JP2001000823A - Film- or sheet-like moisture absorbing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture absorbing material by which moisture condensation on the inner surface is prevented when the material is used as a bag or a container, housed matter is prevented from being brought into direct contact with the moisture absorbing material, moisture absorption is regulated by timewisely controlling moisture absorbing function, moreover, spalling of separated moisture resulting from moisture absorption and moisture-absorbed crystalline powder is prevented and which is and suitable for a forming material of a housing bag or container for food, precision component, etc. SOLUTION: In the film- or sheet-like moisture absorbing material, the film- like moisture absorbing material S is heat bonded on one side surface of a moisture absorbing base material 1 constituted by kneading a moisture absorbing agent 10 of a plastic-made film magnesium compd. and also the plastic-made perforated film 7 in which numberless fine pores 70 are perforated is bonded on the other side surface of a moisture absorbing base material 1 by interposing a plastic air permeable membrane 12 being a thin film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film- or sheet-shaped hygroscopic material, and is used as a bag or container for storing precision parts or chemicals.

[0002]

2. Description of the Related Art Conventionally, as a moisture absorbing bag, a desiccant such as silica gel or zeolite is contained in the bag itself by kneading it into a plastic film constituting the bag.
Because the hygroscopic action is adsorption and retention of water on those porous bodies,
Re-release of water may occur due to separation. In this regard,
Recently, a film-shaped moisture-absorbing bag wrapped and containing a magnesium compound has been developed, and re-release of water is prevented by crystallization of the magnesium compound due to moisture absorption, and it has begun to be used effectively. However, there is a problem that magnesium crystal powder generated by moisture crystallization floats on the film surface, separates, and falls into the bag. For this reason, it was unsuitable as a storage bag for chemicals or precision parts that disliked the inclusion of foreign substances.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention can prevent the dew condensation on the inner surface of a bag or a container when it is made into a bag or a container, and can prevent the container from directly contacting the desiccant, and can reduce the moisture absorption effect in time. In the case of using a hygroscopic agent of a chemical substance that can be controlled and adjusted to absorb moisture and that further crystallizes and absorbs moisture, by preventing separation of the crystal powder, a hygroscopic material suitable as a material for forming a housing bag or container of precision parts or the like is provided. Things.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a film or sheet-shaped hygroscopic material, wherein a plastic film or plastic sheet contains a hygroscopic substrate containing a hygroscopic agent such as a magnesium compound or silica gel. This is a moisture absorbing material having a structure comprising a film or sheet-shaped moisture-proof material adhered to one surface thereof and a plastic breathable film adhered to the other surface of the moisture-absorbing substrate. In addition, the breathable film,
A perforated plastic film innumerable of micropores may be used.After attaching a plastic film to the other surface of the moisture-absorbing base material, a heated needle is inserted from the surface of the film to the moisture-absorbing base material. The holes may be formed into holes to form a perforated film. A film or sheet-shaped moisture-absorbing material, in which a film or sheet-shaped moisture-proof material is adhered to one surface of a moisture-absorbing substrate comprising a plastic film or a plastic sheet containing a moisture-absorbing agent such as a magnesium compound or silica gel. In addition, a configuration may be adopted in which a perforated plastic film in which micropores are innumerably penetrated is attached to the other surface of the moisture-absorbing substrate via a thin plastic gas-permeable film. A perforated film having conductivity by containing a conductive material such as carbon or metal powder may be used.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to illustrated embodiments. In the embodiment shown in FIGS. 1 and 2,
Reference numeral 1 denotes a polyethylene film-shaped moisture-absorbing substrate into which a magnesium compound serving as a moisture absorbent 10 has been kneaded. The film 6 is applied.

The biaxially oriented polypropylene film 4,
The adhesive layer 5 and the nylon film 6 become the moisture proof material S. Actually, since the manufacturing process is different, the polyethylene film 2 attached to one surface of the moisture-absorbing substrate 1 and the polyethylene film 3 of the moisture-proof material S are bonded by heat. The moisture-proof material S is formed by lamination by heat deposition or dry lamination. The propylene film 4 has an excellent moisture-proofing effect, and the nylon film 6 has a structure having excellent gas impermeability by applying a coating treatment such as silica deposition in addition to the reinforcing base material.

[0007] After extruding a polyethylene film on the other surface of the moisture-absorbing substrate 1 by extrusion lamination, a heated hot needle is inserted from the surface of the film to the moisture-absorbing substrate 1 so that the fine holes 70 are melted. Thus, a perforated film 7 is formed. That is, the film portion is melted by the insertion of the hot needle, and the fine holes 70 in the trace of the hot needle are hardened and formed. The micropore 70 has an average pore diameter of 0.4 mm and 0.7 mm.
It is transparently provided at intervals.

At this time, since the surrounding film resin is pushed and expanded by the insertion of the hot needle body, a projection ring 71 having a thickness of 3 to 4 times the film thickness is provided around the fine hole 70. That is, the outer surface of the film becomes finely uneven (see FIG. 2). Further, since the thermal needle is inserted into the moisture-absorbing substrate 1, the insertion portion is melted and hardened, but retains moisture permeability.

The thickness of this example is 30 μm for the moisture-absorbing substrate 1, 20 μm for each of the polyethylene films 2 and 3, 20 μm for the polypropylene film 4, 5 μm for the adhesive layer 5, 15 μm for the nylon film 6, and 10 μm for the perforated film 7.
And the total thickness is 120 μm. In the drawings, the boundary lines of the respective films are clearly shown. However, in the case of bonding by thermal welding, the boundary lines are welded to each other, so that the boundary lines become unclear.

In this embodiment, as shown in FIG. 3, if this is formed in a bag having a perforated film 7 as an inner surface as a wrapping material, moisture in the bag passes through the micropores 70 and is absorbed by the moisture absorbing substrate 1. Therefore, moisture from the outside is blocked by the moisture-proof material S. It also has the following excellent effects. First, when the moisture absorbent 10 absorbs moisture and crystallizes, conventionally, the crystal powder is separated and falls into the bag, but in the present embodiment, the fall is prevented by the attachment of the perforated film 7. is there. That is, the fine holes 7
The crystal powder does not pass through the fine holes 70 because the portion of the moisture-absorbing substrate 1 communicating with zero is hardened and the pore size is small. Therefore, it is suitable for accommodating precision parts such as IC parts and precision equipment that dislike foreign substances.

Further, since the innermost surface is the perforated film 7, safety can be ensured because the contents do not come into direct contact with the moisture-absorbing substrate 1, and the surface of the perforated film 7 is formed by the projection ring 71. The surface of the stored object can be protected without being in close contact with the stored object due to the uneven state. Further, the moisture adhering to the surface of the effective film 7 is absorbed through the micropores 70 and does not remain, so that dew condensation can be prevented. In addition, by adjusting the size and the number of transparent holes 70, the opening area of the moisture-absorbing substrate 1 can be adjusted, so that an appropriate moisture-absorbing action can be achieved in accordance with the stored material. You can.

Further, the moisture absorbent 10 of the present embodiment does not adsorb any gas and is made of a moisture proof material S using a gas-impermeable nylon film 6, so that the invasion of gas and moisture from the outside can be prevented. Thus, the hygroscopic effect of the hygroscopic substrate 1 in the bag is improved. Further, in this embodiment, since all the layers are formed by the transparent film, the inside of the bag can be seen through, so that the state of the stored items can be determined well.

Next, an embodiment shown in FIGS. 4 and 5 will be described. Reference numeral 1 denotes a polyethylene film-shaped moisture-absorbing substrate into which a magnesium compound serving as a moisture absorbent 10 has been kneaded. The polyethylene film 2 and 3, a biaxially stretched polypropylene film 4, an adhesive layer 5, and a nylon layer are sequentially welded to one surface of the substrate. The film 6 is applied.

This biaxially oriented polypropylene film 4
The adhesive layer 5 and the nylon film 6 become the moisture proof material S. Actually, since the manufacturing process is different, the polyethylene film 2 attached to one surface of the moisture-absorbing substrate 1 and the polyethylene film 3 of the moisture-proof material S are bonded by heat. The moisture-proof material S is formed by lamination by heat deposition or dry lamination. The propylene film 4 has an excellent moisture-proofing effect, and the nylon film 6 has a structure having excellent gas impermeability by applying a coating treatment such as silica deposition in addition to the reinforcing base material.

On the other surface of the moisture-absorbing substrate 1, a perforated film 7 having a large number of micropores 70 is applied by thermal lamination through a thin plastic gas-permeable film 12 made of polyethylene. The gas permeable membrane 12 has an average thickness of 7 μm, a moisture permeability of about 50 g / m ² (24 hours), and is excellent in moisture permeability. Also, perforated film 7
Is made of polyethylene, and the micropores 70 have an average pore diameter of 0.
It is transparent at 4mm and 0.7mm intervals. At the time of the penetration of the fine holes 70, the surrounding film resin is pushed out by the insertion of the hot needles, or the resin film is hardened around the holes, so that the film thickness is increased. 3 ~
A quadruple projection ring 71 is provided around the film, and the outer surface of the film becomes finely uneven (see FIG. 5).

The thickness of this embodiment is 5 μm for the gas permeable membrane 12, 30 μm for the moisture absorbing substrate 1, 20 μm for each of the polyethylene films 2 and 3, 20 μm for the polypropylene film 4, 5 μm for the adhesive layer 5, and 15 μm for the nylon film 6. The perforated film 7 is 10 μm and the total thickness is 125 μm. In the drawings, the boundary lines of the respective films are clearly shown. However, in the case of bonding by thermal welding, the boundary lines are welded to each other, so that the boundary lines become unclear.

In this embodiment, if this is formed in a bag with the perforated film 7 as the inner surface as shown in FIG.
The moisture-absorbing substrate 1 passes through the air-permeable membrane 12 and the gas permeable membrane 12, and moisture from the outside is blocked by the moisture-proof material S. It also has the following excellent effects. First, moisture absorbent 1
When 0 is absorbed and crystallized, conventionally, the crystal powder is separated and falls into the bag, but in this example, the fall is prevented by the attachment of the gas permeable membrane 12. Therefore, it is suitable for accommodating precision parts such as IC parts and precision equipment that do not like foreign substances and cosmetics, and is excellent as a packaging material for leather products and furniture.

Further, since the innermost surface is the perforated film 7 and the micropores 70 are blocked by the gas permeable membrane 12, the stored material does not come into direct contact with the moisture-absorbing substrate 1, so that the safety can be secured. In addition, the surface of the perforated film 7 can be protected since the surface of the perforated film 7 does not come into close contact with the stored object due to the unevenness due to the projection ring 71. Further, the moisture adhering to the surface of the effective film 7 is absorbed through the micropores 70 and does not remain, so that dew condensation can be prevented. In addition, by adjusting the ventilation amount of the gas permeable membrane 12 and adjusting the size and the number of the perforations 70 of the perforated film 7, the ventilation amount and the opening area to the moisture-absorbing substrate 1 can be adjusted, so that it is suitable for the container. An appropriate moisture absorbing action can be achieved, and the moisture absorbing time can be adjusted.

Further, since the moisture absorbent 10 of this embodiment does not adsorb gas and is made of the moisture proof material S using the gas-impermeable nylon film 6, it is possible to prevent the invasion of gas and moisture from the outside. Thus, the moisture absorbing effect of the moisture absorbing substrate 1 inside the bag is improved. Further, in this embodiment, since all the layers are formed by the transparent film, the inside of the bag can be seen through, so that the state of the stored items can be determined well.

Although the embodiments have been described above, the present invention is not limited to these embodiments. For example, the moisture absorbent may be a substance that crystallizes by moisture absorption, may be conventional silica gel, zeolite, phosphorus pentoxide, or the like, and may be mixed in any plastic material. In the case where a moisture-proof material is applied to one surface of the moisture-absorbing substrate, the structure is also appropriate, and the means for applying the moisture-proof material is not limited. Further, regardless of the configuration of the plastic breathable film to be adhered to the other surface of the moisture-absorbing base material, it is only required that the film has excellent moisture permeability.

Therefore, any plastic film having excellent air permeability may be used. In addition to a perforated film, a plastic film, a plastic nonwoven fabric, or a plastic nonwoven fabric, which has been secured to have air permeability by cutting or puncturing, is reheated and pressed. Alternatively, a nonwoven fabric film which ensures air permeability may be used. In the case of a perforated film, the number, the permeating means and the size of the perforations are appropriate, and the film may be adhered to the moisture-absorbing substrate with its front and back surfaces reversed.

The means for applying the breathable film to the moisture-absorbing substrate is optional. In the case of a different kind of material which cannot be subjected to thermal lamination other than heat welding, dry lamination with an adhesive may be used. In this case, as shown in FIG. 7, the adhesive layer 8 may be partially applied as partial adhesion instead of overall adhesion to ensure moisture permeability in the non-adhesive portion 80 where no adhesive 8 is provided.

When a perforated plastic film having a myriad of micropores is applied on the other surface of the moisture-absorbing substrate through a thin plastic gas permeable film, the thickness and moisture permeability of the gas permeable film are required. The thickness is 5 to 15 μm, and the moisture permeability is excellent in the range of 100 to 500 g / m ² (24 hours). Further, the hygroscopic material may be formed into a sheet by increasing the thickness of the hygroscopic substrate or the film to be adhered to the hygroscopic substrate, or may be used as a container or the like. Further, it may be used as a lid seal for various containers of dried foods such as instant noodles. Furthermore, it may be a perforated film having conductivity by containing a conductive material such as carbon or metal powder, and is excellent in moisture permeability with countless fine pores,
It becomes a moisture absorbing material suitable for electrical products that maintain the antistatic performance.

[0024]

According to the first aspect of the present invention, the moisture absorbent, particularly the moisture-absorbing crystal powder is not separated and dropped by the attachment of the breathable film, and is safe. The bag or the container has the breathable film as the innermost surface. Is formed, it is possible to secure safety since the stored matter does not directly contact the moisture-absorbing base material, and it is suitable for storing foods, medicines, precision parts, and the like. Even when a conventional desiccant such as silica gel or zeolite is used, re-release of moisture and dust due to separation can be prevented by the breathable film.

According to the second aspect, dew condensation can be prevented due to the effective film in which the fine holes are penetrated, and the opening area of the moisture-absorbing base material can be adjusted by selecting the size and the number of the fine holes. It is possible to adjust the hygroscopic action. Claim 3
In this case, it is possible to easily provide the micropores at low cost.

According to the fourth aspect of the present invention, the arrangement of the gas permeable membrane can prevent the hygroscopic agent, particularly the hygroscopic crystal powder from separating and falling off, and is safe. If the bag or the container is formed with the perforated film as the innermost surface, the contents can be stored. Can be secured because it does not directly contact the moisture-absorbing base material, and is suitable for use in foods, pharmaceuticals, and precision parts. Since the opening area can be adjusted, proper adjustment of the moisture absorbing action can be achieved. Even when a conventional drying agent such as silica gel or zeolite is used, re-release of moisture and dust due to separation can be prevented by the gas permeable membrane. According to the fifth aspect, since the perforated film has conductivity, it is excellent in moisture permeability with countless micropores, and can maintain the antistatic performance, so that it is a moisture absorbing material suitable for electric appliances and the like.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional view of one embodiment of the present invention.

FIG. 2 is a further enlarged longitudinal sectional view.

FIG. 3 is a cutaway perspective view of the bag-shaped main part.

FIG. 4 is an enlarged vertical sectional view of another example.

FIG. 5 is a further enlarged longitudinal sectional view.

FIG. 6 is a cutaway perspective view of the bag-shaped main part.

FIG. 7 is an enlarged vertical sectional view of a main part showing bonding of a perforated film by partial dry lamination.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Moisture absorbing base material 10 Hygroscopic agent 12 Gas permeable film S Moisture proof material 7 Perforated film 70 Micropore 71 Protrusion ring 8 Adhesive layer 80 Non-adhesive part

Claims (5)

[Claims] 1. A film or sheet-shaped hygroscopic material,
On plastic film or plastic sheet,
A moisture-absorbing substrate 1 containing a moisture-absorbing agent 10 such as a magnesium compound or silica gel, a film or sheet-like moisture-proof material S to be adhered to one surface thereof, and a plastic breathable film to be adhered to the other surface of the moisture-absorbing substrate 1 And a film- or sheet-shaped hygroscopic material. 2. The moisture-absorbing material according to claim 1, wherein the air-permeable film is a perforated plastic film 7 in which micropores 70 are formed innumerably. 3. A plastic film is applied to the other surface of the moisture-absorbing substrate 1, and then a heated needle is inserted from the surface of the film to the moisture-absorbing substrate 1 to form a fine hole 70 in which a hole is formed. 3. The moisture absorbing material according to claim 2, wherein said film is a perforated film. 4. A film or sheet-shaped hygroscopic material,
A film or sheet-shaped moisture-proof material S is applied to one surface of a moisture-absorbing substrate 1 comprising a plastic film or a plastic sheet containing a moisture absorbent 10 such as a magnesium compound or silica gel. A film or sheet-shaped hygroscopic material, wherein a perforated plastic film 7 in which micropores 70 are innumerably penetrated is adhered to the surface via a thin plastic gas permeable film 12. 5. The moisture-absorbing material according to claim 2, wherein the film is a perforated film having conductivity by containing a conductive material such as carbon or metal powder.