US 12,503,605 B2Granted

Low-dielectric-tangent silica sol, and method for producing low-dielectric-tangent silica sol

AssigneeNissan Chemical Corporation

InventorsTakeshi Nakada, Kazuya Ebara, Megumi Araki, Masatoshi Sugisawa

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Abstract

Silica particles have a dielectric loss tangent of 0.01 or less at 1 GHz and satisfy the requirements (i), (ii) and (iii): (i) an average primary particles diameter of 5 nm to 120 nm; (ii) a ratio of a specific surface area by water vapor adsorption (SH2O) to a specific surface area by nitrogen adsorption (SN2); i.e., (SH2O/SN2) of 0.6 or less; and (iii) a total silanol group content of 5% or less as determined by the following Formula (1): total silanol group content (%)=(Q2×2/4+Q3×1/4+Q4×0/4) . . . Formula (1) [in Formula (1), each of Q2, Q3 and Q4 is the proportion (%) of the peak areas derived from silicon atom structures], and a silica dispersion.

Claims18

Dependent claims

Silica particles having a dielectric loss tangent of 0.01 or less at 1 GHz and satisfying the following (i), (ii), and (iii):

(i) an average primary particle diameter of 5 nm to 120 nm;
(ii) a ratio of a specific surface area by water vapor adsorption (SH2O) to a specific surface area by nitrogen adsorption (SN2);
i.e., (SH2O/SN2) of 0.6 or less;
and
(iii) a total silanol group content of 5% or less as determined by the following Formula (1):
total
⁢
silanol
⁢
group
⁢
content
⁢
(
%
)
=
(
Q
⁢
2
×
2
/
4
+
Q
⁢
3
×
1
/
4
+
Q
⁢
4
×
0
/
4
)
Formula
⁢
(
1
)
[in Formula (1), each of Q2, Q3, and Q4 is the proportion (%) of the peak area derived from a silicon atom structure relative to the total (100%) of the peak areas derived from silicon atom structures as determined by 29Si NMR measurement, wherein Q2 is the proportion of the peak area derived from the structure of a silicon atom bonded to two oxygen atoms and two hydroxy groups, Q3 is the proportion of the peak area derived from the structure of a silicon atom bonded to three oxygen atoms and one hydroxy group, and Q4 is the proportion of the peak area derived from the structure of a silicon atom bonded to four oxygen atoms],
wherein at least a portion of the surface of each of the silica particles is coated with an organic silicon compound having at least one substituent selected from the group consisting of an alkyl group, a C6-12 aryl group, and a substituent having an unsaturated bond, and
wherein the surfaces of the silica particles are coated with or bonded to the organic silicon compound in an amount of 0.5 to 6 molecules per nm2 of the surface area of the silica particles.

47 more elements

A production method for surface-modified silica particles having a dielectric loss tangent of 0.01 or less at 1 GHz, the production method comprising the following steps (A) to (C):

step (A):
a step of preparing a silica sol containing silica particles having an average primary particle diameter of 5 to 120 nm, a ratio of a specific surface area by water vapor adsorption (SH2O) to a specific surface area by nitrogen adsorption (SN2);
i.e., (SH2O/SN2) of 0.6 or less, and a total silanol group content of 5% or less as determined by the following Formula (1):
total
⁢
silanol
⁢
group
⁢
content
⁢
(
%
)
=
(
Q
⁢
2
×
2
/
4
+
Q
⁢
3
×
1
/
4
+
Q
⁢
4
×
0
/
4
)
Formula
⁢
(
1
)
[in Formula (1), each of Q2, Q3, and Q4 is the proportion (%) of the peak area derived from a silicon atom structure relative to the total (100%) of the peak areas derived from silicon atom structures as determined by 29Si NMR measurement, wherein Q2 is the proportion of the peak area derived from the structure of a silicon atom bonded to two oxygen atoms and two hydroxy groups, Q3 is the proportion of the peak area derived from the structure of a silicon atom bonded to three oxygen atoms and one hydroxy group, and Q4 is the proportion of the peak area derived from the structure of a silicon atom bonded to four oxygen atoms] as a dispersoid, and a C1-4 alcohol as a dispersion medium,
step (B):
a step of stirring an organic silicon compound and the silica sol prepared in step (A) under heating at 40 to 100° C. for 0.1 to 10 hours,
wherein at least a portion of the surface of each of the silica particles is coated with the organic silicon compound which has at least one substituent selected from the group consisting of an alkyl group, a C6-12 aryl group, and a substituent having an unsaturated bond, and
wherein the surfaces of the silica particles are coated with or bonded to the organic silicon compound in an amount of 0.5 to 6 molecules per nm2 of the surface area of the silica particles;
and
step (C):
a step of removing the C1-4 alcohol from the silica sol after step (B).

50 more elements

A production method for a surface-modified silica dispersion, the production method comprising the following steps (A) and (B):

step (A):
a step of preparing a silica sol containing silica particles having a dielectric loss tangent of 0.01 or less at 1 GHz and having an average primary particle diameter of 5 to 120 nm, a ratio of a specific surface area by water vapor adsorption (SH2O) to a specific surface area by nitrogen adsorption (SN2);
i.e., (SH2O/SN2) of 0.6 or less, and a total silanol group content of 5% or less as determined by the following Formula (1):
total
⁢
silanol
⁢
group
⁢
content
⁢
(
%
)
=
(
Q
⁢
2
×
2
/
4
+
Q
⁢
3
×
1
/
4
+
Q
⁢
4
×
0
/
4
)
Formula
⁢
(
1
)
[in Formula (1), each of Q2, Q3, and Q4 is the proportion (%) of the peak area derived from a silicon atom structure relative to the total (100%) of the peak areas derived from silicon atom structures as determined by 29Si NMR measurement, wherein Q2 is the proportion of the peak area derived from the structure of a silicon atom bonded to two oxygen atoms and two hydroxy groups, Q3 is the proportion of the peak area derived from the structure of a silicon atom bonded to three oxygen atoms and one hydroxy group, and Q4 is the proportion of the peak area derived from the structure of a silicon atom bonded to four oxygen atoms] as a dispersoid, and a C1-4 alcohol as a dispersion medium;
and
step (B):
a step of stirring an organic silicon compound and the silica sol prepared in step (A) under heating at 40 to 100° C. for 0.1 to 10 hours,
wherein at least a portion of the surface of each of the silica particles is coated with the organic silicon compound which has at least one substituent selected from the group consisting of an alkyl group, a C6-12 aryl group, and a substituent having an unsaturated bond, and
wherein the surfaces of the silica particles are coated with or bonded to the organic silicon compound in an amount of 0.5 to 6 molecules per nm2 of the surface area of the silica particles.

48 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/579,628Filed 25 Jan 2023
Priority: JP 2022-01217028 Jan 2022
Published: US 2024/0270973 A115 Aug 2024
Granted: 23 Dec 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification20 codes

C01B 33/18
Silica; Hydrates thereof, e.g. lepidoic silicic acid: preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof
C09C 1/3081
Silicic acid: treatment with organo-silicon compounds
C01B 33/145
Colloidal silica, e.g. dispersions, gels, sols: preparation of hydroorganosols, organosols or dispersions in an organic medium
C08K 3/36
Silicon-containing compounds: silica