JP2500218B2 - Breathable foam pipe and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breathable foam pipe and a method for manufacturing the same.

[0002]

2. Description of the Related Art Recently, fish and shellfish resources have been decreasing year by year due to overfishing, marine pollution and the like.

On the other hand, there is a strong demand for high-grade fish and shellfish and live fish.

[0004] For this reason, the production and cultivation of fisheries such as cultivated fisheries and aquaculture have been developed, and the production of artificial seedlings for release or aquaculture tends to increase year by year.

Diseases caused by pathogenic organisms are the most troublesome problems in such artificial seedlings. For this reason, the ozone sterilization method is generally used in the cultivation fish and shellfish center.

The ozone sterilization method is a method for sterilizing microorganisms existing in water by blowing ozone generated by a silent discharge method or a solid polymer electrolyte membrane electrolysis method into a treatment pond through a pipe.

This ozone exerts not only the bactericidal action of microorganisms but also the action of increasing dissolved oxygen, and as a result, the growth of fish and shellfish can be accelerated by approximately 30%. There is an advantage that it can be tripled.

[0008] Conventionally, as prior art of this kind of ozone delivery pipe, Japanese Utility Model Publication No. 48-23874 and Japanese Utility Model Publication No. 56-5.
9855, Jitsuko Sho 61-33344 and the like are known.

No. 48-23874 and No. 56
No. 59859 discloses an ozone delivery pipe made by sintering resin powder.

Further, Japanese Utility Model Publication No. 61-33344 discloses an ozone delivery pipe formed by extruding a composition comprising regenerated rubber powder regenerated from an old tire, regenerated polypropylene and a chemical foaming agent such as azodicarboxylic acid amide into a pipe shape. It is disclosed.

[0011]

However, pipes made by sintering resin powder have weak mechanical strength, poor flexibility, and poor productivity because they are produced by a batch production method. .

On the other hand, the latter pipe produced from recycled rubber has a drawback that it is inferior in ozone resistance and weak in tensile strength and tear strength. For this reason, there is a drawback that ozone cracks are generated in a short period of time by supplying ozone and the service life is extremely short. In addition, since the tensile strength and tear strength are inherently weak, it is necessary to set the wall thickness of the pipe to be thick, resulting in deterioration of the bending characteristics and handling workability of the pipe, and in the hole of the pipe However, there is a problem that foreign matter such as, for example, may enter and cause clogging.

The present invention has been made in view of the above points, and its object is to solve the above-mentioned drawbacks of the prior art, and to provide excellent ozone resistance, mechanical properties, light weight and uniform An object of the present invention is to provide an air-permeable foam pipe having air permeability and a method for manufacturing the same.

[0014]

The gist of the present invention lies in the following two points.

A resin fine powder 10 having a small melt adhesion with the thermoplastic elastomer and a particle diameter of 10 to 100 μm with respect to 100 parts by weight of the thermoplastic elastomer.
A breathable foamed pipe, which is obtained by extruding a composition comprising -80 parts by weight and an appropriate amount of a chemical foaming agent into a pipe shape.

A resin fine powder 10 having a small melt adhesion with the thermoplastic elastomer and a particle diameter of 10 to 100 μm per 100 parts by weight of the thermoplastic elastomer.
A composition comprising -80 parts by weight and an appropriate amount of a chemical foaming agent is extruded into a pipe shape by an extruder, and a high temperature pipe immediately after extrusion is stretched in the length direction and then cooled. Method of manufacturing breathable foam pipe.

In the present invention, examples of the thermoplastic elastomer include a styrene-based thermoplastic elastomer, an olefin-based thermoplastic elastomer, a vinyl chloride resin-based thermoplastic elastomer, a urethane-based thermoplastic elastomer, an ester-based thermoplastic elastomer, and an amide-based thermoplastic elastomer. Can be used.

If necessary, these thermoplastic elastomers can also undergo a chemical crosslinking reaction such as silane water crosslinking.

In the present invention, the resin fine powder may be any one having a small melt adhesion with a thermoplastic elastomer and a high heat distortion temperature, such as polytetrafluoroethylene fine powder, polyvinylidene fluoride fine powder and high molecular weight polyethylene. Fine powder, high molecular weight polypropylene fine powder, cross-linked polyethylene fine powder and the like are used.

In the present invention, the heat distortion temperature of the resin fine powder is appropriately higher than the decomposition temperature of the chemical foaming agent to be blended.

In the present invention, the particle size of the resin fine powder is 10
The reason why the size is limited to -100 μm is that the dispersibility with the thermoplastic elastomer is improved when the particle size is 10 μm or less, but the dimensional accuracy of the foamed molded pipe obtained is poor, and when the particle size is 100 μm or more, the machine for the foamed molded pipe obtained is 100 μm or less. This is because the strength of the target suddenly deteriorates.

In the present invention, the amount of the resin fine powder to be blended is limited to 10 to 80 parts by weight because if the amount is 10 parts by weight or less, the foamed pipe obtained has poor air permeability and dimensional stability. This is because if the amount is 100 parts by weight or more, the appearance and mechanical strength of the foam-molded pipe obtained will deteriorate.

In the present invention, N, N is used as the chemical foaming agent.
-Dinitrosopentamethylenetetramine, azodicarbonamide, etc. can be used. Further, a composite foaming agent containing azodicarbonamide as a main component can also be used. Further, in order to change the decomposition temperature of the chemical foaming agent, a foaming auxiliary agent such as a urea compound, an organic acid compound, a metal chlorine compound, etc. can be appropriately used in combination.

Further, in the present invention, a filler, a pigment, a stabilizer and the like may be blended in appropriate amounts as needed.

In the present invention, it is appropriate that the extrusion temperature is not lower than the decomposition temperature of the compounded chemical foaming agent. That is,
With respect to 100 parts by weight of the thermoplastic elastomer, the melt adhesive strength with the thermoplastic elastomer is small and the particle size is 1
A composition comprising 10 to 80 parts by weight of a resin fine powder of 0 to 100 μm and an appropriate amount of a chemical foaming agent is put into an extruder, and these are melt-kneaded and the head temperature of the extruder is set to a temperature not lower than the decomposition temperature of the chemical foaming agent. After being decomposed by heating, it is extruded into a pipe shape, then stretched and further cooled.

[0026]

The breathable foam pipe and the method for producing the same of the present invention have the following actions and effects.

A resin fine powder 10 having a small melt adhesive strength with the thermoplastic elastomer and a particle diameter of 10 to 100 microns with respect to 100 parts by weight of the thermoplastic elastomer.
-80 parts by weight and a suitable amount of the chemical foaming agent are extruded into a pipe shape while rapidly decomposing and foaming with the chemical foaming agent, so that they have a small melt adhesive strength to each other at a high extrusion temperature, that is, they are mutually phase-bonded. It is possible to effectively phase-separate a poorly thermoplastic thermoplastic elastomer and a resin fine powder, and as a result, it is possible to obtain an permeable foamed pipe having effective open cells.

Since the breathable foamed pipe of the present invention is made of a novel thermoplastic elastomer, resin fine powder and chemical foaming agent, it exhibits excellent ozone resistance, mechanical strength and light weight, and has other useful life. Is long and has excellent workability.

A resin fine powder 1 having a small melt adhesion with the thermoplastic elastomer and a particle diameter of 10 to 100 μm per 100 parts by weight of the thermoplastic elastomer.
A composition comprising 0 to 80 parts by weight and an appropriate amount of a chemical foaming agent is extruded into a pipe shape by an extruder, and then a hot pipe immediately after extrusion is stretched in the longitudinal direction and then cooled, The inner diameter of the open cells formed on the wall surface of the pipe becomes large, and the cells are cooled and solidified in a state where the formation of bubbles in the skin layer between the inner surface and the outer surface is promoted, and as a result, excellent air permeability can be exhibited. A breathable foam pipe can be obtained.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the breathable foam pipe and the method for producing the same according to the present invention will be described with reference to the drawings.

FIG. 1 is a front explanatory view showing a method for manufacturing a breathable foamed pipe of the present invention.

In FIG. 1, 1 is an extruder, 2 is a head part,
3 is a melt drawing part, 4 is a cooling water tank, 5 is a take-up machine, 6 is a take-up machine, and 7 is a breathable foam pipe.

That is, in the method for producing an air-permeable foamed pipe of the present invention, the composition was uniformly dry blended with a Hensil mixer, and the obtained dry blend composition was charged into the extruder shown in FIG. The pipe is extruded while being uniformly melt-kneaded at 100 to 170 ° C. in the machine, and the high temperature pipe immediately after the extruding is stretched in the portion of the melt-stretching section 3 by the take-up machine 5 and the winding machine 6. Is pulled, then cooled in the cooling water tank 4, and finally wound by the winder 6 via the take-up machine 5.

Stretching varies depending on various conditions, but generally 0.5 to 30% is appropriate.

In FIG. 1, 7 is the obtained air-permeable foamed pipe having an inner diameter of 18 mm and an outer diameter of 26 mm.

FIG. 2 is a partial cross-sectional explanatory view of the obtained air-permeable foam pipe.

In FIG. 2, 8 is a foamed air-permeable portion, and 9 is a resin fine powder.

[Example 1] The olefin thermoplastic elastomer having a hard segment of polypropylene and the soft segment of ethylene propylene rubber and the olefin thermoplastic elastomer have a low melt adhesion and a high heat distortion temperature. Moreover, an ultrahigh molecular weight high density polyethylene (molecular weight of 2,000,000 or more) fine powder having an average particle diameter of 30 microns was used, azodicarbonamide was used as a chemical foaming agent, and a blue colorant was further added to prepare a composition. The composition of the composition is as follows.

Olefinic thermoplastic elastomer 100.0 parts by weight Ultra high molecular weight high-density polyethylene fine powder 10.0 parts by weight Azodicarbonamide 1.5 parts by weight Blue colorant 2.0 parts by weight Total 163.5 parts by weight The composition of Example 1 was uniformly dry blended with a Hensil mixer, and then the dry blend composition was charged into the extruder shown in FIG. The pipe is extruded while being uniformly melted and kneaded in an extruder at 160 to 170 ° C., and the high temperature pipe immediately after the extrusion is subjected to a stretching treatment in a portion of the melt stretching section 3, and then cooled in a cooling water tank 4, and finally, It was wound by the winder 6 via the take-up machine 5.

Example 2 The same as Example 1 except that the compounding amount of the ultrahigh molecular weight high-density polyethylene fine powder was 20.0 parts by weight with respect to 100.0 parts by weight of the olefinic thermoplastic elastomer. The air-permeable foam pipe of Example 2 was obtained.

Example 3 The same as Example 1 except that the compounding amount of the ultra high molecular weight high density polyethylene fine powder was 40.0 parts by weight with respect to 100.0 parts by weight of the olefinic thermoplastic elastomer. The air-permeable foam pipe of Example 3 was obtained.

[Example 3] The same as Example 1 except that the compounding amount of the ultra-high molecular weight high-density polyethylene fine powder was 60.0 parts by weight with respect to 100.0 parts by weight of the olefinic thermoplastic elastomer. The air-permeable foam pipe of Example 3 was obtained.

[Example 4] The same as Example 1 except that the compounding amount of the ultrahigh molecular weight high-density polyethylene fine powder was 80.0 parts by weight with respect to 100.0 parts by weight of the olefinic thermoplastic elastomer. The air-permeable foam pipe of Example 4 was obtained.

[Example 5] Example 3 except that the ultrahigh molecular weight high-density polyethylene fine powder to be blended was 10 microns.
A breathable pipe of Example 5 was obtained in the same manner as in.

[Example 6] Example 3 except that the ultra high molecular weight high density polyethylene fine powder to be blended was 50 microns
A breathable foam pipe of Example 6 was obtained in the same manner as in.

[Example 7] An air-permeable foam pipe of Example 7 was obtained in the same manner as in Example 3 except that the ultra-high molecular weight high-density polyethylene fine powder to be blended was 100 microns.

Example 8 EP-51 manufactured by Japan Synthetic Rubber Co., Ltd. as a crystalline ethylene propylene elastomer
An ultra high molecular weight high density polyethylene fine powder having an average particle diameter of 30 microns, a chemical foaming agent azodicarbonamide, a blue colorant, and a reactive monomer vinylsilane,
A composition was prepared consisting of the peroxide, dicumyl peroxide, the foam decomposition promoter, dibutyltin dilaurate, and the stabilizer, 4,4-thiobis (6t-butyl-m-cresol).

The composition of the composition is as follows.

Amorphous ethylene propylene elastomer 100.0 parts by weight Ultra high molecular weight high density polyethylene fine powder 50.0 parts by weight Azodicarbonamide 2.0 parts by weight Blue colorant 2.0 parts by weight Vinylsilane 2.5 parts by weight Di Cumiyl peroxide 0.2 parts by weight Dibutyltin dilaurate 0.1 parts by weight 4,4-thiobis (6t-butyl-m-cresol) 0.3 parts by weight 157.1 parts by weight The above composition was mixed with a Hensyl mixer. After uniformly dry blending, the dry blend composition was loaded into the extruder shown in FIG. The pipe is extruded while being uniformly melt-kneaded at 100 to 120 ° C. in an extruder, and the high temperature pipe immediately after the extrusion is stretched in the melt stretching section 3 and then passed through a cooling water tank at 60 to 80 ° C. It was crosslinked with silane water, and was wound by the winder 6 via the take-up machine 5.

[Comparative Example 1] A breathable foamed pipe having an inner diameter of 18 mm and an outer diameter of 26 mm was prepared by sintering resin powder as in the conventional case.

[Comparative Example 2] A breathable foamed pipe having an inner diameter of 18 mm and an outer diameter of 26 mm produced from regenerated rubber as in the past was prepared.

[Comparative Example 3] A comparative example was carried out in the same manner as in Example 1 except that the compounding amount of the ultra high molecular weight high density polyethylene fine powder was 5 parts by weight with respect to 100.0 parts by weight of the olefinic thermoplastic elastomer. A breathable foamed pipe of No. 1 was obtained.

[Comparative Example 4] A comparative example was carried out in the same manner as in Example 1 except that the compounding amount of the ultra high molecular weight high density polyethylene fine powder was 100 parts by weight with respect to 100.0 parts by weight of the olefinic thermoplastic elastomer. A breathable foam pipe of 2 was obtained.

[Comparative Example 5] A breathable foamed pipe of Comparative Example 3 was obtained in the same manner as in Example 3 except that the ultra high molecular weight high density polyethylene fine powder to be blended was 5 microns.

[Comparative Example 6] An air-permeable pipe of Comparative Example 4 was obtained in the same manner as in Example 3 except that the ultrahigh molecular weight high-density polyethylene fine powder to be blended was 110 microns.

[Characteristic Test Results] Next, the long breathable foamed pipes of Examples 1 to 8 and Comparative Examples 1 to 4 thus obtained were cut into a length of 5 m, and various tests were conducted.

Appearance The smoothness was visually observed, and the smooth ones were indicated by ⊚ and the others were indicated by x.

Mechanical Properties A breathable foamed pipe having a length of 0.5 m was taken, and the tensile strength in the longitudinal direction was measured.

Lightness: A breathable foamed pipe having a length of 0.5 m was taken, and the weight thereof was measured by an analytical balance. When Comparative Example 1 was set to 100, those smaller than 80 were marked with ⊚, and other specimens were marked with x. It was

Handling workability A breathable foamed pipe having a length of 5 m and easily bent by hand is shown as ⊚, and other items are shown as x.

Dimensional accuracy A breathable foamed pipe having a length of 5 m was taken, and the variation of the outer diameter in the longitudinal direction was measured.

Air Permeability of Pipe A gas permeable foamed pipe having a length of 5 m was taken, one end of the pipe was heat-sealed and sealed, and a vinyl pipe for ozone supply was connected to the other end.

Next, the air-permeable foam pipe connected to this ozone-sending vinyl pipe was fixed at a depth of 1 m in the ozone treatment pond, and then ozone-mixed air having an ozone concentration of 0.1 ppm was blown at a pressure of 0.3 kg /. It was sent out in cm ² , and the quality of air permeability was evaluated.

As a result, the ozone-mixed air is uniformly and in large numbers blown out along the length of the air-permeable foam pipe, and the diffused amount is 0.15 m ³ / m or more. Indicated by.

Ozone Resistance Test An ozone test was conducted on the cut short breathable foamed pipe. In the ozone test, the sampled short breathable pipe was wound into a coil shape having eight times the outer diameter, set in an ozone tester, and then ozone-mixed air having an ozone concentration of 1 ppm was passed for 60 days. The results are shown by ⊚ when cracks did not occur and by x when cracks occurred.

[0066]

[Table 1]

As can be seen from Table 1, the conventional air-permeable foam pipes of Comparative Examples 1 and 2 have problems in all characteristic items. Comparative Example 3 in which the composition is out of the scope of the present invention
Breathable pipes of ~ 6 have some drawbacks.

On the other hand, the breathable foamed pipes of Examples 1 to 8 showed excellent test results in all items.

[0069]

According to the breathable foam pipe and the method for producing the same of the present invention, the appearance, the mechanical characteristics, the lightness, the handling workability,
It is possible to obtain a breathable foamed pipe having excellent dimensional accuracy, breathability, and ozone resistance, and is industrially useful.

[Brief description of drawings]

FIG. 1 is a front explanatory view showing a method for producing a breathable foamed pipe of the present invention.

FIG. 2 is a partial cross-sectional explanatory view of a breathable foam pipe of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder 2 Head part 3 Melt drawing part 4 Cooling water tank 5 Drawer 6 Winder 7 Breathable pipe 8 Foaming breathable part 9 Resin fine powder

Claims (2)

(57) [Claims] 1. 10 to 80 parts by weight of a resin fine powder having a small melt adhesion with the thermoplastic elastomer and a particle diameter of 10 to 100 μm, and a chemical foaming agent, relative to 100 parts by weight of the thermoplastic elastomer. A breathable foamed pipe, characterized in that the composition is extruded into a pipe shape in an appropriate amount. 2. 10 to 80 parts by weight of a resin powder having a small melt adhesion with the thermoplastic elastomer and a particle diameter of 10 to 100 μm, and a chemical foaming agent are suitable for 100 parts by weight of the thermoplastic elastomer. A method for producing an air-permeable foamed pipe, comprising: extruding a composition comprising a quantity of the composition into a pipe shape by an extruder, and then subjecting the hot pipe immediately after the extrusion to a lengthwise stretching treatment and then cooling.