JPH05320626A - Production of carrier for oily material - Google Patents

Abstract

PURPOSE:To obtain a carrier from which an oily material hardly ooze out by dispersing the oily material in a base material comprising an ethylene-alpha-olefin copolymer having a specified density and crosslinking the dispersion. CONSTITUTION:An oily material (e.g. a paraffin wax) is dispersed in a base material which comprises an ethylene-alpha-olefin copolymer (e.g. an ethylene- propylene copolymer) having a density of 0.88g/cm<3> or lower and, if necessary, contg. a polyolefin (e.g. a high-density polyethylene) for improving the strengths of the copolymer. The resulting dispersion is crosslinked (e.g. peroxide crosslinking) to give the objective carrier, which has a low tackiness and undergoes little shape change due to expansion and contraction caused by repeated heating and cooling. The strengths of the carrier can be increased by the addition of the polyolefin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an oily substance carrier. When the oily substance is a crystalline substance, the oily substance is useful as a heat storage body,
When the oily substance is liquid, the oily substance is useful as an elastic material used for a mat or the like.

[0002]

2. Description of the Related Art Various types of oily substance-supporting bodies have been proposed in which a liquid oily substance is supported on a substrate to form a solid state. Among them, an oily substance carrier in which an oily substance such as paraffin is supported on a resin is proposed as a heat storage medium in JP-A-59-170180 and JP-A-62-187782.

This heat storage material is a latent heat storage material that utilizes the latent heat required for the phase transition between the solid phase and the liquid phase of an oily substance. In the latent heat storage material utilizing such a solid-liquid phase transition, its handling becomes a problem. In other words, consideration must be given to preventing the liquid from flowing out when it becomes liquid due to the phase transition. Therefore, such a latent heat storage material must usually be stored in a container made of metal or resin. There wasn't. On the other hand, when paraffin is contained in the resin by mixing the resin and paraffin, which is a latent heat storage material, the paraffin can be handled as a solid without becoming liquid even when the paraffin is melted. JP-A-59-170180 proposes ultra-high molecular weight polyethylene as a resin, and JP-A-62-187782 proposes polyolefins such as polyethylene and polypropylene.

[0004]

However, the above-mentioned conventional oily substance-supporting body has a problem that the exudation of the oily substance is large. It is an object of the present invention to provide a method for producing an oily substance-supporting body in which the oily substance does not seep out.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an oily substance-supported material for carrying out a crosslinking treatment on a mixture of an ethylene-α-olefin copolymer having a density of 0.88 g / cm ³ or less and an oily substance. A method of manufacturing a body is provided. The oily substance-supporting body thus obtained has transparency, but the conventional oily substance-bearing body described above could not impart transparency.

In order to solve the above-mentioned problems, the present invention also provides an oily substance-supporting material which is crosslinked to a mixture of a polyolefin, an ethylene-α-olefin copolymer having a density of 0.88 g / cm ³ or less, and an oily substance. A manufacturing method is provided. The oily substance used in the present invention is preferably compatible with the ethylene-α-olefin copolymer, and specific examples thereof include hydrocarbons (paraffins and paraffin waxes), fatty acids and fatty acid esters (hereinafter, these two types are used. May be referred to as “fatty acids”).

Examples of the ethylene-α-olefin copolymer used in the present invention include those in which α-olefin is copolymerized with ethylene at a ratio of about 10 to 70 mol% so that the density is 0.88 g / cm ³ or less. Be done. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene and 1-octene, and at least one selected from these is used. Particularly preferred is propylene. Further, a third component such as a diene may be copolymerized with these copolymers.

In the present invention, in order to improve the strength of the oily substance-supporting material, the above copolymer and polyolefin can be used in combination as the resin. Polyethylene, for example, is used as the polyolefin. As polyethylene, for example, at least one selected from medium density polyethylene and high density polyethylene is used. The use ratio of the polyolefin may be set appropriately according to the strength of the oily substance-supporting body and is not particularly limited. As the amount of the oily substance used increases, it is more useful to use polyolefin as the resin in combination with the above copolymer to improve the strength of the oily substance carrier.

In the present invention, the mixing ratio of the resin and the oily substance is appropriately set according to the application of the oily substance carrier and is not particularly limited. For example, from the viewpoint of securing the ability to carry the oily substance, It is desirable that the resin content is 10 wt% or more. When the oily substance-supporting body is used as a heat storage body, the resin content is 10 to 70 wt% and the oily substance is 30 to 90 wt% in order to secure heat storage performance and support performance. If the ratio of the resin is less than the above range, the melt release amount (bleeding amount) may increase. If the resin ratio exceeds the above range, the heat storage amount may be too low.

The method of dispersing the oily substance in the resin is not particularly limited, but for example, a temperature above the melting point of the copolymer and the oily substance (when a polyolefin is used,
It is carried out by melt mixing such as kneading with a kneader or the like at a temperature higher than the melting points of the polyolefin, the copolymer and the oily substance). By doing so, a uniform mixture can be obtained. This mixture can be formed into a desired shape if necessary. Depending on the cross-linking method,
A peroxide or other crosslinking agent may be added to this mixture in advance.

A cross-linking treatment is applied to this mixture. Resin crosslinking methods include sulfur vulcanization, peroxide crosslinking, γ
Examples include radiation crosslinking with an electron beam or an electron beam, which are appropriately set depending on the type of resin, application, etc., and are not particularly limited. When using an ethylene-α olefin copolymer having almost no double bonds such as an ethylene-propylene copolymer, peroxide crosslinking or radiation crosslinking is preferable. When the oily substance carrier is used as a heat storage medium, it is preferable to crosslink only the surface to form the resin coating layer because the amount of latent heat decreases when the crosslinks penetrate to the inside. For this reason, the crosslinking method is not limited to the crosslinking method using an organic peroxide or γ-rays that crosslinks the inside of the heat storage body, but a crosslinking method using an electron beam having weak permeability, but is not limited thereto.

[0012]

In the present invention, the mixture obtained by dispersing the oily substance in the substrate composed of the ethylene-α olefin copolymer having a density of 0.88 g / cm ³ or less is subjected to the crosslinking treatment, so that when the oily substance is liquid, The amount of the oily substance oozing out is reduced, and an oily substance-supporting material having shape retention can be formed. This oily substance carrier has transparency.

Polyolefin and density 0.88 g / cm ³
By subjecting a mixture obtained by dispersing an oily substance to a substrate composed of the following ethylene-α-olefin copolymer to a crosslinking treatment, an oily substance-supporting material in which the amount of the oily substance melted out is very small when the oily substance is in a liquid state Can be formed. The use of polyolefin in this oily substance-supported material can improve the strength. Further, it is possible to form an oily substance-supporting body that is less likely to change in shape due to expansion and contraction due to repeated cold heat.

[0014]

EXAMPLES Specific examples and comparative examples of the present invention will be shown below, but the present invention is not limited to the following examples.
In the following, "part" means "part by weight". The resins used in the following Examples and Comparative Examples are shown in Table 1, and the oily substances are shown in Table 2. Table 1 shows the product number, type, and density (test method JIS-K67
60). Table 2 shows the product number, type, chemical structure, melting point and latent heat amount.

[0015]

[Table 1]

[0016]

[Table 2]

Paraffin 125 product is a hydrocarbon manufactured by Nippon Seiro Co., Ltd. Tufmer P0680 is an ethylene-α olefin copolymer (α olefin is propylene) manufactured by Mitsui Petrochemical Co., Ltd., Tuffmer A408.
5 is an ethylene-α-olefin copolymer (α-olefin is 1-butene) manufactured by Mitsui Petrochemical Co., Ltd., EUL1
30 and VL100 are ethylene-α-olefin copolymers manufactured by Sumitomo Chemical Co., Ltd. (α-olefin is 1-butene), S6006M is high-density polyethylene manufactured by Showa Denko KK, 240M is ultra-made by Mitsui Petrochemical Co., Ltd. High molecular weight polyethylene.

(Examples 1 to 6) The resin to be added and the oily substance were kneaded at a predetermined ratio while heating at 140 ° C. to prepare a uniform mixture having a predetermined mixing ratio. This mixture is a non-crosslinked oily substance carrier and also a heat storage medium. The mixture obtained by kneading has a plate shape (50 mm x 50 mm x
5 mm). An accelerating voltage of 1.5 was applied to each formed body.
Electron beams were irradiated at MV and a current of 50 μA for crosslinking to obtain the oily substance-supported material of the present invention. Table 3 shows the types and blending amounts of the resin and the oily substance, and the irradiation dose.

[0019]

[Table 3]

(Example 7) Paraffin 1 as an oily substance
25 products (manufactured by Nippon Seiro Co., Ltd., melting point 52 ° C.), density 0.
Tufmer P0680 (manufactured by Mitsui Petrochemical Co., Ltd.) as an ethylene-α olefin copolymer of 88 g / cm ³ or less, and 1,3-bis (t-butylperoxy-isopropyl) benzene as a peroxide crosslinking agent After kneading at a predetermined ratio with heating to 100 ° C, crosslinking is performed in a nitrogen atmosphere at 160 ° C for 10 minutes to form a plate (50 mm × 5
An oil-based material carrier having a size of 0 mm × 5 mm was prepared.

[0021]

[Table 4]

(Comparative Examples 1 to 8) Density 0.88 shown in Table 5
An ethylene / α-olefin copolymer or polyolefin of g / cm ³ or less and a crystalline organic compound (oil substance) were mixed by the same method as in the example to prepare an oil substance carrier (heat storage body). No crosslinking treatment was performed.

[0023]

[Table 5]

(Experiment 1) With respect to the oily substance-supporting bodies produced in the above Examples and Comparative Examples, the oily substance was paraffin 1
In the case of 25 products, a 200-cycle cold test was conducted in an atmosphere of temperature conditions shown in FIG. 1 and in the case of an oily substance of butyl stearate or capric acid, in an atmosphere of temperature conditions shown in FIG. After the test, the oily substance-supported body was taken out and the temperature (80 ° C) above the melting point of the crystalline organic compound (oily substance)
The oily substance exuded around the oily substance carrier was wiped off with, and the exudation rate was measured from the reduced weight. The exudation rate here was determined by a relational expression of (weight reduction amount of oily substance carrier / initial oily substance content) × 100 [%]. The shape stability and transparency of the oily substance-supporting material were also investigated.

The shape stability was evaluated according to the following criteria by visually observing the shape after the above test. ◯: The shape before the test was retained. Δ: Partially deformed. X: Fluidized. The transparency was evaluated according to the following criteria.

◯: Transparent (characters are clearly visible through the oily substance carrier) Δ: Translucent (characters are blurred through the oily substance carrier) X: Opaque (characters are not visible through the oily substance carrier) 6 shows.

[0027]

[Table 6]

As is clear from the results in Table 6, the non-crosslinked ethylene-α-olefin copolymers having a density of 0.88 g / cm ³ or less and the oily substances (Comparative Examples 1 to 4) were deformed during the test. In the case of a mixed product of ethylene-α olefin copolymer having a density higher than 0.88 g / cm ³ and an oily substance (Comparative Examples 5 and 6) or a mixed product of polyethylene and an oily substance (Comparative Examples 7 and 8). In the case of No. 3, the deformation was small, but the amount of exudation was large, and the oily substance did not have transparency even at a liquid temperature. As can be seen from the results of Examples 1 to 7, the oil substance carrier according to the present invention has a stable shape and transparency. Comparing Examples 1 to 5 with Example 6, it can be seen that it is particularly effective to impart transparency by using an ethylene-propylene copolymer as a substrate.

Next, examples and comparative examples in the case of using a substrate composed of a polyolefin and an ethylene-α-olefin copolymer will be shown. The polyolefin, ethylene-α-olefin copolymer and oily substance used in the following examples and comparative examples are as follows. SHOLEX6006 (manufactured by Showa Denko KK), which is a high-density polyethylene as a polyolefin, Toughmer P0880 (manufactured by Mitsui Petrochemical Co., Ltd., α-olefin is propylene, density 0.87 g / cm ³ ), an ethylene-α-olefin copolymer, and oily Paraffin 135, which is a hydrocarbon
Products (manufactured by Nippon Seiro Co., Ltd., melting point 58 ° C., heat of fusion 47.
5 cal / g) was used.

(Examples 8 to 10) 1 part of the above polyethylene was used.
0 parts, 20 parts of ethylene-propylene copolymer and 70 parts of paraffin are kneaded while heating to 140 ° C.,
A uniform mixture having a predetermined mixing ratio was prepared. This mixture is a non-crosslinked oily substance carrier and also a heat storage medium. The mixture obtained by kneading is disc-shaped (diameter 50
mm, thickness 15 mm), and cooled at a cooling rate of 1 ° C./min. Each of the formed compacts was irradiated with an electron beam on both sides of the disk at an accelerating voltage of 1.5 MV and a current of 50 μA, and crosslinking was performed to obtain an oily substance-supporting body of the present invention. The electron beam irradiation dose is set to 3 types of 5, 10 and 30 Mrads on one side, and 3
A sample was prepared.

Comparative Example 9 30 parts of the above polyethylene and 70 parts of paraffin were used, and no copolymer was used.
An oily substance-supporting body (heat storage body) was produced by mixing and molding in the same manner as in 10. No crosslinking treatment was performed. (Comparative Example 10) An oily substance-supporting body (heat storage body) was produced in the same manner as in Examples 8 to 10 except that the crosslinking treatment was not performed in Examples 8 to 10.

(Experiment 2) With respect to the oily substance-supporting bodies prepared in Examples 8 to 10 and Comparative Examples 9 and 10, a 200-cycle cold heat test was conducted in an atmosphere of temperature conditions shown in FIG. After the test, the oily substance-supporting body was taken out, the oily substance that had permeated around the oily substance-supporting body was wiped off at a temperature (80 ° C.) higher than the melting point of the oily substance, and the melt release rate was measured from the reduced weight. The melt release rate here was determined by a relational expression of (weight reduction amount of oily substance carrier / initial oily substance content) × 100 [%]. Moreover, the diameter change rate of the oily substance-supporting body before and after the cold heat test was measured. Table 7 shows the average value of 3 samples
Shown in. Table 7 also shows the presence or absence of tackiness of the oily substance-supporting body.

[0033]

[Table 7]

As shown in Table 7, as compared with Comparative Example 9 consisting of two components of polyethylene and paraffin, the melt-separation rate of Comparative Example 10 of three components in which the ethylene-α-propylene copolymer was also added was very small and was 1/20. It became the following. In comparison with Comparative Example 10 which is non-crosslinked with such three components, the melt release rate of the oil substance carrier (Example 9) irradiated with electron beam as described above at 10 Mrads is 1/2 or less, and the diameter change rate is 1
/ 10 or less. The surface of the oily substance-supported bodies (Examples 8 to 10) crosslinked with the three components was more dry than the non-crosslinked ones, and no tackiness was felt. The oily substance carrier according to the present invention has a stable shape and has low adhesiveness.

[0035]

According to the present invention, an oily substance and a density of 0.
By subjecting the mixture of the ethylene-α-olefin copolymer of 88 g / cm ³ or less to the crosslinking treatment, the exudation of the oily substance is reduced, and the oily substance-supporting body whose shape is not deformed can be produced. Also, when polyolefin is not used,
An oily substance carrier having transparency when the oily substance is in a liquid state can be produced.

According to the present invention, an oily substance is obtained by subjecting a mixture obtained by dispersing an oily substance to a substrate composed of a polyolefin and an ethylene-α-olefin copolymer having a density of 0.88 g / cm ³ or less to a cross-linking treatment. The amount of bleeding from is greatly reduced. According to the present invention, it is possible to produce an oily substance-supporting material having reduced adhesiveness and less change in shape due to expansion and contraction due to repeated cold heat. By using polyolefin, it is possible to improve the strength of the oily substance-supporting body.

[Brief description of drawings]

FIG. 1 is an explanatory view of cold heat test conditions.

FIG. 2 is an explanatory diagram of cold test conditions.

[Explanation of symbols]

 None

Front Page Continuation (72) Inventor Kiyozo Yoshio 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Inventor, Tai Maeda 1048, Kadoma, Kadoma City, Osaka Matsushita Electric Works, Ltd. (72) Invention Mitsuhiro Tsurugi, 1048, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (4)

[Claims] 1. A method for producing an oily substance-supported body, wherein a mixture comprising an oily substance dispersed in a substrate made of an ethylene-α-olefin copolymer having a density of 0.88 g / cm ³ or less is crosslinked. .. 2. The density of polyolefin is 0.88 g / cm.
^A method for producing an oily substance-supporting body, which comprises subjecting a mixture comprising an oily substance dispersed in a substrate comprising an ethylene-α-olefin copolymer of ³ or less to a crosslinking treatment. 3. The method according to claim 1, wherein the oily substance is at least one selected from hydrocarbons, fatty acids and fatty acid esters. 4. The method according to claim 3, wherein the oily substance is a crystalline substance having a heat of fusion of 20 cal / g or more.