EP0846139A1

EP0846139A1 - Functionalised inorganic oxide hydroxylated carrier and method for preparing same

Info

Publication number: EP0846139A1
Application number: EP96929346A
Authority: EP
Inventors: Christian Fischer; Gérard Mignani; Christian Priou
Original assignee: Rhodia Chimie SAS
Current assignee: Rhodia Chimie SAS
Priority date: 1995-08-22
Filing date: 1996-08-19
Publication date: 1998-06-10
Also published as: WO1997008225A1; FR2738011A1; MX9801132A; JPH11512128A; FR2738011B1; BR9610103A; TR199800276T1; US6132874A; AU6878096A; AU718012B2; CA2227557A1; TW337494B

Abstract

A hydroxylated inorganic oxide carrier is functionalised by grafting one or more types of polyhydrogenosiloxane oils with 10 - 200 siloxane units, said grafting being provided by the covalent bonds formed by a dehydrogenocondensation reaction between Si-H groupings of the polyhydrogenosiloxane oil and free hydroxyls of the hydroxylated carrier, and by the hydrogen bonds between the hydroxyls of the hydroxylated carrier and oxygen atoms of the polyhydrogenosiloxane oil, which has free Si-H groupings.

Description

Inorganic oxide hydroxyl support, functionalized, and process for its preparation.

The present invention relates to hydroxyl supports of inorganic oxide, in particular of the silica, alumina, titanium oxide and rare earth oxide type, which are functionalized and suitable for use in multiple applications, in particular in the field of fillers. functionalized, for example for tires, paper anti-adhesion, RTV (elastomers vulcanizable at room temperature), anti-foam and pigmentation for electronics. The invention also applies for example to the production of hydrophobic supports, of supports for enantiomeric separation, for heterogeneous catalysis. The invention also relates to a process for their preparation.

The association of silicones with silica is widely used today.

Silica can be used as a mineral filler intended to improve the mechanical properties of silicones. This application brings into play the strong interactions existing between the silanols in silica and the Si-O-Si groups. In this case, it is also known to modify these interactions by treating the surface of the silica, for example using Mβ3Si groups giving a certain hydrophobicity to the silica which makes it possible to facilitate the incorporation of the filler in the silicone or in polymeric matrices.

Attempts have also been made to functionalize the silica using linear silicones in order to obtain a functionalized silica having particular surface characteristics which confer useful properties on the silica.

T. Suhara et al., Colloids and Surfaces, Physicochemical and Engineering Aspects 95 (1995) 1-9, thus use a tetramethylcyclotetrasiloxane (TMCTS) to coat the particles with a silica powder. The linear silicone is deposited on the silica by a vapor deposition method at 80 ° C., which makes it possible to obtain a covering of the silica by the silicone. The Si-H groups of the polymethylsiloxane layer formed on the surface of the silica particles can react with various functional derivatives by a hydrosilylation reaction. It is thus possible to increase the dispersibility by grafting olefins or hydroalcoholic groups, forming a matrix for anion exchange by grafting diethylamino ionic groups or rendering the surface of the silica hydrophobic by grafting groups such as diethylamino or octadecyl. The authors describe the reaction of silica coated with its polymethylsiloxane layer with p-chloromethylstyrene in the presence of a platinum-based catalyst, then with an N, N-dimethyl-n-alkylamine. Depending on the length of the grafted carbon chain, the final product can be hydrophobic or hydrophilic. This process takes advantage of the volatile nature of TMCTS at temperature high and is not applicable to silicones having a higher number of units.

The article by H. W. Stuurman et al. in Chromatographia Vol. 25, no. 4, April 1988, relates to the preparation of a stationary silica phase useful in enantiomeric separation. The process described provides for a partial hydrosilylation reaction of an oligomer or siloxane polymer (having for example 22 or 35 units SiH on the silicone chain) and quinine in the presence of a platinum-based catalyst, then the chemical bonding of the compound obtained above to a silica gel (see also W. Rôder et al., Journal of High Resolution Chromatography & Chromatography Communications, Short Communication 10710, Vol. 10, 665-667, December 1987). This process does not make it possible to obtain a homogeneous coating and is not necessarily applicable to any type of functionalization, in particular of molecules of large size without modify the reactivity of the Si-H patterns of silicone, as well as limiting the quantity of molecules that can be grafted.

Patent application FR-A-2 666 999 describes a process for obtaining a silica-based support useful in analytical or preparative chromatography, in particular in high performance liquid chromatography, in solid / liquid extraction, in heterogeneous catalysis or in capillary electrophoresis. The process consists in grafting on hydrogen silos with 1 silicon atom in the presence of a catalyst which is a metal complex, so as to obtain 100% of Si-O-Si bonds.

For applications in separative chromatography, a frequent approach was to react a completely hydroxylated silica with triorganochlorosilanes according to a silanization reaction leading to organosiloxane type bonds. The method generally includes the catalytic addition of a SiH unit with a terminal olefin, the assembly forming the silanization reagent, namely the triorganochlorosilane. The main drawback of this approach is linked to the use of chlorosilanes making it difficult to separate the functionalized silica from the reaction residues. For disposal, the formed hydrochloric acid has to be trapped by a base such as pyridine, resulting in a solid hydrochloride ^'difficult to remove. A mixture of two solids is then obtained, the separation of which makes the process generally unacceptable industrially (see for example JE Sandoval and JJ Pesek in Anal. Chem. 1989, 61, 2067-2075).

Patent application WO-A-94 12275 describes the preparation of optically active adsorbents useful for the chromatographic separation of enantiomers. A tartaric acid derivative is network polymerized on a silica gel. In particular, the derivative is polymerized by hydrosilylation in the presence of hydrosilanes or hydrosiloxanes of general formula.

wherein R is an alkyl group having 1 to 4 carbon atoms or H or a mixture thereof, X is (CH2) _ιrι or O, Y is R or the group -0-Si (R) 3, n is an integer from 0 to 3000 and m an integer from 1 to 10. The reaction is carried out in the presence of a catalyst formed from a metal complex at temperatures ranging from 50 to 180 ° C. In the case of hydrosiloxanes, there is a pretreatment introducing vinyl patterns on the surface of the silica. This process is applied to a type of functionalization.

Patent application EP-A-0212870 describes the production of fillers coated with patterned silicone oils Si-H, these buildings with Si-H patterns can then undergo a hydrosilylation reaction in order to provide specific properties. In the operating mode described, the silicone oil with Si-H units is added to the mineral filler and the dehydrogenocondensation of the Si-H units is obtained with residual water to form Si-O-Si bridges between chains silicones. This procedure does not make it possible to obtain covalent bonds between the mineral filler and the silicone oil. The oil is simply adsorbed on the surface of the load.

The present invention aims to remedy the shortcomings and disadvantages of the previous methods and supports by providing a functionalization process and hydroxyl supports of inorganic oxides functionalized with silicone oils so as to have a good covering of the support. while leaving an optimal amount of SiH units available for grafting molecules of interest.

Another objective of the invention is to provide a process allowing easy grafting of various molecules, even of large size.

Yet another objective of the invention is to provide a process which is easy to implement and which in particular allows easy recovery of the functionalized support, for example by simple filtration or centrifugation and avoiding the presence of organic or inorganic salts on the surface of the charge. .

Yet another objective of the invention is to provide a functionalized support having significant potential for the grafting of various molecules and of varied applications.

Yet another objective of the invention is to provide a functionalized and grafted support having a long lifespan and great stability with respect to molecules. grafted, in particular great stability to hydrolysis.

The subject of the invention is therefore a hydroxylated inorganic oxide support functionalized by grafting at least one type of polyhydrogenosiloxane oil having 10 to 200 siloxane units, the grafting being provided on the one hand by covalent bonds formed from a dehydrogenocondensation reaction between Si-H groups of the polyhydrogenosiloxane oil and free silanols of the silica, and on the other hand by hydrogen bonds between hydroxyls of the hydroxyl support and oxygen atoms of the polyhydrogenosiloxane oil, which retains free SiH groups. After grafting, there remain in fact free Si-H groups, the amount of which can be varied according to the operating conditions (temperature, duration of treatment).

More particularly, the polyhydrogenosiloxane oil has from 30 to 60 siloxane units, preferably around 50.

Before their grafting on the support, the polyhydrogenosiloxane oils preferably correspond to the general formula:

R R <2SiO- (SiR ^,, 20) _χ - (SiHR ^, "0) _y -SiR < ₂ R with

- R = H or R '

- R ', R ", R" ¹ = C 1 to C ₆ alkyl, preferably Cι_, or aromatic, preferably phenyl,

- if x is equal to 0, y = 10 to 200

- if x is different from 0, x + y = 10 to 200

The polyhydrogenosiloxane oils can also be mixed oils with SiH and SiOR functions, R preferably being methyl or ethyl.

The hydroxyl support is any useful inorganic support, but is preferably chosen from the group consisting of silica, alumina, titanium oxide (anatase or rutile), rare earth oxides, zinc oxide and magnesium oxide. These include calcination, precipitation or chromatography silica.

The polyhydrogenosiloxane coating having free SiH groups allows the grafting of interesting molecules. In this case, the support has, in addition to the X molecules linked to the Si atoms (not involved in a covalent bond with the inorganic oxide) of the polyhydrogenosiloxane oil according to the following scheme:

- 0 ^ R "

^ If '

- 0 "^ ^^ X

The molecule X can be chosen from molecules known to those skilled in the art to be useful in a given application.

In particular, the molecule X may be an alkyl group preferably having from 6 to 25 carbon atoms or polybutadienyl (preferably Mn = 1000 to 20,000) in order to obtain a hydrophobic and / or reactive support in the case of polybutadiene.

Details and other non-limiting examples of X molecules are given below.

The subject of the invention is also a process for functionalizing a hydroxyl inorganic oxide support, for obtaining a support as defined above, in which this support is reacted with at least one polyhydrogenosiloxane oil with Si-H units and having from 10 to 200 siloxane units, in the presence of a dehydrogenocondensation catalyst so that the reaction takes place with evolution of hydrogen.

The catalyst is preferably chosen from the group consisting of catalysts based on platinum, rhodium, ruthenium, cobalt, tin (in particular dibutyltin dilaurate), titanium and mineral (NaOH, KOH, etc.) and organic (pyridine, etc.) bases. The catalyst is in particular a platinum-based catalyst, in particular of the Karstedt Pt ₂ (ViSiMe ₂ -0-SiMe2Vi) 3, H ₂ PtCl6.6H ₂ 0 type. Mention may also be made in particular of RhCl (P (C ₆ H ₅ ) ₃ ) ₃ , Ru ₃ (CO) ₁₂ , Co ₂ (CO) ₈ , (C ₆ H ₅ ) ₂ Ti (CH3) ₂ , (C ₆ H ₅ ) Ti (CH ₃ ) ₃ .

The reaction is generally carried out at a temperature between 50 and 200 ° C, preferably between 100 and 150 ° C.

It can be carried out in a liquid medium with the catalyst in solution in a solvent (for example toluene, xylene, cyclohexane, methylcyclohexane, toluene being preferred), or in bulk with the catalyst dissolved in the mass.

The grafting reaction can be characterized by infrared spectrometry (FTIR) in diffuse reflection on a BIORAD FTS45A device and by solid NMR (nuclear magnetic resonance) of ²⁹ Si.

In accordance with the invention, it has been possible to demonstrate the reduction in free silanols (for example 3740 cm ^-1 ) together with the reduction in Si-H in the silicone oil (for example 2170 cm ^-1 ) and the solid NMR of ²⁹ If has shown without ambiguity the presence of groupings of type

S o

I

Sic; O If CHo, s = silica

I

O

S

In a second step, it is possible to graft onto the support formed from the inorganic oxide and from the polyorganosiloxane oil molecules with a terminal unsaturated unit, which can in particular be a linear or branched α-unsaturated hydrocarbon having from 6 to 25 atoms of carbon, preferably C6 to C12, according to a hydrosilylation reaction catalyzed by organometallic complexes of platinum, rhodium or cobalt. One can in particular graft a 1-alkene in C6-C25, in particular in C6-C12, having a terminal unsaturated motif.

This makes it possible to obtain hydrophobic supports or to confer a certain compatibility with respect to a matrix such as an elastomeric matrix.

For example, in the case of functionalization with 1-octene, the synthesis and functionalization scheme, since the reaction between silica and polyhydrogenosiloxane oil, is as follows:

It is also possible to graft an α, ω diene R in particular with R = C2 to C4, so as to confer a hydrophobic character, compatibility with respect to a matrix or reactivity via the remaining unsaturated units, allowing for example the addition of an interesting group, in particular a carbon or sulfur radical.

It is also possible to graft polyenes, in particular of the polybutadiene type, in order to obtain a hydrophobic and reactive support.

It is also possible to deposit tvpe metals [Pd ^° ] according to L. Fry, J. Chem. Soc. Chem. Corn. 1993, 997, via the reduction by the Si-H units of PdCl ₂ in [Pd °]. We are therefore moving towards heterogeneous catalysis applications, for example for hydrogenation or carbonylation reactions.

It is also possible to graft chiral molecules for the production of supports for enantiomeric separation. It is especially possible to graft quinine derivatives such as the trimethylsilyl derivative:

or type chiral lactic derivatives

O ^ / O ^ Vy

with in particular R = CH3, ethyl or benzyl.

It is also possible to graft complexing molecules of transition metals, in particular of ty ^y p ^F e CH 2 _? = CH-CH λ ₇ - nC-CH ₂ 2- nC-CH ₃ 3 0 0

We can also graft molecules photodissociable, in particular of the spirobenzopyrane type: see M. Ueda et al., J. Mater. Chem. 1994, 4 (6), 883-889.

The subject of the invention is therefore the grafting of various molecules which are usually used in the functionalization of supports based on inorganic oxides, for the applications indicated above.

The invention therefore also relates to the supports formed from inorganic oxide and from polyorganosiloxane oil and onto which the above molecules have been grafted.

Example 1: Synthesis of silica functionalized with polyhydrogenosiloxane groups.

100 g of combustion silica (A200) are introduced into a 2-liter Sovirel glass reactor, with stirring under nitrogen sweep. At room temperature, 8.25 g of a polyhydrogenosiloxane oil (1.55% equiv / Si-H) are then introduced via a dropping funnel (45 min). After 30 min of stirring, addition of 2 g of a platinum catalyst (0.3% Pt, mass) in solution in hexane. The temperature then rose for 2 hours to 120 ° C, with a vacuum (15 mm Hg) for the last 15 minutes. The IR spectrum of the product obtained is produced in comparison with the starting silica (A 200). It is observed that the interaction of the oil with the surface takes place essentially at the level of the free silanols of the silica (υOH: 3700 cm ^-1 ), bands at 2966 and 2909 cm ^-1 (uC-H) indicating the presence oil with its residual Si-H groups (υSi-H: 2169 cm ^-1 ).

Example 2: Functionalization of silicas with polyhydrogenosiloxane groups. a) Functionalization with n-octene.

2 g of silica functionalized with polyhydrogenosiloxane groups of Example 1, 50 ml of dry toluene and 7.8 g of n-octene (0.07 mole) and 10 μl of nitrogen are introduced into a 100 ml three-necked flask under nitrogen Karstedt catalyst (21093) at 12% by mass of platinum. It is left to react for 16 h at 90 ° C. The mixture is left to return to ambient temperature and filtered on a paper filter. Wash with 1 1 of dry toluene and 1 1 of hexane. Then dried under vacuum pump (1 mm Hg) for 4 h at 25 ° C. 1.7 g of a white solid are recovered. The IR spectrum of the final product is produced. There is a sharp decrease in the vibration band of the Si-H patterns. The microanalysis results show:% C = 3.06 and% H = 0.9, which makes it possible to evaluate a rate of octyl units of the order of 1.2 octyl unit / nm ² if we consider a specific surface of 160 m ² / g.

b) Functionalization with polybutadiene.

2 g of silica functionalized with polyhydrogenosiloxane groups from Example 1, 50 ml of dry toluene and 8.3 g of polybutadiene RICON 156 (Mn: 2540, Mw: 2920,, CH are introduced into a 100 ml three-necked flask under nitrogen = CH: 65%, CH = CH ₂ : 35%) and 10 μl of Karstedt catalyst (21093) at 12% by mass of platinum. It is left to react for 16 h at 90 ° C. The mixture is left to return to ambient temperature and filtered on a paper filter. Washed with 1 l of dry toluene and 1 l of hexane, then dried under vacuum pump (1 mm Hg) for 4 h at 25 ° C. 1.6 g of a white solid are recovered. The IR spectrum of the final product is produced. There is a sharp decrease in the vibration band of the Si-H patterns. The microanalysis results show:% C = 4.58 and% H = 1, 02.

Example 3: Synthesis of precipitated silica functionalized with polyhydrogenosiloxane groups.

100 g of precipitation silica (Z 175 MP) are introduced into a two-liter Sovirel glass reactor, with stirring under a nitrogen sweep. At room temperature, 8.25 g of a silicone oil with Si-H units of general formula: Me ₃ SiO (MeHSiO) 5 ₀ are introduced dropwise over 45 min, using a dropping funnel. SiMe ₃ (1.55% equiv / Si-H)

After approximately 30 min of stirring, 2 g of a Karstedt catalyst solution (0.3% of Pt / mass) are added. The temperature then rose for 2 h to 120 ° C, with a vacuum (15 mm Hg) for the last 15 minutes. IR analyzes show that the interaction of the silicone oil with the surface takes place essentially at the level of the free silanol units of the silica. IR analysis shows that there remains - 47% of the Si-H units introduced, ie - 0.055 mole of Si-H units / 100 g of charge. Microanalysis shows the following results:% C: 3.35,% H: 1.55.

Example 4: functionalization reaction: 1-octene.

5.00 g of the product of Example 3, 10.00 g of 1-octene (0.089 mole), 100 ml of dry toluene and 150 are introduced into a 250 ml reactor surmounted by a condenser. ppm of [Pt] (Karstedt catalyst). The whole is brought to 100 ° C. It is left to react for 16 h at this temperature. The mixture is allowed to return to room temperature, filtered, the silica is washed with 500 ml of toluene and 1200 ml of hexane, then dried for 16 h in an oven. under nitrogen at ~ 40 "C. 4.9 g of a white solid is recovered, the elementary analysis of which is as follows:% C: 4.84 and% H: 1.60. The IR analysis shows this reactivity of the patterns Si- H.

Example 5: functionalization reaction: Polybutadiene.

5.00 g of the product of Example 3, 10.00 g of polybutadiene (Type RICON 156, Mn: 2540, Mw: 2920, CH) are introduced into a 250 ml reactor surmounted by a condenser. = CH: 65%, CH = CH ₂ : 35%), 100 ml of dry toluene and 150 ppm of [Pt] (Karstedt catalyst). The whole is brought to 100 ° C. It is left to react for 16 h at this temperature. The mixture is allowed to return to room temperature, filtered, the silica is washed with 500 ml of toluene and 1200 ml of hexane, then dried for 16 h in an oven under nitrogen at -40 ° C. 4.8 g of a white solid are recovered, the elementary analysis of which is as follows:% C: 5.60,% H: 1.65. IR analysis shows the reactivity of these Si-H motifs.

Example 6: functionalization reaction: 1,5-hexadiene.

5.00 g of the product of Example 3, 10.00 g of 1.5-hexadiene (0.12 mole), 100 ml of dry toluene and 150 ppm of [Pt] (Karstedt catalyst). The whole is brought to 100 ° C. It is left to react for 16 h at this temperature. The mixture is allowed to return to room temperature, filtered, the silica is washed with 500 ml of toluene and 1200 ml of hexane, then dried for 16 h in an oven under nitrogen at -40 ° C. 4.99 g of a white solid are recovered, the elementary analysis of which is as follows:% C: 7.0,% H: 2.0. Example 7: functionalization reaction: Polybutadiene.

426.6 g of a silica with Si-H units (H68 + Silica Z 1165 MP with 0.043 mole of Si-H units / 100 g of carbon dioxide) are introduced into a 2 1 reactor surmounted by a condenser. silica), 400 g of Polybutadiene (Type RICON156, Mn: 2540, Mw: 2920, CH = CH: 65%, CH = CH ₂ : 35%), 100 ml of dry toluene and 150 ppm of [Pt] (catalyst of Karstedt). The whole is brought to 100 ° C. It is left to react for 16 h at this temperature. The mixture is allowed to return to room temperature, filtered, the silica is washed with 3 l of toluene and 1 l of cyclohexane, then dried for 5 h at 80-110 ° C under 1 mm Hg. 546 g of a white solid are recovered, the elementary analysis of which is as follows:% C: 7.15,% H: 1.75. An assay of Si-H units by volumetry shows a content of 32.10 ^-3 mole of Si-H units / 100 g of filler. It is then subjected to a treatment with dry ethanol (50 ml) in the presence of Karstedt catalyst (100 ppm) at 60 ° C for 16 h. After filtration and drying under vacuum pump (1 mm Hg, 5 h at 25 ° C), 530 g of a white solid is obtained which contains 4.10 ^-3 mole of Si-H units / 100 g of filler. Elemental analysis shows% C: 6.65,% H: 1.70. IR analysis shows a very strong decrease in the quantity of the remaining Si-H patterns.

Claims

1 - hydroxyl inorganic oxide support functionalized by grafting at least one type of polyhydrogenosiloxane oil having 10 to 200 siloxane units, the grafting being provided on the one hand by covalent bonds formed from a dehydrogenocondensation reaction between Si-H groups of the polyhydrogenosiloxane oil and free hydroxyls of the hydroxyl support and on the other hand by hydrogen bonds between hydroxyls of the hydroxyl support and oxygen atoms of the polyhydrogenosiloxane oil, which has free SiH groups.

2 - Support according to claim 1, characterized in that the polyhydrogenosiloxane oil has 30 to 60 siloxane units, preferably about 50.

3 - Support according to claim 1 or 2, characterized in that the polyhydrogenosiloxane oils correspond to the general formula:

RR ' ₂ SiO- (SiR " ₂ 0) _χ - (SiHR" ¹ 0) _y -SiR' ₂ R with

- R = H or R '

- R ', R ", R"' = C1 to Cβ alkyl, preferably Cι_, or aromatic, preferably phenyl,

- if x is equal to 0, y = 10 to 200

- if x is different from 0, x + y = 10 to 200

4 - Support according to one of claims 1 to 3, characterized in that the polyhydrogenosiloxane oils are mixed oils with SiH and SiOR functions, R being methyl or ethyl.

5 - Support according to one of claims 1 to 4, characterized in that the hydroxyl support is chosen from the group consisting of silica, alumina, titanium oxide and rare earth oxides. in that it is calcination silica or precipitation silica.

7 - Support according to one of claims 1 to 6, characterized in that it has, in addition, X molecules linked to the Si atoms of the polyhydrogenosiloxane oil according to the following diagram:

8 - Support according to claim 7, characterized in that the molecule X is an alkyl group, having from 6 to 25 carbon atoms, preferably from 6 to 12, or polyene, preferably polybutadienyl.

9 - Process for the functionalization of a hydroxyl inorganic oxide support, for obtaining a support according to any one of claims 1 to 8, in which this support is reacted with at least one polyhydrogenosiloxane oil with Si units -H and having from 10 to 200 siloxane units, in the presence of a dehydrogenocondensation catalyst so that the reaction takes place with evolution of hydrogen.

10 - Process according to claim 9, characterized in that the catalyst is chosen from the group consisting of catalysts based on platinum, rhodium, ruthenium, cobalt, tin, titanium and mixtures of at least two of them.

11 - Process according to claim 10, characterized in that the catalyst is a platinum catalyst, in particular of the Karstedt type.

12 - Method according to one of claims 9 to 11, characterized in that the reaction is carried out at a temperature between 50 and 200 ° C, preferably between 100 and 150 "C.

13 - Method according to one of claims 9 to 12, characterized in that the reaction is carried out in a liquid medium with the catalyst in solution in a solvent.

14 - Method according to one of claims 9 to 12, characterized in that one conducts the bulk reaction with the catalyst dissolved in the mass.

15 - Method according to one of claims 9 to 14, characterized in that grafted to the support formed of inorganic oxide and polyorganosiloxane oil of molecules with terminal unsaturated pattern.

16 - Process according to claim 15, characterized in that the molecule with terminal unsaturated unit is a linear or branched unsaturated hydrocarbon having from 6 to 25 carbon atoms, preferably 6 to 12.

17. Method according to one of claims 9 to 14, characterized in that the molecules chosen from the group consisting of: grafted to the support formed of inorganic oxide and polyorganosiloxane oil

- a, ω diene, preferably in C2-C4

- polyene, preferably polybutadiene

- metals, preferably [Pd °]

- chiral molecules, preferably derived from quinine or lactic derivatives

- complexing molecules of transition metals photodissociable molecules, preferably of the spirobenzopyrane type.

18 - Support likely to be obtained by the implementation of the method according to any one of claims 9 to 17.