CN1218074A - Bituminous compositions prepared with process treated vulcanized rubbers - Google Patents

Abstract

Stable rubberized bitumen concentrates are prepared by initially forming a mass comprising bitumen and crumb rubber particles in an amount of at least about 15 wt.% of the mass with the crumb rubber being swollen in-situ, and applying shear and temperature conditions to the mass to dissociate the vulcanizate network of the rubber particles and to incorporate the disgested vulcanizate into the bitumen. The stable rubberized bitumen concentrate is stable against sedimentation of rubber particles both following storage of the concentrate at about 320 DEG F for 48 hours and dilution to a lower concentration in the ASTM solubility test.

Description

The bituminous composition that the vulcanized rubber of processing with processing prepares

The present invention relates to the vulcanized rubber powder digestion in the middle of the pitch to make the method for rubber asphalt concentrate, this concentrate can use separately whereby, or with the pitch of various variety classeses or grade and polymeric additive blending with the bituminous composition of preparation rubber and/or plastics stabilisation, be used for various pitch purposes.

The application is that the part of the U.S. Patent application 08/464,874 of submission on December 29th, 1993 continues.

As everyone knows, the characteristic expected of many people of pitch can improve by mixing therein some polymeric material, especially elastomeric material. For example, authorize the shell international research European Patent Publication No 317,025 a kind of bituminous composition that can be used for paving the way is disclosed, it comprises a kind of more asymmetric star block copolymer of high tenacity and intensity that has. The PCT publication number WO 90/02776 that authorizes Elf Aquitaine discloses a kind of rubber-containing bituminous composition, and it obtains modification by with the coupling agent such as sulphur the copolymer of styrene and conjugated diene being implemented vulcanization in situ.

The shoddy that to take from the automobile of recovery and other kind tires joins the way in the pitch, from not only bringing the improvement of composition properties but also can realize the angle that scrap rubber reclaims considers it is very desirable whereby.

Useless pimpled rubber represents a kind of important vulcanizate resource, and it comprises various rubber polymer, mainly is butadiene-styrene rubber. Usually, useless pimpled rubber becomes the freshening glue of powder or particle form by mechanical shearing or grinding. The pimpled rubber that proposed to give up joins the suggestion of going in the asphalt pavement material. Divide substantially, useless pimpled rubber is incorporated into the method for going in the asphalt pavement material two kinds, i.e. wet method and dry method.

In dry method, useless pimpled rubber is added in the aggregation of heating rather than joins in the asphalt mastic, perhaps joins in the hot blending asphalt mixture during the preparation asphalt mixture. Be dry mixed in the method at this kind, the chemical change that is conducive to pitch binder such as the stabilisation of bond fission or additive seldom may occur.

On the other hand, in wet method, be conducive to the variation of Binder Properties, those change as disclosed in the present invention, then are easy to realize by suitably sneaking into the additive that is generally polymer. In the specific implementation, the pimpled rubber of giving up to be incorporated into and go in the asphalt mastic to pass through intermittently blending, the pimpled rubber of namely will giving up when producing is carried out blending with asphalt mastic in batches, or utilizes continuously blending of continuous producing apparatus, perhaps final with the time mode such as blending implement. Asphalt mastic binding agent with useless pimpled rubber modification is called asphalt rubber.

In a kind of wet process that adopts polymer, heated bitumen (about 190 ℃～220 ℃) mixes with the useless pimpled rubber of about 25～30% (weight), then dilutes with kerosene. A kind of conversion scheme of the method adopts about 22% (weight) pimpled rubber of giving up, and dilution is then adopted and filled oil. Originally thought that useless pimpled rubber and at high temperature blending of pitch can promote the limited chemical bonding between each composition. Yet this composition but only shows the stability of short-term, therefore deployed must the use at short notice afterwards.

A kind of wet method scheme that occurs recently is disclosed in United States Patent (USP) 4,992, in 492. The method relate to pitch or with the pitch (81～86%) of sulphuring treatment, useless pimpled rubber (8～10%), fill oil (4～6%) and HMW (＞100,000) olefinic unsaturated synthetic rubber (2～3%) is deployed into a kind of mixture about 2 hours of 175 ℃～180 ℃ lower blending.

According to disclosed content, the method is different from the present invention in many importances. In this method of indication, shoddy is dispersed in the pitch, its vulcanized network, although there is chemical dissociation to occur, also very limited. If not adding high MW (weight average molecular weight) (〉=100,000) the olefinic unsaturated synthetic rubber of this article prescription protection, this kind rubber particle composite will become unstable. The synthetic rubber chain of the free solvation of this high MW may play, " without stir, in 160 ℃～165 ℃ the closed container " greatly reduce the effect that viscosity and softening point change in the longest 10 days, thereby improved stability. Other conversion scheme of wet method are disclosed among WO 95/20623 and the EP 439,232.

In WO 93/17076, the rubber grain that grinds is in being similar to the oxidation or " blowing " pitch preparation process of using for the production of roofing level pitch traditionally, carry out deep oxidation with high temperature (220 ℃～260 ℃) air that injects under the pressure, particularly on particle surface. Although this kind that thin rubbery granule is carried out processed on the spot and improved desired rubber dispersiveness and compatibility, given again this bitumen base with undesirable fragility simultaneously.

The present invention relates to a kind of vulcanizate particle digestion for grinding to pitch to prepare the method for rubber asphalt concentrate, and relate to rubber and/or the modifying plastics bituminous composition of planting thus concentrate and variety classes and other pitch of level and polymeric additive blending and making, pave the way, application aspect varied pitch consumption markets such as roofing, coating, waterproof and industrial product. The rubber-containing bituminous composition made from said method is contained in the present invention.

According to one aspect of the present invention, a kind of stable rubber asphalt concentrate is provided, it comprises pitch and accounts for the disassociation vulcanizate network at least about 15% (weight) of described composition, the combination of it and pitch reaches such degree, measured by the polymer separating experiment, this rubber grain does not precipitate in composition, and this rubber grain does not precipitate in composition when being diluted to lower disassociation vulcanizate network concentration with pitch. This polymer layering test sees below described.

This vulcanizate network can account for composition at least about 5% (weight), preferably at least about 25 % (weight), the highest even reach 50% (weight) or higher. This concentrate can be diluted by pitch, the concentration of disassociation vulcanizate network is reduced, in order to use under the concentration of greatly dilution.

Another aspect of the present invention provides a kind of bituminous composition, and a kind ofly is contained in concentrate in the composition as asphalt modifier. This modifier can be a kind of independent asphalt modifier, perhaps can be the composite modifier that forms with at least a synthetic rubber.

This kind synthetic rubber can be elastomer copolymer, comprising:

● styrol copolymer, such as butadiene-styrene rubber (SBR), s-B-S

Block copolymer (SBS), styrene-ethylene-butadiene-styrene block copoly merization

Thing (SEBS) and SIS (SIS);

● olefin copolymer, such as polypropylene copolymer, vinyl-vinyl acetate copolymer

(EVA), ethylene methyl acrylate copolymer (ethylene methylacrate

Copolymers) (EMA) and ethylene propylene diene rubber (EPDM);

● other polymer, such as acrylonitrile-butadiene rubber (NBR), polyvinyl chloride (PVC), poly-different

Butylene and polybutadiene (PB).

The mixture of two or more in the above-mentioned polymer also can join in this bituminous composition with this concentrate.

Another aspect of the present invention provides a kind of stable bituminous composition, and it comprises the dispersion of pelletized polyolefin in pitch, and wherein contained concentrate is a kind of composition of this pelletized polyolefin to prevent from precipitating of stablizing.

Another aspect of the present invention provides a kind of method for preparing the rubber asphalt concentrate, and it comprises that (A) provides a kind of material, and it comprises: (a) pitch; And (b) initial content accounts for the rubber grain that comprises vulcanized network at least about 15% (weight) of this material, wherein this rubber grain by swollen on the spot in pitch, form the network-like structure in a kind of pitch, it is easy to vulcanize the disassociation of particle in the high shear field of force; And (B) allow this material stand enough shearings and the processing of temperature conditions, the vulcanized network of rubber grain is dissociated, thereby the vulcanizate that makes this digestion is attached in the pitch and goes, the degree of its combination reaches such degree, measured by the polymer separating experiment, this rubber grain does not precipitate in composition, and this rubber grain does not precipitate in composition when being diluted to lower disassociation vulcanizate network concentration with pitch.

According to the pimpled rubber of the inventive method processing, its size distribution can be very wide, generally from about 0.5 inch to about 200 orders, be preferably about 10～about 80 orders. Can add certain process oil, to impel the pimpled rubber swollen by certain mechanism and to strengthen the solvability of pitch.

The so-called shearing and temperature conditions, refer to allow material under the shear stress condition through being heated and the effect of mechanical energy, this action intensity should be enough to make particle generation internal division and shearing at least, causes the decomposition that occurs vulcanized network under the impact that is applied to the shear stress on the granule materials. Apply and shear and duration of temperature conditions preferably should make any carbon black granules that may emit from rubber grain remain dispersity and possesses the stability of antisolvent precipitation.

In the rubber concentrate of initial formulation, can add again a collection of at least pimpled rubber, then repeat said method, so that the digestion vulcanized network that is generated by described a collection of at least interpolation is attached in the middle of this rubber asphalt concentrate.

Can dilute with the rubber asphalt concentrate of the inventive method preparation is the lower form of bound rubber granule density, in order to be applied to the various purposes of being used as pitch with the form of dilution.

In view of sulfidation is reversible, thus term " desulfurization " some choose words inappropriately. The in the present invention on the spot desulfurization of vulcanizate refers to, the process that the structural network of the vulcanizate that grinds (being tire sealant and other Industry Waste rubber) (or chemical crosslinking essence) disassociation occurs or breaks, the desulfurization material that generates directly is attached in the pitch, it has been in conjunction with having reached the processed complete digestion of this vulcanizate or be stable at degree among the pitch, thereby goes through for a long time under the variable concentrations level and also do not separate with the hot liquid form from pitch. The present invention need to use specific composition to be attached to the purpose of going in the pitch to reach devulcanized rubber particle stabilizedly, also will illustrate in further detail below this point.

Below, will describe and in the methods of the invention employed various key element (see the following form 1 in regulation) needed for the preparation present composition in detail. These key elements are:

1) pitch (herein sometimes also slightly " AC ");

2) rubber powder;

3) rubber grain of swollen (by composition 1) and 2 in AC or AC-oil mixture) obtain

);

4) the minimum addition of rubber powder in pitch is namely at least about 15% (weight).

Key element 1,2,3 and 4 be combined in herein and sometimes be also referred to as " material ". Following table 1 provides the more detailed information of relevant these key elements.

Table 1

Key element	Definition/note/for example	The requirement of this method
			Pitch	Can take from multiple source, comprise straight run decompression residuum; Decompression residuum reaches the mixture of diluent such as vacuum tower washing oil, paraffin distillate, oil flux oil, aromatic hydrocarbons and naphthenic oil. Other bituminous materials such as kir, naturally occurring pitch or air oxidation pitch and coal tar, also can use.	Need
Rubber powder (GR)	Take from the pimpled rubber of most of kinds in following source: whole tire, tyre surface, mill tire buffings, sidewall and industry/commercial scrap rubber, such as EPDM scrap rubber, conveyer belt etc. General particle size range: low mesh number-Yue 0.5 inch ten/high order number-the highest about 200 orders, for simplicity about 10～about 80 orders.	Need
			Swollen GR on the spot	This GR particle in pitch need to be at abundant swollen under the shear-mixed condition in pitch or pitch-oil mixture. If on the spot swollen does not occur in used GR particle under the regulation processing conditions, just then the GR vulcanizate of this type is unsuitable for processing with the inventive method. For example, NBR and neoprene are weighed the effect that highly tolerates pitch or any other hydrocarbon-type oil by solubility, so their particle vulcanizate just can not be processed according to the inventive method.	Need

Minimum effective addition of GR	Require the GR of swollen in pitch to contain at least about the initial addition of the certain level of 15% (weight). Require pimpled rubber with this minimum initial effective content abundant swollen to occur all, in the pitch medium, have the tendency that forms network-like structure, be beneficial to the disassociation of vulcanizate particle in high shearing field. If this addition is excessively low, although then swollen also occurs the vulcanizate particle, can not in high shearing field, be dissociated. This lower limit (15% (weight)) is in the past few years to be engaged on the basis of experience that experimental study of the present invention obtains according to us to draw. The best higher glue amount of initially mixing changes with many factors, reaches the additive that wherein comprises such as vulcanizate source, kind, composition/prescription, also depends on to a great extent the parameter of blending equipment.	Need
			Processing oil	Processing oil comprises aromatic hydrocarbons and naphtalene oil, oil flux oil and other hydrocarbon-type oils. The solvability that the adding of any oil, its purpose are to improve the swollen degree of pimpled rubber (or vulcanizate) in the pitch medium and strengthen pitch, rather than resemble in the conventional wet in order to reduce the use viscosity of final products. For some pimpled rubber, the reason that this method require to add oil be by rubber industry cause due to the difference aspect the vulcanizate material, comprise kind, prescription, crosslinked difference with aspects such as chemicals.	Optional

Sum up the content of the discussions in the above table 1, have 4 types and weigh the GR vulcanizate that performance may be different by the present invention: the first GR vulcanizate only has the pitch of cooperation to use could to work well; The aromatic naphtha of the second GR vulcanizate in being dissolved in pitch uses and can promote the particle swollen; Anyly in the third GR vulcanizate and the above two kinds of situations all can finely play a role; The 4th kind of GR vulcanizate is all inoperative in those two kinds of situations in front.

Only have when whole 4 kinds, or in the situation that randomly 5 kinds of above-mentioned key elements all exist, just might provide stock of the invention process and the condition of being fit to. The pimpled rubber glue amount of mixing is on request mixed with pitch, so, the hydrocarbon-type oil that this pimpled rubber is contained in the pitch is swollen on the spot, this hydrocarbon-type oil can be on the spot exist or add, should meet all that can to allow oil penetrate into rubber powder particle surface layer inner, and make its structure softening and this requirement of swollen. The material that is made into is processed thereupon again.

Comprise 4 kinds basic or randomly, 5 kinds of key elements should " material ", must accept enough shearings subsequently and temperature conditions is processed, in order to make rubber grain generation desulfurization. Allow material under the shear stress condition through being heated and the effect of mechanical energy, this action intensity should be enough to make particle generation internal friction and shearing at least, cause under the shear stress impact that is applied on the granule materials, the vulcanizate particle begins to disintegrate, and probably experiences breaking of cross-bond between sulphur-sulfide linkage, sulphur-carbon bond and the polymer molecule therebetween. The vulcanizate network that this operation has increased at least part of disassociation enters dissolubility and the compatibility of pitch phase.

Under shearing and the effect of temperature conditions to this " material ", the cross-linked network that is present in the vulcanizate has just dissociated (or decomposition) basically. This material must be machined to, thereby makes vulcanizate be able to fully digestion or be attached in the pitch degree that forms the rubber asphalt concentrate fully.

The condition that the disassociation of vulcanizate particle is taked should determine that the below will discuss these factors according to some factors. Particularly, temperature should be selected in about 100 ℃～about 300 ℃ of scopes, being applied to simultaneously mechanical energy on the particle must produce the friction of granule interior and shearing under certain shear stress, this shear stress may be significantly different according to the difference of other machined parameters, yet it should be enough to make the granule materials recurring structure to decompose at least. For example, pimpled rubber is processed to require to adopt higher granule interior shear stress at a lower temperature, and under higher temperature, the granule interior shear stress just can relatively hang down. The application time of heat and mechanical energy is may difference quite large, such as from about 15 minutes to about 8 hours or longlyer do not wait, and the properties of product of concrete composition, machined parameters and hope according to using and deciding. In addition, this processing can also be carried out continuously.

Generally speaking, realize that the inventive method of at least part of disassociation of pimpled rubber vulcanized network can be controlled by some variable factors, the kind, the initial concentration, the processing conditions that adopt of oil in pitch that comprise hydrocarbon-type oil, such as the relation of apparatus-form, granule interior shear stress, temperature and shear rate and temperature, addition and the time of whether using additional desulfurizing agent, the arrangement of time that adds particle, its granularity and adding speed, crosslinking agent, also will discuss below this point, and may join molecular weight rubber and kind in the composition and even the degree of functionality of this rubber. Utilize the various various combinations of parameter, can control the degree of dissociation of scrap rubber to produce various products.

Shear stress when applying heat and mechanical energy to being dispersed in swollen pimpled rubber particle in the pitch, should be enough at least realize granule interior friction and shearing, with the disassociation that causes the vulcanizate network and the vulcanizate grain graininess is constantly reduced, the degree that this granularity reduces depends on the time length that composition is applied shear stress, also depends in addition other machined parameters discussed above. If the time that this kind processing is carried out is enough, then all rubber grains are all dissociated and are attached in the pitch and gone, therefore, rubber grain in the composition is according to below the polymer layering of general introduction being tested at this moment, do not precipitate, and when being diluted to lower disassociation vulcanizate network concentration with pitch, the rubber grain in the composition does not precipitate.

Yet this kind shear stress processing also may be carried out to such an extent that be enough to make the disassociation of the vulcanizate network generation degree of depth, and can generate a kind of oily liquefied material this moment, and this product mixes those and heat paves the way and ideal so the relevant purposes with roofing. This kind oily liquefied material is as the diluent in the pitch and then comparatively suitable take non-pitch as main coating and fluid sealant.

This can be on the spot with the ability of vulcanizate disassociation so that can be made into the rubber that viscosity is lower than initial consumption/asphalt mixture product. So, allow again in this rubber asphalt concentrate, to add again pimpled rubber. Within the scope of the invention, by progressively adding so that the addition of rubber in pitch reaches as high as about 50% or higher like this. This result and conventional method form distinct contrast, and the mixture that the latter makes has just become dry when lower content.

The unique distinction of mixing the glue concentrate that adopts the inventive method to obtain is that also said composition is that indefinite duration is stable, and desulfurization glue never is separated from bituminous composition. Compare with the similar formulation for preparing not according to condition of the present invention, adopt the prepared remarkable improvement of concentrate on stability of the present invention, only have when the dilution of this bi-material come carefully to be investigated for their final type of service again, just can be experienced fully. In fact the follow-up dilution of mixing the glue concentrate by the inventive method preparation can proceed to any rarer concentration and desulfurization glue being separated in bitumen base can not occur.

Can in this desulfurization composition, add other materials to give its special character, for example can add carbon black and/or asphalt.

The pimpled rubber that comes from automobile tire contains the carbon black of significant proportion usually. Disassociation handling procedure used in the present invention often causes carbon black granules to be emitted from pimpled rubber. With regard to typical case, this kind carbon black granules is usually separated mutually from continuous pitch by precipitation. The carbon black of emitting in the present invention, surface grafting is to these carbon black granules because the vulcanizate network of at least part of disassociation passes through radical chain transfer reaction, thereby granule stability is improved, so these carbon black granules will be dispersed in the liquid vulcanizate and can not be precipitated out.

Generally speaking, this material that highly dissociates can be dispersed in the pitch, thereby remains in the liquid phase with the aqueous colloidal dispersion form. Yet, begin to dissociate and when generating the interstage of highly dissociating between the material when being in, wherein still exist degraded rubber grain precipitable, that disperse, and in order to make this kind degraded rubber grain stably be dispersed in the pitch, just must carry out chemical reaction by the crosslinked action of certain unsaturated rubber composition, these unsaturated rubber compositions can comprise the vulcanizate that degraded before this left behind, in order to make the rubber grain stabilisation of degraded and unlikelyly be precipitated out from pitch.

An importance of the present invention is exactly to control the degree of dissociation or the level of vulcanizate network. Can use separately the material of certain degree of dissociation, perhaps more advantageously, be used in combination the material of the various different degrees of dissociation, can add therebetween or do not add as discussed above auxiliary modifier.

This kind be the vulcanizate network of the degree of depth disassociation in pitch by solubilization or compatibilized, can vulcanize on the spot by adding normally used crosslinking agent subsequently again. The modified pitch that this kind vulcanizes again demonstrates elasticity and the toughness of improvement, and because have and pitch between irreversible chemical bonding thereby without the anxiety that is separated.

For implementing the crosslinked and/or grafting of this kind, can adopt any easily crosslinking agent, comprise sulphur, sulfur donor, wherein with or without accelerating additive, also comprise other radical initiators such as hydrogen peroxide. Generally speaking, the consumption of cross-bond is about 0.05～about 5% (weight) of pitch, preferred about 0.2～about 3% (weight). Cross-bond can add in any easily stage of processing.

In another embodiment of the invention, through or can add and be attached to mixing in the glue bituminous composition of above-mentioned height disassociation without the vulcanized rubber powder particle of Partial digestion. In this kind composition, the rubber network of at least part of disassociation can chemically be bonded on the surface of this vulcanizate particle, thereby forms stable composition.

Adopt the method for progressively adding rubber powder granule, can in the product bituminous composition, accumulate the rubber of the very high stable dispersion of total content, be generally about 15～about 80% (weight), be preferably about 25～about 50% (weight), the highest about 75% (weight). The material that this kind is concentrated; or title masterbatch; available pitch is diluted; be made into the composition that requires to contain the stable shoddy of wishing concentration; generally in about 3～about 40% (weight); the purposes that namely can be used for various pitch comprises that the paving the way of all kinds, prefabricated paving brick, roof membrane, shide, waterproof membrane, fluid sealant, filleting thing, potting are with resin and protective finish. Alternatively, this kind concentrate can be mixing with filler and/or polymer, and the mixing composition that obtains can be made granular composition through granulation, in order to joining later on the bituminous composition for such use.

In the International Patent Application WO 93/07219 of delivering (corresponding to United States Patent (USP) 5,280,064 and 5,494,966, its disclosed content is incorporated as the reference of this paper), narrated relevant preparation of stablizing bituminous composition, wherein polyethylene particle turns into being remained decentralized photo by spatial stability. Mention in the explanation, this pitch comprises the continuous principal phase of bituminous composition of polymer modification, this polymer relies on spatial stability to turn into being dispersed in pitch, this stabilisation is by fixing the first component at polymer, then reaching in conjunction with the second component that is dissolvable in water pitch on the first component.

In addition, in the international patent application no WO 94/14896 that delivers with Polyphalt company name, propose, can in bituminous composition, add homopolymers or copolymer composition, comprise styrol copolymer, olefin copolymer and second the third glue, form particle dispersion, wire dispersion, solution and the forms such as combination of the two, wherein the homopolymers of this interpolation and copolymer composition have passed through anti-separating stable processing.

Can be with the vulcanizate network of at least part of disassociation of preparing in a manner described, join in this bituminous composition same as before or with the form of stable dispersion in the middle of pitch, so that residual rubber powder granule consists of the part of this stable dispersion phase, thereby be provided as replenishing or the part substitute polyethylene in the said composition or other polymer beads. Can utilize the unsaturated composition of vulcanizate network of this at least part of disassociation and any unsaturated rubber that may add as steric stabilizer, replace whole or in part take the stabilizing agent of polybutadiene as the basis. If used unsaturated glue and it is functionalized in the process of this at least part of disassociation vulcanized network of preparation, then available this unsaturated glue replaces aforesaid second component of being combined with the first component, and is fixed on this dispersed polymeres.

The method of this paper forms the principle of the stabilising dispersions of pimpled rubber in pitch, can combine with the stabilisation measure that the polyethylene to dispersion described above and other olefin polymers are taked, and improves the characteristic of dispersion. Paveio(u)r comprises aggregation usually, such as rubble, sand etc. Equally, also can use other additives, join in this bituminous composition, specifically will decide according to the final use of bituminous composition. Such as, roofing can by add such as asbestos, carbonate, silica, wood-fibred, mica, sulfate, clay, pigment and/or as chlorinated wax the suitable fillers such as fire retardant obtain. As broken filler, it may be favourable adding oxide.

Mechanism

About acting on the shearing force of above-mentioned material composition, in traditional high shear mixer, rely on what kind of mechanism that the swollen rubber network that is mixed in vulcanizate/pitch is dissociated, still imperfectly understand at present. Yet, do not intend being limited to any theory, the inventor thinks, method of the present invention can cause being present in sulphur-sulfide linkage, sulphur-carbon bond or other cross-bond fractures in the vulcanizate cross-linked structure, even may also have the fracture of carbon-carbon bond, so that reach the treated complete digestion of vulcanizate or be stable at degree in the pitch, thereby though under the variable concentrations level, still can from pitch, not separate with the hot liquid form through long storage time.

The application of glue concentrate is mixed in desulfurization

The glue pitch concentrate of mixing by the inventive method preparation can be without diluting or being used for various purposes with the form that pitch dilutes, and the front is talked about, and is now blanket as follows:

1) feature with the rubber asphalt concentrate of the inventive method preparation is:

● but a kind of gel content is up to about 15～about 50 or the binding agent of higher high temperature process;

● a kind of stable, unique heterogeneous blend, wherein whole vulcanizates are all by digestion.

This concentrate can be used as the final products such as fluid sealant in some industrial use, perhaps can with some polymer and/or the direct blending of inorganic filler so that machinework to be provided.

2) through the mixing the glue concentrate and can use independently of pitch dilution, or mix different polymer and/or other additives to prepare diversified final products. These products are fit to be used as that various pitch articles is used for paving the way, roofing, coating, waterproof and industrial product market. This is mixed the glue concentrate and can be used with common AC, air oxidation AC and/or polymer modified asphalt:

● as modifier independently, rubber phase all can not occur under different dilution factors divide

From;

● as composite modifier, be used with synthetic rubber, so that stable complex composition to be provided;

● as stabilizing agent, be used for just borrowing in the polyolefin plasticity dispersion of hot liquid pitch

In the process of ground reaction and stabilisation, in this case, the vulcanizate of this processing

The unvulcanised glue that is used as in the on the spot spatial stability method of WO 93/07219 becomes

The substitute that divides.

Embodiment

In the example below, adopt the polymer layering test to being undertaken by the pitch sample such as modulated, this bituminous composition is estimated in the stability of hot lay up period. Modulation program is as follows: put into about 70 gram binding agents and store 48 hours (or 2 days) by vertical baking oven that is placed on 320 °F in 0.75 inch aluminum pipe. After heat-storage, from the pipe epimere and from the sampling of pipe hypomere and 275 °F or 356 °F of lower adhesive viscosities of measuring gained, obtain ratio of viscosities by relatively. If this ratio is between 0.80～1.20, the separation degree that then it has been generally acknowledged that this decentralized photo is acceptable.

Usually, if the 275 °F lower viscosity of this polymer modified asphalt system before heat-storage are about 3000 centipoises or lower, then above-mentioned placement condition under 320 °F is defined in 48 hours generally is acceptable. Yet, if viscosity is too high or owing to the reason of pitch itself (for example being oxidized asphalt) is higher than this scope owing to polymer addition in the pitch, then in some situation in the pitch separation (if unstable) of polymerization phase may carry out excessively slowly. This moment is necessary, perhaps composition is diluted to lower polymer content, perhaps adopts higher laying temperature and/or longer time, obtains correct reflection with the stability/unstability that guarantees contained polymer in the pitch medium.

Mixing in all examples all ties up in the 1 liter of mixer that adopts Brinkman Polytron high shear (model PT45/80) homogenizer to be carried out.

Example 1

First group of experiment is to adopt simultaneously traditional program and prepare the identical final composition of pimpled rubber in same variety asphalt according to program of the present invention, so that directly compared. The result of this group experiment is provided in the table below 2.

In this group experiment, use from 3 makers' 4 kinds of broken vulcanizate sources of difference. Each broken vulcanizate sample is all taken from sidewall, yet prescription may be different because of manufactory. The granularity of shoddy (GR) from 0.5 inch to 100 orders, change quite large. The order number system mean value of each GR that table 2 provides.

Employed pitch has identical viscosity grade (AC-5) in this group experiment, and character is as follows: needle penetration 148 dmm under 77 °F; 113 °F of softening points; Brookfield viscosity 233 centipoises under 275 °F.

Adopt the conventional procedures of describing in the prior art to prepare respectively these 4 kinds of pimpled rubber and a series of blends of this pitch (AC-5) by different mixing proportions (5%, 8% and 12% (weight) sees Table shown in 2).

Pitch is heated to 356 °F in mixer, disperse therein to reach 2 hours under about 392 °F higher temperature and shear conditions with relief shoddy particle. Although the rubber powder granule of swollen has disperseed fully under the effect of this kind high shear mixing, however under less than the low-mix glue amount condition of 15% (weight) they fail to dissolve and/or digestion in the middle of pitch. The experimental result of all compositions shows that the rubber of processing with conventional procedures (being prior art) all has the tendency (or pimpled rubber is deposited on the bottom) that is separated in the self-heating liquid bitumen at the lay up period that does not add stirring. Yet this experimental result also shows, the same glue amount of mixing because rubber powder source is different, and the different glue amount of mixing in identical source, all demonstrates to a certain degree difference in the speed that is separated. In a word, all unstable in hot liquid pitch at the rubber grain of all processing under the conventional wet processing conditions.

Adopt program of the present invention to process to identical formulation, at first make the rubber concentrate, then be diluted to for the final composition of testing with pitch, wherein the pimpled rubber through so processing all stably remains in this binding agent under any rarer rubber concentrations.

In this group experiment, the rubber concentrate is to adopt the program that progressively adds glue to prepare in identical high shear mixer. To maintaining under the continuous condition that stirs of about 356 °F hot liquid pitch, at first add about 17% (weight) pimpled rubber. Under this initial addition, though obtain that a kind of viscosity is high still can process, machinable high viscosity mixture still in the Polytron high shear mixer in other words. Married operation has carried out half an hour under about 392 °F and high shear conditions. The viscosity of this mixture begins to descend, and then is reduced to the degree that can progressively add pimpled rubber in this mixture, and the glue amount of finally mixing that this example reaches is 25% (weight). Subsequently, this mixture being imposed same shear conditions processes. Total elapsed time is 2 hours, and the result makes the fine and smooth glue concentrate mixture of mixing, and wherein the vulcanizate particle of all addings is all by digestion and/or be attached in the middle of the pitch. The concentrate that generates is diluted to different final compositions with the same pitch from traditional prior art example use and mixes the glue amount. All are all stablized according to the composition (seeing Table 2) that the present invention mixes the preparation of glue amount by 4 kinds of pimpled rubber sources by difference, and lay up period is not found residual particles glue precipitation.

Table 2 traditional program

Composition/trade mark	GR-1-1	GR-1-2	GR-1-3	GR-2-1	GR-2-2	GR-2-3	GR-3-1	GR-3-2	GR-3-3	GR-4-1	GR-4-2	GR-4-3	The GR-4-3 of dilution
														Pitch (AC-5)	95	92	88	95	92	88	95	92	88	95	92	88	95
GR-1 (80 order)	5	8	12
														GR-2 (40 order)				5	8	12
GR-3 (20 order)							5	8	12
														GR-4 (40 order)										5	8	12	5
Stability data (2 days, 320 °F)
														135 ℃ of viscosity, CP
Epimere	293	613	1422	325	425	1082	335	475	1705	321	950	3275	340
														Hypomere	1363	1270	2965	1227	1698	4440	1323	3015	3195	1148	1280	3445	2420
Index of stability (ratio)	0.21	0.48	0.48	0.26	0.25	0.24	0.25	0.16	0.52	0.28	0.74	0.95	0.14
														Bin stability	Unstable	Unstable	Unstable	Unstable	Unstable	Unstable	Unstable	Unstable	Unstable	Unstable	Unstable	Unstable	Unstable

Unstable continued 2 programs of the present invention of sample when * it is diluted to 5% gel content

Composition/trade mark	DGR-1-1	DGR-1-2	DGR-1-3	DGR-2-1	DGR-2-2	DGR-2-3	DGR-3-1	DGR-3-2	DGR-3-3	DGR-4-1	DGR-4-2	DGR-4-3
													Pitch (AC-5)	95	92	88	95	92	88	95	92	88	95	92	88
GR-1 (have 25%GR-1 mix glue concentrate)	5	8	12
													GR-2 (have 25%GR-2 mix glue concentrate)				5	8	12
GR-3 (have 25%GR-3 mix glue concentrate)							5	8	12
													GR-4 (have 25%GR-4 mix glue concentrate)										5	8	12
Stability data (2 days, 320 °F)
													135 ℃ of viscosity, CP
Epimere	510	890	1635	553	943	1672	425	713	1163	490	840	1535
													Hypomere	515	875	1620	523	900	1690	435	688	1120	507	850	1540
Index of stability (ratio)	0.99	1.02	1.01	1.06	1.05	0.99	0.98	1.04	1.04	0.97	0.98	1.00
													Bin stability	Stable	Stable	Stable	Stable	Stable	Stable	Stable	Stable	Stable	Stable	Stable	Stable

Example 2

In second group of experiment, use pitch identical with the pitch (AC-5) of use in the example 1, tire sealant is the shoddy (trade mark GR-5) of being made by waste tire. The particle mean size of GR-5 is about 40 orders, is that Baker rubber company car tire (having removed fiber and steel wire) is produced. Employed processing oil is a kind of hydrolene (blown oil) circulation agent (H-90), and its total arene content is 83.6%, saturate content 16.3%, asphalitine 0.1%.

By traditional prior art method, two kinds of different glue amounts of mixing (5% and 7.5% (weight)), prepared the blend (shown in following table 3) of this GR and pitch. This GR-5 is different from employed the sort of vulcanizate in the example 1, need to be in containing the pitch of a certain proportion of processing oil abundant swollen. After conventional procedures, reasonably well disperseed although the rubber powder granule of swollen and swollen occurs under 428 °F～464 °F high temperature and high shear mixing effect this GR-5 particle, yet still fail to dissolve and/or digestion in the middle of pitch. Experimental result also shows, compares with the result of tyres of different types glue in the example 1, and is higher in the identical speed that is separated of mixing this example under the glue amount condition.

The blend (being shown in Table 3 sample GR-5-3) that has prepared again identical gel content by disclosed principle in the prior art (EP 0439232) with GR-5. This tire sealant (GR-5) mixes under 338 °F and shear conditions, then transfers in the other container, and stands low shear agitation and process, in circulation under 410 °F the higher temperature more than 10 hours. The result shows that the rubber of processing by EP 0439232 also shows the tendency that is separated at the lay up period that does not add stirring.

Adopt program of the present invention to prepare the final composition of same composition, at first be prepared into and mix the glue concentrate, be diluted to final composition requirement to be measured with pitch subsequently.

This glue concentrate system of mixing that contains GR-5 rubber adopts the program progressively mix glue to prepare in identical high shear mixer. About 20% (weight) pimpled rubber is to add wherein in 1: 1 the hot liquid pitch/processing oil blend situation about stirring keeping Comparative Examples. Still can process this point in this Polytron high shear mixer though mixture viscosity is high, be by measuring and send out from this initial glue of effectively mixing, and be aided with that the swollen degree that improves the dispersion rubber particle reaches. Mixed process has continued 1.5 hours under about 464 °F and high-shear conditions. Mixture viscosity begins to descend, and then reaches the degree that can mix glue, has reached in this example at last the glue amount of finally mixing of 50% (weight), the results are shown in following table 4. Mixture stands same shear conditions to be processed, and total elapsed time is about 4 hours, obtains at last the fine and smooth glue concentrate binding agent of mixing, and wherein the particle vulcanizate of all addings is all by digestion and/or be attached in the pitch. The concentrate that obtains is diluted to the composition of same concentrations with identical pitch, and lay up period is stable, the phenomenon (seeing Table 3 contained results) that pimpled rubber is deposited in the bottom do not occur.

Concentrate after the dilution comprises a kind of desulfurization glue, replace a kind of unvulcanised glue as stabilizer element with it, prepare polyethylene with the preparation of this concentrate in stabilising dispersions in the used identical pitch, its preparation method is WO 93/07219 disclosed prior art spatial stability method. The result of the test of this sample is stated from table 3 (DGR-5/PE-1), and the data in the table show that the compatibility of this desulfurization tire sealant and pitch and reactivity all are enough to make it to play the elastomer layer effect of stabilization of polyolefins Particle Phase in above-mentioned spatial stability method.

Table 3

	Comparative Examples				The inventive example
							Composition/trade mark	GR-5-1	GR-5-2	GR-5-3	GR-5/PE-1	DGR-5-1	DGR-5/PE-1
Pitch (AC-5)	77.5	80	80	96.27	77.5	96.27
							GR-5 (40 order)	7.5	5	5	0.38
Processing oil	15	15	15	0.75
							GR-6 is (at concentrate RC-1*In)					7.5	0 38
(in the concentrate RC-1*) processing oil					15	0.75
							Regeneration ethene (PE)				2		2
Maleic anhydride grafting PE				0.3		0.3
							FPB (Hycar activity gel)				0.2		0.2
Sulphur				0.1		0.1
							Stability data (2 days, 320 °F)
275 °F viscosity, CP
	Epimere	525	500	508	485	457	375
Hypomere								2850	3250	3100	275	466	380
	Index of stability (ratio)	0.18	0.15	0.16	1.76	0.98	0.99
Bin stability								Unstable	Unstable	Unstable	Unstable	Stable	Stable

* mix glue concentrate compositions table 4 shown in the table 4 and mix glue concentrate composition

Composition/trade mark	RC-1	RC-2
			Pitch (AC-5)	25
Pitch (dilution type)		25
			Processing oil	25	25
GR-5 (40 order)	50
			GR-6 (30 order)		50

Example 3

The another kind of rubber that uses in the another experiment according to example 2 programs (trade mark GR-6) is the reclaimed rubber of taking from car tire and truck tire mixture.

GR-6 rubber with flux oil/processing oil mixture by with example 2 in the same program of GR-5 is processed. Rubber concentrate by GR-6/ flux oil/processing oil mixture preparation is shown in table 4. This flux oil is provided by Amoco Clark company, and according to examining, it is the sort of pitch for air oxidation. The character of this pitch (flux oil) is 77 °F needle penetration 302 dmm; 100 °F of softening points; 350 °F Brookfeild viscosity 32 centipoises. Pitch (oxidation) is a kind of typical roofing level pitch that is obtained through air oxidation (or oxidation) by flux oil, and character is as follows: 77 °F needle penetration 17 dmm; 212 °F of softening points; 350 °F Brookfeild viscosity 770 centipoises. Air oxidation pitch is considered to a kind of pitch of extremely difficult modification usually, because the compatibility of it and polymer is poor. Identical in employed processing oil and the example 2. But adopt program of the present invention to be diluted the prepared glue concentrate of mixing with this air oxidation pitch, still obtained high stability rubber asphalt product, shown in following table 5. Make us more being surprised to find, aspect the elastic layer of the polyolefin particles phase in the in-situ stabilized air oxidation pitch, its solubility also all is enough (seeing Table the result of relevant this example (DGR-6/PE-1) in 4) with reactivity by the tire sealant of digestion in the air oxidation pitch. Table 5 is with air oxidation bituminous-treated GR, and in this pitch with the LDPE of this GR stabilisation

	Comparative Examples		The inventive example
					Composition/trade mark	GR-6-1	GR-6/PE-l	GR-6-1	DGR-6/PE-1
Pitch (oxidation)	80	85	80	85
					Pitch (dilution)	5	3	5	3
Processing oil	5	3
					GR-6 (30 order)	10	6
Processing oil is (at concentrate RC-2*In)			5	3
					GR-6 is (at concentrate RC-2*In)			10	6
Reclaim PEF (PE)		2		2
					Maleic anhydride grafting PE		0.5		0.5
FPB (Hycar activity gel)		0.3		0.3
					Sulphur		0.2		0.2
Stability data (5 days, 425 °F)
					375 °F viscosity, CP
Epimere	665	545	375	1740
					Hypomere	1000	2400	373	1780
Index of stability (ratio)	0.67	0.23	1.0l	0.98
					Bin stability	Unstable	Unstable	Stable	Stable

* mix glue pitch concentrate composition shown in the table 4

Example 4

Shoddy (GR-1) is used for the 4th group of experiment again.

GR-1 by processing with preparation condition identical described in the example 1, has prepared the concentrate of mixing glue amount 25% with harder bottom pitch (AC-20).

The character of this AC-20 bottom pitch is: 77 °F needle penetration 67 dmm; 115 °F of softening points; 275 °F Brookfeild viscosity 368 centipoises.

This is mixed the glue concentrate and is diluted to 3 kinds of different shoddy concentration (6 %, 8% and 10% (weight)) with AC-20 bottom pitch, subsequently 1.25%SBS was disperseed 30 minutes in the concentrate of 356 °F above-mentioned dilution, then make it under uniform temp and high shear, carry out on the spot chemical reaction with 0.15% elementary sulfur, amount to 90 minutes or longer.

In Comparative Examples, processing conditions with final form with example of the present invention in identical, difference is that shoddy (GR-1) is directly processed in composition, rather than passes through mixing the glue concentrate stage according to process of the present invention. Result in the following table 6 shows, employing is forming 3 kind different mix glue amount situation in identical from conventional example according to the final mixture that concentrate obtained of program preparation of the present invention, all performance is stable, does not occur the phenomenon of bottom pimpled rubber precipitation under standard storage requirement.

The GR that table 6 is processed is with the situation that contains elastomeric bituminous composition stabilisation and mix

	Comparative Examples				The inventive example
								Composition/trade mark	GR/SBS-1	GR/SBS-2	GR/SBS-3	Dilution GR/SBS-3	DGR/SBS-1	DGR/SBS-2	DGR/SBS-3
Pitch (AC-20)	92.6	90.6	88.6	92.6	92.6	90.6	88.6
								GR-1 (80 order)	6	8	10	6
GR-1 (mixing in the glue concentrate 25%)					6	8	10
								SBS(Enichem 161B)	1.25	1.25	1.25	1.25	1.25	1.25	1.25
Sulphur	0.15	0.15	0.15	0.15	0.15	0.15	0.15
Stability data (2 days, 320 °F)
								275 °F viscosity, CP
Epimere	1525	2045	3285	1070	1645	2163	2367
								Hypomere	2295	2815	3435	1665	1560	2273	2365
Index of stability (ratio)	0.66	0.75	0.97	0.64	1.05	0.95	1.00
								Bin stability	Unstable	Unstable	Unstable	Unstable	Stable	Stable	Stable

* since its to be diluted to 6% sample unstable

Sum up above disclosure, the invention provides a kind of novel dissolving rubber pitch concentrate composition, the method that comprises said composition and prepare said composition. Various modifications within the scope of the present invention may exist.

Claims (16)

1. stable rubber asphalt concentrate, it comprises:

Pitch, and it is characterized in that

Account for the disassociation vulcanizate network of at least 15% (weight) of described composition, the combination of it and this pitch reaches such degree, measured by the polymer separating experiment, this rubber grain does not precipitate in composition, and this rubber grain does not precipitate in composition when being diluted to lower disassociation vulcanizate network concentration with pitch.

2. desired concentrate in the claim 1 is characterized in that, described disassociation vulcanizate network accounts at least 25% (weight) of said composition.

3. desired concentrate in the claim 1, its available pitch is diluted to lower disassociation vulcanizate network concentration.

4. bituminous composition, it comprises pitch and as each desired pitch concentrate in the claim 1～3 of the modifier of described pitch.

5. the desired composition of claim 4 is characterized in that, described modifier is the independent modifier of this pitch.

6. the desired composition of claim 4 is characterized in that, described modifier is the composite modifier of this pitch, and it and at least a synthetic rubber are used.

7. the desired composition of claim 6 is characterized in that, described synthetic rubber is the elasticity unsaturated polymer.

8. stable bituminous composition, it comprises the dispersion of pelletized polyolefin in pitch, it is characterized in that each desired concentrate comprises and makes described pelletized polyolefin keep stable, the anti-composition that is precipitated out from pitch in the claim 1～3.

9. method for preparing the rubber asphalt concentrate is characterized in that it may further comprise the steps:

A) provide a kind of material, it comprises:

A) pitch, and

B) comprise the pimpled rubber of vulcanizate network, its initial content accounts at least 15 % (weight) of this material, wherein said pimpled rubber is formed a kind of network-like structure in pitch by swollen on the spot, and vulcanizate particle is wherein dissociated in the high shear field of force easily; And

B) allow described material stand to be enough to make the vulcanizate network of this rubber grain to dissociate, thereby the vulcanizate that makes digestion is attached to the shearing and the temperature conditions that go in the pitch and processes, this combination reaches such degree, measured by the polymer separating experiment, this rubber grain does not precipitate in composition, and this rubber grain does not precipitate in composition when being diluted to lower disassociation vulcanizate network concentration with pitch.

10. the desired method of claim 9 is characterized in that, the granularity of described pimpled rubber is 0.5 inch～200 orders.

11. the desired method of claim 10 is characterized in that, described granularity is 10～80 orders.

12. the desired method of claim 9 is characterized in that described material also comprises a kind of processing oil, the solvability that the purpose of its adding is to promote the swollen of pimpled rubber and strengthens pitch.

13. each desired method among the claim 9-12, it is characterized in that, described material stands the heat that applied by described shearing and temperature conditions and the effect of mechanical energy, the shear stress that forms therebetween is enough to make particle generation internal friction and shearing, thereby makes the vulcanizate network issue solution estranged in the shear stress impact that is applied on this granule materials.

14. each desired method among the claim 9-12, it is characterized in that, mix to this and to add at least more a collection of pimpled rubber in glue concentrate, then repeat said method so that by the formed digestion vulcanizate of described a collection of at least interpolation network integration in the middle of this rubber asphalt concentrate.

15. each desired method is characterized in that among the claim 9-12, and described rubber asphalt concentrate is diluted to lower bound rubber granule density.

16. each desired method is characterized in that among the claim 9-12, applying described shearing and temperature conditions duration should be so that may maintain dispersity and antisolvent precipitation from any carbon black granules that rubber grain is emitted.