JPH05194809A - Flame retardant composition for chlorinated polymer, excellent in prevention of smoking, and its production - Google Patents

Abstract

PURPOSE:To produce the subject composition which exhibits excellent flame retarding properties, especially prevention of smoking, while maintaining excellent heat resistance. CONSTITUTION:Porous carrier grains each comprising a silicate retaining in its pores an organic compounding agent having masking and chelating functions for zinc chloride are mixed under grinding conditions with a zinc compound particulate having a ZnO content of at least 45wt.% and a number-average primary particle size of from 0.1 to 5mum as measured by electron microscopy in proportions such that the amount of the zinc compound particulate is 3 to 50wt.% based on the total, thereby producing the objective composition characterized in that the porous carrier grains are present in the form of core grains, and that most of the zinc compound particulate is present in the form of a shell layer covering the core grains. Thus, the rapid resin degradation in the processing of a chlorinated polymer and the emission of smoke in combustion, which are drawbacks of the zinc compound, can very effectively be inhibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame retardant composition for a chlorine-containing polymer, which has an excellent combination of smoke elimination and thermal stability, and a process for producing the same.

[0002]

2. Description of the Related Art In order to prevent a large social turmoil caused by fires in high-rise buildings and fires in cables running underground in recent years, coating resins for electrical wiring used in home appliances, industrial machinery, computers, etc. It is required to impart flame retardancy to organic synthetic resins for interior and exterior as materials and building materials. Chlorine-containing polymers are one of the comparatively flame-retardant thermoplastic resins, but once a resin molded product has a flame, it is easily satisfied that it self-heats. Absent.

Conventionally, in order to impart flame retardancy to resins,
Various inorganic compounds or organic compounds have been blended as flame retardants. Among these flame retardants, the zinc-based inorganic compound, after burning the compounded resin composition,
It is known to leave a sticky combustion residue with electrical insulation. For example, in Japanese Examined Patent Publication No. 56-67363, resin is zinc borate and Al ₂ O ₃ , SiO ₂ , Sb ₂ O _3, Z.
It is described to blend with a metal compound of nO or ZrO. Further, in Japanese Patent Laid-Open No. 63-137988 (Prior Art A), the heat resistance obtained by mixing an oxide of an alkaline earth metal and a hydroxide on the surface of zinc borate particles under grinding is described. An improved flame retardant composition and a method for producing the same are described, and it is also shown that a resin containing this composition is useful for coating electric wires, cables and the like. Further, JP-A-60-11543 discloses a chlorine-containing resin composition containing a zinc compound such as zinc oxide, zinc carbonate or zinc silicate for the purpose of reducing smoke emission. Furthermore, Japanese Patent Application Laid-Open No. 1-2974489 (Prior Art B) discloses an antimony trioxide containing a polyhydric alcohol that traps zinc chloride in order to prevent zinc burning, and a chlorine-containing smoke-containing zinc oxide. Resin compositions are described.

[0004]

Problems to be Solved by the Invention Prior Art A and B
Is relatively excellent in flame retardance due to zinc compounds such as zinc borate and zinc oxide, but when a chlorine-containing polymer containing this is heated, it tends to cause black discoloration called so-called zinc burning. The above-mentioned proposal suppresses the decrease in heat resistance due to the zinc burning.

By the way, in the case of a flame retardant compounded in a chlorine-containing polymer, it is important to make the compounded composition difficult to ignite, and to extinguish the composition once it is ignited. From the standpoint of facilitating the operation and facilitating the digestive activity and the rescue operation, it is desired that less smoke is generated even when ignited. That is, since the chlorine-containing polymer burns while generating intense black smoke once ignited, and continues to smolder while emitting smoke even after the flame is extinguished,
The latter function will have a particularly important meaning. The present inventors have found that the use of a zinc compound having a relatively high content of ZnO and having a fine particle diameter as a granular material forming a composite structure with carrier particles holding a specific organic compounding agent is excellent. It has been found that while maintaining heat resistance, the flame retardancy and smoke elimination properties are remarkably improved.

That is, an object of the present invention is to provide a flame retardant composition for a chlorine-containing polymer which is excellent in flame retardancy, especially smoke elimination property while maintaining excellent heat resistance, and a method for producing the same. Another object of the present invention is to mask zinc chloride on porous carrier particles which are silicates of Group IIa metals of the Periodic Table or composites of silicates and oxides or hydroxides of said metals. To, consisting of composite particles in which a zinc compound fine particle is coated on a porous carrier holding an organic compounding agent having a chelating action, while maintaining excellent heat resistance, yet excellent in flame retardancy, particularly smoke elimination property A flame retardant composition for a chlorine-containing polymer and a method for producing the same.

[0007]

According to the present invention, porous carrier particles for holding an organic compounding agent having a masking or chelating action for zinc chloride in the pores, and ZnO
Content of 45% by weight or more, and zinc compound fine particles having a number average primary particle diameter of 0.1 to 5 μm as determined by electron microscopy.
Characterized in that the porous carrier particles are present in the form of core particles, and most of the zinc compound fine particles are present in the form of a shell layer covering the core particles, in the amount ratio of 0% by weight. A flame retardant composition for a chlorine-containing polymer having excellent smoke elimination properties is provided.

According to the present invention, the porous carrier particles and an organic compounding agent having a masking or chelating action for zinc chloride are mixed to keep the organic compounding agent in the pores of the porous carrier particles. Step, organic compound-supporting porous carrier, and zinc compound having a content of ZnO of 45% by weight or more and a number average primary particle diameter of 0.1 to 5 μm by electron microscopy of 3 to 50% by weight based on the whole And a step of mixing the mixture under milling conditions and pulverizing the mixture to form porous carrier particles as a core and coating the core with a zinc compound in the form of fine particles. A method of making a flame retardant composition for a chlorine-containing polymer is provided.

[0009]

In the present invention, the content of ZnO as a zinc compound is 45% by weight or more, particularly 50% by weight or more, and the number average primary particle diameter by electron microscopy is 0.1 to 5 μm.
The first feature is to select and use one within the range of. Although the mechanism of imparting flame retardancy to a chlorine-containing polymer of a zinc compound is not yet clear, the zinc compound captures hydrogen chloride generated during combustion of the chlorine-containing polymer and becomes zinc chloride. It is generally said to accelerate the decomposition of the chlorine-containing polymer and form a nonflammable shell composed of zinc chloride and carbon. When the incombustible and dense shell is formed around the combustion part, it traps particles in the smoke, so that it is considered that the flame-extinguishing effect is simultaneously achieved.

The zinc compound used in the present invention has a large ZnO content of 45% by weight or more, especially 50% by weight or more, while the ZnO content of the conventional zinc compound, zinc borate, is about 37% by weight. Since it has a great ability to capture zinc to form zinc chloride, it has an advantage of being particularly excellent in imparting flame retardancy and smoke eliminating action. Further, since these functions of the zinc compound are carried out through the surface of the particles, by making the particle size as fine as 0.1 to 5 μm,
The flame retardancy and smoke eliminating effect are further improved.

By the way, the fact that the ZnO content is high, the hydrogen chloride scavenging performance is high, and the ability to form zinc chloride is high brings about a significant disadvantage in terms of heat resistance. That is, the zinc chloride formed serves as a catalyst for causing a dehydrochlorination reaction in the chlorine-containing polymer. From such a point of view, under heating conditions such that the chlorine-containing polymer does not lead to combustion, the action of zinc chloride on the chlorine-containing polymer is blocked, while under the combustion conditions of the chlorine-containing polymer, zinc chloride-containing polymer It is necessary to devise such that the contact action with the polymer is sufficiently exerted.

In the present invention, the above zinc compound is combined with porous carrier particles having an organic compounding agent having a masking or chelating action for zinc chloride in the pores, and the porous carrier particles are used as a core. The second characteristic is that the zinc compound fine particles are present as particles and are present as a shell for coating the core particles.

Under ordinary heating conditions, the organic compounding agent retained on the porous carrier (core particle) masks zinc chloride even if zinc chloride is produced by the reaction between hydrogen chloride and a zinc compound. By chelating, so-called blackening by zinc burning is controlled, and Zn as an active ingredient is controlled by this.
Despite the use of a zinc compound having a high O concentration, heat resistance can be significantly improved.

It is also important to use the organic compounding agent supported on the porous carrier. That is, when the organic compounding agent alone is used in combination with the zinc compound, the organic compounding agent tends to plate out from the chlorine-containing polymer, so that a predetermined masking or chelating action cannot be obtained, or , Even if it is obtained in the early stages, the sustainability of the effect cannot be expected. On the other hand, by holding the organic compounding agent on the porous carrier, the plate-out tendency is alleviated,
Due to the gradual release of the organic compounding agent, a stable and stable heat resistance can be obtained.

Furthermore, when an organic compounding agent is held on a porous carrier and used in combination with a zinc compound, the porous carrier particles serve as a core, and the zinc compound serves as a shell to coat the zinc compound in the form of fine particles with a composite particle. It is an unexpected advantage that In this composite particle, the organic compounding agent is close in distance to the zinc oxide particles and easily acts, so that the masking or chelating action during heating is rapid and the occurrence of zinc burning is effectively prevented. Further, since the zinc compound fine particles are already present in the form of a shell, there is an advantage that the formation of a non-combustible shell is surely and effectively performed during combustion. still,
In forming the composite particles, the organic compounding agent acts as a binder in forming the shell of the zinc compound particles,
On the other hand, it is recognized that the porous carrier particles act as a grinding medium for making the zinc compound into fine particles (making secondary particles into primary particles) or preventing agglomeration of fine zinc compounds.

[0016]

Preferred Embodiment of the Invention

(Zinc Compound) As a zinc compound, an active ingredient (Zn
Zinc oxide is most preferable in terms of O) content concentration. As zinc oxide (zinc white), any zinc oxide that has been conventionally used as a pigment can be used. Although this zinc oxide can have a wide range of particle diameters, it improves flame retardancy (oxygen index), improves mechanical properties such as elongation and impact strength, and improves the surface smoothness of the molded product. In order to facilitate the formation of the shell layer in the composite particles of the present invention, it is desirable to use those having an average particle size of 5 μm or less, particularly 0.1 to 2.5 μm.

Of course, zinc compounds other than zinc oxide, such as zinc carbonate, zinc silicate, and complex oxides of zinc and other metals, can be used as long as the concentration is within the above range. As the zinc compound, those having an oil absorption of 50 ml / 100 g or less, particularly 30 ml / 100 g or less are suitable, and those having a small oil absorption are effective for preventing zinc burning and improving heat resistance.

(Porous carrier particles) The porous carrier particles have a pore volume of 0.4 cc / g or more, particularly 0.6 to 0.
8 cc / g of inorganic compound carrier is used. The carrier may be inert per se, but one having a heat stabilizing effect on the chlorine-containing polymer is preferable, and from this viewpoint, a silicate of a Group II metal salt of the periodic table is advantageous. Used for.

As the silicate, magnesium silicate,
Alkaline earth metal silicates such as calcium silicate, barium silicate, strontium silicate, silica IIb
Group metal salts may be used alone or in combination of two or more. Of these silicates, magnesium silicate,
Calcium silicate is preferably used.

The metal II salt of silicic acid may be a so-called normal salt, a basic salt or an acidic salt.

[Equation 1] In the formula, M represents a Group II metal of the periodic table, and n is preferably a number of 0.5 to 4. The silicate II metal salt of the present invention generally has a particle size distribution such that 10% or less of particles having a particle size of 40 μm or more and 50% or more of particles having a particle size of 20 μm or less. Is desirable from the viewpoint of uniform dispersion in the chlorine-containing polymer and the effect of thermal stability.

Examples of the organic compounding agent held on the carrier include polyhydric alcohols, amino alcohols, hydroxycarboxylic acids or esters or salts thereof, β-diketones, β-keto acid esters, aminocarboxylic acids or salts thereof. Be done. More specifically, examples of the polyhydric alcohols include mono- or dipentaerythritol, neopentyl glycol, glycerin, diglycerin, glycerin monofatty acid ester, mannitol, sorbitol, glucose, lactose and the like. Examples of amino alcohols include triethanolamine and N-hydroxylethylethylenediamine. Examples of the oxycarboxylic acid or its ester include glycolic acid, tartaric acid, citric acid or their esters, β-diketones or β
-As keto acid ester, acetylacetone, benzoylacetone, ethyl acetoacetate, ethyl propionyl acetate, ethyl benzoylacetate, α-acetylγ-butyl lactone, and as aminocarboxylic acid, ascorbic acid, glycine, aspartic acid, ethylenediaminetetraacetic acid, ethylene glycol Examples thereof include diethyl ether diamine tetraacetic acid, diethylene triamine pentane acetic acid, β-aminoethylphosphonic acid diacetic acid, and salts thereof. In addition, thiourea, thioglycolic acid, etc. can also be used.

The organic compound used in the present invention is preferably stable at the processing temperature of the chlorine-containing polymer and substantially non-volatile at the processing temperature. The amount ratio of the porous body and the organic compounding agent retained therein can be widely varied, but is generally 0.4: 1 based on the total amount of both.
It is preferred to be present in a weight ratio of to 1: 0.5, in particular 0.5: 1 to 1: 1. The organic compounding agent-holding carrier particles preferably have a particle size of generally 1.0 to 20 μm, particularly 5.0 to 10 μm.

(Production Method) In producing the flame retardant composition according to the present invention, an organic compound having a masking or chelating action for zinc chloride is used at least until the compound is mixed with the resin. It is of particular importance that it is supported on a porous silicate. Furthermore, the flame retardant composition according to the present invention is difficult to achieve the object of the present invention by simply mixing the three components,
For that purpose, an oxidation for forming a shell layer with the porous carrier as a core through the mixing step (A) and the grinding step (B) and efficiently forming a part of the organic compounding agent retained in the porous carrier It must be used as a binder for zinc to form a composite of the composition.

The method comprising the steps (A) and (B) for producing the composition satisfying the above requirements may be either wet or dry mixing / milling, but the mixing step (A)
In, it is important to support the organic compounding agent on the porous silicate in advance. For the purpose of wet or dry mixing / grinding, a crusher, a sand grinder mill, an attritor, a Nara type crusher, a wet or dry ball mill, a vibrating ball mill, a high speed shearing stirrer or the like or a combination thereof is used. From the viewpoint of efficiently forming the zinc oxide shell layer, in view of the ease with which the organic compounding agent supported on the porous carrier can be transferred to zinc oxide, wet mixing / milling is particularly performed because the mixing is performed uniformly. Although the dry mixing / milling tends to result in a slightly incomplete formation of the shell layer, it has many advantages in terms of simplicity of treatment.

Further, in the present invention, the above-mentioned composite material is used, if necessary, by a rolling granulator to have an average particle diameter of 0.1 to 2 mm.
It can also be used by granulating the particles. Further, it is possible to add various resin compounding agents described later during the granulation. For rolling granulation, a mixer-type granulating machine such as a Henschel mixer or a super mixer is used in addition to a normal rolling granulator.

(Use) The flame retardant composition of the present invention can be used in an amount of 1 to 40 parts by weight, particularly 5 to 30 parts by weight, based on the chlorine-containing polymer. This flame retardant composition can be blended in the resin as a flame retardant component alone or in combination with other flame retardants such as antimony, zircon, molybdenum oxide, hydroxide and sulfide.

Examples of the chlorine-containing polymer to which the flame retardant composition of the present invention can be blended include polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, chlorinated rubber, vinyl chloride-vinyl acetate copolymer. , Vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, vinyl chloride-
Isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-acrylonitrile copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-
Propylene chloride copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride-acrylic acid ester copolymer, vinyl chloride-maleic acid ester Copolymers, vinyl chloride-methacrylic acid ester copolymers, vinyl chloride-acrylonitrile copolymers, polymers such as internally plasticized polyvinyl chloride, and these chlorine-containing polymers with polyethylene, polybutene, ethylene-vinyl acetate copolymers. Polymer, ethylene-propylene copolymer, polystyrene,
Blended products such as acrylic resins, acrylonitrile-butadiene-styrene copolymers, acrylic acid ester-butadiene-styrene copolymers and the like can be mentioned.

The chlorine-containing copolymer contains various additives known per se, such as stabilizers, plasticizers, antioxidants, light stabilizers, lubricants, antistatic agents, antifog agents, and nucleating agents. , A filler, etc. can be added. These additives may be blended in the polymer or the flame retardant composition of the present invention in advance, or may be blended simultaneously when kneading the flame retardant composition of the present invention and the polymer.

[0029]

EXAMPLES The present invention will be specifically described in the following examples. Example 1 (Production of porous carrier particles) Commercial magnesium oxide and Si
Amorphous silica having an O ₂ content of 98.5% by weight (Shilton A manufactured by Mizusawa Chemical Industry Co., Ltd.) was added to ion-exchanged water in a 2 L beaker so that the molar ratio of MgO: SiO ₂ was 4: 3. Was stirred to prepare a 10% slurry. Then, 800 g of the above slurry was charged into a 1 L autoclave (made of pressure-resistant glass) and stirred at 30 rpm at 180 ° C. for 17 hours.
Hydrothermal reaction was carried out under the condition of hr and cooled to room temperature to obtain a magnesium silicate porous carrier slurry.

(Production of Porous Carrier for Retaining Organic Compounding Agent) To 100 g of the dry slurry of the above-mentioned porous carrier slurry, 50 g of sorbit manufactured by Towa Gosei Co., Ltd. was added and dissolved by stirring, followed by heating at 110 ° C. for 24 hours to volatilize. After removing water, crushed with a sample mill made by Tokyo Atomizer,
An organic compound-holding porous core having a secondary particle size of 5 to 30 μm (hereinafter, this prepared core is referred to as d-1) was produced. A scanning electron micrograph of d-1 is shown in FIG.

(Production of Zinc Compound Coated Porous Carrier Particles)
The average primary particle diameter of the coating zinc compound is 0.1 to 5 μm.
FIG. 2 shows zinc oxide (# 200 manufactured by Kamijima Chemical Co., Ltd.) of m. 70 g of this zinc oxide and the above-mentioned d-1 and 30 g were mixed and ground using a 200 ml tabletop mixer and a sample mill manufactured by Tokyo Atomizer to obtain the zinc oxide-coated porous carrier particles (sample name D-1) shown in FIG. Manufactured.

(Preparation of soft PVC sheet for flame retardancy test)
Soft P with Zinc Compound Coated Porous Carrier Particles D-1
A PVC blend was prepared from the VC sheet according to the formulation shown in Table 1, and the mixture was kneaded and molded in a 3.5 inch differential roll mill at 150 ° C. for 10 minutes. Then, it was subjected to a flame retardant test described below, and the results are shown in Table 2. As the stabilizer, a lead-based stabilizer (Mizusawa Chemical Co., Ltd. tribasic lead sulfate and lead stearate) was used. Furthermore, the PVC stabilizer was changed to a lead-free stabilizer (Ba-Zn stabilizer manufactured by Mizusawa Chemical Industry Co., Ltd.), and a soft PVC sheet was similarly prepared and subjected to a flame retardant test, and the results are shown in Table 3. Indicated.

(Flame Retardant Test Items) * Plate Out Resistance A PVC admixture was prepared according to the formulation shown in Table 1, and 3.5
Inch differential roll mill at 150 ℃ 1
After kneading for 0 minutes, the degree of stain on the roll surface is visually evaluated. ○ No plate-out (no roll stains) × Plate-out (roll stains) * Heat resistance (min) Time (min) until the kneading-molded PVC sheet is heated to 170 ° C in the oven to cause deterioration and coloring Was measured to evaluate the heat resistance of the flame retardant-containing sheet. * Oxygen index concentration (%) Using the candle method combustion tester manufactured by Toyo Seiki Seisakusho Co., Ltd., the limiting oxygen index (O · I value%) was measured according to JIS-K-7201B method to show flame retardancy. evaluated. * Relative visual density Using an NBS smoke tester manufactured by Toyo Seiki Seisakusho,
The sample PVC sheet is heated with a heat radiation amount of 2.5 / cm ² ,
The smoke was emitted, and the smoke intensity was evaluated using the specific visual density calculated from the white light transmittance of the smoke.

Example 2 Zinc oxide-coated porous carrier particles D- were all carried out in the same manner as in Example 1 except that the weight ratio of the organic compounding agent-holding porous carrier core d-1 to zinc oxide was 40:60. No. 2 was manufactured, and its flame retardancy evaluation is shown in Tables 2 and 3.

Example 3 Zinc oxide-coated porous carrier particles D- were all carried out in the same manner as in Example 1 except that the weight ratio of the organic compounding agent-holding porous carrier core d-1 to zinc oxide was 50:50. 3 was manufactured, and its flame retardancy evaluation is shown in Tables 2 and 3.

Example 4 A zinc compound coating agent was changed from zinc oxide to basic zinc carbonate (2ZnCO ₃ .3Zn (OH) ₂ .H ₂ O manufactured by Kanto Chemical Co., Inc.)
And the weight ratio of d-1 to basic zinc carbonate is 70: 3.
Zinc carbonate-coated porous carrier particles D-4 were produced in the same manner as in Example 1 except that the value was set to 0, and the flame retardancy evaluation thereof is shown in Tables 2 and 3.

Example 5 The zinc compound coating material was changed from zinc oxide to basic zinc carbonate (2ZnCO ₃ .Zn (OH) ₂ .H ₂ O manufactured by Kanto Chemical Co., Ltd.), and the weight of d-1 and basic zinc carbonate was changed. Ratio 70:30
Zinc carbonate-coated porous carrier particles D-5 were produced in the same manner as in Example 1 except that the above was used, and the flame retardancy evaluation thereof is shown in Tables 2 and 3.

Example 6 Zinc oxide coated porous carrier particles D-2 prepared in Example 2
And antimony trioxide (manufactured by Toko Sangyo Co., Ltd.) were mixed at 50:50, D-6 was used as a PVC blend according to Table 1, and a PVC sheet was prepared under the same conditions as in Example 1 to obtain flame retardance. The sex was evaluated and shown in Tables 2 and 3.

Comparative Example 1 Zinc Oxide # 200 manufactured by Kamishima Chemical Co., Ltd. was used as H-1 to make a PVC mixture according to Table 1, and PV was mixed under the same conditions as in Example 1.
C sheet was molded, and the flame retardancy evaluation results thereof are shown in Tables 2 and 3.
It was shown to.

Comparative Example 2 A mixture of mannite and zinc oxide in a weight ratio of 10:90 was used as H-2 to make a PVC mixture according to Table 1, and a PVC sheet was molded under the same conditions as in Example 1. The flame retardancy evaluation results are shown in Tables 2 and 3.

Comparative Example 3 A mixture of magnesium silicate and zinc oxide prepared in Example 1 in a weight ratio of 10:90 was designated as H-3, and a PVC mixture was prepared according to Table 1, under the same conditions as in Example 1. PV below
C sheet was molded, and the flame retardancy evaluation results thereof are shown in Tables 2 and 3.
It was shown to.

Comparative Example 4 Magnesium silicate prepared in Example 1 was used as H-4 to make a PVC admixture according to Table 1, a PVC sheet was molded under the same conditions as in Example 1, and the flame retardancy evaluation results were shown. The results are shown in Tables 2 and 3.

Comparative Example 5 Zinc borate FR-100 manufactured by Mizusawa Chemical Industry Co., Ltd. was used as H-5 to make a PVC admixture according to Table 1, and a PVC sheet was molded under the same conditions as in Example 1, and its flame retardancy was evaluated. The results are shown in Tables 2 and 3.

Example 7 As a silicic acid raw material, an acid slurry containing 30% α-cristobalite from Matsune, Higashidagawa-gun, Yamagata Prefecture was wet-milled in a pot mill to obtain an aqueous slurry having a CaO: SiO ₂ molar ratio of 0.8. Slaked lime was added so as to obtain a mixture, and the mixture was stirred for 3 hours under heating at 95 ° C., and cooled to room temperature to obtain a porous carrier core particle slurry. Then, 50 g of dipentaerythritol adipate (manufactured by Ajinomoto Co., Inc., Planerizer ST210) per 100 g of the slurry dry matter was added to the slurry.
Was added and the mixture was wet-milled for 1 hour with a pot mill to produce an organic compounding agent-holding porous carrier slurry. After adding 150 g of zinc oxide # 200 manufactured by Kamijima Chemical Industry Co., Ltd., wet milling for 1 hour in a pot mill, filtering, drying at 120 ° C., grinding by sample mill manufactured by Tokyo Atomizer, and zinc oxide coating porous Carrier particles D-7 were produced. Figure 4 for D-7
Shown in. Thereafter, a flexible PVC sheet for flame retardancy test was prepared using D-7 by the same operation as in Example 1, and the test results are shown in Tables 2 and 3.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[Brief description of drawings]

FIG. 1 Porous core d holding an organic compounding agent according to the present invention
It is a scanning electron microscope (SEM) photograph of -1.

FIG. 2 is an SEM photograph of zinc oxide used in the present invention.

FIG. 3 is a SEM photograph of zinc oxide-coated porous carrier particles D-1 of the flame retardant and composition of the present invention.

FIG. 4 is a SEM photograph of zinc oxide-coated porous carrier particles D-7 of the flame retardant composition of the present invention.

Claims (6)

[Claims] 1. A porous carrier particle which holds an organic compounding agent having a masking or chelating action for zinc chloride in its pores, and its content as ZnO is 45% by weight or more, and the number average primary by electron microscopy. Particle size is 0.1 to 5 μm
And a zinc compound fine particle which is a compound of the present invention in an amount ratio of 3 to 50% by weight based on the whole zinc compound fine particle, wherein the porous carrier particles are in the form of core particles, and most of the zinc compound fine particles are Is present in the form of a shell layer that covers the core particles, and a flame retardant composition for a chlorine-containing polymer having excellent smoke elimination properties. 2. The flame retardant composition according to claim 1, wherein the zinc compound fine particles are zinc oxide fine particles. 3. The flame retardant composition according to claim 1, wherein the zinc compound fine particles are fine particles of zinc carbonate or zinc silicate. 4. The flame retardant composition according to claim 1, wherein the porous carrier is a silicate of a Group IIa metal of the periodic table or a composite of a silicate and an oxide or hydroxide of the metal. 5. The flame retardant composition according to claim 1, wherein the organic compounding agent is a polyhydric alcohol, a β-keto acid ester or a β-diketone. 6. A step of mixing the porous carrier particles and an organic compounding agent having a masking or chelating action for zinc chloride to retain the organic compounding agent in the pores of the porous carrier, and an organic compounding agent retaining step. Porous carrier, 3 to 50% by weight based on the whole, content of ZnO is 45% by weight or more, and number average primary particle diameter by electron microscopy is 0.1 to 5
a step of mixing with a zinc compound of μm, and a step of mixing the mixture under grinding conditions and pulverizing to make the porous carrier particles the core, and coating the zinc compound in the form of fine particles on the core. A method for producing a flame retardant composition for a chlorine-containing polymer, which is characterized by the above.