JP2002137234A - Foam and method for manufacturing molding having foam layer, as well as apparatus for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plurality of foams capable of suppressing a loss of a raw material to a minimum limit and a method capable of efficiently manufacturing a molding having a foam layer as well as an apparatus for manufacturing the same. SOLUTION: The foam is foamed by a mechanical frothing method. The method for molding having the foam layer of various type roller or the like comprises the steps of supplying a foam raw material 7 corresponding to 100 to 120% of a required amount from the vicinity of a bottom of a cavity 11, then heating the material at it is, and curing the material. The apparatus for manufacturing the molding comprises a mold 1 having a plurality of cavities and two or more raw material supply passages 12 for casting the foam raw material, and a slide bottom having a raw material supply port communicating with a raw material supply source and capable of moving in close contact with the surface of the mold to sequentially open the openings 121 of the surface of the mold of the passage and having a size capable of closing all the openings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a foam and a foam layer capable of minimizing the loss of raw materials and efficiently producing a foam and a molded article having the foam layer. The present invention relates to a method for manufacturing a molded article and a manufacturing apparatus used for the method. ADVANTAGE OF THE INVENTION According to the manufacturing method and manufacturing apparatus of this invention, generation | occurrence | production of the void of a foam, a pinhole, etc. can be suppressed, and the foam used for various rollers, a packing, a sealing material, etc. can be manufactured. Examples of the roller include a toner supply roller, a transfer roller, a cleaning roller, and a curl removing roller that is used after being compressed and deformed, which is incorporated in a copying machine, a facsimile, a printer, and the like.

[0002]

2. Description of the Related Art The mechanical floss method is a molding method of forming a foam by mixing an inert gas in advance into a foam material without mechanically mixing water or a foaming agent and mechanically stirring the mixture. According to this method, for example, in the case of a polyurethane foam, such as a polyurethane slab foam, physical expansion of a blowing agent due to heat of reaction at the time of curing, or generation of carbon dioxide due to a reaction between water and polyisocyanate, As a result, the cell does not grow in the vertical direction, and the cell has no anisotropy. Therefore, it is used in many applications such as rollers, packings and sealing materials. In particular, when it is used in contact with other members like a roller and used, the pressing force on its peripheral surface is constant. There are advantages too.

In this mechanical floss method, conventionally,
By closing the pair of split molds, a molding die is used in which a cavity having a shape similar to the product is formed.After the mold is opened, a mixed liquid that is a raw material is injected, and after closing the mold, The foam is formed by heating, hardening the mixture, and then demolding. Air pools and the like generated during the injection of the raw material are discharged from pores penetrating from the cavity to the outer surface of the mold, so-called vent holes.

In the case of producing a long molded product, a molding die having a vertically long cavity whose vertical direction is the vertical direction is used. As shown in FIG. A vent hole c for discharging gas is provided at the bottom, that is, below the mold, and is provided above the cavity, that is, above the mold. In this mold, the raw material is supplied in a closed state in order to sufficiently fill the raw material, but still sufficiently suppresses the accumulation of air and the like causing voids, pinholes, etc. in the upper part of the cavity. It is not possible. For this reason, air and the like are discharged together with the raw material from the vent hole.
Burr formation is inevitable.

On the other hand, the nozzle d after the supply of the raw material is removed from the raw material injection section, and the mold is immediately set so that the longitudinal direction of the cavity is horizontal, thereby preventing leakage of the raw material from the raw material injection section. After the vent hole is directed upward, heating and curing are performed. This is because if the nozzle is not removed from the raw material injection section, the raw material is hardened in the raw material injection section, and it becomes impossible to supply the raw material thereafter. However, as a result, due to the dripping of the raw material due to the desorption of the nozzle and the formation of burrs in the vent hole, an excessive amount of raw material exceeding the required amount for the molded product is supplied, which contributes to an increase in production cost. Has become.

Further, in order to reduce the loss of the raw material due to the dripping of the raw material due to the desorption of the nozzle, a conventional method is used.
As shown in FIG. 11, a raw material is supplied from a single raw material injection port e to a plurality of cavities a. However, in such a structure, a large number of branches f are formed in the raw material supply path, and the back pressure fluctuates every time the raw material reaches the branch. As a result, the dispersed air bubbles may coalesce, resulting in voids or rough cells.

On the other hand, when the raw material gas-liquid mixed in the chamber is supplied to one cavity formed inside the molding die to produce a molded product, there is no branch in the flow path.
The back pressure applied to the raw materials does not change much, and there is no major problem. However, when supplying raw materials to multiple cavities,
When the flow of the raw material is repeatedly stopped, this stop causes the back pressure to change greatly each time. In order to suppress this change in back pressure, the supply of raw materials is usually continued during the supply of raw materials to each cavity,
Large loss of raw materials, including contamination of surrounding work environment, etc.
It is a problem.

Further, when manufacturing rollers for office equipment or the like by the mechanical floss method, conventionally, a core metal is previously arranged in a cavity of a molding die, and a foam raw material is supplied to this. A method has been employed in which a foam layer such as a foamed polyurethane layer and a core are integrally formed. However, such a method of manufacturing a roller requires a mold having a cavity having a predetermined size and shape for each roller having a desired diameter and length, which contributes to an increase in manufacturing cost.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides a method for producing a foam by a mechanical floss method and a molded article having a foam layer.
And a production apparatus used for the same, and a production method capable of forming a foam having a reduced number of voids and pinholes and a foam layer with a minimum necessary raw material, and a production apparatus used therefor. Aim. The foam produced by the method of the present invention using the production apparatus of the present invention can be used in a wide range of applications, and is particularly useful as a foam layer of molded articles such as rollers for office equipment. The foam that can be produced by the mechanical floss method includes a polyurethane foam, an acrylic resin foam, a latex rubber foam, and the like.

[0010]

In the mechanical floss method, air or the like which causes voids, pinholes, etc. is apt to be mixed into the foam raw material supplied to the cavity of the mold.
However, if the longitudinal direction of the cavity is the vertical direction and the foam raw material is supplied from the vicinity of the bottom, air and the like causing the generation of voids, pinholes, etc., rise in the raw material and escape from the upper part of the cavity. Or accumulate at the top. Therefore, even after the raw material is supplied, even if it is cured as it is, a foam having a desired shape and dimensions can be manufactured from the minimum necessary raw material without being affected by air or the like, and the productivity is improved. be able to. The present invention has been made based on such findings.

According to a first aspect of the present invention, in the method for producing a foam by the mechanical floss method, a portion corresponding to 100 to 120% of a required amount of the foam from the vicinity of the bottom of the cavity of the molding die. The method is characterized in that, after supplying the foamed raw material mixed with the liquid, the foamed raw material is heated and cured as it is. Then, after the raw material is cured, the foam can be obtained by demolding.

Although the shape and dimensions of the "cavity" are not particularly limited, it is preferable that the ratio of the length to the cross-sectional area is large, since the action and effect of the present invention can be obtained particularly sufficiently. This cavity is preferably open at the upper surface of the mold as described in claim 2, whereby air or the like mixed into the raw material is easily discharged, and voids,
The occurrence of pinholes and the like is sufficiently suppressed. In addition, it is preferable that the cross-sectional area of the opening is equal to or larger than the cross-sectional area near the upper end of the foam to be formed, because the back pressure does not change.

The "forming die" can be formed by a pair of split dies, and the outer wall surface of one split die and the inner wall surface of the split die have a cavity. It is preferable that a raw material supply path that opens to the vicinity of the bottom of the concave portion to be formed is formed. If the raw material is supplied near the bottom of the concave portion, that is, near the bottom of the cavity, air and the like can be sufficiently removed from the total amount of the supplied raw material.

Further, it is preferable that the raw material supply path is opened at a portion including a parting line near the bottom of the cavity. In this way, not only near the parting line but also in the opposing parting line, the raw material is easily supplied along these lines, and the formation of the concave portion due to the insufficient supply of the raw material to the parting line portion. Etc. are prevented. In addition, as described in claim 5, it is particularly preferable that the shape of the opening surface at the part including the parting line is symmetrical with the parting line as an axis. When the raw material is supplied from such an opening, the raw material is more uniformly supplied in the circumferential direction of the cavity, and a uniform foam can be obtained.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a molded article having a foam layer, the method including a cored bar, and a foamed layer formed on a peripheral surface of the cored bar by a mechanical floss method. In the method, a temporary shaft is disposed in a cavity of a molding die, and a gas-liquid mixed foam material equivalent to 100 to 120% of a required amount of the foam layer is supplied from near the bottom of the cavity. The foam raw material is cured as it is, and then the temporary shaft is pulled out of the foam layer, then the mold is removed, and the core is inserted into a hollow portion formed by pulling out the temporary shaft. It is characterized by comprising a step.

The above "core metal" needs to have a mechanical strength that does not cause deformation or the like when rotating or when used for a long period of time. Therefore, although a rod-shaped body made of a metal such as stainless steel and having a circular cross section is usually used, the cross section does not necessarily have to be circular.

The "temporary shaft" is for obtaining a foam having a hollow portion for inserting a cored bar. Usually, the temporary shaft is a rod-shaped body made of a metal having a good heat conductivity and having a circular cross section. However, the shaft is not necessarily made of a metal and has a circular cross section, and a rod made of a resin may be used. Further, after the provisional shaft is provided to form a foam, the provisional shaft is pulled out, and the obtained cylindrical foam such as a cylindrical foam is cut into a desired length, and a core having a predetermined size is formed in the hollow portion. By inserting gold and then, if necessary, polishing the surface of the foam, a molded article having a foam layer can be produced. Thus, according to the method of the sixth aspect, it is possible to produce molded articles having foam layers of various lengths with one type of molding die.

Also in the manufacturing method according to the sixth aspect, the relationship between the cross-sectional area of the cavity and the foam, the form of the material supply path of the molding die composed of a pair of split dies, and the like are also the same. It is preferable to make the same as in the case of the invention described in claims 2 to 5 in the above.

The molded article having the foam layer may be a toner supply roller or a transfer roller incorporated in a copying machine, a facsimile, a printer, or the like to which electrophotography, electrostatic recording technology or the like is applied. , Cleaning roller,
In particular, various office equipment rollers, such as a curling roller used after being compressed and deformed, can be used.

In the method for producing a foam according to the first aspect and the method for producing a molded article having a foam layer according to the sixth aspect, the supply amount of the “foam raw material” is one of the required amounts.
00 to 120%, 100 to 110%, especially 100
It is preferable to set it to 105%. The foam material is 120
%, It is possible to form a uniform foam having no underfill and a foam layer even if the required amount is 110% or less, particularly 105% or less. .

According to an eighth aspect of the present invention, there is provided an apparatus for producing a foam formed by a mechanical floss method, wherein the plurality of cavities and one end side are open to at least one cavity, and the other end is a mold surface. A molding die having a plurality of raw material supply paths that are open to the container, and a raw material supply port communicating with the raw material supply source, and moving in close contact with the surface of the molding die in which the opening of the raw material supply path is formed. In this case, a slide plate having a size capable of opening the raw material supply port to the opening and closing all the openings is provided.

[0022] This manufacturing apparatus is configured as follows.
A temporary shaft is provided in each of the plurality of cavities, and a fixing jig for fixing the upper end side of each temporary shaft at a predetermined interval can be provided. In this way, it is possible to easily manufacture a cylindrical foam such as a cylindrical shape provided on the peripheral surface of the cored bar in the office equipment roller or the like.

The material of the "mold" is not particularly limited.
Although a mold, a resin mold, and the like can be used, a mold having good heat conductivity is more preferable, and a mold made of an aluminum alloy, stainless steel, or the like is often used.

Although the shape and size of the "cavity" are not specified, it is preferable that a plurality of cavities having the same shape and the same size are formed at equal intervals. In this case, a plurality of the same foams can be efficiently manufactured. In addition, the number of cavities is not particularly limited. However, in order to efficiently supply the raw material uniformly and sufficiently to all cavities in a short time, usually 2 to 12 cavities are used.
The number is preferably set to 4 to 8, in particular.

The number of the "raw material supply passages" can be set appropriately according to the number of cavities. The raw material supply path may be provided for each of the plurality of cavities, or the supply path from the raw material supply side may be branched midway and opened to the plurality of cavities. In this case, it is preferable that the number of cavities to which the raw material is supplied from one opening on the raw material supply side is two. When the number of the cavities becomes three or more, the raw material is uniformly and sufficiently supplied to each cavity. It becomes difficult. Further, when the number of branches in the raw material supply path increases, the raw material in the mold and air are mixed, and voids and the like may be generated, which is not preferable.

It is preferable that the raw material supply passages are opened near the bottoms of the respective cavities.
In this way, the raw material supplied from below is filled upward, so that gas such as air is easily released to the outside from above the cavity, and a good foam without voids or the like is obtained. be able to. This claim 8
In the foam manufacturing apparatus according to any one of the first to ninth aspects, the relationship between the cross-sectional area of the cavity and the foam, the form of the material supply path of the molding die including a pair of split dies, and the like are defined in the first aspect of the present invention. It is preferable to make the same as in the inventions described in the above-described embodiments.

The above-mentioned "slide plate" is preferably made of a metal of the same quality as that of the molding die, and the surface on the sliding side of the molding die is preferably smooth so that the raw material does not leak easily. Further, the slide plate has a length capable of closing all of the above “openings” on the surface of the forming die of the raw material supply path, and a gap is generated on the sliding surface with the die surface when moving. It is necessary to have rigidity without. The slide plate is provided with the above-mentioned "raw material supply port", and is made of rubber which communicates with the raw material supply port and communicates with a gas-liquid mixing chamber or the like which is a raw material supply source at an opening opening on the other surface of the slide plate. And the like are connected. The raw material supply port is preferably provided at the edge of the slide plate. With such a slide plate, all the openings can be closed with a minimum length.

According to a tenth aspect of the present invention, in the method for producing a foam by the mechanical floss method, a plurality of cavities, one end of which is open to at least one cavity, and the other end of which is open to the mold surface. A plurality of raw material supply passages, and among the openings of the raw material supply passages on the surface of the forming die having the plurality of raw material supply passages, communicate with the raw material supply source from an opening located on one end side of the mold surface to an adjacent opening. The raw material supply port of the slide plate having the raw material supply port to be opened is sequentially opened to supply the foam raw material, and the respective openings are sequentially closed by the slide plate, and then the foam is heated. It is characterized in that the raw material is cured.

Further, the method for producing a foam according to claim 11 is characterized in that the method for producing a foam according to claim 10 is specified in more detail in the order of steps. FIG. 8 is a flowchart in the case where this step is adopted in the embodiment described later.

In the manufacturing method according to the tenth and eleventh aspects, particularly, the manufacturing apparatus according to the eighth aspect can be used. In the slide plate, the raw material supply port is provided at one end side of the surface of the mold first. And a predetermined amount of raw material is supplied. Thereafter, the slide plate is moved to a position where the raw material supply port is opened to the opening of the adjacent raw material supply path, and at the same time, the opening where the raw material supply port was previously opened is closed. In this way, the raw material supply port is opened at the opening of the raw material supply path located at the other end of the surface of the mold, the foam raw material is supplied, and the slide plate is further moved to open the other end. Until the unit is closed, the supply of the raw material, the movement of the slide plate, and the closing of the opening of the raw material supply path are repeated. Next, this is heated to cure the raw material. Thereafter, the foam can be obtained by demolding. In addition, also in these manufacturing methods, in order to obtain a homogeneous foam, as described in claim 12,
It is preferable that one raw material supply path is open to two cavities.

According to a thirteenth aspect of the present invention, there is provided a method for producing a molded article having a foam layer, the method comprising a cored bar and a foamed layer formed on a peripheral surface of the cored bar by a mechanical floss method. A mold having a plurality of cavities in which a temporary shaft is disposed, and a plurality of raw material supply passages having one end opening near the bottom of at least one of the cavities and the other end opening on the mold surface. The raw material of a slide plate having a raw material supply port communicating with a raw material supply source from an opening located on one end side of the molding die to an adjacent opening among openings of the raw material supply path on the surface. The supply ports are sequentially opened to supply the foam raw material, and the respective openings are closed by the slide plate. Thereafter, heating is performed to cure the foam raw material, and then the temporary shaft is pulled out and removed. Type and then Characterized in that it comprises the step of inserting a core bar into the hollow part formed by pulling out the Yafuto.

A method of manufacturing a molded article having a foam layer according to a fourteenth aspect is characterized in that the method of manufacturing a molded article having a foam layer according to the thirteenth aspect is specified in more detail in the order of steps. FIG. 9 is a flowchart in the case where this step is adopted in an embodiment described later.

In the manufacturing method according to the thirteenth and fourteenth aspects, in particular, the manufacturing apparatus according to the ninth aspect can be used, and the cavity of the mold has a shape and dimensions for forming a foam layer. A mold is used in which a plurality of long cylindrical cavities are formed at regular intervals. In addition, the operation and procedure from the operation of the material of the slide plate and the like and the operation of operating the slide plate to sequentially supplying the foam raw material to each cavity, and then heating and curing the raw material are described in claims 10 to 11. It is the same as in the case of the invention of the above. In the invention according to claims 13 and 14, after the raw material is cured, the temporary shaft is pulled out, the mold is removed, and then the core is inserted into the formed hollow portion. By polishing and finishing, a molded article having a foam layer can be manufactured.

In these manufacturing methods, examples of the molded article having a foam layer include a roller for office equipment. In addition, in order to form a uniform foam layer, it is preferable that one raw material supply passage is opened to two cavities.

In the method for producing a molded article having a foam and a foam layer according to claims 10 to 16, the cavities are arranged in a vertical direction, one end of the material supply path is opened near the bottom of the cavity, and the other end. Are preferably opened side by side on the surface of the mold. With such a configuration, the operation of moving the slide plate in the horizontal direction and sequentially supplying the raw materials is easy.

After the raw material is supplied, it is more preferable that the material is heated and cured while the cavity is kept in the vertical direction. When heating and curing the molding die horizontally after supplying the raw material, it is necessary to fill the cavity with the raw material regardless of the predetermined length of the molded product such as a roller. Otherwise, the uncured raw material will flow easily in the cavity and cannot be formed into a foam layer having a predetermined shape. On the other hand, by heating and curing in the vertical direction, the required amount of the foam layer is 100 to 120%, particularly 10%.
The supply amount can be 0 to 110%, that is, the supply amount does not greatly exceed the required amount. In this way, it is possible to further suppress the loss of the raw material, and it is not necessary to prepare a mold having a plurality of cavities having different dimensions depending on predetermined dimensions of a molded article such as a roller.

In the case of a polyurethane foam which is a typical foam formed by the mechanical froth method, first, a polyol component containing a polyol, a catalyst, a chain extender and the like and containing no foaming agent is prepared. A foam raw material comprising a foam stabilizer, a polyisocyanate, and the like is supplied into the chamber, and at the same time, an inert gas is supplied, and the mixture is stirred by a stirrer such as an Oaks mixer and a Hobart mixer, and gas-liquid mixed. Then, the foam raw material mixed in gas-liquid in the chamber is discharged into the molding die. Then, the polyurethane foam can be formed by heating the mold to a required temperature and curing the foam material.

As the polyol, polyether polyol, polyester polyol, and polyether ester polyol obtained by copolymerizing polyether polyol and polyester polyol can be used.
Further, in the mechanical floss method, a polymer polyol is usually used in combination to form a foam having a sufficient tensile strength or the like. The polymer polyol is a polyol obtained by graft-polymerizing an ethylenically unsaturated compound such as acrylonitrile, styrene, or methyl methacrylate with a polyether polyol at a solid content of 10 to 40% by mass, preferably 15 to 30% by mass. Say.

Examples of the polyisocyanate include tolylene diisocyanate (TDI), crude TDI, 4,4'-diphenylmethane diisocyanate (MDI), and crude MD
I, and 1,6-hexamethylene diisocyanate (H
DI), crude HDI, 1,5-naphthalene diisocyanate, paraphenylene diisocyanate, 2,2,4-
Trimethylhexamethylene diisocyanate, 2,4
4-trimethylhexamethylene diisocyanate, 4,
4'-dicyclohexylmethane diisocyanate, m-
Xylene diisocyanate, hexamethylene diisocyanate, hydrogenated MDI, isophorone diisocyanate, etc.
Various aromatic and aliphatic compounds can be used. Besides these, a prepolymer type polyisocyanate can also be used.

Examples of the catalyst include organotin compounds such as stannas octoate, dibutyltin diacetate and dibutyltin dilaurate; organozinc compounds such as zinc octylate;
Organic nickel compounds such as nickel acetylacetoate and nickel diacetylacetoate; organic iron compounds such as iron acetylacetoate; alkali metal or alkaline earth metal alkoxides such as sodium acetate; and metal catalysts such as phenoxide can be used. . Furthermore, in addition to tertiary amine catalysts such as triethylamine, triethylenediamine, N-methylmorpholine dimethylaminomethylphenol, imidazole, 1,8-diazabicyclo [5,4,0] undecene, organic acid salts and the like can also be used. it can.

As the chain extender, ethylene glycol,
Short-chain diols such as diethylene glycol, propylene glycol, dipropylene glycol, and 1,4-butanediol, and triols such as glycerin and trimethylolpropane can be used. In the case where a trifunctional or higher functional polyol such as a triol is used as a chain extender, a crosslinked structure can be introduced into the molecular chain. Further, in order to form a foam having a lower hardness, an ester oligomer chain-extended with ε-caprolactone using ethylene glycol or trimethylolpropane as an initiator, and a trifunctional polyether polyol having a molecular weight of about 400 to 700, It is preferable to use a chain extender having a large molecular weight.

As the foam stabilizer, a block copolymer of dimethylpolysiloxane and polyether can be generally used. Further, a foam stabilizer in which an organic functional group is added to polysiloxane can also be used. Thus, silicone foam stabilizers are frequently used as foam stabilizers. In addition, raw materials generally used for urethane blending, such as an ultraviolet absorber, an antioxidant, an organic and inorganic filler, and a coloring agent, can be appropriately used as the foam raw material.

[0043]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the embodiments shown in FIGS. (1) Production of polyurethane foam Example 1 Polymer polyol (trade name “P” manufactured by Mitsui Chemicals, Inc.)
OP2430 ") 90 parts by mass (hereinafter abbreviated as" part "), 8 parts of polyester polyol (manufactured by Daicel Chemical Industries, Ltd., trade name" PCL305 "), catalyst (nickel acetylacetonate, manufactured by OSi Specialties Inc.) 2 parts of trade name "LC-5615") and amine catalyst (manufactured by Sankyo Air Products Co., Ltd., trade name "DAB"
CO-33LV ") was mixed and stirred to prepare a polyol component.

Thereafter, the polyol component, 8 parts of a silicone foam stabilizer (trade name "L-5614", manufactured by OSi Specialties, Inc.) and 14 parts of polyisocyanate (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) "MT
L ”) was supplied to the chamber, and nitrogen gas was supplied to the foam at 0 ° C. and 1 atmosphere at a flow rate corresponding to 200 cm ³ / min. Next, the foamed foam raw material 7 that was mixed and stirred in the chamber was prepared, and the inside diameter thereof was 7 m.
m temporary shaft 6 is inserted and the cavity 11 of the mold 1 maintained at 90 ° C. (inner diameter: 20 mm, length: 3
(50 mm) from the raw material supply path 12 near the bottom.

Further, the mold 1 was directly placed in a cure furnace and heated at 120 ° C. for 30 minutes to cure the raw material. Thereafter, the temporary shaft 6 is pulled out and then released from the mold, and as shown in FIG. 2, a cylindrical polyurethane foam 8 having an outer diameter of 20 mm and a length of 330 mm (cut margin; 50 mm).
I got Next, as shown in FIG. 3, a core metal 92 having an outer diameter of 8 mm is cut into the hollow portion 8 c formed by cutting out the temporary shaft 6 by cutting the cut portions 8 a and 8 b to have a length of 300 mm. Press-fit, product outer diameter 19m
m was polished to a roller 9 for office equipment. The foam raw material supplied to obtain the office equipment roller was 30 g in total including 1.5 g of the raw material supply path 12 of the molding die 1 and the cut margins 8a and 8b.

COMPARATIVE EXAMPLE 1 A foam having the same composition as in Example 1 was prepared.
It was fed to a mold maintained at 0 ° C. Then, the supply was stopped when the raw material overflowed from the upper vent hole together with the air, and then the mold was placed sideways, placed in a cure furnace, and heated at 120 ° C. for 30 minutes to cure the foam raw material. Next, the temporary shaft is pulled out, removed from the mold, and has an outer diameter of 20 mm and a length of 350 mm (cut margin: 50 mm).
Was obtained. After that, the cut margin is cut to make the length 300 mm, and the outer diameter 8 mm
Was press-fitted and polished to an outer diameter of 19 mm to obtain a roller for office equipment. The foam raw material supplied to obtain the office equipment roller is supplied to the raw material supply path of the molding die in the amount of 1.5.
g, 3.5 g overflowing from the vent hole, and 35.5 g in total, including the cut margin.

As described above, the rollers for office equipment (external shape:
19 mm, length: 300 mm) In Comparative Example 1, 35.5 g of foam raw material was required. On the other hand, in Example 1, 30 g of foam material is required,
Comparative Example 1 required about 18% more raw material than Example 1.

(2) Manufacturing Apparatus and Manufacture of Office Equipment Roller Using This Apparatus Example 2 Mold Used The mold is a form in which two half molds 1a and 1b are combined. FIG. 3 is a front view showing a state where each half mold is opened. Also, FIG.
FIG. 4 is a front view showing a state in which a slide plate is attached with the. In FIG. 5, the slide plate has its raw material supply port opened to the second opening from the right side among the openings on the mold surface of the four raw material supply paths, and the rightmost opening. Is a state in which the slide plate 3 is closed by the opening closing portion 32.

In FIG. 5, eight columnar cavities are arranged at equal intervals in the horizontal direction, and the top in the longitudinal direction is open at the upper surface of the mold 1 and the bottom in the radial direction. A cylindrical path 13 for fixing the lower end of the temporary shaft 6 is formed in the center. In addition, a raw material supply path is formed from an intermediate position below two adjacent bottoms of the eight cavities to near the bottom of each cavity. This raw material supply path is formed toward the mold surface at a portion branched right and left, and communicates with four openings 121 which are opened at equal intervals in the lateral direction on the mold surface.

FIG. 6 shows that the upper end of the temporary shaft 6 is
FIG. 7 is a perspective view showing a state in which it is inserted into through holes provided at equal intervals in the upper plate and is fixed. The fixing jig is fitted and fixed to the upper surface of the molding die by a fitting portion 22. A required number of fixing jigs are provided on the upper plate such that each temporary shaft is disposed at the radial center of each cavity. A through hole is provided.

FIG. 7 is a perspective view of the molding die and the slide plate disposed on the rail 4 as viewed obliquely from above. The slide plate includes a raw material supply section 31, an opening closing section 32 extending therefrom, and a pedestal 33 on which the raw material supplying section and the opening closing section are placed and fixed, and both sides of a lower surface of the pedestal. (The rollers 3a and 3b are shown in FIG. 7, but actually two more rollers are mounted at positions facing each other across the rail. ing.). With these four rollers pressing the rail 4 from both sides,
The slide plate can move on the rail 4 stably. In addition, the surface of the raw material supply unit and the surface of the opening closing unit that slide on the mold surface form a series of smooth surfaces without any level differences.

A raw material supply port communicating with the opening on the other surface is opened on the surface of the raw material supply section, and a raw material supply pipe 5 from a raw material supply source is connected to this opening. Further, the slide plate is arranged so that the central portion in the vertical direction (width direction) can be brought into contact with the four openings 121 opening on the surface of the mold, and the slide plate is disposed in the lateral direction (length) of the opening closing portion. The dimension of (direction) is such that all the four openings can be closed by supplying the raw material from all the openings and moving it slightly to the left.

Production of Office Equipment Rollers 90 parts by mass (hereinafter abbreviated as "parts") of a polymer polyol (trade name "POP243", manufactured by Mitsui Chemicals, Inc.)
0 "), 8 parts of a polyester polyol (manufactured by Daicel Chemical Industries, Ltd., trade name" PCL305 "), 2 parts of a metal catalyst (nickel acetylacetonate, manufactured by OSi Specialties, trade name" LC-5615 "), And 0.1 part of an amine catalyst (manufactured by Sankyo Air Products Co., Ltd., trade name "DABCO-33LV") and stirred to prepare a polyol component.

Thereafter, the polyol component, 8 parts of a silicone-based foam stabilizer (trade name “L-5614”, manufactured by OSi Specialties, Inc.) and 14 parts of a polyisocyanate (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) "MT
L)) was supplied to the chamber, and nitrogen gas was supplied at 0 ° C. and 1 atm at a flow rate corresponding to 200 cm ³ / min. Next, the foamed raw material which was mixed and stirred in the chamber was prepared, and eight cavities 11 (inner diameter: 20 mm) of the mold 1 in which a temporary shaft 6 having an inner diameter of 7 mm was provided and maintained at 90 ° C. , Length: 350 mm) from the four openings 121 on the mold surface communicating with the vicinity of the bottom.

The supply of the foam material is sequentially performed from the rightmost opening (the material is supplied to the two right cavities) in FIGS. 5 to 7 while keeping the supply rate of the material constant. The slide plate was moved to the left opening (the raw material was supplied to two adjacent cavities, respectively). No leakage of the raw material from the gap between the surface of the forming die and the slide plate was observed during the operation of supplying the raw material and during the transfer of the forming die to the curing furnace.

The mold was left standing in a curing oven controlled at 120 ° C. for 20 minutes while keeping it in the vertical direction, and after the raw material was hardened, it was taken out of the curing oven, allowed to cool, and cooled to room temperature. From the upper part, the temporary shaft is pulled out from the upper part, and then removed from the mold, and the outer diameter is 20 mm and the length is 3 mm.
Eight 50 mm tubular polyurethane foams were obtained. After that, the cut margin is cut and removed, and the length is 300 mm.
A core having an inner diameter of 8 mm is inserted into a hollow portion formed after the temporary shaft is pulled out, and the outer peripheral surface is polished by polishing the peripheral surface.
An office equipment roller similar to that of Example 1 having a 9 mm polyurethane foam layer was obtained.

It should be noted that the present invention is not limited to the above specific embodiments, but may be variously modified within the scope of the present invention according to the purpose and application. For example, the polyurethane foam may have various shapes such as a cylinder, a rectangular parallelepiped, and the like, in addition to a cylindrical shape.

[0058]

According to the first aspect of the present invention, a foam having a desired length can be produced from a minimum necessary amount of raw material in one type of mold, and voids, pinholes, and the like can be produced. Can be suppressed. Further, according to the method of the sixth aspect, similarly, it is possible to efficiently produce various quality rollers for office equipment and the like with the minimum necessary amount of raw materials. Furthermore,
According to the manufacturing apparatus of the eighth aspect, it is possible to minimize the loss of the foam raw material and obtain a homogeneous foam.
According to the manufacturing method of claims 10 and 11, a homogeneous foam can be easily and efficiently manufactured,
According to the manufacturing method of the thirteenth and fourteenth aspects, it is possible to efficiently manufacture various types of office equipment rollers and the like having excellent quality.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in a molding die before a foam material is supplied and cured in Example 1.

FIG. 2 is a perspective view of a cylindrical polyurethane foam before being processed to a predetermined length in Example 1.

FIG. 3 is a perspective view of the office equipment roller obtained in Example 1.

FIG. 4 is a front view showing a state in which a mold formed by combining half molds is opened.

FIG. 5 is a front view showing a state in which a mold formed by combining half molds is closed.

FIG. 6 is a perspective view showing in detail a method of fixing the upper end portion of the temporary shaft.

FIG. 7 is a perspective view showing details of a slide plate.

FIG. 8 is a flowchart showing the steps of the method for producing a foam according to claim 11;

FIG. 9 is a flowchart showing steps of a method for manufacturing a molded article having a foam layer according to claim 14;

FIG. 10 is a schematic diagram for explaining supply and deaeration of a raw material.

FIG. 11 is a schematic diagram showing a state of branching of a raw material supply path when a raw material is supplied from one raw material supply port to four cavities.

[Explanation of symbols]

1; Mold, 1a, 1b; Half mold, 11; Cavity,
111; an opening above the cavity, 12; a raw material supply path, 121; an opening on the mold surface of the raw material supply path, 1
3; a cylindrical path for fixing the lower end of the temporary shaft; 2;
Jig for fixing the upper end of the temporary shaft, 21; through hole, 22; fitting portion, 31; raw material supply portion; 32, opening closing portion; 33, pedestal, 3a, 3b; Raw material supply pipe, 6; temporary shaft, 7; foam raw material,
8: cylindrical polyurethane foam, 8a, 8b; cut-off portion, 8c; hollow portion, 9; roller for office equipment, 9
1; polyurethane foam layer, 92; core metal.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) EF49 EW02 EW21

Claims (16)

[Claims] In a method for producing a foam by a mechanical floss method, a foam raw material in a gas-liquid mixture corresponding to 100 to 120% of a required amount of the foam is supplied from near a bottom of a cavity of a molding die. Thereafter, the foam raw material is cured as it is by heating the foam raw material as it is. 2. The method for producing a foam according to claim 1, wherein the cavity has an opening in an upper surface of the mold, and a cross-sectional area of the opening is equal to or larger than a cross-sectional area near an upper end of the foam. 3. The molding die comprises a pair of split dies, an outer wall surface of one of the split dies, and an inner wall surface of the one of the split dies, in the vicinity of the bottom of a concave portion for forming the cavity. ,
3. A raw material supply path which is open to the outside is formed.
3. The method for producing a foam according to item 1. 4. The molding die includes a pair of split dies, and includes an outer wall surface of one of the split dies and a parting line near a bottom of the cavity formed by the one split dies and the other split dies. The method for producing a foam according to claim 1, wherein a raw material supply passage that opens to the part is formed. 5. The method for producing a foam according to claim 4, wherein the shape of the opening surface at a portion of the raw material supply path including the parting line is symmetric about the parting line. 6. A method of manufacturing a molded product having a cored bar and a foam layer formed on a peripheral surface of the cored bar by a mechanical floss method, comprising: disposing a temporary shaft in a cavity of a mold; From the vicinity of the bottom of the cavity, the required amount of the foam layer is 100 to
After supplying the gas-liquid mixed foam material equivalent to 120%, the material is heated as it is to cure the foam material, and then the temporary shaft is pulled out from the foam layer.
A method for producing a molded article having a foam layer, comprising a step of inserting the core metal into a hollow portion formed by removing a mold and pulling out a temporary shaft. 7. The method for producing a molded article having a foam layer according to claim 6, wherein the molded article is a roller for office equipment. 8. An apparatus for producing a foam formed by a mechanical floss method, comprising: a plurality of cavities; a plurality of raw material supply paths having one end opening to at least one cavity and the other end opening to a mold surface; A mold having a raw material supply port communicating with a raw material supply source, and moving the raw material supply port in close contact with the surface of the molding die in which the opening of the raw material supply path is formed. An apparatus for producing a foam, comprising: a slide plate having a size capable of being opened in an opening and capable of closing all the openings. 9. The foam manufacturing apparatus according to claim 8, wherein a temporary shaft is disposed in each of the plurality of cavities, and a fixing jig for fixing upper ends of the temporary shafts at predetermined intervals. . 10. A method for producing a foam by a mechanical floss method, comprising: a plurality of cavities; and a plurality of raw material supply passages having one end opened to at least one cavity and the other end opened to a mold surface. Of the opening of the material supply passage on the surface of the mold, from an opening located on one end side of the mold surface to an adjacent opening, a slide plate having a material supply port communicating with a material supply source. The foaming is characterized in that the raw material supply ports are sequentially opened, the foam raw material is supplied, and the respective openings are sequentially closed by the slide plate, and then the foam raw material is cured. How to make the body. 11. A method for producing a foam by a mechanical floss method, wherein (1) a pair of split dies are closed, and a plurality of cavities and one end are opened to at least one of the cavities. A step of forming a molding die having a plurality of raw material supply paths, the other ends of which are open on the die surface,
(2) The material supply port of the slide plate, which has a material supply port communicating with the material supply source and can be moved closely to the surface of the mold, is provided at one end of the surface of the mold. (3) a step of supplying a predetermined amount of foam raw material from the opening located on one end side, and (4) moving the slide plate to set the raw material supply port to the above-mentioned position. Opening the opening adjacent to the opening located on one end side and closing the opening located on the one end side with the slide plate; and (5) removing a predetermined amount of the opening from the adjacent opening. And a step of supplying a foam raw material in this order, and the raw material supply ports of the slide plate are sequentially opened in adjacent openings, and after supplying the foam raw material from all the openings, Move the slide plate further to open all openings Closed, then, heated and method for producing foam, characterized in that curing the foam material. 12. The method for producing a foam according to claim 10, wherein the one end of the raw material supply path is open to two cavities. 13. A method for manufacturing a molded product having a cored bar and a foam layer formed on a peripheral surface of the cored bar by a mechanical floss method, comprising: a plurality of cavities in which a temporary shaft is disposed. A plurality of raw material supply paths, one end side of which is open near the bottom of at least one cavity, and the other end of which is open to the mold surface; From the opening located at one end of the mold to the adjacent opening, the raw material supply port of the slide plate having the raw material supply port communicating with the raw material supply source is sequentially opened to supply the foam raw material. Closing each opening by the slide plate, then heating and curing the foam material, then pulling out the temporary shaft, demolding, and then pulling out the temporary shaft, the hollow portion formed To core Method for producing a molded article having a foam layer, characterized in that it comprises the inserting step. 14. A method of manufacturing a molded article having a cored bar and a foam layer formed on the peripheral surface of the cored bar by a mechanical floss method. (1) A method comprising: (1) closing a pair of split dies; Forming a mold having: a cavity; and a plurality of raw material supply passages, one end of which opens into at least one of the cavities, and the other end of which opens on the surface of the mold. Disposing a temporary shaft inside each of the plurality of cavities; and (3) the raw material of a slide plate having a raw material supply port communicating with a raw material supply source and capable of moving closely to the mold surface. A step of opening a supply port to an opening of the raw material supply passage located at one end of the mold surface; and (4) a step of supplying a predetermined amount of foam raw material from the opening located at the one end. , (5) moving the slide plate, Opening a material supply port at an opening adjacent to the opening located at the one end side, and closing the opening located at the one end side with the slide plate; and (6) the adjacent opening portion And a step of supplying a predetermined amount of the raw material, in this order, and the raw material supply ports of the slide plate were sequentially opened in adjacent openings, and the foam raw material was supplied from all the openings. Thereafter, the slide plate is further moved to close all the openings, and then heated, the foam material is cured, the temporary shaft is pulled out, the mold is removed, and then the temporary shaft is pulled out. A method for producing a molded article having a foam layer, comprising a step of inserting the core metal into the formed hollow portion. 15. The method for producing a molded article having a foam layer according to claim 13, wherein the molded article is a roller for office equipment. 16. The method for producing a molded article having a foam layer according to claim 13, wherein the one end of the raw material supply path is open to two of the cavities.