JP2017144646A - Vulcanization method of luminous epdm extrusion molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a luminous EPDM molded article having luminous brightness equal to conventional silicone rubber and excellent in mechanical strength and material cost by using an autoclave without problems such as tackiness or whitening of a surface.SOLUTION: There is provided a vulcanization method of a luminous EPDM extrusion molded article including means for mixing a luminous EPDM composition containing organic peroxide, means for extrusion molding the EPDM composition to a sheet shape, means for sandwiching the extrusion molded sheet with PTFE glass clothes, sealing terminals of the glass clothes by a tape and vulcanizing the same with an autoclave. There is provided a vulcanization method of a luminous EPDM extrusion molded article where the content of a luminous agent of the EPDM extrusion molded article is 10 to 20 wt.%.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for vulcanizing phosphorescent EPDM extrudates.

  Luminescent self-luminous materials have the property of self-luminous for a long time in the dark after absorbing light energy such as sunlight and fluorescent lamps. Such materials are used as indicators and signs for nighttime guidance and safety, and also as materials with a high design effect not found in conventional color materials.

  Among the phosphorescent materials, phosphorescent rubber or phosphorescent elastomer is applied to a curved surface or used as an accessory by taking advantage of an elastic body that can be easily deformed (see Patent Document 1).

  Such phosphorescent rubber moldings are often made by molding a composition in which a phosphorescent agent is added to a transparent or translucent silicon rubber substrate. Development of phosphorescent rubber moldings based on synthetic rubbers such as ethylene-propylene-diene terpolymer rubber (hereinafter abbreviated as EPDM) is progressing depending on the application (see Patent Document 2).

Japanese Patent Laying-Open No. 2005-171013 (described in paragraphs 0022 to 0024) JP 2012-200908 A (described in paragraphs 0003 to 0019)

A luminous rubber molded product based on silicon rubber has a problem that physical properties such as tensile strength and tear strength are inferior to those of general synthetic rubber.

There is also a problem that the material cost of the silicon rubber itself is high.

  The problems of the above silicon rubber can be solved by using EPDM as the base material of the luminous rubber molding. In this case, it is possible to obtain a material with high transparency of the base material and high luminance by using a compound vulcanized with an organic peroxide having a low coloring property. An EPDM composition using an organic peroxide is vulcanized by press molding in which an unvulcanized material is sandwiched between molds and applied with temperature and pressure, or the unvulcanized material is molded with an extruder or the like. Then vulcanize in an autoclave. This is to prevent stickiness from occurring due to inhibition of vulcanization due to reaction with oxygen on the surface of the material in the vulcanization process of the molded product.

However, when the phosphorescent EPDM composition is actually put in an autoclave and vulcanized, the portion of the surface of the molded product touched by water vapor is whitened and becomes opaque, resulting in a decrease in luminance.

  An object of the present invention is to produce a luminous phosphoric EPDM molded article having luminous intensity equivalent to that of conventional silicone rubber and having excellent mechanical strength and material cost by using an autoclave without problems such as surface stickiness and whitening. is there.

The present invention provides means for kneading a luminous EPDM composition containing an organic peroxide, means for extruding the EPDM composition into a sheet, and sandwiching the extruded sheet with PTFE glass cloth. A method of vulcanizing a luminous EPDM extrudate, comprising means for sealing the end of the glass cloth with a tape and vulcanizing with an autoclave.

  2. The method of vulcanizing a luminous EPDM extrudate according to claim 1, wherein the content of the phosphorescent agent in the EPDM extrudate is 10 to 20% by weight.

2. The phosphorescent EPDM according to claim 1, wherein the vulcanization condition of the EPDM extrudate is vulcanized for 30 ± 10 minutes while maintaining the vapor pressure inside the autoclave at 0.6 ± 0.2 megapascal. This is a method of vulcanizing an extruded product.

2. The vulcanization of the phosphorescent EPDM extrudate according to claim 1, wherein the vulcanization conditions of the EPDM extrudate are vulcanized for 30 ± 10 minutes while maintaining the temperature inside the oven at 140 to 240 ° C. Is the method.

  According to the vulcanization method of the present invention, it is possible to produce a luminous phosphoric EPDM molding superior in mechanical strength compared to a conventional luminous phosphor molding based on silicon.

The luminous EPDM molded product in the present invention is superior to conventional products using silicon in terms of material cost.

Since the phosphorescent EPDM molded product in the present invention is vulcanized in an oxygen-free state using an autoclave, surface stickiness due to vulcanization inhibition can be prevented.

Since the phosphorescent EPDM molded product in the present invention is vulcanized in a state of being sealed with a PTFE glass cloth and a tape, water vapor does not touch the surface of the molded product to cause whitening.

It is a figure which shows the state before sealing a molded sheet. It is a figure which shows the state which sealed the molded sheet. It is AA sectional drawing of the embodiment of FIG. It is a graph which shows the afterglow brightness | luminance after 30 minutes of a luminous EPDM molding. It is a graph which shows the afterglow brightness | luminance after 60 minutes of a luminous EPDM molding. It is a graph which shows the material cost ratio of phosphorescent EPDM molding compared with phosphorescent silicone rubber composition.

   Hereinafter, the vulcanization method of the phosphorescent EPDM extrudate of the present invention will be described.

  The present invention comprises a three-stage process of kneading the luminous EPDM composition, extrusion molding of the EPDM composition, and autoclave vulcanization of the EPDM molding.

  FIG. 1 shows an embodiment of the method for vulcanizing an extruded product according to the present invention. In this state, a lower PTFE glass cloth 2 is placed on a vulcanizing dish 3 and a luminous EPDM extruded sheet 4 is placed thereon. Show.

The phosphorescent EPDM extruded sheet 4 is prepared by extruding a phosphorescent EPDM composition. The phosphorescent EPDM composition is a rubber composition containing EPDM as a main component and a phosphorescent pigment.

The phosphorescent EPDM composition contains an organic peroxide vulcanizing agent.

  As the phosphorescent agent, known phosphorescent pigments such as sulfide phosphors and aluminate phosphors can be used.

  It is important for the phosphorescent EPDM composition to contain the phosphorescent agent in an amount of 10 to 20% by weight in order to exhibit the self-luminous effect. It is preferable to use an EPDM composition having translucency or transparency. If the content of the phosphorescent agent is about 10% by weight, the luminous performance is inferior, and if it exceeds 20% by weight, the improvement in the luminous performance with respect to the added amount of the phosphorescent agent is reduced, while the material cost of the entire composition is increased. It is not preferable from the aspect of the counter effect (see FIGS. 4, 5, and 6).

The phosphorescent EPDM composition blends various compounding agents (sub-materials) such as white fillers, plasticizers and anti-aging agents used in general rubbers in addition to the above compounding agents within the range not impairing the object of the present invention. be able to.

In the kneading step of the luminous EPDM composition, a kneading machine such as a closed kneader such as a Banbury mixer or a kneader or a kneading roll machine can be used as in the case of a general rubber composition.

  In the process of extruding the luminous EPDM composition into a sheet, a screw type extruder or a gear pump type extruder can be used as in the case of a general rubber composition.

  FIG. 2 shows the state of the embodiment of FIG. 1 with the top PTFE glass cloth 1 overlapped from above and the ends of the two glass cloths sealed with the end sealing tape 5.

  The upper PTFE glass cloth 1 and the lower glass cloth 2 shown in FIG. 2 are materials obtained by impregnating and firing PTFE (fluororesin) into a glass fiber fabric. The PTFE glass cloth used in the present invention is preferably one having a smooth surface and sufficient heat resistance in the vulcanization temperature range.

  As the tape 4 used for sealing the four sides of the PTFE glass cloth, a tape that maintains adhesiveness even in high-temperature high-pressure steam is used.

3 is a cross-sectional view taken along the line AA in FIG. As shown in the cross-sectional view, it is necessary that the phosphorescent EPDM extruded sheet 4 is sandwiched and adhered with PTFE glass cloths 1 and 2 from above and below, and the ends of the glass cloth are sealed with tape 4 and vulcanized.

Although not shown here, vulcanization may be performed by folding a single PTFE glass cloth and sandwiching a phosphorescent EPDM extrusion molding sheet between them and sealing the end of the glass cloth with a tape.

  2 and FIG. 3 in an autoclave under the conditions of a vapor pressure of 0.6 ± 0.2 megapascals and a vulcanization time of 30 ± 10 minutes with the phosphorescent EPDM extruded sheet in a sealed state placed on a vulcanizing dish. Vulcanize.

  Instead of vulcanizing the phosphorescent EPDM extruded sheet in an autoclave, the furnace temperature in the oven may be 140 to 240 ° C. and vulcanized for 30 ± 10 minutes.

EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

Example 1
A phosphorescent EPDM composition was prepared by adding 5% by weight of a phosphorescent agent to an EPDM composition containing EPDM as a main component. This composition was molded into a sheet according to the above embodiment and then vulcanized in an autoclave to obtain a phosphorescent EPDM extruded sheet having a thickness of 2 mm.
(Example 2)
A phosphorescent EPDM extruded sheet was obtained in the same manner as in Example 1 except that the amount of phosphorescent agent added was increased to 10% by weight.
(Example 3)
A phosphorescent EPDM extruded sheet was obtained in the same manner as in Example 1 except that the amount of phosphorescent agent added was increased to 15% by weight.
Example 4
A phosphorescent EPDM extruded sheet was obtained in the same manner as in Example 1 except that the amount of phosphorescent agent added was increased to 20% by weight.
(Example 5)
A phosphorescent EPDM extruded sheet was obtained in the same manner as in Example 1 except that the addition amount of the phosphorescent agent was increased to 25% by weight.

  The afterglow luminance test was performed by cutting the phosphorescent EPDM extruded sheets of Examples 1 to 5 into a size of 40 mm × 40 mm. The test pieces of Examples 1 to 5 were shielded from light for 48 hours, and then excited by irradiating with an illuminance of 200 lx for 20 minutes using a regular light source D65. The afterglow luminance of each sample after excitation was measured with a luminance meter until 60 minutes had elapsed.

  The afterglow brightness | luminance test result of Examples 1-5 is shown with a graph in FIG. 4 and FIG. When the addition amount of the luminous agent was less than 10% by weight, the luminance after 60 minutes was about 10 mcd and the visibility was poor. When the addition amount of the phosphorescent agent exceeded 20% by weight, the increase in the afterglow luminance with respect to the addition amount of the phosphorescent agent slowed down.

FIG. 6 is a graph showing the material cost ratio of the luminous EPDM composition used in Examples 1 to 5 compared with a general luminous silicone rubber composition. The phosphorescent EPDM composition has sufficient material cost advantage over the silicon rubber composition (as a guide, the material cost ratio is 0.8 times or less) when the amount of phosphorescent agent added is 20% by weight or less. It becomes.

From the results of Examples 1 to 5 described above, it is desirable that the phosphorescent EPDM composition in the present invention is blended so that the addition amount of the phosphorescent agent is 10 to 20% by weight.

  The phosphorescent EPDM extrudate of the present invention can be widely used as an indicator or sign for nighttime guidance and safety. Specifically, as a member of accessories such as armbands, footwear, safety vests, helmets, rubber bands for goggles, as well as housing items such as handrails, door knobs, stair mats, interior wall guards, switch plates, outlet covers, etc. Components, components of radiant heaters, hot air heaters, heating appliances such as electric kotatsu and electric blankets, components of electrical appliances such as lighting fixtures, refrigerators, washing machines, air conditioner indoor units, fire extinguishers, emergency carry-out bags, high It can be used as a member of emergency supplies such as emergency evacuation equipment, simple stretchers, tents, and sleeping bags.

DESCRIPTION OF SYMBOLS 1 Upper surface PTFE glass cloth 2 Lower surface PTFE glass cloth 3 Vulcanization dish 4 Luminescent EPDM extrusion molding sheet 5 End part sealing tape

Claims (4)

    Means for kneading phosphorescent EPDM composition containing organic peroxide, means for extruding the EPDM composition into a sheet, and sandwiching the extruded sheet with PTFE glass cloth, A method of vulcanizing a luminous EPDM extrudate comprising means for sealing an end of a glass cloth with a tape and vulcanizing with an autoclave.     2. The vulcanizing method for a luminous EPDM extrudate according to claim 1, wherein the content of the phosphorescent agent in the EPDM extrudate is 10 to 20% by weight.   2. The phosphorescent EPDM extrusion molding according to claim 1, wherein the vulcanization condition of the EPDM extrusion molding is vulcanization for 30 ± 10 minutes while keeping the vapor pressure inside the autoclave at 0.6 ± 0.2 megapascal. Vulcanization method. The vulcanization method for luminous EPDM extrudates according to claim 1, characterized in that the vulcanization conditions of the EPDM extrudates are vulcanized for 30 ± 10 minutes while maintaining the temperature inside the oven at 140 to 240 ° C.

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