Conjugated diene-based polymer, method for producing the same, and impact-resistant styrene-based resin composition

Abstract

A conjugated diene polymer, wherein the cumulative luminescence of the weak luminescence produced by the chemical reaction is 150 × 10⁻⁶. 5 Below cps, the Δb value before and after heating at 160℃ for 2 hours is below 4.0.

Description

Technical Field

[0001] This invention relates to conjugated diene polymers, methods for their manufacture, and impact-resistant styrene resin compositions. Background Technology

[0002] Styrene-based resins possess excellent rigidity, transparency, and processability, making them widely used in everything from everyday consumer goods to industrial applications. However, styrene-based resins are hard but brittle, exhibiting weak impact strength. On the other hand, if uncured rubber is used as a toughening agent and grafted copolymerized with styrene monomers through bulk polymerization, solution polymerization, or bulk suspension polymerization, the rubber particles will be dispersed within the polystyrene matrix. This dispersed rubber absorbs impact, thus improving the impact strength of styrene-based resins and resulting in impact-resistant styrene-based resin compositions. These impact-resistant styrene-based resin compositions offer an excellent balance between impact strength and rigidity, and are widely used as various packaging materials and containers, primarily in the household appliance and food containers industries.

[0003] Recently, there has been a growing demand for higher quality, particularly regarding the appearance of impact-resistant styrene-based resin compositions. Furthermore, gloss and impact strength are crucial properties of these compositions, and the need to improve the balance between these two seemingly contradictory properties remains significant. Regarding improving the balance between gloss and impact strength, reducing the amount of gelling of the conjugated diene polymer used as rubber particles can be considered. This is because less gelling occurs, and all added conjugated diene polymers participate in the graft polymerization.

[0004] For example, Patent Document 1 proposes to suppress gelation in rubber particles by mixing a specific sulfur-containing phenolic stabilizer into a specific low-cis-conjugated diene polymer obtained by continuous polymerization.

[0005] Patent document 2 proposes a conjugated diene polymer with good appearance, which reduces gel formation in continuous polymerization by lowering the temperature at which the monomer is supplied to the polymerization reactor.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 11-228742

[0009] Patent Document 2: Japanese Patent Application Publication No. 2014-108977 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, for the conjugated diene polymers described above, there is still room for improvement in order to fully satisfy the balance between the appearance, gloss and impact strength of the improved impact-resistant polystyrene polymer.

[0012] Therefore, in order to solve the above-mentioned problems, the object of the present invention is to provide a conjugated diene polymer that provides an excellent balance between appearance, gloss and impact strength in an impact-resistant styrene resin composition, a method for manufacturing the conjugated diene polymer and an impact-resistant styrene resin composition comprising the conjugated diene polymer.

[0013] Methods for solving problems

[0014] In order to solve the above-mentioned problems, the inventors conducted in-depth research and completed this invention.

[0015] That is, the present invention is as follows.

[0016] <1>

[0017] A conjugated diene polymer, wherein the cumulative luminescence of the weak luminescence produced by the chemical reaction is 150 × 10⁻⁶. 5 Below cps, the Δb value before and after heating at 160℃ for 2 hours is below 4.0.

[0018] <2>

[0019] According to the conjugated diene polymer described in <1> above, the viscosity (SV) of the 5% by mass styrene solution of the conjugated diene polymer at 25°C is 50 < SV ≤ 75 (mPa·s).

[0020] <3>

[0021] According to the conjugated diene polymer described in <1> above, the viscosity (SV) of the 5% by mass styrene solution of the conjugated diene polymer at 25°C is 75 < SV ≤ 280 (mPa·s).

[0022] <4>

[0023] The conjugated diene polymer according to any one of <1> to <3> above, wherein the P (phosphorus) content of the conjugated diene polymer is 20 ppm or less.

[0024] <5>

[0025] The conjugated diene polymer according to any one of <1> to <4> above, wherein the Δb value is 3.0 or less.

[0026] <6>

[0027] The conjugated diene polymer according to any one of <1> to <5> above, wherein the cumulative luminescence intensity is 40 × 10⁻⁶. 5 Below CPS.

[0028] <7>

[0029] The conjugated diene polymer according to any one of <1> to <6> above, wherein the molecular weight distribution (Mw / Mn) of the conjugated diene polymer as determined by GPC (gel permeation chromatography) is 1.5 or more and 2.5 or less.

[0030] <8>

[0031] The conjugated diene polymer according to any one of <1> to <7> above, wherein the conjugated diene polymer is polybutadiene.

[0032] <9>

[0033] The conjugated diene polymer according to any one of <1> to <8> above, wherein the conjugated diene polymer is polybutadiene for impact-resistant styrene polymer compositions.

[0034] <10>

[0035] A method for manufacturing a conjugated diene polymer, comprising: Polymerization process: 1,3-Butadiene or 1,3-butadiene and aromatic vinyl compounds, along with an inert solvent, are continuously fed into a polymerization reactor, where an organolithium compound is used as an initiator for continuous polymerization to obtain a conjugated diene polymer with active ends; and The following procedures (1) to (3): (1) Deactivator addition step: adding a deactivator to deactivate the active polymerization end of the above-mentioned conjugated diene polymer containing active ends; (2) Neutralizer addition process, adding a neutralizer to neutralize lithium hydroxide; (3) Stabilizer addition process, adding stabilizer.

[0036] <11>

[0037] According to the method for manufacturing conjugated diene polymers described in <10> above, the above-described deactivator addition step, the above-described neutralizer addition step, and the above-described stabilizer addition step are performed sequentially.

[0038] <12>

[0039] An impact-resistant styrene-based polymer composition comprising any one of the conjugated diene polymers described in <1> to <9> above.

[0040] Invention Effects

[0041] According to the present invention, a conjugated diene polymer that provides an excellent balance between appearance, gloss and impact strength in an impact-resistant styrene resin composition, a method for manufacturing the conjugated diene polymer, and an impact-resistant styrene resin composition comprising the conjugated diene polymer are provided. Detailed Implementation

[0042] Hereinafter, specific embodiments of the present invention (hereinafter referred to as "this embodiment") will be described in detail. The following embodiments are illustrative of the present invention and are not intended to limit the present invention to the following content. The present invention can be appropriately modified and implemented within the scope of its essential points.

[0043] [Conjugated diene polymers]

[0044] The cumulative luminescence of the conjugated diene polymer in this embodiment, which exhibits weak luminescence due to chemical reaction, is 150 × 10⁻⁶. 5 The cps are below 4.0, and the Δb value before and after heating at 160°C for 2 hours is below 4.0. Although there are no particular limitations, polybutadiene can be cited as an example of a conjugated diene polymer in this embodiment, and further, polybutadiene for impact-resistant styrene polymer compositions can be cited.

[0045] (Cumulative luminescence)

[0046] The cumulative luminescence (hereinafter sometimes simply referred to as "cumulative luminescence") of the conjugated diene polymer in this embodiment, which exhibits weak luminescence due to chemical reaction, is 150 × 10⁻⁶. 5 Below cps, preferably 75×10 5 cps, preferably 40×10 5 Below cps. Here, "cumulative luminescence of weak luminescence produced by chemical reactions in conjugated diene polymers" refers to the total luminescence produced by oxidation reactions in the detected conjugated diene polymers. Cumulative luminescence can be determined, for example, by the following methods.

[0047] The apparatus used for measuring cumulative luminescence employs an extremely weak luminescence detection spectrophotometer (manufactured by Tohoku Electronics Industry Co., Ltd.: CLA-FS4) and a heated sample chamber (manufactured by Tohoku Electronics Industry Co., Ltd.: CLS-SH1). Under an oxygen atmosphere of 50 ml / min, the temperature is increased from the initial measurement temperature of 50°C to 200°C at a rate of 20°C / min. The temperature is then maintained at 200°C for 10 minutes after the start of heating. The total luminescence emitted during these 10 minutes is taken as the cumulative luminescence. This measures the luminescence caused by the oxidation reaction of conjugated diene polymers when heated in air or oxygen. In other words, higher luminescence indicates a more extensive oxidation reaction, suggesting poorer thermal stability. Impact-resistant styrene polymer compositions made using conjugated diene polymers with poor thermal stability tend to exhibit a deterioration in the balance between gloss and impact strength.

[0048] (Δb value)

[0049] "b-value" is a value related to color difference, representing the intensity of a hue for yellow and blue-violet. In the conjugated diene polymer of this embodiment, "Δb-value before and after heating at 160°C for 2 hours" (hereinafter sometimes simply referred to as "Δb-value") refers to the difference between the b-value before heating and the b-value after heating at 160°C for 2 hours. Detailed conditions are described in the examples.

[0050] In this embodiment, the Δb of the conjugated diene polymer is 4.0 or less, preferably 3.0 or less. Within this range, there is a tendency to obtain impact-resistant styrene polymer compositions with excellent appearance and low yellowing when preparing such compositions.

[0051] (5% by mass styrene solution viscosity (SV))

[0052] The conjugated diene polymer of this embodiment can be defined as having a viscosity (hereinafter sometimes simply referred to as "SV") of 5% by mass of a styrene solution at a measurement temperature of 25°C, which is 50 < SV ≤ 75 (mPa·s). "Viscosity of 5% by mass of a styrene solution at a measurement temperature of 25°C" refers to the value obtained by measuring a 5% by mass solution of the conjugated diene polymer in styrene at 25°C using a Canon-Fensk viscometer. SV can be measured using the method described in the examples below. Using a conjugated diene polymer with SV in this range readily yields impact-resistant styrene polymer compositions with small rubber particles and a tendency towards excellent gloss. From this perspective, 55 ≤ SV ≤ 75 (mPa·s) is preferred as SV, and more preferably 60 ≤ SV ≤ 70 (mPa·s).

[0053] Furthermore, the conjugated diene polymer of this embodiment can achieve an SV of 75 < SV ≤ 280 (mPa·s). Using a conjugated diene polymer with an SV in this range readily yields impact-resistant styrene polymer compositions with large rubber particles, exhibiting excellent impact resistance. From this perspective, an SV of 85 ≤ SV ≤ 250 (mPa·s) is preferred, and an SV of 140 ≤ SV ≤ 180 (mPa·s) is more preferable.

[0054] (Molecular weight, molecular weight distribution)

[0055] The conjugated diene polymer of this embodiment preferably has a mass-average molecular weight (Mw) of 200,000 to 800,000, more preferably 250,000 to 700,000, and even more preferably 300,000 to 600,000, as determined by gel permeation chromatography (GPC). From the perspective of suppressing cold flow in the obtained conjugated diene polymer, Mw is preferably 200,000 or more; furthermore, from the perspective of its correlation with the solution viscosity of the conjugated diene polymer, Mw is preferably 800,000 or less.

[0056] Furthermore, from the perspective of improving productivity, it is preferable that the ratio of mass-average molecular weight (Mw) to number-average molecular weight (Mn) (molecular weight distribution: Mw / Mn) is 1.5 or more and 2.5 or less. If the molecular weight distribution of the conjugated diene polymer is within this range, it tends to exhibit an excellent balance between gloss and impact strength when preparing impact-resistant styrene polymer compositions. Additionally, when the conjugated diene polymers of this embodiment exhibit the same molecular weight distribution (SV), a larger molecular weight distribution tends to result in better cold flow properties. Typically, to improve cold flow properties, methods such as using coupling agents or other methods to introduce branched components are employed during polymerization. However, this method increases the amount of polymerization initiator used, increasing the cost of both the polymerization initiator and the coupling agent; therefore, a large molecular weight distribution is preferred. Here, a large molecular weight distribution refers to a molecular weight distribution of 1.5 or more.

[0057] Mooney viscosity

[0058] The conjugated diene polymer of this embodiment can enable the determination of Mooney viscosity (ML) at a temperature of 100°C. 1+4 The value is between 25 and 100. This is achieved by adjusting the Mooney viscosity (ML) to a value between 25 and 100. 1+4 A Mooney viscosity of 25 or higher indicates a tendency to further suppress cold flow. Furthermore, considering the briquetting properties during industrial production, the Mooney viscosity (ML)... 1+4 The value is preferably below 100.

[0059] Preferred Mooney viscosity (ML) 1+4The value is 30 to 80, more preferably 30 to 75, and even more preferably 40 to 60 from the perspective of gloss and impact resistance when making the impact-resistant styrene resin composition, and the mixing and stirring of the raw materials of the impact-resistant styrene resin composition.

[0060] (P content)

[0061] The phosphorus (P) content of the conjugated diene polymer in this embodiment is preferably 150 ppm, more preferably 100 ppm or less, more preferably 50 ppm or less, and particularly preferably P-free. Here, "P-free" means that the P content is 20 ppm or less. P mostly exists in conjugated diene polymers in the form of phosphate esters, which are expected to improve color tone. Sometimes it hydrolyzes to produce phosphoric acid, which can corrode metals and cause rusting, or it can be polluting. In addition, substances with added phosphate esters are prone to slippage. For example, after polymerization, the extruder may slip during the dehydration process using stripping to remove the solvent, resulting in a conjugated diene polymer containing a large amount of water, or requiring more time to dry than usual. If the water content in the conjugated diene polymer increases, for example, when polymerizing impact-resistant styrene polymers, the desired impact-resistant styrene polymer may not be obtained.

[0062] [Methods for manufacturing conjugated diene polymers]

[0063] The conjugated diene polymer of this embodiment can be synthesized, for example, by the following manufacturing method. The manufacturing method of the conjugated diene polymer of this embodiment (hereinafter sometimes referred to as "the manufacturing method of this embodiment") includes a polymerization step: continuously feeding 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound and an inert solvent into a polymerization reactor, continuously polymerizing with an organolithium compound as an initiator to obtain a conjugated diene polymer containing active ends; and the following steps (1) to (3).

[0064] (1) Deactivator addition process, adding a deactivator to deactivate the active polymerization end of the conjugated diene polymer containing active ends; (2) Neutralizer addition process, adding a neutralizer to neutralize lithium hydroxide; (3) Stabilizer addition process, adding stabilizer.

[0065] The manufacturing method of this embodiment may also include other processes before and after each process. In addition, after the polymerization process, the order of processes (1) to (3) (especially the order of processes (1) and (2)) is not limited, and any one of them can be performed first, or they can be performed simultaneously.

[0066] The cumulative luminescence of the conjugated diene polymer in this embodiment can be adjusted by controlling the order of each addition step and the amount of stabilizer added.

[0067] Regarding the "Δb value" of the conjugated diene polymer in this embodiment, apart from the amount of stabilizer added and the order of each addition step, it can be adjusted, for example, by replacing the neutralizer addition step, or by performing a deashing step to remove metals from the conjugated diene polymer solution based on the neutralizer addition step and controlling the conditions of that step.

[0068] <Polymerization Process>

[0069] In the manufacturing method of this embodiment, during the polymerization step, monomers (1,3-butadiene alone or 1,3-butadiene and aromatic vinyl compounds) and inert solvents are continuously supplied to the polymerization reactor, and an organolithium compound is used as an initiator to continuously (co)polymerize the monomers, thereby obtaining a conjugated diene polymer with active ends.

[0070] The aforementioned conjugated diene polymers are homopolymers of 1,3-butadiene or copolymers of 1,3-butadiene and aromatic vinyl compounds.

[0071] In the manufacturing method of this embodiment, by supplying monomers and inert solvents to a polymerization reactor, the monomers are continuously polymerized, and a polymer with a wide molecular weight distribution can be obtained.

[0072] (Polymerization temperature)

[0073] In the manufacturing method of this embodiment, from the perspective of efficient production, the polymerization temperature is preferably 70°C or higher, and from the perspective of reducing side reactions, it is preferably 130°C or lower.

[0074] (Polymerization reactor)

[0075] In the manufacturing method of this embodiment, the shape of the polymerization reactor is not particularly limited, and for example, a tank-type, tube-type, or tower-type reactor with a stirrer can be used.

[0076] The form of the polymerization reactor is not particularly limited; for example, it can be a completely mixed reactor or a plug flow reactor. The aforementioned reactors include those located midway through the pipeline for transport. The aforementioned plug flow reactors are not particularly limited and include static mixers and dynamic mixers with stirring functions.

[0077] In the manufacturing method of this embodiment, one or more reactors connected in parallel or in series can be used.

[0078] (Aromatic vinyl compounds)

[0079] In the manufacturing method of this embodiment, the aromatic vinyl compound is not particularly limited as long as it is a monomer capable of copolymerizing with a conjugated diene compound, especially 1,3-butadiene. Examples include styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, and diphenylethylene. Styrene is preferred from the perspective of industrial availability. Furthermore, from the perspective of preventing cold flow of the polymer obtained through the polymerization process, multifunctional aromatic vinyl compounds such as divinylbenzene for controlling branching can be used. One type can be used alone, or two or more can be used in combination.

[0080] (organolithium compounds)

[0081] In the manufacturing method of this embodiment, the organolithium compound used as a polymerization initiator is not particularly limited, and examples include mono-organolithium compounds and multifunctional organolithium compounds.

[0082] Examples of single organolithium compounds include, but are not limited to, low molecular weight compounds, soluble oligomer organolithium compounds, compounds having carbon-lithium bonds in the form of bonding between organic groups and lithium, and compounds having nitrogen-lithium bonds.

[0083] As a carbon-lithium compound, there are no particular limitations; examples include n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and lithium mesodephenylethylene.

[0084] As a compound with a nitrogen-lithium bond, there are no particular limitations; examples include lithium dimethylamino, lithium diethylamino, lithium dipropylamino, lithium di-n-hexylamino, lithium diisopropylamino, lithium hexamethyleneimino, lithium pyrrolidine, lithium piperidinium, lithium heptamethyleneimino, lithium morpholine, etc.

[0085] As a multifunctional organolithium compound, there are no particular limitations. Examples include 1,4-dilithium butane, the reaction product of sec-butyllithium and diisopropenylbenzene, 1,3,5-trilithiumbenzene, the reaction product of n-butyllithium with 1,3-butadiene and divinylbenzene, and the reaction product of n-butyllithium with polyacetylene compounds.

[0086] As an organoalkali metal compound, there is no particular limitation; for example, known organoalkali metal compounds disclosed in U.S. Patent No. 5,708,092, British Patent No. 2,241,239, U.S. Patent No. 5,527,753 may also be used.

[0087] From the perspective of ease of industrial acquisition and ease of controlling the polymerization reaction, n-butyllithium and sec-butyllithium are preferred as organolithium compounds.

[0088] Organic lithium compounds can be used alone or in combination of two or more.

[0089] (Polymerization solvent (inert solvent))

[0090] In the manufacturing method of this embodiment, the polymerization reaction of the monomer is carried out in an inert solvent.

[0091] Inert solvents are not particularly limited; examples include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. They are not limited to the following substances; specifically, examples include aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; and hydrocarbons composed of mixtures thereof.

[0092] (Propylene derivatives)

[0093] In the manufacturing method of this embodiment, from the perspective of improving the effect of inhibiting gel formation, it is preferable to coexist the propylene compounds, monomers, and inert solvents in the polymerization system. On the other hand, in order to ensure that the coupling reaction proceeds sufficiently and to obtain the required degree of branching, it is preferable to control the total concentration (by mass) of propylene compounds in the polymerization system within a specific range. The total concentration (by mass) of propylene compounds relative to the monomers is preferably 50 ppm to 350 ppm, more preferably 60 ppm to 300 ppm, and even more preferably 70 ppm to 250 ppm.

[0094] Examples of alladienes include, for example, alladiene and 1,2-butadiene.

[0095] (Other additives)

[0096] To induce random copolymerization of butadiene with aromatic vinyl compounds, or to control the amount of 1,2-vinyl bonds in butadiene bonding units, or to promote the polymerization reaction, polar compounds can be added to the polymerization reactor.

[0097] There are no particular limitations on polar compounds. For example, ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis(2-tetrahydrofuranyl)propane can be used; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinyl ethane, trimethylamine, triethylamine, pyridine, and quinine ring; alkali metal alkoxides such as potassium tert-pentoxide, potassium tert-butoxide, sodium tert-butoxide, and sodium pentanol; and phosphine compounds such as triphenylphosphine.

[0098] These polar compounds can be used alone or in combination of two or more.

[0099] The amount of polar compound used is not particularly limited and can be selected according to the purpose, etc. Specifically, it is preferably 0.01 mol to 100 mol relative to 1 mol of polymerization initiator. Such polar compound (vinylating agent) can be used as a regulator of the microstructure of the butadiene moiety of the polymer, depending on the desired amount of vinyl bonding. Most polar compounds also have an effective randomizing effect in the copolymerization of butadiene and aromatic vinyl compounds, and can be used as a distribution regulator of aromatic vinyl compounds or a regulator of the amount of styrene blocks. As a method for randomizing butadiene and aromatic vinyl compounds, for example, a copolymerization reaction can be initiated using a portion of styrene and 1,3-butadiene, with the remaining 1,3-butadiene added intermittently during the copolymerization reaction.

[0100] (Conjugated diene polymers with active ends)

[0101] In the manufacturing method of this embodiment, as described above, a conjugated diene polymer containing active ends is obtained in the polymerization process.

[0102] The microstructure of the butadiene moiety in the aforementioned conjugated diene polymers is not particularly limited, but it is preferred that the 1,2-vinyl content is between 10% and 80% and the cis-1,4- content is between 10% and 85%. In particular, in its use as a modifier for styrene-based resins, the 1,2-vinyl content is preferably between 10% and 25%.

[0103] Regarding the method for adjusting the 1,2-vinyl content mentioned above, polar compounds as described above can be used. For example, in the polymerization process, this can be achieved by feeding ethers such as tetrahydrofuran (THF) together with monomers and inert solvents into the reactor for polymerization.

[0104] Here, regarding the amount of vinyl bonds (1,2-bonds) in the butadiene bonded unit, when the aromatic vinyl compound in the manufacturing method of this embodiment is styrene, the amount of vinyl bonds (1,2-bonds) in the butadiene bonded unit can be determined by the Hampton method (RR Hampton, Analytical Chemistry, 21, 923 (1949)).

[0105] In addition, the amount of bonded aromatic vinyl groups in the conjugated diene polymer is not particularly limited, but is preferably 0% to 20% by mass, more preferably 1% to 10% by mass.

[0106] Here, the amount of bonded aromatic vinyl groups can be determined by ultraviolet absorption of the phenyl group.

[0107] In this embodiment, when two or more monomers are used, the conjugated diene polymer (copolymer) with active ends can be a random copolymer or a block copolymer.

[0108] The compositional distribution of monomer units in a random copolymer chain is not particularly limited. Examples include completely random copolymers with a statistically close random composition and progressive (gradient) random copolymers with a gradually changing composition. The bonding forms of butadiene, such as 1,4-bonds and 1,2-bonds, can be homogeneous or distributed.

[0109] Examples of block copolymers include type 2 block copolymers (diblock copolymers) consisting of two blocks, type 3 block copolymers (triblock copolymers) consisting of three blocks, and type 4 block copolymers (tetrablock copolymers) consisting of four blocks. For example, if the blocks composed of aromatic vinyl compounds such as styrene are represented by "S" and the blocks composed of butadiene are represented by "B", then the block copolymers can be represented as SB type 2 block copolymers, SBS type 3 block copolymers, SBSB type 4 block copolymers, etc.

[0110] In the above formula, the composition of each block does not necessarily have to be uniform. For example, block B can be a copolymer of butadiene and an aromatic vinyl compound.

[0111] Furthermore, similarly, the boundaries of each block in the above formula do not necessarily need to be clearly distinguished. For example, if block B is a copolymer of butadiene and aromatic vinyl compounds, the aromatic vinyl compounds in block B can be uniformly distributed or gradually distributed. Additionally, in block B, there can be two or more uniformly distributed and / or gradually distributed portions of aromatic vinyl compounds. Moreover, in block B, there can be two or more segments with different amounts of aromatic vinyl compounds. In copolymers where blocks S and B each exist in multiples, their molecular weights, compositions, and other structures can be the same or different. Here, the compositional distribution of the monomers can be determined by osmium tetroxide decomposition or ozone decomposition methods.

[0112] <Coupled Process>

[0113] The manufacturing method of this embodiment may include a coupling step. The coupling step may be performed between the polymerization step and the deactivator addition step.

[0114] In the coupling process, the coupling agent shown in the following formula (1) is continuously added to the active end of the above conjugated diene polymer to react with it, so that branched conjugated diene polymers can be continuously obtained.

[0115] [Chemistry 1]

[0116] (In formula (1), R independently represents an alkyl group with 1 to 10 carbon atoms or an aryl group with 6 to 10 carbon atoms. n is an integer of 0 or 1.)

[0117] In the manufacturing method of this embodiment, a polymer with a wide molecular weight distribution can be obtained by continuously carrying out the above coupling reaction.

[0118] (Coupled agent)

[0119] In the manufacturing method of this embodiment, by using the coupling agent shown in the above formula (1), it is possible to manufacture a conjugated diene polymer that does not contain halogen compounds and has an excellent appearance.

[0120] Examples of coupling agents mentioned above include, but are not limited to, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, etc.

[0121] Among them, tetramethoxysilane and tetraethoxysilane are preferred from the perspectives of ease of industrial acquisition and ease of branching reaction.

[0122] These compounds can be used directly or dissolved in a solvent. When using a solvent, a hydrocarbon solvent that is inert to the active ends of the aforementioned linear butadiene polymers is preferred. Examples of hydrocarbon solvents include benzene, toluene, cyclohexane, and n-hexane.

[0123] (Amount of coupling agent added)

[0124] In the manufacturing method of this embodiment, the amount of the coupling agent added is not particularly limited. Relative to 1 mole of the polymerization initiator, it is preferably 0.1 moles or more and 0.6 moles or less, more preferably 0.13 moles or more and 0.5 moles or less, and even more preferably 0.15 moles or more and 0.4 moles or less. To ensure sufficient branching degree of the conjugated diene polymer, it is preferably 0.1 moles or more. Furthermore, to avoid reducing the branching degree and increasing costs, it is preferably 0.6 moles or less when adding a necessary amount of coupling agent.

[0125] (Coupling reactor)

[0126] In the manufacturing method of this embodiment, the shape of the coupling reactor is not particularly limited, and for example, a tank-type, tube-type, or tower-type reactor with a stirrer can be used.

[0127] The form of the coupled reactor is not particularly limited; for example, it can be a completely mixed reactor or a plug flow reactor. The aforementioned reactors include those located midway through the pipeline for transport. The aforementioned plug flow reactors are not particularly limited and include static mixers and dynamic mixers with stirring functions.

[0128] (Coupling reaction temperature)

[0129] The coupling reaction temperature in the manufacturing method of this embodiment is not particularly limited, but is preferably 50°C to 130°C, more preferably 60°C to 120°C. In order to prevent the active end from being deactivated and to carry out the coupling reaction efficiently, it is preferable to carry out the reaction at 130°C or below. In addition, from the perspective of the coupling reaction rate, it is preferable to carry out the reaction at 50°C or above.

[0130] (Coupled reaction time)

[0131] The reaction time for the coupling agent to react with the active end of the linear butadiene polymer is not particularly limited. From the perspective of coupling reaction rate, the reaction time is preferably 30 seconds to 120 minutes, more preferably 1 minute to 60 minutes, and even more preferably 2 minutes to 45 minutes. Here, the coupling reaction time refers to the average residence time of the linear butadiene polymer containing the active end in the coupling process.

[0132] (Removal of impurities)

[0133] For example, when monomers and acetylenes contained as impurities in inert solvents are treated with organometallic compounds before polymerization, there is a tendency to obtain polymers with high concentrations of active terminals, and thus a tendency to achieve high coupling rates, which is preferred.

[0134] [Deactivating agent addition process]

[0135] The deactivating agent addition process is, for example, the process of adding a deactivating agent to a solution of the obtained conjugated diene polymer after a polymerization reaction or a coupling reaction, in order to deactivate the active polymeric ends of the conjugated diene containing active ends.

[0136] The deactivating agent mentioned above is not particularly limited; examples include water, methanol, ethanol, isopropanol, and other alcohols. Water is preferred due to its readily available availability.

[0137] (Amount of deactivating agent added)

[0138] In the manufacturing method of this embodiment, the amount of the deactivating agent added is not particularly limited. It is preferably 5 to 50 parts by mass relative to 100 parts by mass of the polymer having active ends, more preferably 7 to 30 parts by mass, and even more preferably 10 to 20 parts by mass. To suppress side reactions caused by polymerically active lithium, the deactivating agent is preferably 5 parts by mass or more, and for cost-effectiveness, it is preferably 50 parts by mass or less.

[0139] [Neutralizer Addition Process]

[0140] The neutralizing agent addition step is the process of adding a neutralizing agent to the solution of the resulting conjugated diene polymer after polymerization or coupling reactions to neutralize lithium hydroxide. Lithium hydroxide is generated, for example, by the reaction of an organolithium phosphate initiator with a deactivating agent.

[0141] The neutralizing agents mentioned above are not particularly limited. Examples include benzoic acid, stearic acid, oleic acid, neodecanoic acid (a mixture of multi-branched carboxylic acids with 9 to 11 carbon atoms, with 10 as the central component), aqueous solutions of inorganic acids, carbon dioxide, etc.

[0142] Lithium reacting with the deactivating agent tends to worsen the aforementioned Δb by reacting with the stabilizer described later. By adding a neutralizing agent, which reacts with lithium, the lithium reacting with the neutralizing agent does not react with the stabilizer, thus suppressing the deterioration of Δb.

[0143] Carbon dioxide is preferred as a neutralizing agent, provided that no unreacted neutralizing agent remains in the conjugated diene polymer.

[0144] (Amount of neutralizing agent added)

[0145] In the manufacturing method of this embodiment, the amount of the neutralizing agent added is not particularly limited. It is preferably 0.5 to 5.0 moles or less, more preferably 0.8 to 3.0 moles or less, and even more preferably 1.0 to 2.0 moles or less, relative to 1 mole of the polymerization initiator. For appearance reasons, the neutralizing agent is preferably 0.5 moles or more; for manufacturing cost reasons, the neutralizing agent is preferably 5.0 moles or less.

[0146] [Stabilizer Addition Process]

[0147] The stabilizer addition step is a process in which a stabilizer is added to a solution of the obtained conjugated diene polymer after the polymerization reaction or coupling reaction. Stabilizers can be categorized as such, and it is preferable to add a stabilizer to the obtained conjugated diene polymer to suppress gel formation caused by thermal processes such as extruders and to improve stability during processing.

[0148] There are no particular limitations on the stabilizer used; known stabilizers such as phenolic stabilizers, phosphorus stabilizers, and sulfur-containing phenolic compounds can be used. Only one compound that can be used as a stabilizer may be used, or two or more may be used in combination.

[0149] As a phenolic stabilizer, there are no particular limitations. Examples include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, octadecyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, 2,2-methylene-bis-(4-methyl-6-tert-butylphenol), and 2,2-ethyl-bis-(4-methyl-6-tert-butylphenol).

[0150] As a phosphorus-based stabilizer, there are no particular limitations; for example, there are tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, and cyclic neopentanetetramethylbis(octadecyl phosphite).

[0151] Regarding the amount of phenolic and phosphorus-based stabilizers added, when carbon dioxide is used as the neutralizing agent, the amounts relative to 100 parts by weight of the conjugated diene polymer are preferably 0.15 parts by weight to 5.0 parts by weight, more preferably 0.20 parts by weight to 3.0 parts by weight, further preferably 0.25 parts by weight to 1.0 parts by weight, and even more preferably 0.45 parts by weight to 0.8 parts by weight, respectively. Furthermore, when carbon dioxide is not used as the neutralizing agent, the amounts of phenolic and phosphorus-based stabilizers relative to 100 parts by weight of the conjugated diene polymer are preferably 0.01 parts by weight to 5.0 parts by weight, more preferably 0.1 parts by weight to 3.0 parts by weight, further preferably 0.25 parts by weight to 1.0 parts by weight, and even more preferably 0.45 parts by weight to 0.8 parts by weight, respectively.

[0152] From the perspective of reducing cumulative luminescence and Δb value, the addition amount of phenolic stabilizer and phosphorus stabilizer is preferably 0.01 parts by mass or more, and from the perspective of manufacturing cost, it is preferably 5.0 parts by mass or less.

[0153] As a sulfur-containing phenolic stabilizer, there are no particular limitations, such as 2,4-bis(n-octylthiomethyl)-6-methylphenol, 2,4-bis(2',3'-dihydroxypropylthiomethyl)-3,6-dimethylphenol, 2,4-bis(2'-acetoxyethylthiomethyl)-3,6-dimethylphenol, etc.

[0154] The amount of sulfur-containing phenolic stabilizer added relative to 100 parts by weight of the conjugated diene polymer is preferably 0.01 parts by weight or more and 2.0 parts by weight, more preferably 0.10 parts by weight or more and 1.5 parts by weight, and even more preferably 0.13 parts by weight or more and 1.0 parts by weight.

[0155] From the perspective of reducing cumulative luminescence and Δb value, the amount of sulfur-containing phenolic stabilizer added is 0.01 parts by mass or more, and from the perspective of manufacturing cost and odor, it is preferably 2.0 parts by mass or less.

[0156] Regarding the order of the deactivator addition step, the neutralizer addition step, and the stabilizer addition step, it is preferable to perform them in the order of deactivator addition, neutralizer addition, and stabilizer addition. Polymerized active lithium reacts with the deactivator, and its reactant (lithium hydroxide) reacts with the neutralizer, thereby inhibiting the reaction between lithium and the stabilizer. Δb is improved by inhibiting the reaction between lithium and the stabilizer. Furthermore, by inhibiting the reaction between lithium and the stabilizer, a conjugated diene polymer containing a stabilizer amount equivalent to the amount added can be obtained.

[0157] <Methods for obtaining conjugated diene polymers>

[0158] In the manufacturing method of this embodiment, the method for obtaining the conjugated diene polymer from the polymer solution is not particularly limited, and known methods can be used. Examples include: separating the solvent by stripping or the like, filtering out the polymer, and further dehydrating and drying it to obtain the polymer; concentrating it in a flash tank and then performing devolatilization using an exhaust extruder or the like; directly performing devolatilization using a rotary dryer or the like; and so on.

[0159] (Hydrogenation reaction)

[0160] In the manufacturing method of this embodiment, a step can be included to convert all or part of the double bonds into saturated hydrocarbons by further hydrogenating the conjugated diene polymer in an inert solvent. From the perspective of improving heat resistance and weather resistance, and preventing product deterioration during processing at high temperatures, such a step is preferred, resulting in the product exhibiting superior performance in various applications such as automotive applications.

[0161] More specifically, the hydrogenation rate of the unsaturated double bond in butadiene (sometimes referred to as "hydrogenation rate" below) can be arbitrarily chosen according to the purpose, without any particular limitation.

[0162] When used as a rubber for modifying resins such as impact-resistant styrene-based resin compositions, it is preferable that the double bonds of the butadiene portion remain partially. From this perspective, the hydrogenation rate of the butadiene portion in the conjugated diene polymer is preferably 3% to 70%, more preferably 5% to 65%, and even more preferably 10% to 60%.

[0163] It should be noted that when the conjugated diene polymer contains monomer units based on aromatic vinyl compounds, the hydrogenation rate of the aromatic double bond based on the aromatic vinyl compound is not particularly limited, but is preferably 50% or less, more preferably 30% or less, and even more preferably 20% or less. The hydrogenation rate can be determined by nuclear magnetic resonance (NMR) or the like.

[0164] The method of hydrogenation is not particularly limited, and known methods can be used. A particularly preferred method is hydrogenation by blowing gaseous hydrogen into a polymer solution in the presence of a catalyst. Examples of catalysts include heterogeneous catalysts such as catalysts that support noble metals on porous inorganic materials; catalysts that soluble salts of nickel, cobalt, etc., and react with organoaluminum compounds; and homogeneous catalysts that use metallocene catalysts such as titanocene. Among these, titanocene catalysts are particularly preferred from the perspective of being able to select mild hydrogenation conditions. Furthermore, the hydrogenation of aromatic groups can be carried out using catalysts supported on noble metals.

[0165] Specific examples of hydrogenation catalysts include: (1) supported heterogeneous hydrogenation catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silicon oxide, aluminum oxide, diatomaceous earth, etc.; (2) so-called Ziegler-type hydrogenation catalysts using transition metal salts such as organic acid salts of Ni, Co, Fe, and Cr or acetylacetone salts and reducing agents such as organoaluminum; (3) so-called organometallic complexes such as organometallic compounds of Ti, Ru, Rh, and Zr; etc. For example, as hydrogenation catalysts, known hydrogenation catalysts described in Japanese Patent Publication Nos. 42-8704, 43-6636, 63-4841, 1-37970, 1-53851, 2-9041, and 8-109219 can be used. As a preferred hydrogenation catalyst, a reaction mixture of a titanium cadmium compound and a reducing organometallic compound can be cited.

[0166] The conjugated diene polymer composition of this embodiment also includes a conjugated diene polymer composition containing 0.01 to 0.5 parts by mass of organic fatty acids relative to 100 parts by mass of the above-mentioned conjugated diene polymer.

[0167] There are no specific limitations on organic fatty acids, including capric acid, lauric acid, myristic acid, pentadecanoic acid, palmitic acid, palmitoleic acid, heptadecanoic acid, stearic acid, oleic acid, isoleic acid, linoleic acid, succinic acid, citric acid, malic acid, etc.

[0168] From the perspective of ensuring the demolding properties of the rubber in the extruder and not hindering the free radical polymerization during the manufacture of the impact-resistant styrene-based resin composition, the total content of organic fatty acids is preferably 0.01 parts by mass or more and 0.5 parts by mass or less per 100 parts by mass of the conjugated diene polymer.

[0169] [Impact-resistant styrene-based polymer composition]

[0170] When the conjugated diene polymer of this embodiment is used for the modification of styrene resins such as impact-resistant polystyrene polymer compositions, the conjugated diene polymer of this embodiment can be used alone or blended with linear butadiene polymers or styrene-butadiene copolymers.

[0171] Impact-resistant styrene-based polymer compositions can be manufactured using the conjugated diene polymer of this embodiment, for example, by bulk polymerization. Specifically, styrene and the conjugated diene polymer of this embodiment are added to a reactor equipped with a stirrer, and stabilizers, chain transfer agents, etc., are added as needed. The mixture is stirred and dissolved to prepare a pre-polymerization solution. A catalyst such as di-tert-butyl peroxide is added to the solution as needed, and the mixture is heated to carry out polymerization, thereby obtaining the impact-resistant styrene-based polymer composition.

[0172] There are no particular limitations on the method for manufacturing impact-resistant styrene-based resin compositions, as long as the technical features of this embodiment can be satisfied, and known methods can be used.

[0173] Typically, the preferred method is as follows: a rubber solution is obtained by dissolving a conjugated diene polymer (1) or a random copolymer (2) in an aromatic vinyl monomer or a mixture of an aromatic vinyl monomer and a monomer capable of copolymerizing therewith; while stirring the rubber solution to apply shear stress, a polymerization process such as bulk polymerization, bulk suspension polymerization or solution polymerization is carried out to perform graft polymerization, thereby obtaining an impact-resistant styrene resin composition in which rubber particles are dispersed in a matrix formed by an aromatic vinyl monomer or a copolymer of an aromatic vinyl monomer and a monomer capable of copolymerizing therewith.

[0174] Aromatic vinyl monomers used in the manufacturing method of impact-resistant styrene-based resin compositions include, for example, α-alkyl-substituted styrene such as styrene, vinylnaphthalene, α-methylstyrene, α-ethylstyrene, and α-methyl-p-methylstyrene; styrene with alkyl substituents on the ring such as m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ethylvinylbenzene, and p-tert-butylstyrene; halosterstyrene such as monochlorostyrene, dichlorostyrene, tribromostyrene, and tetrabromostyrene; and p-hydroxystyrene and o-methoxystyrene. They can be used individually or as a mixture of two or more. Among these, styrene, α-methylstyrene, and p-methylstyrene are preferred.

[0175] Other copolymerizable monomers besides aromatic vinyl monomers include monomers selected from unsaturated nitrile monomers, (meth)acrylates, and other copolymerizable monomers.

[0176] Examples of unsaturated nitrile monomers include, but are not limited to, acrylonitrile and methacrylonitrile. They can be used alone or as a mixture of two or more. Acrylonitrile is particularly preferred.

[0177] Examples of (meth)acrylates include, but are not limited to, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, dodecyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, dodecyl methacrylate, and cyclohexyl methacrylate. They can be used alone or as a mixture of two or more. Methyl methacrylate is particularly preferred.

[0178] Other copolymerizable monomers include, but are not limited to, acrylic acid, methacrylic acid, vinyl acetate, maleic anhydride, N-methylmaleimide, N-phenylmaleimide, etc.

[0179] In addition, in the method for manufacturing impact-resistant styrene-based resin compositions, an inert solvent may be added to the above-mentioned aromatic vinyl monomer or a mixture of aromatic vinyl monomer and monomers capable of copolymerizing therewith for polymerization.

[0180] Examples of inert solvents include, but are not limited to, ethylbenzene and toluene. In addition, one or more polar solvents such as methyl ethyl ketone and cyclohexanone can be used.

[0181] The amount of these inert solvents is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, relative to 100 parts by mass of the aromatic vinyl monomer mixture containing the conjugated diene polymer (1) and random copolymer (2).

[0182] In the method for manufacturing the impact-resistant styrene resin composition of this embodiment, when free radical polymerization is carried out on an aromatic vinyl monomer, or a mixture of an aromatic vinyl monomer and a monomer capable of copolymerizing therewith, in which the conjugated diene polymer (1) and random copolymer (2) are dissolved, polymerization can be carried out in the presence of an organic peroxide or an azo compound.

[0183] Examples of organic peroxides include, but are not limited to, peroxide ketals such as 1,1-bis(tert-butylperoxide)cyclohexane and 1,1-bis(tert-butylperoxide)3,3,5-trimethylcyclohexane; dialkyl peroxides such as di-tert-butylperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane and dicumyl peroxide; diacyl peroxides such as benzoyl peroxide, m-toluyl peroxide, and lauroyl peroxide; dicarbonate peroxides such as dimyristyl peroxide and diisopropyl peroxide; ester peroxides such as tert-butyl peroxyisopropyl carbonate, tert-butyl peracetate, di-tert-butyl dipperoxyisophthalate, and tert-butyl peroxybenzoate; ketone peroxides such as cyclohexanone peroxide and methyl ethyl ketone peroxide; and hydrogen peroxides such as terpene hydrogen peroxide, tert-butyl hydrogen peroxide, and cumyl hydroperoxide.

[0184] In addition, examples of azo compounds include, but are not limited to, azobisisobutyronitrile and azobiscyclohexanenitrile.

[0185] They can be used in one or in combination of two or more.

[0186] Regarding the amount of organic peroxide or azo compound used, it is preferably in the range of 10 ppm to 1,000 ppm in the above-mentioned aromatic vinyl monomer, or a mixture of aromatic vinyl monomer and monomers that can copolymerize therewith.

[0187] Furthermore, in the method for manufacturing impact-resistant styrene-based resin compositions, it is preferable to use a known chain transfer agent in the above-mentioned graft polymerization step.

[0188] As a chain transfer agent, it can be used, but is not limited to, thiols, terpenes, halogen compounds, etc., such as n-dodecyl mercaptan, tert-dodecyl mercaptan, α-methylstyrene dimer, 1-phenylbutene-2-fluorene, dipentene, chloroform, etc.

[0189] In impact-resistant styrene resin compositions, known antioxidants and UV stabilizers can be added.

[0190] Examples of antioxidants include, but are not limited to, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6-di-tert-butyl-4-methylphenol, 2-(1-methylcyclohexyl)-4,6-dimethylphenol, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 2,4-bis[(octylthio)methyl]-o-cresol, triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], tris(dinonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, etc.

[0191] The amount of antioxidant added is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 2 parts by weight, relative to 100 parts by weight of the impact-resistant styrene resin composition of this embodiment.

[0192] Examples of UV stabilizers include, but are not limited to, triazole systems such as 2-(5-methyl-2-hydroxyphenyl)benzotriazole and 2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole; hindered amine systems such as bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate; and p-tert-butylphenyl salicylate and 2,2'-dihydroxy-4-methoxybenzophenone.

[0193] Triazole-based and hindered amine-based systems, either alone or in combination, are particularly preferred.

[0194] The amount of these UV stabilizers added is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 2 parts by weight, relative to 100 parts by weight of the impact-resistant styrene resin composition of this embodiment.

[0195] Internal lubricants such as liquid paraffin, mineral oil, and organopolysiloxanes can be added to impact-resistant styrene resin compositions as needed.

[0196] For example, relative to 100 parts by weight of the impact-resistant styrene-based resin composition, 0.005 to 10 parts by weight of polydimethylsiloxane as an organopolysiloxane may be added.

[0197] In the impact-resistant styrene-based resin composition of this embodiment, flame retardants and flame retardant additives may be mixed in as needed to impart flame retardancy.

[0198] As a flame retardant, existing known flame retardants can be used, and halogenated flame retardants and phosphorus-based flame retardants are effective.

[0199] Flame retardants include, but are not limited to, decabromodiphenyl ether, tetrabromobisphenol A, oligomers of tetrabromobisphenol A, tris-(2,3-dibromopropyl-1)isocyanurate, ammonium phosphate, red phosphorus, tricresyl phosphate, etc.

[0200] Examples of flame retardant additives include, but are not limited to, antimony trioxide, antimony pentoxide, sodium antimonate, antimony trichloride, antimony pentachloride, zinc borate, barium metaborate, and zirconium oxide.

[0201] The amount of flame retardant mixed with the impact styrene resin composition of this embodiment is preferably 5 to 40 parts by weight per 100 parts by weight, and the amount of flame retardant additive is preferably 2 to 20 parts by weight per 100 parts by weight of the impact styrene resin composition of this embodiment.

[0202] In the impact-resistant styrene resin composition of this embodiment, various additives such as lubricants, release agents, fillers, antistatic agents, and colorants may be mixed in as needed.

[0203] Furthermore, other thermoplastic resins can also be mixed in, such as commonly used polystyrene, AS resin, ABS resin, AES resin, MBS resin, polyphenylene ether, polycarbonate, styrene-butadiene copolymer, methyl methacrylate-styrene copolymer resin, maleic anhydride-styrene copolymer resin, polyamide resin, polyester resin, etc. By adding these resins, heat resistance, rigidity, impact resistance, appearance, paintability, etc., are imparted, and one or more resins can be used depending on the application.

[0204] Example 1

[0205] The present invention will be described in more detail through the following embodiments, but the present invention is not limited to any of the following embodiments. It should be noted that the analysis of the samples was performed by the method shown below.

[0206] (1) Mooney viscosity

[0207] Mooney viscosity was determined using a Mooney viscometer (Kamijima Manufacturing Co., Ltd., "VR1132") according to JIS K6300 (ISO289-1). The measurement temperature was set to 100°C.

[0208] First, the sample was preheated for 1 minute, then the rotor was rotated at 2 rpm, and the torque was measured after 4 minutes, which was taken as the Mooney viscosity (ML). 1+4 ).

[0209] (2) Viscosity (SV) of 5% styrene solution by mass

[0210] 2.385 g of the sample was dissolved in 50 mL of styrene and measured using a Canon-Fensk viscometer (viscometer number: 350) manufactured by Shibata Scientific Co., Ltd. at 25 °C. However, since only sample B had a high SV, a Canon-Fensk viscometer (viscometer number: 400) manufactured by Shibata Scientific Co., Ltd. was used for the measurement.

[0211] (3) Molecular weight distribution (Mw / Mn)

[0212] A GPC assay apparatus (Tosoh HLC-8320GPC) consisting of three columns packed with polystyrene-based gel was used. Chromatograms were measured, and the mass-average molecular weight (Mw) and number-average molecular weight (Mn) were determined based on a standard curve using standard polystyrene. The molecular weight distribution (Mw / Mn) was calculated. Tetrahydrofuran (THF) was used as the eluent. The columns consisted of a guard column (Tosoh TSKguardcolumn SuperMP(HZ)-H) and three columns (Tosoh TSKgelSuperMultipore HZ-H) connected in series. An RI detector (Tosoh HLC8320) was used at an oven temperature of 40°C and a THF flow rate of 1.0 mL / min. 10 mg of the sample was dissolved in 20 mL of THF to prepare the assay solution, and 200 μL of the assay solution was injected into the GPC assay apparatus for measurement.

[0213] (4) P content

[0214] The phosphorus (P) content in the conjugated diene polymers of the examples and comparative examples described below was determined using inductively coupled plasma (ICP, manufactured by Shimadzu Corporation, device name: ICPS-7510).

[0215] First, the conjugated diene polymer is completely dissolved using sulfuric acid and nitric acid. The aqueous solution containing the metal components is sprayed into argon plasma, and the intensity of the wavelengths of the light emitted from it, which are inherent to the various metal elements, is measured. The amount of phosphorus (ppm) contained in 100 parts by mass of the conjugated diene polymer is then determined using the standard curve method.

[0216] (5) Cumulative luminescence

[0217] The 1mm thick sample was cut into 1cm × 1cm pieces and placed in a 20mm diameter aluminum dish. Measurements were performed according to ISO 4765:2022 using a weak luminescence imaging apparatus (CLA-FS4) and sample chamber (CLS-SH1) manufactured by Tohoku Electronics Industries Co., Ltd. Under an oxygen atmosphere (50ml / min), the temperature was increased from 50℃ to 200℃ at a rate of 20℃ / min, and then maintained at 200℃ for 10 minutes after the start of the heating. The cumulative luminescence over 10 minutes was calculated.

[0218] (6) Δb value

[0219] Cut the sample into pieces with a diameter of 5 cm and a height of 15 mm, and place them in stainless steel dishes with the same diameter of 5 cm and height of 15 mm. Heat at 160℃ for 2 hours. Measure the b value before and after heating, and calculate the Δb value based on the following formula.

[0220] Δb value = (b value after heating) - (b value before heating)

[0221] In addition, the b-value was measured in the thickness direction using a colorimeter ZE6000 manufactured by Nippon Denshoku Kogyo Co., Ltd. by means of reflection measurement.

[0222] (7) Gloss

[0223] Using injection-molded test pieces (3cm×3cm×3mm), the gloss of the gate and end gate was measured according to ASTM D-523 (incident angle 60°), and the average value was calculated.

[0224] (8) Izod impact strength

[0225] The test was performed according to ISO 180 using injection-molded test pieces with a thickness of 4.0 mm (with notches).

[0226] (9) Appearance

[0227] For the b-value of the injection-molded test piece (3cm×3cm×3mm), the thickness direction was determined by reflection measurement using a colorimeter ZE6000 manufactured by Nippon Denshoku Kogyo Co., Ltd.

[0228] (10) Moisture content

[0229] The water content of the conjugated diene polymers in the examples and comparative examples described below was determined according to ISO 248-2.

[0230] If the water content is greater than 0.5% by mass, it may hinder the polymerization of impact-resistant styrene polymers. Therefore, the polymerization of impact-resistant styrene polymers was carried out after confirming that the water content was below 0.5% by mass.

[0231] [Example 1]

[0232] The polymerization reactor is a high-pressure vessel (a tank reactor with a stirrer) with an internal volume of 11L, an internal height-to-diameter ratio (L / D) of 4, an inlet at the bottom, an outlet at the top, and a jacket for stirring and temperature adjustment.

[0233] 1,3-Butadiene, after being pre-treated to remove moisture and other impurities, is mixed at 30.6 g / min, 1,2-Butadiene at 0.014 g / min, and n-hexane at 149.2 g / min, and continuously fed to the bottom of the reactor. Then, n-Butyllithium, acting as a polymerization initiator, is supplied to the bottom of the reactor at a rate of 0.243 mmol / min, and the polymerization reaction continues (polymerization step) with the reactor outlet temperature set at 114°C.

[0234] Water, acting as a terminator, was continuously added to the conjugated diene polymer solution containing active terminals flowing from the top of the reactor at a rate of 10 g per 100 g of butadiene polymer, and the mixture was stirred using a static mixer (terminator addition step). Next, carbon dioxide, acting as a neutralizing agent, was continuously added at a molar ratio of 1:1.0 to the added n-butyllithium, and the mixture was stirred using a static mixer (neutralizing agent addition step). Finally, octadecyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate (stabilizer 1) and 2,4-bis[(octylthio)methyl]-o-cresol (stabilizer 2) were continuously added at rates of 0.50 g and 0.15 g per 100 g of butadiene polymer, respectively, and the mixture was stirred using a static mixer to terminate the polymerization reaction (stabilizer addition step). The resulting conjugated diene polymer solution was stripped to remove the solvent, and residual moisture was removed by blowing off the solvent with an open mill for 10 minutes to obtain sample A.

[0235] The analytical results of sample A are shown in Table 1.

[0236] [Examples 2-5, Example 7, Comparative Example 2]

[0237] The steps are the same as in Example 1, and the conditions are as shown in Table 1.

[0238] The analytical results of samples B to E, G and I are shown in Table 1.

[0239] [Example 6]

[0240] Using the same polymerization reactor as in Example 1, 1,3-butadiene (after removing moisture and other impurities) was mixed at 22.9 g / min, 1,2-butadiene at 0.014 g / min, and n-hexane at 95.8 g / min and continuously fed to the bottom of the reactor. Then, n-butyllithium, acting as a polymerization initiator, was supplied to the bottom of the first reactor at a rate of 0.228 mmol / min, and the polymerization reaction continued (polymerization step) with the reactor outlet internal temperature at 90°C.

[0241] The temperature of the second reactor was maintained at 90°C. A linear butadiene polymer solution flowing from the top of the first reactor was continuously supplied from the bottom. Tetramethoxysilane, as a coupling agent, was then added from the bottom of the second reactor at a rate of 0.046 mmol / min to carry out the coupling reaction (coupling step). Water, as a terminator, was continuously added to the branched butadiene polymer solution flowing from the top of the second reactor at a rate of 20 g per 100 g of butadiene polymer, and the mixture was stirred using a static mixer (terminator addition step). Next, carbon dioxide, as a neutralizing agent, was continuously added at a molar ratio of 1:1.0 relative to the added n-butyllithium, and the mixture was stirred using a static mixer (neutralizer addition step). Finally, octadecyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate as stabilizer 1 and 2,4-bis[(octylthio)methyl]-o-cresol as stabilizer 2 were added continuously at amounts of 0.50 g and 0.15 g per 100 g of butadiene polymer, respectively. The mixture was stirred in a static mixer to complete the polymerization reaction (stabilizer addition step). The resulting conjugated diene polymer solution was stripped to remove the solvent, and residual moisture was blown away with an open mill for 10 minutes to obtain sample F.

[0242] [Example 8]

[0243] Using the same polymerization reactor as in Example 1, 1,3-butadiene (after removing moisture and other impurities) was mixed at 42.2 g / min, 1,2-butadiene at 0.008 g / min, and n-hexane at 198.8 g / min and continuously fed to the bottom of the reactor. Then, n-butyllithium, acting as a polymerization initiator, was fed to the bottom of the first reactor at a rate of 1.20 mmol / min, and the polymerization reaction continued (polymerization step) with the reactor outlet internal temperature at 100°C.

[0244] The temperature of the second reactor was maintained at 100°C. A linear butadiene polymer solution flowing from the top of the first reactor was continuously supplied from the bottom. Tetramethoxysilane, as a coupling agent, was then added from the bottom of the second reactor at a rate of 0.31 mmol / min to carry out the coupling reaction (coupling step). Water, as a terminator, was continuously added to the branched butadiene polymer solution flowing from the top of the second reactor at a rate of 20 g per 100 g of butadiene polymer, and the mixture was stirred using a static mixer (terminator addition step). Next, carbon dioxide, as a neutralizing agent, was continuously added at a molar ratio of 1:1.0 relative to the added n-butyllithium, and the mixture was stirred using a static mixer (neutralizer addition step). Finally, octadecyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate as stabilizer 1 and 2,4-bis[(octylthio)methyl]-o-cresol as stabilizer 2 were added continuously at amounts of 0.50 g and 0.15 g per 100 g of butadiene polymer, respectively. The mixture was stirred in a static mixer to complete the polymerization reaction (stabilizer addition step). The resulting conjugated diene polymer solution was stripped to remove the solvent, and residual moisture was blown away with an open mill for 10 minutes to obtain sample L.

[0245] [Example 9]

[0246] The polymerization and stabilizer addition processes were performed in the same manner as in Example 1. The obtained conjugated diene polymer solution was desolventized by stripping, and polyoxyethylene alkyl ether phosphoric acid was added at a rate of 0.3 g per 100 g of conjugated diene polymer. Residual moisture was removed by blowing with an open mill roll to obtain sample M. The time required to remove residual moisture with an open mill roll to a water content of 0.5% by mass was 40 minutes.

[0247] [Comparative Example 1]

[0248] The polymerization of the conjugated diene polymer with active ends was carried out in the same manner as in Example 1. Neutralizing agents and terminators were not added to the butadiene polymer solution with active ends flowing from the top of the reactor. Stabilizer 1 and stabilizer 2 were continuously added at a rate of 0.10 g and 0.10 g respectively per 100 g of the conjugated diene polymer with active ends. The mixture was stirred using a static mixer to complete the polymerization reaction. The resulting conjugated diene polymer solution was stripped to remove the solvent, and residual moisture was blown away using an open mill roll for 10 minutes to obtain sample H.

[0249] The analytical results of sample H are shown in Table 1.

[0250] [Comparative Example 3]

[0251] The steps are the same as in Comparative Example 1, and the conditions are as shown in Table 1.

[0252] The analytical results of the obtained sample J are shown in Table 1.

[0253] [Comparative Example 4]

[0254] Polymerization of the conjugated diene polymer with active ends was carried out in the same manner as in Example 1. Stabilizer 1 and stabilizer 2 were continuously added to the butadiene polymer solution with active ends flowing from the top of the reactor at a ratio of 0.50 g and 0.15 g per 100 g of the conjugated diene polymer, respectively, and the mixture was stirred using a static mixer (stabilizer addition step). Next, water as a terminator was continuously added at a ratio of 10.0 g per 100 g of the conjugated diene polymer with active ends, and the mixture was stirred using a static mixer (terminator addition step). Furthermore, carbon dioxide was continuously added at a molar ratio of 1:1.0 relative to the added n-butyllithium, and the mixture was stirred using a static mixer (neutralizer addition step). The resulting conjugated diene polymer solution was desolventized by stripping, and residual moisture was blown away with an open mill roll for 10 minutes to obtain sample K.

[0255] The analytical results of sample K are shown in Table 1.

[0256] [Table 1]

[0257] <Synthesis of Impact-Resistant Styrene-Based Resin Compositions>

[0258] Impact-resistant styrene-based resin compositions are manufactured using the following bulk polymerization method.

[0259] 91.76% by mass of styrene and 7.97% by mass of sample A were added to a reactor equipped with a stirring device.

[0260] Next, 0.23% by mass of octadecyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate as a stabilizer and 0.02% by mass of tert-dodecyl mercaptan as a chain transfer agent were added and stirred to dissolve, preparing a pre-polymerization solution. 0.02% by mass of di-tert-butyl peroxide was added to this solution, and polymerization was carried out at 105°C for 6 hours with stirring. Subsequently, polymerization was carried out at 135°C, 150°C, and 170°C for 2 hours each without stirring, followed by a heat treatment at 220°C for 30 minutes. After cooling, the solution was screened using a 5mm mesh. The pulverized material was pulverized using a pulverizer and dried under reduced pressure at 80°C for 3 hours to obtain an impact-resistant styrene-based resin composition. The pulverized material was then injection molded (mold temperature 60°C, nozzle tip temperature 220°C) to produce test specimens, and its physical properties were determined. The physical properties of the obtained impact-resistant styrene-based resin composition are shown in Table 1.

[0261] Using samples B to M respectively, impact-resistant styrene-based resin compositions were obtained through the same steps.

[0262] Samples A to G, L, and M yielded impact-resistant styrene-based resin compositions with excellent appearance, gloss, and a good balance of impact strength.

Claims

1. A conjugated diene polymer, wherein, The cumulative luminescence of the faint light emitted by the chemical reaction is 150 × 10⁻⁶. 5 Below cps, the Δb value before and after heating at 160℃ for 2 hours is below 4.

0.

2. The conjugated diene polymer according to claim 1, wherein, The viscosity (SV) of the conjugated diene polymer in a 5% by mass styrene solution, measured at 25°C, is 50 < SV ≤ 75, where SV is in mPa·s.

3. The conjugated diene polymer according to claim 1, wherein, The viscosity (SV) of the conjugated diene polymer at 25°C for a 5% styrene solution is 75 < SV ≤ 280, where SV is measured in mPa·s.

4. The conjugated diene polymer according to claim 1, wherein, The P content (i.e., phosphorus content) of the conjugated diene polymer is below 20 ppm.

5. The conjugated diene polymer according to claim 1, wherein, The value of Δb is below 3.

0.

6. The conjugated diene polymer according to claim 1, wherein, The cumulative luminescence is 40 × 10 5 Below CPS.

7. The conjugated diene polymer according to claim 1, wherein, The molecular weight distribution (Mw / Mn) of the conjugated diene polymer, as determined by GPC (gel permeation chromatography), is above 1.5 and below 2.

5.

8. The conjugated diene polymer according to claim 1, wherein, The conjugated diene polymer is polybutadiene.

9. The conjugated diene polymer according to claim 1, wherein, The conjugated diene polymer is polybutadiene used in impact-resistant styrene polymer compositions.

10. A method for manufacturing a conjugated diene polymer, comprising: Polymerization process: 1,3-Butadiene or 1,3-butadiene and aromatic vinyl compounds, along with an inert solvent, are continuously fed into a polymerization reactor, where an organolithium compound is used as an initiator for continuous polymerization to obtain a conjugated diene polymer with active ends; and The following procedures (1) to (3): (1) Deactivator addition step, adding a deactivator to deactivate the active polymerization end of the conjugated diene polymer containing active ends; (2) Neutralizer addition process, adding a neutralizer to neutralize lithium hydroxide; (3) Stabilizer addition process, adding stabilizer.

11. The method for manufacturing the conjugated diene polymer according to claim 10, wherein, The deactivating agent addition process, the neutralizing agent addition process, and the stabilizer addition process are performed sequentially.

12. An impact-resistant styrene polymer composition comprising any one of the conjugated diene polymers according to claims 1 to 9.

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