Halogen-containing polymer

Abstract

To provide a halogen-containing polymer that exhibits excellent flame retardancy, flowability and impact resistance when blended into a resin.SOLUTION: The invention provides a halogen-containing polymer represented by the general formula (1) in the figure whose polymer chain terminals have at least one terminal group selected from the group consisting of the formulas (2) to (5) in the figure, where the proportion of the haloethyl terminal group represented by formula (2) among the terminal groups represented by the formulas (2) to (5) is 70% or more. (In the formulas, R represents an alkylene group, -S-, or the like, and Y represents a halogen atom.)SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to halogen-containing polymers for use as flame retardants and the like. [Background technology]

[0002] Flame retardants are well known as additives that impart flame retardancy to resins by mixing with them. For example, compounds containing multiple halogen atoms have long been used as halogen-based flame retardants. However, some low-molecular-weight halogen-based flame retardants (e.g., polybrominated biphenyls) are subject to the RoHS Directive due to their harmful properties. For this reason, high-molecular-weight halogen-based flame retardants have been developed in recent years.

[0003] As a high molecular weight bromine-based flame retardant, for example, a halogen-containing polymer having high heat resistance in which tetrabromobisphenol A is linked via an ethylene group is known (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-77857 A Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally known halogen-containing polymers do not necessarily exhibit sufficient flame retardancy when blended with a resin, and have problems in that the mechanical properties, such as the flowability and impact resistance, of the blended resin are not fully satisfactory.

[0006] The present invention has been made in view of the above-mentioned background art, and an object of the present invention is to provide a halogen-containing polymer which exhibits excellent flame retardancy, flowability and impact resistance when blended with a resin. [Means for solving the problem]

[0007] As a result of intensive research, the present inventors have found that the following invention can solve the above problems, and have completed the present invention.

[0008] That is, the present invention relates to the following halogen-containing polymer.

[0009] [1] The following general formula (1)

[0010] [ka]

[0011] (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO2-, and n represents a real number.) The halogen-containing polymer is represented by the following formula (2) to (5) at the polymer chain end:

[0012] [ka]

[0013] (In the formula, O represents an oxygen atom bonded to a benzene ring. Y represents a halogen atom. Formula (4) represents a phenolic hydroxyl group.) and wherein the proportion of haloethyl terminal groups represented by formula (2) is 70% or more among the terminal groups represented by formulas (2) to (5).

[0014] [2] The halogen-containing polymer according to [1], which has a weight average molecular weight of 1,000 to 8,000 in terms of standard polystyrene as measured by gel permeation chromatography.

[0015] [3] The halogen-containing polymer according to [1] or [2], wherein in general formula (1), R is an alkylene group having 1 to 3 carbon atoms.

[0016] [4] The halogen-containing polymer according to [1] or [2], wherein in general formula (1), R is a 2,2-propylene group. Effect of the Invention

[0017] The halogen-containing polymer of the present invention has the effect of achieving high flame retardancy when blended with a resin, and ensuring excellent mechanical properties of the blended resin, as compared with conventionally known halogen-containing polymers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention will now be described in further detail.

[0019] One aspect of the present invention is a compound represented by the following general formula (1):

[0020] [ka]

[0021] (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO2-, and n represents a real number.) The halogen-containing polymer is represented by the following formula (2) to (5) at the polymer chain end:

[0022] [ka]

[0023] (In the formula, O represents an oxygen atom bonded to a benzene ring. Y represents a halogen atom. Formula (4) represents a phenolic hydroxyl group.) and wherein the proportion of haloethyl terminal groups represented by formula (2) is 70% or more among the terminal groups represented by formulas (2) to (5).

[0024] The alkylene group having 1 to 6 carbon atoms represented by R is not particularly limited, but examples thereof include a methylene group, an ethylene group, a 2,2-propylene group, a 2,2-butylene group, a hexadiene group, and a 1,1-cyclohexylene group.

[0025] R is preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a 2,2-propylene group, in that the resin containing the halogen-containing polymer has excellent flame retardancy and mechanical properties.

[0026] In formula (1), n ​​represents the average number of repeating units of the halogenated polymer, and in the present invention, n represents a real number.

[0027] The n is preferably a real number from 3 to 18, more preferably a real number from 4 to 15, and even more preferably a real number from 5 to 12, in order to provide a resin containing a halogen-containing polymer with excellent flame retardancy and mechanical properties.

[0028] For example, when R is a 2,2-propylene group, the terminal structure is a 2-chloroethyl group, and n is 10, the theoretical average molecular weight of the halogenated polymer of the present invention is 5,798.

[0029] The halogen-containing polymer of the present invention is characterized in that it has at least one terminal group selected from the group consisting of formulas (2) to (5) at its polymer terminal, and that the proportion of terminal groups represented by formula (2) is 70% or more among the terminal groups represented by formulas (2) to (5) (the total of these being 100%).

[0030] In order to provide a resin containing a halogen-containing polymer with excellent flame retardancy and mechanical properties, the proportion of terminal groups represented by the above formula (2) is more preferably 80% or more, and even more preferably 90% or more.

[0031] The terminal groups represented by the formulas (2) to (5) can be identified by high-resolution NMR analysis, and their abundance ratios can be quantified by analyzing the element abundance ratios calculated from the area ratios of the NMR chart.

[0032] The halogen-containing polymer of the present invention has a weight average molecular weight, calculated as standard polystyrene, of preferably 1,000 to 8,000, more preferably 2,000 to 8,000, and even more preferably 2,500 to 7,500, as measured by gel permeation chromatography, in order that a resin containing the halogen-containing polymer will have excellent flame retardancy and mechanical properties.

[0033] In terms of obtaining higher heat resistance, the halogen-containing polymer of the present invention preferably has a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) in terms of standard polystyrene, as measured by gel permeation chromatography, of 1.0 to 4.0, more preferably 1.0 to 3.0, and even more preferably 1.0 to 2.5.

[0034] The method and conditions for measuring the weight average molecular weight of the halogen-containing polymer of the present invention by gel permeation chromatography were in accordance with ISO 16014-3:2012 (JIS K 7252-3:2016). The method and conditions are described in more detail in the Examples.

[0035] The halogen-containing polymer of the present invention preferably has a bromine content of 50 to 60% by weight, more preferably 52 to 60% by weight, in that high flame retardancy is expected.

[0036] The halogen-containing polymer of the present invention is not particularly limited, but as an example, it can be produced by heating a mixture containing a compound represented by the following general formula (6), a compound represented by the following general formula (7), a base, a radical trapping agent, and a solvent, with stirring, in the range of 110 to 150°C.

[0037] [ka]

[0038] (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO2-.)

[0039] [ka]

[0040] (In the formula, X and Y each independently represent a halogen atom.) The compound represented by the above general formula (6) is not particularly limited, but examples thereof include tetrabromobisphenol A, tetrabromobisphenol F, bis(4'-hydroxy-3',5'-dibromophenyl)sulfone, etc. Among these, tetrabromobisphenol A is preferred in that it provides excellent flame retardancy and mechanical properties to resins containing halogen-containing polymers.

[0041] In the compound represented by the above general formula (7), the halogen atoms represented by X and Y are not particularly limited, but may be, for example, chlorine, bromine, or iodine. Among these, chlorine is preferred in that the resin containing the halogen-containing polymer has excellent flame retardancy and mechanical properties.

[0042] The compound represented by the above general formula (7) is not particularly limited, but examples thereof include ethane dichloride, ethane dibromide, ethane diiodide, 1-bromo-2-chloroethane, 1-chloro-2-iodoethane, and 1-bromo-2-iodoethane.

[0043] In the production of the halogen-containing polymer of the present invention, the base is not particularly limited, and examples thereof include lithium hydroxide, potassium hydroxide, sodium hydroxide, cesium hydroxide, lithium hydrogen carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, cesium hydrogen carbonate, lithium carbonate, potassium carbonate, sodium carbonate, cesium carbonate, calcium hydroxide, strontium hydroxide, barium hydroxide, etc. Among these, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, or potassium hydrogen carbonate is preferred, and potassium carbonate is more preferred, in that a halogenated polymer capable of imparting excellent flame retardancy and mechanical properties to a resin can be obtained.

[0044] In the production of the halogen-containing polymer of the present invention, the solvent is not particularly limited as long as it does not react with the substrate, and examples thereof include aprotic polar solvents.

[0045] The aprotic polar solvent is not particularly limited, but examples thereof include tetrahydrofuran, dioxane, pyridine, N-methylpyrrolidone, propylene carbonate, dimethylacetamide, dimethylformamide, dimethylsulfoxide, etc. Among these, N-methylpyrrolidone, dimethylacetamide, dimethylformamide, and dimethylsulfoxide are preferred in that they can give a halogenated polymer that can impart excellent flame retardancy and mechanical properties to a resin. In the production of the halogen-containing polymer, the reaction temperature is preferably in the range of 110°C to 150°C, and more preferably in the range of 120°C to 145°C.

[0046] The radical trapping agent is not particularly limited, but examples thereof include at least one radical trapping agent selected from the group consisting of phenol-based radical trapping agents, quinone-based radical trapping agents, phosphite-based radical trapping agents, amine-based radical trapping agents, and sulfur-based radical trapping agents. More specifically, for example, 4-methoxyphenol, 6-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, 4-tert-butylphenol, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol (also known as dibutylhydroxytoluene), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 3,6-dihydroxybenzonorbornane, 2,2'-methylenebis(6-cyclohexyl-p-cresol), hydroquinone, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 1,4-benzoquinone, 2-tert-butyl-1,4-benzoquinone, 4-tert-butylcatechol, pentaerythritol, tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], diphenylamine, N,N-diethylhydroxylamine, ammonium nitrosophenylhydroxylamine, 2,2,6,6-tetramethylpiperidine-1-oxyl, 2-benzimidazolethiol, phenothiazine, 3,3'-thiodipropionate didodecyl, 3,3'-thiodipropionate dioctadecyl, triethyl phosphite, trihexyl phosphite, tris(1,1,1-hexafluoro-2-propyl) phosphite, triphenyl phosphite, tris(2-methylphenyl) phosphite, tris(4-methylphenyl) phosphite, tris(4-nonylphenyl) phosphite, pentaerythritol bis(2,4-di-tert-butylphenyl phosphite), or tris(2,4-di-tert-butylphenyl) phosphite.

[0047] In producing the halogen-containing polymer of the present invention, the mixing ratio of the compound represented by the general formula (6) to the compound represented by the general formula (7) is preferably 1.2 to 2.0 molar parts, more preferably 1.3 to 1.8 molar parts, and still more preferably 1.3 to 1.6 molar parts of the compound represented by the general formula (7) per 1 molar part of the compound represented by the general formula (6).

[0048] In the production of the halogen-containing polymer of the present invention, the amount of the base used is preferably 0.8 to 2.5 parts by mol, more preferably 0.9 to 2.0 parts by mol, and still more preferably 1.0 to 1.8 parts by mol, relative to 1 part by mol of the compound represented by the above general formula (6).

[0049] In the production of the halogen-containing polymer of the present invention, the amount of the radical trapping agent used is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 8 parts by mass, and still more preferably 0.01 to 5 parts by mass, relative to 100 parts by mass of the compound represented by the general formula (6).

[0050] In the production of the halogen-containing polymer of the present invention, the amount of the solvent used is preferably 200 to 2,000 parts by mass, more preferably 250 to 900 parts by mass, and still more preferably 250 to 500 parts by mass, relative to 100 parts by mass of the compound represented by the general formula (6).

[0051] In addition, the production of the halogen-containing polymer of the present invention is preferably carried out under conditions of low water content. When water is generated during the reaction as the production reaction proceeds, it is preferable to set the temperature for heating the reaction liquid to 100° C. or higher and carry out the reaction while removing water from the reaction system.

[0052] The method for controlling the water content in the reaction system is not particularly limited, other than the above-mentioned method of removing water by heating, but an example thereof is a method of adding a dehydrating solvent to the reaction system.

[0053] The dehydrating agent is not particularly limited, but examples thereof include molecular sieves and zeolites.

[0054] In the production of the halogen-containing polymer of the present invention, the water content in the reaction system is preferably controlled to 10,000 ppm or less, more preferably 5,000 ppm or less, and even more preferably 300 ppm or less.

[0055] The production of the halogen-containing polymer of the present invention may be carried out under any condition of reduced pressure, normal pressure, or increased pressure. However, in terms of obtaining a polymer having excellent heat resistance, it is preferable to carry out the production under normal pressure or increased pressure.

[0056] The production of the halogen-containing polymer of the present invention can be carried out in a continuous manner or in a batch manner.

[0057] By the above-mentioned production method, a halogen-containing polymer can be produced in the reaction system. By mixing the reaction solution in which the halogen-containing polymer of the present invention is produced with a poor solvent (a solvent that has a low ability to dissolve the halogen-containing polymer), the solid of the halogen-containing polymer can be precipitated.

[0058] The poor solvent includes, for example, water, methanol, ethanol, and the like.

[0059] The halogenated polymer of the present invention can impart flame retardancy to a resin by blending it with the resin.

[0060] The resin is not particularly limited, but examples thereof include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl vinyl acetate, polyurethane, acrylonitrile butadiene styrene resin, acrylic resin, phenolic resin, epoxy resin, melamine resin, urea resin, polyester resin, alkyd resin, polyurea, polyimide, polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, polyetheretherketone, and polyamideimide.

[0061] The amount of the halogenated polymer of the present invention mixed with the resin is preferably 5 to 30 parts by mass, more preferably 10 to 28 parts by mass, and even more preferably 12 to 25 parts by mass, per 100 parts by mass of the resin.

[0062] The halogenated polymer of the present invention can impart flame retardancy to fibers by impregnating the fibers.

[0063] The fiber is not particularly limited, but examples thereof include polyethylene, polypropylene, polyvinyl chloride, acrylic, modacrylic, acrylate, acetate, rayon, melamine, polyurethane, polyimide, polyamide, polyacetal, polyester, polylactic acid, polyarylate, polyphenylene sulfide, and polyether ester. EXAMPLES

[0064] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples in any way. <Measurement of weight average molecular weight> For the polymer samples synthesized in the examples and the like, a column for molecular weight measurement (TSKgel (registered trademark) SuperAW2500 + 3000 + 5000, manufactured by Tosoh Corporation) was connected to a gel permeation chromatography apparatus (HLC-8320GPC, manufactured by Tosoh Corporation), and measurement was carried out under the detection conditions of a chloroform eluent with a flow rate of 0.6 mL / min, a temperature of 40 °C, and UV (254 nm). Furthermore, using standard polystyrene, the weight average molecular weight of the sample in terms of standard polystyrene was measured. For other matters, it was carried out in accordance with JIS-K-7252 series. <Analysis of Polymer Terminal Structure by NMR> Apparatus: Bruker AVANCE NEO 700 Probe: 10 mmφ PABBO BB Solvent: 1,1,2,2-tetrachloroethane-d2 Sample concentration: approximately 10% (w / v) 13C NMR (176.07 MHz), number of integration times: 2048 times Measurement mode: Inverse gated decoupling (quantitative method) For the polymer samples synthesized in the examples, 13C NMR was measured under the above measurement conditions, and the terminal structure was analyzed from the average integration value of each peak.

[0065] The 13C on the carbon having a chlorine atom in the terminal group represented by formula (2) and where Y is a chlorine atom is observed at around 42.1 (t) ppm. The 13C on the carbon having a hydroxy group in the terminal group represented by formula (3) is observed at around 62.0 (s) ppm. The 13C on the carbon having a phenolic hydroxy group in the terminal group represented by formula (4) is observed at around 147.3 (m) ppm. Also, the 13C on the outer carbon of the double bond in the terminal group represented by formula (5) is observed at around 91.9 (s) ppm.

[0066] Based on the integration values of the 13C NMR peaks derived from each of the above terminal groups, the ratio of each terminal was calculated.

[0067]

Chemical formula

[0068] <Weight loss temperature measurement> As an index of the thermal stability of the halogen-containing polymer, the weight loss temperature was measured under the following conditions.

[0069] Analytical equipment: Rigaku ThermoPlus TG8120 Measurement conditions: 10 mg sample, heated in air at a rate of 10°C / min. <Synthesis of halogen-containing polymer> Example 1 In a 5L cylindrical glass separable flask equipped with a stirrer and a reflux condenser, 800.0g (1.471mol) of tetrabromobisphenol A, 254.1g (1.839mol) of potassium carbonate, 4.00g (26.6mmol) of 4-tert-butylphenol, 4.01g (6.19mmol) of tris(2,4-di-tert-butylphenyl) phosphite, and 2100g of dimethylformamide were added and heated to 130°C while stirring and mixing. At this temperature, 218.3g (2.206mol) of ethane dichloride was added, and the mixture was stirred at 130°C for 4 hours, and then cooled to room temperature. Methanol was added to the reaction liquid to precipitate a solid. The precipitated solid was filtered, washed with water, and then dried. A white solid halogen-containing polymer (A) corresponding to the halogen-containing polymer of the present invention was obtained in a yield of 81%.

[0070] The weight average molecular weight of the obtained halogen-containing polymer (A) was 3,400. Analysis by 13C NMR showed that the proportion of the polymer end structure was 93% chloroethyl end (corresponding to the above formula (2) when Y is a chlorine atom) and 0% (below the detection limit) phenol end (corresponding to the above formula (4)). The 5% weight loss temperature was 374°C. The analysis results are shown in Table 1.

[0071] Example 2 The same procedure as in Example 1 was carried out except that the amount of dichloroethane used was changed from 218.3 g (2.206 mol) to 211.1 g (2.133 mol) in Example 1, and a white solid halogenated polymer (B) corresponding to the halogen-containing polymer of the present invention was obtained in a yield of 94%. The analytical results of the obtained halogenated polymer (B) are shown in Table 1.

[0072] Example 3 The same procedure as in Example 1 was carried out except that the amount of dichloroethane used was changed from 218.3 g (2.206 mol) to 203.8 g (2.059 mol) in Example 1, and a white solid halogenated polymer (C) corresponding to the halogen-containing polymer of the present invention was obtained in a yield of 91%. The analytical results of the obtained halogenated polymer (C) are shown in Table 1.

[0073] Comparative Example 1 A halogen-containing polymer was synthesized according to the method of Example 8 described in Patent Document 1 (JP 2019-77857 A), and a white solid halogen-containing polymer (D) was obtained in a yield of 95%. The analytical results of the obtained halogen-containing polymer (D) are shown in Table 1.

[0074] Comparative Example 2 A halogen-containing polymer was synthesized according to the method of Example 14 described in JP-B-56-8809, and a white solid halogen-containing polymer (E) was obtained in a yield of 78%. The analytical results of the obtained halogen-containing polymer (E) are shown in Table 1.

[0075] [Table 1]

[0076] <Evaluation of flame retardancy and mechanical properties of halogen-containing polymer blend resin> Examples 3 to 6 and Comparative Example 3 The materials used in the evaluation of the compounded resins are shown below.

[0077] Polypropylene resin: Japan Polypropylene BC3AD Flame retardant additive: Suzuhiro Chemical's AT-3CN (antimony trioxide) Inorganic filler: Matsumura Sangyo 5000PJ (talc) Using the halogen-containing polymers obtained in Examples 1 to 3 and Comparative Example 1, the individual components shown in Table 2 were fed into a twin-screw extruder (ZSK-26, manufactured by Coperion), mixed at a maximum temperature of 235°C, discharged as strands, and pelletized. The pellets obtained were molded using an injection molding machine (J55AD manufactured by Japan Steel Works, Ltd.) to obtain test pieces (125 mm x 15 mm x 1.5 mm) for combustion testing.

[0078] Flame retardancy of the test pieces was evaluated by conducting a combustion test according to the UL94V standard. Flame retardancy is expressed as V-0, V-1, and V-2 from highest to lowest. The results are shown in Table 2.

[0079] The pellets obtained above were used to measure the melt flow rate (hereinafter referred to as MFR) using a melt indexer (TP-401 manufactured by Tester Sangyo Co., Ltd.) in accordance with JIS K 7210 (measurement conditions: temperature 230°C, load 3.80 kg). The results are shown in Table 2.

[0080] The pellets obtained above were molded by an injection molding machine (Japan Steel Works, Ltd. J55AD) to obtain test pieces for Izod impact strength testing. Izod impact strength (hereinafter referred to as IZOD) was measured in accordance with JIS K 7110. The results are shown in Table 2.

[0081] [Table 2]

[0082] The results in Table 2 show that the halogen-containing polymer of the present invention exhibits superior flame retardancy, fluidity and impact resistance when blended into a resin, as compared with conventional halogen-containing polymers.

Claims

1. The following general formula (1) 【Chemistry 1】 (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ２ - and n indicates a real number.) The halogen-containing polymer is represented by the following formula (2) to (5) at the polymer chain end: 【Chemistry 2】 (In the formula, O represents an oxygen atom bonded to a benzene ring. Y represents a halogen atom. Formula (4) represents a phenolic hydroxyl group.) and wherein the proportion of haloethyl terminal groups represented by formula (2) is 70% or more among the terminal groups represented by formulas (2) to (5).

2. 2. The halogen-containing polymer according to claim 1, which has a weight average molecular weight of 1,000 to 8,000 in terms of standard polystyrene as measured by gel permeation chromatography.

3. 2. The halogen-containing polymer according to claim 1, wherein in general formula (1), R is an alkylene group having 1 to 3 carbon atoms.

4. 2. The halogen-containing polymer according to claim 1, wherein in general formula (1), R is a 2,2-propylene group.

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