JPH05331243A - Production of multi-branched polymer - Google Patents

Abstract

PURPOSE:To simply produce a multi-branched polymer consisting of a core polymer component and an arm polymer component, using isobutylene as a main component monomer constituting the graft polymer component and useful as a viscosity controlling agent, etc., for lubricating oil. CONSTITUTION:The objective multi-branched polymer consists of a core polymer component and an arm polymer component and is produced by carrying out cationic polymerization in a step producing a core polymer component by polymerizing a monomer having >=2 cationic-polymerizable unsaturated bond and a step producing the arm polymer component by polymerizing a monofunctional cationic-polymerizable monomer consisting essentially of isobutylene.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscosity adjusting agent for a lubricating oil, which comprises a nuclear polymer component and an arm polymer component, and the arm polymer component is a polymer of a monomer whose main component is isobutylene. The present invention relates to a method for producing a hyperbranched polymer useful as the above.

[0002]

2. Description of the Related Art Heretofore, a multi-branched polymer obtained by hydrogenating a polymer containing a conjugated diolefin block by anionic polymerization has been known. This multi-branched polymer is a viscosity adjusting agent for lubricating oil or a sheet. , A film or other molded article (Japanese Patent Laid-Open No. 61-50120).
See Japanese Patent Laid-Open No. 3-167207). However,
In this multi-branched polymer, a hydrogenation step is indispensable for improving the heat resistance of the polymer, and therefore, an expensive catalyst is usually used, and a complicated operation of carrying out the reaction under a high-pressure hydrogen atmosphere Was needed. Therefore, there has been a strong demand for a more convenient method for producing a multibranched polymer having a saturated polymer skeleton. On the other hand, Kennedy et al. Have proposed a method for producing an isobutylene-based hyperbranched polymer having a saturated skeleton by cationic polymerization using a polyfunctional initiator (for example, Polym.
1, 19 , 43-50 (1988)), this polymer has no nuclear polymer component, and the arm polymer chain is simply branched from the polymerization initiator, so that it is a multi-branched polymer. Is substantially determined only by the arm polymer polymer component, and the number of arm polymer chains is limited to 4, and the properties as a multi-branched polymer have not been fully provided. However, there were restrictions in terms of characteristics balance, application, etc. considering not only heat resistance but also mechanical characteristics. Higashimura et al. Also proposed a method for producing a hyperbranched polymer including a step of polymerizing vinyl ether using a HI-ZnI ₂ -based cationic polymerization initiator (for example, Macromolecules, 1991 (2).
4), 2309-2313), this multi-branched polymer is not suitable as a viscosity modifier for lubricating oils, for example, since the arm polymer component is a polar polymer having an oxygen atom.

[0003]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned technical background, and its object is to include a core polymer component and a arm polymer component, and to provide the arm polymer component. The main constituent monomer is isobutylene, which makes it useful as a viscosity modifier for lubricating oils,
An object of the present invention is to provide a method for easily producing a multi-branched polymer which can have various property balances.

[0004]

Means for Solving the Problems In producing a hyperbranched polymer composed of a nuclear polymer component and an arm polymer component, the present invention provides a monomer having two or more cationically polymerizable unsaturated bonds in a molecule. A step of polymerizing a cation-polymerizable monomer containing a monomer as a main component to produce a nuclear polymer component, and polymerizing a monofunctional cation-polymerizable monomer containing isobutylene as a main component to form an arm polymer component. The present invention relates to a method for producing a hyperbranched polymer, characterized in that the step of forming is carried out in multiple steps using a cationic polymerization initiator.

The present invention will be described in detail below. First, the nuclear polymer component of the multi-branched polymer contains a monomer having two or more cationically polymerizable unsaturated bonds in the molecule (hereinafter, referred to as "polyfunctional monomer") as a main component. It is produced by cationically polymerizing a cationically polymerizable monomer.

Examples of the polyfunctional monomer include polyvinyl compounds such as divinyl compounds and trivinyl compounds,
Examples thereof include polyallyl compounds such as diallyl compounds and triallyl compounds, and among them, divinyl aromatic compounds and divinyl ether compounds are preferable.

Specific examples of the polyfunctional monomer include divinylbenzene, divinyl ether, divinylcyclohexane, divinyldichlorosilane, divinyldimethoxysilane, divinyldimethylsilane, 1,3-divinyl-1,
1,3,3-tetramethyldisiloxane, diallylbenzene, diallyl ether, diallyldichlorosilane, diallyldimethoxysilane, diallyldimethylsilane, trivinylbenzene, trivinylcyclohexane, trivinylmethylsilane, triallylbenzene, triallylcyclohexane, Tetravinylsilane etc. can be mentioned. Of these, divinylbenzene and divinyl ether are preferable. These polyfunctional monomers can be used alone or in combination of two or more.

The content of the polyfunctional monomer in the monomer forming the nuclear polymer in the present invention is in the range of 50 to 100 mol%. The content of the polyfunctional monomer is preferably higher from the viewpoint of the yield of the multibranched polymer, the average degree of branching of the multibranched polymer produced, and the like. On the other hand, if the content of the polyfunctional monomer is too high, the polyfunctional monomers are likely to react with each other outside the reaction system before being added to the reaction system, and it is difficult to obtain a desired multibranched polymer. May be The polyfunctional monomer content is preferably 50 to 95 mol%, more preferably 60 to 90 mol%.

In the present invention, a monofunctional cationically polymerizable unsaturated monomer copolymerizable with isobutylene and / or isobutylene (hereinafter referred to as a monomer copolymerizable with isobutylene) is used as a monomer constituting the nuclear polymer component. It is preferable that the functional cationically polymerizable unsaturated monomer is referred to as a "monofunctional comonomer") together with the polyfunctional monomer. The content of isobutylene and / or monofunctional comonomer in this case is less than 50 mol%. The monofunctional comonomer is generally described below, but preferred monofunctional comonomers used for the production of the nuclear polymer are 2-methyl-1-butene, 3-methyl-1-butene, Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α
-Methylstyrene, dimethylstyrene, monochlorostyrene, isoprene and indene.

The nuclear polymer component in the present invention may contain polar atoms derived from divinyl ether or the like to some extent. This is because the solvation of the resulting multi-branched polymer is mainly described later. Since it depends on the non-polar or low-polarity arm polymer polymer component, there is no particular problem in terms of properties or applications.

Next, the arm-branching polymer component of the multi-branched polymer is composed of isobutylene or a mixture of isobutylene and a monofunctional comonomer, and a monofunctional cationically polymerizable unsaturated containing 50 to 100 mol% of isobutylene. It is produced by cationically polymerizing a monomer. Examples of the monofunctional comonomer include propylene, 1-butene, 2-butene, 2-methyl-1-butene, 3-methyl-1-butene, pentene, 4-methyl-1-pentene,
Hexene, vinyl cyclohexane, butadiene, isoprene, cyclopentadiene, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, styrene, methylstyrene, ethylstyrene, α-methylstyrene, dimethylstyrene, monochlorostyrene, dichlorostyrene, α-chlorostyrene, β-pinene, indene, Vinyltrichlorosilane, vinylmethyldichlorosilane, vinyldimethylchlorosilane, vinyldimethylmethoxysilane, vinyltrimethylsilane, allyltrichlorosilane, allylmethyldichlorosilane, allyldimethylchlorosilane, allyldimethylmethoxysilane,
Allyltrimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropyldimethylmethoxysilane, γ-methacryloyloxypropyltrimethylsilane and the like can be mentioned. These monofunctional comonomers may be used alone or in combination of two or more.

Monofunctional comonomers used to form armature polymers include 2-methyl-1-butene and 3-methyl-butene.
1-butene, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, dimethylstyrene, monochlorostyrene, isoprene and indene are preferred.

The content of isobutylene in the monofunctional cationically polymerizable unsaturated monomer for producing the armband polymer in the present invention is in the range of 50 mol to 100%. The preferable range is appropriately selected according to the characteristics of the armature polymer, the desired application of the hyperbranched polymer, the type and content of the monofunctional comonomer used in combination, and the like.
That is, the main point of the present invention is to produce a non-polar or low-polar arm polymer containing 50% by mole or more of isobutylene in order to obtain a multi-branched polymer useful as a viscosity modifier for lubricating oils. Therefore, when the monofunctional comonomer used in combination is a monomer having a relatively high polarity, and / or the ratio of the monomer having a relatively high polarity in the total monofunctional comonomer is large. In this case, it becomes necessary to increase the isobutylene content. Generally, the content of isobutylene is preferably 55 to 95 mol%, more preferably 60 to 90 mol%.

When cationically polymerizing these monofunctional cationically polymerizable unsaturated monomers containing isobutylene, isobutylene or a mixture thereof with a monofunctional comonomer is used.
It can be added by an appropriate method such as batch addition, divided addition, continuous addition, or a combination thereof, and when a mixture of isobutylene and a monofunctional comonomer is used, before or addition of isobutylene After that, the monofunctional comonomer can be added all at once, dividedly or continuously.
Further, the component or composition of the monofunctional cationically polymerizable unsaturated monomer containing isobutylene to be added can be changed stepwise (one step or multistep) or continuously.

In the present invention, the components of the monofunctional cationically polymerizable unsaturated monomer, the composition and the addition method are variously combined to obtain AB type, ABA type,
(AB) A multi-block copolymer segment such as _n -type or a block copolymer segment in which the component or composition of each polymer block is changed stepwise or continuously is introduced into the arm polymer component. be able to. The preferred block copolymer segment in this case is
For example, a polymer block composed of two or more kinds of polymer blocks having different glass transition points can be mentioned. As a combination of polymer blocks having different glass transition points in the block copolymer segment, a polymer block containing isobutylene having a glass transition point of -40 ° C or lower and an isobutylene having glass transition point of + 50 ° C or higher are contained. Those comprising a polymer block containing no such compound are particularly preferred. This-
Examples of the polymer block having a glass transition point of 40 ° C. or lower include a homopolymer of isobutylene or a random copolymer of isobutylene and isoprene (molar charge ratio of isobutylene and isoprene = 1/99 to 12/8).
The thing which consists of 8) can be mentioned. Also, +50
Examples of the polymer block having a glass transition point of ° C or higher include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, dimethylstyrene, pt-butylstyrene and p. A polymer composed of at least one monomer of the group consisting of -chlorostyrene can be mentioned.

The multi-branched polymer according to the present invention comprises (1)
In producing a multi-branched polymer composed of a nuclear polymer component and an arm polymer component, a step of polymerizing a cationically polymerizable monomer containing a polyfunctional monomer as a main component to produce a nuclear polymer component, , A step of polymerizing a monofunctional cationically polymerizable unsaturated monomer containing isobutylene as a main component to produce an arm polymer component is carried out in multiple steps by cationic polymerization. The preferred production method is (2) by polymerizing a monofunctional cationically polymerizable unsaturated monomer containing isobutylene as a main component, and then adding a cationically polymerizable monomer containing a polyfunctional monomer as a main component. Polymerization is continued or (3) a cationically polymerizable monomer having a polyfunctional monomer as a main component is polymerized in the presence of a cationic polymerization initiator, and then a monofunctional cationically polymerizable compound having isobutylene as a main component is used. It consists of adding an unsaturated monomer and continuing the polymerization.

The cationic polymerization initiator used in the above-mentioned (2) polymerization is (a1) the general formula (I).

[Wherein X is a halogen atom, RCOO- group or R
R ¹ represents an O-group (wherein R is a monovalent organic group).
Represents a monovalent group having an aromatic ring or a substituted or unsubstituted monovalent aliphatic hydrocarbon group, R ² and R ³ may be the same or different from each other, and a hydrogen atom or a substituted or unsubstituted 1 Represents a valent hydrocarbon group (provided that R ¹ is a substituted or unsubstituted monovalent aliphatic hydrocarbon group, R ² and R ³ are substituted or unsubstituted monovalent hydrocarbon groups) .)] And a compound containing (b) a Lewis acid (hereinafter referred to as “cationic polymerization initiator”). )
Is. In the cationic polymerization initiator, (a1) and
Each of the component (b) can be used alone or in combination of two or more.

The cationic polymerization initiator used in the above-mentioned (3) polymerization is (a2) the general formula (II)

[In the formula, X is a halogen atom, RCOO- group or R
O-group (where R is a monovalent organic group, preferably 1 carbon atom)
~ 6 monovalent aliphatic hydrocarbons. A plurality of Xs may be the same or different from each other, R ⁴ represents an n-valent group having an aromatic ring or a substituted or unsubstituted n-valent aliphatic hydrocarbon group, R ² and R ^{2 3} may be the same or different from each other, and are a hydrogen atom or a substituted or unsubstituted 1
Represents a valent hydrocarbon group (provided that R ⁴ is a substituted or unsubstituted n-valent aliphatic hydrocarbon group, R ² and R ³ are substituted or unsubstituted monovalent hydrocarbon groups) ) And n are integers of 1-6. ] A compound containing a compound represented by the formula (b) and a Lewis acid (hereinafter referred to as "cationic polymerization initiator").
) ”. ). In the cationic polymerization initiator, the components (a2) and (b) are each one type or two types.
A mixture of two or more species can be used.

Specific examples of the components of the cationic polymerization initiator and the components (a1) and (a2) are generally the compound A (Y) a ((III)) represented by the formula (III). III) [In the formula, A represents an a-valent group having 1 to 4 aromatic rings, and Y represents the formula (IV).

[Chemical 3] {Here, R ⁵ and R ^{6, which} may be the same or different, each represents a hydrogen atom, a monovalent substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and X represents a halogen atom or a RCOO- group. Or, a RO- group (wherein R is a monovalent organic group) is shown, and a plurality of Ys may be the same or different from each other. } Is a group represented by the formula, a is an integer of 1 to 6], and a compound represented by the formula (V) B (Z) c ... (V) [wherein B is a tertiary carbon] Represents a substituted or unsubstituted c-valent hydrocarbon group having 4 to 40 carbon atoms, and Z is B
Represents a halogen atom bonded to the tertiary carbon atom of, an RCOO- group or an RO- group (wherein R is a monovalent organic group), and a plurality of Zs may be the same or different from each other,
c is an integer of 1 to 4. ], And an oligomer having an α-halostyrene unit.

A in the formula (III) may have a fused ring or may have a non-fused ring. Specific examples of A include a 1- to 6-valent phenyl group, a biphenyl group, a naphthalene group, an anthracene group, a phenanthrene group, a pyrene group, and a φ- (CH ₂ ) e-φ group (where φ is a benzene ring, e is an integer of 1 to 10.) and the like. The group A having these aromatic rings is substituted with a linear or branched aliphatic hydrocarbon group having 1 to 20 carbon atoms, a functional group such as a hydroxyl group, an ether group, a vinyl group, or a group having these functional groups. It may have been done.

On the other hand, B in the formula (V) is preferably a substituted or unsubstituted aliphatic hydrocarbon group. When the carbon number of B is 3 or less, the Z group cannot be bonded to the tertiary carbon atom and the polymerization rate is remarkably slowed, which is not suitable.

The above-mentioned α-halostyrene unit-containing oligomer may be, for example, an α-chlorostyrene oligomer, a copolymer oligomer of α-chlorostyrene and a comonomer, or the like.

In the cationic polymerization initiator, the general formula
Specific examples of the compound represented by (I) include, for example,

[Chemical 4] ,

[Chemical 5] ,

[Chemical 6] ,

[Chemical 7] ,

[Chemical 8] ,

[Chemical 9] ,

[Chemical 10] ,

[Chemical 11] ,

[Chemical formula 12] ,

[Chemical 13] ,

[Chemical 14] (Where X is F, Cl, Br, I, CH ₃ O-, C ₂ H ₅ O-, CH ₃
Indicates COO- or C ₂ H ₅ COO-. ) Etc. can be mentioned. Of these compounds,

[Chemical 15] ,

[Chemical 16] ,

[Chemical 17] ,

[Chemical 18] and

[Chemical 19] Is preferred.

In the cationic polymerization initiator, specific examples of the compound represented by the general formula (II) are the same as those of the cationic polymerization initiator of the general formula (I) when n = 1. In the case of n = 2 to 6,
For example

[Chemical 20] ,

[Chemical 21] ,

[Chemical formula 22] ,

[Chemical formula 23] ,

[Chemical formula 24] ,

[Chemical 25] ,

[Chemical formula 26] ,

[Chemical 27] ,

[Chemical 28] ,

[Chemical 29] ,

[Chemical 30] ,

[Chemical 31] (Where X is F, Cl, Br, I, CH ₃ O-, C ₂ H ₅ O-, CH ₃
COO − or C ₂ H ₅ COO − is shown, and a plurality of Xs may be the same or different from each other. ) Etc. can be mentioned. Of these compounds,

[Chemical 32] ,

[Chemical 33] ,

[Chemical 34] ,

[Chemical 35] ,

[Chemical 36] ,

[Chemical 37] ,

[Chemical 38] ,

[Chemical Formula 39] ,

[Chemical 40] Chlorine-containing compounds such as

[Chemical 41] ,

[Chemical 42] ,

[Chemical 43] ,

[Chemical 44] ,

[Chemical 45] ,

[Chemical 46] ,

[Chemical 47] ,

[Chemical 48] ,

[Chemical 49] ,

[Chemical 50] ,

[Chemical 51] A methoxy group-containing compound such as

[Chemical 52] ,

[Chemical 53] ,

[Chemical 54] ,

[Chemical 55] ,

[Chemical 56] ,

[Chemical 57] ,

[Chemical 58] ,

[Chemical 59] ,

[Chemical 60] ,

[Chemical formula 61] Acetoxy group-containing compounds such as

In the present invention, as the cationic polymerization initiator, the component (a1) represented by the general formula (I) or the general formula (I) is used.
By using the one containing the component (a2) represented by I), a polymer having a uniform molecular weight distribution can be obtained. By adjusting the amount of component (a1) or component (a2) used, it is possible to control the molecular weight of the resulting polymer,
The preferable amount thereof is 0.0002 to the monofunctional cationically polymerizable unsaturated monomer forming the arm polymer.
30% by weight, more preferably 0.004 to 20
% By weight.

Next, the Lewis acid which is the component (b) of the cationic polymerization initiator used in the present invention has a formula M (X ') m
(In the formula, M represents a metal atom, X ′ represents a halogen atom, and m is a valence of M.). Specific examples of this Lewis acid include BCl ₃ , AlCl ₃ and Sn.
Examples thereof include Cl ₄ , TiCl ₄ , VCl ₅ , FeCl ₃ , BF ₃ . Of these Lewis acids, BCl ₃ , AlCl ₃ , TiCl ₄ , BF _{3 and the} like are preferable, and BCl ₃ and TiCl ₄ are particularly preferable. The amount of these Lewis acids used is preferably 1 to 50 mol, and more preferably 3 to 20 mol, per 1 mol of (a1) and / or (a2).

In the present invention, the component (a1) or (a2)
A multi-branched polymer having good properties can be obtained by using a two-component cationic polymerization initiator composed of the component (b). Further, the third component (c) is an amide and an amine. By using at least one nitrogen-containing organic compound selected from the group, a branched polymer having an extremely narrow molecular weight distribution and a multibranched polymer having more excellent properties can be produced.

This (c) nitrogen-containing organic compound has the formula

[Chemical formula 62] ,

[Chemical 63] ,

[Chemical 64] ,

[Chemical 65] Or

[Chemical 66] It is represented by. Here, R ⁷ to R ¹¹ may be the same or different from each other and are a group selected from the group consisting of a hydrogen atom and a monovalent hydrocarbon group having 1 to 20 carbon atoms.

Specific examples of the (c) nitrogen-containing organic compound include CH ₃ CONH ₂ , CH ₃ CON (CH ₃ ) ₂ , (CH ₃ CO) ₂ NCH ₃ and (CH ₃ ) ₂ N.
_{H, (CH 3) 3 N} , (C 2 H 5) 2 NH, (C 2 H 5) 3 N, [(CH 3) 2 CH] 2 NC 2 H
₅ ,

[Chemical 67] ,

[Chemical 68] ,

[Chemical 69] ,

[Chemical 70] ,

[Chemical 71] ,

[Chemical 72] ,

[Chemical 73] Etc. can be mentioned.

Of these (c) nitrogen-containing organic compounds,
CH ₃ CON (CH ₃ ) ₂ , (C ₂ H ₅ ) ₂ NH, (C ₂ H ₅ ) ₃ N, [(CH ₃ ) ₂ CH] ₂ NC ₂
H ₅ ,

Embedded image

Embedded image

Embedded image

Embedded image and

[Chemical Formula 73] is preferable, and especially CH ₃ CON (CH ₃ ) ₂ and (C ₂ H ₅ ) ₂ NH
, (C ₂ H ₅ ) ₃ N,

Embedded image is preferred.

Of the (c) nitrogen-containing organic compound in the present invention
The amount used per mol of the component (a1) and / or the component (a2) is preferably 0.1 to 5 mol, more preferably 0.1.
It is 3 to 2 mol. However, the amount of the (c) nitrogen-containing organic compound used is preferably within a range not exceeding the number of moles of the (b) Lewis acid component. This is because if the amount of the (c) nitrogen-containing organic compound used exceeds the number of moles of the (b) Lewis acid component, the polymerization rate will be remarkably low and the polymerization will hardly progress.

In the present invention, the average number of bonds of the armature polymer component in the multi-branched polymer is determined by the number of cationically polymerizable unsaturated bonds in the polyfunctional monomer and the cationically polymerizable compound forming a nuclear polymer. Although it depends on the content of the polyfunctional monomer in the monomer, the average number of bonds can be 5 or more.

The cationic polymerization in the present invention is carried out in a system that does not impair the polymerization initiation function of the cationic polymerization initiator, that is, in an inert gas atmosphere, for example, bulk polymerization, solution polymerization in an organic solvent, precipitation polymerization, or the like. You can The polymerization temperature at this time is usually -30 to -100 ° C.

[0034]

EXAMPLES Hereinafter, specific modes and effects of the present invention will be described based on Examples and Comparative Examples, but the present invention is not limited to these Examples. Example 1 100 ml of methylene chloride and 150 ml of methylcyclohexane dried by calcium hydride treatment and dried in a pressure-resistant glass container under a dry nitrogen atmosphere, (2-methoxyisopropyl) benzene ((a1) component. Hereinafter, "CumOMe")
That. ) 10 ml of a 2/3 volume ratio methylene chloride / methylcyclohexane solution containing 2 mmol and N, N-
Dimethylacetamide ((c) component. Hereinafter, "DMeA"
That. ) 2 mmol was added and cooled to -50 ° C. Then, 20 g of isobutylene dehydrated through a column packed with barium oxide was added and cooled to -78 ° C.
Then, a methylene chloride / methylcyclohexane solution 10 containing 32 mmol of TiCl ₄ (component (b)) at a volume ratio of 2/3 was used.
ml was pre-cooled to -78 ° C and added to initiate the polymerization of the first stage arm polymer component. Two hours after the initiation of polymerization, 10 ml of the reaction solution was sampled and poured into a large amount of methanol to precipitate the polymer, which was used as a sample for analysis. Further, to the reaction solution, a solution composed of 5.5 g of divinylbenzene, 4.5 g of ethylstyrene, 4 ml of methylene chloride and 6 ml of methylcyclohexane was cooled to −78 ° C. in advance and added dropwise to give the second stage nuclear polymer. Polymerization of the components was continued. After the addition of the monomer solution of the nuclear polymer component was completed, the polymerization was continued at -78 ° C for 1.5 hours, 20 ml of methanol was added to stop the reaction, and then the reaction solution was poured into a large amount of methanol. At this point, the resulting polymer was precipitated. Then, the unreacted raw materials and the solvent were removed to obtain a hyperbranched polymer. The polymerization conversion rate was 91%. Regarding this multi-branched polymer, in order to confirm that the armature polymer component produced in the first-stage polymerization was bonded to the nuclear polymer component in the second-stage polymerization, the obtained multi-branched polymer was obtained. The combined product was dissolved in cyclohexane, which is a good solvent for both arm polymer and nuclear polymer components, and allowed to stand for one day and then filtered through a 400-mesh wire mesh. The percentage (% by weight) was determined. This cyclohexane-insoluble matter is a combination of arm polymer components and nuclear polymer components. In addition, Mw / Mn (where Mw is a weight average molecular weight and Mn is a number average molecular weight) was measured for the analysis sample by gel permeation chromatography. further,
Using the obtained multi-branched polymer, a sheet having a thickness of 2 mm was prepared by electrothermal pressing and subjected to a tensile test (tensile strength, breaking elongation). The tensile test was carried out according to JIS K6311. The results are shown in Table 1.

Example 2 Polymerization and measurement were carried out in the same manner as in Example 1 except that 20 g of isobutylene was used in combination with 1 g of isoprene in the first stage polymerization. The polymerization conversion rate was 90%. The results are shown in Table 1.

Example 3 In the first-stage polymerization, the amount of 2,6-di-t-butylpyridine ((c) component shown in Table 1 was used in place of DMeA of Example 1, hereinafter referred to as "Dt-BuPy". Was used in the same manner as in Example 1, except that the polymerization of isobutylene was continued after the polymerization of styrene in the amounts shown in Table 1.
Polymerization and measurement were performed. The polymerization conversion rate was 92%. The results are shown in Table 1.

Example 4 As the cationic polymerization initiator, the amount of 1,4-as shown in Table 1 was used.
Bis (2-methoxy-isopropyl) benzene ((a2) component. Hereinafter referred to as "DCumOMe".), Using TiCl ₄ and DMEA, and nuclear polymer component by polymerizing divinylbenzene and ethylstyrene in the first stage Was produced, and polymerization and measurement were carried out in the same manner as in Example 1 except that isobutylene was polymerized in the second step to produce the armband polymer component. The polymerization conversion rate was 90%.
The results are shown in Table 1.

Example 5 Polymerization and measurement were carried out in the same manner as in Example 1 except that a cationic polymerization initiator comprising the components (a1) and (b) was used. The polymerization conversion rate was 90%. The results are shown in Table 1.

COMPARATIVE EXAMPLE 1 A multi-branched polymer having isoprene homopolymer as an arm polymer component was prepared according to the following conventional procedure. First, 25 g of isoprene in 175 g of cyclohexane.
To the solution containing g, 5 ml of a sec-butyllithium solution (concentration 100 mmol / liter) was added to initiate anionic polymerization, and polymerization was carried out at 50 ° C. for 3 hours to produce a arm polymer component. . This arm polymer component had Mn = 46,000 and Mw / Mn = 1.20. Then, the reaction solution was cooled to 25 ° C. and then a solution of divinylbenzene (concentration: 197 mmol / liter)
7.6 ml was added. The temperature of the reaction solution was raised to 60 ° C by the addition of divinylbenzene. After the polymerization was continued for 5 hours, the reaction was stopped to obtain a multibranched polymer. The polymerization conversion rate was 92%. Then, after purging the reaction vessel with hydrogen, 4.4 ml of a cyclohexane solution of nickel dioctoate (concentration 0.0728 mol / liter) and 3.1 ml of a hexane solution of triethylaluminum (concentration 0.22 mol / liter) were added to 4 ml.
A hydrogenation catalyst prepared by mixing at 0 ° C was added. Then, the hyperbranched polymer was hydrogenated under conditions of a temperature of 65 ° C. and a hydrogen pressure of 38 Kg / cm ² . After the hydrogenation reaction, the reaction solution was washed with a 1 wt% aqueous citric acid solution and distilled water to extract and remove the hydrogenation catalyst. By this hydrogenation reaction, 95% of all double bonds in the multi-branched polymer are
Was hydrogenated. The results are shown in Table 1.

Comparative Example 2 Instead of the CUMOMe of Example 1, 1,3,5-tris (2-methoxyisopropyl) benzene (hereinafter referred to as "T
CumOMe ”. In accordance with the same procedure as in Example 1 except that) was used, at first, isobutylene as a arm polymer component was polymerized, and then styrene was added to continue the polymerization to have three arm polymer components, A polymer having no polymer component was prepared. The polymerization conversion rate was 92%. The results are shown in Table 1.

[0041]

[Table 1]

As shown in Table 1, the polymer obtained by the multi-step cationic polymerization of the present invention is a multi-branched polymer in which the armature polymer component having a narrow molecular weight distribution is bonded to the nuclear polymer component, Moreover, it does not require a complicated hydrogenation step for improving heat resistance. On the other hand, among conventional multi-branched polymers, those obtained by anionic polymerization (Comparative Example 1)
In addition, a separate hydrogenation step is indispensable, and Example 3
As is clear from the comparison between Comparative Example 2 and Comparative Example 2, the one obtained by cationic polymerization has no nuclear polymer component, and the mechanical strength is low even when the relative proportion of styrene in the polymer is high.

[0043]

According to the present invention, the multi-branched polymer is composed of the core polymer component and the arm polymer component, and isobutylene is used as the main component monomer constituting the arm polymer component. A hyperbranched polymer having good heat resistance and having a variety of property balances can be produced in one pot without requiring a complicated hydrogenation step. This multi-branched polymer is non-polar or low-polar, and is particularly useful as a viscosity modifier for lubricating oils, and by combining the core polymer component and the arm polymer component appropriately, various excellent properties can be obtained. It can be provided with properties and can be suitably used as a sheet, a film or various other molded articles.

Claims (3)

[Claims] 1. A cation whose main component is a monomer having two or more cationically polymerizable unsaturated bonds in a molecule for producing a multi-branched polymer composed of a nuclear polymer component and an arm polymer component. Initiate cationic polymerization in the step of polymerizing a polymerizable monomer to produce a nuclear polymer component and in the step of polymerizing a monofunctional cationically polymerizable monomer containing isobutylene as a main component to produce an arm polymer component. A method for producing a multi-branched polymer, which comprises polymerizing using an agent. 2. A monofunctional cationically polymerizable unsaturated monomer containing isobutylene as a main component is added to (a1) the general formula (I): [In the formula, X represents a halogen atom, RCOO- group or RO- group (wherein R is a monovalent organic group), and R ¹ is a monovalent group having an aromatic ring or a substituted or unsubstituted group. Of R ² and R ³ may be the same or different from each other, and are a hydrogen atom or a substituted or unsubstituted 1
Represents a valent hydrocarbon group (provided that R ¹ is a substituted or unsubstituted monovalent aliphatic hydrocarbon group, R ² and R ³ are substituted or unsubstituted monovalent hydrocarbon groups) .)] And (b) the main component is a monomer having two or more cationically polymerizable unsaturated bonds in the molecule after polymerization in the presence of a cationic polymerization initiator containing a Lewis acid. A method for producing a multi-branched polymer, characterized by comprising adding a cationically polymerizable monomer and continuing the polymerization. 3. A cationically polymerizable monomer containing as a main component a monomer having two or more cationically polymerizable unsaturated bonds in the molecule, wherein (a2) the general formula (II): Wherein, X is a halogen atom, RCOO- group or RO- groups (wherein, R is a monovalent organic group.) Indicates, the X presence of a plurality may be the same or different from each other, R ⁴ Represents an n-valent group having an aromatic ring or a substituted or unsubstituted n-valent aliphatic hydrocarbon group, R ² and R ³ may be the same or different from each other, and are a hydrogen atom or a substituted or unsubstituted 1 Represents a valent hydrocarbon group (provided that R ⁴ is a substituted or unsubstituted 2
In the case of a ~ 6 valent aliphatic hydrocarbon group, R ² and R ³ are substituted or unsubstituted monovalent hydrocarbon groups), and n is an integer of 1-6. ] And (b) after the polymerization in the presence of a cationic polymerization initiator containing a Lewis acid, the monofunctional cationically polymerizable unsaturated monomer containing isobutylene as a main component is added to continue the polymerization. A method for producing a multi-branched polymer, which comprises: