JP4870489B2 - Uncharged desiccant-containing film - Google Patents

Description

  The present invention relates to a non-chargeable desiccant-containing film that is excellent in non-chargeability and excellent in hygroscopicity.

  Conventionally, when an antistatic property is imparted to a container or packaging material, an antistatic agent is added to the resin, but since the low molecular weight antistatic agent is kneaded into the resin, the antistatic agent bleeds out. There was a problem. Further, since the conventional antistatic agent exhibits an antistatic effect by utilizing water molecules in the air, there is a problem that a sufficient antistatic effect cannot be obtained in a low-humidity environment or when a desiccant is present or kneaded. was there.

  There is a disclosure in which a potassium ionomer and a polyvalent hydroxy compound are used as an antistatic agent, kneaded into a resin, and injection molding is performed to obtain a non-chargeable molded product (see, for example, Patent Document 1). As a result, white smoke due to the glycerin of the polyvalent hydroxy compound was raised and mold contamination occurred. After that, the mold was soiled by the resin sticking to the mold, and it was difficult to produce stably.

Moreover, the laminated body which has the layer containing potassium ionomer of an antistatic agent and a desiccant is also disclosed (for example, refer patent document 2 and patent document 3). However, water molecules in the air cannot be used in a low humidity environment, and it has been difficult to exert an antistatic effect.
Japanese Patent Laid-Open No. 10-60186 JP 2002-347850 A JP 2005-15568 A

  An object of the present invention is to provide a non-chargeable desiccant-containing film having excellent hygroscopicity and excellent non-charge properties.

  Another object of the present invention is to provide a non-chargeable desiccant-containing film in which the polyvalent hydroxy compound contained does not bleed out from the intermediate layer and does not stain the mold during molding.

According to the present invention, a non-chargeable desiccant-containing film having on either one or both sides of the intermediate layer and the intermediate layer and the bar rear layer,
An unchargeable desiccant-containing film is provided in which the intermediate layer contains a polyvalent hydroxy compound, a potassium ionomer, and a desiccant.

  As described above, according to the present invention, the polyvalent hydroxy compound contained does not bleed out, maintains a high antistatic effect, and does not contaminate mold contamination or encapsulated products during various moldings, and a desiccant. It is possible to provide a non-chargeable desiccant-containing film having an antistatic effect despite being in contact with the film.

  Hereinafter, embodiments of the present invention will be described in detail.

  The present invention requires an antistatic desiccant-containing film having a resin layer obtained by kneading a polyvalent hydroxy compound, potassium ionomer and a desiccant in a resin as an intermediate layer, and is necessary for obtaining an antistatic effect without causing bleed out. It is characterized by a non-chargeable desiccant-containing film that can be supplied with a hydroxyl group from a polyvalent hydroxy compound and can obtain a sufficient antistatic effect and hygroscopicity.

  FIG. 1 shows a schematic cross-sectional view of an unchargeable desiccant-containing film of the present invention. The non-chargeable desiccant-containing film 1 of the present invention comprises an intermediate layer 3 containing a polyvalent hydroxy compound, a potassium ionomer, a desiccant and a resin, and an inner layer 2 and an outer layer 4 serving as barrier layers on both sides of the intermediate layer. .

  As an embodiment of the non-chargeable desiccant-containing film, there is a form in which a resin layer or an aluminum foil to be the base material 5 is bonded to the outside of the inner layer / outer layer as shown in FIG.

The potassium ionomer, which is an antistatic agent used in the present invention, must exhibit sufficient non-charging properties when used in combination with a polyvalent hydroxy compound, for example, a surface resistivity of 10 at 23 ° C./30% RH. ^It is preferably ¹³ Ω or less, particularly preferably 10 ¹² Ω or less. Further, the charge decay time at 23 ° C./50% RH is 2 seconds or less. In the present invention, the use of a small amount of a non-chargeable potassium ionomer in combination with a polyvalent hydroxy compound in order to impart sufficient non-chargeability allows the supply of a hydroxyl group necessary for obtaining an antistatic effect, in the air. It is possible to receive from a polyvalent hydroxy compound rather than from water molecules.

  The polyvalent hydroxy compound is a compound having two or more alcoholic hydroxyl groups. For example, polyoxyalkylene glycols such as polyethylene glycol, polypropylene glycol, polyoxyethylene / polyoxypropylene glycol having various molecular weights, glycerin, hexanetriol, penta Examples thereof include polyhydric alcohols such as erythritol and sorbitol, adducts of these ethylene oxides, adducts of various amines and alkylene oxides, and particularly high-boiling alcohols having a valence of 2 or more such as glycerin and polyethylene glycol.

  In the intermediate layer of the present invention, the content of the polyvalent hydroxy compound and the potassium ionomer as charging members is preferably 10 to 30% by weight, particularly preferably 15 to 25% by weight. If the content is less than 10% by weight, it is difficult for the molded product to obtain sufficient antistatic performance, and if it exceeds 30% by weight, molding becomes difficult.

  The intermediate layer according to the present invention is a desiccant having a high adsorption rate and physically adsorbing moisture (hereinafter referred to as “physical adsorption desiccant”), and the adsorbed components are not separated once adsorbed. One or both of desiccants that chemically adsorb moisture (hereinafter referred to as “chemical adsorption desiccants”) can be used. In particular, it is preferable to use both in combination with the moisture adsorption rate of the desiccant and its adsorption characteristics, and this can synergistically enhance the dehumidifying effect.

  By using a physical adsorption system and a chemical adsorption system in combination, the moisture desorption from the physical adsorption system desiccant such as zeolite and silica gel, which has been a problem in the past, has been absorbed by the physical adsorption system desiccant. Gradually moves to the adjacent chemical adsorption desiccant, and can be held without desorption even in a high temperature environment.

  The physical adsorption desiccant has a high adsorption rate and can adsorb moisture. Examples of the physical adsorption desiccant include zeolite, silica gel, activated alumina, and the like, and molecular sieves of synthetic zeolite are particularly preferable.

  Zeolite, which is a physical adsorption desiccant, can adsorb moisture quickly because of its high adsorption rate. Molecular sieves, which are zeolites, are porous particulate materials used to separate materials according to the difference in molecular size. Adsorbs and acts as a kind of sieve. In the present invention, the adsorption port diameter is preferably 0.3 nm to 1 nm. In general, molecular sieves having pore sizes of 0.3 nm, 0.4 nm, 0.5 nm, and 1 nm are referred to as molecular sieve 3A, molecular sieve 4A, molecular sieve 5A, and molecular sieve 13X, respectively. In the present embodiment, molecular sieve 3A or molecular sieve 4A is used as a suitable desiccant. The average particle diameter of the molecular sieve is, for example, about 10 μm.

  The adsorption characteristics of molecular sieves are related to the pore size. To increase the adsorption characteristics of moisture, the molecular sieve powder is made finer, the surface area is substantially increased, and the number of pores is reduced. We can cope by increasing.

  The chemical adsorption desiccant has a slower moisture adsorption rate than the above physical adsorption desiccant, but gradually adsorbs, and once adsorbed, the adsorbed components do not separate, so even if exposed to high temperature environments There is no desorption of moisture. Examples of the chemical adsorption desiccant include calcium oxide, calcium chloride, magnesium sulfate, barium oxide, phosphorus pentoxide, potassium hydroxide, sodium hydroxide, potassium bromide, calcium bromide, copper sulfate, zinc chloride, calcium sulfate. And magnesium oxide, and calcium oxide is particularly preferable.

  The mixing ratio of the physical adsorption desiccant and the chemical adsorption desiccant is preferably physical adsorption desiccant: chemical adsorption desiccant = 99: 1 to 1:99, particularly preferably 90:10 to 40:60. . The ratio of the physical adsorbent desiccant is high when the molecular sieve (synthetic zeolite) is used as the physical adsorbent and calcium oxide is used as the chemical adsorbent. The molecular sieve adsorbs moisture up to about 20% by weight of its own weight. On the other hand, the amount of calcium oxide is large up to about 30% by weight of its own weight, and even when the moisture absorbed by the molecular sieve shifts to calcium oxide, it can be retained without being detached in a high temperature environment.

  In the intermediate layer of the present invention, the content of the desiccant is preferably 5 to 70% by weight, particularly preferably 30 to 70% by weight. If the content is less than 5% by weight, it is difficult for the molded product to obtain sufficient drying performance, and if it exceeds 70% by weight, molding becomes difficult.

  The resin material of the intermediate layer is preferably a resin having a high melt flow rate, a low melting point (low softening point), and excellent low-temperature drawdown properties. If it is a high melt flow rate resin, even if the melt flow rate is lowered by adding a desiccant, a certain degree of flow characteristics can be secured. In addition, if the melting point is low, the resin softens at a low temperature, thereby enabling low-temperature extrusion and avoiding the possibility of foaming. If it is resin excellent in low-temperature drawdown property, even if it adds a desiccant, extrusion molding with an extruder is easy.

  From this point of view, the intermediate layer resin includes, for example, LDPE (low density polyethylene), LLDPE (linear low density polyethylene), PP (polypropylene), various copolymers (copolymers), and ionomers (for example, ethylene). Salt of acrylic acid copolymer), EAA (ethylene acrylic acid copolymer), EMAA (ethylene methacrylic acid copolymer), EVA (ethylene vinyl acetate copolymer), EEA (ethylene ethylene acrylate copolymer), EMA (Ethylene methyl acrylate copolymer), EMMA (ethylene methyl methacrylate copolymer), etc. are mentioned, More preferably, LDPE and LLDPE are mentioned.

  When heated to knead the polyvalent hydroxy compound used in the intermediate layer, especially glycerin, etc. into a resin and mold it from the mold, white smoke starts to rise, and the mold contamination that is attached by cooling with the mold occurs as it is When molding is performed, the resin sticks to the mold and stains the mold, making it difficult to perform stable molding, so the inner layer on one side or both sides prevents the resin in the intermediate layer from directly contacting the mold.・ It is essential to provide an outer layer. As a structure of a laminated body, 2 types 3 layers or 3 types 3 layers are preferable.

  The laminate is formed into a film or sheet by extrusion molding such as polyhydric hydroxy compound, potassium ionomer, desiccant and resin with inflation method, blow molding, injection molding or T-die method or co-extrusion. A multilayer film formed by blow molding or injection molding is preferable. Particularly, in the case of an inflation method and blow molding, when a layer is provided on one side, an outer layer is provided on the mold side and an intermediate layer is provided on the inside so as not to contact the mold. It is suitable for. The inflation method is a method for producing a multilayer film by extruding a resin melted by a plurality of extruders into a tube shape, and sending air into the tube to inflate it.

  Resins used for the outer and inner barrier layers include LDPE (low density polyethylene), LLDPE (linear low density polyethylene), polyolefins such as polypropylene and polystyrene, polyethylene terephthalate (PET), polypropylene, polyvinylidene chloride (PVDC) ), Polyvinyl alcohol (PVA), ethylene vinyl acetate copolymer (EVA) and the like, and polyolefin is particularly preferable.

  The substrate provided outside the outer and inner barrier layers may be a layer made of an aluminum foil, an aluminum vapor deposition film, an inorganic thin film such as aluminum oxide and silicon oxide, or the like.

  As for the film thickness of the laminated body in this invention, 50 micrometers-300 micrometers are preferable, More preferably, they are 60 micrometers-200 micrometers. If the thickness is less than 50 μm, the intermediate layer becomes thin and sufficient drying performance is difficult to obtain. On the other hand, if it exceeds 300 μm, molding is difficult. The thickness of the intermediate layer is preferably 30 μm to 150 μm, and the outer layer and inner layer are preferably 10 μm to 100 μm, respectively.

  Hereinafter, the present invention will be described in more detail with specific examples, but the present invention is not limited to these examples.

  As master batch 1 (MB1), 50 parts by weight of molecular sieve 3A was mixed with 50 parts by weight of LDPE (trade name: Petrocene 204, manufactured by Tosoh Corporation) to form a pellet-shaped granular resin.

  As master batch 2 (MB2), 10 parts by weight of glycerin was added to 90 parts by weight of potassium ionomer and kneaded to prepare a pellet-shaped granular resin.

  As master batch 3 (MB3), a pellet-shaped granular resin of potassium ionomer (trade name: High Milan MK153 (glycerin-free), manufactured by Mitsui DuPont Polychemical Co., Ltd.) was used.

Example 1
Multilayer inflation method using blend A in which masterbatch 1 and masterbatch 2 are mixed at a ratio of 9: 1 as an intermediate layer resin, using LLDPE (trade name: ULT XEX 15150J, manufactured by Mitsui Chemicals, Inc.) for the outer and inner layers A two-type three-layer film was prepared by The film thickness of the two-type three-layer film is outer layer / intermediate layer / inner layer = 10 μm / 60 μm / 10 μm, and the total thickness is 80 μm.

  The content of the polyvalent hydroxy compound and potassium ionomer in the intermediate layer was 10% by weight, and the content of the desiccant was 45% by weight.

(Example 2)
A film was produced in the same manner as in Example 1, except that the blend B was mixed with the master batch 1 and the master batch 2 of the intermediate layer at a ratio of 8: 2.

  The content of the polyvalent hydroxy compound and potassium ionomer in the intermediate layer was 20% by weight, and the content of the desiccant was 40% by weight.

(Example 3)
A film was produced in the same manner as in Example 1, except that the blend C was prepared by mixing the master batch 1 and the master batch 2 of the intermediate layer at a ratio of 7: 3.

  The content of the polyvalent hydroxy compound and potassium ionomer in the intermediate layer was 30% by weight, and the content of the desiccant was 35% by weight.

(Comparative Example 1)
A film was produced in the same manner as in Example 2 except that the blend D was mixed with the master batch 1 and the master batch 3 of the intermediate layer in a ratio of 8: 2.

  The intermediate layer did not contain a polyvalent hydroxy compound, the content of potassium ionomer was 20% by weight, and the content of desiccant was 40% by weight.

(Comparative Example 2)
A film was produced in the same manner as in Example 2 except that the intermediate layer was changed to only the master batch 1.

(Comparative Example 3)
In Example 2, a single layer film was prepared in the same manner except that only the intermediate layer was changed without forming the inner and outer LLDPE layers. The film was not constant, and the film could not be formed stably.

  The film obtained by the above production method was evaluated for chargeability, bleed out, and moisture absorption performance. The results are shown in Table 1.

<Chargeability>
The film was given a charge of 5 KV in a 23 ° C./50% RH ambient temperature and humidity environment, and the time until the film decayed to 0.5 KV was measured (Federal Test Method (US Federal Government test standards) 4046)).

<Bleed out>
After leaving the film in an environment of 25 ° C./50% RH for 240 hours, the outer layer surface side was visually observed.

<Hygroscopic performance>
The film was left in an environment of 25 ° C./50% RH for 240 hours, and the moisture absorption rate and the saturated moisture absorption amount were determined from the amount of change in the weight of the adsorption film.

表１の結果から、吸湿性に優れ、非帯電性に優れた非帯電性乾燥剤含有フィルムを提供することが可能となった。

From the results shown in Table 1, it was possible to provide a non-chargeable desiccant-containing film having excellent hygroscopicity and excellent non-charge properties.

It is a schematic sectional drawing of the non-chargeable desiccant containing film of this invention. It is a schematic sectional drawing of another non-chargeable desiccant containing film of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Unchargeable desiccant containing film 2 Outer layer 3 Intermediate layer 4 Inner layer 5 Base material

Claims (9)

On one or both sides of the intermediate layer and the intermediate layer a non-chargeable desiccant-containing film and a bus rear layer,
An uncharged desiccant-containing film, wherein the intermediate layer contains a polyvalent hydroxy compound, potassium ionomer, and a desiccant. The non-chargeable desiccant-containing film according to claim 1, wherein the polyvalent hydroxy compound is a divalent or higher alcohol.   3. The non-chargeable material according to claim 1, wherein in the intermediate layer, the content of the polyvalent hydroxy compound and the potassium ionomer is 10 to 30 wt%, and the content of the desiccant is 5 to 70 wt%. -Containing desiccant-containing film. Uncharged desiccant-containing film according to claim 1, wherein the intermediate layer and the bar rear layer is produced by two or more than two layers of the multilayer inflation method. The non-chargeable desiccant-containing film according to claim 4, wherein an intermediate layer is sandwiched between the barrier layers using polyolefin by the multilayer inflation method. Uncharged desiccant-containing film according to any one of the intermediate layer and the bar rear layer claims 1 to 3 which is produced by two or more than two layers of the multilayer blow molding method. The non-chargeable desiccant-containing film according to claim 6, wherein an intermediate layer is sandwiched between the barrier layers using polyolefin by the multilayer blow molding method. Uncharged desiccant-containing film according to any one of the intermediate layer and the bar rear layer claims 1 to 3 which is produced by two or more than two layers of the multilayer injection molding. The non-chargeable desiccant-containing film according to claim 8, wherein an intermediate layer is sandwiched between the barrier layers using polyolefin by the multilayer injection molding method.

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