JPH09150460A - Method for manufacturing shape memory resin foam - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide a method for manufacturing a shape-memory resin foam which is a thin foam at the time of construction but recovers the thickness after construction to exhibit excellent sealing properties and heat insulating properties. . SOLUTION: A first step of introducing a resin foam 1 into a parallel mold (A) in which a cross-sectional shape of a flow path is from an inlet side to an outlet side, and a cross-sectional shape of an inlet side is a parallel mold (A). Second step of introducing into a compression mold (B) having the same cross-sectional shape on the outlet side as that of the flow channel and gradually reducing the flow path toward the outlet side in the thickness direction, and the cross-sectional shape on the inlet side of the compression mold Third cross-sectional shape which is the same as the cross-sectional shape on the outlet side of the mold (B) and whose cross-sectional shape of the flow path is introduced into the same parallel mold (C) from the inlet side to the outlet side
Is continuously performed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a shape memory resin foam.

[0002]

2. Description of the Related Art Conventionally, as a heat insulating material for a house, a thermoplastic resin foam has been used for a lining of a half-roof for the purpose of sealing and heat insulation of a joint and between an inner wall and an outer wall for the purpose of wall heat insulation. The thermoplastic resin foam has excellent performance for the purpose of ensuring heat insulation and sealing properties, but is difficult to construct, for example, when it is used as a heat insulating material for the lining of a half-roof, it has a certain thickness. If the foams are stuck together, there is a problem that the joint between the foams becomes thick and the construction becomes difficult. On the other hand, when a thin foam is used, there is a problem that a predetermined heat insulating effect cannot be obtained.

Even when sandwiched as a heat insulating material in a wall gap, there is no problem in construction when the shape of the gap is constant. There was a problem that the construction was complicated and difficult in the place where it was.

Hitherto, as a sealing material for a gap, a material in which the cell wall of an open-cell foam is covered with chloroparaffin or the like by an impregnation method and the foam is pressure-bonded has been used.
In this compressed foam, the cell walls adhere to each other, but this adhesion is peeled off by the restoring (recovering) force of the foam, and the foam gradually returns to the starting structure. But,
Since this sealing material was obtained by impregnating the open-cell foam as described above and then compressing it, it did not have a sufficient sealing effect.

Therefore, a sealing material has been proposed in which a liquid impermeable layer is provided on a foam body to gradually restore the original shape after being compressed and deformed (Japanese Patent Publication No. 3-55621, Japanese Patent Laid-Open No. 193465/1989). JP-A-1-216169).

However, this sealing material requires (1) impregnation treatment, which is time-consuming, and (2) impregnated chloroparaffin or the like flows out from the foam, especially when used in an environment of high temperature. However, since it is impregnated, (3) the heat insulating performance is low and it cannot be used as a heat insulating material.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is a foam having a small thickness at the time of construction, but the thickness is recovered after the construction and an excellent seal is obtained. To provide a method for producing a shape memory resin foam exhibiting heat resistance and heat insulation.

[0008]

In the method for manufacturing a shape memory resin foam according to the present invention, the resin foam is introduced into the same parallel mold (A) whose cross-sectional shape of the flow passage is from the inlet side to the outlet side. First step, a compression mold (B) in which the cross-sectional shape on the inlet side is the same as the cross-sectional shape on the outlet side of the parallel mold (A) and the flow path is gradually reduced in the thickness direction toward the exit side. The second step of introducing into the step 1 and the cross-sectional shape on the inlet side is the same as the cross-sectional shape on the outlet side of the compression mold (B), and the cross-sectional shape of the flow passage is the same from the inlet side to the outlet side. It is characterized in that the third step introduced into (C) is continuously performed.

The resin foam used in the present invention includes:
There is no particular limitation, and examples include those molded by extrusion foaming, and those in which a foaming agent is pressed into the molten resin in a pressure vessel and then placed under normal pressure for foaming. Further, as the resin foam, it is preferable that the foaming gas is contained in the foaming cell immediately after production and the foaming gas is not yet replaced with air.

The resin used for the resin foam may be any resin having foamability, and examples thereof include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl acetate. Olefin resin such as copolymer, polybutene, chlorinated polyethylene; polystyrene, styrene-
Styrene resins such as butadiene-styrene copolymer, styrene-isoprene-styrene copolymer; polymethyl acrylate, polymethyl methacrylate, ethylene-
Acrylic resin such as ethyl acrylate copolymer; Vinyl chloride resin such as polyvinyl chloride, polyvinylidene chloride; Amide resin such as 6-nylon, 66-nylon, 12-nylon; Polyethylene terephthalate, polybutylene terephthalate, etc. Ester resin; AB
Examples thereof include S resin, polycarbonate, polyacetal, polyphenylene sulfide, polyether ether ketone, polyether imide, silicon resin, thermoplastic polyurethane, and various elastomers.

As the foaming agent used for the resin foam, when the resin foam is extruded and molded,
Both a physical type foaming agent and a thermal decomposition type foaming agent can be used.

As the physical type foaming agent, a gas (for example, carbon dioxide gas) having a higher permeability coefficient of gas generated from the foaming agent to the resin than that of air is preferable. The boiling point or sublimation point of the foaming agent is preferably 0 ° C. or higher at normal pressure, more preferably 20 ° C. or higher and lower than the softening point of the resin.

Examples of the physical type foaming agent include carbon dioxide gas (sublimation point: -78.5 ° C.), butane (boiling point: −0.
5 ° C), pentane (36 ° C), hexane (69 ° C) and other aliphatic hydrocarbons; benzene (80.1 ° C) and other aromatic hydrocarbons; acetone (56 ° C) and other ketone hydrocarbons; methanol ( 64 ° C.), alcoholic hydrocarbons such as ethanol (78 ° C.); 1,1-dichloro-1-fluoroethane (32 ° C.), 2,2-dichloro-1,1,1-trifluoroethane (27.5) C), 1,1,1,2-tetrafluoroethane (-26.3 ° C), monochlorodifluoroethane (-9.7 ° C), monochlorodifluoromethane (-40.8 ° C), and other halogenated hydrocarbons. These may be used alone or in combination of two or more.

Among the above physical type foaming agents, those having a boiling point near room temperature are easy to control in temperature, and particularly 1,1-dichloro-1-fluoroethane (boiling point 32 ° C.), 2,2-dichloro-1, 1,1-trifluoroethane (boiling point 27.5
C.) and pentane (boiling point 36.degree. C.) are preferred.

The thermal decomposition type foaming agent is preferably a gas having a higher permeability coefficient of gas generated from the foaming agent to the resin than that of air (for example, carbon dioxide gas generated from sodium bicarbonate).

As a manufacturing process of the resin foam,
Although not particularly limited, the use of extrusion molding is more preferable because the first, second, and third steps described below can be continuously performed.

The manufacturing method of the present invention comprises a first method described below.
~ The third step, for example, as shown in the cross-sectional view in FIG. 1, a working die including a parallel die (A), a compression die (B) and a parallel die (C) is used.

In the first step, the resin foam 1 is introduced into the parallel mold (A) having the same flow path cross-sectional shape from the inlet side to the outlet side. In this first step, the resin foam 1 may be heated in order to facilitate the compression in the second step. In order to impart lubricity to the resin foam 1, it is preferable to supply a lubricant to the resin foam 1 and coat the surface of the resin foam 1 with a lubricant film (not shown). In order to supply the agent, another mold (D) may be provided in front of the parallel mold (A).

The following are preferably used as the above lubricant. (A) Polyoxyalkylenes, random, block and graft copolymers of two or more alkylene oxides and their derivatives. Specifically, ether type such as alkyl ethers such as polyoxyethylene lauryl ether, alkyl phenols such as polyoxyethylene nonylphenyl ether; alkyl esters such as polyoxyethylene rosin acid ester, sorbitan such as sorbitan monolaurate Ester types such as alkyl esters and phosphoric acid esters such as polyoxyethylene dicresyl phosphate; Condensation types with amines such as N, N-di (polyoxyethylene) astearylamine; Amides such as polyoxyethylene astearylamide And the condensation type.

(B) Polyhydric alcohols and their alkyl esters and alkyl ethers. Examples thereof include polyhydric alcohols such as polyethylene glycol; alkyl ether types of polyhydric alcohols such as sorbitan and its dehydrated modified palmitate; and ester types of polyhydric alcohols and fatty acids such as mono- or diglycerides of linear fatty acids and resin acids.

(C) Fatty acid alcohol amides such as lauryl ethanolamide. (D) Fatty acid amides such as stearic acid amide. (E) Fatty acids such as stearic acid. (F) Esters of polyhydric carboxylic acids such as dibutyl phthalate and dinonyl phthalate with monohydric alcohols. (G) Phosphoric acid esters such as tributyl phosphate. (H) Polyesters such as polyethylene succinate. (I) Inorganic compounds such as nitrates. (Nu) Metal soaps. (E) Silicon oils. (Wa) Perfluoroethers.

(F) Low molecular weight polyethylene, polypropylene, ethylene ethyl acrylate, ethylene-vinyl acetate copolymer, ethylene methyl methacrylate, polycaprolactone, nylon and the like. (Yo) Water.

The above lubricants may be used alone or 2
More than one species may be used in combination. Furthermore, as a lubricant,
It is preferable that the resin foam has good thermal stability during processing and is easily removed after molding, and examples thereof include a fluorine-based lubricant and a copolymer of ethylene oxide and propylene oxide.

In the second step, the resin foam 1 after the first step has the same cross-sectional shape on the inlet side as the cross-sectional shape on the outlet side of the parallel mold (A) and the thickness of the flow path is It is introduced into a compression mold (B) that is gradually reduced toward the outlet side. In the process of passing through the compression mold (B), the resin foam is gradually compressed and thinned to a predetermined thickness.

The sectional shape ratio (outlet side / inlet side) between the inlet side and the outlet side of the compression mold (B) is preferably in the range of 1/20 to 4/5. If it is less than 1/20, the resin foam is less likely to expand after construction, and if it is larger than 4/5, the compressibility is small and there is a problem in workability.

The temperature of the compression mold (B) is set to a temperature equal to or higher than the boiling point of the foaming agent and lower than the softening temperature of the resin, and the temperature is adjusted by the time the resin foam reaches the outlet of the compression mold (B). It is preferable to set it so that it is cooled to below the boiling point of.

If the temperature of the compression mold (B) becomes low, it becomes difficult to perform the molding with the compression mold and it becomes impossible to obtain a predetermined shape. Further, when the temperature becomes higher than the softening temperature of the resin, the resin foam does not expand in the thickness direction after the construction. Here, the softening temperature means the glass transition point (T
g), and the melting point (Tm) of a crystalline resin.

If the temperature at the outlet of the compression mold (B) becomes lower than the boiling point of the gas, the foam contracts at the time of leaving the mold (B), and a predetermined shape cannot be obtained.

In the third step, the resin foam compressed in the thickness direction in the second step has the same cross-sectional shape on the inlet side as the cross-sectional shape on the outlet side of the compression mold (B). The passages are introduced into the same parallel mold (C) from the inlet side to the outlet side. In the third step, the resin foam is preferably cooled to a temperature below the boiling point to liquefy the foam gas in the foam cells.

The resin foam discharged from the parallel mold (C) to the outside of the mold is wound into a roll to obtain a shape memory resin foam.

Instead of providing the above-mentioned mold (D), when the resin foam body passes through the inside of the processing mold including the molds (A), (B) and (C), friction with the inner surface of the processing mold is caused. In order to reduce the force, the inner surfaces of the molds (A), (B) and (C) may be formed of a porous body, and the lubricant may be supplied through the porous body. In this case, it is preferable to supply the lubricant so that a film of the lubricant is formed between the porous body and the resin foam.

Examples of the lubricant used here include gaseous lubricants in addition to the above-mentioned lubricants (a) to (yo). As the gas lubricant, one that does not react with the resin or one that does not deteriorate the resin is preferable. For example, carbon dioxide gas,
Nitrogen gas or the like is preferably used.

Further, instead of providing the die (D), when the resin foam passes through the die including the die (A), (B), and (C), the inner surface of the die is changed. The molds (A), (B) and (C) may be vibrated in order to reduce the frictional force of. The frequency and amplitude applied to the mold are not particularly limited, but an amplitude of 1 mm or less at a frequency of 10 to 100 kHz is preferable, and a frequency of 15 to 20 kHz and an amplitude of 10 to 50 μm are more preferable.
In an actual manufacturing apparatus, the frequency and amplitude of vibration can be continuously or stepwise changed, and the type of resin,
Depending on the thickness of the resin foam, the processing speed of the resin foam, etc.,
It is preferable that the optimum frequency and amplitude can be selected as appropriate.

(Operation) In the manufacturing method of the present invention, the first
-Third three steps provide a shape memory resin foam in a state in which the resin foam is compressed to have a reduced thickness. The obtained resin foam, after being applied in a thin state, by replacing the foaming gas in the foam cells with air, the resin foam expands in the thickness direction and restores to a predetermined thickness, A sealing effect and a heat insulating effect are exhibited.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto. (Example 1) As a resin, low-density polyethylene ("Yukaron ZC30" manufactured by Mitsubishi Petrochemical Co., melting point 109 ° C, MI =
0.15) 100 parts by weight and 0.1 parts by weight of talc (“MS” manufactured by Nippon Talc Co., Ltd.) as a cell nucleating agent were mixed into a resin composition from a hopper to a vent type screw extruder (diameter: 65 mm). , L / D = 35) and 1,1-dichloro-1-
Fluoroethane was injected at a rate of 15 g / min from a plunger pump and kneaded at 130 ° C, and then the extrusion rate was 10 kg.
Extrusion molding at 10 / hour, 10 mm (thickness) x 500 m
A resin foam of m (width) (foaming ratio 30 times) was obtained.

The resin foam obtained above was introduced into the processing mold shown in FIG. 1, and the volume was contracted under the conditions shown in Table 1. A lubricant mold for continuously supplying a lubricant was installed in front of the parallel mold (A), and polyethylene glycol “Uniloop 50-MB5” manufactured by NOF CORPORATION was used as the lubricant.

Example 2 Carbon dioxide was used as a foaming agent at a concentration of 10
Press in from the plunger pump at a rate of g / min, and
After kneading at 0 ℃, φ1.5 was set at the temperature of 103 ℃
A resin foam was obtained in the same manner as in Example 1 except that the resin was extruded from a metal mold having an extrusion rate of 10 kg / hour.
The resin foam obtained above was introduced into the processing mold shown in FIG. 1 to shrink the volume under the conditions shown in Table 1. A lubricant mold for continuously supplying a lubricant was installed in front of the parallel mold (A), and polyethylene glycol “Uniloop 50-MB5” manufactured by NOF CORPORATION was used as the lubricant.

(Example 3) A resin foam obtained in the same manner as in Example 1 was used to form a porous body on the entire inner surface of the mold of (A), (B) and (C) as shown in FIG. (Prototype Kogyo's "Porcerax", average bubble diameter 7 μm) 2 was introduced into the processing mold, and while the gas lubricant was supplied from the porous body in the direction of the arrow, the volume was increased under the conditions shown in Table 1. Contracted. still,
Nitrogen gas was supplied as a gas lubricant at 3 cm ³ / cm · sec.

(Example 4) The resin foam obtained in the same manner as in Example 1 was provided with vibrators 3 as shown in FIG. 4, and the vibrators 3 (A), (B) and (C) were prepared. Introduced into the processing mold, the vibrator 3 gives a vibration frequency of 20 kHz to the processing mold,
The volume was contracted while applying vibration with an amplitude of 30 μm.

(Comparative Example 1) A resin foam obtained in the same manner as in Example 1 was introduced into a working mold while setting the parallel mold (A) and the compression mold (B) at a preset temperature of 120 ° C. A resin foam was obtained in the same manner as in Example 1 except for the above.

[0041]

[Table 1]

With respect to the resin foam whose volume was shrunk by the above processing mold, the expansion ratio was measured immediately after production and after 30 days, and is shown in Table 2.

[0043]

[Table 2]

[0044]

EFFECTS OF THE INVENTION The method for manufacturing a shape memory resin foam according to the present invention has the above-mentioned constitution, and the construction is easy because the thickness is thin at the time of construction. Provided is a foam exhibiting sex. Therefore, the shape-memory resin foam obtained by the manufacturing method of the present invention can be suitably used for the lining of a half-roof, between the inner and outer walls of wall insulation, and between the walls through which pipes pass.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a processing die used in a manufacturing method of the present invention.

FIG. 2 is a perspective view showing an example of a processing die used in the manufacturing method of the present invention.

FIG. 3 is a schematic view showing an example of a processing die used in Example 3 of the present invention.

FIG. 4 is a schematic view showing an example of a working die used in Example 4 of the present invention.

[Explanation of symbols]

 1 Resin Foam 2 Porous Body 3 Transducer A Parallel Mold B Compression Mold C Parallel Mold D Lubricant Supply Mold

Claims (1)

[Claims] 1. A first step of introducing a resin foam into the same parallel mold (A) having a cross-sectional shape of a flow path from an inlet side to an outlet side, and a cross-sectional shape of an inlet side being a parallel mold (A). Second step of introducing into a compression mold (B) having the same cross-sectional shape on the outlet side as that of the flow channel and gradually reducing the flow path toward the outlet side in the thickness direction, and the cross-sectional shape on the inlet side of the compression mold Third cross-sectional shape which is the same as the cross-sectional shape on the outlet side of the mold (B) and whose cross-sectional shape of the flow path is introduced into the same parallel mold (C) from the inlet side to the outlet side
The method for producing a shape-memory resin foam, which is characterized in that the above steps are continuously performed.