WO2011142520A1

WO2011142520A1 - Hydrotalcite containing zinc and having thermal endurance and chlorine resistance, and product manufactured therefrom

Info

Publication number: WO2011142520A1
Application number: PCT/KR2010/009261
Authority: WO
Inventors: 이대희; 현동호; 이성욱
Original assignee: 주식회사 두본
Priority date: 2010-05-14
Filing date: 2010-12-23
Publication date: 2011-11-17
Also published as: KR20110125910A

Abstract

The present invention relates to a hydrotalcite that, when applied to Spandex fiber and synthetic resins such as PP, PE, and PVC, has good thermal endurance, chlorine resistance, and ion-exchangeability, and to a method for manufacturing the hydrotalcite. Zinc is ion-implanted in hydrotalcite to manufacture a novel form of hydrotalcite which has better initial pigmentation and prolonged thermal endurance as compared to conventional oxide-type hydrotalcites that are partially dehydrated and oxidized, and which can be usefully applied as a stabilizer for various resins. Here, the method used for hydrotalcite synthesis comprises a method for using a metal oxide or hydroxide to manufacture hydrotalcite, and a method for using an ionic metal compound such as metal chloride, etc. to synthesize hydrotalcite. Then, the hydrotalcite is diffused in water or other organic solvent, and an ion impregnation method using electrolysis and aqueous chlorine is implemented to impregnate zinc in a zinc-impregnation method. One aim of the present invention is to provide a zinc-impregnated hydrotalcite in partially dehydroxylated oxide form by providing energy to the particles to induce a structural change and by providing the hydrotalcite with uniform and small particles partially removed of a certain amount of water by means of the dehydration of structural water and the dehydroxylation thereof, as well as the method for manufacturing the hydrotalcite. The hydrotalcite of the present invention thus-obtained can be used to provide distinctive properties that yield more highly favorable effects than those of conventional hydrotalcite.

Description

Zinc-Deposition Hydrotalcite and its Preparations Having Heat Resistance and Chlorine Resistance

The present invention relates to a hydrotalcite on which zinc is deposited in a uniform oxide form that can provide excellent heat resistance and chlorine resistance when added to a synthetic resin and a method for preparing the same.

Hydrotalcite is a kind of metal hydroxide, which is composed of octahedral units repeating with an octahedral structure in which divalent or trivalent metal cations are located in the center and six hydroxide ions (OH ⁻ ) surround the metal cations. It has a double layer structure that forms two layers, and an anion and water molecules are positioned between the double layers to maintain an equilibrium of charge amount. [M ^II _1-x M ^III _x (OH) ₂ (A ^n- ) _{2 /} nmH ₂ O], where M ^II is a divalent metal, M ^III is a trivalent metal, and A ^n- is an anion having a valence of n. The ion of the hydrotalcite intermediate layer has been used as the ion trapping ability of the ion trapping ability having excellent heat resistance and weather resistance when processing the resin by the ability to exchange anions under various conditions.

As a related art related to the manufacture and application of hydrotalcite, a method using a metal salt, a metal oxide, a metal hydroxide, urea, and the like is well known (US Patent No. 4,418,14, Japanese Patent Publication No. 1994-329410 and Nos. 50-30039, US Pat. Nos. 4,044,571 and 552579, and Korean Patent No. 2003-0028666). However, the hydrotalcite prepared by the above method is used in the range of use due to the particle size, its uniformity, and the change of physical properties depending on the amount of water molecules present on the surface and the surface of the hydrotalcite and the amount thereof. Many restrictions have been imposed.

U.S. Patent No. 6,692,828 discloses hydrotalcite coated with a melamine-based compound having excellent heat resistance as a chlorine resistant agent of spandex fiber, but it has been found that the spandex discolors in hot air at 250 ° C.

European Patent Publication No. 1 262 499 A1 has attempted to improve the chlorine resistance of spandex fibers by milling hydrotalcite as an chlorine resistant agent and having an average particle diameter of 1 micron or less. The structure of desited is shown. As described above, in the case of the hydrotalcite which is decarbonized, the chlorine resistance function may be deteriorated when it is determined as a material that determines the ability to trap and exchange ions due to the amount of anions in the intermediate layer.

Hydrotalcite particles have suitable properties to provide molded articles having excellent thermal deterioration resistance when contained in the resin, but hydrotalcite particles are strongly required to have excellent stability against ultraviolet rays and heat to the resin.

Therefore, the inventors of the present invention have further studied in order to meet these demands, and the amount and particle size of the specific metal compound as the element contained and coated in the hydrotalcite, and the water content included in the thermal deterioration and physical properties of various synthetic resins. This study was conducted to identify the causes that affect the properties or properties of molded products during molding of synthetic resins. The present inventors confirmed that the particle size, crystallinity, and water content have a great influence in the manufacturing process of hydrotalcite. In particular, the zinc coating produced by the deposition of zinc on the surface of the hydrotalcite due to the addition of zinc compounds And partially oxidized hydrotalcite has been found to solve all of the above problems.

In addition, with respect to the hydrotalcite particles of the present invention, limiting the total amount of the specific metal compound exhibits a remarkable function for zinc-coated and water-controlled dehydration and dehydration hydrotalcite, and also particles of hydrotalcite. Size was found to affect the properties of the resin. Therefore, in order to obtain a composition having good heat resistance and chlorine resistance when contained in the synthetic resin, (i) the amount and moisture of the metal compound deposited on the hydrotalcite particles should be well controlled, and (ii) It was found that the average secondary particle diameter should be below a predetermined value.

Hydrotalcite is a "co-precipitation" method that dissolves a starting material in a solvent and induces the growth of particles through coprecipitation and aging, or a "high pressure hydrothermal method" that synthesizes particles by hydrothermally reacting a slurry containing the starting material in a high pressure reactor. It is normally manufactured by, for example.

In general, hydrothermal treatment in the preparation of hydrotalcite is known to increase the crystallinity of the particles and their growth. Crystallinity plays a very important role in determining physical properties when applied to synthetic resins, but growth of particles plays a rather poor role. Therefore, the control, uniformity and crystallinity of the particle size of the hydrotalcite are very important factors for improving the physical properties. Coprecipitation, one of the well-known synthesis methods, is a good method for obtaining large crystallinity and small particles by preparing molecular mixtures and compounds and increasing the crystallinity through proper ripening. However, it requires a very long time for aging, which is disadvantageous in terms of industrial efficiency and difficult to uniformly control the particle size.

In general, hydrotalcite contains water molecules adsorbed on the surface in addition to the water molecules between the double layers (ie, crystalline water), and the water molecules adsorbed on the surface of the hydrotalcite are first removed, and higher than this. The heat treatment at the temperature removes water molecules (ie, crystalline water) between the double layers, and it is known that changes in thermal dehydration and thermal decomposition occur as the heat treatment temperature is continuously increased. In other words, hydrotalcite is a kind of metal hydroxide, the octahedral unit is repeated by the octahedral structure in which a divalent or trivalent metal cation is located in the center and six hydroxide ions (OH) surround the metal cation. It has a double layer structure that forms two layers, and an anion and water molecules are positioned between the double layers to maintain the equilibrium of charge amount. In addition, in terms of structure, hydrotalcite decomposition is known to remove crystal water between layers when heat treated at a high temperature, and dehydration and decarbonization are well known when heat treatment is performed at a higher temperature. (Stanimirova etc. Clay Minerals, 39: 177-191, 2004).

Hydrotalcite is widely used as an additive to improve chlorine resistance and heat resistance when manufacturing various synthetic resin molded products such as polyvinyl chloride (PVC) and polyurethane. Not only did not satisfy the processing conditions, but also had a problem that does not play a sufficient role in showing the weather resistance and thermal stability of the synthetic resin, and the result of the presence of the crystal water is causing a bad result. This problem is a result of the structural stability of the hydrotalcite. Since the conventional hydrotalcite has a very low thermodynamic energy and the surrounding has to be in an acidic condition, the use of the hydrotalcite is limited in its use. This situation is not represented.

In general, PVC has a large chlorine group, so chlorine is easily dropped by external energy such as heat or light, and radicals are formed at the place where chlorine is dropped, thereby forming a double bond. The increase of the double bond is a factor that changes the color of the PVC, and if the temperature is increased, the double bond increases rapidly, and the color of the PVC changes to black through red. Due to this weak heat resistance, processing and molding of PVC is possible only by the addition of stabilizers that compensate for the heat resistance.

The present invention provides excellent heat and chlorine resistance containing hydrotalcite, which can be usefully used as an additive in the manufacture of synthetic resins and spandex polymers. It is to provide a site and a manufacturing method thereof.

The present invention relates to a hydrotalcite in the form of a partial oxide in which a new type of zinc is deposited or dyed as a synthetic resin composition having chlorine resistance and thermal deterioration, and an application as a resin stabilizer such as spandex, PVC, PE, PP, etc. More specifically, zinc deposits about 0.01% to 5% of hydrotalcite in hydrotalcite, and is a heat stabilizer for chlorine resistance, maritime resistance, and PVC, such as oxide hydrotalcite and spandex fiber having very excellent properties. It is about use as.

Specifically, a heat stabilizer composed of hydrotalcite particles which are hardly deformed by heat during the heat processing of a synthetic resin and which can provide mechanical properties such as excellent thermal deterioration resistance, high dispersibility, non-aggregation resistance, impact strength, and the like to the resin, and It relates to a resin composition contained at a specific ratio.

More specifically, the present invention is a thermal stabilizer, i.e. containing thermal stabilizer hydrotalcite particles, which prevents the minimization of chemical and physical strength caused by thermal decomposition of the resin during molding or use. It relates to a resin composition and a molded article.

As described above, zinc can be used as an efficient heat stabilizer by increasing the initial coloring and medium and long term heat resistance of PVC by adding chlorine capturing ability of zinc to hydrotalcite capacities of hydrotalcite used as a PVC stabilizer. This makes it possible to provide deposited dehydrated hydrotalcite. Therefore, it is considered to be useful to other fibers, such as spandex and cosmetics, home appliances, household goods and the like that can be used to give various functionalities. In addition, according to the present invention there is an effect that a spandex fiber having excellent chlorine resistance and heat resistance at the same time is provided. Spandex fibers produced according to the present invention can be effectively used in sports clothing, such as underwear, socks, especially swimwear because of their excellent chlorine resistance and heat resistance.

While the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

FIG. 1 is a SEM photograph when various kinds of zinc compounds are added when coating after synthesis of hydrotalcite. (a) ZnCl ₂ (b) ZnO (c) Zn-Stearate

2 is a SEM photograph of Zinc-Stearate in the synthesis of hydrotalcite.

The present invention relates to the production and application of hydrotalcite which synthesizes hydrotalcite crystals and deposits zinc thereon, and is excellent in chlorine resistance and heat resistance when used as a resin stabilizer. There is a method for producing using, and there is a method for synthesizing using a metal oxide or a hydroxide. Synthetic conditions include adding a basic substance to a mixed metal component dissolved in an aqueous solution, coprecipitating the mixed metal component with a hydroxide to prepare a mixed metal compound, and then performing a hydrothermal reaction. have. In addition, according to the method of manufacturing each raw material, the method of preparing a water-soluble metal salt includes MgCl ₂ , AlCl ₃ , Mg (NO ₃ ) ₂ , Al (NO ₃ ) ₃ , MgSO ₄ , Al ₂ (SO ₄ ) _3, etc. There is a method of preparing a metal salt of a raw material and a method of using a metal oxide and a metal hydroxide, such as MgO, Al ₂ O ₃ and Mg (OH) ₂ , Al (OH) ₃ and the like.

As a method of depositing zinc on the synthesized hydrotalcite crystals, there are a deposition method using a water-soluble salt of zinc, and a deposition method using an electrolysis method and a deposition method using a plasma method. The present invention can use all of the various depositable methods, and can achieve the above object in the most effective and efficient manner depending on the conditions. The size of the secondary particles of the synthesized hydrotalcite can be used all hydrotalcite synthesized in various sizes up to 0.01㎛-10㎛. The hydrotalcite thus synthesized was dispersed in water or other organic solution to deposit zinc using an electrolysis method. In other words, disperse hydrotalcite in water or organic solution 1-100wt% (appropriately 20-50wt%) compared to solution, and then send a current by connecting zinc metal to anode and cathode by electrolysis method. Zinc ions were stably deposited between the bilayers or on the porous surface. At this time, the voltage used for the electrolysis was usually used a variable current supply (0-220V) that can adjust the voltage according to the amount of zinc ionization, and the purity of zinc is more than 99.9% high purity plate or high purity wire. . In order to deposit a stable form in an aqueous solution or an organic solution, only hydrotalcite is dispersed in an aqueous solution or an organic solution to supply a current to dye or deposit zinc, and various types of acids, alcohols, and surfactants are used. And other organic materials alone or in combination with hydrotalcite in a predetermined amount (0.01-50 wt%) in a solution (appropriately 0.5-15 wt%), and then there is a method of depositing zinc by electrolysis. . At this time, in order to induce effective deposition, the hydrotalcite was dispersed and appropriately stirred (5-300 rpm), and the temperature of the aqueous solution or the organic solution was heated (under 100 ° C) using a heating plate during electrolysis. .

In addition, it is also possible to apply oxides such as zinc oxide and zinc hydroxide, and compounds having the same combination of hydroxide and zinc salt form compounds such as zinc chloride, zinc sulfate and zinc nitrate with organometallic forms such as stearic zinc. Although the above-mentioned electrolysis method is possible, the method of depositing zinc metal and zinc compound in water and organic solvent and depositing it after the hydrotalcite reaction and before surface coating may have a similar effect. In other words, using a water-soluble zinc compound, zinc oxide, and zinc hydroxide, add 0.1-10% of the zinc material to about 2L of water, and heat-disperse it sufficiently at about 8000rpm at 70-80 ° C. The zinc deposition process takes between 1 and 1 hour. However, it is most preferable when dry and wet coating are put together with the surface coating agent.

In the case of hydrotalcite having a modified structure in which zinc is deposited, the heat treatment during the post-treatment may be performed at 180 to 300 ° C., preferably at 200 to 250 ° C. for 1 to 4 hours, preferably 2 to 3 hours. . That is, it is obtained through complete or partial removal of crystal water (ie, dehydration) and partial removal of hydroxyl groups (ie, dehydration) by heat treatment. Thus, the chemical formula of the dehydrated zinc precipitated hydrotalcite obtained by the heat treatment can be presented as follows.

[M ^II _{4 + x} (M ^III _1-b ^oct M ^III _b ^tet ) ₂ (OH) _{12 + 2x-2y} O _y (A ^n- ) _{2 / n} ] (k) Zn

Where

M ^II is a divalent metal selected from the group consisting of Mg, Ca and Zn;

M ^III is a trivalent metal selected from the group consisting of Al, Fe, Co, Mn and Ti;

M ^{III oct} each represents M ^III constituting the sixth configuration of the octahedron structure;

M ^IIItet represents M ^III , each of which forms a ^fourfold configuration of the tetrahedron structure;

A ^n- is an anion having a valence of n selected from the group consisting of CO ₃ ^2- , NO ^3- , SO ₄ ^2- , OH ⁻ , and Cl ⁻ ; 0 ≦ x ≦ 4, 0 <b ≦ 0.5, and 0 <y ≦ 6.

In the hydrotalcite of the above formula, preferably, M ^II is Mg; M ^III is Al; A ^n- is CO ₃ ^2- .

As used herein, the term "hydrotalcite in the form of zinc deposited oxide" means that some or all of the crystallized water located between the bilayers is dehydrated and some or all of the hydroxyl groups located around the metal are dehydrated to have some oxide phase. It means a hydrotalcite coated with physical and chemical bonds by depositing zinc particles on the surface of the hydrotalcite in this partial oxide form. At this time, dehydration may occur simultaneously in both the divalent metal and the trivalent metal constituting hydrotalcite, and more particularly, dehydration occurs around the trivalent metal. However, since the zinc particles coated on the surface are not affected, they are stable even in the process of controlling moisture through heat treatment.

The dehydration refers to a process in which two hydroxyl groups present in the metal hydroxide layer are separated and react to generate water. By such dehydration, the coordination number of divalent and trivalent metal cations is changed from the existing 6 coordination (octahedron structure) to 5 coordination and 4 coordination (tetrahedron structure) tetrahedron, among the 4, 5, 6 coordination The 4th and 6th coordination can confirm the proportional amount, but the 5th coordination can confirm only the possibility (see FIG. 2). Substantially 6 by combining the: (CO ₃ ^2- Yes) dehydroxylation is an interlayer anion is filled with the oxygen vacancy of the hydroxyl group generated by the dehydroxylation through made in the proportion of up to about 50% of the metal, replacement for a hydroxyl group The octahedral structure of the coordination is dominant, and the tetrahedral structure of the coordination is present in a relatively small amount.

The hydrotalcite heat treated at 240 ° C. for 2 hours showed that the octahedral and tetrahedral structures were mixed by dehydration due to heat treatment, and the interlayer anion that maintained the bond with the metal by the electrostatic attraction for the balance of charge was heat treated. It can be seen that due to the dehydration caused by the unstable bond with the metal causes a change in the symmetrical form. This change in the bonding of the interlayer anions leads to an overall imbalance of the charge, thereby compensating for the surrounding anions, and thus improving the anion removal function of the hydrotalcite.

The hydrotalcite of the formula obtained according to the present invention can be converted into reconstruction hydrotalcite by absorbing the crystallized water again in a short time when left in the atmosphere. Even after reconstruction, the changed metal layer is maintained and only the crystal water is filled between layers. The recrystallized hydrotalcite crystal water is reduced due to the change of electron density due to the change of symmetry of interlayer anion and the change of surrounding environment after reconstruction. It forms weak hydrogen bonds and can escape at lower temperatures than before rebuilding.

The hydrotalcite of the present invention may be added directly to the synthetic resin as an additive when preparing the synthetic resin, but is preferably coated with one or more surface treatment agents. As the surface treatment agent used in the present invention, higher fatty acids such as stearic acid and nonanoic acid; Silane coupling agent (formula: Y-Si (OR) ₃ , wherein Y is an alkyl group, vinyl group, aryl group, amino group, methacryl group, or mercapto group, R is methyl, ethyl, acetyl, propyl, isopropyl , Isopropylphenoxy or phenoxy); Titanium, such as isopropyl triisostearoyl titanate, isopropyl tris (dioctylpyrophosphate) titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, and isopropyl tridecylbenzenesulfonyl titanate Nate type coupling agent; Phosphoric acid esters such as mono or diester of orthophosphoric acid and stearyl alcohol; And aluminum coupling agents such as acetalkoxy aluminum diisopropylate.

The surface treatment agent may be used to coat the hydrotalcite particles of the present invention by conventional wet or dry methods. For example, in the case of the wet method, the surface treating agent may be added to the slurry containing hydrotalcite particles in a liquid or emulsion phase and mixed sufficiently mechanically at a temperature of about 100 ° C. In the dry method, the hydrotalcite particles may be sufficiently mixed under heating or non-heating by adding the surface treatment agent in a liquid, emulsion or solid form while sufficiently stirring the hydrotalcite particles in a mixer such as a Henschel mixer. At this time, the addition amount of the surface treatment agent is preferably 10 parts by weight or less, preferably 0.1 to 5% by weight per 100 parts by weight of hydrotalcite particles.

Such a hydrotalcite of the present invention is a surface-deposited zinc in the form of the whole or partial substitution of a trivalent element consisting of Fe, Co, Mn and Ti instead of Al and a divalent element consisting of Ca and Zn instead of Mg as shown in the formula As it has a small and uniform size, it can be added to synthetic resins such as polyvinyl chloride (PVC) and spandex fiber to provide excellent heat resistance and chlorine resistance, and thus can be usefully used as an additive in preparing synthetic resins. However, in the case of processing to the resin, the secondary agglomerated particle size is usually about 10 μm or less in the case of 90% through powder (d (0.9)) powder for smooth processability, preferably 6 μm or less, and the secondary Preferably, the aggregated particle size is about 3 μm or less on average.

The process of sand grinding or milling hydrotalcite can be milled using conventional bead mills. This milling process is preferably carried out before the surface coating after synthesis, but may be performed after the surface coating. In addition, the prepared hydrotalcite may be used by classifying the secondary aggregated particle size to about 3 μm or less using a classifier. This process change can be judged as a process according to the quality of hydrotalcite related to the condition of the initial raw material, form, purity, etc., and the heat treatment at 180 degrees to 300 degrees is finally performed due to reabsorption of moisture. It is preferable to carry out as. However, in order to prevent reabsorption and deterioration of moisture, silane coating may be finally performed, but it is not preferable because of contamination of the product, increase in price, and complexity of the process.

In addition, in the present invention, the production of zinc-deposited partially dehydrated hydrotalcite is possible with a dryer capable of heating hydrotalcite having crystalline water at about 200 to 390 ° C., but drying using a microwave technique of the state of the art. It is also possible.

Hereinafter, the present invention will be described by the following examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1

Hydrotalcite may be prepared by various methods, but using a method of reacting with a metal hydroxide as an example.

First, 2.0 L of distilled water was added to a 3L stainless autoclave, 56.5 g of Mg (OH) ₂ (> 95%) and 40.56 g of NaHCO ₃ (99.5%) were added thereto, followed by stirring, followed by Al (OH) ₃ (99.8%). ) 32.06g and 5.80g NaAlO ₂ (> 99%) were added and the temperature was raised to 170 ° C while stirring at 350rpm for 2 hours. After completion of the stirring, the pressure was released, the filter and the water washed to obtain a hydrotalcite slurry crystals. 10 g of the obtained hydrotalcite was dispersed in 300 mL of distilled water, and a zinc plate having a purity of 99.99% of a purity of 2x1 cm and a weight of 1.1 g was connected to the electrode of the positive electrode and the negative electrode at a distance of 5 mm. While stirring at a speed of 500 rpm, a zinc ion is deposited on hydrotalcite by applying a current of 30 Volts using a power supply for 0.5-3 hours. After a certain time, the current was stopped and filtered, and the sample was first dried in an oven at 105 ° C. for 2 hours, and the sample was secondly dried at 240 ° C. for 2 hours to dehydrate and dehydrate. Deposited Hydrotalcite Sample 1 was prepared.

Sample 1 was analyzed by ICP to confirm that 1.61% of zinc was deposited. Sample 1 was coated with 2.5% stearic acid, mixed with PVC in the formulation of Table 1, and then kneaded at 185 ° C. for 5 minutes in a roll mill to make a sheet of sample 1 having the same thickness. The sheets were cut to the same size and placed in an oven at 200 ° C., and the sheets of Sample 1 were taken out one by one at 10 minute intervals, and the degree of discoloration was measured.

Example 2

10 g of hydrotalcite prepared under the same conditions as in Example 1 was added to 300 mL of distilled water, coated with 2.5% stearic acid, and dispersed in 1.0% zinc oxide (ZnO), thereby preparing Sample 2.

Sample 2 was analyzed by ICP to confirm that 1.00% of zinc ions were deposited. In addition, the sheet of Sample 2 was made in the same manner as in Example 1.

Example 3

10 g of hydrotalcite prepared under the same conditions as in Example 1 was added to 300 mL of distilled water, coated with 2.5% stearic acid, 1.0% zinc chloride (ZnCl ₂ ), and dispersed to prepare Sample 3.

Sample 3 was analyzed by ICP to confirm that 0.58% of zinc ions were deposited. In addition, the sheet of Sample 3 was made in the same manner as in Example 1.

Example 4

Sample 10 was prepared by taking only 10 g of hydrotalcite prepared under the same conditions as in Example 1, coating 300 mL of distilled water, coating it with 2.5% stearic acid, and then dispersing 1.0% zinc stearate.

Sample 4 was analyzed by ICP to confirm that 0.12% of zinc ions were deposited. In addition, the sheet of Sample 4 was made in the same manner as in Example 1.

Example 5

In the synthesis of hydrotalcite, 2.0L of distilled water was added to a 3L stainless autoclave, 56.5g of Mg (OH) ₂ (> 95%) and 40.56g of NaHCO ₃ (99.5%) were added, followed by stirring and Al (OH). 32.06 g of ₃ (99.8%), 5.80 g of NaAlO ₂ (> 99%) and 1.0 g of ZnO (> 99%) were added thereto, and the mixture was stirred at 350 rpm and heated to 170 ° C for 2 hours. After stirring is complete, the pressure is released, and the filter and the water are washed to obtain hydrotalcite crystals. The sample was first dried in an oven at 105 ° C. for 2 hours, and the sample was further dried at 240 ° C. for 2 hours to prepare hydrotalcite sample 5 containing zinc which was dehydrated and dehydrated.

Comparative Example 1

2.0L of distilled water was added to a 3L stainless autoclave, 56.5g of Mg (OH) ₂ (> 95%) and 40.56g of NaHCO ₃ (99.5%) were added, followed by stirring, followed by Al (OH) ₃ (99.8%) 32.06 g and NaAlO ₂ (> 99%) were added and the temperature was raised to 170 ° C. while stirring at 350 rpm to react for 2 hours. Thereafter, heat treatment is performed for 105 hours and 240 degrees for 2 hours, respectively, to prepare hydrotalcite in the form of a partially dehydrated oxide.

Comparative Example 2

Zinc substituted hydrotalcite (manufacturer: Dubon, trade name: Polylizer121, water content 0.5%, particle size 0.2-0.5㎛, Molar Ratio MgO / Al ₂ O ₃ = 2.8-3.2, ZnO) / Al ₂ O ₃ = 0.8-1.2, pH = 8.6, Bulk Density 0.3-0.5 g / ml, coated with 2.5% stearic acid), mixed with PVC, and kneaded in a roll mill at 185 ° C. for 5 minutes. made. Each sheet was cut to the same size and placed in an oven at 200 ° C., and samples were taken out one by one at 10 minute intervals to measure the degree of discoloration.

Table 1

TABLE 2

TABLE 3

Table 4

[Analysis Method of Particle Size]

A 0.1-0.5 mg sample is placed in a 10 mL vial bottle, followed by 2 ml of ethanol and 2 ml of a dispersant (anionic surfactant). Ethanol is used to remove fatty acids coated on the sample, and dispersants are added to prevent agglomeration of the samples on the powder. The sample thus treated is pretreated in a sonicator for about 30 seconds to 1 minute. Particle size is measured using a particle analyzer (PSA, MASTERSIZER 2000). In order to measure the exact particle size of the sample was measured by inserting the refractive index value of the hydrotalcite 1.52, the refractive index value of the distilled water of the particle analyzer (1.33) was measured. In addition, when measuring particle size, Stirrer / Pump measures 3500rpm and Ultrasound at 100%. When the data have a constant value with no change in the particle size analysis data, the data can be called an accurate particle size.

[Thermal Stability Experiment]

In order to compare and evaluate the effect of improving the thermal stability of the hydrotalcite prepared in Comparative Examples and Examples 1 to 4, 40.0 parts by weight of dioctylphthalic acid (DOP) based on 100 parts by weight of PVC resin, zinc-based stabilizer (Zn-st ) 0.2 parts by weight, 0.05 parts by weight of dibromomethane (DBM) and 2.0 parts by weight of hydrotalcite were mixed and kneaded at about 30 rpm on a 160 ° C. roll for 5 minutes to prepare a sheet having a thickness of about 0.5 mm. The prepared sheet was placed in an oven heated at 195 ° C., and the specimens were taken out at regular intervals to measure thermal stability. Thermal stability was evaluated by measuring the time until the resin changed to a constant black color based on the color change caused by the deterioration of the resin.

Chlorine Resistance Test

Strong retention rate test in chlorine water: Spandex yarn was treated for 2 hours in water at pH 4.2, 97-98 ℃ under 50% elongation, cooled at room temperature, and then immersed in 45L chlorine water with 3.5 ppm of active chlorine at pH 7.5 for 24 hours at room temperature. Afterwards, strong retention was evaluated.

* Strong holding ratio (%) = S / S o × 100 (S o: strong before treatment, S: strong after treatment)

* For strong evaluation, Instron 4301 (Instron, USA) was used, the sample length was 5cm, and the tensile head speed was 300mm / min using a 1kg cell. Measured.

Claims

Hydrotalcite in the form of zinc-deposited oxides: Zinc is deposited on the surface of the hydrotalcite using zinc metal and zinc-containing compounds and electrolysis and ion deposition, followed by heat treatment at 180 to 300 ° C. for 1 to 4 hours. Dehydrated zinc precipitated hydrotalcite obtained by complete or partial removal of crystallized water (ie dehydration) and partial removal of hydroxyl groups (ie dehydration).
The hydrotalcite of claim 1, wherein the amount of zinc deposited comprises less than or equal to 5% in weight percent of hydrotalcite with surface water removed below 120 degrees.
The hydrotalcite according to claim 2, wherein the hydrotalcite particles have an average secondary particle diameter of 3 μm or less, and 90% (D 0.9 ) have a particle size distribution curve within 10 μm.
The hydrotalcite deposited with zinc in the present invention is a fatty acid, alcohol, metal soap, wax, polymer, etc. in a weight percent ratio of 0.01 to 10.0%, possibly 1 to 4% dry coating, wet coating, mechanical coating Hydrotalcite characterized in that it comprises a coating by such a method.
After synthesizing the crystals of hydrotalcite, the zinc metal is either singly or in the form of water-soluble zinc salts such as zinc oxide, zinc hydroxide and zinc chloride, zinc nitrate, zinc sulfate and the like by electrolysis, adhesion of chloride ion, plasma, etc. A process for producing a resin stabilizer hydrotalcite characterized by depositing a compound and organic zinc such as zinc stearate.
When depositing zinc by electrolysis alone or in combination, high purity (more than 99.9) of zinc is connected to both or one side of the positive and negative electrodes either alone or in parallel and electrolytically deposited. The range of 1-100V, the amount of zinc deposited is in the range of 0.01 to 5% by weight.
The method for preparing hydrotalcite according to claim 1, wherein after the zinc is deposited hydrotalcite is synthesized, heat treatment is performed at 200 to 250 ° C. for 1.5 to 2.0 hours.
The method of claim 1, characterized in that it can be used as an additive to improve the heat stabilizer, chlorine resistance and maritime resistance to polymer resins and fibers such as PVC, PP, PE, PS, PU, ABS, spandex fibers, etc. The use of a new dehydroxylated zinc deposit hydrotalcite.