WO2019035664A1 - White pigment comprising zif-based powder, polymer resin film, and method for changing color of medium by using white pigment - Google Patents

Abstract

The present invention provides a white pigment comprising a zeolitic imidazolate framework (ZIF)-based powder having a structure in which zinc (Z) and an imidazole-based organic material are combined with each other, a polymer resin film comprising the white pigment, and a method for changing the color of a medium by using the white pigment.

Description

 Title of the Invention

 Method for changing the color of a medium using a white pigment containing a ZIF powder, a polymer resin film and a white pigment

 TECHNICAL FIELD

 Cross-reference with related application (s)

 This application claims the benefit of priority based on Korean Patent Application No. 10-2017-0103628, dated August 16, 2017, and Korean Patent Application No. 10-2018-0095280, dated August 16, 2018, The entire contents of which are incorporated herein by reference.

 The present invention relates to a white pigment comprising a ZIF powder, a polymer resin film and a method for changing the color of the medium using the same.

 TECHNICAL BACKGROUND OF THE INVENTION

 Inorganic pigments, especially titanium dioxide pigments, are often abused as whiteners, tinting agents or opacifiers in various matrices. Titanium dioxide, in particular, effectively scatters light due to its high refractive index, and is thus the most widely used white pigment in the world as the most important white pigment for applications in paints and coatings, plastics, paper and fibers.

 In addition, it is one of the ingredients that raise annual sales of water trillion won by using toothpaste, paint, and plastic pigment because it is not poisonous even when consuming titanium dioxide.

 However, recent exposure to the EPA by the EPA may lead to the potential for carcinogenicity if it enters the lungs through respiration, posing the potential for carcinogenicity.

 This is because titanium dioxide is a highly stable substance and does not degrade under normal conditions. When it is deposited in the respiratory tract, it does not decompose and remains attached to the inside of the lungs, causing micro-inflammation in the lungs, and this inflammation is highly likely to be transferred to cancer cells .

Asbestos is the most commonly known substance that causes cancer due to inhalation. However, if asbestos is ingested by oral ingestion, it does not cause major problems. However, when asbestos enters the lungs through the respiratory tract as described above, It causes an inflammatory reaction to the lungs, which causes cancer It is reported to be transferred, adding credibility to the above claim.

 Therefore, there is a need for a safe white pigment which is not toxic even when inhaled.

 DISCLOSURE OF THE INVENTION

 [Problem to be solved]

 SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

 Specifically, it is an object of the present invention to provide a safe white pigment which is free from toxicity when inhaled, using a substance decomposed under the conditions inside the respiratory apparatus as a white pigment.

 It is also an object of the present invention to provide a polymeric resin film containing a safe white pigment which is not toxic even when inhaled.

 It is also an object of the present invention to provide a method for changing the color of a medium using a safe white pigment which is not toxic even when inhaled.

 MEANS FOR SOLVING THE PROBLEMS

 The white pigment for achieving this object is characterized in that it contains a ZIF (Zeolite icidazolate framework) powder having a structure in which zinc (Zn) and an imidazole-based organic substance bond.

 The ZIF powder is a kind of metal organic frameworks (MOFs), and the metal organic structure is a microporous crystal material composed of metal atoms or metal clusters and organic linkages connecting them by coordination bonds , A relatively new hybrid organic-inorganic material.

 The pore size and physical / chemical properties of this material can be easily controlled by selection of suitable metal atoms and organic linkages. Because of this particular nature, the potential applications of gas storage and / or absorption, catalysis, and membranes have been demonstrated.

On the other hand, zeolite-imidazolate frameworks (ZIFs) are composed of metal ions (usually zinc or cobalt) connected to an imidazolate (or imidazolate derivative) ligand. ZIF system The metal-bond-metal bond angle (ca. 145) of the material is close to the Si-O-Si bond angle found in many zeolites but has a distinct difference in its constituent elements. Therefore, these ZIF-based materials have attracted attention due to their superior thermal and chemical stability along with ultrafine porosity and have been widely applied in industrial fields.

 However, as described above, ZIF materials have only been used for gas separation, storage and absorption, catalysts, and chemical sensors.

However, recent information has been released which is used as a drug delivery material ZIF-based materials in some studies, ^'it was also released fact that it does not show toxicity in animals in the process. In particular, cancer cells have a weak acidity, and studies have shown that ZIF-based substances dissolve around cancer cells and have the ability to accurately transfer cancer drugs in ZIF-based materials to cancer cells.

 Accordingly, in the present invention, a white pigment which does not accumulate in the lungs has been developed by utilizing the characteristics of the ZIF-based material which is easily dissolved in acidity.

 That is, conventional titanium dioxide, zeolite, and the like are not decomposed under acidic conditions, and when they enter the lungs through inhalation, they are not decomposed but deposited in the lungs. However, when the ZIF-based material is used, The present inventors have completed the present invention by confirming that the possibility of carcinogenesis can be remarkably lowered because the ZIF powder is easily decomposed in the weakly acidic pulmonary cells and the particles are not adhered to the lungs.

 In general, the ZIF-based material is substituted by a functional group other than hydrogen so that at least one of Cd, Zn, Co, B, Mg, Cu and Mn and the 1,3- It is made by bonding with unimidazole derivatives.

Some of the ZIF-based materials that are white in color and made of known non-toxic metals are applicable as white pigments. Also classified as weakly acidic conditions, particularly those that are readily degradable in the lungs of venous blood, and which are expected to be free of inhalation toxicity are as follows: 1. Consisting of Zn ions. 2. It should be composed of imidazole which does not have a functional group that causes pulmonary inflammation like Sul fonate, Amine, and halogen. 3. There is no big difference in price compared to titanium dioxide. ZIF based materials that meet all of the conditions are the Zn and imidazole (imidazole), 2- alkyl include materials such as imidazole (2- _a lkyl imidazole), benzimidazole (benzimidazole).

 Until now, however, the ZIF-based materials have been mainly dimethyl formamide

Dimethylacetamide,

It was synthesized by heating reaction with an amide series solvent such as diethyl formamide and N_methylpyrollidine. However, in this case, the ZIF material itself is white, but it has a light yellow or brown color due to the color of the impurities such as amine which is formed during the heating process of the solvent.

 Therefore, the inventors of the present invention have conducted intensive research and have found that, when Zn_ZIF is produced by 1. a method which does not use an amide series solvent, it produces a pure white product And thus it has been found that ZIF based powders prepared by this method can be replaced with white pigments.

 Such a method of producing a ZIF powder is, for example, completely dissolving zinc nitrate tetrahydrate in ethanol and adding ammonia water to the solution. In another container, dissolve ethanol and benzimidazole completely and mix with the solution prepared in the previous step. Immediately after mixing, a white emulsion is formed. After stirring the resulting emulsion, a white solid ZIF powder can be obtained by using a centrifuge.

Conventionally, such ZIF-based powders have been produced by a small-scale thermal process or a solvent thermal process which takes a long time to form a required level of crystallinity and a porous network. However, recently, in order to produce a large amount of ZIF- Attempts have been made to use ultrasonic waves or to combine electrical / mechanical methods. There is also an approach to redesign the vanishing machine to produce a large amount of ZIF powder. One example is Room-Temperature Synthesis of ZIF 8: The Coexistence of ZnO Nanoneedles {Chew. Mater. 2011 23, 3590-3592) can easily mass produce ZIF-8 using Ball-Mi 11 And Faust ini et al. Proposed a microfluidic method to synthesize various kinds of MOFs continuously in a short period of time (M. Fausti et al., Mi crof luidic approach to contour and ul traft synthesi of metal-organic framework crystal s and hetero structures in confined microdroplets, J. Am. Chem. Soc. 135 (2013) 14619-14626).

 Here, the ZIF-based powder used in the present invention is not limited and can be produced according to the various production methods described above by modifying it so as to satisfy the condition capable of obtaining the pure white beating product.

 On the other hand, the white pigment according to the present invention includes a compound in which zinc (Zn) and imidazole are bonded, a compound in which zinc (Zn) and 2-methylimidazole are bonded, and a zinc (Zn) and benzimidazole are bonded to each other, and specifically, one or more selected from the group consisting of zinc (Zn) and one of imidazole-based organic substances represented by the following formula

 In such a ZIF powder, the zinc (Zn) may have a structure coordinatively bonded to the nitrogen atom of the imidazole-based organic material described above.

 The shape of the ZIF powder may be variously obtained according to the above manufacturing method, and may be, for example, spherical, rhombic, hexahedral, or rod-like. At this time, the shape of the ZIF powder used as the white pigment may be spherical or hexahedral in detail.

When used as a white pigment, such a ZIF powder may be contained in an amount of 80 to 100 parts by weight to ^{1 part} by weight based on the total weight of the white pigment, , And ZIF system words.

On the other hand, when the ZIF powder is contained in an amount of less than 100% by weight, The constitution is not limited to materials that can be used as conventional white pigments, and materials such as, for example, titanium dioxide (TiO ₂ ) may be used together. In addition, the present invention can also provide a polymer resin film containing the white pigment and the polymer resin.

 As described above, the white pigment containing the ZIF (Zeolite ic Imidazolate framework) powder having a structure in which the zinc (Zn) and the imidazole-based organic material are bonded to each other is mixed with or dispersed in the polymer resin, The color of the polymeric resin film can be more easily controlled. The white pigment has a characteristic of being easily decomposed in a weakly acidic condition, in particular, in the venous blood of the lung, and substantially inhaled and toxic, And polymeric materials including polymer.

 The type of the polymer resin included in the polymeric resin film is not particularly limited, and examples thereof include polyacrylonitrile, polypropylene, polyethylene terephthalate terephthalate, polycarbonate, polymethylmethacrylate poly (meth) acrylate Polyamide, polyamide such as polyamide, nylon, polyvinyl chloride, polyethylene oxide, polypropylene oxide, a mixture of two or more of these, a copolymer of two or more thereof, or a composite of two or more thereof .

In addition, the content of the white pigment in the polymer resin film is not limited to a great extent. The content of the white pigment may vary depending on the specific application in which the polymer resin film is used. For example, % To _{30 %} by weight.

The present invention also provides a method for changing the color of a medium using the pigment composition comprising the white pigment.

 At this time, the medium may be plastic, water-soluble gel, paste, paint or coating liquid.

In addition to the ZIF powder, the pigment composition may further include other pigments having a color other than white such as red, blue and green. On the other hand, the content of the white pigment in the pigment composition may be in the range of 0.5% to 99.5% by weight, and the content of the ZIF powder and the color of the medium Can be determined. Further, when the ZIF powder is used as a white pigment, various additives such as a dispersant, a light stabilizer and the like may be added to the medium depending on the properties of the substrate of the medium, but this is not essential.

 【Effects of the Invention】

 As described above, since the white pigment according to the present invention contains ZIF powder, it is stable to moisture and heat, and is decomposed under weakly acidic conditions to be soluble in water. Therefore, when white pigment is used, When entering, it is likely to be easily decomposed in lung cells with weak acidity due to the carbon dioxide in the blood, so that it is not likely to cause inflammation with the lung attached, and thus it can function as a safe white pigment without inhalation toxicity.

 BRIEF DESCRIPTION OF THE DRAWINGS

 1 is a powder photograph of ZIF-8;

 Figure 2 is a powder photograph of ZIF-8;

 FIG. 3 is a photograph immediately after the ZIF-8 powder is put into a slightly acidic solution;

 FIG. 4 is a photograph of the ZIF-8 powder after it is put into a slightly acidic solution and then subjected to sonication using a sound wave of 20 kHz for 5 seconds;

 FIG. 5 is a photograph of the ZIF-8 powder after the addition of the ZIF-8 powder to the weakly acidic solution and sonication using a sound wave of 20 kHz for 5 seconds;

FIG. 6 is a photograph showing the state after the addition of Al ₂ ¾ into a slightly acidic solution, followed by sonication using a sound wave of 20 kHz for 10 minutes;

FIG. 7 is a photograph of TiO ₂ after the addition of TiO ₂ to a weakly acidic solution followed by sonication using a sound wave of 20 kHz for 10 minutes.

 8 shows the polymer resin dispersion and the polymer resin film obtained in Example 3 and Comparative Example 3, respectively:

 DETAILED DESCRIPTION OF THE INVENTION

In the following, reference will be made to the embodiments according to the invention, but for a better understanding of the present invention, But is not limited thereto.

[Examples 1 to 2 and Comparative Examples 1 to 2: Preparation of white pigment]

 ≪ Example 1 >

 0.5 g of zinc nitrate heptahydrate was completely dissolved in 30 ml of ethanol,

5 ml was added to this solution. In another container, 10 ml of ethane and 0.3 g of benzimidazole were completely dissolved and then mixed with the solution prepared in the previous step. Immediately after mixing, a white emulsion was formed. The resulting emulsion was stirred for 10 minutes, and then a white solid ZIF-8 powder was obtained using a centrifuge. A photograph of ZIF-8 powder is shown in Fig.

 Referring to FIG. 1, it was confirmed that ZIF-8 was white in a solid powder state.

≪ Example 2 >

 ZIF-8 powder was also synthesized by a method similar to that of Example 1 above.

 A photograph of this ZIF-8 powder is shown in FIG.

 Referring to FIG. 2, ZIF-8 is also white in powder state. ≪ Comparative Example 1 &

A1 ₂ 0 ₃ powder were prepared.

≪ Comparative Example 2 &

TiO ₂ powder was prepared.

[Experimental Examples 1 and 2]

 Experimental Example 1: Determination of decomposition in a slightly acidic aqueous solution [

The ZIF-8 powder of Example 1, the ZIF-8 powder of Example 2, the Al ₂ O ₃ powder of Comparative Example 1, and the TiO ₂ powder of Comparative Example 2 were each weighed 0.5 g each in a slightly acidic Aqueous solution (pH: 6) to confirm decomposition. This was confirmed in FIGS. 3 to 7 Respectively.

Referring to FIGS. 3 to 7, it can be seen that the Al ₂ O ₃ powder of Comparative Example 1 and the Ti ₃ powder of Comparative Example 2 did not change, while the ZIF powder completely dissolves and dissolves.

<Experimental Example 2: Evaluation of horseshoe toxicity>

 ZIF-8 prepared in Example 1 was subjected to an inhalation toxicity test according to 0ECD Guideline 436 (Acute Inhalation Toxicity-Acute Toxicity Test). Three experimental animals were placed in an inhalation chamber (inhalation chamber), and a sample injection mask was connected to the nose of the specimen, and ZIF-8 aeros was generated through water and injected into the specimen . The injected concentration was set at 5 mg / L, and it was injected for 4 hours, and the condition of the 14 specimens was observed, and one of them died.

 As a result, it was confirmed that ZIF-8 of Example 1 belonged to the non-hazardous substance group at an LC50 (concentration at which 50% of the substance died at the time of inhalation) of 5.2 mg / L.

[Example 3 and Comparative Example 3: Production of polymeric resin film]

 &Lt; Example 3 >

 The ZIF-8 powder of Example 1 and the polyacrylonitrile resin were dispersed in dimethylformamide so as to be 2 wt% and 18 wt%, respectively, and a polymer resin film was prepared therefrom.

&Lt; Comparative Example 3 &

 And dispersed in dimethylformamide so that the amount of the polyacrylonitrile resin became 20% by weight. From this, a polymer resin film was produced. As shown in FIG. 8, the polymer resin film of Comparative Example 3 has a light yellow color, whereas the polymer resin dispersion of Example 3 has an opaque white color, and the polymer resin film to be finally provided also shows an opaque white color .

Claims

Claims:  [Claim 1]  A white pigment comprising a ZIF (Zeolite) imidazole ate f ramework powder having a structure in which zinc (Zn) and an imidazole-based organic substance are bonded.  [Claim 2]  The method of claim 1, wherein the ZIF powder is a compound in which zinc (Zn) and imidazole are combined, a compound in which zinc (Zn) and 2-methylimidazole are combined, and a compound in which zinc (Zn) Wherein the pigment is at least one selected from the group consisting of:  [3]  The method according to claim 1, wherein the ZIF-  A white pigment comprising zinc (Zn) and one of imidazole-based organic substances represented by the formula:

 Claim 4  The white pigment according to claim 1, wherein the ZIF-based powder comprises an organic-inorganic composite in which a nitrogen atom of zinc (Zn) and an imidazole-based organic material forms coordination bonds. [Claim 5]  The method according to claim 1, wherein the ZIF-  A white pigment comprising 80 to 100% by weight, based on the total weight of the white pigment.  [Claim 6]  A polymer resin film comprising the white pigment and the polymer resin of claim 1. 7.  The method according to claim 6, The polymer resin may be at least one selected from the group consisting of polyacrylonitrile, polypropylene, polyethylene, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, A polymeric resin film comprising at least one polymer resin selected from the group consisting of poly (meth) acrylate, polyimide, polyamide, polyvinyl chloride, polyethylene oxide and polypropylene oxide.  [8]  The method according to claim 6 or 7,  Wherein the polymeric resin film comprises 1% by weight to 30% by weight of the white pigment.  9]  A method for changing the color of a medium using a pigment composition comprising a white pigment according to claim 1.  Claim 10  The method according to claim 9, wherein the content of the white pigment in the pigment composition is in the range of 0.5% to 99.5% by weight.