Title of Invention

A CONDITIONED COMPOSITION COMPRISING AT LEAST ONE LIQUID ABSORBED ON A SUPPORT

Abstract

The present invention relates to a conditioned composition comprising at least one liquid absorbed on a support containing a precipitated silica, characterized in that the said silica is in the form of substantially spherical beads and has: - an average bead size in excess of 150 µm, - a packed filling density (PFD) in excess of 0.29, - a 75 µm screen oversize of at least 92% by weight, - an oil absorption value (DOP) of at least 250 ml/100 g, wherein the said composition has a liquid content of at least 50% by weight, in particular between 50 and 65% by weight.

Full Text

The present invention concerns a composition comprising a liquid, in particular a liquid supplement for animal feed, absorbed on a support based on a particular precipitated silica. It also relates to the use of this silica as a support for liquid. It is known to condition liquids, in particular animal feed additives, on solid supports, in particular on a ailiaa support. The aim of this conditioning is generally to convert a liquid which is not, or not readily handleable into a fluid powder that can be stored with ease, for example in bags, and can be handled more straightforwardly, thus being readily dispersible and easy to mix with other divided solid constituents. In the explanation which follows, the term conditioned composition will be used to refer to the composition thus obtained, that is to say a liquid absorbed on a silica support. This conditioned composition is to be readily handleable, which implies a high degree of fluidity and little dust formation, it ia also to contain a fairly large proportion of active material (liquid) and to have a high density. These various requirements are sometimes contradictory, and are often not fulfilled by tha silica upports of to prior art. The principal object of tha invention ia thus to provida a novel form of conditioned composition which furtharmore advantageously haa both & high degree of fluidity, produces vary little or no dust and haa a high density. TO thia end, tha Applicant Company has found it particularly satisfactory to use a precipitated silica whichr amongst other things, haa a highly specific morphology, in the ease in point being in the form of substantially spherical beads, and a relatively high average particle size, as a support for liquids, in particular for vitamin E (or its acetate). In the following explanation, the average particle size is measured according to the standard NF x 11607 (December 1970) by dry screening and determining tha diameter corresponding to a 50% cumulative residue. The packed filling density (FFD) is determined according to the standard NF T 30-042. Tha DOP oil absorption value is aaaeured according to the standard NF T 30-022 (March 1953) using dioctylphthalate. The pore volumes which are given are measured by mercury porosymmetry/. each sample may be prepared as follows each sample is predried for 2 hours in am oven at 200 C, then placed in a test container within 5 minutes after removal from the oven and degassed under vacuum, fox example using e rotary valve pump; the port diameters are calculated using WASHBURN" relationship with a contact angle that equal to 140" and a surface tension gamma equal to 484 dynea/csi (MICROHSRITICS 9300 poroflimefcer). The BET specific surface is determined aocording to th* BRUNAUKR-EMHST-TELLER mathod described in "The journal of the American Chemical Society", Vol. 60, page 309, February 193B and corresponding to tha standard NT T 45007 (November 1987). Tha CTAB specific surface is the external surface area determined according to the standard N? T 45007 (November 19B7) (5.12). Tha flow tine tt of the conditioned compositions, which illustrates their flowabllity, is measured by passing 50 grams of product through a glass hopper with a calibrated orifice: cylinder diameter: 50 mm; cylinder height: 64 μm cone angle.- 53°; passage diameter at cone baset 6 am. According to this method, the hopper, which is closed at its base, is filled using 50 grams of product; then its base is opened and the transit time, referred to as the flow time t, of the product, after all of the said 50 grama have flowed through is noted. The angle of repose is measured according to tha standard OT T 20-221. The composition according to the invention comprises at least one liquid absorbed on a support containing a precipitated silica, the said preeipitated silica being in the form of substantially spherical beads, and having: en average bead si" in axeaas of 150 μm, a packed filling denaity (WD) in exaess of 0.29, m 75 pun acreen. oversize o£ at least 92% by weight. The preeipitated silica used in the conditioned composition according to the invention is thua in a highly specific form, in the aase in point in tho form of substantially spherical beads. The average size of the said beads ia in excess of 150 fan, and advantageously equal to at least 200 μm general, it is at moat 320 μm, preferably at most 300 μm it may be between 200 and 290 μm, in particular between 210 and 285 μm, for example between 215 and 260 μm. This size may, in particular, be between 260 and 2B0 μm The said precipitated silica has u, fairly high densityi its packed filling density (PFD) la in excess of 0.29. It is preferably at least 0.30, in particular at least 0.31. it may be at least 0.32. This silica has a 75 μm screen oversize of at least 92% by weight, preferably at least 93% by weight. This means that at Least 92% by weight, preferably at least 93% by weight, of the particles of this silica are retained by a screen whose mesh size is 75 (m. This silica thus has a low proportion by weight of fine particles. Even more preferably, its 75 μm screen oversize is at leaet 94% by Weight, in particular at least 95% by weight; it may for example be at least 96% by weight, or even at least 97% by weight. It is generally at most 98% by weight, in particular at mast 97,5% by weight. Tbe precipitated silica used in the conditioned gompoeition according to the invention therefore produces little dust. ingeneral, it has an oil absorption value (POP) of at least 250 ml/100 g, preferably between 250 and 280 ml/100 g. It may be between 255 and 275 ml/100 g, for axample between 255 and 270 ml/100 g. The said silica customarily has a pore volume (Vai) made up of pores having a diameter smaller than μm of lass than 1.95cm2/g, in particular of lose than 1.90 eaVg, Its BET specific surface is generally between 140 and 240 »Vg, in particular between 140 and 200 mVg. It is for example between 150 and 190 ma/g. It may in particular be between 160 and 170 aa/g. Its CTAB specific surface may be between 140 «nd 230 mVg, in particular between 140 and 190 mVg. It is for example between 150 and 1B0 aVg, in particular between 150 and 165 ma/g. It generally has a low moisture content; its moisture content (loss on drying at 105"C for 2 hours) la preferably less than 5% by weight. Advantageously, the silica employed in the composition according to the invention results from the use of a nozzle atomizer to dry a suspension at silica obtained by precipitation. Preferably, the said silica suspension to be dried has a solids content of between 22 and 24% by weight/ preferably between 33.5 and 33.5% by weight. this silica may be prepared according to a process of the type comprising the reaction of a nilioate with an acidifying agent* by means of which a suspension of precipitated silica is obtained . following which this suspension is separated and dried using a nozzle atomiser, the precipitation being carried out in the following way: 1) on initial stock solution is formed containing at least some of the total amount of silicate employed in the reaction and, in general, at least one electrolyte, the silicate concentration (expressed as SiOa) in the said initial stock solution being lees than 100 g/1, in particular 90 g/1, and the electrolyte concentration (for example sodium sulphate) in the said initial stock solution being lees then 1? g/1, for example less than 14 g/1, 2) the acidifying agent is added to the said stock solution until a pH value of at least about 7, generally between about 7 and 8, is obtained for the reaction medium, 3) acidifying agent is added to the reaction medium, where appropriate together with the remaining amount of the silicate at the aaae time, the suspention to b« dried having a solids content of between 22 and 24% by weight/ in partioular of between 22.5 and 23.5% fay weight. lt should be noted in general that the process in question is a process for synthesizing silica by precipitation, that ie to say on acidifying agent is reacted with a silicate under specific conditions. J The choice of the acidifying agent and of the silicate is made in a wanner which 1S well known per so. It nay be recalled that the acidifying agent generally used is a strong inorganic acid such ae sulphuric acid, nitric acid or hydrochloric acid, or on organic acid such as acetic acid, formic acid or carbonic acid. The acidifying agent may be dilute or concentrated; its normality may be between 0.4 and 9 N, for example between 0.6 and 1.5 N. In particular, in the case whan the acidifying agent is sulphuric acid, ite concentration may be between 40 and 180 g/1, for example between 60 and 13D G/i. Any common form of silicate, such as metasilicates, diailicatea and advantageously an alkali metal silicate, in particular sodium or potassium silicate, may moreover be used aa the silicate. The silicate stay have a concentration, expressed aa silica, of between 40 and 330 g/1, in particular between 60 and 300 g/1, for example between 60 and 230 g/1. In general, sulphuric aaid is used an the acidifying agent and sodium silicate is used aa the silicate. In the case when sodium eilieate is ue»d, it generally has an 8iO,/NaaO weight ratio of betwaan 2 and 4, for example between 3.0 and 3.7. The initial stock solution generally comprise* an electrolyte. The term electrolyte is intended to be understood here in its normal meaning, that is to say it indicates any ionic or molecular substance which, whan it is in solution/ decampose or dissociates to form ions or charged particles. Examples of electrolytes which may be mentioned include a salt of the group consisting of the salts of the alkali and alkaline-earth metals, in particular the salt of the metal of the starting eilieate and of the acidifying agent, for example sodium chloride in the case of reacting a aodium silicate with hydrochloric acid, or preferably sodium silicate in the case of reacting a sodium silicate with sulphuric acid. In the (preferred) case of « starting stook solution comprising only some of the total amount of the silicate employed in the reaction, simultaneous addition of acidifying agent and the remaining amount of silicate la carried out in step (3). This simultaneous addition is pre£«rably carried out ia such a way that the pH ls continuously equal (to within +/- 0.2) to the value reached at tha and of step (2) . In general, is a subseenient step, an additional amount of acidifying agent ia addad to tha reaction stadium, preferably until the pH obtainad for tha reaction medium has a valua of between 3 and 6,5. in particular between 4 and S.S- It may then bo advantageous, after thia addition of an oxtra amount of acidifying agent. to mature the reaction medium/ it being possible for thia maturation to last, for , from 2 to SO minutes, in particular from 3 to 20 minutes. In tha ease of a starting stock solution containing tha total amount of tha silicate employed in the reaction/ acidifying agant is preferably added in atep (3) until a pH for the reaction medium ia obtained with a valua e£ between 3 and S-S, in particular between * and 6.5. Xt may then be advantageous, after this step (3)/ to mature the reaction medium/ it being possible for this maturation to last, for example. from 2 to 60 minutes, in particular from 3 to 20 minutes. The tenperature of the reaction medium is generally between 70 and 98°C. According to a variant of the process, the reaction is carried out at a constant temperature, preferably of between BO and 95*C. According to another (preferred) variant of the process, tha temperature at the end of the reaction is higher taan the temperature at the start of the reaction: thus, the temperature at the start of the reaction ia preferably maintained at between 70 and 95°C, then tha temperature ia increased, preferably to a value of between 80 and 38*C, at which value it ia maintained until the and of the reaction. At the and of the step* which have just been described, a silica broth is obtained which ia then aaparated (liquid/aolid aeparation), in general/ the said aeparation comprises filtration and washing using a filter equipped with a compacting means. This filter may be a belt filter aquipped with a roller which performs the compaction. Nevertheless, thia filter is preferably a filter press, and the aeparation then generally compriaes filtration, washing than compacting with the aid of the said filter. The suspension of precipitated silica recovered in this way (filter cake) is then spray-dried using a nozzle atomizer. it is highly advantageous for this suspension to have a solids content between 22 and 24% by weight, in particular between 22.5 and 23.5% by weight, immediately before it has been dried. . it should be noted that the filter cake is not always is a form suitable for atomisation, in particular because it has high viacosity. In a mannar which la known par se, tha eaka la then subjected to a crumbling operation. This operation may be carried out by passing the cake through a mill of the colloidal or ball type. The crumbling is generally earried out in the praaenee of an aluminium compound) in particular sodium alumiaato. The crumbling operation makes it possible, in particular, to lowar tha viscosity of the suspension which is subsequently to be drisd. The Applicant Company has found that tha precipitated silica as defined above, therefore having a highly specific morphology, in the case in point being in tha form o£ substantially spherical and densa beads, and a relatively large average particle size, had a high degree of fluidity and produced little dust, and waa particularly vail suited to the conditioning of liquids. Examples of liquids which may be mentioned Include, in particular, organic liquids such as organic acida, surfaotants, for example used in detergents, either of tha ionic type auch as sulphonatas or of the non-ionic type such as alcohols, organic additives for rubber, and pesticides. Preservatives {phosphoric acid, propionic acid in particular), flavourings and colorants may ba used aa the liquids. The Applicant Company has obaerved that the precipitated silica described above was particularly suited to the conditioning of nutritional supplements in liquid form, in particular for animal fead. The liquid contained in the conditioned composition according to the invention ia thus preferably a liquid supplement for animal feed. Mention may be made in particular of choline, ltd chloride salt, vitamins such as vitamins A, B, C, D, X and, preferably, vitamin E (or its acetate). J Tha operation of absorbing the liquid on the support based on the said precipitated silica may be carried out in tha conventional way, in particular by spraying the liquid onto the silica in a mixer. Although the amount of liquid absorbed generally depends on the intended application, the composition according to the invention customarily has, in particular in the case of vitamin E {or its acetate), a liquid content of at least 50% by weight, in particular between 50 and 65% by weight, especially between between 50 and 60% by weight (ralative to the total weight of tha composition); it may for example be between 52 and 56% by weight. Even highar liquid contents may be used, in particular in the case of the chloride salt of cholina. Owing to the presence o£ the precipitated silica having the abovementioaed characteristic , the conditioned composition according to tha invention advantageously produces very littla or no dust and has an exoellent degree of fluidity, these properties being combined with a high density. Thus, preferably, tha said precipitated silica providaa this composition, In particular in the case of vitamin E (or of its acetate), with a 75 μm screen eversiae of at least 97% by weight, in particular of at least 98% by weight. This ratio, in particular in the caaa of vitamin 1 (or of its acetate), is preferably at least 99% by weight, for " example at laaat 99.54 by weight, or even at least 99.7% by weight; it may even be at least 99.8* by weight. This composition thus has an extremely low proportion by weight of fine particlaa. It therefore produces little or no dust. Furthermore, the conditioned composition according to the invention, in particular in the case of vitamin E (or of its acetate), preferably has a flow time tt (measured for 50 grama of product and for a passage diameter of B μm) of lees then 10 seconds, in particular of less than 9 seconds and, for example, at stoat B seconds, which evinces it excellent degree of fluidity. It may be noted that the angle of repo«* of this composition, in particular in the case of vitamin E (or of its aeatata) is generally at most 31", and may be lees than 30°, The conditioned composition according to the invention, in particular in the case of vitamin z (or of its acetate), customarily has a packed filling density (PFD) of at least 0.63, £or example of at least 0.55, and the value may be at least 0.70. The invention also relates to the use of the precipitated silica described above as a support far liquid, such as for example one o£ the liquids mentioned above. The following example illustrates the invention, hut without limiting its scope. EXAMPLE 1) The following ingredients 345 litres of water 7.5 kg of Na,SO4 566 litres of aqueous sodium silicate having an SiO,/NaaO weight ratio equal to 3,5 and a density at 20 C equal to 1.133 are introduced into a atainleea-steel reactor fitted with an impeller stirring system and a jacket heating system. The silicata concentration expressed as SiO2, in the initial stock solution is thus 85 g/1. The mixture is then heated to a temperature of 79°C while continuing to stir it. 386 litres of dilute sulphuric acid, with a density at 20*C equal to 1,050, are than introduced therein until a pK equal to 8.0 is obtained in the reaction medium (value measured at the temperature of tha medium). The reaction temperature is 79 C for the first 25 minutes; it is then increased from 79 to 86"C in 15 minute*, than maintained at 86"c until the and of the reaction. 83 litres of aqueous sodium silicate, of the type described above, and 134 litres of sulphuric acid, also of tha type described above* are then jointly introduced into the reaction medium (that is to say when tha pH of the reaction medium has reached a value of 8-0), this simultaneous introduction of acid and of silicate being carried out in such a way that the pS of tha reaction medium is continuously equal to 6.0 ± 0.1 throughout the introduction period. After all of the silicate has been introduced, introduction of the dilute acid is continued for 9 minutes so as to bring the pE of the reaction medium to a value equal to 5.2. After this introduction of acid, stirring of tha reaction broth which ia obtained is continued for 5 minutes. The total reaction time is 119 minutes. A precipitated silica broth or suspension is thus obtained, which ia then filtered and washed using a filter prase with vertical plates (the said plates being equipped with a deformahle diaphragm allowing tha filtor cake to be compressed by introducing pressurized air), at a pressure of 7-5 bar and for the time needed to obtain a silica cake whose loss on ignition is equal to 77.1% (therefore a solids content of 22.9% by weight). The oake obtained is than fluidizsd by mechanical and chemical action (addition of an amount of sodium aluminate corresponding to an Al/SiO, weight ratio of 3000 ppm). After this crumbling operation, the resulting broth, with a pH equal to 6.6, is driad using a noizzle atomiser. Tha precipitated silica PI whioh id obtained i« in tha form of substantially spherical beads and has the following additional characteristied: formed by the silica P1 prepared in 1}. The vitamin B is plaeed on the support in a 7-litre V mixer rotating at 20 rpm, with an inner shaft rotating at 1900 rpm, fitted with plates through which the vitamin is sprayed, and on which emitter blades are fixed. All of the silica PI is introduced into the mixer, then the vitamin is sprayed (at a temperature of 70 c and at a rate of 100 ml/min) onto this silica. Mixing is carried out for 15 minutes, then homogenisation is carried out for a further 3 minutes. The conditioned composition then obtained contains 45% by weight of precipitated silica PI end 55% by weight of vitamin E, and has the following additional characteristics - 75 / μm screen oversize 99.7% - flow tins t£ 8 seconds - angle of repose 2d.9 - PFD >0.6S This conditioned composition, baaed on a precipitated silica support, in the form of substantially spherical beads, thus has a very high degree of fluidity (which is illustrated in particular by a abort flow tine tf) and produces a negligible amount of duet (which is illustrated In particular by a very high 75 μm acresn ovarszel, while having a high density. CLAIMS 1. conditioned composition comprising at least one liquid absorbed on a support containing a precipitated silica, characterized in that the said silica is in the form of substantially spherical beads and has: an average bead size in excess of 150 μm, a packed filling density (P?D) in excess of 0.29, a 75 μm screen oversize of at least 92% by weight. 2. Composition according to Claim 1, characterized in that the said silica has an average bead size of at least 200 μm, in particular between 200 and 290 μm. 3. Composition according to one of Claims 1 and 2, characterized in that the said silica has a packed filling density of at least 0.30, in particular of at least 0.31. 4. Composition according to one of Claims 1 to 3, characterized in that the said silica has a 75 μm screen oversize of at least 93% by weight, in particular of at least 94% by weight, 5. Composition according to one of Claims 1 to 4, characterized in that the said silica has a DOP oil absorption value of at least 250 ml/100 g, preferably between 250 and 290 ml/100 g, in particular between 355 and 275 ml/100 g. 6. Composition according to one of Claims 1 to 5, characterized in that the said silica has a pore volume (Vu) made up of pores having a diameter smaller than 1 μm of laaa than 1.95 cm2/ g in particular of less than 1.90 om"/g* 7. Composition according to one of claims 1 to 6, characterized in that the said silica results from the use of a nozzle atomizer to dry a suspension of silica obtained by precipitation. 8. Composition according to Claim 7, characterised in that, before it is dried, the amid silica suspension has a aolida content of between 22 and 24% by weight, preferably between 22.5 and 23.5% by weight. 9. Composition according to one of Claims 1 to B, characterized in that the said composition has a liquid content of at least 50% by weight* in particular between 50 and 55% by weight. 10. Composition aoeordlng to one of Claims 1 to 9, characterized in that the said liquid is a preservative/ a flavouring, a colorant or a liquid supplement for animal feed. 11. Composition according to one of Claims 1 to 10, characterized in that the said liquid is vitamin Z or vitamin E acetate. 12. Composition according to one of Claims 1 to 11, characterized in that the said composition has a 75 μm screen oversize of at least 97% by weight, in particular of at least 98% by weight. 13. Composition according to one of Claims 1 to 12, characterized in that tha said composition has a flow time t1 of lass than 10 seconds for 50 grams and for a passage diameter of 8 nan, preferably of lose than 9 seconds. 14. Use of & precipitated silica as a liquid support in particular as a liquid supplement far animal feed, characterized is that the said silica is in the form of substantially spherical beads and has: an average bead site in excess of 150 μm., preferably in excess of 200 μm, a packed filling density (PSD) ia excess of 0.29/ preferably of at leaat 0-30, i 75 μm acraan oversize of at leaat 92% by weight, preferably of at least 93% by weight, 15. Use according to Claim 14, characterised in that the said silica has a DOP oil absorption value of at least 250 ml/10O g, prafarably batwsen 250 and 280 ml/100 g. IS. Use according to one of Claims 14 and 15, characterized in that the said silica has a pore volume (Vfl) made up of pores having a diameter smaller than 1 μm of lass than 1,95 , in particular of less than 1.90 cmVg. 17. Use according to one of Claims 14 to 16, characterized in that the said silica results from the use of a nozzle atomizer to dry a suspension of silioa obtained by precipitation, the said silica suspension preferably having a solids content of between 22 and 24% by weight before it is dried. IB. Use according to one of Claims 14 to 17, characterized in that the said liquid is vitamin or vitamin S acetate. 19. Conditioned composition comprising at least one liquid absorbed on a support containing a precipitated silica substantially as herein described and exemplified.

Documents:

1762-mas-1998 abstract-duplicate.pdf

1762-mas-1998 abstract.pdf

1762-mas-1998 claims-duplicate.pdf

1762-mas-1998 claims.pdf

1762-mas-1998 correspondence-others.pdf

1762-mas-1998 correspondence-po.pdf

1762-mas-1998 description (complete)-duplicate.pdf

1762-mas-1998 description (complete).pdf

1762-mas-1998 form-19.pdf

1762-mas-1998 form-2.pdf

1762-mas-1998 form-26.pdf

1762-mas-1998 form-4.pdf

1762-mas-1998 form-6.pdf

1762-mas-1998 petition.pdf