JP4892419B2 - Calcium hydroxide compound and method for producing the same - Google Patents

Description

  The present invention relates to a calcium hydroxide compound in which Ca near the crystal surface of calcium hydroxide is substituted with Al or Mg and Al, and a method for producing the same. More specifically, by containing the calcium hydroxide compound, water capable of providing a stabilized halogen-containing resin composition excellent in thermal stability, which has remarkably improved the initial coloring which is a defect of calcium hydroxide. The present invention relates to a calcium oxide compound and a method for producing the same.

  Halogen-containing resins are unstable to heat and light. Therefore, it is necessary to add a heat stabilizer before melting. As heat stabilizers, lead compounds, organotin compounds, Cd / Ba metal soaps, Ba / Zn metal soaps, Ca / Zn metal soaps, hydrotalcites and the like have been used.

  As a result of increased social interest in safety and environmental impacts, there has been a tendency to ban or suppress the use of cadmium-based, lead-based, tin-based, and barium-based materials that have been used in heat stabilizers. It was. At the same time, there is an increasing demand for lower prices for heat stabilizers. The conventional heat stabilizer Ca / Zn is non-toxic, but the heat stability is inferior, and hydrotalcites are also non-toxic, but there is a problem of foaming due to the large amount of water of crystallization, and there is also a problem in price. There is.

  Therefore, the present inventor has focused on calcium hydroxide that is non-toxic, inexpensive, does not foam, and has good thermal stability. However, calcium hydroxide has a problem of so-called initial coloration that strongly colors the halogen-containing resin reddish brown. There is also a problem that it is easily carbonated, reacts with carbon dioxide gas or carbonate ions, changes to calcium carbonate, and loses its initial activity over time. Because of these problems, they were rarely used as heat stabilizers.

  Therefore, the present invention provides a novel heat stabilizer for halogen-containing resins that overcomes the above-mentioned problems of calcium hydroxide, is non-toxic, inexpensive, has good initial coloration, has excellent thermal stability, and has good carbonation resistance. The purpose is to do.

  In the present invention, Ca near the crystal surface of calcium hydroxide is substituted with Al or Mg and Al in an amount of 0.5 to 15 mol%, preferably 1 to 10 mol% of the total calcium, more preferably an anionic type. Provided is a novel calcium hydroxide compound surface-treated with a surfactant.

  Furthermore, this invention provides the manufacturing method of this novel calcium hydroxide type compound.

  According to the present invention, by replacing Ca near the crystal surface of calcium hydroxide with Al, or Mg and Al, at least 0.5 mol% or more of the total Ca, initial colorability, non-toxicity, non-foaming property can be obtained. Thus, it is possible to obtain a calcium hydroxide compound useful as a heat stabilizer for an excellent halogen-containing resin at low cost and a method for producing the same.

  The calcium hydroxide compound of the present invention has a structure in which Ca near the crystal surface of calcium hydroxide is partially substituted with Al or Mg and Al. When the surface Ca is partially substituted with Al or Mg and Al, the initial coloring of the halogen-containing resin is greatly improved. Furthermore, carbonation resistance is also improved.

  The reason for this is considered that the hydroxide of Al is extremely insoluble in water and that the electron-accepting Al neutralizes and reduces the strong electron donating property that causes the initial coloring of calcium hydroxide.

  The amount of substitution of Ca by Al or Mg and Al in the calcium hydroxide compound of the present invention is 0.5 to 15 mol%, preferably 1 to 10 mol%, particularly preferably 2 to 6 mol, based on the total calcium. %. When the substitution amount is less than 0.5 mol%, the intended effect of improving the initial coloration is insufficient. Conversely, when the substitution amount is large, foaming is caused at the resin processing temperature at 200 ° C. or less. The amount of desorbed water increases. Even if the substitution amount exceeds 10 mol%, there is no further improvement in initial coloration and thermal stability, and on the other hand, the amount of water of crystallization desorbed at 200 ° C. or less increases, which may cause foaming. Therefore, the upper limit of the substitution amount is not particularly limited, but is preferably 15 mol% or less, more preferably 10 mol% or less. However, since the desorption temperature of crystal water is as low as about 130 ° C., foaming can be prevented by drying at about 150 ° C.

  In the calcium hydroxide compound of the present invention, Ca is substituted with Al or Mg and Al only in the vicinity of the crystal surface, so that almost all is calcium hydroxide in terms of crystal structure. Therefore, the X-ray diffraction pattern is mostly calcium hydroxide only. In other cases, the diffraction pattern of strong calcium hydroxide and the mixed hydroxide of Ca and Al or Ca, Mg and Al are used. This is a mixture of the estimated weak diffraction, d (plane spacing) = 7.6 mm.

In order for the calcium hydroxide compound of the present invention to function as a good halogen-containing resin heat stabilizer, it is preferable that the primary particles are small and the secondary particles formed by aggregation of the primary particles are also small. Specifically, the BET specific surface area is about 3 m ² / g or more, preferably 5 to ²⁰ m ² / g, particularly preferably 7 to ²⁰ m ² / g. The secondary particle size determined by the particle size distribution measurement is 2 μm or less, preferably 1.5 μm or less, particularly preferably 1 μm or less, with a cumulative 50%.

  The calcium hydroxide compound of the present invention can be used as it is, but using a surface treated with an anionic surfactant or the like increases the compatibility with the halogen-containing resin, resulting in initial coloring, It is effective in improving the thermal stability and the like, which is preferable.

  In the production of the calcium hydroxide compound of the present invention, calcium hydroxide is dispersed in a medium containing water, and with stirring, an aqueous aluminum solution or a mixed aqueous solution of aluminum and magnesium is about 100 ° C. or less, preferably about 40 to 90 ° C. Can be carried out by addition reaction. Instead of calcium hydroxide used here, a mixed hydroxide of calcium hydroxide and magnesium hydroxide obtained by hydrating dolomite after firing can be used. Examples of the water-soluble aluminum salt include aluminum nitrate, aluminum chloride, sodium aluminate, aluminum acetate, aluminum sulfate, and isoproxide.

  The surface treatment of the calcium hydroxide compound of the present invention is carried out by using an anionic surfactant such as higher fatty acid, alkali metal salt of higher fatty acid, phosphoric ester, alkylbenzene sulfonic acid soda, polycarboxylic acid, or its alkali, or ammonium salt. To about 0.1 to 10%, preferably about 0.5 to 5%, particularly preferably about 1 to 4% based on the weight of the calcium hydroxide compound. The coating treatment with the surface treatment agent can be carried out by a method known per se. However, the calcium hydroxide compound of the present invention is dispersed in a water-containing medium, and the aqueous solution of the anionic surfactant is added with stirring. It is preferable to implement. After the surface treatment, if necessary, for example, means such as washing with water, filtration, granulation, drying, pulverization, and classification can be appropriately selected and carried out to obtain a final product form.

  The stabilized halogen-containing resin obtained in the present invention is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, particularly preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the halogen-containing resin. Of the present invention calcium hydroxide compound. In addition to the calcium hydroxide compound of the present invention, the stabilized halogen-containing resin is (a) 0.01 to 2 parts by weight, preferably 0.1 to 1 part by weight of zinc compound, (b) 0.001. ~ 2 parts by weight, preferably 0.01-1 part by weight β-diketones, (c) 0.001-2 parts by weight, preferably 0.1-1 part by weight polyhydric alcohols, (d) 0 It is preferable to use ˜1 part by weight, preferably 0 to 0.5 part by weight of perchlorate, and (e) 0 to 2 part by weight, preferably 0 to 1 part by weight of hydrotalcite.

  Examples of (a) zinc compounds include zinc salts of organic acids such as lauric acid, palmitic acid and stearic acid, and inorganic zinc compounds such as zinc oxide and zinc carbonate. Preferred is an organic acid salt of zinc. Zinc compounds are useful as an initial color prevention and lubricant.

  (B) β-diketones are compounds useful for preventing initial coloring, and are represented by the following general formula (1)

Wherein R ₁ and R ₃ may be the same or different and are straight or branched alkyl, alkenyl, aryl, or alicyclic groups having up to 30 carbon atoms, R ₂ represents a hydrogen, an alkyl group, or an alkenyl group. Examples of such β-diketones that can be preferably used include dibenzoylmethane (DBM), stearoylbenzoylmethane (SBM), benzoylacetone, acetylacetone, and dehydroacetic acid.

  (C) Polyhydric alcohols are useful for improving thermal stability, and are polyhydric alcohols, or partial esters of polyhydric alcohols with mono- or polycarboxylic acids. Examples of such compounds include mannitol, sorbitol, pentaerythritol, dipentaerythritol, and trimethylolpropane.

(D) Perchlorates are useful for preventing initial coloration, such as metal salts of perchloric acid such as Na, K, Ca, Ba and the following formula (2)
M ²⁺ _1-x Al _x (OH) ₂ (ClO ₄ ) _y (A ⁿ⁻ ) _Z · mH ₂ O (2)
^{(Wherein, M 2+} represents Mg and / or ^{Zn, A n-is} _CO ³ _2-, ClO _4, such as H 2 PO ₃ ^- shows a n-valent anion other than, x, y, z and m are Each of the following ranges, 0.1 <x <0.5, preferably 0.2 ≦ x ≦ 0.4, 0 <y <0.5, preferably 0.2 ≦ y ≦ 0.4, 0 ≦ z And hydrotalcites containing perchlorate ions represented by <y, y + nz = x, 0 ≦ m <3 satisfying 0 or a positive number) as an interlayer anion.

(E) Hydrotalcites are useful in improving the thermal stability, in the formula ^{(2), M 2+} is at Mg and / or ^{Zn, A n-is} _CO ^{3 2-} is, x = 0.25 to It is preferable to use hydrotalcites of 0.4, y = 0 to 0.4.

  Examples of the halogen-containing resin include the following. Polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, chloride Vinyl-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride-styrene-acrylonitrile copolymer, 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-methacrylic acid ester copolymer, vinyl chloride-acrylo Tolyl copolymer, vinyl chloride - various vinyl ether copolymers chlorine-containing synthetic resin. Blends of these chlorine-containing synthetic resins with each other or with other chlorine-free synthetic resins, block copolymers, graft copolymers, and the like.

Other conventional additives can be blended in the resin composition of the present invention. Examples of such other additives include the following. Phosphite-based stabilizing aids such as bisphenol A tetra C _12-15 alkyl diphosphite, tridecyl phosphite, trilauryl phosphite, tris (monophenyl) phosphite. Epoxy stabilization aids such as epoxidized vegetable oils, epoxidized oleates, and epoxidized erucinates. Sulfur-containing compound-based stabilizing aids such as thiodipropionic acid and diethylthiodipropionic acid ester. Phenol stabilizers such as alkyl gallate, phenol such as alkylated phenol, and styrenated phenol. Α-amino acids such as glycine, alanine, leucine, isoleucine, glycinamide, histidine ethyl ester, tryptophan benzyl ester, and functional derivatives thereof. Styrenated paracresol, 2,6-ditertiary butyl-4-methylphenol, butylated anisole, 4,4'-methylenebis (6-tertiarybutyl-3-methylphenol), 2,2'methylenebis ( 6-tertiarybutyl-4-methylphenol), 1,3,5-trimethyl-2,4,6-tris (3,5-ditertiarybutyl-4-hydroxybenzyl) benzene, tetrakis [3- Antioxidants such as (4-hydroxy-3,5-ditertiary butylphenyl) propionyloxymethylene] methane.

  The blending amount of these additives can be appropriately selected. For example, about 0.01 to about 5 parts by weight of stabilizing aids, about 0.01 to about 2 parts by weight with respect to 100 parts by weight of the halogen-containing resin. Antioxidants are exemplified. The present invention contains other conventional additives such as plasticizers, lubricants, processing aids, weather resistance improvers, antistatic agents, antifogging agents, reinforcing agents, fillers, pigments, etc. May be. In the present invention, mixing and kneading of the halogen-containing resin, the additive of the present invention, and other additives may be performed by a conventional method capable of mixing both uniformly. For example, any mixing and kneading means such as a single-screw or twin-screw extruder, a roll, and a Banbury mixer can be adopted. There are no particular restrictions on the molding method. For example, any molding means such as injection molding, extrusion molding, blow molding, press molding, rotational molding, calendar molding, sheet forming molding, transfer molding, laminate molding, vacuum molding, etc. is adopted. it can.

  Hereinafter, based on an Example, this invention is demonstrated in detail. In the following examples,% means% by weight.

Example 1
A commercially available high-purity chemical quicklime (Niimi Okayama) 120g was added to 3 liters of warm water heated to about 70 ° C under stirring with a chemistor and digestion was continued for about 30 minutes. . Thereafter, 2 moles of the passed slurry was passed through a 200-mesh sieve into a reaction vessel of about 5 liters and stirred. To this slurry (about 65 ° C.), an aqueous solution of 0.2 mol / liter aluminum nitrate (corresponding to 3 mol% of total calcium) was added. After filtering, washing with water, re-dispersing in water, heating and raising the temperature to about 70 ° C., 100 ml aqueous solution (about 70 ° C.) in which 5 g of sodium stearate having a purity of 90% is dissolved is added with stirring, surface treatment Went. Then, it filtered, washed with water, dried and pulverized.

As a result of measuring the X-ray diffraction pattern of the pulverized product, a diffraction peak of only calcium hydroxide was observed. The ground product was dissolved in hydrochloric acid and subjected to chelate titration analysis. As a result, the molar ratio of Ca: Al was 96.5: 3.5. The ground product was dissolved in hydrochloric acid, extracted with ether, dried, and the amount of stearic acid measured by gravimetric method was 2.8%. The BET specific surface area measured by the liquid nitrogen adsorption method of the pulverized product was 9 m ² / g.

  After dispersing for 5 minutes in isopropyl alcohol with ultrasonic waves, the average secondary particle size with a cumulative 50% measured by the laser diffraction particle size distribution measurement method was 1.3 μm. As a result of conducting a thermal analysis and measuring a weight change up to 200 ° C., there was a 1.2% weight loss. This is due to an endothermic reaction due to dehydration at about 130 ° C.

(Example 2)
In Example 1, it carried out like Example 1 except having changed the amount of 0.2 mol / l aluminum nitrate to add from 300 milliliters to 500 milliliters (equivalent to 5 mol% with respect to total Ca).

The X-ray diffraction pattern of the pulverized product had a weak diffraction peak at d = about 7.6 mm in addition to calcium hydroxide. The molar ratio of Ca: Al in the pulverized product was 94.8: 5.2. The stearic acid content was 2.7%. The BET specific surface area was 11 m ² / g, and the average secondary particle size with a cumulative 50% was 1.1 μm. The amount of dehydration up to 200 ° C. by thermal analysis was 1.9%.

(Example 3)
In Example 1, instead of adding aluminum nitrate, Example ³ is the same as Example 1 except that 52 ml of an aqueous solution of sodium aluminate with Al ³⁺ = 2.7 mol / liter was added (corresponding to 7 mol% with respect to the total Ca). The same was done.

As for the X-ray diffraction pattern of the pulverized product, only a diffraction peak of calcium hydroxide was observed except that a weak diffraction peak was found at d = about 7.6 mm. The ground product had a Ca: Al molar ratio of 92.8: 7.2 and a stearic acid content of 2.6%. The BET specific surface area was 18 m ² / g, and the average secondary particle size with a cumulative 50% was 0.70 μm. The amount of dehydration up to 200 ° C. by thermal analysis was 1.2%.

(Comparative Example 1)
In Example 1, it carried out like Example 1 except not adding aluminum nitrate.

The X-ray diffraction pattern of the pulverized product was only calcium hydroxide. The stearic acid content was 2.9%, the BET specific surface area was 13 m ² / g, the average secondary particle size of cumulative 50% was 1.7 μm, and the amount of dehydration up to 200 ° C. by thermal analysis was 0%.

Example 4
In Example 1, instead of adding aluminum nitrate, first, 0.5 mol / liter magnesium chloride and 60 ml (corresponding to 1.5 mol% with respect to total Ca) were added, and stirring was continued for about 20 minutes. , 0.2 mol / liter of aluminum nitrate and 150 ml (corresponding to 1.5 mol% of total Ca) were added and reacted in the same manner as in Example 1.

The X-ray diffraction pattern of the pulverized product was a diffraction peak of only calcium hydroxide, except that there was a weak diffraction peak at d = about 7.6 mm. The ground product had a Ca: Mg: Al molar ratio of 97: 1.4: 1.6 and a stearic acid content of 2.7%. The BET specific surface area was 12 m ² / g, and the average secondary particle size with a cumulative 50% was 0.95 μm. The dehydration amount up to 200 ° C. by thermal analysis was 0.90%.

(Comparative Example 2)
In Example 4, Table 1 shows the evaluation results when the calcium hydroxide prepared in Comparative Example 1 was used as the heat stabilizer.

(Comparative Example 3)
In Example 4, the evaluation results when calcium stearate is used as the heat stabilizer are shown in Table 1.

(Comparative Example 4)
In Example 4, as a heat stabilizer, the evaluation results when tribasic lead sulfate and lead stearate are respectively used in a total of 1.07 parts by weight of 0.67 parts by weight and 0.33 parts by weight are shown in Table 1. .

(Example 5)
Foreign high purity dolomite: (Ca, Mg) CO ₃ , (SiO ₂ = 0.1%, Al ₂ O ₃ = trace, Fe ₂ O ₃ = 0.024%, CaO = 31.0%, MgO = 21 0.7%, CO ₂ = 41.0%) was calcined at 1000 ° C. for 10 hours to obtain calcium oxide and magnesium oxide having a BET specific surface area of 9.9 m ² / g. The same procedure as in Example 1 was performed except that 100 g of this oxide was used instead of quicklime used in Example 1.

As a result of measuring the X-ray diffraction pattern of the pulverized product, diffraction peaks of calcium hydroxide and magnesium hydroxide were observed. The ground product had a Ca: Mg: Al molar ratio of 48.8: 48.0: 3.2 and a stearic acid content of 2.7%. The BET specific surface area was 15 m ² / g, and the average secondary particle size with a cumulative 50% was 1.1 μm. The dehydration amount up to 200 ° C. by thermal analysis was 0.7%.

(Example 6)
In the following formulation, after mixing the calcium hydroxide compound obtained in Examples 1 to 5 with polyvinyl chloride as a heat stabilizer, kneading at 165 ° C. for 3 minutes using a roll, A 1 mm sheet was prepared.
[Prescription]
Polyvinyl chloride (Shin-Etsu Chemical Co., Ltd., molecular weight 700) 100 parts by weight
Zinc stearate 0.3 parts by weight
Stearoyl benzoylmethane 0.15 parts by weight
Dipentaerythritol 0.2 parts by weight Thermal stabilizer 1.0 part by weight The obtained sheet was cut into a size of about 3 cm × 3 cm, and used as a test piece. And the degree of initial coloring and the time until blackening were measured visually for thermal stability and foaming. The results are shown in Table 1.

(Example 7)
In Example 4, 0.7 parts by weight of the calcium hydroxide compound obtained in Example 1 and 0.3 parts by weight of hydrotalcite (commercially available Alkamizer 1) were used as heat stabilizers in a total of 1 part. Table 1 shows the evaluation results when 0.0 part by weight is blended.

(Comparative Example 5)
In Example 4, the evaluation results when using hydrotalcites (commercially available Alkamizer 1) as the heat stabilizer are shown in Table 1.

Claims (3)

A calcium hydroxide compound characterized in that Ca near the crystal surface of calcium hydroxide is substituted with Al or Mg and Al, and the substitution amount is 0.5 to 15 mol% of the total calcium. Hydroxidized calcium hydroxide dispersed in water or water-containing solvent or calcium hydroxide / magnesium hydroxide mixture derived from dolomite with stirring, aqueous solution of aluminum, mixed solution of magnesium and water-soluble aluminum, or single aqueous solution of each. The method for producing a calcium hydroxide compound according to claim 1, wherein 0.5 mol% or more is added to 1 mol of calcium and reacted. An aqueous solution of 0.1 to 10% by weight of an anionic surfactant is added to the reaction product according to claim 2 with stirring based on the weight of the mixed hydroxide derived from calcium hydroxide or dolomite, and surface treatment is performed. The method for producing a calcium hydroxide compound according to claim 2.