Process for producing silica-based fine particle dispersion sols, silica-based fine particle dispersion sol, coating composition containing the dispersion sol, curable coating film, and substrate having the curable coating film

• US 9,441,139 B2
• Filed: 04/21/2015
• Issued: 09/13/2016
• Est. Priority Date: 06/24/2009
• Status: Active Grant

• Current Assignee: JGC Catalysts and Chemicals Ltd. (JGC Holdings Corporation)
• Original Assignee: JGC Catalysts and Chemicals Ltd. (JGC Holdings Corporation)
• Inventors: Ishihara, Yoichi, Nishida, Hiroyasu
• Primary Examiner(s): Parvini, Pegah
• Application Number:
  US14/692,110
• Publication Number:
  US 20150225609A1
• Time in Patent Office: 511 Days
• US Class Current: 1/1
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 33/141 Preparation of hydrosols or aqueous dispersions
• CPC Class Codes: C01B 33/145 Preparation of hydroorganosols, organosols or dispersions in an organic medium
• CPC Class Codes: C01P 2004/32 Spheres
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C08G 77/58 Metal-containing linkages C08G77/485 takes precedence
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08K 9/02 Ingredients treated with inorganic substances
• CPC Class Codes: C09C 1/3054 Coating
• CPC Class Codes: C09D 133/00 Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 163/00 Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
• CPC Class Codes: C09D 167/00 Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain based on polyester-amides C09D177/12; based on polyester-imides C09D179/08; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 175/04 Polyurethanes
• CPC Class Codes: C09D 179/04 Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C09D 183/02 Polysilicates
• CPC Class Codes: C09D 183/04 Polysiloxanes
• CPC Class Codes: C09D 183/14 in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms C09D183/10 takes precedence
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: C09D 7/67 Particle size smaller than 100 nm

Abstract

Provided are silica-based fine particle dispersion sols, processes for producing the sols, coating compositions containing the dispersion sol, curable coating films obtained from the coating composition, and substrates having the coating film. The process including (1) mixing an aqueous aluminate solution to an alkaline silica sol which contains water-dispersible silica fine particles in a given ratio; (2) heating the mixture liquid obtained in step (1) to 60 to 200° C. and stirring the mixture liquid at the temperature for 0.5 to 20 hours; and (3) contacting the mixture liquid obtained in step (2) with a cation exchange resin to remove by ion exchange alkali metal ions contained in the mixture liquid and thereby controlling the pH of the mixture liquid to be in the range of 3.0 to 6.0.

Claims

1. A coating composition which comprises:

(A) a silica-based fine particle dispersion sol comprising silica-based fine particles having a negative charge on the surface and having a pH in an acidic region from 3.0 to 6.0, wherein the silica-based fine particles are chain particles having an average particle diameter in the range of 5 to 50 nm as calculated by the equation (L+D)/2 wherein L is a longitudinal length and D is a lateral length measured with respect to a transmission electron micrograph, and the surface of the silica-based fine particles, which has been modified with aluminum, comprises a composite oxide of silica-alumina and the amount of the modification by aluminum is in the range of 0.05×

10<sup>−

6</sup> to 2.0×

10<sup>−

6</sup> mol/m² in terms of Al₂O₃ per unit surface area of the silica-based fine particle; and

(B) a binder component.

2. The coating composition according to claim 1, wherein the binder component is an organosilicon compound represented by Formula (II) below and/or a hydrolysate thereof:

R¹_aR²_bSi(OR³)<sub>4−

(a+b)</sub> 

 

(II)

(wherein R¹ is a C_1-6 alkyl group, a C₈ or lower organic group having a vinyl group, a C₈ or lower organic group having an epoxy group, a C₈ or lower organic group having a methacryloxy group, a C_1-5 organic group having a mercapto group, or a C_1-5 organic group having an amino group;

R² is a C_1-3 alkyl, alkylene, cycloalkyl, halogenated alkyl or allyl group;

R³ is a C_1-3 alkyl, alkylene or cycloalkyl group;

a is an integer of 0 or 1; and

b is an integer of 0, 1 or

     2).

3. The coating composition according to claim 1, wherein the binder component is a thermosetting organic resin or a thermoplastic organic resin.

4. The coating composition according to claim 3, wherein the thermosetting organic resin is at least one selected from urethane resins, epoxy resins and melamine resins.

5. The coating composition according to claim 3, wherein the thermoplastic organic resin is at least one selected from acrylic resins, urethane resins and ester resins.

6. The coating composition according to claim 1, wherein the coating composition is an optical substrate coating composition.

7. The coating composition according to claim 6, wherein the optical substrate coating composition is a coating composition for forming a hardcoat layer.

8. A curable coating film which is obtained by applying the coating composition described in claim 1 onto a substrate.

9. A substrate having a curable coating film, which is obtained by providing the curable coating film described in claim 8 on a substrate.