A syndiotactic polystyrene resin, a method for preparing the same, a resin composition and an article

Abstract

The present application provides a syndiotactic polystyrene resin and a preparation method thereof, a resin composition and an article, the syndiotactic polystyrene resin has a weight average molecular weight of 1.4*10 5 g / mol~2.2*10 5 g / mol, wherein the syndiotactic polystyrene resin with a molecular weight more than 3 times of the weight average molecular weight accounts for ≤10wt%, the syndiotactic polystyrene resin with a molecular weight less than 0.2 times of the weight average molecular weight accounts for ≤6wt%, and the undercooling degree ΔT of the syndiotactic polystyrene resin is 28℃~34℃. In the present application, by controlling the weight average molecular weight of the syndiotactic polystyrene resin and the proportions of high molecular weight syndiotactic polystyrene resin and low molecular weight syndiotactic polystyrene resin within a specific range, and simultaneously controlling the undercooling degree within a specific range, the obtained syndiotactic polystyrene resin has excellent toughness and long-term dimensional stability after demolding.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a syndiotactic polystyrene resin, its preparation method, resin composition, and products. Background Technology

[0002] Syndiotactic polystyrene possesses a high melting point, excellent heat resistance, good chemical resistance, low dielectric constant, and high-speed crystallization characteristics, demonstrating great application potential in fields such as electronics, electrical engineering, and automobile manufacturing. In particular, compositions prepared by combining syndiotactic polystyrene with other components (such as other resins and functional additives) exhibit even better performance.

[0003] However, as a semi-crystalline engineering plastic, syndiotactic polystyrene is inherently brittle. Furthermore, after injection molding, changes in temperature and pressure cause the molecular chains to recrystallize and rearrange, leading to post-shrinkage and affecting the long-term dimensional stability and mechanical reliability of the finished product. Therefore, developing a syndiotactic polystyrene resin that combines excellent toughness with long-term dimensional stability is a key issue for further improving the performance of syndiotactic polystyrene and expanding its application areas. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a syndiotactic polystyrene resin, its preparation method, resin composition, and articles. The syndiotactic polystyrene resin solves the problem that existing syndiotactic polystyrene resins cannot simultaneously achieve excellent toughness and long-term dimensional stability.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a syndiotactic polystyrene resin, wherein the weight-average molecular weight of the syndiotactic polystyrene resin is 1.4 × 10⁻⁶. 5 g / mol ~ 2.2 × 10 5 g / mol, wherein the proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight average molecular weight is ≤10wt%, and the proportion of syndiotactic polystyrene resin with a molecular weight less than 0.2 times the weight average molecular weight is ≤6wt%; the supercooling degree ΔT of the syndiotactic polystyrene resin is 28℃~34℃.

[0007] In this invention, the DSC curve of the syndiotactic polystyrene resin is tested using the following specific method: under a nitrogen atmosphere, the temperature is increased from 50°C to a maximum temperature of 310°C at a heating rate of 20°C / min, held at this temperature for 3 minutes, and then decreased to 50°C at a rate of 20°C / min to obtain the cooling curve of the syndiotactic polystyrene resin; the temperature is held at 50°C for 3 minutes, and then increased again to a maximum temperature of 310°C at a heating rate of 20°C / min to obtain the second heating curve of the syndiotactic polystyrene resin; Tc is the peak temperature of the exothermic peak on the cooling curve, and Tm is the peak temperature of the second endothermic peak on the second heating curve; then ΔT = Tm - Tc.

[0008] In this invention, by controlling the weight-average molecular weight, the proportion of high-molecular-weight syndiotactic polystyrene resin, the proportion of low-molecular-weight syndiotactic polystyrene resin, and the supercooling within specific ranges, it is beneficial to balance the toughness and long-term dimensional stability of the syndiotactic polystyrene resin. A high proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight-average molecular weight leads to poor long-term dimensional stability after demolding; a high proportion of syndiotactic polystyrene resin with a molecular weight less than 0.2 times the weight-average molecular weight results in poor toughness; a high degree of supercooling of the syndiotactic polystyrene resin leads to poor long-term dimensional stability after demolding; a low degree of supercooling reduces toughness; and a high weight-average molecular weight leads to poor long-term dimensional stability.

[0009] In this invention, the weight-average molecular weight (Mw) of the syndiotactic polystyrene resin is 1.4 × 10⁻⁶. 5 g / mol ~ 2.2 × 10 5 g / mol, for example, can be 1.42 × 10 5 g / mol, 1.45×10 5 g / mol, 1.5×10 5 g / mol, 1.55×10 5 g / mol, 1.6×10 5 g / mol, 1.65×10 5 g / mol, 1.7×10 5 g / mol, 1.75×10 5 g / mol, 1.8×10 5 g / mol, 1.85×10 5 g / mol, 1.9×10 5 g / mol, 1.95×10 5 g / mol, 2.0×10 5 g / mol, 2.05×10 5 g / mol, 2.1×10 5 g / mol, 2.15×10 5g / mol or any of the above values.

[0010] In this invention, the proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight-average molecular weight in the syndiotactic polystyrene resin is ≤10wt%, for example, it can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 6.5wt%, 7wt%, 7.5wt%, 8wt%, 8.5wt%, 9wt%, 9.5wt%, 10wt% or any of the above values, more preferably ≤7wt%.

[0011] In this invention, based on cost considerations, it is preferable that the proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight-average molecular weight is ≥4wt%.

[0012] In this invention, the proportion of syndiotactic polystyrene resin with a molecular weight less than 0.2 times the weight-average molecular weight in the syndiotactic polystyrene resin is ≤6wt%, for example, it can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt% or any of the above values, more preferably ≤3wt%.

[0013] In this invention, based on cost considerations, it is preferable that the proportion of syndiotactic polystyrene resin with a molecular weight less than 0.2 times the weight-average molecular weight is ≥1 wt%.

[0014] In this invention, the supercooling degree ΔT of the syndiotactic polystyrene resin is 28℃~34℃, for example, it can be 28℃, 28.2℃, 28.5℃, 28.8℃, 29℃, 29.2℃, 29.5℃, 29.8℃, 30℃, 30.2℃, 30.5℃, 30.8℃, 31℃, 31.2℃, 31.5℃, 31.8℃, 32℃, 32.2℃, 32.5℃, 32.8℃, 33℃, 33.2℃, 33.5℃, 33.8℃, 34℃ or any of the above values, more preferably 29~31℃.

[0015] In this invention, the melt index of the syndiotactic polystyrene resin is 4~30 g / 10 min.

[0016] In this invention, the melt index of the syndiotactic polystyrene resin was tested according to the ISO 1133-1:2022 standard method at 300°C and under a 1.2 kg load.

[0017] In a second aspect, the present invention provides a method for preparing syndiotactic polystyrene according to the first aspect, the method comprising: subjecting styrene monomer to an addition polymerization reaction in the presence of a catalyst and a nitrogen-hydrogen mixture to obtain the syndiotactic polystyrene resin, wherein the catalyst comprises the following components.

[0018] (A) Titanium chromatographite compounds.

[0019] (B) Alkyl aluminum oxane.

[0020] (C) Compounds that can react with titanoceramic metal compounds to form ionic complexes.

[0021] (D) Organoaluminum compounds.

[0022] In this invention, the temperature of the addition polymerization reaction is 60℃~90℃, for example, it can be 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃, 82℃, 85℃, 88℃ or any range between the above values; the pressure of the addition polymerization reaction is 10 kPaG~100 kPaG, for example, it can be 15 kPaG, 20 kPaG, 25 kPaG, 30 kPaG, 35 kPaG, 40 kPaG, 45 kPaG, 50 kPaG, 55 kPaG, 60 kPaG, 65 kPaG, 70 kPaG, 75 kPaG, 80 kPaG, 85 kPaG, 90 kPaG, 95 kPaG or any range between the above values.

[0023] In this invention, the method for preparing the catalyst includes: premixing component (A) and component (C) to obtain a first premix; premixing the first premix with component (D) to obtain a second premix; and mixing the second premix with component (B) to obtain the catalyst.

[0024] In this invention, the contact temperature (i.e., premixing or mixing temperature) of each component in the catalyst is 0℃~100℃, and the contact occurs in an inert atmosphere such as nitrogen or argon.

[0025] Preferably, the general formula of component (A) is R 1 TiX 1 X 2 X 3 .

[0026] Among them, R 1 Selected from any one of substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl, or fused polycyclic cyclopentadienyl containing at least one saturated ring; X 1 X 2 and X 3Each of the substituents is independently selected from any one of hydrogen atom, halogen atom, C1~C12 alkyl, C1~C12 alkoxy, C1~C12 alkylsilyl, C6~C20 aryl, C6~C20 aryloxy, C6~C20 arylsilyl, and C7~C20 aralkyl; the substituents include at least one of halogen atom, C1~C12 alkyl, C1~C12 alkoxy, C6~C20 aryl, C6~C20 aryloxy, and C7~C20 aralkyl, and when the number of substituents is greater than 1, the substituents may be the same or different.

[0027] In this invention, the C1~C12 alkyl group can be, for example, C1, C2, C4, C6, C8, C10, or C11 alkyl groups; it can be a straight-chain alkyl group or a branched-chain alkyl group, and exemplary examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, isobutyl, n-butyl, n-pentyl, n-hexyl, n-decyl, etc.; the same expressions in the following text have the same meaning.

[0028] In this invention, the C1~C12 alkoxy groups can be, for example, C1, C2, C4, C6, C8, C10, or C11 alkoxy groups; exemplary, including but not limited to methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, n-pentoxy, n-hexoxy, and n-decoxy groups; the same expressions in the following text have the same meaning.

[0029] In this invention, C6 to C20 aryl groups can be, for example, C6, C8, C10, C12, C14, C16, or C18 aryl groups; exemplary, including but not limited to phenyl, biphenyl, naphthyl, phenanthryl, anthracene, etc.; the same expressions in the following text have the same meaning.

[0030] In this invention, the C6~C20 aryloxy group can be, for example, C6, C8, C10, C12, C14, C16, or C18 aryloxy groups; the aryloxy group refers to a group formed by replacing one H with an O in the aforementioned C6~C20 aryl groups; the same expression in the following text has the same meaning.

[0031] In this invention, C7-C20 aralkyl groups can be, for example, C8, C10, C12, C14, C16, or C18 aralkyl groups; the aralkyl group refers to a group formed by replacing at least one H in the aforementioned C6-C20 aryl groups with an alkyl group; the same expressions in the following text have the same meaning.

[0032] In this invention, C1~C12 alkylsilyl groups can be, for example, C1, C2, C4, C6, C8, C10, or C11 alkylsilyl groups; the alkylsilyl group refers to a group formed by replacing at least one H in a silane with an alkyl group; the same expressions in the following text have the same meaning; wherein, the linking site can be in an alkyl group or in a silyl group.

[0033] In this invention, C6~C20 arylsilyl groups can be, for example, C8, C10, C14, C16, or C18 arylsilyl groups; the arylsilyl group refers to a group formed by replacing at least one H in a silane with an aryl group; the same expressions in the following text have the same meaning; wherein, the linking site can be in the aryl group or in the silyl group.

[0034] In this invention, the halogen atoms include F, Cl, Br, and I.

[0035] In this invention, the number of substituents in "substituted or unsubstituted" is ≥1. When the number of substituents is greater than 1, the substituents are the same or different.

[0036] In this invention, the titanium-containing metal compounds include cyclopentadienyltriethyltitanium, cyclopentadienyltributyltitanium, cyclopentadienyltrimethyltitanium, pentamethylcyclopentadienyltriethyltitanium, pentamethylcyclopentadienyltrimethyltitanium, pentamethylcyclopentadienyltributyltitanium, cyclopentadienyltrimethoxytitanium, cyclopentadienyltriethoxytitanium, pentamethylcyclopentadienyltrimethoxytitanium, pentamethylcyclopentadienyltrichloride, cyclopentadienyltriphenoxytitanium, cyclopentadienylmonophenoxytitanium chloride, cyclopentadienyltribenzyltitanium, and cyclopentadienyl... At least one of methyl dibenzyl titanium, indene trichloride titanium, indene trimethoxy titanium, indene trimethyl titanium, indene tribenzyl titanium, octahydrofluorenyl trimethoxy titanium, 9-isopropyl-octahydrofluorenyl trimethoxy titanium, 4,5,6,7-tetrahydroindene trimethoxy titanium, 1,2,3,4-tetramethyl-octahydrofluorenyl trimethoxy titanium, 1-trimethylsilyl-2-methyl-4,5,6,7-tetrahydroindene trimethoxy titanium, and 1-dimethylphenylsilyl-2-methyl-4,5,6,7-tetrahydroindene trichloride titanium.

[0037] Preferably, component (B) is selected from C1-C8 straight-chain alkylaluminoxanes.

[0038] In this invention, component (B) is the reaction product of C1~C8 straight-chain alkyl aluminum and water.

[0039] In this invention, the alkylaluminoxane includes at least one of methylaluminoxane, ethylaluminoxane, n-propylaluminoxane, n-butylaluminoxane, n-pentylaluminoxane, n-hexylaluminoxane, and n-heptylaluminoxane.

[0040] Preferably, the general formula of component (C) is: .

[0041] Among them, R 2 Selected from at least one of alkyl groups with ≥1 carbon atom and aryl groups with ≥6 carbon atom, R 2 Same or different; M is selected from at least one of B, Al, Si, P, and As; X 4The group is selected from at least one of C1-C12 alkyl, C1-C12 alkoxy, C6-C20 aryl, C6-C20 aryloxy, C7-C20 aralkyl, and C6-C20 haloaryl, where q is an integer from 2 to 8, and X 4 Same or different.

[0042] In this invention, component (C) includes at least one of triphenylmethyltetraphenylborate, triphenylmethyltetra(pentafluorophenyl)borate, tri(2,4,6-trimethylphenyl)methyltetra(pentafluorophenyl)borate, and triphenylmethyltetra(3,5-bistrifluoromethylphenyl)borate.

[0043] Preferably, the general formula of the component (D) is R. 3 p AlH 3-p .

[0044] Among them, R 3 Selected from C1-C8 alkyl groups, which can be straight-chain alkyl groups or branched alkyl groups, such as C1, C2, C3, C4, C5, C6, C7, and C8 alkyl groups, including but not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, and n-hexyl; 0 ≤ p ≤ 3; when p > 1, R 3 Same or different.

[0045] In this invention, component (D) includes at least one of triisobutylaluminum, trimethylaluminum, triethylaluminum, triisopropylaluminum, diisobutylaluminum hydride, tri-n-butylaluminum, tri-n-hexylaluminum, di-n-butylaluminum, diisopropylaluminum, and n-butylaluminum.

[0046] Preferably, the molar ratio of aluminum to titanium metal compound in component (B) is (10~1000):1, wherein the specific value of (10~1000) can be, for example, 20, 50, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000 or any range between the above values.

[0047] Preferably, the molar ratio of M to the titanoceramic metal compound in component (C) is (0.5~1.5):1, wherein the specific value of (0.5~1.5) can be, for example, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45 or any range of the above values.

[0048] Preferably, the molar ratio of aluminum to titanium metal compound in component (D) is (40~1000):1, wherein the specific value in (10~1000) can be, for example, 45, 50, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000 or any range between the above values.

[0049] Preferably, the concentration of the titanoceramic metal compound relative to styrene is 4 × 10⁻⁶. -5 ~5×10 -4 mol / L, for example, could be 4.5 × 10⁻⁶. -5 5×10 -5 6×10 -5 7×10 -5 8×10 -5 1×10 -4 2×10 -4 4×10 -4 Or any of the above values, more preferably 5 × 10 -5 ~1×10 -4 mol / L.

[0050] In this invention, the volume fraction of hydrogen in the nitrogen-hydrogen mixture is 0.1% to 15%, for example, it can be 0.2%, 0.4%, 0.6%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15% or any range between the above values.

[0051] In this invention, the weight-average molecular weight of syndiotactic polystyrene resin, the proportion of high molecular weight syndiotactic polystyrene resin, the proportion of low molecular weight syndiotactic polystyrene resin, and the supercooling can be controlled by adjusting the composition of the catalyst (including the types and proportions of each component), the preparation method (i.e., the contact sequence), the volume fraction of hydrogen in the nitrogen-hydrogen mixture, and the temperature and pressure of the addition polymerization reaction.

[0052] The preparation method of the syndiotactic polystyrene resin in this invention specifically includes: heating a 100L vertical reactor to 90-110°C, vacuum drying for 1-3 hours, purging with high-purity nitrogen at least three times, and finally purging with a nitrogen-hydrogen mixture with a hydrogen volume fraction of 0.1%-15%. After the reactor temperature drops to the reaction temperature of 60-90°C, styrene is added, and the prepared catalyst is added to the reactor according to the formula for reaction. The reaction pressure is adjusted to 10-100 kPaG using a nitrogen-hydrogen mixture with a hydrogen volume fraction of 0.1%-15%. After the reaction lasts for at least 2 hours, the reaction is terminated with an ethanol solution, followed by washing and drying to obtain syndiotactic polystyrene powder. This powder is then extruded and granulated using a twin-screw extruder at 295-310°C to obtain syndiotactic polystyrene granules, which constitute the syndiotactic polystyrene resin.

[0053] In this invention, the method for preparing the catalyst includes: premixing component (A) and component (C) to obtain a first premix; premixing the first premix with component (D) to obtain a second premix; and mixing the second premix with component (B) to obtain the catalyst.

[0054] In this invention, the preparation method is not overly limited, as long as it can yield the syndiotactic polystyrene resin described herein; exemplaryly, the syndiotactic polystyrene resin can also be prepared by the following method, the method comprising:

[0055] Styrene monomers undergo addition polymerization in the presence of a catalyst, an inert solvent, and a nitrogen-hydrogen mixture to obtain the syndiotactic polystyrene. The catalyst comprises the following components.

[0056] (A1) Titanocene metal compounds.

[0057] (B1) Alkyl aluminum oxane.

[0058] (C1) A compound that can react with titanoceramic metal compounds to form ionic complexes.

[0059] (D1) Organoaluminum compounds.

[0060] The types and contents of components (A1), (B1), (C1), and (D1) are selected from the same range as those of components (A), (B), (C), and (D); the inert solvent includes, but is not limited to, n-hexane.

[0061] The specific method includes: heating the reactor to 90-110℃, vacuum drying for 1-3 hours, purging with high-purity nitrogen 2-5 times, and finally purging with a nitrogen-hydrogen mixture containing 0.1-20% hydrogen gas, maintaining a slightly positive pressure (10-100 kPa) inside the reactor. Once the reactor temperature drops to 60-90℃, 250 kg of pre-treated SPS powder (pre-treated with dry nitrogen) is added to the reactor and dried under nitrogen flow for 1-3 hours. Then, a mixed catalyst is prepared, and the mixed catalyst and styrene are continuously added to the reactor at a flow rate of 90-110 L / h. Simultaneously, an inert solvent is supplied to the reactor. By controlling the reactor pressure and condensate return flow rate, the internal temperature is maintained at 60-90℃. After continuous operation for 2 hours, the bottom discharge valve of the reactor is opened and opened every 10-30 minutes to obtain the syndiotactic polystyrene powder. The syndiotactic polystyrene granules are obtained by extrusion and granulation at 250-350°C using a twin-screw extruder, which yields the syndiotactic polystyrene resin. The preparation method of the mixed catalyst includes: using toluene as a solvent, pre-preparing a toluene solution of component (B1) with a mass fraction of 8-12%, a toluene solution of component (C1) with a mass fraction of 0.5-1.5%, and a toluene solution of component (D1) with a mass fraction of 8-12%. Then, according to the formula amount, the toluene solution of component (C1) and component (A1) are pre-mixed, the toluene solution of component (D1) is added, and finally component (B1) is added to obtain the mixed catalyst.

[0062] In this invention, the sPS powder is syndiotactic polystyrene resin powder, used to maintain the solid-phase dispersion state and ensure the stability of the system phase; the sPS powder is a fine powder with a particle size (D50) of 50-500μm, which is dried to constant weight and then placed in a reactor.

[0063] In this invention, the particle size of the sPS powder is tested using a woven wire sieve according to ISO 3310-1 standard.

[0064] In this invention, the melt flow index of the sPS powder is 4~30g / 10min.

[0065] In this invention, the melt flow index of the sPS powder was tested according to the ISO 1133-1:2022 standard method at 300°C and under a 1.2kg load.

[0066] In this invention, the source of the sPS powder is not limited in much; it can be any commercially available raw material that can achieve the purpose of this invention.

[0067] In this invention, the preparation method of the syndiotactic polystyrene resin is not limited to the above-described method, and any method that can obtain the specific syndiotactic polystyrene resin of this invention is acceptable; for example, the syndiotactic polystyrene resin of this invention can also be obtained by mixing syndiotactic polystyrene resins with different Mw, molecular weight distribution and supercooling.

[0068] Thirdly, the present invention provides a resin composition comprising the syndiotactic polystyrene resin described in the first aspect, and further comprising at least one of fillers, compatibilizers, and other additives.

[0069] Preferably, the mass percentage of the intermediate-sized polystyrene resin in the resin composition is ≥20%, for example, it can be 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90%, 98% or any range of the above values.

[0070] Preferably, by weight, the resin composition comprises 20-100 parts of syndiotactic polystyrene resin (e.g., 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts, or any range between the above values), and 0.5-50 parts of filler (e.g., 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 2...). 5 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts or any of the above values), 0.1 to 10 parts of compatibilizer (e.g., 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts or any of the above values), and 0 to 20 parts of other adjuvants (e.g., 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts or any of the above values).

[0071] Preferably, the filler includes at least one of fibrous filler, granular filler, and powdered filler.

[0072] Preferably, the fibrous filler includes at least one of glass fiber, carbon fiber, whiskers, ceramic fiber, and metal fiber.

[0073] Preferably, the granular filler and the powdered filler are each independently selected from at least one of talc, carbon black, graphite, titanium dioxide, silicon dioxide, mica, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, tin oxide, aluminum oxide, kaolin, silicon carbide, metal powder, glass powder, glass flakes, and glass microspheres.

[0074] In this invention, when the filler is selected from glass fillers, the glass used includes at least one of E glass, C glass, S glass, D glass, ECR glass, A glass, AR glass, boron-free glass, and fluorine-free glass.

[0075] Preferably, the length of the glass fiber is 0.05 mm to 50 mm, for example, it can be 0.1 mm, 0.5 mm, 1 mm, 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm or any of the above values; the diameter is 5 μm to 20 μm, for example, it can be 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm or any of the above values.

[0076] Preferably, the compatibilizer comprises modified styrene-based polymers and / or modified polyphenylene ether-based polymers.

[0077] Preferably, the modified styrene-based polymer includes at least one of the following: styrene-maleic anhydride copolymer, styrene-glycidyl methacrylate copolymer, terminal carboxylic acid modified polystyrene, terminal epoxy modified polystyrene, terminal oxazoline modified polystyrene, terminal amine modified polystyrene, sulfonated polystyrene, styrene-based ionomer, styrene-methyl methacrylate copolymer, styrene-glycidyl methacrylate-methyl methacrylate terpolymer, acrylate-styrene copolymer, styrene-b-glycidyl methacrylate-b-styrene, polybutylene terephthalate-g-polystyrene, maleic anhydride modified syndiotactic polystyrene, fumaric acid modified syndiotactic polystyrene, glycidyl methacrylate modified syndiotactic polystyrene, and amine modified syndiotactic polystyrene.

[0078] Preferably, the modified polyphenylene ether polymer includes at least one selected from styrene-maleic anhydride-polyphenylene ether-grafted polymer, maleic anhydride modified polyphenylene ether, fumaric acid modified polyphenylene ether, glycidyl methacrylate modified polyphenylene ether, and amine modified polyphenylene ether.

[0079] Preferably, the polyphenylene ether in the modified polyphenylene ether polymer includes poly(2,6-dimethyl-1,4-phenylene ether), poly(2,3-dimethyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-chloromethyl-1,4-phenylene ether), poly(2-methyl-6-hydroxyethyl-1,4-phenylene ether), poly(2-methyl-6-n-butyl-1,4-phenylene ether), poly(2-ethyl-6-isopropyl-1,4-phenylene ether), poly(2-ethyl-6-n-propyl-1,4-phenylene ether), poly(2,3,6-trimethyl-1,4-phenylene ether), poly[2-(4′-methylphenyl)-1,4-phenylene ether], poly(2-bromo-6-phenyl-1,4-phenylene ether), poly(2-methyl- At least one of 6-phenyl-1,4-phenylene ether, poly(2-phenyl-1,4-phenylene ether), poly(2-chloro-1,4-phenylene ether), poly(2-methyl-1,4-phenylene ether), poly(2-chloro-6-ethyl-1,4-phenylene ether), poly(2-chloro-6-bromo-1,4-phenylene ether), poly(2,6-di-n-propyl-1,4-phenylene ether), poly(2-methyl-6-isopropyl-1,4-phenylene ether), poly(2-chloro-6-methyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2,6-dibromo-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), and poly(2,6-diethyl-1,4-phenylene ether).

[0080] In this invention, the modified polyphenylene ether polymer can be prepared by polyphenylene ether and a modifier; specifically, it includes: in the presence of an initiator, polyphenylene ether and a modifier are melt-blended on an extruder at a temperature of 250°C to 350°C to obtain the modified polyphenylene ether polymer.

[0081] Preferably, the other additives include at least one of rubbery elastomers, antioxidants, lubricants, crosslinking agents, crosslinking aids, nucleating agents, plasticizers, flame retardants, colorants, and antistatic agents.

[0082] In this invention, the rubber-like elastomer includes, but is not limited to, at least one of styrene-butadiene block copolymer (SBR), hydrogenated styrene-butadiene block copolymer (SEB), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), hydrogenated styrene-isoprene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), and hydrogenated styrene-isoprene-styrene block copolymer (SEPS).

[0083] In this invention, the antioxidants include, but are not limited to, primary antioxidants, such as any one or a combination of at least two of the following: 2,6-di-tert-butyl-p-cresol (BHT), 2,2'-methylene-bis(4-ethyl-6-tert-butylphenol), 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis(4-methyl-6-cyclohexylphenol), 2,2'-methylene-bis(4-methyl-6-nonylphenol), octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, and pentaerythritol tetra(3,5-di-tert-butyl-4-hydroxyhydrocinnamate); and secondary antioxidants, such as tri(nonylphenyl) phosphite and / or dilauryl thiodipropionate.

[0084] In this invention, the lubricant includes, but is not limited to, at least one of ethylene bis-stearamide (EBS), glyceryl monostearate, oleamide, and erucamide.

[0085] In this invention, the crosslinking agent includes, but is not limited to, dicumyl peroxide, benzoyl peroxide, divinylbenzene, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, etc.

[0086] In this invention, the crosslinking aids include, but are not limited to, triallyl isocyanurate, trimethylolpropane trimethacrylate, etc.

[0087] In this invention, the nucleating agent includes, but is not limited to, any one or a combination of at least two of the following: organophosphate nucleating agents, organophosphate metal salt nucleating agents, sorbitol nucleating agents, and carboxylic acid metal salt nucleating agents.

[0088] In this invention, the plasticizers include, but are not limited to, dioctyl phthalate, diisononyl phthalate, dioctyl adipate, dioctyl sebacate, and epoxidized soybean oil.

[0089] In this invention, the flame retardant includes, but is not limited to, ammonium polyphosphate, melamine cyanurate, triphenyl phosphate, resorcinol bisphenyl phosphate, phosphazene compounds, zinc borate, zinc oxide, aluminum hydroxide, antimony trioxide, and organoaluminum hypophosphite.

[0090] In this invention, the antistatic agent includes, but is not limited to, quaternary ammonium salt antistatic agents, fatty acid ester antistatic agents, etc.

[0091] In this invention, the method for preparing the resin composition includes: mixing syndiotactic polystyrene resin and optionally fillers, compatibilizers, and other additives, and extruding to obtain the resin composition.

[0092] Fourthly, the present invention provides an article comprising the syndiotactic polystyrene resin described in the first aspect or the resin composition described in the third aspect.

[0093] Preferably, the articles include electronic / electrical components, automobiles, household electrical products, electronic devices, etc.

[0094] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0095] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0096] The syndiotactic polystyrene resin provided by this invention, by controlling the weight-average molecular weight, the proportion of high molecular weight syndiotactic polystyrene resin, the proportion of low molecular weight syndiotactic polystyrene resin and the supercooling within a specific range, is beneficial to balance the toughness and long-term dimensional stability of syndiotactic polystyrene resin after demolding, and has a low post-shrinkage rate. Detailed Implementation

[0097] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0098] In this invention, the method for determining the weight-average molecular weight of the syndiotactic polystyrene resin includes: using a high-temperature gel permeation chromatography system (GPC-IR, Polymer Char, Spain, equipped with dual infrared and viscosity detectors), with 1,2,4-trichlorobenzene as the mobile phase, a flow rate of 1.0 mL / min, a column temperature of 160℃, a detector temperature of 160℃, and an injector temperature of 160℃. A calibration curve is established using polystyrene standards (weight-average molecular weight range: 266-12,900,000 g / mol). The sample is dissolved in trichlorobenzene (concentration 0.125 mg / mL), and the injection volume is 200 μL. The data are processed using GPC ONE software to obtain the weight-average molecular weight (Mw) and the mass percentage of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight-average molecular weight (denoted as M). 高 The percentage of syndiotactic polystyrene resins with a molecular weight less than 0.2 times the weight-average molecular weight (denoted as M). 低 ).

[0099] In this invention, the method for testing the supercooling of the syndiotactic polystyrene resin includes: following the method in GB / T 19466.1-2004, using a differential scanning calorimeter (DSC) (X3DSC, TA Instruments, USA), under a nitrogen atmosphere, the syndiotactic polystyrene resin is heated from 50°C to a maximum temperature of 310°C at a heating rate of 20°C / min, held at this temperature for 3 minutes, and then cooled to 50°C at a rate of 20°C / min to obtain a cooling curve of the syndiotactic polystyrene resin; the syndiotactic polystyrene resin is held at 50°C for 3 minutes, and then heated again to a maximum temperature of 310°C at a heating rate of 20°C / min to obtain a second heating curve of the syndiotactic polystyrene resin. Tc is the peak temperature of the exothermic peak on the cooling curve, and Tm is the peak temperature of the second endothermic peak on the second heating curve; the supercooling ΔT = Tm - Tc.

[0100] Example 1

[0101] This embodiment provides a syndiotactic polystyrene resin, wherein the Mw of the syndiotactic polystyrene resin is 1.90 × 10⁻⁶. 5 g / mol, of which the molecular weight is greater than 5.7 × 10⁻⁶ g / mol. 5 The proportion of syndiotactic polystyrene resin was 6.4% (g / mol), and the molecular weight was less than 0.38 × 10⁻⁶. 5 The proportion of syndiotactic polystyrene resin was 4.7% (g / mol), and the ΔT was 29.6℃.

[0102] The method for preparing the syndiotactic polystyrene resin includes: subjecting styrene monomer to an addition polymerization reaction in the presence of a catalyst and a nitrogen-hydrogen mixture with a hydrogen gas fraction of 10% to obtain the syndiotactic polystyrene.

[0103] The catalyst comprises the following components.

[0104] (A) Pentamethylcyclopentadienyltrimethoxytitanium.

[0105] (B) Methylaluminoxane.

[0106] (C) Triphenylmethyl-tetra(pentafluorophenyl)borate.

[0107] (D) Triisobutylaluminum.

[0108] The amount of component (A) relative to styrene is 5 × 10⁻⁶. -5 mol / L. The molar ratio of aluminum in component (B) methylaluminoxane to that in component (A) is 200:1; the molar ratio of boron in component (C) to that in component (A) is 1:1; and the molar ratio of aluminum in component (D) to that in component (A) is 100:1.

[0109] The specific method includes: heating a 100L vertical reactor to 100℃, vacuum drying for 2 hours, purging with high-purity nitrogen three times, and finally replacing with a nitrogen-hydrogen mixture with a hydrogen integral of 10%. After the reactor temperature drops to the reaction temperature of 70℃, 60L of styrene is added. First, a toluene solution of 4.2 mmol / L pentamethylcyclopentadienyltrimethoxytitanium and 4.2 mmol / L triphenylmethyl-tetra(pentafluorophenyl)borate is premixed in 500 mL. Then, a toluene solution of 0.42 mmol / L triisobutylaluminum is added in 500 mL, and finally, a toluene solution of 0.84 mmol / L methylaluminoxane is added in 500 mL, mixing to obtain a catalyst solution. Then, according to the formula, the catalyst solution is added to the reactor for reaction, and the reaction pressure is adjusted to 50 kPaG using a nitrogen-hydrogen mixture with a hydrogen integral of 10%. After reacting for 2 hours, the reaction is terminated with an ethanol solution, and then washed and dried to obtain syndiotactic polystyrene powder. The syndiotactic polystyrene granules are obtained by extruding and granulating the product using a twin-screw extruder at 300°C, which is the syndiotactic polystyrene resin.

[0110] Examples 2-7 and Comparative Examples 1-5 each provide a syndiotactic polystyrene resin, wherein the Mw and M of the syndiotactic polystyrene resin are... 高 M 低 ΔT is shown in Table 1-2; unless otherwise specified, the preparation method is the same as in Example 1, the only difference being the type of catalyst, ratio, and reaction conditions, as shown in Table 1-2.

[0111] The value 1 / 200 / 1 / 100 indicates that the molar ratio of component A, component B, component C, and component D in the catalyst is 1:200:1:100.

[0112] Unless otherwise specified, the preparation method of the catalyst is the same as that in Example 1.

[0113] Table 1

[0114]

[0115] Example 8

[0116] This embodiment provides a syndiotactic polystyrene resin, wherein the Mw of the syndiotactic polystyrene resin is 2.02 × 10⁻⁶. 5 g / mol, molecular weight greater than 6.06 × 10 5 The proportion of syndiotactic polystyrene resin at g / mol was 6.6%, and the molecular weight was less than 0.404 × 10⁻⁶. 5 The proportion of syndiotactic polystyrene resin at g / mol was 2.9%, and the ΔT was 30.7℃.

[0117] The method for preparing the syndiotactic polystyrene resin includes: subjecting styrene monomer to an addition polymerization reaction in the presence of a catalyst and a nitrogen-hydrogen mixture with a hydrogen gas fraction of 1% to obtain the syndiotactic polystyrene.

[0118] The catalyst comprises the following components.

[0119] (A1) Pentamethylcyclopentadienyl titanium trichloride.

[0120] (B1) Methylaluminoxane.

[0121] (C1) Triphenylmethyl-tetra(pentafluorophenyl)borate.

[0122] (D1) Triisobutylaluminum.

[0123] The amount of component (A1) relative to styrene is 5 × 10⁻⁶. -5 mol / L. The molar ratio of aluminum in component (B1) methylaluminoxane to component (A1) is 100:1. The molar ratio of triphenylmethyl-tetra(pentafluorophenyl)borate in component (C1) to component (A1) is 1:1. The molar ratio of aluminum in component (D1) triisobutylaluminum to component (A1) is 50:1; the solvent used to prepare the catalyst is toluene. The components triisobutylaluminum, methylaluminoxane, and triphenylmethyl-tetra(pentafluorophenyl)borate were respectively mixed with toluene to prepare a 10% by mass toluene solution of triisobutylaluminum, a 10% by mass toluene solution of methylaluminoxane, and a 1% by mass toluene solution of triphenylmethyl-tetra(pentafluorophenyl)borate. Then, according to the formula, pentamethylcyclopentadienyl titanium trichloride and triphenylmethyl-tetra(pentafluorophenyl)borate were premixed, and then the triisobutylaluminum solution and the methylaluminoxane solution were added sequentially and mixed to obtain a mixed catalyst.

[0124] The specific method includes: heating a 1000L vertical reactor with a twin-screw agitator to 100℃, vacuum drying for 2 hours, purging with high-purity nitrogen three times, and finally replacing with a nitrogen-hydrogen mixture with a hydrogen integral of 1%, maintaining a slightly positive pressure (50KPa) inside the reactor. Once the reactor temperature drops to 70℃, 250kg of pre-treated SPS powder (D50 of 300 microns) is added to the reactor and dried under nitrogen flow for 2 hours. Then, according to the formulation, the mixed catalyst and styrene are continuously added to the reactor at a styrene flow rate of 100L / h, while simultaneously supplying hexane to the reactor. By controlling the reactor pressure and condensate return flow, the internal temperature is maintained at 70±1℃. After continuous operation for 2 hours, the bottom discharge valve of the reactor is opened and opened every 20 minutes to obtain the syndiotactic polystyrene powder. This powder is then extruded and granulated using a twin-screw extruder at 300℃ to obtain syndiotactic polystyrene granules, which constitute the syndiotactic polystyrene resin.

[0125] Example 9

[0126] This embodiment provides a syndiotactic polystyrene resin. The preparation method of the syndiotactic polystyrene resin includes: taking 4.4 kg of the syndiotactic polystyrene resin provided in Comparative Example 4, adding it to 5.6 kg of the syndiotactic polystyrene resin provided in Example 6, and mixing thoroughly and uniformly to obtain the syndiotactic polystyrene resin; the weight-average molecular weight of the syndiotactic polystyrene resin is 1.94 × 10⁻⁶. 5 g / mol, molecular weight greater than 5.82 × 10 5 The proportion of syndiotactic polystyrene resin at g / mol was 6.5%, and the molecular weight was less than 0.388 × 10⁻⁶. 5 The proportion of syndiotactic polystyrene resin was 4.2% (g / mol), and the supercooling was 29.9℃.

[0127] Table 2

[0128]

[0129] Comparative Example 6

[0130] This comparative example provides a syndiotactic polystyrene resin, which differs from Example 1 only in the preparation method of the catalyst. Specifically, in Example 1, toluene solutions of components (A) and (D) are pre-mixed, then a toluene solution of component (B) is added and mixed, followed by the addition of a toluene solution of component (C) to obtain the catalyst. All other preparation methods are the same as in Example 1. The weight-average molecular weight of the syndiotactic polystyrene resin is 1.87 × 10⁻⁶. 5 g / mol, molecular weight greater than 5.61 × 10 5The proportion of syndiotactic polystyrene resin was 6.2% (g / mol), and the molecular weight was less than 0.374 × 10⁻⁶. 5 The proportion of syndiotactic polystyrene resin was 7.2% (g / mol), and the supercooling was 29.9℃.

[0131] In this invention, the materials used in the application examples and comparative application examples can be purchased commercially or prepared using conventional methods; unless otherwise specified, the materials used in this invention are as follows.

[0132] Polyphenylene oxide (PPE): LXR035.

[0133] Compatibilizer 1: Maleic anhydride modified polyphenylene ether (PPE-MAH), the specific preparation method includes: dry mixing 1 kg of the polyphenylene ether, 40 g of maleic anhydride and 0.1 g of dicumyl peroxide, and then melt extruding and granulating at 250°C to obtain the particulate compatibilizer of the maleic anhydride modified polyphenylene ether.

[0134] Compatibilizer 2: Fumaric acid modified polyphenylene ether (PPE-FA), the specific preparation method includes: dry mixing 1 kg of the polyphenylene ether, 40 g of fumaric acid and 0.1 g of dicumyl peroxide, and then melt extruding and granulating at 250 °C to obtain the particulate compatibilizer of the fumaric acid modified polyphenylene ether.

[0135] Glass fiber (GF-1): ECS301HP-3-H.

[0136] Antioxidant 1: RIANOX 1098.

[0137] Antioxidant 2: Revonox 608.

[0138] Lubricant: TR044W.

[0139] Application Examples 1-14, Comparative Application Examples 1-6

[0140] Application Examples 1-14 and Comparative Application Examples 1-6 each provide a resin composition, the formulation of which is shown in Tables 3 and 4 by weight. The preparation method of the resin composition includes: mixing the components, then using a twin-screw extruder to knead the resin composition, extruding it to obtain a granular product, which is the resin composition. The filler needs to be fed separately from the side feed port. The extrusion temperature is 295°C.

[0141] Table 3

[0142]

[0143] Table 4

[0144]

[0145] Performance testing

[0146] The resin compositions provided in the application examples and comparative application examples were used to prepare test specimens using an injection molding machine under molding conditions of a barrel temperature of 295°C and a mold temperature of 50°C.

[0147] (1) Notched impact strength of cantilever beam: The test was conducted according to the standard method of GB / T 1843-2008. The specimen size was 80mm×10mm×4.0mm, the V-notch angle was 45°, and the root radius was 0.25±0.05mm. The test was conducted at 23±2℃ using a pendulum impact testing machine (model: ZwickRoell HIT25P) with an impact velocity of 3.5m / s.

[0148] (2) Post-shrinkage rate: a) Initial shrinkage rate determination (SR1): The sample with an initial size (denoted as L0) of 60mm×60mm×2mm was placed in an environment of 23℃ and 50% humidity for 48h. Its size (denoted as L1) was accurately measured using a two-dimensional image measuring instrument (model: Yuanxing Hengzhun YVM-3020). The initial shrinkage rate was obtained according to (L0-L1) / L0×100%; b) Post-baking shrinkage rate determination (SR2): After SR1 was determined, the sample was placed in an oven at 90℃ for 2h, and then placed in an environment of 23℃ and 50% humidity for 2h. Its size (denoted as L2) was measured. The post-baking shrinkage rate was obtained according to (L0-L2) / L0×100%; c) Post-shrinkage rate = SR2-SR1.

[0149] The specific test results are shown in Table 5.

[0150] Table 5

[0151]

[0152] As shown in Table 5, the syndiotactic polystyrene resin provided by this invention, by controlling the weight-average molecular weight composition and supercooling degree of the syndiotactic polystyrene resin within a specific range, is beneficial in balancing the toughness and long-term dimensional stability of the syndiotactic polystyrene resin. Materials containing the syndiotactic polystyrene exhibit a cantilever beam notched impact strength ≥ 9.0 kJ / m. 2 The shrinkage rate after shrinkage is ≤0.100%.

[0153] As can be seen from Application Example 1 and Comparative Application Examples 1, 4, and 6, when the supercooling is in the range of 28~34℃, the proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight average molecular weight is too high. The product does not crystallize sufficiently during the molding stage, resulting in poorer dimensional stability in the subsequent heating environment. The proportion of resin with a molecular weight less than 0.2 times the weight average molecular weight is too high, which leads to poor toughness.

[0154] As can be seen from Application Example 1 and Comparative Application Examples 2 and 3, when the proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight average molecular weight is ≤10wt%, and the proportion of syndiotactic polystyrene resin with a molecular weight less than 0.2 times the weight average molecular weight is ≤6wt%, the supercooling of the syndiotactic polystyrene resin is too high, the post-crystallization shrinkage is increased, and the long-term dimensional stability is worse; the supercooling is too low, and the toughness is reduced.

[0155] As can be seen from Application Example 1 and Comparative Application Example 5, when the proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight-average molecular weight is ≤10wt%, and the proportion of syndiotactic polystyrene resin with a molecular weight less than 0.2 times the weight-average molecular weight is ≤6wt%, and the supercooling is in the range of 28~34℃, the weight-average molecular weight of the syndiotactic polystyrene resin is relatively high (greater than 2.2×10). 5 (g / mol), subsequent shrinkage rate increases, and long-term dimensional stability deteriorates.

[0156] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A syndiotactic polystyrene resin, characterized in that, The weight-average molecular weight of the syndiotactic polystyrene resin is 1.4 × 10⁻⁶. 5 g / mol ~ 2.2 × 10 5 g / mol, wherein the proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight average molecular weight is ≤10wt%, and the proportion of syndiotactic polystyrene resin with a molecular weight less than 0.2 times the weight average molecular weight is ≤6wt%; The supercooling ΔT of the syndiotactic polystyrene resin is 28℃~34℃.

2. The syndiotactic polystyrene resin according to claim 1, characterized in that, The proportion of syndiotactic polystyrene resin with a molecular weight greater than 3 times the weight-average molecular weight is ≤7wt%.

3. The syndiotactic polystyrene resin according to claim 1, characterized in that, The proportion of syndiotactic polystyrene resin with a molecular weight less than 0.2 times the weight-average molecular weight is ≤3wt%.

4. A method for preparing syndiotactic polystyrene resin according to any one of claims 1 to 3, characterized in that, The preparation method includes: subjecting styrene monomer to an addition polymerization reaction in the presence of a catalyst and a nitrogen-hydrogen mixture to obtain the syndiotactic polystyrene resin, wherein the catalyst comprises the following components: (A) Titanocene metal compounds; (B) Alkyl aluminum oxane; (C) Compounds that can react with titanium metal compounds to form ionic complexes; (D) Organoaluminum compounds; The temperature of the addition polymerization reaction is 60℃~90℃, and the pressure of the addition polymerization reaction is 10kPaG~100kPaG; The concentration of the titanium-containing metal compound relative to styrene is 4 × 10⁻⁶. -5 mol / L ~ 5×10 -4 mol / L; The volume fraction of hydrogen in the nitrogen-hydrogen mixture is 0.1% to 15%. The method for preparing the catalyst includes: premixing component (A) and component (C) to obtain a first premix; premixing the first premix with component (D) to obtain a second premix; and mixing the second premix with component (B) to obtain the catalyst.

5. The preparation method according to claim 4, characterized in that, The general formula of component (A) is R 1 TiX 1 X 2 X 3 ; Among them, R 1 Selected from any one of substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl, or fused polycyclic cyclopentadienyl containing at least one saturated ring; X 1 X 2 and X 3 Each of the substituents is independently selected from any one of hydrogen atom, halogen atom, C1-C12 alkyl, C1-C12 alkoxy, C1-C12 alkylsilyl, C6-C20 aryl, C6-C20 aryloxy, C6-C20 arylsilyl, and C7-C20 aralkyl; the substituents include at least one of halogen atom, C1-C12 alkyl, C1-C12 alkoxy, C6-C20 aryl, C6-C20 aryloxy, and C7-C20 aralkyl, and when the number of substituents is greater than 1, the substituents may be the same or different; The component (B) is selected from C1~C8 straight-chain alkylaluminoxanes; The general formula of component (C) is ; Among them, R 2 Selected from at least one of alkyl groups with ≥1 carbon atom and aryl groups with ≥6 carbon atom, R 2 Same or different; M is selected from at least one of B, Al, Si, P, and As; X 4 Selected from at least one of C1-C12 alkyl, C1-C12 alkoxy, C6-C20 aryl, C6-C20 aryloxy, C7-C20 arylalkyl, and C6-C20 haloaryl; q is selected from an integer from 2 to 8, X 4 Same or different; The general formula of the component (D) is R 3 p AlH 3-p ; Among them, R 3 Selected from C1~C8 alkyl groups, where 0≤p≤3 and p>1, R 3 Same or different.

6. The preparation method according to claim 5, characterized in that, The molar ratio of aluminum to titanium metal compound in component (B) is (10~1000):

1.

7. The preparation method according to claim 4, characterized in that, The molar ratio of M to the titanoceramic metal compound in component (C) is (0.5~1.5):1; The molar ratio of aluminum to titanium metal compound in component (D) is (40~1000):

1.

8. A resin composition, characterized in that, The resin composition comprises the syndiotactic polystyrene resin as described in any one of claims 1 to 3, and further comprises at least one of fillers, compatibilizers, and other additives.

9. The resin composition according to claim 8, characterized in that, The resin composition contains ≥20% by mass of meso-tactic polystyrene resin; The resin composition comprises, by weight, 20-100 parts of syndiotactic polystyrene resin, 0.5-50 parts of filler, 0.1-10 parts of compatibilizer, and 0-20 parts of other additives; The filler includes at least one of fibrous filler, granular filler, and powdered filler; The fibrous filler includes at least one of glass fiber, carbon fiber, whiskers, ceramic fiber, and metal fiber; The granular filler and powdered filler are each independently selected from at least one of talc, carbon black, graphite, titanium dioxide, silicon dioxide, mica, calcium carbonate, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, tin oxide, aluminum oxide, kaolin, silicon carbide, metal powder, glass powder, glass flakes, and glass microspheres. The glass fiber has a length of 0.05 mm to 50 mm and a diameter of 5 μm to 20 μm; The compatibilizer includes modified styrene-based polymers and / or modified polyphenylene ether-based polymers; The modified styrene-based polymers include at least one of the following: styrene-maleic anhydride copolymer, styrene-glycidyl methacrylate copolymer, terminal carboxylic acid modified polystyrene, terminal epoxy modified polystyrene, terminal oxazoline modified polystyrene, terminal amine modified polystyrene, sulfonated polystyrene, styrene-based ionomers, styrene-methyl methacrylate copolymer, styrene-glycidyl methacrylate-methyl methacrylate terpolymer, acrylate-styrene copolymer, styrene-b-glycidyl methacrylate-b-styrene, polybutylene terephthalate-g-polystyrene, maleic anhydride modified syndiotactic polystyrene, fumaric acid modified syndiotactic polystyrene, glycidyl methacrylate modified syndiotactic polystyrene, and amine modified syndiotactic polystyrene. The modified polyphenylene ether polymer includes at least one selected from styrene-maleic anhydride-polyphenylene ether-grafted polymer, maleic anhydride modified polyphenylene ether, fumaric acid modified polyphenylene ether, glycidyl methacrylate modified polyphenylene ether, and amine modified polyphenylene ether. The modified polyphenylene ether polymers include poly(2,6-dimethyl-1,4-phenylene ether), poly(2,3-dimethyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-chloromethyl-1,4-phenylene ether), poly(2-methyl-6-hydroxyethyl-1,4-phenylene ether), poly(2-methyl-6-n-butyl-1,4-phenylene ether), poly(2-ethyl-6-isopropyl-1,4-phenylene ether), poly(2-ethyl-6-n-propyl-1,4-phenylene ether), poly(2,3,6-trimethyl-1,4-phenylene ether), poly[2-(4′-methylphenyl)-1,4-phenylene ether], poly(2-bromo-6-phenyl-1,4-phenylene ether), poly(2-methyl-6- At least one of the following: phenyl-1,4-phenylene ether, poly(2-phenyl-1,4-phenylene ether), poly(2-chloro-1,4-phenylene ether), poly(2-methyl-1,4-phenylene ether), poly(2-chloro-6-ethyl-1,4-phenylene ether), poly(2-chloro-6-bromo-1,4-phenylene ether), poly(2,6-di-n-propyl-1,4-phenylene ether), poly(2-methyl-6-isopropyl-1,4-phenylene ether), poly(2-chloro-6-methyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2,6-dibromo-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), and poly(2,6-diethyl-1,4-phenylene ether); The other additives include at least one of the following: rubbery elastomers, antioxidants, lubricants, crosslinking agents, crosslinking aids, nucleating agents, plasticizers, flame retardants, colorants, and antistatic agents.

10. An article characterized in that, The article comprises the syndiotactic polystyrene resin according to any one of claims 1 to 3 or the resin composition according to claim 8 or 9.

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