JP4798782B2 - Surface treatment agent for preparing flame retardant composition having magnesium hydroxide particles as a core, method for preparing flame retardant composition, and flame retardant composition - Google Patents

Description

  The present invention relates to a surface treatment agent for preparing a flame retardant composition having magnesium hydroxide particles as a core, a method for preparing the flame retardant composition, and a flame retardant composition. As a clean flame retardant composition that does not generate toxic gas, the magnesium hydroxide particles as the core and the surface treatment agent attached to it are used as covering materials such as communication cables and electric wires, and as building materials such as wallpaper. in use. Such a flame retardant composition is used in various forms. In many cases, it is usually used together with a carrier and kneaded with a synthetic resin such as a polyolefin resin. Magnesium hydroxide particles are classified into natural products and synthetic products, and natural products are manufactured by dry-grinding naturally produced magnesium hydroxide ore, that is, natural brucite ore. In recent years, it is cheaper than synthetic products. However, the surface treatment agent that adheres to the magnesium hydroxide particles adheres as uniformly as possible to the surface of the magnesium hydroxide particles, and as a result, the resulting flame retardant composition is, for example, described above. When the product is kneaded with synthetic resins and molded from the kneaded product, flame retardancy having sufficient water resistance can be imparted to the product, and the inherent properties of the synthetic resins, such as melt flowability, It is required that the electrical insulation, mechanical strength, etc. are not impaired. The present invention relates to a surface treatment agent for preparing a flame retardant composition having magnesium hydroxide particles as a core, a method for preparing the flame retardant composition, and a flame retardant composition that meet such requirements.

  Conventionally, as a surface treatment agent for preparing a flame retardant composition having magnesium hydroxide particles as a core, fatty acid, fatty acid metal salt, fatty acid amide, aliphatic alcohol, alcohol phosphate ester, silane coupling agent, aluminum coupling agent , Titanate coupling agents, dicarboxylic acid monoesters and the like are known (see, for example, Patent Documents 1 to 5).

However, these conventional surface treatment agents are generally difficult to uniformly adhere to the surface of the magnesium hydroxide particles, and the flame retardant composition prepared using them is kneaded with, for example, synthetic resins. When a product is molded from a product, the water resistance of the product decreases as the use rate of the flame retardant composition increases, and the inherent properties of synthetic resins, such as melt fluidity, electrical insulation, tensile strength, tensile elongation, and other machinery There is a problem of lowering the mechanical strength and the like.
JP-A-4-45404 JP 7-161230 A JP-A-10-226789 JP 2003-3167 A JP 2005-179615 A

  The problem to be solved by the present invention is a surface treatment agent for preparing a flame retardant composition having magnesium hydroxide particles as a core, which uniformly adheres to the surface of the magnesium hydroxide particles and is prepared using the same. For example, when a flame retardant composition is kneaded with synthetic resins and a product is molded from the kneaded product, the surface treatment agent can impart flame resistance with sufficient water resistance to the product without impairing the original properties of the synthetic resin. The present invention provides a method for preparing a flame retardant composition using such a surface treating agent and a flame retardant composition obtained by such a preparation method.

  Accordingly, as a result of studies conducted by the present inventors to solve the above-mentioned problems, a surface treatment agent for preparing a flame retardant composition having magnesium hydroxide particles as a core is composed of a specific alkenyl succinic anhydride. Has been found to be correct and suitable. As a method for preparing a flame retardant composition having magnesium hydroxide particles as a core, natural brucite ore is coarsely pulverized, and the surface treatment agent is added to the coarsely pulverized product in a predetermined ratio and mixed while finely mixing. We have found that grinding is correct and suitable. Furthermore, it has been found that a flame retardant composition having magnesium hydroxide particles as a core is correctly obtained by the above preparation method.

  That is, the present invention provides a surface treatment agent for preparing a flame retardant composition having magnesium hydroxide particles as a core, comprising an alkenyl succinic anhydride represented by the following chemical formula 1: Related.

In chemical formula 1,
R: an alkenyl group having 14 to 60 carbon atoms

  In the present invention, natural brucite ore is coarsely pulverized, and the surface treatment agent according to the present invention is added at a ratio of 0.1 to 7 parts by mass with respect to 100 parts by mass of the coarsely pulverized product. The present invention relates to a method for preparing a flame retardant composition to be finely pulverized.

  Furthermore, the present invention relates to a flame retardant composition obtained by the preparation method according to the present invention.

  First, a surface treatment agent for preparing a flame retardant composition having magnesium hydroxide particles as a core according to the present invention (hereinafter simply referred to as the surface treatment agent of the present invention) will be described. The surface treatment agent of the present invention comprises an alkenyl succinic anhydride represented by Chemical Formula 1, and this alkenyl succinic anhydride has an alkenyl group having 14 to 60 carbon atoms as a substituent as represented by Chemical Formula 1. It has succinic anhydride. Similarly, even if the succinic anhydride having an alkenyl group as a substituent has an alkenyl group having 13 or less carbon atoms or an alkenyl group having 61 or more carbon atoms, it is difficult to use magnesium hydroxide particles as a nucleus. The desired effect as a surface treatment agent for preparing a fuel composition is not achieved. In order to achieve the desired effect better, those having an alkenyl group having 16 to 30 carbon atoms are preferred.

  The alkenyl succinic anhydride represented by Chemical Formula 1 used as the surface treating agent of the present invention may be a single compound or a mixture. For example, a succinic anhydride having an alkenyl group having 16 carbon atoms or a succinic anhydride having an alkenyl group having 18 carbon atoms may be used, but a succinic acid having an alkenyl group having 16 carbon atoms may be used. It may be a mixture of an anhydride and a succinic anhydride having an alkenyl group having 18 carbon atoms, or a mixture of a plurality of alkenyl succinic anhydrides in which the alkenyl group has a carbon number ranging from 20 to 28. It may be.

  The alkenyl succinic anhydride itself used as the surface treatment agent of the present invention can be synthesized by a known method as described in JP-A-60-115571 and JP-A-64-79163. . For example, an alkenyl succinic anhydride can be obtained by reacting an α-olefin having a predetermined carbon number with maleic anhydride in a nitrogen gas atmosphere under heating at about 150 to 200 ° C.

  The surface treatment agent of the present invention described above is a surface treatment agent used for preparing a flame retardant composition having magnesium hydroxide particles as a core. Magnesium hydroxide particles using the surface treating agent of the present invention may be natural products or synthetic products, and among them, those prepared from natural brucite ore are preferable.

  Next, the preparation method of the flame retardant composition according to the present invention (hereinafter simply referred to as the preparation method of the present invention) will be described. In the preparation method of the present invention, natural brucite ore is roughly pulverized, and the ratio of the surface treatment agent of the present invention is 0.1 to 7 parts by mass, preferably 1 to 3 parts by mass per 100 parts by mass of the coarsely pulverized product. In addition, it is a method of pulverizing while mixing. Here, a known coarse pulverizer can be used for coarse pulverization of natural brucite ore. Examples of this include a jaw crusher, a hammer crusher, a gyratory crusher, and a roll crusher. A known fine pulverizer can also be used for mixing and finely pulverizing the coarsely pulverized product and the surface treatment agent. Examples thereof include a jet mill, a ball mill, a high-speed rotary mill (impact pulverizer), and the like.

  Finally, the flame retardant composition according to the present invention (hereinafter simply referred to as the flame retardant composition of the present invention) will be described. The flame retardant composition of the present invention is a flame retardant composition obtained by the preparation method of the present invention. As a result, the surface treatment agent of the present invention uniformly adheres to the surface of magnesium hydroxide particles derived from natural brucite ore. Is.

  The flame retardant composition of the present invention is not particularly limited in particle size, but is classified by pulverization in the preparation method of the present invention as described above, and an average particle size of 0.1 to 10 μm. What was made into 0.5 to 7 micrometers was more preferable. A known machine or apparatus can be applied to the classification. This includes, for example, a circular vibrating screen, a high-precision air classifier, an ultrafine powder classifier, and the like.

  The use of the flame retardant composition of the present invention is not particularly limited, but the effect is high with respect to polyolefin-based synthetic resins among synthetic resins. Examples of such polyolefin-based synthetic resins include polypropylene, polyethylene, ethylene / propylene copolymer, ethylene / ethyl acrylate copolymer, ethylene / vinyl acetate copolymer, and the like. Application is preferred. When the flame retardant composition of the present invention is applied to synthetic resins, for example, polyolefin synthetic resins, the amount used is usually 20 to 150 parts by mass per 100 parts by mass of polyolefin synthetic resin.

  The surface treatment agent of the present invention uniformly adheres to the surface of the magnesium hydroxide particles, and when a flame retardant composition prepared using the same is kneaded with, for example, a synthetic resin and a product is formed from the kneaded product, The flame retardancy having sufficient water resistance can be imparted to the product without impairing the original characteristics of the synthetic resin.

  Hereinafter, in order to make the configuration and effects of the present invention more specific, examples and the like will be described. However, the present invention is not limited to these examples. In the following Examples and Comparative Examples, “part” means “part by mass” and “%” means “% by mass”.

Test category 1 (synthesis of surface treatment agent)
Example 1 {Synthesis of surface treatment agent (a-1)}
In a glass reaction vessel equipped with a stirrer, 319 parts of a mixture of a plurality of α-olefins having a carbon number of 20 to 28 (trade name Dialen 208 manufactured by Mitsubishi Chemical Corporation), 98 parts of maleic anhydride and 0.4 of hydroquinone The reaction system atmosphere was purged with nitrogen, and the reaction was continued for 20 hours while stirring at a temperature of 180 ° C. The product obtained by this reaction was a mixture of a plurality of alkenyl succinic anhydrides having a solid state at room temperature and having 20 to 28 carbon atoms in the alkenyl group. This was designated as surface treating agent (a-1).

Examples 2 to 4 and Comparative Examples 1 to 4 {Synthesis of surface treatment agents (a-2) to (a-4) and (r-1) to (r-4)}
In the same manner as the surface treatment agent (a-1) of Example 1, the surface treatment agents (a-2) to (a-4) of Examples 2 to 4 and the surface treatment agents of Comparative Examples 1 to 4 (r- 1) to (r-4) were synthesized. Table 1 summarizes the contents of the surface treatment agents obtained in the above examples.

Test Category 2 (Preparation of flame retardant composition)
Example 5 {Preparation of flame retardant composition (P-1)}
Natural brucite ore is coarsely pulverized to a particle size of 10 mm or less, and 100 parts of the coarsely pulverized product and 1 part of the surface treatment agent (a-1) of Test Category 1 are put into a fine pulverizer and mixed for 2 hours. While finely pulverizing, classification was performed using a sieve to obtain a flame retardant composition (P-1). This flame retardant composition (P-1) contains the surface treating agent (a-1) at a ratio of 1 part per 100 parts of magnesium hydroxide particles, and the average particle diameter is 4 μm. The surface treating agent (a-1) was uniformly adhered to the entire surface of the magnesium hydroxide particles.

About the said flame retardant composition (P-1), the following method measured or evaluated the content rate of the surface treating agent, the average particle diameter, and the adhesion state of the surface treating agent.
-Content ratio of surface treatment agent: Using a Soxhlet extractor, the surface treatment agent was extracted using xylene as an extraction solvent, and weighed to determine the content ratio.
Average particle size: measured using a laser diffraction particle size distribution analyzer (LA-920 manufactured by Horiba, Ltd.).
-Adhesion state of surface treatment agent on magnesium hydroxide particle surface: Using a scanning electron microscope (T-300 manufactured by JEOL Ltd.), a secondary electron image and a reflected electron image on the same screen of the flame retardant composition Photographs were taken, 20 particles were arbitrarily selected from these photographed images, and the surface treatment agent was attached to 90% or more of the surface of the magnesium hydroxide particles for the selected individual particles. The case of adhering was evaluated as 3 points, similarly, the case of 70% or more and less than 90% was evaluated as 2 points, and the case of less than 70% was evaluated as 1 point.
◎: Score is 55 points or more ○: Score is 50 points or more and less than 54 points △: Score is 35 points or more and less than 50 points ×: Score is less than 35 points

Examples 6 to 8 and Comparative Examples 5 to 10 {Preparation of flame retardant compositions (P-2) to (P-4) and (R-1) to (R-6)}
In the same manner as the flame retardant composition (P-1) of Example 5, the flame retardant compositions (P-2) to (P-4) of Examples 6 to 8 and the flame retardant compositions of Comparative Examples 5 to 10 (R-1) to (R-6) were prepared. Table 2 summarizes the contents of the flame retardant composition of each example prepared above and the measurement or evaluation results.

In Table 2,
* 1: Stearic acid * 2: Stearic acid amide

Test Category 3 (Evaluation of flame retardant composition)
-Preparation of sample Using a kneader having a twin screw type blade (Laboplast Mill manufactured by Toyo Seiki Co., Ltd.), the flame retardant composition prepared in Test Category 2 was added with ethylene / ethyl acrylate in the addition amount shown in Table 3. In addition to a polymer (produced by Nippon Polyolefin Co., Ltd., ethyl acrylate content ratio 15%, melting point 100 ° C., MFR 0.75), the mixture was kneaded at 150 ° C. for 3 minutes to obtain a kneaded product. This kneaded product was press-molded at 150 ° C. to prepare a sheet having a thickness of 2 mm.

Evaluation test Melt fluidity was determined for the kneaded product in each example, and eluted magnesium, volume resistivity, tensile strength, tensile elongation, and oxygen index were determined for the sheet in each example as follows. 3 is shown collectively.
Melt fluidity: Based on JIS-K7210, the melt fluidity of the kneaded product was measured under conditions of a temperature of 190 ° C. and a load of 2.16 kg. The larger the value, the better the melt fluidity.
-Eluted magnesium (eluting Mg): Cut out two test pieces of 32 mm length x 20 mm width from the prepared sheet, soak them in 500 ml of distilled water, and continue carbon dioxide gas in the soaked water at 23 ° C for 3 days. Then, the test piece was taken out and subjected to a water resistance test. The magnesium ion concentration of the immersion water was measured by ICP emission spectroscopy. The lower the magnesium ion concentration, the better the water resistance.
-Volume resistivity: Based on JIS-K6911, the volume resistivity was measured about the test piece before the said water resistance test, and the test piece after the water resistance test. The smaller the decrease in the value before and after the water resistance test, the better the water resistance.
-Tensile strength: Based on JIS-K7113, the tensile strength was measured about the test piece before the said water resistance test. The larger the value, the better the mechanical strength.
-Tensile elongation: Based on JIS-K7113, the tensile elongation was measured about the test piece before the said water resistance test. The larger the value, the better the tensile elongation.
-Oxygen index: Based on JIS-K7201-2, the oxygen index was measured about the test piece before the said water resistance test. The larger the value, the better the flame retardancy.

In Table 3,
* 1: Addition part of flame retardant composition to 100 parts of ethylene / ethyl acrylate copolymer * 2: Magnesium hydroxide particles having an average particle diameter of 4 μm without addition of surface treatment agent

Claims (7)

A surface treatment agent for preparing a flame retardant composition having magnesium hydroxide particles as a core, comprising an alkenyl succinic anhydride represented by the following chemical formula 1:

(In chemical formula 1,
R: an alkenyl group having 14 to 60 carbon atoms   2. The surface treating agent according to claim 1, wherein the alkenyl succinic anhydride represented by Chemical Formula 1 is one in which R in Chemical Formula 1 is an alkenyl group having 16 to 30 carbon atoms.   It is difficult to coarsely pulverize natural brucite ore, add the surface treatment agent according to claim 1 or 2 per 100 parts by mass of the coarsely pulverized product so as to have a ratio of 0.1 to 7 parts by mass, and finely grind while mixing. Preparation method of a fuel composition.   A flame retardant composition obtained by the preparation method according to claim 3.   The flame retardant composition according to claim 4, which is fine particles having an average particle size of 0.1 to 10 μm.   The flame retardant composition according to claim 4 or 5, which is for a polyolefin-based synthetic resin. The flame retardant composition according to claim 6, wherein the polyolefin-based synthetic resin is an ethylene / ethyl acrylate copolymer.