JPH058937B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Field of Application) The present invention relates to a light-colored rubber composition that is excellent in green strength, tensile stress, tear strength, impact resilience, etc. of a vulcanizate. (Prior Art) Conventionally, in order to obtain light-colored rubber compositions with improved green strength and mechanical properties after vulcanization, rubbers into which polar groups such as carboxyl groups have been introduced, such as maleic anhydride, have been used as rubbers. It is known to use rubbers with added compounds such as or glyoxyzar.
However, these rubbers have the disadvantage of insufficient mechanical properties as a vulcanizate because side reactions such as rubber gelation and molecular weight reduction are likely to occur during the modification reaction. It has been difficult to use it for applications centered on tires, which require excellent physical and mechanical properties. (Problems to be Solved by the Invention) Therefore, the inventor of the present invention has conducted various studies in order to develop a modified rubber composition that does not have such drawbacks.
The present invention has discovered a light-colored rubber composition that can be used for light-colored tire members, etc., which has excellent green strength when made into an unvulcanized rubber compound, and excellent tensile stress, tear strength, and impact resilience when made into a vulcanized product. reached. (Means for Solving the Problems) That is, the present invention provides an organic compound having a group represented by the formula -CH=N- and a formula -COX ( A white filler is blended into a modified rubber obtained by reacting an organic acid halide having a group represented by (X is halogen) or a mixture of this modified rubber and another rubber. A colored rubber composition is provided. Rubbers having unsaturated bonds (hereinafter sometimes referred to as unsaturated rubbers or rubbers) used for preparing the modified rubber in the present invention include conjugated rubbers such as butadiene, isobrene, piperylene, 2,3-dimethylbutadiene, and chlorobrene. Homopolymer rubbers of dienes, copolymer rubbers of these conjugated dienes and other monomers, ring-opening polymer rubbers of cycloolefins such as cyclopentene and norbornene, polymers of dienes such as ethylidene norbornene and cyclopentadiene. , polyolefin rubbers such as copolymers of the diene and olefin, and other rubbers having ordinary unsaturated carbon bonds. Typical examples include natural rubber, guayule rubber, polyisobrene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, butadiene-isobrene copolymer rubber, and isobrene-
Styrene copolymer rubber, butadiene-isobrene-styrene copolymer rubber, butadiene-piperylene copolymer rubber, butadiene-propylene alternating copolymer rubber, polypentenamer, ethylene-propylene-diene copolymer rubber, butyl rubber, butadiene-acrylonitrile Copolymer rubber, butadiene-isobrene-acrylonitrile copolymer rubber, polychloroprene rubber, styrene-butadiene-styrene block copolymer rubber, styrene-
Examples include isobrene-styrene block copolymer rubber. More specifically, the organic compound (hereinafter sometimes referred to as a compound) having a group represented by the formula -CH=N- used in the present invention has the general formula R-
In CH=N-R', R and R' are aliphatic, alicyclic, or aromatic residues (these residues are atomic groups such as alkoxyl groups, cyano groups, carbalkoxyl groups, carboxyl groups, dialkylamino groups, etc.) ). Specific examples include benzylidene methylamine, benzylidene butylamine, benzylidene aniline,
Benzylidenecyclohexylamine, propylidenebutylamine, propylideneaniline, cyclohexylidenebutylamine, cyclohexylideneaniline, ethoxybenzylidenebutylaniline, 4-carboxylbenzylidenebutylaniline, 4-carbomethoxybenzylidenebutylamine, benzylidene 4-cyanoaniline, benzylidene 4- Examples include carboxylaniline, dimethylaminobenzylidenebutylaniline, and the like. In the present invention, the organic acid halide (hereinafter sometimes referred to as a compound) having a group represented by the formula -COX is more specifically a general formula R″-COX in which X is a halogen, R″ is an aliphatic group, It is a compound that is an alicyclic or aromatic residue (these residues can have an atomic group such as an alkoxyl group or a halocarbonyl group as appropriate). Specific examples thereof include acetyl chloride, acetyl bromide, benzoyl chloride, benzoyl bromide, carbomethoxybenzoyl chloride, oxalyl chloride, terephthalic acid chloride, acrylic acid chloride, methacrylic acid chloride, etc. The compound and the amount used are not particularly limited. , each per 100 parts by weight of normally unsaturated rubber.
The amount is 0.001 to 30 parts by weight, preferably 0.1 to 10 parts by weight. Generally known Friedel-Crafts catalysts can be used in the present invention. Typical examples thereof are metal or metalloid halides, such as Be, B, Al, Si, P, S, Ti, V,
Fe, Zn, Ga, Ge, As, Se, Zr, Nb, Mo,
Halides or organic halides of elements such as Cd, Sn, Sb, Te, Ta, W, Hg, Bi, U, etc. or oxygen-element bonds such as PO, SeO, SO, SO ₂ , VO, or complexes thereof, etc. It is. More specifically, BF ₃ , BF ₃ O(C ₂ H ₅ ) ₂ , (CH ₃ ) ₂ BF, BCl ₃ ,
AlCl ₃ , AlBr ₃ , (C ₂ H ₅ )AlCl ₂ , POCl ₃ , TiCl ₄ ,
VCl ₄ , MOCl ₄ , BnCl ₄ , (CH ₅ )SnCl ₃ , SbCl ₅ ,
TeCl ₄ , TeBr ₄ , FeCl ₃ , WCl ₆ , (C ₂ H ₅ ) ₂ AlCl,
Examples include ZnCl ₂ , (C ₂ H ₅ ) ₃ Al, and AgBF ₄ . Among these, SnCl ₄ , SbCl ₅ , AlCl ₃ , TiCl ₄
etc. are particularly suitable because they have a high reaction rate and few side reactions. The amount of Friedel-Crafts catalyst used is not particularly limited, but is usually 0.01 to 5 mol, preferably 0.05 to 2 mol, based on the compound.
It is a mole. The reaction for preparing the modified rubber in the present invention is usually carried out in the presence of a suitable solvent. Industrially, it is advantageous to carry out the reaction in the rubber cement after the polymerization has ended. As the solvent, any solvent can be used, such as aromatic solvents such as benzene and toluene, paraffinic solvents such as butane and hexane, alicyclic solvents such as cyclohexane, and halogenated hydrocarbon solvents such as chloroform and dichloroethane. However, those that are inert to the reaction and that dissolve the rubber are suitable. It is also possible to carry out in a rubber kneader in the absence of a solvent. The compound, the compound, and the Friedel-Crafts catalyst may be added in their entirety to the reaction system at the beginning, or may be added in portions or continuously during the reaction. Further, the compound, the compound and the Friedel-Crafts catalyst may be added to the reaction system separately, or two or three of these may be mixed in advance and then added to the reaction system. When carrying out the reaction, it is necessary to maintain the reaction system in an anhydrous state or under a limited amount of water (usually 100 ppm or less). The reaction temperature is not particularly limited, and is usually -20°C to 180°C, preferably -10°C to
It is 60℃. The reaction time is also not particularly limited, and is appropriately set between 10 seconds and 10 hours. When the reaction is carried out in a solvent, for example, by adding a large amount of alcohol or alkaline aqueous solution, the reaction can be completely stopped and the rubber can be coagulated. Next, various residues in the rubber are removed by washing as required, and then dried to obtain a modified rubber. In the present invention, other rubbers can be used in combination with the modified rubber thus obtained, within the range where the object of the present invention is achieved. Other rubbers that may be mixed with modified rubber include:
Natural rubber (Hebiya), guayule rubber, synthetic polyisobrene rubber, butadiene rubber (hereinafter referred to as BR), styrene-butadiene copolymer rubber (hereinafter referred to as BR)
SBR), butadiene piperylene copolymer rubber, butadiene acrylonitrile copolymer rubber, isobrene acrylonitrile copolymer rubber, high styrene rubber, ethylene propylene diene copolymer rubber, butyl rubber, halogenated butyl rubber, polychloroprene rubber, cyclopentene, norbornene, etc. Ring-opened polymer rubbers of cycloolefins, polymer rubbers of dienes such as ethylidene norbornene and cyclopentanediene, and the like. It is of course possible to use two or more of these in combination. These rubbers are appropriately selected depending on the purpose. The white filler used in the composition of the present invention includes calcium carbonate such as activated calcium carbonate, light calcium carbonate, heavy or finely powdered calcium carbonate, and silicic acid (silica) such as hydrous fine powder silicic acid and anhydrous fine powder silicic acid. , kaolin clay, aluminum silicate (clay) such as calcined clay, magnesium carbonate, calcium/magnesium composite carbonate,
Magnesium silicate, calcium silicate, aluminum silicate, titanium oxide, etc. can be used alone or in combination. The amount of white filler used is usually 1 per 100 parts by weight of the rubber component depending on the application.
-300 parts by weight, preferably 5-200 parts by weight. The composition of the present invention may optionally contain a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator/activator, a softening agent, a coupling agent, a tackifier, a coloring agent, an anti-aging agent, and an anti-ozonant agent. It can contain ordinary rubber compounding agents such as. Typical vulcanizing agents include sulfur and sulfur donors such as thiuram and thiazole.
Other peroxides, polyamines, metal oxides,
Urethane vulcanizing agents, resin vulcanizing agents, and the like can also be used as desired. Vulcanization accelerators for sulfur and sulfur donors include sulfenamide, thiuram, thiazole, guanidine,
Mercaptotriazine type, aldehyde-amine type, etc. are used as vulcanization accelerators and activators, metal compounds such as zinc oxide, magnesium oxide, calcium hydroxide, lead carbonate, carboxylic acids such as stearic acid and oleic acid, and stearic acid. Carboxylate salts such as zinc, amines such as diethanolamine and triethanolamine, ethylene glycol, diethylene glycol, and the like are used. Softeners include mineral oils such as paraffin, naphthenic, and aromatic oils, vegetable oils, etc. Coupling agents include silanes and titanates, and tackifiers include rosin and petroleum hydrocarbon resins. , coumarone resin, etc. Colorants include inorganic pigments,
Organic pigments, etc. are used as anti-aging agents, such as amines,
Examples of ozone deterioration inhibitors include phenols and waxes. The method of mixing the components constituting the composition of the present invention is not particularly limited, and various rubber kneaders are usually used. (Effect of the invention) Among the rubber compositions of the present invention, especially 50 to 100% by weight of modified polyisoprene rubber and 0 to 50% of vinyl bonds.
BR and/or styrene bond content is 15-35% by weight
The amount of vinyl bond in the butadiene part is 0 to 50%.
SBR and/or natural rubber and/or guayule rubber and/or synthetic polyisoprene rubber and/or ethylene-propylene-diene copolymer rubber and/or halogenated butyl rubber 50-0% by weight averaged over 100 parts by weight of rubber or rubber mixture Particle size 10
A composition containing 45 to 100 parts by weight of ~40 mμ silica and 0 to 10 parts by weight of a silane coupling agent has high green strength, tensile stress, tear strength, and rebound resilience, and is useful for various light-colored tire parts, especially tread rubber, Suitable for sidewalls and carcass rubber. The rubber composition of the present invention has extremely excellent green strength as well as the tensile stress, tear strength, and impact resilience of its vulcanizate, so it can be used in belts, hoses, anti-vibration rubber, boots, canvas, balls, etc. It is also suitably used for other ordinary light-colored compounded compositions. According to the method of the present invention, compounds and compounds were confirmed to be added to unsaturated rubber chains. It is believed that the addition of these compounds improves the green strength of the unvulcanized rubber compound and the tensile stress, tear strength, impact resilience, etc. of the vulcanized product. (Example) The present invention will be described in more detail with reference to Examples below. In addition, parts and % in Examples and Comparative Examples
Unless otherwise specified, data are based on weight. The methods for preparing unvulcanized blends and vulcanized products of modified rubber and the methods for testing their physical properties in each example are as follows. [Preparation of unvulcanized rubber compound] The modified rubber was kneaded and mixed in a small Banbury mixer with various compounding ingredients in the compounding recipe of the example except for sulfur and vulcanization accelerator, and the resulting mixture was mixed with sulfur and vulcanized. A rubber unvulcanized compound was prepared by adding a sulfur accelerator and kneading on a small roll. [Wallace plasticity] By Wallace's rapid plastometer
Measured at 100℃. [Green strength] The unvulcanized rubber compound was press-molded at 100℃ for 5 minutes to form a 2 mm thick unvulcanized rubber sheet.
Punch out dumbbell-shaped JIS No. 3 test pieces, 23℃,
It is shown as the value of tensile stress at 500% elongation when a tensile test is performed at a tensile speed of 500 mm/min. [Tensile test] The unvulcanized rubber compound was press-vulcanized at 150°C for a predetermined period of time to form a 2 mm thick sheet, and a dumbbell-shaped No. 3 test piece specified in JIS-K6301 was punched out.
The tensile speed was mm/min. [Rebound Resilience] The vulcanizate obtained by press-vulcanizing the unvulcanized rubber compound at 150°C for a predetermined period of time was measured at 23°C using a Dunlop lipometer. [Tear strength] From a 2mm thick vulcanized sheet, width 15mm and length 100mm
A rectangular specimen was punched out, and a 6 mm incision was made perpendicular to the side edge with a safety razor blade in the center of one longitudinal edge.
It was carried out at a tensile speed of min, and the average value of 6 samples, 3 each in the grain direction and in the direction perpendicular to the grain, was expressed. Example 1 Polyisoprene rubber (98% cis 1,4 bonds)
Dissolve 160 g in dehydrated toluene from step 3 and dilute each of the compounds listed in Table 1 and Friedel-Crafts catalyst with dehydrated benzene while stirring at 25°C under a nitrogen atmosphere in a sealed glass container (separable flask). was added and reacted for 1 hour. Then 500 ml of methyl alcohol was poured (this stopped the addition reaction). The obtained semi-solidified rubber solution was poured into methyl alcohol from Step 3 to completely solidify the rubber, and the solidified product was washed in small pieces. Then, about 2
The coagulated pieces were immersed in methyl alcohol 3 containing an antiaging agent (2,6-di-tert-butyl-4-methylphenol), washed, and dried overnight in a vacuum dryer. Then,
Modified polyisoprene rubber sample A shown in Table 1,
B, C, and D were obtained.

[Table] Next, for the samples shown in Table 1, the physical properties of the unvulcanized compound and the vulcanized product were measured using the following formulation. The results are shown in Table 2. Compounding recipe Sample rubber 100 Zinc oxide 5 Hydrous fine silicic acid ¹⁾ 60 Process oil 5 Stearic acid 3 Sulfur 3 N-oxydiethylene-2-benzothiazylsulfenamide 1.15 Tetramethylthiuram disulfide 0.1 Triethanolamine 2 1 ) High Sil 233 manufactured by PPG Industries

[Table] It can be seen that Examples A to D of the present invention have significantly improved green strength, 300% tensile stress, and impact resilience compared to unmodified polyisoprene rubber. Example 2 150 g of polyptadiene rubber was dissolved in dehydrated benzene from step 3 and reacted for 1 hour at 25°C under the reaction conditions listed in Table 3 in a nitrogen atmosphere in a sealed glass container (separable flask). Then, 100 ml of methanol was added to stop the reaction. Next, add the reaction solution to 2,6
- Ditertiary-butyl-4-methylphenol 1% methanol solution 3 was poured to completely coagulate the rubber and the coagulated material was washed as fine pieces. Thereafter, samples E to G were obtained by drying in a vacuum dryer for a day and a night.

[Table] Next, for the samples shown in Table 3, the physical properties of the unvulcanized compound and the vulcanized product were measured using the following formulation. The results are shown in Table 4. Compounding recipe Sample rubber 100 Zinc oxide 5 Hydrous fine silicic acid ¹⁾ 60 Process oil 5 Stearic acid 3 Sulfur 2 Dibenzothiazyl disulfide 1.5 Tetramethylthiuram disulfide 0.1 Ethylene glycol 5 1) HiSil 233 manufactured by PPG Industries

[Table] It can be seen that the examples of the present invention are significantly superior in 300% tensile stress and rebound resilience. Example 3 Polyisoprene rubber (98% cis 1,4 bonds) 2
Kg in 40 volumes of dehydrated toluene and diluted with 40 volumes of dehydrated benzene with 0.35 moles of benzylidenebutylamine, acetyl chloride and SnCl ₄ dissolved in 40 volumes of dehydrated benzene while stirring at 25°C under a nitrogen atmosphere in a stainless steel closed container. was added and reacted for 40 minutes. Then, methyl alcohol of 1 was poured in (this stopped the addition reaction). Pour the resulting rubber solution into a total of 100 ml of methyl alcohol,
The rubber was completely coagulated and the coagulum was washed in pieces. The rubber was then immersed in several portions of the coagulated strips in 10 methyl alcohol containing about 20 g of an anti-aging agent (2,6-tertiary butyl-4-methylphenol) and washed. By drying it all day and night in a vacuum dryer,
A modified polyisoprene rubber sample was obtained. Rubber compositions prepared according to the formulations shown in Table 5 were evaluated for their physical properties. The results are shown in Table 5. Inventive Examples 3 and 4 have high green strength, 300% tensile stress, tear strength, and impact resilience, and despite having a large amount of hydrated fine powder silicic acid, they have low Wallace plasticity and good workability. It is superior to No. 2, and is particularly suitable as a light-colored tire member for tire carcass rubber, tire tread rubber, and tire sidewall rubber.

[Table] Example 4 The physical properties of a rubber composition prepared according to the formulation shown in Table 6 (the rubber was the same as that used in Example 3) were evaluated. The results are shown in Table 6. Inventive Example 6 has green strength, 300% tensile stress,
It can be seen that the tear strength and impact resilience are large and superior to Comparative Example 5.

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Claims (1)

[Claims] 1. In the presence of a Friedel-Crafts catalyst, an organic compound having a group represented by the formula -CH=N- and a group represented by the formula -COX (X is a halogen) are added to a rubber having an unsaturated bond. 1. A light-colored rubber composition, characterized in that a white filler is blended into a modified rubber obtained by reacting an organic acid halide having a group with a white filler, or a mixture of this modified rubber and another rubber.