JPH05132869A - Liquid filter and liquid extracting bag or the like composed of fibrous material - Google Patents

Abstract

PURPOSE:To obtain the subject liquid filter, safe in aspects of food sanitation and capable of instantaneously permeating hot water or water without falling off fine grains, etc., in the interior of a wrapping material by applying a specific amount of specified sucrose ester of a fatty acid to a nonwoven fabric composed of synthetic fiber. CONSTITUTION:A liquid filter composed of a fibrous material is obtained by applying, e.g. a monoester expressed by the formula (R is alkyl) and prepared by adding a fatty acid in an amount of 0.01-10wt.% based on the weight of fiber to a nonwoven fabric composed of synthetic fiber. The filter is safe in aspects of food sanitation, capable of instantaneously passing hot water or water and suitable as liquid extracting bags such as coffee bags or tea bags. Furthermore, a nonwoven fabric having >=5g/m<2> basis weight and 10-500mum pore size or a melt blown nonwoven fabric having <=5mum average fiber diameter and >=5g/m<2> basis weight, etc., according to the purpose of the liquid extracting bags can be exemplified as a preferred material for the nonwoven fabric.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid filter made of fibrous material, a soup bag, and the like.

More specifically, it is a liquid filter which is safe in terms of food hygiene, in which fine particles and the like inside the packaging material do not fall out of the packaging material, and hot water or water can permeate instantly. The present invention relates to a liquid filter made of a fibrous material that can be optimally used in the field of packaging materials for soup bags such as black tea and green tea) bags and soup bags.

[0003]

2. Description of the Related Art Conventionally, in the field of packaging materials such as so-called soup bags, such as coffee bags, tea bags and dashi bags, tea and fine granules inside the packaging materials do not fall off from the packaging materials, and further extraction It is necessary to have a basic function such that hot water or water passes through the packaging material instantly and extracts or dissolves tea or fine granules inside the packaging material to go out, and it is also an inexpensive material. Since it is necessary, a paper-made one has been used. However, a paper product needs to be thin in order to have an extracting function, and thus has a drawback that it is easily broken.

[0006] As one measure to eliminate such a drawback,
It is conceivable to use a synthetic fiber non-woven fabric having a high strength, but generally, the synthetic fiber non-woven fabric has poor water absorption, and liquid permeability and the like are coffee bags as described above.
It is not fully satisfactory when considering the uses such as tea bags and dashi bags.

On the other hand, generally, as a method for imparting water absorption to a nonwoven fabric made of synthetic fibers, application of a water-absorbing compound,
Surface treatment techniques such as applying a surfactant, chemical treatment, corona discharge treatment, and plasma treatment have also been proposed.Even with each of these techniques, water will pass through instantly and from a food hygiene perspective. The reality is that a liquid filter consisting of a safe fibrous material has not been realized. Further, in recent years, use of an alkylolamide type compound has been proposed as a method for imparting water absorption to polyolefin fibers (Japanese Patent Publication No. 350030/1993), but any of these methods including any of the above-mentioned water absorption imparting techniques is also known. Even in the case of food hygiene, there was a problem and it could not be used depending on the application.

In order to obtain a liquid filter made of a fibrous material by using a nonwoven fabric made of synthetic fibers, it is necessary to make a nonwoven fabric having fine voids according to the purpose so that tea and fine particles inside do not fall off. For that purpose, it is indispensable to form a sheet and absorb water with ultrafine fibers. However, in order to achieve them, there is a drawback that the cost is higher than that of paper, and it has not been put to practical use at present.

On the other hand, in recent years, coffee bags using spunbonded non-woven fabric have been marketed, but those used for fine grains such as finely ground coffee inevitably contain undissolved fine coffee powder at the bottom of the container after extraction. There was a problem such as falling off and sedimentation. This is mainly because fine voids are not obtained.

[0008]

In consideration of the above-mentioned problems, the present inventors obtain a liquid filter which is safe from the viewpoint of food hygiene, low in cost, and made of a fibrous material through which water can instantaneously pass. As a result of intensive studies for the purpose, the present invention has finally been reached.

Furthermore, the present invention provides a dashi bag used as a high-performance coffee bag, tea bag, dashi bag, etc., which uses such a liquid filter, and more particularly, a coffee bag, a tea bag, The purpose is to provide the most suitable stock bag.

[0010]

The liquid filter of the present invention which achieves the above-mentioned object is a nonwoven fabric made of synthetic fibers,
A sucrose fatty acid ester having a monoester content of at least 40% represented by the following general formula 1 is provided in an amount of 0.01% by weight or more and 10% by weight or less with respect to the fiber weight. Is a liquid filter.

[0011]

[Chemical 2]

In the above liquid filter of the present invention, preferably, the nonwoven fabric made of synthetic fiber has a basis weight of 5 g / m ² or more, and a pore size (the diameter of the largest void portion inside the nonwoven fabric) is 10 μm or more. It is less than 500 microns.

Alternatively, in the above-mentioned liquid filter of the present invention, preferably, the nonwoven fabric made of synthetic fibers is a melt blown nonwoven fabric having an average fiber diameter of 5 microns or less and a basis weight of 5 g / m ² or more.

Alternatively, in the above-mentioned liquid filter of the present invention, preferably, the nonwoven fabric made of synthetic fibers has an average fiber diameter of 10 microns or more and a basis weight of 10 g / m ^2.
That is all.

Alternatively, in the above-mentioned liquid filter of the present invention, preferably, the nonwoven fabric made of synthetic fibers is a melt-blown nonwoven fabric A having an average fiber diameter of 5 μm or less and a basis weight of 5 g / m ² or more, and an average fiber diameter of 10 μm. As described above, the nonwoven fabric B having a basis weight of 10 g / m ² or more is formed in a laminated form of at least two layers, and the nonwoven fabrics A and B are joined and integrated by partial joining, and the pore size (the inside of the nonwoven fabric is The diameter of the largest void portion of the above is 10 microns or more and 500 microns or less.

The soup bag of the present invention is a soup bag used for foods, which is formed by forming the liquid filter made of the above fibrous material into a bag shape.

Further, the coffee bag of the present invention is made of a nonwoven fabric having a basis weight of 5 g / m ² or more and a pore size (the diameter of the largest void portion inside the nonwoven fabric) of 10 microns or more and 150 microns or less. The liquid filter of the present invention is a coffee bag formed into a bag shape and used at least.

The tea or soup bag of the present invention is
As a non-woven fabric, especially the basis weight is 5 g / m ² or more, and the pore size (the diameter of the largest void portion inside the non-woven fabric) is 10
The liquid filter of the present invention, which has a size of at least micron and at most 500 micron, is a tea or dashi bag formed into a bag shape and used at least.

[0019]

The liquid filter, soup bag and the like made of the fibrous material of the present invention will be described in more detail below.

First, the liquid filter is mainly required to have a property of capturing particles and allowing the liquid to pass therethrough. Therefore, the maximum pore size of the filter nonwoven fabric (the diameter of the largest void inside the nonwoven fabric) is
It must be smaller than the particle size and have excellent wettability with a liquid. On the other hand, when it is used for food and drink-related packaging materials such as coffee bags, tea bags, and dashi bags, soup stock bags, etc., sufficient safety for living organisms must be guaranteed.

According to the knowledge of the present inventors, for example, even if the finely ground coffee has the finest particle size, fine powder does not fall off if the packaging material has a pore size of 150 microns or less, preferably 100 microns or less. From this point of view, it has been found that fine powder does not fall off if the nonwoven fabric has an average fiber diameter of 5 microns or less. Particularly, when the average fiber diameter is 4 microns or less, the pore size is stably reduced, and when the average fiber diameter is 3 microns or less, it does not fall off even if it is poked with a spoon or a stick for stirring. Therefore, it is more preferably used.

Further, the packaging material such as a tea bag or a dashi bag is preferable if it has a pore size of 500 μm or less because fine powder does not fall off and the extraction efficiency can be used with good efficiency.

On the other hand, the lower limit of the pore size is not particularly limited, but if the pore size is about 10 μm or more, there is no problem that the extraction efficiency is remarkably lowered and the cost becomes high. preferable. That is, those having a pore size of less than 10 microns generally tend to cause problems such as high cost and poor extraction efficiency.

Regarding the method of imparting water absorbency to a nonwoven fabric made of synthetic fibers, as described above, a hydrophilic resin is added to a polymer and kneaded to form a fibrous nonwoven fabric, or a hydrophilic surfactant is added to the nonwoven fabric. Etc. are common, but there is a concern about the safety of the living body, and it cannot be used for the said purpose.

On the other hand, in the present invention, as a method for imparting excellent water absorption to a nonwoven fabric made of synthetic fiber in terms of food hygiene, a sucrose fatty acid ester having a monoester content of at least 40% is used. It was achieved by adding 0.01% by weight or more to the fiber weight. In particular, if the applied amount is 0.05% by weight or more, a more uniform and stable water absorbent fiber sheet can be obtained, which is more preferable. The upper limit of the applied amount is practically set to 10% by weight (based on the weight of the fiber) because the water absorption effect becomes saturated and the cost becomes high. Therefore, those in the range of 0.1% by weight to 5% by weight are more preferably used.

On the other hand, this sucrose fatty acid ester is theoretically considered to be addition of 8 molecules of fatty acid to 1 molecule of sugar, that is, octaester, but if the monoester content is 40% or more, it is effective. Can be demonstrated, and further 50
If it is at least%, a stable effect can be exhibited even if it is used in a small amount, and the cost can be reduced, so that it is preferably used. The method for applying the sucrose fatty acid ester may be any method such as a spray coating method, a gravure coating method, a kiss coating method and an impregnation method, and is not particularly limited.

On the other hand, as a method for producing a non-woven fabric, a single-component resin is discharged from a small hole, or a multi-component resin is discharged from a small hole to obtain at least one of the components and remove the other components to obtain a composite spinning. The non-woven fabric obtained by cutting the fibers into short fibers, web-making and needle punching,
The basic process is to draw the molten polymer that has come out of the nozzle and has fallen to a temperature at which it can be fiberized, and draw it by suction with a high-speed suction gas. A non-woven fabric obtained by the spunbond method, and a heated high-velocity gas body is sprayed onto a fine stream of a molten polymer, and the molten polymer stretches the molten polymer into ultrafine fibers and collects it to form a sheet. The method is not particularly limited, but it is easier to obtain the melt blow method and stable strength characteristics because the manufacturing method is easier and the cost is cheaper than other methods. In addition, since the manufacturing method is simple and the manufacturing cost is low, a spunbonded non-woven fabric is preferable, and the fiber-forming component is used as the core component and the adhesive component. And the spunbonded nonwoven fabric made of core-sheath type composite fibers as a sheath component, more powerful is obtained, more preferably used since such that workability is improved at the time of bag making by heat seal.

Further, a non-woven fabric in which at least two layers of the above-mentioned melt blown non-woven fabric and spun-bonded non-woven fabric are laminated and are integrally bonded by partial adhesion is also preferably used. These non-woven fabrics are used alone or as a laminated sheet depending on the purpose, and are not particularly limited, but when used for large items such as tea bags, they are used as a single sheet of spun-bonded non-woven fabric, Also, when used as a packaging material for extracting fine particles such as coffee bags, a melt-blown non-woven fabric with a small pore size and a spun-bonded non-woven fabric for reinforcement are laminated to form a partial adhesive. A non-woven fabric integrally bonded is preferably used.

The melt blown nonwoven fabric in this case is
If the average fiber diameter is 5 microns or less and the basis weight is 5 g / m ² or more, the object can be achieved, but it is preferably 10 g / m ² or more because stable efficiency can be obtained. The upper limit of the basis weight is not particularly limited, but if it is too large, problems such as a decrease in water absorption efficiency and a high cost occur, so that a unit weight of 30 g / m ² or less is preferably used. The spunbonded non-woven fabric is made of synthetic fibers, and the average fiber diameter is 10 μm or more and the basis weight is 10 g / m ² or more.
is preferably m ² or more of, the other hand, the upper limit of the basis weight is not particularly limited, than arise problems such as water absorption efficiency too large a comparatively high cost lowered, 30 g / Those having m ² or less are preferably used.

The resin forming the constituent fibers of these non-woven fabrics may be any polymeric substance capable of forming fibers, such as polyolefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon 6, nylon 6, Nylon 66
Polyamide such as and copolymers thereof, polyvinyl chloride, acrylic and acrylic copolymers, polystyrene, polysulfone, polytrifluorochloroethylene, polycarbonate, polyurethane and the like, but not particularly limited, suitable for melt blow spinning Therefore, polyolefins such as polypropylene and polyethylene are preferable, and among them, polypropylene is particularly preferable because it has stable spinnability. For the spunbonding method, polyolefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon 6 Polyamide such as nylon 66 is widely used.

Various methods can be adopted as a method for obtaining a non-woven fabric that has been bonded and integrated by partial adhesion, and a non-woven fabric prepared in advance and another non-woven fabric prepared in advance are simply laminated or prepared in advance. There is no particular limitation such as spraying melt-blown ultrafine fibers on the nonwoven fabric to be laminated, and further, the obtained laminate may be partially bonded, such as hot embossing, ultrasonic wave or high frequency. However, the heat embossing method having a concavo-convex pattern is preferably used in view of cost advantages and practicality.

Further, subjecting the surface to calendering treatment within a range that does not impair the function is a means often used as finishing treatment, and the present invention may be subjected to the treatment.

The liquid filter made of the fibrous material according to the present invention can be formed into a bag shape and used as a soup bag such as a coffee bag, a tea bag, a dashi bag, or a packaging material. A processing method such as heat sealing can be used for forming into a bag shape.

Further, even if it is not formed into a bag shape, it can be used as a sheet shape as it is as a liquid filter material.

[0035]

As described above, the liquid filter made of the fibrous material of the present invention is harmless to humans and animals and has excellent water absorption. Hot water and water pass through the sheet instantly, so that fine particles inside the sheet are removed. It has good characteristics that it dissolves and goes out.

Further, since the pore size is small, there is no problem that undissolved coffee fine powder falls and settles, and since it is a fiber sheet, it is superior in flexibility as compared with paper and it is low in cost. , Tea bags,
It can be optimally used for packaging materials such as dashi bags and soup stock bags.

[0037]

EXAMPLES The following examples are for clarifying the present invention, but the present invention is not limited thereto.

The physical properties in the examples were measured by the following methods.

(1) Water absorption: JIS-L-1079 (2) Average fiber diameter: The fiber diameter of 300 or more fibers was read from an enlarged photograph of 1000 times (scanning electron microscope) and taken as the average value.

(3) Pore size of non-woven fabric: COLULTE
It was measured by R POROMETER II (Coulter).

Example 1 Melt flow index (load 2.16 kg, 230
℃) 60g / 10min polypropylene (melting point 157.6
Melt melt spinning method to obtain a melt blown nonwoven fabric having an average fiber diameter of 3 microns and a basis weight of 20 g / m ² .

A 3% aqueous solution of sucrose fatty acid ester (DK Ester S-160, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) having a monoester content of 70% was applied to the nonwoven fabric so as to be 2 parts per 100 parts of the fiber component. And dried. The water absorption of this product was measured and found to be 53 mm. The pore size of this nonwoven fabric was measured and found to be 57 microns.

Example 2 The monoester content of the nonwoven fabric obtained in Example 1 was 70%.
Sucrose fatty acid ester (DK ester S-L18A,
A 3% aqueous solution of Daiichi Kogyo Seiyaku Co., Ltd. was applied so as to be 1 part per 100 parts of the fiber component and dried. The water absorption of this product was measured and found to be 105 mm.

Example 3 The nonwoven fabric obtained in Example 1 and the average fiber diameter of 25 μm were 3
Laminated with a spunbonded nonwoven fabric with a basis weight of 0 g / m ² ,
A heat-bonding sheet was obtained at a pressure of 50 Kg / cm while being sandwiched between a concavo-convex textured roll (upper roll) and a plain roll (lower roll) at 140 ° C. A 3% aqueous solution of sucrose fatty acid ester (DK Ester S-160, Daiichi Kogyo Seiyaku Co., Ltd.) having a monoester content of 70% was applied to this laminated heat-adhesive sheet in an amount of 3 parts per 100 parts of the fiber component. And dried.
Using this sheet, a coffee bag was created and immersed in boiling water, and coffee was extracted smoothly. The water absorption of this product was measured and found to be 63 mm. At this time, the spunbonded nonwoven fabric had a pore size of 201 microns, and the melt-blown nonwoven fabric portion of the laminated thermal adhesive sheet had a pore size of 46 microns.

Example 4 The monoester content of the laminated sheet obtained in Example 3 was 70%.
Sucrose fatty acid ester (DK ester S-L18A,
A 3% aqueous solution of Daiichi Kogyo Seiyaku Co., Ltd. was applied so as to be 1 part per 100 parts of the fiber component and dried. The water absorption of this product was measured and found to be 117 mm.

Comparative Example 1 The water absorption of the non-woven fabric obtained in Example 1 (non-woven fabric in a state before application of sucrose fatty acid ester) was measured.
It was 2 mm.

Comparative Example 2 The water absorption of the laminated sheet obtained in Example 3 (nonwoven fabric laminated sheet in a state before application of sucrose fatty acid ester) was 2 mm.

Comparative Example 3 The laminated sheet obtained in Example 3 had a monoester content of 30%.
3% aqueous solution of sucrose fatty acid ester (DK Ester S-50, Daiichi Kogyo Seiyaku Co., Ltd.) was applied so as to be 1 part to 100 parts of the fiber component and dried. When a coffee bag was prepared using this sheet and soaked in hot water, the entire coffee bag floated up and the hot water did not penetrate forever. The water absorption of this product was measured and found to be 2 mm. Comparative Examples 4 to 5 Two commercially available coffee bags of two companies were purchased, and the water absorption of each packaging material was measured.
It was 8 mm. Further, the coffee particle diameter was measured using an image processing device (manufactured by Pierce Co., Ltd.), and the average diameter was 594 microns, the minimum diameter was 168 microns, and the average diameter was 14 microns.
It had a diameter of 09 microns and a minimum diameter of 146 microns.

Example 5 ^Two spunbonded non-woven fabrics having an average fiber diameter of 25 microns and a basis weight of 20 g / m ² were laminated and sandwiched between a concavo-convex embossed roll (upper roll) and a plain roll (lower roll) at 140 ° C. A heat-bonding sheet was obtained at a pressure of 50 Kg / cm. A 3% aqueous solution of sucrose fatty acid ester (DK Ester S-160, Daiichi Kogyo Seiyaku Co., Ltd.) having a monoester content of 70% was applied to this laminated heat-adhesive sheet in an amount of 3 parts per 100 parts of the fiber component. And dried. When a tea bag was made using this sheet and soaked in boiling water, the tea was extracted smoothly. The water absorption of this product was measured and found to be 85 mm. The pore size of the nonwoven fabric at this time is
It was 201 microns, which was judged unsuitable for a coffee bag.

As is clear from the above Examples 1 to 4 and Comparative Examples 1 to 5, those according to the present invention have a pore size much smaller than the commercially available coffee particle size, have water absorbability, and are food hygienic. However, it is safe and suitable for packaging materials such as coffee bags and dashi bags.

In particular, the sheet and the like shown in Example 5 were liquid filters made of fibrous material suitable for packaging materials such as tea bags and dashi bags.

Claims (8)

[Claims] 1. A non-woven fabric made of synthetic fiber, and the following general formula 1
The sucrose fatty acid ester having a monoester content of at least 40% represented by 0.01% by weight based on the fiber weight
A liquid filter made of a fibrous material, characterized in that it is provided in an amount of 10% by weight or less. [Chemical 1] 2. A non-woven fabric made of synthetic fibers has a basis weight of 5 g /
The liquid filter comprising a fibrous material according to claim 1, wherein the liquid filter has a pore size of m ² or more and a pore size (the diameter of the largest void portion inside the nonwoven fabric) of 10 microns or more and 500 microns or less. 3. A synthetic fiber non-woven fabric has an average fiber diameter of 5
A liquid filter comprising a fibrous material according to claim 1 or 2, which is a melt blown non-woven fabric having a micrometer or less and a basis weight of 5 g / m ² or more. 4. A non-woven fabric made of synthetic fibers has an average fiber diameter of 1.
The liquid filter comprising the fibrous material according to claim 1 or 2, which has a weight per unit area of 0 micron or more and a basis weight of 10 g / m ² or more. 5. A synthetic fiber non-woven fabric has an average fiber diameter of 5.
Melt blown non-woven fabric A having a weight of 5 g / m ² or more with a micron or less and 10 g with an average fiber diameter of 10 microns or more
/ M ² or more of the non-woven fabric B having a laminated shape of at least two layers, the non-woven fabrics A and B are joined and integrated by partial joining, and the pore size (the maximum void portion inside the non-woven fabric is The liquid filter comprising the fibrous material according to claim 1 or 2, having a diameter of 10 to 500 microns. 6. A soup stock bag used for foods, which is formed by forming a liquid filter made of the fibrous material according to claim 1, 2, 3, 4 or 5 into a bag shape. 7. The liquid according to claim 2, wherein the non-woven fabric has a basis weight of 5 g / m ² or more and a pore size (the diameter of the largest void portion inside the non-woven fabric) of 10 microns or more and 150 microns or less. A coffee bag, wherein the filter is formed into a bag shape and used at least. 8. The liquid according to claim 2, wherein the non-woven fabric has a basis weight of 5 g / m ² or more and a pore size (the diameter of the largest void portion inside the non-woven fabric) of 10 microns or more and 500 microns or less. A tea or soup bag, characterized in that the filter is formed into a bag shape and is used at least.