JPH0412902B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a composition that has excellent softening point, penetration, elongation, and strength, and is suitable for asphalt for road paving, waterproof sheets, sound insulation sheets, roofing, etc. Regarding things,
More specifically, the present invention relates to a bituminous composition comprising a bituminous material and a block copolymer comprising a conjugated diene and a vinyl aromatic hydrocarbon having a specific composition distribution. [Conventional technology] Conventionally, natural rubber, styrene, butadiene,
By mixing synthetic rubber such as rubber or nitrile rubber, the properties of bituminous materials, which are brittle at low temperatures and prone to impact fracture, and properties that are prone to plastic deformation at high temperatures, are improved and durability is improved. It is known that the amount of carbon dioxide increases, and it is already being used in Japan and other countries for roads, civil engineering, architecture, industrial applications, etc. A method for producing a rubber-containing bituminous composition includes a method in which rubber is mixed in advance with a bituminous material using an oven roll to create a master patch with a high rubber content, and the master patch is poured into a heated and melted bituminous material to dissolve it; A method in which rubber in the form of powder or latex is poured directly into a bituminous material heated and melted, and a block copolymer consisting of a conjugated diene and a vinyl aromatic hydrocarbon such as pellets, crumb or powder is dissolved in a bituminous material heated and melted. There is a method of dissolving it by dissolving it in water. Particularly in recent years, there has been a tendency for bituminous compositions mixed with block copolymers, which have better solubility during mixing and relatively lower viscosity at high temperatures than conventionally used bituminous compositions mixed with natural rubber or synthetic rubber, to be used favorably. It is in. For example, in Japanese Patent Publication No. 17319/1982 and Japanese Patent Publication No. 33058/1989, a bituminous material using a block copolymer of a vinyl aromatic compound and a conjugated diene compound or a hydrogenated product thereof is described as a rubber-like material. The composition is shown. [Problems to be Solved by the Invention] However, the above-mentioned block copolymer-containing bituminous compositions have poor balance performance among softening point, penetration, elongation, and strength, and improvement thereof is desired.
Attempts have been made to improve these problems by increasing the molecular weight of the block copolymer or increasing the content of vinyl aromatic compounds, but the former increases melt viscosity and significantly deteriorates processability. However, the latter poses problems such as decreased penetration and elongation. [Means and effects for solving the problems] In view of the current situation, the present inventors have conducted extensive studies on improving the softening point, penetration, elongation, etc. of the composition of bituminous material and block copolymer. As a result, the present inventors have discovered that the object can be achieved by using a block copolymer having a specific composition distribution in compositional analysis by high performance liquid chromatography, and have completed the present invention. That is, the present invention
(a) has at least one polymer segment mainly composed of a vinyl aromatic hydrocarbon and at least one polymer segment mainly composed of a conjugated diene, and the weight ratio of the vinyl aromatic hydrocarbon to the conjugated diene is is 10/
90 or more and 60/40 or less, or its hydrogenated product, component A (vinyl aromatic hydrocarbon whose main peak is vinyl aromatic hydrocarbon content) determined from composition analysis by high performance liquid chromatography. component B (the vinyl aromatic hydrocarbon content is less than the main peak vinyl aromatic hydrocarbon content and the difference is 5% by weight or more) A block copolymer whose total amount is 20 to 80%. (b) Bituminous material. A bituminous composition comprising: The present invention will be explained in detail below. The block copolymer of component (a) used in the present invention has at least one, preferably two or more polymer segments mainly composed of vinyl aromatic hydrocarbons and at least one polymer segment mainly composed of conjugated dienes. and the weight ratio of vinyl aromatic hydrocarbon to conjugated diene is 10/90 or more and 60/40 or less, preferably
It is a block copolymer of 15-85-55/45. If the vinyl aromatic hydrocarbon content is less than 10/90, the softening point and strength will be poor, and if it exceeds 60/40, the penetration and elongation will deteriorate, which is not preferable. In the present invention, a polymer segment mainly containing vinyl aromatic hydrocarbons is a polymer segment with a content of vinyl aromatic hydrocarbons of 50% by weight or more, and a copolymer segment with a conjugated diene and a vinyl aromatic hydrocarbon. It is composed of a combined portion and/or a vinyl aromatic hydrocarbon polymer portion. In addition, a polymer segment mainly composed of conjugated dienes refers to a polymer segment with a vinyl aromatic hydrocarbon content of 50%.
Less than % by weight of the polymer segment is composed of a conjugated diene and vinyl aromatic hydrocarbon copolymer portion and/or a conjugated diene polymer portion.
The vinyl aromatic hydrocarbon in the copolymer portion of the conjugated diene and the vinyl aromatic hydrocarbon may be uniformly distributed in the polymer chain or may be distributed in a tapered manner. Further, the copolymer portion may include a plurality of portions in which vinyl aromatic hydrocarbons are uniformly distributed and/or a plurality of portions in which vinyl aromatic hydrocarbons are distributed in a tapered manner. In such a case, the proportions of conjugated diene and vinyl aromatic hydrocarbon in each copolymerization portion may be the same or different. The biggest feature of the block copolymer of component (a) used in the present invention is that it is capable of being liquid chromatographed (detected at a wavelength of 254 nm using an ultraviolet absorption photometer as a detector).
Component A (component whose vinyl aromatic hydrocarbon content is higher than the vinyl aromatic hydrocarbon content of the main peak and the difference is 5% by weight or more) and component B (vinyl aromatic hydrocarbon content) determined from composition analysis by components whose hydrogen content is lower than the vinyl aromatic hydrocarbon content of the main peak and the difference is 5% by weight or more)
and the total amount is 20 to 80%, preferably 30 to 70%. If the total amount of component A and component B is outside the above range, it is not preferable because a product with excellent balance of softening point, penetration, elongation and strength cannot be obtained. In the present invention, compositional analysis by high-performance liquid chromatography is a method developed by Professor Tanaka of the University of Agriculture and Technology (Makromol.Chem., Rapid Commun.
5, 719-722 (1984) and Proceedings of the Society of Polymer Science, Vol. 32, No. 9, 2227-2230 (1983)), and acrylonitrile-ethylene glycol dimethacrylate copolymer gel (particle size 2.5-5.0 μm). The eluent composition gradient method (hexane/
This is a method of separating and analyzing polymers based on their compositional differences using chloroform). An ultraviolet absorption photometer is used as a detector, and detection is performed at a wavelength of 254 nm. The composition of the eluted component is determined using a calibration curve prepared using a standard sample prepared by the method described in the above-mentioned literature. In the present invention, the vinyl aromatic hydrocarbon content of the main peak is defined as 254 nm in the high performance liquid chromatogram obtained by the above method.
This is the vinyl aromatic hydrocarbon content (% by weight) corresponding to the portion with maximum absorbance at the wavelength of . In addition, when there are two or more parts with the maximum absorbance at a wavelength of 254 nm in the high-performance liquid chromatogram, the part with the higher vinyl aromatic hydrocarbon content is determined to be the main peak. The proportion of component A in the present invention is determined by calculating the area of the part corresponding to the component whose vinyl aromatic hydrocarbon content is 5% by weight or more higher than the vinyl aromatic hydrocarbon content of the main peak in a high-performance liquid chromatogram. It is found by dividing by the area of . Similarly,
The proportion of component B is determined by dividing the area of the portion corresponding to the component whose vinyl aromatic hydrocarbon content is 5% by weight or more less than the vinyl aromatic hydrocarbon content of the main peak by the area of all components. . In the present invention, when the vinyl aromatic hydrocarbon content of the main peak is equal to or lower than the vinyl aromatic hydrocarbon content of the entire block copolymer, the former is preferably smaller than the latter, and the difference is preferably 1 weight. % or more, the penetration and elongation are particularly excellent; conversely, when the vinyl aromatic hydrocarbon content of the main peak exceeds the vinyl aromatic hydrocarbon content of the entire block copolymer, the former is preferable. If it is larger than the latter and the difference is 1% by weight or more, it has a particularly excellent softening point and can be used for various purposes depending on the state of the composition distribution. The block copolymer of component (a) used in the present invention has a weight average molecular weight (hereinafter referred to as w) and a number average molecular weight (hereinafter referred to as n) of the vinyl aromatic hydrocarbon polymer block in the block copolymer. ) ratio is
A value in the range of 1.2 to 3.0, preferably 1.3 to 2.0 is recommended in terms of workability and the stability of the above-mentioned properties. Vinyl aromatic hydrocarbon polymer block w/
Mn can be measured as follows. A vinyl aromatic hydrocarbon polymer component (L, M,
KOLTHOFF, et al., J.Polym.sci.1, 429
(1946)) using gel permeation chromatography (GPC), and using a conventional method (for example, the method described in "Gel Chromatography (Basic Edition)").
This refers to the value calculated according to the method described in the publication by Kodansha. The calibration curve for GPC is created using standard polystyrene commercially available for GPC. The block copolymer of component (a) used in the present invention can be obtained by polymerization in a hydrocarbon solvent using an organolithium compound as an initiator. Hydrocarbon solvents include aliphatic hydrocarbons such as butane, pentane, hexane, isopentane, heptane, octane, isooctane; cyclopentane,
Alicyclic hydrocarbons such as methylcyclopentane, cyclohexane, methylcyclohexane, and ethylcyclohexane; or aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene can be used. Organolithium compounds have 1 in the molecule.
It is an organic lithium compound containing two or more lithium atoms, such as ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, hexamethylene dilithium, butadienyl dilithium. Examples include lithium and isoprenyl dilithium. In the present invention, vinyl aromatic hydrocarbons include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, etc. However, styrene is a particularly common one.
These may be used not only alone, but also as a mixture of two or more. The conjugated diene is a diolefin having a pair of conjugated double bonds, such as 1,
3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-
Examples include butadiene, 1,3-pentadiene, 1,3-hexadiene, and particularly common ones include 1,3-butadiene and isoprene. These may be used not only alone, but also as a mixture of two or more. When producing the block copolymer of component (a) used in the present invention, the method for forming a copolymer portion of vinyl aromatic hydrocarbon and conjugated diene is as follows: (i) Vinyl aromatic hydrocarbon and conjugated diene (ii) Copolymerizing a vinyl aromatic hydrocarbon and a conjugated diene using a polar compound or a randomizing agent. Can be adopted. As polar compounds and randomizing agents, ethers such as tetrahydrofuran, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether, amines such as triethylamine and tetramethylethylenediamine, thioethers, phosphines,
Examples include phosphoramides, alkylbenzene sulfonates, and potassium and sodium alkoxides. The bonding state of the vinyl aromatic hydrocarbon copolymerized into the copolymer portion of the vinyl aromatic hydrocarbon and conjugated diene by the above method is determined by a method developed by Professor Tanaka et al. of the University of Agriculture and Technology to form a block copolymer. (Japan Rubber Association Journal, 54(9), 564 (1981)) can be determined by ozone decomposition. If the proportion of the component corresponding to styrene monomer to the component corresponding to styrene tetramer measured by this method is less than 5% by weight of the total vinyl aromatic hydrocarbon in the block copolymer, A bituminous composition with a relatively good softening point can be obtained, and a bituminous composition with relatively good penetration and elongation can be obtained when the amount is 5 to 40% by weight. The block copolymer of component (a) used in the present invention has a polymer structure of the general formula (a) (A-B) _o+1 (b) A-(B-A) _o (c) B-(A -B) _o+1 (In the above formula, A is a polymer block mainly composed of vinyl aromatic hydrocarbons, and B is a polymer block mainly composed of conjugated diene. The boundary between A block and B block do not necessarily have to be clearly distinguished. n is an integer of 1 or more, generally an integer of 1 to 5.) Or the general formula, (d) [(B-A) _o ] _n+1 X (e) [(A-B) _o ] _n+1 X (f) [(B-A) _o B] _n+1 X (g) [(A-B _o A] _n+1 , A, B are the same as above,
X represents, for example, a residue of a coupling agent such as silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, or an ester of carboxylic acid, or a residue of an initiator such as a polyfunctional organolithium compound. m and n are integers of 1 or more. Generally, it is an integer from 1 to 5. ) or any mixture thereof. Particularly preferred is a block copolymer in which both ends of the polymer chain are formed of polymer blocks containing mainly vinyl aromatic hydrocarbons. The method for producing the block copolymer of component (a) used in the present invention involves adding a new catalyst during production, or adding a deactivator such as alcohol or carboxylic acid during production to activate the copolymer. Deactivating some of the dots, causing a chain transfer reaction by adding a chain transfer agent such as toluene, allenes, vinyl acetylenes, or secondary amines, adjusting the miscibility within the polymerization system, or Alternatively, there may be a method in which these methods are used in combination, but the method is not limited to these. Any method may be used as long as the ratio of component A and component B falls within the range defined by the present invention. The molecular weight of the block copolymer of component (a) used in the present invention is 10,000 to 1,000,000, preferably 20,000 to 1,000,000.
5000000. In addition, block copolymers can be treated with hydroxyl groups, thiol groups, nitrile groups, sulfonate groups, etc. by hydrogenation, halogenation, hydrohalogenation, or chemical reaction within a range that does not impair their basic properties, such as the effect of improving impact resistance. Modifications such as introduction of functional groups such as acid groups and amino groups may also be performed. In particular, a hydrogenated block copolymer is a preferred method of improvement because it improves heat aging resistance and weather resistance. It is recommended that the block copolymer before hydrogenation has a 1,2-vinyl bond content of 20 to 60%, preferably 25 to 50%, based on the conjugated diene. As catalysts used for hydrogenation reactions, (1) metals such as Ni, Pt, Pd, Ru, etc. are combined with carbon,
A supported heterogeneous catalyst supported on a carrier such as silica, alumina, diatomaceous earth, etc., and (2) Ni, Co, Fe, Cr.
organic acid salts or acetylacetone salts and organic
Homogeneous catalysts are known, such as a so-called Ziegler type catalyst using a reducing agent such as Al, or a so-called organic acid catalyst such as an organometallic compound such as Ru or Rh. For specific methods, see Japanese Patent Publication No. 42-8704,
Special Publication No. 43-6636 or JP-A-59-
According to the method described in Japanese Patent No. 133203, hydrogenation is performed in an inert solvent in the presence of a hydrogenation catalyst to obtain a hydrogenated product, and the hydrogenated block copolymer used in the present invention can be synthesized. At this time, at least 80% of the aliphatic double bonds based on the conjugated diene compound of the vinyl aromatic compound-conjugated diene compound block copolymer are hydrogenated, and the polymer block mainly composed of the conjugated diene compound is transformed into an olefin in morphology. The compound can be converted into a polymer block. In addition, hydrogenation of aromatic double bonds based on vinyl aromatic compounds copolymerized into polymer block A mainly composed of vinyl aromatic compounds and, if necessary, polymer block B mainly composed of conjugated diene compounds. Although there is no particular restriction on the hydrogenation rate, it is preferable that the hydrogenation rate is 20% or less. The amount of unhydrogenated aliphatic double bonds contained in the hydrogenated block copolymer can be easily determined using an infrared spectrophotometer, nuclear magnetic resonance apparatus, or the like. The bituminous material of component (b) used in the present invention is as follows:
Examples include by-products of petroleum refining (petroleum asphalt), natural products (natural asphalt), or mixtures of these with petroleum, the main component of which is bitumen. It is called. Specifically, straight asphalt, semi-blown asphalt, blown asphalt, cutback asphalt containing tar, pitch, or oil, asphalt emulsion, and the like can be used. These may be used in combination. The preferred bituminous material in the present invention has a penetration degree of
30-130, more preferably 45-120 straight asphalt. When a material having a penetration degree within this range is used, a composition having excellent softening point, elongation, and strength can be obtained. The amount of the block copolymer (component (a)) in the bituminous material composition of the present invention varies depending on the type and use of the bituminous material to be improved, but takes into account physical properties, processability, and workability. Then, generally component (b)
The amount ranges from 0.5 to 500 parts by weight, preferably from 1 to 100 parts by weight, and more preferably from 3 to 70 parts by weight, per 100 parts by weight of the bituminous material. In addition, in the present invention, for the purpose of improving the properties of component (a), 1 part by weight or more and less than 20 parts by weight, preferably 5 to 15 parts by weight, of the component per 100 parts by weight of the block copolymer, etc. of component (a). It is also possible to incorporate (b). The composition of the present invention may contain any additive in any amount as required. Types of additives include clay, talc, calcium carbonate, zinc oxide, inorganic fillers such as glass beads,
Aggregates such as crushed stone, gravel, and sand, fibrous reinforcing materials such as glass fiber and asbestos, organic reinforcing agents such as carbon black, tackifying resins such as coumaron indene resin and terpene resin, paraffinic, naphthenic, and aromatic materials. Examples include softening agents such as oil, thermoplastic resins such as polyolefin resins, polystyrene resins, and polyvinyl chloride resins, and synthetic rubbers such as natural rubber, polybutadiene rubber, styrene, butadiene rubber, and nitrile rubber. In the present invention, the method of mixing component (a) and component (b) is not particularly limited, but a particularly desirable method is to pelletize or powder component (a) and heat-melt the component. This is a method of adding it to (b) and mixing it. [Effects of the Invention] The composition of the present invention can be used for various purposes by taking advantage of its excellent balance of softening point, penetration, elongation, and strength. That is, by appropriately selecting the amount of component (a) in the composition, the bituminous material can be used for road paving, waterproofing, rust prevention, automobile base coating, roofing, pipe coating, and joint applications. It can be used in almost all applications, and in each application, it can contribute to improved temperature sensing performance, improved resistance to plastic deformation, improved impact resistance, and improved durability. Examples are shown below to explain the present invention in more detail, but these examples are intended to demonstrate the excellent effects obtained by the present invention, and do not limit the scope of the present invention. It's not something you do. The block copolymers used in the examples of the present invention were produced as follows. [Block copolymer A] After purging the autoclave internally with nitrogen gas,
A cyclohexane solution containing 3 parts by weight of purified and dried styrene and an n-hexane solution containing 0.026 parts by weight of n-butyllithium were added and polymerized at 70°C for 1 hour. Next, add styrene 6 to the polymerization solution.
A cyclohexane solution containing 0.026 parts by weight of n-butyllithium and an n-hexane solution containing 0.026 parts by weight were added and polymerized at 70°C for 1 hour. Furthermore, a cyclohexane solution containing 16 parts by weight of styrene and an n-hexane solution containing 0.053 parts by weight of n-butyllithium were added to the polymerization solution, and polymerization was carried out at 70 DEG C. for 1 hour. Then add butadiene 60 to the polymerization solution.
By adding a cyclohexane solution containing parts by weight
After polymerization at 70°C for 2 hours, a cyclohexane solution containing 15 parts by weight of styrene was further added and polymerization was performed at 70°C for 1 hour. The styrene content of the obtained block copolymer was 40% by weight. [Block copolymer B] A cyclohexane solution containing 10 parts by weight of styrene and an n-hexane solution containing 0.07 parts by weight of n-butyllithium were added to an autoclave similar to the above, and polymerized at 70°C for 1 hour. Next, a cyclohexane solution containing 15 parts by weight of styrene and an n-hexane solution containing 0.035 parts by weight of n-butyllithium were added to the polymerization solution, and polymerization was carried out at 70°C for 1 hour. Thereafter, a cyclohexane solution containing 60 parts by weight of butadiene and 3 parts by weight of styrene was added to the polymerization solution, and the polymerization was carried out at 70°C for 2 hours. Polymerized for hours. The styrene content of the obtained block copolymer was 40% by weight. [Block Copolymer C] A cyclohexane solution containing 5 parts by weight of styrene and an n-hexane solution containing 0.08 parts by weight of n-butyllithium were added to the same autoclave as above and polymerized at 70°C for 1 hour. Next, a cyclohexane solution containing 20 parts by weight of styrene and an n-hexane solution containing 0.08 parts by weight of n-butyllithium were added to the polymerization solution, and polymerization was carried out at 70 DEG C. for 1 hour. Thereafter, 35 parts by weight of butadiene and 2.5 parts by weight of styrene were added to the polymerization solution and polymerized at 70°C for 1 hour.
Parts by weight were added and polymerized at 70°C for 1 hour. Thereafter, 0.074 parts by weight of silicon tetrachloride was added to this polymer solution, and the mixture was reacted at 70°C for 30 minutes. The styrene content of the obtained block copolymer was 30% by weight.
It was hot. [Block copolymer D] A cyclohexane solution containing 15 parts by weight of styrene and 5 parts by weight of butadiene and an n-hexane solution containing 0.2 parts by weight of n-butyllithium were added to an autoclave similar to the above and heated at 70°C. Polymerized for hours. Next, a cyclohexane solution containing 2.5 parts by weight of styrene and 20 parts by weight of butadiene was added to the polymerization solution and polymerized at 70°C for 1 hour.
A cyclohexane solution containing 2.5 parts by weight and 20 parts by weight of butadiene was added and polymerized at 70°C for 1 hour. Then, a cyclohexane solution containing 10 parts by weight of styrene and 5 parts by weight of butadiene was added to
After polymerization for 1 hour at °C, 0.025 parts by weight of methanol was added. Further, a cyclohexane solution containing 9 parts by weight of styrene was added and polymerized at 70°C for 30 minutes, and then 0.025 parts by weight of methanol was added. Then, after adding a cyclohexane solution containing 6 parts by weight of styrene and polymerizing at 70°C for 30 minutes,
0.025 parts by weight of methanol was added. Finally, a cyclohexane solution containing 5 parts by weight of styrene was added and polymerized at 70°C for 30 minutes. The resulting block copolymer had a styrene content of 50% by weight. [Comparative Example Block Copolymer E] A cyclohexane solution containing 25 parts by weight of styrene and an n-hexane solution containing 0.105 parts by weight of n-butyllithium were added to the same autoclave as above and polymerized at 70°C for 1 hour. . Next, a cyclohexane solution containing 60 parts by weight of butadiene was added to the polymerization solution, and polymerization was carried out at 70°C for 2 hours. Further, a cyclohexane solution containing 15 parts by weight of styrene was added thereto, and polymerization was carried out at 70°C for 1 hour. The styrene content of the obtained block copolymer was 40% by weight.
It was hot. [Comparative Example Block Copolymer F] A cyclohexane solution containing 70 parts by weight of styrene and an n-hexane solution containing 0.16 parts by weight of n-butyllithium were added to the same autoclave as above and polymerized at 70°C for 1 hour. . Next, a cyclohexane solution containing 30 parts by weight of butadiene was added to the polymerization solution, and polymerization was carried out at 70°C for 2 hours. Thereafter, 0.106 parts by weight of silicon tetrachloride was added to this polymer solution, and the mixture was reacted at 70°C for 30 minutes. The styrene content of the obtained block copolymer was 30% by weight. Each of the block copolymers obtained as described above contained 4-methyl-2,6-di-tert- as a stabilizer.
After adding 0.5 parts by weight of each of butylphenol and tris-nonylphenyl phosphate to 100 parts by weight of the block copolymer, the solvent was distilled off under heating. Next, the composition of each block copolymer was analyzed based on the aforementioned method developed by Professor Tanaka et al. of the University of Agriculture and Technology. The analyzed high-performance liquid chromatogram generally shows the absorbance detected at a wavelength of 254 nm on the vertical axis, and the horizontal axis shows the vinyl aromatic hydrocarbon content of the eluted component (using a calibration curve prepared in advance according to the elution amount). ) will be displayed. The first example is
Shown in the figure. In FIG. 1, 1 and 2 represent block copolymers A and B defined in the present invention, respectively, and 3 represents block copolymer E as a comparative example. Examples 1 to 3 and Comparative Examples 1 to 4 Straight asphalt (Stoas 60/80, manufactured by Maruzen Sekiyu Co., Ltd.) 100%
A composition was prepared by adding 5 parts by weight to 5 parts by weight, and the following performance evaluations were performed. Penetration is according to JISK2207, 25℃ in a constant temperature water bath.
The length that a specified needle penetrates into the sample kept at 5 seconds was measured. The softening point is determined according to JISK2207, when a specified ring is filled with a sample, supported horizontally in a water bath, a 3.5g ball is placed in the center of the sample, and the bath temperature is increased at a rate of 5℃/mm. The temperature was measured when the sample touched the bottom plate of the ring stand using the weight of the ball. Elongation is JISK2207
According to
When the sample was pulled at a speed of mm, the distance it stretched until it broke was measured. Toughness and tenacity are measured according to the method specified by the Japan Road Association, using a metal hemisphere with a diameter of 2 cm with the spherical surface facing down, and a diameter of 5 cm and a depth of 2.7 cm.
buried in an asphalt sample in an aluminum container,
When pulled out at a speed of 50 cm/mm at a temperature of 25°C, the load applied to the hemisphere was recorded on the vertical axis and the displacement on the horizontal axis, and the total energy was measured as toughness and the energy at the hem as tenacity. These results are shown in Table 1, and it can be seen that the composition using the block copolymer defined by the present invention exhibits excellent penetration, softening point, elongation, and strength. In addition, block copolymers G and H of comparative examples are the same as block copolymers A except that the amount of styrene used is changed.
Manufactured in the same manner as. Further, a block copolymer of a comparative example was prepared by mixing block copolymers having different styrene contents produced in the same manner as block copolymer A. [Table] [Table] Examples 4 to 6 and Comparative Examples 5 and 6 Asphalt compositions were prepared by blending the block copolymers shown in Table 2 with straight asphalt (Stoas 60/80), and their performance was evaluated. did.
The results are shown in Table 2. [Table] Examples 7 to 10 Styrene content produced by the same method as Example 1 is 20% by weight, styrene content in the main peak in composition analysis is 24% by weight, total amount of ratio of component A and component B using a block copolymer with 50%
Asphalt compositions were prepared according to the formulation shown in Table 3, and their performance was evaluated. The results are shown in Table 3. [Table] [Table] Example 11 A composition containing bituminous material was prepared according to the following formulation. Γ20/30 blown asphalt 15 parts by weight Γ Block copolymer B 15 parts by weight Γ Ground calcium carbonate 60 parts by weight Γ Finely powdered silica 10 parts by weight The tensile strength of the obtained composition was 12 Kg/cm ² and the tensile elongation was 200. %, and the tear strength was 9 Kg/cm ² . Example 12 5 parts by weight of the composition of Example 4 and 95 parts by weight of aggregate were mixed at about 200°C to prepare an asphalt mixture for road paving. The resulting composite material had excellent heat resistance, stability, low-temperature properties, and abrasion resistance, and was suitable for use in road paving. Example 13 In the production method of block copolymer A, polymerization was carried out in the same manner as the production method of block copolymer A, except that the total amount of styrene used was 30% by weight and tetrahydrofuran was used as the vinylizing agent.
30% by weight, the amount of 1,2-bonds in the polybutadiene part is
A 35% block copolymer was obtained. This block copolymer was hydrogenated by the method described in JP-A-59-133203 to obtain a block copolymer (J) with a hydrogenation rate of 98%. The block copolymer is
The total amount of component A and component B in composition analysis is 55%
It was hot. Next, a composition was prepared by blending 5 parts by weight of block copolymer J and 100 parts by weight of straight asphalt (Stoas 60/80). The resulting composition had a softening point of 65°C, a penetration of 551/10 mm, and an elongation of 45 cm.

[Brief explanation of drawings]

Figure 1 shows the block copolymer A,1, of the present invention.
The relationship between absorbance and styrene content (wt%) of block copolymers B, 2 and comparative example block copolymers E, 3 is shown.

Claims (1)

[Scope of Claims] 1 (a) having at least one polymer segment mainly composed of vinyl aromatic hydrocarbon and at least one polymer segment mainly composed of conjugated diene; Component A (vinyl aromatic hydrocarbon content is higher than the vinyl aromatic hydrocarbon content of the main peak and the difference is 5% by weight or more) and component B
(components whose vinyl aromatic hydrocarbon content is less than the vinyl aromatic hydrocarbon content of the main peak and the difference is 5% by weight or more)
a bituminous composition comprising a block copolymer (b) of 20 to 80% bituminous material;