JPS60243155A - Flame-retardant thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition obtained by compounding a resin with an inorganic flame-retardant comprising magnesium hydroxide having a BET specific surface area and the ratio of the BET specific surface area to the Blaine specific surface area falling within specific respective ranges, and having excellent dispersibility to the resin, moldability, flame-retardancy, etc. CONSTITUTION:(A) 100pts.wt. of a thermoplastic resin is compounded homogeneously with (B) about 5-250pts.wt. of magnesium hydroxide having a BET specific surface area of about <=20m<2>/g, preferably about 1-10m<2>/g and the ratio of the BET specific surface area to the Blaine specific surface area of about 1-3, preferably 1-2.8, especially 1-2.5. The magnesium hydroxide is prepared by contacting magnesium chloride or magnesium nitrate with ammonia or calcium hydroxide in an aqueous medium under agitation, and heating the resultant basic magnesium chloride or nitrate in an aqueous medium under pressure, and is preferably surface-treated with sodium stearate, etc. before mixing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an inorganic flame retardant for thermoplastic resins, which has excellent dispersibility, non-agglomeration, moldability, and resistance to molding. - Improving the appearance of molded products,
The present invention relates to a flame-retardant thermoplastic resin composition containing a specific range of an inorganic flame retardant of the magnesium hydroxide type, which has particularly excellent properties in terms of flame retardancy and the like.

More specifically, the present invention provides a BET specific surface area of about 20 fi"7 g or less, preferably about 1 to about 10 m2/g, and a BET specific surface area/g of 100 parts by weight of the thermoplastic resin.
The present invention relates to a flammable mobile resin composition comprising about 50 to about 250 parts by weight of magnesium hydroxide having a specific surface area in the range of about 1 to about 6.

Conventionally, it has been known to utilize magnesium hydroxide as a flame retardant or flame retardant filler for thermoplastic resins.

Various proposals have been made for magnesium hydroxide suitable for such purposes.

For example, in JP-A-51-82334, a thermoplastic resin with a melt index of 10 to 0.1 g/10 minutes is disclosed.
In order to prevent poor appearance, especially the occurrence of Silno 9-streaks, during extrusion or injection molding of a self-extinguishing resin composition containing 25% by weight and 45 to 75% by weight of magnesium hydroxide, a specific surface area of 45 m'/ Proposals have been made to use magnesium hydroxide with Q or less.

For example, Japanese Patent Application Laid-Open No. 52-5964!1 has a bulk density of 0.35 to 0.70 q/cc-c and a specific surface area of 1.
0 to 60 m2/g, and (1103
It has been proposed to use magnesium hydroxide in which the ratio of the crystallite thickness in the direction perpendicular to the plane to that of the [001] plane is 1.7 to 2.7.

In addition, in the Japanese Special Publication No. 52-4566”, the average particle size is 1.
5 μ or less, oil absorption amount of 50 m1/g or less, and activity value of 50 m
? The use of magnesium hydroxide below IQ has been proposed.

The applicant of the present application has also conducted research for many years to develop magnesium hydroxide, which is excellent as an inorganic flame retardant for thermoplastic resins. They succeeded in developing magnesium hydroxide with a new structure and proposed it in Japanese Patent Application Laid-Open No. 115799/1983.

As a result of further research, we found that, depending on the specific factors mentioned above that have been used to specify magnesium hydroxide, it has excellent dispersibility in resins, non-agglomeration, moldability, In terms of imparting excellent physical properties, improving the appearance of molded products, and flame retardancy, it is not possible to combine these properties, and in order to combine these properties, it is necessary to It has been discovered that BET specific surface area/Bree specific surface area acts as a very important factor.

As a result of further research based on this discovery, the BET specific surface area is about 20 m"/g or less, preferably about 1 to about 1
0 m2/g, and the ratio of BET specific surface area/plain method area is in the range of about 1 to about 6, and magnesium hydroxide is extremely useful for combining the above-mentioned particularly excellent properties. discovered.

Furthermore, the strain in the <101> direction in the x3 diffraction method disclosed in JP-A-52-115799 is 10Xio-
3 or less, preferably the crystal grain size in this direction is 8
More than 0 OA, more preferably BET ratio normal surface area 0
Even if magnesium hydroxide has m2/y, depending on its production method, it may not satisfy the ratio specified in the present IA invention, and therefore it is difficult to achieve the combination of the above particularly excellent properties. I understand. For example, even with magnesium hydroxide having the new structure disclosed in this proposal, the BET specific surface area obtained is 2Qm” Even if it is less than 71, the EET specific surface area/play specific surface area is &i~7
．． When ammonia and slaked lime are used, magnesium hydroxide with the above ratio of 1 to 5 is formed, which has a high ratio of about 6 and has the above particularly excellent properties, and when ammonia and slaked lime are used. It has been discovered that it can be done. It has been discovered that magnesium hydroxide having a ratio of 1 to 6, which has not been recognized in any of the previous proposals, is particularly useful for combining the above properties.

Furthermore, the aforementioned Unexamined Patent Application Publication No. 1iF! As disclosed in No. 151-82334, concentrated bittern or a seed magnesium hydroxide additive is added under vigorous stirring when adding an alkali hydroxide such as caustic soda or calcium hydroxide, and then Magnesium hydroxide, Kai, produced by heating at ~100°C, preferably 70~80°C, can also be used in seawater or Magnesium ions in the bittern are precipitated as magnesium hydroxide by separating them with an alkali, such as calcium hydroxide, caustic soda, potassium hydroxide, lithium hydroxide, and aqueous ammonia, preferably using caustic soda and calcium hydroxide. Conventionally proposed magnesium hydroxide, such as magnesium hydroxide formed by maintaining the usage amount of magnesium ions in seawater or bittern in the range of 95 to 125 t, with an equivalent point of 100 t; , in the conventional commercially available magnesium hydroxide, the above-mentioned BE specified in the present invention
It is not possible to provide magnesium hydroxide that satisfies both the T specific surface area and the above ratio.

The BET specific surface area specified in the present invention is approximately 'lQm'' 7g
Below, preferably about 1 to about 10fi”7g and BET
Specific surface area/prey specific surface area is in the range of about 1 to about 3, preferably 1 to 2.8, more preferably 1 to 2.5.
It has now been discovered that magnesium hydroxide, which is a magnesium hydroxide, specifically possesses the above-mentioned improved properties to a high degree.

Therefore, the object of the present invention is to provide particularly excellent properties such as excellent dispersibility in resin, non-agglomeration, moldability, excellent ability to impart physical properties, improved appearance of molded products, and flammability. It is an object of the present invention to provide a flame-retardant thermoplastic resin composition that has both the above-mentioned properties and contains a magnesium hydroxide flame retardant that also has the above-mentioned properties.

The above objects as well as many other objects and advantages of the present invention will become more apparent from the following description.

The non-am fuel used in the present invention has a BET specific surface area of about 20
m”/g or less, preferably about 1 to about 10 m”7g
and the ratio of BET specific surface M/plain method specific surface area is about 1
~3, preferably 1-z8, more preferably 1-2.
5, consisting of magnesium hydroxide. The magnesium hydroxide can be prepared by using ammonia or slaked lime as an alkaline substance in the method for producing magnesium hydroxide having a novel structure described in JP-A-52-115799. What is necessary is to select and use one that satisfies the above requirements. The details of the above manufacturing method will be omitted since it would be unnecessary to repeat them here, but they will be summarized below. The following formula can be formed by bringing magnesium chloride or magnesium nitrate into contact with ammonia or calcium hydroxide in an aqueous medium under conditions that allow sufficient contact, for example under stirring conditions.In the formula, A is Ct. or NO, where X is a number of 0<Z<0.2 and m is a number of 0 to 6. Basic magnesium chloride or nitrate is heated under pressurized conditions in an aqueous medium. The above magnesium hydroxide can be produced by the following steps.

The formation of the basic magnesium chloride or nitrate can be carried out, for example, at a temperature of about 0 to about 50<0>C, preferably about 10 to about 20<0>C. The reaction is carried out by adding an alkaline substance selected from the group consisting of ammonia and calcium hydroxide to a water bath solution of magnesium chloride, magnesium nitrate, or magnesium chloride and calcium chloride, preferably under stirring conditions. OH〕 (
In the case of ammonia, it acts in the form of NH, OH), and the equivalent ratio of alkali to magnesium chloride or magnesium nitrate (CMy'') satisfies the relationship 2[OH]/[Mg2+]=0.5 to 0.95. However, only when using ammonia, the equivalence ratio may exceed 0.95.In this case, the reaction may be carried out under conditions where chlor or nitrate ions are sufficiently present. preferable.

The basic magnesium chloride or nitrate that can be formed as described above is also a compound that has not been described in the literature prior to the disclosure in the above proposal. Magnesium hydroxide utilized in the present invention is prepared by adding basic chloride- or U-nitric acid-magnesium obtained as described above in an aqueous medium under pressurized conditions as detailed in the proposal. below, preferably about 5 to 9 cm2 or more, such as about 5 to about 30
'9 / t: Heating under pressure conditions of m 2, for example about 1
It can be obtained by heating to 50 to about 250°C. Magnesium hydroxide thus obtained, which satisfies both the BET specific surface area conditions and the BET specific surface area/Pley ratio specific surface area conditions, can be used in the present invention.

In addition, in the present invention, the Blaine method specific surface area and BET
The specific surface area is as follows.

Plain method specific surface area: Measured and determined according to JIS R5201-1964. However, the porosity is set to 0.714, and the amount of sample corresponding to the porosity is used for measurement.

EET specific surface area: "Catalyst" Vot, 2, flatness 4.475
(19/) 0) Based on Noriyuki Takagi.

In the present invention, magnesium hydroxide, which can be formed by selecting the method summarized above and more specifically disclosed in JP-A-52-115799, is used, especially BET specific surface area conditions and BET specific surface area/plane. A flame-retardant thermoplastic resin composition having both of the excellent properties described above can be provided by selecting a material whose ratio of surface area satisfies the requirements of the present invention. More later, along with examples.

As shown in the comparative example, even if the 13ET specific surface area condition is satisfied, it is difficult to achieve the outstanding improvement of the present invention by using magnesium hydroxide whose ratio does not satisfy the present invention condition. .

Magnesium hydroxide that satisfies both the BET specific surface area conditions and the BET specific surface area/plain method specific surface conditions used in the present invention has a plate-like crystal shape and a crystal particle size (diameter) of approximately 0. .1-10μ, preferably 0.5
~5μ. When ammonia is used, the crystal particle size is larger and the dispersibility is better than when slaked lime is used as the alkaline substance.

In addition to using the hydrated magnesium used in the present invention as it is, it can also be used after surface treatment with an anionic surfactant. Compatibility with the resin and dispersibility can be further improved, and favorable results can be given by improving moldability and physical properties of molded products. For example, the above magnesium hydroxide powder is added to a water bath solution of an anionic surfactant such as sodium stearate under sufficient stirring conditions, or stearic acid is added to a suspension of the magnesium hydroxide powder. The anionic surfactant can be chemically adsorbed onto the surface of the magnesium hydroxide used in the present invention by adding an aqueous soda solution under sufficient stirring conditions. The amount of surfactant adsorbed is preferably on the order of about 0.1 to about 10% by weight based on the weight of magnesium hydroxide.

The anionic surfactant used in the above surface treatment is a higher fatty acid alkali salt represented by the formula RCOOM (wherein, RiiC, ~C3° represents an alkyl group, and M represents an alkali metal atom); RO5O,M (in the formula,
an alkyl sulfate represented by the formula R5O,M (wherein R and M are the same as above); an alkyl sulfonate represented by the formula R-aryl-50
3M (wherein R and M are the same as defined above); and a sulfokonolyl sulfonate represented by the formula %ROCOCH5O,M (wherein R and M are the same as defined above); Examples include acid ester salts. Specific examples of such surfactants include:
Sodium stearate, potassium stearate, sodium oleate, potassium oleate, sodium nogrumitate, potassium nogrumitate, sorta laurate, potassium laurate, potassium behenate, sodium laurylbenzenesulfonate, otadecyl Wt potassium acid , sodium lauryl sulfonate, disodium 2-sulfoethyl α-sulfostearate, sodium-N-methyl-N-oleoyl taurate, and the like.

In the composition of the present invention, about 50 to 250 parts of the magnesium hydroxide specified in the present invention, with or without surface treatment with an anionic surfactant, is added to 100 parts by weight of the synthetic resin.
Blend in overlapping parts. Examples of thermoplastic synthetic resins used in such compositions include polymers or copolymers of ethylene, propylene, butene-1 and other α-olefins; one or more of these α-olefins; Copolymers of multiple species and conjugated or non-conjugated dienes; polystyrene or styrenic copolymers such as A
BS resin; polyester or copolyester;
Examples include polycanibonate resins, polyvinyl chloride, various types of coams such as EpD rubber, polyamide, and the like. In particular, non-polar to weakly polar thermoplastic resins are preferred. There are no special restrictions on the method of blending these thermoplastic resins and magnesium hydroxide, and any means that can uniformly mix these additives into the resin, such as extrusion mixing or roll mixing, may be used.1. It can be carried out at any temperature below that which causes thermal degradation of the lW fat. Molding can be performed by any means such as injection molding or extrusion molding. The flame-retardant Kumano resin composition of the present invention can further contain other conventional additives. Examples of such other additives include asbestos, fiberglass, talc,
Fillers such as mica, noglastonite, calcium silicate, aluminum silicate, calcium carbonate; carbon black, phthalocyanine, quinacridone, indoline, azo pigments, titanium oxide, cadmium pigments, yellow lead,
Coloring agents such as Bengara; Antioxidants such as di-t-butyl-p-cresol, distearyl theodizolo 2onate, dilauryl thiodipropionate; calcium stearate, zinc stearate, butyl stearate, Lubricants such as ethylene bisstearamide; 2-hydroxy-4-octoki7penzophenone, 2 (2'-
Examples include ultraviolet absorbers such as hydroxy-5-methylphenyl)benzotriazole, □ethyl-2-cyano b, and 5-diphenylacrylate. The blending amounts of these additives can be selected as appropriate, for example, about 10 to about 100 parts by weight of fillers and about 0.1 to about 10 parts by weight of colorants to 100 parts by weight of synthetic resin. kind,
Examples include about 0.1 to about 10 parts by weight of antioxidants, about 0.1 to about 511 parts by weight of lubricants, and about 0.1 to about 10 parts by weight of ultraviolet absorbers. I can do it.

Hereinafter, several embodiments of the present invention will be explained in more detail with reference to examples and comparative examples.

Example 1 Using ammonia as an alkaline substance, 2COH
] The reaction was carried out at an equivalent ratio of 7'My" = 0.95, followed by hydrothermal treatment in an autoclave at 160° C. for 6 hours. The obtained magnesium hydroxide was washed with water, dehydrated and dried, and pulverized. This was mixed with i?lipropylene and then melted and kneaded using an extruder at about 220°C to make pellets.This was molded using an injection molding machine.

The results are shown in Table 1 below.

Example 2 Water-washed magnesium hydroxide obtained in Example 1 2K
9 was suspended in about 20 t of water and heated to about 80°C,
While thoroughly stirring, a solution 11 containing 40y of sodium stearate at about 80°C was added and stirred for about 50 minutes. After that,
It was dehydrated, dry-brined, crushed, and the same operations as in Example 1 were performed to produce molded products.

The results are shown in Table 1 below.

Example 3 Powdered slaked lime was used as the alkaline substance, and the amount of magnesium chloride was 1.5 m/! /l, 2! ! 2COH]/MQ in desalinated seawater (containing calcium chloride) at 5℃
" = 0.85, and stirred thoroughly. Then, hydrothermal treatment was performed at 160°C for 4 hours. After washing with water and dehydration, the surface was treated with sodium stearate in the same manner as in Example 2. After that, the same fabrication as in Example 1 was carried out.The results are shown in Table 1 below.

Comparative Examples 1 to 3 Comparative magnesium hydroxide shown in Table 1 below was
Since it is difficult to pass through the extruder as it is, in each of Comparisons 1 to 3, 6 each 10:1 Kfit% was added with stearic acid.
, 7-fold IS, 5.551% by weight, and bath-melted, cross-wired, and molded in the same manner as in Example 1. The results are shown in Table 1 below. Table 1 also shows the results of molding polypropylene in the same manner as Control Example 1.

Examples 4 to 7 Magnesium hydroxide having the physical properties shown in Table 2 was mixed with sodium oleate (Example 4 and Comparative Example 4) and sodium stearate (
Example 5 and Comparative Example 5), sodium laurylbenzenesulfonate (Example 6 and Comparative Example 6), and NaN-methyl-N-oleoyl taurate (Example 7 and Comparative Example 7)
) were surface-treated at the ratios of 2%, 6%, 2%, and 2% by weight to magnesium hydroxide, respectively, and propylene-ethylene copolymers (Example 4 and Comparative Example 4), high-density polyethylene (Example 5 and Comparative Example 5), Hl grade folystyrene (Example 6)
and Comparative Example 6), 6-nylon (Example 7 and Comparative Example 7)
) were kneaded and granulated to make pellets, which were then injection molded. The results are shown in Table 2.

Claims (1)

[Claims] 1. The BET specific surface area is approximately 20 m''/rt or less based on 100 parts by weight of the thermoplastic resin, and the BET specific surface area/
A flame retardant thermoplastic resin composition comprising about 50 to about 250 parts by weight of magnesium hydroxide having a specific surface area in the range of about 1 to about 6. 2. The flame-retardant thermoplastic resin composition according to claim 1, wherein the BET specific surface area is about 1 to about 10 2/g.