JPH0985751A - Die for molding of thermoplastic resin, molding method and molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a molded body being excellent in surface characteristics without reducing the productivity by a method wherein a thermoplastic polyimide resin to form a coating which is provided on the die surface of a cavity contains an aromatic diamine compound which is expressed by a specified formula, as the diamine component. SOLUTION: This die for thermoplastic resin molding is the one which is used for the molding of a thermoplastic resin, and on the die surface to partition its cavity, a coating layer consisting of a thermoplastic polyimide resin, is provided. Then, the thermoplastic polyimide resin forming the coating layer contains an aromatic diamine compound expressed by the formula, as the diamine compound. In this case, R represents -H, -CH3 or -C2 H5 in the formula. This die for thermoplastic resin molding can be adapted to any molding method as long as it is basically a type of molding method wherein a thermoplastic resin under a molten state is shaped. The die for thermoplastic resin molding especially displays the effects in the improvement of surface characteristics of blow-molded articles which conventionally have had many problems.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a mold used for molding (particularly blow molding) a thermoplastic resin, a molding method using this mold, and a thermoplastic resin molded body molded by this molding method, Although not particularly limited, for example, a thermoplastic resin molding die suitably used for producing a molded article having excellent surface smoothness and luster suitable for an industrial part such as an automobile outer plate, and the like. And a molded body molded by this molding method.

[0002]

2. Description of the Related Art In injection molding or blow molding of a thermoplastic resin, an injection pressure (a blow pressure in the case of blow molding) is used in order to improve transferability of a surface shape of a mold and improve gloss of a molded product. The resin temperature or the mold temperature is raised, and it is said that raising the mold temperature is the method which can expect the greatest effect.

However, increasing the mold temperature increases the time required for cooling and solidifying the plasticized resin, which lengthens the molding cycle and reduces the efficiency of the molding process. Further, a method may be considered in which a heating medium and a cooling medium are alternately flown through the mold to repeat heating and cooling, but the thermal efficiency is poor and the molding cycle itself is not generally shortened.

Therefore, in order to accelerate the response speed of the heating and cooling, a method has been proposed in which the die has a thin structure to reduce the heat capacity (die technology, Vol. 9, No. 13, No. 23 to 23).
34, 1994), but the applicable structure is limited due to problems such as insufficient mold strength, which is not common. Further, a method of rapidly heating only the mold surface by high frequency induction heating has been proposed (Japanese Patent Publication Nos. 58-40504 and 57-57).
No. 4748), however, the high-frequency induction heating device is very expensive, and this method is not common.

By the way, recently, by providing a low thermal conductive layer on the surface of the mold that defines the cavity of the mold, it is possible to prevent the molten resin from rapidly cooling and solidifying in the cavity,
Techniques have been proposed for obtaining a molded product having good surface smoothness. For example, Japanese Patent Application Laid-Open No. 54-142266 discloses a coating layer made of a fluororesin or epoxy resin, and Japanese Patent Application Laid-Open No. 4-219912 discloses a coating layer made of various metal acid values or ceramics. 5-111
In 937, No. 5-169456, No. 6-91736 and No. 6-246797, coating layers made of epoxy resin or polyimide resin are adopted as low thermal conductivity layers.

However, in the coating layer made of a fluororesin or an epoxy resin, since the mold is made of a material typified by iron, its adhesiveness to the mold surface is low and it is difficult to cover it. Also, it lacks durability. In addition, the coating layer consisting of metal oxides and ceramics can only be coated by the plasma spraying method, and this plasma spraying does not give a dense coating layer, which makes it impossible to perform mirror-finishing, and the spraying cost is high. There is a problem that it is not practical.

Further, the coating layer made of polyimide resin is
Although most promising as a method for forming a layer having low thermal conductivity, polyimide resins are generally insoluble and infusible, and therefore, in these reported examples, they are dissolved in a solvent in the state of polyamic acid which is a precursor of polyimide resin. A complicated process of applying this solvent solution to a mold to volatilize the solvent and then heating it to a higher temperature to form a coating layer of a polyimide resin by a dehydration ring-closing reaction is adopted (Japanese Patent Laid-Open No. Hei 5). -16217
No. 2 and No. 7-178803).

For this reason, the use of the coating layer made of this polyimide resin as the low thermal conductivity layer provided on the surface of the mold is
It is difficult to apply to large molds because equipment for heating the entire mold to high temperature is required, and contraction during dehydration ring closure reduces adhesion to the mold surface and peels off the coating layer. However, there is a problem that a special process such as surface polishing and vapor deposition polymerization is required to obtain a smooth coating layer.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a mold for molding a thermoplastic resin capable of producing a molded product having excellent surface characteristics without lowering productivity. Another object of the present invention is to provide a molding method for molding a molded article using such a mold, and further to provide a thermoplastic resin molded article that is molded by this molding method and has excellent surface characteristics. .

[0010]

That is, the present invention is a mold used for molding a thermoplastic resin, and a coating layer made of a thermoplastic polyimide resin is provided on the surface of the mold that defines the cavity of the mold. The thermoplastic polyimide resin that forms the compound has the following general formula (1) as its diamine component.

Embedded image (Wherein R is -H, shows a -CH ₃ or -C ₂ H ₅₎ is a thermoplastic resin mold containing aromatic diamine compound represented by the.

Further, according to the present invention, in molding a thermoplastic resin using the above-mentioned mold for molding a thermoplastic resin, the mold is
It is a method for molding a thermoplastic resin, which comprises heating at a temperature not higher than the glass transition temperature of the thermoplastic polyimide resin forming the coating layer on the surface of the mold and at a temperature not lower than the glass transition temperature of the thermoplastic resin to be molded.

Further, according to the present invention, the center line average roughness (R) according to JIS-B0601 is formed by the above-mentioned forming method.
a thermoplastic resin molded product having surface characteristics such that the surface roughness defined in a) is 0.2 μm or less and / or the 60 ° specular gloss defined by JIS-K7105 is 60% or more. is there.

Hereinafter, the present invention will be described in more detail. The polyimide resin used in the present invention has the following general formula (1) as a part or all of the diamine component.

Embedded image (Wherein R represents —H, —CH ₃ or —C ₂ H ₅ ), and the heat obtained by using the aromatic diamine compound. It is possible to impart excellent solvent solubility and excellent thermoplasticity of melting by heating without impairing the high heat resistance of the thermoplastic polyimide resin.

Specific examples of the aromatic diamine represented by the general formula (1) include 9,9'-bis (3-methyl-4).
-Aminophenyl) fluorene, 9,9'-bis (3-
Ethyl-4-aminophenyl) fluorene, 9,9'-
Bis (4-aminophenyl) fluorene and the like can be mentioned. From the high reaction rate during polymerization, 9,9′-bis (4
-Aminophenyl) fluorene is preferably used. The amount used is 10% or more, preferably 50% or more of the total amount of the diamine component in terms of mole fraction, and if it is less than 10%, the produced polyimide resin may be poor in solvent solubility or heat fusibility. .

The other diamine component which can be used in combination with the aromatic diamine represented by the above general formula (1) is not particularly limited, and diamines used in the production of ordinary polyimide resins can be used as they are. . For example,
As aromatic diamines, p-diaminobenzene, m
-Diaminobenzene, 2,4-diaminotoluene, 2,
6-diaminotoluene, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,
3′-diaminobenzophenone and the like, and as the aliphatic diamine, ethylenediamine, propylenediamine, butylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, and the like, and further as the alicyclic diamine, , 1,4
-Bisaminomethylcyclohexane and the like. These diamine components may be used alone or in combination of two or more.

Specific examples of the tetracarboxylic dianhydride, which is an acid anhydride component to be reacted with the diamine component, include:
Pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4
4'-biphenyltetracarboxylic dianhydride, bis (2,3-dicarboxyphenyl) sulfonic acid dianhydride, 2,2-bis (3,4-biscarboxyphenyl)
Examples include -1,1,1,3,3,3-hexafluoropropane dianhydride and the like. Particularly, it is preferable to use benzophenonetetracarboxylic dianhydride, since it is easy to dissolve and melt to improve the processability, and biphenyltetracarboxylic dianhydride improves the heat resistance. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

Examples of the method for synthesizing the thermoplastic polyimide resin used in the present invention include the following methods. That is, as the aromatic diamine of the general formula (1),
For example, 9,9′-bis (4-aminophenyl) fluorene, and hexamethylenediamine as the aliphatic diamine, and tetracarboxylic dianhydride 3,3 ′, 4 as the acid anhydride component. , 4'-benzophenone tetracarboxylic acid dianhydride, equimolar amounts of these diamine component and acid anhydride component were dissolved in m-cresol, and then the reaction solution was heated at 180 ° C under a nitrogen stream.
The temperature is raised to 0 ° C., and the reaction is carried out at this temperature for 8 hours with stirring to obtain a yellow transparent and uniform reaction solution. After allowing the reaction solution to cool, it was poured into a large amount of methanol to precipitate the polymer,
The polymer is filtered off and dried to obtain the desired polyimide resin powder.

The polyimide resin thus obtained is m-cresol, tetrachloroethane, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, o.
-It has a thermoplastic property such that it can be dissolved at a predetermined concentration in a solvent such as cresol, 1,2-dichloroethane, N, N-dimethylsulfoamide, and can be molded at a predetermined temperature.

In the present invention, the method for forming the coating layer on the surface of the mold that defines the cavity of the mold using the above-mentioned thermoplastic polyimide resin is not particularly limited, but the following method is preferable. Can be mentioned.

That is, in the first method, first, the thermoplastic polyimide resin is mixed with a predetermined solvent such as m-cresol, tetrachloroethane, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, o-cresol,
It is dissolved in a solvent such as 1,2-dichloroethane or N, N-dimethylsulfoamide at a concentration of 5% by weight or more, preferably 10 to 30% by weight, and the obtained solvent solution is applied to the surface of a mold and then heated. This is a method of forming by volatilizing this solvent below. The thermoplastic polyimide resin used here preferably has a glass transition temperature of 250 ° C. or higher. This is because when a polyimide resin having a glass transition temperature of less than 250 ° C. is used, the range of resin that can be molded is significantly limited.

In the second method, a thermoplastic polyimide resin having a glass transition temperature of 250 to 400 ° C. is used, and the thermoplastic polyimide resin is melt-molded to form a polyimide resin molding, which is obtained. In this method, the polyimide resin molded body is attached to the surface of the mold by means such as using an adhesive. Here, the use of a thermoplastic polyimide resin having a glass transition temperature of 250 to 400 ° C. means that if the lower limit of the glass transition temperature (250 ° C.) is too low, the type of thermoplastic resin that can be molded and processed is significantly limited, and This is because if the upper limit of the glass transition temperature (400 ° C.) is too high, the molding temperature at the time of melt molding becomes too high, which is disadvantageous in cost. The mold prepared by the second method cannot be applied to molding a thermoplastic resin that requires a molding temperature higher than the glass transition temperature of the thermoplastic polyimide resin forming the coating layer on the mold surface.

Here, an example of the melt molding in the second method will be described. First, after the thermoplastic polyimide resin powder is sufficiently dried, it is filled in a mold and 100 to 150 kgf at room temperature. Preforming is performed under a pressure of / cm ² , a predetermined number of the obtained mat-like preforming bodies are stacked and placed in a mold, and the temperature is in the range of 350 to 450 ° C. depending on the glass transition temperature of the thermoplastic polyimide resin. Up to
100-300 kgf / cm after reaching this target temperature
^{It is} held under the pressure of ² for about 10 minutes, then cooled while being pressurized, and then the pressure is released, and then the polyimide resin molded body is taken out.

Since the polyimide resin molded body of the present invention molded in this manner is easy to cut, it can be processed into an arbitrary shape and attached to the surface of the mold defining the cavity of the mold. It is possible. Further, the thermoplastic polyimide resin of the present invention is molded under the molding conditions (3000 kgf / 450 ° C.) at the time of melt molding of a general polyimide resin as described in, for example, JP-A-2-58538.
Unlike the high temperature and high pressure condition of cm ² ), 350 to 450
Melt molding is possible under mild molding conditions of 200 kgf / cm ² or less at 0 ° C., which is extremely advantageous in obtaining a large molded product having a large projected area.

The thickness of the thermoplastic polyimide resin coating layer provided on the surface of the mold by the above method is usually 0.
It is appropriately selected within the range of 1 to 3.0 mm. If the thickness of this coating layer is less than 0.1 mm, the heat insulation effect is insufficient,
Also, if it exceeds 3.0 mm, the cooling effect of the mold decreases,
Longer molding cycle.

In the present invention, for the purpose of further improving the durability and surface smoothness of the coating layer provided on the surface of the mold, another coating is further provided on the coating layer as long as the heat insulating effect of the coating layer is not impaired. It is also possible to stack layers of materials of
Examples thereof include layers formed by coating various hard coating agents such as silicone-based, epoxy acrylate-based, urethane acrylate-based, various plating processes, vapor deposition and thermal spraying of metals and metal oxides, and ceramics.

The material of the mold to which the present invention is applied is not particularly limited, and the material of the mold conventionally used as a mold for molding a thermoplastic resin can be mentioned. Specifically, iron or steel containing iron as a main component,
Examples thereof include aluminum or alloys containing aluminum as a main component, zinc alloys, and the like.

The thermoplastic resin molding die of the present invention can be used for injection molding, blow molding, extrusion molding, compression molding, vacuum molding, etc.
Basically, any molding method can be applied as long as it is a molding method of shaping a thermoplastic resin in a molten state, but in particular, a blow-molded product which has been conventionally said to have many problems. It exerts a tremendous effect on improving the surface properties of.

The thermoplastic resin which can be used in the thermoplastic resin molding die of the present invention is also not particularly limited.
For example, styrene resins such as GP, HI and ABS resins, polyolefin resins such as low density polyethylene, high density polyethylene and polypropylene, various thermoplastic elastomers, PET resins, PBT resins, acrylic resins, polyamide (nylon) Examples thereof include resins, polycarbonate resins, polyacetal resins, modified PPE resins, and the like.

Further, when a thermoplastic resin is molded using the thermoplastic resin molding mold of the present invention, the mold is
Heating is performed at a temperature not higher than the glass transition temperature of the thermoplastic polyimide resin forming the coating layer on the mold surface and not lower than the glass transition temperature of the thermoplastic resin to be molded. When the thermoplastic resin to be molded is an amorphous resin, the molding temperature is
It is preferable that the glass transition temperature of the thermoplastic resin is 100 ° C. or higher, and at the same time, it is lower than the glass transition temperature of the polyimide resin that covers the mold. On the other hand, when the thermoplastic resin to be molded is a crystalline resin, the molding temperature is preferably higher than the melting point of this thermoplastic resin by about 50 ° C. or more, and at the same time, lower than the glass transition temperature of the polyimide resin coating the mold. Is desirable.

The thermoplastic resin molded product molded by the molding method of the present invention using the mold of the present invention is particularly excellent in the surface characteristics, and has the features of the mold and the molding method of the present invention. Regarding the surface characteristics of JIS-B06,
The surface roughness defined by the center line average roughness (Ra) of No. 01 is 0.2 μm or less, and / or JIS-K710.
It is desirable that the 60 ° specular gloss defined by 5 is 60% or more.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION

[Synthesis of Thermoplastic Polyimide Resin] An aromatic diamine of the general formula (1) as a diamine component, a tetracarboxylic dianhydride as an acid anhydride component, and a reaction solvent were charged in a reaction vessel and stirred under a nitrogen stream. While heating, make it react,
The resulting reaction solution is poured into a solvent such as methanol, the precipitated polymer is filtered off and dried to obtain a powdery thermoplastic polyimide resin.

[Preparation of Mold for Thermoplastic Resin Molding] As a first method, a thermoplastic polyimide resin is dissolved in a solvent such as tetrachloroethane to prepare a 10 to 30 wt% polyimide resin solution. For example, the solution is applied to the surface of a heated mold using a temperature control pipe to evaporate the solvent, and at this time, this operation is repeated multiple times to apply multiple layers, and finally to a predetermined temperature. The solvent is completely removed, and a coating layer having a desired thickness is formed on the surface of the mold.

As a second method, a thermoplastic polyimide resin is filled in, for example, a flat plate molding die, and preformed under a predetermined pressure at room temperature or under appropriate heating, and a plurality of layers are formed according to the final plate thickness. The mat-shaped preform is placed in a mold and finally heated to a temperature not lower than the glass transition temperature of the thermoplastic polyimide resin while gradually increasing the temperature, and kept at that temperature for a predetermined time under a predetermined pressure and then applied. It is cooled to room temperature under pressure and taken out, and the obtained polyimide resin molded body is attached to the surface of the mold using an adhesive.

[0034]

EXAMPLES The present invention will be described in more detail with reference to synthetic examples of thermoplastic polyimide resins, examples and comparative examples. In the following examples and comparative examples, blow molding in which the effect of the present invention is most prominent will be described as an example, but the scope of application of the present invention is not limited thereto. Further, as the effect of the present invention, the surface roughness and the glossiness are listed as the indexes, but the effect of the present invention is not limited to these, and is also effective for a large deformation generally called sink mark, warp or the like.

Synthetic Example 1 A 500 ml four-necked flask equipped with a thermometer, a nitrogen inlet tube, an ester condensation tube, and a stirrer was used. Aminophenyl) fluorene 27.876 g, benzophenone tetracarboxylic acid dianhydride 25.778 g, and m-cresol 400
The reaction mixture was charged with ml and reacted at 180 ° C. for 8 hours with stirring under a nitrogen stream to obtain a yellow transparent and uniform reaction solution. The reaction solution was poured into methanol, the precipitated polymer was filtered off and dried to obtain a polyimide resin A in powder form. The obtained polyimide resin A had an inherent viscosity of 0.80 (dl) at 30 ° C. in an N-methyl-2-pyrrolidone solution.
/ G), and the glass transition temperature was 380 ° C.

Synthetic Example 2 As described above, except that a mixture of 13.928 g of 9,9'-bis (4-aminophenyl) fluorene and 4.648 g of hexamethylenediamine (1: 1 in molar ratio) was used as the diamine component. A polyimide resin B in powder form was obtained in exactly the same manner as in Synthesis Example 1. The obtained polyimide resin B is N-
The inherent viscosity at 30 ° C. in a methyl-2-pyrrolidone solution was 1.12 (dl / g), and the glass transition temperature was 277 ° C.

Example 1 The polyimide resin A obtained in Synthesis Example 1 was dissolved in tetrachloroethane to prepare a 20 wt% polyimide resin solution. On the surface of the blow molding die (400 × 700 × 20 mm flat plate die) heated to 80 ° C. using the temperature control pipe,
The polyimide resin solution was applied and the solvent was evaporated.
Repeat this operation twice to coat again, and finally 150 ℃
The temperature was raised to completely remove the solvent. The layer thickness (m) of the coating layer provided on the surface of the mold thus prepared
m) and center line average roughness (Ra) of JIS-B0601.
Was measured. The results are shown in Table 1.

Next, this mold is used for the NB120S of Japan Steel Works.
Installed in a blow molding machine, molding temperature: 200 ℃, mold temperature: 100 ℃, blowing pressure: 0.6 MPa and blowing + cooling + exhaust time (time from mold closing to mold opening): ABS for 120 seconds Blow molding of a resin (trade name: Psycolac EX22C, glass transition temperature: 100 ° C., manufactured by Ube Saikon Co., Ltd.) was performed, and the surface characteristics of the obtained molded product [JIS-B06
01 center line average roughness (Ra) and JIS-K7105
Of 60 ° specular gloss]. The results are shown in Table 1.

The filled EXAMPLE 2 Polyimide resin A to 300 × 300 mm flat mold, and preformed under pressure of 125kgf / cm ² at room temperature, matted preform obtained in accordance with the final thickness Five bodies are put in a mold and gradually heated up to 450 ° C., and finally heated at 450 ° C.
It was kept under a pressure of 250 kgf / cm ^{2 for} a minute, and then it was cooled to room temperature while being pressurized and taken out. The obtained polyimide resin molded body (plate thickness 2.0 mm) was attached to the surface of a blow molding die (400 × 700 × 20 mm flat plate die) using an epoxy adhesive.

The layer thickness (mm) of the coating layer provided on the surface of the mold thus prepared and JIS-B0601
The average roughness (Ra) of the center line was measured. Further, using this mold, the ABS resin was blow-molded in the same manner as in Example 1, and the surface characteristics of the obtained molded product were examined. The results are shown in Table 1.

Example 3 Polyimide resin B was dissolved in tetrachloroethane to prepare 20
A wt% polyimide resin solution was prepared. Blow molding die (400 x 7) heated to 80 ° C using temperature control piping
The above polyimide resin solution was applied to the surface of a (00 × 20 mm flat plate mold) to evaporate the solvent. This operation was repeated twice for repeated coating, and finally the temperature was raised to 150 ° C. to completely remove the solvent. The layer thickness (mm) of the coating layer provided on the surface of this mold and the center line average roughness (Ra) of JIS-B0601 were measured. Further, using this mold, the ABS resin was blow-molded in the same manner as in Example 1, and the surface characteristics of the obtained molded product were examined. The results are shown in Table 1.

[0042] filling the Example 4 Polyimide resin B to 300 × 300 mm flat mold, and preformed under pressure of 125kgf / cm ² at room temperature, matted preform obtained in accordance with the final thickness Five pieces are placed in a mold and gradually heated up to 350 ° C, and finally heated at 350 ° C for 10
It was kept under a pressure of 125 kgf / cm ² for one minute, and then it was cooled to room temperature while being pressurized and taken out. The obtained polyimide resin molded body (plate thickness 2.0 mm) was attached to the surface of a blow molding die (400 × 700 × 20 mm flat plate die) using an epoxy adhesive. The layer thickness (mm) of the coating layer provided on the surface of this mold and JIS-B060
The center line average roughness (Ra) of 1 was measured. Further, using this mold, the ABS resin was blow-molded in the same manner as in Example 1, and the surface characteristics of the obtained molded product were examined. The results are shown in Table 1.

Reference Example 1 A molded product obtained by blow molding an ABS resin in the same manner as in Example 1 except that the mold temperature was set to 50 ° C. using the mold obtained in Example 1. The surface characteristics of The results are shown in Table 1.

Reference Example 2 A molded product obtained by blow molding an ABS resin in the same manner as in Example 2 except that the mold temperature was set to 50 ° C. using the mold obtained in Example 2 The surface characteristics of The results are shown in Table 1.

Comparative Example 1 A stainless steel plate was attached to the surface of a blow molding die (400 × 700 × 20 mm flat plate die), and ABS resin was blow-molded in the same manner as in Example 1 to obtain the obtained molding. The surface characteristics of the product were investigated. The results are shown in Table 1.

[0046]

[Table 1]

Comparative Example 2 An attempt was made to form a coating layer by applying a polyamic acid solution of the same polyimide resin as in Synthesis Example 1 on the surface of a mold and heating the mold to form a polyimide. It peeled off and the coating layer could not be formed.

Comparative Example 3 An attempt was made to form a coating layer by applying a polyamic acid solution of the same polyimide resin as in Synthesis Example 2 on the surface of a mold and heating it to form a polyimide layer. It peeled off and the coating layer could not be formed.

[0049]

According to the present invention, it is possible to remarkably improve the surface characteristics of the thermoplastic resin molding such as the appearance without impairing the productivity. For example, after sanding, which has been performed in the field of blow molding. The treatment step can be omitted, and the present invention has high industrial value in a wide range of fields such as automobiles, home appliances, and office automation equipment.

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Claims (4)

[Claims] 1. A mold used for molding a thermoplastic resin, wherein a coating layer made of a thermoplastic polyimide resin is provided on the surface of a mold that defines the cavity, and the thermoplastic polyimide resin forming the coating layer is As a diamine component, the following general formula (1): (Wherein R is -H, shows a -CH ₃ or -C ₂ H ₅₎ Thermoplastic resin mold which comprises an aromatic diamine compound represented by the. 2. The coating layer provided on the surface of the mold is formed by applying a solvent solution of a thermoplastic polyimide resin to the surface of the mold and then volatilizing the solvent under heating. The thermoplastic resin molding die described. 3. When molding a thermoplastic resin using the thermoplastic resin molding die according to any one of claims 1 and 2, the thermoplastic resin is used to form a coating layer on the surface of the mold. At a temperature below the glass transition temperature of the polyimide resin, and
A method for molding a thermoplastic resin, which comprises heating to a temperature not lower than the glass transition temperature of the thermoplastic resin to be molded. 4. The surface roughness defined by the molding method according to claim 3 and defined by the center line average roughness (Ra) of JIS-B0601 is 0.2 μm or less, and / or JIS. A thermoplastic resin molded product having a 60 ° specular gloss of 60% or more as defined by K7105.