JPH0681003A - Production of die - Google Patents

Abstract

(57) [Summary] [Purpose] Manufacturing of molds without using machining, etc.
The purpose is to make it easy. [Composition] Metal powder or an alloy powder containing the metal as a main component is kneaded with a binder to produce a metal plastic composition, and a product model is pressed against the metal plastic composition to form a female mold, and then the female mold is formed. Characterized by sintering the mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a mold used for manufacturing a product.

[0002]

2. Description of the Related Art Generally, when many products having the same shape are manufactured, a mold having a recess having the same shape as the product shape is formed, and a molten material is poured or filled into the mold to solidify. After that, a method is adopted in which the solidified material is extracted from the mold. By the way, in most cases, the metal mold is usually manufactured by forming the above-mentioned concave portion on a metal block formed of a molten metal by machining such as cutting or electrical discharge machining.

[0003]

However, in such a conventional method of manufacturing a mold, casting equipment for manufacturing a metal ingot as a raw material is required, and a machine for forming a recess is required. There is a problem that equipment is required and large-scale equipment is required. Further, since the recess is formed by machining or electric discharge machining, there is also a problem that machining requires time.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to provide a mold manufacturing method capable of effectively eliminating the problems and problems remaining in the above-mentioned conventional techniques. In the method for producing a mold, a metal powder or an alloy powder containing the metal as a main component is kneaded with a binder to produce a metal plastic composition, and a product model is pressed against the metal plastic composition to form a female mold. Then, the female mold is dried and then sintered. According to a second aspect of the present invention, there is provided a method of producing the first die, wherein the metal powder is one type selected from Ag, Cu, Ni, Cr, W, and Mo. Is characterized by.
The method for producing a mold according to claim 3 is the same as the method for producing a mold according to claim 1, wherein the alloy powder is Ag, Cu,
It is one kind selected from alloys containing Ni, Cr, W, and Mo as main components. Further, the method for manufacturing a mold according to claim 4 is the method according to claim 1 to claim 3.
In the method for producing a mold according to any one of items 1 to 3, the binder is a thermoplastic resin binder and / or a water-soluble cellulose-based resin binder.

[0005]

According to the mold manufacturing method of the present invention, when a metal powder or an alloy powder and a binder are kneaded to form a metal plastic composition, and a product model is pressed against the metal plastic composition, The metal-plastic composition is deformed by its plasticity to form a female mold having a recess similar to the outer shape of the product model.

Then, by baking this female mold,
The remaining binder is removed and the metal powder or alloy powder is sintered to form a mold having a recess having a predetermined product shape.

Specific examples and formulation examples of the respective components of the metal plastic composition used in the present invention will be described below.

[Metal powder or alloy powder] Metal powder or alloy powder is spherical with an average particle size of 200 μm or less,
A powder of irregular shape or flat shape is used.
One selected from Ag, Cu, Ni, Cr, W, and Mo, or an alloy thereof is used.
This metal powder or alloy powder thereof is used selectively depending on the material of the product to be molded, and when the material is used in a molten state, it has a melting point higher than the melting point of the material, A metal or its alloy that does not react with this material is selected.

The compounding ratio is 50 when the binder is a water-soluble cellulose resin binder.
% By weight, and when a thermoplastic resin binder is used, 82% by weight to 96% by weight,
Further, when the water-soluble cellulose resin binder and the thermoplastic resin binder are mixed and used, the content is 70% by weight to 97% by weight. When the compounding ratio exceeds the upper limit, it is not preferable from the viewpoint of elongation and cracking of the obtained metal plastic composition, and when the compounding ratio is below the lower limit, the shrinkage ratio during sintering becomes large and the accuracy is improved. Since it is not preferable, it is set within the above range. Further, if the average particle size exceeds 200 μm, the elongation and strength of the metal plastic composition decrease, so it is preferable to set it to 200 μm or less.

[Binder composition] A: In the case of a water-soluble cellulose resin binder (a) Water-soluble cellulose resin As the water-soluble cellulose resin, methyl cellulose or ethyl cellulose is used, and it is rapidly gelated by heating. It is added to facilitate solidification and shape self-holding property, and its compounding ratio is 0.4% by weight to 16.
It is 5% by weight. If the mixing ratio exceeds the upper limit, the viscosity becomes too large, making it difficult to mold, and
If it is less than the lower limit value, the above-mentioned function of self-holding property cannot be obtained, so that it is set within the above range.

(B) Surfactant This surfactant is added in order to enhance the mixing property of the above-mentioned metal powder or alloy powder and the water-soluble cellulose-based resin, and is anionic such as alkylbenzene sulfonate and fatty acid soap. An ionic surfactant is used, and its compounding ratio is 0.0
It is from 01% by weight to 8.5% by weight. If the compounding ratio exceeds the upper limit, the viscosity of the metal plastic composition is lowered to adversely affect the shape self-holding property, and if it is less than the lower limit, the above-mentioned effects cannot be sufficiently obtained. , Is set within the above range.

(C) Fats and Oils This fat and oil is added to reduce the adhesion of the obtained metal plastic composition to other substances (ie, to reduce the adhesion to the product model and enhance the releasability). What is done,
Phthalates such as diN-octyl phthalate and diN-butyl phthalate, and alcohols such as polyvinyl alcohol, polyethylene glycol and ethers are used, and the compounding ratio thereof is 1.2% by weight to 25% by weight. . If the blending ratio exceeds the upper limit value, it becomes excessively slippery, and if it falls below the lower limit value, the above-mentioned effects cannot be obtained, so that the blending ratio is set within the above range. (D) Remaining water and inevitable impurities.

B: In the case of a thermoplastic resin binder (a) Thermoplastic resin An acrylic resin such as polymethylmethacrylate is used as the thermoplastic resin, and the shape of the obtained metal plastic composition is kept good, And, by the combination with the plasticizer described later, at a relatively low temperature in the metal plastic composition,
It imparts properties such as plasticity, self-adhesiveness, elongation, and crack prevention, and the compounding ratio thereof is 2% by weight to 10% by weight. When the compounding ratio is less than the lower limit value, the above-mentioned characteristics are not sufficiently obtained, and when the compounding ratio exceeds the upper limit value, deformation, sagging, or foaming occurs when degreasing and sintering the metal plastic composition. Etc. are not preferable,
It is set within the above range.

(B) Plasticizer As described above, the plasticizer imparts characteristics such as plasticity, self-adhesiveness, elongation, and crack prevention to the above-mentioned metal plastic composition, and includes diN-butyl phthalate and phthalate. A phthalic acid compound such as diethylhexyl acid salt or diN-octyl phthalate, and one or more selected from alcohols such as polyethylene glycol, ethylene glycol and glycerin are used, and the compounding ratio thereof is 2% by weight to 10% by weight
Is. When the compounding ratio is less than the lower limit, plasticity, elongation, and properties such as crack prevention cannot be sufficiently obtained, and when the compounding ratio exceeds the upper limit, self-adhesiveness is decreased, and Since air bubbles are trapped inside the mold during molding, and the strength of the mold is reduced, it is set within the above range.

(C) Dispersant This dispersant is preferably added, for example,
A surfactant such as sorbitan monooleate is used to enhance the mixing property of the metal powder or alloy powder with the binder, and in the range of 0.05 wt% to 6 wt% together with inevitable impurities. Is added.

C: In the case of a mixed binder of a thermoplastic resin binder and a water-soluble cellulosic resin binder (a) Thermoplastic resin The thermoplastic resin is an acrylic resin such as polymethylmethacrylate, in which oil and fat components coexist. As a result, the resuscitability of the metal plastic composition is improved, the shape is maintained well, and properties such as plasticity, elongation, and crack prevention are given. When the blending ratio (that is, the blending ratio after the solvent component is removed) is less than 0.1% by weight, good resuscitability cannot be obtained, and properties such as elongation and crack prevention are insufficient. On the other hand, if it exceeds 5% by weight, the metal plastic composition is fluidized by being heated during sintering, and it becomes impossible to sinter the molded body into a desired shape. The compounding ratio is set to 0.1% by weight to 5% by weight.

(B) Water-soluble Cellulose Resin As the water-soluble cellulose resin, methyl cellulose, ethyl cellulose or the like is used, which has the effect of imparting plasticity and shape-retaining properties to the metal plastic composition. In addition to the effect of adjusting the properties such as shape retention, plasticity, elongation, and crack prevention of the metal-plastic composition provided by this acrylic resin in combination with the acrylic resin, it is characterized that it solidifies when water is dried. By this, the degree of progress of drying and solidification of the metal plastic composition is adjusted. If the compounding ratio is less than 0.1% by weight, the hardness and strength required for the molded article cannot be obtained because the solidification is insufficient even if the water is dried, while if it exceeds 5% by weight. Since the viscosity of the metal plastic composition is lowered and the plasticity, that is, the moldability is remarkably lowered, the compounding ratio of the water-soluble cellulose resin is 0.
It is set to 1 to 5% by weight.

(C) Fats and Oils These fats and oils are vegetable oils, animal oils, synthetic oils, or
A higher organic acid such as phthalic acid or oleic acid, a higher organic compound such as diN-butyl phthalate, ethylhexyl phthalate, or sorbitan monooleate, or a higher alcohol such as polyethylene glycol is used. The purpose of this is to adjust the plasticity of and to prevent the product from sticking to the model during molding. And
If the blending ratio is less than 0.1% by weight, the effect cannot be obtained. If the blending ratio exceeds 5% by weight, the elongation property is remarkably deteriorated.
It is set to 5% by weight to 5% by weight.

(D) Lower Alcohol This lower alcohol uses ethylene glycol, glycerin, etc. to suppress cracks and the like during molding of the obtained metal plastic composition. Depending on the characteristics required, it is not always necessary to mix them. When the blending ratio exceeds 5% by weight, the viscosity of the metal plastic composition is lowered and the plasticity (same as above) is remarkably lowered. Therefore, the blending ratio is 5
It is set to be less than or equal to weight%.

(E) Surfactant As the surfactant, sodium lauryl sulfate or the like is used to facilitate the kneading and mixing of the compound during the production of the metal plastic composition and to shorten the time required for it. However, it is not always necessary to mix them depending on the production conditions. Since the above-mentioned effect is not changed even if the content exceeds 0.5% by weight, the content of the surfactant is set to 0.5% by weight or less.

[0021]

EXAMPLES The present invention will be described below with reference to examples. First, a metal plastic composition using a water-soluble cellulose resin binder (Example 1), a metal plastic composition using a thermoplastic resin binder (Example 2), and a metal plastic composition using a binder in which both are mixed. For each of the compositions (Example 3), a metal plastic composition was produced in the following blending ratio.

Example 1: Methyl cellulose; 9% by weight,
Alkylbenzene sulfonate; 3% by weight, diN-octyl phthalate; 10% by weight, and the balance: water and unavoidable impurities were made into a binder, and 22% by weight of this binder and 78% by weight of Ag powder having an average particle size of 40 μm were prepared. Was kneaded to obtain a metal plastic composition.

Example 2 These were mixed in ethanol so that the compounding ratio after evaporation and drying was 4% by weight of acrylic resin, 4% by weight of diN-butyl phthalate; 4% by weight, sorbitan monooleate; 2% by weight. After stirring and mixing at room temperature, Ag powder having an average particle size of 30 μm was stirred and mixed into this solution so that the compounding ratio after evaporation and drying was also 90% by weight.
This mixed solution was spread on a vat and kept at a temperature of 40 ° C. for 24 hours to be naturally dried to obtain a metal plastic composition.

Example 3; The compounding ratio after evaporation and drying was as follows: polymethylmethacrylate; 2.7% by weight, diN-butyl phthalate; 2.1% by weight, and sorbitan monooleate.
These were mixed by stirring in ethanol at room temperature so as to be 0.5% by weight, and this solution had an average particle size of 30 μm.
Similarly, Ag powder of was mixed with stirring so that the compounding ratio after evaporation and drying would be 84.9% by weight, and then this mixed solution was spread in a vat and naturally dried by holding at a temperature of 40 ° C. for 24 hours. , This is methyl cellulose; 1.0
%, Sodium lauryl sulfate; 0.02, balance: water and unavoidable impurities were kneaded with a jelly composition obtained by kneading to obtain a metal plastic composition.

Then, the metal plastic composition W of each example thus obtained is filled in a mold 1 as shown in FIG. 1 and the exposed surface is smoothed.

The metal plastic composition W filled in this way is exposed from the exposed surface side thereof with a product model as shown in FIG. 2 (in this embodiment, a relief-shaped product model is shown) 2 And press it with a predetermined pressure until the back surface of the product model 2 and the surface of the metal-plastic composition W are aligned, as shown in FIG.

In the state shown in FIG. 3, in Example 1, the metal plastic composition W is dried by natural drying or forced drying until it becomes a semi-cured state or a solidified state. Here, the drying conditions in Example 1 are as follows. Natural drying: 48 hours at room temperature Forced drying: 6 hours at 80 ° C

Then, after drying the metal plastic composition W in Example 1 in this manner, and directly in Examples 2 and 3, the product model 2 was directly produced from the metal plastic composition W. With the mold release, the mold 1
After that, each of the metal plastic compositions W is fired in the atmosphere under the conditions of temperature: 900 ° C., time: 1 hour or more.

As a result, the binder of the metal plastic composition W is completely removed, and the Ag powder is sintered to have the recess 3 having the same shape as the product model 2 as shown in FIG. The mold 4 is formed.

Then, the mold 4 obtained as described above
By injecting or filling an appropriate molten metal material, clay or the like into the recess 3 and then releasing the die, a product having the same shape as the product model 2 shown in FIG. 2 is obtained.

As described above, according to the method for producing a mold of the present invention, a metal-plastic composition W is produced and the product model 2 is pressed against the metal-plastic composition W, so that the same process as the product model 2 is performed. The recess 3 is easily formed, and the metal-plastic composition W in which the recess 3 is formed is fired to remove the binder of the metal-plastic composition W and to sinter the metal powder. Mold 4 with 3
Is easily obtained.

Therefore, it becomes possible to manufacture a mold without the need for machining or the like. As a result, the mold manufacturing apparatus can be simplified, and the mold can be manufactured by a simple operation that does not require the skill of pressing the product model 2 against the metal plastic composition W. Due to the action, the manufacturing cost of the mold is significantly reduced.

The above embodiment is an example, and can be variously modified within the scope of the technical idea of the present invention.

For example, in the above-mentioned embodiment, the mold used for the relief-shaped product is exemplified, but instead of this, as shown in FIGS. 5 and 6, the manufacture of a three-dimensional product such as a cylindrical product. It can also be applied to the split mold used for.

In this case, a pair of molds 10 filled with the metal-plastic composition W is prepared in advance, and these molds 10 are butted so as to sandwich the product model 11, and approximately half of the product model 11 is prepared. To be embedded in the metal-plastic composition W in both the molds 10, and after drying the metal-plastic composition W in this state as needed, the product model 11 is released and baked. By this, a split mold is obtained.

Further, in the case of manufacturing such a split mold, it is necessary to provide a core for forming a stuffer integrally with or separately from the product model 11.

[0037]

As described above, according to the mold manufacturing method of the present invention, a metal plastic composition is produced,
By pressing the product model on the metal plastic composition, a recess similar to that of the product model is formed, and then the metal plastic composition is fired to remove the binder of the metal plastic composition and burn the metal powder. Since the metal mold having the recess is obtained by binding, the following excellent effects are obtained.

[0038] It is possible to manufacture a mold without the need for work such as machining, thereby simplifying the mold manufacturing apparatus and requiring the skill to press the product model onto the metal plastic composition. The mold can be manufactured by a simple operation that does not occur. Therefore, the synergistic effect of these can significantly reduce the manufacturing cost of the mold.

[Brief description of drawings]

FIG. 1 is an external perspective view for explaining a method for manufacturing a mold of the present invention, showing a state in which a mold is filled with a metal plastic composition.

FIG. 2 is an external perspective view showing an example of a product model for explaining the method for manufacturing a mold of the present invention.

FIG. 3 is an external perspective view for explaining the method for producing a mold of the present invention, showing a state in which a product model is pushed into a metal plastic composition filled in a mold.

FIG. 4 is a perspective view showing an appearance of a mold manufactured by the mold manufacturing method of the present invention.

FIG. 5 is a perspective view showing a modification of the method for manufacturing a mold of the present invention, showing a mold filled with a metal plastic composition and a product model.

FIG. 6 is an external perspective view showing a modified example of the method for producing a mold of the present invention, showing a state in which a product model is pushed into one of the molds filled with a metal plastic composition. is there.

[Explanation of symbols]

 W Metallic plastic composition 1 Formwork 2 Product model 3 Recesses 4 Mold 10 Formwork 11 Product model

Claims (4)

[Claims] 1. A metal powder or an alloy powder containing the metal as a main component is kneaded with a binder to form a metal plastic composition, and a product model is pressed against the metal plastic composition to form a female mold. A method of manufacturing a die, comprising sintering the female die. 2. The metal powder is Ag, Cu, Ni, C
The method for manufacturing a mold according to claim 1, wherein the mold is one selected from r, W, and Mo. 3. The alloy powder is Ag, Cu, Ni, C
The method of manufacturing a mold according to claim 1, wherein the method is one type selected from alloys containing r, W, and Mo as main components. 4. The method for producing a mold according to claim 1, wherein the binder is a thermoplastic resin binder and / or a water-soluble cellulose-based resin binder.