JPH0576583A - Sustained release function type porous body - Google Patents

Abstract

PURPOSE:To prevent the dislodgment of a sustained releasing agent and to maintain a stable sustained release function over a long period of time by constructing multilayered composite hollow yarn membranes alternately laminated with homogeneous membranes and porous membranes in such a manner hat the inside surface and outside surface thereof consist of the porous membranes. CONSTITUTION:The multilayered composite hollow yarn membranes 2 consisting of the homogeneous membranes A having <=5mum film thickness and the porous membranes B bearing a reinforcing function are alternately laminated with the homogeneous membranes A and the porous membranes B and are constructed in such a manner that the inside surfaces and outside surface of the multilayered composite hollow yarn membranes 2 consist of the porous membranes B. A material contg. volatile components is incorporated into at least the hollow part of the multilayered composite hollow yarn membranes 2. The dislodgment of the sustained releasing agent is obviated in this way and the sustained release function stable over a long period of time is maintained Since the amt. of the sustained releasing agent to be used can be decreased, the inexpensive and compact sustained releasing container is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material having a sustained release function, and more particularly to a multilayer composite hollow fiber membrane having a sustained release function, which contains a vaporizable substance such as an aromatic agent and an insect repellent.

[0002]

2. Description of the Related Art Conventionally known materials having a sustained release function are porous films and fibers impregnated with a substance containing a vaporizable component.

[0003]

However, a problem with the conventional one is that if the impregnated substance is a liquid substance, it easily falls off. Further, since it is porous, the evaporation rate of the vaporizable component is high, and there is a problem that stable sustained release performance cannot be maintained for a long period of time.

An object of the present invention is to provide a sustained-release functional porous material in which the sustained-release agent does not fall off and has a stable sustained-release function for a long period of time, and further, the sustained-release agent is compactly packed. ..

[0005]

The gist of the present invention is a multilayer composite hollow fiber membrane comprising a homogeneous membrane (A) having a membrane thickness of 5 μm or less and a porous membrane (B) having a reinforcing function. (A) and the porous membrane (B) are alternately laminated, and the inner surface and outer surface of the multilayer composite hollow fiber membrane have a structure composed of the porous membrane (B), and the multilayer composite hollow fiber membrane Is a sustained-release functional porous body containing a substance containing a vaporizable component in at least the hollow portion thereof.

The multilayer composite hollow fiber membrane used in the sustained-release functional porous material of the present invention comprises a homogeneous membrane (A) and a porous membrane (B) having a reinforcing function, as shown in the schematic view of FIG. And has at least a three-layer structure. The homogeneous membrane (A) and the porous membrane (B) are laminated alternately, and the inner surface and the outer surface of the multilayer composite hollow fiber membrane are composed of the porous membrane (B), that is, the homogeneous membrane (A) is porous. It has a sandwich structure sandwiched between the membranes (B). In this multilayer composite hollow fiber membrane, the homogeneous membrane (A) is basically sufficient as one layer, but may have a multilayer structure of two or more layers.

The film thickness of the homogeneous film (A) is 5 μm or less. On the other hand, the thickness of both porous membranes (B) sandwiching the homogeneous membrane (A) is not particularly limited as long as it has a thickness capable of reinforcing the function of the multi-layer composite hollow fiber membrane, and both the inner and outer layers are porous The film thicknesses of the film (B) may be the same or different.

The polymer material constituting the homogeneous membrane (A) is not limited to a silicone rubber type polymer having excellent gas permeability, but may be a silicone rubber type polymer such as polydimethylsiloxane, a copolymer of silicon and polycarbonate, Polyolefin polymers such as -4-methylpentene-1, linear low-density polyethylene, fluorine-containing polymers such as perfluoroalkyl polymers, cellulose polymers such as ethyl cellulose, polyphenylene oxide, poly-4-vinylpyridine and these polymer materials Various polymers such as copolymers or blends of

In order to effectively and sustainably release the vaporizable component for a long time, it is necessary to set the thickness of the homogeneous film to 5 μm or less. When the gas permeability is used as an index, the oxygen gas permeation rate is 1 × 10 ^-6 [cm ³ (STP) / cm ² · sec · cm
Hg] or more is preferable.

Examples of the polymer material constituting the porous membrane (B) include polyolefin polymers such as polyethylene, polypropylene, poly-3-methylbutene-1, poly-4-methylpentene-1, polyvinylidene fluoride and polytetrafluoro. Examples thereof include fluorine-based polymers such as ethylene, and hydrophobic polymers such as polystyrene and polyether ether ketone.

The combination of the polymer material forming the homogeneous film (A) and the polymer material forming the porous film (B) is not particularly limited, and different polymers may be the same kind. Since the homogeneous membrane (A) has a sandwich structure in which it is physically sandwiched between the porous membranes (B), even if the adhesiveness between both membranes is poor, no practical adverse effect occurs.

The porous membrane (B) mainly has a role of reinforcing the homogeneous membrane (A), and has pores of such a degree that the gas permeability of the multilayer composite hollow fiber membrane as a whole is not largely restricted. There is no particular limitation on the size of the pores as long as they have.

In such a multilayer composite hollow fiber membrane, for example, a polymer forming a homogeneous membrane (A) and a polymer forming a porous membrane (B) are alternately and by using a multi-cylindrical spinning nozzle. Under the condition that the polymer forming the homogeneous membrane (A) is arranged so as to be sandwiched and melt-spun, and then only the porous membrane (B) is made porous without making the homogeneous membrane (A) porous. It is manufactured by a stretching method.

The substance containing a vaporizable component is contained in the hollow portion of the multilayer composite hollow fiber membrane and the porous membrane (B).
When a substance containing a vaporizable component is contained in the hollow portion of the multilayer composite hollow fiber membrane and the portion of the porous membrane (B) on the hollow side, for example, the methods shown in FIGS. 2 and 3 can be considered.

In the method shown in FIG. 2, the multilayer composite hollow fiber membranes 2 are arranged in a bundle in the container 1. Both ends of the hollow fiber 2 are fixed by a potting agent (partition wall) 3 while maintaining the open state of the ends of the hollow fiber. The hollow portion of the hollow fiber communicates with the sustained release agent storage portion 4 provided in the container 1.

In the method shown in FIG. 3, the multilayer composite hollow fiber membrane 2 is arranged in a U-shape in the container 1. Both ends of the hollow fiber 2 are fixed by a potting agent (partition wall) 3 while maintaining the open state of the ends of the hollow fiber. The hollow part of the hollow fiber is the container 1
It communicates with the sustained release agent storage portion 4 provided in the.

In both the methods shown in FIGS. 1 and 2, the sustained release agent diffuses from the inside of the hollow fiber through the hollow fiber membrane to the outside of the hollow fiber. Moreover, since the sustained-release agent diffuses outside the hollow fiber, it is desirable that the container 1 be a porous body in order to improve the diffusion.

A substance containing a vaporizable component is added to the outer portion of the multilayer composite hollow fiber membrane and the porous membrane (B) outside the homogeneous membrane (A).
When it is contained in the portion of, the method as shown in FIGS. 4 and 5 can be considered.

In the method shown in FIG. 4, a multi-layer composite hollow fiber membrane 2 is arranged in a bundle in a container 1. Both ends of the hollow fiber membrane 2 are fixed by a potting agent (partition wall) 3 while keeping the open state of the ends of the hollow fiber. The sustained-release agent accommodating portion 4 is configured so that the homogeneous membrane (A) of the multilayer composite hollow fiber membrane 2, the container 1 and the potting agent (partition wall) 3 maintain an airtight state.

In the method shown in FIG. 5, a multi-layer composite hollow fiber membrane 2 is arranged in a U shape in a container 1. Both ends of the hollow fiber 2 are fixed by a potting agent (partition wall) 3 while maintaining the open state of the end of the hollow fiber. The sustained-release agent accommodating portion 4 is configured so that the homogeneous membrane (A) of the multilayer composite hollow fiber membrane 2, the container 1 and the potting agent (partition wall) 3 maintain an airtight state.

In both the methods shown in FIGS. 4 and 5, the sustained-release agent diffuses from the outside of the hollow fiber through the hollow fiber membrane to the inside of the hollow fiber. By adopting such a method, a large amount of sustained release agent can be contained in a compact size.

[0022]

EXAMPLES The present invention will be described in more detail with reference to examples. Examples 1 to 4 and Comparative Examples 1 to 3 For a hollow fiber manufacturing nozzle having three discharge ports arranged concentrically, high density polyethylene is supplied to the intermediate layer as a polymer material to be supplied to the inner layer and the outer layer. Using segmented polyurethane as the polymer material, discharge temperature 175 ° C, discharge linear velocity 3 cm / min, winding speed 30 m /
spun at min.

The hollow undrawn yarn obtained has an inner diameter of 250 μm.
And 30 μm, 1 μm and 30 μm from the innermost layer, respectively.
It consisted of three concentric layers with a thickness of μm. This hollow undrawn yarn was annealed at 95 ° C. for 1 hour. Then, the annealed yarn is stretched by 80% at room temperature, and then thermally stretched in a heating furnace heated to 95 ° C. until the total stretch amount reaches 300%, and the multilayer composite hollow fiber membrane having the structure shown in FIG. Got

The hollow fiber membrane obtained had an inner diameter of 200 μm.
m, and from the innermost layer consisted of three concentrically arranged layers with thicknesses of 25 μm, 0.7 μm and 25 μm, respectively. The oxygen permeation rate of this hollow fiber membrane is 1.1 ×
It was 10 ⁻⁶ [cm ³ (STP) / cm ² · sec · cmHg].

By the same method, a linear low density polyethylene, a copolymer of silicon (dimethylsiloxane) and polycarbonate (Coper LR33) was used as the polymer material for the intermediate layer.
20, manufactured by General Electric Co.) or poly-4-
Methylpentene-1 was used, and high-density polyethylene or poly-4-methylpentene-1 was used as a reinforcing membrane material in combination with these to spin and stretch to obtain the multilayer composite hollow fiber shown in Table 1.

The sustained-release container having the structure shown in FIG. 2 was prepared by using various multilayer composite hollow fiber membranes shown in Table 1, polypropylene,
It was prepared by using a microporous hollow fiber membrane made of polyethylene.
All hollow fiber membranes were installed so that the membrane area was 150 cm ^2, and 1.5 g of a commercially available liquid fragrance was added as a sustained-release agent containing a vaporizable component, and the weight loss was measured with time to measure the divergence degree. Was measured. The results are shown in Fig. 6.

It can be seen that the sustained release container using the multilayer composite hollow fiber membrane according to the present invention maintains stable sustained release performance for a long period of time as compared with the microporous membranes shown in Comparative Examples 1 and 2. .. However, in Comparative Example 3, stable sustained release performance is maintained for a long period of time, but since the film thickness of the homogeneous film (A) is large, the fragrance of the fragrance is small and it is judged to be practical.

[0028]

INDUSTRIAL APPLICABILITY The sustained-release functional porous material of the present invention comprises a homogeneous membrane (A) and a porous membrane (B) alternately laminated, and the inner and outer surfaces of the multilayer composite hollow fiber membrane are porous. Since it has a structure composed of the membrane (B), the sustained-release agent does not fall off as compared with the conventional microporous membrane, and can have a stable sustained-release function for a long period of time.

Further, since the sustained-release agent does not drop out and has a stable sustained-release function for a long period of time, the amount of the sustained-release agent used can be reduced, so that an inexpensive and compact sustained-release container can be provided. ..

[0030]

[Table 1]

[Brief description of drawings]

FIG. 1 is a diagram schematically showing the structure of a multilayer composite hollow fiber membrane that constitutes the sustained-release functional porous material of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of the internal structure of a sustained-release container using the sustained-release functional porous material of the present invention.

FIG. 3 is a schematic cross-sectional view showing an example of the internal structure of a sustained-release container using the sustained-release functional porous material of the present invention.

FIG. 4 is a schematic cross-sectional view showing an example of the internal structure of a sustained-release container using the sustained-release functional porous material of the present invention.

FIG. 5 is a schematic cross-sectional view showing an example of the internal structure of a sustained-release container using the sustained-release functional porous material of the present invention.

FIG. 6 is a graph showing the ratio of the number of days elapsed and the amount of residual sustained release agent.

[Explanation of symbols]

 1 container 2 multi-layer composite hollow fiber membrane 3 potting agent (partition wall) 4 sustained release agent storage section

Claims (1)

[Claims] 1. A multilayer composite hollow fiber membrane comprising a homogeneous membrane (A) having a thickness of 5 μm or less and a porous membrane (B) having a reinforcing function, the homogeneous membrane (A) and the porous membrane (B). Are alternately laminated, and the inner surface and outer surface of the multilayer composite hollow fiber membrane have a structure composed of a porous membrane (B), and a vaporizable component is present in at least the hollow portion of the multilayer composite hollow fiber membrane. A sustained-release functional porous body containing a substance containing the same.