RU2767536C1 - Polymer-bitumen composition for roofing materials and block copolymer included in it - Google Patents

Abstract

FIELD: building materials.

SUBSTANCE: invention relates to a polymer-bitumen composition, which is used in the production of roofing materials. The polymer-bitumen composition for roofing materials includes (A) 61.6-68.6 wt.% of bitumen, (B) 5.5-7.4 wt.% of block copolymer, and (C) 25.9-31.0 wt.% of a mineral filler, where block copolymer is copolymer of conjugated diene and monovinyl aromatic monomer and is characterized by the content of bound monovinyl aromatic monomer from 32 to 39 wt.%, the content of 1,2-links from 20 to 40 wt.% per polymer block of conjugated diene, the content of two-block from 16 to 20 wt.% per 100 wt.% of block copolymer, average molecular weight from 160,000 to 180,000 Da, and glass transition temperature of the elastic block from -88 to -74°C. In this case, block copolymer is represented by the formula (AB)nX (i) and the formula AB (ii), where A is a polymer block of monovinyl aromatic hydrocarbon, B is a polymer block of conjugated diene. Block copolymer of conjugated diene and monovinyl aromatic monomer, which is part of the specified composition, is also described.

EFFECT: provision of a polymer-bitumen composition characterized by a reduced dynamic viscosity, namely, at 170°C, the dynamic viscosity decreases by at least 2000 MPa×s, improved heat resistance – the softening temperature (ring-and-ball method) increases by at least 10°C, and frost resistance – the temperature, at which flexibility remains on R15 beam (according to GOST 2678-94) decreased by 5°C, while penetration remains unchanged.

12 cl, 16 ex, 2 tbl

Description

The field of technology to which the invention belongs

The invention relates to polymer-bitumen mixtures, which are used in the production of roofing and waterproofing materials, road construction.

Namely, the invention relates to polymer-bitumen compositions with reduced Brookfield dynamic viscosity and improved low-temperature and high-temperature properties.

State of the art

As you know, most modern roofing materials are made on the basis of bitumen. According to its natural properties, bitumen is extremely unstable to ultraviolet radiation, temperature extremes and mechanical resistance. Therefore, its modification is necessary to obtain a roofing product with optimal waterproofing characteristics.

Bitumen modification is a purposeful change in their properties due to the introduction of special polymeric additives - modifiers. Proper selection of the modifier allows you to give roofing materials such properties as elasticity, heat and frost resistance, durability, as well as the ability to increase resistance to fatigue loads. To date, styrene-butadiene block copolymer is one of the most common bitumen modifiers. Roofing materials modified with styrene-butadiene block copolymers are characterized by high elasticity, frost resistance, and good performance characteristics. In particular, the service life of polymer-bitumen materials is 5-10 times longer than that of unmodified bitumen materials.

Modification of bitumens with the help of block copolymers is carried out by creating a three-dimensional network - a polymer matrix, inside which bitumen is distributed. In order to obtain high-quality modified bitumen, it is necessary to ensure the compatibility of bitumen and polymer. By varying the properties of the used block copolymer, using bitumen of different grades with different compositions, and selecting the optimal formulation of the composition, it is possible to obtain a bitumen-polymer composition with optimal characteristics for the consumer. Such a composition finds application in various materials intended for operation in different climatic regions.

In particular, patent RU2276678 (AS BASHKORTOSTAN PETROCHEM PROCESS INST (RU), May 20, 2006) describes the production of a bitumen-polymer composition, which is used for roofing, gluing rolled materials, waterproofing building, concrete and metal structures, and is characterized by increased resistance to frost and other atmospheric influences, as well as an increase in service life. Such a technical result is achieved due to a certain bitumen-polymer composition, including a bituminous component - asphalt formed during the deasphalting of West Siberian oil tar with propane, or West Siberian oil tar, a block copolymer of a conjugated diene and a monovinyl aromatic hydrocarbon with an intrinsic viscosity of more than 1 dl / g, a mineral filler - spent aluminosilicate catalyst.

The disadvantage of the known invention is the limited choice of bitumen and mineral filler, as well as the low softening temperature of the bitumen-polymer composition (70-75°C, according to measurements by the ring and ball method - K&Sh), which, in turn, limits the use of such a polymer-bitumen mixtures in hot regions.

From patent EP728815 (TOTALFINAELF FRANCE (FR), 04.08.2004) polymer-bitumen compositions are also known, consisting of (a) at least 25-97 wt.% bitumen, (b) at least 1-25 wt.% polymer and (c) at least 2-50 wt.% aromatic compounds, and the ratio (c):(b)=0.5-10. The composition obtained according to EP728815 is characterized by improved physical and mechanical properties, reduced Fraas brittleness temperature and increased storage stability.

In Europe and North America, the use of compositions containing aromatic substances is legally restricted due to their high toxicity. Also, the use of aromatic compounds limits the choice of bitumen suitable for the composition, since aromatic compounds are less soluble in saturated hydrocarbons. If the bitumen contains an increased amount of saturated hydrocarbons, then the addition of aromatic compounds to the polymer-bitumen mixture contributes to its rapid separation.

It is also known that the mechanical properties of bitumen compositions can be improved by chemically bonding the polymer with bitumen. This chemical bonding, usually carried out by cross-linking polymer molecules with bitumen molecules, also makes it possible to expand the range of applications for bitumen-polymer compositions. For example, in patents US6087420 (ELF ANTAR FRANCE (FR), April 21, 1997) and FR2376188 (ELF UNION (FR), April 20, 1979), methods for producing polymer-bitumen compositions are described, including crosslinking with sulfur-containing substances.

The disadvantage of this modification with sulfur-containing substances is the high cost of such branching agents and the impossibility of controlling the degree and uniformity of crosslinking.

Patent EP2589624 (KRATON POLYMERS RES BV (NL), 04/01/2015) describes a method for obtaining a polymer-modified bituminous binder composition in the almost complete absence of crosslinking agents by heating the bitumen component in a tank with a stirrer and adding a block copolymer composition to the bitumen. The result is a homogeneous modified bitumen composition showing improved processability, reduced cure time, and reduced phase separation. The block copolymer composition used in the known invention contains a diblock copolymer containing one monovinyl aromatic hydrocarbon block and one conjugated diene block having a maximum molecular weight of 30,000 to 78,000 atomic mass units (amu) and a vinyl content of 35 up to 80 wt.%.

The disadvantage of the known invention is the reduction of the softening temperature and the reduction of physical and mechanical properties.

From patent US6759454 (KRATON POLYMERS RES BV (NL), 07/06/2004) a method for producing polymer-bitumen compositions is known, which are mixtures containing bitumen, and from about 0.5 to about 25% anionic block copolymer, where one of blocks is a controlled distribution copolymer of a conjugated diene and a monoalkenyl arene having a specific, defined arrangement of monomers in a block copolymer. This method improves the softening point and penetration by using a linear or branched block copolymer as a modifier.

The disadvantage of the known invention is the high content of styrene in the used block copolymer, due to which the elasticity of the polymer-bitumen composition is reduced, and the brittleness temperature also increases, which negatively affects the performance properties at low temperatures.

Application EP1612243A1 (KRATON POLYMERS RES BV (NL), 01/04/2006) describes a method for producing a bitumen-polymer composition that contains from 2 to 20 wt.% polymer modifiers based on block copolymers containing 75-85 wt.% diblock copolymer . The bitumen-polymer composition obtained according to EP1612243 has a wide operating temperature range (high resistance to cold bending and flow resistance), good high-temperature flow resistance (pseudo-plastic behavior), resistance to gelation.

However, with the advantages obtained - reduced viscosity of the polymer-bitumen mixture - the softening temperature decreases and penetration increases, which negatively affects the heat resistance of the finished product and technological processing.

Patent TWI336341 (KRATON JSR ELASTOMERS KK (JP), 01/21/2011) describes a block copolymer composition for asphalt modification, consisting of block copolymers of various structures, one of the block copolymers having a content of vinyl bonds from 10 to 50% by weight , the weight average molecular weight of the polymer polystyrene block is from 500 to 20000, and the total weight average molecular weight of the polymer blocks of polystyrene is from 1000 to 30000, and the other block copolymer is characterized by the content of vinyl bonds from 10 to 50 wt.%, and the weight average molecular weight of the polystyrene block is copolymer from 10,000 to 20,000.

The disadvantage of the known composition is the impossibility of its use in roofing and waterproofing materials, because due to the high content of aromatic vinyl compounds, the hardness of the bituminous composition increases and, accordingly, the elasticity of the finished product decreases, and the brittleness temperature increases, which negatively affects the frost resistance of roofing materials.

Patent US4530652 (PHILLIPS PETROLEUM COMPANY, 07/23/1985) describes a polymer-bitumen composition consisting of a block copolymer and bitumen. The known composition has improved physical and mechanical properties, such as viscosity and elasticity, due to the use of a block copolymer of a conjugated diene and a monovinyl aromatic monomer as a bitumen modifier, and the block copolymer is characterized by at least 25% content of 1,2- links.

However, in accordance with US4530652, the content of the block copolymer in the composition is from about 10 to 25 wt.%. A large consumption of the block copolymer, as a result, leads to an increase in the cost of the entire composition.

The closest in technical essence and the achieved result to the claimed invention is a method for producing a block copolymer and a polymer-bitumen composition based on it, described in patent RU2185403 (SHELL INT RESEARCH (NL), 07/20/2002) and selected as a prototype. The bituminous composition according to the prototype contains a bituminous component, at least one block copolymer (I), in which at least one block is formed by a conjugated diene and at least two blocks are formed by a monovinyl aromatic hydrocarbon, and 25 wt.% or less than the diblock copolymer (II) based on the total content of the block copolymer (I), wherein the diblock copolymer (II) has an apparent molecular weight in the range from 100,000 to 170,000. The vinyl content in the block copolymer composition is at least 25 wt .% of the total content of the diene. The technical result is to obtain bituminous mixtures characterized by useful low-temperature and high-temperature characteristics, as well as increased resistance to aging.

The disadvantage of the invention according to the prototype is the use in the synthesis of the sec-butyllithium block copolymer as an initiator, which is unstable during storage under normal conditions. The invention does not mention the effect of the content of vinyl units in the block copolymer on the high temperature properties of the bituminous composition, in particular on the softening point. High molecular weights of the polymer modifier lead to a significant increase in the viscosity of the polymer-bitumen composition.

The essence of the invention

The objective of the present invention is to reduce the viscosity of the roofing polymer-bitumen composition while improving its heat resistance and frost resistance.

The problem is solved by obtaining a polymer-bitumen composition for roofing materials, including (A) 61.6-68.6 wt.% bitumen, (B) 5.5-7.4 wt.% block copolymer and (C) 25 .9-31.0 wt.% of a mineral filler, where the block copolymer is a copolymer of a conjugated diene and a monovinyl aromatic monomer and is characterized by a content of bound monovinyl aromatic monomer from 32 to 39 wt.%, a content of 1.2 units from 20 to 40 wt.% in terms of the polymer block of the conjugated diene, the content of diblock copolymer from 16 to 20 wt.% in terms of 100 wt.% block copolymer, weight average molecular weight from 160,000 to 180,000 atomic mass units (a.m.u.) and glass transition temperature Tg of the elastic block from -88 to -74°C.

The technical result of the present invention is to obtain a polymer-bitumen composition that demonstrates a decrease in dynamic viscosity at 170°C by at least 2000 mPa s, while maintaining improved heat resistance (an increase in the softening temperature according to the ring and ball method (R&B) by at least 10° C) and frost resistance (reduction of temperature at which flexibility is maintained on R15 timber according to GOST 2678-94 by 5°C), while penetration remains unchanged.

Detailed description of the invention

According to the invention, block copolymers of general formula (i) (AB)n X and general formula (ii) AB are used as a block copolymer, which is part of the claimed polymer-bitumen composition, where A is a polymer block of a monovinyl aromatic hydrocarbon, B is a conjugated diene polymer block, n is an integer from 3 to 6, and X is a branching agent residue. The content of the block copolymer of formula (ii) AB is from 16 to 20 wt.%, the content of the block copolymer of formula (i) (AB)n X is from 80 to 84 wt.% based on 100 wt.% block copolymer.

The block copolymer (i) of general formula (AB)n X used in the present invention is obtained by polymerizing a monovinyl aromatic hydrocarbon and a conjugated diene in a hydrocarbon solvent medium, using an electron donor additive, an organolithium initiator, and introducing a branching agent after polymerization is completed.

In accordance with the present invention, styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, vinyltoluene, vinylnaphthalene, vinylxylene, α-methylstyrene, or mixtures thereof are used as said monovinyl aromatic hydrocarbons; most preferred are styrene and α-methylstyrene.

The required content of monovinyl aromatic hydrocarbon in the final block copolymer is from 32 to 39 wt.%, preferably from 33 to 39 wt.% and most preferably from 33 to 34 wt.% of the total weight of the block copolymer.

As conjugated dienes according to the invention, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piperylene, 2-methyl-3-ethyl-1,3-butadiene, 3-methyl-1,3 -pentadiene, 2-methyl-3-ethyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-hexadiene, 2-methyl-1,3-hexadiene, 1,3-heptadiene, 3 -methyl-1,3-heptadiene, 1,3-octadiene, 3-butyl-1,3-octadiene, 3,4-dimethyl-1,3-hexadiene, 4,5-diethyl-1,3-octadiene, phenyl -1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2,3-di-n-propyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3-butadiene, or their mixtures.

Preferred conjugated dienes are 1,3-butadiene and isoprene, with 1,3-butadiene being the most preferred.

The desired content of the conjugated diene in the final block copolymer is from 61 to 68 wt.%, preferably from 61 to 67 wt.% and most preferably from 66 to 67 wt.% of the total weight of the block copolymer.

In the present invention, any suitable polyfunctional branching agent known to a person skilled in the art is used as a branching agent, for example, silicon tetrachloride, silicon tetrabromide, hexachlorodisilane, bis-trichlorosilanelethane. By "multifunctional branching agent" in the context of the present invention is meant compounds having at least 4 reactive groups.

The use of silicon tetrachloride as the polyfunctional branching agent is most preferred.

The amount of branching agent used is calculated in a molar ratio per 1 mol of lithium, while, according to the claimed invention, the molar ratio of halogen to lithium is in the range from 0.5 to 1. This range provides the required degree of branching of the block copolymer, since when using a smaller amount of branching agent, the content of diblock copolymer AB in the block copolymer is more than 20 wt.%. The branching agent is applied as a 1-20% solution in a hydrocarbon solvent.

As a hydrocarbon solvent, aliphatic and aromatic solvents or mixtures thereof are used. In accordance with the invention, solvents such as hexane, toluene, cyclohexane are used. Most preferably, a hydrocarbon solvent is used, which is a mixture of cyclohexane and nefras in the ratio (65-75):(30-35), where nefras is a hexane-heptane fraction of paraffinic hydrocarbons of dearomatized catalytic reforming gasolines with boiling point limits of 65-75°C .

The content of 1,2 units in the block copolymer is regulated by the introduction of a certain electron donor additive and its dosage. Within the framework of the present invention, it was found that the content of 1,2-units affects the Brookfield dynamic viscosity index of the resulting bitumen-polymer composition. To obtain optimal dynamic viscosity (in terms of application and processing, as well as the relationship with other properties), a block copolymer containing 20-40 wt% 1,2-units is used.

Methods for increasing the content of vinyl units in a block copolymer are well known in the art. In particular, compounds selected from the class of ethers, for example, diethyl ether, di-n-butyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether; from the class of alkyltetrahydrofuryl ethers such as methyltetrahydrofuryl ether, ethyltetrahydrofuryl ether, propyltetrahydrofuryl ether, butyltetrahydrofuryl ether, hexyltetrahydrofuryl ether, octyltetrahydrofuryl ether, tetrahydrofuran (THF), 2,2-di(tetrahydrofuryl)propane (DTHFP), tetrahydrofuryl alcohol methyl ether, butyl ether of tetrahydrofuryl alcohol, or from the class of amines such as triethylamine butyl ether, pyridine, N,N,N',N'-tetramethylethylenediamine (TMEDA), triethylamine, tripropylamine, ethylenetriamine, dipiperidinoethane.

The most preferred electron donor additive according to the present invention is 2,2-di(tetrahydrofuryl)propane (DTHFP).

The amount of electron donor additive (ED) used is calculated based on its molar ratio to lithium, and varies in the range from 0.10 to 1.00 depending on the required microstructure of the block copolymer: the greater the dosage of the electron donor additive used, the higher the content of 1, 2 units in a block copolymer.

Preferably, the molar ratio of ED to lithium is in the range from 0.10 to 0.80, in the most preferred embodiment of the invention from 0.10 to 0.30.

As an organolithium initiator, ethyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, phenyllithium, ethyllithium, methyllithium, dimethylaminopropyllithium, α-methylstyryldilithium, lithium pyrrolidide, tert-butyldimethylsiloxypropyllithium, 2-naphthyllithium, 4-phenylbutyllithium, propyllithium, isopropyllithium.

Most preferably, n-butyllithium is used.

The amount of initiator used is in the range from 16 to 17 mmol per 1 kg of monomers. More or less initiator will not make it possible to obtain a polymer with the required molecular weight values.

Obtaining a block copolymer of a conjugated diene and a monovinyl aromatic monomer is carried out by anionic copolymerization in a reactor equipped with a stirrer and a jacket for heat removal, in a hydrocarbon solvent medium, in the presence of an electron donor additive, an organolithium initiator, and a branching agent. Polymerization is initiated by adding an initiator solution to the reactor to a solution of a vinyl aromatic hydrocarbon in a hydrocarbon solvent in the temperature range from 35 to 60°C, forming a polyvinyl aromatic polymer block with active lithium at the end. After complete conversion (10-30 minutes) of the vinylaromatic monomer, a conjugated diene is added in the temperature range from 45 to 55°C, and at the second stage of the process, polymer synthesis is continued by forming a polydiene block in the temperature range of 45-95°C, for 10-20 minutes .

At the final stage of polymerization, cross-linking of the resulting diblock block copolymer is carried out to obtain a block copolymer (AB) _n X structure. To do this, the calculated amount of branching agent is introduced into the diblock block copolymer. The amount of branching agent is calculated so that the content of the diblock copolymer in the block copolymer composition is 16-20 wt.%. Crosslinking is carried out for 5-10 minutes at a temperature of 90 to 115°C. After crosslinking, residual active lithium is neutralized with a stopper. As a stopper, compounds with active hydrogen are used, in particular alcohols, acids, water and similar compounds.

Alternatively, the diblock and triblock copolymers are synthesized separately, and then mixed, for example, in an equalizer, in such proportions that the content of the diblock copolymer in the final block copolymer is 16-20 wt.%.

After the active sites have been deactivated, the polymerizate is stabilized with any suitable antioxidant before degassing begins. Most preferably, a mixture of phenolic, amine and sulfur containing antioxidants is used. The dosage of the antioxidant is typically 0.4-0.6% by weight, based on 100% by weight of the copolymer. This dosage is necessary and sufficient for effective stabilization of the polymer.

Then the block copolymer is subjected to water-steam degassing to remove the solvent and subsequent drying. In laboratory and industrial conditions for block copolymers, a wide range of options for the ongoing processes of degassing, molding and drying the product, which are traditional in the art and well known to the specialist, are used.

The block copolymer obtained in accordance with the present invention has the following characteristics: the content of bound monovinyl aromatic monomer is from 32 to 39 wt.%, the content of 1,2 units is from 20 to 40 wt.% per conjugated diene block, the content of diblock copolymer is from 16 to 20 wt.% based on 100 wt.% block copolymer, weight average molecular weight from 160,000 to 180,000 a.m.u. and the glass transition temperature of the elastic block from -88 to -74°C.

The method for producing a polymer-bitumen composition according to the present invention includes two stages: (1) mixing bitumen and block copolymer for 45±5 minutes using a high shear nozzle at a temperature of 185±5°C and a mixing speed of 6000±500 rpm/ min; (2) adding to the mixture obtained in stage (1), mineral filler and mixing until completely homogeneous. Mixing with mineral filler is carried out using a paddle mixer at the same temperature and stirring speed from 800 to 1000 rpm for 20-30 min until complete homogenization.

The bitumen used in the method according to the present invention is selected from any bitumen, both natural and artificial, obtained from the processing of oil, fossil fuels, bituminous rocks. In addition, petroleum and coal tars obtained by cracking can be used as a component of the polymer-bitumen composition. It is also permissible to use mixtures of different bituminous materials. Examples of suitable bitumens include, in particular, straight-run bitumen, precipitated bitumen, oxidized bitumen, or mixtures thereof. It is also possible to use mixtures of one or more of these bitumens with fillers such as petroleum extracts, for example aromatic extracts.

Suitable bitumens are those having a penetration in the range of about 25 to about 400 dmm at 25° C., preferably 100 to about 250 dmm, most preferably bitumens having a penetration of about 150 to about 220 dmm.

The proportion of bitumen in the bitumen-polymer composition ranges from 61.6 wt.% to 68.6 wt.%, preferably bitumen is used in an amount of 64-68.6 wt.%, most preferably 65-68.6 wt.%.

An increase in the amount of bitumen in excess of the specified range leads to a decrease in the consumer characteristics of the polymer-bitumen composition below the required values. Reducing the amount of bitumen worsens the frost resistance of the polymer-bitumen composition. To neutralize this negative effect, it is necessary to increase the dosage of the polymer modifier, which leads to its overconsumption.

As a mineral filler, various minerals of the carbonate class such as low magnesian, magnesian and dolomitic lime, limestone, dolomite, magnesite, or of the silicate class, such as talc, are used. Preferably the use of carbonates, most preferably the use of dolomite and dolomitic lime.

The content of the mineral filler in the composition of the claimed bitumen-polymer composition is from 25.9 wt.% to 31.0 wt.%, most preferably 25.9-28.5 wt.%.

An increase in the amount of filler above the specified range reduces the frost resistance of the polymer-bitumen composition, and its decrease negatively affects the penetration and heat resistance.

The content of the block copolymer in the composition of the bitumen-polymer composition of the present invention is in the range from 5.5 wt.% to 7.4 wt.%, most preferably 5.5-6.5 wt.%.

It should be noted that an increase in the content of the block copolymer above the specified range will increase the viscosity of the polymer-bitumen mixture, and its decrease will lead to the fact that the viscosity of the polymer-bitumen composition will meet the technological requirements, but the softening temperature will decrease and penetration will increase.

The obtained polymer-bitumen composition according to the present invention has the following characteristics: dynamic viscosity at 170°C is from about 12200 to about 18000 mPas; softening point (K&S) 109-125°C; temperature at which flexibility is maintained on the R15 timber (according to GOST 2678-94) from -30 to -20 ° C; penetration at 25°C from about 28 to about 52 dmm.

EXAMPLES OF CARRYING OUT THE INVENTION

The following describes exemplary embodiments of the present invention. Specialists in this field it is clear that the examples presented should not be considered as limiting the present invention, and the same effect can be achieved in other embodiments that do not go beyond the essence of the claimed invention.

The following describes the test methods used to evaluate the properties of the block copolymer and polymer-bitumen composition according to the present invention.

1) The molecular weight characteristics of the samples of block copolymers are determined by gel permeation chromatography according to an internal method. Measurements are carried out on a Gel-Permeation Chromatography Agilent 1260 Infinity II gel chromatograph with columns connected in series: 1) PLgel MIXED-C 300 (7.5 mm; 2) PLgel MIXED-C 300 (7.5 mm; 3) PLgel MIXED-C 300 (7.5 mm, as well as on a Breeze gel chromatograph (Waters) with a refractometric detector. Samples of the block copolymer are dissolved in freshly distilled tetrahydrofuran, the mass concentration of the polymer in the solution is 2 mg/mm, universal calibration according to polystyrene standards. The calculation is carried out using Mark's constants -Kuhn-Houwink (for block copolymers containing monovinyl aromatic hydrocarbon and conjugated diene K=0.00041, α=0.693).Determination conditions:

- a bank of 4 columns with high resolution (length 300 mm, diameter 7.8 mm) filled with styrogel, HR3, HR4, HR5, HR6, allowing the analysis of polymers with a molecular weight from 500 to 1 × 107 amu .;

- solvent - tetrahydrofuran, flow rate - 1 cm ³ /min;

- the temperature of the thermostat columns and refractometer 30°C.

2) Determination of the microstructure of samples of block copolymers is carried out according to the internal method. The method is based on recording the IR spectrum of the analyzed sample on an infrared Fourier spectrometer using the MATRT (multiple frustrated total internal reflection) attachment and further measuring the optical density maxima of the analytical absorption bands in the ranges:

- for 1,4-trans links from 960 cm ^-1 to 980 cm ^-1 ;

- for 1,2-links from 900 cm ^-1 to 920 cm ^-1 ;

- for bound styrene from 690 cm ^-1 to 710 cm ^-1 .

3) The glass transition temperature of the polymer is determined by differential scanning calorimetry.

4) The softening temperature of the polymer-bitumen composition is determined by the ring and ball method (R&B). To this end, two disks of polymer-bitumen composition are placed in brass rings with flanges, heated at a controlled rate in a liquid bath until each disk holds a steel ball. The softening temperature is defined as the average temperature at which each ball, coated with a polymer-bitumen composition, moved down a distance of 25 mm (1 inch) (according to GOST 11506-73).

5) Determination of flexibility on a bar with a radius of 15 mm (R15) of a polymer-bitumen composition (according to GOST 2678-94) consists in cooling and periodic bending of a sample of a polymer-bitumen composition and determining the temperature at which cracks appear or a sample of a polymer-bitumen composition breaks. Tests are carried out in air.

6) Determining the depth of penetration of the needle into the polymer-bitumen composition consists in measuring the depth to which the penetrometer needle is immersed in the test sample of the polymer-bitumen composition under certain conditions. The penetration of solid or viscous bitumen is expressed in the depth of penetration of the needle, measured in units of dmm, equal to 0.1 mm (according to GOST 11501-78).

7) Determination of the dynamic viscosity of the polymer-bitumen composition according to Brookfield is as follows: a torque is applied to the spindle (for example, a cylinder) rotating in a special container with the test sample and the relative resistance of the spindle to rotation and, consequently, the dynamic viscosity of the sample of the polymer-bitumen is measured. compositions.

The essence of the proposed technical solution is illustrated by the following examples of specific performance, which illustrate, but do not limit the scope of the claims of this invention. Those skilled in the art will appreciate that it is not limited to them and that the same effect can be achieved by applying equivalent formulas.

Example 1 Prototype

180.0 g of styrene are added to the reactor to 6 l of cyclohexane at 50° C., after which 8.31 mmol of sec-butyllithium initiator are added. Styrene polymerization reaction is carried out for 40 min. After that, 1.46 ml of diethoxypropane are added to the polystyrene, and then 418.0 g of butadiene (styrene/butadiene ratio 30/70) are dosed into the reactor over 10 minutes. The temperature of the reaction mixture was increased by self-heating up to 60°C. Polymerization at this temperature is carried out for 85 minutes. Then add 4.16 mmol branching agent silicon tetrachloride to obtain a product with a diblock copolymer content of 10.0 wt.%.

After cooling the reaction mixture, the resulting block copolymer was stabilized with 0.6% of a phenol-type antioxidant. The product is isolated by distillation with water vapor, obtaining a polymer crumb.

Mixed 7.4 wt.% of the obtained block copolymer and 61.6 wt.% bitumen using a mixer with high shear forces, this bitumen is heated to 160°and gradually add the block copolymer. During the addition of the polymer, the temperature is raised to 180° C. and kept constant by turning the high shear mixer on and off. Stirring is continued until a homogeneous mixture is obtained. The mixing time is 60 minutes. The resulting polymer-bitumen mixture is mixed with mineral filler, taken in the amount of 31.0 wt.%.

The properties of the obtained block copolymer are presented in table 1, the properties of the polymer-bitumen composition are presented in table 2.

Example 2 According to the Invention

In a reactor equipped with a stirrer and a jacket for heat removal, 159.4 g of styrene are added to 3 l of a mixture of cyclohexane and nefras in a ratio of 75:25, respectively, after which 0.79 mmol of 2,2-di(tetrahydrofuryl)propane is added (DTHFP), after which 7.20 mmol of an organolithium initiator, n-butyllithium, are added to the resulting mixture. The molar ratio electron donor additive:n-butyllithium is 0.11. The mixture in the reactor is heated to 40°C with a stirring intensity of 250 rpm. Polymerization of the first block lasts 20 minutes. Then, after exhaustion of the monomer (styrene), add 287.2 g of 1,3-butadiene and heat the reaction mixture to 75°C (mass ratio of styrene/butadiene - 34.3/65.7). The polymerization of the second block lasts 30 minutes. Then a branching agent is added - silicon tetrachloride at a dosage of 4.37 mmol to obtain a block copolymer with a diblock copolymer content of 7.0 wt.%. The branching process is carried out for 5 minutes. The molar ratio branching agent:n-butyllithium is 0.63 based on the chlorine content.

0.6 wt.% of an antioxidant composition consisting of phenolic, amine and sulfur-containing antioxidants is added to the reaction mixture for stabilization. The finished polymer is isolated by water-steam degassing.

The preparation of the polymer-bitumen composition is carried out in two stages: (1) 65.0 wt.% bitumen and 6.5 wt.% block copolymer are mixed for 45 minutes using a high shear nozzle at a temperature of 185 ° C and a stirring speed

6000 rpm, (2) the mixture obtained in stage (1), mixed with a mineral filler, taken in an amount of 28.5 wt.%, based on 100 wt.% polymer-bitumen composition. Stirring is carried out using a paddle mixer at the same temperature and stirring speed up to 1000 rpm for 20 minutes.

The properties of the obtained block copolymer are presented in table 1, the properties of the polymer-bitumen composition are presented in table 2.

Example 3

The synthesis of butadiene-styrene block copolymer is carried out analogously to example 2 with the difference that styrene is used in the amount of 142.9 g, butadiene - 303.4 g (mass ratio of styrene/butadiene 32/68). The molar ratio of the electron donor additive to n-butyllithium is 0.15.

The characteristics of the resulting block copolymer are presented in Table 1 No. p/p 3, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 4. Comparative

Synthesis of the block copolymer is carried out analogously to example 2 with the difference that the content of styrene is 151.7 g, butadiene - 294.5 g (mass ratio of styrene/butadiene 34/66). Tetrahydrofuran (THF) is used as an electron donor. The molar ratio of the electron donor additive to n-butyllithium is 0.43.

The characteristics of the block copolymer are presented in Table 1 No. 4, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 5. Comparative

Synthesis of butadiene-styrene block copolymer is carried out analogously to example 4 with the difference that the content of styrene is 167.3 g, and butadiene - 278.9 g (mass ratio of styrene/butadiene - 37.5/62.5).

The characteristics of the resulting block copolymer are presented in Table 1 No. 5, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 6. Comparative

Synthesis of butadiene-styrene block copolymer is carried out analogously to example 4 with the difference that the molar ratio of the branching agent to n-butyllithium is

0.56. The content of diblock copolymer in the obtained block copolymer is 22.0 wt.%.

The characteristics of the resulting block copolymer are presented in Table 1 No. 6, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 7

Obtaining butadiene-styrene block copolymer is carried out analogously to example 2 with the difference that the dosage of n-butyllithium is 7.68 mmol.

The characteristics of the block copolymer obtained are presented in Table 1 No. n/p 7, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 8

Obtaining butadiene-styrene block copolymer is carried out analogously to example 2 with the difference that the dosage of n-butyllithium is 6.78 mmol.

The characteristics of the resulting block copolymer are presented in Table 1 No. p/n 8, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 9

Synthesis of the block copolymer is carried out analogously to example 2 with the difference that styrene is added in the amount of 149.0 g, butadiene - 297.2 g (mass ratio of styrene/butadiene 33.4/66.6), the mole ratio of electron donor additives to n-butyl lithium is 0.15, the molar ratio branching agent: n-butyl lithium is 0.69. The content of diblock copolymer in the block copolymer is 16.3 wt.%. The initiator n-butyllithium is used at a dosage of 6.68 mmol.

The characteristics of the resulting block copolymer are presented in Table 1 No. 9, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 10

The method for obtaining a block copolymer is carried out analogously to example 9, with the difference that diethyl ether is used as an electron donor additive in a molar ratio to n-butyllithium equal to 0.3.

The characteristics of the obtained block copolymer are presented in Table 1 No. 10, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 11

The method for obtaining a block copolymer is carried out analogously to example 2, with the difference that the amount of styrene is 178.5 g, butadiene - 267.7 g (mass ratio of styrene/butadiene 39/61), the molar ratio of DTHFP: n-butyllithium is 0, eighteen. Hexachlorodisilane is used as the branching agent, the molar ratio of the branching agent to n-butyllithium is 0.58. The content of the diblock copolymer is 20.0 wt.%, n-butyllithium is used at a dosage of 6.40 mmol.

The characteristics of the resulting block copolymer are presented in Table 1 No. p/n 11, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 12

The method for obtaining a block copolymer is carried out analogously to example 2, with the difference that α-methylstyrene is used as a monovinyl aromatic hydrocarbon. The amount of α-methylstyrene is 142.8 g, the amount of butadiene is 303.4 g (mass ratio of α-styrene/butadiene 32/68). Diglyme is used as an electron donor additive. The molar ratio of the electron donor additive to n-butyllithium is 0.16.

The characteristics of the obtained block copolymer are presented in Table 1 No. 12, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in Table 2.

Example 13

The method for obtaining a block copolymer is carried out analogously to example 2, with the difference that isoprene is used as the conjugated diene. The amount of isoprene is 290.0 g, styrene - 156.3 g (mass ratio of styrene/isoprene 35/65). The molar ratio of the electron donor additive to n-butyllithium is 0.10. Silicon tetrabromide is used as a branching agent, the molar ratio of branching agent: n-butyllithium is 0.69. The content of diblock copolymer is 16.0 wt.%. The amount of n-butyllithium is 6.63 mmol.

The characteristics of the obtained block copolymer are presented in table 1 No. p / p 13, the properties of the polymer-bitumen composition obtained using this block copolymer are presented in table 2.

Example 14

Obtaining a block copolymer is carried out analogously to example 2.

Obtaining a polymer-bitumen composition analogously to example 2 with the difference that the amount of block copolymer is 5.5 wt.%, the amount of bitumen is 68.6 wt.%, the amount of mineral filler is 25.9 wt.%.

The properties of the polymer-bitumen composition are presented in table 2.

Example 15

Obtaining a block copolymer is carried out analogously to example 2.

The preparation of a polymer-bitumen composition is carried out analogously to example 2 with the difference that the amount of block copolymer is 7.4 wt.%, the amount of bitumen is 61.6 wt.%, the amount of mineral filler is 31.0 wt.%.

The properties of the polymer-bitumen composition are presented in table 2.

Example 16

Obtaining a block copolymer is carried out analogously to example 2.

The preparation of a polymer-bitumen composition is carried out analogously to example 2 with the difference that the amount of block copolymer is 6.5 wt.%, the amount of bitumen is 62.5 wt.%, the amount of mineral filler is 31.0 wt.%.

The properties of the polymer-bitumen composition are presented in table 2.

Table 1

Molecular Weight Characteristics and Microstructure of Block Copolymers

No. p / p Monomers ED SA* Content of bound MM**, % Content of 1,2 units, % Content of diblock copolymer % Weight average molecular weight of the polymer, Mw×103 Glass transition temperature of elastic block, °C 1 (P) Styrene, 1,3-butadiene 1,2-diethoxypropane SiCl4 30.0 61.0 10.0 218 -48 2 DTHFP 34.3 27.8 17.0 170 -76 3 32.0 22.0 17.0 167 -86 4 (C) THF 34.0 10.0 17.0 167 -96 5 (C) 37.5 10.0 17.0 167 -96 6 (C) 34.0 10.0 22.0 167 -96 7 DTHFP 34.0 27.8 17.0 160 -76 8 34.0 27.8 17.0 180 -76 nine 33.4 35.3 16.3 162 -74 10 diethyl ether 33.4 36.2 16.3 160 -75 eleven DTHFP Hexachloro-disilane 39.0 40.0 20.0 180 -74 12 α-methylstyrene, 1,3-butadiene Diglim SiCl4 32.0 23.0 17.0 168 -84 13 Styrene, isoprene DTHFP SiBr4 35.0 20.0 16.0 165 -88

Note

CA* - branching agent

MM** - monovinyl aromatic monomer

table 2

Composition and properties of the polymer-bitumen composition

No. p / p Bitumen, wt.% Block copolymer, wt.% Mineral filler, wt.% Dynamic viscosity according to Brookfield at 170°С, mPa×s Softening point (KiSh), °С Penetration at 25°С, dmm Flexibility on R15 timber, °С 1 (P) 61.6 7.4 31.0 20000 110 40 -20 (5/5) 2 65.0 6.5 28.5 15600 119 44 -20 (5/5) 3 65.0 6.5 28.5 12200 110 45 -30 (5/5) 4 (C) 65.0 6.5 28.5 22000 120 27 -15 (3/5) 5 (C) 65.0 6.5 28.5 23000 127 31 -15 (5/5) 6 (C) 65.0 6.5 28.5 21600 112 35 -25 (4/5) 7 65.0 6.5 28.5 13600 109 52 -25 (5/5) 8 65.0 6.5 28.5 18000 113 40 -25 (5/5) nine 63.0 7.0 30.0 13800 123 thirty -20 (5/5) 10 66.5 6.0 27.5 14200 118 42 -20 (5/5) eleven 65.0 6.5 28.5 16200 124 28 -20 (4/5) 12 65.0 6.5 28.5 12200 117 43 -30 (5/5) 13 65.0 6.5 28.5 16000 120 40 -20 (5/5) fourteen 68.6 5.5 25.9 15600 117 46 -20 (5/5) 15 61.6 7.4 31.0 15600 121 42 -20 (5/5) 16 62.5 6.5 31.0 16000 125 39 -15 (3/5)

From table 2 it is obvious that the polymer-bitumen composition obtained according to the invention is characterized by a reduced Brookfield dynamic viscosity (viscosity at 170°C decreased by more than 10,000 MPa×s), improved heat resistance (softening point (K&S) increased by at least by 10°C) and frost resistance (expressed in the value of the temperature at which flexibility is maintained on the R15 timber (according to GOST 2678-94), according to the invention, it decreased by 5°C).

The improvements achieved are clearly visible against the background of comparative examples 4-6, in which block copolymers were obtained having a content of 1,2 units below 20 wt.% and a low glass transition temperature. As a consequence, polymer-bitumen compositions made using such block copolymers have a high Brookfield dynamic viscosity and low flexibility on the bar.

Claims (12)

1. Polymer-bitumen composition for roofing materials, comprising (A) 61.6-68.6 wt.% bitumen, (B) 5.5-7.4 wt.% block copolymer and (C) 25.9- 31.0 wt.% mineral filler, where the block copolymer is represented by the formula (AB)nX (i) and the formula AB (ii), where A is a monovinyl aromatic hydrocarbon polymer block, B is a conjugated diene polymer block, n is an integer from 3 to 6 and X represents the residue of a branching agent and is characterized by a content of bound monovinyl aromatic monomer from 32 to 39 wt.%, a content of 1,2 units from 20 to 40 wt.% per polymer block of a conjugated diene, a content of a diblock copolymer from 16 to 20 wt.% based on 100 wt.% block copolymer, weight average molecular weight from 160,000 to 180,000 a.m.u. and the glass transition temperature of the elastic block from -88 to -74°C. 2. Composition according to claim 1, characterized in that the composition preferably comprises 64-68.6 wt.% bitumen, most preferably 65-68.6 wt.% bitumen. 3. Composition according to claim 1, characterized in that the composition most preferably comprises 5.5-6.5% by weight of a block copolymer. 4. The composition according to claim 1, characterized in that the composition most preferably includes 25.9-28.5 wt.% mineral filler. 5. The composition according to any one of paragraphs.1-4, characterized by a dynamic viscosity at 170°C in the range from about 12200 to about 18000 mPas; softening temperature (K&S) 109-125°C; the temperature at which flexibility is maintained on the R15 timber, from -30 to -20°C; penetration at 25°C from about 28 to about 52 dmm. 6. Block copolymer for polymer-bitumen composition according to claims 1 to 5, represented by formula (AB)nX (i) and formula AB (ii), where A is a polymer block of a monovinyl aromatic hydrocarbon, B is a polymer block of a conjugated diene, n is an integer from 3 to 6 and X is the remainder of the branching agent and is characterized by a content of bound monovinyl aromatic monomer from 32 to 39 wt.%, a content of 1,2 units from 20 to 40 wt.% per polymer block of conjugated diene, a diblock content from 16 to 20 wt.%, weight average molecular weight from 160,000 to 180,000 a.m.u. and the glass transition temperature of the elastic block from -88 to -74°C. 7. Block copolymer according to claim 6, characterized in that the block copolymer of formula (ii) AB is from 16 to 20 wt.% based on 100 wt.% of the block copolymer. 8. Block copolymer according to claim 6, characterized in that the block copolymer of formula (i) (AB)nX is from 80 to 84 wt.% based on 100 wt.% of the block copolymer. 9. Block copolymer according to claim 6, characterized in that the content of monovinyl aromatic hydrocarbon in the block copolymer is preferably from 33 wt.% to 39 wt.% and most preferably from 33 to 34 wt.% of the total weight of the block copolymer. 10. Block copolymer according to claim 6, characterized in that the content of the conjugated diene in the block copolymer is from 61 wt.% to 68 wt.%, preferably from 61 wt.% to 67 wt.% and most preferably from 66 to 67 wt. .% of the total weight of the block copolymer. 11. The block copolymer according to claim 6, characterized in that, as the conjugated diene, a conjugated diene selected from 1,3-butadiene and isoprene, most preferably 1,3-butadiene, is used as the conjugated diene to obtain the block copolymer. 12. The block copolymer according to claim 6, characterized in that styrene and/or α-methylstyrene is preferably used as the monovinyl aromatic hydrocarbon to obtain the block copolymer.