摘要:
Precipitated silicas including clusters of large primary silica particles having at the surface thereof small primary silica particles, have a specific surface area CTAB (SCTAB) ranging from 60 to 400 m2/g; a cluster average size d50, as measured by XDC grading after ultrasound deagglomeration, such that d50 (nm)>(6214/SCTAB (m2/g)+23; a pore volume distribution such that V(d5-d50)/V(d5-d100)>0.906−(0.0013×SCATB (m2/g)); and a pore size distribution such that Mode (nm)>(4166/SCTAB (m2/g))−9.2; such silicas are useful reinforcing fillers for polymers.
摘要:
Precipitated silicas including clusters of large primary silica particles having at the surface thereof small primary silica particles, have a specific surface area CTAB (SCTAB) ranging from 60 to 400 m2/g; a cluster average size d50, as measured by XDC grading after ultrasound deagglomeration, such that d50 (nm)>(6214/SCTAB (m2/g)+23; a pore volume distribution such that V(d5-d50)/V(d5-d100)>0.906−(0.0013×SCATB (m2/g)); and a pore size distribution such that Mode (nm)>(4166/SCTAB (m2/g))−9.2; such silicas are useful reinforcing fillers for polymers.
摘要:
A diene rubber composition for tires based on at least (i) one diene elastomer, (ii) one reinforcing inorganic filler and (iii) one coupling agent which provides the bonding between the inorganic filler and the elastomer. The inorganic filler comprises at least one silica capable of being obtained by the preparation process of the type comprising the reaction of a silicate with an acidifying agent, whereby a silica suspension is obtained, followed by the separation and the drying of this suspension. The reaction of the silicate with the acidifying agent is carried out according to the following successive stages: (i) an aqueous suspension of precipitated silica, exhibiting a pH of between 2.5 and 5.3, is brought into contact (mixing) with acidifying agent and silicate, in such a way that the pH of the reaction medium is maintained between 2.5 and 5.3, (ii) silicate is added to the reaction medium obtained, so as to increase the pH of the reaction medium up to a value of between 4.7 and 6.3.
摘要:
A diene rubber composition for tires based on at least (i) one diene elastomer, (ii) one reinforcing inorganic filler and (iii) one coupling agent which provides the bonding between the inorganic filler and the elastomer. The inorganic filler comprises at least one silica capable of being obtained by the preparation process of the type comprising the reaction of a silicate with an acidifying agent, whereby a silica suspension is obtained, followed by the separation and the drying of this suspension. The reaction of the silicate with the acidifying agent is carried out according to the following successive stages: (i) an aqueous suspension of precipitated silica, exhibiting a pH of between 2.5 and 5.3, is brought into contact (mixing) with acidifying agent and silicate, in such a way that the pH of the reaction medium is maintained between 2.5 and 5.3, (ii) silicate is added to the reaction medium obtained, so as to increase the pH of the reaction medium up to a value of between 4.7 and 6.3.
摘要:
The invention relates to a method for preparing precipitated silica, consisting in: (i) forming a starter having a pH of between 2 and 5; (ii) simultaneously adding silicate and acid, such that the pH of the reaction medium is between 2 and 5; (iii) adding silicate until the pH is between 7 and 10; (iv) simultaneously adding silicate and acid, such that the pH is between 7 and 10; (v) adding acid until the pH is between 2.5 and 5.3; (vi) bringing the reaction medium into contact with the acid and the silicate, such that the pH is between 2.5 and 5.3; and (vii) adding silicate, such as to increase the pH to a value between 4.7 and 6.3.
摘要:
The invention relates to a method for preparing precipitated silica, consisting in: (i) forming a starter having a pH of between 2 and 5; (ii) simultaneously adding silicate and acid, such that the pH of the reaction medium is between 2 and 5; (iii) adding silicate until the pH is between 7 and 10; (iv) simultaneously adding silicate and acid, such that the pH is between 7 and 10; (v) adding acid until the pH is between 2.5 and 5.3; (vi) bringing the reaction medium into contact with the acid and the silicate, such that the pH is between 2.5 and 5.3; and (vii) adding silicate, such as to increase the pH to a value between 4.7 and 6.3.