JPH06313099A - Capsule type flame retardant - Google Patents

Abstract

PURPOSE:To obtain the subject flame retardant for flame-resistant resins not generating a decomposition gas and good in thermal stability, etc., by coating an or-ganic halide compound such as a halogenated aromatic carbonate type flame retardant with metal halide fine particles such as silicon dioxide. CONSTITUTION:A halogen-substituted dihydric phenol of formula I [A is 1-10C (substituted)alkylene, alkylidene, S, SO, SO2, O, CO, etc.; X1, X2 are halogen; (m) is 1, 2] (e.g. tetrabromobisphenol A) and a halogen-nonsubstituted dihydric phenol of formula II (B is the same as A; R1, R2 are 1-3C alkyl; (n) is 0, 1, 2) (e.g. p-tbutylphenol) are reacted with phosgene to produce a halogenated aromatic carbonate type flame retardant of formula III ((p)is 1-50; (q) is 0 or a positive integer; q<=p/2). The compound of formula III is mixed with metal oxide fine particles such as silica and subsequently capsuled to provide the objective capsule type flame retardant comprising the organic halide compound of formula III coated with the metal oxide fine particles.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a capsule type flame retardant. More specifically, it relates to a capsule-type flame retardant capable of producing a flame-retardant resin composition having excellent thermal stability.

[0002]

2. Description of the Related Art Thermoplastic polyester resins such as polybutylene terephthalate resin and polyethylene terephthalate resin have excellent mechanical properties, electrical properties, and other physical and chemical properties, and are therefore engineering plastics for automobiles, electric and electronic devices. It is used in a wide range of applications such as. Since such polyester resin is inherently flammable, its application is limited in the early stage of development, and especially in the field of electric and electronic devices, flame retardancy is strongly required from the viewpoint of fire defense, and various flame retardants have been proposed. ing. Generally, the flame retardancy of a flammable resin is achieved by the combined use of an organic halogen compound and antimony oxide as a flame retardant aid, and the polyester resin is also provided with excellent flame retardancy by the combined use of an organic halogen compound and antimony oxide. Has been converted.

Antimony oxide, especially antimony trioxide, is
It is known that it reacts with an organic halogen compound to generate antimony halide, which has a flame retarding effect when the polyester resin is burned. However, antimony trioxide causes a decomposition reaction of the organic halogen compound when the polyester resin is heated and melted, and at the same time accelerates the decomposition reaction of the polyester resin, which adversely affects the color tone of the polyester resin. Furthermore, when a flame-retardant polyester resin composition containing an organic halogen compound and antimony trioxide is used in a hermetically sealed relay case or the like, the gas generated by the decomposition reaction adheres to the contact, causing a problem of poor conductivity. .

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flame retardant capable of producing a flame-retardant resin composition which is free from gas generation due to decomposition and is excellent in thermal stability.

The inventors of the present invention have made extensive studies on the thermal stabilization of the organic halogen compound with the object of achieving the above object. As a result, it has been found that the capsule type flame retardant coated with the metal oxide fine particles is mixed with the polyester resin. If
The inventors have found that a flame-retardant polyester resin composition excellent in thermal stability, in which almost no gas is generated by the decomposition reaction, is obtained, and the present invention has been accomplished.

[0006]

The present invention relates to a capsule type flame retardant obtained by coating an organic halogen compound with metal oxide fine particles.

The organohalogen compound targeted by the present invention is a powdery organohalogen compound used as a flame retardant for thermoplastic resins. Examples of such organic halogen compounds include halogenated aromatic carbonate type flame retardants, halogen-substituted dihydric phenol derivatives and other organic halogen compounds, which may be used alone or in a mixture of two or more kinds. Of these, halogenated aromatic carbonate type flame retardants are the most preferable because excellent effects can be obtained. In addition, a binder, a lubricant, a stabilizer, a coloring agent, a flame retardant auxiliary agent, etc. can be added to the organic halogen compound as required.

The halogenated aromatic carbonate type flame retardant has the following general formula [1]:

[0009]

[Chemical 2]

[Wherein A and B are the same or different and are substituted or unsubstituted alkylene groups having 1 to 10 carbon atoms, alkylidene groups, -S-, -SO-, -SO _2- , -O- or -CO-, X ₁ and X ₂ are the same or different halogen atoms, R ₁ and R ₂ are the same or different alkyl groups having 1 to 3 carbon atoms, m is 1 or 2, n is 0, 1 or 2, and p is 1 to 5
An integer of 0, q is a positive integer of 0 and q ≦ p / 2. ] The flame retardant represented by the formula is a carbonate oligomer of a halogen-substituted dihydric phenol or a copolymerization type carbonate oligomer of a halogen-substituted dihydric phenol and a halogen-unsubstituted dihydric phenol, and an average value of repeating units of the halogen-substituted dihydric phenol. Is preferably 50 or less, particularly preferably 20 or less, and in the case of a copolymerization type, the average value of the repeating units of the halogen-unsubstituted dihydric phenol is not more than half of the repeating units of the halogen-substituted dihydric phenol. preferable. Such halogenated aromatic carbonate flame retardant,
Alkaline aqueous solution of halogen-substituted dihydric phenol, or alkaline aqueous solution of halogen-substituted dihydric phenol and halogen-unsubstituted dihydric phenol in a predetermined ratio and phosgene in the presence of an organic solvent, and, if necessary, in the presence of a terminator or catalyst. Obtained by reacting.

The halogen-substituted dihydric phenol used here has the following general formula:

[0012]

[Chemical 3]

[In the formula, A is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, an alkylidene group, -S-, -S.
_{O -, - SO 2 -,} - O- or -CO-, X ₁ and X ₂
Are the same or different halogen atoms, and m is 1 or 2. ] A halogen-substituted dihydric phenol represented by
For example, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane (common name tetrabromobisphenol A), 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane (common name tetrachlorobisphenol) A), bis (3,5-dibromo-4-hydroxyphenyl) sulfone (common name tetrabromobisphenol S), bis (3,5-dichloro-4-hydroxyphenyl) sulfone (common name tetrachlorobisphenol S),
1,1-bis (3,5-dibromo-4-hydroxyphenyl) ethane, 1,1-bis (3,5-dichloro-4-)
Hydroxyphenyl) ethane, 1,1-bis (3,5-
Dibromo-4-hydroxyphenyl) cyclohexane,
1,1-bis (3,5-dichloro-4-hydroxyphenyl) cyclohexane, bis (3,5-dibromo-4-)
Hydroxyphenyl) sulfide, bis (3,5-dichloro-4-hydroxyphenyl) sulfide, bis (3,5-dibromo-4-hydroxyphenyl) oxide, bis (3,5-dichloro-4-hydroxyphenyl) oxide, Bis (3,5-dibromo-4-hydroxyphenyl) sulfoxide, bis (3,5-dichloro-
4-hydroxyphenyl) sulfoxide, bis (3,5)
-Dibromo-4-hydroxyphenyl) ketone, bis (3,5-dichloro-4-hydroxyphenyl) ketone and the like can be mentioned, and these can be used alone or in combination of two or more kinds. Of these, tetrabromobisphenol A, tetrachlorobisphenol A, tetrabromobisphenol S, and tetrachlorobisphenol S are preferable. Halogen-unsubstituted dihydric phenol has the following general formula

[0014]

[Chemical 4]

[In the formula, B is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, an alkylidene group, -S-, -S.
_{O -, - SO 2 -,} - O- or -CO-, R ₁ and R ₂
Are the same or different alkyl groups having 1 to 3 carbon atoms, n is 0,
1 or 2. ] It is a dihydric phenol represented by,
The halogen-substituted dihydric phenol is not substituted by halogen, and these can be used alone or in combination of two or more. Bisphenol A and bisphenol S are particularly preferable. As the terminal terminator, monovalent phenols are preferable, for example, phenol, cresol, s-
Butylphenol, tert-butylphenol, nonylphenol, octylphenol, cumylphenol, hydroxychroman compounds, 2,4,6-tribromophenol, pentabromophenol and the like can be mentioned, and these can be used alone or in combination of two or more kinds. . Examples of the organic solvent include methylene chloride, 1,2-dichloroethane, tetrachloroethane, chloroform, carbon tetrachloride,
Examples thereof include chlorobenzene, dichlorobenzene and chlorotoluene, which may be used alone or in combination of two or more.

Examples of the halogen-substituted dihydric phenol derivative include an epoxy compound obtained by the reaction of tetrabromobisphenol A and epichlorohydrin, tetrabromobisphenol A bromoethyl ether oligomer, tetrabromobisphenol A bis (2,3-dibromopropyl ether). ), Tetrabromobisphenol A bis (allyl ether), tetrabromobisphenol A bis (2-hydroxyethyl ether), tetrabromobisphenol S bis (2,3-dibromopropyl ether), and the like.

Examples of other organic halogen compounds include decabromodiphenyl ether, octabromodiphenyl ether, tetrabromodiphenyl ether, hexabromocyclododecane, hexabromobenzene, tetrabromophthalic anhydride, tribromophenol, bis (tribromophenoxy) ethane, poly Dibromophenylene oxide, bis (pentabromophenoxy) ethane, ethylenebistetrabromophthalimide, brominated polystyrene, poly (pentabromobenzyl) acrylate, chlorinated paraffin, perchlorocyclopentadecane, chlorendic acid, tetrachlorophthalic anhydride, tribromo Examples thereof include halogen-containing phosphate-based compounds such as phenyl phosphate.

The metal oxide fine particles used for coating the organic halogen compound must be fine powder having a smaller particle size than the organic halogen compound, and the average particle size is usually 0.001 to 100 μm, preferably Is 0.005
It is 50 μm. As the metal oxide fine particles, silicon oxide fine particles are preferable, and particularly preferable fine particles are silicon oxide fine particles obtained by hydrolyzing purified silicon tetrachloride in an oxyhydrogen flame, and silicon oxide fine particles obtained by decomposing sodium silicate with hydrochloric acid. , Fine particles of silicon oxide obtained by air-oxidizing silicon, silica gel obtained by neutralizing and dehydrating silicate glass in a solvent to grow particles.

Any method may be used to coat the organic halogen compound with the metal oxide fine particles. For example, there is a method using an impact type hitting means. The impact type hitting means is a rotating plate having a mixture of organic halogen compound particles serving as mother particles and metal oxide fine particles serving as child particles in a closed container having a large number of protrusions containing a rotating plate having a large number of protrusions. 5 to
It is rotated at a peripheral speed of 160 m / sec, and at the same time, a large amount of gas (air or inert gas) is circulated. As a result, the particle group is repeatedly hit hard and the child particles are embedded or firmly fixed to the surface of the mother particle, and the surface of the mother particle is covered with the child particles.

The thus obtained capsule type flame retardant of the present invention is extremely useful not only as a polyester resin but also as a flame retardant for other thermoplastic resins.

Various kinds of stabilizers can be added to the organic halogen compound, if necessary. Among these stabilizers, phosphorus-based stabilizers such as trialkyl phosphates, triaryl phosphites, pentaerythritol diphosphites, etc. It is preferable to use an agent and a fatty acid ester-based stabilizer of a monohydric or polyhydric alcohol in combination.

[0022]

EXAMPLES The present invention will be further described with reference to the following examples. In the examples, “parts” means “parts by weight”, and thermal stability shows polybutylene terephthalate [TRB-J] 85 manufactured by Teijin Ltd.
10 parts of halogenated aromatic polycarbonate type flame retardant terminated with p-tert-butylphenol and 5 parts of antimony trioxide are mixed in the above parts, and the cylinder temperature is 260 ° C. by a 30 mmφ extruder [manufactured by Nakatani Machine Co., Ltd.]. After pelletizing and drying the obtained pellets at 120 ° C. for 5 hours, a 3 ounce injection molding machine [manufactured by Meiki Co., Ltd.] was made to stay at a cylinder temperature of 260 ° C. for 10 minutes to prepare a molded plate. The amount of p-tert-butylphenol generated by the decomposition reaction of the flame retardant was quantified by headspace gas chromatography under a heating condition of 150 ° C. for 72 minutes, and the molded plate was determined by this amount.

[0023]

Example 1 Tetrabromobisphenol A, p-tert-
100 parts of powdered halogenated aromatic carbonate type flame retardant having an average degree of polymerization of 15 and an average particle size of 100 μm, obtained by a conventional method from butylphenol (molecular weight modifier) and phosgene, and fine powdery anhydrous powder having an average particle size of 0.015 μm. A mixture of 0.5 parts of silica [Aerosil manufactured by Nippon Aerosil Co., Ltd.] was capsuled for 1 minute at a rotation speed of 6,400 times / minute by an impact type impact device [Hybridizer NHS-1 machine manufactured by Nara Machinery Co., Ltd.]. When the flame-retardant after the chemical treatment was observed with a scanning electron microscope, the surface of the flame-retardant was firmly coated with anhydrous silica. In addition, p-
The amount of tert-butylphenol generated was 0.4 ppm, indicating good thermal stability.

[0024]

Example 2 The same encapsulation treatment as in Example 1 except that 0.5 part of finely powdered hydrous silicon oxide having a mean particle size of 1 μm [Nipseal manufactured by Nippon Silica Industry Co., Ltd.] was used instead of anhydrous silica. When observed by a scanning electron microscope, the surface of the flame retardant was fixedly coated with silicon oxide. Also,
The amount of p-tert-butylphenol generated in the thermal stability test was 0.5 ppm, which was a good thermal stability.

[0025]

Comparative Example 1 When the powdery halogenated aromatic carbonate type flame retardant used in the above example was subjected to a thermal stability test without encapsulation treatment, the amount of p-tert-butylphenol generated was as high as 2.4 ppm, which was low. It showed thermal stability.

[0026]

When the capsule-type flame retardant of the present invention is blended with various thermoplastic resins including polyester resin, a flame-retardant resin composition having a small amount of gas generated by the decomposition reaction and excellent in thermal stability is obtained. And the industrial effects that it produces are exceptional.

Claims (2)

[Claims] 1. A capsule-type flame retardant obtained by coating an organic halogen compound with metal oxide fine particles. 2. An organic halogen compound is represented by the following general formula [1]: [In the formula, A and B are the same or different, and are a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, an alkylidene group,
S -, - SO -, - SO 2 -, - O- or -CO-, X
₁ and X ₂ are the same or different halogen atoms, R ₁ and R
₂ is the same or different alkyl group having 1 to 3 carbon atoms, m is 1
Or 2, n is 0, 1 or 2, p is an integer of 1 to 50, q is an integer of 0 to positive, and q ≦ p / 2. ] The halogenated aromatic carbonate type flame retardant represented by the above, and the capsule type flame retardant according to claim 1, wherein the metal oxide fine particles are silicon oxide fine particles.