JPS62176823A - Method of molding laminated sheet for thermoforming - Google Patents

Abstract

PURPOSE:To perform satisfactory molding by varying molding pressure in multi- stages or non-stage in case of a pressure forming; that is, the molding pressure in an initial stage is made lower than that in a later stage and the pressure is increased in the subsequent molding stage. CONSTITUTION:When Pb-Sn, Pb-Sn-Cd, Zn-Al and so on are used as an ultra- placticity alloy and the following resins are used as a laminated sheet for an aging molding, molding is performed under the condition of each specific temp. In case of an acrylic modified polyvinyl chloride resin, the temp. of the laminated sheet is set at higher than 11 deg.C and the die temp. at 10 deg.C-70 deg.C: in case of a modified olefin resin, at higher than 40 deg.C and at 30 deg.C-120 deg.C: in case of an aromatic polyether resin at higher than 150 deg.C and at 30 deg.C-130 deg.C respectively. In terms of specific molding pressure, a molding in an initial stage is done under a pressure of 0.1-5kg/cm<3> for 1-20sec and in the subsequent stage under a pressure of 3kg/cm<3>, or under 0.1-3kg/cm<3> in an initial stage and under 5-10kg/cm<3> in the subsequent stage. Resin sheets 2 for aging molding are laminated on both surfaces of an ultra-placticity alloy 1 with an adhesive 3 or without any interposal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermoforming method and a laminate forming method suitable for manufacturing a housing having electromagnetic wave shielding properties by air pressure forming.

[Prior art]

Conventionally, in order to manufacture a housing having electromagnetic wave shielding properties, methods such as applying metal spraying to the housing or coating the housing with a conductive paint have been used. However, with the former method, the sprayed metal or alloy tends to peel off from the housing body (and with the latter method, the metal particles contained in the paint oxidize and change over time, resulting in a deterioration of the electromagnetic wave shielding ability). Furthermore, both methods had the disadvantage of being expensive in themselves.Therefore, a method of forming a laminate made by layering metal foil and resin was proposed, but these laminates The metal foils used for this laminate are Fe foil and Al foil, which do not have sufficient formability and can only be formed shallowly.Therefore, it is preferable that the metal foil used for this laminate has superplasticity. It is expected that this material will be formed integrally with the resin.However, although Zn-A1 alloy, Pb-Sn alloy, etc. are known as superplastic alloys, laminates using these superplastic alloys have not yet been produced. It is not commercially available, and the molding conditions are not completely clear at present.

[Problem that the invention seeks to solve]

When pressure forming metal superplastic materials, the forming time is long because the superplastic material only shows large elongation below a certain deformation rate.
The molding time for a plate of m thickness is about 1 to 3 minutes. -When molding a resin plate for universal molding, the pressure inside the female mold is reduced to remove air.3? A method is used to lower the constant pressure around /d, and
The molding time is approximately within seconds (often within 10 seconds). Furthermore, in pressure molding of resin, most of the deformation ends immediately after the start of molding, and the remaining molding time is required to sharpen edges and create fine irregularities. For example, use acrylic modified PVC (Tsutsunaka Glasstic Industry Co., Ltd. (Koji product name: Kaidak)) with a width of 200 mm and a length of 200 mm.
The temperature is 160'C to mold a case with a depth of 35mm.
It took 10 seconds at a pressure of 5 Kp/cr/l. but,
The molded product under the above conditions with pressure applied for 2 seconds had fairly rounded edges, but the shape was that of a casing, and the amount of deformation over 90 degrees had already been completed. The molding conditions such as molding speed are very different between superplastic material and thermoforming resin plate.When the above-mentioned laminate is air-formed using the conventional method of resin molding, the deformation speed, especially the deformation speed at the initial stage of molding, is significantly different from that of the superplastic alloy plate. This is too fast compared to the deformation speed that causes large elongation, so the drawing ratio is shallow, the edges are rounded, etc. (although molding can be done with molds of limited shapes, in general, the deformation of the superplastic metal is not transferred to the resin, and the molding process is slow. Cracks would occur in the metal plate after the molding process, and peeling would occur between the resin plate and the metal plate. Although such cracking and peeling of the metal plate can be prevented by lowering the molding pressure, in this case, the mold Reproducibility becomes insufficient.

[Failure to solve the problem]

The present inventors conducted repeated molding tests on thermoforming laminates made by layering superplastic alloys such as Pb-Sn, Pb-8n-Cd, and Zn-AI with various thermoforming resins. ,the above! When air-forming #plates, the molding pressure is changed in multiple stages or steplessly, with the initial molding pressure being lower than the subsequent molding pressure, and then increasing the pressure, or increasing the pressure sequentially while performing subsequent molding. As a result, we obtained a novel finding that was completely unthinkable in the past: that the laminate can be formed well. The present invention was completed based on these findings.

Namely, the present invention focuses on the fact that the deformation speeds of a superplastic alloy and a thermoforming resin are different. First, the superplastic alloy is molded at a pressure that allows it to deform, and then the pressure is increased or molded while being increased to improve mold reproducibility. The main point is to obtain. Accordingly, in the present invention, the initial forming pressure is meant to be a relatively low pressure at which the superplastic alloy is deformable and the thermoforming resin is preformed.

These initial molding pressures and subsequent pressures are achieved by changing the pressure in multiple steps, preferably in two steps, or by changing the pressure steplessly.

In the present invention, the superplastic alloy is a two-phase or three-phase or more alloy system with fine crystal grains, so that it can be used at an ambient temperature of 300°C or less, which is the general molding temperature for aged plastic resins (thermoforming resins). 5゜Specifically, it is a Pb-Sn alloy with an Sn content of 19%.
-97.5 wt%, Pb-an-Cd alloy with Snn water content of 10-62 wt% and Cd content of 0.5
-30wt, or Zn-AJ alloys with an AI content of 21 to 23wt%, and those improved by adding Cu, Mg, etc. in an amount of 1% or less. 1. Since the present invention is to form a laminate made by laminating these superplastic alloys and thermoforming resin into a housing or the like by pressure forming, it is natural that superplastic alloys exhibit superplasticity at the molding temperature of the resin. Since it basically does not need to be rigid, it should be made as thin as possible (without making holes).
, I have to keep up with resin molding. For this purpose, the thickness of the superplastic alloy plate is preferably about 0.3 to 0.01+m.

In addition, the resin for thermoforming in the present invention must be a sheet suitable for air pressure molding that satisfies the main functions when two sheets are to be formed, and the following resins are suitable.

In other words, it is a group consisting of acrylic modified PVC resin or additives added thereto, such as the product name Kaidac (Tsutsunaka Plastic Industry 0 rumor), modified olefin resin, or a group consisting of additives added thereto. For example, the product name Olepic (Tsutsunaka Plastic Industry ■), aromatic polyether resin, or a group consisting of additives added thereto, such as the product name Noryl (Tsutsunaka Plastic Industry ■).
), ABC resin, PVC, /recarbonate, etc. These sheets of thermoforming resin have a thickness of 0, 1
= about 10 m is preferable.

As shown in the attached Fig. 1, these superplastic alloy plates and thermoforming resin sheets are made of a thermoplastic resin film with a low melting point, etc. on both sides of a superplastic alloy plate 1. They are laminated with an adhesive or pressure-sensitive adhesive 3 or without any inclusions. Also, as shown in Figure 2, the laminate is
The thermoforming resin 2 may be layered only on one side of the superplastic alloy plate 1 via an adhesive or pressure-sensitive adhesive 3, or without any inclusions.

In accordance with the present invention, the laminate as described above is formed at a relatively low initial forming pressure and then subjected to subsequent forming at a pressure higher than the initial forming pressure.

The initial molding pressure is set within a range in which the superplastic alloy is superplastically modified and the thermoforming resin is preformed, as described above.
Specifically, if the pressure is less than 0.1 Kf/art, the forming will be insufficient, and if it exceeds rsKp/di, cracks will occur in the alloy plate, so the pressure is preferably 0.1 to 5 Kp/d. Furthermore, if the amount of deformation of the molded body is large, the deformation of the alloy plate will not follow the deformation of the resin, so it is desirable that the amount of deformation is 3 Kp/cd or less. Saruni&i! The structure of the plate was a superplastic alloy plate laminated with thermoforming resin on only one side. If the molding pressure is within 1.5 p/ad, it is desirable that the pressure be within 1.5 p/ad. It is obvious that the pressure does not necessarily have to be applied by pressure, but may be applied by reduced pressure.If the holding time of these initial molding pressures is less than 1 second, the amount of deformation of the laminate will be small (the effect of molding at low pressure). If the molding time exceeds 20 seconds, molding will take a long time at low pressure, and the laminate will be cooled by the mold, resulting in poor mold reproducibility even if molded at high pressure afterwards. Therefore, it is preferable to set the molding time to 1 to 20 seconds.In addition, taking a molding time at an unnecessarily low pressure will increase the total molding time and is industrially meaningless.

The molding pressure after the initial molding is 3 Ky/c from the viewpoint of mold reproducibility.
It is preferable that t-ζ be 1 or more, but depending on the shape and pattern of the bottle, it is desirable that it be 5KIP/- or more.

But 1OK51/1-11! It is not practical to exceed this.

In the case of a laminate using a Pb-Sn alloy as a superplastic alloy, the forming temperature is preferably 120 to 183°C. That is, at temperatures below 120°C, superplasticity is not sufficiently exhibited, and at temperatures above 183°C, the PB gold alloy melts. Further, when it is desired to obtain sufficient superplasticity due to a large drawing ratio, etc., it is more desirable that the temperature of the laminate be in the temperature range of 150°C to 170°C. In addition, when using Pb-8n-Cd superplastic alloy, the temperature of the laminate is 110°C to 145°C.
It is desirable to set the temperature to ℃. That is, at temperatures below 110°C, superplasticity is not sufficiently exhibited, and at temperatures above 145°C, the PB gold alloy melts. In addition, if you want to obtain sufficient superplasticity due to a large drawing ratio, etc., a temperature range of 125 to 135°C is desirable. The melting point at which a plastic metal plate no longer exhibits superplasticity or Zn-AA! In the case of alloys, the upper limit is limited by the transformation point, and the lower limit is limited by the temperature that satisfies the required deformation rate. - Considering the universal plastic resin, the lower limit temperature of the laminate is determined at the temperature at which the 111 resin is insufficiently softened. In addition, the lower limit of the mold temperature is the temperature at which the resin does not sufficiently harden after molding, or the temperature at which the cooling of the layer plate during molding significantly reduces mold reproducibility or uneven thickness, causing resin shrinkage. The upper limit is the temperature that has a significant negative effect on mold reproducibility. That is, when using acrylic modified PVC resin as the resin for the laminate, the appropriate temperature for the laminate is 110°C or higher, and the temperature for the mold is 10 to 70°C, but this may vary depending on various combinations. Therefore, it is not limited to this.

Similarly, when using a modified olefin resin, the appropriate laminate temperature is 140°C or higher and the mold temperature is 30 to 120°C, and when aromatic polyether resin is used, the laminate temperature is 150°C or higher. However, the appropriate mold temperature is 30-130°C.

It may vary depending on various combinations, so it is not limited to this.

[For production]

(Thus, in the present invention, when molding a thermoforming laminate, the initial molding pressure is set to be lower than the subsequent molding pressure, and then the pressure is increased, or the pressure is increased sequentially while subsequent molding is performed. The super-heavy alloy is superplastically deformed, and at the same time most of the thermoforming resin is deformed, completing the preforming process.The subsequent high-pressure load causes the edges of the resin to become even sharper, improving mold reproducibility. will be achieved.

Examples are shown below. Example 1 shows an example of two-stage molding, Example 2 shows an example of multi-stage molding, and Example 3 shows an example of stepless molding. In each of the examples, a mold for molding the casing was used, which had a width of 100 cm, a length of 200 cm, a depth of 35 m, and a part of the bottom surface had unevenness with a width of about 3 days.

Example 1 Thermoforming resins include an acrylic modified PVC resin under the trade name Kaidac (manufactured by Tsutsunaka Plastic Industries), a modified melefin resin under the trade name Olepik (manufactured by Tsutsunaka Plastic Industries), and an aromatic polyether resin. Polyphenylene oxide, trade name Noryl (manufactured by Tsutsunaka Plastic Industry ■), was used as the material. As a superplastic alloy, 16 is a 0.2 m thick 70%Pb-30%Sn alloy plate, 10
Similar to 38%Pb-62%Sn alloy with 0.1 m thickness, 22
A 64%Pb-16%5n-20%Cd alloy plate with a thickness of 0.2 mm.

21 is 64%Pb-16%5n-2 with 0.1 iwa thickness
A 0% Cd alloy plate was used. Also, all other laminates are 0.
An alloy of 38%Pb-62%Sn with a thickness of 2 m was used.

As for the lamination method, the first method is used for 1 to 17 and 21 and 22.
As shown in the figure, a superplastic alloy was bonded between 2 m and 1 m+ thick Kaidak via a polyolefin adhesive film (trade name: Atomer Film VE300, manufactured by Tohcello Chemical Co., Ltd.). In addition, as for Nos. 18 to 20 and 23 to 28, a superplastic alloy was laminated on one side of the resin as shown in FIG. And for 18-20, Atomer film VE300 and thickness 2
For 23 to 25 m thick Kaidak, polyolefin adhesive film (manufactured by Tocello Chemical ■, trade name Atmer Film
In No. 8, Atomer film XEO70 and Noryl with a thickness of 2wx were used.

As a result of the example, we will consider the lack of money. Regarding the first stage molding pressure, molding is possible even in the case of 14, which is a low example. In the case of 1, which is an example of too high a value, the superplastic deformation of the PB alloy plate could not catch up with the deformation of the resin, and the PB alloy plate was broken. In addition, when using the lamination method as shown in Figure 2, the deformation of the PB alloy plate is not sufficient compared to the case as shown in Figure 1, and 5
At 3 Kt/ad, the PB plate breaks and the resin and PB
Poor adhesion may occur due to gaps between the alloy plate and the alloy plate. In case No. 8, which is an example in which the first stage forming time is too short, the second stage pressure cuff Kg/cd was applied without sufficient primary forming, resulting in cracks in the PB alloy plate.

Furthermore, in the case of samples 2, 13, and 19, which are too long examples, the horizontal layer plate was cooled by the mold before the second stage molding, resulting in insufficient mold reproducibility. The pressure in the second stage is 5 K as seen in Example 20.
A pressure higher than W/crd is good, but as inferred from the case of Example 2, sufficient mold reproducibility cannot be obtained at a pressure as low as 2'tt/cr/l. Note that good results were not obtained in Examples 1, 2, 18, and 19, which were not based on the method of the present invention.

(Left below) Example 2 Kaidac with a thickness of 1 sheet and Pb-62% with a thickness of 0.1 m
Sn alloy plates were laminated as shown in Figure 1, and the laminated plate temperature was 160.
℃, and the mold temperature was 50℃.

In the case of molding by applying a pressure of s Ky/di for 20 seconds, cracks appeared in the PB board.

However, all of the moldings molded in three stages under the pressure conditions shown in Table 2 had good mold reproducibility, and no cracks occurred in the PB alloy plate.

Table 2 Example 3 1.5 tram thickness and 0.1 tram thickness
Laminate the pb alloy plates of a as shown in Figure 2, and set the laminated plate temperature to 1.
Air pressure molding was performed at 60°C and a mold temperature of 80°C.

7. The mold reproducibility was good for the molded material under a pressure of 7 Ktlad for 20 seconds, but cracks occurred in the PB alloy plate, and the molded material for 30 seconds at a pressure of xKp/di had poor mold reproducibility.
Although there were no cracks in the alloy plate b, the mold reproducibility was insufficient. However, the pressure at the start of molding is 0.1 Ky/cr.
0 immediately after starting molding at i. IKp/cd to 7 Kylc
The elongation of the PB alloy plate was formed by gradually increasing the pressure to 7 and sea at a constant speed for 20 seconds to R&.

The mold reproducibility was also good.

[Effects of the Invention] According to the present invention as described above, a method for efficiently molding a laminate of a superplastic alloy and a thermoforming resin into a shape such as a roll body with good mold reproducibility is obtained. The effect is great.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are explanatory cross-sectional views of a thermoforming laminate according to the present invention. l... Super rodent alloy plate 2... Resin sheet for thermoforming 3... Adhesive or adhesive

Claims (1)

[Claims] 1. When pressure-forming a thermoforming laminate made by laminating a superplastic alloy and a thermoforming resin, the initial molding pressure is lower than the subsequent molding pressure; A method for forming a thermoforming laminate, characterized in that subsequent forming is carried out while increasing or gradually increasing the temperature. 2. The method according to claim 1, wherein the molding pressure is varied in multiple stages. 3. Claim 1 in which molding pressure is varied steplessly
The method described in section. 4. The method according to any one of claims 1 to 3, wherein the pressure at the initial stage of molding is within a range in which the superplastic alloy is superplastically deformed and the thermoforming resin is preformed. 5. Initial molding 1-2 at a pressure of 0.1-5Kg/cm^2
The method according to any one of claims 1 to 4, wherein the molding is performed for 0 seconds, and the subsequent molding is performed at a pressure of 3 kg/cm^2 or more. 6. The initial molding pressure is 0.1-3Kg/cm^2,
The method according to claim 5, wherein the subsequent molding pressure is 5 to 10 kg/cm^2. 7. The thermoforming laminate is a superplastic alloy plate with thermoforming resin laminated only on one side, and the initial molding pressure is 0.1.
〜1.5Kg/cm^2〜 Claim 1〜
The method according to any of paragraph 6. 8. According to any one of claims 1 to 7, the thermoforming resin is an acrylic modified PVC resin, the temperature of the laminate is 110°C or higher, and the mold temperature is 10 to 70°C. the method of. 9. According to any one of claims 1 to 7, wherein the thermoforming resin is a modified olefin resin, the temperature of the laminate is 140°C or higher, and the mold temperature is 30 to 120°C. Method. 10. The thermoforming resin is an aromatic polyether resin, the temperature of the laminate is 150°C or higher, and the mold temperature is 30-13°C.
The method according to any one of claims 1 to 7, wherein the temperature is 0°C.