JP5050334B2 - Desiccant-containing resin molded body and production method thereof, container using desiccant-containing resin molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an instantaneous drying agent-containing resin molded product having high instantaneous property of water-absorbing ability, free from elution of a drying agent, free from sanitary problems and having long life of water-absorbing ability and to provide a method for producing the molded product. <P>SOLUTION: The method for producing the resin molded product comprises mixing and dispersing calcium oxide and molecular sieve having a water-absorbing property into a synthetic resin molding material as a base to prepare a primary mixed molding material, further mixing and dispersing a polymer water-absorbing body having an instantaneous water-absorbing property into the primary mixed molding material to prepare a secondary mixed molding material and then molding the molding material by an injection molding method using the secondary mixed molding material. In the molded product, molecular sieve 12, calcium oxide 13 and polymer water-absorbing body 14 are mixed and dispersed in a synthetic resin base 11 of the molded product 10. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  TECHNICAL FIELD The present invention relates to an instantaneous desiccant-containing resin molded article that is used as a desiccant in a container that stores contents that require a high drying environment, or a method for producing the same.

  Conventionally, synthesis based on a desiccant in a container that stores contents that require a high drying environment, such as sensors for blood sugar levels, test paper for detecting urine protein, sublimation, electronic components, organic electroluminescence elements, etc. A desiccant-containing resin molded body in which a molding material mixed and dispersed in a resin is injection-molded has been present. For example, when polyolefin is used as the base resin, molecular sieves and glycols as the drying agent are mixed and dispersed in the polyolefin, and fine cracks are generated in the synthetic resin base of low-density polyethylene due to water absorption of the glycol. There has been known a desiccant-containing resin molded article having a water content.

  However, since the above-mentioned conventional desiccant-containing resin molded article uses glycol, when the moisture absorption rate increases, glycol elutes on the surface and a film of glycol is formed on the surface. There was a risk of adversely affecting the contents stored in the container. And if the film | membrane of glycol begins to be made, a water absorption capability will fall rapidly. In addition, glycol adheres to the contents and fingers. In addition, since the main component of the desiccant is molecular sieve, the water absorption effect disappeared quickly and the total water absorption amount was low.

  The present invention solves the problems of the above-mentioned conventional desiccant-containing resin molded articles, has high water absorption ability, has no elution of desiccant, has no hygienic problems, and has a life of water absorption ability. The present invention provides a flashing desiccant-containing resin molded article having a long length and a method for producing the same.

That is, the first invention of the present invention, the water absorption of the calcium oxide and molecular sieves to prepare a mixture dispersion to primary mixing the molding material in a synthetic resin molding material containing no acrylic acid-based polymer water-absorbent structure, said primary the mixed molding, further, water absorption by mixing and dispersing the acrylic acid polymer water absorber to produce a secondary mixture molding materials, desiccant-containing resin molded by injection molding using the secondary mixing molding materials A molded body,
The blending ratio of the primary mixed molding material is 25 to 35% by weight of molecular sieve, 25 to 33% by weight of calcium oxide, and 40% by weight or more of a synthetic resin molding material that does not contain an acrylic polymer water absorbent , and In the blending of the secondary mixed molding material, the desiccant-containing resin molded body is characterized in that the acrylic polymer water-absorbing body mixed and dispersed in the primary mixed molding material is 5% by weight or less.

Next, the second invention of the present invention, the water absorption of the calcium oxide and molecular sieves, and mixed and dispersed in the synthetic resin molded material containing no acrylic acid-based polymer water absorber to produce a primary mixed molding material, wherein a primary mixing molding material, further, the water absorption of the acrylic acid polymer water absorber mixed and dispersed to prepare a secondary mixing molding materials, desiccant-containing molded by injection molding using the secondary mixing molding materials A method for producing a resin molded body, comprising:
In the blending of the primary mixed molding material, the molecular sieve is 25 to 35% by weight, the calcium oxide is 25 to 33% by weight, the synthetic resin molding material not containing the acrylic polymer water absorbent is 40% by weight or more, and In the blending of the next mixed molding material, the desiccant-containing resin molded body is characterized in that the acrylic polymer water-absorbing body mixed and dispersed in the primary mixed molding material is 5% by weight or less.

And 3rd invention of this invention is a container using the desiccant containing resin molding object shape | molded by the injection molding method,
The container comprises an inner container and an outer container,
The inner container has a water absorption of calcium oxide and molecular sieves, and mixed and dispersed in the synthetic resin molded material containing no acrylic acid-based polymer water absorber to produce a primary mixed molding material, the primary mixing molding material, further the water absorption of the acrylic acid polymer water absorber mixed and dispersed to prepare a secondary mixing molding materials, formed from the desiccant-containing resin molded body formed by injection molding using the secondary mixing molding materials And
The blending ratio of the primary mixed molding material is 25 to 35% by weight of molecular sieve, 25 to 33% by weight of calcium oxide, and 40% by weight or more of a synthetic resin molding material that does not contain an acrylic polymer water absorbent , and It is a container using a desiccant-containing resin molded body characterized in that, in blending of the secondary mixed molding material, the acrylic polymer water-absorbing body mixed and dispersed in the primary mixed molding material is 5% by weight or less.

As shown in FIG. 1, the instantaneous desiccant-containing resin molded product of the present invention is a mixture of a molecular sieve (12), calcium oxide (13), and a polymer water absorbent (14) in a synthetic resin base (11). Is distributed. When this instantaneous desiccant-containing resin molded product is present in the container, water absorption starts under a high humidity environment in the container, but in this first stage of water absorption, as shown in FIG. The polymer water-absorbing body close to the surface first starts water absorption (reference numeral 14w in the figure indicates the water-absorbing polymer water-absorbing body). Next, in the second stage of water absorption in a medium humidity environment, as shown in FIG. 2B, calcium oxide close to the surface also starts to absorb water (reference numeral 13w in the figure indicates the absorbed calcium oxide). Then, in the third stage of water absorption under a constant humidity environment, as shown in FIG. 2C, the molecular sieve also starts to absorb water (reference numeral 12w in the figure indicates the absorbed molecular sieve), and further absorbs and expands. As a result, fine cracks (11c) are generated in the synthetic resin base around the polymer water absorbent and calcium oxide, and the inner molecular sieve, calcium oxide and molecular sieve also absorb water. As a result, the instantaneous desiccant-containing resin molded product of the present invention has a high instantaneous water absorption capability and a long lifetime of the water absorption capability.

  In addition, the instant desiccant-containing resin molded article of the present invention does not use a glycol-based component as a desiccant unlike the conventional desiccant-containing resin molded article, so that the desiccant does not elute and is hygienic. there is no problem.

  In the instant desiccant-containing resin molded body of the present invention, the mixed and dispersed polymer water-absorbing body alleviates the deterioration in strength of the synthetic resin base due to the water absorption expansion of calcium oxide, and the hydroxylation due to the water absorption of calcium oxide. Prevents the generation of trace foreign matter of calcium.

  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 molecular sieve (12), calcium oxide (13), and polymer water absorption as a desiccant in a synthetic resin base (11). The body (14) is mixed and dispersed. The molecular sieve to be used is a powder of 10 to 30 μm, absorbs water up to 30% by weight, and has excellent instantaneous properties. A type of zeolite that absorbs only water molecules called 3A is used. Calcium oxide is a powder of 10 to 300 μm, absorbs moisture up to 30% by weight, and expands in volume. The polymer water-absorbing body is a water-absorbing body having a three-dimensional structure in which acrylonitrile is added to sodium acrylate and subjected to alkali hydrolysis. The water-absorbing body absorbs water up to 400% by weight in a 10-50 μm powder under high humidity. Moisture is absorbed instantaneously, and the amount and expansion rate when absorbing moisture are large. As the base synthetic resin, thermoplastic resins such as low-density polyethylene, linear low-density polyethylene, and polypropylene are used. However, the calcium oxide or polymer water-absorbing agent of the desiccant expands when it absorbs water, so it has moderate flexibility. It is desirable to have Therefore, if necessary, ethylene propylene rubber (EPR) or ethylene propylene three-dimensional copolymer (EPDM) may be mixed with the base synthetic resin in order to impart flexibility. Moreover, you may use a flexible styrene-type elastomer and a polyethylene terephthalate-type elastomer as a base synthetic resin.

The method for producing the instantaneous desiccant-containing resin molded body of the present embodiment is to produce a primary mixed molding material by mixing and dispersing water-absorbing molecular sieve and calcium oxide in a base synthetic resin molding material. A secondary water-absorbing polymer material is further mixed and dispersed in the molding material to produce a secondary mixed molding material, which is then molded by an injection molding method. In order to determine the composition of the primary and secondary mixed molding materials, the following various composition evaluations were performed.
(Composition evaluation of primary mixed molding materials)
Six types of primary mixed molding materials with different blending ratios of base synthetic resin, molecular sieve and calcium oxide were prepared, and six types of sensor containers (20) shown in FIG. 3 were produced by injection molding using these primary mixed molding materials. After the inner containers (200) were prepared and stored in an environment of 90% RH at 40 ° C. for 26 hours, the water absorption amount (initial water absorption amount) of each inner container was measured. The results are shown in Table 1. The base synthetic resin is a mixture of low density polyethylene and linear low density polyethylene in a ratio of 1: 1. In addition, as shown in FIG. 3, the inner container (200) is a cylindrical container having an outer appearance including a peripheral wall (201) and a bottom plate (204). An insertion ring (203) that is locked by a locking protrusion (114) of the container body (110) is provided on the outer periphery of the upper end of the peripheral wall, and the outer peripheral surface of the peripheral wall below the insertion ring is a triangle that continues in the circumferential direction A gap (202) is formed between the inner wall surface of the container body (110) and the peripheral wall (111), and the container body is formed on the lower surface of the bottom plate (204) as shown in FIGS. Four contact ribs (205) that contact the upper surface of the bottom plate (115) of (110) are provided radially from the center at equal intervals.

表１に示すように、乾燥剤のモレキュラシーブが３０重量％で酸化カルシウムが３０重量％の配合のところに、初期吸水量のピークがあり、モレキュラシーブが２５〜３５重量％で酸化カルシウムが２５〜３３重量％の配合のところが、初期吸水量が大きいことが判明した。これは、酸化カルシウムの吸水による膨張により周辺のベース樹脂に微細なクラックが入って瞬発性が向上する効果と、瞬発性能力の大きいモレキュラシーブが多いことによる瞬発性が向上する効果の相乗効果である。なお、射出成形性の問題から、ベース樹脂は４０重量％以上必要であることが判明した。
（二次混合成形材料の配合評価）
ベース合成樹脂とモレキュラシーブと酸化カルシウムを混合した一次混合成形材料に、アクリル酸系の高分子吸水体を配合比率を変えて混合して、４種類の二次混合成形材料を作製した。そして、これら二次混合成形材料を用いて、射出成形法により６種類の図３に示すセンサー容器（２０）の内容器（２００）を作製し、これら内容器を４０℃で９０％ＲＨの環境下で２６時間保管したのち、それぞれの内容器の吸水量（初期吸水量）を測定した。その結果を表２に示す。なお、ベース合成樹脂は、一次混合成形材料と同様に、低密度ポリエチレンと直鎖状低密度ポリエチレンとを１対１の比率で混合したものである。また、内容器の仕様も一次混合成形材料と同様である。

As shown in Table 1, there is a peak of initial water absorption when the desiccant molecular sieve is 30% by weight and calcium oxide is 30% by weight, the molecular sieve is 25-35% by weight and the calcium oxide is 25-33%. It was found that the initial water absorption amount was large when the weight percentage was mixed. This is a synergistic effect of the effect of improving fineness due to minute cracks in the surrounding base resin due to the expansion of calcium oxide due to water absorption, and the effect of improving the instantaneous property due to the large number of molecular sieves with high instantaneous properties. . It has been found that the base resin needs to be 40% by weight or more from the problem of injection moldability.
(Compounding evaluation of secondary mixed molding materials)
Four types of secondary mixed molding materials were prepared by mixing the primary synthetic molding material in which the base synthetic resin, the molecular sieve and the calcium oxide were mixed with an acrylic acid-based polymer water-absorbing material at different blending ratios. Then, using these secondary mixed molding materials, six types of inner containers (200) of the sensor container (20) shown in FIG. 3 are produced by injection molding, and these inner containers are in an environment of 90% RH at 40 ° C. After storing for 26 hours, the water absorption amount (initial water absorption amount) of each inner container was measured. The results are shown in Table 2. The base synthetic resin is a mixture of low-density polyethylene and linear low-density polyethylene in a 1: 1 ratio, similar to the primary mixed molding material. The specification of the inner container is the same as that of the primary mixed molding material.

表２に示すように、高分子吸水体の含有量に応じて、初期吸水量が増加する。しかしながら、高分子吸水体の含有量が７重量％になると、合成樹脂ベースに形状を損なうクラックが発生してしまうため、形状保持性の面から高分子吸水体の配合比率は、５重量％以下が望ましいことが判明した。
（各種内容器による容器内湿度評価）
次に、一次混合成形材料と二次混合成形材料を用いて、射出成形法により各２種類ずつ４種類の図３に示す内容器（２００）を作製し、また、別途に、ポリプロピレンを用いて、射出成形法により図３に示す外容器（１００）を作製し、４種類の内容器をそれぞれ外容器の容器本体（１１０）内に挿着して図３に示すセンサー容器（２０）を４種類作製した。これら４種類のセンサー容器の内容器内に、それぞれ湿度検出センサーを挿入して蓋部を閉じて密封し、３０℃で８０％ＲＨの環境下で保管し、容器内の湿度が１０％ＲＨになるまでの経過時間を測定した。その結果を表３及び表４に示す。なお、外容器は、図３に示すように、容器本体（１１０）の上端開口部に蓋部（１２０）が後方のヒンジ（２０１）を介して開閉可能に接続する外観円柱状の容器であり、容器本体は、周壁（１１１）と底板（１１５）とからなり、周壁の上端外周面に蓋部（１２０）との咬合リング（１１２）を設け、上方外周面に蓋部受けリング（１１３）を設け、上方内周面に周方向に内容器（２００）を係止する複数の係止突条（１１４）を設け、蓋部（１２０）は、天板（１２１）と周壁（１２３）とからなり、天板下面に、容器本体を封止するインナーリング（１２２）（外周面を容器本体の周壁上端部内周面に密接）を垂設し、周壁の前方下端に開
閉用つまみ（１２５）を突設し、周壁の下端内周面に容器本体との咬合リング（１２４）を設けるものである。

As shown in Table 2, the initial water absorption increases according to the content of the polymer water absorbent. However, when the content of the polymer water absorbent becomes 7% by weight, cracks that impair the shape occur in the synthetic resin base. Therefore, the blending ratio of the polymer water absorbent is 5% by weight or less from the viewpoint of shape retention. Turned out to be desirable.
(In-container humidity evaluation using various internal containers)
Next, using the primary mixed molding material and the secondary mixed molding material, two types of inner containers (200) shown in FIG. 3 are produced by injection molding, and separately, using polypropylene. The outer container (100) shown in FIG. 3 is produced by an injection molding method, and four types of inner containers are respectively inserted into the container main bodies (110) of the outer containers, and the sensor container (20) shown in FIG. Kinds were made. The humidity sensor is inserted into each of the four types of sensor containers, the lid is closed and sealed, and stored in an environment of 80% RH at 30 ° C., and the humidity in the container is 10% RH. The elapsed time to become was measured. The results are shown in Tables 3 and 4. As shown in FIG. 3, the outer container is a cylindrical container having an outer appearance in which the lid (120) is connected to the upper end opening of the container main body (110) through the rear hinge (201) so as to be opened and closed. The container body includes a peripheral wall (111) and a bottom plate (115), and an occlusal ring (112) with a lid portion (120) 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 locking protrusions (114) for locking the inner container (200) in the circumferential direction are provided on the upper inner peripheral surface, and the lid (120) includes a top plate (121), a peripheral wall (123), and An inner ring (122) for sealing the container 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), and an opening / closing knob (125) at the lower front end of the peripheral wall. And an occlusal ring (124) with the container body is provided on the inner peripheral surface of the lower end of the peripheral wall It is intended.

一次混合成形材料により作製した２種類の内容器を、それぞれ外容器の容器本体内に挿着した２種類のセンサー容器の容器内湿度の１０％ＲＨになるまでの経過時間は、表３に示すように、モレキュラシーブが３０重量％、酸化カルシウムが３０重量％、ベース樹脂が４０重量％の配合ａの内容器の場合には、経過時間が６時間であり、モレキュラシーブが２０重量％、酸化カルシウムが３６重量％、ベース樹脂が４４重量％の配合ｃの内容器の場合には、経過時間が７時間であった。

Table 3 shows the elapsed time until 10% RH of the humidity in the container of the two types of sensor containers in which the two types of inner containers made of the primary mixed molding material are inserted into the container body of the outer container, respectively. Thus, in the case of the inner container of Formulation a with 30% by weight of molecular sieve, 30% by weight of calcium oxide and 40% by weight of the base resin, the elapsed time is 6 hours, 20% by weight of molecular sieve and 20% by weight of calcium oxide. In the case of the inner container of Formulation c having 36% by weight and 44% by weight of the base resin, the elapsed time was 7 hours.

二次混合成形材料により作製した２種類の内容器を、それぞれ外容器の容器本体内に挿着した２種類のセンサー容器の容器内湿度の１０％ＲＨになるまでの経過時間は、表４に示すように、モレキュラシーブが３６重量％、酸化カルシウムが２０重量％、ベース樹脂が４４重量％の一次混合成形材料にアクリル酸系の高分子吸水体を３重量％混合した配合ｈの内容器の場合には、経過時間が５時間であり、モレキュラシーブが２０重量％、酸化カルシウムが３６重量％、ベース樹脂が４４重量％の一次混合成形材料にアクリル酸系の高分子吸水体を５重量％混合した配合ｉの内容器の場合には、経過時間が４時間であった。一次混合成形材料で作製した内容器の場合より二次混合成形材料で作製した内容器の場合の方が瞬発吸水性が大きかった。

Table 4 shows the elapsed time until 10% RH of the humidity in the container of the two types of sensor containers in which the two types of inner containers made of the secondary mixed molding material are respectively inserted into the container body of the outer container. As shown, in the case of the inner container of the compounding h in which the molecular sieve is 36% by weight, the calcium oxide is 20% by weight, the base resin is 44% by weight, and the acrylic polymer polymeric water absorbent is mixed by 3% by weight. The elapsed time is 5 hours, the molecular sieve is 20% by weight, the calcium oxide is 36% by weight, and the base resin is 44% by weight. In the case of the inner container of Formulation i, the elapsed time was 4 hours. The instantaneous water absorption was larger in the case of the inner container made of the secondary mixed molding material than in the case of the inner container made of the primary mixed molding material.

  From the results of the above-described evaluation of the mixing of the primary mixed molding material, the evaluation of the mixing of the secondary mixed molding material, and the humidity evaluation in the containers using various inner containers, the mixing of the primary mixed molding material is 25 to 35% by weight of molecular sieve and calcium oxide. The secondary mixed molding material was prepared by setting the polymer water-absorbing body to 25 to 33% by weight, the synthetic resin molding material to 40% by weight or more, and the polymer water absorbent mixed and dispersed in the primary mixed molding material to 5% by weight or less.

It is explanatory drawing which shows the state before water absorption of the molecular sieve mixed with the synthetic resin base of the instantaneous drying agent containing resin molding of one Embodiment of this invention, calcium oxide, and a polymeric water absorbing body. It is explanatory drawing which shows the state before water absorption of the molecular sieve mixed with the synthetic resin base of the instantaneous desiccant containing resin molding shown in FIG. 1, calcium oxide, and a polymer water absorbing body, (a) is water absorption 1st. (B) is the state of the second stage of water absorption, and (c) is the state of the third stage of water absorption. It is sectional drawing of the container used for evaluation which inserts the inner container which consists of a flashing desiccant containing resin molding in a container main body. It is a bottom view of the inner container of the container of FIG.

Explanation of symbols

10 …… Molded body 11 …… Synthetic resin base 11c …… Crack 12 …… Molecular sieve 12w …… Water-absorbed molecular sieve 13 …… Calcium oxide 13w …… Water-absorbed calcium oxide 14 …… Polymer water-absorbing body 14w …… High water absorption Molecular water absorbent 20 ... Container 100 ... Outer container 101 ... Hinge 110 ... Container body 111, 123, 201 ... Peripheral walls 112, 124 ... Occlusal ring 113 ... Lid receiving ring 114 ... Locking ridge 115, 204 ... Bottom plate 120 ... Lid 121 ... Top plate 122 ... Inner ring 125 ... Opening / closing knob 200 ... Inner container 202 ... Gap 203 ... Insertion ring 205 ... Abutment rib

Claims (3)

A water absorption of calcium oxide and molecular sieves, and mixed and dispersed in the synthetic resin molded material containing no acrylic acid-based polymer water absorber to produce a primary mixed molding material, the primary mixing molding material, further, the water-absorbent acrylic and mixing and dispersing the acid-based polymer water absorber to produce a secondary mixture molding materials, a desiccant-containing resin molded body formed by injection molding using the secondary mixing molding materials,
The blending ratio of the primary mixed molding material is 25 to 35% by weight of molecular sieve, 25 to 33% by weight of calcium oxide, and 40% by weight or more of a synthetic resin molding material that does not contain an acrylic polymer water absorbent , and A desiccant-containing resin molded article characterized in that, in the blending of the secondary mixed molding material, the acrylic polymer water-absorbing body mixed and dispersed in the primary mixed molding material is 5% by weight or less. A water absorption of calcium oxide and molecular sieves, and mixed and dispersed in the synthetic resin molded material containing no acrylic acid-based polymer water absorber to produce a primary mixed molding material, the primary mixing molding material, further, the water-absorbent acrylic and mixing and dispersing the acid-based polymer water absorber to produce a second mixed molding material, a manufacturing method of the desiccant-containing resin molded body formed by injection molding using the secondary mixing molding materials,
In the blending of the primary mixed molding material, the molecular sieve is 25 to 35% by weight, the calcium oxide is 25 to 33% by weight, the synthetic resin molding material not containing the acrylic polymer water absorbent is 40% by weight or more, and A method for producing a desiccant-containing resin molded article, characterized in that, in blending of the secondary mixed molding material, the acrylic polymer water-absorbing body mixed and dispersed in the primary mixed molding material is 5% by weight or less. A container using a desiccant-containing resin molded article molded by an injection molding method,
The container comprises an inner container and an outer container,
The inner container has a water absorption of calcium oxide and molecular sieves, and mixed and dispersed in the synthetic resin molded material containing no acrylic acid-based polymer water absorber to produce a primary mixed molding material, the primary mixing molding material, further the water absorption of the acrylic acid polymer water absorber mixed and dispersed to prepare a secondary mixing molding materials, formed from the desiccant-containing resin molded body formed by injection molding using the secondary mixing molding materials And
The blending ratio of the primary mixed molding material is 25 to 35% by weight of molecular sieve, 25 to 33% by weight of calcium oxide, and 40% by weight or more of a synthetic resin molding material that does not contain an acrylic polymer water absorbent , and A container using a desiccant-containing resin molded body characterized in that, in the blending of the secondary mixed molding material, the acrylic polymer water-absorbing body mixed and dispersed in the primary mixed molding material is 5% by weight or less.

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