JP2011016715A - Specialized silica, rubber composition containing specialized silica and product with component thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide specialized silica which when mixed as a reinforcing filler of a rubber composition, does not cause a viscosity increase of a rubber mixture by sulfur, rubber compositions containing the silica, particularly sulfur-cured rubber compositions, and articles of manufacture having a component of the rubber composition.SOLUTION: There is provided allyl-functionalized precipitated silica containing a substituent of at least one allyl group defined by a specific formula and having (A) a BET nitrogen surface area within a range of 120-300 m/g, (B) a CTAB surface area within a range of 100-300 m/g, and (C) a ratio of the BET/CTAB surface area within a range of 0.8-1.3.

Description

  This application claims priority based on US Provisional Patent Application No. 61 / 223,434, filed July 7, 2009.

FIELD OF THE INVENTION The present invention relates to allyl functionalized precipitated silica, rubber compositions containing such silica, in particular sulfur cured rubber compositions, and products having members of the rubber composition, such as tires. The invention particularly relates to synthetic amorphous silicas treated with allylsilane, in particular precipitated silicas, in particular precipitated silicas containing allyl functional groups.

  Rubber compositions are often reinforced with a reinforcing filler such as at least one of rubber reinforced carbon black and synthetic amorphous silica (eg, precipitated silica).

  Various products contain at least one member comprised of such a rubber composition. For example, a tire.

  In order to enhance the rubber reinforcing effect of precipitated silica, a coupling agent is typically used in combination with precipitated silica.

  Such coupling agents are typically elastomers (eg, diene based elastomers) that contain moieties (eg, alkoxysilane groups) that react with hydroxyl groups (eg, silanol groups) on precipitated silica and carbon-carbon double bonds. ) And other different moieties that interact with (eg, polysulfide as the part where sulfur acts).

  A typical disadvantage of such polysulfide moieties of silica coupling agents is their sulfur action on the uncured rubber composition at high temperatures. For example, during physical mixing of an uncured rubber composition, it interacts with the carbon-carbon double bonds of the elastomer in the rubber composition to promote a significant increase in the viscosity of the rubber composition, so that Increased difficulty or challenges. Such a phenomenon is well known to those skilled in the art.

For the present invention, BET nitrogen surface areas in the range of 120~300m ² / g; with CTAB surface area in the range of 100 to 300 m ² / g, the ratio of BET / CTAB surface area such range of 0.8 to 1.3 Rubber-reinforced precipitated silica, which can usually be characterized as having the properties typical of synthetic precipitated silica used for reinforcing rubber compositions, is used.

  The BET nitrogen surface area can be measured according to ASTM D1993 or equivalent and the CTAB surface area according to DIN 53535.

Significance of providing a precipitated silica having a BET / CTAB ratio required for the rubber reinforcing purposes, for example 120~300m with CTAB surface area of BET surface area and for example 100 to 300 m ² / g of ² / g, for example 0. Illustrated in the patent literature as values in the range of 8 to 1.3. See, for example, US Patent Application No. 2008/0293871, US Pat. No. 6,013,234 and European Patent Publication No. 0901986.

  The DBP absorption value (or absorption coefficient) can be measured according to DIN 53601 or equivalent standard.

In one embodiment, such precipitated silica could be characterized by, for example, mercury porosimeter parameters. For example, a surface area in the range of 100-240 m ² / g and a pore size distribution maximum in the range of 20-75 nm (nanometers) as measured by a CARLO-ERBA porosimeter 2000 or equivalent device.

  In the present case, it has been found that allyl functionalized rubber reinforced precipitated silica can be used as a silica reinforcing agent for rubber compositions. Such allyl functionalized silica does not contain a polysulfide moiety so that sulfur is not available for premature interaction with the elastomer in the rubber composition. When the allyl functionalized precipitated silica is formed, for example, by treating the precipitated silica with allyltrialkoxysilane or allylhalosilane, the alkoxysilane portion of the allylalkoxysilane or the halogen portion of the allylhalosilane is, for example, that of the precipitated silica. It is envisaged to react with hydroxyl groups (eg silanol groups) and / or hydrogen groups. This results in the treated silica containing allyl hydrocarbon groups, which are diene elastomers (polymerization of monomers containing diene hydrocarbons) in the presence of a sulfur curing agent during subsequent vulcanization of the rubber composition. And thus the silica and the diene elastomer are coupled.

  Further, if desired, the allyl-functionalized silica can be beneficially mixed with the elastomer at a relatively high temperature without adding sulfur and the sulfur cure accelerator to the rubber mixture without increasing the viscosity of the rubber mixture with sulfur. Is also envisaged. Such high temperature mixing of the rubber composition is believed to provide an opportunity for more efficient mixing of the rubber composition with shorter mixing times.

  In addition, the presence of allyl functionality on the surface of the silica (eg, precipitated silica) will provide some degree of hydrophobicity to the silica surface, thereby enhancing or improving the dispersion of the silica within the rubber mixture, resulting in silica. It is also conceivable that the reinforcement of the rubber composition is enhanced or improved.

  Representative examples of various allylsilanes for producing allyl functionalized silica are, for example, allyltriethoxysilane, allyltrimethoxysilane, allyldimethylchlorosilane, allyltrichlorosilane, allylmethyldichlorosilane, diallylchloromethylsilane, diallyldichlorosilane. And triallylchlorosilane.

  In the description of the present invention, the term “phr” refers to parts by weight of material or component per 100 parts by weight of elastomer. The terms “rubber” and “elastomer” are used interchangeably unless otherwise specified. The terms “curing” and “vulcanization” are also used interchangeably unless otherwise noted.

US Patent Application No. 2008/0293371 US Pat. No. 6,013,234 European Patent Publication No. 0901986

SUMMARY OF THE INVENTION AND MODE FOR CARRYING OUT THE INVENTION

  In accordance with the present invention, allylsilane treated (modified) synthetic amorphous silica (precipitated silica) is provided. This may also be referred to herein as allyl functionalized precipitated silica.

  Such allyl functional precipitated silica is provided by treating synthetic amorphous silica (precipitated silica) with at least one allylsilane.

In the case of the present invention, an allyl functional precipitated silica comprising precipitated silica containing at least one allylic substituent is provided. Here, the precipitated silica is
(A) BET nitrogen surface area in the range of 120-300 m ² / g,
(B) with a CTAB surface area in the range of 100-300 m ² / g, and (C) a ratio of the BET / CTAB surface area in the range of 0.8-1.3, wherein the allyl-functionalized precipitated silica has the general formula (I):

[Wherein Z represents precipitated silica; R ² and R ³ are alkyl groups containing 1 to 4 carbon atoms, cycloalkyl groups, phenyl groups, and alkenes containing 3 to 18 carbon atoms. Or the same or different group comprising a cycloalkene group having 5 to 8 carbon atoms; and R ¹ is an allyl hydrogen-containing hydrocarbon group, preferably the allyl-containing hydrocarbon group is
-CH ₂ -CH = CH ₂ (allyl hydrocarbon radical),
_{-CH 2 -CH = CH-CH 3} (2- butene group),
_{-CH 2 -CH = C- (CH 3} ) 2 ( dimethallyl hydrocarbon radical) and _{-CH 2 -C (CH 3) =} CH-CH 3 (2- methyl-2-butene group)
Including at least one of
Wherein a is an integer in the range of 0-2, b is an integer in the range of 0-2, and c is an integer in the range of 1-3.

In one embodiment, the precipitated silica is, for example,
(A) A surface area in the range of 100 to 240 m ² / g, and (B) a mercury porosimeter parameter of a maximum pore size distribution in the range of 20 to 75 nm.

  Indeed, the allyl-functionalized precipitated silica can be in the form of aggregates of its fused primary particles, with an average aggregate size ranging from, for example, about 0.8 to about 1.2 microns.

  Further in accordance with the invention, the allylsilane has the general formula (II):

[Wherein R ² and R ³ are the same or different and each represents an alkoxy group containing 1 to 8 carbon atoms, a cycloalkoxy group containing 5 to 8 carbon atoms, or 1 to 4 carbon atoms. Containing alkyl groups, cyclohexyl groups, phenyl groups, alkenes containing 3 to 18 carbon atoms, or cycloalkenes having 5 to 8 carbon atoms;
Where X is chlorine, hydroxy, or hydrogen;
In the formula, R ¹ is an allyl hydrogen-containing hydrocarbon group, and preferably, the allyl hydrogen-containing hydrocarbon group is
-CH ₂ -CH = CH ₂ (allyl hydrocarbon radical),
_{-CH 2 -CH = CH-CH 3} (2- butene group),
_{-CH 2 -CH = C- (CH 3} ) 2 ( dimethylallyl hydrocarbon group) and _{-CH 2 -C (CH 3) =} CH-CH 3 (2- methyl-2-butene group)
Including at least one of
Where a is an integer in the range of 0-3, b is an integer in the range of 0-3, c is an integer in the range of 1-3, and d is an integer in the range of 0-3. And the sum of a, b, c and d is 4;
At least one of said X, R ² and R ³ is present;
When d = 0, at least one of R ² and R ³ is an alkoxy group].

In the case of allyl functionalized precipitated silica, R ² and R ³ of the allyl silane are the same or different,
(A) an alkoxy group containing an ethoxy or methoxy group,
(B) a cycloalkoxy group,
(C) an alkyl group containing a methyl, ethyl or propyl group,
(D) a cycloalkyl group,
It is considered that it can be selected from at least one of (E) a phenyl group and (F) an allyl hydrogen-containing alkene group. Such alkene groups desirably include allyl, 2-butenedimethylallyl or 2-methyl-2-butane groups.

  Representative examples of the allyl-functionalized silane for functionalizing precipitated silica include, for example, allyltriethoxysilane, allylalkoxysilane containing at least one of allyltrimethoxysilane, and allyldimethylchlorosilane, allyltrichlorosilane, allylmethyl. An allylhalosilane containing at least one of dichlorosilane, diallylchloromethylsilane, and diallyldichlorosilane. A preferred allyl functionalized silane is allyltrichlorosilane.

  Further in accordance with the present invention, a rubber composition comprising a reinforcing filler comprising said allyl functionalized precipitated silica, and further comprising at least one of rubber reinforced carbon black and an additional precipitated silica not containing allyl functional groups Offer things. Such a rubber composition may further contain at least one silica coupling agent for assisting the coupling of the precipitated silica to the elastomer contained in the rubber composition. Indeed, the coupling agent has a portion that reacts with hydroxyl groups (eg silanol groups) on the silica and another different portion that interacts with the elastomer contained in the rubber composition.

For example, based on 100 parts by weight of rubber per part by weight (phr),
(A) 100 phr of at least one conjugated diene elastomer;
(B) about 10 to about 120, or about 40 to about 100 phr of reinforcing filler, wherein said reinforcing filler is
(1) about 40 to about 100, alternatively about 50 to about 80 phr of allyl functionalized precipitated silica (allyl silane treated precipitated silica);
(2) 0 to about 60, or about 3 to about 30 phr rubber reinforced carbon black, and (3) optionally precipitated silica up to about 70 phr (other than allyl functionalized precipitated silica).
And a reinforcing filler containing the rubber composition.

While various methods for preparing allylsilane functionalized precipitated silica are contemplated during the preparation of precipitated silica, one method envisioned is for rubber reinforcement purposes based on the method described in US Pat. No. 5,723,529. Relates to the manufacture of precipitated silica for The method
(A) reacting at least two inorganic materials with a strong base in the presence of water to form an aqueous solution of the product;
Here, based on 100 parts by weight of the inorganic material,
(1) 60-99.9 parts of silicon dioxide, and (2) 0.1-40 parts of at least one additional inorganic material capable of forming the aqueous solution, the inorganic material comprising:
(A) oxides of aluminum, iron, magnesium, boron, titanium, zirconium, zinc, vanadium and niobium,
(B) a phosphate, sulfate and halide salt of aluminum, iron, magnesium, boron, titanium, zirconium, zinc, vanadium and niobium, and (c) at least one selected from natural and synthetic aluminum silicates That;
(B) The aqueous solution is treated with the addition of a mineral acid to react with the product to form the reaction product, and the precipitated particles of the reaction product are produced as a precipitate by lowering the pH of the solution. Let;
(C) If desired, interrupting the acid addition of step (B) to the aqueous solution and aging the precipitate for a while, then restarting the acid addition and then further until the desired pH is reached. To complete the reaction and precipitation of the reaction product;
(D) if desired, after completion of the acid addition of step (B) and / or step (C) if used, the precipitate is aged for a while;
(E) filtering and washing the precipitate, drying the precipitate and collecting the particles in the form of their aggregates;
(F) Step (B) selected from at least one of carbonate, silicate, aluminate, borate, aluminosilicate, phosphate, sulfate, halide, titanate and zirconate ), An anion in any one of (C) and (D), and at least one electrolyte having a cation selected from at least one of lithium, sodium, potassium, magnesium and / or calcium;
(G) treating the precipitate with at least one ionic and / or nonionic surfactant; and (F) converting at least one of the allylsilanes (as described herein above) to (C) , (B), (D) and (E) may be added during or after any of the steps. Therefore, preferably, the allylsilane is
CH ₂ -CH = CH ₂ (aryl hydrocarbon),
_{CH 2 -CH = CH-CH 3} (2- butene),
_{CH 2 -CH = C- (CH 3} ) 2 ( dimethylallyl hydrocarbons) and _{CH 2 -C (CH 3) =} CH-CH 3 (2- methyl-2-butene)
Including at least one of

  Indeed, the allyl functionalized precipitated silica may be formed by pretreating precipitated silica with the allyl silane before adding it to the rubber composition, or the precipitated silica and the allyl silane are individually rubber compositions. It may be processed in situ within the rubber composition by adding it.

  Furthermore, according to the present invention, there is provided a product such as a tire having at least one member containing the rubber composition. Such a tire member can be, for example, at least one of a tire sidewall, a tire sidewall insert, a tire sidewall apex, a ply coating, a wire coating, and a tread.

  From a historical point of view, according to U.S. Pat. Nos. 5,708,069, 7,550,610 and 5,789,514, silica gels are, for example, silica hydrogels such as organomercaptosilanes and alkylsilanes. It can be derived by making it hydrophobic and drying the product. The resulting hydrophobized silica gel can be blended with natural rubber and / or synthetic rubber.

A general description of silica gel and precipitated silica can be found, for example, in Encyclopedia of Chemical Technology , 4th edition (1997), Volume 21, Kirk-Othmer, pages 1020-1023.

Although the silica gel is in the form of precipitated silica, the present invention relates to a BET surface area of 10 to 130 m ² / g and 10 to 10 as presented and described in European Patent Publication EP 0 634 015 and US Patent Application Publication No. 2008/0293971. It has been shown to be useful as a polishing and / or thickening component in toothpaste (rather than a suitable rubber reinforcement) having a BET to CTAB surface area ratio of about 1 to 5.2 with a CTAB surface area of 70 m ² / g. Not intended to be significantly different from the precipitated silicas described above, but in the sense that it also has its narrow required ratios in the range of 0.8 to 1.3 along with the required BET and CTAB surface area characteristics described above. is doing.

  A rubber composition is commonly referred to as a “non-productive” mixing step (or stage) in which other rubber compounding components other than diene rubber, carbon black, and sulfur rubber curatives are heated to high shear rubber mixing conditions. Mix in at least one sequential mixing step using at least one mechanical mixer, then in the final mixing step (or stage), add a sulfur-based curing agent, such as sulfur and a sulfur curing accelerator, and rubber during the mixing stage Often manufactured by mixing at a low mixing temperature so that the mixture does not unnecessarily prematurely cure. The terms “non-productive” and “productive” mixing stages are well known to those in the rubber mixing art.

  It should be understood that the rubber composition is typically cooled to a temperature of less than about 40 ° C. between the aforementioned mixing steps.

  The sulfur vulcanizable elastomer may comprise, for example, at least one of at least one polymer of isoprene and 1,3-butadiene and a copolymer of styrene and at least one of isoprene and 1,3-butadiene.

If desired, at least one of the sulfur vulcanizable elastomers is
(A) a coupled elastomer comprising at least one polymer of isoprene and 1,3-butadiene and a copolymer of styrene and at least one of isoprene and 1,3-butadiene, wherein the coupled elastomer is tin And / or at least one functionalized of a styrene / butadiene copolymer elastomer (SBR), a cis 1,4-polybutadiene elastomer and a cis 1,4-polyisoprene elastomer. An elastomer; wherein the functionalized elastomer is
(1) an amine functional group that reacts with the allyl functionalized precipitated silica, or (2) a siloxy functional group that reacts with the rubber reinforcement of the allyl functionalized precipitated silica filler, or (3) reacts with the allyl functionalized silica. A combination of amine and siloxy functional groups, or (4) a silane / thiol functional group that reacts with the allyl functionalized silica, or (5) a hydroxyl functional group that reacts with the allyl functionalized precipitated silica, or (6) the allyl An epoxy group that reacts with the functionalized precipitated silica, or (7) contains a functional group that includes a carboxyl group that reacts with the allyl functionalized precipitated silica,
Can be included.

FIG. 1 is a graph plotting torque at a constant temperature of 150 ° C. against time in minutes.

  The following examples are provided to further illustrate the present invention. In the examples, the amounts and percentages of materials are by weight unless otherwise specified.

Example I
Preparation of Allyl Functionalized Precipitated Silica Precipitated silica (agglomerated synthetic amorphous silica aggregates) was obtained as a product of Rhodia, Zeosil® 1165MP (Micropearl).

  The agglomerated form of precipitated silica was placed in a high speed blender for 3 minutes and then crushed into a lower density precipitated silica aggregate form (ie, somewhat agglomerated).

  The crushed silica agglomerated silica aggregate is referred to as silica A in this specification.

(A) Treatment with allyltrichlorosilane 30 grams of precipitated silica aggregate was placed in a round bottom flask equipped with a Dean-Stoke trap with dry toluene.

  The silica / toluene suspension was heated and refluxed in a flask and a water / toluene mixture containing about 1.65 ml of water was recovered by azeotropic distillation (removed from the reflux suspension). The recovered (removed) water / mixture contained about 5.5 weight percent of the original silica.

  To the remaining silica / toluene mixture, 2.6 grams of allyltrichlorosilane was added dropwise to the reflux suspension in the flask. When allyltrichlorosilane was added, the suspension became less viscous and clearer, indicating that it was in solution formation. The solution was stirred under reflux conditions for 2 hours, then cooled and filtered to obtain treated (allyl functionalized) precipitated silica.

  The recovered treated (allyl functionalized) precipitated silica is referred to herein as silica B.

(B) Treatment with allylchlorodimethylsilane 30 grams of precipitated silica agglomerates were similarly treated with 1.19 grams of allylchlorodimethylsilane.

  The recovered treated (allyl functionalized) precipitated silica is referred to herein as silica C.

(C) Treatment with allyltriethoxysilane 30 grams of precipitated silica agglomerates were similarly treated with 1.82 grams of allyltriethoxysilane.

  The recovered treated (allyl functionalized) precipitated silica is referred to herein as silica D.

(D) Treatment with N-propyltriethoxysilane (not allylalkoxysilane) 30 grams of precipitated silica aggregates were similarly treated with 1.83 grams of N-propyltriethoxysilane.

  The recovered treated precipitated silica is referred to as silica E in this specification.

Example II
Evaluation of Pretreated Precipitated Silica The treated sample of precipitated silica of Example I was evaluated in a rubber composition. Table A below shows a general rubber compounding table. Parts and percentages are by weight unless otherwise specified.

  A sample of the rubber composition is obtained by mixing the components in a closed rubber mixer with two separate sequential mixing stages or steps, a first non-productive mixing stage (NP) that is relatively hot, followed by significantly lower mixing. Produced by blending using a second productive mixing stage (PR) where the temperature is reduced to the sulfur, sulfur cure accelerator and zinc oxide are added. Such rubber mixing procedures are well known to those skilled in the art.

  For the non-productive mixing stage (NP), mixing the ingredients for about 4 minutes results in a drop temperature of about 150 ° C., which is self-generated by high shear mixing in a closed rubber mixer. At this point, the batch is “dropped” or removed from the associated closed rubber mixer. The batch is stretched into sheets and allowed to cool to a temperature below 40 ° C. The batch is then mixed in a productive mixing stage (PR). During this time, free sulfur, vulcanization accelerator and zinc oxide are added and mixed for about 2 minutes, resulting in a drop temperature of about 110 ° C.

  The curing behavior of each sample and various physical properties after curing are shown in Table 1 below. For the cured rubber samples, the samples were individually cured for about 30 minutes at a temperature of about 150 ° C.

  The rubber samples are distinguished from control rubber sample A and experimental rubber samples B, C, D and E.

  From Table 1, both 100 percent and 300 percent modulus values used propylsilane treated silica E for rubber samples B, C and D using allylsilane treated (allyl functionalized) silica B, C and D, respectively. It can be seen that it was higher than the experimental rubber sample E.

  The rubber samples B, C, and D using allylsilane-treated (allyl-functionalized) silica also used propyltriethoxysilane (non-allyl-containing silane) -treated silica E to achieve 300 percent strain. It can be seen that it is higher than E. The energy to achieve 300 percent strain is taken as a measure of polymer cross-linking, entanglement and polymer / filler interaction. Since the cure system and rubber (natural rubber) are the same in the rubber sample, an increase in energy to achieve 300 percent strain indicates an increase in the polymer / filler interaction of allylsilane treated (allyl functionalized) precipitated silica. .

  The MDR difference between the maximum and minimum torques is that rubber samples B and D containing allylsilane treated (allyl functionalized) precipitated silica B and silica D, respectively, compared to rubber sample F containing propylalkoxysilane treated silica F. It is low.

  The MDR difference between the maximum torque and the minimum torque may be slightly higher for rubber sample C containing allylsilane treated (allyl functionalized) precipitated silica C compared to rubber sample F containing propylalkoxysilane treated silica F. I understand.

  The combination of low or substantially equal maximum and minimum torque differences and high modulus values results in the amount of rubber / filler interaction for rubber samples B, C, and D containing allylsilane treated (allyl functionalized) precipitated silica It is thought that it further shows that it is increasing compared to the rubber sample F containing propylalkoxysilane-treated silica F.

  It is concluded herein that allyl groups on allylsilane treated (allyl functionalized) precipitated silica are involved in the sulfur vulcanization process in a manner that creates a coupling bond from precipitated silica to rubber.

Example III
Evaluation of Precipitated Silica Treated In Situ Precipitated silica (agglomerated synthetic amorphous silica aggregates) was obtained as a product of Rhodia, Zeosil 1165MP (Micropearl).

  Rubber samples were prepared by blending allyl alkoxy silane and propyl alkoxy silane (non-allyl silane) separately and separately with the precipitated silica-containing rubber composition.

  In this way, the precipitated silica is treated with allylalkoxysilane or propylalkoxysilane in situ in the rubber composition in a closed rubber mixer.

  This rubber sample is referred to as rubber sample X and rubber sample Y in this specification.

  In the case of rubber sample X, the allylalkoxysilane was allyltriethoxysilane.

  In the case of rubber sample Y, the propylsilane was N-propyltriethoxysilane.

  A sample of the rubber composition was prepared as in Example I, except that precipitated silica and allylalkoxysilane or propylalkoxysilane were added separately.

  Table B below shows a general rubber compounding table. Parts and percentages are by weight unless otherwise specified.

  The ingredients were those used in Table A of Example II except for precipitated silica in agglomerated form.

  The curing behavior of each sample and various physical properties after curing are shown in Table 3 below. For the cured rubber samples, the samples were individually cured for about 30 minutes at a temperature of about 150 ° C.

  From Table 2, both 100 percent and 300 percent modulus values indicate that rubber sample F using silica treated in situ with allylalkoxysilane uses rubber treated in situ with propylalkoxysilane. It can be seen that it was higher than Sample G.

  The energy to achieve 300 percent strain is also in the case of rubber sample F using silica treated in situ with allylalkoxysilane compared to rubber sample G using silica treated in situ with propylsilane. It can be seen that the difference between the maximum and minimum torque values of the MDR is substantially equal. The high energy to achieve 300 percent strain and the difference between the maximum and minimum torque values is substantially equal, indicating that the rubber / filler interaction in Sample F is using precipitated propylalkoxysilane to precipitate precipitated silica. This shows an improvement over the rubber sample G processed in situ.

  The loss tangent is lower in rubber sample F where silica is treated in situ with allylalkoxysilane compared to rubber sample G where silica is treated in situ with propylalkoxysilane. This indicates that the rubber / filler interaction of rubber sample F has been improved, and thus the internal heat generation of the rubber composition of sample F is low, and the automobile tire having a tread of such a rubber composition. It shows that rolling resistance is beneficially low.

  It is concluded herein that allyl groups on precipitated silica treated in situ with allylalkoxysilanes are involved in the sulfur vulcanization process in a manner that creates a coupling bond to the rubber.

Example IV
Additional treated precipitated silica was prepared as in Example I and identified herein as Silica X and Silica Y.

  Silica X was produced by treating precipitated silica with allyltriethoxysilane and contained 3 percent allyl groups on its surface.

  Silica Y was produced by treating precipitated silica with propyltriethoxysilane and contained 3 percent propyl groups on its surface.

  The rubber composition was produced separately using silica X and silica Y, respectively, and also using untreated silica identified herein as silica Z.

  Silica Z is a precipitated silica composed of bis (3-triethoxysilylpropyl) polysulfide such as Si69 (registered trademark) manufactured by Evonic Degussa, which bridges the polysulfide bridge (two 3-ethoxysilylpropyl groups). In the range of about 3.4 to 3.8 linked sulfur atoms.

  Table C below shows a general rubber compounding table. Parts and percentages are by weight unless otherwise specified.

  Rubber samples HM were prepared as in Example I.

  The curing behavior of each sample and various physical properties after curing are shown in Table 3 below. For the cured rubber samples, the samples were individually cured for about 30 minutes at a temperature of about 150 ° C.

  The rubber samples are distinguished from the control S-SBR rubber sample H and the experimental S-SBR rubber samples I and J. The control natural rubber is sample K, and the experimental natural rubber is samples L and M.

  From Table 3, rubber sample I containing silica X (allyltrialkoxysilane treated precipitated silica) has a higher modulus value, higher tensile strength and higher than rubber sample J containing silica Y (propylalkoxysilane treated precipitated silica). It can be seen that it has a high energy (at 300 percent modulus). This indicates an increase in rubber / filler interaction due to the presence of allyl groups on the precipitated silica.

  It can also be seen from Table 3 that Sample I has a higher modulus value, higher tensile strength, and higher energy to achieve 300 percent strain than Rubber Sample H. Since rubber sample H uses a silica coupling agent, this is considered surprising here. This again shows an increase in rubber / filler interaction due to the presence of allyl groups on the precipitated silica.

  In Table 3, the scorch times TS1 and TS2 of the rubber samples H to M are reported. It can be seen that rubber samples J and M containing propylalkoxysilane treated silica (silica Y) had the longest scorch time. This indicates the ability to process the rubber composition without premature curing or scorching. This is not considered surprising herein because the propyl group does not react with the elastomer.

  It can be seen that rubber samples I and L containing allylsilane treated (allyl functionalized) precipitated silica (silica X) had the next long scorch time. This is considered a benefit herein. Because silica X has the ability to bind elastomers, it has increased processing time (up to scorch) compared to rubber samples H and K using conventional couplings including coupling agents. It is because it has.

Drawing In order to further illustrate the invention shown in this Example IV, a drawing is provided as FIG. 1 (FIG. 1). This figure is a graph plotting time in minutes (x-axis) versus torque at a constant temperature of 150 ° C. Torque (y-axis) is reported in dNm.

In the figure, it can be seen from FIG . 1 that for the control rubber sample H using untreated silica, the torque begins to increase immediately. This phenomenon indicates a reaction between the coupling agent bonded to silica and the rubber during mixing of the rubber composition at high temperature.

  This immediate increase in torque indicates a rapid increase in the Mooney viscosity of the rubber composition and is therefore considered unsuitable for manufacturing plant rubber processing herein. The increase in rubber viscosity is not generally suitable for the subsequent processing of the rubber composition as well as during its mixing in a closed rubber mixer. Subsequent processing means imparting resistance to the flow of rubber in a rubber mold for processing by molding (for example by extrusion) and for molding and curing a rubber composition, for example in the manufacture of rubber tires. It is processing by.

  For experimental rubber sample I, it can be seen that the torque remained stable and did not rise significantly during the first 4 minutes of mixing. This retarding effect is considered here to be important for reducing the increase in Mooney viscosity of the rubber composition, thereby facilitating better and more efficient processing in a closed rubber mixer. Is done.

  It can also be seen that the experimental rubber sample I has a high torque increase rate after the aforementioned mixing time of 4 minutes. This indicates that faster (shorter) rubber molding times are possible for the manufacture of rubber products.

Example V
The rubber reinforcing effect of allyl-treated precipitated silica and allyl-treated silica gel is evaluated.

  Precipitated silica is identified here as silica P, and allylic precipitated silica is identified here as silica AP.

  Silica gel is identified here as silica G, and allylated silica gel is identified here as silica AG.

  In the case of this example, the precipitated silica used was Zeosil 1165MP (registered trademark) manufactured by Rhodia.

  In the case of this example, the silica gel used was SiliacBond (registered trademark) manufactured by Silicicle.

  Table D below shows a general rubber compounding table. Parts and percentages are by weight unless otherwise specified.

  Rubber samples N, O, and P were prepared as in Example I. The curing behavior and physical properties of each sample are shown in Table 4 below. For the cured rubber sample, the sample was cured at a temperature of about 150 ° C. for about 30 minutes.

  The rubber samples are identified as control rubber sample N (with precipitated silica reinforcement), experimental rubber sample O (with allyl-treated precipitated silica AP) and experimental rubber sample P (with allyl-treated silica gel AG).

  From Table 4, the rubber sample O containing silica AP (allyl-treated precipitated silica) is similar in tensile strength to rubber sample N containing a conventional silica coupling agent together with precipitated silica (not allyl-treated). It can be seen that the cured rubber had stress-strain physical properties such as modulus and elongation and dynamic physical properties such as storage modulus (G ′) and loss tangent (RPA measurement).

  This is particularly true in the sense that precipitated silica (non-allylated precipitated silica) required a silica coupling agent to achieve the same cured rubber properties as allyl treated precipitated silica that did not include a silica coupling agent. is important.

  This observation is truly remarkable and is considered to be significantly different from the prior art.

  Furthermore, such overall rubber properties of rubber sample N include the overall rubber properties of rubber sample O (using allylated silica gel), including a significant decrease in energy to achieve 300 percent strain. Better and dramatically better.

  This is particularly important in the sense that the achievement of beneficial cured rubber properties was also observed only in allyl-treated precipitated silica (rubber reinforcement quality silica), not allyl-treated silica gel.

  These significant physical differences are that in this document allyl treated precipitated silica (silica AP) has a significantly greater rubber reinforcement capacity than allyl treated silica gel (silica AG). It is considered an obvious manifestation.

  Furthermore, it can be seen that the treatment of silica gel with allylsilane was insufficient to make the silica gel suitable as a rubber reinforcing agent.

  Thus, it is clear that the structure of the silica is important, especially in the case of precipitated silica, the combination of BET nitrogen surface area, CTAB surface area and BET / CTAB ratio in the range of 0.8-1.3.

  Thus, herein, a particular precipitated silica structure and its allylation combination is considered an important aspect of the present invention for providing rubber reinforcement.

For the purpose of illustrating the invention, certain representative embodiments and details have been shown, but it will be apparent to those skilled in the art that various modifications and changes can be made therein without departing from the spirit or scope of the invention. I will. [Aspect of the Invention]
1 an allyl-functionalized precipitated silica comprising precipitated silica containing at least one allyl group substituent,
The allyl functionalized precipitated silica has the general formula (I):

[Wherein Z represents precipitated silica; R ² and R ³ are alkyl groups containing 1 to 4 carbon atoms, cycloalkyl groups, phenyl groups, and alkenes containing 3 to 18 carbon atoms. The same or different groups including groups or cycloalkene groups having 5 to 8 carbon atoms; and R ¹ is
-CH ₂ -CH = _{CH 2,
-CH 2 -CH = CH-CH 3} ,
_{-CH 2 -CH = C- (CH 3} ) 2 and _{-CH 2 -C (CH 3) =} CH-CH 3
An allyl hydrogen-containing group containing at least one of
Wherein a is an integer in the range of 0-2, b is an integer in the range of 0-2, and c is an integer in the range of 1-3.

2 The allyl functionalized precipitated silica according to 1, wherein R ² and R ³ are the same or different groups including an alkyl group containing 1 to 4 carbon atoms.

The allyl functionalized precipitated silica according to 1, wherein 3 R ¹ is an allyl hydrogen-containing group represented as —CH ₂ —CH═CH ₂ .

The allyl functionalized precipitated silica according to 1, wherein 4 R ¹ is an allyl hydrogen-containing group represented as —CH ₂ —CH═CH—CH ₃ .

The allyl functionalized precipitated silica according to 1, wherein 5 R ¹ is an allyl hydrogen-containing group represented as —CH ₂ —CH═C— (CH ₃ ) ₂ .

The allyl functionalized precipitated silica according to 1, wherein 6 R ¹ is an allyl hydrogen-containing group represented as —CH ₂ —C (CH ₃ ) ═CH—CH ₃ .

7. An allyl functionalized precipitated silica comprising precipitated silica treated with at least one allylsilane,
The allylsilane has the general structural formula (II):

[Wherein R ² and R ³ are the same or different and each represents an alkoxy group containing 1 to 8 carbon atoms, a cycloalkoxy group containing 5 to 8 carbon atoms, or 1 to 4 carbon atoms. Containing alkyl groups, cyclohexyl groups, phenyl groups, alkenes containing 3 to 18 carbon atoms, or cycloalkenes having 5 to 8 carbon atoms;
Where X is chlorine, hydroxy, or hydrogen;
Where R ¹ is
-CH ₂ -CH = _{CH 2,
-CH 2 -CH = CH-CH 3} ,
_{-CH 2 -CH = C- (CH 3} ) 2 and _{-CH 2 -C (CH 3) =} CH-CH 3
An allyl hydrogen-containing group comprising at least one of
Where a is an integer in the range of 0-3, b is an integer in the range of 0-3, c is an integer in the range of 1-3, and d is an integer in the range of 0-3. And the sum of a, b, c and d is 4;
At least one of said X, R ² and R ³ is present;
Allyl-functionalized precipitated silica having d = 0, at least one of R ² and R ³ is an alkoxy group.

  8 The allyl functionalized precipitated silica according to 7, wherein the allylsilane is allylalkoxysilane or allylchlorosilane.

  9 The allyl-functionalized precipitated silica according to 7, wherein the allylsilane comprises at least one of allyldimethylchlorosilane, allyltrichlorosilane, allylmethyldichlorosilane, diallylchloromethylsilane, diallyldichlorosilane, and triallylchlorosilane.

10 A method for producing an allyl functionalized precipitated silica, the method comprising treating a precipitated silica having a hydroxyl group thereon with at least one allylsilane compound;
The precipitated silica is
(A) BET nitrogen surface area in the range of 120-300 m ² / g,
(B) having a CTAB surface area in the range of 100-300 m ² / g, and (C) a ratio of the BET / CTAB surface area in the range of 0.8-1.3,
The allylsilane compound has the general structural formula (II):

[Wherein R ² and R ³ are the same or different and each represents an alkoxy group containing 1 to 8 carbon atoms, a cycloalkoxy group containing 5 to 8 carbon atoms, or 1 to 4 carbon atoms. Containing alkyl groups, cyclohexyl groups, phenyl groups, alkenes containing 3 to 18 carbon atoms, or cycloalkenes having 5 to 8 carbon atoms;
Where X is chlorine, hydroxy, or hydrogen;
Where R ¹ is
-CH ₂ -CH = _{CH 2,
-CH 2 -CH = CH-CH 3} ,
_{-CH 2 -CH = C- (CH 3} ) 2 and _{-CH 2 -C (CH 3) =} CH-CH 3
An allyl hydrogen-containing group comprising at least one of
Where a is an integer in the range of 0-3, b is an integer in the range of 0-3, c is an integer in the range of 1-3, and d is an integer in the range of 0-3. And the sum of a, b, c and d is 4;
At least one of said X, R ² and R ³ is present;
And when d = 0, at least one of R ² and R ³ is an alkoxy group].

  11 The allylsilane includes at least one of allyltriethoxysilane, allyltrimethoxysilane, allyldimethylchlorosilane, allyltrichlorosilane, allylmethyldichlorosilane, diallylchloromethylsilane, diallyldichlorosilane, and triallylchlorosilane. the method of.

  12 Allyl functionalized precipitated silica produced by the 10 method.

  13. A rubber composition comprising at least one sulfur-cured sulfur vulcanizable elastomer containing at least one reinforcing filler comprising 1 of said allyl functionalized precipitated silica.

  14 The rubber composition according to 13, wherein the reinforcing filler comprises at least one of carbon black and the precipitated silica having no allyl substituent.

  15 A rubber composition according to 13, comprising a silica coupling agent having a part that reacts with hydroxyl groups contained on the precipitated silica and another different part that interacts with the sulfur vulcanizable elastomer.

  16 A rubber composition according to 14, comprising a silica coupling agent having a part that reacts with hydroxyl groups contained on the precipitated silica and another different part that interacts with the sulfur vulcanizable elastomer.

17 The sulfur vulcanizable elastomer is
(A) at least one polymer of isoprene and 1,3-butadiene and a copolymer of styrene and at least one of isoprene and 1,3-butadiene;
(B) a coupled elastomer comprising at least one polymer of isoprene and 1,3-butadiene and a copolymer of styrene and at least one of isoprene and 1,3-butadiene, wherein the coupled elastomer is tin and silica (C) at least one functionalized elastomer of a styrene / butadiene copolymer elastomer (SBR), a cis 1,4-polybutadiene elastomer, and a cis 1,4-polyisoprene elastomer, Wherein the functionalized elastomer is
(1) an amine functional group that reacts with the allyl functionalized precipitated silica, or (2) a siloxy functional group that reacts with the rubber reinforcement of the allyl functionalized precipitated silica filler, or (3) reacts with the allyl functionalized silica. A combination of amine and siloxy functional groups, or (4) a silane / thiol functional group that reacts with the allyl functionalized silica, or (5) a hydroxyl functional group that reacts with the allyl functionalized precipitated silica, or (6) the allyl An epoxy group that reacts with the functionalized precipitated silica, or (7) contains a functional group that includes a carboxyl group that reacts with the allyl functionalized precipitated silica,
14. The rubber composition according to 13, comprising at least one of the following.

18 The precipitated silica is
(A) Treat the precipitated silica with the allylsilane before adding it to the rubber composition, or (B) Allyl functionalize by treating the precipitated silica with the allylsilane in situ within the rubber composition. 14. A rubber composition according to item 13.

  19 A product having at least one member comprising 13 rubber compositions.

  A tire having at least one member comprising 2013 rubber composition.

Claims (20)

An allyl functionalized precipitated silica comprising precipitated silica containing at least one allyl group substituent comprising:
The precipitated silica is
(A) BET nitrogen surface area in the range of 120-300 m ² / g,
(B) having a CTAB surface area in the range of 100 to 300 m ² / g, and (C) a ratio of the BET / CTAB surface area in the range of 0.8 to 1.3;
The allyl functionalized precipitated silica has the general formula (I):

[Wherein Z represents precipitated silica; R ² and R ³ are alkyl groups containing 1 to 4 carbon atoms, cycloalkyl groups, phenyl groups, and alkenes containing 3 to 18 carbon atoms. The same or different groups including groups or cycloalkene groups having 5 to 8 carbon atoms; and R ¹ is
-CH ₂ -CH = _{CH 2,
-CH 2 -CH = CH-CH 3} ,
_{-CH 2 -CH = C- (CH 3} ) 2 and _{-CH 2 -C (CH 3) =} CH-CH 3
An allyl hydrogen-containing group containing at least one of
Wherein a is an integer in the range of 0-2, b is an integer in the range of 0-2, and c is an integer in the range of 1-3. The allyl functionalized precipitated silica of claim 1, wherein R ² and R ³ are the same or different groups including alkyl groups containing 1 to 4 carbon atoms. The allyl functionalized precipitated silica according to claim 1, wherein R ¹ is an allyl hydrogen-containing group represented as —CH ₂ —CH═CH ₂ . The allyl functionalized precipitated silica according to claim 1, wherein R ¹ is an allyl hydrogen-containing group represented as —CH ₂ —CH═CH—CH ₃ . The allyl functionalized precipitated silica according to claim 1, wherein R ¹ is an allyl hydrogen-containing group represented as —CH ₂ —CH═C— (CH ₃ ) ₂ . The allyl functionalized precipitated silica according to claim 1, wherein R ¹ is an allyl hydrogen-containing group represented as —CH ₂ —C (CH ₃ ) ═CH—CH ₃ . An allyl-functionalized precipitated silica comprising precipitated silica treated with at least one allylsilane,
(A) The precipitated silica is
(B) BET nitrogen surface area in the range of 120-300 m ² / g,
(C) having a CTAB surface area in the range of 100-300 m ² / g, and (D) having a ratio of the BET / CTAB surface area in the range of 0.8-1.3; and the allylsilane has the general structural formula (II ):

[Wherein R ² and R ³ are the same or different and each represents an alkoxy group containing 1 to 8 carbon atoms, a cycloalkoxy group containing 5 to 8 carbon atoms, or 1 to 4 carbon atoms. Containing alkyl groups, cyclohexyl groups, phenyl groups, alkenes containing 3 to 18 carbon atoms, or cycloalkenes having 5 to 8 carbon atoms;
Where X is chlorine, hydroxy, or hydrogen;
Where R ¹ is
-CH ₂ -CH = _{CH 2,
-CH 2 -CH = CH-CH 3} ,
_{-CH 2 -CH = C- (CH 3} ) 2 and _{-CH 2 -C (CH 3) =} CH-CH 3
An allyl hydrogen-containing group comprising at least one of
Where a is an integer in the range of 0-3, b is an integer in the range of 0-3, c is an integer in the range of 1-3, and d is an integer in the range of 0-3. And the sum of a, b, c and d is 4;
At least one of said X, R ² and R ³ is present;
Allyl-functionalized precipitated silica having d = 0, at least one of R ² and R ³ is an alkoxy group.   The allyl functionalized precipitated silica of claim 7, wherein the allylsilane is allylalkoxysilane or allylchlorosilane.   8. The allyl functionalized precipitated silica of claim 7, wherein the allylsilane comprises at least one of allyldimethylchlorosilane, allyltrichlorosilane, allylmethyldichlorosilane, diallylchloromethylsilane, diallyldichlorosilane, and triallylchlorosilane. A method for producing an allyl functionalized precipitated silica comprising treating a precipitated silica having a hydroxyl group thereon with at least one allylsilane compound;
The precipitated silica is
(A) BET nitrogen surface area in the range of 120-300 m ² / g,
(B) having a CTAB surface area in the range of 100 to 300 m ² / g, and (C) a ratio of the BET / CTAB surface area in the range of 0.8 to 1.3;
The allylsilane compound has the general structural formula (II):

[Wherein R ² and R ³ are the same or different and each represents an alkoxy group containing 1 to 8 carbon atoms, a cycloalkoxy group containing 5 to 8 carbon atoms, or 1 to 4 carbon atoms. Containing alkyl groups, cyclohexyl groups, phenyl groups, alkenes containing 3 to 18 carbon atoms, or cycloalkenes having 5 to 8 carbon atoms;
Where X is chlorine, hydroxy, or hydrogen;
Where R ¹ is
-CH ₂ -CH = _{CH 2,
-CH 2 -CH = CH-CH 3} ,
_{-CH 2 -CH = C- (CH 3} ) 2 and _{-CH 2 -C (CH 3) =} CH-CH 3
An allyl hydrogen-containing group comprising at least one of
Where a is an integer in the range of 0-3, b is an integer in the range of 0-3, c is an integer in the range of 1-3, and d is an integer in the range of 0-3. And the sum of a, b, c and d is 4;
At least one of said X, R ² and R ³ is present;
And when d = 0, at least one of R ² and R ³ is an alkoxy group].   The allyl silane comprises at least one of allyl triethoxysilane, allyltrimethoxysilane, allyldimethylchlorosilane, allyltrichlorosilane, allylmethyldichlorosilane, diallylchloromethylsilane, diallyldichlorosilane, and triallylchlorosilane. The method described.   12. Allyl functionalized precipitated silica produced by the method of any of claims 10 and 11.   A rubber composition comprising at least one sulfur cured sulfur vulcanizable elastomer containing at least one reinforcing filler comprising the allyl functionalized precipitated silica of any of claims 1-9 and 12.   The rubber composition of claim 13, wherein the reinforcing filler comprises at least one of carbon black and the precipitated silica free of allyl substituents.   15. A silica coupling agent according to any of claims 13 and 14, comprising a silica coupling agent having a moiety that reacts with hydroxyl groups contained on the precipitated silica and another different moiety that interacts with the sulfur vulcanizable elastomer. Rubber composition. The sulfur vulcanizable elastomer is
(A) at least one polymer of isoprene and 1,3-butadiene and a copolymer of styrene and at least one of isoprene and 1,3-butadiene;
(B) a coupled elastomer comprising at least one polymer of isoprene and 1,3-butadiene and a copolymer of styrene and at least one of isoprene and 1,3-butadiene, wherein the coupled elastomer is tin and silica (C) at least one functionalized elastomer of a styrene / butadiene copolymer elastomer (SBR), a cis 1,4-polybutadiene elastomer, and a cis 1,4-polyisoprene elastomer, Wherein the functionalized elastomer is
(1) an amine functional group that reacts with the allyl functionalized precipitated silica, or (2) a siloxy functional group that reacts with the rubber reinforcement of the allyl functionalized precipitated silica filler, or (3) reacts with the allyl functionalized silica. A combination of amine and siloxy functional groups, or (4) a silane / thiol functional group that reacts with the allyl functionalized silica, or (5) a hydroxyl functional group that reacts with the allyl functionalized precipitated silica, or (6) the allyl An epoxy group that reacts with the functionalized precipitated silica, or (7) contains a functional group that includes a carboxyl group that reacts with the allyl functionalized precipitated silica,
The rubber composition according to any one of claims 13 to 15, comprising at least one of the following. The precipitated silica is
(A) Treat the precipitated silica with the allylsilane before adding it to the rubber composition, or (B) Allyl functionalize by treating the precipitated silica with the allylsilane in situ within the rubber composition. The rubber composition according to any one of claims 13 to 16.   The product which has at least 1 member containing the rubber composition in any one of Claims 13-17.   A tire having at least one member containing the rubber composition according to claim 13.   A tire having a tread containing the rubber composition according to claim 13.

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