion spraying or gravity fall through orifice
C264S013000, C264S009000, C264S004000
Reexamination Certificate
active
06719933
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a method of making a spherical seamless capsule formed by encapsulating a filler material comprising a medicine, a flavor, a spice, a fragrance, and the like with a capsule shell material made of gelatin and the like.
BACKGROUND ART
For making such a seamless capsule, a concentric multiple nozzle comprising a center nozzle and an annular nozzle concentrically surrounding the center nozzle has conventionally been used. Namely, while a liquid filler material is caused to flow out of the center nozzle of the concentric multiple nozzle, a liquid capsule shell material is caused to flow out of the annular nozzle surrounding the center nozzle, thereby forming a composite flow having a concentric columnar form in which the capsule shell material flows so as to cover the outside of the filler material flow. The composite flow is sequentially cut from its front end, so as to form a droplet, which is then brought into contact with a curing liquid, thereby making a spherical seamless capsule in which the filler material is encapsulated with the capsule shell material.
However, there are cases where the above-mentioned conventional method of making a seamless capsule causes various defects in seamless capsules made thereby, for example, such as large eyes shown in
FIG. 3A
, eccentricity shown in
FIG. 3B
, deformation shown in
FIG. 3C
, and a bump shown in FIG.
3
D.
It is an object of the present invention to provide a method of efficiently making a seamless capsule having no defects.
DISCLOSURE OF THE INVENTION
The inventors conducted various studies in order to achieve the above-mentioned object and, as a result, have found that the above-mentioned drawbacks occur due to the fact that there are cases where the liquid capsule shell material supplied to the concentric multiple nozzle does not have a desirable state or physical property. In particular, while the viscosity of the liquid capsule shell material is determined by temperature, there are cases where the viscosity becomes very low due to various reasons even when the capsule shell material supplied to the concentric multiple nozzle has a predetermined temperature.
Therefore, the present invention provides a method of making a seamless capsule formed by encapsulating a filler material with a capsule shell material, the method comprising a step of preparing a concentric multiple nozzle having a center nozzle and an annular nozzle concentrically surrounding the center nozzle; a step of storing a liquid filler material in a first tank; a step of storing a liquid capsule shell material at a predetermined first temperature in a second tank; a step of preparing a curing bath for storing a curing liquid adapted to cure the liquid capsule shell material by coming into contact therewith; a step of supplying the liquid filler material from the first tank to the center nozzle of the concentric multiple nozzle and supplying the liquid capsule shell material from the second tank to the annular nozzle of the concentric multiple nozzle; a step of forming a droplet by cutting a flow of the liquid filler material caused to flow out of the center nozzle and a flow of the liquid capsule shell material caused to flow out of the annular nozzle and flow about the flow of the filler material; and a step of bringing the capsule shell material of the droplet from the concentric multiple nozzle into contact with the curing liquid stored in the curing bath so as to cure the capsule shell material; wherein, while transferring the liquid capsule shell material from the second tank to the annular nozzle of the concentric multiple nozzle, the capsule shell material is gradually caused to raise temperature by heating so as to attain a predetermined second temperature, higher than the first temperature, when entering the annular nozzle. Preferably, the first temperature is a temperature at which the liquid capsule shell material stored in the second tank maintains a substantially constant viscosity.
Thus, the liquid capsule shell material stored in the second tank maintains a substantially constant viscosity. The heating of the capsule shell material is limited to a predetermined time during the transfer to the concentric multiple nozzle, whereas the predetermined second temperature is always attained at last, whereby the liquid capsule shell material flowing out of the concentric multiple nozzle yields a substantially constant viscosity. As a consequence, the physical property or state of the liquid capsule shell material flowing out of the concentric multiple nozzle becomes stable, whereby the ratio of occurrence of defects is greatly reduced.
Also, it will be effective if a double tube is prepared as a transfer tube for transferring the liquid capsule shell material between the second tank and the annular nozzle, and the heating of the capsule shell material is carried out by circulating the liquid capsule shell material through the inner tube of the double tube while circulating a heating fluid for heating the capsule shell material in an annular space between the inner and outer tubes in the double tube.
When the raising of temperature becomes insufficient, a heater having a spiral tube communicating with the inner tube of the double tube may be provided in the middle of the double tube, so as to carry out the heating of the capsule shell material by circulating the heating fluid for heating the capsule shell material about the spiral tube.
A vibration or vibrations may be imparted to the liquid filler material and/or liquid capsule shell material supplied into the concentric multiple nozzle, so as to cut the flow of liquid filler material and flow of liquid capsule shell material flowing out of the concentric multiple nozzle, whereby the droplet can be formed. As a consequence, the flows can be cut at a desirable position, whereby a droplet having a fixed size can reliably be formed.
The vibration may be applied by providing a movable wall as a wall portion defining a part of a flow path within the concentric multiple nozzle and vibrating the movable wall.
Preferably, droplets from the concentric multiple nozzle are dispersed in the curing liquid within the curing bath such that a droplet descending path and a next droplet descending path are horizontally distanced from each other. This broadens the gap between droplets in a substantially vertical direction, thereby preventing the droplets from attaching to each other to flocculate.
REFERENCES:
patent: 5223185 (1993-06-01), Takei et al.
patent: 5595757 (1997-01-01), Kiefer et al.
patent: 59-46540 (1984-03-01), None
patent: 61-149150 (1986-07-01), None
patent: 4-322741 (1992-11-01), None
patent: 4-338230 (1992-11-01), None
Matsuda Isao
Nakajima Hiroyuki
Nakamura Takeshi
Nemoto Kaoru
Chugai Seiyaku Kabushiki Kaisha
Morgan & Lewis & Bockius, LLP
Sergent Rabon
Tran Thao
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