Highly dispersible precipitated silica having a high surface area
View Patent ↗The present invention relates to a highly dispersible silica which has a high surface area, a process to manufacture the aforesaid silica and its use as a tire filler for utility vehicles, motor cycles and high speed vehicles.
1. A utility vehicle tire, a motor cycle tire or a high speed passenger tire comprising a precipitated silica which has the following properties:
a BET surface area ranging from
200-250
m 2 /g,
a CTAB surface area
170-220
m 2 /g,
ranging from
a DBP number ranging from
305-400
g/(100 g), and
a Sears number V 2 ranging from
23-35
ml/(5 g).
2. The utility vehicle tire, motor cycle tire or high speed passenger tire as claimed in claim 1 which has a WK coefficient of less than or equal to 3.4, wherein the WK coefficient is the ratio of the peak height of particles that are not broken-down by ultrasound in the size range 1.0-100 μm to the peak height of the broken-down particles in the size range of less than 1.0 μm.
3. The utility vehicle tire, motor cycle tire or high speed passenger tire as claimed in claim 1 , wherein the surface area of the precipitated silica is modified with one or more organosilanes of Formula I to III:
[SiR 1 n (RO) r (Alk) m (Ar) p ] q [B] (I),
SiR 1 n (RO) 3-n (Alkyl) (II),
or
SiR 1 n (RO) 3-n (Alkenyl) (III),
with the following meanings
B: —SCN, —SH, —Cl, —NH 2 , —OC(O)CHCH 2 —, —OC(O)C(CH 3 )CH 2 — (if q=1) or —Sw— (if q=2), wherein B is chemically bonded to Alk,
R and R 1 are an aliphatic, olefinic, aromatic or arylaromatic radical having 2 to 30 C atoms, which can optionally be substituted by the following groups: hydroxyl, amino, alcoholate, cyanide, thiocyanide, halogen, sulfonic acid, sulfonic acid ester, thiol, benzoic acid, benzoic acid ester, carbonic acid, carbonic ester, acrylate, methacrylate or an organosilane radical, and where R and R has an identical or different meaning or substitution,
n is 0, 1 or 2,
Alk is a divalent unbranched or branched hydrocarbon radical having 1 to 6 carbon atoms,
m is 0 or 1,
Ar is an aryl radical having from 6 to 12 carbon atoms, which may be substituted by the following groups: hydroxyl, amino, alcoholate, cyanide, thiocyanide, halogen, sulfonic acid, sulfonic acid ester, thiol, benzoic acid, benzoic acid ester, carbonic acid, carbonic acid ester, acrylate, methacrylate or an organosilane radical,
p is: is 0 or 1, wherein p and n are not simultaneously 0,
q is 1 or 2,
w is a number from 2 to 8,
r is 1, 2 or 3, wherein r+n+m+p=4,
Alkyl is a monovalent unbranched or branched saturated hydrocarbon radical with 1 to 20 carbon atoms, and
Alkenyl is a monovalent unbranched or branched unsaturated hydrocarbon radical having from 2 to 20 carbon atoms.
4. The utility vehicle tire, motor cycle tire or high speed passenger tire as claimed in claim 1 , wherein the Sears no. ranges from 26-35 ml/(5 g).
5. The utility vehicle tire, motor cycle tire or high speed passenger tire as claimed in claim 1 , wherein the DBP no. ranges from 310-350 g/(100 g).
6. A utility vehicle tire, a motor cycle tire or a high speed passenger tire comprising a precipitated silica which has the following properties:
a BET surface area ranging from
200-250
m 2 /g,
a CTAB surface area
170-300
m 2 /g,
ranging from
a DBP number ranging from
305-400
g/(100 g), and
a Sears number V 2 ranging from
23-35
ml/(5 g).
7. The utility vehicle tire, motor cycle tire or high speed passenger tire as claimed in claim 6 which has a WK coefficient of less than or equal to 3.4, wherein the WK coefficient is the ratio of the peak height of particles that are not broken-down by ultrasound in the size range 1.0-100 μm to the peak height of the broken-down particles in the size range of less than 1.0 μm.
8. The utility vehicle tire, motor cycle tire or high speed passenger tire as claimed in claim 6 , wherein the surface area of the precipitated silica is modified with one or more organosilanes of Formula I to III:
[SiR 1 n (RO) r (Alk) m (Ar) p ] q [B] (I),
SiR 1 n (RO) 3-n (Alkyl) (II),
or
SiR 1 n (RO) 3-n (Alkenyl) (III),
with the following meanings
B: —SCN, —SH, —Cl, —NH 2 , —OC(O)CHCH 2 —, —OC(O)C(CH 3 )CH 2 — (if q=1) or —Sw— (if q=2), wherein B is chemically bonded to Alk,
R and R 1 are an aliphatic, olefinic, aromatic or arylaromatic radical having 2 to 30 C atoms, which can optionally be substituted by the following groups: hydroxyl, amino, alcoholate, cyanide, thiocyanide, halogen, sulfonic acid, sulfonic acid ester, thiol, benzoic acid, benzoic acid ester, carbonic acid, carbonic ester, acrylate, methacrylate or an organosilane radical, and where R and R has an identical or different meaning or substitution,
n is 0, 1 or 2,
Alk is a divalent unbranched or branched hydrocarbon radical having 1 to 6 carbon atoms,
m is 0 or 1,
Ar is an aryl radical having from 6 to 12 carbon atoms, which may be substituted by the following groups: hydroxyl, amino, alcoholate, cyanide, thiocyanide, halogen, sulfonic acid, sulfonic acid ester, thiol, benzoic acid, benzoic acid ester, carbonic acid, carbonic acid ester, acrylate, methacrylate or an organosilane radical,
p is: is 0 or 1, wherein p and n are not simultaneously 0,
q is 1 or 2,
w is a number from 2 to 8,
r is 1, 2 or 3, wherein r+n+m+p=4,
Alkyl is a monovalent unbranched or branched saturated hydrocarbon radical with 1 to 20 carbon atoms, and
Alkenyl is a monovalent unbranched or branched unsaturated hydrocarbon radical having from 2 to 20 carbon atoms.
9. The utility vehicle tire, motor cycle tire or high speed passenger tire as claimed in claim 6 , wherein the Sears no. ranges from 26-35 ml/(5 g).
10. The utility vehicle tire, motor cycle tire or high speed passenger tire as claimed in claim 6 , wherein the DBP no. ranges from 310-350 g/(100 g).