The invention relates to dioctahedral phyllosilicates 2:1 whose basal spacing is at least equal to 2.0.times.10.sup.-9 m and which in the interlayer space comprise pillars based on at least one of the compounds that is selected from the group that is formed by SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, V.sub.2 O.sub.5, or any combination of the latter. Preferably, they contain fluorine. The invention also relates to a process for their preparation that includes treatment with a surfactant, followed by treatment with a primary or secondary amine and at least one alkoxide of an element that is selected from the group that is formed by the elements Si, Al, Zr, Ti and V. The invention also relates to a catalyst that comprises said phyllosilicate, at least one matrix, and optionally a zeolite Y. The invention also relates to a process for converting hydrocarbons with this catalyst, and in particular a hydrocracking process.

FIELD OF THE INVENTION 
This invention relates to dioctahedral phyllosilicates 2:1, preferably 
synthesized in a fluoride medium in the presence of hydrofluoric acid 
and/or another source of fluoride anions, whereby said phyllosilicates are 
pillared and have a large basal spacing; whereby the basal spacing that is 
represented by d.sub.001 is the sum of the thickness of a layer and the 
interlayer spacing. 
The invention also relates to a preparation process for obtaining said 
phyllosilicate. 
These phyllosilicates can fall within the composition of catalysts that are 
used for hydrocracking. 
This invention also relates to a catalyst that comprises at least one 
dioctahedral phyllosilicate 2:1, preferably synthesized in a fluoride 
medium (in the presence of hydrofluoric acid and/or another source of 
fluoride anions) and then pillared, whereby said phyllosilicate has a 
large basal spacing (whereby the basal spacing is the sum of the thickness 
of a layer and the interlayer spacing), whereby the catalyst also 
comprises at least one matrix and optionally at least one zeolite Y with a 
faujasite structure. The invention also relates to a process for 
converting hydrocarbon feedstocks that use this catalyst, in particular a 
hydrocracking process. 
BACKGROUND OF THE INVENTION 
Hydrocracking of heavy petroleum cuts is a very important refining process 
which makes it possible, starting from excess heavy feedstocks which are 
of low value, to produce lighter fractions such as gasolines, jet fuels, 
and light gas-oils. The refiner seeks to adapt production to demand. 
Compared to catalytic cracking, the advantage of catalytic hydrocracking 
is to provide middle distillates, jet fuels, and light gas-oils of very 
good quality. By contrast, the gasoline that is produced has a much lower 
octane number than the one that is derived from catalytic cracking. 
The catalysts that are used in hydrocracking are all of the bifunctional 
type that combine an acid function with a hydrogenating function. The acid 
function is provided by substrates with large surface areas (generally 150 
to 800 m.sup.2.g.sup.-1) that have a surface acidity, such as halogenated 
aluminas (chlorinated or fluorinated in particular), combinations of boron 
oxides and aluminum oxides, amorphous silica-aluminas, and zeolites. The 
hydrogenating function is provided either by one or more metals of group 
VIII of the periodic table, such as iron, cobalt, nickel, ruthenium, 
rhodium, palladium, osmium, iridium, and platinum, or by a combination of 
at least one metal from group VI of the periodic table, such as chromium, 
molybdenum and tungsten, and at least one metal of group VIII. 
The balance between the two acid and hydrogenating functions is the main 
parameter that controls the activity and selectivity of the catalyst. A 
weak acid function and a strong hydrogenating function provide 
low-activity catalysts that work at a generally high temperature (greater 
than or equal to 390.degree. C.) and at a volumetric flow rate at low feed 
rate (VVH expressed by volume of feedstock to be treated per unit of 
volume of catalyst and per hour is generally lower than or equal to 2), 
but which have very good selectivity for middle distillates. Conversely, a 
strong acid function and a weak hydrogenating function provide very active 
catalysts but have poor selectivity for middle distillates. It is 
therefore possible, by judiciously choosing each of the functions, to 
adjust the activity/selectivity pair of the catalyst. 
Thus, one of the great advantages of hydrocracking is to have great 
flexibility at various levels: flexibility at the level of the catalysts 
that are used, which ensures flexibility of the feedstocks that are to be 
treated, and at the level of the products that are obtained. An easy 
parameter to control is the acidity of the substrate of the catalyst. 
The vast majority of the conventional catalysts for catalytic hydrocracking 
consist of weakly acidic substrates, such as amorphous silica-aluminas, 
for example. These systems are used to produce middle distillates of very 
good quality and, when their acidity is very low, oil bases. 
The family of amorphous silica-aluminas is among the not very acid 
substrates. Many catalysts on the hydrocracking market consist of combined 
silica-alumina, either a metal of group VIII or, preferably when the 
contents of heteroatomic poisons of the feedstock to be treated exceed 
0.5% by weight, of a combination of sulfides of the metals of groups VIB 
and VIII. These systems have very good selectivity for middle distillates, 
and the products that are formed are of good quality. The less-acid 
representatives of these catalysts can also produce lubricating bases. The 
drawback of all these catalytic systems with an amorphous substrate base 
is, as mentioned, their low activity. 
SUMMARY OF THE INVENTION 
The research work done by the applicant has led him to show that, 
surprisingly, a catalyst that contains at least one dioctahedral 
phyllosilicate 2:1, preferably synthesized in a fluoride medium (in the 
presence of HF acid and/or another source of fluoride anions), then 
pillared (preferably by the method described here), and optionally 
combined with a zeolite Y of faujasite structure, makes it possible to 
achieve a selectivity in middle distillates that is considerably superior 
to that of the catalysts that are known in the prior art. 
This invention relates more specifically to a dioctahedral phyllosilicate 
2:1, whose basal spacing, represented by d.sub.001, is at least equal to 
2.0.times.10.sup.-9 m and that comprises in the interlayer space pillars 
based on (or comprising or eventually consisting of) at least one of the 
compounds that is selected from the group that is formed by SiO.sub.2, 
Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, V.sub.2 O.sub.5, or any 
combination of the latter. 
Preferably, said phyllosilicate contains fluorine. 
According to this invention, the pillared dioctahedral phyllosilicates 2:1 
(preferably previously prepared in a fluoride medium in the presence of HF 
acid and/or another source of fluoride anions) have a basal spacing 
d.sub.001 that is at least equal to 2.0.times.10.sup.-9 m, preferably at 
least equal to 2.65.times.10.sup.-9 m, and even more preferably greater 
than 2.8.times.10.sup.-9 m or else 3.0.times.10.sup.-9 m; distances at 
least equal to 3.3.times.10.sup.-9 m can be achieved particularly in the 
case of pillars SiO.sub.2 --ZrO.sub.2. Said distance is generally less 
than or equal to 6.0.times.10.sup.-9 m, preferably 5.0.times.10.sup.-9 m. 
The basal spacing, represented by d.sub.001, represents the sum of the 
thickness of a layer and interlayer spacing. This value is directly 
accessible by the standard method of X-ray diffraction on oriented powder. 
The invention also relates to a process for the preparation of said 
phyllosilicates in which the phyllosilicate is suspended in a solution of 
a surfactant; then, after the solid is separated from the solution, the 
phyllosilicate is brought into contact with a mixture that comprises at 
least one primary or secondary amine and at least one alkoxide of an 
element that is selected from the group that is formed by Si, Al, Zr, Tl, 
V. 
Dioctahedral phyllosilicates 2:1 are minerals that result from the 
superposition of elementary layers. Although the chemical bonds between 
the elements of the structure of the phyllosilicates are ionocovalent, 
they will be considered ionic in order to simplify the description. 
Starting with a representation where O.sup.2- ions are in contact with one 
another in a plane, it is possible to obtain a plane that has a hexagonal 
cavity, so-called hexagonal plane, by removing one O.sup.2- ion of two in 
a row of two of O.sup.2- ions. 
The structure of a phyllite can be simply represented starting from 
arrangements of hexagonal planes of O.sup.2- ions and compact planes of 
O.sup.2- and OH-- ions. The OH ions fill the cavities of the hexagonal 
planes of O.sup.2- ions. The superposition of two compact planes that are 
situated between two hexagonal planes makes it possible to define an 
octahedral layer (O) between two tetrahedral layers (T), hence the name 
TOT layers. 
Such an arrangement, also referred to as 2:1, makes it possible to define a 
plane of octahedral cavities that is located in the octahedral sheet 
between two planes of tetrahedral cavities, one in each tetrahedral sheet. 
Each tetrahedron has an O.sup.2- ion that is common with the octahedral 
sheet, and each of the three other O.sup.2- ions is shared with another 
tetrahedron of the same tetrahedral sheet. 
The crystalline unit cell thus consists of 6 octahedral cavities that have 
4 tetrahedral cavities on both sides. In the case of a phyllite that 
consists of elements Si, Al, O, H, such an arrangement corresponds to the 
ideal formula Si.sub.4 (Al.sub.4 .quadrature..sub.2)O.sub.20 (OH).sub.4. 
The tetrahedral cavities contain the element silicon, octahedral cavities, 
and the element aluminum, but in this case, one octahedral cavity out of 3 
is empty (.quadrature.). Such a unit is electrically neutral. Often, a 
half unit cell is used, which has as its formula: 
EQU Si.sub.4 (Al.sub.2 .quadrature.)O.sub.10 (OH).sub.2 
The tetrahedral silicon element can be substituted by trivalent elements, 
such as, for example, aluminum or gallium or iron (Te.sup.54). Likewise, 
the octahedral aluminum element can be substituted by: 
the trivalent elements that are cited above, or a mixture of these 
elements, 
divalent elements (Mg). 
These substitutions impart negative charges to the structure. Said negative 
charges account for the existence of exchangeable compensation cations 
that are located in the interlayer space. The thickness of the interlayer 
space depends on the nature of the compensation cations and their state of 
hydration. Furthermore, this space is able to collect other chemical 
radicals, such as water, amines, salts, alcohols, bases, etc. 
The existence of --OH groups produces thermal instability due to the 
dehydroxylation reaction of the equation: 2 --OH-- --O-- +H.sub.2 O. In 
this connection, the introduction, during synthesis, of the fluorine 
element into the structure in place of groups O--H leads to 
phyllosilicates of considerably improved thermal stability. 
The phyllosilicates according to the invention are dioctahedral 
phyllosilicates 2:1, whose characteristics are presented below, in which 
the pillars have been introduced into the interlayer space (whereby the 
pillars are selected from among SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, 
ZrO.sub.2, V.sub.2 O.sub.5) to reach a basal spacing d.sub.001 of at least 
2.0.times.10.sup.-9 m. 
The general chemical formula (for half a unit cell-mesh) of the starting 
dioctahedral phyllosilicates 2:1, preferably synthesized in a fluoride 
medium in the presence of HF acid and/or another source of fluoride 
anions, before pillaring, is the following: 
EQU M.sup.m+.sub.x/m ((Si(.sub.1-z)T.sub.x)(T.sub.2 1)O.sub.10 
(OH)(.sub.2-y)F.sub.y).sup.x- 
where 
T represents an element that is selected from the complex that is formed by 
the elements of group IIIA (such as, for example, B, Al, Ga) and iron. 
M is at least one compensation cation that is selected from the group that 
is formed by the cations of the elements of groups IA, IIA, and VIII, 
whereby the organic cations contain nitrogen, the ammonium cation, and 
cations of rare earths. The cation comes from the reaction medium into 
which introduction is done by at least one exchange process. 
Advantageously, the cation that comes from the reaction medium is selected 
from the group that is formed by the alkalines (except lithium), the 
ammonium cation (NH.sub.4.sup.+), the organic cations that contain 
nitrogen (among which figure alkylammonium and arylammonium), and the 
organic cations that contain phosphorus (among which are alkylphosphonium 
and arylphosphonium). M can also be a compensation cation that is 
introduced by post-synthesis ion exchange, selected from the group that is 
composed of the cations of the elements of groups Ia, IIA, and VIII of the 
periodic table, the cations of rare earths (cations of elements with 
atomic numbers of from 57 to 71 inclusive), organic cations that contain 
nitrogen (among which are alkylammonium and arylammonium), and the 
ammonium cation. 
m is the valence of cation M, 
x is a number between 0 and 2, preferably 0.1 and 0.8; 
y is a number between 0 and 2; if the phyllosilicate contains fluorine, Y 
is greater than 0; 
and .quadrature. represents an octahedral cavity. 
The x-ray diffraction diagram of the starting dioctahedral phyllosilicate 
2:1 (before pillaring) is characterized by the presence of the following 
lines: 
a line that characterizes the d.sub.001 that is equal to 
1.49.+-.0.01.times.10.sup.-10 m in the case where the dioctahedral 
phyllosilicate 2:1 comprises an octahedral sheet whose composition is as 
follows Si(Al.sub.2 .quadrature.). 
at least one reflection 001 such that d.sub.001 is equal to 
1.25.+-.0.3.times.10.sup.-9 m, depending on the nature of the compensation 
cation and its hydration state at the moisture level in question. 
Preferably, the fluorine content is such that molar ratio F/Si is between 
0.1 and 4, and preferably 0.1 and 2. 
Dioctahedral phyllosilicate 2:1 that is fluorinated in synthesis also has 
at least one signal with rotation at the magic angle of .sup.19 F, 
determined and well known to one skilled in the art. The chemical 
displacement of this signal also depends on the composition of the 
octahedral sheet. Thus, it corresponds to a value of: 
133 ppm (.+-.5 ppm) in NMR with rotation at the magic angle of .sup.19 F, 
in the case where the first neighbors of F are two aluminum atoms; this 
corresponds to an octahedral sheet whose composition is Si(Al.sub.2 O), 
108 ppm (.+-.5 ppm) in NMR with rotation at the magic angle of .sup.19 F, 
in the case where the first neighbors of F are two gallium atoms; this 
corresponds to an octahedral sheet whose composition is Si(Ga.sub.2 
.quadrature.), 
118 ppm (.+-.5 ppm) in NMR with rotation at the magic angle of .sup.19 F, 
in the case where the first neighbors of F are an aluminum atom and a 
gallium atom; this corresponds to an octahedral sheet whose composition is 
the following Si(Ga,Al.quadrature.). 
Said phyllosilicates can advantageously be synthesized in a fluoride medium 
in the presence of HF acid and/or another source of fluoride anions and at 
a pH of less than 9, and preferably between 0.5 and 6.5. 
The preparation of these kinds of solids in fluoride medium and their 
characterization are described in the references below, whose teaching is 
included in this description: Patent FR-A-2673930, a publication at the 
202nd meeting of the American Chemical Society (ACS) in New York in August 
1991, whose contents were published in Synthesis of Microporous Materials, 
Extended Clays and Other Microporous Solids (1992), a report from the 
Academie des Sciences [Academy of Sciences] Paris, t. 315, Series II, pp. 
545-549, 1992. 
These dioctahedral phyllosilicates 2:1 are pillared by, for example, a new 
process that comprises the following stages: 
the dioctahedral phyllosilicate 2:1, preferably in its NH.sub.4 form, is 
suspended in a solution of a surfactant whose concentration varies between 
0.01 mol/liter and 1 mol/liter, and preferably between 0.05 and 0.7 
mol/liter. The surfactants that can be used in this stage are of the 
anionic type, such as, by way of nonlimiting examples, alkylsulfates and 
alkylsulfonates or else of the cationic type which include, e.g., the 
halides or hydroxides of tetraalkylammonium such as ketyltrimethylammonium 
chloride or geminate alkylammonium. 
By way of example, hexadecyltrimethylammonium bromide, 
ethylhexadecyldimethylammonium bromide, octadecyltrimethyl ammonium 
bromide, dodecyltrimethylammonium bromide, and didodecyldimethylammonium 
bromide can be used. It is possible to use neutral surfactants, such as, 
for example, triton X-100 or polyethylene oxides (POE). 
After a period of contact, during which the medium is stirred, of between 5 
minutes and 12 hours and preferably between 15 minutes and 6 hours, and 
even more preferably between 15 minutes and 3 hours, the entire complex is 
filtered and then washed with distilled water, and then finally dried 
under air or inert gas at a temperature of between 40 and 150.degree. C.; 
for a period of between 5 minutes and 24 hours and preferably between 30 
minutes and 12 hours. 
In the case where the phyllosilicate is not in ammonium form, it can first 
undergo any treatment that is known to one skilled in the art to obtain 
the dioctahedral phyllosilicate 2:1, which is for the most part in its 
ammonium form. It is possible to cite, by way of a nonlimiting example of 
a treatment to bring about this transformation, ion exchange by aqueous 
solutions of an ammonium salt (ammonium nitrate and/or ammonium chloride). 
dioctahedral phyllosilicate 2:1 that is treated according to the operating 
procedure that is described in the preceding stage is then brought into 
contact with a mixture that comprises: 
i) at least one primary amine of RNH.sub.2 type or a secondary amine R'RNH, 
where R and R' are advantageously selected from among the entire complex 
that is formed by the carbon-containing, alkyl, iso-alkyl, naphthenyl, and 
aromatic groups that may or may not be substituted by other groups and can 
contain 1 to 16 carbon atoms, 
ii) at least one alkoxide of one element or a mixture of alkoxides, whereby 
the element is selected from the entire complex that is formed by silicon, 
aluminum, zirconia, titanium, and vanadium, of general formula M(OR)n, 
where M is the element that is described above, n is the valence degree of 
said element, and R is a group that is advantageously selected from the 
entire complex that is formed by the alkyl, iso-alkyl, naphthenyl, and 
aromatic groups, which may or may not be substituted. The various --OR 
groups can be identical or different, depending on the nature of group R 
that is selected from the entire complex that is defined above. 
The entire complex is allowed to remain in contact, preferably while being 
stirred, during a period of between 5 minutes and 12 hours and preferably 
between 5 minutes and 8 hours, 
iii) the dioctahedral phyllosilicate 2:1 that is thus pillared is next 
filtered and then dried under air or under inert gas at a temperature of 
between 40 and 150.degree. C.; for a period of between 5 minutes and 24 
hours and preferably between 30 minutes and 12 hours. 
This pillaring process makes it possible to introduce simply and quickly 
pillars SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, V.sub.2 O.sub.5 
or a mixture of these pillars into the interlayer space of the 
dioctahedral phyllosilicates 2:1, which are advantageously prepared in a 
fluoride medium. 
Compared to the basic dioctahedral phyllosilicate 2:1, the phyllosilicate 
according to the invention has an x-ray diffraction spectrum that makes it 
possible to evaluate the basal spacing d.sub.001, which is thus clearly 
increased to a value of at least 2.0.times.10.sup.-10 m. It is also 
observed that the specific surface area has increased; it is then 
generally between 200 and 1000 m.sup.2 /g and preferably between 250 and 
700 m.sup.2 /g. X-ray spectrum lines d.sub.060 and NMR lines in rotation 
at the magic angle of .sup.19 F are preserved. 
This invention also relates to a catalyst that comprises at least one 
dioctahedral phyllosilicate 2:1 (as described above), whose basal spacing 
is at least equal to 2.0.times.10.sup.-9 m and which comprises pillars 
based on at least one of the compounds that are selected from the group 
that is formed by SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2 and 
V.sub.2 O.sub.5 or any combination of the latter, at least one matrix, and 
optionally one zeolite Y. 
The catalyst of this invention can also contain a zeolite Y with a 
faujasite structure (Zeolite Molecular Sieves Structure, Chemistry and 
Uses, D. W. BRECK, J. WILLEY and Sons 1973), in particular a dealuminated 
zeolite Y with a crystalline parameter of 24.24 to 24.55.times.10.sup.-10 
m. Among zeolites Y that can be used, a stabilized zeolite Y, commonly 
called ultrastable or DSY, will preferably be used either in at least 
partially exchanged form with metal cations, for example, alkaline-earth 
metal cations and/or cations of rare earth metals with an atomic number of 
57 to 71 inclusive, or in hydrogen form. 
An acidic zeolite H-Y is particularly advantageous and is characterized by 
various specifications: an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio of 
between 8 and 70 and preferably between about 12 and 40; a sodium content 
that is less than 0.15% by weight that is determined in the zeolite that 
is calcined at 1 100.degree. C.; a crystalline parameter of the elementary 
unit cell that is between 24.55.times.10.sup.-10 m and 
24.24.times.10.sup.-10 m and preferably between 24.38.times.10.sup.-10 m 
and 24.26.times.10.sup.-10 m; a sodium ion uptake capacity CNa, expressed 
in grams of Na per 100 grams of modified zeolite, neutralized and then 
calcined, of greater than about 0.85; a specific surface area, determined 
by the B.E.T. method, of greater than about 400 m.sup.2 /g, and preferably 
greater than 550 m.sup.2 /g; an adsorption capacity for water vapor at 
25.degree. C. at a partial pressure of 2.6 Torr (or 34.6 MPa) of greater 
than about 6%, a pore distribution, determined by nitrogen physisorption, 
that encompasses between 5 and 45% and preferably between 5 and 40% of the 
total pore volume of the zeolite that is contained in the pores with a 
diameter of between 20.times.10.sup.-10 m and 80.times.10.sup.-10 m, and 
between 5 and 45% and preferably between 5 and 40% of the total pore 
volume of the zeolite that is contained in the pores with a diameter of 
greater than 80 to 10.sup.-10 m and generally less than 
1000.times.10.sup.-10, whereby the rest of the pore volume is contained in 
the pores with a diameter of less than 20.times.10.sup.-10 m. 
The catalyst of this invention also contains at least one matrix that is 
usually amorphous or poorly crystallized and is selected from, for 
example, the group that is formed by alumina, silica, magnesia, titanium 
oxide, zirconia, aluminum phosphates, titanium phosphates or zirconium 
phosphates, boron oxide, combinations of at least two of these compounds, 
and boron alumina-oxide combinations. 
The matrix is preferably selected from the group that is formed by silica, 
alumina, magnesia, silica-alumina combinations, and silica-magnesia 
combinations. 
The catalyst of this invention therefore contains: 
a) From 1 to 80%, or else 4 to 70%, preferably 10 to 60% and even more 
preferably 15 to 50% by weight of at least one dioctahedral phyllosilicate 
2:1 that is preferably synthesized in a fluoride medium and pillared, 
b) 0 (or 0.1) to 30%, preferably 0 (or 0.1%) to 20% and even more 
preferably 0 (or 0.1) to 10% of at least one zeolite Y with a faujasite 
structure, hydrogen form, preferably having the characteristics that are 
set forth above, 
c) 1 to 99% by weight of at least one matrix that is defined above. 
The catalyst of this invention can be prepared by any methods that are well 
known to one skilled in the art. One of the preferred methods in this 
invention consists in mixing the pillared dioctahedral phyllosilicate 2:1 
and optionally a zeolite Y in a wet alumina gel for several tens of 
minutes and then passing the paste that is thus obtained through a die to 
form extrudates with a diameter of between 0.4 and 4 mm. 
Generally, the catalyst also contains at least one catalytic element, for 
example a metal that has a hydro-dehydrogenating function. The 
hydro-dehydrogenating function is generally provided by at least one metal 
or metal compound of group VIII, such as nickel and cobalt in particular. 
It is possible to use a combination of at least one metal or metal 
compound of group VI (in particular molybdenum or tungsten) and at least 
one metal or metal compound of group VIII (in particular cobalt or nickel) 
of the periodic table. The total concentration of metal oxides of groups 
VI and/or VIII is between 1 and 40% by weight and preferably between 3 and 
40%, advantageously between 8 and 40%, even 10 to 40% and even better 
10-30% by weight, and the ratio by weight, expressed in metal oxide of 
metal (or metals) of group VI to metal (or metals) of group VIII, is 
between 1.25 and 20 and preferably between 2 and 10. Moreover, this 
catalyst can contain phosphorus. The phosphorus content, expressed in 
phosphorus oxide concentration P.sub.2 O.sub.5, will be less than 15% by 
weight and preferably less than 10% by weight. 
The hydrogenating function as defined above (metals of group VIII or a 
combination of metal oxides of groups VI and VIII) can be introduced into 
the catalyst with various levels of preparation and in various ways. 
Said hydrogenating function can be introduced either in part only (case of 
combinations of metal oxides of groups VI and VIII) or in its entirety at 
the time when dioctahedral phyllosilicate 2:1, synthesized in the fluoride 
medium and pillared, is mixed with the oxide gel that is selected as 
matrix. Said hydrogenating function can be introduced by one or more ion 
exchange operations on the calcined substrate that consists of the 
dioctahedral phyllosilicate 2:1 that is synthesized in a fluoride medium 
and optionally pillared and distributed in the selected matrix, with the 
aid of solutions that contain the precursor salts of the metals that are 
selected when the latter belong to group VIII. Said hydrogenating function 
can be introduced by one or more impregnation operations of the substrate 
that is shaped and calcined, by a solution of the precursors of the metal 
oxides of groups VIII (in particular cobalt and nickel) when the 
precursors of the metal oxides of groups VI (in particular molybdenum or 
tungsten) have been previously introduced at the time of mixing of the 
substrate. Finally, said hydrogenating function can be introduced by one 
or more impregnation operations of the calcined substrate that consist of 
a dioctahedral phyllosilicate 2:1 that is synthesized in a fluoride medium 
and pillared and of the matrix, by solutions that contain the precursors 
of the metal oxides of groups VI and/or VIII, whereby the precursors of 
the metal oxides of group VIII are preferably introduced after those of 
group VI or at the same time as the latter. 
In the case where the metal oxides are introduced in several impregnations 
of the corresponding precursor salts, an intermediate calcination stage of 
the catalyst should be carried out at a temperature of between 250 and 
600.degree. C. 
The impregnation of molybdenum can be facilitated by adding phosphoric acid 
to the solutions of ammonium paramolybdate. 
The catalysts that are thus obtained are used in general for the conversion 
of hydrocarbons, and in particular for hydrocracking. In hydrocracking, 
compared to the prior art, they have greater selectivity for the 
production of middle distillates of very good quality. 
The feedstocks that are used in the process are gas-oils, gas-oils under 
vacuum, deasphalted or hydrotreated residues or equivalents. These can be 
heavy fractions that consist of at least 80% by volume of compounds whose 
boiling points are between 350 and 580.degree. C. (i.e., corresponding to 
compounds that contain at least 15 to 20 carbon atoms). They generally 
contain heteroatoms such as sulfur and nitrogen. The nitrogen content is 
usually between 1 and 5000 ppm by weight, and the sulfur content is 
between 0.01 and 5% by weight. The hydrocracking conditions, such as 
temperature, pressure, hydrogen recycling rates, and hourly volume 
velocity, can be highly variable depending on the nature of the feedstock, 
the quality of desired products, and the installations that the refiner 
uses. 
The temperatures are generally greater than 230.degree. C. and are often 
between 300.degree. C. and 480.degree. C., preferably less than 
450.degree. C. Pressure is greater than or equal to 2 MPa and in general 
greater than 3 MPa, even 10 MPa. The hydrogen recycling rate is at least 
100 and often between 260 and 3000 liters of hydrogen per liter of 
feedstock. The hourly volume velocity is in general between 0.2 and 10 
h.sup.-1. 
The results that are important to the refiner are activity and selectivity 
for middle distillates. The targets that are set should be achieved under 
conditions that are compatible with economic reality. Thus, the refiner 
seeks to reduce the temperature, the pressure, and the hydrogen recycling 
rate and to maximize the hourly volume velocity. It is known that 
conversion can be increased by raising temperature, but this is often at 
the expense of selectivity. Selectivity for middle distillates is improved 
if the pressure or hydrogen recycling rate is increased, but this is at 
the expense of the economy of the process. This type of catalyst makes it 
possible to achieve, under standard operating conditions, selectivities 
for middle distillates with a boiling point of between 150.degree. C. and 
380.degree. C. that are greater than 65%, for conversion levels, in 
products with a boiling point of less than 380.degree. C. (380.degree. 
C.), or more than 55% by volume. This catalyst also exhibits, under these 
conditions, remarkable stability. Finally, because of the composition of 
the catalyst, the latter can be easily regenerated. 
In general, it has been observed that dioctahedral phyllosilicates 2:1 
according to the invention have remarkable thermal stability since they 
are able to withstand temperatures of 800.degree. C. without degradation.

The following examples illustrate this invention without, however, limiting 
its scope. 
EXAMPLE 1 
Preparation of a Pillared Dioctahedral Phyllosilicate 2:1 (PDP1), which is 
of the Beidellite Type in a Na Form, According to the Invention. 
For this preparation, the following are added to 36 g of distilled water 
successively and according to the indications provided: 
0.31 g of NaF salt (Prolabo) while being stirred moderately, 
0.66 g of HF acid at 40% (Fluka), 
2.35 g of hydrated AlOOH oxyhydroxide (Catapal B Vista) while being stirred 
vigorously, 
2.50 g of powdered SiO.sub.2 oxide (Aerosil 130 from Degussa), while being 
stirred moderately. 
The composition of the hydrogel that is thus prepared, referred to one mol 
of SiO.sub.2 oxide, is 
EQU 1.0 SiO.sub.2 ; 0.382 Al.sub.2 O.sub.3 ; 0.177 NaF; 0.20 HF; 48 H.sub.2 O 
or, in terms of molar ratio: 
______________________________________ 
Si/Al = 1.309 
Na'/Si = 0.177 
F/Si = 0.377 
HF/Si = 0.20 
H.sub.2 O/Si = 48. 
______________________________________ 
This composition does not take into account the water that is supplied by 
the aluminum source and by the HF acid. 
The hydrogel that is thus obtained is cured for 4 hours at ambient 
temperature (20.degree. C.) while being stirred moderately. The pH is then 
close to 5. 
Crystallization is then carried out in a steel autoclave, sheathed with a 
coating of polytetrafluoroethylene (Teflon), with a capacity of 120 ml, at 
220.degree. C., under autogenous pressure for 168 hours without stirring. 
The autoclave is then cooled with ambient air. The pH at the end of 
synthesis is about 4. 
The product is then recovered, filtered, and washed thoroughly with 
distilled water. It is then dried at 40-50.degree. C. for 24 hours. At the 
end of these 24 hours, the product that is obtained, at 50% relative 
humidity, is characterized by is x-ray diffraction diagram that is 
indicated below: 
______________________________________ 
d.sub.hkl (A) 
I/Io 
______________________________________ 
12.42 100 
6.22 6 
4.46 55 
2.55 21 
2.48 15 
2.25 2 
2.22 3.5 
1.74 6 
1.73 6 
1.69 13 
1.66 7 
1.62 2 
1.48 20 
______________________________________ 
The swelling properties of the phyllosilicate that is obtained are recorded 
in the table below: 
______________________________________ 
14% glycerol in 
HR 50% HR 80% ethanol 
______________________________________ 
d.sub.hkl (A) 
12.4 15.5 17.6 
______________________________________ 
HR: Relative humidity. 
The content by weight of the phyllosilicate fluorine that is obtained is 
3.15%. A signal at -133 ppm, which is obtained with rotation at the magic 
angle of .sup.19 F of the phyllosilicate that is prepared according to 
this example, is present in the NMR spectrum. 
The solid that is thus prepared is then subjected to three successive 
ion-exchange treatments with an ammonium nitrate solution to obtain the 
NH.sub.4.sup.4 form of the phyllosilicate. For this purpose, 10 grams of 
phyllosilicate that is prepared in advance is suspended in 250 ml of a 
molar solution of ammonium nitrate and then stirred under reflux for 2 
hours. The solid is then filtered and washed. This treatment cycle is 
repeated twice more. The solid that is obtained in then dried at 
60.degree. C. for 10 hours. 
The dioctahedral phyllosilicate 2:1 that is thus prepared is referred to as 
PD1. The latter will then undergo a pillaring stage according to the 
operating procedure that is described below. 
8 g of the dioctahedral phyllosilicate 2:1 that is thus prepared and is 
referred to as PD1 and in the form of NH.sub.4 is suspended in 80 ml of a 
hexadecyltrimethylammonium chloride (CTMA-C1) solution with a 
concentration of 0.1 M. After an hour of stirring at ambient temperature, 
the entire complex is filtered, washed with 200 ml of distilled water 
twice, and then dried at 60.degree. C. for 8 hours. The PD1 sample, which 
was previously treated with CTMA, is suspended with a mixture that 
consists of 4.48 g of octylamine (C.sub.8 H.sub.17 NH.sub.2) and 60.32 g 
of ethyl tetraorthosilicate (Si(OEt).sub.4. After 30 minutes of stirring, 
the entire complex is filtered and then dried at 60.degree. C. for 8 
hours. The sample is then calcined at 530.degree. C. for 3 hours under air 
and then for 2 hours under pure oxygen. 
The d.sub.001 of the sample after calcination is 34.6 .ANG., and its 
specific surface area is 390 m.sup.2 /g. 
The dioctahedral phyllosilicate 2:1 that is thus prepared is referred to as 
PDP1. 
EXAMPLE 2 
Preparation of Catalyst C1 (According to the Invention) 
Dioctahedral phyllosilicate 2:1 PP1 as described in Example 1 is mixed with 
the alumina of type SB3 that is supplied by the Condea Company. The mixed 
paste is then extruded through a die with a diameter of 1.4 mm. The 
extrudates are impregnated dry with a solution of a mixture of ammonium 
heptamolybdate, nickel nitrate, and orthophosphoric acid, and finally 
calcined under air at 55020 C. in situ in the reactor. The contents by 
weight of active oxides are as follows (relative to the catalyst): 
2.5% by weight of phosphorus oxide P.sub.2 O.sub.6 
15% by weight of molybdenum oxide MoO.sub.3 
5% by weight of nickel oxide NiO 
The pillared clay content in the entire catalyst is 30%. 
EXAMPLE 3 
Preparation of a Pillared Diooctahedral Phyllosilicate 2:1 PDP2, which is a 
Beidellite in Ammonium Form, According to the Invention. 
For this preparation, the following are added to 36 g of distilled water 
successively and according to the indications provided: 
0.385 g of NH.sub.4 F salt (Prolabo) while being stirred moderately, 0.312 
g of HF acid at 40% (Fluka), 
2.71 g of hydrated AlOOH oxyhydroxide (Catapal B Vista) while being stirred 
vigorously, 
2.50 g of powdered SiO.sub.2 oxide (Aerosil 130 from Degussa), while being 
stirred moderately. 
The composition of the hydrogel that is thus prepared, referred to one mol 
of SiO.sub.2 oxide, is 
EQU 1.0 SiO.sub.2 ; 0.44 Al.sub.2 O.sub.3 ; 0.25 NH.sub.4 F; 0.15 HF; 48 
H.sub.2 O 
or in terms of molar ratio: 
______________________________________ 
Si/Al = 1.136 
NH.sub.4 '/Si = 0.25 
F/Si = 0.40 
HF/Si = 0.15 
H.sub.2 O/Si = 48. 
______________________________________ 
This composition does not take into account the water that is supplied by 
the aluminum source and by the HF acid. 
The hydrogel that is thus obtained is cured for 4 hours at ambient 
temperature (20.degree. C.) while being stirred moderately. The pH is then 
close to 5. 
Crystallization is then carried out in a steel autoclave, sheathed by a 
Teflon coating, with a capacity of 120 ml, at 220.degree. C., under 
autogenous pressure for 168 hours without stirring. The autoclave is then 
cooled with ambient air. The pH at the end of synthesis is about 5.5. 
The product is then recovered, filtered, and washed thoroughly with 
distilled water. It is then dried at 40-50.degree. C. for 24 hours. At the 
end of these 24 hours, the product that is obtained, at 50% relative 
humidity, is characterized by its x-ray diffraction diagram, which is 
similar to the one that is provided in the table of Example 1. 
The content by weight of the phyllosilicate fluorine that is obtained is 
2.9%. A signal at -133 ppm, which is obtained with rotation at the magic 
angle, of .sup.19 F of the phyllosilicate that is prepared according to 
this example is present in the NMR spectrum. 
The dioctahedral phyllosilicate 2:1 that is thus prepared is referred to as 
PD2. The latter will then undergo a pillaring stage according to the 
operating procedure that is described below. 
8 g of the dioctahedral phyllosilicate 2:1 that is thus prepared and 
referred to as PD2 and is ammonium form is suspended in 80 ml of a 
hexadecyltrimethylammonium chloride solution (CTMA-Cl) with a 
concentration of 0.1 M. After one hour of stirring at ambient temperature, 
the entire complex is filtered, washed with 2.times.200 ml of distilled 
water, and then dried at 60.degree. C. for 8 hours. The PD2 sample that is 
treated with CTMA above is suspended in a mixture that consists of 4.48 g 
of octylamine (C.sub.8 H.sub.17 NH.sub.2) and 60.32 g of ethyl 
tetraorthosilicate (Si(OEt).sub.4) and 2.96 g of aluminum isoproxide. 
After 30 minutes of stirring, the entire complex is filtered and then 
dried at 60.degree. C. for 8 hours. The sample is then calcined at 
530.degree. C. for 3 hours under air and then for 2 hours under pure 
oxygen. 
The d.sub.001 of the sample after calcination is 31.2 .ANG. and a specific 
surface area of 375 m.sup.2 /g. 
The dioctahedral phyllosilicate 2:1 that is thus prepared is referred to as 
PDP2. 
EXAMPLE 4 
Preparation of Catalyst C2 (According to the Invention) 
Catalyst C2 is prepared according to the same operating procedure as the 
one that is described in Example 2, but this time using dioctahedral 
phyllosilicate 2:1 PDP2. 
The pillared clay content by weight in the entire catalyst is 30%. 
EXAMPLE 5 
Preparation of a Pillared Dioctahedral Phyllosilicate 2:1 PDP3, which is an 
H-Shaped Beidellite with SiO.sub.2 --ZrO.sub.2 Pillars 
10 g of beidellite PD2, prepared according to Example 3 of this patent and 
calcined at 550.degree. C. for 4 hours, is suspended in 442 ml of an 
ethylhexadecyldimethylammonium bromide solution (EtC.sub.16 DMABr) of 0.1 
M. After 1 hour of stirring at ambient temperature, the entire complex is 
filtered and then dried at 60.degree. C. for 1 night (about 12 hours). 
5 g of the PD2 beidellite that is treated by EtC.sub.16 DMABr is suspended 
in a mixture that consists of 37.7 g of ethyl tetraorthosilicate (TEOS), 
1.4 g of Zr(OC.sub.3 H.sub.7).sub.4, and 2.8 g of octylamine 
(TEOS/octylamine=8.2 and TEOS/Zr(OC.sub.3 H.sub.7).sub.4 =40 molar 
ratios). The entire complex is stirred for 30 minutes at room temperature, 
and then filtered and dried at 60.degree. C. for 12 hours. The material is 
then calcined at 600.degree. C. according to the following program: 
temperature raised from ambient temperature to 600.degree. C. in 8 hours, 
calcination under dry air at 600.degree. C. for 4 hours, and then 
temperature is dropped back to ambient temperature. 
The mass loss due to calcination is on the order of 23%. Periodicity 
d.sub.001 of product PDP3 is 37.4 .ANG., and the specific surface area is 
on the order of 530 m.sup.2 /g. 
EXAMPLE 6 
Catalyst C4 according to the invention is then prepared according to the 
operating procedure that is described in Example 2 using the PDP3 sample. 
The content by weight of pillared beidellite PDP3 according to the 
invention, in the entire catalyst C4, is 50%. 
EXAMPLE 7 
Preparation of a Pillared Dioctahedral Phyllosilicate 2:1 PDP4, which is an 
H-Shaped Beidellite with by SiO.sub.2 Pillars. 
5 g of beidellite in the form of treated hydrogen EtC.sub.18 DMABr is 
suspended in a mixture of 37.7 g of TEOS and 1.26 g of decylamine 
(C.sub.10 H.sub.21 NH.sub.2). After 30 minutes of stirring, the entire 
complex is filtered and dried at 60.degree. C. before being calcined at 
600.degree. C. according to the operating procedure that is described 
above in Example 5. 
The mass loss as a result of calcination in this case reaches 22%. 
Periodicity d.sub.001 of referenced sample PDP4 is 37 .ANG., and the 
specific surface area is about 460 m.sup.2 /g. 
EXAMPLE 8 
Catalyst C5 according to the invention is then prepared according to the 
operating procedure that is described in Example 2 by using sample PDP4. 
The content by weight of pillared beidellite PDP4 according to the 
invention, in the entire catalyst C5, is 40%. 
EXAMPLE 9 
Preparation of Catalyst C3 (Not According to the Invention) 
For this example, a zeolite H-Y is used whose physiochemical 
characteristics are as follows: 
Overall atomic Si/Al (measured by X fluorescence): 17.5 
skeleton atomic Si/Al (determined by NMR of .sup.29 Si): 21 
Na content (ppm by weight): 450 
crystalline parameter (x-ray diffraction) (.ANG.): 24.27 
3% by weight of pure nitric acid is added to 67% by dry weight of zeolite 
powder H-Y to ensure the peptization of the powder. After mixing, the 
paste that is obtained is extruded through a die with a diameter of 1.4 
mm. The extrudates are calcined, then impregnated dry with a solution of a 
mixture of ammonium heptamolybdate, nickel nitrate and orthophosphoric 
acid, and finally calcined under air at 550.degree. C. in situ in the 
reactor. The contents by weight of active oxides are as follows (relative 
to the catalyst): 
2.5% by weight of phosphorus oxide P205, 
15% by weight of molybdenum oxide MoO3, 
5% by weight of nickel oxide NiO. 
The content by weight of H-Y zeolite in the entire catalyst is 10%. 
EXAMPLE 10 
Evaluation of Catalysts C1, C2, C3, C4, and C5 in a Hydrocracking Test 
Catalysts C1, C2, C3, C4 and C5, the steps for whose preparation are 
described in the examples above, are used under hydrocracking conditions 
on a petroleum feedstock whose main characteristics are as follows: 
______________________________________ 
starting point 277.degree. C. 
10% point 381.degree. C. 
50% point 482.degree. C. 
90% point 531.degree. C. 
end point 545.degree. C. 
pour point +39.degree. C. 
density (20/4) 0.919 
sulfur (% by weight) 2.46 
nitrogen (% by weight) 930 
______________________________________ 
The catalytic test unit comprises a fixed-bed reactor, with upward 
circulation of the feedstock ("up-flow"), into which is introduced 80 ml 
of catalyst. Each of the catalysts is sulfurated with an 
n-hexane/DMDS+aniline mixture up to 320.degree. C. The total pressure is 9 
MPa, the hydrogen flow is 1000 liters of gaseous hydrogen per liter of 
injected feedstock, and the hourly volume velocity is 1.0. 
The catalytic performance levels are expressed by coarse selectivity, which 
is measured for a coarse conversion of 70% by weight. These catalytic 
performance levels are measured on the catalyst after a stabilization 
period, generally at least 48 hours, has elapsed. 
Coarse conversion CB is set equal to: 
CB=% by weight of 380- in the effluents 
Coarse selectivity (% by weight) SB is set equal to: 
##EQU1## 
______________________________________ 
C3 C5 
C1 C2 not C4 accord- 
according according according according ing to 
to the to the to the to the in- 
Catalysts invention invention invention invention vention 
______________________________________ 
SB (70% CB) 
73.5 72.9 68.2 74.1 73.0 
______________________________________ 
The use of a pillared dioctahedral phyllosilicate 2:1 according to the 
invention therefore makes possible a substantial gain in selectivity for 
middle distillates with iso-conversion. 
EXAMPLE 11 
Evaluation of Catalysts C1, C2 and C3 in a Low-Pressure Hydrocracking Test 
Catalysts C1, C2, and C3 have been compared in a low-pressure hydrocracking 
test, which is also called mild hydrocracking. The feedstock that is used 
during the catalytic test is the same as the one used in Example 10. 
The catalytic test unit comprises a fixed-bed reactor, with upward 
feedstock circulation ("up-flow"), into which is introduced 80 ml of 
catalyst. Each of the catalysts is sulfurated with an 
n-hexane/DMDS+aniline mixture to 320.degree. C. The total pressure is 5 
MPa, the hydrogen flow is 500 liters of gaseous hydrogen per liter of 
injected feedstock, and the hourly volume velocity is 0.5. 
The catalytic performance levels are expressed by coarse selectivity for a 
coarse conversion of 50%. These catalytic performance levels are measured 
on the catalyst after a stabilization period, generally at least 48 hours, 
has elapsed. 
Coarse conversion CB is set equal to: 
CB=% by weight of 380- in the effluents 
Coarse selectivity (% by weight) SB is set to equal to: 
##EQU2## 
______________________________________ 
C3 
C1 C2 not according 
according to the according to the to the 
Catalyst invention invention invention 
______________________________________ 
SB (50% CB) 
84.2 84.8 80.5 
______________________________________ 
The preceding examples can be repeated with similar success by substituting 
the generically or specifically described reactants and/or operating 
conditions of this invention for those used in the preceding examples. 
The entire disclosure of all applications, patents and publications, cited 
above, and of corresponding French applications No. 97/12.864 and 
97/12.865, are hereby incorporated by reference. 
From the foregoing description, one skilled in the art can easily ascertain 
the essential characteristics of this invention, and without departing 
from the spirit and scope thereof, can make various changes and 
modifications of the invention to adapt it to various usages and 
conditions.