JPS60152691A - Die for plastic molding and its production - Google Patents

Abstract

PURPOSE:To produce a titled die having extremely high accuracy and resistance to compression by forming an electroforming metallic layer including the die surface of a cavity part on the outside surface of a matrix made of a metal and laminating and forming successively a plating metal layer and casting metal layer on the rear surface thereof. CONSTITUTION:An electroforming metallic layer 11 including the die surface of a cavity part is formed by an electroforming method on the outside surface of a metallic matrix having the same shape as the shape in the prescribed part of a desired molding. A plating metal layer 12 for adhesion is then formed on the rear of the layer 11 and thereafter a casting alloy is further cast on the rear thereof to form a casting alloy layer 13 as a backing member, by which a die 1A for plastic molding is obtd. The layer 11 is preferably constituted of at least one kind among Cu, Ni, Ni-Co alloy, Ni-Fe alloy and Ni-P alloy, the layer 12 of at least one kind among Sn, Sn-Zn alloy and Sn-Pb alloy and the layer 13 of at least one kind among alloys consisting of Bi, Sn, Zn, Cd, Pb, Ag, Sb, etc.

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a plastic molding mold and a method for manufacturing the same;
In particular, the present invention relates to a mold with ultra-high precision and excellent compression resistance, and a method for manufacturing the same.

Prior Art The male or female mold part (cavity part) of a plastic molding mold is mainly formed by machining a metal material, casting a metal, or forming a metal layer on a prefabricated mother mold by electroplating. It is made using the so-called electroforming method. this house.

It is impossible to finish the concave mold surface with ultra-high precision using machining methods. The metal casting method is advantageous in that it requires a short manufacturing time and is technically simple to create molds with complex shapes.

With this method, it is impossible to finish the mold surface that requires precise dimensions and precise surface conditions. The electroforming method is extremely superior to the former two methods from the viewpoint of precision, and this method allows the production of molds with ultra-high precision mold surfaces.

However, it has a fatal drawback in that it takes too long to manufacture the mold. For example, it takes about 3 to 4 weeks to form a 5 mm thick metal layer.

Therefore, a method that takes advantage of only the advantages of these mold manufacturing methods is to electroform a metal master mold (mother mold) of nickel or the like to a certain thickness, and then cast a zinc alloy or the like as a backing material on top of it. be. However, although this method looks like a mold body, the electroformed metal layer and the cast alloy layer do not adhere at all, so both layers peel off during use and eventually break. Resulting in. Moreover, the mold may become deformed due to the solidification and shrinkage of the cast metal.

Sometimes shrinkage of the cast metal makes it impossible to separate the master mold from the electroforming mold. As a result, precise molds cannot be manufactured.

Therefore, if electroformed metal and cast metal could be completely bonded together, and the solidification shrinkage of the cast metal could be controlled, accuracy would be high, the cavity manufacturing process could be significantly shortened, and production costs could be reduced. It is predicted that a mold will be made.

OBJECTS OF THE INVENTION An object of the present invention is to provide a plastic molding die having an ultra-high precision cavity portion and a method for manufacturing the same. Another object of the present invention is to provide a plastic molding die with excellent compression resistance and a method for manufacturing the same.

SUMMARY OF THE INVENTION The present invention involves plating the surface of an electroformed metal layer with tin, tin-zinc alloys of various compositions, or tin-lead alloys of various compositions to a thickness of 5 to 20 μm by electroplating. Based on the inventor's discovery that when zinc, tin-zinc alloy, tin, tin-lead alloy5 or zinc-tin-aluminum alloy is cast, the electroformed metal layer and the cast metal layer are strongly bonded and never separate. It was completed.

Therefore, the plastic molding mold of the present invention includes an electroformed metal layer including the mold surface of the cavity portion, a plated metal layer located on the back side of the electroformed metal layer, and a banking located on the back side of the plated metal layer. and a cast alloy layer as a member,
This achieves the above objective. Also, how is this mold manufactured?

(1) A step of forming an electroformed metal layer including the mold surface of the cavity portion by electroforming on the outer surface of a metal mother mold having the same shape as a predetermined portion of the desired molded product; A step of forming a plated metal layer on the back surface of the cast metal layer by a plating method, and (3) a step of casting a cast alloy on the back surface of the plated metal layer to form a cast alloy layer as a backing member, This achieves the above objective.

The mold of the present invention further includes a reinforcing metal outer wall surrounding the cast alloy layer via a second plated metal layer, thereby achieving the above object.

0 This mold manufacturing method consists of: (1) forming an electroformed metal layer including the mold surface of the cavity portion on the outer surface of a metal mother mold having the same shape as a predetermined portion of a desired molded product by electroforming; (2) forming a first layer on the back surface of the electroformed metal layer by a plating method;
The process of forming a plating metal layer.

(3) At a predetermined distance from the first plated metal layer.

A step of arranging a reinforcing metal outer wall provided with a second plated metal layer so that the second plated metal layer side faces the first plated metal layer, and (4) injecting a casting alloy between the plated metal layers to form a backing. forming a cast alloy layer as a member, thereby achieving the above object.

The electroformed metal layer is made of at least one member selected from the group consisting of, for example, copper, 2.7 Kel, nickel-cobalt alloy, nickel-iron alloy, and nickel-phosphorus alloy. The thickness of the metal layer is not particularly limited, but it depends on the workability and usage conditions of the resulting mold. Usually 0
．． It is set in the range of 2w to 5N.

The plated metal layer is made of at least one member selected from the group consisting of, for example, tin, tin dizinc alloy, gold, and tin-lead alloy. This metal layer may function as an adhesive for bonding the electroformed metal layer and the cast alloy layer, and its thickness is not particularly limited. Usually several μm to several IOμm1
For example, it is set in a range of 5 μm to 20 μm.

The smaller the casting shrinkage of the casting alloy used as the backing metal, the higher the dimensional accuracy and surface accuracy of the resulting mold cavity. Expandable metals may also be used. Such casting alloys include bismuth-tin and bismuth-tin-zinc.

Bismuth-cadmium, tin-lead-cadmium.

tin-cadmium, tin-lead, tin-zinc, tin-silver,
Lead-cadmium, cadmium-zinc and cadmium-
At least one selected from the group consisting of antimony is used. When casting metal for banking, water cooling and/or heating tubes made of copper or the like are cast at the same time, thereby making it possible to control the temperature of the mold during molding of the plastic material. In addition, if a cast alloy is plated with 20 to 40% by weight of fine metal grains such as iron, which have a diameter of 0.5 to 5N, the solidification shrinkage rate of the cast alloy can be minimized. The compression resistance of the cast alloy can be improved. These metal particles can minimize the solidification shrinkage rate of the cast alloy, and there are no particular restrictions on the type of metal.

Example The present invention will be described below with reference to examples.

Example 1 Copper, nickel, nickel-cobalt alloy, nickel-iron alloy, nickel-phosphorus alloy, or nickel-tin alloy is deposited on a male brass mold by electroforming by about 0.2 to 5%.
Electroforming was performed to a thickness of mm to form an electroformed metal layer 11 as shown in FIG. The back surface of this metal layer 11 was further plated with a tin-zinc alloy to a thickness of 10 μm by electroplating to form a plated metal layer 12. Put this into a mold and tin
A cast alloy layer 13 was formed by casting a zinc alloy. The electroformed metal layer 11 and the cast alloy layer 13 of the obtained mold IA were completely integrated. Solidification shrinkage of tin-zinc casting alloy is also small.

3 Therefore, an ultra-high precision mold surface was obtained. 14 is a mounting screw hole. When this was assembled into an injection mold and injection molded using various thermoplastic materials, 1
It was found that it had sufficient durability without any abnormality even after being used 00,000 times.

Example 2 In the cavity manufacturing process of Example 1, for the purpose of improving the compression resistance of the mold IA, as shown in FIG. A cast alloy was cast in a state in which the electroformed metal layer 11 and the reinforcing outer wall 16 were firmly integrated through the plating layers 12 and 15, respectively, to form a cast alloy layer 13. The resulting mold IB was able to significantly improve its compression resistance due to the effect of the reinforcing iron outer wall 16.

Example 3 As shown in FIG. 3, an iron backing case 17 was provided with an adhesive plating layer 15 having a shape almost similar to that of the electroforming mold, on the back surface of the electroformed metal layer 11 produced by the same method as in Example 1. was placed, and the cast alloy was injected under pressure from the injection hole 170 of the packing case 4-17 to form the cast alloy layer 13. The electroformed metal layer 11 of the obtained mold IC and the backing case 17 were completely integrated and firmly adhered to each other by the metal layer 13 made of the injection alloy. This cavity mold IC had the best compression resistance and dimensional accuracy.

Example 4 When manufacturing the molds of Examples 1 and 2, as shown in FIG.
The cast alloy layer 13 was formed by disposing the steel pipe 18 subjected to the coating. The obtained mold ID was assembled into an injection mold, and the mold temperature was adjusted using the steel pipe 18 as a water cooling hole or heating hole.

This makes it possible to shorten molding time. It was also possible to improve the appearance and dimensional accuracy of the obtained molded product.

Example 5 30% by weight of fine iron particles (diameter 1 to 31 cm) whose surface had been previously plated for adhesion was mixed into the cast alloy used in Examples fl+, (21, +31, and (4)),
When a cast alloy layer was constructed using this, the solidification shrinkage rate of the gold on the casting table 5 could be suppressed to an even smaller level.

Furthermore, the compression resistance of the cast alloy could be further improved.

Effects of the Invention In this way, the mold of the present invention firmly adheres and fixes the electroformed metal layer and the cast alloy layer by the plated metal layer, and the electroformed metal layer constituting the mold surface has high dimensional accuracy. The cast alloy layer that banks this has ultra-high precision and can be easily formed in a short period of time. Therefore, the mold of the present invention has extremely high precision and can be manufactured easily and inexpensively. Moreover, it has extremely good compression resistance.

[Brief explanation of drawings]

1 to 4 are cross-sectional front views showing one embodiment of the mold of the present invention, respectively. IA, IB, IC, ID... Mold, 11... Electroformed metal layer, 12, 15, 180... Adhesive plating layer, 13
...Casting alloy layer, 16... Reinforcing outer wall, 17...
backing case. Attorney: Patent Attorney Shusaku Yamamoto 6 Figure 1 I Figure 2 Figure 3 IC 1 Figure 4 Procedural Amendment (Voluntary) February 8, 1985 Commissioner of the Japan Patent Office Plastic molding molds and their manufacturing method 3 , Relationship with the case of the person making the amendment Patent Applicant Address 5-5-1 Takadono, Asahi-ku, Osaka City, Osaka Name Nacro Co., Ltd. Representative Masaru Kaken (1 idiot) 4. Agent 530 Address Osaka, Osaka Prefecture 4-3-17-5 Nishitenma, Ichikita-ku, Number of inventions increased by amendment: 0 6, Detailed description of the invention in the specification to be amended. 7. Contents of the amendment (1) The following words will be added next to "was." on page 15, line 6 of the specification: [In particular, the backing case 17 is formed with a reverse taper in the vertical direction. Therefore, the adhesive force of the plating layer 15 works effectively between the banking case 17 and the cast alloy layer 13, and the banking case 17 strongly adheres to the alloy layer 13 and never separates. ”

Claims (1)

[Claims] 1. An electroformed metal layer including a mold surface of a cavity portion. a plated metal layer located on the back side of the electroformed metal layer; A plastic molding die having a cast alloy layer as a banking member located on the back side of the plated metal layer, the electroformed metal layer and the cast alloy layer being firmly adhered by the plated metal layer. 2. The mold according to claim 1, wherein the electroformed metal layer is made of at least one member selected from the group consisting of copper, nickel, nickel-cobalt alloy, nickel-iron alloy, and nickel-phosphorus alloy. 3. The mold according to claim 1, wherein the plated metal layer is made of at least one member selected from the group consisting of tin, tin-zinc alloy, and tin-lead alloy. 4. The cast alloy layer is bismuth-tin, bismuth-tin-zinc, bismuth-cadmium, tin-lead-cadmium, tin-cadmium, tin-lead. Tin-zinc, tin-silver, lead-cadmium, cadmium-
The mold according to claim 1, which is made of at least one member selected from the group consisting of zinc and cadmium-antimony. 5. The mold according to claim 1, wherein at least a water cooling or heating tube is cast into the casting alloy layer. 6. The mold according to claim 1, wherein fine metal particles whose surface is plated are mixed into the casting alloy layer. 7. An electroformed metal layer including the mold surface of the cavity part. a first plated metal layer located on the back side of the electroformed metal layer;
A banking member located on the back side of the plated metal layer includes a cast alloy layer and a reinforcing metal outer wall surrounding the cast alloy layer via a second plated metal layer, and the electroformed metal layer and the A mold for plastic molding with excellent compression resistance, in which a cast alloy layer is firmly bonded to the plated metal layer. 8. The mold according to claim 7, wherein the electroformed metal layer is made of at least one member selected from the group consisting of nickel, nickel-cobalt alloy, nickel-iron alloy, and dissolurin alloy. 9. The mold according to claim 7, wherein the plated metal layer is made of at least one member selected from the group consisting of tin, tin-zinc alloy, and tin-lead alloy. 10. The cast alloy layer is bismuth-tin, bismuth-tin-zinc, bismuth-cadmium, tin-lead-cadmium, tin-cadmium, tin-lead. Tin-zinc, tin-silver, lead-cadmium, cadmium-
The mold according to claim 7, which is made of at least one member selected from the group consisting of zinc and cadmium-antimony. 11. The mold according to claim 7, wherein the reinforcing metal outer wall is made of steel. 12. The mold according to claim 7, wherein at least a water cooling or heating tube is cast into the casting alloy layer. 13. The mold according to claim 7, wherein fine metal particles whose surface is plated are mixed into the casting alloy layer. 14111 A step of forming an electroformed metal layer including the mold surface of the cavity portion by electroforming on the outer surface of a metal mother mold having the same shape as a predetermined portion of a desired molded product. (2) a step of forming a plated metal layer on the back surface of the electroformed metal layer by a plating method; and (3) a step of casting a cast alloy on the back surface of the plated metal layer to form a cast alloy layer as a backing member. . 2. A method for manufacturing a plastic mold, wherein the electroformed metal layer and the cast alloy layer are firmly bonded by the plated metal layer. 15. The mold according to claim 14, wherein the electroformed metal layer is made of at least one member selected from the group consisting of copper, nickel, nickel-cobalt alloy, nickel-iron alloy, and nickel-phosphorus alloy. 16. The plated metal layer is tin, tin-zinc alloy and tin-
The mold according to claim 14, which is made of at least one member selected from the group consisting of lead alloys. 17. The cast alloy layer is bismuth-tin, bismuth-tin-zinc, bismuth-cadmium, tin-lead-cadmium, tin-cadmium, tin-lead. Tin-zinc, tin-silver, lead-cadmium, cadmium-
The mold according to claim 14, consisting of one or more metal molds selected from the group consisting of zinc and cadmium-antimony. 18. At least a water cooling or heating tube is cast into the cast alloy layer. 19. The mold according to claim 14, wherein fine metal grains whose surface is plated are mixed in the cast alloy layer. 20111 Desired. A step of forming an electroformed metal layer including the mold surface of the cavity part by electroforming on the outer surface of a metal master mold having the same shape as a predetermined part of the molded product. (2) Forming the electroformed metal layer including the mold surface of the cavity part Step of forming a first plated metal layer on the back surface by a plating method. (3) At a predetermined interval from the first plated metal layer, place the reinforcing metal outer wall provided with the second plated metal layer on the side of the second plated metal layer. and (4) injecting a cast alloy between the plated metal layers to form a cast alloy layer as a backing member. A method for producing a plastic molding die having excellent compression resistance, in which the electroformed metal layer is firmly adhered to the plated metal layer by the plated metal layer. 21. The mold according to claim 20, which is made of at least one member selected from the group consisting of iron alloys and nickel-phosphorus alloys.22.
The mold according to claim 20, which is made of at least one member selected from the group consisting of lead alloys. 23. The cast alloy layer is bismuth-tin, bismuth-tin-zinc, bismuth-cadmium, tin-lead-cadmium, tin-cadmium, tin-lead. Tin-zinc, tin-silver, lead-cadmium, cadmium-
The mold according to claim 20, which is made of at least one member selected from the group consisting of zinc and cadmium-antimony. 24. The mold according to claim 20, wherein at least a water cooling or heating tube is cast into the casting alloy layer. 25. The mold according to claim 20, wherein fine metal particles whose surface is plated are mixed into the casting alloy layer.