KR20000071224A - Polymer stabilized bitumen granulate - Google Patents

Abstract

Particulate asphalt compositions comprise a bitumen amount in an amount of about 45 to about 80 weight percent and a crystalline and / or rigid polymer in an amount of about 15 to about 50 weight percent, and the composition is stabilized or synthesized in an amount of about 3 to about 25 weight percent It is combined with rubber and bitumen. The bitumen used in the compositions has a wide range of penetration of soft base to solid base and is a major component of the composition up to about 80% by weight. The resulting compositions can be in the form of particles and the particles are stored over a significant period of time without sticking together. Particles readily disperse quickly in bitumen to dilute the polymer content of the polymer, while the polymer remains stable in bitumen. Particles are useful in a variety of applications, such as paving, roofing and other construction industries, and can be transported there for ease of use.

Description

Polymer stabilized bitumen granulate

Asphalt is a black, sticky cementitious material that varies widely in consistency from elastically hardened solids to soft "solids" at normal room temperature. Polymers such as rubbers or plastics are added to improve the performance of bitumen without changing the traditional means for storage and transportation. In most applications, such as in the manufacture of bitumen compositions for paving, roofing and industrial applications, unmodified asphalt and polymer-modified asphalts from plant It is supplied in hot liquid form and stored hot in insulated tanks for ease of use.

Over the years, the asphalt industry has made considerable efforts to produce asphalt particles that can be stored at normal room temperature without loss of free flow properties, but the results have been limited.

In DE-PS 29 33 339, the preparation of a powder bitumen concentrate is described by spraying hot liquid bitumen on about 10 to 80% by weight of silica so that the silica is completely covered with bitumen. However, asphalt coated with composites tends to stick during storage due to static pressure forces.

In U.S. Patent No. 5,382,348 to Karl-Hans Muller, a process for producing free flowing bitumen particles by atomizing hot liquid base asphalt cement, and simultaneously forming a coating on the bitumen droplets under the flow of cooling air. A process for introducing a filler such as silica, which acts as a powdering agent and a separating agent, is presented. Particle compositions through this process are limited to hard bitumen forms such as hard bases. Moreover, the composition is stored at elevated temperatures, and bitumen impairs freeflow properties by moving the surface.

Although the addition of polymers (especially rigid plastics) to the asphalt cement at increasing loading levels can be expected to improve the asphalt's ability to form particles, the poor miscibility or incompatibility of the two components ( Incompatibility makes it difficult to provide a pelletized composition if bitumen is minimal or does not act as an extender in polymer based materials. Particulate compositions resulting from such asphalt with increased amounts of polymer based materials tend to stick under static pressure during storage due to the movement of the asphalt relative to the mixture surface.

Therefore, a problem arises in preparing polymer stable bitumen particles that can be stored for long periods of time without loss of free flow properties and can be easily diluted in bitumen while still maintaining the ability to improve the levels of polymer deformation.

The present invention relates to a composition of polymer stabilized bitumen particles, to a process for their preparation and to a commercial application thereof.

In accordance with the present invention, new bitumen mixtures of highly dispersed polymer concentrates are provided that can be purified or granulated, and the pellets or particles thus formed remain in their free flowing state. In addition, pellets or particles can be easily diluted with bitumen to a lower polymer loading level, where the dispersed polymer remains stable and can add properties to the resulting bituminous composition that improve performance.

According to the present invention there is provided a bituminous composition suitable for tableting or granulating into stable free flowing pellets or particles, the composition being stabilized or bitumen using at least one rubber in an amount of about 3 to 25% by weight. About 10-50% by weight of at least one crystalline and / or rigid polymer bound. The crystalline or rigid polymer (s) is preferably present in an amount of about 15-30% by weight, and the rubber (s) are preferably present in an amount of about 5-15% by weight.

Bitumen is the main component of the composition and is present in an amount of about 45 to about 85 weight percent, preferably about 50 to 75 weight percent. Bituminous compositions retain the ability of polymers to improve performance as modified asphalt, resist polymer phase separation upon dilution with asphalt, and act as a fixer after the composition is dissolved.

The bitumen used here has a wide range of penetration from soft base to hard base. Bitumen is a major component in the composition from which pellets or particles are formed and can be present in amounts up to about 85% by weight of the composition.

The bitumen compositions of the present invention exhibit significant homogeneity and storage stability upon bitumen and dilution with lower polymer concentration, and the pellets formed therefrom are free-flowing and can be easily and quickly dispersed in bitumen for use. In addition to purification or granulation of the composition, other shapes and forms may be provided, such as bricks, pucks and sheets of bituminous composition.

General description of the invention

The term " bitumen " as used herein refers to a class of materials having a black or dark color (solid, semi-solid or viscous) cementitious properties, which include asphalts, tars, pitches and asphalt teats ( asphaltites are mainly composed of typical high molecular weight hydrocarbons. The term "asphalt" as used herein is bitumen, in which the dominant constituents are naturally occurring in themselves or obtained as a residue in petroleum refining, and are materials having a black or dark brown cementitious nature, solid or Means semisolid.

The provision of the high levels of the dispersed polymer phase achieved here can be accomplished using a variety of different stabilization systems for the dispersed polymer phases, as discussed in detail below. . Such stabilization systems include steric stabilization, depletion stabilization, and domain stabilization.

Co-pending U.S. Patent Application Nos. 08 / 563,600 and 5,280,064, 5,494,966 and 5,708,061, filed November 28, 1995, and the corresponding WO 93 / of which the inventor of the present invention is named as inventor In 07219, crystalline polyethylene in bitumen by the formation of a chemical bond between a polyethylene having functionality as an anchor polymer and a polybutadiene having functionality as a stabilized part to provide stable dispersion of polyethylene in bitumen And steric stabilization of other crystalline polyolefins. The steric stabilization of elasticity described herein can be used to provide the compositions of the present invention.

According to the disclosure of WO 94/22957, the disclosure of which is hereby incorporated by reference, one or more additional polymers may be combined into the stereostable compositions of the aforementioned patents. Such additional polymers are generally copolymers and may include residual unsaturation. Such additional copolymers are often incompatible with bitumen and generally separate or coalesce quickly when stirring of the composition is stopped. However, according to the invention of WO 94/22957, when these copolymers are combined into the stable polyolefin compositions of WO 93/07219, they are stabilized and resist separation from bitumen. Some copolymers that can be used herein may already be compatible with bitumen to some extent or by appropriate processing. In the worst case, the presence of a dispersed polyolefin phase in the reverse clearings containing such materials does not destabilize such materials and can often improve such stability.

The way in which the additional copolymers are stable in the composition of WO 94/22957 depends on the nature of the polymer used and may include entanglement, physical entrapment, chemical crosslinking or combination of two or more of these mechanisms. have.

Copolymers that can be combined with the bituminous compositions according to the invention include elastomeric copolymers, which include:

Styrene copolymers such as styrene-butadiene rubber (SBR), styrene-butadiene-styrene block copolymers (SBS), styrene-ethylene-butadiene-styrene block copolymers (SEBS) and styrene Isoprene-styrene block copolymer (SIS);

Olefin copolymers, such as polypropylene copolymers, ethylene-vinyl acetate copolymers (EVA), ethylene methacylate copolymers (EMA) and ethylene propylene diene polymers (EPDM);

Other polymers such as nitrile-butadiene rubber (NBR), polyvinyl chloride (PVC), polyisobutene and polybutadiene (PB).

Mixtures of two or more of these polymers may be combined with the polyolefin into bituminous compositions. The compositions of WO 94/22957 do not necessarily use components such as process oils, making the polymers more compatible with bitumen.

In general, the choice of the copolymer bound with bitumen in the composition of WO 94/22957 is influenced by the following parameters as well as others:

-Asphalt Chemical Composition

-Molecular weight of asphalt

Molecular weight of the polymer (s)

Shear force applied during mixing of the components

The component ratio of the copolymer, such as the molecular ratio of E: VA in EVA

The polymers may be present in the bituminous composition in the form of particulate dispersion, strand-like dispersion, dissolution and bonding in which the (co) polymer (s) are stable to separation.

In the disclosure of WO 97/28220, the inventor of which is hereby referred to herein, the mechanism of depletion stabilization by the use of reduced polymeric materials in bitumen and the chemical bonding or physical between polymeric and particulate polyolefins The stabilization of polyolefins in bitumen is described by stabilizing the dispersed polyolefins against separation without the need to form a physical attachment. The dissolved polymeric material in bitumen provides a potential energy barrier to coalescence and flocculation of the dispersed polymer phase to maintain stable dispersion of the particulate polyolefin phase. In this case, the polyolefin having functionality does not need to provide stability.

The polymers used in the depletion stabilization of the dispersion of polyolefin particles in bitumen are unsaturated polymers or copolymers which are elastomers such as polybutadiene, styrene-butadiene-styrene (SBS) block copolymers, random styrene-butadiene copolymers (SBR), or other polybutadiene-based copolymers, and may be provided in the form of devulcanized or otherwise separated rubber vulcanizates. Other polymeric materials that can be used include natural rubber, polyisoprenes and nitrile-butadiene rubbers. These polymers have a molecular weight of about 5,000 to about 300,000 or more if the molecules can be dissolved in bitumen or fully cooked into bitumen.

The crystalline polyolefin used in the present invention may be pure or recycled polyethylene (PE), polypropylene (PP), combined PE / PP and / or male anhydride functionality in the case of steric stabilization. For example, it may be high or low in density and high or low in melt flow. Generally, the percentage of polyethylene having functionality based on the total amount of crystalline polyolefin polymers used is in the range of 3 to 100% by weight, preferably 10 to 20% by weight, based on the total amount of crystalline polymers used. Functional polyethylene is an anchor polymer in a stereostable system and acts as a receiving structure that binds to a polyethylene having a non-functional mixture.

Effective dispersion temperatures for polyethylene or other polyolefins are obtained at melting or fusion temperatures of the dispersed polyolefins of at least about 10 ° C. or more, depending on factors such as polymer molecular weight, matrix viscosity and shear stress of mixing.

Therefore, the grade of polyethylene having a melting or fusing point of 130 ° C to 135 ° C can be dispersed at a temperature of 140 ° C or higher. Therefore, generally found low density, linear low density and high density polyethylenes are dispersed and stabilized by the stabilization system of the present invention including steric stabilization and depletion stabilization. Therefore, most polyethylenes are dispersed and stabilized by the stabilizers of the present invention. Most polyethylenes used in consumer products have a fusion temperature in the acceptable range, and polyethylene mixtures which can be obtained by purifying recycled material, flaked or pulverized reclaimed material are obtained according to the present invention. It can be moderately stable to dispersion.

Synthetic rubbers, which act as co-stabilizers with polyethylene having the functionality for the dispersion of crystalline polymers in the bitumen of steric stabilization, are described as diene rubbers which may have a wide range of molecular weights as described in the above-mentioned US patents. To the total amount of treated diene rubber vulcanate, such as polybutadiene (BR), styrene-diene rubbers (including SBS, SB and SBR), or devulcanized rubber, and rubber stabilizer components Small proportions such as poly (butadiene-co-acrylonitride) having an amine functionality of about 3 to about 35% by weight, preferably about 5 to about 20% by weight. There is a tire rubber produced according to the procedure of WO 94/14896, combined with a polymer based on a diene with amine-functionality. Two rubbers used as co-stabilizers, non-functional rubbers and functional rubbers, are co-crosslinked, in situ adapted to bitumen, and have an effect in the presence of sulfur or other suitable reagents.

In WO 94/14896, the disclosure of which is hereby incorporated by reference, discloses a method of devulcanizing rubber and forming bituminous compositions comprising devulcanized material. Softened and expanded rubber particles are subject to high shear stresses, breaking the rubber vulcanization network more effectively, and then bonding to bitumen.

Provided herein by reference, the inventor named herein in WO 97/30121, provides a composition of elastomeric triblock copolymers comprising at least two polystyrene segments and stabilized and adapted in bitumen This is explained. The dispersed particulate polymer phase, consisting of polystyrene or rigid styrene-based copolymers that are compatible with the polystyrene in the molten state, is dispersed in bitumen and may generally be incompatible with bitumen and is an elastomer triblock by zone stabilization. It is stable against separation from bitumen by the copolymer.

Bitumen-soluble elastomeric copolymers containing styrene segments have an effect on two functions, namely (1) uniform dispersion of rigid polymers based on polystyrene, which may generally be incompatible with bitumen, and (2) from bitumen The provision of the styrene zone as a receiving unit for the stabilization of rigid polymers based on polystyrene dispersed for separation is carried out. For reasons of stabilization or compatibilization of the elastomeric triblock copolymer in bitumen, the polystyrene zones dispersed throughout the bitumen can be bound into the bitumen by accepting the polystyrene particulates into zones of rigid polystyrene polymers that can normally be inadequate. To be. The zones in the rubber treated bitumen continuous phase are further enlarged once the rigid polystyrene polymers are mixed and increased in size to an increasing level of dispersed rigid polystyrene.

The zone of the elastomeric copolymer of styrene, which is readily dispersed or stabilized in bitumen, is used in the elastomeric triblock copolymer in which butadiene rubber segments may be compatible with or dissolved in bitumen, or may be compatible with bitumen or dissolved in bitumen. Provided by The elastomeric triblock copolymers comprise about 20 to about 80 percent of terminal styrene blocks, preferably about 24 to about 45 percent.

Examples of block copolymers that can be used are styrene-butadiene-styrene triblock copolymers (SBS), styrene-ethylene / butylene-styrene triblock copolymers (SEBS) and styrene-isoprene-styrene block copolymers (SIS). These triblock polymers are used to form stable dispersions of rigid styrene polymers in bitumen.

Elastomeric block copolymers that can be used in the compositions of the present invention have a molecular weight (Mn) of about 30,000 to about 375,000, preferably about 75,000 to about 275,000.

Stiffly dispersed rigid styrene polymers in bitumen according to the invention are polystyrene homopolymers such as crystalline polystyrene or polystyrene foam, or fused copolymers and physical mixtures / alloys with various rubbers ), Or polymers of styrene derivatives such as poly (alpha-methylstyrene), poly (p-tert-butylstyrene) and polychlorostyrene. Rigid styrene polymers also include rigid copolymers based on styrene such as poly (styrene-co-vinylacetate) and poly (styrene-co-vinylthiophene). Styrene polymers are natural or recycled polymers, including comixed compositions of styrene polymers.

If the microparticles can be received by the polystyrene zones because the polymer can be miscible with the polystyrene in the dissolved state, SEBS, SBS or SIS triblock copolymers can be used to disperse other polymers and form a stable dispersion of them instead of polystyrene. Can be. One such polymer is polyphenylene oxide (PPO), which is difficult to disperse in bitumen but can be miscible with polystyrene in the dissolved state at any rate and disperse and bind to bitumen by zone effects.

Such styrene polymers may have a molecular weight of about 40,000 to about 1,400,000, preferably about 100,000 to about 300,000.

In addition to the specific stabilization systems using steric stabilization, depletion stabilization and zonal stabilization described above in detail, the present invention is also applicable to other systems of bitumen crystalline or rigid polymers using the procedure described herein.

In general, the binding of the above-mentioned chemically reacted mixtures to the bitumen to the bitumen is a two-step reaction procedure for producing a polymer stable asphalt composition that can be in the form of particles or otherwise treated in the desired physical form. Is performed. Procedures that can be used according to the invention include the steps of 1) mixing the components of the polymer with bitumen respectively; And 2) incrementally adding a crosslinker such as sulfur to chemically bond the polymers to bitumen.

According to the invention, crystalline and / or rigid polymers, such as polyethylene and polystyrene, in the particle compositions are bonded in situ in a bitumen base matrix at elevated temperatures.

In the case of polyolefins, the polymer is heated above the crystallization temperature of the polymer used to produce a large amount of dispersed extremely fine particles of the dissolved polyolefin.

Polyolefin (s) that are stably bound in the bitumen matrix do not lose their ability to crystallize once cooled below their dissolution temperature.

The loading levels of crystalline or rigid polymers in small sized crystalline or rigid polymer microparticles and compositions bonded with bitumen are high in stiffness and high enough for the compositions to be granular or purified. It has a cohesion and ensures that their particulate properties are maintained over a significant storage period at ambient temperature.

The compositions provided according to the present invention may be granulated or purified by any conventional or suitable particle forming process. Alternatively, the compositions can be processed into any desired physical shape.

The ability to produce free-flowing pelletized polymer-modified bitumen from free-flowing purified polymers, as shown here, provides a much broader distribution area by providing bitumen in this form. This less important polymer is important in that it can be supplied from a modified asphalt manufacturing facility. The need for insulated tanks to keep the asphalt dissolved from the plant to the site of use is nullified.

Purified or particulate matter that remains free-flowing may be packaged in a convenient form such as a box or bulk container and shipped to the user in bulk.

In the field of use, as a result of the elastic stabilization by the techniques described above, the pellets provide polymer-modified asphalt, in which dispersed polymers, which are generally polyethylene or polystyrene, are still stable and can give bitumen beneficial properties to the bitumen. Dilute under low shear stress agitation and lay down with molten asphalt.

Alternatively, the pellets or particles can be mixed directly in a pug mill of a hot asphalt mixing plant to produce a polymer-modified hot asphalt mixture.

Other formulations may be prepared in a refined composition for stone plaster asphalt (SMA) in which other commercial purposes, such as cellulosic fibers, are added to minimize the release of asphalt sticking agent from the aggregate. .

Dilution of asphalt and pellets can reach any desired degree of polymer deformation for the final composition consistent with the intended purpose of use, such that the bitumen-type composition provided while the polymer is stably dispersed in the final composition is intended for use. Is diverse.

The supply of free-flowing polymer-modified bitumen pellets or particles is thus improved from the polymer-modified asphalt manufacturing plant, since the production of materials in the purified form can usually take place during any off-season of the plant. Yields results.

The pellets flow freely at ambient temperature and therefore do not require special tanking or heating associated with the storage and use of the pellets. Free flowing polymer-modified bitumen pellets are stored in any suitable packaging at ambient temperature, reducing energy consumption resulting from elimination of the heated tank.

The compositions of bitumen produced therefrom from pellets or other physical forms of concentration are found in roofing members, knuckle plates, waterproofing members, sealing materials, cokes, potting resins and protective finishes. As well as discovering applications, it can be used as a packaging material for all types of paving. In general, paving materials include aggregates such as crushed stone, gravel, sand, etc. along with bituminous compositions. Similarly, other additives may be used in the bituminous composition, depending on the intended use of the present invention. For example, roofing materials can be obtained by adding suitable fillers, such as flame retardants such as asbestos, carbonates, silicas, cellulose fibers, mica, sulfates, clays, pigments and / or chlorinated waxes. have. In order to apply the gap-filler, oxides can be advantageously added.

The following examples illustrate the incorporation of bituminous compounds into particles that can form a mixture in which the polypolymer components are chemically reacted. In each case, the compositions were prepared by a two step procedure in which at least three polymer components were reactively mixed in bitumen and then the polymers were chemically bonded to the bitumen by incrementally adding crosslinker to the mixture.

The composition prepared according to the embodiments has a viscosity range of 100 poise to 10 poise at a temperature of about 200 ° C. The resulting compositions were purified in solid form at room temperature by conventional granulators. The resulting pellets were stored over a considerable period of time at normal ambient temperature without losing their free flowing properties. The storage stability of the pellets was tested using the ASTM 5892-96 test method when mixed with asphalt at a polymer loading level of about 2% and during hot storage at 320 ° F. for 48 hours.

According to this method, the stability was considered satisfactory if the difference in softening temperature between the samples of the samples after storage at high temperature was less than 4 ° F.

Example 1:

In 1 liter of mixing vessel, 391 g of asphalt (Petro-Canada Box River, 150/200 Penetration Grade) were heated to 180 ° C. 139 g of polyethylene (regenerated low density, melt index 1, RLDPE), 22 g maleic anhydride grafted polyethylene (fusabond 101; linear low density, melt density 12, anhydride reaction content: 0.7%), 35 g styrene-butadiene rubber (SB copolymer; Firestone sterone 210, Amine functionalized poly (butadiene-co-acrylonitride) copolymer (Hycar; ABTN; 10% acrylonitrile) with 14 g of amine functionality and solids having a molecular weight of about 70,000 Nitride reaction, amine equivalent at 1200) was added to the asphalt and reactively mixed under high shear stress using a Brinkman Polytron Mixer for 1.5 hours at about 180 ° C to 200 ° C. During still mixing, sulfur was added to the mixture, with the total amount added in increments of three portions of 1 g, 0.5 g and 0.5 g at half hour intervals, followed by a gradual loading of sulfur. The mixing and reaction continued for 1.5 hours at about 180 ° C. to 240 ° C. to form a polymer-stable bitumen composition having a viscosity of about 70 poises at 200 ° C. The stability of the composition was about 2% by loading with bitumen. The difference in softening point between large and small was 1 ° F. showing acceptable stability.The resulting compositions were poured into a container and cooled at room temperature to form a solidified mass.

Conventional granulation group was used to about _^1/4 to _^1/2-inch tablets into small pellets for free flow of the solid. The pellets were packaged in plastic bottles and stored at room temperature for 30 months without loss of their free flowing properties.

Example 2:

The method of Example 1 was repeated with regenerated low density polyylene with a high melt flow index (MI: 100). The viscosity of the resulting composition was 25 poise at 200 ° C., which was significantly lower than the viscosity of the composition in Example 1. Pellets made from the compositions continued to maintain their free flowing properties for the same 30 months shelf life and conditions as in the samples from Example 1.

Example 3:

The method of Example 1 was repeated again using the same polyethylene as used in Example 2, except using 110 g polyethylene instead of 139 g, rather than 35% of the polymers as in Examples 1 and 2 An asphalt composition in the form of a final particle comprising 30% stable polymers was prepared. The viscosity of this composition was about 18 poises at 200 ° C. The particles obtained from this formulation also exhibited good free flow characteristics after 30 months storage under the same conditions as set in Example 1.

Example 4:

The procedure of Example 1 uses the polyethylene of Example 1 and is also prepared according to WO 94/14896 which comprises a 40/20/40 mixture of devulcanized debris rubber, oil and bitumen rather than styrene-butadiene rubber It was repeated again by combining. The viscosity of the resulting composition was about 75 poises at 200 ° C. Pellets made from the composition continued to maintain their free flowing properties for the 30 month shelf life and conditions as set in Example 1.

Example 5:

The procedure of Example 1 was repeated using the polyethylene of Example 1 except using stronger bitumen, ie AC-20. The stability of the composition prior to purification was tested by diluting the composition to a load level of 2%. The difference in softening point between large and small was 2 ° F, showing acceptable stability. The pellets were made from the composition and maintained their free flowing properties for the 30 month shelf life and conditions as set in Example 1.

The following table summarizes the compositions used in the examples.

Pellet Compositions

Disclosure of the Invention

In summary of this disclosure, the present invention provides that polymer modifiers stably disperse crystalline or rigid polymers, maintain homogeneous free flow conditions for many months of storage and still readily disperse in hot bitumen and Continued to maintain stable dispersion of the modifier, providing new bitumen particles that retain the beneficial properties of the polymer modifier. Modifications are possible within the scope of the invention.

Claims (14)

In bituminous composition, About 45 to about 85 weight percent bitumen; About 10 to about 50 weight percent of particulate crystalline or rigid polymer; And Comprising about 3 to about 25 weight percent of rubber suitable for bitumen and for binding and stabilizing particulate polymer in bitumen, A bituminous composition characterized in that it is stable against the separation of the particulate polymer upon dilution of the bitumen with the composition for the intended use. The method of claim 1 wherein the polymer is present in an amount of about 15 to 30% by weight, the bitumen is present in an amount of 65 to about 75% by weight and the rubber is present in an amount of about 5 to 15% by weight. A bituminous composition characterized by the above. The bituminous composition according to claim 2, wherein the polymer is a crystalline polyolefin. 4. The bituminous composition according to claim 3, wherein the polyolefin is polyethylene. 5. The bituminous composition according to claim 4, wherein the polyethylene remains stable against separation by steric stabilization. 5. The bituminous composition according to claim 4, wherein the polyethylene remains stable against separation by depletion stabilization. 3. The bituminous composition of claim 2 wherein the polymer is a polymer based on rigid styrene. 3. The bituminous composition of claim 2 wherein the styrene-based polymer is a rigid polystyrene. 9. The bituminous composition according to claim 8, wherein the rigid polystyrene remains stable against separation by zone stabilization. 8. A bituminous composition according to claim 7, characterized in that it is purified into pellets freely flowing at ambient temperature or granulated into particles. 2. The bituminous composition according to claim 1, which has been processed in the form of blocks, pucks or sheets. A method of forming a bituminous composition as claimed in claim 1, (1) mixing the components of the polymer with bitumen respectively; And (2) adding a crosslinking agent incrementally to chemically bind the components of the polymer to the bitumen. The method of claim 12, wherein the crosslinking agent is sulfur. 13. The method according to claim 12, wherein the composition is granulated into particles or freed into pellets freely flowing at ambient temperature.