JPH09262839A - Mold using nonmetal matrix and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a mold using a nonmetal matrix hard to generate the peeling of a metal plating layer and high in durability. SOLUTION: In this mold using a nonmetal material as a matrix, a first intermediate layer composed of a resin mixed with a hard metal powder of iron, metal silicon or ferrosilicon is formed on the surface of the nonmetal matrix and a second intermediate layer composed of a resin mixed with a soft metal powder of metal aluminum or copper is formed on the first intermediate layer. A metal layer is formed on the second intermediate layer by electroless plating and a nonmetal matrix having a fluoroplastic coating layer formed thereon is used on the metal plating layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold using a non-metal base material having a non-metal base material whose surface is metal-plated to provide hardness and wear resistance, and a method for producing the mold.

[0002]

2. Description of the Related Art Conventionally, as a mold for injection molding of casting molds and resins used in the production of sand mold castings, molds such as iron and aluminum alloys have been used for mass production.
Wooden molds and resin molds are used for small-volume production. The former has good durability but is difficult to process and high in cost, and the latter has the drawback that it is easy to process and low in cost, but lacks wear resistance and has a short life. Therefore,
As a mold having improved processability to reduce cost and durability, for example, a metal is formed on the surface of a thermosetting resin base material described in, for example, JP-A-62-110823 and JP-B-7-106576. Plated resin molds are used.

A resin mold with such a metal plating is
A conductive intermediate layer is formed on the surface of a resin base material with a resin coating containing conductive metal powder such as copper, and a metal plating layer is formed on the conductive intermediate layer to increase wear resistance. .

[0004]

However, in the case of the above-mentioned conventional one-layer intermediate layer made of the resin coating material containing metal powder such as copper, the hardness of the intermediate layer is low and the pressure resistance is insufficient. However, the intermediate layer is required to have a certain hardness in order to increase the pressure resistance of the mold. On the other hand, in the case of an intermediate layer made of a resin coating mixed with iron powder or the like, there is a problem that the hardness is increased but the adhesion of the plating is poor and the plating layer is easily peeled off.

Further, when a plurality of identical molds are made, a resin mold made by pouring an epoxy resin or the like into a female mold is used, but when only one mold is manufactured, it is cut out from reinforced wood. Wood-based base materials made are also used. Also, in the case of a resin mold, when locally repairing a worn portion, reinforced wood is planted locally and repaired. If metal plating can be applied to the master mold of wood or the mold locally repaired with wood in this manner, the wear resistance of the mold can be increased and a durable mold can be obtained. Furthermore, in the sand mold casting master mold, a mold release agent is applied so that the molding sand does not easily adhere to the mold during sand mold production, but if a mold that does not easily adhere to sand is obtained, it will take time and effort to apply the mold release agent. It is economical because it can save labor.

Therefore, the present invention solves such a problem and uses a non-metal base material which is easy to process with a non-metal material as a die base material, improves surface hardness and wear resistance, and has good sand separation. And a manufacturing method thereof.

[0007]

As described above, in the conventional metal-plated resin mold, the metal plating is applied on one intermediate layer in which metal powder such as copper is mixed. The hardness is low and the proof strength of the mold is insufficient, so the plating layer is easily peeled off during use and the life is short. Therefore, the present inventor forms an intermediate layer with a resin coating in which a powder of a hard metal such as iron or metal silicon is mixed instead of a soft metal such as copper in order to increase the hardness of the intermediate layer and increase the mold life. Then, a resin mold was formed by forming the metal mold on the resin mold.
However, it was found that the hardness of the intermediate layer was obtained, but the adhesion of the electroless plating was poor, and the plating layer was easily peeled off. Further, in order to improve the surface roughness such as finishing the surface of the mold of the product to a mirror surface, the finish roughness of the surface of the intermediate layer under plating affects, but the intermediate layer containing the iron or silicon powder is fine. Surface finish is difficult,
It was found that a highly precise surface mold such as a mirror finish could not be obtained after plating.

Therefore, as a result of research, the present inventor has found that the electroless plating layer has good adhesion to the first hard intermediate layer having a sufficient hardness to increase the yield strength of the mold, and the surface finish is soft. It has been found that a mold using a non-metal base material having a long mirror life and a long life can be obtained by using a two-layered intermediate layer in which the second intermediate layer is formed. Further, they have found that it is effective to apply a fluororesin coating in order to reduce the amount of release agent applied when this mold is used as a casting mold for sand casting.

In order to achieve the above object, a mold using a non-metal base material of the present invention is a mold using a non-metal base material, and the surface of the non-metal base material is made of iron or metal silicon or ferrosilicon. A first intermediate layer made of a resin mixed with a hard metal powder is formed, and a second intermediate layer made of a resin mixed with a soft metal powder of metallic aluminum or copper is formed on the first intermediate layer. (2) A metal plating layer is formed on the intermediate layer by electroless plating.

That is, the first intermediate layer made of a resin mixed with a hard metal powder of iron or metal silicon or ferrosilicon formed on the surface of the non-metal base material has good adhesion to the base material and is a conductive material required for plating. Since it has sufficient hardness to impart mold resistance as well as properties, it prevents peeling due to deformation or cracking of the plating layer due to insufficient strength of the intermediate layer. However, since the first intermediate layer has poor adhesion of plating, it is not preferable to directly plate the first intermediate layer. Further, as described above, since it is difficult to process a fine surface, the surface after plating tends to be rough. Therefore, by forming on the first intermediate layer a second intermediate layer made of a resin mixed with a metal aluminum or copper soft metal powder, which has good adhesion of plating and can be easily surface-processed, a highly accurate mirror surface can be obtained. It was possible to obtain a plating layer having a plating surface of No peeling and increasing the durability of the mold.

An aluminum alloy mold is used as the mold of the mold. That is,
When an aluminum frame is used as a mold for sand casting, if the second intermediate layer is an intermediate layer containing metallic aluminum powder, the aluminum form of the non-metallic base material is subjected to metal plating processing. The surface is also plated by the same treatment at the same time, and there is an advantage that the mold surface can be prevented from wearing at the same time. Furthermore, the mold surface usually has many irregularities, but if a metal plating layer is formed by electroless plating, the plating layer is uniformly formed on the irregular surface, wear can be reduced, and the mold life can be increased.

When the mold is used for sand casting, in order to improve the sand release and reduce the use of the release agent to improve the working efficiency, the metal plating layer may contain metal powder or It is desirable to form a fluororesin coating layer with a fluororesin that does not contain it. The fluororesin coating layer may be pure fluororesin, but by mixing the fluororesin with a metal powder, the releasability is slightly lowered but the abrasion resistance is improved.

The non-metal matrix may be a thermosetting resin or wood. That is, since the plating treatment of the present invention can be applied not only to resin but also to wood, even in the case of a one-piece wood mold or a mold in which reinforced wood or the like is embedded in the repair part during local repair of the mold. Applicable. Further, by forming the metal plating layer by low temperature treatment electroless plating,
It is possible to obtain a mold having a high surface hardness on which a uniform plating film is applied without lowering the strength of the mold or causing deformation of the mold. As the low-temperature treatment electroless plating, electroless plating of nickel-boron alloy is desirable.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a manufacturing process of a mold using a non-metal base material according to an embodiment of the present invention. The numbers in the figure indicate the order of steps. 2 is a plan view of a sand casting mold using the non-metal base material according to the embodiment of the present invention, and FIG. 3 is a sectional view taken along line AA of FIG. Hereinafter, the manufacturing process of the mold for the sand mold casting of the present invention using the epoxy resin as the non-metal material will be specifically described with reference to the drawings. The mold used in this embodiment is one in which the edge of a resin mold 22 is fixed by an aluminum alloy mold 24 as shown in the figure. The mold 24 is fixed to the sand molding machine to manufacture a sand mold.

First, a method of manufacturing the resin mold base material 22 will be described. As shown in FIG. 3, a female mold 21 having a mold-shaped cavity for manufacturing (usually the female mold 21 is made of gypsum) is heated. A curable epoxy resin is poured to form a resin type base material 22 (step 1). At this time, in order to increase the strength of the mold, a filler 2 such as glass fiber, carbon fiber or sand 2
3 is normally used. As described above, the periphery of the resin mold base material 22 is fixed by the mold frame 24.

After the epoxy resin has hardened, the resin mold base material 2 taken out from the female mold 21 is washed with a thinner or the like to remove stains such as a release agent adhering to the surface during molding. (Step 2). Next, the surface of the die base material is sandblasted to form fine irregularities on the surface as shown in FIG. 2 (step 3). The grain size of the blast sand at this time is 2
00 # is preferable. By making the surface uneven in this way, the adhesion between the resin type base material and the first intermediate layer formed thereon is improved.

Next, a method for forming the first intermediate layer and the second intermediate layer will be described. The first intermediate layer was formed by applying an epoxy resin paint mixed with iron powder as a conductive material on the surface of the base material subjected to the sandblasting process (step 4). In the present embodiment, this paint is applied by spraying, but it may be applied by brushing, or a slurry-like paint may be poured and applied. In this way, the epoxy resin paint mixed with iron powder is used as the first intermediate layer because the intermediate layer has good adhesion to the resin mold base material and has the required hardness for obtaining the proof stress of the mold. Because it is necessary. The amount of the iron powder is 60 to 90% by weight of the resin. This mixing ratio is determined depending on the application, but when it is used as a mold material, it is preferably about 80%, and the coating thickness is preferably about 10 to 15 μm. Further, as the conductive material of the first intermediate layer, powder of metallic silicon or ferrosilicon may be used in addition to iron powder. This is dried at room temperature for 5 hours (step 5), and the next second intermediate layer is applied in a dry state in which the surface is not completely dried so that the second intermediate layer is easily attached.

For the second intermediate layer, an epoxy resin paint mixed with metal aluminum powder as a conductive material was applied in the same manner as the first intermediate layer (step 6). Here, the conductive material is aluminum powder because it improves the adhesion of the electroless metal plating layer and because the aluminum is soft, the surface can be easily finished with high precision and the plating layer formed on this This is because it is easy to obtain a mirror finish on the surface, and when an aluminum alloy is used for the mold, metal plating can be applied to the mold under the same conditions, and abrasion of the mold can be prevented. However, the conductive material of the second intermediate layer is not limited to aluminum, but may be copper, nickel powder, or the like. The mixing amount of the metal aluminum powder is preferably about 50% by weight with respect to the resin, and the coating thickness is 10 to 15
About μm is desirable. After applying the second intermediate layer, it is allowed to stand at room temperature for 24
Dry for ~ 48 hours and dry until fully cured (step 7).

After drying, the surface finish of the second intermediate layer is performed using a paper buff, and the surface roughness of the second intermediate layer is smoothly polished so that the surface of the plating layer formed on the second intermediate layer is smooth. (Step 8). The precision of the surface finish affects the precision of the surface after plating, but as described above, the resin layer mixed with aluminum can easily finish and obtain a smooth surface with high precision. Next, a sandblasting process is performed to form fine irregularities on the surface of the second intermediate layer (step 9). The grain size of the blast sand at this time is 2
00 # is preferable. By forming fine irregularities on the surface in this way, the adhesion between the second intermediate layer and the plating layer formed thereon is improved. The mold base material on which the second intermediate layer is formed is washed with an alkali to remove the aluminum oxide layer formed on the surface of the resin coating of the second intermediate layer, and washed with water, neutralized with acid and washed with water (step 10), electroless plating is rapidly performed before oxidation progresses to form a plating layer (step 11).

When a plating layer is formed by electroless plating, it is difficult to obtain a uniform plating layer by electrolytic plating in the case of a mold having many irregularities, such as a mold. This is because a uniform plating layer can be obtained. For the electroless plating, nickel-boron-based plating, which can be subjected to low temperature bath plating, was performed in order to avoid deterioration of the mold strength and deformation. The nickel-boron system plating gave better results than other low temperature treatment plating in terms of plating property. The thickness of the plating layer is preferably about 20 μm, and the hardness of the plating layer is Hv750-800. After the plating process, the product is washed, dried and finished (step 12). As a result of the above steps, a plating layer was formed on the surface of the aluminum alloy mold as well as the resin mold, so that wear on the mold surface could be reduced.

Although it is possible to use the mold as it is with the metal plating applied, when it is used as a mold for sand mold casting, a fluororesin coating is applied on the plating layer to improve the separation of sand. Is desirable. In the present embodiment, Teflon coating is performed on the plating layer (step 13) and dried and finished (step 14). The thickness of this Teflon coating may be about 5 μm. In addition, when the coating is performed with a mixture of Teflon and metal powder, the abrasion resistance of the Teflon coating layer can be increased.

The case where the thermosetting resin is used as the mold base material has been described above. However, as shown in the following examples, not only the resin but also the wood can be subjected to the same processing as the base material, and the same effect can be obtained. To be Further, in this embodiment, the mold is made of aluminum alloy, but it can be applied not only to molds made of other materials but also to cases where the mold is not used.

[0023]

[Example 1] A sand casting mold was prepared under the following conditions, and an on-site use experiment was conducted. [Mold manufacturing conditions] Mold material: Epoxy resin First intermediate layer thickness: 10 μm First intermediate layer thickness: 10 μm Nickel plating thickness: 20 μm Teflon coating thickness: 5 μm [Result of use] As a result of using this mold, Teflon The casting sand rarely adheres to the mold due to the coating, and in the conventional mold, it was necessary to apply the mold releasing agent to each mold, but in this mold, it was almost unnecessary to apply the mold releasing agent. In addition, as a result of using it in an actual casting line, it could be used without any abnormality after using 6000 shots.

[0024]

[Example 2] A test mold was made of epoxy resin and reinforced wood under the same conditions as those of the above mold, and the result of measuring the amount of wear of the mold when incorporated into a line of a sand blowing machine and blown for 6000 shots is shown in Fig. 4. .

As can be seen from FIG. 4, in the case of the base material of the epoxy resin, when the surface treatment of the present invention was not carried out, it was worn on average 0.12 mm after 6000 shots, whereas when the treatment of the present invention was carried out, it was 0. Wear of 01mm and wear amount is 1
It decreased to one-half. Also, the same effect can be obtained in the case of the base material of the reinforced wood, and when it is not treated, it is 0.007 mm, which is almost 10
It became a value close to one-half. As described above, it was found that the treatment of the present invention has the same effect as that of the base material of the epoxy resin on the wood.

As described above, according to the mold using the non-metal base material of the present invention and the method for producing the same, the resin or the resin in which the hard metal powder such as iron is mixed on the non-metal base material of wood is used. The first intermediate layer has a high hardness and the second intermediate layer is a soft second intermediate layer made of a resin in which a soft metal powder such as metal aluminum is mixed, and two metal intermediate layers are formed on the intermediate layer by electroless plating. Since the layer is formed, the first intermediate layer increases the adhesion with the non-metal base material and also increases the proof stress of the mold, and the second intermediate layer improves the adhesion of the plating to improve the plating property when the mold is used. A mold having peeling prevention and high durability and long life can be obtained. At the same time, the second with good workability and good plating adhesion
The intermediate layer improves the surface roughness of the first intermediate layer and improves the finishing accuracy of the mold surface. That is, in the case of a conventional one-layer intermediate layer, in the case of an intermediate layer mixed with a soft metal, the intermediate layer has a low proof stress, so that the plating layer is deformed or cracked during use and the plating layer peels off, while the hard metal In the case of the intermediate layer, there are problems that the adhesion of the plating is poor and peeling is easy, and sufficient surface roughness such as mirror finish of the mold cannot be obtained. The present invention includes a hard first intermediate layer and a soft second intermediate layer.
This is solved by using layers.

Further, when the second intermediate layer is a resin layer containing metallic aluminum powder, when the aluminum alloy frame is used as the mold for sand casting, the surfaces of the mold base material and the aluminum mold are The same plating process can be used to prevent wear of the aluminum formwork surface. Furthermore, by forming a metal plating layer by nickel-boron electroless plating, it is possible to form a plating layer uniformly on the uneven surface of the mold by low temperature treatment, preventing mold deformation and reducing mold wear. The mold life can be increased.

Further, by forming a fluororesin coating layer on the metal plating layer, when used as a sand casting mold, the release of sand is improved, the use of release agent is reduced, and the work efficiency is improved. . At this time, if the metal powder is mixed with the fluororesin, the abrasion resistance is improved.

Since the plating treatment of the present invention can be applied not only to resin but also to wood, the non-metal base material may be thermosetting resin or wood, in the case of a one-piece mold made of reinforced wood. Alternatively, the manufacturing method of the present invention can be applied to a portion repaired with reinforced wood during mold repair.

Although the sand casting mold is described in this embodiment, the use of the mold of the present invention is not limited to this, and it goes without saying that it can be used for other uses such as resin injection molding. Absent.

[0031]

As described above, according to the mold using the non-metal base material of the present invention and the method of manufacturing the same, the hard first intermediate layer formed on the non-metal base material and Since the metal plating layer is formed after forming the two intermediate layers of the soft second intermediate layer formed by the above, the first intermediate layer having a hardness for supporting the die strength and the first adhesive layer having good adhesion of the plating. Together with the two intermediate layers, it is possible to obtain a highly durable mold without peeling of the metal plating layer. Further, since the second intermediate layer has good workability, a mold having high surface finishing accuracy can be obtained.

Further, when a mold made of aluminum alloy is used, the surfaces of the base material and the mold can be plated by the same treatment, and a separate treatment for preventing wear of the mold surface is not required. Furthermore, by forming the metal plating layer by nickel-boron electroless plating, a uniform plating layer having high hardness can be formed on the uneven surface of the mold by low temperature treatment.

Further, by forming a fluororesin coating layer on the metal plating layer, the release of sand is improved, so that the use of a release agent is reduced and the work efficiency is improved when used as a sand casting mold. Wear resistance is improved by mixing metal powder with this fluororesin.

The plating treatment of the present invention can be applied not only to resin but also to wood, and the manufacturing method of the present invention can be applied to a mold of one item made of reinforced wood, a repaired part of reinforced wood at the time of mold repair, etc. Applicable.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a manufacturing process of a mold using a non-metal base material according to an embodiment of the present invention.

FIG. 2 is a plan view of a sand casting mold according to an embodiment of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a diagram showing measurement results of wear amount of a mold using the non-metal base material according to the embodiment of the present invention.

[Explanation of symbols]

 21 Female Mold 22 Epoxy Resin 23 Filler 24 Formwork

Claims (7)

[Claims] 1. A mold comprising a non-metal material as a base material, wherein a first intermediate layer made of a resin mixed with a hard metal powder of iron or metal silicon or ferrosilicon is formed on the surface of the non-metal base material, 1 a resin made by mixing metal aluminum or copper soft metal powder on the intermediate layer 2
A mold using a non-metal base material, wherein an intermediate layer is formed and a metal plating layer is formed on the second intermediate layer by electroless plating. 2. The mold using a non-metal matrix according to claim 1, wherein a fluororesin coating layer of fluororesin containing or not containing metal powder is formed on the metal plating layer. 3. The mold using the non-metal base material according to claim 1, wherein the non-metal base material is a thermosetting resin or wood. 4. The mold using a non-metal base material according to claim 1, wherein the metal plating layer formed by electroless plating is made of a nickel-boron alloy. 5. A mold using a non-metal base material according to any one of claims 1 to 4, wherein an aluminum alloy mold is used as the mold of the mold. 6. A first intermediate layer is formed on the surface of a non-metal base material with a resin in which a hard metal powder of iron or silicon metal or ferrosilicon is mixed, and a metal aluminum or copper layer is formed on the first intermediate layer. A second intermediate layer is formed of a resin mixed with soft metal powder, and a metal plating layer is formed on the second intermediate layer by electroless plating. Method. 7. A mold using a non-metal matrix according to claim 6, wherein a fluororesin coating layer is formed on the metal plating layer with a fluororesin containing or not containing metal powder. Production method.