JPS612535A - Aging method of thermoplastic resin film-shaped foam - Google Patents

Abstract

PURPOSE:To obtain an excellent re-expansion effect by winding a filmy foam on a core material in a comparatively large inner diameter, removing the core material and maturing the foam. CONSTITUTION:A thermoplastic resin film-shaped foam 11 molded by using a physical foaming agent is wound on a core material 6 in a comparatively large diameter. It is preferable that the inner diamter of winding extends over 300mm. or more. It is because there is no position of relief for the thermoplastic resin film-shaped foam 11 on aging and the magnification of expansion is inhibited when the inner diameter is less than 300mm.. The core material 6 for the wound thermoplastic resin film-shaped foam 11 is removed, and the foam is matured. The core material 6 can be removed easily because backing plates 3 are separated from the inner circumferential surface of the thermoplastic resin film- shaped foam 11 when screws 5 are loosened and arms 4 are retreated into a holding cylinder 2. 12hr or more, preferably, 20hr or more, at the normal temperature is desirable as the conditions of maturing. Accordingly, when the thermoplastic resin film-shaped foam expands, the expansion section escapes to a space from which the core material is removed, thus resulting in no inhibition of the effect of re- expansion, then obtaining the high effect of re-expansion.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for aging a thermoplastic resin membrane foam.

[Background Art and Problems Therein] Thermoplastic resin film-like foams have a property that the expansion ratio increases further after production. In particular, when foaming is performed using a physical blowing agent, the bubbles shrink due to the escape of the blowing agent immediately after foam molding, and then the remaining blowing agent is replaced with air, which takes several days of aging to return to the original expansion ratio. Requires processing.

Therefore, if the feeding speed of the thermoplastic resin film-like foam is slowed down in order to carry out this aging treatment continuously, a long treatment facility would be required, which would be industrially impossible.

As a method to solve this problem, methods have been proposed to increase the re-expansion rate by treating with various solvents. However, this solvent treatment method is not industrially desirable due to the use of solvent, recovery and utilization, and environmental degradation.

Another solution is to wind the thermoplastic resin film-like foam so that no tension is applied to it; specifically, insert a rod-shaped body between the membrane-like bodies, wind it up, and then pull out the rod-shaped body at the end. A method has been proposed: (1) A method in which both sides of a membrane-like body are rolled up with thick walls, and then the thick parts are removed. However, even these twill winding methods are not preferable because they require auxiliary materials and cause loss of removed portions.

[Object of the Invention] The object of the present invention was to overcome the drawbacks of such conventional methods, and to provide a heat+i7 plastic resin film that can obtain an excellent re-expansion effect by a simple method. An object of the present invention is to provide a method for aging a shaped foam.

[Means and actions to solve the problem] Therefore,
In the present invention, after a thermoplastic resin membrane foam molded using a physical foaming agent is wound around a core material with a relatively large inner diameter,
When the core material is removed and aged, the expansion of the thermoplastic resin membrane foam expanded by this aging can escape into the space from which the core material has been removed, so that an excellent re-expansion effect can be obtained by a simple method. I can do it.

Specifically, as shown in FIG. 1, a thermoplastic resin film-like foam is molded using a physical foaming agent. Here, the membrane-like foam may be either sheet-like or film-like.

Subsequently, the molded thermoplastic resin membrane foam is wound around a core material to a relatively large diameter. For example, as shown in FIG.
Holding cylinders 2 are integrally formed at right angles at intervals of 90 degrees on the outer periphery of the cylinders, and an arm 4 having an arcuate receiving plate 3 at its tip can be freely advanced and retracted on each holding cylinder 2, and can be attached to an arbitrary position using a screw 5. Using a core material 6 that can be fixed in position, the outer diameter of the receiving plate 3 of this core material 6 is set to a relatively large diameter, for example, 300 mm.
After the above settings are made, the thermoplastic resin membrane foam 11 is wound around the outer periphery of the receiving plate 3. At this time, the shape of the roll may be arbitrary, such as circular, rectangular, or triangular. However, the inner diameter of the winding is 300 mm or more, preferably 50 mm.
It is desirable that it is 0 mm or more. This is because, although it depends on the number of winding layers, if the inner diameter is less than 300 mm, there is no place for the thermoplastic resin film-like foam to escape during ripening, and the expansion ratio is suppressed. Incidentally, when the inner diameter is 500 mm, the number of calendars per volume is preferably 200 or less.

Thereafter, the core material 6 of the wound thermoplastic resin membrane foam 11 is removed, and the core material 6 is aged under predetermined conditions for a predetermined period of time.

To remove the core material 6, loosen the screw 5 and move the arm 4 backward into the holding tube 2, and the thermoplastic resin membrane foam 1 is removed.
Since the receiving plate 3 is separated from the inner peripheral surface of the core material 6, the core material 6 can be easily removed. At this time, the aging conditions are at room temperature (25°C) for at least 12 hours, preferably for 20 hours.
More than an hour is preferable. As a result, as shown in Figure 3,
When the thermoplastic resin membrane foam expands, the expansion escapes into the space from which the core material has been removed, so the re-expansion effect is not suppressed.

As a result, there is no need for special equipment for aging, there are no problems associated with the use of solvents, there is no loss in the board wrapping method, and a high re-expansion effect can be obtained. Incidentally, the aged thermoplastic resin membrane foam is wound around a winding core 21, as shown in FIG.

C Example 1 First, polypropylene (density 0, 91 g/cm',
Melt index: 0.6 g/10 min) 100 parts by weight of trichloromonofluoromethane and 25 parts by weight of dichlorotetrafluoroethane were added to 150 parts by weight of ioo.
Press in at K g/c rn' and knead thoroughly until 12
After cooling to 5°C to make a homogeneous solvent, it is extruded into the atmosphere through a circular die (die diameter: 30 mmφ) to obtain a resin foam sheet.

Example 1 Example 2 The foam sheet had an inner diameter of 600 mm in one roll immediately after molding.
After skein-rolling and removing the core material, it was aged at 25°C for 24 hours.

Immediately after molding the foam sheet, the inner diameter of the roll is 1200.
After the core material was removed, the mixture was aged at 25°C for 24 hours.

Immediately after forming the foam sheet, the inner diameter of the rolled form is 200 m.
After skein winding at 25°C and removing the core material,
Aging was performed for 4 hours.

Immediately after forming the foam sheet, the inner diameter of the roll is 100 m.
25° while winding the core material.
Aging was performed at C for 24 hours.

Table 1 shows the expansion ratio of the intermediate layer portion of each foam sheet after aging under the conditions of Examples 1 to 3 and Comparative Example 1. In addition, the foaming ratio immediately after extrusion of the foam sheet is 1.
10 times, sheet thickness is 1.5mm, sheet length is 300mm
It is m.

Table 1 From the above results, it seems that there is no practical problem as long as the winding inner diameter is 200 mm or more, but preferably 300 mm.
An excellent re-expansion effect can be achieved if the length is at least m, ideally at least 500 mm.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a method for aging a thermoplastic resin film-like foam that can obtain an excellent re-expansion effect using a simple method.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the aging method of the present invention, Fig. 2 is a front view showing the rolled up state of the thermoplastic resin membrane foam, and Fig. 3 shows the thermoplastic resin membrane foam during aging. Front view,
FIG. 4 is a diagram showing a state in which the thermoplastic resin film-like foam is rolled up after aging. 6... Core material, 11... Thermoplastic resin membrane foam.

Claims (2)

[Claims] (1) A thermoplastic resin characterized in that a thermoplastic resin membrane foam formed using a physical foaming agent is wound around a core material with a relatively large inner diameter, and then the core material is removed and aged. Method for aging membrane foam. (2) A method for aging a thermoplastic resin membrane foam according to claim 1, characterized in that the thermoplastic resin membrane foam is rolled up to an inner diameter of 300 mm or more.