CN109251262B

CN109251262B - Low cis-polybutadiene rubber and preparation method thereof, and HIPS resin and preparation method thereof

Info

Publication number: CN109251262B
Application number: CN201710573884.3A
Authority: CN
Inventors: 李建成; 徐林; 王雪; 毕海鹏; 赵姜维
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2017-07-14
Filing date: 2017-07-14
Publication date: 2021-02-05
Anticipated expiration: 2037-07-14
Also published as: CN109251262A

Abstract

The invention relates to the field of synthetic rubber and modified resin thereof, in particular to low cis-polybutadiene rubber and a preparation method thereof, and HIPS resin and a preparation method thereof. The molecular weight of the low-cis polybutadiene rubber is trimodal distribution, the number average molecular weight of a first peak is 125,000-; wherein the peak area of the number average molecular weight of the first peak is 40-79%, the peak area of the number average molecular weight of the second peak is 20-60%, and the peak area of the number average molecular weight of the third peak is 1-10%. The low cis-polybutadiene rubber provided by the invention has a trimodal molecular weight, has a proper vinyl content and a proper solution viscosity, can be used as a toughening agent in HIPS resin synthesis, and the obtained HIPS resin has higher glossiness and impact resistance.

Description

Low cis-polybutadiene rubber and preparation method thereof, and HIPS resin and preparation method thereof

Technical Field

The invention relates to the field of synthetic rubber and modified resin thereof, in particular to low cis-polybutadiene rubber and a preparation method thereof, and HIPS resin and a preparation method thereof.

Background

In the preparation of HIPS resin (i.e., high impact polystyrene), the rubber conventionally selected as the toughening agent may be low cis-polybutadiene rubber, high cis-polybutadiene rubber, butadiene-isoprene copolymer, solution polymerized styrene-butadiene rubber, styrene-butadiene-styrene copolymer, and particularly, low cis-polybutadiene rubber and high cis-polybutadiene rubber are the most preferable. For low-temperature toughness resin, low cis-polybutadiene rubber and its derivative block styrene-butadiene rubber are generally selected for toughening. However, the molecular weight and the distribution of the toughened rubber have obvious influence on the impact resistance of the continuous bulk HIPS resin, and generally, the rubber molecular weight is too small, so that the toughening effect is poor; the rubber has too high molecular weight, and the HIPS resin has poor glossiness. In the selection of the toughening agent, rubbers with different particle sizes need to be matched, so that the rubbers with different particle sizes act synergistically to realize the balance of glossiness and impact resistance. The matching of multistage particle sizes of the same rubber is difficult to realize, and the matching can be realized by compounding different types of rubbers, but the polymerization process is more complicated.

Disclosure of Invention

The invention aims to obtain rubber with multi-level particle size distribution by a simple polymerization mode, overcomes the defect that the conventional flexibilizer for HIPS resin is difficult to obtain HIPS resin products with high glossiness and high impact resistance, and provides low cis-polybutadiene rubber serving as the flexibilizer and capable of obtaining the HIPS resin with high glossiness and high strength, a preparation method of the low cis-polybutadiene rubber, the HIPS resin and the preparation method of the HIPS resin.

In order to achieve the above object, the present invention provides, in one aspect, a low-cis polybutadiene rubber having a trimodal molecular weight distribution, a first peak number average molecular weight of 125,000-; wherein the peak area of the number average molecular weight of the first peak is 40-79%, the peak area of the number average molecular weight of the second peak is 20-60%, and the peak area of the number average molecular weight of the third peak is 1-10%.

The second aspect of the present invention provides a method for producing the low-cis polybutadiene rubber, comprising:

(1) in an organic solvent, in the presence of an organic lithium initiator and a structure regulator, carrying out anionic solution polymerization reaction on 1, 3-butadiene until the conversion rate of the 1, 3-butadiene is more than 99%;

(2) subjecting the product of the anionic solution polymerization reaction to a coupling reaction in the presence of a first coupling agent and a second coupling agent; wherein the first coupling agent is one or more of dihaloalkane coupling agents, and the second coupling agent is one or more of silane coupling agents;

(3) terminating the product of the coupling reaction in the presence of a terminating agent.

In a third aspect, the present invention provides a process for preparing a HIPS resin, the process comprising: in benzene solvent, in the presence of free radical initiator, styrene and toughening agent are polymerized; wherein the toughening agent contains the low cis-polybutadiene rubber; wherein the benzene solvent is one or more of unsubstituted or C1-C4 alkyl substituted benzene.

In a fourth aspect, the present invention provides a HIPS resin prepared by the above process.

The low cis-polybutadiene rubber provided by the invention has a trimodal molecular weight, has a proper vinyl content and a proper solution viscosity, can be used as a toughening agent in HIPS resin synthesis, and the obtained HIPS resin has higher glossiness and impact resistance.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In one aspect, the invention provides a low-cis polybutadiene rubber, wherein the molecular weight of the low-cis polybutadiene rubber is trimodal, the first peak number average molecular weight is 125,000-; wherein the peak area of the number average molecular weight of the first peak is 40-79%, the peak area of the number average molecular weight of the second peak is 20-60%, and the peak area of the number average molecular weight of the third peak is 1-10%.

According to the invention, the low-cis polybutadiene rubber provided by the invention has a trimodal molecular weight distribution, which is realized by a first coupling agent and a second coupling agent which are described below, and the trimodal molecular weight distribution enables the particle size of the low-cis polybutadiene rubber provided by the invention to be distributed in multiple stages, so that when the low-cis polybutadiene rubber is used as a toughening agent (aiming at HIPS resin or ABS resin), rubbers with different particle sizes act synergistically to obtain HIPS resin (or ABS resin) with balanced glossiness and impact resistance.

According to the present invention, it is preferable that the first peak number average molecular weight in the low-cis polybutadiene rubber is 135,000-210,000, preferably 150,000-200,000. Preferably, the second peak number average molecular weight is 90,000-130,000, preferably 95,000-125,000. Preferably, the third peak number average molecular weight is 45,000-65,000, preferably 48,000-62,000.

Wherein, the peak area of the number average molecular weight of the first peak is preferably 45 to 70%, preferably 50 to 65%. Preferably, the peak area of the number average molecular weight of the second peak is 25 to 50%, preferably 30 to 45%. Preferably, the peak area of the number average molecular weight of the third peak is 1 to 8%, preferably 2 to 5%.

Generally, controlling the peak area of the first peak number average molecular weight > the peak area of the second peak number average molecular weight > the peak area of the third peak number average molecular weight enables obtaining a rubber of lower solution viscosity, thereby contributing to improvement of resin glossiness. The low cis-polybutadiene rubber having a trimodal molecular weight distribution in the present invention may be understood as a mixture of polybutadienes having molecular weights within the above three ranges.

According to the present invention, in order to obtain the low-cis polybutadiene rubber having the above-mentioned trimodal molecular weight distribution, the low-cis polybutadiene rubber may be obtained by containing a coupling residue structure provided by a first coupling agent and a coupling residue structure provided by a second coupling agent, preferably, the first coupling agent is one or more of dihaloalkane coupling agents and the second coupling agent is one or more of silane coupling agents.

The dihalogenated alkane coupling agent can be various dihalogenated alkane coupling agents which are conventional in the field, and is preferably dihalogenated alkane of C4-C10. Wherein the halogen on the dihalogenated C4-C10 alkane may be the same or different and each is independently selected from fluorine, chlorine, bromine and iodine, wherein the dihalogenated C4-C10 alkane may be, for example, dihalobutane, dihalopentane, dihalohexane, dihaloheptane, dihalooctane, dihalononane, dihalodecane, etc. Preferably, the dihaloalkane coupling agent is one or more of 1, 4-dibromobutane, 1, 5-dibromopentane and 1, 8-dibromooctane.

Among them, the silane coupling agent is preferably silicon tetrachloride and/or silicon tetrabromide.

According to the present invention, preferably, the molar ratio of the coupling residue structure provided by the first coupling agent to the coupling residue structure provided by the second coupling agent is 1: 0.3 to 4, preferably 1: 0.33-2.3, more preferably 1: 0.38 to 1.8, more preferably 1: 0.5-1.5. When the molar ratio of the coupling residue structure is controlled, the peak areas of different molecular weights of the low cis-polybutadiene rubber can be better controlled, so that the low cis-polybutadiene rubber with better toughening performance is obtained.

According to the present invention, it is preferable that the total content of the coupling residue structure provided by the first coupling agent and the coupling residue structure provided by the second coupling agent is 0.1 to 0.5% by weight based on the total weight of the low-cis polybutadiene rubber. By controlling the content of the coupling residue structure within the above range, the proportion of the small-particle-size rubber can be controlled to 1 to 10% by weight.

According to the present invention, it is preferred that the low cis-polybutadiene rubber has a viscosity of a 5 wt% styrene solution at 25 ℃ of 100cp or less, preferably 30 to 100cp, more preferably 40 to 80 cp. Controlling the viscosity of a 5 wt.% styrene solution of low cis polybutadiene rubber at 25 ℃ in the above range and preferred ranges allows the resulting HIPS resin to achieve higher gloss and impact resistance.

According to the present invention, it is preferred that the low-cis polybutadiene rubber has a vinyl group content of 8 to 20% by weight, preferably 10 to 16% by weight. This ensures grafting and later moderate crosslinking of the continuous bulk HIPS resin.

According to the present invention, the low cis-polybutadiene rubber of the present invention can obtain a lower color, preferably a color of less than 10APHA, preferably 8APHA or less, more preferably 5APHA or less, for example, 1 to 5APHA in a 5 wt% styrene solution of the low cis-polybutadiene rubber.

According to the present invention, the above-mentioned production process of the present invention can obtain the low-cis polybutadiene rubber of the present invention described hereinabove, and therefore the above-mentioned description about the characteristics of the low-cis polybutadiene rubber also applies to the definition of the production process of the present invention.

According to the present invention, the low-cis polybutadiene rubber of the present invention is prepared in such a manner that the content of 1, 3-butadiene is 10 to 20% by weight, preferably 10 to 16% by weight, based on the total weight of the organic solvent and 1, 3-butadiene. The organic solvent may be any of various organic solvents conventionally used in the art, and preferably, the organic solvent is one or more of an alkane solvent and a cycloalkane solvent. Wherein the alkane solvent is preferably one or more of C4-C8 alkane solvents, and more preferably one or more of n-pentane, n-hexane, n-heptane and isooctane. Wherein, the naphthenic solvent is preferably one or more of C4-C8 naphthenic solvents, and more preferably one or more of cyclopentane, cyclohexane and cycloheptane.

According to the present invention, the organolithium initiator is not particularly limited, and various organolithium initiators conventionally used in the preparation of polybutadiene rubber in the art may be used, and preferably, the organolithium initiator is of the formula R¹A compound represented by Li, wherein R¹Alkyl selected from C1-C10; more preferably, the organolithium initiator is one or more of n-butyllithium, sec-butyllithium, iso-butyllithium, and tert-butyllithium, more preferably n-butyllithium and/or sec-butyllithium, and still more preferably n-butyllithium. Wherein, the organic lithium initiator is added into the polymerization system in the form of solution, the solvent of the organic lithium initiator can be one or more of hexane, cyclohexane, heptane and the like, and the concentration is preferably 0.1-1 mol/L.

The amount of the initiator used in the present invention can be reasonably selected according to the amount of the monomer and the molecular weight of the low cis-polybutadiene rubber to be obtained, and the amount can vary within a wide range, and preferably, the molar ratio of 1, 3-butadiene to the organolithium initiator is 700-: 1, preferably 750-: 1, more preferably 800-: 1.

according to the present invention, the anionic solution polymerization is performed in the presence of a structure modifier, which may be conventionally selected in the art, and preferably, the structure modifier is one or more of an ether compound structure modifier and an amine compound structure modifier.

Preferably, the ether compound structure regulator is one or more of aliphatic monoethers, aliphatic polyethers, aromatic ethers and cyclic ethers.

More preferably, the aliphatic monoether is one or more of aliphatic symmetrical monoether and aliphatic asymmetrical monoether, the aliphatic symmetrical monoether is one or more of methyl ether, ethyl ether, propyl ether and butyl ether, and the aliphatic asymmetrical monoether is methyl ethyl ether.

More preferably, the aliphatic polyether is one or more of aliphatic symmetrical polyether and aliphatic asymmetrical polyether, the aliphatic symmetrical polyether is one or more of ethylene glycol di-C1-C4 alkyl ether, diethylene glycol di-C1-C4 alkyl ether and diethylene glycol di-C1-C4 alkyl ether, preferably one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether and diethylene glycol diethyl ether, and the aliphatic asymmetrical polyether is ethylene glycol methyl ethyl ether and/or diethylene glycol methyl ethyl ether.

Preferably, the aromatic ether is anisole and/or diphenyl ether.

Preferably, the cyclic ether is one or more of tetrahydrofuran, tetrahydrofurfuryl alcohol C1-C4 alkyl ether and 1, 4-dioxycyclohexane, preferably one or more of tetrahydrofuran, tetrahydrofurfuryl alcohol methyl ether, tetrahydrofurfuryl alcohol ethyl ether, tetrahydrofurfuryl alcohol propyl ether, tetrahydrofurfuryl alcohol isopropyl ether, tetrahydrofurfuryl alcohol butyl ether and 1, 4-dioxycyclohexane.

Preferably, the amine compound structure regulator is one or more of N, N' -tetramethylethylenediamine, N-dimethyltetrahydrofurfuryl amine, triethylamine and tripropylamine.

In a preferred embodiment of the present invention, the structure modifier is one or more of tetrahydrofuran, tetrahydrofurfuryl alcohol methyl ether, tetrahydrofurfuryl alcohol ethyl ether, tetrahydrofurfuryl alcohol propyl ether, tetrahydrofurfuryl alcohol isopropyl ether, tetrahydrofurfuryl alcohol butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether and diethylene glycol diethyl ether, more preferably one or more of tetrahydrofurfuryl alcohol methyl ether, tetrahydrofurfuryl alcohol ethyl ether and tetrahydrofurfuryl alcohol propyl ether, and particularly preferably tetrahydrofurfuryl alcohol ethyl ether.

Wherein the molar ratio of the amounts of the structure regulator and the organolithium initiator is preferably from 0.01 to 1: 1, preferably 0.02 to 0.5: 1, more preferably 0.02 to 0.08: 1. this allows the vinyl content of the low cis-polybutadiene rubber to be within the specified range, while increasing the reaction rate.

According to the invention, the anionic solution polymerization reaction of step (1) will result in a conversion of 1, 3-butadiene of 99% or more; preferably, the anionic solution polymerization conditions include: the temperature is 0-100 ℃, preferably 40-100 ℃, and more preferably 60-100 ℃; the time is 20-80min, preferably 30-60 min; the gauge pressure is 0.1 to 1MPa, preferably 0.2 to 0.5 MPa.

According to the present invention, the selection of the first coupling agent and the second coupling agent is as described above, and the present invention will not be described in detail.

Wherein, the dosage molar ratio of the first coupling agent and the second coupling agent can be properly selected according to the proportion of corresponding coupling residue structures, and preferably, the dosage molar ratio of the first coupling agent and the second coupling agent is 1: 0.3 to 4, preferably 1: 0.33-2.3, more preferably 1: 0.38 to 1.8, more preferably 1: 0.5-1.5. Wherein the amount of the first coupling agent and the second coupling agent is suitably selected according to the content of the corresponding coupling residue structure in the resulting low-cis polybutadiene rubber, and preferably, the molar ratio of the total amount of the first coupling agent and the second coupling agent to the organolithium initiator is 0.3 to 0.5: 1, preferably 0.32 to 0.45: 1, more preferably 0.35 to 0.42: 1. wherein the coupling agent is added into the polymerization system in the form of solution, the solvent of the coupling agent can be one or more of hexane, cyclohexane, heptane and the like, the concentration of the first coupling agent is preferably 0.05-0.5mol/L, and the concentration of the second coupling agent is preferably 0.05-0.5 mol/L.

According to the present invention, preferably, the conditions of the coupling reaction include: the temperature is 50-80 deg.C, the time is 20-40min, and the gauge pressure is 0.1-1MPa (preferably 0.2-0.5 MPa).

Preferably, steps (1) and (2) are carried out in an inert atmosphere provided by a non-reactive gas selected from one or more of nitrogen, neon and argon.

According to the present invention, in the step (3), the coupling reaction may be terminated by using a terminator, and a polymerization solution of the low cis-polybutadiene rubber may be obtained, and in order to extract the low cis-polybutadiene rubber, the solvent or the like may be removed (for example, by vapor condensation desolvation treatment) and dried after the termination, and the low cis-polybutadiene rubber may be extracted.

Preferably, the terminating agent is one or more of a C1-C4 alcohol, an organic acid, and carbon dioxide, preferably one or more of isopropanol, stearic acid, citric acid, and carbon dioxide, more preferably carbon dioxide. The carbon dioxide is adopted for termination reaction, and the carbon dioxide can form carbonate with metal ions (Li, Mg, Al, Fe and Zn) in a polymerization system to be separated from the polymer, so that the color development reaction of the metal ions is avoided, and the product has lower chroma. The carbon dioxide herein may be introduced into the reaction system in the form of a gas (for example, carbon dioxide gas having a gauge pressure of 0.2 to 1MPa (for example, 0.3 to 0.6MPa) or may be introduced into the reaction system in the form of an aqueous dry ice solution (for example, having a concentration of 0.1 to 5% by weight).

The amount of the terminator to be used is not particularly limited, but is preferably 0.05 to 0.2 parts by weight per 100 parts by weight of the 1, 3-butadiene monomer.

In order to achieve the oxidation resistance of the low cis-polybutadiene rubber obtained, an antioxidant may be further introduced into the low cis-polybutadiene rubber, and preferably, after the termination in step (3), an antioxidant is introduced into the reaction system obtained by the termination, so that the polymerization solution of the low cis-polybutadiene rubber obtained may contain the antioxidant, and if it is desired to extract the low cis-polybutadiene rubber, the desolvation treatment may be performed after the introduction of the antioxidant. The antioxidant of the present invention is not particularly limited, and may be any of various antioxidants conventionally used in the art. For example, the antioxidant is one or more of 4, 6-bis (octylthiomethyl) o-cresol (trade name: antioxidant 1520), N-octadecyl β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (trade name: antioxidant 1076), N- (1, 3-dimethylbutyl) -N '-phenyl-p-phenylenediamine (trade name: antioxidant 4020), N-cumyl-N' -phenyl-p-phenylenediamine (trade name: antioxidant 4010NA), and N-phenyl-2-naphthylamine (trade name: antioxidant D), preferably a combination of antioxidant 1520 and antioxidant 1076, more preferably a combination of antioxidant 1076 in a weight ratio of 1: 1-3 of 1520 antioxidant and 1076 antioxidant.

Preferably, the weight ratio of the antioxidant to the 1, 3-butadiene is 0.1-0.4: 100.

The benzene solvent is one or more of unsubstituted or C1-C4 alkyl substituted benzene. Among them, the C1-C4 alkyl group may be, for example, one or more of methyl, ethyl, n-propyl, isopropyl, n-butyl, etc., and the C1-C4 alkyl-substituted benzene as the benzene-based solvent may be either single-or multi-substituted, and preferably, the benzene-based solvent is one or more of benzene, toluene, ethylbenzene, and xylene. The benzene solvent may be used in an amount conventionally used in the art for preparing HIPS resin, and preferably, the benzene solvent is used in an amount of 6 to 18% by weight, based on the total weight of the styrene, the benzene solvent and the toughening agent.

According to the present invention, although the toughening agent contains the low cis-polybutadiene rubber obtained by the above method of the present invention, the HIPS resin with high gloss and high impact resistance can be obtained, in order to obtain the HIPS resin with more excellent performance, the weight ratio of styrene to the toughening agent on a dry basis is preferably 550-1900: 100, preferably 600-: 100, more preferably 800-: 100, more preferably 900-: 100.

according to the present invention, the radical initiator may be various initiators conventionally used in the art for preparing HIPS resins, for example, the radical initiator may be one or more of thermal decomposition type initiators, preferably one or more selected from peroxide type initiators and azobisnitrile type compound initiators, more preferably one or more selected from t-butyl peroxy-2-ethylhexyl tert-carbonate, diacyl peroxide, peroxydicarbonate, peroxycarboxylate, alkyl peroxide and azobisnitrile type compounds, still more preferably one or more selected from dibenzoyl peroxide, di-o-toluyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, azobisisobutyronitrile and azobisisoheptonitrile. Preferably, the weight ratio of the amount of the styrene to the amount of the radical initiator is 2500-: 1, more preferably 3000-: 1, more preferably 4000-: 1, more preferably 5000-: 1.

according to the present invention, the polymerization reaction may incorporate various additives to provide a better balance of properties to the HIPS. The additive is preferably mineral oil. Preferably, the mineral oil is used in an amount of 2 to 5 parts by weight, relative to 100 parts by weight of styrene.

According to the present invention, preferably, the polymerization conditions include: the polymerization conditions include: the temperature is 100 ℃ and 150 ℃, and the time is 7-9 h. The polymerization reaction may be carried out with stirring, for example, with stirring at 100-400 rpm.

In another preferred embodiment of the present invention, according to the present invention, the polymerization conditions comprise: first reacting at 100-110 ℃ for 1-3h, then reacting at 115-125 ℃ for 1-3h (e.g. 1-2h), then reacting at 130-140 ℃ for 1-3h (e.g. 1-2h), and finally reacting at 145-155 ℃ for 1-3h (e.g. 1-2.5 h). More preferably, the polymerization conditions include: firstly reacting at 110 ℃ for 1.5-2.5h, then reacting at 125 ℃ for 1.5-2.5h, then reacting at 135 ℃ for 1.5-2.5h, and finally reacting at 155 ℃ for 1.5-2.5 h. The polymerization reaction may be carried out with stirring, for example, with stirring at 100-400 rpm.

In a fourth aspect, the invention provides a HIPS resin made by the above process.

Preferably, the HIPS resin of the present invention has a styrene content of from 85 to 95% by weight, preferably from 88 to 94% by weight (it being understood that the remaining content is mainly structural units provided for butadiene, i.e. the content of said butadiene structural units is from 5 to 15% by weight, preferably from 6 to 12% by weight); the weight average molecular weight of the HIPS resin is 150,000-400,000g/mol, more preferably 200,000-300,000 g/mol; the molecular weight distribution coefficient is 2-2.5.

The HIPS resin prepared by the method has higher contentImpact resistance, higher gloss. Preferably, the HIPS resin has an Izod impact strength of 10kJ/m²Above, preferably 12kJ/m²Above, preferably 12 to 15kJ/m²(ii) a The 60 ℃ surface gloss is 68 or more, preferably 70 or more, more preferably 75 or more, for example, 75 to 85.

The present invention will be described in detail below by way of examples.

In the following examples and comparative examples, the monomer conversion was determined gravimetrically, i.e.the weight of polymer after removal of solvent as a percentage of the theoretical polymer production.

The content of 1, 2-polymerized structural units in the low-cis polybutadiene rubber is measured by an AVANCEDRX400MHz type nuclear magnetic resonance apparatus produced by BRUKER, wherein the frequency is 400MHz, the solvent is deuterated chloroform, and the built-in standard is tetramethylsilane.

The molecular weight and the molecular weight distribution were measured by using a gel permeation chromatograph model HLC-8320 from Tosoh corporation, Japan, wherein the test conditions included: the chromatographic column is TSKgel SuperMultiporeHZ-N, the standard column is TSKgel SuperMultiporeHZ, the solvent is chromatographically pure THF, the calibration standard sample is polystyrene, the mass concentration of the sample is 1mg/mL, the sample amount is 10.00 mu L, the flow rate is 0.35mL/min, and the test temperature is 40 ℃.

The viscosity of a 5% by weight rubber solution at 25 ℃ was measured at a constant temperature of 25 ℃ using a capillary viscometer.

HIPS mechanical properties were tested using an INSTRON 5567 Universal Material testing machine, UK. Wherein the notched Izod impact Strength is measured in accordance with GB/T1843-1996 (kJ/m)²) (ii) a The 60 ℃ gloss was measured according to ASTM D526(60 ℃).

The pressure of carbon dioxide is hereinafter referred to as gauge pressure.

Antioxidant 1520 was purchased from national pharmaceutical agents; antioxidant 1076 was purchased from enokay reagent.

Tetrahydrofurfuryl alcohol ether is available from carbofuran reagent.

The first coupling agent and the second coupling agent were provided in the form of a hexane mixed solution in which the concentration of the first coupling agent was 0.1mol/L and the concentration of the second coupling agent was 0.1 mol/L.

N-butyllithium and sec-butyllithium were supplied from carbofuran reagent, and each was diluted with hexane to a 0.4mol/L hexane solution,

example 1

This example illustrates the low cis polybutadiene rubber of the present invention and its preparation.

(1) Under the protection of nitrogen, adding an organic solvent, a 1, 3-butadiene monomer and a structure regulator into a reactor, heating to a specified temperature, adding an organic lithium initiator, and then carrying out an anionic solution polymerization reaction at the temperature and a specified reaction pressure (the conditions are shown in table 1, and the dosages listed in the table are all measured by pure compounds), so as to obtain the monomer conversion rate shown in table 2;

(2) and then adding a first coupling agent and a second coupling agent (the kind and the amount are shown in Table 2, and the amounts are all measured as pure compounds) to the product of the anionic solution polymerization reaction to carry out the coupling reaction at a specified temperature and pressure (the conditions are shown in Table 2);

(3) terminating the coupling reaction by using a terminator (the type and the amount of which are shown in table 2), adding an antioxidant (the type and the amount of which are shown in table 2), mixing to finally obtain a low cis-polybutadiene rubber polymerization solution, wherein the content of the low cis-polybutadiene rubber is 13 wt%, and performing steam condensation desolvation treatment and drying on the obtained polymerization solution to obtain the low cis-polybutadiene rubber PB 1. The resulting polymer was subjected to structural and property measurements, and the results are shown in Table 3.

Examples 2 to 6

According to the method described in example 1, except that the reactions were carried out using the parameters shown in tables 1 and 2, to obtain low cis-polybutadiene rubbers PB2-PB6, respectively, wherein the low cis-polybutadiene rubber content in the respective low cis-polybutadiene rubber solutions was: PB 2: 14% by weight; PB 3: 15 wt%; PB 4: 12% by weight; PB 5: 13% by weight; PB 6: 13% by weight. The resulting polymer was subjected to structural and property measurements, and the results are shown in Table 3.

Example 7

According to the process described in example 1, except that isopropanol was used in place of the aqueous carbon dioxide solution as the terminator in the step (3) and the amount of isopropanol was 0.12g per 100g of 1, 3-butadiene, low-cis polybutadiene rubber PB7 was obtained, wherein the low-cis polybutadiene rubber content in the polymerization solution of the low-cis polybutadiene rubber was 13% by weight. The resulting polymer was subjected to structural and property measurements, and the results are shown in Table 3.

Comparative example 1

According to the method of example 1, except that no silicon tetrachloride is added in the step (2), but 1, 8-dibromooctane with the same amount is used to replace the silicon tetrachloride, wherein the monomer conversion rate before coupling is 100%; thus, low cis-polybutadiene rubber DPB1 was obtained, in which the content of low cis-polybutadiene rubber in the polymerization solution of low cis-polybutadiene rubber was 13% by weight. The resulting polymer was subjected to structural and property measurements, and the results are shown in Table 3.

Comparative example 2

According to the method of example 1, except that 1, 8-dibromooctane is not added in the step (2), but 1, 8-dibromooctane is replaced by equal amount of silicon tetrachloride, wherein the monomer conversion rate before coupling is 100%; thus, low cis-polybutadiene rubber DPB2 was obtained, in which the content of low cis-polybutadiene rubber in the polymerization solution of low cis-polybutadiene rubber was 13% by weight. The resulting polymer was subjected to structural and property measurements, and the results are shown in Table 3.

Comparative example 3

According to the process described in example 1, except that 1, 8-dibromooctane was used in an amount of 0.8mmol and silicon tetrachloride was used in an amount of 0.6mmol in the step (2), low-cis polybutadiene rubber DPB3 was obtained, wherein the content of the low-cis polybutadiene rubber in the polymerization solution of the low-cis polybutadiene rubber was 13% by weight. The resulting polymer was subjected to structural and property measurements, and the results are shown in Table 3.

Comparative example 4

According to the process described in example 1, except that in step (1), n-butyllithium was used in an amount of 4mmol, 1, 8-dibromooctane was used in an amount of 0.8mmol, and silicon tetrachloride was used in an amount of 0.6mmol, thereby obtaining a low-cis polybutadiene rubber DPB4 in which the low-cis polybutadiene rubber content in the polymerization solution of the low-cis polybutadiene rubber was 13% by weight. The resulting polymer was subjected to structural and property measurements, and the results are shown in Table 3.

TABLE 1

TABLE 2

TABLE 3

As can be seen from Table 3, the low cis-polybutadiene rubber with a trimodal molecular weight distribution obtained by the invention has appropriate 5% styrene solution viscosity and vinyl content, has low chroma, and is particularly suitable for HIPS modification.

Example 9

This example illustrates the HIPS resin of the present invention and the method of preparing the same.

Mixing 100g of low cis-polybutadiene rubber PB1, 150g of ethylbenzene and 1100g of styrene monomer, adding 45g of mineral oil (provided by Beijing Yanshan petrochemical company, chemical industry and factory, density 0.85-0.88g/ml, the same below) and 0.2g of tert-butyl peroxy-2-ethylhexyl carbonate, mixing, polymerizing for 2h at a stirring speed of 300rpm and a polymerization temperature of 105 ℃, and then heating to 120 ℃ for polymerizing for 2 h; heating to 135 ℃ at the stirring speed of 100rpm, polymerizing for 2h, finally heating to 150 ℃, polymerizing for 2h, and carrying out vacuum flash evaporation on the reaction product to remove unreacted monomers and solvent to obtain the HIPS resin P1.

The HIPS resin was dried and subjected to structural and performance measurements, the results of which are shown in Table 4.

Example 10

Mixing 120g of low cis-polybutadiene rubber PB2, 120g of xylene and 1100g of styrene monomer, adding 50g of mineral oil and 0.2g of azobisisobutyronitrile, mixing, polymerizing for 1.5h at the stirring speed of 350rpm and the polymerization temperature of 110 ℃, and then heating to 120 ℃ for polymerizing for 2.5 h; heating to 130 ℃ under the stirring speed of 200rpm, polymerizing for 1.5h, finally heating to 155 ℃ for polymerizing for 2h, and carrying out vacuum flash evaporation on the reaction product to remove unreacted monomers and solvent to obtain the HIPS resin P2.

Examples 11 to 16

According to the method described in example 9, except that low cis-polybutadiene rubber PB3-PB7 is used instead of low cis-polybutadiene rubber PB1, respectively, the reaction product is subjected to vacuum flash evaporation to remove unreacted monomers and solvent, so as to obtain HIPS resins P3-P7, respectively.

Comparative examples 1 to 4

According to the method described in example 9, except that the low cis-polybutadiene rubber PB1 was replaced by low cis-polybutadiene rubber DPB1-DPB4, respectively, the reaction product was subjected to vacuum flash evaporation to remove unreacted monomers and solvent to obtain HIPS resins DP1-DP4, respectively.

Comparative examples 5 to 6

According to the method described in example 9, except that low cis polybutadiene rubber PB1 was replaced by linear products 35AE and 55AE (solvent removed) from the Japanese Asahi continuous polymerization process, respectively, the reaction product was subjected to vacuum flash evaporation to remove unreacted monomers and solvent to obtain HIPS resins DP5-DP6, respectively.

TABLE 4

As can be seen from Table 4, by using the low cis-polybutadiene of the present invention as a toughening agent, it is possible to obtain a HIPS resin having more excellent properties, particularly impact resistance and gloss, and the HIPS resin obtained by the present invention has a great improvement in impact resistance and gloss as compared with the HIPS resin obtained by using a commercially popular toughening agent.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A low-cis polybutadiene rubber, which is characterized in that the molecular weight of the low-cis polybutadiene rubber is trimodal distribution, the first peak number average molecular weight is 125,000-; wherein the peak area of the number average molecular weight of the first peak is 40-79%, the peak area of the number average molecular weight of the second peak is 20-50%, and the peak area of the number average molecular weight of the third peak is 1-10%.

2. The low-cis polybutadiene rubber as described in claim 1, wherein in said low-cis polybutadiene rubber, said first peak number average molecular weight is 135,000-210,000;

the second peak number average molecular weight is 90,000-130,000;

the third peak number average molecular weight is 45,000-65,000.

3. The low-cis polybutadiene rubber as described in claim 2, wherein in said low-cis polybutadiene rubber, said first peak number average molecular weight is 150,000-200,000;

the second peak number average molecular weight is 95,000-125,000;

the third peak number average molecular weight is 48,000-62,000.

4. The low-cis polybutadiene rubber according to claim 2, wherein the viscosity of a 5 wt% styrene solution at 25 ℃ is 100cp or less.

5. The low cis-polybutadiene rubber of claim 4, wherein the low cis-polybutadiene rubber has a 5 wt% styrene solution viscosity at 25 ℃ of 30-100 cp.

6. The low cis-polybutadiene rubber of claim 5, wherein the low cis-polybutadiene rubber has a 5 wt% styrene solution viscosity at 25 ℃ of 40-80 cp.

7. The low-cis polybutadiene rubber according to claim 2, wherein the vinyl content in the low-cis polybutadiene rubber is 8 to 20% by weight.

8. The low-cis polybutadiene rubber according to claim 7, wherein the vinyl content in the low-cis polybutadiene rubber is 10 to 16% by weight.

9. The low-cis polybutadiene rubber of any one of claims 1-8, wherein the peak area of the first peak number average molecular weight is 45-70%;

the peak area of the number average molecular weight of the second peak is 25-50%;

the peak area of the number average molecular weight of the third peak is 1-8%.

10. The low-cis polybutadiene rubber of claim 9, wherein the peak area of the first peak number average molecular weight is 50-65%;

the peak area of the number average molecular weight of the second peak is 30-45%;

the peak area of the number average molecular weight of the third peak is 2-5%.

11. The low-cis polybutadiene rubber of any one of claims 1-8 and 10, wherein said low-cis polybutadiene rubber contains a coupling residue structure provided by a first coupling agent and a coupling residue structure provided by a second coupling agent; wherein the first coupling agent is one or more of dihaloalkane coupling agents, and the second coupling agent is one or more of silane coupling agents.

12. The low-cis polybutadiene rubber of claim 11, wherein the dihaloalkane coupling agent is a dihalogenated C4-C10 alkane.

13. The low-cis polybutadiene rubber of claim 12, wherein the dihaloalkane coupling agent is one or more of 1, 4-dibromobutane, 1, 5-dibromopentane, and 1, 8-dibromooctane.

14. The low-cis polybutadiene rubber of claim 11, wherein the silane-based coupling agent is silicon tetrachloride and/or silicon tetrabromide.

15. The low-cis polybutadiene rubber of claim 11, wherein the molar ratio of the coupling residue structure provided by the first coupling agent to the coupling residue structure provided by the second coupling agent is 1: 0.3-4.

16. The low-cis polybutadiene rubber of claim 15, wherein the molar ratio of the coupling residue structure provided by the first coupling agent to the coupling residue structure provided by the second coupling agent is 1: 0.35-2.3.

17. The low-cis polybutadiene rubber of claim 16, wherein the molar ratio of the coupling residue structure provided by the first coupling agent to the coupling residue structure provided by the second coupling agent is 1: 0.38-1.8.

18. The low-cis polybutadiene rubber of claim 17, wherein the molar ratio of the coupling residue structure provided by the first coupling agent to the coupling residue structure provided by the second coupling agent is 1: 0.5-1.5.

19. The low-cis polybutadiene rubber of claim 18, wherein the total content of coupling residue structure provided by the first coupling agent and the coupling residue structure provided by the second coupling agent is 0.1-0.5% by weight, based on the total weight of the low-cis polybutadiene rubber.

20. A process for preparing the low-cis polybutadiene rubber of any one of claims 1-19, which comprises:

21. The method of claim 20, wherein the organolithium initiator is of formula R¹A compound represented by Li, wherein R¹Selected from C1-C10 alkyl groups.

22. The process of claim 21, wherein the organolithium initiator is one or more of n-butyllithium, sec-butyllithium, iso-butyllithium, and tert-butyllithium.

23. The process of claim 22, wherein the organolithium initiator is n-butyllithium and/or sec-butyllithium.

24. The process as claimed in claim 21, wherein the molar ratio of 1, 3-butadiene to the organolithium initiator is 700-1300: 1.

25. the process as claimed in claim 24, wherein the molar ratio of 1, 3-butadiene to the organolithium initiator is 750-: 1.

26. the process as claimed in claim 25, wherein the molar ratio of 1, 3-butadiene to the organolithium initiator is 800-: 1.

27. the method of claim 21, wherein the anionic solution polymerization conditions comprise: the temperature is 0-100 ℃; the time is 20-80 min; gauge pressure is 0.1-1 MPa.

28. The method of claim 27, wherein the anionic solution polymerization conditions comprise: the temperature is 40-100 ℃; the time is 30-60 min; gauge pressure is 0.2-0.5 MPa.

29. The process of claim 28, wherein the anionic solution polymerization temperature is 60-100 ℃.

30. The method as claimed in any one of claims 20 to 29, wherein the dihaloalkane coupling agent is a dihalogenated C4-C10 alkane.

31. The method as claimed in claim 30, wherein the dihaloalkane coupling agent is one or more of 1, 4-dibromobutane, 1, 5-dibromopentane, and 1, 8-dibromooctane.

32. The method of claim 30, wherein the silane-based coupling agent is silicon tetrachloride and/or silicon tetrabromide.

33. The method of claim 30, wherein the first coupling agent and the second coupling agent are used in a molar ratio of 1: 0.3-4.

34. The method of claim 33, wherein the first coupling agent and the second coupling agent are used in a molar ratio of 1: 0.35-2.3.

35. The method of claim 34, wherein the first coupling agent and the second coupling agent are used in a molar ratio of 1: 0.38-1.8.

36. The method of claim 35, wherein the first coupling agent and the second coupling agent are used in a molar ratio of 1: 0.5-1.5.

37. The process of claim 30, wherein the molar ratio of the total amount of the first and second coupling agents to the organolithium initiator is from 0.3 to 0.5: 1.

38. the process of claim 37, wherein the molar ratio of the total amount of the first and second coupling agents to the organolithium initiator is from 0.32 to 0.45: 1.

39. the process of claim 38, wherein the molar ratio of the total amount of the first and second coupling agents to the organolithium initiator is from 0.35 to 0.42: 1.

40. the method of claim 30, wherein the conditions of the coupling reaction comprise: the temperature is 50-80 deg.C, the time is 20-40min, and the gauge pressure is 0.1-1 MPa.

41. The method of any one of claims 20-29 and 31-40, wherein the terminating agent is one or more of a C1-C4 alcohol, an organic acid, and carbon dioxide.

42. The method of claim 41, wherein the terminating agent is one or more of isopropanol, stearic acid, citric acid, and carbon dioxide.

43. The method of claim 42, wherein the terminating agent is carbon dioxide.

44. A method of preparing a HIPS resin, the method comprising: in benzene solvent, in the presence of free radical initiator, styrene and toughening agent are polymerized; wherein the toughening agent comprises the low cis polybutadiene rubber of any one of claims 1 to 19; wherein the benzene solvent is one or more of unsubstituted or C1-C4 alkyl substituted benzene.

45. The method of claim 44, wherein the benzene-based solvent is used in an amount of 6 to 18 wt%, based on the total weight of the styrene, the benzene-based solvent, and the toughening agent.

46. The method as set forth in claim 45 wherein the weight ratio of styrene to toughener on a dry weight basis is 550-1900: 100.

47. the method as claimed in claim 46, wherein the weight ratio of styrene to flexibilizer on a dry weight basis is 600-1600: 100.

48. the method as set forth in claim 47, wherein the weight ratio of styrene to the toughening agent on a dry weight basis is 800-1400: 100.

49. the method as set forth in claim 48, wherein the weight ratio of styrene to the toughening agent on a dry weight basis is from 900 to 1300: 100.

50. the method of any one of claims 44-49, wherein the free radical initiator is one or more of diacyl peroxides, peroxydicarbonates, peroxycarboxylates, alkyl peroxides, and azobisnitriles.

51. The method of claim 50, wherein the free radical initiator is one or more of t-butyl peroxy-2-ethylhexyl tert-carbonate, dibenzoyl peroxide, di-o-methylbenzoyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, azobisisobutyronitrile, and azobisisoheptonitrile.

52. The method as claimed in claim 50, wherein the weight ratio of the amount of styrene to the amount of the radical initiator is 2500-12000: 1.

53. the method as claimed in claim 52, wherein the weight ratio of the amount of styrene to the amount of the radical initiator is 3000-9500: 1.

54. the process as claimed in claim 53, wherein the weight ratio of the amount of styrene to the amount of the radical initiator is 4000-9000: 1.

55. the method as claimed in claim 54, wherein the weight ratio of the amount of styrene to the amount of the radical initiator is 5000-8500: 1.

56. the method of any of claims 44-49 and 51-55, wherein the polymerization conditions comprise: the temperature is 100-150 ℃, and the time is 7-9 h;

alternatively, the polymerization conditions include: firstly reacting at 110 ℃ for 1-3h, then reacting at 125 ℃ for 1-3h, then reacting at 140 ℃ for 1-3h, and finally reacting at 155 ℃ for 1-3 h.

57. The method of claim 56, wherein the polymerization conditions comprise: firstly reacting at 110 ℃ for 1.5-2.5h, then reacting at 125 ℃ for 1.5-2.5h, then reacting at 135 ℃ for 1.5-2.5h, and finally reacting at 155 ℃ for 1.5-2.5 h.

58. HIPS resin produced by the process of any of claims 44-57.

59. The HIPS resin of claim 58, wherein the content of structural units of styrene in the HIPS resin is 85 to 95% by weight; the weight average molecular weight of the HIPS resin was 150,000-400,000 g/mol.

60. The HIPS resin of claim 59, wherein the HIPS resin has a weight average molecular weight of 200,000-300,000 g/mol.

61. The HIPS resin of claim 59, wherein the HIPS resin has a surface gloss of 68 or more at 60 °.

62. The HIPS resin of claim 61, wherein the HIPS resin has a surface gloss of 70 or more at 60 °.

63. The HIPS resin of claim 62, wherein the HIPS resin has a surface gloss of 75 or more at 60 °.