JP2795216B2 - Mold for molding, molding method, molding material, and molded product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding a thermoplastic resin, a blow molding method, an injection molding method, a thermoplastic resin material, and a molded product.

[0002]

2. Description of the Related Art As a method for obtaining a resin molded product, there are an injection molding method and a blow molding method. In the injection molding method, the molten resin is placed in a closed mold at a high pressure (200 to 1000 kg / cm).
^In this method, the molding surface of the mold is transferred to resin by injection in ² ). Because of the high pressure, the transfer of the molding surface is performed accurately. Therefore, it is suitable for obtaining a molded product having a mirror surface or a grained surface. However, since a mold that can withstand high pressure is required, the structure of the mold is complicated and the cost is high, which is not suitable for high-mix low-volume production. In addition, since a special device is required for molding a hollow product, the production process is complicated. In the blow molding method, a parison (a hollow cylindrical resin in a melted and softened state) is supplied between molds, the mold is clamped, and a fluid is pressure-fed to the hollow portion so that the outer surface of the parison is a molding surface of the mold. This is a method of transferring the image by pressing it onto Since it is pressed by the pressure of the fluid, the pressure is relatively low (4 to 10 kg / cm ² ), so that the molding surface is not transferred cleanly, which is not suitable for obtaining a molded product having a mirror surface or a grain surface. However, it is widely used because it is suitable for mass production of hollow articles. JP-A-58-102732 discloses a thin inner mold for molding,
A hollow molding die provided with a cooling outer die capable of contacting / isolating the inner molding die is disclosed. In this mold, the inner mold for molding is heated before the parison is supplied for the purpose of improving the surface gloss of the hollow molded article, and after the parison is brought into contact with the molding surface of the inner mold for cooling, it is cooled. By bringing the inner surface of the outer mold into contact with the outer surface of the inner mold for molding, the inner mold for molding is rapidly cooled to obtain a molded product. JP-A-4-77231
In the gazette, when the parison is brought into contact with the molding surface of the mold, the temperature of the mold is maintained between a temperature near the maximum crystallization speed of the parison and a melting point. Blow molding that prevents die lines and weld lines from remaining on the surface of the molded product and circulates refrigerant through the hollow part of the parison during molding to prevent a prolonged molding cycle time. A method is disclosed. In Japanese Patent Publication No. 6-73903,
A lid having good heat conductivity and a large number of through-holes is fixed to a container-like mold frame to form a mold surface area including the lid and an intermediate layer behind the mold, and the intermediate layer is formed. There is disclosed a molding die in which a resin or metal having low heat conductivity is filled, or a reinforcing rib provided with a conduction hole is provided.

[0003]

There is a demand for obtaining a resin molded product having a mirror surface or a grain surface using a mold having a relatively simple structure. There is also a demand for producing a hollow resin molded product having a mirror surface or a grain surface (eg, an air spoiler of an automobile) by a simple process. JP-A-58-1
In the mold for hollow molding disclosed in Japanese Patent No. 027334, the molding surface is clearly transferred by heating the molding inner mold. However, the molding inner mold is relatively displaced and brought into contact with the cooling outer mold. Since the resin is cooled by the method, the structure of the mold may be complicated and weakened, and the cooling time may be prolonged. Further, there is no mention of the optimum range of the heating temperature and the cooling temperature for cleaning the surface of the resin molded product and shortening the entire cycle time of the molding. JP-A-4-77
In the blow molding method of JP-A-231-231, the molding surface is cleaned by heating and maintaining the temperature of the mold at the above-mentioned temperature. The effect is not very large. Further, since the parison is cooled from the inside by circulating the refrigerant, temperature control for heating and maintaining the temperature of the mold at the above-mentioned temperature becomes complicated. In the apparatus disclosed in Japanese Patent Publication No. Hei 6-73903, heating and cooling of a molding surface are performed by heating a large number of conduction holes provided inside or on the back surface of a lid (mold surface area) on which the molding surface is formed.・ It is performed by passing a cooling medium, and also by sending a heating / cooling medium into the intermediate layer behind the molding surface, but in this device, the heat transfer in the intermediate layer is slow. Therefore, it is difficult to shorten the cycle time. An object of the present invention is to produce a resin molded product having a good mirror surface or grain surface in a relatively short cycle time. It is another object of the present invention to produce a resin molded product having a good mirror surface or grain surface in a relatively simple process. In addition, even if mechanical strength cannot be increased sufficiently because the mold forming the molding surface is relatively thin, it can sufficiently withstand the pressure applied to the molding surface by the molten resin, and the mold has a sufficiently long service life. An object of the present invention is to provide a molding die having excellent properties. It is another object of the present invention to obtain a molded product having good dimensional stability and high accuracy by using this mold.

[0004]

According to the first aspect of the present invention, there is provided a mold having a molding surface for pressing a molten thermoplastic resin against a molding surface so that the thermoplastic resin adheres to and solidifies the molded resin. (A) the molding surface is heated to a temperature not lower than the Vicat softening temperature (T) ° C. of the thermoplastic resin. Means for supplying and enclosing a heating fluid having a bulk modulus of 1 × 10 ^{4 to} 4.5 × 10 ⁴ [kg / cm ² ] into the space; (b) forming the molding surface at (Vicat softening temperature (T) − 10)
A cooling means for cooling to a temperature of not more than ℃. The heating means (a) includes, for example, mechanisms 70 and 71 for supplying heating oil into the space B on the back surface side of the molding surface 30 and a communication with the space B after the space B is filled with oil. A mechanism (valve) 72,77 for closing the flow channel that is being used. Bulk modulus is 1 × 10 ⁴ or more
A 4.5 × 10 ⁴ [kg / cm ² ] fluid is a so-called incompressible fluid (however, in practice, a slight compression occurs).
It is. After the fluid is filled and sealed in the space B, the mold body 4 and the fluid and the mold are exposed to the pressure (blow pressure, injection pressure) of the molten resin applied to the molding surface 30 of the mold body 3. The body 3 acts as an integral rigid body. Therefore, type 3
Even when the resin itself is relatively thin and brittle, it can sufficiently withstand the pressure of the molten resin, and problems such as deformation of the molding surface 30 can be prevented. Since this fluid is also a heating medium, it is supplied into the space B to heat the molding surface 30 to a Vicat softening temperature (T) ° C. or higher. For this reason,
The molding surface 30 is clearly transferred to the surface of the resin, and the transfer of the textured surface and the mirror surface is improved. The cooling means of the above (b) is, for example, a mechanism for injecting a cooling medium such as cooling air or cooling oil onto the back surface 31 of the molding surface 30 of the mold body 3 or for sealing the cooling medium into the space B. , 72. Space B
For example, a fluid having a bulk modulus of 1 × 10 ^{4 to} 4.5 × 10 ⁴ [kg / cm ² ] can be suitably used as a cooling medium to be sealed in the container. Since the molding surface 30 is rapidly cooled to (Vicat softening temperature (T) -10) ° C. or lower by the cooling means (b), the molded product can be quickly removed from the mold, and the molding cycle can be shortened. In addition, since the molding surface 30 of the molding die may be heated and cooled by a medium containing water as a component, the mold body 4 and the molding body 3 are provided with rust prevention measures as necessary. Is done. As a countermeasure, mold materials such as stainless steel, copper alloy, ceramics,
Use of an aluminum alloy or the like may be used. Preferably, stainless steel is used. Other measures include passivation treatment of the metal surface (for example, nitriding treatment), application of a rust preventive paint, and application of a silicone-based sol-gel type paint.

According to a second aspect of the present invention, in addition to the first aspect of the present invention, there is further provided (c) a play between the supported portion around the mold and the support portion of the mold body corresponding to the supported portion. A fitting member provided between the supported portion and the support portion so that the play allows the relative displacement generated between the supported portion and the support portion due to thermal expansion to be absorbed by the holding portion and loosely fitted; d) A molding die to which a component such as a seal member (9) provided in the play portion of the fitting member is added. The fitting member (c) is, for example, a mechanism that loosely fits the convex portion 36 around the mold 3 with play into the concave portion 46 of the corresponding portion of the mold body 4, This is a mechanism for loosely fitting a convex portion (not shown) of a corresponding portion of the mold body 4 into a concave portion (not shown) around the body 3 with play. This mechanism is provided in the whole area or a part of the periphery of the mold 3. Since it is loosely fitted with play,
Even when relative displacement occurs due to thermal expansion between the mold and the mold body 4, the difference can be absorbed to prevent problems such as distortion and damage. According to the second aspect of the invention, since the connecting portion between the mold 3 and the mold body 4 is loosely fitted with play, the heating fluid sealed in the space B, the mold 3 and the mold body 4 to function as an integral rigid body to withstand the pressure of the molten resin applied from the molding surface 30 side, it is necessary to reliably seal the above-mentioned connecting portion and prevent the heating fluid from leaking from the connecting portion. There is. Therefore, the above (d)
Is provided. As this sealing member,
O-ring 9, oil seal, synthetic rubber, metal, felt, leather, cork, etc. can be used. Since the joint between the mold 3 and the mold body 4 can be sealed by this seal member, the heating oil or cooling air or cooling water filled in the space B leaks from the joint between the mold 3 and the mold body 4. Can be prevented. In addition, the heating oil is supplied into the space B
The interior of the space B can be set to a desired pressure because the interior can be sealed at a desired pressure. The sealing member 9
Since the molding surface 30 is heated to the Vicat softening temperature (T) ° C. or higher, it is required that the material be durable at this temperature.

According to a third aspect of the present invention, in addition to the second aspect of the present invention, there is further provided: (e) a thermal conductivity provided between the supported portion of the mold body and the support portion of the mold main body is zero. .001 to 1 [kcal / mh
° C] and the modulus of longitudinal elasticity is 0.1 × 10 ⁴ -100 ×
10 ⁴ [kg / cm ^2] heat-insulating supporting member (1) of; (f) provided on the inner surface of the mold body facing the space, thermal conductivity 0.001~1 [kcal / mh ℃] Heat insulation material
(2); a molding die to which the structural requirement of (1) is added. The heat insulating support member 1 of (e) has a thermal conductivity of 0.001 to 1
[kcal / mh ° C], preferably 0.005 to 0.8 [kcal / mh
° C], more preferably 0.01 to 0.5 [kcal / mh ° C]
And the longitudinal elastic modulus is 0.1 × 10 ^{4 to} 100 × 10
⁴ [kg / cm ² ], preferably 0.2 × 10 ⁴ to 40 × 10
⁴ [kg / cm ² ], more preferably 1 × 10 ^{4 to} 20 × 10 ⁴ [k
g / cm ² ] and may have a thermal conductivity of 0.001 to 1 [kcal / mh ° C.], preferably 0.00
5 to 0.8 [kcal / mh ° C], more preferably 0.01 to
0.5 [kcal / mh ℃] material and longitudinal elastic modulus 0.1 × 1
0 ^{4 to} 100 × 10 ⁴ [kg / cm ² ], preferably 0.2 × 1
0 ⁴ to 40 × 10 ⁴ [kg / cm ² ], more preferably 1 × 10 4
^It may be configured as a laminated structure using a material of ^{4 to} 20 × 10 ⁴ [kg / cm ² ]. In other words, if the mold 3 and the mold body 4 can be thermally insulated, and the mold 3 can be reliably supported by the mold body 4 without backlash against the pressing force applied from the mold body 3 to the mold body 4 side. Good. The reason why the above range is indicated as the thermal conductivity of the heat-insulating support member is that if the thermal conductivity is less than 0.001 [kcal / mh ° C], a special material is required and the material becomes impractical. If it exceeds 1 [kcal / mh ° C], the desired heat insulating effect cannot be obtained. The reason why the above range is indicated as the longitudinal elastic modulus of the heat insulating support member is that the longitudinal elastic modulus is 0.1 × 10 ⁴ [kg / cm ² ].
If it is less than 10, the rigidity is insufficient and the seal is insufficient, and
If it exceeds 0 × 10 ⁴ [kg / cm ² ], it becomes difficult to process the heat insulating support. Thermal conductivity 0.001 to 1 [kcal / mh
° C] and the longitudinal elastic modulus is 0.1 × 10 ^{4 to} 100 × 10
⁴ [kg / cm ² ] materials include polyarylate, polyetheretherketone, polyphenylene oxide, modified polyphenylene oxide, polyamide, acetal resin, ethylene tetrafluoride resin, ceramics, PC, phenolic resin, urea, melamine, Glass, unsaturated polyester, and the like. Preferred are phenol resins, urea resins, melamine, and unsaturated polyesters, and more preferred are phenol resins. Heat insulation member 2 of (f) above
The heating oil or the like supplied into the space is
By insulating the heating oil, the temperature of the heating oil or the like is prevented from lowering. Materials for the heat insulating member 2 include polyarylate, polyether ether ketone, polyphenylene oxide, modified polyphenylene oxide, polyamide, acetal resin, tetrafluoroethylene resin, ceramics, PC, phenolic resin, urea, melamine,
Glass, unsaturated polyester, etc., asbestos, rigid urethane foam, rock wool, glass wool, calcium silicate, polystyrene foam, water-repellent pearlite, cork, wood (cedar), rubber, quartz glass, foam beads, etc., and these Two or more combinations can be used. Preferably, phenolic resin, urea, melamine, unsaturated polyester, asbestos, rigid urethane foam, foam beads can be used.

[0007] The invention of claim 4 is the invention of claim 1, claim 2,
The invention according to claim 3, further comprising: (g) a position in said space for heating said molding surface to a temperature equal to or higher than a Vicat softening temperature (T) ° C. of said thermoplastic resin and facing a back surface of said molding surface. And a radiant heating means (5) for radiantly heating the back surface. Radiation heating means of the above (g)
5 can be configured, for example, by providing a halogen heater 5 so as to face the back surface 31 of the molding surface 30 of the mold 3.
The molding surface 30 to which the molten resin is pressed and adhered is heated not only by the heating fluid sealed in the space B but also by the heat radiated from the halogen heater 5 to rise to the Vicat softening temperature (T) ° C. or higher. Since the molding surface 30 is heated, the molding surface 30 can be clearly transferred to the surface of the resin, and the transfer of the grained surface and the mirror surface is improved. The fluid sealed in the space B may be heated by the halogen lamp 5.

According to a fifth aspect of the present invention, there is provided a method according to any one of the first to fourth aspects of the present invention, further comprising the steps of:
+100) The modulus of longitudinal elasticity at ℃ is 0.01 to 10 [kg /
cm ² ], preferably in the range of 0.05 to 2 [kg / cm ² ],
More preferably, a hollow parison using a thermoplastic resin in the range of 0.1 to 1 [kg / cm ² ] is supplied, and the outer surface of the hollow parison is 100 [kg / cm ² ] or less on the molding surface. It is preferably pressed and adhered at a pressure of 1 to 10 [kg / cm ² ], and in this case, preferably, for the purpose of further improving the transferability by further improving the adhesion between the outer surface of the parison and the molding surface. The air between the parison and the molding surface is discharged to the outside by, for example, vacuum suction or the like through a fine gap provided in the molding surface, and the molding surface is heated to a Vicat softening temperature (T) ° C. or higher, preferably (Vicat softening temperature (T). T) +10) ° C. or higher, more preferably (Vicat softening temperature (T) +20) ° C. or higher, and then the molding surface is heated to (Vicat softening temperature (T) −10) ° C. or lower, preferably (Vicat softening temperature). (T) -20) C or lower More preferably to obtain a molded article was cooled to (Vicat softening temperature (T) -40) ° C. temperature below a blow molding process. The reason that the above range is indicated as the longitudinal elastic modulus at (Vicat softening temperature (T) +100) ° C. of the thermoplastic resin is that the longitudinal elastic modulus is less than 0.01 [kg / cm ² ]. In the case of (1), drawdown of the parison occurs and stable molding cannot be performed. On the other hand, if the longitudinal elastic modulus exceeds 10 [kg / cm ² ], a large molding pressure is required for forming the parison. This is because a very large blow pressure is required to inflate the parison and press it against the molding surface. Molding material suitable for this molding method, that is, (Vicat softening temperature + 100) ° C
Examples of the thermoplastic resin having a modulus of elasticity in the range of 0.01 to 10 [kg / cm ² ] include AS resin, polystyrene, high impact polystyrene, and acrylonitrile-
Graft copolymer of butadiene rubber-styrene (ABS resin), graft copolymer of acrylonitrile-butadiene rubber-styrene-α-methylstyrene (heat-resistant ABS resin), acrylonitrile-ethylene-
Graft copolymer (AES resin) composed of propylene rubber-styrene and / or methyl methacrylate, graft copolymer composed of acrylonitrile-hydrogenated diene rubber-styrene and / or methyl methacrylate, acrylonitrile-silicone rubber-styrene And / or a graft copolymer of methyl methacrylate, polyethylene, polypropylene, polycarbonate, polyphenylene ether, polyoxymethylene, nylon, methyl methacrylate polymer, polyether sulfone, polyarylate, chloride Vinyl, maleimide compound-copolymer and rubbery polymer composed of styrene and / or acrylonitrile and / or α-methylstyrene-maleimide compound-
Examples include graft copolymers of styrene and / or acrylonitrile and / or methyl methacrylate and / or α-methylstyrene, and composites thereof, and resins obtained by adding a filler to these. Examples of molded articles suitably molded by this molding method include, for example, housings, sports products, playground equipment, vehicle products, furniture products,
Sanitary products, building material products, kitchen products, furthermore, the molded product is a molded product having a foam layer in the hollow portion, the molded product is manufactured by a multilayer blow molding method, the molded product is plated, This is a molded product that has been sputtered, deposited, and painted. Specific examples of these molded articles include, as a housing, a cooler box, a TV, an audio device, a printer, a facsimile, a copier, a game machine, a washing machine, an air conditioner, a refrigerator, a vacuum cleaner, an attache case, a musical instrument case, and a tool. There are boxes, containers, camera cases, etc.
Sports products include, for example, swimming boards,
Surfboards, windsurfing, skiing, snowboarding, skateboarding, ice hockey sticks, curling balls, gateball rackets, tennis rackets, canoes, boats and the like. As playground equipment, for example,
There are bats, blocks, blocks, fishing tackle cases, pachinko underframes, and the like. Products for vehicles include, for example, air spoilers, doors, bumpers, fenders, bonnets, sunroofs, rear gates, wheel caps, instrument panels,
There are glove box, console box, armrest, headrest, fuel tank, driver's seat cover, trunk tool box, etc. Furniture products include, for example, drawers, desk tops, bed tops / bottoms, mirror frame plates,
There are a box box, a front door, a chair back plate, a bottom plate, a tray, a tray, an umbrella stand, a vase, a medicine box, a hanger, a makeup box, a storage box plate, a book stand, an office desk top plate, an OA desk top plate, and an OA rack. . Sanitary products include, for example, shower heads, toilet seats, toilet plates, drain pans, water tank lids, vanity doors, bathroom doors, and the like. Examples of building material products include ceiling boards, floor boards, wall boards, window frames, doors, benches, and the like. Examples of kitchen products include cutting boards and kitchen doors. Examples of the molded article having the foam layer in the hollow portion include a refrigerator front door and a cooler box. Examples of the molded article manufactured by the multilayer blow molding method include a fuel tank and the like. Examples of the molded product on which the molded product is plated, sputtered, vapor-deposited, and painted include, for example, vehicle exterior parts and electronic equipment soldering. In addition, these are illustrations, and molded articles other than these can also be suitably molded.

According to a sixth aspect of the present invention, in the molding die according to any of the first to fourth aspects, the bulk modulus of elasticity is 1 × 10 ⁴ or more in the space.
In the range of 4.5 × 10 ⁴ [kg / cm ² ], preferably 1 × 10 ⁴ [kg / cm ² ]
Kg3 × 10 ⁴ [kg / cm ² ], more preferably 1 × 1
A heating fluid in the range of 0 ^{4 to} 2 × 10 ⁴ [kg / cm ² ] is supplied and sealed, a molten thermoplastic resin is injected into a closed mold between the molding surfaces, and the molding surface is vicated. Softening temperature (T) ° C or higher, preferably (Vicat softening temperature (T) +
10) C. or higher, more preferably to (Vicat softening temperature (T) +20) .degree. C. or higher, and then the molding surface is heated to (Vicat softening temperature (T) -10) .degree. C. or lower, preferably (Vicat softening temperature (T)). This is an injection molding method in which a molded product is obtained by cooling to a temperature of -20) C or lower, more preferably (Vicat softening temperature (T) -40) C or lower. In the above, the bulk modulus is 1 × 10 ^{4 to} 4.5 × 10
Heating fluids in the range of ⁴ [kg / cm ² ] include machine oil,
Gear oil, refrigerating machine oil, lubricating oil for internal combustion engines, bearing oil, cutting oil, rust preventive oil, turbine oil and the like can be used. Examples of the thermoplastic resin having a modulus of longitudinal elasticity at (Vicat softening temperature +100) ° C of 0.01 to 10 [kg / cm ² ] include, for example, AS resin, polystyrene, high-impact polystyrene, acrylonitrile-butadiene. Graft copolymer (ABS resin) composed of rubber-styrene
Graft copolymer of acrylonitrile-butadiene rubber-styrene-α-methylstyrene (heat-resistant ABS resin), graft copolymer of acrylonitrile-ethylene-propylene rubber-styrene and / or methyl methacrylate (AES resin), acrylonitrile -Hydrogenated diene rubber-graft copolymer comprising styrene and / or methyl methacrylate, SX, polyethylene, polypropylene, polycarbonate, polyphenylene ether, polyoxymethylene, nylon, methyl methacrylate polymer , Polyethersulfone, polyarylate,
Copolymer of vinyl chloride, maleimide compound-styrene and / or acrylonitrile and / or α-methylstyrene, rubbery polymer-maleimide compound-styrene and / or acrylonitrile and / or methyl methacrylate and / or α-methylstyrene And a resin obtained by adding a filler to these composites and the like.

[0010]

【Example】

First Embodiment FIG. 1A shows a first embodiment. FIG. 3 shows a mounting structure of a corner portion of a molding die of each embodiment. Each molding die includes a mold body 3 having a molding surface 30 and a mold body 4 supporting the mold body 3. Having. The mold 3 and the mold body 4 are both made of stainless steel. As shown in FIG. 3, a supported plate 36 projecting around the periphery of the mold body 3 has a play A in a groove 46 provided in the mold body 4 so as to correspond to the supported plate 36. , So that the mold 3 is supported by the mold body 4. Note that the groove 46 is provided in the main body plate 40 having the overhang portion 400a.
0 is attached to the main body 401 with bolts 403. Also, as shown in FIG. 3A, corners of four main body plates 400 arranged in a rectangular shape in a top view of the molding surface 30 are provided at the corners.
A gap S of approximately 0.1 [mm] is provided between adjacent main body plates 400. A heat insulating layer (heat insulating support member) 1 made of phenol resin having a thickness of 10 [mm] is provided on the surfaces of both opposing walls of the groove 46.
An O-ring 9 is fitted in the gap. For this reason, even when the mold 3 and the mold body 4 are thermally expanded by the heat during the molding of the molten resin, and the relative displacement between the supported plate 36 and the groove 46 occurs, the displacement is caused by the play. Absorbed by A,
The adverse effects (bending, distortion, shortening of life, etc. of the mold 3) are prevented. Moreover, a precise molded product can be obtained.
Further, the mold body 3 meets the conditions of the present invention (the modulus of longitudinal elasticity is 0.1 × 1).
0 ⁴ ~100 × 10 ⁴ through the insulation layer 1 of phenolic resin that satisfies the material) of [kg / cm ^2] because it is supported on the die body, the problem of rattling or the like is prevented. Also, type 3
Since the space B formed between the back side of the mold and the mold body 4 is sealed by the O-ring 9, the valve 72 and the pipe 7
1. Heating oil supplied to and enclosed in the space B at the time of heating through the nozzle 70 and cooling oil similarly enclosed in the space B at the time of cooling are connected to the connecting portion (mold) of the mold 3 and the mold body 4. Three
Supported by the mold 4 = supported plate 36 and groove 46
Part) and the space generated in that case
The pressure in B is prevented from lowering, and the molding surface 30 is prevented from bending due to the lowering. The heating oil / cooling oil injected into the space B is discharged through the pipe 76 and the valve 77. As shown in FIG. 3B, a phenol resin layer 22 having a thickness of 10 [mm] and an asbestos layer 21 having a thickness of 2 [mm] are provided on the inner surface of the mold body 4 facing the space B. Is provided, the heat of the heating medium in the space B escapes through the mold body 4 and the external heat passes through the mold body 4 The problem of being transmitted to the cooling water is prevented. Therefore, the temperature of the heating oil supplied into the space B is prevented from lowering, and the transferability and dimensional stability of the molding surface are improved. In the first embodiment, ABS45A (Vicat softening temperature 105 ° C., manufactured by Nippon Synthetic Rubber Co., Ltd.) having a modulus of longitudinal elasticity at 205 ° C. of 0.3 [kg / cm ² ] was used as the thermoplastic resin material. Using IPB-EP-55 (manufactured by Ishikawajima-Harima Heavy Industries, Ltd.) as a blow molding machine, blow molding was performed at the timing of FIG. 4 under the following conditions. That is, the conditions are as follows: (1) Extruder temperature: 220 ° C. (2) Mold clamping force: 15 ton (3) Parison blowing pressure: 6 kg / cm ² (4) Heating machine oil sealed in heating space B of molding surface 30 Pressure: 6 kg / cm ² Final temperature of molding surface 30: 140-150
℃ Heating and holding time of molding surface 30: 10 sec (5) Cooling of molding surface 30 Pressure of cooling machine oil filled in space B: 6 kg / cm ² Final cooling temperature of molding surface 30: 70 ℃ Cooling and holding of molding surface 30 Time: 60 sec Total process time: 150 sec. The heating and cooling machine oil used was Daphne Thermic Oil 32 manufactured by Idemitsu Kosan Co., Ltd. Comparing the molded product (Example product) molded in this way with the molded product (Comparative product) molded without heating (4) enclosing the heating oil in the space B above (Example product) Has a surface gloss of 95% and a corner R of 0.5 or less and has no deformation, whereas the comparative product has a surface gloss of 20% or less and a corner R of 0.5 or more and is deformed. was there. In other words, the product of Example has a better transfer of the molding surface, and the corner portion R which cannot be obtained by the conventional blow molding is obtained.
However, a small molded product could be molded with high accuracy, and the dimensional stability was excellent. The outside dimensions of the mold: 460 (L) x 560 (W) x 720
(H) [mm] Molded product size: 120 (L) x 40 (W) x 480 (H) [mm].

Second Embodiment FIG. 1B shows a second embodiment. Hereinafter, a configuration different from the first embodiment will be described, and a description of the same configuration as the first embodiment will be omitted. In the second embodiment, as the heating means, a configuration was used in which the machine oil sealed in the space B was heated in the halogen lamp 5 provided in the space B. The total output of the halogen lamp 5 is 60 [kW] (30 [kW] on one side), and the ultimate temperature of the molding surface 30 is the same as that of the first embodiment. Also in the case of the second embodiment, the same effect as in the case of the first embodiment was obtained.

Third Example Injection molding was performed using a molding die represented as a schematic diagram equivalent to FIG. 1A. That is, as a thermoplastic resin material, ABS15 (Vicat softening temperature of 100 ° C. manufactured by Japan Synthetic Rubber Co., Ltd.) and a longitudinal elastic modulus at 200 ° C. of 0.2 [k]
g / cm ² ]) and the injection molding machine IS170FA3-
Using 5A (manufactured by Toshiba Corporation), injection molding was performed under the following conditions. The conditions are as follows: (1) Cylinder temperature: 210 ° C. (2) Gate: Two places of side gates (3) Heating of molding surface 30 Pressure of heating machine oil sealed in space B: 6 kg / cm ² Final temperature: 140-150
° C (4) Cooling of the molding surface 30 Pressure of the cooling machine oil sealed in the space B: 6 kg / cm ² Final cooling temperature of the molding surface 30: 50 ° C. The heating and cooling machine oil used was Daphne Thermic Oil 32 manufactured by Idemitsu Kosan Co., Ltd. A comparison between the molded product (Example product) molded in this way and the molded product (Comparative product) molded without heating by enclosing the heating oil in the molding surface 30 (Comparative product) in the above (3) The surface glossiness of the sample was 95% and no weld was observed and there was no deformation. On the other hand, the surface glossiness of the comparative example was 85% and the weld was observed and deformed. That is, the example product had better transfer of the molding surface, was superior in preventing weld, and had good dimensional stability. The outside dimensions of the mold: 400 (L) x 400 (W) x 350
(H) [mm] Molded product dimensions: 50 (L) x 3.2 (W) x 80 (H) [mm].

Another Embodiment FIG. 2A shows a structure of the structure shown in FIG.
A plurality of rod-shaped reinforcing ribs 6 are provided between the back side of the mold 3 and the inner surface of the mold body 4 (the surface facing the back 31 of the mold 3). It is a supporting structure. Further, FIG. 2B shows the structure between the back side of the mold 3 and the inner surface of the mold body 4 (the surface facing the back 31 of the mold 3) in the structure of FIG. 1B. Multiple bar-shaped reinforcing ribs 6
The reinforcing rib 6 is used to support the back side of the mold 3. Thus, in the other embodiment, the reinforcing rib
6, the pressure of the heating machine oil / cooling machine oil supplied to and enclosed in the space B through the valve 72, the pipe 71, and the nozzle 70 is applied from the molding surface 30 side of the mold body 3. Even when the pressure is lower than the pressure (parison blowing pressure / injection pressure), the mold body 3 can be supported, and deformation of the molded product due to bending of the molding surface 30 can be prevented.

[0014]

According to the present invention, a resin molded article having a good mirror surface or grain surface can be produced in a relatively short cycle time. In addition, it can be produced by a relatively simple process. Also, even if the mechanical strength cannot be sufficiently increased because the mold forming the molding surface is relatively thin, it can sufficiently withstand the pressure applied to the molding surface by the molten resin, and the life of the mold is sufficiently long. A molding die with excellent durability can be obtained. In addition, a molded product with good dimensional stability and high accuracy can be obtained using this mold.

[Brief description of the drawings]

FIGS. 1A and 1B are schematic diagrams showing a mold according to an embodiment, wherein FIG. 1A shows a first embodiment and FIG. 1B shows a second embodiment.

FIG. 2 is a schematic view showing a mold according to another embodiment, and FIG.
Shows another embodiment corresponding to the first embodiment, and (b) shows another embodiment corresponding to the second embodiment.

3A and 3B show a mounting structure of a corner portion of each molding die of the embodiment, wherein FIG. 3A is a view as viewed from the molding surface 30 side, and FIG. 3B is a sectional view taken along the line II of FIG.

FIG. 4 is a timing chart showing steps of a blow molding method according to an embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat insulation layer (heat insulation support member) 2 Heat insulation layer (heat insulation member) 3 Mold 30 Molding surface 4 Mold main body 5 Halogen lamp 6 Bar-shaped reinforcing rib

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B29L 22:00 (72) Inventor Fumio Kurihara 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) Reference Document JP-A-61-19327 (JP, A) JP-A-6-328549 (JP, A) JP-A-2-88216 (JP, A) JP-A-7-1459 (JP, A) JP-A-62 130762 (JP, A) Tokuhyo Hei 4-505294 (JP, A) (58) Fields surveyed (Int. Cl. ⁶ , DB name) B29C 33 / 02,33 / 38,45 / 26,45 / 73, 49/00

Claims (8)

(57) [Claims] 1. A mold provided with a molding surface for pressing and adhering a molten thermoplastic resin to a molding surface so as to be adhered and solidified, and a mold is provided by securing a space between the molding surface and the back surface of the molding surface. A molding die supported by a main body and having the following components (a) and (b): (a) heating the molding surface to a temperature equal to or higher than the Vicat softening temperature (T) ° C. of the thermoplastic resin. Means for supplying a heating fluid having a bulk modulus of 1 × 10 ^{4 to} 4.5 × 10 ⁴ [kg / cm ² ] into the space so as to fill the space; (b) setting the molding surface to (Vicat softening temperature (T -10)
Cooling means for cooling to a temperature of not more than ° C. 2. The method according to claim 1, further comprising:
(D) a molding die having the respective constituent requirements: (c) a supported portion around the mold and a supporting portion of the die body corresponding to the supported portion are gently provided with play. A fitting member provided on the supported portion and the support portion so that a relative displacement generated between the supported portion and the support portion due to the fitting and thermal expansion is absorbed by the play; A sealing member provided at the play portion of the member. 3. The method according to claim 2, further comprising:
(F) a molding die having the respective constituent requirements: (e) a thermal conductivity provided between the supported portion of the die and the support portion of the die body, wherein the thermal conductivity is 0.001 to 1 [ kcal / mh
° C] and the modulus of longitudinal elasticity is 0.1 × 10 ⁴ -100 ×
10 ⁴ heat-insulating supporting member ^{[kg / cm 2]; (} f) provided on the inner surface of the mold body facing the space, the heat insulating member of the heat conductivity 0.001~1 [kcal / mh ℃] . 4. The molding die according to claim 1, further comprising the following component (g): (g) a vicat of said thermoplastic resin with said molding surface. Radiation heating means provided in the space and at a position facing the back surface of the molding surface to heat the back surface to a temperature equal to or higher than the softening temperature (T) ° C. for radiantly heating the back surface. 5. The modulus of longitudinal elasticity between the molding surfaces of the molding die according to claim 1 at (Vicat softening temperature (T) +100) ° C. is from 0.01 to 10 kg / cm ^2. ], A hollow parison using a thermoplastic resin is supplied, and the outer surface of the hollow parison is set to 100 [kg / cm] on the molding surface.
² ] The molded surface is heated to a temperature higher than or equal to the Vicat softening temperature (T) ° C. by pressing under the following pressure, and then the molded surface is heated to (Vicat softening temperature (T) −1).
0) A blow molding method in which a molded product is obtained by cooling to a temperature of not more than ° C. 6. The molding die according to claim 1, wherein a bulk modulus of elasticity is 1 × 10 ^{4 to} 4.5 × 10 ⁴ [kg] in said space.
/ cm ² ] by supplying a heating fluid and injecting a molten thermoplastic resin into a closed mold between the molding surfaces, heating the molding surface to a Vicat softening temperature (T) ° C. or higher, and thereafter , And the molding surface is (Vicat softening temperature (T) -1)
0) An injection molding method in which a molded product is obtained by cooling to a temperature of not more than ° C. 7. A vicat softening temperature which is supplied as a hollow parison between the molding surfaces of the molding die according to claim 1 and is adhered to the molding surface at a pressure of 100 [kg / cm ² ] or less. After being heated to (T) ° C. or higher, it is cooled to a temperature of (Vicat softening temperature (T) −10) ° C. or lower to obtain a molded article. The longitudinal elastic modulus at (Vicat softening temperature (T) +100) ° C. Is a thermoplastic resin material of 0.01 to 10 [kg / cm ² ]. 8. A modulus of longitudinal elasticity at (Vicat softening temperature (T) +100) ° C. of 0.01 to 10 [kg / cm] between the molding surfaces of the molding die according to any one of claims 1 to 4. ² ], a hollow parison using a thermoplastic resin material is supplied, and is adhered to the molding surface at a pressure of not more than [kg / cm ² ] and heated to a Vicat softening temperature (T) ° C. or higher. Temperature (T) -10) A molded article obtained by cooling to a temperature of not more than 10 ° C.