JP2007289881A - Instantaneously developing desiccant containing resin molded object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an instantaneously developing desiccant containing resin molded object having highly instantaneous developing capacity of a water absorbing capacity, not causing the elution of a component eluted to a surface and having sanitary properties and the lasting properties of a water absorbing capacity. <P>SOLUTION: A polymer water absorbing body (13) with a water content of 0.5-7 wt.%, which is expanded upon the absorption of water to develop fine cracks in a synthetic resin molded object (11) formed by injection or extrusion molding to form a water-containing jelly like route, and calcium oxide (12) with a mixing ratio of 30-65 wt.% exapanded upon the absorption of water to develop fine cracks in the synthetic resin molded object, are mixed with and dispersed in the synthetic resin molded object (11) as the desiccant. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an instantaneous desiccant-containing resin molded article having an instantaneous property and durability that is used as a desiccant in a container that stores contents that require a high dry environment or used as a member. Is.

  Conventionally, in a container for storing contents that require a high dry environment with a humidity of 10% RH or less, such as a sensor chip for blood sugar level, test paper for detecting urine protein, health food, electronic parts, pharmaceutical tablets, etc. Used a desiccant-containing resin molded article injection-molded with a molding material in which a desiccant was mixed and dispersed in a synthetic resin for drying in the container. For example, a polyolefin resin is used as a synthetic resin, and a molecular sieve and glycol as main components are mixed and dispersed in the polyolefin, and a crack is generated around the molecular sieve due to water absorption of the glycol, thereby providing an instantaneous property. The desiccant-containing resin molded body of the container of this type has been known.

  However, the above-mentioned desiccant-containing resin molded article uses glycol, and when the moisture absorption rate increases, the glycol is eluted on the surface, and a glycol film is formed on the surface. There was a risk of adversely affecting the contents stored in the. For example, it is not suitable for food applications. In addition, when the glycol film started to appear, the water absorption rapidly decreased, and the total amount of water absorption also decreased. In addition, a glycol film may adhere to the contents or fingers.

  The present invention solves the problems of the above-mentioned conventional desiccant-containing resin molding, has a high water absorption capability, is hygienic without any elution on the surface, and has a sustained water absorption capability. A flashing desiccant-containing resin molding is provided.

  That is, according to the first aspect of the present invention, the synthetic resin molded body that has been injection-molded or extruded is water-absorbed and expanded as a desiccant to develop fine cracks in the synthetic resin molded body, thereby forming a water-containing jelly-like route. An instantaneous desiccant-containing resin molded article characterized by mixing and dispersing a polymer water-absorbing body to be formed and calcium oxide which absorbs water and expands to develop fine cracks in the synthetic resin molded article.

  According to a second aspect of the present invention, the mixing ratio of the polymer water-absorbing body is 0.5 to 7% by weight, and the mixing ratio of the calcium oxide is 30 to 65% by weight. It is a flashing desiccant-containing resin molded article described in the invention.

As shown in FIG. 1, the instantaneous desiccant-containing resin molded body (10) of the present invention comprises calcium oxide (12) and polymer water absorbent (13) mixed and dispersed in a synthetic resin molded body (11). is doing. When this desiccant-containing resin molded product is present in the container, water absorption starts under a high humidity environment in the container. First, as shown in FIG. 2 (a), the surface is close to the surface. The polymer water-absorbing body starts to absorb water (reference numeral 13w in the figure indicates the water-absorbing polymer water-absorbing body). The water-absorbing polymer water-absorbing body expands to generate fine cracks (11c) in the surrounding synthetic resin molded body (11) to form a water-containing jelly-like path. This water-containing jelly-like route reaches the calcium oxide (12) and the polymer water-absorbing body (13) near the inside. Next, as a second stage, as shown in FIG. 2 (b), the calcium oxide (12w) and the polymer water-absorbing body (13w) absorbed by the water-containing jelly-like route expand and the surrounding synthetic resin molded bodies ( 11) A fine crack (11c) is generated, and this crack reaches the adjacent inner calcium oxide (12) or polymer water absorbent (13), and passes through a jelly-like path containing water in the crack. Adjacent inner calcium oxide and polymer water absorber absorb water. Furthermore, as shown in FIG. 2 (c), as the third stage, the water-absorbed calcium oxide (12w) and the polymer water-absorbing body (13w) expand, and fine cracks are formed in the surrounding synthetic resin molded body (11). (11c) is generated, and the adjacent calcium oxide (12) and the polymer water-absorbing body (13) absorb water further through the jelly-like route containing the water in the crack. By proceeding with such a water absorption mechanism, the inner calcium oxide and the polymer water absorber sequentially absorb water. The polymer water-absorbing body quickly absorbs moisture in the air when the humidity is high. In addition, since the network structure of the water absorption mechanism is sequentially formed from the surface to the inside of the synthetic resin molded body, it becomes possible to constantly develop new drying ability. Due to the characteristics of the polymer water-absorbing body and the water-absorbing mechanism described above, the desiccant-containing resin molded body of the present invention exhibits instantaneousness and sustainability.

  In addition, the desiccant-containing resin molded product having flashiness and durability of the present invention does not use a glycol-based component as a desiccant, unlike the conventional desiccant-containing resin molded product, so that it elutes on the surface. There are no hygiene issues in food applications. In addition, the contents and fingers in the container are not contaminated with the eluate.

  Next, one embodiment of the instantaneous desiccant-containing resin molded body of the present invention will be described in detail with reference to the drawings and tables.

As shown in FIG. 1, the instantaneous desiccant-containing resin molded body (10) of the present embodiment includes a polymer water absorbent (13) as a desiccant in an injection molded or extruded synthetic resin molded body (11). ) And calcium oxide (12) are mixed and dispersed. The polymer water-absorbing body to be used is acrylic acid and has a particle size of 10 to 150 μm. The acrylic acid-based polymer water-absorbing body absorbs water up to 400 times its weight. The mixing ratio is 0.5 to 7% by weight. When the mixing ratio of the polymer water absorbent is less than 0.5% by weight, cracks do not occur in the synthetic resin molded article even when the water absorbs and expands. The film is coated with the water-absorbing polymer water-absorbing body, and the water-absorbing path due to cracks on the surface and the water-absorbing mechanism from the surface do not function. Further, calcium oxide having a particle size of 5 to 150 μm is used. Calcium oxide absorbs water up to 30% by weight. The mixing ratio is 30 to 65% by weight. When the mixing ratio of calcium oxide is less than 30% by weight, cracks in the synthetic resin molded body due to the water absorption expansion of calcium oxide do not occur, making it difficult to form a network due to cracks. Extrusion becomes difficult.
<Production of various blending containers>
In a synthetic resin in which low density polyethylene and linear low density polyethylene are mixed at a ratio of 1: 1, calcium oxide and acrylic polymer water absorbent (ST500MPA) are mixed and dispersed. Molding materials of various types of composition were prepared, and an inner container made of three types of desiccant-containing resins was prepared by injection molding using each molding material. Separately, an outer container was produced by injection molding using polypropylene. And the water absorption amount of the various inner containers which hold | maintain the humidity in a container which hold | maintains the humidity in a container in which the humidity in a container which inserted various inner containers to 10% RH or less, and 10% RH or less was evaluated.

なお、インナー容器（２００）は、図４（ａ）に示すように、周壁（２０１）と底板（２０４）とからなるカップ状容器であり、周壁（２０１）には、図４（ａ）及び図５に示すように、上面（２０２）から外周面下端に連続させて、周方向へ等間隔に断面Ｖ字状通
気溝（２０３）を複数個設け、底壁（２０４）には、図４（ａ）及び（ｂ）に示すように、多数の通気孔（２０５）を設けるものである。インナー容器は、上端外径寸法がφ２６．８ｍｍで、高さ寸法が４２．８５ｍｍである。周壁の外周に設けられた断面Ｖ字状通気溝と、底壁を貫通する通気孔とにより、容器内の内容器による吸水が良好となり、また、内容器を外容器本体内にセットするときのセット性が良好となる。

In addition, as shown to Fig.4 (a), an inner container (200) is a cup-shaped container which consists of a surrounding wall (201) and a baseplate (204), and a surrounding wall (201) has shown Fig.4 (a) and FIG. As shown in FIG. 5, a plurality of V-shaped ventilation grooves (203) are provided at equal intervals in the circumferential direction from the upper surface (202) to the lower end of the outer peripheral surface, and the bottom wall (204) is provided with FIG. As shown to (a) and (b), many ventilation holes (205) are provided. The inner container has an upper end outer diameter of 26.8 mm and a height of 42.85 mm. The V-shaped cross-sectional ventilation groove provided on the outer periphery of the peripheral wall and the vent hole penetrating the bottom wall improve water absorption by the inner container in the container, and when the inner container is set in the outer container body Good setability.

Further, as shown in FIG. 3, the outer container (100) has an outer cylindrical shape in which the lid (120) is connected to the upper end opening of the container main body (110) so as to be opened and closed via the rear hinge (101). The container body includes a peripheral wall (111) and a bottom plate (115), an occlusal ring (112) with a lid is provided on the outer peripheral surface of the upper end of the peripheral wall, and a lid receiving ring (113) is provided on the upper outer peripheral surface. A plurality of lateral locking ridges (114) for locking the inner container (200) in the circumferential direction on the upper inner peripheral surface, and the lid (120) includes a top plate (121) and a peripheral wall ( 123), and an inner ring (122) for sealing the container main body (the outer peripheral surface is in close contact with the inner peripheral surface of the upper end of the peripheral wall of the container main body) is suspended from the top plate lower surface, and an opening / closing knob is provided at the front lower end of the peripheral wall (125) is projected, and the occlusal ring (1 4) is intended to provide a top end outside diameter of the container body in .phi.30 mm, height of the container body is 47 mm.
(Evaluation of the time when the humidity inside the container with various inner containers is 10% RH or less)
After storing each of the three types of inner containers (a, b, c) having different blending compositions described above into the outer container, each container is stored in an open state at 30 ° C. and 80% RH for 1 minute. After the lid was closed, the humidity in the container over time was measured, and the time when it became 10% RH or less was examined. The results are shown in Table 2.

表２に示すように、容器内湿度が１０％ＲＨ以下になる時間は、配合ｃのインナー容器を挿着した容器が４時間で、配合ｂのインナー容器を挿着した容器が５時間で、配合ａのインナー容器を挿着した容器が７時間以上であった。つまり、配合ｃのインナー容器を挿着した容器が、最も初期瞬発があった。この初期瞬発性は、高分子吸水体の添加量に起因していた。しかし、前述したように、７重量％以上では、合成樹脂成形体の表面全体が吸水した高分子吸水体で被膜されてしまう。
（容器内湿度を１０％ＲＨ以下に保持する各種インナー容器の吸水量の評価）
前述した配合組成の異なる３種類（ａ，ｂ，ｃ）のインナー容器を外容器に挿着したそれぞれの容器を、開蓋状態で３０℃で８０％ＲＨの環境下で２４時間保管したときに、容器内湿度が１０％ＲＨ以下を保持するインナー容器の吸水量を調べた。その結果を表３に示す。

As shown in Table 2, the time when the humidity in the container is 10% RH or less is 4 hours for the container in which the inner container of the compounding c is inserted, and 5 hours for the container in which the inner container of the compounding b is inserted, The container inserted with the inner container of the blend a was 7 hours or longer. That is, the container in which the inner container of the blending c was inserted had the most initial flash. This initial flashing property was attributed to the amount of addition of the polymer water-absorbing body. However, as described above, when the content is 7% by weight or more, the entire surface of the synthetic resin molded body is coated with the polymer water absorbent that has absorbed water.
(Evaluation of water absorption of various inner containers that keep the internal humidity below 10% RH)
When each of the above-described three types (a, b, c) of inner containers different in composition is inserted into the outer container and stored for 24 hours in an 80% RH environment at 30 ° C. with the lid open. The water absorption amount of the inner container in which the humidity in the container is kept at 10% RH or less was examined. The results are shown in Table 3.

表３に示すように、容器内湿度が１０％ＲＨ以下を保持するインナー容器の吸水量は、配合ａのインナー容器が５００±１０ｍｇで、配合ｂのインナー容器が４００±１０ｍｇで、配合ｃのインナー容器が３００±１０ｍｇであった。

As shown in Table 3, the water absorption amount of the inner container in which the humidity in the container is kept at 10% RH or less is 500 ± 10 mg for the inner container of the blend a, 400 ± 10 mg for the inner container of the blend b, The inner container was 300 ± 10 mg.

It is explanatory drawing which shows the state of the polymeric water absorbing body and calcium oxide which are mixed and dispersed in the synthetic resin molding before water absorption of the instantaneous drying agent containing resin molding of this embodiment. It is explanatory drawing which shows the water absorption mechanism of the instantaneous drying agent containing resin molding of this embodiment, (a) shows the 1st step water absorption state, (b) shows the 2nd step water absorption state, (C) shows the water absorption state in the third stage. It is sectional drawing of the container used for the evaluation which inserted the inner container which consists of the instantaneous desiccant containing resin molding of this embodiment in the outer container. (A) is sectional drawing of the inner container which consists of a desiccant containing resin molding which has the instantaneous property and sustainability of this embodiment used for evaluation, (b) is the bottom view. It is the top view which notched a part of inner container of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Desiccant containing resin molding 11 ... Containing resin molding 11c ... Crack 12 ... Calcium oxide 12w ... Water absorption calcium oxide 13 ... Polymer water absorption body 13w ... Water absorption polymer water absorption body 20 ... ... container 100 ... outer container 101 ... hinge 110 ... container main body 111, 123, 201 ... peripheral wall 112, 124 ... occlusal ring 113 ... lid receiving ring 114 ... locking protrusion 115, 204 ... Bottom plate 120 ... Lid 121 ... Top plate 122 ... Inner ring 125 ... Opening / closing knob 200 ... Inner container 202 ... Top surface 203 ... Ventilation groove 205 ... Ventilation hole

Claims (2)

  In a synthetic resin molded article that has been injection-molded or extruded, as a desiccant, a polymeric water-absorbing body that absorbs and expands by water and expresses fine cracks in the synthetic resin molded body to form a water-containing jelly-like path; An instantaneous desiccant-containing resin molded article, wherein the synthetic resin molded article is mixed and dispersed with calcium oxide that exhibits fine cracks.   2. The instantaneous desiccant-containing resin molded article according to claim 1, wherein a mixing ratio of the polymer water-absorbing body is 0.5 to 7 wt% and a mixing ratio of the calcium oxide is 30 to 65 wt%. .

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