JP2017114539A - Thermoplastic resin container and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin container capable of obtaining a container which can sufficiently suppress gas permeability and is inexpensive by adding mica to a thermoplastic resin and mold the thermoplastic resin, and to provide a method for producing the same.SOLUTION: There is provided a thermoplastic resin container in which a sealed space is formed by a container wall, where a composition is prepared which contains a modified olefin resin, a rubber component and 20-50% of mica having an aspect ratio of 10-100 and a particle size of 1-300 μm is added to a polyolefin-based resin and the composition is heated and molded to form a container wall. The mica is a resin pellet obtained by subjecting gold mica or white mica to surface treatment, subjecting the mica to extrusion work, and cooling and cutting the mica.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a container such as a fuel tank formed using a thermoplastic resin as a base material, and more particularly to a thermoplastic resin container capable of suppressing gas permeability in the container to the outside and a method for manufacturing the same.

  In general, the thermoplastic resin does not have a gas barrier function except for a part of nylon or the like, and therefore, selection of the material of the thermoplastic resin for various containers is limited to a part. Conventionally, as a method of molding a container such as a fuel tank, for example, a multilayer blow molding method, an injection molding method, or the like is used. Among these, in multilayer blow molding, gas permeability is suppressed by using a gas barrier material for the inner layer, and in the injection molding method, gas permeability is suppressed by using nylon resin. . For example, Patent Document 1 discloses a publication relating to a container such as a fuel tank.

JP 2006-160094 A

  However, in such a thermoplastic resin container, when it is molded by the multilayer blow molding method, an extruder for multilayer blow is required as equipment, and a continuous extrusion method of raw materials for stabilizing the barrier layer and It is a mass production method, and it is easy to be disadvantageous in terms of costs, such as initial investment and maintenance of equipment, and is not suitable for small lot production. In addition, when molded by the injection molding method, the nylon resin becomes more expensive than a resin such as polyethylene, and a welding process for forming a container is required. Handling is also burdensome due to possession.

  The present invention has been made in view of such circumstances, and an object of the present invention is to add a mica to a thermoplastic resin and mold it so that gas permeability can be sufficiently suppressed and an inexpensive container can be obtained. It is in providing a plastic resin container and its manufacturing method.

  In order to achieve this object, the thermoplastic resin container according to the first aspect of the present invention is a thermoplastic resin container having a space sealed inside by a container wall, and the container wall is a polyolefin-based container. It is formed by curing a composition obtained by adding 20 to 50% of mica having a modified olefin resin, a rubber component, and an aspect ratio of 10 to 100 and a particle size of 1 to 300 μm to the resin.

  The method for producing a thermoplastic resin container of the invention according to claim 2 is a method for producing a thermoplastic resin container in which a space sealed inside is formed by a container wall, wherein a modified olefin resin is added to the polyolefin resin. And a rubber component and an aspect ratio of 10 to 100 and a particle size of 1 to 300 μm mica is added to prepare a composition, and the composition is thermoformed to form the container wall. To do. The invention according to claim 3 is characterized in that the mica is a resin pellet obtained by subjecting gold mica or white mica to a surface treatment, extruding, cooling and cutting.

  According to the thermoplastic resin container of the first aspect of the present invention, it is formed by curing a composition in which mica having an aspect ratio of 10 to 100 and a particle size of 1 to 300 μm is added to an inexpensive polyolefin resin. Therefore, it is possible to suppress the gas permeability inside the container with mica uniformly arranged in a planar shape, and to suppress deterioration of the properties of the polyolefin-based resin due to the addition of mica by adding a modified olefin resin and a rubber component, etc. It is possible to obtain an inexpensive container that can sufficiently suppress gas permeability without impairing basic physical properties.

  According to the method for producing a thermoplastic resin container according to claim 2, a composition obtained by adding mica having an aspect ratio of 10 to 100 and a particle size of 1 to 300 μm to an inexpensive polyolefin resin is heat-cured. Therefore, it is possible to suppress the gas permeability inside the container with mica arranged evenly in a plane, and by adding the modified olefin resin and rubber component, it is possible to suppress the deterioration of the physical properties of the polyolefin resin due to the addition of mica. An inexpensive container that can sufficiently suppress gas permeability without impairing physical properties can be easily produced.

  According to the invention of claim 3, in addition to the effect of the invention of claim 2, the mica is a resin pellet obtained by subjecting gold mica or white mica to surface treatment, extrusion, cooling and cutting. Moreover, mica having a predetermined particle diameter can be easily produced, and the arrangement thereof can be improved to further suppress the gas permeability.

Sectional drawing which shows one Embodiment of the thermoplastic resin container concerning this invention Schematic diagram enlarging part A of Fig. 1 Process drawing showing an example of the manufacturing method of the container Process diagram showing how to make the same mica mixed resin pellet The figure which shows the Example of the same invention Diagram showing the comparative example The figure which shows the characteristic value of the Example Illustration of gas permeability test method Illustration of ESCR test method

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a fuel tank used in a mowing machine or the like as a thermoplastic resin container according to the present invention. As shown in FIG. 1, a fuel tank (hereinafter referred to as a container 1) has container walls 1a to 1c that form a bottom surface, four side surfaces, and an upper surface, a space 2 is formed inside, and a container wall. A fuel supply port 3 is provided at an appropriate position 1c. The space 2 is hermetically sealed by tightly attaching a detachable cap 4 to the fuel supply port 3. An outlet 6 for taking out the fuel in the container 1 is provided at a predetermined position on the container walls 1a and 1b.

  And the said container walls 1a-1c are formed by blow-molding the resin kneaded material as a composition mentioned later, for example, as shown in the cross-sectional schematic diagram of FIG. 2 inside the container walls 1a-1c, The mica 5 is arranged in a substantially flat shape in the container walls 1a to 1c. The arrangement of the mica 5 suppresses the permeability of the container 1 to the outside through the container walls 1a to 1c, for example, gas vaporized from gasoline or the like housed in the space 2 of the container 1 as will be described later. Become.

  The container 1 is manufactured as shown in FIGS. That is, first, a mica mixed resin pellet is prepared (K01). As shown in FIG. 4, the mica mixed resin pellets are prepared by sieving and sieving (K011) mica raw ore such as gold mica and white mica, and pulverizing and classifying (K012). Then, the mica that has been crushed and classified is adjusted (K013) based on a required standard such as a particle size to create mica particles having a predetermined particle size (1 to 300 μm).

  Next, the thermoplastic polyolefin resin, the modified olefin resin, the rubber component, and the mica particles are kneaded (K014) and extruded (K015) with an extruder. The processed product continuously processed by the extruder is cooled by passing through a cooling tank filled with a coolant (K016), and the cooled processed product is cut into a predetermined dimension by a cutter (K017). To do. Thereby, a mica mixed resin pellet is produced. That is, mica grains are produced in steps K011 to K013 of FIG. 4, and mica mixed resin pellets are produced in steps K014 to K017.

  The mica mixed resin pellets thus produced are resin kneaded and heated (K02) as shown in FIG. And the parison which heated the kneaded material (composition of this invention) resin-kneaded with the extruder was extruded according to the metal mold | die size of a blow molding machine (K03), after that, it clamped (K04), Then, molding is performed for a predetermined time (K05) by supplying air or the like.

  When the parison is cured (solidified) by molding, the mold is opened (K06) and the cured product is taken out (K07) to obtain a blow molded product. A cap 4 separately molded at the fuel supply port 3 of this blow molded product is obtained. The container 1 is manufactured by mounting and processing the outlet 6 parts as necessary.

  In addition, when mica 5 added in a predetermined amount to the composition at the time of molding K05 in the container preparation process is dispersed in a non-uniform direction in the polyolefin resin at the composition stage, the polyolefin at the time of parison injection Since the orientation follows the flow of the system resin, the orientations are aligned, and inside the container walls 1a to 1c, as shown in FIG. By the mica 5 in this arrangement state, leakage of gas in the space 2 from the inside to the outside of the container walls 1a to 1c is suppressed, that is, gas permeability is suppressed. In addition, the molding of the container 1 is not limited to single-layer blow molding, and an injection molding machine or other molding machines can be used, and it goes without saying that the container 1 is appropriately changed according to the molding machine that uses the above steps.

  Next, an embodiment of the present invention will be described with reference to FIG. In Examples 1 to 8 of FIG. 5, as shown in the compounding material column, HDPE (high density polyethylene) as a polyolefin resin, MODICPE as a polyolefin adhesive resin (modified olefin), and kernel KS240T as a rubber component (metallocene plastomer) As mica, Repco Co., Ltd. gold mica W40H (with fatty acid treatment), gold mica S200HG (without fatty acid treatment), gold mica S400 (without fatty acid treatment), Repco Co., Ltd. white mica M200 (no fatty acid treatment), white mica M200W (with fatty acid treatment) and white mica M325 (without fatty acid treatment) were used. In addition, the numerical value shown in the compounding material column of FIG. 5 has shown the compounding ratio.

  And about each Example 1-8, the result as shown in the characteristic value column of FIG. 5 was obtained. In the measurement of gas permeability, as shown in the test method of FIG. 8, fuel 12 (CE10) is charged into the aluminum container 11 and sandwiched between the washer 13 and the O-ring 14 in the opening of the aluminum container 11. The sample piece S1 is arranged, and the brass lid 15 is screwed into the opening. And the change of the weight of the aluminum container 11 was measured, and gas permeability was calculated (HDPE simple substance was calculated as 100%). In addition, sample piece S1 cuts a part of container 1 formed by the shaping | molding method mentioned above in the predetermined shape.

  In addition, as shown in the test method of FIG. 9, the ESCR (stress crack resistance) measurement is performed using a pressing plate 16 and a jig case 18 of a test jig having a pressing plate 16, a pressing bolt 17, a jig case 18, and the like. A sample piece S <b> 2 is placed between them and is immersed in an aqueous solution 20 of a 10% surfactant in the test tank 19. Then, the pressing plate 16 was moved by a certain amount at a test temperature of 50 ° C., the sample piece S2 was compressed, and the time Hr until cracking occurred in the sample piece S2 was measured. As shown in FIG. 9B, the sample piece S2 is formed in a semicircular arc shape having a height of h and a width of w. In this test, the width w1 of the sample S2 is the predetermined amount, for example, 15 mm. It is determined that the width is w2 after being compressed.

  From the results (characteristic values) of the respective Examples 1 to 8, the polyolefin resin (HDPE), the modified olefin resin (polyolefin adhesive resin), the rubber component, and the mica 5 are shown in the ratios shown in the respective Examples 1 to 8. It became clear that the container 1 with a gas permeability of 20 to 35% with a target setting of less than 40% can be obtained by blending.

  FIG. 6 shows Comparative Examples 1-9. In these Comparative Examples 1 to 9, the blending ratio of HDPE is 58-100, which is larger than that of Examples 1-8, the blending ratio of the modified PE is 2 or less, and the blending ratio of the rubber component is 10 or less. I have to. As mica 5, 10-30% of gold mica W40H (with fatty acid treatment), gold mica SC30, white mica C20, and white mica C40 were mixed. In these Comparative Examples 1 to 9, the gas permeability was higher than the target setting (40% or more). From the characteristic values of Examples 1 to 8 and Comparative Examples 1 to 9, the application range of the container 1 of the present invention is preferably the value shown in the application range of FIG. 7, and the value shown in the optimum range is most preferable. .

  As described above, according to the container 1, since mica 5 having an aspect ratio of 10 to 100 and a particle size of 1 to 300 μm is added to an inexpensive polyolefin resin and cured, it is uniformly arranged in a planar shape. The mica 5 can suppress the gas permeability inside the container 1, and the addition of the modified olefin resin and the rubber component can suppress the deterioration of the physical properties of the polyolefin-based resin due to the addition of the mica 5, without impairing the basic physical properties. An inexpensive container 1 that can sufficiently suppress the permeability can be obtained.

  Moreover, since mica within the optimum range is used for extrusion and cutting after cooling, stable mica mixed resin pellets can be obtained. As a result, the arrangement of mica 5 during parison injection molding is improved. And the suppression of gas permeability of the container 1 can be further enhanced. In particular, by using the mica 5 that has been subjected to fatty acid treatment, the dispersibility of the mica 5 can be increased, and the suppression of gas permeability can be further increased.

  In addition, since the container 1 can be formed by single layer blow molding or the like, an existing general-purpose molding machine such as a blow molding machine or an extrusion molding machine can be used, and initial investment costs and equipment maintenance costs can be suppressed. The molding operation itself can be easily performed, and the manufacturing cost can be reduced. Further, since the container walls 1a to 1c of the container 1 are configured in a single layer structure, the structure is simplified and the weight can be reduced as compared with the multilayer structure. A simple container 1 can be obtained easily.

  In addition, in the said embodiment, although applied to container 1 itself, of course, it is also possible to utilize for the said cap 4 which block | closes the fuel supply port 3, for example, the shape of container 1 itself, the process drawing of its manufacturing method, etc. This is also an example, and an appropriate configuration can be adopted without departing from the gist of each invention according to the present invention.

  The present invention is not limited to fuel tanks such as gasoline, but can be used for all thermoplastic resin containers in which liquids that easily vaporize are contained, such as food containers and cosmetic containers.

DESCRIPTION OF SYMBOLS 1 ... Container 1a-1c ... Container wall 2 ... Space 3 ... Fuel supply port 4 ... ...... Cap 5 ... Mica 6 ... Outlet 11 ... Aluminum container 12 ... Fuel 13 ············································································································· 17 ... Pressing bolt 18 ... Jig case 19 ... Test tank 20 ... Aqueous solution S1, S2 ... Sample piece

Claims (3)

A thermoplastic resin container having a space sealed inside by a container wall,
The container wall is formed by curing a composition obtained by adding 20 to 50% of mica having a modified olefin resin, a rubber component, and an aspect ratio of 10 to 100 and a particle size of 1 to 300 μm to a polyolefin resin. A thermoplastic resin container characterized by A method for producing a thermoplastic resin container in which a sealed space is formed inside by a container wall,
A composition obtained by adding 20 to 50% of mica having a modified olefin resin, a rubber component, and an aspect ratio of 10 to 100 and a particle diameter of 1 to 300 μm to a polyolefin resin is prepared. A method for producing a thermoplastic resin container, comprising forming a wall.   The method for producing a thermoplastic resin container according to claim 2, wherein the mica is a resin pellet obtained by subjecting gold mica or white mica to a surface treatment, extruding, cooling, and cutting.

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