JP7432819B2 - Halogen-containing polymer and its manufacturing method - Google Patents

Description

The present invention relates to a halogen-containing polymer used as a flame retardant and a method for producing the same.

Flame retardants are well known as additives that impart flame retardancy to resins by mixing them into resins. Among these, compounds containing a large amount of bromine have been added to many resins and used as halogen flame retardants for a long time. For example, tetrabromobisphenol A, which is one of the representative brominated flame retardants, is known as the halogenated flame retardant produced in the largest amount in the world.

Regarding brominated flame retardants, there is a tendency to shift to high molecular weight type agents due to environmental considerations.

For example, ethylene-crosslinked oligomers of tetrabromobisphenol A have been reported (Patent Documents 1 to 4).

The oligomer is defined as having a molecular weight of 1,000 to 5,000 and a melting point of 120 (or 150)°C to 250°C, and is said to be useful for flame retardant polystyrene and reinforced polyester.

Japanese Unexamined Patent Publication No. 51-117737 Special Publication No. 56-8809 Japanese Unexamined Patent Publication No. 53-128656 Special Publication No. 62-1973

The oligomers reported in Patent Documents 1 to 4 cannot be said to have sufficiently high heat resistance, and there is a need for flame-retardant materials with even better heat resistance.

The present invention has been made in view of the above-mentioned background art, and its object is to provide a brominated bisphenol polymer crosslinked with aliphatic hydrocarbon groups that has excellent heat resistance.

As a result of intensive studies to solve the above problems, the present inventors found that in the presence of a lactam compound, a prepolymer compound in which a crosslinking agent was added to both ends of a brominated bisphenol compound, a brominated bisphenol compound, and an alkali metal We discovered a production method in which a salt compound or an alkaline earth metal salt compound is reacted, and succeeded in obtaining a polymer with a high molecular weight that could not be synthesized using conventional production methods. Furthermore, it was discovered that the polymer obtained by this production method has superior heat resistance compared to conventionally known oligomers, leading to the completion of the present invention.

That is, the present invention is a halogen-containing polymer and a method for producing the same as shown below.
[1] A polymer having a repeating unit represented by the following general formula (1), which has a weight average molecular weight of 15,000 or more in terms of standard polystyrene.

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -.)
[2] The polymer according to [1], which has a melting point of 255°C or higher.
[3] The polymer according to any one of [1] to [2], wherein the weight loss temperature of 20% by weight is 380°C or higher at a heating rate of 10°C/min.
[4] Reacting a compound represented by the following general formula (2), a compound represented by general formula (3), and an alkali metal salt compound or an alkaline earth metal salt compound in the presence of a lactam compound. A method for producing a polymer according to any one of [1] to [3].

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -. X represents a halogen atom.)

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -.)

The polymer of the present invention has a higher molecular weight, a higher melting point, a higher weight loss temperature, and superior heat resistance than conventionally known oligomers composed of the same type of units obtained by conventional production methods.

Since the polymer of the present invention has superior heat resistance compared to conventionally known oligomers, it can be kneaded and molded at higher temperatures than before, and has the effect of improving the productivity of flame-retardant resins.

The present invention will be described in more detail below.

The compound of the present invention is a polymer having a repeating unit represented by the following general formula (1), and is characterized by having a weight average molecular weight of 15,000 or more in terms of standard polystyrene.

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -.)
One form of the polymer of the present invention can have a structure represented by the following general formula (1a).

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -. n represents the repeating number and represents an integer of 1 or more.)
Due to the manufacturing method of the polymer of the present invention, the terminal group of the polymer is a 2-haloethyl group or a phenolic hydroxyl group, but it may be either of these. Since both of these terminal groups are reactive functional groups, the terminal portions can also be blocked with unreactive or low-reactivity functional groups. The sealing method is not particularly limited, but for example, 4-bromophenol, 1,3,5-tribromophenol, pentabromophenol, benzyl chloride, halogenated benzyl in which the aromatic nucleus is substituted with halogen, etc. (a compound capable of reacting with a 2-haloethyl group or a phenolic hydroxyl group) and the polymer of the present invention whose terminal group is a 2-haloethyl group or a phenolic hydroxyl group. Polymers whose terminal groups are thus capped with unreactive or low-reactivity functional groups are also included in the polymers of the present invention.

The alkylene group having 1 to 6 carbon atoms represented by R is not particularly limited, but includes, for example, a methylene group, an ethylene group, a 2,2-propylene group, a 2,2-butylene group, a hexadiene group, or Examples include 1,1-cyclohexylene group.

R is preferably a methylene group, a 2,2-propylene group, -S-, or -SO ₂ -, and more preferably a 2,2-propylene group, from the viewpoint of excellent heat resistance.

The polymer of the present invention is characterized by having a weight average molecular weight of 15,000 or more in terms of standard polystyrene, and more preferably a weight average molecular weight of 20,000 or more in terms of standard polystyrene, and 30,000 or more in terms of standard polystyrene. ,000 or more is more preferable, and 40,000 or more is more preferable.

Although not particularly limited, the polymer of the present invention preferably has a melting point of 255° C. or higher, more preferably 260° C. or higher in terms of improved compatibility with the highly heat-resistant resin. Generally, the higher the molecular weight of a molecule, the higher the melting point, and the polymer of the present invention has a higher melting point than conventionally known oligomers.

The polymers of the present invention exhibit a high weight loss temperature when compared to conventionally known oligomers. Specifically, the polymer of the present invention has excellent heat resistance (low thermal decomposition), and for example, at a heating rate of 10°C/min, the temperature at which the weight decreases by 20% is 380°C or higher. The temperature is preferably 390°C or higher, and more preferably 390°C or higher.

Based on the physical properties of the polymer of the present invention, the polymer of the present invention can improve the flame retardancy of highly heat-resistant resins such as polyamide, which has been difficult to achieve with conventionally known flame-retardant oligomers. It has a strikingly different effect. Further, since the polymer of the present invention has a high coloring initiation temperature, it has the effect of improving the appearance and aesthetics of a resin blended with the polymer of the present invention.

Therefore, the polymer of the present invention can be expected to have effects such as quality improvement and productivity improvement in resin processing performed at temperatures around 250 to 350°C.

Although the polymer of the present invention is not particularly limited, for example, in the presence of a lactam compound, a compound represented by the following general formula (2), a compound represented by the general formula (3), an alkali metal salt compound or It can be produced by reacting with an alkaline earth metal salt compound.

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -. X represents a halogen atom.)

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -.)
The definition and preferred range of the alkylene group having 1 to 6 carbon atoms in general formulas (2) and (3) are the same as the definition and preferred range of the alkylene group having 1 to 6 carbon atoms in general formula (1).

In the production method of the present invention, the compound represented by general formula (2) can be obtained by reacting a brominated bisphenol compound and an excess amount of dihalogenated ethane in the presence of a base. Further, as the compound represented by the general formula (3), a commercially available brominated bisphenol compound can be used as is, or a brominated bisphenol compound produced based on a conventionally known production method can also be used.

The brominated bisphenol compound mentioned above is not particularly limited, and examples thereof include brominated bisphenol A, brominated bisphenol F, and the like. Among these, brominated bisphenol A is preferred because it provides a polymer with excellent heat resistance.

The dihalogenated ethane mentioned above is not particularly limited, and examples thereof include 1,2-dichloroethane, 1-bromo-2-chloroethane, and 1,2-dibromoethane. Among these, 1,2-dichloroethane is preferred because it provides a polymer with excellent heat resistance.

The above-mentioned lactam compound refers to a compound in which a carboxy group and an amino group are dehydrated and condensed to form a ring, and examples thereof include, but are not limited to, β-lactam compounds, γ-lactam compounds, δ-lactam compounds. compounds, or ε-lactam compounds, and more specifically, 2-azeditinone, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-piperidone, N- Examples include methyl-2-piperidone and ε-caprolactam. Among these, 2-azeditinone, 2-pyrrolidone, N-methyl-2-pyrrolidone, or N-vinyl-2-pyrrolidone is preferable, and N-methyl-2-pyrrolidone is preferable in that a polymer with excellent heat resistance can be obtained. More preferred.

The alkali metal salt compound or alkaline earth metal salt compound is not particularly limited, but includes, for example, a lithium salt compound, a sodium salt compound, a potassium chloride, a cesium chloride, a magnesium salt compound, a calcium salt compound, or barium salt compounds; more specifically, lithium hydroxide, potassium hydroxide, sodium hydroxide, cesium hydroxide, lithium hydrogen carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, cesium hydrogen carbonate, lithium carbonate, Examples include potassium carbonate, sodium carbonate, cesium carbonate, calcium hydroxide, strontium hydroxide, and barium hydroxide. Among these, sodium salt compounds or potassium chloride are preferable, and potassium hydroxide, sodium hydroxide, potassium bicarbonate, sodium bicarbonate, potassium carbonate, and sodium carbonate are preferable in that a polymer with excellent heat resistance can be obtained.

The halogen atom represented by X is not particularly limited, and examples thereof include chlorine, bromine, and iodine. Among these, chlorine is preferable since a polymer with excellent heat resistance can be obtained.

Note that the production method of the present invention may be further carried out in the presence of a solvent (excluding the above-mentioned lactam compound). The solvent is not particularly limited as long as it does not react with the raw materials, and examples thereof include aprotic polar solvents.

Examples of the aprotic polar solvent include, but are not limited to, tetrahydrofuran, dioxane, pyridine, propylene carbonate, dimethylacetamide, dimethylformamide, and dimethylsulfoxide. Among these, dimethylacetamide, dimethylformamide, or dimethyl sulfoxide is preferred in that a high molecular weight polymer can be obtained.

In the production method of the present invention, the reaction temperature is not particularly limited, but can be carried out, for example, in a range of 70°C to 180°C.

The production method of the present invention may be carried out under reduced pressure, normal pressure, or elevated pressure, but it is preferably carried out under normal pressure or elevated pressure because a polymer with excellent heat resistance can be obtained.

The manufacturing method of the present invention can be carried out either continuously or batchwise.

Regarding the production method of the present invention, it is preferable to carry out the polymerization reaction in a non-aqueous system since a polymer with a higher molecular weight can be obtained. Methods for carrying out the polymerization reaction in a non-aqueous system are not particularly limited, but examples include using a dehydrating solvent, dehydrating the polymerization reaction system using a dehydrating agent, and using raw materials that cause water to be produced during the reaction. Examples include avoiding the use of The above-mentioned dehydrating agent is not particularly limited, and examples thereof include molecular sieves and zeolites.

The production method of the present invention is characterized in that it uses raw materials and techniques different from conventionally known production methods, and can suppress the volatilization and uneven distribution of the crosslinking agent in the gas phase at high temperatures during the polymerization reaction. Since the conditions are such that the product therein has good solubility, the monomer balance is less likely to be disrupted, and it is thought that it is possible to stably produce high molecular weight polymers compared to conventionally known production methods.

By mixing the polymer of the present invention with a resin, it is possible to impart flame retardancy to the resin.

The resin is not particularly limited, but includes, for example, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl chloride, polyvinyl acetate, polyurethane, acrylonitrile butadiene styrene resin, acrylic resin, phenol resin, epoxy resin, Melamine resin, urea resin, polyester resin, alkyd resin, polyurethane, polyurea, polyimide, polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, poly Examples include ether sulfone, polyether ether ketone, polyimide, and polyaidimide.

EXAMPLES Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples in any way.
<Molecular weight analysis method>
For the polymer samples synthesized in Examples etc., a molecular weight measurement column (TSKgel SuperAW2500+3000+5000, manufactured by Tosoh Corporation) was connected to a GPC device (manufactured by Tosoh Corporation, HLC-8320GPC), and the flow rate was 0.6 mL/min and the temperature was adjusted using chloroform eluent. The measurement was performed at 40° C. and under the detection conditions of UV (254 nm). Furthermore, using standard polystyrene, the weight average molecular weight of the sample was measured in terms of standard polystyrene.
<Measurement of weight loss temperature>
Using a TG-DTA measuring device (manufactured by Bruker AXS, TG-DTA2020SA), TG analysis was performed on the polymer samples synthesized in Examples and the like. The measurement conditions were a heating rate of 10° C./min for 10 mg of sample in air.
<Measurement of melting point and coloring start temperature>
The melting points of the polymer samples synthesized in Examples etc. were measured using a melting point measuring device (ATM-01, manufactured by As One Corporation). In conjunction with this, the temperature at which coloring started was measured as the temperature continued to rise. The measurement conditions were a temperature increase rate of 3° C./min in the atmosphere.

Reference example 1. Preparation of bis(2-chloroethyl) ether of tetrabromobisphenol A In a 2L glass separable flask equipped with a stirrer, condenser, and dropping funnel, add 200 g (0.368 mol) of tetrabromobisphenol A and 399 g (2-chloroethyl) ethane dichloride ( 4.70 mol), 6.3 g (18.5 mmol) of tetrabromoammonium hydrosulfate, and 250 g of pure water were added in this order at room temperature, and the mixture was heated to 60° C. while being mixed in a nitrogen stream. A 23% by weight aqueous sodium hydroxide solution was added dropwise over 20 minutes at the same temperature, followed by a reaction at 90° C. for 24 hours. After the reaction was completed, the reaction solution was allowed to cool to room temperature and poured into methanol. The precipitated solid was filtered, washed, and dried to obtain a white solid in a yield of 83%.

1H-NMR (ppm): 1.64 (s, 6H), 3.95 (m, 4H), 4.32 (m, 4H), 7.35 (s, 4H).

Example 1. Synthesis of Polymer In a 300 mL glass eggplant-shaped flask, 58.1 g (84.8 mmol) of the bis(2-chloroethyl) ether of tetrabromobisphenol A obtained in Reference Example 1 and 47.2 g (84.8 mmol) of tetrabromobisphenol A were added. After adding 8 mmol), 17.2 g (170 mmol) of sodium hydrogen carbonate, and 108 mL of N-methyl-2-pyrrolidone, the temperature was raised to 135° C. while mixing. After stirring at the same temperature for 17 hours, the mixture was allowed to cool to room temperature. Next, after adding water to the reaction solution, the precipitated solid was filtered, washed, and dried to obtain a white solid (polymer) in a yield of 98%. The obtained polymer had a standard polystyrene equivalent weight average molecular weight of 40,000.

Example 2. Synthesis of polymer A white solid (polymer) was obtained in the same manner as in Example 1 except that 86 mL of N-methyl-2-pyrrolidone was used instead of 108 mL of N-methyl-2-pyrrolidone. The yield was 98%. The obtained polymer had a standard polystyrene equivalent weight average molecular weight of 30,000.

Comparative example 1. Oligomer synthesis (conventional method)
An oligomer was synthesized according to the method of Example 14 described in Patent Document 2 (Japanese Patent Publication No. 56-8809), and an oligomer having a standard polystyrene equivalent weight average molecular weight of 3,500 was obtained in a yield of 78%.

Comparative example 2. Oligomer synthesis (conventional method)
Oligomers were synthesized according to the method (Example 14) described in Patent Document 2 (Japanese Patent Publication No. 56-8809), except that the reaction time was 17 hours, and an oligomer with a standard polystyrene equivalent weight average molecular weight of 5,000 was obtained. The yield was 86%.

For each sample (polymer or oligomer) obtained in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 using a TG-DTA measuring device (manufactured by Bruker AXS, TG-DTA2020SA), TG analysis was performed. The results are shown in Table 1.

The melting point and coloring onset temperature of each sample of the polymer of Example 1 and the oligomer of Comparative Example 1 were measured using a melting point measuring device (manufactured by As One Corporation, ATM-01). The results are shown in Table 2.

Claims (3)

A compound represented by the following general formula (2), a compound represented by the general formula (3), and an alkali metal salt compound or an alkaline earth metal salt compound are reacted in the presence of a lactam compound, A method for producing a polymer having a repeating unit represented by the following general formula (1) and having a weight average molecular weight of 15,000 or more in terms of standard polystyrene.

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -.)

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -. X represents a halogen atom.)

(In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ₂ -.) The manufacturing method according to claim 1 , wherein the melting point of the polymer is 255°C or higher. The manufacturing method according to claim 1 or 2, wherein the weight loss temperature of 20% by weight of the polymer is 380°C or higher at a heating rate of 10°C/min.