JPH0780876A - Foaming resin mold and manufacture thereof - Google Patents

Abstract

PURPOSE:To remarkably improve the releasability of a foaming resin molded article by a method wherein composite film layer, which is produced through the dispersed eutectoid of finely divided polytetrafluoroethylene particles in Ni-P matrix formed by electroless nickel plating, is formed on the surface of mold base material. CONSTITUTION:The mold concerned has composite film layer 3, which is produced through the uniformly dispersed eutectoid of finely divided polytetrafluoroethylene(PTFE) particle in electroless plating plated through ground layer 2 on the surface 11 of the base of mold base material 1 such as aluminum alloy or the like. At the formation of the composite film layer 3, the base material 1 is buffed, cleansed with ethane and degreased and cleaned with weak alkali so as to form the ground layer 2 for zinc film on the surface 11 of the base. Next, PTFE is dispersed in electroless nickel plating solution having hypophosphate as reducer. After that, composite film layer 3 is preferably formed by directly immersing the base material 1, on which the ground layer 2 is formed, in the mixed liquid just mentioned above at normal temperature for 10-24 hours.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precise mold for molding a foamed resin, which is used for producing a foamed resin molded product and has a good releasability, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, it has been known that a mold for producing a resin molded product uses a mold release agent to improve the mold release property and prevent sink marks due to galling or seizure. ,
Since the work is complicated, the productivity cannot be improved, and the cost becomes high, it is often used to subject the molding die to a surface treatment such as Teflon coating or chrome plating.

[0003]

However, in the conventional Teflon coating process or plating process, about 400
Since the surface oil is removed by coating at a high temperature of ℃, the material of the base material such as aluminum alloy changes, resulting in weakness in strength, and peeling phenomenon due to long-term use. There are problems that dust and adhered substances are easily attached due to static electricity generation and cleaning is complicated, and that scratches are caused to deteriorate the appearance quality of the molded product and reduce the commercial value. The present invention is intended to eliminate these conventional drawbacks, greatly improves the mold releasability of the molded product, properly prevents galling and seizure, and significantly reduces the friction coefficient. It is not easily scratched and does not peel off, and it has a strong adhesion to the base material substrate and has excellent durability, and also has good thermal conductivity and an antistatic effect, and also has a gloss on the surface of the molded product. It is intended to make a foamed resin molding die that can be taken out to improve the appearance quality and enhance the commercial value.Also, after degreasing the surface of the base material of the aluminum alloy molding die base material, before interposing the underlying layer The purpose is to simply manufacture a precision molding die having an antistatic effect by means of forming a composite film by treatment.

[0004]

The present invention provides an electroless nickel-plated Ni-P matrix plated on the surface of an aluminum alloy or other metal molding die base material,
It is a composite coating layer in which fine particles of polytetrafluoroethylene (PTFE) are uniformly dispersed and co-deposited. Also,
To make a foamed resin molding die, after a preliminary degreasing step of buffing a molding die base material made of aluminum or aluminum alloy and ethane cleaning, weak alkaline degreasing is performed, and then a zinc coating base layer is provided. When performing electroless nickel plating, dope pickling is performed by immersing in a mixed solution containing polytetrafluoroethylene for 10 to 24 hours at room temperature in an electroless nickel plating solution containing a chemical reducing agent, and a molding die base material It forms a composite coating layer in which fine particles of polytetrafluoroethylene (PTFE) are uniformly dispersed and co-deposited in an electroless nickel-plated Ni-P matrix plated on the surface.

[0005]

[Function] A molding die base material made of an aluminum alloy or the like is soaked at room temperature in a mixed solution containing polytetrafluoroethylene in an electroless plating solution containing a chemical reducing agent to obtain Zn and Ni. The self-lubricating property of polytetrafluoroethylene fine particles dispersed and co-deposited in the Ni-P matrix of the electroless nickel film plated on the surface of the molding die base material by the substitution reaction by the ion exchange action, and the mold release Adhesion as a composite film layer with good properties, lower friction coefficient than nickel-plated or chrome-plated layer, for example 0.08-
0.12μ, which has an antistatic effect, has a strong adhesion with the base material, and does not peel off the coating layer even after long-term use, and the composite coating layer is a resin coating layer. However, the heat conductivity is good, the surface of the molding die is glossy, and the molded article is also glossy, so that it can be made into a precision die to improve the appearance quality of the molded article and significantly increase the commercial value.

[0006]

EXAMPLES The present invention will be described with reference to the examples in which the present invention is applied to the foamed resin molding die of FIGS. 1 to 3. Surface treatment for adhering a coating layer to the surface of the molding die base material 1 of aluminum alloy or other metal. Therefore, as the composite coating layer 3 in which the particles of polytetrafluoroethylene (PTFE) are uniformly dispersed and co-deposited on the electroless nickel plating plated on the substrate surface 1 ₁ of the molding base material 1 via the underlayer 2. It is used as a foaming resin molding die.

In this case, the composition of the composite coating layer 3 is as follows: nickel (Ni) 83 to 90% by weight, phosphorus (P) 7
-10% by weight, polytetrafluoroethylene (PTFE)
It becomes an electroless nickel coating layer consisting of 1 to 8% by weight,
Base surface 1 of a molding die base material 1 made of an aluminum alloy
_When performing the surface treatment to adhere the composite coating layer 3 to ₁ ,
After a preliminary degreasing step 4 in which the molding die base material 1 is buffed by a buffing means and washed with ethane, a weak alkali, for example, a pH of 6 to 6 is used so that aluminum is not dissolved by the alkali.
8 temperature of 80 to 100 ° C. due to close alkaline degreasing solution in neutral, then pretreated with the cleaning process step 5 by a weak alkali degreasing, the underlying layer 2 of a zinc coating on base material surface 1 ₁ in the base treatment process 6 After being formed, washed with water and dried, in an electroless nickel plating step 7, a mixed solution containing PTFE in an electroless nickel plating solution using hypophosphite as a reducing agent is used at room temperature to 50 ° C. for 10 It is treated for 24 hours, preferably for 15-20 hours, by dobu-zuke to form a composite coating layer in which polytetrafluoroethylene fine particles are uniformly dispersed and co-deposited in a Ni-P matrix on the surface of a molding die base material. It is good to do so, because it is soaked at room temperature, there is no change in the material of the base material 1, there is no adverse effect on strength, and it can be processed even in the eyes of the slits so that the Styrofoam resin is baked. It can be a precision molds, such as there is no clogging due.

The electroless nickel plating layer contains
Polytetrafluoroethylene having a particle size of 1 μm or less, 7 to
The Ni-P alloy containing 10% phosphorus is added to the P
Of TFE and conversion to Ni-P matrix composite coating layer 3 were uniformly dispersed eutectoid as fine particles to be close contact with deployed into a green body surface 1 _1. That is, for low friction, the content of the fluororesin is large, for example, 5 to 8% by weight, and the density is 6.0 to 7.
It is recommended to set it to 0 g / cm ³ and the hardness after plating is 2
400 to 500 if heat treated at 50 to 350 mHv
The hardness can be mHv. Further, in order to obtain a composite coating layer 3 having a low PTFE content and abrasion resistance, a content of 1.0 to 4.0, preferably 1.5 to 3.0% by weight and a density of 7. If it is about 0-7.5 g / cm ³ ,
The hardness can be 400 to 500 mHv after plating, and can be 750 to 900 mHv by heat treatment.

Therefore, since the composite coating layer 3 has a low friction property and an antistatic effect, the flow of the raw material is good at the time of molding the Styrofoam product, and the filling property can be greatly improved, and at the same time, the molding die can be improved. The surface is glossy and the molded product is also glossy, which can enhance the commercial value of the product.

Further, since the composite coating layer 3 contains polytetrafluoroethylene particles, it is useful for preventing galling and baking, has good non-adhesive property and has good releasability, and a release agent can be omitted. In addition to greatly increasing the productivity of, the hardness of the coating is increased and scratches are less likely to occur, and the adhesion to the base material surface of the base material is strong and durability is enhanced.

Pretreatment using a zinc coating as the underlayer 2 has a good substitution reaction between Zn and Ni in an electroless nickel plating tank, and the surface of the base material of the molding die base material 1 1 ₁ to be effective in the conversion of the composite coating layer 3 of Ni-based, has helped in the production of precision molds is increased in the dimensional accuracy maintaining the uniformity of the film thickness greatly.

[0012]

According to the present invention, fine particles of polytetrafluoroethylene (PTFE) are uniformly dispersed in an electroless nickel-plated Ni-P matrix plated on the surface of an aluminum alloy or other metal molding die base material. The deposited composite film layer has a low coefficient of friction, has an antistatic effect, and has strong adhesion with the base material, so that the film layer does not peel off even after long-term use. , Although the composite coating layer is a resin coating layer, it has good heat conductivity, and the surface of the molding die is glossy, and the molded article also has gloss, which makes it a precision die and improves the appearance quality of the molded article. , The product value can be significantly increased. In addition, after performing a weak alkaline degreasing through a preliminary degreasing step of buffing the molding die base material made of aluminum alloy and cleaning with ethane, a zinc coating base layer is provided, and when performing electroless nickel plating, chemical reduction is performed. Electroless nickel-plated Ni plated on the surface of the molding die base material by immersing in a mixed solution containing polytetrafluoroethylene in an electroless plating solution containing an agent at room temperature for 10 to 24 hours -By forming a composite coating layer in which fine particles of polytetrafluoroethylene (PTFE) are uniformly dispersed and co-deposited in a P matrix to form a close contact layer, Z in the electroless nickel plating tank is formed.
The substitution reaction between n and Ni is good, it is effective for the formation of the Ni-based composite coating layer on the surface of the base material of the molding die, the uniformity of the coating thickness is maintained, and the dimensional accuracy is greatly enhanced. Since polytetrafluoroethylene fine particles are dispersed and co-deposited in the composite coating layer, it helps prevent galling and baking, and also has good non-adhesive releasability, eliminating the need for a mold release agent. In addition to greatly increasing the productivity, the coating hardness is increased and scratches are less likely to occur, the adhesion to the base material surface of the base material is also strong and durability is improved, and it is simple without changing the material of the molding die base material. Can be manufactured.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a part of a molding die before a substitution reaction according to an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of the example of FIG. 1 after a substitution reaction.

FIG. 3 is a block diagram showing a process of the molding die of the present invention.

[Explanation of symbols]

1 Molding die base material 1 ₁ Base surface 2 Underlayer 3 Composite coating layer 4 Preliminary degreasing process 5 Cleaning process 6 Undercoating process 7 Electroless nickel process

Claims (2)

[Claims] 1. A composite in which fine particles of polytetrafluoroethylene (PTFE) are uniformly dispersed and co-deposited in an electroless nickel-plated Ni-P matrix plated on the surface of an aluminum alloy or other metal molding die base material. A foamed resin molding die characterized by being a film layer. 2. A base metal layer of a zinc coating is provided on a molding die base material made of aluminum or an aluminum alloy through a preliminary degreasing step of buffing and cleaning with ethane, followed by degreasing with a weak alkali, followed by electroless nickel plating. The surface of the molding die base material is immersed in a mixed solution containing polytetrafluoroethylene (PTFE) in an electroless nickel plating solution containing a chemical reducing agent for 10 to 24 hours at room temperature. Of a foamed resin molding die, characterized in that a composite coating layer in which fine particles of polytetrafluoroethylene (PTFE) are uniformly dispersed and co-deposited in an electroless nickel-plated Ni-P matrix Production method.