JP2001181444A - Flame resistance-imparting agent for thermoplastic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame resistance-imparting agent which is used for thermoplastic resins and can improve the flame resistance without deteriorating the original physiological properties of the thermoplastic resins. SOLUTION: This flame resistance-imparting agent for thermoplastic resins, characterized by comprising the sulfonation product of a styrenic polymer produced by a cation polymerization.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame retardant for a thermoplastic resin capable of improving the flame retardancy without impairing the physical properties of the thermoplastic resin.

[0002]

2. Description of the Related Art In general, thermoplastic resins have excellent impact resistance in addition to excellent moldability. Therefore, thermoplastic resins are used in various fields such as automobile parts, home electric appliances, and OA equipment parts. However, thermoplastic resins are flammable and their uses are limited.

[0003] Conventionally, as a method of making a thermoplastic resin flame-retardant, for example, a halogen compound, a phosphorus compound,
It is known to add a flame retardant such as an inorganic compound to a thermoplastic resin, thereby achieving a certain degree of flame retardancy. However, in recent years, the demand for fire safety has been increasing, and in addition to the development of advanced flame retardant technology, there is a strong demand for the development of technology that does not cause environmental problems or decrease in physical properties. .

On the other hand, various compositions are known in which an aromatic vinyl resin in which a sulfonic acid group is substituted on an aromatic ring, such as a polystyrene sulfonate, is added. For example, a method for producing a stabilized resin of sodium polystyrene sulfonate and polyvinyl chloride (JP-A-7-268028), a method of producing a stabilized resin of sodium polystyrene sulfonate and polyolefin (JP-A-6-331883, Japanese Unexamined Patent Publication No. Hei 1-8090), a thermal printing paper containing an alkanolamine salt of polystyrene sulfonic acid (Japanese Patent Laid-Open No. 2-1).
No. 36285), a thermosensitive recording material comprising an acrylic emulsion containing a polystyrene sulfonate (JP-A-2-69283), a thermosetting resin containing a polystyrene sulfonate and a polystyrene containing a methylol group (JP-A-1-69283). 294729), a heat-sensitive recording material containing a polystyrene sulfonate (JP-A-6-33).
12883, Japanese Patent Application Laid-Open No. 1-8090), a material for organic semiconductor containing polystyrene sulfonate (Japanese Patent Application Laid-Open No.
No. 3,215,722), an antistatic polyester film containing sodium polystyrene sulfonate (Japanese Patent Application Laid-Open No. 6-141525), and a microcapsule for pressure-sensitive copy paper containing polystyrene sulfonate (German Patent No. 3232811, 3037309). Publication), heat-resistant resin composed of polystyrene / polyphenylene oxide alloy [Proceedings of the 6th Son
y Research Forum p.552 (1996)], Compatibility of Polymer Systems with Sulfonate Incorporated into Polystyrene / Polyphenylene Oxide [Polymer, Vol. 33, No. 6, 1210 (199)
2)] and the like, but those described in each of these publications are completely different from the flame-retardant imparting agent for thermoplastic resin of the present invention in the purpose and technical concept (structure, etc.). It is.

On the other hand, Japanese Patent Application Laid-Open No. 11-172603 discloses a flame-retardant thermoplastic resin molding material using polystyrene sulfonate as a flame retardant for a thermoplastic resin. However, there is a problem that the polystyrene sulfonate used in the above publication does not yet exhibit sufficient flame retardancy.

[0006]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned conventional problems and the like.
An object of the present invention is to provide a flame retardant-imparting agent for a thermoplastic resin that can impart excellent flame retardancy to the thermoplastic resin without impairing the physical properties of the thermoplastic resin.

[0007]

Means for Solving the Problems In view of the above-mentioned conventional problems and the like, the present inventors have conducted intensive studies for imparting flame retardancy to a thermoplastic resin, and as a result, a sulfonated product of a specific styrene-based polymer has been obtained. The present invention has been completed by finding out that it has an extremely excellent effect of imparting flame retardancy and at the same time retains the original physical properties of the thermoplastic resin. That is, the flame retardant imparting agent for a thermoplastic resin of the present invention is characterized by comprising a sulfonated styrene polymer produced by cationic polymerization.

[0008]

Embodiments of the present invention will be described below in detail. The flame retardant imparting agent for thermoplastic resin of the present invention is characterized by comprising a sulfonated styrene polymer produced by cationic polymerization.

The styrene polymer of the present invention means, for example, a homopolymer of styrene, a homopolymer of α-methylstyrene, or a copolymer of styrene or α-methylstyrene with another monomer. Examples of other monomers include hydrocarbons having an olefinic double bond such as vinyltoluene, vinylnaphthalene, butadiene, isoprene, pentadiene, cyclopentadiene, ethylene, propylene, butene, and isobutylene. The proportion of styrene or α-methylstyrene in these copolymers is preferably from 50 to 99% by mass. Particularly preferred is a homopolymer of styrene or α-methylstyrene.

[0010] The present invention is characterized in that the polymerization method is carried out by cationic polymerization. There are many cationic polymerization methods using a cationic polymerization catalyst, but a method using a metal halide as a catalyst is preferable. Particularly, the method described in JP-A-3-52902 by the same applicant as the present invention is preferable. That is, upon polymerization, tin dichloride, tin tetrachloride, a metal halide as a catalyst such as aluminum chloride,
This is a method in which polymerization is carried out at 30 to 150 ° C. using a halogenated hydrocarbon containing water at least three times the mol of the metal halide as a solvent. As the halogenated hydrocarbon, for example,
Examples include dichloroethane, dichloromethane, carbon tetrachloride, chloroform and the like. After the polymerization, if necessary, the metal halide catalyst is neutralized with ammonia or the like, and the precipitate formed is removed by filtration, washing with water, or the like. In this way, a styrene-based polymer having a narrow distribution of the degree of polymerization can be obtained at a high conversion.

Next, a sulfonation reaction is carried out. As the sulfonating agent, for example, sulfuric anhydride, sulfuric acid, fuming sulfuric acid and the like are used, and sulfuric anhydride is preferred. As the solvent, an inert halogen hydrocarbon is used for the sulfonating agent. In particular, Japanese Patent Application Laid-Open No.
In the case of the polymerization method described in Japanese Patent No. 2902, the solvent in the polymerization can be used as it is, so that it is economical to shift to the sulfonation step without once isolating the polymer. After the sulfonation is completed, the mixture is neutralized with a known neutralizing agent such as sodium hydroxide, potassium hydroxide, ammonia, or an organic amine, and the solvent is removed by distillation or the like, followed by drying to obtain the desired sulfonated styrene polymer. obtain. The weight average molecular weight of the sulfonated styrene polymer produced by the cationic polymerization is 400 to 500,000.
0, preferably 1000 to 300,000, preferably 2000 to 100,000.

The flame retardant of the present invention can be used for various thermoplastic resins. Examples of the thermoplastic resin include polycarbonate-based, polyphenylene ether-based, polystyrene-based, poly (meth) acrylate-based, polyester-based, polyolefin-based, polyvinyl chloride-based, polyamide-based, and polyphenylene sulfide-based resins. Among these, it can be particularly preferably used for polycarbonate-based, polyester-based, and polyphenylene ether-based thermoplastic resins.

The flame retardant-imparting agent for a thermoplastic resin of the present invention thus constituted can exert an extremely excellent effect of imparting flame retardancy without impairing the physical properties of the thermoplastic resin. . The amount of the flame retardant-imparting agent of the present invention added to the thermoplastic resin is 100 parts by mass of the thermoplastic resin (hereinafter, referred to as the thermoplastic resin).
(Hereinafter simply referred to as “parts”).
Preferably, 0.01 to 5 parts, more preferably, 0.0
2-3 parts. If the amount of the flame retardant is less than 0.01 part, it is difficult to obtain sufficient flame retardancy.
If the amount exceeds the weight part, the physical properties of the resin are apt to deteriorate, which is not preferable.

The thermoplastic resin to which the flame retardancy-imparting agent is added may be added to the thermoplastic resin, if necessary, within a range that does not impair the object of the present invention. Synthetic resins, elastomers, etc. can be blended. The inorganic filler is compounded for the purpose of improving or increasing the mechanical strength and durability of the resin composition, for example, glass fiber, glass beads, glass flakes, carbon black, calcium sulfate, calcium carbonate, silica Calcium oxide, titanium oxide, alumina,
Examples include silica, asbestos, talc, clay, mica, and quartz powder. Examples of the various additives include antioxidants such as hindered phenols, phosphites, phosphates, and amines; ultraviolet absorbers such as benzotriazoles and benzophenones; and light absorbers such as hindered amines. Examples include stabilizers, aliphatic carboxylic acid esters, paraffins, internal lubricants such as silicone oil and polyethylene wax, common flame retardants, flame retardant auxiliaries, mold release agents, antistatic agents, coloring agents, and the like.

Other synthetic resins include, for example, polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polyamide, polyethylene, polypropylene, polystyrene, acrylonitrile / styrene (AS) resin, acrylonitrile / butadiene / styrene (ABS) resin, Methyl methacrylate and the like can be mentioned. Furthermore, examples of the elastomer include isobutylene-isoprene rubber, styrene-butadiene rubber, ethylene-propylene rubber, acrylic elastomer, polyester elastomer, polyamide elastomer, MBS and MAS which are core-shell type elastomers.

The flame-retardant thermoplastic resin can be prepared by blending and kneading the sulfonic acid group-containing styrenic polymer of the present invention, the thermoplastic resin, and various additives used as necessary. . For the above blending and kneading, a method commonly used, for example, a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single screw extruder, a twin screw extruder, a co-kneader, a multi-screw extruder, etc. It can be performed by the method used. The flame-retardant thermoplastic resin obtained in this way can be molded by applying various known molding methods, for example, injection molding, hollow molding, extrusion molding, compression molding, calender molding, rotational molding, etc. in the home appliance field. And other various molded articles.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Polymers used in Examples and Comparative Examples were produced according to Production Examples 1 and 2 and Comparative Production Example 1 described below. The molecular weight of the obtained polymer and the sulfonic acid group introduction rate in the polymer were measured by the following methods.

(Method of measuring molecular weight of polymer) Using a standard sodium polystyrene sulfonate as a standard substance,
TSK-G3000S manufactured by Tosoh Corporation as a separation column
Using W and G4000SW (7.5 mm ID x 30 cm), G using an ultraviolet detector (measuring wavelength 238 nm)
It was determined by the PC method.

(Measurement method of sulfonic acid group introduction ratio in polymer) Elemental analyzer (EA-1108 manufactured by Carlo Elba)
), The sulfonic acid group introduction rate was calculated from the sulfur atom content measured by the above method. When a sulfate was contained in the water-soluble polymer, the amount was determined by ion chromatography, and the amount of sulfur was subtracted from the amount of sulfur obtained by an elemental analyzer.

[Production Example 1 (Production of polymer)] Polystyrene having a weight average molecular weight of 5,000 (JP-A-3-5290)
No. 2, 100 parts of the polymer described in Example 1
Dissolved in 400 parts of dichloroethane and further added 1.0 part by weight of acetophenone to prepare a raw material solution. This raw material solution was continuously supplied to a sulfonation reactor equipped with a turbine type stirrer together with SO _{3 as} a sulfonating agent,
The sulfonation reaction was performed at 5 ° C. In this case, feed rate, feed solution 24 g / min, SO ₃ 3.61 g / min, molar ratio of SO ₃ to styrene units in the polystyrene 0.98 also, the reactor volume 400 jacketed
ml. 10% of the obtained sulfonated product
After neutralization with an aqueous solution of potassium hydroxide, separation, concentration and drying were performed to obtain a powder of potassium polystyrene sulfonate.
The weight average molecular weight of the resulting potassium polystyrene sulfonate (Polymer A) by cationic polymerization is 10,000.
0, the total sulfonic acid group introduction rate with respect to the styrene unit is 95.
%Met.

[Production Example 2 (Production of polymer)] 1,2-
0.15 parts of anhydrous tin tetrachloride was added to 100 parts of dichloroethane (containing 5.1 moles of water with respect to tin tetrachloride), and the mixture was stirred under reflux. Add styrene 100
Was added dropwise over 5 hours. After completion of the dropwise addition, the mixture was further stirred under reflux for 3 hours. The weight average molecular weight of the obtained polystyrene was 5,000. 200 parts of 1,2-dichloroethane was further added to the obtained polystyrene solution to prepare a raw material solution. This raw material solution was continuously supplied to a sulfonation reactor equipped with a turbine type stirrer together with SO _{3 as} a sulfonating agent, and a sulfonation reaction was performed at 45 ° C. In this case, the feed rate was 24 g / min of the raw material solution, SO
₃ 4.05 g / min, the molar ratio of SO _{3 to} styrene units in polystyrene was 1.10, and the reactor was jacketed and had a capacity of 400 ml. The resulting sulfonated product was neutralized with a 10% aqueous sodium hydroxide solution, and then separated and concentrated. Further, sodium sulfate was removed by a recrystallization method and dried to obtain a powder of sodium polystyrene sulfonate. The weight average molecular weight of the obtained sodium polystyrene sulfonate (polymer B) by cationic polymerization is 13,700, and the total sulfonic acid group introduction ratio to styrene units is 105% (two sulfonic acid groups are bonded to a benzene skeleton. Is more than 100% because some of them are produced).

Comparative Production Example 1 (Production of Comparative Polymer) 100 parts of polystyrene produced by a known radical polymerization having a weight average molecular weight of 20,000 was dissolved in 400 parts of 1,2-dichloroethane, and concentrated sulfuric acid was added. 000 parts and stirred at 80 ° C. for 3 hours. The reaction mixture is
After dilution with 0 parts of water, the mixture was neutralized with an aqueous sodium hydroxide solution. After concentration, sodium sulfate was removed by a recrystallization method,
Further, by drying, a powder of sodium polystyrene sulfonate was obtained. The weight average molecular weight of the obtained sodium polystyrene sulfonate (Polymer C) is 40,
000, the total sulfonic acid group introduction ratio to the styrene unit was 100%.

Examples 1 to 3 and Comparative Example 1 A polycarbonate (PC) resin (Iupilon S-3000, manufactured by Mitsubishi Engineering-Plastics Corp.)
Each of the polymers prepared in Comparative Examples 1 to 2 and Comparative Production Example 1 was blended at the ratios shown in Table 1 (parts by mass), supplied to an extruder, kneaded at 300 ° C., and pelletized. The obtained pellet was dried at 120 ° C. for 4 hours, and then injection-molded at a molding temperature of 300 ° C. using an injection molding machine to obtain 126 mm ×
A test piece of 13 mm × 3 mm was obtained. With respect to the obtained test pieces, the limiting oxygen index, heat resistance and light resistance were measured or evaluated by the following methods. The results are shown in Table 1 below.

(Method of measuring critical oxygen index) JIS K7
201 (Test conditions: 126 mm x 13 mm x 3 m
m test piece). The limiting oxygen index is a value indicating the minimum oxygen concentration required for the test material to maintain combustion under the above test conditions by volume% in air. The larger the value, the higher the flame retardancy of the material.

(Evaluation method of heat resistance) The degree of turbidity of the resin plate after the test piece (resin plate) was stored at 140 ° C. for 500 hours was visually compared with that before storage, and those having no change were evaluated as ○ or slightly. Those with deterioration were evaluated as Δ, and those with deterioration were evaluated as x.

(Evaluation method of light resistance) The degree of yellowing after irradiating a test piece (resin plate) with a xenon lamp for 300 hours was visually compared with that before irradiation, and those having no change were evaluated as ○,
Those that were slightly yellowed were evaluated as Δ, and those that were yellowed were evaluated as X.

[0028]

[Table 1]

As is clear from the results in Table 1 above, the flame retardancy-imparting agents of Examples 1 to 3 which fall within the scope of the present invention are compared with Comparative Example 1 produced by radical polymerization which falls outside the scope of the present invention. It has been found that they are excellent in heat resistance and light resistance and can exhibit excellent flame retardancy.

[0030]

According to the present invention, there is provided a flame retardant-imparting agent for a thermoplastic resin which imparts excellent flame retardancy to a thermoplastic resin and which has excellent heat resistance and light resistance of the resin. You.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yoichiro Kono 1-3-7 Honjo, Sumida-ku, Tokyo F-term in Lion Corporation (reference) 4J002 BC121 4J100 AA02Q AA03Q AA06Q AB00Q AB02P AB03P AB04Q AR17Q AS02Q AS03Q BA56H CA01 CA04 CA31 HA61 HB52

Claims (1)

[Claims] 1. A flame retardant for a thermoplastic resin, comprising a sulfonated styrene polymer produced by cationic polymerization.