JP4941050B2 - Storage method of conjugated diene polymer - Google Patents

Description

  The present invention relates to a method for storing a conjugated diene polymer.

  As a polymer composition used for an automobile tire, a polymer composition containing a conjugated diene polymer such as polybutadiene or butadiene-styrene copolymer and a filler such as carbon black or silica is used. In recent years, due to increased interest in environmental issues, demand for fuel saving has been increasing for automobiles, and as a conjugated diene polymer from which a polymer composition for automobile tires with excellent fuel economy can be obtained, A polymer obtained by modifying a polymer obtained by polymerizing butadiene or copolymerizing butadiene and styrene using an alkyl lithium as a polymerization initiator with an aminoalkoxysilane compound or the like has been proposed (for example, see Patent Documents 1 and 2). ).

JP-A 63-186748 JP 2001-131230 A

However, the viscosity of a conjugated diene polymer modified with an aminoalkoxysilane compound or the like may increase during storage, and the conventional storage method is not sufficiently satisfactory in viscosity retention of the polymer. It was.
In such a situation, the problem to be solved by the present invention is a storage method of a conjugated diene polymer modified with an aminoalkoxysilane compound or the like, and provides a storage method that is excellent in viscosity retention of the polymer There is to do.

［式中、Ｒ¹及びＲ²はそれぞれ独立に、炭化水素基、炭化水素オキシ基又は水酸基を表し、ｍは０〜１０の整数を表し、Ａ¹は活性水素を持たない極性官能基を表す。］ In the present invention, a conjugated diene polymer having a monomer unit based on a conjugated diene and a group represented by the following formula (I) has a thickness of 30 μm to 150 μm and a moisture permeability of 0.7 g / m ^2. -It is based on the storage method of the conjugated diene polymer which is packaged and stored with a film of day or less.

[Wherein, R ¹ and R ² each independently represents a hydrocarbon group, a hydrocarbon oxy group or a hydroxyl group, m represents an integer of 0 to 10, and A ¹ represents a polar functional group having no active hydrogen. . ]

  According to the present invention, it is possible to provide a storage method for a conjugated diene polymer modified with an aminoalkoxysilane compound or the like, which is excellent in viscosity retention of the polymer.

［式中、Ｒ¹及びＲ²はそれぞれ独立に、炭化水素基、炭化水素オキシ基又は水酸基を表し、ｍは０〜１０の整数を表し、Ａ¹は活性水素を持たない極性官能基を表す。］ The conjugated diene polymer used in the present invention is a polymer having a monomer unit based on a conjugated diene and a group represented by the following formula (I).

[Wherein, R ¹ and R ² each independently represents a hydrocarbon group, a hydrocarbon oxy group or a hydroxyl group, m represents an integer of 0 to 10, and A ¹ represents a polar functional group having no active hydrogen. . ]

  Examples of the conjugated diene include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 1,3-hexadiene, and these may be one kind. Two or more kinds may be used. From the viewpoint of availability in production, 1,3-butadiene and isoprene are preferable.

R ¹ and R ² each independently represents a hydrocarbon group, a hydrocarbon oxy group, or a hydroxyl group. Examples of the hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. Further, the hydrocarbon group may be a group composed of a polymer chain such as a polymer chain having a monomer unit based on a conjugated diene. As these hydrocarbon groups, a methyl group and an ethyl group are preferable. Examples of the hydrocarbon oxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, and a ter-butoxy group. As these hydrocarbon oxy groups, a methoxy group and an ethoxy group are preferable.

R ¹ and R ² are preferably a hydrocarbon oxy group, more preferably a methoxy group or an ethoxy group, from the viewpoint of improving fuel economy.

  m represents an integer of 0 to 10. From the viewpoint of improving fuel economy, it is preferably 3 or more, and from the viewpoint of improving economy during production, it is preferably 4 or less.

［式中、Ｒ³及びＲ⁴はそれぞれ独立に、窒素原子、酸素原子又はケイ素原子を有していてもよい炭素原子数が１〜６の炭化水素基を表し、Ｒ³及びＲ⁴は結合して環構造を形成していてもよい。］

［式中、Ｘは酸素原子を有していてもよい炭素原子数が１〜６の２価の炭化水素基を表し、Ｒ⁵は水素又は炭素原子数が１〜６の炭化水素基を表す。］ A ¹ represents a polar functional group having no active hydrogen, and examples thereof include a group represented by the following formula (II) and a group represented by the following formula (III).

[Wherein, R ³ and R ⁴ each independently represents a hydrocarbon group having 1 to 6 carbon atoms which may have a nitrogen atom, an oxygen atom or a silicon atom, and R ³ and R ⁴ represent a bond Thus, a ring structure may be formed. ]

[Wherein, X represents a divalent hydrocarbon group having 1 to 6 carbon atoms which may have an oxygen atom, and R ⁵ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms. . ]

R ³ and R ⁴ each independently represent a hydrocarbon group having 1 to 6 carbon atoms which may have a nitrogen atom, an oxygen atom or a silicon atom. Examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, isopentyl group, and n-hexyl. Group, cyclohexyl group, phenyl group, methoxymethyl group, methoxyethyl group, methoxypropyl group, methoxybutyl group, methoxypentyl group, ethoxymethyl group, ethoxyethyl group, ethoxypropyl group, ethoxybutyl group, ethoxypentyl group, trimethylsilyl group And t-butyldimethylsilyl group.

R ³ and R ⁴ may be bonded, and examples of the group to which R ³ and R ⁴ are bonded include alkylene groups such as trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group; oxydiethylene group, oxydi An oxyalkylene group such as a propylene group; a nitrogen-containing group such as a group represented by —CH ₂ CH ₂ —NH—CH ₂ —, a group represented by —CH ₂ CH ₂ —N═CH—, and the like. it can.

R ³ and R ⁴ are preferably a methyl group, an ethyl group, an n-propyl group, or a trimethylsilyl group. The group to which R ³ and R ⁴ are bonded is preferably a group represented by —CH ₂ CH ₂ —NH—CH ₂ — or a group represented by —CH ₂ CH ₂ —N═CH—.

  X represents a divalent hydrocarbon group having 1 to 6 carbon atoms which may have an oxygen atom. Examples of the hydrocarbon group include an ethylene group, a propylene group, a butylene group, a 1-oxyethylene group, a 1-oxytrimethylene group, and a 1-oxytetramethylene group.

  X is preferably a 1-oxytrimethylene group.

R ⁵ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, isopentyl group, and n-hexyl. Group, cyclohexyl group, phenyl group and the like.

R ⁵ is preferably hydrogen or a methyl group.

  Examples of the group represented by the formula (II) include an acyclic amino group and a cyclic amino group. Examples of the acyclic amino group include a dimethylamino group, a diethylamino group, an ethylmethylamino group, a di (methoxymethyl) amino group, a di (methoxyethyl) amino group, a di (ethoxymethyl) amino group, and a di (ethoxyethyl) amino group. , Di (t-butyldimethylsilyl) amino] group, [di (trimethylsilyl) amino group, and the like. Examples of the cyclic amino group include 1-pyrrolidinyl group, piperidino group, 1-hexamethyleneimino group, 1-heptamethyleneimino group, 1-octamethyleneimino group, 1-decamethyleneimino group, 1-dodecamethyleneimino group, Examples thereof include 1-polymethyleneimino groups such as 1-tetradecamethyleneimino group and 1-octadecamethyleneimino group. Examples of the cyclic amino group include 1-imidazolyl group, 4,5-dihydro-1-imidazolyl group, 1-imidazolidinyl group, 1-piperazinyl group, morpholino group and the like.

  Examples of the group represented by the formula (III) include 3-glycidoxyethyl group and 3-glycidoxypropyl group.

A ¹ is preferably a group represented by the formula (II) from the viewpoint of economy and availability, and more preferably an acyclic amino group.

  The conjugated diene polymer may have a monomer unit based on another monomer in addition to the monomer unit based on the conjugated diene (conjugated diene unit) and the group represented by the formula (I). . Examples of the other monomer include aromatic vinyl, vinyl nitrile, and unsaturated carboxylic acid ester. Examples of the aromatic vinyl include styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, divinyl benzene, trivinyl benzene, and divinyl naphthalene. Examples of the vinyl nitrile include acrylonitrile, and examples of the unsaturated carboxylic acid ester include methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate. Among these, styrene is preferable from the viewpoint of availability.

  The conjugated diene polymer preferably has an aromatic vinyl-based monomer unit (aromatic vinyl unit) from the viewpoint of increasing strength, and the content of the aromatic vinyl unit is preferably a conjugated diene unit. And the total amount of aromatic vinyl units is 100% by weight, preferably 10% by weight or more (the content of conjugated diene units is 90% by weight or less), more preferably 15% by weight or more (the content of conjugated diene units) Is 85% by weight or less). Further, from the viewpoint of improving fuel economy, the content of the aromatic vinyl unit is preferably 50% by weight or less (the content of the conjugated diene unit is 50% by weight or more), more preferably 45% by weight or less (conjugated). The diene unit content is 55% by weight or less).

The Mooney viscosity (ML _{1 + 4} ) of the conjugated diene polymer is preferably 10 or more, more preferably 20 or more, from the viewpoint of increasing mechanical strength. Moreover, from a viewpoint of workability, Preferably it is 200 or less, More preferably, it is 150 or less. The Mooney viscosity (ML _{1 + 4} ) is measured at 100 ° C. according to JIS K6300 (1994).

The vinyl bond content of the conjugated diene polymer is preferably 70 mol% or less, more preferably 60 mol% or less, from the viewpoint of improving fuel economy by setting the content of the conjugated diene unit to 100 mol%. Moreover, from a viewpoint of improving the grip performance of a tire, Preferably it is 10 mol% or more, More preferably, it is 15 mol% or more. The vinyl bond amount is determined from the absorption intensity in the vicinity of 910 cm ^−1, which is the vinyl group absorption peak, by infrared spectroscopy.

  The conjugated diene polymer can be produced by a known method. For example, the methods described in JP-A-63-186748 and JP-A-2001-131230 can be used.

The film used for packaging the conjugated diene polymer is a film having a moisture permeability of 0.7 g / m ² · day or less. If the moisture permeability is too high, viscosity retention may be reduced. Preferably it is 0.5 g / m ² · day or less, more preferably 0.1 g / m ² · day or less. The moisture permeability is measured by JIS Z0208 (cup method) under the conditions of 40 ° C. and 90% RH.

  The film used for packaging the conjugated diene polymer has a thickness of 30 μm to 150 μm. If the thickness is too thin, the strength may decrease, and if it is too thick, the packaging workability may decrease. Preferably they are 40 micrometers-110 micrometers, More preferably, they are 50 micrometers-100 micrometers.

  Examples of the film used for packaging the conjugated diene polymer include a film having a barrier layer made of aluminum, stainless steel, nickel, titanium, copper, aluminum oxide, silicon oxide, polyvinylidene chloride, or the like.

  The film used for packaging the conjugated diene polymer is preferably a multilayer film having at least one layer selected from the group consisting of a metal aluminum layer, an aluminum oxide layer and a silicon oxide layer, and a base material layer. The metal aluminum layer may be a laminate of aluminum foils or a deposit of aluminum. In addition, as the aluminum oxide layer and the silicon oxide layer, those obtained by vapor-depositing aluminum oxide and silicon oxide are usually used. When the aluminum foil is used, the thickness of the metal aluminum layer is usually 5 μm to 20 μm. When vapor deposition is performed, the thickness of each of the metal aluminum layer, the aluminum oxide layer, and the silicon oxide layer is usually 35 nm to 100 nm.

  Examples of the base material layer include layers made of polypropylene resin, polyamide resin, polyester resin, and the like. The base material layer may be a laminate of films obtained by stretching these resins. Moreover, the thickness of a base material layer is 15 micrometers-70 micrometers normally. The base material layer is preferably one surface layer.

  The film used for packaging the conjugated diene polymer preferably has a seal layer made of polyethylene resin. The thickness of the sealing layer is usually 10 μm to 80 μm.

  In addition, the film used for packaging the conjugated diene polymer may be provided with a moisture absorbing layer made of a resin composition containing a hygroscopic filler, an ethylene-vinyl alcohol copolymer, a polyvinyl alcohol resin, or the like.

  As a method for producing a film used for packaging the conjugated diene polymer, a known method, an inflation molding method, a T-die molding method, or the like can be used. In the case of a multilayer film, a known lamination method such as a co-extrusion method, an extrusion lamination method, or a dry lamination method can be used.

  As a method for packaging the conjugated diene polymer, the conjugated diene polymer may be wrapped with a film, the film may be formed into a bag, and the conjugated diene polymer may be packaged in the bag. The packaged film or bag mouth is usually brought into contact with the outside air by wrapping the conjugated diene polymer after packaging by a method such as tying with a polyethylene resin string, heat sealing, or closing with an aluminum foil adhesive tape. Do not. Among these, it is preferable to use the method of heat sealing and the method of closing with an aluminum foil adhesive tape.

  The shape of the conjugated diene polymer used for packaging may be a bale that is a lump of cuboid of about 20 kg to 35 kg, or may be a flake. In the case of a veil, the whole of several bales stacked in several stages may be packaged, or the veil may be packaged with a rubber packaging film used for preventing mutual adhesion.

  The conjugated diene polymer stored by the method of the present invention is used for tires, shoe soles, flooring materials, vibration-proofing materials, and the like, and particularly preferably used for automobile tires.

Hereinafter, the present invention will be described by way of examples.
The physical properties were measured by the following method.

1. Mooney viscosity (ML _{1 + 4} )
It measured at 100 degreeC according to JISK6300 (1994).

2. Vinyl content (unit: mol%)
It was determined from the absorption intensity in the vicinity of 910 cm ^−1, which is the vinyl group absorption peak, by infrared spectroscopy.

3. Styrene unit content (unit:% by weight)
The refractive index was obtained from the refractive index according to JIS K6383 (1995).

4). Moisture permeability (unit: g / m ² · day)
According to JIS Z0208 (cup method), it carried out on the following conditions.
Temperature: 40 ° C
Humidity: 90% RH

Example 1
[Production of Conjugated Diene Polymer]
A stainless steel polymerization reactor was charged with n-hexane as a solvent, 1,3-butadiene, styrene and other additives as monomers. Next, n-butyllithium diluted with n-hexane is added as an initiator, and the temperature in the polymerization reaction vessel is adjusted to 65 ° C. or lower, while 1,3-butadiene and styrene are supplied, Copolymerization of 3-butadiene and styrene was performed to obtain a polymer solution.

  55 parts by weight of a modifier [3- (diethylamino) propyl] trimethoxysilane is added to the obtained polymer solution with respect to 100 parts by weight of n-butyllithium as an initiator, and 1,3-butadiene-styrene is added. The polymer was modified.

To this polymer solution, 2-tertiarybutyl-6- (3-tertiarybutyl-2-hydroxy-5-methylbenzyl) -4-methylphenylacrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer GM), Pentaerythrityl tetrakis (3-lauryl propionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) was added and mixed.
Finally, this polymer solution was heated and the solvent was removed under reduced pressure to obtain a conjugated diene polymer having a vinyl content of 58.3 mol% and a styrene unit content of 24 wt%.

[Storage of conjugated diene polymers]
The conjugated diene polymer was molded into a sheet having a thickness of 2 mm by a roll molding machine adjusted to 115 ° C. When the Mooney viscosity was measured using the sheet, it was 71.
Next, a film having a water vapor transmission rate of 0.1 g / m ² · day (OPP-AL laminate made by Murakumi Co., Ltd., thickness: 57 μm, configuration: stretched polypropylene resin layer (base material layer) 20 μm / polyethylene resin layer 15 μm ( Adhesive layer) / aluminum foil layer 7 μm / polyethylene resin layer (seal layer) 15 μm seal layer) is heat sealed to produce a bag, and then 100 g of a conjugated diene polymer sheet is placed in the bag and the bag mouth is heated. Sealed and sealed. Next, the bag containing the sheet of the conjugated diene polymer was stored for 3 days in a thermo-hygrostat set to a temperature of 40 ° C. and a humidity of 90% RH. After storage, the sheet of conjugated diene polymer was taken out of the bag and the Mooney viscosity was measured. The difference in Mooney viscosity (ΔML) between the conjugated diene polymer before and after storage was 4.

Comparative Example 1
As a film used for storage of the conjugated diene polymer, a film having a moisture permeability of 3.8 g / m ² · day (Pyrene Film-OT P3162 (SL) manufactured by Toyobo Co., Ltd., thickness: 50 μm, constitution: stretched polypropylene The same procedure as in Example 1 was carried out except that a single resin layer was used. The difference (ΔML) in Mooney viscosity of the conjugated diene polymer before and after storage was 16.

Comparative Example 2
As a film used for storage of the conjugated diene polymer, a film having a moisture permeability of 12.5 g / m ² · day (low density polyethylene F218-0 (density 919 kg / m ³ ) manufactured by Sumitomo Chemical Co., Ltd.) is formed by inflation molding. This was carried out in the same manner as in Example 1 except that the obtained monolayer film having a thickness of 50 μm was used. The difference (ΔML) in Mooney viscosity of the conjugated diene polymer before and after storage was 20.

Comparative Example 3
The storage of the conjugated diene polymer was performed in the same manner as in Example 1 except that the conjugated diene polymer was not packaged with a film. The difference (ΔML) in Mooney viscosity of the conjugated diene polymer before and after storage was 22.

  The results of Example 1 and Comparative Examples 1 to 3 are summarized in Table 1.

Claims (2)

A conjugated diene polymer having a monomer unit based on a conjugated diene and a group represented by the following formula (I) has a thickness of 30 μm to 150 μm and a moisture permeability of 0.7 g / m ² · day or less. A method for storing a conjugated diene polymer, wherein the film is packaged and stored in a film.

[Wherein, R ¹ and R ² each independently represents a hydrocarbon group, a hydrocarbon oxy group or a hydroxyl group, m represents an integer of 0 to 10, and A ¹ represents a polar functional group having no active hydrogen. . ]   The film for packaging the conjugated diene polymer is a multilayer film having at least one layer selected from the group consisting of a metal aluminum layer, an aluminum oxide layer and a silicon oxide layer, and a base material layer. The storage method of the conjugated diene polymer according to claim 1.