BRPI0708861A2 - process for preparing rubber composition, rubber composition obtained therefrom, and use thereof - Google Patents

Abstract

PROCESS TO PREPARE RUBBER COMPOSITION, RUBBER COMPOSITION OBTAINED FROM THE SAME, AND USE OF THE SAME. The present invention relates to a process for preparing a rubber precursor or a rubber composition comprising an modified inorganic particulate material containing oxygen comprising the steps of: a) preparing a mixture of the modified inorganic particulate material containing oxygen and a first solvent; and b1) adding the mixture to a rubber precursor comprising at least one polymer and optionally a second solvent; or b2) adding the mixture to the rubber composition comprising at least one monomer of a rubber precursor and optionally a second solvent, and polymerizing the monomer (s) to form a rubber precursor; c) optionally cross-linking the rubber precursor in the presence of a cross-linking agent to form a rubber composition; and d) optionally removing the first and / or second solvents before, during or after any of steps b1), b2), and c). The invention further relates to rubber compositions comprising rubber and an inorganic particulate material containing oxygen modified with a coupling agent.

Description

Patent Descriptive Report for "PROCESSOPARA PREPARING RUBBER COMPOSITION, RUBBER COMPOSITION OBTAINED FROM IT, AND USE OF THE SAME".

The present invention relates to a process for preparing a rubber composition comprising rubber and an oxygen-containing inorganic particulate material modified with a coupling agent.

Such processes are known from US6,509,423, wherein the preparation of a silicon rubber composition comprising an organo polysiloxane, an organohydrosilane, an inorganic filler, and a hydrosilylation catalyst is disclosed. Cargainorganic fillers generally have an average particle size of 0.1 to 500 μηι. These inorganic fillers can also be treated with an organosilicon compound.

US 6,830,811 describes a process for preparing partially aggregated hydrophobic colloidal silica. An aqueous medium / organic solvent suspension of an organosilane-modified colloidal silica is obtained in this process. After asylum modification, water is removed, and from the subsequent suspension the remaining solvent is removed by evaporation or spray drying. Hydrophobic colloidal silica aggregates obtained in this manner may be used in silicones.

EP 0 982 268 discloses a method for making non-aggregated hydrophobic silicoacolloid suitable for use as fillers in silicone rubber compositions. To this end, an unaggregated hydrophobic colloidal desylic aqueous suspension is reacted with at least one organosilicon compound to effect hydrophobization of the colloidal silica. Hydrophobic colloidal asylum is subsequently obtained in its dry form before dry solids are added to the liquid silicone.

The disadvantage of the prior art processes is that modified colloidal silica agglomerates are added to the boron crack precursor, giving the resin precursor cure a boron crack composition where the colloidal silica is not evenly distributed. homogeneous. This inhomogeneous distribution causes the rubber composition to have non-ideal physical properties.

It is an object of the present invention to provide an improved process for preparing rubber compositions. Another objective is to provide a rubber composition with improved physical properties.

This objective is achieved by a process for preparing a rubber precursor or a rubber composition comprising a modified inorganic oxygen-containing particulate material, comprising the steps of:

a) preparing a mixture of the oxygen-containing inorganic modified particulate material and a first solvent; and

b1) contacting the mixture with a rubber precursor comprising at least one polymer and optionally a second solvent; or

b2) contacting the mixture with a monomer composition comprising at least one monomer and optionally a second solvent, and polymerizing the monomer (s) to form a boron crack precursor;

c) optionally cross-linking the rubber precursor in the presence of a crosslinking agent to form a rubber composition; and

d) optionally removing the first and / or second solvents before, during or after any of steps bl), b2), and c).

The use of the modified particulate material mixture and the first solvent (step a)) allows the particulate material to be well dispersed before the mixture is combined with the rubber precursor or its monomers. In this way, the particulate material can be well dispersed in the non-agglomerated or minimally agglomerated rubber precursor. In contrast, prior art processes, for example as described in EP 0 982 268, use hydrophobic silica in solid form, which generally causes agglomerates of the modified silica to be present in the final silicone composition. This agglomeration may require a milling or grinding step in conventional processes, making them more complex and less economically attractive to the process of the invention.

In addition, the mixture of the modified particulate material and the first solvent in step a) can be easily handled since it generally has a low viscosity, and also allows easy mixing in the rubber precursor of step b1) or ( s) monomer (s) of same as step b2). Generally, during the process of the invention the first solvent will evaporate greatly or even completely without a separate evaporation step, and without the formation of gaps in the final rubber composition, in particular when the rubber is a silicone rubber.

The process of the present invention provides a rubber composition comprising modified inorganic particulate material containing oxygen with improved properties such as durability, tensile strength, elongation, modulus, tear strength, and improved optical properties.

The process of the invention comprises two alternative steps b1) and b2). In step b1) the first solvent / particulate material mixture is added to the rubber precursor without a reaction between the modified particulate material and the rubber precursor. In step b2) the mixture of step a) is added to at least one monomer. of the rubber precursor, monomer (s) which is subsequently polymerized (s).

In one embodiment of this process, the oxygen-containing i-norganic particulate material is modified with a coupling agent comprising a first functional group reactive with the particulate material and a second functional group reactive with the monomer (s) and / or rubber opecursor. In this case, the second functional group may react with the monomer (s) during polymerization thereof, causing the particulate material to be chemically bonded to the rubber precursor. Alternatively, the second functional group may react with the rubber precursor with curing of the precursor in step c), causing the modified particulate material to be chemically bonded to the rubber composition.

The first and second solvents used in the process of the invention may be any solvent suitable for use in this process and known to one skilled in the art. Such first and / or second solvents may be the same or different and preferably are a solvent compatible with the modified particulate material, i.e. a solvent in which the particulate material is well dispersed as distinct and unaggregated particles, as well as with the rubber precursor, monomers and / or the resulting rubber composition.

The first and second solvents include alcohols, such as methanol, ethanol, isopropanol, and n-butanol; ketones, such as methyl amyl ketone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; unsaturated acrylic esters such as butyl acrylate, methyl methacrylate and trimethylol propane triacrylate aromatic hydrocarbons such as toluene and xylene; and ethers, such as dibutyl ether, tetrahydrofuran (THF), and methyl tert-butyl ether (MTBE).

In a preferred embodiment of the above process, the first and second solvents are an alkoxylated alcohol according to the formula.

where R1 is C1 -C4 alkyl, R2 is hydrogen or methyl, and η is an integer from 1 to 5.

Examples of such alkoxylated alcohols are ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene mono t-butyl ether glycol, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol monobutyl ether monobutyl ether, propylene glycol, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, propylene glycol mono-t-butyl ether, propylene glycol monohexyl ether, pro monophenyl ether -pylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, having mono n-propyl ether, dipropylene glycol monoiso-propyl ether, dipropylene glycol monobutyl ether and dipropylene glycol. Of these alcohols, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether are less preferred because they are teratogenic and may cause health problems.

The most preferred alkoxylated alcohols are depropylene glycol monomethyl ether and propylene glycol monoethyl ether. Solvents are available, for example, from Shell (Oxitol / Proxitol) and Dow (DowanoI) and UnionCarbide (Carbitol / Cellosolve). Also contemplated is the use of two or more alkoxylated alcohols in the process of the invention.

In the context of the present application the term "modified oxygen-containing inorganic particulate material" refers to a particulate material having an average size between 1 and 1,000 nm in at least one direction, which material is modified with a coupling agent.

Typically, the oxygen-containing inorganic particulate materials of the invention have a numerical average particle diameter, determined using a dynamic light scattering method, between 1 and 1,000 nm, a solids content of 10 to 50 by weight. Preferably, the numerical average particle diameter ranges from 1 to 150 nm, and more preferably the numerical average particle diameter ranges from 1 to 100 nm. It is contemplated that the inorganic oxygen-containing particulate material according to the invention may comprise particle size or polymodal particle size distributions.

Oxygen-containing inorganic particulate matter may be any particulate material known to the person skilled in the art. It is envisaged that the inorganic particulate material of the present invention may already be modified, for example, it may contain organic constituents or be encapsulated in a second inorganic material, prior to being modified according to the processes of the invention. Oxygen-containing inorganic particulate matter is generally selected from oxides, hydroxides, calcium compounds, zeolites, and talc.

Examples of suitable oxides and hydroxides are silica (ie silicon dioxide), alumina, aluminum trihydrate, titanium dioxide, tenincide oxide, iron oxide, zirconium oxide, cerium oxide, antimony oxide, bismuth oxide, cobalt oxide, dysprosium oxide, erbium oxide, europium oxide, indium oxide, indium hydroxide, magnesium oxide, deneodymium oxide, nickel oxide, terbium oxide, pellet oxide, oxide tungsten, and yttrium oxide.

Examples of calcium compounds are calcium carbonate and calcium phosphates.

Preferred oxygen-containing inorganic particulate materials are oxides and hydroxides, and in particular silica, alumina, aluminum trihydrate, titanium dioxide, and zinc oxide.

The most preferred particulate material is silica. Examples of aqueous colloidal silica are Nyacol® ex Akzo Nobel N.V., Snowtex® ex Nissan Chemalics Ltd., and Klebosol® ex Clariant.

The present invention also encompasses modification of mixtures of two or more of the above inorganic particulate materials.

Any coupling agent capable of reacting with the oxygen-containing inorganic particulate material may be used in the process of the invention; Suitable coupling agents are known to the person skilled in the art. In general, the coupling agent of the invention comprises at least one element selected from the group consisting of Si, Al, Ti, Zr, B, Zn, Sn, and V. Preferably, the coupling agent comprises at least least one element selected from the group consisting of Si, Al, -Ti1 Zr, and Β.

The coupling agent of the invention is generally a

-coupling according to the formula:

<formula> formula see original document page 8 </formula>

wherein Mi and M2 are independently selected from the group consisting of Si, Al, Ti, Zr, and B, and at least one of RrR6 is independently selected from hydroxyl, chlorine, an acetoxy having from 1 to 10 atoms. carbon, an alkoxy having from 1 to 20 carbon atoms, an organophosphate comprising two hydrocarbon groups comprising 1 to 20 carbon atoms, and an organopyrophosphate comprising two hydrocarbon groups comprising 1 to 20 carbon atoms, acetoxy, alkoxy, organophosphate or organopyrophosphate thereof which optionally comprise at least one functional group, and the remaining Rr R6 are independently selected from hydroxyl, chlorine, a hydrocarbon having from 1 to 10,000 carbon atoms, which hydrocarbon optionally comprises at least one functional group, an acetoxy having from 1 to 5 carbon atoms, and an alkoxy having from 1 to 20 carbon atoms, which alkoxy optionally comprises at least one functional group, siloxane and silazane, siloxane and / or silazane which are optionally emanel structures, stairway structures or cage-like structures or form a ring structure, a stairway structure or a jay-like structure with any of the remaining groups R1- R6; and X represents oxygen or, if M1 and / or M2 are Si, X represents O, N, S, disulfide, polysulfide, R7-S4-Rs and / or R7-S2-Re, where R7 and R8 are independently selected from a hydrocarbon. having 1 to 6 carbon atoms, and ρ represents an integer from 0 to 50, provided that if M1 is Al or B1 R3 is absent and / or if M2 is Alou B, R5 is absent. The functional group may be any functional group known to the person skilled in the art. Examples of such functional groups are hydroxyl, epoxy, isocyanate, thiol, oligosulfides, amine, and halogen. A combination of two or more coupling agents may be used in the process of the invention. Coupling agents may be contacted with oxygen-containing inorganic particulate material as a mixture or separately. The ratio of coupling agents may vary as desired. The proportion of coupling agents is expected to change over time as they are added to the particulate material.

If the oxygen-containing inorganic particulate material is silica, the preferred coupling agent is a silicon-based compound. Silicon-based compound is typically selected from the group consisting of silanes, disilanes, silane oligomers, silazane, silane-functional silicones, silane modified resins, and silsesquioxanes. Preferred silicon based compounds are silanes and silazanes. Suitable silanes for use in the process of the invention are silanes according to formulas I-VI:

<formula> formula see original document page 9 </formula>

wherein each of R 1, R 2, R 3, R 4 is independently selected from hydrogen or hydrocarbon having from 1 to 20 carbon atoms, which hydrocarbon optionally comprises at least one functional group. If silane according to any one of IV to V1 is used in the process of the invention, the ions, and in particular Cl ", are preferably removed from the mixture, for example using ion exchange techniques. To avoid a step For additional ion removal silanes according to any of formulas I-III are preferred.

Examples of silanes according to the invention are tributyl methoxy silane, dibutyl dimethoxy silane, butyl trimethoxy silane, dodecyl trimethoxy silane, trimethyl chlorosilane, tributyl chlorosilane, dimethyl dichlorosilane, dibutyl dichlorosilane, butyl trichlorosilane, trichlorosilane, do-decyl trichlorosilane, methyl trimethoxy silane (Dynasylan® MTMS), methyl triethoxysilane (Dynasylan® MTES), propyl trimethoxy silane (Dynasylan® PTMO), propyltriethoxyl silane (Dynasylan® PTEO), isobanyl trimetyl silane (Dynasylan® MTTE) ), isobutyl triethoxy silane (Dynasylan® IBTEO), octyl trimethoxy silane (Dy-nasylan® OCTMO), octyl triethoxy silane (Dynasylan® OCTEO), hexadecyl tri-methoxy silane (Dynasylan® 9116), phenyl trimethoxy silane (Dynasylan® 9116) , phenyl triethoxy silane (Dynasylan® 9265) 3-glycidyloxypropyl trimethoxy silane (Dy-nasylan® GLYMO), glycidyloxypropyl triethoxy silane (Dynasylan® GLYEO), 3-mercapto trimethoxy silane (Dynasylan® M TMO), 3-mercaptopropyl methyl dime-oxy silane (Dynasylan® 3403), 3-methacryloxypropyl trimethoxy silane (Dynas-ylan® MEMO), vinyl triethoxy silane (Dynasylan® VTEO), vinyl trimethoxy silane (Dynasylan® VTis) (2-methoxyethoxy) silane (Dynasylan® VTMOEO), acetoxypropyl trimethoxy silane, methyl triacethoxy silane, 3-acryloxy propyl trimethoxysilane, 3-acryloxypropyl dimethyl methoxy silane, allyl trimethoxy silane, allyl triethoxyl dimethoxydietanoyl, ethoxy silane, n-hexadecyl triethoxy silane, 3-mercaptopropyl triethoxy silane, methyl dodecyl diethoxysilane, methyl-n-octadecyl diethoxy silane, methyl phenyl diethoxy silane, methyl phenyldimethoxy silane, n-octadecyl triethoxy silane, n-octadecyl trimethymethoxy trimethyl silane, trimethyl ethoxy silane, trimethyl methoxy silane, vinyl methyl diethoxysilane, octanothioic acid, S- (triethoxysilyl) propyl ester, tetrasulfetobis (3-triethoxysilylpropyl) (Si69® ex Degussa ), bis (3-triethoxysilylpropyl) disulfide, gamma-mercaptopropyl trimethoxysilane (SiSiB® PC2300 ex PCC), and 3-octaneylthio-1-propyl triethoxysilane (NXT® ex GE). Further examples of silane coupling agents can be seen in WO99 / 09036, whose silane coupling agents are incorporated herein by reference. It is also envisaged that the silane used in the process of the invention is a mixture of two. or more silanes according to any of formulas I-VI.

Examples of suitable disilanes are bis (2-hydroxyethyl) -3-aminopropyl triethoxy silane, 1,2-bis (trimethoxysilyl) ethane, bis (trimethoxy silyl) benzene, and 1,6-bis (trimethoxyl silyl) hexane .

Examples of suitable silane oligomers are vinyl trimethoxy silane oligomer (Dynasylan® 6490), vinyl triethoxy silane oligomer (Dynasylan®6498).

Examples of suitable silazanes are hexamethyl disilazane (Dynasylan® HMDS), tetramethyl disilazane, cyclic dimethyl silazane, 1,1,1,2,3,3,3-heptamethyl disilazane, and N-methyl silazane resin (PS117 exPetrarch).

Examples of suitable siloxanes are 1,1,3,3-tetramethyl-1,3-diethoxy disiloxane, silanol-terminated polydimethylsiloxane (e.g. PS 340, PS 340.5, PS 341, PS 342.5 and PS 343 ex Fluorochem), diacetoxy-functional polydimethylsiloxane (PS 363.5 ex Fluorochem), methyldiacethoxy functionalized polydimethylsiloxane (PS 368.5 and PS 375 ex Fluoro-chem), dimethylethoxy terminated polydimethyl siloxane (PS 393 ex Fluoro-chem), and dimethylmethoxy terminated polydimethyl siloxane (PS 397 ex Fluo-rochem) ).

Silane-modified resins are generally polymer containing mono-, di- or trialcoxysilyl moieties or their corresponding hydroxysilyl, acetoxysilyl or chlorosilyl moieties which may be prepared by the introduction of silicon-containing monomers during polymerization or resin modification, as will be apparent. Preferred silane-modified resins are polymers containing mono-, di- or trialcoxysilyl moieties because they are more stable and do not require further processing steps to remove undesirable by-products such as acids and chlorides. . Examples of such silane modified resins are trimethoxysilyl modified polyethylenimine (PS 076 ex Fluoro-chem), methyldimethoxysilyl modified polyethylenimine (PS 076.5 ex Fluo-rochem), N-triethoxysilylpropyl-o-polyethylene oxideurethane (chem 077 ex) , and methyldiethoxysilyl-modified 1,2-polybutadiene (PS 078.8 exFluorochem).

Examples of suitable silsesquioxanes are polymethyl silsesquioxane (PR 6155 ex Fluorochem), polyphenyl propyl silsequioxane (PR 6160 exFluorochem), and OH-functional polyphenyl propyl silsesquioxane (PR 6163 ex Fluorochem).

Other preferred coupling agents in the invention process are titanium, aluminum, boron, and zirconium organometalates.

Examples of titanium-containing coupling agents are isopropyl isostearoyl titanate, isopropyl dimethacryl triisoostearoyl titanate, isopropyl dimethacryl isostearoyl titanate, tetraisopropyldi ((dioctyl) phosphite) titanate, tetra (2,2-diallyl dioxy) titanate (ditridecyl) phosphite), isopropyl tri ((dioctyl) pyrophosphate) titanate, isopropoxy triisostea-roila titanate, di ((dioctyl) pyrophosphate) oxoethylene titanate, di ((dioctyl) phosphate) ethylene titanate, di (dioctyl) titanate pyrophosphate) ethylene, tetraoctyl titanate di (ditridecyl) phosphite, titanium (IV) 2,2- (bis 2-propenolatomethyl) butanolate, tris (dioctyl) pyrophosphate-O, and dialkoxy bis (triethanolamine) titanate.

Examples of aluminum-containing coupling agents are diisopropyl acetoalkoxy aluminate, diisopropyl isopropyl aluminate, and isopropyl dioctyl phosphate aluminate.

Examples of boron-containing coupling agents are trimethyl borate (TMB ex Semichem), triethyl borate (TEB ex Semichem), tripropyl eborate.

Examples of zirconium-containing coupling agents isopropyl triisoostearoyl zirconate, butyl triisoostearoyl zirconate, butyl trioleyl zirconate, isopropyl trilinoleyl zirconate, zyconatodi (cumyl) phenyl oxoethylene zirconate (dibutyl) cumyl (cumyl) zirconate phenyl propyl.

In one embodiment of the process of the invention, the oxygen-containing inorganic particulate material which has been modified with at least one of the above coupling agents is subsequently modified with another coupling agent or with a reacting compound attached to the particulate material. . For example, the modified particulate material is treated with hexamethyl disilazane (HMDS), which gives a modified oxygen-containing particulate material that is more hydrophobic and therefore more compatible with hydrophobic matrices.

The rubber precursor prepared with the process of the invention is a rubber precursor which with curing or vulcanization can be converted into rubber. Such rubber precursors as well as the formed rubbers thereof are known to the person skilled in the art.

Examples of rubbers include natural rubber (NR), styrene butadiene rubber (SBR) polyisoprene (IR), polybutadiene (BR), polyisobutylene (IIR), halogenated polyisobutylene, nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), styrene-isoprene-styrene (SIS) and similar (hydrogenated) block styrenic copolymers15 (SBS, hydrogenated SIS, hydrogenated SBS), po-li (epichloroidrin) rubbers (CO, ECO, GPO), silicon rubbers (Q), chloroprene rubber (CR), ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), fluorine rubbers (FKM), ethylene vinylacetate rubber (EVA), polyacrylic rubbers (ACM), polynorbornene ( PNR), polyureos, and thermoplastic polyester / ether elastomers. Preferred rubbers are natural rubber, SBR, EPDM, polyurethane, and silicone rubber.

In the context of the present application the term "rubber composition" refers to a composition comprising rubber and oxygen-containing modified inorganic particulate material, and optionally other additives.

The rubber precursor of the invention may optionally be cured in the presence of a crosslinking agent to form the rubber composition. Rubber precursor cure processes are known to those skilled in the art. The crosslinking agent may be any crosslinking agent suitably used to cure rubber precursors. Such crosslinking agents are known in the art and include a Group VIII metal complex (such as Pt and Ru), a Group VIII metal based supported catalyst, a sulfur-containing curing agent, a peroxide, or combinations thereof.

In one embodiment of the invention the rubber is a desilicone rubber. The production of silicone rubbers is generally known to those skilled in the art, and is described for example in chapters 3.4 and 5 of "Silicones", Kirk Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, Inc., date of Publication online: December 20, 2002. In essence, the production of silicones takes place via polymerization of demonomers to form a silicone precursor, after which silicone precursors are crosslinked to form silicone. The disilicone precursors used in the process of the invention are known to the skilled artisan. It is noted that the silicone precursor is preferably liquid, so that the mixture of the modified particulate material and the first solvent can be easily mixed with the precursor to obtain a homogeneous and uniform distribution of the particulate material throughout the silicon cone precursor.

In one embodiment of the process of the invention the desilicone precursor obtained in either step b1) and b2) is cured to form the silicon cone, for example silicone rubber or silicone foam rubber. Such cure typically causes the formation of a structure. three-dimensional mesh consisting of cross-linked polydiorganosiloxane chains. Curing generally takes place via peroxide-induced free radical processes, via hydrosilylation addition processes using a Group VII metal complex (such as Pt and Ru) or a Group VII ummetal supported catalyst, or via condensation reactions. Examples of each of these healing processes can be found in Chapter 5: "Silicone Network Formation", "Silicones", Kirk Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, Inc., published online: Dec 20 By curing the silicone precursor, silicone rubber or rubber foams can be obtained.

The use of oxygen-containing inorganic particulate material which is modified with a coupling agent is intended to comprise a first reactive functional group with the particulate material and a second reactive functional group with the silicone precursor during the dry step as such (e.g. as the product of step b1)) or as a particulate material already bonded to the silicone precursor (e.g. as products of step b2)). In this way, the second functional groups of the coupling agents attached to the particulate material may also react with the silicone precursor to form a bond between two or more chains of the silicone precursor. The resulting silicone rubber or foam comprises modified particulate material which is chemically bonded thereto.

Suitable examples of the second functional groups mentioned above are hydroxyl, vinyl, chloride, hydride, thiol, acrylate, methacrylate, or acetoxy.

The invention further relates to a process for preparing a rubber precursor or a rubber composition comprising the steps of:

a) preparing a mixture of an aqueous suspension of oxygen-containing inorganic particulate matter and an alkoxylated alcohol according to the formula

<formula> formula see original document page 15 </formula>

wherein R1 is C1 -C4 alkyl, R2 is hydrogen or methyl, and an integer from 1 to 5;

b) optionally contacting the mixture with at least one monomer and optionally polymerizing the monomer (s) to form a rubber precursor, and / or at least one rubber precursor;

c) contacting at least one coupling agent with the mixture and modifying the oxygen-containing inorganic particulate material at least partially;

d) optionally contacting at least one monomer with resulting mixture and polymerizing the monomer (s) to form a rubber precursor, or contacting at least one rubber precursor with the resulting mixture;

e) optionally curing the rubber precursor (s); and where optionally water and / or alkoxylated alcohol are partially removed from the mixture before, during or after any of the preceding steps. In a particular embodiment water is removed prior to step b) and / or step d).

The process of the invention provides a modified inorganic oxygen-containing particulate material which has good resin compatibility. Due to the good compatibility of the solvent with water, the particulate material, and the rubber precursor and / or monomers, it is possible to obtain a stable dispersion of the modified particulate material in the rubber precursor. Another advantage of the process of the invention is that the process generally requires fewer steps and less solvent, enabling a higher yield of inorganic particulate matter per unit volume, making the process more efficient than conventional processes for making modified particulate matter. The use of alkoxylated alcohol causes a more efficient removal of water from the mixture comprising inorganic particulate matter containing oxygen, alkoxylated alcohol, and water. The alkoxylated alcohol also has the advantage of being compatible with most rubber precursors, making it unnecessary to use other solvents in which the resin dissolves (more) easily. Consequently, the process of the invention in general is simpler, more economically attractive, and more environmentally friendly than conventional processes.

In the process of the invention, water, in particular water originating from the aqueous suspension, and / or the first and second solvents may be removed at any time during the process. In one embodiment, water, the first and / or second solvents are removed prior to the curing step to prevent water or solvent from being trapped within the rubber. Removal may be accomplished by any method known in the art, such as evacuation, distillation, evacuation combined distillation, and the use of a membrane, for example, an ultrafiltration membrane, which is capable of selectively removing water from the mixture.

In certain applications the presence of water may cause undesirable deterioration of the rubber precursor or monomers thereof; in such applications the amount of water in the mixture of step a) - if the monomers / or rubber precursor used in step b) are water sensitive - or c) is generally reduced to less than 5 weight percent (weight%) based on the total weight of the resulting mixture in step a) or c), preferably less than 2 wt%, and more preferably less than 1 wt% water.

In another preferred embodiment of the present invention, an aqueous suspension of oxygen-containing inorganic particulate material is used, and in particular an aqueous silica, which is deionized. "Deionized" means that any free ions such as anions such as Cl "and cations such as Mg2 + and Ca2 + are removed from the aqueous suspension to a desirable concentration using techniques known to the skilled artisan, such as ion exchange techniques." Free ions "refers to The ions are dissolved in the solvents and can migrate freely through the mixture.The amount of free ions is typically less than 10,000 ppm, preferably less than 1,000 ppm, and more preferably less than 500 ppm.

The present invention further relates to a process for preparing a rubber precursor or rubber composition comprising the steps of:

a) preparing a mixture of an aqueous suspension of oxygen-containing inorganic particulate matter and a first solvent;

b) adding at least one monomer or a boron precursor, wherein at least one monomer is a coupling agent;

c) polymerize the monomer (s) to form a rubber precursor;

d) optionally curing the rubber precursor; and where optionally water and / or the first solvent are removed at least partially from the mixture before, during or after any of the preceding steps.

The first solvent may be any solvent compatible with water and the modified particulate material, that is, in which the particulate material is well dispersed as distinct and unaggregated particles, as well as with the rubber precursor, its monomers and / or the resulting rubber composition. Preferably, the solvent is an alcohol such as methanol, ethanol, isopropanol, and n-butanol, or an alkoxylated alcohol as defined above. The most preferred solvent is alkoxylated alcohol.

The advantage of this process is that it allows modification of oxygen-containing inorganic particulate matter and the preparation of the rubber precursor in one step. It is noted that polymerization of the monomers in general requires initiation, for example, using an initiator such as a peroxide, or using a catalyst. This enables modification of the particulate material before polymerization is initiated. Alternatively, modification and polymerization may occur simultaneously.

In a preferred embodiment of this process, the monomer which also acts as a coupling agent comprises a first functional group reactive with the particulate material and a second functional group reactive with the monomer (s) and / or rubber precursor. The detailed use of the monomer causes the particulate material to be chemically bonded to the rubber precursor.

In the context of the present invention the term "aqueous suspension of oxygen-containing inorganic particulate material" refers to a suspension in which at least part of the solid particles of oxygen-containing inorganic particulate material having a size between 1 and 1,000 nm in at least least one direction are dispersed in an aqueous medium.

The invention further relates to rubber compositions comprising rubber and oxygen-containing inorganic particulate material modified with a coupling agent wherein the oxygen-containing inorganic particulate material is between 1 and 1,000 nm in at least one direction. The advantage of the inventive rubber compositions is that they have greater durometer hardness and tensile strength, and greater elongation and modulus, and greater tear strength over conventional silicones comprising modified particulate material.

These properties are even better if the oxygen containing particulate material is modified with a coupling agent comprising a first functional group reactive with the particulate material and a second functional group reactive with rubber or the rubber precursor.

Generally, the amount of modified particulate material present in the rubber composition of the present invention ranges from 0.1 to 60% by weight, based on the total weight of the rubber composition, preferably from 0.5 to 50%. by weight, and most preferably, ranges from 1 to 30% by weight. It is noted that with respect to conventional rubber compositions, the rubber composition of the present invention generally requires less modified particulate material to have similar mechanical properties.

The invention also relates to a plastic transformation obtainable by any of the aforementioned processes comprising rubber precursor and an oxygen-containing inorganic particulate material having a size between 1 and 1,000 nm in at least one direction, which particulate material It is modified with a coupling agent, where the amount of particulate material ranges from 5 to 80% by weight, based on the total weight of the plastic transformation, and the amount of rubber precursor ranges from 20 to 95% by weight.

Preferably, the amount of particulate material ranges from 15 to 75% by weight, based on the total weight of the plastic transformation, and the amount of rubber precursor ranges from 25 to 85% by weight.

mixtures of highly concentrated additives that may be used in the preparation of rubber compositions. Such master batches are contacted with at least one rubber precursor which does not contain the modified particulate material of the invention to form the rubber composition of the invention. The advantage of plastic transformation is that it can be prepared at one location, transported to another location, and used to prepare the final rubber composition.

A preferred embodiment of the plastic transformation comprises a coupling agent-modified particulate material comprising a functional group reactive with the particulate material and an organic group reactive with the rubber or the rubber precursor.

The rubber compositions of the present invention may be suitably applied in tire manufacturing, such as car tires including winter tires, truck tires, mountain tires, and airplane tires, in latex products including gloves, preservatives rubber coated balloons, catheters, latex wires, foam, carpet liners, and co-co and hair fiber, in footwear, in civil engineering products such as bridge supports, laminated metal supports and rubber, belts and hoses, in different automotive applications including motor mounts, rubber bearings, seals, insulating rings, washers, and housings, on wire and cable, in tube seals, medical closures , cylinders, small solid tires, holders for home and commercial appliances, rubber balls and tubing, supplemental padding, and other agricultural applications.

In one embodiment of the invention the modified inorganic oxygen-containing particulate material is used in a tire rubber composition, in particular car tires. The rubber in the rubber composition may be any rubber conventionally used in tires. Examples of such rubbers are natural rubber, non-crosslinked styrene-butadiene rubber, cross-linked styrene-butadiene rubber, butadiene rubber, vinyl butadiene rubber, and synthetic rubber. Mixtures of these rubbers are also commonly used.

The rubber composition according to the invention may be used on any part of the tire where an inorganic filler such as carbon black or precipitated silica is conventionally used. In particular, the rubber composition may be used at the base of the tread subband or tread, the tread, the sidewall, the rim bandage, the inner layer, the carcass, the trim, and in straightness. It is also envisaged to use a combination of the modified particulate material of the invention and a conventional inorganic filler such as carbon black or precipitated silica. The use of modified particulate material allows a reduction in the total amount of inorganic filler in the rubber composition while maintaining similar or improved mechanical properties.

In a preferred embodiment, the inorganic modified oxygen-containing particulate material is modified with a coupling agent comprising a vulcanizable group. Such a coupling agent may be a silane-type coupling agent such as bis (3-triethoxysilylpropyl) tetrasulfide (Si69® ex Degussa), bis (3-triethoxysilylpropyl) disulfide, gamma-mercaptopropyl trimethoxysilane (SiSiB® PC2300 ex PCC), and -octanoylthio-1-propyl triethoxysilane (NXT® ex GE).

The advantage of these modified particulate materials is that the time required to produce a green tire can be reduced. In addition, the dimensional stability of the uncured tire as well as the pneufinal will be better.

In conventional processes, precipitated silica is added to the rubber along with a coupling agent such as bis (3-triethoxysilylpropyl) tetrasulfide, the rubber composition is allowed to react at high temperatures, the ethanol produced is removed, and a tire is obtained. uncured, which is then cured at a higher temperature to cause vulcanization and to form the tire. The use of invention modified particulate materials, in particular coupling agent modified particulate materials having a vulcanizable group, in the production of tires has the advantage that the coupling agent is already attached to the particulate material and does not form ethanol, causing a reduction in processing time that can increase the production rate of green tires. If a combination of modified particulate material and conventional filler such as precipitated silica is used, a coupling agent may be separately added to the mixture so that it can react with precipitated asylum; The amount of coupling agent is generally less than the amount used in conventional processes. The modified particulate material may be added to the rubber as a (colloidal) suspension in a suitable solvent (containing no water or almost no water), or may be added in a diluent oil, or as solids. In the case of a diluent oil or solids, it is not necessary to remove the solvent, leading to further reduction in processing time and increased process safety.

If the rubber composition is a silicon composition comprising silicone rubber and the modified particulate material according to the present invention, such as rubber composition may suitably be applied to coating products including pressure aids, direct plastic coatings, coatings paper coating, fiber finishing applications including textile and hair care applications, seals, adhesives, encapsulants, solar cell units.

The invention further relates to the use of the rubber composition according to the invention in solar cell units. In a preferred embodiment, the rubber of the rubber composition is a transparent rubber. Transparent eraser is an eraser that is transparent to visible light. Examples of such transparent rubbers are polyurethane, ethylene vinyl acetate rubber, and silicone rubber. Preferably, the transparent rubber is a silicone rubber. The solar cell unit may be any solar cell unit known in the art. Examples of such solar cell units are crystalline Si solar cells, amorphous silicon solar cells, crystalline silicon thin-film solar cells, and compound semiconductor cells based, for example, on CdTe, Culn-Se2, Cu (ln, Ga ) (Se, S) 2 (the so-called CIGS), and Gratzel cells. Further details can be found in F. Pfisterer ("Photovoltaic Cells", Chap-er 4: "Types of Photovoltaic Cells," Ullmann's Encyclopedia of Industrial Technology, published date June 15, 2000).

The rubber composition used in solar cell units can serve to connect two juxtaposed layers in the unit. The advantage of the rubber composition of the present invention is its transparency to visible light, which allows its application in the position where light passes through rubber composition before light reaches the cell part where light is converted into electrical energy. The rubber composition may also serve to connect the solar cell unit to a substrate, for example a plate or a roof tile. In such cases the rubber composition need not be transparent. Generally, the rubber composition has improved mechanical properties over conventional rubber compositions.

One embodiment of the present invention relates to a solar cell unit comprising a rear electrode, a photovoltaic layer, a front electrode, and a transparent upper layer where a layer of the rubber composition of the invention is present between the front electrode and the transparent top layer. As indicated above, the rubber of the rubber composition is preferably a transparent rubber, and more preferably the rubber is a silicone rubber. Rubber backing serves as an adhesive layer or as a bonding layer for the transparent upper layer and the front electrode. Due to the above improved improved mechanical properties, increased adhesion power and tear strength of the rubber composition and the solar cell unit (in use) is better able to withstand the influences of weather or other mechanical forces to which it may be exposed. Consequently, the life span of the solar cell unit is increased. In addition, the rubber composition of the invention is transparent to visible light, which results in higher light output and greater solar energy recovery over solar cell units comprising the rubber composition with particle sizes within wavelength range. visible light or greater than these, ie between 400 and 800 nm.

Solar cell units comprising a back electrode, a photovoltaic layer, a front electrode, and a transparent top layer are known to the person skilled in the art. Generally, the rear electrode, a photovoltaic layer, a front electrode, and a transparent upper layer are provided in layers on top of each other. A more detailed description of such solar cell units can be found in EP 1 397 837 and EP 1 290 736, whose specific descriptions of the rear electrode, photovoltaic layer, lead electrode and transparent upper layer are incorporated herein. reference it.

The invention is illustrated by the following examples.

EXAMPLESExample 1

In a 3-neck three-neck round bottom flask equipped with a mechanical stirrer, thermometer, and distillation unit were introduced 647.0 grams of Nyacol 2034DI (ex Akzo Nobel) containing 222.56 grams. of silica, and 970.5 grams of Ethyl Proxitol (ex Shell). The temperature was increased to 38 ° C and the pressure was reduced to 60mbar to distill a water / solvent mixture. Over a period of 3 hours the pressure was slowly reduced to 4 KPa (40 mbar). Then the reaction was stopped, resulting in an organosol with a water content of 2.4% by weight determined by the Karl Fisher method. The solids content was 30.7% by weight of nanosilica (determined in an oven at 140 ° C until no further solvent loss was observed).

In a 250 ml four-neck round-bottomed flask equipped with a mechanical stirrer, a dropper funnel, a reflux condenser, and a thermometer, 131.51 grams of the organosolid Example 1 containing 40.4 grams of modified nanosilica. The temperature was increased to 110 ° C and then a mixture of 19.08 grams (0.129 mol) of vinyl trimethoxy silane (ex Aldrich), 8.35 grams (0.46 mol) of water, 0.1 gram of Nyacol 2034DI, and 38.16 grams of Ethyl Proxitol were added over a period of 100 minutes.

The temperature was then raised to 130 ° C to remove the distillation volatiles resulting from silane and a portion of the solvent. The remaining solution contained 36.35% by weight of modified nanosilica (determined in an oven at 140 ° C until no further solvent loss was observed).

Example 3

The silicone resin used in this Example was Wacker S-LM61211 # 268, a two-component Pt-cured silicone resin (ex Wacker) consisting of one component A, which does not contain the Pt-based catalyst, and one component. B containing the Pt-based catalyst. The organosol of Example 1 was added to component A in varying amounts, namely 1 wt.%, 2 wt.% And 5 wt.% Based on the total weight of the AeB components. . Subsequently, component A was mixed with component B, followed by deaeration in a vacuum oven at room temperature.

Two sheets made of ethylene tetrafluoroethylene copolymer (ETFE; surface modified ETFE ex Asahi) were adhered together using the modified silicone resin. The modified silicone resin was then cured in a Bürkle press for 20 minutes at 120 ° C using 2.5 MPa (2.5 bar) pressure.

As reference, an unmodified silicone produced in the manner described above was used, except that the organosol of Example 2 was not added to component A.

The adhesion and strength of silicone rubbers were determined in 10x1 cm2 samples using a CECO, CopperClad Peeltester TA630.

In all cases a cohesive break in the silicone resin resulted, but no failure in the ETFE silicone interface was observed. The peel strengths resulting from the different silicone rubber samples are shown in Table below.

<table> table see original document page 126 </column> </row> <table>

From the above results it can be concluded that the addition of the orgasosol of example 2 results in an increase in strength.

Claims (10)

A process for preparing a rubber precursor or rubber composition comprising an inorganic modified oxygen-containing particulate material comprising the steps of: a) preparing a mixture of the modified oxygen-containing inorganic particulate material and a first solvent; and b1) contacting the mixture with a rubber precursor comprising at least one polymer and optionally a second solvent, or b2) contacting the mixture with a monomer composition comprising at least one monomer and optionally a second solvent, and polymerizing the monomer (s). s) to form the rubber precursor c) optionally cross-linking the rubber precursor in the presence of a crosslinking agent to form a rubber composition; and d) optionally removing the first and / or second solvents during or after any of steps b1), b2), and c). A process according to claim 1 wherein the first second solvents are alkoxylated alcohols according to the formula wherein R 1 is a C 1 -C 4 alkyl, R 2 is hydrogen or methyl. , and η is an integer from 1 to 5. A process for preparing a rubber precursor or rubber composition comprising the steps of: a) preparing a mixture of an aqueous suspension of oxygen-containing inorganic particulate matter and an alkoxylated alcohol according to the formula <formula> formula see original document page 28 < wherein R1 is a C1 -C4 alkyl, R2 is hydrogen or methyl, and η is an integer from 1 to 5. b) optionally contacting the mixture with at least one moiety and optionally polymerizing the monomer (s) to form the rubber precursor, and / or with at least one rubber precursor, c) contacting at least one coupling agent with the mixture and modifying the oxygen-containing inorganic particulate material at least partially; optionally contacting at least one monomer with resulting mixture and polymerizing the monomer (s) to form a rubber precursor, or contacting at least one rubber precursor with the resulting mixture; rubber sores; and where optionally water and / or alkoxylated alcohol are at least partially removed from the mixture during or after any of steps c) to e). A process for preparing a rubber precursor or rubber composition comprising the steps of: a) preparing a mixture of an aqueous suspension of oxygen-containing inorganic particulate material and a first solvent, b) contacting the mixture with at least one monomer, where at least a monomer is a coupling agent c) polymerize the monomer to form a rubber precursor d) optionally cure the rubber precursor; and where optionally water and / or alkoxylated alcohol are removed at least partially from the mixture during or after any of the steps c) to d). Rubber composition obtainable by a process as defined in any one of the preceding claims, comprising rubber and a modified oxygen-containing inorganic particulate material with a coupling agent, wherein the inorganic oxygen-containing particulate material is between 1 and 1,000 nm in size. least one direction. Rubber composition according to claim 5, wherein the coupling agent comprises a reactive functional group as particulate material and a rubber-reactive organic group or common rubber precursor. A plastic transformation obtainable by a process as defined in any one of claims 1-4, comprising a rubber precursor and an inorganic oxygen-containing particulate material having a size between 1 and 1,000 nm in at least one direction, particulate material. This stock is modified with a coupling agent wherein the amount of particulate material ranges from 5 to 80% by weight, based on the total weight of the plastic transformation, and the amount of rubber precursor ranges from 20 to 95% by weight. Plastic transformation according to claim 7, wherein the coupling agent comprises a functional group reactive with the particulate material and an organic group reactive with the rubber or the rubber precursor. A solar cell unit comprising a layered structure comprising a back electrode, a photovoltaic layer, a front electrode, and a transparent upper layer where a layer of the rubber composition as defined in any of claims 5-6; It is present between the front electrode and the transparent upper layer, where the rubber is a transparent rubber composition, preferably a silicone rubber. Use of the rubber composition as defined in any one of claims 5 and 6, in solar cell units, the rubber preferably being a silicone rubber.