JP2900829B2 - 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 The pressure is relatively low (4 to 10 kg / cm ² ) due to the pressure of the fluid, so the molding surface is not transferred cleanly and is not suitable for obtaining a molded product having a mirror surface or grain surface. It is. However, it is widely used because it is suitable for mass production of hollow articles. In this blow molding method, before the parison is pressed against the mold surface, the radiant heating means is inserted so as to face the mold surface and the mold surface is heated by the radiant heating means, and then the radiant heating means is retracted. After that, a method of supplying a parison and pressing it against a mold surface is disclosed in Japanese Patent Application Laid-Open No. 2-88216.
Japanese Patent Application Laid-Open No. 58-102732 discloses a hollow molding die having a thin molding inner die and a cooling outer die capable of contacting / isolating the molding inner die. In this mold,
The inner mold for molding is heated before the parison is supplied to improve the surface gloss of the hollow molded article, and after the parison contacts the molding surface of the inner mold for molding, the inner surface of the outer mold for cooling is cleaned. By contacting the outer surface of the inner mold for molding, the inner mold for molding is rapidly cooled to obtain a molded product. JP-A-4-77
No. 231 discloses that, when a parison is brought into contact with a molding surface of a molding die and molded, the temperature of the molding die is maintained between a temperature near a temperature at which the crystallization speed of the parison is maximum and a melting point. A blow line that prevents die lines and weld lines from remaining on the surface of a molded product and circulates a refrigerant through the hollow portion of the parison during molding, thereby preventing a prolonged molding cycle time. A molding method is disclosed. Japanese Patent Publication No. 6-73903 discloses that a lid having good heat conductivity and a large number of conductive holes is fixed to a container-shaped die frame, and a die surface area formed by the lid and a rear surface of the die are formed. There is disclosed a molding die in which an intermediate layer is formed and the intermediate layer is filled with a resin or metal having low heat conductivity, or a reinforcing rib provided with a conductive 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-2-88
No. 216, for example, before the parison is supplied, the radiant heating means is inserted and heated so as to face the mold surface, and then the radiant heating means is retracted, and then the parison is supplied. In the method, when the mold surface heated by the radiant heating means is a mirror surface (usually a mirror surface),
Since most of the radiant heat is reflected on the mold surface, there is a problem that the heating efficiency is poor. JP-A-58
In the mold for hollow molding disclosed in JP-A-10-27334, the molding surface is clearly transferred by heating the molding inner mold, but the molding inner mold is relatively displaced and brought into contact with the cooling outer mold. Since the resin is cooled by this, the structure of the mold may become complicated and weak, 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-
In the blow molding method disclosed in Japanese Patent No. 77231, the molding surface is cleaned by heating and maintaining the temperature of the molding die 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. It is another object of the present invention to heat the molding surface quickly.

[0004]

According to the first aspect of the present invention, there is provided a mold having a molding surface (30) for pressing a molten thermoplastic resin against a molding surface (30) so as to be adhered and solidified. Body (3)
With a space (B) secured between the mold surface and the back surface of the molding surface, and supported by the mold body (4): (a) The molding surface (30) is heated to the Vicat softening temperature of the thermoplastic resin ( T) the space to be heated to a temperature of at least
(B) radiant heating means (5) provided in a position facing the back surface (31) of the molding surface (30) and radiantly heating the back surface (31); (b) the molding surface (30) ) To (Vicat softening temperature (T) -1)
0) cooling means for cooling to a temperature of not more than ° C; (c) a pair of a supported portion around the mold (3) and the supported portion;
With play (A) between the mold and the supporting part of the mold body (4).
Gently fit, and with the supported part by thermal expansion
Absorb the relative displacement that occurs with the support by the play (A)
So as to be provided on the supported portion and the support portion.
A molding die having the components of the fitting member . The radiant heating means (a) can be composed of, for example, a halogen heater 5 that radiates radiant heat to the back surface 31 of the molding surface 30 of the mold 3.
Since the molding surface 30 to which the molten resin is pressed and adhered is heated to the Vicat softening temperature (T) ° C. or higher by the radiant heating means (a), the molding surface 30 can be transferred to the surface of the resin neatly,
Good transfer of textured surface and mirror surface. In addition, radiation heating
Not to the (generally specular) molding surface 30, but to the molding surface 30
Since the heat is applied to the back surface 31 of the molding surface having a lower radiant heat reflectance than the radiant heat, heating by the radiant heat is quick, and the time required to reach a desired temperature is short. The cooling means (b) can be constituted by, for example, mechanisms 70, 71, 72 for injecting cooling air or cooling water onto the back surface 31 of the molding surface 30 of the mold 3.
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. Further, since the main molding die may be heated and cooled with a medium containing water as a component,
Rust prevention measures have been applied to the mold and the body 3 as necessary.
As a countermeasure, use of a stainless steel, a copper alloy, a ceramic, an aluminum alloy, or the like, which does not easily rust, as a material of the mold can be cited. 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.

The fitting member (c) is, for example, a mold 3
A mechanism that loosely fits the convex portion 36 around the mold into the concave portion 46 of the corresponding portion of the mold body 4 with play, and conversely,
3 is a mechanism for loosely fitting a convex portion (not shown) of the corresponding portion of the mold body 4 with play into a concave portion (not shown) around the mold 3. This mechanism is provided in the whole area or a part of the periphery of the mold 3. Because it is loosely fitted with play,
Even when a relative displacement occurs between the mold body 3 and the mold body 4 due to thermal expansion, the difference can be absorbed and problems such as distortion and damage can be prevented.

A second aspect of the present invention is the method according to the first aspect , further comprising: (d) a surface treatment formed on the back surface of the molding surface so as to favorably absorb the radiation radiated from the radiant heating means. Part; a molding die having the following constitutional requirements. The surface treatment section (d) includes: (1) In addition to the case where the molding surface back surface 31 is surface treated,
(2) When applying a paint with good heat absorption properties on the back of the molding surface,
(3) In some cases, the surface area of the molding surface back surface 31 is increased to increase the heat absorption. The above (1) includes a carburizing method, a cyaniding method, a nitriding method, a metal infiltration method, an electric plating, a hot dip plating, a metal spraying method, a vacuum evaporation method, and fading. The above (2) includes application of a dark color coating, black dyeing, application of a light selective absorbing coating, and application of a heat ray absorbing coating. As (3) above,
There are mountain cutting and grooving sandblasting. The amount of heat absorbed by the back surface 31 of the molding surface can be increased by one or more of these treatments, and the heating efficiency by the radiant heating means (a) can be increased.

[0007] The invention of claim 3 is claim 1 or claim.
In 2, further, (e) and the supported portion of the mold body (3) provided between the support portion of the mold body (4), the thermal conductivity of 0.001 to 1 [k
cal / mh ° C] and the modulus of longitudinal elasticity is 0.1 × 10 ⁴ -1
It is a molding die having a constitutional requirement of 00 × 10 ⁴ [kg / cm ² ] of a heat-insulating support member (1). (E) above
Thermal insulation support member 1 has a thermal conductivity of 0.001 to 1 [kcal /
mh ° C], preferably 0.005 to 0.8 [kcal / mh ° C],
More preferably, it is 0.01 to 0.5 [kcal / mh ° C.] and the longitudinal elastic modulus is 0.1 × 10 ^{4 to} 100 × 10 ⁴ [kg / c
m ² ], preferably 0.2 × 10 ⁴ to 40 × 10 ⁴ [kg / c
m ² ], more preferably 1 × 10 ^{4 to} 20 × 10 ⁴ [kg / c
m ² ] and may have 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] material and longitudinal elastic modulus 0.1 × 10 ⁴ ~
100 × 10 ⁴ [kg / cm ² ], preferably 0.2 × 10 ⁴ to
40 × 10 ⁴ [kg / cm ² ], more preferably 1 × 10 ⁴ to 2
It may be configured as a laminated structure using a material of 0 × 10 ⁴ [kg / cm ² ]. In other words, the mold body 3 and the mold body 4 can be supported in an insulated state, and the mold body 3 is rattled by the mold body 4 against the pressing force applied from the mold body 3 side to the mold body 4 side. It is sufficient if it can be supported without any problem. 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. , 1 [kcal / mh ℃]
This is because a desired heat insulating effect cannot be obtained if the ratio exceeds the range. The reason that 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
^If it is less than ⁴ [kg / cm ² ], the rigidity is insufficient and the sealing is not sufficient, and if it exceeds 100 × 10 ⁴ [kg / cm ² ], it becomes difficult to process the heat insulating support. Thermal conductivity 0.001
At 1 [kcal / mh ° C], the modulus of longitudinal elasticity is 0.1 × 10 ⁴ -10
Materials of 0 × 10 ⁴ [kg / cm ² ] 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.

[0008] The invention of claim 4 is the invention of claim 1, claim 2,
Or in claim 3 , further comprising: (f) a fluid supply means for introducing and / or discharging a fluid into the space; (g) a seal member (9) provided at the play portion of the fitting member; (H) a heat insulating member having a thermal conductivity of 0.001 to 1 [kcal / mh ° C.] provided on an inner surface of the mold body facing the space.
(2); The fluid supply means (f) can be constituted by a pipe, a valve, a pump, a nozzle, or the like for feeding a heating fluid (liquid, gas) or a cooling fluid (liquid, gas) into the space (B). By supplying the fluid into the space (B), the pressure in the space (B) can be balanced with the pressure of the molten resin applied from the molding surface 30 side. As the sealing member of the above (g), O
Ring 9, oil seal, synthetic rubber, metal, felt,
Skin, cork and the like can be used. Since the connection between the mold body 3 and the mold body 4 can be sealed by this seal member,
Heated steam, heated oil, cooling air, or cooling water supplied to the space B can be prevented from leaking from the connection between the mold 3 and the mold body 4. Further, since the heating steam and the heating oil can be sealed in the space B at a desired pressure, the inside of the space B can be set to a desired pressure. In addition,
Since the molding surface 30 is heated to the Vicat softening temperature (T) ° C. or higher, the sealing member 9 is required to be a material having durability at this temperature. (H) above
The heat insulating member 2 serves to insulate the heating steam or heating oil supplied into the space B from the mold body 4 to prevent the temperature of the heating steam or heating oil from lowering. Examples of the material of the heat insulating member 2 include polyarylate, polyetheretherketone, polyphenylene oxide, modified polyphenylene oxide, polyamide, acetal resin, tetrafluoroethylene resin, ceramics, PC, phenolic resin, urea, melamine, glass, and unsaturated. Polyester, asbestos, hard urethane foam, rock wool, glass wool, calcium silicate, polystyrene foam, water-repellent perlite, cork, wood (cedar), rubber, quartz glass, foam beads, etc., and two or more of these Combinations can be used. Preferably, phenolic resin, urea, melamine, unsaturated polyester, asbestos, rigid urethane foam, foam beads can be used.

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, which comprises 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, for example, a cooler box, a TV, an audio device, a printer, a fax, a copier, a game machine, a washing machine, an air conditioner, a refrigerator, a vacuum cleaner, an attache case, an 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, the longitudinal elastic modulus at (Vicat softening temperature (T) +100) ° C. is set in the closed mold surrounded by the molding surface of the molding die of the first to fourth aspects. 0.01 to 10 kg / cm ² , preferably 0.05 to
2 [kg / cm ² ], more preferably 0.1 to 1 [kg / cm ² ]
Is injected in a molten state, and the molding surface is subjected to a Vicat softening temperature (T) ° C. or higher, preferably (Vicat softening temperature (T) +10) ° C. or higher, more preferably (Vicat softening temperature (T) ) +20) Heat to above ℃,
Thereafter, the molding surface is set to (Vicat softening temperature (T) -1).
0) C. or lower, preferably (Vicat softening temperature (T) -2)
0) ° C. or lower, more preferably (Vicat softening temperature (T)
-40) This is an injection molding method in which a molded product is obtained by cooling to a temperature of not more than ℃. In the above, (Vicat softening temperature +
100) As a thermoplastic resin having a longitudinal elastic modulus at a temperature of 0.01 to 10 [kg / cm ² ], for example, AS resin,
Polystyrene, high-impact polystyrene, acrylonitrile-butadiene rubber-styrene graft copolymer (ABS resin), acrylonitrile-butadiene rubber-styrene-α-methylstyrene graft copolymer (heat-resistant ABS resin), acrylonitrile-
Graft copolymer (AES resin) composed of ethylene-propylene rubber-styrene and / or methyl methacrylate, acrylonitrile-hydrogenated diene rubber-graft copolymer composed of styrene and / or methyl methacrylate, SX, polyethylene, Polypropylene, polycarbonate, polyphenylene ether, polyoxymethylene, nylon, methyl methacrylate polymer, polyether
Tersulfone, polyarylate, vinyl chloride, maleimide compound-styrene and / or acrylonitrile and / or
Or a copolymer comprising α-methylstyrene; a rubbery polymer; a maleimide compound; a graft copolymer comprising styrene and / or acrylonitrile and / or methyl methacrylate and / or α-methylstyrene; and a composite thereof. And a resin to which a filler is added.

[0011]

【Example】

First Embodiment FIG. 1 shows a first embodiment, in which (a) shows a case where a surface treatment for improving heat absorption characteristics is not performed on the back surface 31 of the molding surface, and (b) shows a case where heat absorption characteristics are improved on the back surface 31 of the molding surface. This shows the case where surface treatment (black dyeing + mountain cutting) has been performed. 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 all made of stainless steel. As shown in FIG.
A supported plate 36 projecting around the periphery of the mold body 3 is provided in a groove provided in the mold body 4 so as to correspond to the supported plate 36.
The mold body 3 is loosely fitted with a play A into the mold body 46 so that the mold body 3 is supported by the mold body 4. The groove 46 is provided on the main body plate 400 having the overhang 400a.
Is attached to the main body 401 with bolts 403. As shown in FIG. 3A, the corners of each of the four main body plates 400 arranged in a rectangular shape in a top view of the molding surface 30 are substantially zero between the adjacent main body plates 400. A gap S of 1 [mm] is provided. 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. By being absorbed by A and the gap S, adverse effects (bending, distortion, shortening of life, etc. of the mold body 3) are prevented, and a precise molded product can be obtained. Further, the mold body 3 meets the conditions of the present invention (the longitudinal elastic modulus is 0.1%).
Since it is supported by the mold main body through the heat insulating layer 1 of phenol resin which satisfies × 10 ^{4 to} 100 × 10 ⁴ [kg / cm ² ], problems such as rattling can be prevented. Further, since the space B formed between the back side of the mold body 3 and the inner surface of the mold body 4 is sealed by the O-ring 9, the valve 72 passes through the pipe 71, further passes through the nozzle 70, The pressurized air injected into the space B during heating, and the cooling water and air injected into the space B during cooling, cause the connection between the mold 3 and the mold body 4 (the mold 3 is supported by the mold 4). Part = supported plate 36
And the groove 46). In addition,
The air and cooling water injected into the space B are
Exhausted through 77. In the space B, at a position facing the molding surface back surface 31, a total output 6 serving as a radiant heating means is provided.
A halogen lamp 5 of 0 [kW] (30 [kW] on one side) is provided. When the halogen lamp 5 radiates and heats the rear surface 31 of the molding surface, the halogen lamp 5 passes through the bulb 72, the pipe 71, and the nozzle 70.
Air injected at a pressure of [kg / cm ² ] strikes the molding surface back surface 31, and this is balanced with the parison blowing pressure applied from the molding surface 30 side. The rear surface 31 of the molding surface, which is radiantly heated by the halogen lamp 5, is subjected to a surface treatment shown in any of FIGS. 5A to 5E for the purpose of improving the heat absorption characteristics of radiant heat. (A) is an example in which the endothermic property is increased by the black dyeing treatment, (b) is an example in which the surface area is increased by hill cutting, (b) is an example in which the surface area is increased by grooving, and (d) is an example. FIG. 1B shows an example in which the processes (a) and (b) are used in combination, and FIG. 1E shows an example in which the processes (a) and (c) are used in combination. By performing such treatment, most of the heat radiated from the halogen lamp 5 can be absorbed by the mold 3. Also,
As shown in FIG. 3B, a phenol resin layer having a thickness of 10 mm is provided on the inner surface of the mold body 4 facing the space B.
Since the heat insulating layer (heat insulating member) 2 composed of 22 and an asbestos layer 21 having a thickness of 2 [mm] is provided, the heat in the space B (the amount of heat of the air heated by the halogen lamp 5 in the space B) Is prevented from escaping through the mold body 4. Therefore, the temperature in the space B is prevented from lowering, and the transferability and the dimensional stability of the molding surface are improved. In the first example, ABS45A (Vicat softening temperature 105 ° C. manufactured by Nippon Synthetic Rubber Co., Ltd.) was used as the thermoplastic resin material.
Using a modulus of elasticity at 205 ° C. of 0.3 [kg / cm ² ] and IPB-EP-55 (manufactured by Ishikawajima-Harima Heavy Industries, Ltd.) as a blow molding machine, under the following conditions: The blow molding was performed at the timing of 4. The conditions are (1) extruder temperature: 220 ° C. (2) clamping force: 15 ton (3) parison blowing pressure: 6 kg / cm ² (4) heating of molding surface 30 radiation heating by halogen lamp 5 radiation heating Injection pressure of air from the nozzle 70: 6 kg / cm ² Final temperature of the molding surface 30: 150 ° C. Heat retention time of the molding surface 30: 10 sec (5) Cooling of the molding surface 30 Injection from the nozzle 70 (cooling water + air) ) Pressure: 6 kg / cm ² Final cooling temperature of molding surface 30: 70 ° C. Cooling holding time of molding surface 30: 60 sec. The time required for the molding surface 30 to reach 150 ° C. during the radiant heating by the halogen lamp 5 was examined. When the blackening treatment shown in FIG. 5A was performed: 25 [sec] (D) When the black dyeing process and the mountain cutting process are performed: 20 [sec] When the special process is not performed: 90 [sec], and the surface treatment for improving the heat absorption characteristics is performed on the molding surface back surface 31. , It was confirmed that the temperature was raised quickly. 5 (b), 5 (c) and 5 (e) are also set to 150
It was confirmed that the time required to reach ° C was shortened. Molded product molded in this way (Example product)
In comparison with (4) a molded product (comparative example product) molded without heating the molding surface 30 in the above, the surface glossiness of the example product is 95% and the R of the corner portion is 0.5 or less. On the other hand, the surface glossiness of the comparative example product was 20% or less, and the R of the corner portion was 0.5 or more. That is, the example product is
The transfer of the molding surface was good, and a molded product having a small R at the corner, which could not be obtained by conventional blow molding, could be molded with high precision, and the dimensional stability was also 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 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. Injection molding was performed using a molding die represented as a schematic diagram equivalent to FIG. That is, ABS 15 (Vicat softening temperature 100 ° C., manufactured by Japan Synthetic Rubber Co., Ltd.) as a thermoplastic resin material, 20
Injection molding was performed under the following conditions using a longitudinal elastic modulus at 0 ° C. of 0.2 [kg / cm ² ]) and IS170FA3-5A (manufactured by Toshiba Corporation) as an injection molding machine. That is, the conditions are as follows: (1) Cylinder temperature: 210 ° C. (2) Gate: Two places of side gates (3) Heating of molding surface 30 Radiant heating by halogen lamp 5 Air jet pressure from nozzle 70 during radiant heating: 6 kg / cm ² Final temperature of molding surface 30: 150 ° C Heating and holding time of molding surface 30: 10 sec (4) Cooling of molding surface 30 Pressure (cooling water + air) injected from nozzle 70: 6 kg / cm ^{2 of} molding surface 30 Final cooling temperature: 50 ° C. The time required for the molding surface 30 to reach 150 ° C. during the radiant heating by the halogen lamp 5 was examined. When the blackening treatment shown in FIG. 5A was performed: 25 [sec] (D) When the black dyeing process and the mountain cutting process are performed: 20 [sec] When the special process is not performed: 90 [sec], similar to the first embodiment, the second process is performed. Also in the case of the example, it was confirmed that the surface treatment for improving the heat absorption characteristics was performed on the rear surface 31 of the molding surface, whereby the temperature was raised quickly. 5 (b), 5 (c) and 5 (e) are also set to 150
It was confirmed that the time required to reach ° C was shortened. Molded product molded in this way (Example product)
In comparison with (3) a molded product (comparative example product) molded without heating the molding surface 30, the surface glossiness of the example product was 95% and no weld was observed. The surface glossiness of the comparative example product was 85%, and a weld was observed. That is, the transfer of the molded surface was better in the example product, and the prevention of weld was also excellent. 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 heated steam / air / cooling water injected into the space B through the valve 72, the pipe 71, and the nozzle 70 is applied to the pressure applied from the molding surface 30 side of the mold 3 (parison blowing). Pressure / injection pressure)
The mold 3 can be supported, and the deformation of the molded product due to the bending of the molding surface 30 can be prevented.

[0014]

According to the present invention, it is possible to produce a highly accurate resin molded product having a good mirror surface and a grained surface, excellent dimensional stability, and a relatively short cycle time. In addition, it can be produced by a relatively simple process. In addition, since the heating of the molding surface is performed by radiant heating from the back surface of the molding surface, the heating efficiency is good, and the time required to reach a desired temperature is short.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a mold according to a first embodiment;
(A) is an example in which no surface treatment is applied to the molding surface back surface 31,
(B) is an example in which (black dyeing + mountain cutting) processing is performed.

FIG. 2 is a schematic view showing a mold according to another embodiment, and FIG.
2 shows another embodiment corresponding to FIG. 1A, and FIG. 2B shows another embodiment corresponding to FIG. 2B.

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.

FIG. 5 is an explanatory view showing a surface treatment of a back surface of a molding surface.

[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 31 Molding surface back surface 31a Black dyeing processing 31b Mountain cutting processing 31c Grooving processing 31d (black dyeing + grooving) processing 31e (black dyeing + grooving) processing

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B29K 101: 12 (72) Inventor Fumio Kurihara 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Japan Synthetic Rubber Co., Ltd. (56 ) References JP-A-7-1459 (JP, A) JP-A-63-297004 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 33/02-33/04 B29C 33 / 38,45 / 26,45 / 73 B29C 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) to (c) : (a) heating the molding surface to a temperature equal to or higher than the Vicat softening temperature (T) ° C. of the thermoplastic resin; Radiant heating means provided in the space to face the rear surface of the molding surface to radiate and heat the rear surface; (b) setting the molding surface to (Vicat softening temperature (T) -10)
(C) cooling means for cooling to a temperature of not more than 0 ° C. or less;
With play and the support part of the mold body
Mating and thermal expansion produce
The aforementioned relative displacement is absorbed by the play,
A fitting member provided on the supported portion and the support portion. 2. The method according to claim 1 , further comprising:
(D) a surface treatment portion formed on the back surface of the molding surface so as to favorably absorb radiation radiated from the radiant heating means. 3. A molding die according to claim 1 or 2 , further comprising: (e) a supporting part of the die body and a support of the die body. Thermal conductivity of 0.001 to 1 [kcal / mh provided between
° C] and the modulus of longitudinal elasticity is 0.1 × 10 ⁴ -100 ×
10 ⁴ [kg / cm ² ] heat insulating support member. 4. A molding die according to claim 1, 2 or 3 , further comprising the following components (f), (g) and (h): (f) fluid in the space. (G) a seal member provided at the play portion of the fitting member; (h) heat provided at the inner surface of the mold body facing the space. A heat insulating member having a conductivity of 0.001 to 1 [kcal / mh ° C]. 5. A method according to claim 1 to claim between the molding surface of the molding die 4 (Vicat softening temperature (T) +100) modulus at the ℃ is 0.01~10 [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. A claims 1 mold the molding surface in a closed-mold surrounded of 4 (Vicat softening temperature (T)
+100) The modulus of longitudinal elasticity at ℃ is 0.01 to 10 [kg /
cm ² ] of a thermoplastic resin in a molten state, and the molding surface is heated to a Vicat softening temperature (T) ° C. or higher. Thereafter, the molding surface is heated to (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. supplied as a hollow parison between the molding surface of the mold of claim 1 to claim 4, wherein in close contact with the molding surface at 100 [kg / cm ^2] or less of pressure Vicat softening temperature 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 longitudinal elastic modulus at (Vicat softening temperature (T) +100) ° C. of 0.01 to 10 kg / cm ² between the molding surfaces of the molding die according to any one of claims 1 to 4. Is supplied with a hollow parison made of a thermoplastic resin material and heated to a Vicat softening temperature (T) ° C. or higher by closely contacting the molding surface with a pressure of 100 kg / cm ² or less. Temperature (T) -10) A molded article obtained by cooling to a temperature of not more than 10 ° C.