JPS5938209A - Branched conjugated diene polymer - Google Patents

Abstract

PURPOSE:A branched conjugated diene polymer excellent in processability, strength, elasticity, etc., containing a branched conjugated diene polymer in which the bond of the branch bond portion comprises a metal-carbon bond, and in which the terminal of polymer molecule has a functional group consisting of a tert. amino group. CONSTITUTION:A conjugated diene (e.g., 1,3-butadiene) or its mixture with an aromatic vinyl compoune (e.g., styrene) is solution-polymerized in a hydrocarbon solvent by using a lithium amide compound as an initator. Then, the coupling reaction of the product is effected by the addition of a coupling agent such as tin tetrachloride, germanium tetrachloride or solicon tetrachloride to obtain the purpose branched conjugated diene polymer. The produced polymer contains 0- 40wt% combined aromatic vinyl compound, contains tert. amino groups on polymer terminals, and contains at least 20wt% branched conjugated polymer in which the bond of the branched bond portion consists of a bond between carbon and a metal selected from the group consisting of Sn, Si, and Ge.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to branched conjugated diene polymers having improved processability.

Branched butadiene polymers do not exhibit low-temperature flow during storage, and their vulcanizates have excellent rebound properties and modulus, making them suitable as rubber materials for tires with low fuel consumption. (% Publication 44-4996, Japanese Patent Publication 57-1999)
-55912) However, on the other hand, it has poor adhesiveness, and raw rubber 90
- It has drawbacks such as poor roll windability and poor roll windability of carbon kneaded material.

Conventionally, polymers with good roll processability have been produced by continuous polymerization using an organolithium compound as an initiator.
It can be obtained by blending a high molecular weight polymer and a low molecular weight polymer, by polymerizing in the presence of a chain transfer agent, by campling a polymer with an active anion end with a halogenated hydrocarbon compound, etc. It was a polymer with a wide molecular weight distribution. However, these polymers are inadequate in terms of modulus and rebound, and are therefore unsuitable as tire rubber materials for fuel-efficient tires.

As a result of intensive research into rubber materials with excellent processability, modulus, and rebound properties, the present inventors found that a polymer obtained using a lithium amide compound as an initiator has a functional group consisting of a tertiary amino group at the end. It has been found that a branched conjugated diene polymer has excellent modulus, rebound, and breaking strength, and has excellent processability such as roll processability.

An object of the present invention is to provide a novel branched conjugated diene polymer that has improved processability and excellent fracture strength and impact resilience.

That is, the present invention provides a branched conjugated diene polymer solution-polymerized in a hydrocarbon solvent using a lithium amide compound as an initiator, comprising: (1) 0 to 40% by weight of a bonded aromatic vinyl compound (
2) Contains at least 20% by weight or more of a branched conjugated diene polymer in which the branch bond portion is a metal-carbon (metal: one or more selected from tin, silicon, germanium) bond (3) Polymer terminal The object of the present invention is to provide a branched conjugated diene polymer characterized in that it has a functional group consisting of an 8th-class amino group in its moiety.

The branched conjugated diene polymer of the present invention is produced by solution polymerizing a conjugated diene or a conjugated diene and an aromatic vinyl compound in a hydrocarbon solvent using a lithium amide compound [t] as an initiator, and then adding a tin halide compound, a halogenated germanium Q compound, silicon halide compound, vinyl tin compound,
It is obtained by performing a coupling reaction with an allyl tin compound, an alkoxy silicon compound, etc.

As the initiator, a lithium amide compound obtained by reacting an equal amount of a secondary amine compound with lithium metal or an organic lithium compound is used. The presence of an excessive amount of organolithium compound or secondary amine compound is not preferable because a polymer containing no 8th-class amino group at the polymer terminal is formed.

As a specific example of the initiator, the general formula Li N RI RI2
(R1 and R2 are 01 to B alkyl groups or cyclohexyl groups), lithium diethylamide, lithium dipropylamide, lithium dibutylamide, lithium dioctylamide, lithium dicyclohexylamide, lithium morpholinamide, lithium piperazineamide, etc. Can be mentioned. The amount of initiator is monomer 100
0.1 to 100 milligram equivalents of lithium atoms are used per g.

As the conjugated diene, 1,8-butadiene, isoprene, etc. are used. Among these, 1,8-butadiene is preferred.

As the aromatic vinyl compound used in the copolymerization reaction with the conjugated diene, styrene, vinyltoluene, p-methylstyrene, m-methylstyrene, p-methoxystyrene, vinylnaphthalene, etc. are used. Among these, styrene is preferred.

As the solvent, hydrocarbon solvents such as pentane, hexane, heptane, octane, methylcyclopenkune, cyclohexane, benzene, and xylene are used.

Coupling agents include tin 10genide compounds such as tin tetrachloride, tin tetrabromide, and methyl tin trichloride; vinyl tin compounds such as tetravinyltin and butyltrivinyltin; tetraallyltin, diethyl diallyltin, and Allyltin compounds such as (2-octenyl)tin, tin compounds such as tetraphenyltin and tetrabenzyltin, 7-logenated silicon compounds such as silicon tetrachloride, silicon tetrabromide, methyl silicon trichloride, butyl silicon trichloride, Examples include alkoxy silicon compounds such as tetraethoxy silicon, tetramethoxy silicon, and tetraethoxy silicon, and germanium halides such as germanium tetrachloride. Most preferred for the purposes of the present invention are polymers containing branched styrene-butadiene polymers in which the linkages in the branching moieties are tin-conjugated diene bonds; is obtained by adding 1 to 20 moles of conjugated diene per atomic equivalent of lithium and then adding a coupling agent.

The polymerization reaction and the coupling reaction are carried out in the range of 0 to 120°C, and may be performed under isothermal conditions or under elevated temperature conditions.

The polymerization method may be either a batch polymerization method or a continuous polymerization method.

The microstructure of the conjugated diene portion of the polymer is composed of ethers and 8th class amines such as tetrahydrofuran, diethyl ether, dimethoxybenzene, dimethoxyethane, ethylene glycol shiftyl ether, triethylamine, pyridine, NNN'N'-tetramethylethylenediamine, and dimethoxyethane. It can be freely changed within the range of 10 to 95% by adding the compound to the polymerization system 2).

If you want to improve the wet kid resistance as a rubber for outdoor tire treads, use vinyl-containing -@:f8 in the conjugated diene part.
The purpose can be achieved by setting it to 0% or more.

Mooney viscosity (M L1+ 4
．． (100°C) is 30 to 150, and if it is less than 80, the tensile properties and rebound properties will deteriorate, which is not preferable.

Moreover, if it exceeds 150, the workability will be poor and it is not preferable.

The amount of bound aromatic vinyl compound is 0 to 40% by weight, preferably 10 to 85% by weight. If it exceeds 40% by weight, the impact resilience and tensile strength will be poor, which is not preferable.

The molecular weight distribution is limited to a range of 1.5 to 5.0 by Mw/F'A n (Mw: weight average molecular weight, n: number average molecular weight) determined from a gel permeation chromatogram. Branched polymers having a narrow molecular weight distribution with Mw/M n of less than 1.5 are usually difficult to manufacture, and when Mw/M n exceeds 5, the impact resilience is significantly reduced.

However, in the branched polymer of the present invention, the bond of the branched portion is metal-
A branched polymer containing at least 20% by weight of a branched polymer consisting of carbon bonds (metals: tin, silicon, germanium), where the proportion of the branched polymer in the polymer is less than 20% by weight, the tensile properties It is unfavorable in terms of rebound resilience.

In the case where the branched polymer of the present invention is a branched styrene-butadiene copolymer, the tin-butadienyl bond in the branch bond portion is lower than the tin-styrene bond in terms of processability, and the rebound resilience of the vulcanizate is lower. is also the most excellent and is preferred.

Furthermore, the branched polymer of the present invention is characterized by having a functional group consisting of an 8th-class amino group at the end of the polymer. A tertiary amino group is introduced at one end per polymer chain molecule (Tai Chuncheng J, Pol
ymer 8 ci, (Poly+ner
Ohem, Edit 1on) 17, 184
7-1.848 (1,f'+79) or Macro
molecules 14(3) 664-66.8(
19FS1), etc.) By introducing a tertiary amino group into the terminal portion of the polymer, roll workability is improved, and the vulcanizate becomes a polymer with excellent tensile strength and impact resilience.

The branched conjugated diene polymer of the present invention can be used alone or in combination with natural rubber, high cis polyisoprene, emulsion polymerized styrene-butadiene copolymer, and bonded styrene containing no tertiary amino group at the terminal end of the polymer. 40 m·%, solution polymerized styrene-butadiene copolymer with a vinyl content of 10 to 80%, I'tH1Co, '1. '+s Rubber selected from one or more of high cis polybutadiene obtained using a Nd catalyst, low cis polybutadiene obtained using an organolithium catalyst, and ethylene propylene diene terpolymer. After being blended and subjected to various formulations and vulcanization, the tire tread can be used for tire applications such as carcass and sidewalls, belts, anti-vibration rubber, window frames, hoses, and industrial products.

The present invention will be explained below with reference to Examples, but is not limited by these Examples.

In the example, the content of aromatic vinyl compound in the copolymer is 1
00 MHz nuclear magnetic resonance apparatus.

The microstructure of the conjugated diene moiety was determined by an infrared method (Morello method). The proportion of branched polymers in the polymer can be determined using bimodal gel permeation chromatography (GP).
It was determined from the ratio of the peak area of the high molecular weight side of O).

The roll windability of the mixed wire material was determined by the rollability of the mixed wire material kneaded with a plastic bender at 60° C. on a 6-inch roll.

The rebound resilience was measured at 70°C to serve as an index of the tire's rolling friction resistance. A Dunlop tributometer was used as the measuring device.

The tensile properties were measured according to JIS K6fllO].

Examples 1 to 8, Comparative Examples 1 to 8] After charging cyclohexane, monomers, and tetrahydrofuran to the O1 reactor according to the recipe shown in Table 1,
Using a polymerization initiator shown in Table 1, overlaying was carried out for 60'C1 hour. After 5 minutes of adding 5.9 g of 1.8-butadiene, tin tetrachloride was added in the amount shown in Table 1, and a coupling reaction was carried out at 60 DEG C. for 180 minutes.

After adding 3.5 I of 2,6-di-tertiary-butyl-P-cresol to the heavy threat solution, the solvent was removed by steam stripping, and the mixture was further dried with a hot roll at 110° C. to obtain a polymer.

The properties of the polymers are shown in Table 2. The properties of the vulcanizate were determined by kneading and compounding the polymer with 250τ Brabender and 6 indylol according to the formulation shown in Table 8, and then vulcanizing it at 145°C for 20 minutes, and performing various measurements using the vulcanizate. Obtained.

The branched styrene-butadiene copolymer of Example 1.2 had better processability compared to the branched styrene-butadiene copolymer of Comparative Example t (using n-butyllithium). It has excellent modulus, tensile strength, and impact resilience compared to styrene-butadiene copolymers (without polymer) and 8 (high styrene content).

The branched polybutadiene of Example 4 is a polymer that has excellent roll processability, as well as excellent modulus and impact resilience.

Example 4 The same procedure as in Example 1 was carried out except that isoprene was used in place of 1.8-butadiene and styrene, tetrahydrofuran was not used, and the polymerization time was 8 hours. Results first
It is shown in Table 2.

Table 3 1) N-phenyl-N'-isopropyl-13-phenylenediamine 2) Sodium-dibutyldithio-nocmate 8) Diphenylguanidine 4) Dibenzothiazyl disulfide Reference example Using a lithium amide compound as an initiator The following experiment proves that 1 equivalent of amino groups are introduced into the polymer per molecule of the polymer chain, and that no amino groups are introduced into the polymer using an alkyllithium compound as an initiator. In the case of a molecular weight suitable for use as a rubber (Mooney viscosity 30 to 150), the amount of initiator used is small, and it is difficult to confirm the amino group content in the produced polymer by conventional analytical methods due to analytical accuracy. This study was carried out on low molecular weight polymers using amide compounds as initiators.

50 (20 g of lithium morpholinide, 7.5 g of tetrahydrofuran, and 250 g of cyclohexane were added to an ICC reactor equipped with a stirrer, and stirred at 60°C for 30 minutes.1
．． 3-butadiene a, 7511s styrene 1.25
The polymerization was carried out at 60° C. for 1 hour.

The resulting polymer solution was poured into 500 ml of methanol to precipitate the polymer. After vacuum drying the polymer at 50° C. for 115 hours, the number average molecular weight of the polymer was measured by vapor pressure osmosis method and found to be 1,320.

In addition, when the nitrogen content was measured using the Kelsol method [Handbook of Analytical Chemistry (edited by the Japanese Society of Analytical Chemistry), revised third edition, p. 218 (1981, round neck)], the nitrogen content was 11%.

It is clear that approximately one equivalent of monoxide, ie, an 8th-class amino group, is contained in the molecular value.

@ ■ Noritium morpholinide 2. () The same procedure as (1) was carried out except that 0.82 g of n-butyllithium was used instead of ji.For the number average molecule, it was 1. (150, for the nitrogen edible, it was (1%). It can be seen that it contains no nitrogen at all.

Patent Applicant Japan Synthetic Rubber Co., Ltd. Agent Patent Attorney Akira Ito Proceedings Amendment River (Method) % Formula %] ■ Case Indication 1982 Special W [Application No. 148514 2 Name of Invention Branched Conjugated Diene System] Polymer 3 Relationship with the supplementary IF case Patent applicant address 2-11-24 Tsukiji, Chuo-ku, Tokyo Name [21 Honsei Com Co., Ltd. Representative Hisashi Yoshimasa 4° Agent, □. Address: Jinbocho 2-chome Φ2-5, JinH, Chiyoda-ku, Tokyo
Date of amendment order: November 1z, 1980 (Shipping date: November 30, 1982) 6. Column for detailed description of the invention for the subject specification of supplement 11 (the frame line of the table is unclear) 7. Amendment As shown in the attached sheet (replacement with table) Table 8 υ N-phenylene A, N/ (soprobyl-P-phenylenediamine sodium-dibutyl dithiocarpamate 8) diphenylguanidine

Claims (1)

[Claims] (1) A solution-polymerized conjugated diene polymer containing 0 to 40% by weight of a bonded aromatic vinyl compound, which has an 8th-class amino group at the end of the polymer, and which contains at least a branched conjugated diene polymer. 20% by weight, and the bond of this branched bond portion is a bond with one or more metal atoms and carbon atoms selected from tin, silicon, and germanium (r-Featured branched conjugated diene polymer .