JP2976117B2 - Method of manufacturing ribbed separator and manufacturing equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a ribbed separator for a storage battery and an apparatus for manufacturing the same.

[Conventional technology]

The following production method is known as a conventional method for producing a ribbed separator. That is, (a) by an extrusion molding machine,
A compound composed mainly of a polyolefin-based resin and mixed with settling silica and a pore-forming agent is heated and melted, and is extruded from a die with a screw. A separator with ribs is manufactured by extracting and removing the pore-forming agent with a solvent.
(B) The above compound is heated and melted by an extruder, and the compound is extruded by a screw into a relatively thick flat molded sheet member from a die. The sheet is rolled to a predetermined thickness while passing between a pressure roll having grooves formed in parallel with a plurality of annular concave grooves for forming and a pressure roll having a flat peripheral surface opposed thereto, and the grooves are formed at the same time. Forming a ribbed separator to form a plurality of parallel ribs according to these concave groove shapes by projecting the flesh of the sheet into a plurality of parallel annular rib forming concave grooves of the pressure roll, Next, a method for producing a ribbed separator by removing the pore-forming agent with a solvent. (C) The compound is heated and melted by an extruder, and the compound is extruded with a screw into a flat molded sheet member from a die, and then cooled and solidified. A plurality of parallel, semi-molten molded rib members extruded by a separate extruder are guided by grooved pressure rolls and pressed between opposing pressure rolls, and then pressed together. A method for producing a ribbed separator by removing the pore-forming agent by treating with an organic solvent in the same manner as in the above.
Alternatively, (d) a separately prepared rib member such as a string is pressed against a microporous flat sheet member surface made of a nonwoven fabric made of synthetic resin fiber or the like with a pair of pressure rolls via an adhesive. There is a method of manufacturing a separator by attaching a rib by sticking.

[Problems to be solved by the invention]

The conventional methods for manufacturing a ribbed separator described in (a) to (d) have the following disadvantages.

That is, since high-temperature resistance is required as a ribbed separator for a recent automobile storage battery, in order to satisfy this request, the above-described compound mainly composed of ultra-high-molecular-weight polyethylene having particularly high-temperature resistance is used as a material. When the ribbed separator is manufactured by the manufacturing methods of (a) and (b), the ribbed separator is formed along the ribs during its production or after storage, handling, or in use in a battery. It is often seen to tear. When the cause was clarified, when the ribs were integrally molded in the production of (a) and (b), particularly, the ultra-high-molecular-weight polyethylene had poor moldability. It is extremely difficult to extrude and mold a ribbed separator at once. Further, according to the manufacturing method (b), when a flat molded sheet member is rolled, it is relatively difficult to form a part of the meat into a protruding groove in the multiple grooves of the grooving roll. Not only that, the pair of pressure rolls makes a large difference between the pressure applied to the rib forming portion and the pressure applied to the flat sheet base surface between these rib forming portions. Since a large pressure is applied, the base surface of the sheet tends to have a crystal orientation in its longitudinal direction, whereas a small pressure is applied to the rib forming portion. Difference can be made. As a result, the formed ribbed separator is apt to be torn in the stretching direction between the rib formed portion and the sheet base surface portion, and during the handling of the manufacturing process and after assembly of a storage battery, or use as a separator. It has been observed that cracks often form along the ribs.

Further, in the manufacturing method (c) described above, since the molded rib member in a semi-molten state is simply pressed to the surface of the cooled and solidified molded sheet member by a pair of pressing members, the fusion bonding property between the two members is reduced. Since there is no rib, there is a disadvantage that the rib is easily peeled off from the sheet surface due to an impact received thereafter or contact with another object. Further, the manufacturing method (d) requires the use of an adhesive, which is troublesome and uneconomical to manufacture, and also brings about a disadvantage that the bonded portion is easily peeled off by impact or contact with other objects.

[Means for solving the problem]

The present invention solves the above-mentioned various disadvantages of the ribbed separator manufactured by the above conventional manufacturing method, does not peel off the ribs, and uses an ultrahigh molecular weight resin such as ultrahigh molecular weight polyethylene as a molding material. Also, without producing cracks as in the past, stable and good production can be performed, eliminating production loss,
Further, the present invention provides a method for producing a ribbed separator which is stable and robust even when used at a high temperature in a storage battery such as an automobile storage battery. A compound formed by mixing a body and a pore-forming agent with heat melting and forming a flat molded sheet member with at least one kind of synthetic resin alone or a plurality of parallel forming rib members formed by heating and melting the compound; The two members are press-bonded to each other through a pair of pressure rolls facing each other at a predetermined interval in a semi-molten state to form a ribbed molded sheet, which is then cooled and then opened. In producing the ribbed separator by removing the agent, the plurality of parallel semi-molten molded rib members are heated to one side by forming a plurality of parallel annular guide grooves on the peripheral surface. groove The pressurizing roll and the guide are guided on the semi-molten molded sheet member surface while being fitted in the respective annular guide grooves, and are passed between the other heated pressurizing roll and parallel to the molded sheet portion. A method for producing a ribbed separator, comprising rolling and binding a molded rib member with a substantially uniform pressure.

Further, the second invention provides an apparatus for producing the ribbed separator of the present invention, wherein the die of the extruder comprises a flat sheet member forming die and a plurality of parallel rib member forming dies. And a semi-molten molding sheet and a plurality of parallel semi-molten molding rib members extruded from these dies, respectively, in front of the composite die. A pair of pressure rolls having a pair of heating means for pressing and binding while maintaining a semi-molten state with each other are disposed facing each other at a predetermined interval, and a cooling device is provided in front of the pressure rolls.

Further, the third invention provides an apparatus which is convenient for manufacturing the ribbed separator of the present invention by using different materials for the rib and the separator, and provides an extruder having a flat sheet member forming die. Extrusion molding machine provided with a molding machine and a plurality of parallel rib member molding dies, and a press roll provided with a pair of heating means immediately in front of the respective dies, the respective dies being arranged in close proximity to each other. Are arranged at predetermined intervals, and a cooling device is provided in front of them.

(Operation)

In the above manufacturing method of the present invention, since the formed rib members as well as the formed sheet members are pressure-bonded together in a semi-molten state, the contact surface of each formed rib member and the contact of the formed sheet in the semi-molten state The surfaces are merged with each other and then solidified by cooling in this fusion-bonded state, so that a stable rib-formed sheet molded body in which the respective rib members are firmly bonded to the molded sheet member and are not easily separated can be obtained. Thus, in the next step, the pore-forming agent is extracted and removed by the solvent, but the microporous treatment is smoothly and smoothly provided without fear of peeling of each rib material during such treatment, and thus the stable ribbed separator is provided. Is obtained.

In this case, in joining each formed rib member to the formed sheet member, one heated grooved roll formed by forming a plurality of parallel annular guide grooves on the peripheral surface is used,
Each of the forming rib members in the semi-molten state is guided to the surface of the forming sheet in the semi-molten state while being fitted into the corresponding annular guide groove of the grooved roll, so that these forming ribs are positioned at predetermined positions. In addition to the member being provided, the other pressing roll that presses the flat molded sheet member facing the semi-molten state from the outside is also heated, so that both members are heated by a pair of heated members. Since good rolling pressure bonding can be performed while the semi-molten state is well maintained by the pressure roll, the production of the separator in which the formed rib members are firmly bonded is ensured. In this case, when a synthetic resin such as ultra-high-molecular-weight polyethylene such as ultra-high-molecular-weight polyethylene alone or a compound molding material containing the same as a main component is used, a pair of heated pressure rolls forms a molding rib member. Each of the molded sheet members is given an appropriate pressure and temperature necessary for crystallization. Thus, when substantially the same pressure and temperature are applied to the molded sheet member and the molded rib member parallel to the molded sheet member, substantially identical crystal orientation can be generated in these members. And a good-quality ribbed separator with good stability and no risk of being drawn in the stretching direction.

When using the compound, ultra-high molecular weight synthetic resin
A mixture of 40 to 60% by weight of an inorganic powder and 40 to 60% by weight of an inorganic powder mixed with 30 to 60% by weight of a pore-forming agent facilitates molding.
Good and a good quality ribbed separator with small electric resistance can be obtained.

In this case, both the molded rib member and the molded sheet member are 140
By heating and pressing through a pair of pressure rolls heated to 100-140 ° C in a semi-molten state at ~ 170 ° C, good roll forming can be obtained with relatively small pressing force, and ultra-high polymer synthetic resin Alternatively, when a compound mainly composed of the compound is used as a molding material, the crystallization can be favorably obtained.

In the above manufacturing apparatus of the present invention, since a composite die incorporating a sheet member molding die and a plurality of parallel rib member molding dies is used as a die of an extrusion molding machine,
One molding machine is sufficient, and the manufacturing equipment and occupied space are small. Further, since a pressure roll provided with a pair of heating means is disposed immediately before the composite die, by setting the required temperature, a plurality of extruded parallel rib members are mutually in a semi-molten state. The separator with pressure can be bonded to the separator, and a stable ribbed separator with no rib members peeled off can be manufactured smoothly.

In addition, as another manufacturing apparatus, an extruder for forming a rib member and an extruder for forming a flat sheet member are prepared, and the respective die for forming a rib member and the die for forming a sheet member are arranged adjacent to each other, By disposing a pair of pressure rolls in the immediate vicinity and further arranging a cooling device adjacent thereto, the ribbed separator of the present invention can be obtained by the same operation as when the above-mentioned composite die is used.

In this case, when one of the pair of pressure rolls is constituted by a grooved pressure roll and the heating means is incorporated therein, and the other pressure roll is incorporated with the heating means, a semi-molten shaped rib member is provided. Can be disposed at predetermined intervals on the surface of the semi-molten molded sheet member, and both can be pressure-bonded to each other in a favorable semi-molten state. In this case, steam, an electric or electronic heater is used as the heating means, and the surfaces of the pair of pressure rolls are heated to a desired temperature.

〔Example〕

Next, an embodiment of a method for manufacturing a ribbed separator according to the present invention will be described with reference to the accompanying drawings, together with an embodiment of the manufacturing apparatus.

FIG. 1 shows an extruder 1 used in an example of a production apparatus (seventh illustration) for implementing the method for producing a ribbed separator of the present invention, and the extruder 1 has a screw inside. It comprises a heating body 2 and a die 3. As a molding material, for example, ultra-high molecular polyethylene, polyethylene,
A hopper of the extruder 1 is made of a compound mainly composed of a thermoplastic synthetic resin typified by a polyolefin-based synthetic resin such as a copolymer, and mixed with an inorganic powder and a pore-forming agent at an appropriate ratio. (Not shown), the mixture is heated and melted by a heating cylinder, and the melted compound is fed and fed to a die 3 in front by a screw therein.

As the inorganic powder, sedimentable silica powder, diatomaceous earth, carbon black, alumina, calcium carbonate, kaolin, talc, titanium oxide, and the like are used, and preferably, fine powder having a size of 20 μm or less is used.

The pore-opening agent may be any substance soluble in water or an organic solvent, but is preferably a motor oil, a mineral oil such as liquid paraffin, a vegetable oil such as soybean oil, linseed oil, or an ester such as a phthalate ester. , Glycols and the like are used.

According to the invention, in particular the die 3 comprises a composite die as follows. That is, the die 3 is provided with a passage 5 extending in the width direction on both sides in a front portion of the neck supply passage 4 of the cylinder body 2 of the extruder 1, and a wide narrowing passage which becomes narrower as it goes below the passage 5. A rib member forming die composed of a multiplicity of string-shaped manifold passages 6, 6, ... hanging down at a fixed interval via 5a and forming nozzles 7, 7, ... at the tips thereof.
3a and the rear part of the supply passage 4, a passage 8 extending in the width direction on both sides, a flat sheet passage 9 having an appropriate predetermined width hanging therefrom, and a slit-shaped nozzle 10 opening on the lower surface thereof.
And a flat die 3b for forming a sheet member composed of the following components.

Each string-like passage 6 of the rib member forming die 3a is provided with a nozzle 7
An orifice 14 is formed by opposing an adjusting screw 12 for making the passage freely squeezable and a recess 13 facing the adjusting screw 12 so that the squeezing can be appropriately adjusted by the adjusting screw 12.
In the lower part of the flat sheet passage 9 near the opening of the die 3b for forming a sheet member, a choke bar 15 extending horizontally over the entire width thereof and a number of abutting against the back surface thereof for moving the choke bar 15 forward and backward. And a lip bar 17 extending horizontally over the entire width thereof, and a number of lip adjusting bolts 18 abutting on the rear surface thereof. Thus, each of the adjusting screws 12 is
The adjusting bolts 16 and 18 which are screwed in from the front surface and arranged above and below are screwed from the rear surface, so that they can be easily reached and adjusted easily.

The ribbed separator manufacturing apparatus M of the present invention includes a pair of pressure rolls 19, 20 in the vicinity of directly below the composite die head 11 with a slight distance of, for example, about 15 to 20 cm, in addition to the extruder 1. Are arranged before and after at a predetermined interval, and a cooling device 21 is provided adjacent to the pair of pressurizing rolls 19 and 20. In the illustrated example, a cooling roll is provided.
One of the pair of pressure rolls 19, 20 is fitted with a plurality of semi-molten parallel molding rib members a, a, ... which are extruded from the rib member molding die 3a. A plurality of annular guide grooves 19a, 19a,... Arranged in parallel with each other at corresponding positions on the peripheral surface thereof for joint guiding were formed in a grooved pressure roll. A semi-molten molded sheet member b extruded from the sheet member molding die 3b is supported from the back surface and has an opposing peripheral surface that is pressed toward the pressure roll 19. The other pressure roll 20 is provided between the grooved pressure roll 19 and the pressure roll 20 which are opposed to each other, and a semi-molten molded rib member a, a,. b.

In this case, according to the present invention, these semi-molten members
a and b are not cooled and solidified at the time of pressurization by the pair of pressurizing rolls, so that a good rolling binding can be obtained in a state where the semi-molten state is well maintained. In the case of a resin, a steam or electric heater connected to a heating source is provided inside each of the pair of pressure rolls 19 and 20 so that the resin can be heated to a desired temperature so that the crystallization can be performed well. And the pressurizing rolls 19 and 20 having a pair of heating means capable of raising the pressurizing surfaces of the pair of pressurizing rolls 19 and 20 to a desired temperature. For example, this causes a pair of pressure rolls 19 and 20 to be heated at about 100 ° C.
Heat to about 140 ° C.

The width and depth of each annular guide groove 19a of the grooved pressure roll 19 are just fitted, taking into account the thickness of the molded sheet member and the cross-sectional shape and height of the molded rib member in the semi-molten state, and It is preferable that the molded sheet member is designed so that it can be rolled with the same narrow pressure when pressed.

The cooling roll 21 is cooled by cooling water passing through a built-in cooling passage, and on its peripheral surface, passes through the pair of heated pressure rolls 19 and 20 to cool a rolled formed sheet that has been roll-formed. Then, the integrally bonded state of the formed rib member and the formed sheet member is solidified as it is, whereby the formed sheet with a stable and good rib in which each formed rib member is firmly bonded to the sheet member surface. Is obtained. Thereafter, this is subjected to extraction and removal of the pore-forming agent through a solvent bath and a drier and a heat-drying process, though not shown, in a conventional manner.
The ribbed separator of the present invention is obtained.

Next, an example of manufacturing the ribbed separator of the present invention using the above-described manufacturing apparatus of the present invention will be described.

As a molding material to be charged into a heating body 2 of the molding machine from a hopper (not shown) of the extrusion molding machine 1, generally, a main material is a synthetic resin, and an inorganic powder and a pore-forming agent are mixed with the main material. Use a compound consisting of The compounding ratio of the compound is 40-60% by weight of synthetic resin, 40-60% of inorganic powder.
% By weight, preferably in the range of 30 to 60% by weight based on the total amount of these. If the compounding amount of the synthetic resin is less than 40% by weight, the shape of the molded sheet of the compound cannot be maintained, and if the compounding amount exceeds 60% by weight, the electric resistance becomes high. Is preferred.

When the amount of the inorganic powder is less than 40% by weight, it is not possible to adsorb and hold the liquid pore opening agent sufficient to obtain a good microporous separator, and the compound is in a granular state which can be easily put into an extrusion molding machine. And the molding workability is lowered, and the hydrophilicity of the separator is lowered. On the other hand, if it exceeds 60% by weight, the fluidity during extrusion melting is poor, and the resulting molded article tends to be brittle. Therefore, it is preferable to use within the above range.

If the amount of the pore-forming agent is less than 30% by weight, the contribution to the formation of microporosity of the microporous separator decreases, and a sufficient porosity cannot be obtained. On the other hand, if it exceeds 60% by weight, extrusion molding becomes difficult, and sufficient mechanical strength cannot be obtained in the molded sheet. Therefore, it is preferable to use within the above range.

The following describes a production example of a tough, thin ribbed separator having high electric resistance, no cracks, and low electric resistance.

Select from the ranges of the respective compounding amounts described above. For example, 50% by weight of ultra-high-molecular-weight polyethylene as a synthetic resin, 50% by weight of a precipitating silica fine powder as an inorganic powder, and liquid paraffin as a pore-forming agent with respect to a mixture thereof. 40% of each compound was mixed and mixed well, and the mixture was extruded using the extruder 1
And heated by the heating cylinder to heat and melt the ultra-high-molecular-weight polyethylene, that is, to form a heated melt of the compound, and to knead the softened compound with an internal screw. Are fed to the composite dies 3a, 3b of the composite head 11, and the orifice-shaped nozzles 7, 7,... Of the front die 3a are extruded to form string-shaped rib members a, a, a. The flat sheet member b is extruded from the formed sheet nozzle 10.
Thus, a plurality of extruded parallel molded rib members a, a,... In the semi-molten state and the molded sheet member b in the semi-molten state are heated to a pair of heated pressure rolls immediately below the composite rib. Pass between 19 and 20. The interval between the pressure rolls 19, 20 is set in advance so that substantially the same degree of compression is applied to the formed rib members a, a,... Having a predetermined thickness and the formed sheet member b having a predetermined thickness. I have. In this case, the pressure roll 19 receives the respective semi-molten molded rib members a, a,... Through the annular guide grooves 19a, 19a. , a,... are guided to a predetermined position on the softened surface in the semi-molten state of the formed sheet member b and are rolled together with the sheet member, so that the members a and b are fused and bonded to each other. In this case, the pair of pressure rolls 19 and 20 are
When heated to about 140 ° C., the two members a and b are sufficiently roll-formed with a relatively low pressing force, and the formed sheet member b and the formed rib members b, b,. Equal crystal orientation is obtained and a good quality ribbed molded sheet is obtained. Immediately after the sheet passes through the pair of heated pressure rolls 19 and 20, the sheet is cooled while being brought into contact with and transferred to the peripheral surface of the next cooling roll 21, and is strongly pressed in its semi-molten state. In a state of being bonded and in a uniform crystallization arrangement, the whole of the formed sheet member b and each of the formed rib members a are firmly bonded together by cooling and solidifying, and a stable and high-temperature-resistant formed sheet with ribs is formed. A compact M is obtained. Next, this compact M
Is immersed and passed through a solvent in an extraction solvent tank by a conventional method, thereby removing most of the fine particles of the opening agent finely dispersed and mixed in the molded product M, and forming a myriad of microporous holes on the trace. Generate evenly. Next, this is guided to a dryer and dried by heating, and then cut to a predetermined size to obtain the high temperature resistant ribbed separator of the present invention. In place of the above continuous production method, the elongated rib-shaped molded sheet M is cut into a predetermined separator size, and the obtained rib-shaped molded sheet M is suspended and held in an extraction solvent tank. And the product of the present invention may be obtained by treating with a dryer.

FIG. 9 shows a ribbed separator P of the present invention. The ribbed separator P is a tough and stable product in which a large number of parallel ribs B, B,... Are fused and bonded as if integrally formed on a microporous sheet A mainly composed of ultra-high-molecular-weight polyethylene. It is. In this product example, since the raw material is the compound described above, each rib B is also obtained with microporosity.

In order to manufacture the ribbed separator of the present invention by using a material different from the material of the porous sheet A and the material of the rib B, an extrusion molding machine equipped with a rib member back molding die 3a as shown in FIG. 1 'and an extruder 1 "provided with a sheet member forming die 3b, and a pair of extruders 1a and 3b are arranged in the same manner as in FIG. It can be manufactured by using the ribbed separator manufacturing apparatus of the present invention in which the heated pressure rolls 19 and 20 and the cooling roll 21 are provided.
Any cooling device 21 such as a cooling box may be used.

Thus, for both extruders 1 ', 1 ", the same material may be used as the respective molding material, but it is generally preferred to use different materials, ie, for example, for forming one rib member. One or two or more synthetic resins are used alone as a raw material for the extrusion molding machine 1'.Generally, a general polyolefin resin, ultra-high-molecular-weight polyethylene, or the like is used as a raw material, and this is supplied to the heating cylinder 2. In the other extruder 1 "for forming a sheet member, the above-mentioned compound is used as a molding material, which is put into a heating cylinder 2 and heated and melted. Extrude more. The extruded plurality of parallel forming rib members a, a,... And the forming sheet member b are respectively heated in a semi-molten state in a pair of heating and pressing rolls 19, 20 in front thereof.
Then, the semi-molten ribbed formed sheet is cooled by the cooling roll 21, and the integrally bonded state is solidified as it is to obtain a ribbed formed sheet M. By removing the porosity with a solvent and drying with a drier, nonporous rib members A, A,
Are firmly bound to obtain a ribbed separator P. The separator P is wound around a winding drum (not shown) via a guide roll 22.

Here, as the synthetic resin raw material, a polyolefin resin is generally preferably used, and a copolymer of simple species ethylene such as polyethylene, polypropylene, polybutadiene and vinyl acetate or the like may be used alone or in combination of two or more. Can be used.

Also, ultra-high molecular weight synthetic resin refers to those having a weight average molecular weight of about 1,000,000 or more, and in the case of ultra-high molecular weight polyethylene, about
Use one in the range of 1 to 3.5 million.

As a modified example of the pressure roll 20, a grooved pressure roll 19
By disposing a slightly protruding ridge 20a at a position facing each annular guide groove 19a on the surface facing the
The mutual bonding between the semi-molten formed rib members a and the semi-molten surface of the semi-molten molded sheet can be further strengthened.

 Next, a more detailed embodiment will be described.

Example As a molding material, 25% by weight of ultra-high-molecular-weight polyethylene having a weight average amount of 2,000,000, 25% by weight of precipitated silica fine powder, and 50% by weight of a paraffin-based oil as a pore-forming agent were added to the total of these. Prepare a compound consisting of a mixture,
The compound is put into the twin-screw extruder 1 shown in FIG. 1, the resin is heated and melted at 240 to 260 ° C., and the compound is kneaded, and then a number of string-like ribs are formed from the composite die 3 (3a, 3b). The member and the film-like sheet member are simultaneously extruded and formed, and a large number of the parallel forming rib members a, a, in the range of 140 to 170 ° C. in the semi-molten state in the range of 140 to 170 ° C. Immediately through the pair of pressure rolls 19 and 20 heated to a temperature in the range of 100 to 140 ° C., the substantially uniform 200 to 700 kg / cm ² is mutually bonded to the molded sheet member b by pressing force. ,
A semi-molten molded rib member on the semi-molten surface of the molded sheet member b
a, a,… are fused together. The ribbed formed sheet thus obtained is cooled and solidified on the peripheral surface of the cooling roll 21 to firmly fix the strong binding between the two members, and then passed through a solvent bath (not shown) to be finely and finely. Most of the myriad of paraffinic oils dispersed and mixed were dissolved and removed to obtain the microporous ribbed separator of the present invention in which the paraffinic oil remained slightly.

For comparison, an extruder for forming sheet members
Using the same compound as above as the raw material, the conventional (b)
A ribbed separator was manufactured by the manufacturing method described. That is,
The sheet member is extruded by a sheet member forming extruder, and between the non-heated rib forming grooved pressure roll and the non-heated flat pressure roll while the formed sheet member is in a semi-molten state. After passing through, the sheet member is strongly pressed to compress the member, and a plurality of parallel ribs are formed so as to protrude, and the rib-formed sheet molded body is roll-formed, and then cooled and solidified as a whole. In the same manner as described above, the mixture was passed through a solvent bath to remove paraffinic oil in the same manner as described above to obtain a ribbed separator.

Next, various characteristics of the ribbed separator according to the present method and the ribbed separator according to the conventional method described above were measured. The results are shown in Table 1 below.

As is clear from the above table, the thickness and the rib height of the product of the present invention and the conventional product are almost the same, but the ratio of the stretching direction and the transverse direction of the product of the present invention is almost the same in the tensile strength and elongation. In contrast, the conventional product has a tensile strength that is significantly larger in the stretching direction than that in the transverse direction, and its elongation is smaller than that in the transverse direction. A large difference is observed, and this property proves that a ribbed separator is easily torn in the lateral direction.

As a result of various tests and investigations, when the ratio of the tensile strength in the stretching direction to the tensile strength in the transverse direction of the tensile strength is 1.3 or more, it is easy to tear along the direction along the rib, and to less than 0.1.
Within the range of 8 to 1.2, it was considered that generation of such cracks could be prevented, and a stable ribbed separator could be obtained.

Incidentally, in the embodiment of the production method of the present invention, the pressure roll 1
According to 9 and 20, pressure was applied so that the compression ratio of the formed sheet member and the compression ratio of the formed rib member on the formed sheet member became the same value as shown in Table 2 below.

[Effects of the Invention] As a molding material, a compound formed by mixing an inorganic powder and a pore-forming agent with a synthetic resin as a main component is heated and melt-molded to form a flat molded sheet member with at least one synthetic resin alone or A plurality of parallel forming rib members formed by heating and melt-forming the compound are pressed and bound to each other through a pair of pressure rolls facing each other at a predetermined interval in a semi-molten state and the ribs are joined. In order to form a molded sheet with a sheet, then cool it, and then remove it with a pore-forming agent to produce a ribbed separator, the plurality of parallel molded rib members in a semi-molten state are surrounded by a peripheral surface. A plurality of parallel annular guide grooves are formed on one of the heated pressure-provided rolls with grooves, while being fitted into the respective annular guide grooves, guided onto the semi-molten state of the formed sheet member while heating. The other Between the pressurizing roll, the forming sheet portion and the forming rib member parallel to the forming so as to be rolled and bound at a substantially uniform pressure, such a pair of heated pressurizing rolls, these The semi-solid molded rib member can be guided to each predetermined position on the surface of the semi-molten molded sheet member, and can be satisfactorily bonded to the molded sheet member with a relatively low pressing force. Both the member and the forming rib member can be securely held in a semi-molten state, and sufficient rolling and forming binding can be performed. Therefore, after cooling, when the pore-forming agent is removed and dried by a solvent, the rib member is not peeled off from the molded sheet member at all. The ribbed separator of the present invention can be manufactured without manufacturing loss, and can be used stably and robustly for battery assembly.

In addition, when a high-molecular synthetic resin is used as a material for the two members, by uniformly heating and pressing the molded sheet member and the molded rib member, it is possible to obtain good crystallization and uniform crystallization. As a result, a stable, good-quality, high-temperature-resistant ribbed separator that does not easily tear in the stretching direction can be obtained, and provides a long service life when used in a battery.

In this case, when the temperature of the semi-molten state of each of the forming rib member and the forming sheet member is set in the range of 140 to 170 ° C, and the heating temperature of the pair of pressure rolls is set in the range of 100 to 140 ° C, Good rolling binding can be performed with a relatively small pressing force, and good crystallization can be obtained from the ultrahigh molecular weight synthetic resin.

In addition, as a molding material, when using a compound mainly composed of an ultra-high molecular weight synthetic resin as a molding material as described above,
40-60% by weight of super-polymer synthetic resin and 40-60% by weight of inorganic powder
If a compound obtained by mixing and mixing 30 to 60% by weight of a pore-forming agent with respect to the whole is used, it is possible to obtain a good-quality ribbed separator having good molding operation and moldability and low electric resistance. .

Thus, the manufacturing apparatus for a ribbed separator that carries out the method for manufacturing a ribbed separator of the present invention described above includes a composite die formed by incorporating a sheet member forming die and a rib member forming die into one. Use an extruder equipped with a die or an extruder for forming a sheet member and an extruder for forming a rib member. And, immediately in front of the respective adjacent dies, that is, a pair of opposing pressure rolls is disposed at a short distance where the two-part molded members extruded from these dies are still in a semi-molten state, The formed sheet member and the plurality of formed rib members which are respectively formed by extrusion from the dies provided together can be press-bonded to each other in a semi-molten state. Also, in this case, by incorporating an arbitrary heating means such as steam or an electric or electronic heater for heating and heating the pair of pressure rolls to a desired temperature, the pressure bonding can be performed more easily and favorably. Has effects that can be performed. In this case, one of the pair of pressure rolls is a pressure roll with a groove, and the pressure roll with the groove protrudes to a position facing the plurality of annular guide grooves on a surface of the other pressure roll facing the other. If a plurality of projecting ridges are used, the pair of pressure rolls further press the mutual pressure bonding surface between the plurality of semi-molten rib members and the semi-molten molded sheet member. It has the effect of being able to favorably produce a stable and strong ribbed separator without rib separation.

[Brief description of the drawings]

FIG. 1 is a front view of an example of an extruder used in a manufacturing apparatus of a ribbed separator of the present invention, FIG. 2 is a longitudinal sectional view of a main part thereof, and FIG. III-III line sectional view, FIG. 4 is its IV-IV line sectional view, FIG. 5 is its VV line sectional view, FIG. 6 is its VI-VI line sectional view,
FIG. 7 is a side view of one example of an apparatus for manufacturing a ribbed separator according to one embodiment of the present invention equipped with the molding machine, and FIG.
FIG. 9 is a cross-sectional view of a pair of pressure rolls, FIG. 9 is a perspective view of a ribbed separator product, and FIG. 10 is a side view of a ribbed separator manufacturing apparatus according to another embodiment of the present invention. Is shown. 1. Extruder 2. Heating body (3a, 3b) Die, composite die 3a Die for forming rib member 3b ... Die for forming sheet member 19 ... Groove pressure roll 20 ... Pressure roll 21: Cooling device, cooling roll M: Rib separator manufacturing device

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01M 2/16-2/18 B29C 65/00

Claims (8)

(57) [Claims] 1. A molding material comprising a synthetic resin as a main component, and a mixture of an inorganic powder and a pore-forming agent mixed therein, which is heated and melt-molded to form a flat molded sheet member and at least one synthetic resin alone or The two members with a plurality of parallel forming rib members formed by heating and melting the compound of
In a semi-molten state, a pair of pressure rolls facing each other at a predetermined interval are pressed and bound together to form a ribbed molded sheet, which is then cooled, and then a pore-forming agent is removed. In producing a ribbed separator, the plurality of parallel forming rib members in a semi-molten state are formed by forming a plurality of parallel annular guide grooves on a peripheral surface, and one heated grooved pressure roll. The molding rib member parallel to the molding sheet portion while being guided to the semi-molten molding sheet surface while being fitted into the respective annular guide grooves, and passing between the other heated pressure rolls. Characterized by rolling and binding under substantially uniform pressure. 2. A molded rib member in a semi-molten state at 140 to 170 ° C.
A molded sheet member in a semi-molten state at 140 to 170 ° C. and 100 to 140
200 kg / cm ² 〜 7 through a pair of pressure rolls heated to ℃
2. The method for producing a ribbed separator according to claim 1, wherein the separator is pressed and rolled at a pressure of 00 kg / cm < ² >. 3. The method for producing a ribbed separator according to claim 1, wherein the synthetic resin is an ultrahigh molecular weight synthetic resin resin. 4. The compound according to claim 1, wherein the compound is an ultrahigh molecular weight synthetic resin
2. The composition according to claim 1, which comprises a mixture of 60% by weight, 40 to 60% by weight of inorganic powder and 30 to 60% by weight of a pore-forming agent, based on the blend.
4. The method for producing a ribbed separator according to 2 or 3. 5. A die of an extruder is constituted by a composite die comprising a flat sheet member forming die and a plurality of parallel rib member forming dies, and immediately before the composite die. And a pair of heating means for pressing and binding the semi-molten molded sheet and a plurality of parallel semi-molten molded rib members extruded from these dies, respectively, while maintaining the semi-molten molded rib members in the semi-molten state. An apparatus for manufacturing a ribbed separator, comprising pressure rolls facing each other at a predetermined interval and a cooling device provided in front of the pressure rolls. 6. An extruder provided with a flat sheet member forming die and an extruder provided with a plurality of parallel rib member forming dies, each of which is provided adjacent to and adjacent to each other. An apparatus for manufacturing a ribbed separator, comprising: a pressure roll provided with a pair of heating means disposed at a predetermined interval immediately in front of an attached die, and a cooling device provided in front of the pressure roll. 7. One of the pressure rolls provided with the pair of heating means has, on its peripheral surface, a plurality of parallel rolls for fitting and guiding the plurality of parallel forming rib members in a semi-molten state. A pressurized roll with grooves formed therein with an annular guide groove and incorporating a heating means for heating to a required temperature; the other has a pressurizing surface for pressing a semi-molten molded sheet member from outside, and 7. The manufacturing apparatus for a ribbed separator according to claim 5, wherein the pressure roll includes a heating means for heating the separator. 8. The apparatus according to claim 7, wherein said built-in heating means is a steam, electric or electronic heater connected to a heating source.