Halogen-containing polymer, and flame-retardant resin composition and molded article including the same

Abstract

To provide a halogen-containing polymer that has superior dielectric characteristics.SOLUTION: The present invention provides a halogen-containing polymer, having at least one repeating unit represented by general formula (1) (where, R represents a C1-6 alkylene group, -S-, or -SO2-, and n represents the average number of repeats and is expressed as a real number), the halogen-containing polymer having, at an end of the polymer chain, at least one terminal group selected from the group consisting of formulas (2) through (5), wherein among the formulas (2) through (5), the percentage of the hydroxy terminal groups represented by the formulas (3) and (4) is 20% or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a halogen-containing polymer, and a flame-retardant resin composition and molded article containing the same. [Background technology]

[0002] Flame retardants are well known as additives that impart flame retardancy to resins by mixing them into the resin. Among them, compounds containing a large amount of bromine have been added to many resins as halogen-based flame retardants for a long time. For example, tetrabromobisphenol A, one of the representative bromine-based flame retardants, is known as the most widely produced halogen-based flame retardant in the world.

[0003] Brominated flame retardants, a type of halogenated flame retardant, generally tend to exhibit superior physical properties in terms of performance and cost compared to other types of flame retardants (phosphorus-based, inorganic, etc.), but due to considerations of their impact on living organisms and the environment, the manufacture of some halogenated flame retardants has become subject to restrictions. In response to this situation, recent development of brominated flame retardants has tended to focus on polymer-type brominated flame retardants, which are considered to have a relatively small impact on living organisms and the environment.

[0004] For example, halogen-containing polymers in which tetrabromobisphenol A is linked via ethylene groups have been reported (eg, Patent Documents 1 to 5). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 51-117737 [Patent Document 2] Special Publication No. 56-8809 [Patent Document 3] Japanese Patent Application Publication No. 53-128656 [Patent Document 4] Special Publication No. 62-1973 [Patent Document 5] JP 2020-200371 A Summary of the Invention [Problem to be solved by the invention]

[0006] Conventionally known halogen-containing polymers tend to have high dielectric loss, making them difficult to use as flame retardants for low-dielectric materials applied to electronic devices and devices used in high-speed communications using high-frequency radio waves.

[0007] 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 having a small dielectric loss, and uses thereof. [Means for solving the problem]

[0008] As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by the following invention, and have completed the present invention.

[0009] That is, the present invention relates to the following halogen-containing polymer, a flame-retardant low dielectric characteristic resin composition containing the halogen-containing polymer, and a flame-retardant low dielectric characteristic resin molding made of the flame-retardant low dielectric characteristic resin composition.

[0010] [1] The following general formula (1)

[0011] [ka]

[0012] (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO2-. n represents the average number of repetitions and is represented by a real number.) and at the polymer chain end, a repeating unit represented by any one of the following formulas (2) to (5) is present:

[0013] [ka]

[0014] (In formula (2), Y represents a halogen atom.) and among the terminal groups represented by general formulae (2) to (5), the proportion of hydroxyl terminal groups represented by formulae (3) and (4) is 20% or less, and further, the content of alkali metal ions contained in the halogen-containing polymer is 1.5% by mass or less, where the total amount of the halogen-containing polymer is 100% by mass.

[0015] [2] The halogen-containing polymer according to [1], wherein the proportion of hydroxyl terminal groups represented by formulae (3) and (4) among the terminal groups represented by general formulae (2) to (5) is 0 to 10%.

[0016] [3] The halogen-containing polymer according to [1], having an alkali metal ion content of 0.0001 to 1 mass %.

[0017] [4] A flame-retardant, low dielectric resin composition comprising the halogen-containing polymer according to any one of [1] to [3] and a resin component.

[0018] [5] A flame-retardant low dielectric characteristic resin molding comprising the flame-retardant low dielectric characteristic resin composition according to [4]. Effect of the Invention

[0019] The halogen-containing polymer of the present invention has a smaller dielectric loss than conventionally known halogen-containing polymers, and therefore when added to a low dielectric resin, it has the effect of making the resin flame-retardant without impairing the inherent dielectric properties of the resin. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, one embodiment of the present invention will be described in detail.

[0021] In this specification, the symbol "to" means a range of values ​​including both ends.

[0022] The halogen-containing polymer according to one embodiment of the present invention has a small dielectric loss, and therefore when added to a low dielectric resin, it can make the resin flame-retardant without impairing the inherent dielectric properties of the resin.

[0023] Furthermore, since the halogen-containing polymer according to one embodiment of the present invention has excellent heat resistance, it can be kneaded or molded at high temperatures, and can contribute to improving the productivity of various flame-retardant resins.

[0024] The halogen-containing polymer according to one embodiment of the present invention is represented by the following general formula (1):

[0025] [ka]

[0026] (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO2-. n represents the average number of repetitions and is represented by a real number.) and at the polymer chain end, a repeating unit represented by any one of the following formulas (2) to (5) is present:

[0027] [ka]

[0028] (In formula (2), Y represents a halogen atom.) and among the terminal groups represented by general formulae (2) to (5), the proportion of hydroxyl terminal groups represented by formulae (3) and (4) is 20% or less. The composition is further characterized by having an alkali metal ion concentration of 1.5% by mass or less.

[0029] 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.

[0030] From the viewpoint of excellent dielectric properties, the above R is preferably a methylene group, a 2,2-propylene group, -S-, or -SO2-, and more preferably a 2,2-propylene group.

[0031] The halogen-containing polymer according to one embodiment of the present invention is not particularly limited, but examples thereof include a condensation polymer obtained from tetrabromobisphenol F and dichloroethane, a condensation polymer obtained from tetrabromobisphenol A and dichloroethane, a condensation polymer obtained from bisphenol F, tetrabromobisphenol F and dichloroethane, or a condensation polymer obtained from bisphenol A, tetrabromobisphenol A and dichloroethane, etc. Among these, a condensation polymer obtained from tetrabromobisphenol A and dichloroethane is preferred.

[0032] A halogen-containing polymer according to one embodiment 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 the proportion of terminal groups represented by formulas (3) and (4) is 20% or less among the terminal groups represented by formulas (2) to (5) (which is taken as 100%). Based on such characteristics, it is possible to provide a halogen-containing polymer having unprecedentedly low relative dielectric constant and dielectric loss tangent.

[0033] The terminal groups represented by the formulae (2) to (5) can be identified by high-sensitivity NMR analysis, and the abundance ratios of the elements can be quantified by analyzing the element abundance ratios calculated from the area ratios of the NMR charts.

[0034] Among the terminal groups represented by the general formulae (2) to (5), the proportion of the terminal groups represented by the formulae (3) and (4) is preferably 1 to 10%, and more preferably 1 to 5%, in terms of excellent dielectric properties of the halogen-containing polymer.

[0035] The alkali metal ion is not particularly limited, but examples thereof include a lithium ion, a sodium ion, a potassium ion, a rubidium ion, and a cesium ion.

[0036] Furthermore, as described above, the halogen-containing polymer according to one embodiment of the present invention is characterized in that the alkali metal ion content is 1.5 mass% or less. In terms of excellent dielectric properties, the content is preferably 0.0001 to 1 mass%, more preferably 0.0005 to 0.8 mass%, even more preferably 0.001 to 0.6 mass%, and even more preferably 0.01 to 0.5 mass%.

[0037] In terms of obtaining higher heat resistance, the halogen-containing polymer according to one embodiment of the present invention has a weight average molecular weight, calculated as equivalent to standard polystyrene, determined by gel permeation chromatography measurement of preferably 2,000 or more, more preferably 3,000 or more, and even more preferably 4,000 or more.

[0038] The weight average molecular weight is preferably from 2,000 to 50,000, more preferably from 3,000 to 30,000, and even more preferably from 4,000 to 15,000, from the viewpoint of excellent handling properties as a flame retardant.

[0039] The halogen-containing polymer according to one embodiment 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, measured by gel permeation chromatography, of 1.0 to 4.0. However, the smaller the Mw / Mn, the narrower the molecular weight distribution of the polymer, and the higher the flame retardancy and heat resistance of the polymer itself, so that Mw / Mn is more preferably 1.0 to 3.0.

[0040] The method and conditions for measuring the molecular weight of the halogen-containing polymer according to one embodiment of the present invention by gel permeation chromatography were in accordance with ISO 16014-3:2012 (JIS K 7252-3:2016). The detailed conditions are as shown in the examples.

[0041] The real number n as an average value of the halogen-containing polymer according to one embodiment of the present invention is determined by gel permeation chromatography measurement, and from the viewpoint of excellent heat resistance, it is preferably 2 or more, more preferably 3 or more, and even more preferably 5 or more.

[0042] The real number n is preferably 3 to 100, more preferably 5 to 60, and even more preferably 7 to 30, in terms of excellent heat resistance and ease of handling as a flame retardant.

[0043] For the halogen-containing polymer according to one embodiment of the present invention, the bromine content is preferably 50 to 60 mass %, but from the viewpoint that the higher the bromine content, the more improved the flame retardancy of the flame retardant itself in general, the more preferable the bromine content is 53 to 60 mass %.

[0044] The bromine content (mass%) of the halogen-containing polymer of the present invention is not particularly limited, but can be quantified by combustion-ion chromatography. The specific analysis method and analysis conditions of the combustion-ion chromatography are described in IEC 62321-3-2. The detailed conditions are as shown in the examples.

[0045] The halogen-containing polymer according to one embodiment of the present invention can be produced by heating a reaction solution containing at least a tetrabromobisphenol compound represented by the following general formula (6), a dihalogenated ethane represented by the following general formula (7), a weak base compound, and a radical trapping agent as raw materials all at once to cause a polymerization reaction, and then thoroughly washing and removing the alkali metal salt compound contained in the halogen-containing polymer that is the reaction product.

[0046] [ka]

[0047] (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO2-. X and Z each independently represent a halogen atom.) In the above-mentioned production method, if no side reactions are taken into consideration, the halogen-containing polymer of the present invention should have a terminal which is a phenolic hydroxy group derived from a tetrabromobisphenol compound or a halogenated ethyl group derived from a dihalogenated ethane.

[0048] However, in actual production processes, the above-mentioned ethyl halide groups may be influenced by the above-mentioned base and some of them may be converted to vinyl groups, ethyl halide groups, or other groups.

[0049] That is, the terminals of the halogen-containing polymer of the present invention are, in reality, terminal groups represented by any one of the above formulas (2) to (5) or other terminal groups.

[0050] It is generally recognized that the phenolic hydroxyl group represented by the above formula (3) can improve the hydrophilicity of chemical substances, deteriorate the dispersibility in organic solvents, and deteriorate the filterability.Therefore, it is considered effective to reduce the content of hydroxyl groups in order to improve the dispersibility of chemical substances in organic solvents, but in the prior art related to the halogen-containing polymer of the present invention, no study has been made on the production method aimed at reducing the content of hydroxyl groups.

[0051] The tetrabromobisphenol compound represented by the general formula (6) is not particularly limited, but examples thereof include tetrabromobisphenol F, tetrabromobisphenol A, tetrabromobisphenol sulfone, and tetrabromobisphenol sulfide.

[0052] The dihalogenated ethane represented by the following general formula (7) is not particularly limited, but examples thereof include 1,2-dichloroethane, 1,2-dibromoethane, 1,2-diiodoethane, and 1-bromo-2-chloroethane.

[0053] The weak base compound is not particularly limited, but examples thereof include ammonia, organic amine compounds, alkali metal hydrogen carbonate compounds, and alkali metal carbonate compounds.

[0054] Regarding the weak base compound, in terms of excellent dielectric properties, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, cesium hydrogen carbonate, lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, or cesium carbonate is preferable, and sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, or potassium carbonate is more preferable.

[0055] The radical trapping agent is not particularly limited, but may be at least one selected from the group consisting of phenol compounds, hindered amine compounds, and phosphoric acid ester compounds. More specifically, it may be 4-tert-butylphenol, 2,6-ditert-butylphenol, 2,6-ditert-butyl-p-cresol (also known as dibutylhydroxytoluene), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), or tris(2,4-di-tert-butylphenyl) phosphite.

[0056] In the method for producing a halogen-containing polymer according to one embodiment of the present invention, the temperature of the polymerization reaction is not particularly limited, but is preferably in the range of, for example, 70 to 180° C. From the viewpoint of removing water in the reaction system, which will be described later, the temperature of the reaction is more preferably in the range of 100 to 180° C., and further preferably in the range of 110 to 170° C.

[0057] In the method for producing a halogen-containing polymer according to one embodiment of the present invention, it is preferred to use a solvent for the polymerization reaction.

[0058] The solvent is not particularly limited as long as it does not react with the raw materials, but examples thereof include aprotic polar solvents, and more specifically, nitrogen-containing organic solvents and ether-based organic solvents.

[0059] The nitrogen-containing organic solvent is not particularly limited, but examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, pyridine, pyrrole, acetonitrile, nitrobenzene, etc. Among these, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone are preferred, and N,N-dimethylformamide and N-methyl-2-pyrrolidone are more preferred.

[0060] The ether-based organic solvent is not particularly limited, but may be tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, cyclopentyl methyl ether, diethyl ether, polyethylene glycol, methyl cellosolve, etc. Among these, tetrahydrofuran, 2-methyltetrahydrofuran, or 1,4-dioxane is preferred, and tetrahydrofuran is more preferred.

[0061] It is preferable to use the above-mentioned solvent from which water has been removed in advance, in order to suppress the production of the terminal group represented by formula (3).

[0062] It is also preferable to use raw materials other than the solvent used in the polymerization reaction that have a low water content.

[0063] In the polymerization reaction, the initial concentration of the tetrabromobisphenol compound represented by the general formula (6) is preferably 10 to 32 mass%, more preferably 16 to 30 mass%, and even more preferably 18 to 28 mass%, relative to the total amount of the charge when charged all at once, which is 100 mass%.

[0064] In the above polymerization reaction, the amount of the dihalogenated ethane represented by the general formula (7) added is preferably 1.0 to 1.6 mol, more preferably 1.05 to 1.5 mol, and even more preferably 1.1 to 1.4 mol, per 1 mol of the tetrabromobisphenol compound represented by the general formula (6).

[0065] In the polymerization reaction, the amount of the weak base compound added is preferably 1.0 to 2.0 mol, more preferably 1.1 to 1.6 mol, and even more preferably 1.2 to 1.5 mol, per 1 mol of the tetrabromobisphenol compound represented by general formula (6).

[0066] In the polymerization reaction, the amount of the radical trapping agent added is preferably 0.00005 to 0.3 parts by mass, more preferably 0.0001 to 0.2 parts by mass, and even more preferably 0.0001 to 0.1 parts by mass, per part by mass of the tetrabromobisphenol compound represented by the general formula (6) above.

[0067] In addition, in the case where moisture is generated during the polymerization reaction due to decomposition of the base or the like, it is preferable to set the temperature to which the reaction solution is heated to 100°C or higher and carry out the reaction while removing moisture from the polymerization reaction system.

[0068] The method for controlling the water content in the reaction system, other than the above-mentioned method of removing water by heating, is not particularly limited, but for example, a method of adding a dehydrating agent to the reaction system can be mentioned.

[0069] The dehydrating agent is not particularly limited, but examples thereof include molecular sieves and zeolites.

[0070] In the above polymerization reaction, 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.

[0071] The polymerization reaction may be carried out under reduced pressure, normal pressure, or increased pressure, but is preferably carried out under normal pressure or increased pressure in that a polymer having excellent heat resistance can be obtained.

[0072] The polymerization reaction can be carried out in a continuous manner or in a batch manner.

[0073] The polymerization reaction can produce a halogen-containing polymer in the reaction system. The reaction solution in which the polymerization reaction is carried out is mixed with a poor solvent (a solvent that has a low ability to dissolve the halogen-containing polymer), so that the halogen-containing polymer solid can be precipitated.

[0074] The poor solvent includes, for example, water or methanol.

[0075] The precipitated halogen-containing polymer solid usually contains a salt formed from weakly basic compound ions and halide ions produced in the reaction system, and the salt content is often 2 mass % or more.

[0076] In the method for producing a halogen-containing polymer according to one embodiment of the present invention, the salts are extensively washed away from the halogen-containing polymer solids.

[0077] Examples of methods for thorough washing and removal include centrifugal filtration while spraying ultrapure water, and finely pulverizing the halogen-containing polymer solid by physical force and then passing a large amount of ultrapure water through the powder to wash the particles.

[0078] Moreover, the term "cleaned away to a high degree" means that the content of alkali metal ions in the halogen-containing polymer according to one embodiment of the present invention is reduced to 1.5% by mass or less.

[0079] From the viewpoint of excellent dielectric properties, the alkali metal ion content in the halogen-containing polymer according to one embodiment of the present invention is preferably 0.0001 to 1 mass%, more preferably 0.0005 to 0.8 mass%, even more preferably 0.001 to 0.6 mass%, and even more preferably 0.01 to 0.5 mass%.

[0080] The halogen-containing polymer of the present invention has its (Dk) 0.5 The dielectric properties expressed as ×Df are 0.1×10 -3 ~30×10 -3Preferably, the concentration is 1×10 -3 ~25×10 -3 More preferably, 5×10 -3 ~20×10 -3 It is more preferable that:

[0081] The halogen-containing polymer according to one embodiment of the present invention can impart flame retardancy to a resin by being mixed with the resin. The mixing method is not particularly limited, but examples thereof include dry mixing, wet mixing, melt kneading, etc.

[0082] The flame-retardant low dielectric resin composition according to one embodiment of the present invention includes the halogen-containing polymer of the present invention and a resin component. The amount of the halogen-containing polymer mixed with the resin component is preferably 1 to 100 parts by mass, more preferably 1 to 50 parts by mass, per 100 parts by mass of the resin component.

[0083] The resin component 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, polyurethane, polyurea, polyimide, polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, polyetheretherketone, polyimide, polyamideimide, liquid crystal polymer, polyphenylene ether, and polybutadiene.

[0084] The flame-retardant low dielectric characteristic resin composition of the present invention may further contain other additives as necessary, such as other flame retardants, fillers, lubricants, modifiers, fragrances, antibacterial agents, pigments, dyes, heat resistance agents, weather resistance agents, antistatic agents, ultraviolet absorbing agents, or stabilizers.

[0085] The flame-retardant low dielectric resin composition of the present invention has its (Dk) 0.5 The dielectric properties expressed as ×Df are 0.1×10 -3 ~30×10 -3 Preferably, the concentration is 1×10 -3 ~20×10 -3 More preferably, 5×10 -3 ~10×10 -3 It is more preferable that:

[0086] In one embodiment of the present invention, a flame-retardant low dielectric characteristic resin molded product made of the flame-retardant low dielectric characteristic resin composition can be produced by molding the flame-retardant low dielectric characteristic resin composition. As the molding method, a known method can be used, for example, injection molding, extrusion molding, press molding, vacuum molding, etc.

[0087] The flame-retardant low dielectric resin molding of the present invention has a small dielectric loss, and is therefore suitable as a resin material for electronic devices and devices, particularly for electronic devices and devices used for high-speed communication using high-frequency radio waves. Electronic devices used for high-speed communication using high-frequency radio waves are not particularly limited, but include, for example, mobile phones, smartphones, personal computers, mobile routers, data center communication equipment, base stations, radars, robots, drones, wearable computers, measurement and measuring equipment used in various industries such as automobiles, aircraft, industry, agriculture, logistics, and civil engineering, or high-speed wireless communication equipment. Specific examples of electronic devices used for high-speed communication using high-frequency radio waves include semiconductors, electronic displays, and electric and electronic components. Examples of the electric and electronic components include, for example, capacitors, printed circuits, connectors, various sensors, inductors, switches, and housings. [Brief description of the drawings]

[0088] [Figure 1] 1 shows an NMR chart of the halogen-containing polymer synthesized in Example 1. [Explanation of symbols]

[0089] 1. Peak derived from the terminal vinyl group (Formula (5)) 2. Peak derived from the terminal chloroethyl group (represented by Formula (2) and Y being a chlorine atom) 3. Peak derived from the terminal hydroxyethyl group (Formula (3))

Example

[0090] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples at all. <Molecular weight analysis method> Regarding the polymer sample synthesized in Examples etc., a column for molecular weight measurement (TSKgel (registered trademark) SuperAW2500 + 3000 + 5000, manufactured by Tosoh Corporation) was connected to a gel permeation chromatography device (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. Other matters were carried out in accordance with JIS - K - 7252 system. <Ratio 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 integrations: 2048 times Measurement mode: Inverse gated decoupling (quantitative method) Regarding the polymer sample synthesized in the example, 13C NMR was measured under the above measurement conditions, and the terminal structure was analyzed from the average integral value of each peak.

[0091] 13C on the carbon bearing a chlorine atom in the terminal group represented by formula (2) where Y is a chlorine atom is observed at about 42.1(t) ppm. 13C on the carbon bearing a hydroxyl group in the terminal group represented by formula (3) is observed at about 62.0(s) ppm. 13C on the carbon bearing a phenolic hydroxyl group in the terminal group represented by formula (4) is observed at about 147.3(m) ppm. 13C on the outer carbon of the double bond in the terminal group represented by formula (5) is observed at about 91.9(s) ppm.

[0092] The proportion of each end group was calculated based on the integral value of the 13C NMR peak derived from each of the above end groups.

[0093] [ka]

[0094] <Method for evaluating the dielectric properties of halogen-containing polymers> Measurement method: Cavity resonator method Measurement frequency: 1GHz 2.0 g of the halogen-containing polymer was sealed in a PTFE container, and the results of the above-mentioned measurement method with and without the sample sealed were compared to calculate the relative dielectric constant Dk and the dielectric loss tangent Df.

[0095] In addition, the dielectric loss (α d ) can be calculated by the following formula:

[0096] [ka]

[0097] α d : dielectric loss, K: proportionality constant, f: frequency, D k :Relative permittivity, D f : Dielectric tangent The above K and f are constants. Therefore, the magnitude of dielectric loss is (Dk) 0.5 × Df. Therefore, the dielectric loss is (Dk) 0.5The magnitude of ×Df was used as an index for evaluation. <Evaluation method for flame retardancy and mechanical properties of halogen-containing polymer-blended polypropylene (PP) resin> 43 parts by mass of polypropylene resin (BC3AD manufactured by Japan Polypropylene), 7 parts by mass of antimony trioxide (AT-3CN manufactured by Suzuhiro Chemical Industry), 30 parts by mass of talc (5000PJ manufactured by Matsumura Sangyo Co., Ltd.), and 20 parts by mass of the halogen-containing polymer described in the Examples were charged into a twin-screw extruder (ZSK-26, manufactured by Coperion), kneaded at a maximum temperature of 235°C, discharged as a strand, and pelletized. The obtained PP pellets 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 tests.

[0098] Flame resistance of the test pieces was evaluated by conducting a combustion test according to the UL94V standard. Flame resistance is expressed as V-0, V-1, and V-2, from highest to lowest.

[0099] The PP pellets obtained above were molded by an injection molding machine (J55AD manufactured by Japan Steel Works, Ltd.) to obtain test pieces for measuring the oxygen index. The oxygen index value was measured in accordance with JIS K 7201.

[0100] The melt flow rate (hereinafter, abbreviated as MFR) of the PP pellets obtained above was measured using a melt indexer (TP-401 manufactured by Tester Sangyo) in accordance with JIS K 7210 (measurement conditions: temperature 230° C., load 3.80 kg).

[0101] The PP pellets obtained above were molded by an injection molding machine (J55AD manufactured by Japan Steel Works, Ltd.) to obtain test pieces for Izod impact strength testing. The Izod impact strength (hereinafter referred to as IZOD) was measured in accordance with JIS K 7110. <Method for evaluating dielectric properties of halogen-containing polymer-blended polyphenylene ether (PPE) resin> 100 parts by mass of polyphenylene ether resin (Zylon S203A manufactured by Asahi Kasei) and 20 parts by mass of the halogen-containing polymer described in the Examples were fed into a twin-screw extruder (TEM-26SX manufactured by Toshiba Machine), kneaded at a maximum temperature of 250°C, discharged as a strand, and pelletized. The obtained PPE pellets were vacuum-dried at 80°C for 30 minutes, and then 0.7 g of the PPE pellets were pressed in a 50 mm x 50 mm x 0.25 mm metal frame with a vacuum manual press at 10 kN for 30 seconds and then at 60 kN for 30 seconds to form the pellets, which were then cut to obtain test pieces (35 mm x 35 mm x 0.25 mm) for evaluating dielectric properties.

[0102] Using the test piece obtained above, the relative dielectric constant Dk and the dielectric loss tangent Df were measured at room temperature and at a measurement frequency of 90 GHz by the balanced disk resonator method. The dielectric loss was (Dk) 0.5 The magnitude of ×Df was used as an index for evaluation.

[0103] Example 1 In a 300 mL glass eggplant flask, 20.0 g (1.0 equivalent, 37 mmol) of tetrabromobisphenol A, 4.7 g (1.3 equivalent, 48 mmol) of ethane dichloride, 6.4 g (1.3 equivalent, 46 mmol) of potassium carbonate, 0.2 g (0.4 equivalent, 1.3 mmol) of 4-tert-butylphenol (PTBP), and 75 g of dimethylformamide were added and heated to 140°C while stirring. After stirring at 140°C for 2 hours, the mixture was allowed to cool to room temperature. Water was added to precipitate a solid.

[0104] The precipitated solid was put into a centrifugal filter, and centrifugal filtration was performed for 10 minutes while spraying ultrapure water (speed 20 mL / min, average droplet size 200 μm) to wash the solid (spray washing), and then dried. A white solid (halogen-containing polymer (a) of the present invention) having a weight average molecular weight of 12,000 calculated as standard polystyrene by gel permeation chromatography was obtained in a yield of 94%.

[0105] The ultrapure water used was produced using Direct-Q 3 UV (Merck).

[0106] The concentration of alkali metal ions remaining in the solid of the resulting halogen-containing polymer (a) was measured and found to be 0.02% by mass.

[0107] Furthermore, the analysis of the obtained halogen-containing polymer (a) by 13C-NMR showed that the proportions of the polymer terminal structures were 82.4% for chloroethyl groups (corresponding to the above formula (2)), 6.4% for hydroxyethyl groups (corresponding to the above formula (3)), 6.4% for phenolic hydroxy groups (corresponding to the above formula (4)), below the detection limit (1%), and 11.2% for vinyl groups (corresponding to the above formula (5)). That is, the proportion of the terminal groups represented by formulas (3) and (4) among the terminal groups represented by formulas (2) to (5) was 6.4%.

[0108] Furthermore, the obtained halogen-containing polymer (a) was evaluated based on the above-mentioned <Method for evaluating the dielectric properties of halogen-containing polymers>. As a result, the relative dielectric constant (Dk) was 2.73, the dielectric loss tangent (Df) was 0.0077, and the dielectric loss index (Dk) was 1.0. 0.5 ×Df was 0.0127.

[0109] In addition, the polyphenylene ether resin containing the obtained halogen-containing polymer (a) was evaluated based on the above-mentioned <Method for evaluating the dielectric properties of polyphenylene ether (PPE) resin containing halogen-containing polymer>. The dielectric constant (Dk) was 2.46, the dielectric loss tangent (Df) was 0.00443, and the dielectric loss index (Dk) was 1.0. 0.5 ×Df was 0.00695.

[0110] Example 2 The same procedure as in Example 1 was carried out except that 5.1 g (1.4 equivalents, 52 mmol) of ethane dichloride was used, and a white solid (halogen-containing polymer (b) of the present invention) having a weight average molecular weight of 4,800 calculated as standard polystyrene by gel permeation chromatography was obtained in a yield of 87%.

[0111] The content of alkali metal ions remaining in the solid of the resulting halogen-containing polymer (b) was measured and found to be 0.11% by mass.

[0112] Furthermore, analysis of the obtained halogen-containing polymer (b) by 13C-NMR showed that the proportions of the polymer terminal structures were 94.2% for chloroethyl groups (corresponding to the above formula (2)), 1.9% for hydroxyethyl groups (corresponding to the above formula (3)), 1.9% for phenolic hydroxy groups (corresponding to the above formula (4)) below the detection limit (1%), and 3.9% for vinyl groups (corresponding to the above formula (5)). That is, the proportion of the terminal groups represented by formulas (3) and (4) among the terminal groups represented by formulas (2) to (5) was 1.9%.

[0113] Example 3 In a 300 mL glass eggplant flask, 20.0 g (1.0 equivalent, 37 mmol) of tetrabromobisphenol A, 4.9 g (1.35 equivalent, 50 mmol) of ethane dichloride, 6.4 g (1.3 equivalent, 46 mmol) of potassium carbonate, 0.2 g (0.4 equivalent, 1.3 mmol) of 4-tert-butylphenol (PTBP), and 75 g of dimethylformamide were added and heated to 140°C while stirring. After stirring at 140°C for 2 hours, the mixture was allowed to cool to room temperature. Water was added to precipitate a solid.

[0114] The precipitated solid was filtered by suction and washed with 100 g of pure water. The obtained solid was placed in a 300 mL glass cylindrical separable flask, and 100 g of pure water was added and stirred to disperse. The solid was then filtered by suction, washed with 100 g of pure water, and then dried. A white solid (the halogen-containing polymer (c) of the present invention) having a weight average molecular weight of 7,600 calculated as standard polystyrene by gel permeation chromatography was obtained in a yield of 90%.

[0115] The concentration of alkali metal ions remaining in the solid of the resulting halogen-containing polymer (a) was measured and found to be 0.48% by mass.

[0116] Furthermore, the analysis of the obtained halogen-containing polymer (a) by 13C-NMR showed that the proportions of the polymer terminal structures were 91.0% for chloroethyl groups (corresponding to the above formula (2)), 2.6% for hydroxyethyl groups (corresponding to the above formula (3)), 2.6% for phenolic hydroxy groups (corresponding to the above formula (4)) below the detection limit (1%), and 6.4% for vinyl groups (corresponding to the above formula (5)). That is, the proportion of the terminal groups represented by formulas (3) and (4) among the terminal groups represented by formulas (2) to (5) was 2.6%.

[0117] Comparative Example 1 The same operation as in Example 1 was carried out except that, instead of the precipitated solid being charged into a centrifugal filter and centrifugal filtration being carried out while spraying ultrapure water, ultrapure water was poured in in a rod-like form while centrifugal filtration was carried out, thereby obtaining a white solid (halogen-containing polymer (d)) having a molecular weight of 12,000 in a yield of 93%.

[0118] The content of alkali metal ions remaining in the solid of the resulting halogen-containing polymer (d) was measured and found to be 2.2% by mass.

[0119] Furthermore, the analysis of the obtained halogen-containing polymer (d) by 13C-NMR showed that the proportions of the polymer terminal structures were 82.4% for chloroethyl groups (corresponding to the above formula (2)), 6.4% for hydroxyethyl groups (corresponding to the above formula (3)), 6.4% for phenolic hydroxy groups (corresponding to the above formula (4)) below the detection limit (1%), and 11.2% for vinyl groups (corresponding to the above formula (5)). That is, the proportion of the terminal groups represented by formulas (3) and (4) among the terminal groups represented by formulas (2) to (5) was 6.4%.

[0120] Furthermore, the obtained halogen-containing polymer (d) was evaluated based on the above-mentioned <Method for evaluating dielectric properties>. As a result, the relative dielectric constant (Dk) was 2.99, the dielectric loss tangent (Df) was 0.0240, and the dielectric loss index (Dk) was 1.0. 0.5 ×Df was 0.0415.

[0121] Comparative Example 2 Various evaluations were carried out using tetrabromobisphenol A (manufactured by Tosoh Corporation) instead of the synthesized halogen-containing polymer.

[0122] For tetrabromobisphenol A, no residual alkali metal ions were detected in the solid.

[0123] For tetrabromobisphenol A, the proportion of the polymer terminal structure was evaluated to be 100% phenolic hydroxyl group (corresponding to the above formula (4)) from the analysis by 13C-NMR. In other words, the proportion of the terminal groups represented by formulae (3) and (4) among the terminal groups represented by formulae (2) to (5) was 100%.

[0124] In addition, when tetrabromobisphenol A was evaluated based on the above-mentioned <Method for evaluating dielectric properties>, the relative dielectric constant (Dk) was 5.41, the dielectric dissipation factor (Df) was 0.0774, and this is an index of dielectric loss (Dk). 0.5 ×Df was 0.1800.

[0125] [Table 1]

[0126] [Table 2]

[0127] As described above, it has been confirmed that the halogen-containing polymer of the present invention is remarkably superior in low dielectric properties to conventional products.

[0128] From the correlation between the measurement results of the proportion (%) of hydroxyl end groups and the alkali metal ion concentration (mass%) of the halogen-containing polymer of Example 1 and the low dielectric properties, it is easily conceivable that the halogen-containing polymers of Examples 2 and 3 also have significantly superior low dielectric properties compared to the conventional techniques.

[0129] By using the halogen-containing polymer, it is possible to provide a flame-retardant resin composition having excellent flame retardancy and remarkably low dielectric loss, and further, it is possible to provide a flame-retardant resin molding having excellent flame retardancy and remarkably low dielectric loss. [Industrial Applicability]

[0130] Since the halogen-containing polymer of the present invention has excellent low dielectric properties, it is expected to be used as a flame retardant for low dielectric materials applied to electronic devices and devices used in high-speed communications using high-frequency radio waves.

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 -. n represents the average number of repetitions and is expressed as a real number.) and at a polymer chain end thereof, a repeating unit represented by any one of the following formulae (2) to (5) is present: 【Chemistry 2】 (In formula (2), Y represents a halogen atom.) and among the terminal groups represented by general formulae (2) to (5), the proportion of hydroxyl terminal groups represented by formulae (3) and (4) is 20% or less, and further, the halogen-containing polymer has an alkali metal ion concentration of 1.5% by mass or less, where the total amount of the halogen-containing polymer is taken as 100% by mass.

2. 2. The halogen-containing polymer according to claim 1, wherein the proportion of hydroxyl end groups represented by formulae (3) and (4) among the end groups represented by general formulae (2) to (5) is 0 to 10%.

3. 2. The halogen-containing polymer according to claim 1, wherein the alkali metal ion concentration is from 0.0001 to 1% by mass.

4. A flame-retardant, low dielectric property resin composition comprising the halogen-containing polymer according to any one of claims 1 to 3 and a resin component.

5. A flame-retardant, low dielectric characteristic resin molding comprising the flame-retardant, low dielectric characteristic resin composition according to claim 4.

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