JPH0360340B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for producing a stabilizer for chlorine-containing polymers, and more specifically, the present invention relates to a method for producing a stabilizer for chlorine-containing polymers, and more specifically, the present invention relates to a method for producing a stabilizer for chlorine-containing polymers, which has a remarkable suppressing effect on the tendency of decomposition and coloration caused by amines. The present invention relates to a method for producing a drug. Prior Art and Technical Problems of the Invention Chlorine-containing polymers such as vinyl chloride polymers tend to become colored or have deteriorated mechanical properties due to thermal decomposition reactions such as dehydrochlorination during hot molding or subsequent thermal history. It is generally necessary to incorporate stabilizers to prevent this. As stabilizers, lead-based stabilizers such as tribasic lead sulfate have particularly excellent performance, and non-toxic stabilizers that do not contain lead include alkaline earth, zinc or aluminum hydroxides. Inorganic stabilizers such as compounds, complex hydroxides, basic salts or silicates, polyhydric alcohols, phenols, nitrogen compounds, sulfur compounds, organophosphoric acid compounds, organotin compounds, and metallic stones. Organic stabilizers such as Ken-based stabilizers are known. However, when a chlorine-containing polymer composition containing these known stabilizers is used as a polyurethane foam top sheet for chairs, seats, etc., the sheet of the chlorine-containing polymer composition may have an undesirable color. It was found that the phenomenon of discoloration occurs. The reason for this is that foamed polyurethane contains terminally reacted amines used as chain extenders, and these amines volatilize over time, or amines decompose over time as the foamed polyurethane decomposes. This is thought to be because these amines promote the dechlorination reaction of chlorine-containing polymers. No stabilizer has yet been found which has an excellent effect of inhibiting the tendency of chlorine-containing polymers to decompose and become colored due to amines. Outline of the Invention The present inventors have discovered that an ion exchanger in which the carbonate radicals of hydrotalcites are replaced with perhalogen oxygen radicals in a certain range has a remarkable suppressive effect (hereinafter simply referred to as simply They have found that they exhibit excellent heat stabilizing effect and prevention of initial discoloration of chlorine-containing polymers. The present inventors have found that when this ion exchanger is used in a chlorine-containing polymer in the form of a polyhydric alcohol or a metal fatty acid salt in the form of a composite, the above-mentioned properties are significantly improved. Purpose of the invention That is, the purpose of the present invention is to
It is an object of the present invention to provide a method for producing a stabilizer for chlorine-containing polymers that has a remarkable effect of inhibiting coloring tendency. Another object of the present invention is to provide a method for producing a stabilizer for chlorine-containing polymers that has the above-mentioned properties and is also excellent in heat stabilizing effect, initial discoloration prevention ability, and foaming suppressing effect. Composition of the Invention According to the present invention, a perhalogen oxyacid is added to an aqueous dispersion of hydrotalcites with thorough stirring and mixed uniformly, and then the mixture is stirred at a low speed until the generation of carbon dioxide gas stops. 20 to 80% of divalent anions such as carbonate ions are exchanged with perhalogen acid ions to obtain a slurry-like hydrosite perhalogen oxygen acid ion exchanger with a pH of 4 to 7. Provided is a method for producing a stabilizer for chlorine-containing polymers, which comprises adding an alkaline earth metal hydroxide or oxide so as to transfer to the alkaline side. According to the present invention, it has also been found that when this ion exchanger is used in a chlorine-containing polymer in combination with a polyhydric alcohol, a metal fatty acid salt, etc., the above-mentioned properties are significantly improved. Preferred Embodiments of the Invention The present invention will be explained in detail below. Raw Materials Hydrotalcites used as raw materials in the present invention have the general formula M ²⁺ xM ³⁺ y(OH) _2x+3y-2z (A ^2- ) _z・aH ₂ O (1) where, M ²⁺ is a divalent metal ion such as Mg, M ³⁺ is a trivalent metal ion such as Al, A ^2- is a divalent anion such as CO ₃ , and x, y, and z are 8≧x/y≧1/ 4 and z/
It is a positive number that satisfies x+y>1/20, and a is a number that satisfies 0.25≦a/x+y≦1.0. It is a composite metal hydroxide with Among these composite metal hydroxides, the compound represented by the formula Mg ₆ Al ₂ (OH) ₁₆ CO ₃・4H ₂ O (2) is a natural mineral known as hydrotalcite, and this mineral and Homologues are the special public interest patent application filed in 1977 by Kyowa Chemical Industry Co., Ltd.
-32198, 48-29477, and 48-29478. It is already known that these hydrotalcites, especially compounds with the formula Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ 3H ₂ O...(3), have excellent chloride ion scavenging performance. It is also known to use this product as a stabilizer for chlorine-containing polymers. However, when hydrotalcites are actually blended into chlorine-containing polymers, the thermal stabilization effect obtained is not so great, and the chlorine-containing polymers are already colored at the initial stage of blending. . In the present invention, by utilizing the property that these hydrotalcites are easily ion-exchanged in a state sufficiently dispersed in water, that is, the property that carbonate ions are ion-exchanged with other anions, This method involves introducing perhalogen oxyacid ions in an amount within a certain range. Among the hydrotalcites used as raw materials, in general formula (1), M ²⁺ is Mg, M ³⁺ is Al,
Those in which A ^2- is CO ₃ are preferred, and those of general formula (3) are also most preferred. This product is easily available from Kyowa Chemical Industry Co., Ltd. under the trade name DHT-4A. In the present invention, the other raw material used is a perhalogen oxyacid. As a perhalogen oxygen acid,
Examples include perchloric acid and periodic acid, but peroxyacid is most preferred in terms of stability of the product itself and amine resistance. Reaction In the present invention, hydrotalcites and perhalogen oxygen acids are brought into contact with each other in the presence of water to perform ion exchange. It is extremely important for the purposes of the present invention that 70% be exchanged with perhalogen oxyacid ions. That is, according to the present invention, by introducing perhalogen oxygen acid ions into hydrotalcites, it is possible to impart amine resistance that has not been observed at all to hydrotalcites, and to improve thermal stability. It is possible to prevent the initial coloring tendency. If the amount of perhalogen oxygen acid ions introduced is less than the above range, the amine resistance will not be improved to a satisfactory level, the thermal stability will be unsatisfactory, and there will be a tendency for initial discoloration, as shown in the example below. is also accepted. On the other hand, if the substitution of perhalogen oxygen acid ions exceeds the above range, the substituted hydrotalcites themselves have a marked tendency to deteriorate (decompose and color) the chlorine-containing polymer. This is easily supported by the fact that hydrotalcites highly substituted with perhalogen oxygen acid ions exhibit a pH on the acidic side, and the fact that chlorine in many acidic substances promotes the decomposition and coloring of the polymers they contain. It will probably be done. The crystal structure of hydrotalcites belongs to a trigonal or hexagonal system, and shows a structure close to oxygen re-packing, in which Al ³⁺ partially replaces Mg ²⁺ in Mg(OH) ₂ and becomes positively charged. It consists of a basic layer (skeleton) and a negatively charged intermediate layer consisting of anions and water, and the surface charge is positive. Hydrotalcites are brought into contact with a predetermined amount, that is, an aqueous solution of perhalogen oxyacid corresponding to the exchange rate mentioned above, to exchange divalent anions such as carbonate ions in the hydrotalcites with perhalogen oxyacid ions. In particular, in order to increase the exchange rate, it is important to determine how the two react. In the present invention, the following procedure is used. (1) Hydrotalcites are uniformly dispersed in water to form an aqueous dispersion (slurry). (2) Add a predetermined amount of perhalogen oxyacid gradually to the aqueous dispersion of hydrotalcites while stirring at high speed (to ensure sufficient stirring) and mix uniformly. (3) Next, due to the ion exchange reaction, carbon dioxide gas etc. are generated, so stir at low speed, and continue to stir at low speed until the generation of carbon dioxide gas etc. stops and the pH of the slurry rises to 4 to 7 to carry out the reaction. . In this way, an ion exchanger slurry is obtained in which 20 to 80% of divalent anions such as carbonate ions of hydrotalcite are exchanged with perhalogen oxyacid ions. The reaction takes place at room temperature. The reaction is usually carried out at room temperature, but heating may be used to accelerate the reaction. A reaction time of 30 to 300 minutes is generally sufficient. Usually, the reaction time for high-speed stirring in (2) above is about 20 to 30 minutes, and the reaction time for low-speed stirring in (3) is about 30 to 180 minutes. When the temperature is low, it takes time, but the formation of perhalogen oxyacid is suppressed and the ion exchange reaction is uniformly carried out. (4) Next, an alkaline earth metal hydroxide or oxide is added to the slurry in order to raise the pH of the ion exchanger slurry to an alkaline side, for example 8 to 10, and stabilize the ion exchanger. (5) The ion exchanger slurry is then evaporated to dryness, or filtered under reduced pressure, heated and dried, and pulverized to produce a hydrotalcite perhalogen oxygen acid ion exchanger. In the above reaction procedure, (1) to (3) are important for increasing the ion exchange rate of divalent anions such as carbonate ions between the layers of hydrotalcites.
When hydrotalcites are brought into direct contact with an aqueous perhalogenated oxygen acid solution without being dispersed in water, they not only undergo the above ion exchange but also react with the Mg and Al bases that form the skeleton, producing perhalogenated oxygen acids such as Mg and Al. do.
In particular, perhalogen oxyaltates of Al are extremely deliquescent. Procedures (1) to (3) are necessary to suppress this reaction and increase the ion exchange rate. In addition, (4), the effect of adjusting the pH of the ion exchange slurry to the alkaline side is to eradicate the influence of strongly deliquescent perchlorate, which is produced as a by-product when the hydrotalcite skeleton is dissolved. In another preferred embodiment of the present invention, when the above-mentioned ion exchanger is used in a chlorine-containing polymer, a polyhydric alcohol, a metal fatty acid salt, and the like are co-blended. Suitable polyhydric alcohols include, but are not limited to, mono- and dipentaerythritol, other polypentaerythritols, mannitol, sorbitol, glycose, fructose, trimethylolpropane, polyethylene glycols, such as those with a molecular weight of 200 to 9,500, polypropylene glycols, such as those with a molecular weight of 200 to 9,500. More than 1000 polyoxypropylene - polyoxyethylene -
Block polymers such as those having a molecular weight of 1,900 to 9,000 include solid polyhydric alcohols such as adducts of polyhydric alcohols such as glycerin, pentaerythritol, and sorbitol with ethylene oxide or propylene oxide. These polyhydric alcohols are used in an amount of 10 to 100 parts by weight, especially 65 to 100 parts by weight, per 100 parts by weight of hydrotalcites.
Preferably it is present in an amount of 85 parts by weight. Products and effects The products produced by the method of the present invention contain divalent anions.
Since 20 to 80% of the content is substituted with perhalogen oxygen acid ions, it has several characteristics not found in raw material hydrotalcites. Figure 1 of the attached drawings is an X-ray diffraction image of hydrotalcite after terminal substitution or substitution treatment, and curve A
is an X-ray diffraction image of the raw material hydrotalcites of general formula (3), curve B is an X-ray diffraction image of the divalent anion of hydrotalcites completely ion-exchanged with perchloric acid, and curve C is an This is an X-ray diffraction image of 62.5% of divalent anions of hydrotalcites ion-exchanged with perchloric acid. In addition, Figure 2-A is an infrared absorption spectrum of the raw material hydrotalcites, and Figure 2-B is an infrared absorption spectrum of hydrotalcites whose divalent anions have been completely ion-exchanged with perchloric acid. Figure 2-C is an infrared absorption spectrum of a product in which 62.5% of divalent anions were ion-exchanged with perchloric acid. According to these results, when carbonate ions are completely replaced with perchlorate ions, the diffraction peaks at 2θ = 11.57° and 23.28°, which are characteristic of the raw material hydrotalcite, disappear and are replaced by 2θ with a large interplanar spacing. =
It is clear that new diffraction peaks appear at 9.68° and 19.16°, whereas both peaks are present in the ion exchanger according to the invention. Also, in the infrared absorption spectrum, in a perfect ion exchanger,
The absorption peak at a wave number of 1370 to 80 cm ^-1 , which is characteristic of carbonate roots, virtually disappears, and is replaced by a wave number of 1370 to 80 cm -1, which is characteristic of perchlorate roots.
It can be seen that while an absorption peak of 1090 to 1150 cm ^-1 appears, the ion exchanger according to the present invention has both absorption peaks. The perhalogenated oxygen acid ion-exchanged hydrotalcites according to the present invention not only exhibit excellent heat stabilizing effect and ability to prevent initial coloring when blended with chlorine-containing polymers, but also exhibit excellent thermal stabilization and initial discoloration prevention ability when blended with chlorine-containing polymers. It also exhibits a novel effect in that the tendency to decompose and discolor is significantly suppressed even when Moreover, this product has the significant additional advantage that it is extremely stable in the presence of heat, light, moisture, etc. and is easy to handle as a powder. Conventionally, it is already known that perhalogen oxyacids are used as stabilizer components for chlorine-containing polymers, but such salts are invariably highly deliquescent and difficult to handle stably as a powder. Moreover, the blended composition also has the disadvantage of being susceptible to the influence of humidity, but according to the present invention, such a disadvantage can be overcome very effectively. Moreover, the products according to the invention have the advantage of superior amine resistance and thermal stabilizing action compared to known perhalogen oxyacids, such as barium perchlorate. Applications The ion exchanger product according to the invention is preferably used in combination with the chlorine-containing polymer in an amount of 0.1 to 10 parts by weight, particularly 0.5 to 1.0 parts by weight, per 100 parts by weight of the polymer. Examples of chlorine-containing polymers include polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, chlorinated rubber, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, and vinyl chloride-propylene copolymer. Polymer, vinyl chloride-styrene copolymer, vinyl chloride-isotyrene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride ternary copolymer, vinyl chloride-styrene-acrylonitrile copolymer combination, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-
Vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-acrylic acid ester copolymer, vinyl chloride-maleic acid ester copolymer, vinyl chloride-
Polymers such as methacrylic acid ester copolymers, vinyl chloride-acrylonitrile copolymers, and internally plasticized polyvinyl chloride, and these chlorine-containing polymers and α-olefins such as polyethylene, polypropylene, polybutene, and poly-3-methylbutene. Polymers or polyolefins such as ethylene-vinyl acetate copolymers, ethylene-propylene copolymers and their copolymers, polystyrene, acrylic resins, styrene and other monomers (e.g. maleic anhydride, butadiene, acrylonitrile, etc.) copolymer with, acrylonitrile-butadiene-styrene copolymer, acrylic ester-butadiene-
Examples include styrene copolymers, blends with methacrylic acid ester-butadiene styrene copolymers, and the like. Of course, the stabilizer for chlorine-containing polymers according to the present invention may contain various additives known per se, such as other stabilizers such as nitrogen-containing nonmetallic stabilizers, organotin stabilizers, and basic inorganic acid salts. or stabilizing agent, plasticizer,
Antioxidants, light stabilizers, nucleating agents, fillers, epoxy stabilizers, organic chelators, pigments, antistatic agents, antifogging agents, plate-out inhibitors, surface treatment agents, lubricants, flame retardants, fluorescent agents, anti-oxidants It can be blended with fungicides, fungicides, photodegradants, processing aids, mold release agents, etc. Example 1 Commercially available synthetic hydrotalcite DHT-4A
(manufactured by Kyowa Chemical) 0.591 mol was dispersed in 3 parts of water under forced high-speed stirring to prepare a slurry liquid. To this, 0.518 mol of perchloric acid in a 70% aqueous solution was gradually added under high-speed stirring (addition time: 5 minutes), and the mixture was stirred at high speed for 30 minutes at room temperature, and slowly stirred for another 90 minutes until the generation of carbon dioxide gas stopped. Mix it up and PH5.6
A hydrotalcite perchlorate ion exchanger slurry was prepared. Next, to stabilize the ion exchanger, 0.01 mol of calcium hydroxide powder was added to raise the pH of the slurry to 9.5. Thereafter, the ion exchanger slurry was evaporated to dryness or filtered under reduced pressure, and the resulting cake was dried at 110°C for 3 hours and ground to form a hydrotalcite-perchlorate ion exchanger (ion exchange ratio 40.5%, sample S). -1) was prepared. The ion exchange ratio was calculated from the following formula by measuring the amount of residual carbon dioxide generated by the ion exchanger using an alkaline meter. Ion exchange ratio = (a-b) / a × 100 [%] a; Number of moles of carbonate radicals in hydrotalcite before ion exchange b; Number of moles of carbonate radicals remaining in the ion exchanger This ion exchanger (sample S-1) was blended into a chlorine-containing resin composition and subjected to tests such as initial color development, heat resistance, amine resistance, and foamability. The basic formulation and test method are as follows. PVC resin (Vinicron 4000M) 100PHR DOP 50 Barium stearate 0.5 Zinc stearate 0.5 Dipentaerythritol 0.2 Sample S-1 0.5 The above blend was heated to 150℃ using two 4-inch rolls.
After kneading for 7 ^minutes at The heat resistance over time was investigated. Also, the above-formed sheet was immersed in a 5% solution of pentamethyldiethylenetriamine for 10 minutes and then taken out.
It was subjected to a low temperature heat aging test in a gear oven at 120°C to measure amine resistance. In addition, a PVC sheet that was press-molded in the same way was
Pressing was performed at 200° C. for 10 minutes at Kg/cm ² , and the foaming state of the sheet was visually determined. Foaming evaluation: ○No foaming. △ Rarely foaming occurs. ×Foaming is significant. The above results are shown in Table-1. Comparative Example 1 As a comparative example, synthetic hydrotalcite DHT-4A (sample H-1) was used instead of sample S-1 (ion exchanger) of Example 1 and the basic formulation of the chlorine-containing resin composition.
Sample H-1 was blended into a chlorine-containing composition in the same manner as in Example 1, and various performance tests were conducted in the same manner as in Example 1. The results are also listed in Table-1. Comparative Example 2 According to the same procedure as in Example 1, 0.591 mol of synthetic hydrotalcite DHT-4A was dispersed in 3 parts of water under forced high-speed stirring to prepare a slurry liquid. To this, 0.518 mol of perchloric acid in a 70% aqueous solution was gradually added under high speed stirring (addition time: 5 minutes), stirred at room temperature for 5 minutes (PH < 1), and filtered under reduced pressure.
The cake was dried at 110℃ for 3 hours and crushed to form a hydrotalcite-perchlorine mixture (ion exchange ratio
10.7%, sample H-2) was prepared. Sample H-2 was blended into a chlorine-containing resin composition in the same manner as in Example 1, and various performance tests were conducted in the same manner as in Example 1. The results are also listed in Table-1.

[Table] Example 2 Hydrotalcite-perchlorate ion exchanger (ion exchange ratio 72%, sample S-1) was prepared. Sample S-2 was then blended into a chlorine-containing polymer composition in the same manner as in Example 1, and a performance test was conducted, and the results are shown in Table-1. Comparative Example 3 0.591 mol of hydrotalcite DHT-4A was added to water
0.8 and dispersed under forced high-speed stirring to prepare an aqueous paste of hydrotalcite. Next, perchloric acid was added in the same manner as in Comparative Example 2,
A hydrotalcite-perchloric acid mixture (ion exchange ratio 3.4%, sample H-3) was prepared. Sample H-3 was blended into a chlorine-containing polymer composition in the same manner as in Example 1, and a performance test was conducted, and the results are shown in Table 1. Comparative example 4 Hydrotalcite DHT-4A 0.591 mol in water
After making an aqueous paste of hydrotalcite in the same manner as in Comparative Example 3, 0.518 mol of perchloric acid in a 70% aqueous solution was gradually added to this with high-speed stirring, and the mixture was treated with high-speed stirring for 30 minutes at room temperature. After, 110
A hydrotalcite-perchloric acid mixture (ion exchange ratio: 9.5%, sample H-4) was prepared by drying at °C. Sample H-4 was then blended into a chlorine-containing polymer composition in the same manner as in Example 1, and a performance test was conducted, and the results are shown in Table 1. Example 3 0.591 mol of synthetic hydrotalcite DTH-4A was dispersed in water 3 under forced high-speed stirring, and
Gradually add 0.518 mol of 35% aqueous perchloric acid under high-speed stirring, stir at high speed for 30 minutes at room temperature, and then slowly stir for another 180 minutes to obtain hydrotalcite with a pH of 6.4. A perchlorate ion exchanger slurry was made. Next, 0.02 mol of magnesium oxide powder was added to the slurry and stirring and mixing was continued to raise the slurry pH to 9.6. Thereafter, the ion exchanger was filtered under reduced pressure, and the cake was dried at 110° C. for 3 hours and pulverized to prepare a hydrotalcite-perchlorate ion exchanger (ion exchange ratio: 42.6%, sample S-3). Thereafter, sample S-3 was blended into a chlorine-containing resin composition in the same manner as in Example 1, and various performances were tested. The results are also listed in Table-1. Example 4 Hydrotalcite synthesized in the same manner as Example 1
After ion-exchanging DTH-4A with a perchloric acid aqueous solution, the process was carried out in the same manner as in Example 1, except that the pH of the ion exchanger slurry was maintained at 5.6. Sample S
-3) was adjusted. Thereafter, sample S-3 was blended into a chlorine-containing resin composition in the same manner as in Example 1, and various performance tests were conducted in the same manner as in Example 1. The results are also listed in Table-1. Example 5 and Comparative Example 4 Using the samples used in the above Examples and Comparative Examples, the dispersibility of soft vinyl chloride resin (PVC) was tested in the following manner. Soft vinyl chloride resin Smilitz SX-11 (contains 0.05 part of carbon black) 20 g DOP 12 g Sample 1.0 g is mixed with a kneading roll heated to 155 ± 2°C with a roll interval of 0.5 mm, and kneaded for 5 minutes after being wrapped around the rolls.
Draw out into mm thick sheets. Observe the state of sample dispersion on the surface of this sheet. The number and size of white spots due to poor sample dispersion are observed and evaluated into three grades: good and slightly poor. These results are also listed in Table-1. From the results in Table 1, ion exchangers S-1, S-2, and S-3 produced by the production method of the present invention
and S-4 are all hydrotalcite H-
1. Mixture of hydrotalcite and perchloric acid H-
It can be seen that the properties such as initial colorability, heat resistance, amine resistance, foamability, and soft PVC dispersibility are far superior to those of 2. H-3 and H-4. In addition, the ion exchanger slurry after the ion exchange reaction is
S-1, S-2, and S-3, which were stabilized by raising the pH to 8 to 10, were superior to S-4, which was not stabilized, in terms of foamability and soft PVC dispersibility. I know that there is.

[Brief explanation of drawings]

Figure 1 shows the X-ray diffraction image of hydrotalcite after terminal substitution and perchloric acid substitution treatment, where curve A is raw hydrotalcite, curve B is completely substituted product, and curve C is partially substituted product. Showing the body, the second -
Figure A is the infrared absorption spectrum of the raw material hydrotalcite, Figure 2-B is the infrared absorption spectrum of the product completely anion-exchanged with perchloric acid, and Figure 2-C is the infrared absorption spectrum of the raw material hydrotalcite that was completely anion-exchanged with perchloric acid. It is an infrared absorbing specter.

Claims (1)

[Claims] 1. To the aqueous dispersion of hydrotalcites, add perhalogen oxygen acid and mix uniformly with sufficient stirring. Then, stir at low speed until the generation of carbon dioxide gas stops, and divalent ions such as carbonate ions are added. 20 to 80% of the anions are exchanged with perhalogen acid ions to obtain a hydrotalcite perhalogen oxygen acid ion exchanger in the form of a slurry with a pH of 4 to 7. A method for producing a stabilizer for chlorine-containing polymers, which comprises adding an earth metal hydroxide or oxide.