JP2016165878A - Gas-permeable molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas-permeable molded body that is injection-molded from a synthetic resin material, less likely to allow water permeation, and has good gas permeability.SOLUTION: An injection molded body 1 formed by filling a synthetic resin material from a gate port into an injection molding die comprises: a skin layer 1D formed of a synthetic resin film formed on a surface of the injection molded body; a gate mark end 1C formed on a first surface 1A of the injection molded body; and a skin layer removed end 1F located on a second surface 1B opposite the first surface 1A having the gate mark end 1C and formed removing the skin layer 1D on a surface facing the gate mark end 1C. A part from the gate mark end 1C to the skin layer removed end 1F is used as a gas permeation passage. The synthetic resin contains long and narrow fillers 2 and is molded by injection from the gate port, and the fillers are linearly oriented in a direction from the gate mark end 1C to the skin layer removed end 1F.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas permeable molded body that hardly permeates moisture and facilitates gas permeation.

In sealed electrochemical devices such as capacitors and lithium batteries that have an electrolyte, the electrolyte is sealed so that it does not leak out of the exterior body, so it can be repeatedly charged and discharged or left at high temperatures. When the electrolyte is decomposed by short circuit, overcharge, reverse charge, etc., gas such as hydrogen gas or carbon dioxide gas is generated in the exterior body, and the internal pressure is rapidly increased by accumulating the gas in the exterior body. The gas permeable molded body appropriately discharges the generated gas to the outside of the exterior body so as not to accumulate too much in the exterior body because the exterior body may rise or rupture. Is desired.

As the gas permeable molded body, in Patent Document 1, a material containing glass fiber, synthetic fiber, and cellulose fiber containing ceramic powder and a fusion material in a predetermined amount ratio is melted by paper making and heat treatment to form a sheet. A packing having a gas permeability or air permeability formed by punching out the sheet is proposed.

However, in the packing which is a gas permeable molded body of Patent Document 1, it is necessary to perform water repellent treatment in order to impart waterproofness, that is, water impermeability.

JP 2003-105687 A

In order to solve the above-described problems, an object of the present invention is to provide a gas permeable molded article that is less permeable to moisture and has good gas permeability without performing water repellent treatment.

The gas permeable molded body of the present invention is an injection molded body made by filling a synthetic resin material into an injection mold from a gate port, a skin layer made of a synthetic resin film formed on the surface of the injection molded body, A gate trace end formed on the first surface of the injection-molded body, and a second surface opposite to the gate trace end on the second surface opposite to the gate trace end. It is characterized by comprising a skin layer removal end portion from which the skin layer has been removed, and a portion extending from the gate trace end portion to the skin layer removal end portion is used as a gas permeation path. The invention according to claim 2 is characterized in that the area of the skin layer removal end portion of the second surface is made larger than the area of the gate trace end portion of the first surface. The invention according to claim 3 is the gas permeable molded body according to claim 1 or 2, wherein the skin layer removal end of the second surface is longer than the length from the first surface to the second surface. It is an end face of the projecting end portion that is largely projected from the second surface. The invention according to claim 4 is the gas permeable molded body according to any one of claims 1 to 3, wherein the synthetic resin material contains a plurality of elongated fillers, and is injected from a gate port. The filler is linearly arranged in the direction from the gate trace end to the skin layer removal end in the gas permeation path from the gate trace end to the skin layer removal end by filling the mold. It is characterized by. The invention according to claim 5 is the gas permeable molded article according to claim 4, wherein the filler is made of a fibrous inorganic material.

The gas permeable molded body of the present invention is an injection molded body made by filling a synthetic resin material into an injection mold from a gate port, a skin layer made of a synthetic resin film formed on the surface of the injection molded body, A gate trace end formed on the first surface of the injection-molded body, and a second surface opposite to the gate trace end on the second surface opposite to the gate trace end. It consists of a skin layer removal end from which the skin layer has been removed, and the portion from the gate trace end to the skin layer removal end is used as a gas permeation path, so use the skin layer, gate trace and skin layer removal. Thus, it is possible to provide a gas permeable molded article that hardly permeates moisture and has good gas permeability without performing water repellency treatment.

It is sectional drawing which shows a gas permeable molded object in Embodiment 1 of this invention. It is a top view same as the above It is sectional drawing which shows a mold clamping state in the formation process of a gas permeable molded object same as the above. It is sectional drawing which shows formation of a gate trace edge part by mold opening at the shaping | molding process of a gas permeable molded object same as the above. It is sectional drawing which shows formation of a skin layer removal end part in the formation process of a gas permeable molded object same as the above. It is sectional drawing which shows a gas permeable molded object in Embodiment 2 of this invention. It is sectional drawing which shows a mold clamping state in the formation process of a gas permeable molded object same as the above. It is sectional drawing which shows formation of a gate trace edge part by mold opening at the shaping | molding process of a gas permeable molded object same as the above. It is sectional drawing which shows formation of a skin layer removal end part in the formation process of a gas permeable molded object same as the above. It is sectional drawing which shows the mold open state of a slide type | mold in the formation process of a gas permeable molded object same as the above. It is sectional drawing which shows the sealing type electrochemical device to which the gas permeable molded object of this invention is applied.

The inventor of the present applicant focuses on a skin layer made of a synthetic resin film formed on a surface in contact with an injection mold in an injection molded body formed by filling an injection mold with a synthetic resin material, Synthetic resin material or liquid crystal polymer that is used as a part that suppresses the permeability of moisture and gas due to the presence of this skin layer, and further contains a large number of elongated fillers typified by fibers such as inorganic materials and metal materials By focusing on the orientation of the elongated filler and liquid crystal polymer by injection molding, and using the portion where this orientation occurs as a gas permeation path, it is difficult to permeate moisture, such as hydrogen gas or carbon dioxide gas. Developed a gas permeable molded body that makes it easy to permeate. Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
The gas permeable molded object 1 is demonstrated with reference to FIG. 1 and FIG.

1 and 2, the gas permeable molded body 1 is made of a flat injection molded body, and a skin layer 1D made of a synthetic resin film formed on the surface of the injection molded body and the injection molded body. A gate trace end 1C formed on the first surface 1A, and a surface opposite to the gate trace end 1C on the second surface 1B opposite to the first surface 1A with the gate trace end 1C. This is a gas permeable molded body comprising a skin layer removal end portion 1F from which the skin layer 1D has been removed and having a portion extending from the gate trace end portion 1C to the skin layer removal end portion 1F as a gas permeation path. The skin layer removal end portion 1F is formed on the end face of the protruding end portion 1E protruding from the second surface 1B. The protruding end portion 1E has a columnar or prismatic shape, and its height T is the first surface 1A. Larger than the length t from the first surface to the second surface 1B. Since the end face of E is larger than the area of the gate trace end 1C, the skin layer removal end 1F larger than the area of the gate trace end 1C is removed by removing the skin layer 1D on the end face of the protruding end 1E. Is formed.

The synthetic resin material of the gas permeable molded body 1 contains a large number of elongated fillers 2. By filling the injection mold from the gate port 3 (see FIG. 3), the skin layer is formed from the gate trace end 1 C. The elongated filler 2 is oriented so as to be arranged linearly in the direction from the gate trace end 1C to the skin layer removal end 1F at the part reaching the removal end 1F, and this part is used as a gas permeation path. The synthetic resin material includes thermoplastic resins such as polyamide resin, polypropylene resin, polybutylene terephthalate resin and polyphenylene sulfide resin, and thermosetting resins such as phenol resin, epoxy resin, polyimide resin and unsaturated polyester resin. A resin material may be used in combination of these or other materials. Examples of the material of the filler 2 include fibers made of glass, ceramics, inorganic materials such as clay minerals, and metal materials such as aluminum (including alloys), and the shape thereof has a diameter of 1 to 50 μm. A cylinder is desirable, and when the diameter is a short axis, it is a fiber having an elongated shape whose length in the long axis direction is 2 to 10 times the length in the short axis direction.

(Molding Step of Gas Permeable Molded Body 1 of Embodiment 1)
3 to 5 show a molding process of the gas permeable molded body 1 made of a flat injection molded body.

In FIG. 3, the upper mold A has a gate 3 through which a synthetic resin material containing a large number of elongated fillers 2 is injected, the lower mold B is a fixed mold, and the lower surface A1 of the upper mold A Is flat, and the upper surface B1 of the lower mold B is a first recess formed so as to have the shape of the gas permeable molded body 1 and a second column or prism column corresponding to the protruding end 1E hanging from the center thereof. The cavity of the injection mold is formed by the recess. In the cavity of this injection mold, the bottom B2 of the second recess is integrally formed so as to be heated at the same temperature as the lower mold B. Therefore, the upper die A moves downward, presses against the lower die B, is clamped so as to close the first recess and the second recess, and is heated at a predetermined temperature. The first and second recesses are injected and filled with a synthetic resin material containing a large number of elongated fillers 2 melted from the above. At this time, in the part from the gate port 3 to the second recess, a plurality of elongated fillers 2 are arranged in a straight line in the filling direction. Next, after finishing the filling and cooling while maintaining the pressure-holding state, the upper mold A moves upward in FIG. 4 to open the first and second recesses of the lower mold B. Since the injection molded body having a flat plate shape having the protruding end 1E is obtained and the gate trace end 1C is formed on the first surface 1A, the injection molded body is taken out from the lower mold B. Thus, an injection-molded body that becomes the gas-permeable molded body 1 having the gate trace end 1C is obtained. At this time, a plurality of elongated fillers 2 are linearly arranged in a direction from the gate trace end 1C to the projecting end 1E at the site from the gate trace end 1C to the projecting end 1E. . Further, in the injection-molded body that becomes the gas-permeable molded body 1 that is injection-molded, as shown in FIG. 5, except for the surfaces in contact with the injection molds of the upper mold A and the lower mold B, that is, the gate port 3, The surface (first surface 1A) in contact with the lower surface A1 of the upper mold A, the surface in contact with the first recess (second surface 1B) and the surface in contact with the second recess (protrusion) of the lower mold B A thin skin layer 1D made of a synthetic resin material is formed at the end 1E). However, the gas permeable molded body 1 requires a skin layer removal end portion 1F obtained by removing the skin layer 1D from the end face of the protruding end portion 1E as shown in FIG. Therefore, in FIG. 5, the gas permeable molding having the skin layer removal end 1 </ b> F by removing the skin layer 1 </ b> D on the end face of the projection end 1 </ b> E with a jig Z such as laser processing or mechanical grinding on the end face of the projection end 1 </ b> E Body 1 is obtained.

The skin layer 1D formed in the molding step of the gas permeable molded body 1 is formed on the end face of the projecting end 1E as shown in FIG. 5, but the skin layer 1D is not formed on the end face of the projecting end 1E. And will be exemplified below. 3 and 4, unlike the first embodiment, the bottom B2 of the second recess is attached to the lower mold B via a heat insulating material, and the temperature is higher than the temperature at which the upper mold A and the lower mold B are heated. The temperature is controlled so that it can be heated at a low temperature. Therefore, the upper mold A is pressed against the lower mold B so that the first recess and the second recess are closed, and the upper mold A and the lower mold B are heated at a predetermined temperature. A synthetic resin material containing a large number of elongated fillers 2 melted from the mouth 3 is injected and filled into the first recess and the second recess. At that time, the bottom B2 of the second recess is heated at a temperature lower than the predetermined temperature. Next, after the injection / filling is completed, the upper mold A and the lower mold B are cooled together with the bottom B2, and then the upper mold A moves upward to open the lower mold B, whereby the gas permeable molded body 1 is injected. A molded body is obtained. In this injection molded body, the skin layer 1D such as the first surface 1A and the second surface 1B is not formed on the end surface of the protruding end portion 1E, and the so-called skin layer 1D is removed. Yes. By using the bottom B2 of the second recess, it is not necessary to remove the skin layer 1D by laser processing and mechanical grinding the end surface of the protruding end 1E as shown in FIG. The gas permeable molded object 1 which has the part 1F is obtained.

A synthetic resin material containing a large number of elongated fillers 2 is filled into an injection mold, and a gas permeation path with good gas permeability is obtained by the linear orientation of the fillers 2. However, the property of aligning along the flow direction in the molding of the liquid crystal polymer may be utilized. That is, a thermoplastic liquid crystal polymer is formed into a molded body with an injection mold, and is injected from the gate port 3 toward the projecting end 1E having the skin layer removal end 1F, and from the gate trace end 1C to the skin layer removal end 1F. The part leading to is a gas permeation path. Examples of the material of the thermoplastic liquid crystal polymer include polyester-based liquid crystal polymers, and other synthetic resin materials exemplified in Embodiment 1 may be blended.

(Embodiment 2)
FIG. 6 shows a gas permeable molded body 11 having a skin layer removal end portion 11F different from that of the first embodiment.

In FIG. 6, the gas permeable molded body 1 is made of a flat injection molded body made of the same material as that of the first embodiment, and a skin layer 1D made of a synthetic resin film formed on the surface of the injection molded body. The gate trace end 1C formed on the first surface 1A of the injection molded body and the gate trace end 1C on the second surface 1B opposite to the first surface 1A where the gate trace end 1C is located The skin layer removal end portion 11F from which the skin layer 1D on the opposite surface has been removed is formed, and a portion from the gate trace end portion 1C to the skin layer removal end portion 11F is used as a gas permeation path. As in the first embodiment, the skin layer 1D is removed to be larger than the region of the gate trace edge 1C. The skin layer removal end portion 11F is flush with the second surface 1B, and the protruding end portion 1E as in the first embodiment is not formed.

(Molding Step of Gas Permeable Molded Body 11 of Embodiment 2)
7 to 10 show a molding process of the flat gas permeable molded body 11.

In FIG. 7, the upper mold A has a gate port 3 through which a synthetic resin material containing a large number of elongated fillers 2 is injected, and the lower mold is a fixed mold with respect to the upper mold A. Are formed of slide molds C and D that open and close on the base E to the left and right. The lower surface A1 of the upper mold A is flat, and the upper surfaces C1 and D1 of the slide molds C and D to be the lower mold are recessed so as to have the shape of the gas permeable molded body 1 in its closed state, and A cavity of the injection mold is constituted by the half-shaped recesses C2 and D2 having a shape corresponding to the undercut portion 4 depending from the center. The slide molds C and D are respectively provided with ejector pins E1 and E2 that are movable up and down from the bottom of the base E. The slide molds C and D are closed, and the upper mold A moves downward so that the recesses (the recesses formed so as to have the shape of the gas permeable molded body 1 and the half-shaped recesses C2 and D2) are formed. In a state where the mold is clamped so as to be closed and heated at a predetermined temperature, a synthetic resin material containing a large number of elongated fillers 2 melted from the gate port 3 is injected and filled into the recess. Next, after the filling and cooling, in FIG. 8, the upper mold A is moved upward and the mold is opened to form a flat plate-like first surface 1A on which the gate trace end 1C is formed. The body is obtained. Next, in FIG. 9, by operating the ejector pins E1 and E2 so as to protrude above the upper surfaces C1 and D1 of the slide molds C and D, the undercut portion is formed from the second surface 1B of the injection molded body. 4 is separated, the skin layer 1D is removed, and a skin layer removal end portion 11F that is flush with the second surface 1B is formed. Next, in FIG. 10, the slide molds C and D are opened to the left and right together with the ejector pins E1 and E2 on the base E, whereby the undercut portions 4 remaining in the half-shaped recesses C2 and D2 of the slide molds C and D are obtained. Are removed from the halved recesses C2 and D2. Examples of the removing method include blowing or sucking air or ejecting operation (not shown) with ejector pins similar to the ejector pins E1 and E2. When the projecting end portion 1E as shown in FIG. 6 is used as the skin layer removing end portion 11F that is flush with the second surface 1B, the undercut portion 4 is not used and the projecting end portion 1E The base may be ground with a jig such as laser processing or mechanical grinding to form the skin layer removal end portion 11F that is flush with the second surface 1B. No processing is required.

(Use of gas permeable molding)
FIG. 11 shows a gas permeable molded body of the present invention formed on an exterior body of a sealed electrochemical device having an electrode element and an electrolyte solution, and water generated in the exterior body by blocking moisture such as water vapor. An example of application to a sealed electrochemical device that facilitates discharge to the outside will be shown.

FIG. 11 shows a sealed electrochemical device in which a pair of electrode terminals 6 are arranged side by side on a lid body 5 of the exterior body. This sealed electrochemical device is a capacitor (electrolytic solution 8), a lithium battery, etc. A sealed electrochemical device in which a lid 4 of an exterior main body made of a synthetic resin material having an elliptical shape or a rectangular shape is joined so as to close a cylindrical or rectangular box-shaped case 51 having an open end. Of the exterior body. In the interior sealed by the exterior body, the connection portion 61 of the electrode terminal 6, the lead 62 electrically connected to the connection portion 61, the electrode element portion 7 electrically connected to the lead 62, and the electrolyte 8 are sealed. Is contained. Thus, in a sealed electrochemical device such as a capacitor or a lithium battery having the electrode element portion 7 and the electrolytic solution 8, the electrolytic solution 8 is sealed so as not to leak out. Repeatedly, left at high temperature, or the electrolyte solution 8 is decomposed by short circuit, overcharge, reverse charge, etc., and gas such as oxygen and carbon dioxide is generated, and the internal pressure rapidly increases due to accumulation of the gas. Since the exterior body may rise or rupture, the lid body 5 has a gas transmission function so that the generated gas does not accumulate in the exterior body. It is possible to prevent the gas from being continuously accumulated by being discharged to the outside of the exterior body by appropriately forming the through hole 5A and the through hole 5A. However, since moisture such as water vapor easily flows into the exterior body only with this through hole 5A, it is necessary to make it difficult for moisture to permeate in this sealed electrochemical device and to allow gas to permeate.

Accordingly, the lid 5 of the exterior body shown in FIG. 11 is made of a metal material such as aluminum (including its alloy) or stainless steel, and a through hole 5A is formed at the center position thereof. The gas permeable molded product of the present application is used. Examples of the method using the gas permeable molded body include a method in which the gas permeable molded body 1 is molded, welded, or adhesively bonded integrally with the lid body 5 so that the protruding end portion 1E of the gas permeable molded body 1 is disposed in the through hole 5A of the lid body 5. it can. In the gas permeable molded body 11 that does not have the protruding end 1E and the skin layer removal end 11F is formed flush with the second surface 1B, the skin layer removal end 11F is the lid 5. The closed-type electrochemical device which is arranged so as to close the through-hole 5A and is made to adhere to the lid body 5 by molding, welding or adhesive bonding integrally with the lid body 5, thereby making it difficult for moisture to permeate and gas to permeate easily. Can be provided.

Thus, in Embodiments 1 and 2, a gas permeable molded body made of a flat injection molded body is shown, but even a gas permeable molded body made of an injection molded body having an uneven surface shape. Good.

The gas permeable molded product of the present invention can be used as a packing as described in Patent Document 1, but is particularly useful as a sealed electrochemical device such as a capacitor or a lithium battery having an electrolytic solution in a sealed main body.

DESCRIPTION OF SYMBOLS 1,11 Gas permeable molded object 1A 1st surface 1B 2nd surface 1C Gate trace edge part 1D Skin layer 1E Projection edge part 1F Skin layer removal edge part 2 Filler 3 Gate part

Claims (5)

An injection molded body formed by filling an injection mold with a synthetic resin material from a gate port, a skin layer made of a synthetic resin film formed on the surface of the injection molded body, and a first surface of the injection molded body And a skin layer removal end formed by removing a skin layer on a surface opposite to the gate trace end on the second surface opposite to the first surface where the gate trace end is formed. A gas permeable molded body characterized in that a portion from the gate trace end to the skin layer removal end is used as a gas permeation path. 2. The gas permeable molded article according to claim 1, wherein an area of the skin layer removal end portion of the second surface is larger than an area of the gate trace end portion of the first surface. The skin layer removal end portion of the second surface is an end face of a protruding end portion that protrudes from the second surface to be larger than a length from the first surface to the second surface. 3. A gas permeable molded article according to 1 or 2. The synthetic resin material contains a large number of elongated fillers, and the filler is filled in the gas permeation path from the gate opening to the injection mold and from the gate trace end to the skin layer removal end. The gas permeable molded product according to any one of claims 1 to 3, wherein the gas permeable molded product is linearly arranged in a direction from a gate trace end to the skin layer removal end. The gas permeable molded article according to claim 4, wherein the filler is made of a fibrous inorganic material.

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