JPH02123114A - Production of unsaturated random copolymer - Google Patents

Abstract

PURPOSE:To obtain the title copolymer capable of providing a cured rubber having low hardness and small compressive set by polymerizing alpha-olefin and non-conjugated diene compound having a specific structure at a specific ratio using a Ziegler-Natta catalyst. CONSTITUTION:(A) 4-20C alpha-olefin (preferably hexene-1) is polymerized with (B) a non-conjugated diene compound (preferably 7-methyl-1,6-octadiene) expressed by the formula (n is 2-10; R<1> is 1-8C alkyl; R<2> and R<3> are H or 1-8C alkyl) used so that content of the component B is 1-40mol%, in the presence of a Ziegler-Natta catalyst to provide the aimed copolymer. The polymerization temperature is preferably 20-60 deg.C and polymerization pressure is ordinarily 0-20 atomic pressure. Furthermore. triethylaluminum or tributyl aluminum is preferably used as an organoaluminum compound constituting Ziegler-Natta catalyst.

Description

[Detailed Description of the Invention] r Industrial Application Field] The present invention relates to an unsaturated random copolymer, and more specifically to an olefinically unsaturated random copolymer which is unsaturated and has excellent adhesive properties. Regarding the manufacturing method.

[Conventional technology]

Conventionally, olefin-based unsaturated random copolymers include ethylene-propylene=-nonconjugated diene copolymers,
Ethylene-butene-1-nonconjugated diene copolymer, ethylene-1,4-diene copolymer (JP-A-56-30413
JP-A-56-30414) and propylene 1,4-diene copolymer (JP-A-56-30414) are known and are industrially produced.

On the other hand, as an unsaturated random copolymer using an olefin having 4 or more carbon atoms, butene-1 hexene-1-4
(or 5)-methyl-1,4 hexadiene copolymer (
Hexene-1-1゜7-octadiene copolymer (U.S. Pat. Nos. 3933769, 3991262, 43407)
No. 05, No. 4551503), etc., and are used in cushion rubber for artificial joints, etc., taking advantage of their excellent resistance to flex crack growth and weather resistance. However, these copolymers had the drawback of high compression set.

[Problem to be solved by the invention]

An object of the present invention is to solve the problems of the prior art described above and to provide a method for producing an olefinically unsaturated random copolymer having a low hardness of a crosslinked product and a small compression set.

[Means to solve the problem]

The present invention provides at least one kind selected from α-olefins having 4 to 20 carbon atoms and - Formula I (where n is 2 to 10
an integer of 2 to 5, preferably an integer of 2 to 5, R' has 1 to 8 carbon atoms
(R2 and R3 are the same or different hydrogen atoms or alkyl groups having 1 to 8 carbon atoms)
and at least one kind selected from the non-conjugated diene compounds represented by
Provided is a method for producing an unsaturated random copolymer, characterized in that the polymerization is carried out using a Ziegler-Natta catalyst so that the following is obtained.

The α-olefins having 4 to 20 carbon atoms used in the present invention include butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1,
undecene-11 dodecene = 1, tridecene-1, tetradecene-1, pentadecene-11 hexadecene-I,
heptadecene-1, octadecene-1, nonadecene-1,
Examples include eicosene-1,3-methylbutene-1,4-methylpentene-1,4,4-dimethylpentene-1, among which butene-1, hexene-1, octene-11 decene-1, dodecene-1, etc. I is preferred, particularly hexene-1.

Examples of the non-conjugated diene compound represented by formula I used in the present invention include 5-methyl-15-hebutadiene, 6-methyl-1,5-hebutadiene, and 6-methyl-15-hebutadiene.
1,6-octadiene, 7-methyl-1,6-octadiene, 7-methyl-1,7-nonadiene, 8-methyl-
1,7-nonadiene, 8-methyl-1,8-decadiene, 9methyl-1,8-decadiene, 9-methyl-1゜9
-undecadiene, 10-methyl-1,10-dodecadiene, 11-methyl-1,10-dodecadiene, 11-
Methyl-ixt-tridecadiene, 12-medyl-i,z-tridecadiene, 12-methyl-1,12-tetradecadiene, 13-methyl-1,12-tetradecadiene, 13-methyl-1,13-pentadeca Jien,
Examples include 14-methyl-1,13-pentadecadiene, among which 6-methyl-1,5-hebutadiene, 7-methyl-1,6-octadiene, 8-methyl-1
, 7-nonadiene and 9-methyl-18-decadiene are preferred, and 7-methyl-1,6-octadiene is particularly preferred.

In the present invention, the molecular weight of the unsaturated random copolymer is preferably a polystyrene equivalent number average molecular weight of to, ooo to 1,000,000, more preferably 100,000 to 500,000, from the viewpoint of roll workability. can be,
And the weight average molecular weight in terms of polystyrene is 100,000
~5,000°000 is preferable, more preferably 1
．． 000000 to 3,000,000.

Further, in the present invention, the content of the non-conjugated diene compound represented by formula I in the unsaturated random copolymer is 1 to 4 mol%, preferably 3 to 4 mol%, from the viewpoint of vulcanization rate and mechanical strength of the crosslinked product. It is 20 mol%.

The unsaturated random copolymer of the present invention comprises (1) titanium,
A supported titanium catalyst containing magnesium as an essential component, and (2
) can be polymerized using a Ziegler-Natta catalyst in combination with an organoaluminum compound.

(1) The supported titanium catalyst containing titanium and magnesium as essential components includes a magnesium compound such as magnesium chloride, dialkoxymagnesium, fatty acid magnesium, titanium tetrachloride, titanium trichloride, or a composition thereof (for example, TiC1, etc.).

Supporting titanium compounds such as A1C1,), ethoxytitanium trichloride, and tetrabutoxytitanium, along with electron-donating compounds such as organic acid esters, water, amines, amides, monotyls, and alcohols, as the case may be. A supported titanium compound obtained by further reducing the titanium compound and/or the supported titanium compound thus obtained with an organic aluminum compound or the like can be used.

As the organic aluminum compound (2), a trialkylaluminum can be used, and an electron-donating compound such as an organic acid ester compound or an alkyltrialkoxysilane compound can also be used in combination. Examples of trialkylaluminium include trimethylaluminum,
Triethylaluminum, triisobutylaluminum, 1-n-butylaluminum, tri-n-hexylaluminum, etc. are used, and among these, triethylaluminum and triisobutylaluminum are preferred. In addition, ethyl benzoate,
Methyl p-toluate, phenyltriethoxysilane, etc. can also be used in combination with trialkylaluminum.

Regarding the ratio of the supported titanium catalyst to the organoaluminum compound, the Affi/Ti molar ratio is preferably 100 or less, more preferably 70 or less. Af/T
When the molar ratio of i exceeds 100, the low molecular weight component increases,
Broad molecular weight distribution may occur. Further, the molar ratio of all monomers used in the present invention to titanium in the supported titanium catalyst is preferably 1000 or more. The molar ratio is 1o
If it is less than oo, the molecular weight may decrease.

Although there are no particular restrictions on the polymerization conditions, the polymerization temperature is usually O to io'c, preferably 20 to 60°C, and the polymerization pressure is O to 20 atm (gauge pressure). Furthermore, hydrogen or an alkylzinc compound can also be used as a molecular weight regulator during polymerization.

The unsaturated random copolymer of the present invention can be made into a composition by containing a reinforcing agent, a crosslinking agent, and, if necessary, a softener, a vulcanization accelerator, a crosslinking aid, an activator, a lubricant, an antiaging agent, etc. ,
It can be a crosslinked product.

As the reinforcing agent, reinforcing agents used for commercially available natural rubber, synthetic rubber, etc. can be used, such as carbon black, white carbon, basic magnesium carbonate, activated calcium carbonate, ultrafine magnesium silicate, hard clay, etc. Of these, carbon black and white carbon are particularly preferred.

As the crosslinking agent, sulfur, organic peroxide, etc. are used. As the sulfur, powdered sulfur, flower sulfur, colloidal sulfur, insoluble sulfur, etc. are used, and as the organic peroxides, there are used t-butyl peroxide, t-butyl peroxide, etc.
Butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-25-di(L-butylperoxy)hexane, 2,5-dimethyl-2,5-di(L-butylperoxy)hexane-3, 1,3-bis(butylperoxyisopropyl)benzene, 11-bis(L
-butylperoxy)-3,3,5-trimethylcyclohexane, etc. are used.

As the softener, paraffinic process oil, naphthenic process oil, aromatic process oil, silicone oil, etc. can be used, and among these, paraffinic process oil and naphthenic process oil are preferred.

The amount of the reinforcing agent and softening agent used is 1 part by weight per 100 parts by weight of the copolymer, 0 to 200 parts by weight of the reinforcing agent, and 0 to 1 part by weight of the softening agent.
A range of 0.00 parts by weight is preferred. If the reinforcing agent exceeds 200 parts by weight, the elongation of the crosslinked product may decrease, and if the softener exceeds 100 parts by weight, the mechanical strength of the crosslinked product may not be sufficient. The amount of the crosslinking agent used is preferably 0.5 to 5 parts by weight based on 100 parts by weight of the copolymer.

When sulfur is used as a crosslinking agent, as a vulcanization accelerator,
Thiazole accelerator, dithiocarbamate accelerator,
Thiuram-based accelerators, thiourea-based accelerators, etc. are used, and when organic peroxide is used as a crosslinking agent,
As a crosslinking aid, sulfur, dibenzoquinone dioxime,
Benzoquinone dioxime, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, divinylbenzene, triallylisocyanurate, maleic anhydride, and the like are used.

As the activator, metal oxides such as zinc white, activated zinc white, zinc carbonate, and magnesium oxide, metal carbonates, amine fatty acids, and derivatives thereof are used.

Commercially available natural rubber, synthetic rubber, etc. may be blended into the unsaturated random copolymer composition as long as the low hardness and low compression set, which are the characteristics of the copolymer, are not achieved. can. As the synthetic rubber, IR, SBR
, NBR, EPM, EPDM, I IR, BR, C3M
(chlorosulfonated polyethylene), AR, silicone rubber, fluororubber, chlorinated polyethylene, and the like.

The composition can be manufactured using a kneading machine such as a Banbury mixer, a kneader, an intermixer, a continuous kneader, or a roll.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Parts and % in the examples refer to parts by weight and % by weight unless otherwise specified.

In addition, in the examples, the molecular weight of the copolymer is 802U manufactured by Tosoh Corporation.
Measurement was performed at 40°C using R-type CPC (column 'r'sK GMII3).

The content of the general 2) non-conjugated diene compound in the copolymer is
It was determined using JNM-FXI00 type Proton I manufactured by JEOL Ltd.

Vulcanized rubber and physical properties were measured according to JIS K 6301.

Example 1 A. Preparation of catalyst In a stainless steel ball mill that had been purged with nitrogen in advance, 100 mmol of magnesium chloride and 7.5 mmol of ethyl benzoate were added.
mmol, titanium tetrachloride 15 mmol, n-hexane 6
4 ml was charged and ground in a vibration mill at room temperature for 7 hours. After crushing, take out the entire contents and add 400 m/2 of n-hexane.
After washing with water five times, 700 mff of n-hexane was added to prepare a titanium catalyst slurry. The titanium 4 degree of this titanium catalyst slurry was 0.02 mol/i.

B1 Polymerization N-hexane 3 dehydrated and purified in a 51 separable flask that had been purged with nitrogen! , dehydrated purified hexene-1
(Product name manufactured by Mitsubishi Kasei Corporation, Dai A Ren-6) 450mA
, dehydrated purified 7-methyl-1,6-octadiene (2
-Methyl-2,7-octadiene) (manufactured by Shell Chemical Co., Ltd.)
Prepare 90roff, triisobutyl aluminum 2
2.5 mmol 0.45 mmol of the titanium catalyst prepared in A above was charged to start the polymerization reaction. After stirring for 60 minutes, -
(10 mE of Tsubujinobyl alcohol was added to stop the reaction, methanol was coagulated, and the mixture was vacuum-dried.

The yield of the produced polymer was 155 g, the number average molecular weight in terms of Boristine 1/ton was 301,000, and the weight average molecular weight in terms of polystyrene was 1,656,000.

In addition, the content of 7-methyl-12 6-octadiene is 10
, 0 mol%.

Comparative Example I B1 Polymerization Example]. In B, polymerization was carried out in the same manner as in Example IB, except that the amount of 7-methyl-1,6-octadiene was changed to 10 m2.

The yield of the polymer was 165 g, the number average molecular weight in terms of polystyrene was 401,000, and the weight average molecular weight in terms of polystyrene TFI was 2,150,000.

In addition, the content of 7-methyl-16-octadiene is 0,
It was 9 mol%.

Example 2 B9 Polymerization Polymerization was carried out in the same manner as in Example 1B, except that in Example IB, the amount of 7-methyl-1,6-octadiene was changed to 45 ml.

The yield of the polymer was 171 g, the number average molecular weight in terms of polystyrene was 373,000, and the weight average molecular weight in terms of polystyrene was 2,050,000.

In addition, the content of 7-methyl-1,6-octadiene is 4,8
It was mol%.

Example 4 B3 polymerization example]. In B, special application Sho Ei was used as a titanium catalyst.
2 1 8 0 7 2 Catalyst-1 in No. 6 Example 1
Polymerization was carried out in the same manner as in Example IB, except that .

The yield of the produced polymer was 151 g, polystyrene (the arithmetic average molecular weight was 333,000, the weight average molecular weight in terms of boristyrene was 1,860,000, and the weight of 7-methyl-1,6-octadiene was 9.8 It was mol%.

Example 5 B1 Polymerization Example t In B, 100 rri of hexene-1,
A reaction mixture was prepared in the same manner as in Example IB, except that 7-methyl-1,6-octadiene was changed to 20JTρ and triisobutylaluminum was changed to 45ml.

The yield of the produced polymer was 54g, and the number average molecular weight in terms of polystyrene was 25,000. The polystyrene modified weight average molecular weight was 126,000. Also, 7-methyl-1,6-
The content of octadiene was 10.3 mol%.

Example 6 B0 Polymerization Polymerization was carried out in the same manner as in Example IB, except that in Example IB, 13.5 mmol of methyl p-)rulyate was added.

The yield of the produced polymer was 73 g, the number average molecular weight in terms of polystyrene was 560,000, and the weight average molecular weight in terms of polystyrene was 3.230,000.

Also, the content of 7-methyl-1,6-octadiene is 7.2
It was mol%.

Test Examples 1 to 3> The polymers of Examples 1 and 4 were kneaded using a 250 cc Laboplastomill, respectively, according to the formulation shown in Table 1.

Margin table below *1... White carbon, manufactured by Nippon Silica *2...
・FEF carbon, manufactured by Tokai Carbon Co., Ltd. Sulfur/AccCZ*3/AccM"/AccTRA
"/AccTT"/AccTL"=0.5/Ilo,
510.7510j 510.75 (p hr) of vulcanizing agent and vulcanization accelerator were kneaded on a roll machine, and 160
Press vulcanization was performed at a vulcanization temperature of °C for a predetermined period of time, and physical property tests were conducted. The results are shown in Table 2.

Volume 3: N-cyclohexyl-2-benzothiazylsulfenamide Car 4: Mercabbuthenzothiazur*5; Dipentamethylene lentiuramchi I-Rasulfi City 6: Te1-ramethylene lentiuram disulfide*7: Tellurium diethyl dimethyl dithiocarbame] *8...For compression set test pieces, the vulcanization time was increased by 5 minutes.

The vulcanized rubber of this test example exhibits low hardness and has excellent properties with extremely low compression set.

〔Effect of the invention〕

The copolymer of the present invention provides a vulcanized rubber with low hardness and low compression set. These vulcanized rubbers are useful for various rubber products such as rubber rolls, packings, belts, and hoses.

Claims (1)

[Claims] (1) At least one type selected from α-olefins having 4 to 20 carbon atoms and general formula I ▲Mathematical formulas, chemical formulas, tables, etc.▼〔I〕 (However, n is an integer from 2 to 10, R^ 1 is carbon number 1-8
and R^2 and R^3 are the same or different hydrogen atoms or alkyl groups having 1 to 8 carbon atoms. A method for producing an unsaturated random copolymer, which comprises polymerizing using a Ziegler-Natta catalyst so that the compound content is 1 to 40 mol%.