JPH05412B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a blend rubber composition suitable for tires and the like having excellent green strength and properties after vulcanization. (Prior Art) Conventionally, in order to obtain rubber compositions with improved green strength and adhesiveness after vulcanization, rubbers into which polar groups such as carboxyl groups have been introduced, such as maleic anhydride and glyoxy It is known to use added rubber such as saar. However, these rubbers have the disadvantage that their strength properties as a vulcanizate are insufficient because side reactions such as rubber gelation and molecular weight reduction are likely to occur during the modification reaction. In particular, even if polar groups such as carboxyl groups are introduced into synthetic polyisoprene rubber, which has a structure closest to that of natural rubber, by conventionally known methods, due to the above-mentioned drawbacks, it is used mainly in tires for large buses and trucks. It was difficult to use. (Problems to be Solved by the Invention) As a result of various studies in order to develop a modified polyisoprene rubber composition free from such drawbacks, the present inventor has found that the green strength and The inventors have discovered a modified polyisoprene rubber composition whose vulcanizate has significantly superior strength properties, impact resilience, etc., and has arrived at the present invention. (Means for Solving the Problems) That is, the present invention provides polyisoprene rubber with an organic compound having a group represented by the formula -CH=N- and a formula -COX (X is a halogen) in the presence of a Friedel-Crafts catalyst. ) A blended rubber consisting of 5 to 95% by weight of a modified polyisoprene rubber obtained by reacting an organic acid halide having a group represented by the following and 95 to 5% by weight of another rubber is blended with carbon black. The present invention provides a blended rubber composition characterized by: The polyisoprene rubber in the present invention is defined as including synthetic polyisoprene rubber (hereinafter sometimes referred to as synthetic IR), as well as natural rubber (snake) and guayule rubber having a polyisoprene structure. More specifically, the organic compound having a group represented by the formula -CH=N- (hereinafter sometimes referred to as compound I) 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 include acetyl chloride, acetyl bromide, benzoyl chloride, benzoyl bromide, carbomethoxybenzoyl chloride, oxalyl chloride, terephthalic acid chloride, acrylic acid chloride, methacrylic acid chloride, and the like. The amount of the compound used is not particularly limited, but it is usually 0.001 to 30 each per 100 parts by weight of IR.
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, or oxygen-element bonds such as Po, SeO, SO, SO ₂ , VO, or complexes thereof etc. More specifically, _BF3 , _BF3O ( _C2H5 ) ₂ , ( _CH3 ) _2BF , _{BCl3 ,
AlBr3} , ( _C2H5 ) _{AlCl2 , POCl3} , _TiCl4 , _VCI4 ,
_MoCl6 , _SnCl4 , ( _CH3 ) _SnCl3 , _SbCl5 , _TeCl4 ,
_{TeBr4 , FeCl3} , _WCl6 , ( _C2H5 ) _2AlCl , _ZnCl2 ,
Examples include (C ₂ H ₅ ) ₃ Al and AgBF ₄ . Among these, SnCl ₄ , SbCl ₅ , AlCl ₃ , TiCl ₄ and the like are particularly suitable because they have a high reaction rate and cause few side reactions. The amount of Friedel-Crafts catalyst used is not particularly limited, but is usually 0.01 to 10 mol, preferably 0.05 to 3 mol, based on the compound. The modification reaction of the present invention is usually carried out in a solvent.
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 dissolve IR are suitable. It is also possible to carry out in a rubber kneader in the absence of a solvent. The compound, compound and Lewis acid are in the reaction system,
The entire amount may be added 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 IR can be solidified. Next, various residues in the rubber are removed by washing as required, and then dried to obtain a modified IR. In the present invention, other rubbers to be mixed with the modified IR include natural rubber (Hebiya), guayule rubber, synthetic polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, butadiene-piperylene copolymer rubber, and butadiene-acrylonitrile copolymer rubber. rubber, isoprene acrylonitrile copolymer rubber, high styrene rubber, ethylene propylene diene copolymer rubber, ring-opening polymer rubber of cycloolefins such as cyclopentene and norbornene,
Examples include polymer rubbers of dienes such as ethylidenenorbornene and cyclopentadiene, and polyolefin rubbers such as copolymers of dienes and olefins. It is of course possible to use two or more of these in combination. These rubbers are appropriately selected depending on the application, but for tires, polybutadiene rubber (hereinafter sometimes referred to as BR), styrene-butadiene copolymer rubber (hereinafter sometimes referred to as SBR), natural rubber, BR and SBR, BR and natural rubber, and SBR and natural rubber are representative examples.
And the effect is also noticeable. Examples of BR include those with a vinyl bond content of 0 to 98% and a trans 1.4 bond content of 0 to 95%, prepared by liquid polymerization using a conventional catalyst such as a Ziegler type catalyst or an organic alkali metal catalyst. Can be mentioned. Also,
For example, SBR is prepared by ordinary emulsion polymerization or solution polymerization, and has a styrene bond content of 5.
~40% by weight, the amount of vinyl bond in the butadiene part is 0
Up to 98% of cases are mentioned. The carbon black used in the present invention is not particularly limited, but has an average particle size of 10 mμ to 500 mμ.
Preferably, the commonly used abbreviations are EPC, MPC,
Channel black for HPC, CC, etc., SAF,
ISAF, HAF, MAF, FEF, HMF, SRF,
It is appropriately selected from furnace blacks such as SPF, GPF, APE, FF, and CF, thermal blacks such as FT and MT, and acetylene blacks. The amount of carbon black to be used is appropriately determined depending on the application, but it is usually selected from the range of 10 to 150 parts by weight, preferably 20 to 120 parts by weight, per 100 parts by weight of the total amount of rubber. The composition of the present invention may optionally contain conventional rubber compounds such as vulcanizing agents, vulcanization accelerators, vulcanization aids, softeners, tackifiers, fillers, reinforcing agents other than carbon black, and anti-aging agents. may contain additives for use. 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 include sulfenamide, thiuram, thiazole, guanidine, mercaptotriazine, aldehyde-amine, etc., and vulcanization aids include carboxylic acids such as stearic acid and oleic acid, and zinc stearate. , metal compounds such as zinc oxide, magnesium oxide, calcium hydroxide, and lead carbonate; softening agents include paraffin-based, naphthenic-based, and aromatic-based process oils; tackifiers include rosin-based and carbonized petroleum Hydrogen resins, coumaron resins, phenol-terpene resins, etc. are used as fillers, calcium carbonate, clay, talc, etc. are used as fillers, silicic acid and its salts are used as reinforcing agents other than carbon black, and as anti-aging agents. Examples include amine type and phenol type. The above-mentioned vulcanization accelerator and vulcanization aid are mainly used in the case of vulcanization using sulfur or a sulfur donor. The method of mixing the components constituting the composition of the present invention is not particularly limited, and various rubber kneading machines are usually used, but in particular, carbon black and various process oils are used in the raw rubber manufacturing process or modification process. They can also be mixed to make a carbon masterbatch and an oil masterbatch, respectively.
Further, other rubbers may be allowed to coexist during IR modification, or may be blended in a solution state in a cement tank or the like after completion of the modification reaction. (Effect of the invention) Among the blend rubber compositions of the present invention, especially
BR with IR75~95% by weight and vinyl bond content 0~50%
and/or SBR25 with a styrene bond content of 15 to 35% by weight and a vinyl bond content of the butadiene portion of 0 to 50%
A composition containing 45 to 70 parts by weight of rubber furnace carbon black with an average particle size of 10 to 50 mμ to 100 parts by weight of blended rubber with ~5% by weight has excellent impact resilience, heat generation property, and tensile stress, and is suitable for large trucks, Suitable for bus tire treads, etc. Also modified IR5~
SBR95 with a styrene bond content of 35% by weight and a styrene bond content of 15 to 35% by weight and a vinyl bond content of the butadiene portion of 0 to 50%.
A composition containing 100 parts by weight of blended rubber with ~65% by weight and 45 to 70 parts by weight of furnace carbon black for rubber with an average particle size of 10 to 50 mμ has excellent impact resilience and tensile stress, and is suitable for tire treads of passenger cars. It is. In addition, modified IR 35-65% by weight and vinyl bond amount 0-50% BR and/or styrene bond amount are
Blend rubber with 15-35% by weight and SBR65-35% by weight with a vinyl bond content of 0-50% in the butadiene part
A composition containing 100 parts by weight and 40 to 50 parts by weight of a rubber furnace carbon black having an average particle size of 25 to 70 mμ has high rebound resilience, excellent heat generation properties and tensile stress, and is suitable for tire sidewalls and the like. In addition, modified IR50~95% by weight and vinyl bond amount 0~50%
BR and/or styrene bond amount is 15-35% by weight
The amount of vinyl bond in the butadiene part is 0 to 50%.
A composition containing 40 to 60 parts by weight of rubber furnace carbon black with an average particle size of 20 to 90 mμ to 100 parts by weight of blended rubber with 50 to 5% by weight of SBR has high green strength, tensile stress, and rebound resilience, and is used for tire carcass, etc. suitable for In addition, modified IR80~95% by weight and vinyl bond amount 0
~50% BR and/or styrene bond amount 15-35
The amount of vinyl bond in the butadiene part is 0 to 50 by weight.
A composition in which 70 to 100 parts by weight of furnace carbon black for rubber with a diameter of 10 to 40 mμ is blended with 100 parts by weight of blended rubber with 20 to 5% by weight of SBR has rebound resilience,
It has high tensile stress and hardness and is suitable for tire bead fillers, rim cushions, etc. Furthermore,
Modified IR75~25% by weight and vinyl bond amount 35~98%
BR and/or styrene bond amount is 5 to 35% by weight
The amount of vinyl bond in the butadiene part is 30 to 85%.
A composition containing 40 to 70 parts by weight of rubber furnace carbon black with an average particle size of 10 to 50 mμ to 100 parts by weight of blended rubber with 25 to 75% by weight of SBR has high impact resilience and is suitable as a tread for low fuel consumption tires. It is. In addition to the above, the blended rubber composition of the present invention also includes:
It is also suitably used in ordinary rubber products such as tire inner liners, belts, hoses, anti-vibration rubber, footwear, and canvas fabrics. According to the method of the present invention, compounds and compounds were confirmed to add to IR. It is believed that the addition of these compounds improves the green strength of the unvulcanized blended rubber compound, the tensile stress, impact resilience, etc. of the vulcanized blended rubber compound. (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 IR and the methods for testing their physical properties in each example are as follows. [Preparation of unvulcanized rubber compound] Modified IR 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. [Vulcanization speed] By oscillating disk rheometer
It is expressed as the time (T ₉₅ ) required for the torque measured at 150°C to reach 95% of the maximum torque. [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 vulcanized product 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. [Heat generation (HBU)] Tested in accordance with ASTM D623-58 using a cylindrical vulcanized rubber test piece with a diameter of 0.7 inches and a height of 1 inch, using a Gutdrich tester at a frequency of 1800 rpm, a load of 25 pounds, and a stroke of 0.175 inches. Temperature 100℃,
It is shown as the value of temperature rise (°C) measured under test conditions of 25 minutes. [Pico Wear] Measured using a Gutdrich Pico Abrasion Tester in accordance with ASTM D-2228. [Wet skid resistance] Measured using a portable skid tester (manufactured by Stanley, UK) at 19°C on an ASTM E-303-74 road surface (outdoor type B, black safety walk manufactured by 3M). [Hardness] Measured at 23°C according to the spring type hardness test (Type A) described in JIS K-6301. Example 1 160 g of synthetic IR (98% of cis 1,4 bonds) was dissolved in dehydrated toluene from step 3, and while stirring at 25°C under a nitrogen atmosphere in a sealed glass container (separable flask), the mixture was prepared as described in Table 1. and a Friedel-Crafts catalyst diluted with dehydrated benzene were added and reacted for 1 hour. after that,
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. Next, the coagulated pieces were immersed in methyl alcohol 3 containing about 2 g of anti-aging agent (2,6-di-ter-shaributyl-4-methylphenol), washed, and then dried in a vacuum dryer overnight. Thus, modified IR samples A, B, C, and D shown in Table 1 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 85 BR(1) 15 HAF(2) 50 Zinc oxide 5 Stearic acid 2 Sulfur 2.5 Aromatic oil 5 N-oxydiethylene-2-benzothiazyl sulfenamide (vulcanization accelerator) 0.8 N -Isopropyl-N'-phenyl-p-phenylenediamine 1 (1) Nippon Zeon Co., Ltd. BR1220 (2) Tokai Carbon Co., Ltd. Seast 3

[Table] It can be seen that the green strength, 300% tensile stress, and impact resilience of Examples A to D of the present invention are significantly improved compared to the comparative example. Example 2 Synthesis IR (98% cis-1,4 bonds) 2 kg was dissolved in 40% dehydrated toluene, and while stirring at 25°C under nitrogen atmosphere in a stainless steel sealed container, 0.35 mol of benzylidenebutylamine and acetyl chloride were dissolved. and SnCl ₄ diluted with 40 times the volume of dehydrated benzene were added and reacted for 40 minutes. then 1
of methyl alcohol (this stopped the addition reaction). Total the resulting rubber solution
The rubber was poured into 100 ml of methyl alcohol to completely coagulate the rubber and the coagulated material was washed in pieces. Next, add about 20g of anti-aging agent (2,6
The coagulated pieces were immersed in methyl alcohol (10) containing 4-methylphenol and 4-methylphenol in several portions, washed, and then dried overnight in a vacuum dryer to produce modified IR. Sample E was obtained. The physical properties of rubber compositions prepared according to the formulations shown in Table 3 were evaluated. The results are shown in Table 3. Experiment numbers 1 and 6 were applied to bias tire carcass of large trucks and buses; experiment numbers 2, 3, 4,
Test numbers 7, 8, and 9 are examples of formulations suitable for passenger car tire carcass, and run numbers 5 and 10 are suitable for large truck and bus steel radial tire carcass. Among these, it can be seen that Examples 6, 7, 8, 9, and 10 of the present invention have high green strength, 300% tensile stress, and impact resilience, and are superior to Comparative Examples with low heat generation.

【table】

[Table] Example 3 The physical properties of a rubber composition prepared according to the formulation shown in Table 4 (the rubber was the same as that used in Example 2) were evaluated. The results are shown in Table 4. Run numbers 11, 12, 13, 16, 17 and 18 are examples of formulations suitable for large truck and bus tire treads. Among these, it can be seen that Examples 16, 17, and 18 of the present invention are superior to Comparative Examples 11, 12, and 13 in terms of high impact resilience and 300% tensile stress, and low heat generation. Run numbers 14 and 19 are examples of formulations suitable for tire sidewalls. Inventive example 19 has rebound resilience of 300
% tensile stress is large and heat generation is small, which is superior to Comparative Example 14. Run numbers 15 and 20 are examples of formulations suitable for passenger car tire treads. Inventive example 20 has a large 300% tensile stress, high impact resilience, and generates little heat, which is superior to the comparative example.

【table】

[Table] Example 4 Table 5 shows the results of physical property evaluation based on formulation examples suitable for tire bead fillers and the like. The rubber used was the same as that used in Example 2. The composition of the present invention has high 100% tensile stress, hardness, and impact resilience, and despite having a large amount of carbon black, it has low Wallace plasticity and good workability, and is significantly superior to the comparative example. Example 5 Table 6 shows the results of evaluating the physical properties of a rubber composition prepared according to the formulation shown in Table 6 (an example of a formulation suitable for treads of low fuel consumption tires, etc.). From the same table, it can be seen that the composition of the present invention has a high impact resilience and is superior to the composition of the comparative example, although the pico wear amount and the wet skid resistance are almost the same.

【table】

【table】

【table】

Claims (1)

[Claims] 1. 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 polyisoprene rubber in the presence of a Friedel-Crafts catalyst. A blended rubber composition characterized by blending carbon black into a blended rubber consisting of 5 to 95% by weight of modified polyisoprene rubber obtained by reacting an organic acid halide with 95 to 5% by weight of another rubber. .