JPS5862025A - Manufacture of polycarbonate foamed body - Google Patents

Abstract

PURPOSE:To obtain a foamed body that has been uniformly and highly foamed, by heating a polycarbonate molded body impregnated with an organic solvent to at least its melting point in a mold, then cooling it to a specified temperature, and releasing the pressure in an approximately closed mold to allow it to foam. CONSTITUTION:The molded body of polycarbonate[e.g. polycarbonate prepared from carbonic acid and 2,2-bis(4-oxyphenyl) propane]is impregnated with an organic solvent having a boiling point lower than the glass transition point of said polycarbonate (e.g. cychlohexane and trichlorotrifluoroethane), then the molded body is introduced in a mold, is heated under pressure to a temperature of at least the melting point of said polycarbonate, and then is cooled to a temperature range of from the glass transition temperature to the melting point. Then the pressure is released, and the molded body is allowed to foam in an approximately closed mold to obtain a highly foamed polycarbonate molded body. If the foaming is effected in an approximately closed mold diverged in one direction, a foamed body having elongated cells and a skin can be obtained. USE:Dielectric material, heat insulating materials, and construction materials.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing foam from polycarbonate moldings.

Polycarbonate foam has excellent properties.

For example, due to its good electrical properties, high heat resistance, good carpeting properties, high aging resistance, and good water resistance, it is suitable for use in concrete applications such as insulation materials and construction materials. be.

Conventionally, polycarbonate foams, like other thermoplastic resin foams, have been made using thermally decomposable blowing agents or volatile foams.
A manufacturing method using one agent as a blowing agent is known.

However, when the thermally decomposable blowing agent decomposes, the amino group, =
However, volatile JIIail agents do not have the above disadvantages, but they do have the disadvantage that the hapolycarbohydrate remains decomposed due to metal compounds containing O nitrogen-containing groups such as nitrogen groups. Since foaming is performed by heating the material impregnated with the agent and vaporizing and expanding the organic solvent, it has the disadvantage that only a foam with a low magnification can be obtained.

SUMMARY OF THE INVENTION In view of the above drawbacks, it is an object of the present invention to provide a method for producing a foam with a high magnification by using an organic solvent as a blowing agent. Another object of the present invention is to provide a method for producing a foam having a skin layer and high strength.

That is, the O-ruled W of the present invention is.

1 Polycarbonate molded body, the polycarbonate) 0
The polycarbonate is impregnated with an organic solvent having a boiling point lower than the glass transition temperature, supplied to a mold, and heated in the mold to a temperature higher than the melting point of the polycarbonate while being pressurized. Cool thoroughly.

A method for producing a polycarbonate foam O, which is characterized in that the pressure is then decompressed and the foam is foamed in a substantially sealed mold; , supplying 111c for molding.

The mold is heated to a temperature above the melting point of the polycarbonate while being pressurized in the mold, and then rapidly cooled to a temperature axis from the polycarbonate O guff χ transition temperature to the melting point.

A method for producing polycarbonate oil is provided.

The polycarbonate used in the VC of the present invention is a polyester of carbonic acid and glycol or bisphenol, and the aromatic polycarbonate having the molecule flAK diphenylalkane has good crystallinity, high melting point, heat resistance, weather resistance, and acid resistance. Examples of the above-mentioned aromatic polycarbonates, which are preferable because of their excellent properties, include 2,2-bis(4-oxyphenyl)propane, X,Z-bis(
4-oxyphenyl)butane, 1,1-bis(4-quaternary)
diphenyl)cyclohexane, 1.1-bis(4-oxyphenyl)butane, 1.1-bis(4-oxyphenyl)inbutane, 1.1-bis(4-oxyphenyl)
Examples include polycarbonates made from bisphenols such as ethane. In the present invention, the polycarbonate is formed into a molded body, but any conventional molding method may be employed (for example, extrusion molding).

Examples include injection molding and compression molding.

The aiming agent used in the present invention is one that can be impregnated into the polycarbonate, has a boiling point lower than the glass transition temperature of the polycarbonate, and has a boiling point of F
The temperature is preferably 10° C. or higher, and examples include aliphatic hydrocarbons such as pentane, impentane, hexane, inhexane, heptane, octane, and cyclohexane, trichlorotrifluoroethane, dichlorodetoffluoroethane,
Examples include fluorinated aliphatic hydrocarbons such as tetrachloride and difluoroethane, aromatic hydrocarbons such as benzene, toluene and xylene, alcohols such as butyl alcohol and propyl alcohol, and ethers. And when it is impregnated with polycarbonate, it turns white with polycarbonate,
Those that do not react with polycarbonate are preferred, and pentane, impentane, heptane, inhebutane, cyclohexane and trichlorotrifluoroethane are preferred;
More preferred are cyclohexane and trichlorotrifluoroethane.

In the present invention, the polycarbonate molded body at rt is impregnated with the organic solvent, and any method, short or short, may be adopted as the impregnation method. For example, the polycarbonate molded body and the organic solvent are placed in a pressure vessel, and if necessary, baii[
A method is adopted in which a bulk gas, an inert gas such as carbon dioxide gas, is supplied, and the organic solvent is heated to a temperature higher than the boiling point and pressurized.

In the present invention, the polycarbonate molded body impregnated with an organic solvent is then fed to a molding m, and heated to a temperature higher than the melting point of the polycarbonate while being pressurized. The above-mentioned conditions are not particularly limited, but it is preferable to press under Zoo-400 conditions, and the heating condition is preferably 10 to 40° C. higher than the melting point of the polycarbonate.

In the present invention, after heating and pressurizing, the polycarbonate molded body is cooled to a temperature in the range of 11 degrees from the glass transition temperature to the melting point. Any method may be used for cooling, such as water cooling, air cooling, etc. It is preferable that the surface temperature is cooled to a temperature 10 to 40° C. higher than the glass transition temperature.

When the pressure is released, the polycarbonate molded body starts foaming, but in the present invention, Fi foaming is carried out in a substantially closed mold. Any method may be used for the above foaming, for example, when the polycarbonate molded body is decompressed, the polycarbonate molded body is *Method of foaming by supplying it to a closed mold, heating and pressurizing it with a press.

After cooling, expand the press and place spacers around the press.
Examples include a method of installing foam and foaming.

In addition, the polycarbonate molded body was heated and pressurized to a temperature above the melting point in a mold, and then rapidly cooled to a temperature range from the glass transition temperature to the melting point vs. When foamed in a mold, the polycarbonate molded body is cooled by IN-, but the inside is not cooled and foams only in one direction, resulting in a foamed body with a skin and elongated cells in one direction. It will be done.

When producing a polycarbonate shaped body, lubricants and lubricants that are commonly used in polycarbonate molding may be added, and calcium carbonate, talc, clay, mica powder, perlite, silica, kaolin, and other additives may be added. fine bubbles 4
11 agents may be added.

The structure of the present invention is the above-mentioned j#), in which a polycarbonate molded body is impregnated with an organic solvent, heated and pressurized in a mold, and then cooled to a temperature range from the glass transition temperature to the melting point.
Since the pressure is decompressed and foamed in a nearly closed mold, the impregnated
The ll&solvent does not vaporize and escape during heating and pressurization, and does not escape into the atmosphere during foaming, resulting in a foamed product uniformly foamed with O and having a high expansion ratio. Furthermore, when the material is rapidly cooled and foamed in a substantially closed mold expanded in one direction, a foam with a high expansion ratio having a skin and elongated cells in one direction can be obtained. Furthermore, since the blowing agent used in the present invention is an A#1 agent, there is no risk of polycarbonate decomposing, and the properties of polycarbonate such as electrical properties, mechanical properties, heat resistance, aging resistance, and water resistance are maintained. It does not deteriorate and is suitably used for thermal insulation materials, electrical insulation materials, am materials, etc.

Next, the manufacturing method of the present invention will be explained using examples.

Example 1 A spacer with a square inner diameter of 120 x 126 cm and a paper thickness of 1 MO was placed on a press plate, and a granular polycarbonate resin [manufactured by Teijin Kago Co., Ltd., product name: Panlite-1100, 2J] was placed inside the spacer. polycarbonate from bis(4-oxyphenyl)propane] and heated at 280°C for 1
Press molding was carried out for 5 minutes at 50°C to obtain a polycarbonate plate.

Add 3 tons of beef sun to the obtained polycarbonate plate and cyclo
The mixture was supplied to a pressure vessel of 1.5 mm and heated in an oil bath maintained at 170° C. for 80 minutes to impregnate the polycarbonate plate with cyclohexane.

After cooling the inside of the pressure vessel to room temperature, we took out the polycarbonate plate and measured the heavy lid.
It was impregnated with a weight of 9 g.

The polycarbonate plate impregnated with cyclohexane was supplied to the spacer, and the plate was heated at 240°C and 150°C in the press.
Heat and pressurize for 5 minutes under the condition of 4/-, turn off the power to the press and cool it to 160℃ while keeping the pressure applied, then simultaneously lift the press plate and place the spacer with an inner diameter of 3.0 x
ss.

When I replaced the spacer with a square spacer with a thickness of 9 mm and pressed it again and left it to stand, a 36° x 3fiOX polycarbonate foam with 9 points was obtained.The foamed cells were approximately spherical and were uniformly dispersed. The apparent specific gravity is QO44.
Met.

Example 2 A spacer with an inner diameter of 1@0x16 (1-) square with a thickness of 1 m was placed on a press plate, and a granular polycarbonate resin [manufactured by Kijin Kasei Co., Ltd., trade name: Panlite L-] was placed inside the spacer. 1250,!

049 carbonate] from 2-bis(4-oxyphenyl)propane, ZSO°C, 1sOKf/aIi
A polycarbonate plate was obtained by press molding for S minutes under the following conditions.

When the obtained polycarbonate plate was impregnated with cyclohexane in the same manner as in Example 1, 1! L8
Impregnated by weight.

The above polycarbonate plate impregnated with cyclohexane was fed into a female mold with an inner diameter of The inward direction of the mold is 1110℃.
When the male mold was pulled up and fixed so that the distance between the male mold and the female mold was 2 seconds, a polycarbonate foam of 1 l 10 x 180 x 25 was obtained. Ta.

The obtained foam has a surface layer of about 1 -, in which elongated cells that are easy to shrink in the thickness direction are uniformly dispersed, and the foaming ratio is Fizts.
It was double that.

Example 3 A spacer having a square inner shape of 160 x 160 cm and a thickness of as-1 was placed on a press plate.

Inside the spacer is granular O polycarbonate resin (manufactured by Kijin Kasei Co., Ltd., trade name Panrai) L-1250W, 2! −Bis(
Polycarbonate from 4-oxyphenyl)propane] was supplied at 280°C and 180°C. , 4- for S minutes to obtain a polycarbonate plate.

The obtained polycarbonate plate and 3 tons of trichlorotrifluoroethane were supplied to a St pressure vessel and heated in an oil path kept at 170° C. for 3 hours to impregnate the polycarbonate plate with trichlorotrifluoroethane. After cooling the inside of the pressure vessel to room temperature, the polycarbonate plate was taken out and its weight was measured, and it was found that it was impregnated with trichlorotrifluoroethane in an amount of 15 kg by weight.

The polycarbonate plate impregnated with the above trichlorotrifluoroethane was supplied to the female gold IJIK used in Example 2,
The male mold was heated and pressurized for 10 minutes under the conditions of 240 Kl:, 13 OJlz/mO, and the pressurized body was rapidly cooled with water until the inner surface of the mold became 186', and as the pressure was released, the male mold and When the male mold was pulled up and fixed so that the distance between the female molds was 20 square, a foam of 1@0×160×20 square was obtained.

The obtained foam had a surface of about (LllllIO), elongated cells were uniformly dispersed in the thickness direction, and the foaming ratio was 3 and 8 times.

patent applicant Sekisui Chemical Co., Ltd. Representative Mototoshi Fujinuma

Claims (1)

[Claims] L A polycarbonate molded body is impregnated with an organic solvent having a boiling point lower than the glass transition temperature of the polycarbonate, supplied to a mold, and heated to a temperature higher than the melting point of the polycarbonate while being pressurized in the mold. After that, the polycarbonate foam is cooled to a temperature range from the glass transition humidity to the melting point of the polycarbonate, and then depressurized and foamed in a substantially W-closed mold. 2. The manufacturing method according to claim 1, wherein the polycarbonate is an aromatic polycarbonate. Tortoise Claim 11 in which the boiling point of the organic solvent is 0°C or higher
Item 111 or Item 2 ε戟O1l manufacturing method. Table: A polycarbonate molded body is impregnated with an organic solvent having a boiling point lower than the glass transition temperature of the polycarbonate, supplied to a mold, and heated to a temperature higher than the melting point of the polycarbonate while pressurizing within the mold. Glass Transition Sensitivity - A method of manufacturing polycarbonate consisting of rapid cooling to a temperature range and then subsequent cooling. The manufacturing method according to claim 4, wherein polycarbonate or aromatic polycarbonate is used. Kame Patent claim m11 in which the organic solvent has a boiling point of 0°C or higher
The manufacturing method described in Section 14 or Fi Section S.