JPH0592986A - Organic phosphorus compound and flame-retardant heat-stable resin composition containing the same - Google Patents

Abstract

PURPOSE:To provide a new compound having low volatility and being excellent in heat-stability and flame-retardancy. CONSTITUTION:The compound of formula I (R1 to R4 are 1-5C alkyl; R5 and R6 are H or 1-5C alkyl), e.g. the compound of formula II. The compound of formula I can be produced by reacting pentaerythritol with phosphorus oxychloride and reacting the obtained compound of formula III with desired monohydric phenol (e.g. 2,6-dimethylphenol). A flame-retardant heat-stable resin composition is produced by adding 0.1-100 pts.wt. of the compound to 100 pts.wt. of an organic polymer such as PE.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel organic phosphorus compound, and a flame-retardant heat-stable resin composition containing the organic phosphorus compound as an addition-type flame retardant and having excellent flame retardancy and heat stability. In particular, the present invention relates to a flame-retardant heat-stable resin composition capable of forming a molded body that does not cause dripping of molten resin when burned.

[0002]

2. Description of the Related Art Organic polymers such as thermoplastic resins such as polypropylene, polystyrene and acrylonitrile-butadiene-styrene (ABS) resins have excellent properties such as relatively low cost and easy molding. It is widely used in all kinds of daily necessities including electronic parts and automobile parts. However, since these organic polymers are flammable, they easily burn and disappear once a fire occurs. Cable fires have a particularly great impact on society. Nowadays, flame retardation is obligatory in some of the fields of use of these organic polymers such as electric products, automobile interior parts and textile products.

In order to impart flame retardancy to organic polymers,
A method of adding a flame retardant at the time of adjusting a resin molded product is adopted. As the flame retardant, inorganic compounds, organic phosphorus compounds,
Examples include organic halogen compounds and halogen-containing organic phosphorus compounds. Among the above compounds, the organic halogen compound and the halogen-containing organic phosphorus compound exhibit the excellent flame retardant effect. However, these halogen-containing compounds are thermally decomposed during resin molding to generate hydrogen halide, corrode the mold, and deteriorate the resin itself to cause coloring.
There is also a problem that the working environment is deteriorated. In addition, there is also a problem that toxic gas such as hydrogen halide, which is harmful to the human body, is generated during combustion due to fire or the like.

As the flame retardant containing no halogen, there are inorganic compounds such as magnesium hydroxide. But,
These inorganic compounds have a remarkably low flame retardant effect, and it is necessary to add a large amount to obtain a sufficient effect. This has the drawback that the physical properties of the resin are impaired.

Organophosphorus compounds have been widely used as flame retardants containing no halogen and capable of obtaining a relatively good flame retarding effect. Triphenyl phosphate (TPP) is well known as a typical organic phosphorus compound. However, triphenyl phosphate has the disadvantages of poor heat resistance and high volatility.

As the organic phosphorus compound having a low volatility, there are condensed phosphoric acid esters described in JP-A-51-19858 and JP-A-2-18336. However, even though these materials have better heat resistance than triphenyl phosphate, engineering plastics that have been developed in recent years and high-performance plastics such as super engineering plastics require a high temperature of around 300 ° C for molding. , Can not stand such high temperature.
Further, since the condensed phosphoric acid ester described in these patents is a liquid compound, the physical properties of the resin are remarkably deteriorated such as lowering the heat distortion temperature of the resin composition.

Various standards such as ASTM, UL, MIL, JIS are known as flame retardancy tests and flame retardancy standards for various molded products, and each test method is applied according to the intended use of the molded product. Has been done. For example, a resin that meets the criteria of UL-94 V-0 or V-1 grade is a resin that does not drip the molten resin when burned. When the above organic phosphorus compound is used, the resin is melted and easily dropped when burned. Thus, when the above organic phosphorus compound as a flame retardant, UL-9
It is not possible to obtain a product with flame retardance that fully meets the V-0 or V-1 standard of 4.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and its object is to use it as a flame retardant capable of imparting excellent flame retardancy to various resins. It is possible to provide a compound which is excellent in heat resistance, does not deteriorate or corrode the resin when mixed with the resin and is subjected to a molding process, and has extremely little deterioration in the physical properties of the resin. Another object of the present invention is to form a molded article containing the above compound and a resin, which is excellent in heat resistance and flame retardancy and which does not cause dripping of molten resin when burned. It is intended to provide a flame-retardant heat-stable organic polymer composition to be obtained.

[0009]

As a result of intensive studies, the present inventors have found that an organophosphorus compound having a specific structure has low volatility and excellent thermal stability, and that the resin is flame-retardant without impairing the physical properties of the resin. The present invention has been completed by discovering that a molded body can be formed in which a molten resin is not dripped when burnt and burned. The organophosphorus compound of the present invention is represented by the following formula (1), thereby achieving the above object.

[0010]

[Chemical 2] Wherein _{R 1, R 2, R 3} , R 4 are each independently an alkyl group of 1 to 5 carbon atoms, R _5, R ₆ is hydrogen or an alkyl group having 1 to 5 carbon atoms. Many organic phosphorus compounds having a ring structure similar to the formula (1) are known, for example, US Pat. No. 3,090,799 and US Pat.
281 and the like. In these, compounds represented by the following general formula (2) are disclosed.

[0011]

[Chemical 3] Here, R is alkyl, aryl and the like.

However, the above-mentioned patent is mainly concerned with R of the formula (2) for a phenyl group, and does not describe an aromatic group having a sterically hindering group at the ortho position. As a result of investigating various organophosphorus compounds having the above ring structure, the inventors have found that an organophosphorus compound of the formula (1) having an aromatic group having a sterically hindering group at the ortho position has a sterically hindering group at the ortho position. It was found that it has better thermal stability than those that do not. It was also found that the organophosphorus compound of the present invention also exhibits an effect as an antioxidant. Further, when the compound is added to an organic polymer, the deterioration of the resin physical properties such as heat distortion temperature is extremely small, and a molded article formed from this organic polymer composition has a resin drop melted when burned. It has been found that it has excellent performance such that (dripping) does not occur.

The flame-retardant composition of the present invention comprises an organic polymer and
The above-mentioned object is achieved by containing the above-mentioned organic phosphorus compound as a flame retardant. The organophosphorus compound of the present invention can be produced by a known method. For example, US Pat.
According to the method described in 0,799, it can be produced by reacting pentaerythritol with phosphorus oxychloride and then reacting with monohydric phenols. This reaction is explained by the following reaction equation.

[0014]

[Chemical 4] In the formula, R is an aromatic group. As another method, it can also be produced by reacting arylphosphosulosichloridate with pentaerythritol. This reaction is explained by the following reaction equation.

[0015]

[Chemical 5] In the formula, R is an aromatic group.

In the organophosphorus compound of the present invention, R is an aromatic group having an alkyl group having 1 to 5 carbon atoms in the ortho position, such as 2,6-dimethylphenyl, 2,4,6.
-Trimethylphenyl, 2,6-di-tert-butylphenyl, 2,4,6-tri-tert-butylphenyl and the like.

Organic polymers which can be provided with flame retardancy according to the present invention include thermoplastic resins and thermosetting resins. As the thermoplastic resin, chlorinated polyethylene,
Polyethylene, polypropylene, polybutadiene, styrene resin, high impact polystyrene, polyvinyl chloride,
ACS resin, AS resin, ABS resin, modified polyphenylene oxide, polymethylmethacrylate, polyamide,
Polyester such as polybutylene terephthalate, polycarbonate, polyphenylene sulfide, polysulfone, polyether sulfone, polyimide, polyether ether ketone, polyarylate, polyether ketones, polyether nitrile, polythioether sulfone, polybenzimidazole, polycarbimide, There are liquid crystal resins and composite plastics. Examples of the thermosetting resin include polyurethane, phenol resin, melamine resin, urea resin, unsaturated polyester and diallyl phthalate resin. The above resins may be used alone or in combination of two or more. The flame-retardant composition of the present invention is
The organic polymer, the organic phosphorus compound, and various additives as necessary are contained. Examples of various additives include halogen-based flame retardants, inorganic flame retardants, antioxidants, fillers and lubricants. The type and amount of the organic phosphorus compound used is appropriately determined depending on the organic polymer used and the degree of flame retardancy required. The organic phosphorus compound is usually
It is used in a proportion of 0.1 to 100 parts by weight with respect to 100 parts by weight of the organic polymer. An organic polymer, an organic phosphorus compound and, if necessary, the above additives are kneaded by a known method,
By molding, a flame-retardant molded product can be obtained. The organophosphorus compound is added, for example, together with the monomer charged when the organic polymer is produced by bulk polymerization; added at the end of the reaction of bulk polymerization of the organic polymer; added at the time of molding the organic polymer; or It is provided by being applied as a solution or dispersion on the surface of a polymer product such as a film, a fiber or the like. The resin composition thus obtained is used as plastics, foams, adhesives, paints and the like.

[0018]

INDUSTRIAL APPLICABILITY The novel organic phosphorus compound of the present invention can impart excellent flame retardancy to the organic polymer when mixed with various organic polymers. This organophosphorus compound has low volatility,
Further, it is also excellent in thermal stability, coloring and deterioration of the resin due to thermal decomposition at the time of molding are greatly improved, and further, physical properties of the organic polymer are hardly deteriorated. In particular, the organic polymer of the present invention can form a molded product that does not cause dripping of molten resin when burned.

[0019]

The present invention will be described with reference to the following examples. These examples do not limit the scope of the invention. In the examples below, all parts are by weight and all temperatures are in degrees Celsius unless otherwise noted.

Example 1 A four-necked flask was equipped with a stirrer, a thermometer, and a condenser connected with a water scrubber, and 136 g of pentaerythritol was added to this flask.
(1 mol), 2,6-xylyl phosphorodichloridate (478 g (2 mol)), aluminum chloride (3 g) and toluene (500 g) were added, and a dehydrochlorination reaction was performed for 4 hours under a toluene reflux state to complete the reaction. 200% 10% hydrochloric acid in the reaction solution
g was added, and the remaining catalyst and the like were removed by stirring, followed by washing with water, and then cooling to room temperature with stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed with 200 g of methanol, and dried under reduced pressure at 100 ° C. The obtained crystals were white powdery crystals, and the yield was 314 g and the yield was 67%. This crystal has a structure represented by the following formula (this is referred to as compound 1). The results of elemental analysis of Compound 1 (C ₂₁ H ₂₆ O ₈ P ₂ ) are shown in Table 1 together with the yield.

[Chemical 6]

[0021]

[Table 1]

Example 2 The same procedure as in Example 1 was repeated except that 506 g of 2,4,6-trimethylphenyl phosphorodichloridate was used instead of 478 g of 2,6-xylyl phosphorodichloridate. A white powdery crystal having the structure of the formula was obtained (this is compound 2). The results of elemental analysis of compound 2 (C ₂₃ H ₃₀ O ₈ P ₂ ) are shown in Table 1 together with the yield.

[Chemical 7]

(Example 3) 2,6-xylyl phosphorodichloridate was replaced with 478 g of 2,6-di-tert-.
White powdery crystals having the structure of the following formula were obtained in the same manner as in Example 1 except that 562 g of butylphenyl phosphorodichloridate was used (this is referred to as compound 3).
The results of elemental analysis of compound 3 (C ₂₅ H ₃₈ O ₈ P ₂ ) are shown in Table 1 together with the yield.

[Chemical 8]

Example 4 Poly (2,6-dimethyl-)
Examples 1 to 3 were added to a resin composed of 60 parts of 1,4-phenylene) oxide and 40 parts of rubber-modified impact-resistant polystyrene.
After adding 10 parts of the flame retardant obtained in step 3 and mixing with a mixer,
The compounding pellets were obtained through an extruder maintained at 0 ° C. Put these pellets in the injection molding machine and
Molding was performed at 90 to 300 ° C to obtain a test piece. Using this test piece, flame retardancy, discoloration, heat distortion temperature, Izod impact value, and tensile strength were measured. The results are shown in Table 2. The results of Comparative Example 1 described later are also shown in Table 2.

[0025]

[Table 2]

(Example 5) Polycarbonate resin 100
10 parts of the flame retardant obtained in Examples 1 to 3 was added to the parts, mixed with a mixer, and then passed through an extruder held at 300 ° C to obtain compounding pellets. This pellet was put into an injection molding machine and molded at 290 to 300 ° C. to obtain a test piece. Using this test piece, in the same manner as in Example 4, flame retardancy,
The discoloration property, heat distortion temperature, Izod impact value, and tensile strength were measured. The results are shown in Table 3. The results of Comparative Example 4 described later are also shown in Table 3.

[0027]

[Table 3]

Comparative Example 1 The same as Example 4 except that a test piece was obtained by using TPP and the compound having the following structural formula as a flame retardant.

[0029]

[Chemical 9]

[0030]

[Chemical 10]

[0031]

[Chemical 11]

(Comparative Example 2) The same as Example 5 except that test pieces were obtained using TPP and compounds 4 to 5 as flame retardants. Flame retardancy The flame retardancy of the test piece was determined by the UL-94 test method. It was classified into four types of flame retardant V-0, V-1, V-2 and HB. Discoloration The discoloration of the test piece was visually evaluated. Heat distortion temperature According to ASTM standard D-648, load 18.6 Kg / c
It was measured in m ² . Izod impact strength Measured according to ASTM standard D-256. Tensile Strength Measured according to ASTM standard D-638.

Claims (3)

[Claims] 1. The following formula (1): (In the formula, R ₁ , R ₂ , R ₃ , and R ₄ are each independently an alkyl group having 1 to 5 carbon atoms, and R ₅ and R ₆ are hydrogen or an alkyl group having 1 to 5 carbon atoms) An organic phosphorus compound represented by. 2. A flame-retardant heat-stable resin composition containing the compound according to claim 1 as a flame retardant and an organic polymer. 3. The resin composition according to claim 2, wherein the organic phosphorus compound is contained in an amount of 0.1 to 100 parts by weight based on 100 parts by weight of the organic polymer.