JPH1142650A - Mold assembly for molding thermoplastic resin and method for producing molded article - Google Patents

Abstract

(57) [Summary] [PROBLEMS] During molding, the nest does not break, it can be used for a long time, the state of the nest surface can be reliably transferred to the surface of the molded product, and the mold Provided is a mold assembly having a high degree of freedom in the arrangement position of a nest in a part. A mold assembly for molding a thermoplastic resin includes:
(A) First mold part 10 and second mold part 12, (B)
A nest 17 having a thickness of 0.1 mm to 10 mm, which is disposed in the first mold portion 10 and forms a part of the cavity 16;
And (c) a molten thermoplastic resin introducing portion 15 is provided, and a nested covering portion 14 is provided in the second mold portion 12, and when the mold is clamped, (A) the nested portion 17 and the nested covering portion 14 The clearance (C ₁₁ ) between them is not more than 0.03 mm, (B) the amount of overlap (ΔS ₁₁ ) of the nest covering portion 14 with the nest 17 is not less than 0.5 mm, and the thermal conductivity of the material forming the nest 17 Is 2 × 10 ⁻² cal / cm · sec · ΔC or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold assembly for molding a molded article based on a thermoplastic resin, and a method of manufacturing a molded article using the mold assembly. Assembly which can improve the surface transferability of a molded product formed by a molding method, an injection compression molding method, a blow molding method or the like, and can mold a molded product having no defective appearance, and molding using such a mold assembly The present invention relates to a method for manufacturing a product.

[0002]

2. Description of the Related Art A mold for molding a molded article based on a thermoplastic resin (hereinafter, simply referred to as a mold) is usually provided with a molten thermoplastic resin (mold) in a cavity which is a hollow portion provided in the mold. Hereinafter, it may be simply referred to as a molten resin).
It is made of a metal material that does not deform even by high pressure during filling or filling, for example, carbon steel, stainless steel, aluminum alloy, and copper alloy. Then, by injecting, injecting, or filling the molten resin into a cavity provided in the mold, the mold has a desired shape, and furthermore, a surface constituting the cavity of the mold (hereinafter, for convenience, a cavity surface of the mold). Is obtained. Injecting, injecting, or filling the molten resin into the cavity provided in the mold is hereinafter generally referred to as introducing the molten resin into the cavity provided in the mold.

When molding is performed using such a metal mold, it is not easy to bring the surface state of the molded article closer to the state of the cavity surface of the mold. Usually, the mold is made of a metal material which does not deform even by a high stress such as pressure caused by the introduced molten resin, but these metal materials also have excellent thermal conductivity. Therefore, when the molten resin introduced into the cavity comes into contact with the cavity surface of the mold, it is immediately cooled. As a result, a solidified layer is formed on the portion of the molten resin that has come into contact with the cavity surface of the mold, and appearance defects such as weld marks and flow marks are likely to occur on the molded product. Problems such as poor transfer also occur.

[0004] In order to solve these problems, generally, a method of transferring the cavity surface of the mold to the surface of the molded article by forcing the molten resin at a high pressure, or controlling the mold temperature. There is a method in which the development of a solidified layer of the molten resin is delayed at a high temperature to prevent the occurrence of weld marks and flow marks, and to prevent the occurrence of poor transfer of the mold cavity surface to the molded product surface. However, in the former method, the size of the molding apparatus, the size and thickness of the mold itself increase, which leads to an increase in cost, and the introduction of molten resin at a high pressure causes stress to remain inside the molded product. A problem such as deterioration of the quality occurs. In the latter method, in order to delay the development of the solidified layer by setting the mold temperature slightly lower than the load deflection temperature of the resin used for molding, the cooling time of the resin in the cavity becomes longer, resulting in a molding cycle. However, there is a problem that the length is increased and productivity is reduced.

[0005]

In order to solve these problems, for example, JP-A-55-55839, JP-A-61-100425, and JP-A-62-2089.
No. 19, JP-A-5-111937, JP-A-5-111937
-200789, JP-B-6-35134,
Japanese Patent Application Laid-Open No. Hei 6-218768 discloses that a low thermal conductive material is provided or attached to a cavity surface of a mold to delay the development of a solidified layer of resin introduced into the cavity.
Methods for preventing molding defects such as weld marks and flow marks have been proposed.

When the low thermal conductive material is simply bonded to a part of the mold by using an adhesive, the following problems occur.
The durability of the entire mold is poor, and mass production of molded products is difficult. (1) When there is no gap between the low thermal conductive material mounting portion of the mold and the low thermal conductive material, the temperature rise and the temperature drop of the mold cause
The low thermal conductive material is damaged or the low thermal conductive material stressed by the injection pressure is damaged due to the difference in linear expansion coefficient between the material forming the mold and the low thermal conductive material. (2) On the other hand, when there is a large gap between the low thermal conductive material mounting portion of the mold and the low thermal conductive material, the molten resin intrudes into such a gap, and burrs are generated on the molded product. When taking out the low thermal conductive material, there is a problem that the outer peripheral portion of the low thermal conductive material receives resistance, and as a result, the low thermal conductive material is damaged.

In some cases, the low thermal conductive material is made of a heat resistant plastic, but the rigidity of the low thermal conductive material is low and the surface hardness is inferior. There is a problem that the material is easily damaged. Alternatively, there is a low thermal conductive material formed by forming a ceramic thin film on a metal surface by chemical vapor deposition or the like. Therefore, it is generally used only as a test mold or a simple mold and cannot withstand long-term use.

The applicant of the present invention has proposed in Japanese Patent Application No. 7-152519 (Japanese Patent Application Laid-Open No. 8-318534) a mold assembly comprising a mold, a nest, and a holding plate. This mold assembly is a very excellent mold assembly for solving the above-mentioned problems. However, depending on the shape of the molded product, the holding plate cannot be disposed inside the mold, and the placement position of the nest may be restricted. That is, the nest may not be able to be attached to a mold portion corresponding to a molded product portion to which excellent surface characteristics are to be imparted. For example, when a molded article is provided with an undercut portion, it is necessary to provide a slide core in the mold assembly in order to remove the molded article having the undercut portion from the mold assembly. However, in a mold assembly having such a structure, it is difficult to dispose the holding plate in the mold assembly.

Accordingly, it is an object of the present invention to provide a nest made of a very fragile material such as ceramic or glass during molding without causing breakage, enduring long-term use, and changing the state of the nest forming the cavity surface. A mold assembly for molding a molded article based on a thermoplastic resin, which can be reliably transferred to the surface of the molded article, and has a high degree of freedom in the arrangement position of the nest in the mold section, and such a mold. It is an object of the present invention to provide a method for manufacturing a molded product using a mold assembly.

[0010]

According to a first aspect of the present invention, there is provided a mold assembly for molding a thermoplastic resin, which comprises: (a) molding a molded article based on a thermoplastic resin; A first mold part and a second mold part for performing
And a nest having a thickness of 0.1 mm to 10 mm and forming a part of the cavity.
A molten thermoplastic resin introduction portion provided in the mold portion of the first mold portion, a nested cover portion is provided in the second mold portion, and the first mold portion and the second mold portion are provided. (A) The clearance (C ₁₁ ) between the nest and the nest covering part is 0.03 mm or less (C ₁₁ ≦ 0.03 m
m), and (B) the overlap amount (ΔS ₁₁ ) of the nest covering portion with respect to the nest is 0.5 mm or more (ΔS ₁₁ ≧ 0.5 m).
m), and the thermal conductivity of the material constituting the nest is 2 × 1
0 ⁻² cal / cm · sec · ΔC or less. In addition, the structure of the nest covering portion in the mold assembly having such a structure can be a kind of notch (notch) provided on the surface of the second mold portion facing the nest.

The second object of the present invention to achieve the above object.
The mold assembly for thermoplastic resin molding according to the aspect of,
(A) a first mold part and a second mold part for molding a molded article based on a thermoplastic resin, and (b) a part of the cavity which is disposed in the first mold part. 0.1mm thick
(C) disposed between the nest and the second mold part, attached to the first mold part,
A coating plate provided with a molten thermoplastic resin introduction portion, a nested coating portion is provided on the second mold portion, and a first mold portion and a second mold portion are provided. When the mold is clamped, (A) the clearance (C ₂₁ ) between the nest and the nest covering portion is 0.03 mm or less (C ₂₁ ≦ 0.0
(B) The overlapping amount (ΔS ₂₁ ) of the nest covering portion with respect to the nest (B) is 0.5 mm or more (ΔS ₂₁ ≧ 0.5).
(C) The clearance (C ₂₂ ) between the nest and the cover plate is 0.03 mm or less (C ₂₂ ≦ 0.02 mm).
3D), and (D) the overlapping amount (ΔS ₂₂ ) of the covering plate with respect to the nest is 0.5 mm or more (ΔS ₂₂ ≧ 0.5
mm), the covering plate overlaps only a part of the nest, and the thermal conductivity of the material constituting the nest is 2 mm.
× 10 ^-2 cal / cm · sec · ΔC or less. The molten thermoplastic resin introduction portion in the mold assembly having such a structure may be, for example, a direct gate structure.

A third aspect of the present invention for achieving the above object.
The mold assembly for thermoplastic resin molding according to the aspect of,
(B) No. 1 for molding molded articles based on thermoplastic resin
1 and the second mold section, and (b) the first mold section.
And a part of the cavity, the thickness is 0.1mm
(C) arranged in the second mold part.
And a part of the cavity, the thickness is 0.1mm
A second nest of 子 10 mm and (d) a first nest
A first mold part, a second mold part,
Attach to the second mold part or the first and second mold parts
Coating pre-coated with a molten thermoplastic resin introduction part
A first mold part and a second mold part.
In the mold clamped state, (A) the second of the first nest
A surface facing the nest, a first nest of the second nest,
Clearance between opposing surfaces (C₃₀) Is 0.03m
m or less (C₃₀≦ 0.03 mm), and (B)
A face of the second nest facing the second nest;
1 and the amount of overlap (ΔS₃₀) Is 0.
5mm or more (ΔS₃₀≧ 0.5 mm), and (C) the first
Clearance between the nest and the cover plate
(C₃₁), And the gap between the second nest and the cover plate.
Clearance (C₃₂) Is 0.03 mm or less (C ₃₁≦ 0.0
3mm and C₃₂≦ 0.03 mm), and (D) the first
The amount of overlap of the cover plate with respect to the nest (ΔS₃₁)
Of the coating plate with respect to the second and the second nests (ΔS
₃₂) Is 0.5 mm or more (ΔS₃₁≧ 0.5mm and ΔS₃₂
≧ 0.5 mm), and the coating plate is
Only overlaps a part of the nest, the first and second
The thermal conductivity of the material constituting the nest is 2 × 10^-2cal
/ Cm · sec · ΔC or less.
In addition, the melt thermoplasticity in the mold assembly having such a structure.
Examples of the resin introduction section include a side gate structure.
Can be

The first object of the present invention for achieving the above object is as follows.
The method for manufacturing a molded product according to the aspect of (a) comprises: (a) a first mold portion and a second mold portion for molding the molded product based on a thermoplastic resin.
(B) disposed in the first mold part, constitutes a part of the cavity, and has a nest having a thickness of 0.1 mm to 10 mm, and (c) a second mold part. A molten thermoplastic resin introduction section provided, a second mold section is provided with a nested covering section, and the first mold section and the second mold section are clamped. In (A), the clearance (C ₁₁ ) between the nest and the nest covering portion is 0.03 mm or less (C
₁₁ ≦ 0.03 mm), and (B) the overlapping amount (ΔS ₁₁ ) of the nest covering portion with respect to the nest is 0.5 mm or more (ΔS ₁₁ ).
₁₁ ≧ 0.5 mm), and the heat conductivity of the material constituting the nest is 2 × 10 ⁻² cal / cm · sec · ΔC or less. After the thermoplastic resin is introduced from the molten thermoplastic resin introduction portion into the cavity, the thermoplastic resin is cooled and solidified to form a molded article.

The second object of the present invention to achieve the above object.
The method for manufacturing a molded product according to the aspect of (a) comprises: (a) a first mold portion and a second mold portion for molding the molded product based on a thermoplastic resin.
(B) a nest having a thickness of 0.1 mm to 10 mm, which is disposed in the first mold part and constitutes a part of the cavity, and (c) a nest and a second mold A cover plate provided between the first mold portion and the first mold portion, and provided with a molten thermoplastic resin introduction portion. The second mold portion includes a nested cover portion. In the state where the first mold part and the second mold part are clamped, (A) the clearance (C ₂₁ ) between the nest and the nest covering part is 0.1 mm.
(C ₂₁ ≦ 0.03 mm), and (B) the overlapping amount (ΔS ₂₁ ) of the nest covering portion with respect to the nest is 0.
5 mm or more (ΔS ₂₁ ≧ 0.5 mm), and (C) the clearance (C ₂₂ ) between the nest and the cover plate is 0.1 mm.
A 03mm or less _{(C 22 ≦ 0.03mm), (} D) amount of overlap of the covering plate to the nest ([Delta] S ₂₂₎ 0.
5 mm or more (ΔS ₂₂ ≧ 0.5 mm), the covering plate overlaps only a part of the nest, and the thermal conductivity of the material constituting the nest is 2 × 10 ⁻² cal / cm · s.
ec · 組 立 C or less, using a mold assembly for molding a thermoplastic resin, after introducing the molten thermoplastic resin into the cavity from the molten thermoplastic resin introduction portion, cooling the thermoplastic resin,
It is characterized in that a molded article is formed by solidification.

The third object of the present invention to achieve the above object.
The method for producing a molded article according to the aspect of
First and second mold parts for molding a molded article based on
(B) disposed in the first mold part, and the cavity
And a first part having a thickness of 0.1 mm to 10 mm.
Nest, (c) disposed in the second mold part, and the cavity
And a second part having a thickness of 0.1 mm to 10 mm.
And (d) a first nest and a second nest
Between the first mold part, the second mold part, or
Is attached to the first and second mold parts, and
A covering plate provided with a conductive resin introduction portion,
In a state where the mold part and the second mold part are clamped,
(A) a surface of the first nest facing the second nest,
Clear between the first nest of two nests and the opposite surface
Lance (C₃₀) Is 0.03 mm or less (C₃₀≦ 0.03m
m), (B) facing the second nest of the first nest
And the surface of the second nest facing the first nest
(ΔS₃₀) Is 0.5 mm or more (ΔS₃₀≧ 0.
(C) the first nest and the cover plate
Clearance between (C₃₁), And second nesting and coating
Clearance between plate (C₃₂) Is 0.03 mm
The following (C ₃₁≦ 0.03mm and C₃₂≦ 0.03mm)
And (D) the overlap of the coating plate with respect to the first nest
Amount (ΔS₃₁), And cover play for the second nest
The overlap amount (ΔS₃₂) Is 0.5 mm or more (ΔS₃₁≧
0.5mm and ΔS₃₂≧ 0.5mm)
Sheet overlaps only part of the first and second nests
And the heat conduction of the material constituting the first and second nests
Rate is 2 × 10^-2cal / cm · sec · ΔC or less
Melt thermoplastic using mold assembly for thermoplastic resin molding
Introduce resin into cavity from molten thermoplastic resin inlet
After that, by cooling and solidifying the thermoplastic resin,
It is characterized by molding a molded article.

Usually, a protruding pin is provided on the mold assembly to add a molded product from the mold assembly. However,
Depending on the shape of the molded article, it may be difficult to dispose the ejector pin on the mold assembly because a trace of the tip of the ejected pin remains on the surface of the molded article. In such a case,
In the method for manufacturing a mold assembly for thermoplastic resin molding according to the second or third aspect of the present invention, or the method for manufacturing a molded article according to the second or third aspect, the molded article is taken out from the mold assembly. For this purpose, the cover plate may be provided with a tab forming portion communicating with the cavity. As a result, a tab is formed on the molded product. The molded product may be removed from the mold assembly by applying a protruding pin to the tab portion. Note that the tab portion formed on the molded product may be deleted in a later step.

Here, forming a part of the cavity means forming a cavity surface which defines the outer shape of the molded product. More specifically, the cavity includes, for example, a surface forming a cavity formed in the first mold portion and the second mold portion, a surface forming a cavity formed in a nest, and in some cases, And a surface constituting a cavity formed in the coating plate.
The surfaces constituting these cavities are hereinafter referred to as a cavity surface of the mold part, a cavity surface of the nest, and a cavity surface of the coating plate.

When the thickness of the nest, the first nest, or the second nest (hereinafter, may be simply referred to simply as nest) is less than 0.1 mm, the heat insulation effect by the nest is reduced, and the inside of the cavity is reduced. This leads to rapid cooling of the molten resin introduced into the device, which tends to cause poor appearance such as weld marks and flow marks. When the nest is fixed to the mold part, the nest may be adhered to the mold part using, for example, a thermosetting adhesive. When the film thickness becomes uneven, uneven stress remains in the nest, and the molded product surface undulates,
The nest may be damaged by the pressure of the molten resin introduced into the cavity. On the other hand, the nest thickness is 10m
If m is exceeded, the heat insulation effect of the nesting becomes too large, and if the cooling time of the resin in the cavity is not extended, the molded article may be deformed after the molded article is taken out. Therefore, a problem such as extension of the molding cycle may occur. In addition, the thickness of the nest is 0.1 mm to 10 mm,
Preferably, it is 0.5 mm to 10 mm, more preferably 1 mm to 7 mm, and still more preferably 2 mm to 5 mm.

In the mold clamping state, the clearances (C ₁₁ , C ₂₁ , C ₂₂ , C ₃₀ , C ₃₁ , C ₃₂ ) are set to 0.03.
mm or less, practically 0.001 mm or more and 0.03 m
m or less (0.001 mm ≦ C ₁₁ , C ₂₁ , C ₂₂ , C ₃₀ , C
₃₁ , C ₃₂ ≦ 0.03 mm), preferably 0.003 mm
Not less than 0.03 mm (0.003 mm ≦ C ₁₁ , C ₂₁ ,
C ₂₂ , C ₃₀ , C ₃₁ , C ₃₂ ≦ 0.03 mm). The lower limit of the clearance is that the nest may come into contact with the nest coating part of the mold part, the coating plate or other nests due to the occurrence of minute cracks on the outer periphery of the nest or the nest being thermally expanded when the mold temperature rises. The stress may be applied to the fine cracks on the outer peripheral portion of the nest so that the nest is not damaged. Clearance _{(C 11, C 21, C} 22, C 30, C 31, C 32) is 0.03m
m, the molten resin may flow between the nest and the mold nest cover or the cover plate, or between the first nest and the second nest.
In some cases, cracks may occur in the nest, and burrs may be formed on the molded product, and the nest may be damaged when the molded product is removed from the mold.

The amount of overlap (ΔS ₁₁ , ΔS ₂₁ , ΔS ₂₂ , ΔS
If the value of ( ₃₀ , ΔS ₃₁ , ΔS ₃₂ ) is less than 0.5 mm, fine cracks generated on the outer periphery of the nest come into contact with the molten resin, so that cracks generated in the nest grow and break the nest. There are cases.

In the present invention, it is possible to easily form irregularities, curved surfaces, and the like on the material constituting the nest by ordinary grinding, and it is possible to manufacture a nest having any shape other than a considerably complicated shape. By heat treatment after pressing ceramic powder or molten glass into a molding die,
Nesting can be made. In addition, a nest can also be produced by forming a plate-like object made of glass on a jig and forming it naturally in a furnace.

In the case where the nest is provided with an uneven shape, the edge of the uneven portion is cut with a diamond grindstone in order to prevent a fine crack generated at the edge of the uneven portion from coming into contact with the molten resin and being damaged. It should be polished to avoid stress concentration. Alternatively, in some cases, it is preferable to provide a curvature surface or a C-plane cut having a radius of 0.3 mm or less to avoid stress concentration.

After the nest has been processed into a predetermined shape by grinding or the like, the nest does not fall from the nest mounting portion provided on the mold portion when the nest is mounted, and there is no risk of breakage. When the nest can be mounted on the nest mounting portion, the nest can be directly mounted on the nest mounting portion provided on the mold portion without using an adhesive.
Alternatively, the nest may be bonded to the nest mounting portion using a thermosetting adhesive selected from an epoxy-based, silicone-based, urethane-based, acrylic-based, or the like. Note that the nest mounting core provided with the nest mounting portion may be attached to the mold portion, and the nest may be mounted on the nest mounting portion of the nest mounting core.

The clearance (D) between the nest mounting portion of the mold portion and the nest may be as close as possible to zero, but is practically preferably 0.005 mm or more.
Here, the clearance (D) refers to the clearance between the nest mounting portion of the mold portion and the nest along the cavity surface of the nest. Depending on the coefficient of linear expansion of the material constituting the nest, if the clearance (D) is too small,
In some cases, damage to the nest due to the difference in linear expansion coefficient between the material forming the mold part and the material forming the nest cannot be prevented.
The value may be set so as not to cause such a problem. still,
If the clearance (D) is too large, there is a risk that the nest will be damaged due to the positional shift of the nest and insufficient positional stability. Therefore, the clearance (D) is preferably about 2 mm or less.

The thermal conductivity of the material forming the nest is 2 × 10
⁻² cal / cm · sec · ΔC or less. When nesting is made using a material having a thermal conductivity exceeding this value, the molten resin in the cavity is quenched by the nesting. Only the same appearance as that of the molded article obtained by molding can be obtained.

The nest used in the present invention may be made of a ceramic selected from the group consisting of zirconia-based materials, alumina-based materials, and K ₂ O—TiO ₂ , or soda glass, quartz glass, heat-resistant glass, crystallization It can be made from glass selected from the group consisting of glass. More specifically, the material constituting the nest, the first nest, or the second nest is ZrO ₂ , ZrO ₂ —CaO, Zr
O ₂ —Y ₂ O ₃ , ZrO ₂ —CeO ₂ , ZrO ₂ —MgO, Z
rO ₂ —SiO ₂ , K ₂ O—TiO ₂ , Al ₂ O ₃ , Al ₂ O _{3
-TiC, Ti 3 N 2, 3Al} 2 O 3 -2SiO 2, MgO
—SiO ₂ , 2MgO—SiO ₂ , MgO—Al ₂ O ₃ —S
Preferably, the ceramic is selected from the group consisting of iO ₂ and titania, and among others, ZrO ₂ , ZrO ₂ −
More preferably, it is Y ₂ O ₃ or ZrO ₂ —CeO ₂ . Alternatively, it is preferably made of glass selected from the group consisting of soda glass, quartz glass, heat-resistant glass, and crystallized glass, and more preferably made of crystallized glass.

When the nest is made from crystallized glass,
The nesting has a crystallinity of 10% or more, more preferably a crystallinity of 60% or more, and still more preferably a crystallinity of 70 to 1%.
Preferably, it is made from 00% crystallized glass. 1
When the crystallinity reaches 0% or more, the crystals are uniformly dispersed throughout the glass, so that the thermal shock strength and the interfacial peeling property are dramatically improved, so that the occurrence of breakage of the nest at the time of molding the molded article is significantly reduced. Can be. When the degree of crystallinity is less than 10%, there is a drawback that interface separation easily occurs from the surface during molding. The crystallized glass constituting the nest has a coefficient of linear expansion of 1 × 10 ⁻⁶ / K or less and a thermal shock strength of 40 or less.
It is preferably 0 ° C or more.

[0028] The thermal shock strength is defined as 1
When a glass of 00 mm × 100 mm × 3 mm is thrown into water at 25 ° C., the temperature at which the glass is cracked or not is defined as strength. Thermal shock strength is 4
100 ° C means 100 mm x heated to 400 ° C
When a glass of 100 mm × 3 mm is thrown into water at 25 ° C., it means that the glass does not crack.
The thermal shock strength of the heat-resistant glass is only about 180 ° C. Therefore, when the resin melted at a higher temperature (eg, about 300 ° C.) comes into contact with the nest, the nest may be distorted and the nest may be damaged. Thermal shock strength is also related to the crystallinity of glass,
If the nest is made from crystallized glass having a degree of crystallinity of 0% or more, the nest can be reliably prevented from breaking during molding.

Here, the crystallized glass is a small amount of the original glass.
Quantity of TiO_TwoAnd ZrO_Two1600 ° C
After melting under the above high temperature, press, blow, roll,
It is molded by a casting method, etc.
After the treatment, Li _TwoO-Al_TwoO_Three-SiO_Twosystem
A crystal is grown, and the main crystal phase is β-eucryptite
Of crystals and β-spodumene crystals produced
be able to. Alternatively, CaO-Al_TwoO_Three-SiO
_TwoAfter melting the base glass at 1400-1500 ° C, into water
After transferring and crushing to reduce the particle size, accumulate and refractory setter
After heating into a plate, heat treatment is further performed to
It is possible to exemplify the case where a stone phase is formed.
You. Furthermore, SiO_Two-B_TwoO_Three-Al_TwoO_Three-MgO-K_Two
Heat treatment of OF-based glass to produce mica crystals
Or MgO-Al containing nucleating agent_TwoO_Three-SiO_TwoSystem glass
Example of cordierite crystals generated by heat treatment
Can be shown.

In these crystallized glasses, the ratio of crystal particles present in the glass substrate can be represented by an index called crystallinity. Then, the degree of crystallinity can be measured by measuring the ratio between the amorphous phase and the crystalline phase using an analytical instrument such as an X-ray diffractometer.

When the nest is made of ceramic, a convex projection may be transferred to the surface of the molded product because the nest material is porous. However, crystallized glass has the advantage that the surface of the molded product is easily mirror-finished because the crystal particles are fine, the adhesion between the particles is excellent, and the glass is not porous.

At least one thin film layer made of the above-mentioned material or metal compound may be provided on the surface of the nest by a surface treatment technique such as ion plating, whereby the pores of the ceramic can be filled. In addition, the surface characteristics of the molded article can be further improved. However, the film thickness is preferably 20 μm or less, and if it exceeds this thickness, there is a possibility that the heat insulating effect is reduced, the adhesion of the thin film layer to the nest surface is reduced, and the surface of the thin film layer is undulated.

If the molded product requires mirror surface properties, it is desirable that the surface roughness _Ry of the nested cavity surface is 0.03 μm or less. If the surface roughness _Ry exceeds 0.03 μm, the mirror surface properties may be insufficient, and the properties required for the molded product, for example, the surface smoothness (image clarity) may not be satisfied. To do so, the nested cavity surface created
Until the surface roughness _Ry becomes 0.03 μm or less, for example, diamond lapping may be performed, and if necessary, lapping with cerium oxide may be performed. Lapping can be performed using a lapping machine or the like.
It is desirable that the wrapping be performed in the final step of the nesting process. Compared with the polishing of ordinary carbon steel or the like, for example, in the case of crystallized glass, a mirror surface can be obtained at about half the cost, so that the manufacturing cost of the mold assembly can be reduced. The measurement of the surface roughness R _y is based on JIS B0601.
According to. When molding a molded article having a matte or hella line surface, fine irregularities or lines may be formed on the nested cavity surface by sandblasting or etching the nested cavity surface.

In the method for producing a molded article of the present invention, examples of the method for molding the molded article include an injection molding method, a blow molding method, and a multicolor molding method which are generally used for molding a thermoplastic resin. Although the most preferable method is an injection molding method.

In some cases, the mold assembly according to the present invention may have a structure that allows the volume of the cavity to be variable when molding a molded product. In this case, for example, a core that can be moved by a hydraulic cylinder may be provided in the mold assembly.

Using the mold assembly having such a structure, in the method of manufacturing a molded article of the present invention, the volume (V _C ) of the cavity is larger than the volume (V _M ) of the molded article to be molded at the time of mold clamping. Thus, the first mold part and the second mold part are clamped, the position of the core in the cavity is controlled, and the heat melted in the cavity (volume: V _C ). Molding to introduce the thermoplastic resin, move the core before, at the same time as, during, or after the introduction of the thermoplastic resin (including simultaneously with the completion of the introduction) to mold the volume of the cavity it may be reduced to the goods of the volume (V _M).
The time when the volume of the cavity becomes the volume (V _M ) of the molded article to be molded can be set during or after the introduction of the thermoplastic resin (including simultaneously with the completion of the introduction).

[0037] During the above clamping, the relationship of the molded article of the volume to be formed (V _M) and the volume of the cavity (V _C), the thickness of the molded article to be molded and t _0, molding at mold clamping Δt = t ₁ −t, where t ₁ is the distance of the cavity in the thickness direction of the product
_{When 0} is set, the relationship is preferably such that 0.1 mm ≦ Δt ≦ 6 mm. If Δt <0.1 mm, it may be difficult to mold a molded article using a molten thermoplastic resin having poor fluidity, and it is not possible to reduce the stress remaining on the molded article. If Δt> 6 mm, air may be trapped in the molded product, and the quality of the molded product may be degraded.

Alternatively, in the method of manufacturing a molded product according to the present invention, the mold assembly further includes a pressurized fluid injection device,
A pressurized fluid may be injected from the pressurized fluid injection device into the molten thermoplastic resin introduced into the cavity, thereby forming a hollow portion inside the thermoplastic resin in the cavity. The mounting position of the pressurized fluid injection device depends on the shape of the molded product to be molded, etc., in the molten resin injection nozzle of the injection molding device, in the molten thermoplastic resin introduction portion provided in the mold portion (for example, The inside of the gate portion) or a pressurized fluid injection device mounting portion provided in the mold portion and opened in the cavity may be appropriately selected. The time point at which the injection of the pressurized fluid into the molten thermoplastic resin introduced into the cavity is started may be during, simultaneously with, or after the introduction of the molten thermoplastic resin. It is preferable that the injection of the pressurized fluid into the resin in the cavity is continued even after the resin in the cavity is cooled and solidified. The amount of the molten thermoplastic resin introduced into the cavity may be an amount necessary to completely fill the inside of the cavity with the molten thermoplastic resin, or depending on a molded product, the amount of the molten thermoplastic resin may be introduced into the cavity. The amount may be insufficient to completely fill with the resin.

The pressurized fluid suitable for use in the present invention is a gaseous or liquid fluid at normal temperature and normal pressure, and reacts or mixes with the molten thermoplastic resin when injected into the molten thermoplastic resin. Those that do not are desirable. In particular,
Nitrogen gas, carbon dioxide gas, air, helium gas, and other gaseous substances at room temperature, liquids such as water, and gases liquefied under high pressure can be used. Among them, inert gases such as nitrogen gas and helium gas Is preferred. The pressurized fluid to be injected is
It is more preferable to use an inert pressurized fluid that does not cause burning due to adiabatic compression in the hollow portion of the molded product. When using nitrogen gas, it is desirable to use a fluid having a purity of 90% or more. Further, foamable resin, fiber reinforced resin material, or the like can be used as the pressurized fluid. In this case, the hollow portion is filled with a foamable resin, a fiber-reinforced resin material, or the like, and such a structure is also included in the concept of the hollow portion in the present invention.

Examples of the thermoplastic resin suitable for use in the present invention include a crystalline thermoplastic resin and an amorphous thermoplastic resin, and specifically, a polyolefin resin such as a polyethylene resin and a polypropylene resin; Polyamide 6,
Polyamide resins such as polyamide 66 and polyamide MXD6; polyoxymethylene resins; polyester resins such as polyethylene terephthalate (PET) resins and polybutylene ethylene terephthalate (PBT) resins; polyphenylene sulfide resins; polystyrene resins and ABS
Styrene resins such as resin, AES resin and AS resin;
Methacrylic resin; polycarbonate resin; modified PPE
Resin; polysulfone resin; polyether sulfone resin;
Polyarylate resin; polyether imide resin; polyamide imide resin; polyimide resin; polyether ketone resin; polyether ether ketone resin; polyester carbonate resin;

The density and melting point of the crystalline thermoplastic resin are increased by crystallization, and the hardness and elastic modulus of the molded product are improved. Further, the crystalline thermoplastic resin has a feature that it is difficult for moisture, a dye, a plasticizer, and the like to enter the crystal structure, and thus has excellent chemical resistance. Normally, when molding a molded article using a crystalline thermoplastic resin, the mold temperature is set to be considerably lower than the load deflection temperature of the crystalline thermoplastic resin, and the molten crystalline thermoplastic introduced into the cavity is set. A method of promoting cooling and solidification of the resin has been adopted. In the prior art, since the mold is made of a metal material, it has good thermal conductivity, and when the mold temperature is set considerably lower than the load deflection temperature of the crystalline thermoplastic resin, the mold is introduced into the cavity. When the melted crystalline thermoplastic resin comes into contact with the cavity surface of the mold, it immediately starts cooling. As a result, an amorphous layer or a fine crystal layer with low crystallinity is formed on the surface of the molded product.
In addition, these layers are generally called skin layers. In a molded article on which such a skin layer is formed, there is a problem that physical properties relating to the surface of the molded article are significantly reduced. For example, abrasion resistance and weather resistance of a molded article molded from a polyoxymethylene (polyacetal) resin as a crystalline thermoplastic resin are significantly reduced. In addition, the transferability of the cavity surface of the mold to the surface of the molded product is deteriorated.

In the present invention, since the molten crystalline thermoplastic resin introduced into the cavity is not quenched, the crystallinity of the resin is reduced even when the crystalline thermoplastic resin is used. The degree of crystallinity of the resin surface of the molded article is high, and deterioration of physical properties relating to the resin surface such as cracks due to deterioration of the resin can be prevented.

Further, in the present invention, a thermoplastic resin made of a polymer alloy material can be used. Here, the polymer alloy material is made of a blend of at least two kinds of thermoplastic resins, or a block copolymer or a graft copolymer in which at least two kinds of thermoplastic resins are chemically bonded. Polymer alloy materials are widely used as high-performance materials that can combine the unique properties of each of the single thermoplastic resins. As the thermoplastic resin constituting the polymer alloy material in which at least two kinds of thermoplastic resins are blended, polystyrene resin, ABS resin, AES resin, AS
Styrene resins such as resins; polyolefin resins such as polyethylene resins and polypropylene resins; methacrylic resins; polycarbonate resins; polyamide resins such as polyamide 6, polyamide 66 and polyamide MXD6; modified PPE resins; Polyester resin; polyoxymethylene resin; polysulfone resin; polyimide resin; polyphenylene sulfide resin; polyarylate resin; polyether sulfone resin; polyether ketone resin; polyether ether ketone resin; Can be. As a polymer alloy material obtained by blending two kinds of thermoplastic resins, a polymer alloy material of a polycarbonate resin and an ABS resin can be exemplified. Note that such a combination of resins is referred to as polycarbonate resin / ABS resin. The same applies to the following. Further, as a polymer alloy material in which at least two kinds of thermoplastic resins are blended, polycarbonate resin / PET resin, polycarbonate resin / PBT resin,
Polycarbonate resin / polyamide resin, polycarbonate resin / PBT resin / PET resin, modified PPE resin / HIPS resin, modified PPE resin / polyamide resin,
Modified PPE resin / PBT resin / PET resin, modified PPE
Resin / polyamide MXD6 resin, polyoxymethylene resin / polyurethane resin, PBT resin / PET resin, polycarbonate resin / liquid crystal polymer can be exemplified. Further, as a polymer alloy material composed of a block copolymer or a graft copolymer in which at least two kinds of thermoplastic resins are chemically bonded, HIPS resin, A
Examples include BS resin, AES resin, and AAS resin.

In a molded article molded based on a polymer alloy material, the appearance (particularly, glossiness) of the molded article generally deteriorates, and in particular, poor appearance occurs in a portion where the thickness of the molded article changes or a weld portion. There is a problem that it is easy. This is usually because the mold is made of a metal material with good thermal conductivity, so the molten polymer alloy material introduced into the cavity is instantaneously cooled when it comes into contact with the cavity surface of the mold. start. As a result, a solidified layer is formed on the molten polymer alloy material, resulting in poor transferability and poor gloss. In the present invention, since the molten polymer alloy material introduced into the cavity is not quenched, the gloss of the molded article is extremely improved, and a molded article with excellent mirror finish can be easily obtained. .

In addition, stabilizers, ultraviolet absorbers, release agents, dyes and pigments, etc. can be added to the various thermoplastic resins described above, and glass beads, mica, kaolin,
Inorganic fibers such as calcium carbonate, inorganic fillers, or organic fillers can also be added.

In the method for producing a molded article of the present invention, a thermoplastic resin containing 5% to 80% by weight of inorganic fibers may be used. The average length of the inorganic fiber is 5 μm to 5 mm, preferably 10 μm to 400 μm, when importance is placed on the strength of the molded article, and 5 μm to 5 μm, when the image clarity (mirror property) of the molded article is emphasized. 400μ
m, more preferably 5 μm to 200 μm, and still more preferably 5 μm to 100 μm. In these cases, the average diameter of the inorganic fibers is 0.01 μm.
m to 15 μm, more preferably 0.1 μm to 13 μm
m, more preferably 0.1 μm to 10 μm.

In the prior art, when a molded article is molded using a thermoplastic resin containing inorganic fibers, the appearance of the molded article deteriorates as a result of the inorganic fibers being deposited on the surface of the molded article, or The problem that the performance (specularity) is deteriorated is likely to occur. Therefore, it has been difficult to use a thermoplastic resin containing inorganic fibers for a molded article requiring excellent appearance characteristics and image clarity. In addition, the phenomenon of inorganic fiber precipitation on the surface of a molded article can be recognized by, for example, floating of the inorganic fiber on the surface of the molded article. Therefore, in order to solve the problem such as the precipitation of inorganic fibers on the surface of the molded article, in the prior art, it was responded by lowering the viscosity of the thermoplastic resin and improving the fluidity of the molten resin. . However, when the content of the inorganic fibers is increased, it is difficult to prevent the inorganic fibers from depositing on the surface of the molded article. For this reason, it has been difficult to use a thermoplastic resin containing inorganic fibers for molded articles requiring excellent appearance characteristics, despite having excellent performance. The cause of the inorganic fiber precipitating from the surface of the molded article when the content of the inorganic fiber increases is also related to the material of the mold. Usually, since the mold is made of a metal material having good thermal conductivity, the molten resin containing the inorganic fibers introduced into the cavity starts to cool instantly when it comes into contact with the cavity surface of the mold. As a result, a solidified layer is formed on the molten resin in contact with the cavity surface of the mold, and inorganic fibers are deposited. In addition, there arises a problem that the transferability of the cavity surface of the mold to the surface of the molded product is insufficient. In the present invention, since the molten thermoplastic resin introduced into the cavity is not quenched, no solidified layer is formed on the molten resin in contact with the cavity surface of the mold portion, and the inorganic fiber Can be reliably prevented from being precipitated.

In this case, the proportion of the inorganic fibers contained in the thermoplastic resin (in other words, the proportion of the inorganic fibers added to the thermoplastic resin) is determined by the required flexural modulus (for example, A
The value measured according to STM D790 is 3.0
(GPa or more) as long as it is within a range in which a molded product satisfying (GPa or more) can be molded. The value may be a value at which a molded article cannot be molded. Specifically, when a crystalline thermoplastic resin is used, the upper limit is approximately 80% by weight. When an amorphous thermoplastic resin is used, its fluidity is inferior to that of a crystalline thermoplastic resin.
0% by weight. If the content is less than 5% by weight, the required flexural modulus, elastic modulus and coefficient of linear expansion cannot be obtained.
If the content exceeds 0% by weight, the fluidity of the molten thermoplastic resin is reduced, so that molding of a molded product becomes difficult, or a molded product having excellent mirror surface properties may not be molded.

If the average length of the inorganic fibers is less than 5 μm or the average diameter is less than 0.01 μm, the required bending elastic modulus of the molded product cannot be obtained. On the other hand, the average length of the inorganic fiber exceeds 400 μm or the average diameter is 15 μm.
If the ratio exceeds, there arises a problem that the surface of the molded article is not mirror-finished.

The inorganic fiber having an average length and an average diameter in the above-mentioned ranges is subjected to a surface treatment, preferably using a silane coupling agent or the like, then compounded with a thermoplastic resin, and pelletized to form a molding material. . By molding a molded article using such a molding material and a mold assembly incorporating a nest, high rigidity, a high elastic modulus, a low linear expansion coefficient, and a high load deflection temperature (heat resistance) can be obtained. It is possible to obtain a molded article which has excellent mirror surface properties (mapping properties).

The inorganic fibers include glass fibers, carbon fibers,
It is preferable to be composed of at least one material selected from the group consisting of wollastonite, aluminum borate whisker fiber, potassium titanate whisker fiber, basic magnesium sulfate whisker fiber, calcium silicate whisker fiber and calcium sulfate whisker fiber. . The number of inorganic fibers contained in the thermoplastic resin is not limited to one, and two or more kinds of inorganic fibers may be contained in the thermoplastic resin.

The average length of the inorganic fibers means the weight average length. The length of the inorganic fiber can be measured by immersing a molding pellet or a molded article containing the inorganic fiber in a liquid in which the resin component of the thermoplastic resin is dissolved, and dissolving the resin component, or in the case of glass fiber, at 600 ° C. By burning the resin component at the above high temperature, the remaining inorganic fibers can be measured by observation with a microscope or the like. Usually, a person measures the length by taking a photograph of the inorganic fiber, or obtains the length of the inorganic fiber using a dedicated fiber length measuring device. Since the number average length has too great an effect of the finely broken fibers, it is preferable to use the weight average length. In the measurement of the weight average length, the measurement is performed except for fragments of inorganic fibers that are too small and crushed. If the length is shorter than twice the nominal diameter of the inorganic fiber, the measurement becomes difficult. Therefore, for example, an inorganic fiber having a length twice or more the nominal diameter is measured.

As a molded product obtained by the method for producing a molded product of the present invention using a thermoplastic resin containing an inorganic fiber, an automobile door handle can also be mentioned. The following Table 1 shows an example of physical properties required for a molded article formed of an automobile door handle. In order to satisfy these characteristics, it is preferable to use a thermoplastic resin containing an inorganic fiber satisfying the specifications shown in Table 2 below. An automobile door handle is composed of a main body part fixed to a door and a handle part connected to the main body part by a spring or a fixed part. Type) or a push button type outside door handle, and a pull type inside door handle embedded in a door trim.

[0054]

Table 1 Flexural modulus: 5.0 GPa or more, preferably ^{5 to} 25 GPa Linear expansion coefficient: 3.0 × 10 ⁻⁵ / K or less, preferably 0.5 to 3.0 × 10 ⁻⁵ / K Load deflection Temperature: 140 ° C or more Image clarity: 85% or more

[0055]

Table 2 Average length: 5 μm to 400 μm, preferably 5 μm to 70 μm Average diameter: 0.01 μm to 15 μm, preferably 0.1 μm to 10 μm Content: 15 to 80% by weight, preferably 20 to 60% by weight

The method for producing a molded article of the present invention using a thermoplastic resin containing inorganic fibers may further include a step of forming a light-reflective thin film on at least a part of the surface of the molded article. In this case, the thickness of the light reflecting thin film may be a thickness that can effectively reflect light, and is, for example, at least 50 nm, preferably 50 nm to 50 nm.
The thickness is desirably 0 nm, more preferably 100 nm to 300 nm. If the thickness is less than 50 nm, the reflectance may not be sufficient. On the other hand, if it exceeds 500 nm, the surface smoothness of the molded product may be reduced, causing a problem in the reflectance. As a material constituting the light reflection thin film, for example,
Examples thereof include metals such as gold, platinum, silver, chromium, nickel, phosphorus nickel, aluminum, copper, beryllium, beryllium copper, and zinc, and metal compounds and alloys thereof. Examples of the film formation method include (a) various vacuum evaporation methods such as an electron beam heating method, a resistance heating method, and a flash evaporation method, (b) a plasma evaporation method, (c) a bipolar sputtering method, a DC sputtering method,
Various sputtering methods such as direct current magnetron sputtering, high frequency sputtering, magnetron sputtering, ion beam sputtering, bias sputtering, etc. (d) DC (Direct C
urrent) method, RF method, multi-cathode method, activation reaction method, HCD
PVD (Physic Discharge) method, electric field evaporation method, high-frequency ion plating method, reactive ion plating method, etc.
al Vapor Deposition) method. From the viewpoints of reflectance and cost, it is most preferable to form a light reflecting thin film by vacuum-depositing aluminum.

A mirror can be cited as one form of the molded article thus obtained. More specifically, optical mirrors such as a vehicle mirror such as a room mirror, a door mirror, a fender mirror, and a mirror built into a speedometer, a roof mirror for a camera, an optical system mirror for a copying machine, and a polygon mirror for a laser beam printer. Examples can be given. Physical properties required for the mirror member (the molded product before forming the light reflection thin film) or the molded product composed of the mirror are as shown in Table 3 below. In Table 3, the image clarity is a value for the molded product before the light reflecting thin film is formed. In order to satisfy these characteristics, it is preferable to use a thermoplastic resin containing an inorganic fiber satisfying the specifications shown in Table 4 below. When a molded article made of a mirror is produced by the method for producing a molded article of the present invention, mass production is superior to the conventional mirror production method produced from glass, and even the assembly part can be integrated by molding. It can be expected to reduce the cost and production cost of the mirror.

[0058]

[Table 3] Flexural modulus: 5.0 GPa or more Linear expansion coefficient: 3.0 × 10 ^-5 / K or less Load deflection temperature: 100 ° C. or more Image clarity: 85% or more

[0059]

Table 4 Average length: 5 to 100 μm, preferably 5 to 70 μm Average diameter: 0.01 to 15 μm, preferably 0.1 to 10 μm Content: 15 to 80% by weight

Alternatively, a reflector can be mentioned as another form of the molded article thus obtained. More specifically, a reflector incorporated in a head lamp, a turn lamp, a search light, a rotating light, an emergency light, or the like can be exemplified. The physical properties required of the reflector member (the molded product before forming the light reflection thin film) are exemplified in Table 5 below. In order to satisfy these characteristics, it is preferable to use a thermoplastic resin containing an inorganic fiber satisfying the specifications shown in Table 6 below. If a molded article made of a reflector is produced by the method for producing a molded article of the present invention, mass production is superior to the conventional reflector production method produced from glass, and even the assembly part can be integrated by molding, so that the parts can be integrated. It is expected to reduce the cost and the cost of manufacturing the mirror, and the reflector will not be deformed by the heat from the light source, and the amount of expansion due to the heat will be extremely small.

[0061]

[Table 5] Linear expansion coefficient: 3.0 × 10 ⁻⁵ / K or less, preferably 0.5 to 3.0 × 10 ⁻⁵ / K Load deflection temperature: 140 ° C. or more, preferably 140 to 260 ° C.

[0062]

Table 6 Average length: 5 to 100 μm, preferably 5 to 70 μm Average diameter: 0.01 to 15 μm, preferably 0.05 to 13 μm, more preferably 0.1 to 10 μm Content: 15 to 80% by weight

Alternatively, the method for producing a molded article of the present invention using a thermoplastic resin containing an inorganic fiber may further include a step of forming a coating film on at least a part of the surface of the molded article. In this case, the paint film is preferably at least one paint film selected from the group consisting of an acrylic paint film, a urethane paint film, and an epoxy paint film. That is, after removing dust and the like from the surface of the molded article, brushing paint on the surface of the molded article,
A coating film can be formed on at least a part of the surface of a molded product (for example, an exterior member for automobiles) by applying by a method such as spraying, electrostatic coating, or dipping, and then drying. Since the distortion remaining in the molded article obtained by the present invention is small, cracks in the molded article due to the coating solution hardly occur. Further, the surface of the molded article obtained by the present invention is excellent in image clarity, and a molded article having excellent appearance even after coating can be obtained. It is preferable to use a paint having a curing temperature equal to or lower than the load deflection temperature of the raw material resin. As an exterior member for an automobile, which is one form of the molded product thus obtained, a front fender,
A rear fender, door, bonnet, roof or trunk fade can be exemplified. The following Table 7 shows an example of physical properties required for a molded article as such an exterior member for an automobile. In order to satisfy these characteristics, it is preferable to use a thermoplastic resin containing an inorganic fiber that satisfies the specifications in Table 8 below. It is to be noted that a coating film may be formed on at least a part of the above-described automobile door handle.

[0064]

[Table 7] Flexural modulus: 4.0 GPa or more, preferably 4.5 GPa or more Linear expansion coefficient: 4.0 × 10 ⁻⁵ / K or less, preferably 3.5 × 10 ⁻⁵ / K or less Load deflection temperature: 100 ° C or more, preferably 110 ° C or more

[0065]

Table 8 Average length: 5 to 400 μm, preferably 5 to 200 μm Average diameter: 0.01 to 15 μm, preferably 0.1 to 10 μm Content: 15 to 80% by weight, preferably 20 to 60% by weight

Alternatively, the method for producing a molded article of the present invention using a thermoplastic resin containing an inorganic fiber may further include a step of forming a hard coat layer on at least a part of the surface of the molded article. In this case, the hard coat layer is preferably made of at least one hard coat layer selected from the group consisting of an acrylic hard coat layer, a urethane hard coat layer, and a silicone hard coat layer. That is, after removing dust and the like from the surface of the molded article, a solution selected from an acrylic, urethane or silicone hard coat solution is applied to the surface of the molded article by dipping, flow coating, or spraying. The hard coat layer can be formed on at least a part of the surface of the molded article by applying the composition by a method such as that described above, followed by drying and curing. It is desirable that the thickness of the hard coat layer on the surface of the molded article is 1 μm to 30 μm, preferably 3 μm to 15 μm. If it is less than 1 μm, the durability of the hard coat layer will be insufficient, and if it exceeds 30 μm, cracks will easily occur in the hard coat layer. When the adhesion between the hard coat layer and the molded article is not sufficient, the adhesion can be improved by applying the top coat after applying the primer coat to the molded article. Since the distortion remaining in the molded article is small, cracks are hardly generated in the molded article due to the formation of the hard coat layer. In addition, the surface of the molded article obtained by the present invention has excellent image clarity, and a molded article having an appearance excellent in image clarity even after the formation of the hard coat layer can be obtained. As one form of the molded product thus obtained, a front pillar,
Vehicle pillars such as center pillars or rear pillars can be mentioned. Table 9 below shows examples of physical property values required for the molded article before the hard coat layer is formed. In order to satisfy these characteristics, it is preferable to use a thermoplastic resin containing an inorganic fiber satisfying the specifications shown in Table 10 below.

[0067]

[Table 9] Flexural modulus: 4.0 GPa or more Linear expansion coefficient: 4.0 × 10 ⁻⁵ / K or less Load deflection temperature: 100 ° C. or more

[0068]

Table 10 Average length: 5 to 400 μm, preferably 5 to 200 μm Average diameter: 0.01 to 15 μm, preferably 0.1 to 10 μm Content: 15 to 80% by weight, preferably 20 to 60% by weight

Alternatively, in the method for producing a molded article of the present invention, a metal powder having an average particle diameter of 0.1 μm to 1 mm, preferably 0.2 μm to 0.5 mm, or an average thickness of 0.1 μm to 200 μm, preferably Is 1 to 150μ
metal flakes whose average outer diameter is greater than the average thickness
A thermoplastic resin containing 0.01% to 80% by weight, preferably 0.1% to 60% by weight, more preferably 1% to 50% by weight can be used.

A molded article made of a thermoplastic resin having a metallic color tone is lighter than a metal part and has a metallic appearance, and is used for various automobile parts and industrial product parts. Normally, in order to impart a metallic color to a molded article, a paint containing metal particles imparting a metallic color is applied to the molded article, or the metal particles imparting a metallic color are kneaded into a raw material resin of the molded article. By coating the molded article, a metallic feeling can be relatively easily imparted to the surface of the molded article regardless of the size of the metal particles contained in the paint. However, in order to give a molded product a sense of depth, there is a problem that the clear coat must be applied repeatedly, which increases the number of manufacturing steps for the molded product. On the other hand, in the method in which metal particles are kneaded into the raw material resin, for example, when metal particles having a small particle diameter are used, the molded article tends to be cloudy gray, and it is difficult to impart a metallic feeling to the molded article. Further, when metal particles having a large particle diameter are used, the metal particles precipitate on the surface of the molded product, so that there is a problem that a glittering metallic feeling strongly appears on the surface of the molded product. Therefore, it is necessary to regulate the particle size of the metal particles, but even in such a case, it is not possible to impart a color tone with a sense of depth when the clear coat is applied to the surface of the molded article. For this reason, at present, even when metal particles are kneaded into the raw material resin of the molded article, a clear coat is applied to the surface of the molded article to impart a deep color tone to the surface of the molded article. In the prior art, the reason why a sense of depth cannot be obtained on the surface of a molded article is that metal particles precipitate on the surface of the molded article, and irregularities are generated on the surface of the molded article. This phenomenon is related to the material of the mold. In the prior art, since the mold is made of a metal material having good thermal conductivity, the molten resin filled in the cavity starts to cool instantly when it comes into contact with the cavity surface of the mold. As a result, a solidified layer is formed on the molten resin containing the metal particles,
Metal particles precipitate on the surface of the molded product, resulting in poor gloss.
In the present invention, since the molten thermoplastic resin introduced into the cavity is not quenched, a solidified layer is not formed on the molten resin in contact with the cavity surface of the mold portion, and a molded product is formed. No metal particles are deposited on the surface of the substrate, and poor gloss can be reliably prevented from occurring.

When the content of metal powder or metal flake is 0.
If the amount is less than 01% by weight, the molded product lacks a metallic color tone. On the other hand, if it exceeds 80% by weight, the appearance of the molded product is only glare, or the metal powder or metal flakes precipitate on the surface of the molded product, giving the surface of the molded product a sense of depth. It becomes difficult. If the average particle size of the metal powder is less than 0.1 μm, a deep metallic feeling cannot be obtained. On the other hand, if it exceeds 1 mm, the metal powder tends to precipitate on the surface of the molded product, so that a sense of depth cannot be obtained. When metal flakes are used, if the average thickness is less than 0.1 μm, cracks occur in the metal flakes when kneaded with the resin, so that the metallic color tone of the molded product is reduced. On the other hand, if the average thickness exceeds 200 μm, metal flakes are likely to precipitate on the surface of the molded product, and it is difficult to impart a sense of depth to the surface of the molded product. On the other hand, when the average outer diameter is smaller than the average thickness, it is difficult to impart a sense of depth to the surface of the molded article.

The average particle diameter of the metal powder, the average thickness and the average outer diameter of the metal flake can be measured using an image analyzer. When the metal powder and the metal flake are contained in the resin, the average particle diameter of the metal powder, the average thickness and the average outer diameter of the metal flake may be measured after carbonizing the resin or dissolving the resin with a solvent.

Examples of the metal constituting the metal powder or metal flake include gold, silver, platinum, copper, aluminum, chromium, iron, nickel, and compounds and alloys thereof. Above all, it is preferable from the viewpoint of cost or appearance that the metal powder is composed of chromium oxide powder or aluminum powder, or that the metal flake is composed of aluminum flake in order to obtain a metallic color tone having a deep feeling.

In this case, the thermoplastic resin may contain 1 to 50% by weight, preferably 5 to 40% by weight of inorganic fibers. In this case, it is preferable that the total weight% of the metal powder or the metal filler and the inorganic fiber is 50% by weight or less. As inorganic fiber, glass fiber, glass beads, carbon fiber, wollastonite,
Examples include aluminum borate whiskers, potassium titanate whiskers, basic magnesium sulfate whiskers, calcium silicate whiskers, and calcium sulfate whiskers. If the content of the inorganic fibers is too small, the strength of the molded product may be insufficient. On the other hand, if the content of the inorganic fiber exceeds 50% by weight, the inorganic fiber may be deposited on the surface of the molded product.

Generally, in order to make the molded product less likely to warp due to the shrinkage of the resin after molding, it is necessary to consider the thermal conductivity and thickness of the first and second mold parts and the nesting. It is desirable to minimize the temperature difference between the first and second mold parts during product removal. In particular, when using plastics with excellent heat resistance and strength, such as engineering plastics and super engineering plastics, but with poor moldability, molding is usually performed at a mold temperature of 80 ° C or higher. It is occurring frequently. However, since a heat insulating effect can be obtained by using the mold assembly of the present invention, a molded article having good appearance characteristics can be obtained even when the mold temperature is 80 ° C. or lower.
In addition, even when using a thermoplastic resin containing inorganic fibers, metal powders, and metal flakes, these materials do not precipitate on the surface of the molded product, and have excellent appearance characteristics such as specularity. A molded article can be obtained. This is because the cooling and solidification of the molten thermoplastic resin introduced into the cavity can be delayed by nesting, so that the fluidity and transferability of the molten thermoplastic resin can be improved.
Also, for example, when a polyoxymethylene resin is used as the crystalline thermoplastic resin, in the case of a molded article molded at a mold temperature of 100 ° C. using a mold made of carbon steel, the surface of the molded article is about 50 μm On the other hand, in the method for producing a molded article of the present invention, no skin layer is formed on the molded article even at the same mold temperature,
The friction and wear characteristics and weather resistance of the molded product were dramatically improved.
Alternatively, when molding was performed at a mold temperature of 80 ° C. using a polymer alloy material and a mold made of carbon steel as a mold, poor gloss occurred on the surface of the molded product. On the other hand, in the method for producing a molded article of the present invention, the molded article surface had extremely excellent gloss even at the same mold temperature.

Moreover, since the flowability of the molten thermoplastic resin is improved, the pressure at which the molten thermoplastic resin is introduced into the cavity can be set low, and the stress remaining in the molded article can be reduced. As a result, the quality of the molded product is improved. Further, for example, since the introduction pressure can be reduced, the thickness of the mold portion can be reduced, the size of the molding device can be reduced, and the cost of the molded product can be reduced.

Further, the nest in the present invention is made of a material having a low coefficient of thermal expansion, and is manufactured independently of the mold part and disposed in the mold part, so that the heat insulating effect by the nest is obtained. Not only is large, but nesting is easy to maintain. If the nest is made of crystallized glass, a nest that has a low linear expansion coefficient, is resistant to thermal shock, and is less likely to be damaged or cracked can be manufactured.

According to the mold assembly of the present invention, the heat insulation effect of the nesting is large, the quenching of the molten thermoplastic resin filled in the cavity can be suppressed, and appearance defects such as weld marks and flow marks can be prevented. This can be effectively prevented from occurring. Moreover, by suppressing the nesting by the nesting covering portion or the covering plate within a predetermined clearance or within the range of the overlapping amount, the appearance of the end of the molded product is not impaired, no burrs are generated at the end of the molded product, and furthermore, Can prevent breakage of the nest because the fine craze remaining on the outer periphery of the nest does not come into contact with the molten thermoplastic resin.

In the method for producing a molded article of the present invention, a mold assembly having a nest having heat insulating properties is used.
Rapid cooling of the molten thermoplastic resin introduced into the cavity can be alleviated. Therefore, even at a low mold temperature, it is possible to reliably and easily mold a molded article having excellent mirror finish, and to suppress formation of a solidified layer and a skin layer. Furthermore, by employing the method for producing a molded article of the present invention, it is possible to mold the molded article even when a molten thermoplastic resin having poor fluidity is used. Also, as a result of being able to reduce the introduction pressure of the molten thermoplastic resin,
Since the pressure applied to the nest can be reduced,
Deformation and breakage of the nest can be effectively prevented. In addition, the stress remaining in the molded product can be further reduced, and a high-quality molded product can be molded.

Further, when a mold assembly having a structure capable of making the volume of the cavity variable at the time of molding a molded article is used,
Since it is possible to uniformly compress the surface of the molded product, it is possible to suppress the occurrence of sink marks on the surface of the molded product. Alternatively, if a pressurized fluid is injected into the molten thermoplastic resin in the cavity in the method for producing a molded article of the present invention, the resin in the cavity is pressurized toward the cavity surface. As a result, it is possible to reliably prevent sinks from occurring in the molded product. In addition, since the cooling and solidification of the molten resin that comes into contact with the nest is delayed, it is possible to avoid the occurrence of a phenomenon in which the resin portion that has started to solidify near the cavity surface of the nest and the resin inside are mixed with each other. It is possible to prevent the occurrence of color unevenness and poor appearance on the surface of the molded product near the thick portion.

[0081]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

Example 1 Example 1 relates to a mold assembly for molding a thermoplastic resin and a method of manufacturing a molded product according to the first aspect of the present invention. FIG. 1A is a schematic end view when the mold assembly of Example 1 is clamped, and FIG. 2 is a schematic end view when the mold is opened. 1 (B) and 1 (C) are schematic end views of the mold assembly being assembled.

The mold assembly according to the first embodiment has a first mold section (movable mold section) 10 and a second mold section (fixed mold section) for molding a molded article based on a thermoplastic resin. ) 12 and the first
And a nest 17 having a thickness of 3.00 mm, which forms a part of the cavity 16, and a molten thermoplastic resin introduction portion 15 provided in the second mold portion 12. Have. Then, the second mold portion 12 is provided with a nested cover portion 14. Specifically, the nested covering portion 14
Is a kind of notch (notch) 13 provided on the surface of the second mold portion 12 facing the cavity surface 17A of the insert 17.

As shown in FIG. 1A, in a state where the first mold part 10 and the second mold part 12 are clamped,
The clearance (C ₁₁ ) between the nest 17 and the nest covering portion 14 is set to 0.03 mm or less (C ₁₁ ≦ 0.03 mm). Further, the overlapping amount (ΔS ₁₁ ) of the nest covering portion 14 with respect to the nest 17 is 0.5 mm or more (ΔS ₁₁ ≧ 0.5 m).
m). In Example 1, zirconia (ZrO ₂ ) was used as a material forming the insert 17. The thermal conductivity of this zirconia is 0.8 × 10 ⁻² cal / cm ·
sec · ΔC.

The size of the cavity 16 in the mold assembly of Example 1 is 100 mm × 100 mm × 4 mm, and the shape is a rectangular parallelepiped. The size of the nest 17 is 10
It is 2.00 mm × 102.00 mm × 3.00 mm. The nest 17 is manufactured by grinding.
The cavity surface 17A was polished and finished using a diamond grindstone, and the surface roughness _Ry of the cavity surface 17A of the insert 17 was set to 0.02 μm.

A first mold part (movable mold part) 10 was made of carbon steel S55C. The inner size of the nest mounting portion 11 for the nest 17 is 102.20 mm × 102.20 m
m, and cut so as to have a depth of 3.02 mm to provide a nesting portion 11 (see FIG. 1B).
The nest 17 was adhered to the inside of the nest mounting portion 11 using a silicone-based adhesive (not shown) (see FIG. 1C). When the clearance (D) between the nest 17 and the nest mounting portion 11 was measured using a gap gauge, the minimum clearance was 0.05 mm.

On the other hand, the second mold part (fixed mold part) 12 was made of carbon steel S55C. At the center of the second mold part (fixed mold part) 12, a molten thermoplastic resin introduction part 15 composed of a direct gate having a diameter of 5 mm was provided.

The first mold part (movable mold part) 10 and the second mold part (fixed mold part) 12 thus fabricated were assembled to obtain a mold assembly of Example 1. In this mold assembly, the clearance (C ₁₁ ) between the insert 17 and the insert covering portion 14 is 0.02 mm (C ₁₁ = 0.02 mm).
Met. In addition, the nest covering portion 14 with respect to the nest 17
Amount of overlap of ([Delta] S ₁₁₎ is 1.0mm (ΔS ₁₁ = 1.0m
m). As described above, the structure is such that there is no contact between the end of the insert 17 and the molten resin introduced into the cavity 16.

After the completed mold assembly is attached to the molding apparatus, the mold assembly is heated to 130 ° C. using a mold temperature controller, and then rapidly cooled to 40 ° C., but it is made of zirconia. No damage such as cracks occurred in the nest 17.

As a molding apparatus, Sumitomo Heavy Industries, Ltd.
The mold assembly was heated to 90 ° C using an H-100 injection molding machine. Alloy materials made of polycarbonate resin and polyester resin with glass fiber added as thermoplastic resin (Mitsubishi Engineering Plastics Co., Ltd.
Injection molding was performed using GMB4030 (glass fiber added at 30% by weight). Molding conditions are: mold temperature 90 ° C, resin temperature 290 ° C, injection pressure 800 kgf / cm.
^2- G. The average length of the glass fiber was 400 μm and the average diameter was 13 μm. After a predetermined amount of the molten resin 18 is introduced (injected) into the cavity 16 via the molten thermoplastic resin introduction section (gate section) 15 (see FIG. 3), the thermoplastic resin is cooled and solidified, and after 20 seconds, the gold is cooled. The mold assembly was opened, and the molded product was removed from the mold assembly.

There was no glass fiber floating on the surface of the molded product in contact with the insert 17 and the molded product had very high specularity. There were no molding defects such as flow marks and jetting. In addition, although molding was continuously performed for 10,000 cycles, damage such as cracks did not occur in the insert 17.

(Embodiment 2) In Embodiment 2, nesting
Zirconia (ZrO) _Two)of
Instead, partially stabilized zirconia (ZrO_Two-Y_TwoO_Three)
Using the same mold assembly as in Example 1 was obtained. This part
Minute stabilized zirconia (ZrO_Two-Y_TwoO_Three) Has a thermal conductivity of
0.9 × 10^-2cal / cm · sec · ΔC. Complete
After attaching the completed mold assembly to the molding machine,
After heating the body to 130 ° C using a mold temperature controller, 40 ° C
Made from partially stabilized zirconia even when quenched to C
No damage such as cracks occurred in the nest 17.

Using the same molding apparatus as in Example 1, the mold assembly was heated to 90 ° C. Injection molding was performed under the same conditions as in Example 1 using the same alloy material made of a polycarbonate resin and a polyester resin added with glass fibers as in Example 1 as the thermoplastic resin. The surface of the molded product in contact with the nest 17 had no glass fiber floating, and had very high specularity. There were no molding defects such as flow marks and jetting. In addition, although molding was continuously performed for 10,000 cycles, damage such as cracks did not occur in the insert 17.

(Embodiment 3) In Embodiment 3, nesting
Zirconia (ZrO) _Two)of
Instead, partially stabilized zirconia (ZrO_Two-CeO_Two)
Using the same mold assembly as in Example 1 was obtained. This part
Minute stabilized zirconia (ZrO_Two-CeO_Two) Has a thermal conductivity of
1.0 × 10^-2cal / cm · sec · ΔC. Complete
After attaching the completed mold assembly to the molding machine,
After heating the body to 130 ° C using a mold temperature controller, 40 ° C
Made from partially stabilized zirconia even when quenched to C
No damage such as cracks occurred in the nest 17.

Using the same molding equipment as in Example 1, the mold assembly was heated to 90 ° C. Injection molding was performed under the same conditions as in Example 1 using the same alloy material made of a polycarbonate resin and a polyester resin added with glass fibers as in Example 1 as the thermoplastic resin. The surface of the molded product in contact with the nest 17 had no glass fiber floating, and had very high specularity. There were no molding defects such as flow marks and jetting. In addition, although molding was continuously performed for 10,000 cycles, damage such as cracks did not occur in the insert 17.

Example 4 Example 4 relates to a mold assembly for molding a thermoplastic resin and a method for producing a molded product according to the second aspect of the present invention. FIGS. 4A and 4B are schematic end views when the mold assembly of Example 4 is clamped, and FIG. 6 is a schematic end view when the mold is opened. FIG. 5 is a schematic end view of the mold assembly being assembled.
(A), (B) and (C). 4A, FIG. 5A to FIG. 5C and FIG. 6 are views when the area of the mold assembly including the coating plate is cut along the vertical plane, and FIG. (B) is a view when a region of the mold assembly not including the coating plate is cut along a vertical plane parallel to the vertical plane.

The mold assembly for molding a thermoplastic resin according to the fourth embodiment includes a first mold portion (fixed mold portion) 20 and a second mold portion for molding a molded article based on a thermoplastic resin. Part (movable mold part) 25 and a first mold part 20, forming a part of the cavity, and having a nest 29 having a thickness of 3.00 mm.
Is disposed between the nest 29 and the second mold part 25,
A cover plate 22 attached to the first mold portion 20 and provided with a molten thermoplastic resin introduction portion 23; Then, the second mold portion 25 has a nested covering portion 27.
Is provided. The nest covering portion 27 is a kind of notch (notch) 26 provided on the surface of the second mold portion 12 facing the cavity surface 29A of the nest 29.

In a state where the first mold part 20 and the second mold part 25 are clamped (see FIG. 4A), a clearance (C ₂₁₎ between the nest 29 and the nest covering part 27 is obtained. )
Is set to 0.03 mm or less (C ₂₁ ≦ 0.03 mm), and the overlapping amount of the nest covering portion 27 with the nest 29 (ΔS ₂₁ )
Is 0.5 mm or more (ΔS ₂₁ ≧ 0.5 mm). The clearance (C ₂₂ ) between the nest 29 and the surface 24 of the cover plate 22 facing the nest is set to 0.03 mm.
Hereinafter, (C ₂₂ ≦ 0.03 mm), and the overlapping amount (ΔS ₂₂ ) of the covering plate 22 with respect to the insert 29 is 0.5 mm or more (ΔS ₂₂ ≧ 0.5 mm). As shown in FIGS. 4A and 4B, the cover plate 22 only partially overlaps the nest 29. Also in Example 4, zirconia (ZrO ₂ ) was used as a material forming the insert 29. In the mold assembly according to the fourth embodiment, the molten thermoplastic resin introduction portion 23 provided on the cover plate 22 has a direct gate structure.

The size of the cavity 28 in the mold assembly of the fourth embodiment is 100 mm × 100 mm × 4 mm, and the shape is a rectangular parallelepiped. The size of the nest 29 is 10
It is 2.00 mm × 102.00 mm × 3.00 mm. The nest 29 is manufactured by grinding.
Was polished and finished with a diamond grindstone to make the cavity surface 29A of the insert 29 a surface roughness _Ry of 0.02 μm.

A first mold part (fixed mold part) 20 was made of carbon steel S55C. The inner size of the nest mounting part 21 for the nest 29 is 102.20 mm × 102.20 m
m, and cut so as to have a depth of 3.02 mm to provide a nesting portion 21 (see FIG. 5A).
The nest 29 was adhered to the inside of the nest mounting portion 21 using a silicone-based adhesive (not shown) (see FIG. 5B). When the clearance (D) between the nest 29 and the nest mounting portion 21 was measured using a gap gauge, the minimum clearance was 0.05 mm.

A coating plate 22 was made of carbon steel, and was attached to a first mold portion 20 at a predetermined position with a bolt (not shown) (see FIG. 5C). The covering plate 22
Is provided with a molten thermoplastic resin introduction section (gate section) 23. The surface 24 facing the nest of the covering plate 22
And the clearance (C ₂₂ ) between the nest 29 and
2 mm (C ₂₂ = 0.02 mm), and the amount of overlap (ΔS ₂₂ ) of the covering plate 22 with respect to the nest 29 is 1.0 m
m (ΔS ₂₂ = 1.0 mm).

On the other hand, a second mold part (movable mold part) 25 was made of carbon steel S55C.

The first mold part (fixed mold part) 20 and the second mold part (movable mold part) 25 thus manufactured were assembled to obtain a mold assembly of Example 4. In this mold assembly, the clearance (C ₂₁ ) between the nest 29 and the nest cover 27 is 0.02 mm (C ₂₁ = 0.02 mm).
Met. In addition, the nesting covering portion 27 for the nesting 29
Is an overlap amount (ΔS ₂₁ ) of 1.0 mm (ΔS ₂₁ = 1.0 m)
m). As described above, the structure is such that there is no contact between the end of the insert 29 and the molten resin introduced into the cavity 28.

After the completed mold assembly is attached to the molding apparatus, the mold assembly is heated to 130 ° C. using a mold temperature controller, and then rapidly cooled down to 40 ° C., but it is made of zirconia. No damage such as cracks occurred in the nest 17.

Using the same injection molding machine as in Example 1 as the molding apparatus, the mold assembly was heated to 90 ° C. Injection molding was performed under the same conditions as in Example 1 using the same alloy material made of a polycarbonate resin and a polyester resin added with glass fibers as in Example 1 as the thermoplastic resin. A certain amount of molten resin is introduced into the molten thermoplastic resin introduction section (gate section)
After being introduced (injected) into the cavity 28 through 23,
The thermoplastic resin was cooled and solidified. After 20 seconds, the mold assembly was opened, and the molded product was taken out of the mold assembly.

The surface of the molded product in contact with the insert 29 had no glass fiber floating and had very high specularity. There were no molding defects such as flow marks and jetting. The molding was continuously performed for 10,000 cycles, but no damage such as cracks occurred in the insert 29.

Incidentally, also in the fourth embodiment, the nesting is made of ZrO.
₂ instead of ZrO ₂ —Y ₂ O ₃ or ZrO ₂
It may be made of partially stabilized zirconia such as —CeO ₂ or crystallized glass.

Example 5 Example 5 relates to a mold assembly for molding a thermoplastic resin and a method of manufacturing a molded product according to the third aspect of the present invention. FIG. 7 shows a schematic end view of the mold assembly of the fifth embodiment. 8 to 10 show schematic end views of the mold assembly during assembly. 7 (A), 8 (A) and 9 (C), and FIGS. 9 (A) and 9 (C).
10 (A) and FIG. 10 (A) are views when the area of the mold assembly including the coating plate is cut along the vertical plane, and FIG. 7 (B), FIG. 8 (B), (D), and FIG. 9 (B), (D)
FIG. 10B is a view when a region of the mold assembly not including the coating plate is cut along a vertical plane parallel to the vertical plane.

The mold assembly according to the fifth embodiment includes a first mold section (fixed mold section) 30 and a second mold section (movable mold section) for molding a molded article based on a thermoplastic resin. ) 40 and the first
Of the cavity 5 (fixed mold section).
1 and is disposed on a first insert 35 having a thickness of 3.00 mm and a second mold (movable mold) 40,
A second nest 45, which forms a part of the cavity 51 and has a thickness of 2.00 mm, is disposed between the first nest 35 and the second nest 45, and includes first and second molds. Parts 30, 4
0 and cover plates 33 and 43 provided with a molten thermoplastic resin introduction section (gate section) 50.

Cavity in Mold Assembly of Example 5
The size of 51 is 100 mm x 100 mm x 3 mm
The shape is a rectangular parallelepiped. In the fifth embodiment, the first
Grinding nest 35 and second nest 45 from zirconia
It was produced by processing. The size of the first nest 35 is 10
2.00 mm x 102.00 mm x 3.00 mm
You. With respect to the cavity surface 35A of the first nest 35,
Polishing and finishing using a diamond whetstone
Surface roughness R of the cavity surface 35A of the nest 35 _yTo
It was set to 0.02 μm. The thermal conductivity of the zirconia used is
0.8 × 10^-2cal / cm · sec · ΔC.

A first mold part (fixed mold part) 30 was made of carbon steel S55C. The inner size of the nest mounting portion 31 for the first nest 35 is 102.20 mm × 102.
Cutting was performed so that the depth was 20 mm and the depth was 3.02 mm. The reference number 32
Is a first covering plate mounting portion. Next, the first nest 35 was bonded into the nest mounting portion 31 using a silicone-based adhesive (not shown) (see FIGS. 9C and 9D). When the clearance (D) between the first nest 35 and the nest mounting portion 31 was measured using a gap gauge, the minimum clearance was 0.05 mm.

A second insert 45 was produced by press-forming zirconia so that the cavity surface had a concave shape, followed by firing. The second nest 45 is provided with a concave portion. The outer dimensions of the second nest 45 are 106.0.
It is 0 mm × 106.00 mm. The dimensions of the concave portion are 100.00 mm × 100.00 mm, the thickness of the bottom surface 45B of the concave portion is 2.00 mm, and the thickness (height) of the rising portion 45C from the bottom surface is 5.00 mm.
Therefore, the height (thickness) of the portion forming the cavity 51
Is 3.00 mm. The bottom surface 45B of the concave portion of the second insert 45 and the inner surface 45A of the rising portion 45C (these surfaces are cavity surfaces) are polished and finished using a diamond grindstone, and the surface roughness of these surfaces is adjusted. _Ry was set to 0.02 μm. Further, the boundary between the bottom surface 45B of the concave portion of the second insert 45 and the rising portion 45C is a curved surface having a radius of 0.1 mm. The second mold part 4
0 to attach the second cover plate 43 to the second
A part of the rising portion 45C of the nest 45 has a removed shape (see FIGS. 9A and 9B).

The second mold part (movable mold part) 40 was made of carbon steel S55C. Then, the inner size of the nest mounting portion 41 for the second nest 45 is 106.20 mm ×
Cutting was performed to 106.20 mm and the depth to 5.02 mm, and the nesting portion 41 was provided in the second mold portion 40 (see FIGS. 8A and 8B). Reference numeral 42 is a second covering plate mounting portion. Next, the second nest 45 was bonded into the nest mounting portion 41 using a silicon-based adhesive (not shown) (see FIGS. 9A and 9B). The second nest 45 using a gap gauge
When the clearance (D) between the nesting portion 41 and the nesting portion 41 was measured, the minimum clearance was 0.05 mm.

The first coating plate 33 is made of carbon steel, and the first mold part 3 is bolted (not shown) at a predetermined position.
0 (see FIG. 10B). The first coating plate 33 has a part 50 of the molten thermoplastic resin introduction part.
A is formed. Further, a second cover plate 43 was made of carbon steel, and was fixed to a second mold portion 40 at predetermined positions with bolts (not shown) (see FIG. 10A).
The second cover plate 43 is formed with a part 50B of the molten thermoplastic resin introduction part. In a state where the first mold part and the second mold part are clamped, the first covering plate 33 and the second covering plate 43 form a molten thermoplastic resin introduction part 50.

The thus-fabricated first mold section (fixed mold section) 30 and second mold section (movable mold section) 40 were assembled to obtain a mold assembly of Example 5. In this mold assembly, with the first mold part 30 and the second mold part 40 being clamped, a surface 35A of the first nest 35 facing the second nest, and a second The clearance (C ₃₀ ) between the first nest of the nest 45 and the facing surface 45D is 0.01.
mm. Also, the clearance (C ₃₁ ) between the first nest 35 and the surface 34 of the first coating plate 33 facing the first nest, and the second
The clearance (C ₃₂ ) between the surface 44 facing the nest and the second nest 45 was 0.01 mm. Furthermore, the overlapping amount (ΔS ₃₀ ) of the surface 35A of the first nest 35 facing the second nest and the surface 45D of the second nest 45 facing the first nest is 1.0 mm, First covering plate 3 for first nest 35
The overlap amount (ΔS ₃₁ ) of No. 3 was 1.0 mm. on the other hand,
The amount of overlap (ΔS ₃₂ ) of the second cover plate 43 with respect to the second insert 45 was 3.0 mm. The first and second cover plates 33, 43 overlap only with a part of the first and second inserts 35, 45.

After the completed mold assembly is attached to the molding apparatus, the mold assembly is heated to 130 ° C. using a mold temperature controller, and then rapidly cooled to 40 ° C., but it is made of zirconia. The first and second inserts 35 and 45 did not suffer damage such as cracks.

Using the same injection molding machine as in Example 1 as the molding apparatus, the mold assembly was heated to 90 ° C. As a thermoplastic resin, a glass fiber-added polycarbonate resin (manufactured by Mitsubishi Engineering-Plastics Corporation, GS20
Injection molding was performed using 20MKR, and 20% by weight of glass fiber). The molding conditions are: mold temperature 90 ° C., resin temperature 310 ° C., injection pressure 800 kgf / cm ² -G
And The average length of the glass fiber was 400 μm and the average diameter was 13 μm. After a predetermined amount of molten resin is introduced (injected) into the cavity 51 through the molten thermoplastic resin introduction part (gate part of the side gate structure) 50, the thermoplastic resin is cooled and solidified. Open the solid,
The molding was removed from the mold assembly.

The surface of the molded product in contact with the first and second inserts 35 and 45 had no glass fiber floating, and had very high specularity. There were no molding defects such as flow marks and jetting. The molding was continuously performed for 10,000 cycles.
No damage such as cracks occurred in 5,45.

In the fifth embodiment, the cover plate 3 provided with the molten thermoplastic resin introduction portion (gate portion) 50 is provided.
The third and third embodiments have a structure in which the cover plate is attached to either the first mold unit 30 or the second mold unit 40. It can also be.

Incidentally, also in the fifth embodiment, the nesting is made of ZrO.
₂ instead of ZrO ₂ —Y ₂ O ₃ or ZrO ₂
It may be made of partially stabilized zirconia such as —CeO ₂ or crystallized glass.

Comparative Example 1 FIG. 17 shows a schematic end view of the mold assembly used in Comparative Example 1. R _y 0.02 μm
A first mold part (fixed mold part) 100 made of carbon steel (thermal conductivity 11 × 10 ⁻² cal / cm · sec · ΔC) having a cavity surface of a mold part mirror-finished to
Using the mold assembly composed of the second mold part (movable mold part) 101 and the same thermoplastic resin as in Example 1, molding under the same molding conditions as in Example 1 Was done.
Incidentally, reference numeral 102 is a molten thermoplastic resin introduction part,
Reference numeral 103 is a cavity. However, the fluidity of the molten resin in the cavity 103 is poor, and the cavity 1
No. 03 could not be completely filled with the molten resin. Therefore, the injection pressure 200 kgf / cm ² -G increased was performed molded as 1000kgf / cm ² -G. Molding defects such as flow marks and jetting occurred in the obtained molded product. In addition, glass fibers were floating on the surface of the molded product, and the specularity was significantly inferior to that of Example 1.

(Comparative Example 2) In Comparative Example 2, the clearance (C ₁₁ ) was changed using the mold of Example 1, and the same thermoplastic resin as that of Example 1 was used. Molding was performed under injection conditions. Here, the clearance (C ₁₁ ) was set to 0.00 mm and 0.05 mm. When the clearance (C ₁₁ ) was 0.00 mm, the nest 17 was damaged when the mold assembly was clamped, and molding was not possible. The clearance (C ₁₁ ) is 0.05m
In the case of m, burrs were generated at the end of the molded product, cracks were generated from the end of the insert 17 after 100 shot molding, and molding was impossible.

Comparative Example 3 In Comparative Example 3, FIG.
The mold assembly of the fifth embodiment is modified as shown in a schematic end view of FIG.
The coating plates 33 and 43 were cut and polished to form a cavity of 104 mm × 104 mm × 3 mm. That is, there is no overlap between the surface 35A of the first nest 35 facing the second nest and the surface 45D of the second nest 45 facing the first nest. There was no overlapping amount of the covering plates 33, and the gap between the first insert 35 and the insert mounting portion 31 was opened to the cavity 51.

Using such a mold assembly, molding was performed using the same thermoplastic resin as in Example 5 under the same injection conditions as in Example 5. As a result, due to the high stress at the time of introducing the molten thermoplastic resin, first, at the first shot, burrs are formed on the molded product by the molten resin flowing into the gap between the first covering plate 33 and the first insert 35. At the third shot, cracks occurred from the first nest 35 near the molten thermoplastic resin introduction portion (gate portion of the side gate structure) 50, and molding was impossible.

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments.
The structure of the mold assembly, the thermoplastic resin used, and the injection molding conditions described in the embodiments are merely examples, and can be appropriately changed.

For example, as schematically shown in FIG. 11A, a mold assembly having a structure in which the volume of a cavity can be made variable at the time of molding a molded article can be provided. In this case, for example, a core 60 that can be moved by a hydraulic cylinder (not shown) may be provided in the cavity 28 of the mold assembly. In the example shown in FIG. 11A, the core 60 was incorporated in the mold assembly described in the fourth embodiment. And, in the molding of the molded product, when closing the mold,
The cavity 28 is larger than the volume (V _M ) of the molded article to be molded.
So that the volume (V _C ) of the first mold part 20 increases.
And the second mold part 25 are clamped, and the arrangement position of the core 60 in the cavity is controlled. Then, the thermoplastic resin 1 melted in the cavity (capacity: V _C ) 28
8, the core 60 is moved by the operation of a hydraulic cylinder (not shown) to start the cavity before, simultaneously with, during, or after the introduction of the thermoplastic resin (including simultaneously with the completion of the introduction). 28 volumes of the molded article to be molded to (V _M) is decreased. This state is shown in FIG.
This is schematically shown in FIG. As described above, when using a mold assembly having a structure that can make the volume of the cavity variable at the time of molding the molded product, the surface of the molded product can be uniformly compressed. The occurrence of sink marks can be suppressed.

Alternatively, as schematically shown in FIG. 12A, a mold assembly further provided with a pressurized fluid injection device 70 can be used. In the example shown in FIG. 12A, the mounting position of the pressurized fluid injection device 70 is
A pressurized fluid injection device mounting portion was provided in the mold portion and opened to the cavity. Then, a pressurized fluid is injected from the pressurized fluid injection device 70 into the molten thermoplastic resin 18 introduced into the cavity 28, thereby forming a hollow portion 18A inside the thermoplastic resin in the cavity 28. . FIG. 12B schematically shows the state when the introduction of the molten thermoplastic resin 18 into the cavity 28 is completed, and FIG. 13 shows the state when the injection of the pressurized fluid into the molten thermoplastic resin 18 is completed. Is shown schematically in FIG. In this way, if the pressurized fluid is injected into the molten thermoplastic resin 18 in the cavity 28, the cavity 2
As a result of the resin in 8 being pressed toward the cavity surface,
The occurrence of sink marks in the molded product can be reliably prevented. In addition, since the cooling and solidification of the molten resin in contact with the nest 29 is delayed, it is possible to avoid the occurrence of a phenomenon in which the resin portion which has started to solidify near the cavity surface of the nest and the internal resin are mutually mixed. Thus, it is possible to prevent the occurrence of color unevenness and poor appearance on the surface of the molded product near the thick portion.

FIG. 14 shows a tab forming portion 80 communicating with the cavity 28 for removing a molded product from the mold assembly.
Illustrates a structure provided on the cover plate 22A. The cover plate 22A is attached to the first mold part 20. Incidentally, the clearance C ₂₃ during this case also, the nesting 29 and the cover plate 22A is 0.03m
m or less. This mold assembly has substantially the same structure as the mold assembly described in the fourth embodiment. Two coating plates 22A are also provided in the direction perpendicular to the paper surface of FIG. It should be noted that FIG.
And (A) of FIG.
FIG. 14B is a view when the area of the mold assembly including 2A is cut, and FIGS. 14B and 15B are vertical planes parallel to such vertical planes and do not include the coating plates 22 and 22A. It is a figure when cutting the area | region of a metal mold assembly. By forming the mold assembly in such a structure, a tab portion is formed on the molded product. After the mold assembly is opened (see FIGS. 15A and 15B), a protruding pin (not shown) provided on the second mold portion 25 is applied to the tab portion to form a molded product. , And the molded product may be taken out of the mold assembly. Note that the tab portion formed on the molded product may be deleted in a later step.

FIG. 16A is a schematic end view of a mold assembly for molding a molded product that is a door handle for an automobile. This mold assembly includes a first mold section (fixed mold section) 90 and a second mold section 91. The second mold part 91 includes a movable mold part 92 and slide cores 94A and 94B. It should be noted that two cylindrical slide cores 94A are provided, and are movable in the direction perpendicular to the paper surface of FIG. Further, one slide core 94B is provided, and is movable in the left-right direction on the paper surface of FIG. First
The mold part 90 is provided with a nest 97. Reference numeral 96 is a cavity. Also, the second mold part 9
1 is provided with a molten thermoplastic resin introduction part, but illustration of such a molten thermoplastic resin introduction part is omitted. FIG.
(B) shows a schematic side view of a molded product which is an automobile door handle, and FIG. 16 (C) shows a schematic front view of a molded product which is an automobile door handle. FIG.
As shown in FIG. 6 (B), the door handle for an automobile is provided with an undercut portion. After forming such a molded product, in order to remove the molded product from the mold assembly, first, one slide core 94A is moved upward in the direction perpendicular to the paper surface of FIG. 16A and the other slide core 94A.
Is moved downward in the direction perpendicular to the paper surface of FIG.
Next, the slide core 94B is moved in the right-hand direction in FIG. 16A, and then the first mold part (fixed mold part) 9
0 and the movable mold part 92 are opened. Japanese Patent Application No. 7-152519 discloses a mold assembly having such a structure.
It is difficult to dispose the holding plate disclosed in JP-A-8-318534 in a mold assembly. However, in the present invention, the movable mold part 92 and the slide core 94B, which are the second mold parts 91, are nested in the nested covering parts 9.
By providing 3, 95, the nest 97 can be securely disposed in the first mold portion 90.

[0130]

The nest of the present invention not only has a large heat insulating effect, but also is easy to maintain. Further, in the present invention, rapid cooling of the molten resin filled in the cavity can be suppressed, and appearance defects such as jetting and flow marks can be effectively prevented from occurring in the molded product. Further, even when a thermoplastic resin containing an inorganic fiber or the like is used, it is possible to reliably prevent the inorganic fiber or the like from depositing on the surface of the molded product. Moreover,
In the present invention, even if long-term molding is performed, the nest is not damaged, and the nest is easily and inexpensively manufactured by incorporating the nest within the mold portion within a predetermined clearance or overlap amount range. A molded article having a mirror surface can be formed. In addition, the appearance of the molded article is not impaired, the occurrence of burrs at the end of the molded article can be prevented, the rejection rate of the molded article can be reduced, and the homogenization and high quality of the molded article can be achieved. Cost can be reduced.

Further, since the flowability of the molten thermoplastic resin is improved, the pressure at which the molten thermoplastic resin is introduced into the cavity can be set low, so that the stress remaining in the molded product can be reduced, and the quality of the molded product can be reduced. Is improved. Further, since the introduction pressure can be reduced, the thickness of the mold section can be reduced, the size of the molding device can be reduced, and the cost of the molded product can be reduced.

In addition, in some cases, the mold assembly of the present invention does not require the cover plate to be disposed inside the mold, and the cover plate may be disposed inside the mold portion. Even so, since the covering plate also serves as the molten thermoplastic resin introduction part, there is little restriction on the arrangement position of the nest, and the nest is inserted into the mold part corresponding to the part of the molded product to be given excellent surface characteristics. It becomes possible to arrange.

[Brief description of the drawings]

FIG. 1 is a schematic end view of a mold assembly for molding a thermoplastic resin in Example 1 at the time of mold clamping, and a schematic end view of a mold assembly being assembled.

FIG. 2 is a schematic end view of the mold assembly for thermoplastic resin molding in Example 1 when the mold is opened.

FIG. 3 is a schematic end view showing a state where a molten thermoplastic resin is introduced into a cavity of a mold assembly for molding a thermoplastic resin in Example 1.

FIG. 4 is a schematic end view of a mold assembly for molding a thermoplastic resin in Example 4 at the time of mold clamping.

FIG. 5 is a schematic end view of a mold assembly for molding a thermoplastic resin in Example 4 during assembly.

FIG. 6 is a schematic end view of a mold assembly for molding a thermoplastic resin in Example 4 when the mold is opened.

FIG. 7 is a schematic end view of a mold assembly for molding a thermoplastic resin in Example 5 at the time of mold clamping.

FIG. 8 is a schematic end view of a mold assembly for molding a thermoplastic resin in Example 5 during assembly.

FIG. 9 is a schematic end view of the mold assembly for molding a thermoplastic resin in Example 5 during assembly, following FIG. 8;

FIG. 10 is a schematic end view of a mold assembly for thermoplastic resin molding in Example 5 when the mold is opened.

FIG. 11 is a schematic end view of a mold assembly having a structure capable of making the volume of a cavity variable when molding a molded product, and a mold after introducing a molten thermoplastic resin into the cavity. It is a typical end view of an assembly etc.

FIG. 12 is a schematic end view of a mold assembly further provided with a pressurized fluid injection device at the time of mold clamping, and a schematic diagram of a mold assembly and the like at the time of completion of introduction of a molten thermoplastic resin into a cavity. It is a typical end view.

FIG. 13 is a schematic end view of a mold assembly and the like at the time of completion of injection of a pressurized fluid into a molten thermoplastic resin in a cavity.

FIG. 14 is a schematic end view of a mold assembly having a structure in which a tab forming portion communicating with a cavity is provided on a coating plate in order to take out a molded product from the mold assembly during mold clamping. .

15 is a view showing a state of a movable mold part and a molded product of the mold assembly shown in FIG. 14 after the mold is opened.

FIG. 16 is a schematic end view of a mold assembly having a slide core for molding an automobile door handle when the mold is clamped, and a schematic view of the automobile door handle.

FIG. 17 is a schematic end view of the mold assembly used in Comparative Example 1 when the mold is clamped.

FIG. 18 is a schematic end view of the mold assembly used in Comparative Example 3 when the mold is clamped.

[Explanation of symbols]

10 ... first mold part (movable mold part), 11 ... nested part, 12 ... second mold part (fixed mold part),
13 ... notch (notch), 14 ... nested covering part, 15 ... molten thermoplastic resin introduction part, 16 ...
Cavity, 17: nest, 17A: cavity surface of nest, 18: molten thermoplastic resin, 20 ...
1st mold part (fixed mold part), 21 ... nest mounting part, 22 ... coating plate, 23 ... molten thermoplastic resin introduction part, 24 ... facing the nest of the coating plate Surface, 25... Second mold part (movable mold part), 26.
..Incisions (notches), 27 ... nested covering parts,
28: cavity, 29: nesting, 29A ...
-Nested cavity surface, 30 ... first mold part (fixed mold part), 31 ... nested mounting part, 32 ... first
, The first cover plate, 34 ... the surface of the first cover plate facing the first nest, 35 ... the first nest, 35A ... the first
Nest cavity surface, 40 ... second mold part (movable mold part), 41 ... nest insertion part, 42 ... second
, The second cover plate, 44 ... the surface of the second cover plate facing the second nest, 45 ... the second nest, 45A ... the second
Bottom of nest and inner surface of rising part, 45B
・ Bottom surface of second nest, 45C: rising portion of second nest, 45D: surface of second nest facing first nest, 50: molten thermoplastic resin introduction portion (gate Parts), 50A, 50B: a part of the molten thermoplastic resin introduction part, 51: cavity, 60: core, 7
0 ... pressurized fluid injection device, 80 ... tab forming part, 9
0 ... first mold part (fixed mold part), 91 ... second
Mold part 92, movable mold part 93, 95 ... nested cover part, 94A, 94B ... slide core 96
... cavity, 97 ... nesting

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B29C 49/48 B29C 49/48 // B29K 101: 12

Claims (12)

[Claims] (A) a first mold part and a second mold part for molding a molded article based on a thermoplastic resin; and (b) a first mold part and a second mold part. For molding a thermoplastic resin, comprising a part, a nest having a thickness of 0.1 mm to 10 mm, and (c) a molten thermoplastic resin introduction part provided in the second mold part. In the mold assembly of (1), the second mold portion is provided with a nesting cover portion, and when the first mold portion and the second mold portion are clamped, (A ) The clearance between the nest and the nest cover is less than or equal to 0.03 mm;
mm or more, and the thermal conductivity of the material forming the nest is 2 × 10 ⁻² cal /
A mold assembly for molding a thermoplastic resin, which is not more than cm · sec · ΔC. (A) a first mold part and a second mold part for molding a molded article based on a thermoplastic resin; (b) a first mold part provided in the first mold part; A nest having a thickness of 0.1 mm to 10 mm, which constitutes a part; and (c) disposed between the nest and the second mold part, attached to the first mold part, A mold assembly for molding a thermoplastic resin, comprising a coating plate provided with a thermoplastic resin introduction portion, wherein a second mold portion is provided with a nested coating portion, In a state where the first mold part and the second mold part are clamped, (A) the clearance between the nest and the nest covering part is 0.03 mm or less, and (B) the nest covering part with respect to the nest. The overlap amount is 0.5
(C) the clearance between the nest and the cover plate is 0.03 mm or less; (D) the amount of overlap of the cover plate with respect to the nest is 0.5
mm or more, the covering plate overlaps only a part of the nest, and the thermal conductivity of the material constituting the nest is 2 × 10 ⁻² cal /
A mold assembly for molding a thermoplastic resin, which is not more than cm · sec · ΔC. (A) a first mold part and a second mold part for molding a molded article based on a thermoplastic resin; (b) a first mold part and a second mold part. A first nest having a thickness of 0.1 mm to 10 mm, which constitutes a part; (c) a first nest, which is disposed in the second mold portion and which constitutes a part of a cavity, having a thickness of 0.1 mm to 10 mm The second nest of
And (d) disposed between the first nest and the second nest;
A first mold part, a second mold part, or a first and a second mold part;
A mold plate for molding a thermoplastic resin, comprising: a cover plate attached to a mold portion of the above, and provided with a molten thermoplastic resin introduction portion; and a first mold portion and a second mold portion. (A) The clearance between the surface of the first nest facing the second nest and the surface of the second nest facing the first nest is zero. (B) the amount of overlap between the surface of the first nest facing the second nest and the surface of the second nest facing the first nest is 0.5 mm or more; C) the clearance between the first nest and the cover plate and the clearance between the second nest and the cover plate are not more than 0.03 mm; (D) the amount of overlap of the cover plate with respect to the first nest;
And the amount of overlap of the cover plate with respect to the second nest is not less than 0.5 mm, and the cover plate overlaps only a part of the first and second nests, and the heat of the material forming the first and second nests Conductivity is 2 ×
A mold assembly for molding a thermoplastic resin, which is not more than 10 ^-2 cal / cm · sec · ΔC. 4. In order to remove a molded article from a mold assembly,
The mold assembly for molding a thermoplastic resin according to claim 2 or 3, wherein the coating plate is provided with a tab forming portion communicating with the cavity. 5. A nest, a first nest, or a second nest.
Is ZrO_Two, ZrO_Two-CaO, ZrO
_Two-Y_TwoO_Three, ZrO_Two-CeO_Two, ZrO_Two-MgO, Zr
O_Two-SiO_Two, K_TwoO-TiO_Two, Al_TwoO_Three, Al_TwoO_Three−
TiC, Ti _ThreeN_Two, 3Al_TwoO_Three-2SiO_Two, MgO-
SiO_Two, 2MgO-SiO_Two, MgO-Al_TwoO_Three-Si
O_TwoAnd ceramics selected from the group consisting of titania
Or soda glass, quartz glass, heat-resistant glass
Glass selected from the group consisting of
5. The method according to claim 1, wherein
13. A mold assembly for molding a thermoplastic resin according to item 13. 6. The material constituting the nest, the first nest, or the second nest is ZrO ₂ , ZrO ₂ —Y ₂ O ₃ , ZrO.
₂ -CeO _2, or a thermoplastic resin mold assembly for molding according to any one of claims 1 to 4 characterized in that it is a crystallized glass. 7. A first mold part and a second mold part for molding a molded article based on a thermoplastic resin, and b. A cavity provided in the first mold part. A part having a nest having a thickness of 0.1 mm to 10 mm, and (c) a molten thermoplastic resin introduction part provided in the second mold part, wherein the second mold part has And a nested covering portion is provided. In a state where the first mold portion and the second mold portion are clamped, (A) the clearance between the nesting portion and the nested covering portion is 0.03 mm or less. (B) The overlapping amount of the nest covering portion with respect to the nest is 0.5
mm or more, and the thermal conductivity of the material forming the nest is 2 × 10 ⁻² cal /
Using a mold assembly for molding a thermoplastic resin having a temperature of not more than cm · sec · ΔC, the molten thermoplastic resin is introduced into the cavity from the molten thermoplastic resin introduction portion, and then the thermoplastic resin is cooled and solidified. A method for producing a molded article, characterized in that the molded article is molded by the above method. 8. A first mold part and a second mold part for molding a molded article based on a thermoplastic resin, and (b) a first mold part and a second mold part. A nest having a thickness of 0.1 mm to 10 mm, which constitutes a part; and (c) disposed between the nest and the second mold part, attached to the first mold part, A cover plate provided with a plastic resin introduction part; a nested cover part is provided on the second mold part; the first mold part and the second mold part are clamped. In the state, (A) the clearance between the nest and the nest cover is 0.03 mm or less, and (B) the overlapping amount of the nest cover with respect to the nest is 0.5.
(C) the clearance between the nest and the cover plate is 0.03 mm or less; (D) the amount of overlap of the cover plate with respect to the nest is 0.5
mm or more, the covering plate overlaps only a part of the nest, and the thermal conductivity of the material constituting the nest is 2 × 10 ⁻² cal /
Using a mold assembly for molding a thermoplastic resin having a temperature of not more than cm · sec · ΔC, introducing the molten thermoplastic resin into the cavity from the molten thermoplastic resin introduction portion, and then cooling and solidifying the thermoplastic resin A method for producing a molded article, characterized in that the molded article is molded by the above method. 9. A first mold part and a second mold part for molding a molded article based on a thermoplastic resin, and (b) a first mold part and a second mold part. A first nest having a thickness of 0.1 mm to 10 mm, which constitutes a part; (c) a first nest, which is disposed in the second mold portion and which constitutes a part of a cavity, having a thickness of 0.1 mm to 10 mm The second nest of
And (d) disposed between the first nest and the second nest;
A first mold part, a second mold part, or a first and a second mold part;
(A) the first mold part and the second mold part in a state where the first mold part and the second mold part are clamped. The clearance between the surface of the second nest facing the second nest and the surface of the second nest facing the first nest is not more than 0.03 mm; and (B) the second of the first nest. An overlapping amount of the surface facing the nest and the surface facing the first nest of the second nest is 0.5 mm or more; (C) a clearance between the first nest and the covering plate; (D) the amount of overlap of the coating plate with respect to the first nest,
And the amount of overlap of the cover plate with respect to the second nest is not less than 0.5 mm, and the cover plate overlaps only a part of the first and second nests, and the heat of the material forming the first and second nests Conductivity is 2 ×
Using a mold assembly for molding a thermoplastic resin having a temperature of 10 ^-2 cal / cm · sec · ΔC or less, introducing the molten thermoplastic resin into the cavity from the molten thermoplastic resin introduction portion, and then applying the thermoplastic resin to the cavity. A molded article by cooling and solidifying the molded article. 10. The molded product according to claim 8, wherein the coating plate is provided with a tab forming portion communicating with the cavity for removing the molded product from the mold assembly. Manufacturing method. 11. The material constituting the nest, the first nest, or the second nest is ZrO ₂ , ZrO ₂ —CaO, Zr
O ₂ —Y ₂ O ₃ , ZrO ₂ —CeO ₂ , ZrO ₂ —MgO, Z
rO ₂ —SiO ₂ , K ₂ O—TiO ₂ , Al ₂ O ₃ , Al ₂ O _{3
-TiC, Ti 3 N 2, 3Al} 2 O 3 -2SiO 2, MgO
—SiO ₂ , 2MgO—SiO ₂ , MgO—Al ₂ O ₃ —S
iO selected from ₂ the group consisting of titania ceramic, or soda glass, quartz glass, heat resistant glass, of claims 7 to 10, characterized in that a glass selected from the group consisting of crystallized glass A method for molding a molded article according to any one of the preceding claims. 12. The material constituting the nest, the first nest, or the second nest is ZrO ₂ , ZrO ₂ —Y ₂ O ₃ , Zr
O ₂ -CeO _2, or method of molding a molded article according to any one of claims 7 to 10 characterized in that it is a crystallized glass.