JPH0733910A - Production of metal-oxide-containing polymer composition and metal-oxide-containing polymer composition - Google Patents

Abstract

PURPOSE:To obtain the title composition by mixing a hydrophobic polymer with a metal alkoxide, a proton-generating substance and a hydrophilic polymer to obtain a product in which the formed metal oxide is uniformly dispersed in the hydrophobic polymer. CONSTITUTION:A hydrophobic polymer is mixed with a metal alkoxide, a proton-generating substance and a hydrophilic polymer. This mixing is preferably carried out in the presence of a compatibilizer. Examples of the hydrophobic polymers to be used include polybutadiene, polyisoprene and polychloroprene. Examples of the hydrophilic polymers which function as carriers for hydrolysis include polyether glycol, polyvinyl alcohol and polyacrylic acid. Examples of the proton-generating substances to be used to hydrolyze the metal alkoxide into a metal oxide include water and acetic acid. Examples of the metal alkoxides to be used include alkoxides of metals such as silicon, titanium, aluminum and zirconium, and their alkyl groups have each about 1-8 carbon atoms.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polymer composition containing a metal oxide and the polymer composition.

[0002]

Silica is widely used in the rubber industry as a reinforcing agent next to carbon black. Silica is mixed with a rubber-like polymer using a conventional mixing machine, but it is very difficult to uniformly disperse it in rubber. First, the cross-linked polydimethylsiloxane was treated with tetraethylorthosilicate (TEO) from J.E. Mark (JEMark).
It is reported that a composition reinforced with silica is obtained by swelling with S) and immersing the swollen polydimethylsiloxane in water containing a catalyst to form silica in the polydimethylsiloxane (Macromol. Chem., 185 , 2
609 (1984)). After that, there is a series of reports by the same author on the same method with metal oxides other than silica.

[0003]

Further studies were conducted to further generalize this method and to broadly apply it to hydrophobic polymers. Water as a hydrolyzing agent for alkyl orthosilicate was added to the polymer. Cannot be mixed in the system and (in sit
u) It was difficult to generate silica. As a result of diligent efforts to solve this problem, the present inventors have found that this problem can be solved by interposing a hydrophilic polymer as a carrier for water in a hydrophobic polymer, and the present invention It came to completion.

[0004]

According to the present invention,
A method for producing a metal oxide-containing polymer composition, which comprises mixing a hydrophobic polymer with a metal alkoxide, a proton-generating substance and a hydrophilic polymer, and a hydrophobic polymer with a metal alkoxide, a proton-generating substance and a hydrophilic polymer. There is provided a metal oxide-containing polymer composition, which is characterized by being mixed with a functional polymer.

The hydrophobic polymer used in the present invention means a polymer having no hydrophilic group such as a hydroxyl group and a carboxyl group, and examples thereof include a nonpolar polymer and a hydrophobic group-containing polymer. Examples thereof include polybutadiene, polyisoprene, styrene-butadiene copolymer rubber, isoprene-styrene copolymer rubber, acrylonitrile-butadiene copolymer rubber and polychloroprene rubber. Even polymers other than these are applicable as long as the polymer can mix the hydrophobic polymer and the proton generating substance by coexisting the hydrophilic polymer according to the present invention without evaporating the proton generating substance. be able to.

The metal alkoxide which is a metal oxide forming substance is an alkoxide of a metal such as silicon, titanium, aluminum and zirconium, and the alkyl group of the alkoxide has a carbon number of 1 to 1 such as methyl, ethyl, propyl and butyl.
It is an alkyl group of about 8. For example, tetraethyl orthosilicate (TEOS), tetramethyl orthosilicate, titanium-tri-n-propoxide, aluminum-tri-sec-butoxide, zirconium-tri-n-propoxide and the like are exemplified. .

The amount of metal alkoxide used is not particularly limited, and it is used according to the amount of metal oxide to be contained in the hydrophobic polymer. For example, taking TEOS as an example, Si (OC
_Since there is a stoichiometric relationship of ₂ H ₅ ) ₄ + 2H ₂ O → SiO ₂ + 4C ₂ H ₅ OH, the amount of TEOS to be used as a predetermined amount of silica is required.

Water, acetic acid and the like are typical examples of the proton generating substance for hydrolyzing a metal alkoxide to form a metal oxide, and water is particularly preferable. The amount of water used depends on the amount of metal oxide produced, and it is desirable to use more than the theoretical amount of the above formula.

A feature of the present invention is that it is extremely difficult to mix a solid-state hydrophobic polymer with water, so that a hydrophilic polymer is used in combination as a carrier for water. The hydrophilic polymer includes oligomers to high molecular weight polymers and is not particularly limited as long as it is a water-soluble to water-swellable polymer.

For example, polyether glycol (ethylene oxide, propylene oxide homopolymer, copolymer, etc.), polyvinyl alcohol, partially saponified ethylene-vinyl acetate copolymer, hydroxy-terminated polybutadiene, carboxyl-terminated polybutadiene, poly Acrylic acid, polyacrylamide, polyvinylpyrrolidone, etc. are illustrated.

The amount of the hydrophilic polymer used depends on the molecular weight of the polymer and the content of the hydrophilic group, but usually 10 parts of water is used.
The amount is about 5 to 10 parts by weight per part by weight.

The metal oxide-containing polymer composition of the present invention comprises
Each of the components described above is mixed with any mixer (mixing roll, Banbury mixer, internal mixer, extruder, etc.).
It is manufactured by uniformly mixing with. A preferred embodiment is a method of first mixing the polymer components, then adding the metal alkoxide, and then adding water and mixing.

When the compatibility between the hydrophobic polymer and the hydrophilic polymer used is poor, it is necessary to use a known compatibilizing agent. For example, JP-B-61-362, JP-A-60-137913, and JP-A-61-2520.
Polymers containing an atomic group having> C = N ⁺ <bond in the molecule produced by the method disclosed in Japanese Patent Publication No. 2 or the like, oxazoline group-containing polymers (see Japanese Patent Publication No. 61-500853). Etc. are known. It is not limited to these, and other compatibilizing agents may be used. The amount used is not particularly limited, but depends on the amount used of the hydrophilic polymer, the molecular weight of the compatibilizer, the content of the above atomic groups, and the like.

Metal alkoxides in hydrophobic polymers (in s
The process of hydrolysis to form metal oxides in situ can be accelerated by the use of catalysts. As the catalyst, hydrochloric acid, oxalic acid, acetic acid, formic acid, caustic soda, dimethylformamide, ethylenediaminetetraacetic acid and the like are used. The amount of the catalyst used is usually about 0.1 to 0.3 mol per mol of the metal alkoxide.

In order to form the metal oxide in the hydrophobic polymer, first, a homogeneous mixture of the hydrophobic polymer, the hydrophilic polymer, the metal alkoxide and water is prepared. For that purpose, a hydrophobic polymer and a hydrophilic polymer, if necessary, a mixture in which the hydrophilic polymer and the compatibilizer are sufficiently uniformly mixed in advance is sufficiently mixed to prepare a uniform mixture, A metal alkoxide and water are continuously and gradually added to this, and they are sufficiently uniformly mixed at a temperature at which they do not evaporate (for example, at room temperature, about 10 minutes).

The resulting homogeneous mixture is then heat treated at a temperature below 20 to the boiling point of the lowest boiling point component for 24 to 72 hours to cause a sol-gel reaction, i.
The metal oxide is generated in the nitu. Then, the unreacted metal alkoxide, water and the produced alcohol are removed. It is carried out by a method such as vacuum drying at a temperature near the boiling point of the highest boiling point component.

The polymer composition of the present invention thus obtained is a vulcanization system usually used in the rubber industry [sulfur or a sulfur-providing compound such as tetramethylthiuram disulfide, mophorin disulfide / zinc white / stearic acid / Various vulcanization accelerators (thiourea-based, guanidine-based, thiazo-
Selected from the group consisting of a series, a dithioate type, a sulfenamide type, etc.) or an organic peroxide / crosslinking auxiliary agent], an antiaging agent, an antiozonant, a plasticizer, a processing auxiliary agent, etc. It can be added as appropriate.

[0018]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Example 1 100 parts of high cis polybutadiene (abbreviated as BR), 20 parts of partially saponified ethylene-vinyl acetate copolymer (EVAL EP-E-105 manufactured by Kuraray Co., Ltd.), JP-A-3-
In the compatibilizing agent A of Japanese Patent No. 263468, a styrene-butadiene block copolymer is added to a high cis polyisoprene (G
Standard polystyrene equivalent weight average molecular weight 6 measured by PC
Compatibilizer 15 synthesized under the same conditions except that it was replaced with
The parts were mixed for 5 minutes in a mixing ball at 170 ° C. Then, cooling water was circulated through the roll to cool the polymer mixture to room temperature, and tetraethyl orthosilicate (TEO
S) 67 parts were added and mixed. Further, 30 parts of water was gradually added and mixed. The temperature of the polymer mixture was kept at room temperature during the addition of TEOS and water.

After the mixing was completed, the mixture was taken out from the roll in a sheet form. The sheet-like mixture was put in a polyethylene bag to hydrolyze TEOS and generate silica, and left at room temperature for 24 hours.

After heat treatment, silica was produced (the production of silica was confirmed by infrared spectroscopic analysis and observation of a characteristic X-ray image by an X-ray probe microanalyzer. The production amount was confirmed by a thermogravimetric method). Formulation (1) in Table 1 for the mixture
The vulcanization system was added on a roll according to. The obtained compound was press-vulcanized at 150 ° C. for 20 minutes to give a test thickness of 1 mm.
The sheet was created. A dumbbell-shaped test piece was punched out according to JIS K6301 and a tensile test was conducted. The tensile strength and elongation are shown in Table 2.

[0021]

[Table 1]

The compounds shown in Table 1 were prepared in the same manner as described above, a vulcanized sheet for testing was prepared, and the tensile strength and elongation were measured. The results are also shown in Table 2.

[0023]

[Table 2]

Example 2 100 parts of emulsion-polymerized styrene / butadiene copolymer rubber (abbreviated as SBR; Nipol 1502 manufactured by Nippon Zeon Co., Ltd.),
Terminal hydroxystyrene / butadiene copolymer produced using n-butyllithium as a polymerization catalyst (bound styrene amount 24%, 1,2-vinyl bond 20%, standard polystyrene equivalent weight average molecular weight 5,000 measured by GPC) 10
Parts, TEOS 50 parts, and water 25 parts were mixed on a mixing roll. A mixture was prepared in the same manner as in Example 1 except that the polymer was mixed on a roll in which neither a heating medium nor a cooling medium was circulated. According to the compounding recipe (2) in Table 3, a compounding mixture containing a vulcanizing system was prepared, and this was press-vulcanized at 160 ° C. for 20 minutes to prepare a sheet having a thickness of 1 mm for testing. The test was conducted in the same manner as 1. The results are shown in Table 4.

[0025]

[Table 3]

The compounds shown in Table 3 and their vulcanizates were prepared and tested in the same manner as above. The results are also shown in Table 4.

[0027]

[Table 4]

[0028]

Industrial Applicability It is difficult to hydrolyze a metal alkoxide in situ in a hydrophobic polymer to generate a metal oxide. In the present invention, a hydrophilic polymer is used as a carrier of a hydrolyzing agent (proton generating substance) in a hydrophobic polymer.
By coexisting in the hydrophobic polymer
It became possible to easily generate metal oxides in tu. As a result, it became easy to produce a composition in which the metal oxide was uniformly dispersed in the hydrophobic polymer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihisa Yamamoto 1-2-1 Yokou, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside Zeon Corporation R & D Center

Claims (4)

[Claims] 1. A method for producing a metal oxide-containing polymer composition, which comprises mixing a hydrophobic polymer with a metal alkoxide, a proton-generating substance and a hydrophilic polymer. 2. A metal oxide-containing polymer composition comprising a hydrophobic polymer mixed with a metal alkoxide, a proton-generating substance and a hydrophilic polymer. 3. The method for producing a polymer composition according to claim 1, which further comprises a compatibilizer. 4. The polymer composition according to claim 2, which further comprises a compatibilizer. [0001]