Halogen-including polymer, and flame-retardant resin composition and molded article including said halogen-including polymer

Abstract

Provided is a halogen-including polymer that has superior dielectric characteristics compared to conventional well-known halogen-including polymers.　The present invention uses a halogen-including polymer having at least one repeating unit that is represented by general formula (1) (in this formula, 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), said halogen-including polymer being characterized by having, at an end of the polymer chain, at least one terminal group selected from the group consisting of formulas (2) through (5) (in formula (2), Y represents a halogen atom), wherein among the terminal groups represented by general formulas (2) through (5), the percentage of the hydroxy terminal groups represented by formulas (3) and (4) is 20% or less, and said halogen-including polymer being further characterized in that when the entirety of the halogen-including polymer is treated as 100 mass%, the concentration of alkali metal ions included in the halogen-including polymer is 1.5 mass% or less.

Description

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

[0001] One embodiment of the present invention relates to a halogen-containing polymer, and a flame-retardant resin composition and molded article containing the same.

[0002] Flame retardants are well known as additives that impart flame retardancy to resins by being mixed into them. Among these, compounds containing a large amount of bromine have long been added to many resins as halogenated flame retardants. For example, tetrabromobisphenol A, one of the most representative brominated flame retardants, is known as the most widely produced halogenated 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 price 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 production 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 polymeric brominated flame retardants, which are considered to have relatively little 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 (for example, Patent Documents 1 to 5).

[0005] Japanese Patent Publication No. 51-117737 Japanese Patent Publication No. 56-8809 Japanese Patent Publication No. 53-128656 Japanese Patent Publication No. 62-1973 Japanese Patent Publication No. 2020-200371

[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 radio waves in the high-frequency band.

[0007] An embodiment of the present invention has been made in view of the above-mentioned background art, and an object of the invention is to provide a halogen-containing polymer having a small dielectric loss, and uses thereof.

[0008] As a result of extensive investigations, the present inventors have found that the above-mentioned problems can be solved by the following invention, and have completed one embodiment of 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] That is, one embodiment of the present invention resides in the following [1] to [5].

[0011] [1] The following general formula (1)

[0012]

[0013] (wherein R represents an alkylene group having 1 to 6 carbon atoms, —S—, or —SO ２ n represents the average number of repeating units and is represented by a real number.) A halogen-containing polymer having at least one repeating unit represented by the following formula (2) to (5) at the polymer chain terminal:

[0014]

[0015] (in formula (2), Y represents a halogen atom), and the proportion of hydroxyl terminal groups represented by formulas (3) and (4) is 20% or less among the terminal groups represented by general formulas (2) to (5), 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.

[0016] [2] The halogen-containing polymer according to [1], wherein the proportion of hydroxyl terminal groups represented by formulas (3) and (4) among the terminal groups represented by general formulas (2) to (5) is 0 to 10%.

[0017] [3] The halogen-containing polymer according to [1], wherein the alkali metal ion content is 0.0001 to 1 mass %.

[0018] [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.

[0019] [5] A flame-retardant, low-dielectric-characteristics resin molding made from the flame-retardant, low-dielectric-characteristics resin composition according to [4].

[0020] The halogen-containing polymer according to one embodiment 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 is possible to make the resin flame-retardant without impairing the inherent dielectric properties of the resin.

[0021] Hereinafter, one embodiment of the present invention will be described in detail.

[0022] In this specification, "to" means a range of values ​​including both the upper and lower limits of the range.

[0023] 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.

[0024] Furthermore, the halogen-containing polymer according to one embodiment of the present invention has excellent heat resistance, and therefore can be kneaded or molded at high temperatures, which can contribute to improving the productivity of various flame-retardant resins.

[0025] The halogen-containing polymer according to one embodiment of the present invention is represented by the following general formula (1):

[0026]

[0027] (wherein R represents an alkylene group having 1 to 6 carbon atoms, —S—, or —SO ２ n represents the average number of repeating units and is represented by a real number.) A halogen-containing polymer having at least one repeating unit represented by the following formula (2) to (5) at the polymer chain terminal:

[0028]

[0029] (in formula (2), Y represents a halogen atom), and the proportion of hydroxyl terminal groups represented by formulas (3) and (4) among the terminal groups represented by general formulas (2) to (5) is 20% or less, and further the alkali metal ion concentration is 1.5% by mass or less.

[0030] 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.

[0031] The above R is preferably a methylene group, a 2,2-propylene group, -S-, or -SO because of its excellent dielectric properties. ２ - is preferred, and a 2,2-propylene group is more preferred.

[0032] 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.

[0033] 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 that 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 these characteristics, it is possible to provide a halogen-containing polymer having unprecedentedly low relative permittivity and dielectric loss tangent.

[0034] The terminal groups represented by the formulas (2) to (5) can be identified by high-sensitivity NMR analysis, and the abundance ratios of the elements can be quantified by analyzing the abundance ratios calculated from the area ratios of the NMR charts.

[0035] 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 more preferably 1 to 10%, and even more preferably 1 to 5%, in terms of excellent dielectric properties of the halogen-containing polymer.

[0036] The alkali metal ions are not particularly limited, but examples thereof include lithium ions, sodium ions, potassium ions, rubidium ions, and cesium ions.

[0037] 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%.

[0038] The halogen-containing polymer according to one embodiment of the present invention preferably has a weight average molecular weight, calculated as standard polystyrene, determined by gel permeation chromatography measurement of 2,000 or more, more preferably 3,000 or more, and even more preferably 4,000 or more, in terms of obtaining higher heat resistance.

[0039] The weight average molecular weight is preferably 2,000 to 50,000, more preferably 3,000 to 30,000, and even more preferably 4,000 to 15,000, in terms of ease of handling as a flame retardant.

[0040] 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, as 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. Therefore, Mw / Mn is more preferably 1.0 to 3.0.

[0041] 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 were as shown in the examples.

[0042] 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 is preferably 2 or more, more preferably 3 or more, and even more preferably 5 or more, in terms of excellent heat resistance.

[0043] 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.

[0044] 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, so the bromine content is more preferably 53 to 60 mass %.

[0045] The bromine content (% by mass) of the halogen-containing polymer according to one embodiment of the present invention is not particularly limited, but can be quantified by combustion-ion chromatography. Specific analytical methods and conditions for combustion-ion chromatography are described in IEC 62321-3-2. Detailed conditions are as shown in the examples.

[0046] A halogen-containing polymer according to one embodiment of the present invention can be produced by heating a reaction solution containing at least the following raw materials: 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, 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.

[0047]

[0048] (wherein R represents an alkylene group having 1 to 6 carbon atoms, —S—, or —SO ２ X and Z each independently represent a halogen atom.) In the above production method, if no side reactions are taken into consideration, the halogen-containing polymer according to one embodiment of the present invention should have a terminal phenolic hydroxy group derived from a tetrabromobisphenol compound or a terminal ethyl halide group derived from a dihalogenated ethane.

[0049] However, in actual production processes, some of the ethyl halide groups may be converted to vinyl groups, ethyl halide groups, or other groups under the influence of the above-mentioned base.

[0050] That is, the terminals of the halogen-containing polymer according to one embodiment of the present invention are, in reality, terminal groups represented by any one of the above formulas (2) to (5), or other terminal groups.

[0051] It is generally recognized that the phenolic hydroxy 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, in order to improve the dispersibility of chemical substances in organic solvents, it is considered effective to reduce the content of hydroxy groups, 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 hydroxy groups.

[0052] 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.

[0053] 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.

[0054] The weakly basic compound is not particularly limited, but examples thereof include ammonia, organic amine compounds, alkali metal hydrogen carbonate compounds, and alkali metal carbonate compounds.

[0055] The weak base compound is preferably 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, in terms of excellent dielectric properties, and more preferably sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, or potassium carbonate.

[0056] The radical trapping agent is not particularly limited, but may include at least one selected from the group consisting of phenol compounds, hindered amine compounds, and phosphate ester compounds. More specific examples include 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), and tris(2,4-di-tert-butylphenyl)phosphite.

[0057] 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 from 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 even more preferably in the range of 110 to 170° C.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] The ether-based organic solvent is not particularly limited, but examples thereof include tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, cyclopentyl methyl ether, diethyl ether, polyethylene glycol, methyl cellosolve, etc. Among these, tetrahydrofuran, 2-methyltetrahydrofuran, and 1,4-dioxane are preferred, and tetrahydrofuran is more preferred.

[0062] It is preferable to use the solvent from which water has been removed in advance in order to suppress the amount of the terminal group represented by formula (3) produced.

[0063] It is also preferable to use raw materials other than the solvent used in the polymerization reaction that have a low water content.

[0064] In the polymerization reaction, the initial concentration of the tetrabromobisphenol compound represented by 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 all-at-once charging, which is 100 mass%.

[0065] In the 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, relative to 1 mol of the tetrabromobisphenol compound represented by the general formula (6).

[0066] In the polymerization reaction, the amount of the weakly basic 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).

[0067] 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).

[0068] In addition, in the polymerization reaction, when water is generated during the 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 water from the reaction system of the polymerization reaction.

[0069] 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 agent to the reaction system.

[0070] The dehydrating agent is not particularly limited, but examples thereof include molecular sieves and zeolites.

[0071] In the 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.

[0072] 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 order to obtain a polymer having excellent heat resistance.

[0073] The polymerization reaction can be carried out either continuously or batchwise.

[0074] The polymerization reaction can produce a halogen-containing polymer in the reaction system. The reaction solution in which the polymerization reaction has been carried out can be mixed with a poor solvent (a solvent that has a low ability to dissolve the halogen-containing polymer), thereby precipitating the halogen-containing polymer in solid form.

[0075] The poor solvent may be, for example, water or methanol.

[0076] 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% by mass or more.

[0077] In the method for producing a halogen-containing polymer according to one embodiment of the present invention, the salts are thoroughly washed away from the halogen-containing polymer solids.

[0078] 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, followed by washing with a large amount of ultrapure water.

[0079] Furthermore, "cleaning 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.

[0080] In terms 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 %.

[0081] The halogen-containing polymer according to one embodiment of the present invention has (Dk) ０．５ The dielectric properties expressed by ×Df are 0.1 × 10 －３ ~30 x 10 －３ It is preferable that the －３ ~25 x 10 －３ More preferably, it is 5×10 －３ ~20 x 10 －３ It is more preferable that:

[0082] 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.

[0083] A flame-retardant low dielectric characteristic resin composition according to one embodiment of the present invention includes the halogen-containing polymer according to one embodiment 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.

[0084] 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.

[0085] The flame-retardant low dielectric characteristic resin composition according to one embodiment of the present invention may further contain other additives as needed, such as other flame retardants, fillers, lubricants, modifiers, fragrances, antibacterial agents, pigments, dyes, heat resistance agents, weather resistance agents, antistatic agents, UV absorbers, stabilizers, etc.

[0086] The flame-retardant low dielectric characteristic resin composition according to one embodiment of the present invention has a (Dk) ０．５ The dielectric properties expressed by ×Df are 0.1 × 10 －３ ~30 x 10 －３ It is preferable that the －３ ~20 x 10 －３ More preferably, it is 5×10 －３ ~10 x 10 －３ It is more preferable that:

[0087] In one embodiment of the present invention, a flame-retardant, low-dielectric-characteristics resin molded product can be produced by molding the flame-retardant, low-dielectric-characteristics resin composition. The molding method can be a known method, such as injection molding, extrusion molding, press molding, or vacuum molding.

[0088] The flame-retardant low-dielectric resin molded article according to one embodiment of the present invention has low dielectric loss and is therefore suitable as a resin material for electronic 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 include, but are not limited to, mobile phones, smartphones, personal computers, mobile routers, data center communication equipment, base stations, radar, robots, drones, wearable computers, and measurement and measuring instruments or high-speed wireless communication equipment used in various industries such as automobiles, aircraft, industry, agriculture, logistics, and civil engineering. Specific examples of electronic devices used for high-speed communication using high-frequency radio waves include semiconductors, electronic displays, and electrical and electronic components. Examples of the electrical and electronic components include capacitors, printed circuits, connectors, various sensors, inductors, switches, and housings.

[0089] 1 shows an NMR chart of the halogen-containing polymer synthesized in Example 1.

[0090] 1. Peaks derived from terminal vinyl groups (formula (5)) 2. Peaks derived from terminal chloroethyl groups (represented by formula (2) and where Y is a chlorine atom) 3. Peaks derived from terminal hydroxyethyl groups (formula (3))

[0091] Hereinafter, one embodiment of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. <Molecular Weight Analysis Method> For the polymer samples synthesized in the examples, etc., a molecular weight measurement column (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 measurements were performed using a chloroform eluent at a flow rate of 0.6 mL / min, a temperature of 40°C, and UV (254 nm) detection conditions. Furthermore, the weight average molecular weight of the sample was measured using standard polystyrene. Other matters were carried out in accordance with JIS-K-7252. <Analysis of the ratio of polymer terminal structures 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 accumulations: 2048 Measurement mode: inverse gated decoupling (quantitative method) 13C NMR was measured for the polymer samples synthesized in the examples under the above measurement conditions, and the terminal structures were analyzed from the average integral value of each peak.

[0092] The carbon atom having a chlorine atom in the terminal group represented by formula (2) where Y is a chlorine atom is observed at around 42.1 (t) ppm. The carbon atom having a hydroxyl group in the terminal group represented by formula (3) is observed at around 62.0 (s) ppm. The carbon atom having a phenolic hydroxyl group in the terminal group represented by formula (4) is observed at around 147.3 (m) ppm. The carbon atom on the outer side of the double bond in the terminal group represented by formula (5) is observed at around 91.9 (s) ppm.

[0093] The proportion of each terminal was calculated based on the integral value of the 13C NMR peak derived from each of the above terminal groups.

[0094]

[0095] <Method for evaluating dielectric properties of halogen-containing polymer> Measurement method: cavity resonator method Measurement frequency: 1 GHz 2.0 g of the halogen-containing polymer was sealed in a PTFE container, and the results with and without the sealed sample were compared using the above measurement method to calculate the relative dielectric constant Dk and the dielectric loss tangent Df.

[0096] In addition, the dielectric loss (α ｄ ) can be calculated by the following formula:

[0097]

[0098] α ｄ : dielectric loss, K: proportionality constant, f: frequency, D ｋ : Specific permittivity, D ｆ : Dielectric loss tangent The above K and f are constants. Therefore, the magnitude of the dielectric loss is (Dk) ０．５ × Df. Therefore, the dielectric loss is proportional to (Dk) ０．５ The evaluation was performed using the size of ×Df as an index. <Method for evaluating the 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), 30 parts by mass of talc (5000PJ manufactured by Matsumura Sangyo), 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 The Japan Steel Works, Ltd.) to obtain test pieces (125 mm × 15 mm × 1.5 mm) for combustion tests.

[0099] Flame retardancy of the test specimens was evaluated by carrying out a combustion test according to the UL94V standard, and the flame retardancy was expressed as V-0, V-1, and V-2 in descending order of flame retardancy.

[0100] The PP pellets obtained above were molded using 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.

[0101] The melt flow rate (hereinafter referred to as MFR) of the PP pellets obtained above was measured 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).

[0102] The PP pellets obtained above were molded using an injection molding machine (J55AD manufactured by Japan Steel Works) 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. <Method for evaluating the 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 charged 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 × 50 mm × 0.25 mm metal frame using a vacuum manual press at 10 kN for 30 seconds and then at 60 kN for 30 seconds to form a mold. The molded ...

[0103] Using the test piece obtained above, the relative permittivity Dk and the dielectric loss tangent Df were measured at room temperature at a measurement frequency of 90 GHz by the balanced disk resonator method. ０．５ The size of ×Df was used as an index for evaluation.

[0104] Example 1: 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 placed in a 300 mL glass eggplant-shaped flask 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.

[0105] The precipitated solid was placed in 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 (a halogen-containing polymer (a) according to one embodiment of the present invention) having a weight-average molecular weight of 12,000 as determined by gel permeation chromatography in terms of standard polystyrene was obtained in a yield of 94%.

[0106] The ultrapure water used was produced using Direct-Q 3 UV (manufactured by Merck).

[0107] The concentration of alkali metal ions remaining in the solid of the obtained halogen-containing polymer (a) was measured and found to be 0.02% by mass.

[0108] Furthermore, analysis of the obtained halogen-containing polymer (a) by C-NMR revealed that the proportions of the polymer terminal structures were as follows: chloroethyl group (corresponding to the above formula (2)) 82.4%, hydroxyethyl group (corresponding to the above formula (3)) 6.4%, phenolic hydroxy group (corresponding to the above formula (4)) below the lower detection limit (1%), and vinyl group (corresponding to the above formula (5)) 11.2%. That is, of the terminal groups represented by formulas (2) to (5), the proportion of terminal groups represented by formulas (3) and (4) was 6.4%.

[0109] Furthermore, the obtained halogen-containing polymer (a) was evaluated in accordance with the above-mentioned <Method for evaluating dielectric properties of halogen-containing polymers>. As a result, the relative dielectric constant (Dk) was 2.73, and the dielectric loss tangent (Df) was 0.0077, which is an index of dielectric loss (Dk). ０．５ ×Df was 0.0127.

[0110] Furthermore, 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 a halogen-containing polymer>. As a result, the relative dielectric constant (Dk) was 2.46, and the dielectric loss tangent (Df) was 0.00443, which is an index of dielectric loss (Dk). ０．５ ×Df was 0.00695.

[0111] 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, to obtain a white solid (a halogen-containing polymer (b) according to one embodiment of the present invention) having a weight average molecular weight of 4,800 as determined by gel permeation chromatography relative to standard polystyrene standards, in a yield of 87%.

[0112] The content of alkali metal ions remaining in the solid of the obtained halogen-containing polymer (b) was measured and found to be 0.11% by mass.

[0113] Furthermore, analysis of the obtained halogen-containing polymer (b) by C-NMR revealed that the proportions of the polymer terminal structures were as follows: chloroethyl group (corresponding to the above formula (2)) 94.2%, hydroxyethyl group (corresponding to the above formula (3)) 1.9%, phenolic hydroxy group (corresponding to the above formula (4)) below the lower detection limit (1%), and vinyl group (corresponding to the above formula (5)) 3.9%. That is, of the terminal groups represented by formulas (2) to (5), the proportion of terminal groups represented by formulas (3) and (4) was 1.9%.

[0114] Example 3: 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 placed in a 300 mL glass eggplant-shaped flask 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.

[0115] The precipitated solid was filtered off under suction and washed with 100 g of pure water. The obtained solid was placed in a 300 mL cylindrical separable glass flask, and 100 g of pure water was added and stirred to disperse. The solid was then filtered off under suction, washed with 100 g of pure water, and then dried. A white solid (a halogen-containing polymer (c) according to one embodiment of the present invention) having a weight-average molecular weight of 7,600 calculated as standard polystyrene as determined by gel permeation chromatography was obtained in a yield of 90%.

[0116] The concentration of alkali metal ions remaining in the solid of the obtained halogen-containing polymer (a) was measured and found to be 0.48% by mass.

[0117] Furthermore, analysis of the obtained halogen-containing polymer (a) by C-NMR revealed that the proportions of the polymer terminal structures were as follows: chloroethyl group (corresponding to the above formula (2)) 91.0%, hydroxyethyl group (corresponding to the above formula (3)) 2.6%, phenolic hydroxy group (corresponding to the above formula (4)) below the lower detection limit (1%), and vinyl group (corresponding to the above formula (5)) 6.4%. That is, of the terminal groups represented by formulas (2) to (5), the proportion of terminal groups represented by formulas (3) and (4) was 2.6%.

[0118] Comparative Example 1 The same operation as in Example 1 was carried out, except that the precipitated solid was placed in a centrifugal filter, and centrifugal filtration was carried out while ultrapure water was injected in a rod-like manner, instead of while spraying ultrapure water, to obtain a white solid (halogen-containing polymer (d)) having a molecular weight of 12,000 in a yield of 93%.

[0119] 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.

[0120] Furthermore, analysis of the obtained halogen-containing polymer (d) by C-NMR revealed that the proportions of the polymer terminal structures were as follows: chloroethyl group (corresponding to the above formula (2)) 82.4%, hydroxyethyl group (corresponding to the above formula (3)) 6.4%, phenolic hydroxy group (corresponding to the above formula (4)) below the lower detection limit (1%), and vinyl group (corresponding to the above formula (5)) 11.2%. That is, of the terminal groups represented by formulas (2) to (5), the proportion of terminal groups represented by formulas (3) and (4) was 6.4%.

[0121] Furthermore, the obtained halogen-containing polymer (d) was evaluated in accordance with the above-mentioned <Method for evaluating dielectric properties>. As a result, the relative dielectric constant (Dk) was 2.99, and the dielectric loss tangent (Df) was 0.0240, which are indices of dielectric loss (Dk). ０．５ ×Df was 0.0415.

[0122] Comparative Example 2 Various evaluations were carried out using tetrabromobisphenol A (manufactured by Tosoh Corporation) instead of the synthesized halogen-containing polymer.

[0123] For tetrabromobisphenol A, no residual alkali metal ions were detected in the solid.

[0124] From the analysis of tetrabromobisphenol A by C-NMR, it was evaluated that the proportion of the polymer terminal structure was 100% phenolic hydroxy groups (corresponding to the above formula (4)). That is, among the terminal groups represented by formulas (2) to (5), the proportion of the terminal groups represented by formulas (3) and (4) was 100%.

[0125] Furthermore, when tetrabromobisphenol A was evaluated based on the above-mentioned <Method for evaluating dielectric properties>, the relative dielectric constant (Dk) was 5.41 and the dielectric loss tangent (Df) was 0.0774, which are indicators of dielectric loss (Dk). ０．５ ×Df was 0.1800.

[0126]

[0127]

[0128] As described above, it was confirmed that the halogen-containing polymer according to one embodiment of the present invention is significantly superior in low dielectric properties compared to conventional products.

[0129] From the correlation between the measurement results of the proportion (%) of hydroxyl terminal 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 prior art.

[0130] By using the halogen-containing polymer, it is possible to provide a flame-retardant resin composition having excellent flame retardancy and significantly reduced dielectric loss, and further to provide a flame-retardant resin molding having excellent flame retardancy and significantly reduced dielectric loss. Possible industrial applications

[0131] A halogen-containing polymer according to one embodiment of the present invention has excellent low dielectric properties and is therefore expected to be used as a flame retardant for low dielectric materials applied to electronic devices and devices used in high-speed communications using radio waves in the high-frequency band.

[0132] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

[0133] The entire contents of the specifications, claims, drawings and abstracts of Japanese Patent Application No. 2023-125601 filed on August 1, 2023, and Japanese Patent Application No. 2024-64240 filed on April 11, 2024 are hereby cited and incorporated as the disclosure of the specification of the present invention.

Claims

1. The following general formula (1) (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO ２ n represents an average number of repetitions and is represented by a real number.) A halogen-containing polymer having at least one repeating unit represented by the following formula (2) to (5) at a polymer chain terminal: (in formula (2), Y represents a halogen atom), and among the terminal groups represented by general formulas (2) to (5), the proportion of hydroxyl terminal groups represented by formulas (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 100% by mass.

2. The halogen-containing polymer according to claim 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%.

3. The halogen-containing polymer according to claim 1, wherein the alkali metal ion concentration is 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 made from the flame-retardant, low dielectric characteristic resin composition according to claim 4.

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