KR20200119636A - Moisture absorbent having improved durability and moisture absorbent product comprising the same - Google Patents

Abstract

The present invention relates to a moisture absorbent having excellent long-term durability including a first inorganic material, a second inorganic material, an alkali metal phosphate, and a polymer wax, and a moisture absorbing product including the same. An object of the present invention is to provide the moisture absorbent having high hygroscopicity and release resistance, and excellent in controlling humidity of an internal environment when used.

Description

A desiccant for lamps with good long-term durability, and products containing the same {MOISTURE ABSORBENT HAVING IMPROVED DURABILITY AND MOISTURE ABSORBENT PRODUCT COMPRISING THE SAME}

The present invention relates to a desiccant for a lamp having good long-term durability and a moisture-absorbing product including the same.

With the development of the automobile industry, problems related to condensation such as headlamps, rear lamps, and fog lights during storage and driving of automobiles continue to occur, and industrial losses are increasing.

Automotive lamps may have a large temperature difference inside and outside parts in an environment with high humidity, such as in rainy weather. At this time, when the temperature of the lens of the lamp is low, moisture inside the lamp is condensed and fine water droplets form on the inner surface of the lens, resulting in fogging. As a result, light scattering occurs, which is a major obstacle to safe driving of a vehicle.

Conventionally, in order to solve this problem, a method of using an anti-fog coating agent or mounting a bentonite-based desiccant in a lamp housing has been used. However, the anti-fog coating agent has a problem in that deterioration such as whitening or flow phenomenon occurs due to ultraviolet rays, temperature, or humidity. This has the burden of replacing the automotive lamp module. In addition, after the bentonite-based desiccant absorbs a certain amount of moisture, when the lamp is operated, moisture is re-released in an environment of high temperature and low humidity, and condensation is generated on the inner surface of the lamp lens. This problem leads to deterioration of the functional quality of automobile lamps, and eventually leads to the cost of replacing the lamp module.

Accordingly, there is a need for a new function of a desiccant capable of preventing condensation through humidity control by efficiently absorbing moisture in response to various external environments within a vehicle lamp and minimizing the release of moisture.

Moreover, the desiccant has the property of expanding or curing the volume after moisture absorption, so it can damage or deform the dust cover having a constrained space such as the dust cover, and if the packaging material of the product containing the moisture absorbent is damaged, the contents There is a possibility of leakage.

In order to improve this problem, a new function of a desiccant is required that has remarkably excellent hygroscopic performance and at the same time significantly reduces the swelling phenomenon after moisture absorption to solve problems caused by moisture absorption.

Republic of Korea Patent Publication No. 10-2015-0058825 (2015.05.29.)

The present invention has been devised to solve the above problems,

It has high hygroscopicity and release resistance, and it aims to provide an excellent moisture absorbent for controlling the humidity of the internal environment when used.

An object of the present invention is to provide a moisture absorbent capable of remarkably improving the durability of hygroscopicity.

An object of the present invention is to provide a desiccant capable of significantly reducing the expansion rate after moisture absorption due to moisture absorption, and a moisture absorption product including the same.

To achieve the above purpose,

The present invention provides a) any one or two or more first inorganic substances selected from the group consisting of magnesium chloride, calcium chloride and sodium carbonate, b) any one or two or more second inorganic substances selected from the group consisting of magnesium oxide and calcium oxide, c) It provides a desiccant comprising an alkali metal phosphate and d) polyethylene wax, polypropylene wax, polyamide wax, carnova wax, paraffin wax, and any one or more polymer waxes selected from the group consisting of polytetrafluoroethylene wax. .

The alkali metal phosphate according to an aspect of the present invention may include any one or two or more selected from the group consisting of monosodium phosphate, disodium phosphate, and trisodium phosphate.

The desiccant according to an aspect of the present invention may include 10 to 70% by weight of a first inorganic material, 5 to 50% by weight of a second inorganic material, 1 to 30% by weight of an alkali metal phosphate, and 1 to 30% by weight of a polymer wax.

Another aspect of the present invention is a moisture absorbent product comprising the above moisture absorbent.

The desiccant according to an aspect of the present invention may be enclosed in a breathable packaging material.

The packaging material according to an aspect of the present invention is one side of a breathable film layer made from any one or two or more fibers selected from natural fibers, polyester, polyethylene, polypropylene, polyamide, cellulose fibers, acrylic fibers and rayon fibers, etc. Alternatively, sealing layers may be formed on both sides.

The moisture-absorbing product according to an aspect of the present invention may maintain a relative humidity of 60% or less for 55 days or more under a constant temperature and humidity condition of 40°C and 90%.

The moisture absorption product according to an aspect of the present invention may be for automobile lamps.

The desiccant according to the present invention has the advantage of remarkably improving hygroscopicity and release resistance, and overcoming the limitation of a service life in terms of long-term durability, thereby implementing a remarkably improved long-term durability.

In addition, the hygroscopic agent according to the present invention has an advantage in that the volume after moisture absorption is significantly reduced compared to the prior art by effectively suppressing expansion due to moisture absorption.

In addition, the moisture absorbing product including the moisture absorbing agent according to the present invention realizes continuous moisture absorption, thereby effectively suppressing condensation in the lamp when applied for automobile lamps, and has excellent long-term humidity control performance.

FIG. 1 shows a test of a headlamp of a vehicle equipped with a moisture absorbing product manufactured in Examples 1 and 2 and Comparative Example 1 according to an embodiment of the present invention in a thermo-hygrostat.
2 is a graph showing the moisture absorption rate of the moisture absorbing products prepared in Examples 1 and 2 and Comparative Example 1 according to an embodiment of the present invention.
3 is a graph showing long-term durability measurements of the moisture absorbing products prepared in Examples 1 and 2 and Comparative Example 1 according to an embodiment of the present invention.
4 is a photograph observed with a scanning electron microscope at a magnification of 30,000 times of the desiccant prepared in Example 1 according to an embodiment of the present invention.
5 is a photograph observed with a scanning electron microscope at a magnification of 10,000 times of the desiccant prepared in Comparative Example 1 according to an embodiment of the present invention.

Hereinafter, the desiccant for a lamp having good long-term durability and a moisture absorbing product including the same according to the present invention will be described in more detail. However, the following examples are only one reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

In addition, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. The terms used in the description in the present invention are merely intended to effectively describe specific embodiments and are not intended to limit the present invention.

In addition, the drawings introduced below are provided as an example to sufficiently convey the spirit of the present invention to those skilled in the art. Therefore, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. Also, throughout the specification, the same reference numerals indicate the same elements.

In addition, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context.

Even though the conventional desiccant for automobile lamps implements hygroscopicity, additional damage is caused by expansion due to moisture absorption, and the expiration date is limited because the moisture absorption performance does not persist when used for a long period of time. This is emerging.

Accordingly, the inventors of the present invention further improved the hygroscopicity and at the same time significantly reduced the expansion rate due to moisture absorption, and further discovered a moisture absorbent capable of securing long-term durability and a moisture absorbing product including the same, thereby completing the present invention.

The present invention will be described in detail as follows.

The desiccant according to the present invention is a) any one or two or more first inorganic substances selected from the group consisting of magnesium chloride, calcium chloride and sodium carbonate, b) any one or two or more second inorganic substances selected from the group consisting of magnesium oxide and calcium oxide , c) an alkali metal phosphate, and d) polyethylene wax, polypropylene wax, polyamide wax, carnova wax, paraffin wax, and polytetrafluoroethylene wax.

The hygroscopic agent according to the present invention not only has remarkably excellent hygroscopicity and release resistance, but also suppresses physical expansion after moisture absorption, thereby preventing the contents from leaking or being damaged due to limited space when a hygroscopic product containing a desiccant is mounted in the device. Has excellent stability.

According to an aspect of the present invention, the first inorganic material may include any one or two or more selected from the group consisting of magnesium chloride, calcium chloride, and sodium carbonate. Preferably, it is more effective to include magnesium chloride in terms of implementing improved hygroscopicity and release resistance.

When the first inorganic material is included, when mixed with the second inorganic material, alkali metal phosphate and polymer wax, not only can the hygroscopicity be remarkably improved, but also the liquefaction of the desiccant due to excessive moisture absorption is prevented, thereby improving reliability in terms of product stability. Can be secured.

According to an aspect of the present invention, the first inorganic material may be included in an amount of 10 to 70% by weight based on the total weight of the desiccant. Preferably 20 to 60% by weight, more preferably 30 to 55% by weight may be included. When included in the above content, stability can be ensured and excellent hygroscopicity and release resistance can be realized.

According to an aspect of the present invention, the second inorganic material includes any one or two or more selected from the group consisting of magnesium oxide and calcium oxide. When the second inorganic material is included, when mixed with the first inorganic material, alkali metal phosphate, and polymer wax, it is possible to prevent liquefaction due to deliquescent property after moisture absorption.

Specifically, the second inorganic material may be preferably magnesium oxide, for example, STARMAG 50 of KONOSHIMA CHEMICAL, but is not limited thereto.

According to an aspect of the present invention, the second inorganic material may be included in an amount of 5 to 50% by weight based on the total weight of the desiccant. Preferably 10 to 50% by weight, more preferably 20 to 50% by weight may be included. When included in the above amount, it is more effective in terms of improving the compatibility between components in the desiccant and suppressing the separation phenomenon while securing the persistence of the moisture absorption performance for a long time.

According to an aspect of the present invention, the second inorganic material may have an average particle diameter of 1 to 500 μm, and preferably 10 to 400 μm.

According to an aspect of the present invention, the second inorganic material may include a mixture of a second inorganic material a having an average particle diameter of 1 to 150 μm and a second inorganic material b having an average particle diameter of 200 to 500 μm. Preferably, it may include a mixture of a second inorganic material a having an average particle diameter of 1 to 100 μm and a second inorganic material b having an average particle diameter of 200 to 400 μm. By including the second inorganic material having a different average particle diameter as described above, it is possible to further improve the hygroscopicity and release resistance, as well as to significantly reduce the expansion rate due to moisture absorption, and is more effective in securing the stability of the hygroscopic product. As a specific embodiment, the second inorganic material a may be a light burn, and the second inorganic material b may be a dead burn, but is not limited thereto.

In order to significantly improve the above-described effect, more preferably, the second inorganic material may have an average particle diameter ratio of the second inorganic material a (IO _a ) and the second inorganic material b (IO _b ) is 0.001 to 0.75:1. Preferably, it may be 0.01 to 0.5:1, more preferably 0.05 to 0.2:1.

According to an aspect of the present invention, the alkali metal phosphate may include an alkali metal ion selected from lithium, sodium and potassium. Preferably, it may include an alkali metal phosphate containing sodium metal ions. For a specific example, the alkali metal phosphate may include any one or two or more selected from the group consisting of monosodium phosphate, disodium phosphate, and trisodium phosphate. , Is not necessarily limited thereto.

When the alkali metal phosphate is included, when mixed with the first inorganic material, the second inorganic material, and the polymer wax, expansion caused by moisture absorption can be efficiently suppressed, and humidity control performance under high humidity conditions This is excellent, and long-term durability that can realize a moisture absorption effect for a long time can be secured.

According to an aspect of the present invention, the alkali metal phosphate may be included in an amount of 1 to 30% by weight based on the total weight of the desiccant. Preferably 2 to 25% by weight, more preferably 5 to 25% by weight may be included. When included in the above content, the expansion rate can be further improved during moisture absorption, and thus it is more effective in terms of preventing damage to the moisture absorption product and leakage of contents.

According to an aspect of the present invention, the polymer wax includes any one or two or more selected from the group consisting of polyethylene wax, polypropylene wax, polyamide wax, carnova wax, paraffin wax, and polytetrafluoroethylene wax. . In the case of containing the polymer wax, when the first inorganic material, the second inorganic material and the alkali metal phosphate are mixed together, the temperature inside the car lamp increases or the moisture absorbent changes to a high viscosity liquid according to the temperature change Thus, the release of moisture absorbed can be suppressed, and the function of controlling the moisture absorption rate of the product can be performed at the same time.

According to an aspect of the present invention, the polymer wax may be included in an amount of 1 to 20% by weight based on the total weight of the desiccant. Preferably 5 to 20% by weight, more preferably 5 to 15% by weight may be included. When included in the above amount, it is possible to improve the release resistance of moisture absorbed, and the moisture absorption rate and the moisture absorption rate are also improved, so that it is more effective in terms of imparting excellent moisture absorption persistence.

According to an aspect of the present invention, the desiccant includes all of the first inorganic material, the second inorganic material, an alkali metal phosphate, and a polymer wax, so that not only an improved moisture absorption rate, but also an environment requiring humidity control, especially under extreme humid conditions It realizes excellent humidity control performance and can secure continuous moisture absorption performance. Furthermore, it is more effective in terms of securing stability to prevent occurrence of additional damage due to expansion due to moisture absorption.

According to an aspect of the present invention, the moisture absorbent may further include a polymer additive. The polymer additive may be an anionic polymer having one or two or more functional groups selected from a carboxyl group and a hydroxyl group. In one specific example, selected from the group consisting of alginic acid, alginate, carrageenan, gelatin, hyaluronic acid, polyacrylic acid, polyacrylate, polymethacrylic acid, polymethacrylate, starch, oxidized starch, cellulose and carboxylmethylcellulose, etc. Any one or two or more polymer additives may be further included, but the present invention is not limited thereto. In addition, a coagulant such as A101 and NAP701 may be further included, but is not limited thereto.

According to an aspect of the present invention, the polymer additive may be included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the desiccant. Preferably 0.01 to 5 parts by weight may be included, but is not limited thereto. When included in the above amount, it is possible to further improve the hygroscopic performance for the purpose of the present invention, as well as stable solidification of the internal material after moisture absorption, as well as the expansion inhibition efficiency.

The desiccant according to the present invention has excellent release resistance in which moisture absorbed in the driving environment is not re-released, particularly when applied to an automobile lamp, and can be usefully used for automobile lamps such as automobile headlamps, rear lamps, or fog lights. And the scope of its application is not limited.

Another aspect of the present invention is a moisture absorbent product comprising the above moisture absorbent.

According to an aspect of the present invention, the hygroscopic agent may be included and provided in various hygroscopic products that require the purpose of preventing condensation or removing moisture. Specifically, according to one aspect of the present invention, the moisture absorbing product may include the moisture absorbing agent in a breathable bag, container, bag, or packaging material. Preferably, the desiccant may be sealed in a breathable packaging material.

According to one aspect of the present invention, the breathable packaging material is not particularly limited in shape or size, but can be designed appropriately depending on the purpose. Preferably, the moisture absorbing product may be sealed by putting the moisture absorbing agent according to the present invention in the breathable packaging material through heat-sealing the breathable packaging material.

According to one aspect of the present invention, the breathable packaging material is a person skilled in the art according to Korean Patent Publication No. 10-2013-0027402, Korean Patent Publication No. 10-2012-0093059 and Japanese Patent Publication No. 2010-076826 for the shape of the packaging material. It may be appropriately used those known to, but is not limited thereto. For example, two packaging films cut into a desired shape may be opposed to each other, and a desiccant may be placed between the two sheets of breathable packaging material facing each other.

According to an aspect of the present invention, the breathable packaging material may have a single layer or a stacked structure of two or more layers.

According to an aspect of the present invention, the breathable packaging material may have a double film structure in which a sealing layer is formed on one or both sides of the breathable film layer. By including the moisture absorbent in the breathable packaging material having a double-layer structure as described above, damage due to expansion can be further prevented, and re-release of absorbed moisture can be further prevented.

According to an aspect of the present invention, the breathable film layer may be prepared from any one or two or more fibers selected from natural fibers, polyester, polyethylene, polypropylene, polyamide, cellulose fibers, acrylic fibers and rayon fibers. have.

For a specific example, Tyvek, polypropylene (PP, polypropylene) nonwoven, polyethylene (PE, polyethylene) nonwoven, polyethylene terephthalate (PET, polyethylene terephthalate) nonwoven, kraft paper, selected from the group consisting of paper and cloth, etc. It may include at least one or more, but is not necessarily limited thereto. In terms of securing heat resistance to the breathable packaging material, it may be made of a breathable film layer made of Tyvek.

According to an aspect of the present invention, the sealing layer is formed by applying a coating solution containing a synthetic latex, an ethylene vinyl acetate copolymer (EVA, ethylene-vinyl acetate), a solvent and an additive, etc. on the breathable film layer by a known method. It may be, but is not limited thereto.

According to an aspect of the present invention, the synthetic latex may be, for example, any one or a mixture of two or more selected from acrylic latex adhesives and acrylic latex resins, but is not limited thereto.

According to an aspect of the present invention, it may be a hot melt adhesive including the ethylene-vinyl acetate copolymer, and the ethylene-vinyl acetate copolymer is produced by a copolymerization reaction of ethylene (ethylene) and vinyl acetate (vinyl acetate). It is a polymer. For example, the ethylene-vinyl acetate copolymer may contain 50 to 97% by weight of ethylene and 3 to 50% by weight of vinyl acetate, but is not limited thereto.

According to an aspect of the present invention, the additive may include any one or two or more selected from a curing agent, an inorganic filler, and a resin. For a specific example, the curing agent may be at least one selected from the group consisting of an amine-based curing agent, an acid anhydride-based curing agent, a phenol-based curing agent, and a dicyanic diamide-based curing agent. The inorganic filler may be at least one selected from the group consisting of calcium carbonate, magnesium carbonate, talc, mica, kaolin, graphite, and silica. The resin may be at least one selected from the group consisting of terpene phenol resin, hydrogenated rosin, petroleum resin, xylene resin, and coumarone resin, but is not limited thereto.

According to an aspect of the present invention, the solvent may be at least one or more selected from the group consisting of toluene, acetone, and methyl ethyl ketone, but is not limited thereto.

Preferably, the coating solution is a coating solution comprising 15 to 50% by weight of synthetic latex, 2 to 10% by weight of an ethylene-vinyl acetate copolymer, 40 to 80% by weight of a solvent, and 1 to 5% by weight of other materials, known on the breathable film. It may be formed through a process of applying the coating solution, and after applying the coating solution, a drying process by a known method may be performed as needed, but is not limited thereto.

According to an aspect of the present invention, the thickness of the sealing layer may be 3 to 20 μm, preferably 3 to 10 μm. When formed in a thickness within the above range, the strength of the breathable packaging material can be improved, contamination of the roller portion during processing can be prevented, and moisture permeability can be improved.

According to an aspect of the present invention, the hygroscopic product is excellent in hygroscopicity and can maintain a relative humidity of 60% or less for 55 days or more under a constant temperature and humidity condition of 40°C and 90% relative humidity. Preferably, it is possible to maintain a relative humidity of 60% or more for 60 days or more, more preferably 70 days or more in a thermo-hygrostat under conditions of 40°C and 90% relative humidity.

According to one aspect of the present invention, the moisture absorption product may have a moisture absorption rate of 100% or more, measured by exposing the moisture absorption product in a 30°C, 80% thermo-hygrostat for 21 days. Specifically, it may be 100 to 200%, preferably 140 to 200%.

By having the excellent moisture absorption characteristics as described above, not only can the hygroscopicity be maintained for a long time, but also the moisture absorption rate can be significantly increased compared to the conventional desiccant.

According to an aspect of the present invention, the moisture absorbing product may have an increase rate of 80% or less after moisture absorption measured by exposing the moisture absorbing product in a 30° C., 80% thermo-hygrostat for 21 days. Specifically, it may be 20 to 80%, preferably 20 to 70%, and more preferably 20 to 60%. In spite of absorbing moisture and absorbing a large amount of moisture as described above, having a remarkably low expansion coefficient can be achieved by including all the components of the present invention.

According to an aspect of the present invention, the moisture absorption product may more stably implement moisture absorption, release resistance, and expansion inhibition effect in the driving environment of a vehicle lamp, and in particular, it has excellent long-term durability, such as a car headlamp, a rear lamp, or a fog lamp. It can be usefully used for automobile lamps.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. However, the following Examples and Comparative Examples are only one example for describing the present invention in more detail, and the present invention is not limited by the following Examples and Comparative Examples.

Further, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. The terms used in the description herein are merely to effectively describe specific embodiments and are not intended to limit the invention.

In addition, the unit of the additive not specifically described in the specification may be a weight %.

[Method of measuring properties]

1. Moisture absorption rate

The moisture absorbing product was exposed for 21 days in a 30° C., 80% thermo-hygrostat, and the moisture absorbing rate was measured using Equation 1 below.

[Equation 1]

(Weight of the moisture absorbing product after exposure for 21 days-weight of the first moisture absorbing product) / Weight of the first moisture absorbing product × 100

2. Stability

Product stability, such as phase separation, leakage, and packaging damage, was visually evaluated by exposing the hygroscopic product in an 80% thermo-hygrostat at 30°C for 21 days for 21 days.

○: If there is no phase separation of the contents, leakage of the contents, or damage to the packaging paper, the stability is marked as excellent.

×: If any of the phase separation of the contents, leakage of the contents, or damage to the packaging paper occurs, the stability is marked as not secured.

3. Expansion rate

Based on the volume of the first moisture-absorbing product, the volume increase rate after exposure to 30°C and 80% thermo-hygrostat for 21 days was measured.

4. Durability

The moisture absorbing products prepared in Examples and Comparative Examples were put in a headlamp of an automobile, and the relative humidity in the lamp was measured under conditions of 40°C and 90% relative humidity, and the time at which the internal relative humidity reached 60% was measured.

[Examples 1 to 6 and Comparative Example 1]

According to the composition of Table 1 below, 25 g of a desiccant uniformly mixed using a mixer was prepared.

At this time, magnesium chloride (MgCl ₂ ) used as the first inorganic material was used with a purity of 94% from Aldrich, and magnesium oxide (MgO-1) used as the second inorganic material was made in Japan light burn, particle size 30 Μm was used, and magnesium oxide (MgO-2) was used as a German dead burn and a particle size of 220 µm. In addition, NaH ₂ PO ₄ and KH ₂ PO ₄ used as alkali metal phosphates were each of Aldrich's purity 99%, and polyethylene wax used as a polymer wax was SFC's LH1200 (softening point 109±3℃) ) Was used.

In addition, two breathable packaging materials of 160 mm×145 mm were prepared, and the prepared moisture absorbing agent was added between the breathable packaging materials, and then processed at 120° C. using a heat sealing machine to prepare a moisture absorption product.

At this time, the breathable packaging material is a hot melt coating solution (Multi-Kyung Coating Co., Ltd.: acrylic latex adhesive (transparent cluster) 25% by weight, acrylic latex (resin) 8% by weight, 8% by weight of a hot melt adhesive including ethylene-vinyl acetate resin, and 55% by weight of toluene. % And 4% by weight of a curing agent) were applied to one side of Tyvek film, and a dried double-layer structure (sealing layer/tyvek, sealing layer thickness of 5 μm) was used.

The physical properties of the specimens according to Examples 1 to 6 and Comparative Example 1 were measured by the method described above in the moisture absorption rate, stability of the contents, release resistance, expansion rate and long-term durability in the thermo-hygrostat as shown in FIG. The results are shown in Table 2 below.

division MgCl ₂ MgO-1 MgO-2 NaH ₂ PO ₄ KH ₂ PO ₄ PE wax Example 1 40 17.5 17.5 15 - 10 Example 2 40 20 20 10 - 10 Example 3 40 15 15 20 - 10 Example 4 45 30 - 15 - 10 Example 5 45 - 30 15 - 10 Example 6 40 30 - - 15 10 Comparative Example 1 40 40 - - - 20

division Moisture absorption rate (%) Expansion rate (%) stability Life characteristics (hr) Example 1 156.5 51.4 ○ 1,920 Example 2 149.6 58.3 ○ 1,780 Example 3 143.1 62.7 ○ 1,740 Example 4 137.4 72.7 ○ 1,510 Example 5 139.8 76.5 ○ 1,470 Example 6 125.1 77.1 ○ 1,380 Comparative Example 1 96.7 116.2 × 910

As shown in Table 2, in the case of the desiccant prepared in the example according to the present invention, not only has a remarkably superior moisture absorption rate compared to Comparative Example 1, but also has a significantly lower expansion rate after moisture absorption, so that the expansion inhibiting power due to moisture absorption is remarkably It was confirmed that it was improved.

Specifically, referring to FIG. 2, Example 1 can more clearly confirm this through a 61.8% improved moisture absorption rate and 51.4% improved expansion rate compared to Comparative Example 1. In addition, when the moisture absorption effect was confirmed in the long term, as shown in FIG. 3, the time to maintain the relative humidity of 60% or less in the case of Comparative Example 1 rapidly increased and the relative humidity exceeded 60% at 38 days. However, in contrast to this, in the case of Examples 1 and 2, it was confirmed that the relative humidity was maintained at 60% or less even after 55 days or more, and through this, it was confirmed that it has excellent long-term durability.

Moreover, this is confirmed in the crystal structure of the desiccant as shown in FIGS. 4 and 5, when the desiccant prepared in Example 1 is compared with the desiccant prepared in Comparative Example 1 shown in FIG. , It can be seen that the desiccant prepared in Example 1 can have a more improved moisture absorption performance due to the dense gap between the crystals, and realize a surprising effect of suppressing the volume expansion due to moisture absorption despite a dense structure. there was.

As described above, in the present invention, the desiccant for a lamp having good long-term durability and a moisture absorbing product including the same have been described through the specific matters and limited examples, but this is only provided to aid in a more general understanding of the present invention. It is not limited to the above embodiments, and those of ordinary skill in the field to which the present invention pertains can make various modifications and variations from this description.

Therefore, the spirit of the present invention is limited to the described embodiments and should not be defined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later belong to the scope of the inventive concept.

Claims (8)

a) any one or two or more first inorganic substances selected from the group consisting of magnesium chloride, calcium chloride and sodium carbonate,
b) any one or two or more second inorganics selected from the group consisting of magnesium oxide and calcium oxide,
c) alkali metal phosphate and
d) Any one or two or more polymer waxes selected from the group consisting of polyethylene wax, polypropylene wax, polyamide wax, carnova wax, paraffin wax and polytetrafluoroethylene wax
Desiccant comprising a. The method of claim 1,
The alkali metal phosphate is a desiccant containing one or two or more selected from the group consisting of monosodium phosphate, disodium phosphate, and trisodium phosphate. The method of claim 1,
The desiccant contains 10 to 70% by weight of the first inorganic material, 5 to 50% by weight of the second inorganic material, 1 to 30% by weight of alkali metal phosphate, and 1 to 30% by weight of polymer wax. A moisture absorbing product comprising the moisture absorbing agent of any one of claims 1 to 3. The method of claim 4,
The hygroscopic product is to be enclosed in the breathable packaging material. The method of claim 4,
The packaging material has a sealing layer formed on one or both sides of a breathable film layer made from any one or two or more fibers selected from natural fibers, polyester, polyethylene, polypropylene, polyamide, cellulose fibers, acrylic fibers and rayon fibers. Moisture absorption product. The method of claim 4,
The moisture-absorbing product is a moisture-absorbing product, characterized in that it maintains a relative humidity of 60% or less for 55 days or more under a constant temperature and humidity condition of 40°C and 90%. The method of claim 4,
The moisture absorption product is a moisture absorption product for automobile lamps.

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