FUNCTIONAL GLASS ARTICLE AND METHOD FOR PRODUCING SAME

1 . A functional glass article comprising:

a glass substrate; and

a plurality of particles arranged on a surface of the glass substrate, the plurality of particles having a melting point higher than a softening point of the glass substrate, each of the plurality of particles having a particle diameter of 1 nm or more and 300 nm or less, and the plurality of particles including a particle located partly inside the glass substrate.

2 . The functional glass article according to claim 1 ,

wherein the plurality of particles are made of a material having a Vickers hardness of 9 GPa or higher.

3 . The functional glass article according to claim 2 ,

wherein a Martens hardness of the surface of the functional glass article comprising the plurality of particles is higher, by 150 N/mm 2 or more, than a Martens hardness of the glass substrate.

4 . A functional glass article comprising:

a glass substrate having a first face and a second face on a back face of the first face; and

a plurality of particles arranged on the first face and made of a material having a Mohs hardness of 7 or higher, each of the plurality of particles having a particle diameter of 1 nm or more and 300 nm or less, and the plurality of particles including a particle located partly inside the glass substrate, the first face with the plurality of particles having a higher Martens hardness by 150 N/mm 2 or more than a Martens hardness of the second face.

5 . The functional glass article according to claim 1 ,

wherein portions of at least some of the plurality of particles are exposed to an outside of the glass substrate.

6 . The functional glass article according to claim 4 ,

wherein portions of at least some of the plurality of particles are exposed to an outside of the glass substrate.

7 . The functional glass article according to claim 1 ,

wherein all of the plurality of particles are located partly inside the glass substrate.

8 . The functional glass article according to claim 4 ,

wherein all of the plurality of particles are located partly inside the glass substrate.

9 . The functional glass article according to claim 5 ,

wherein the plurality of particles have a value of an average glass contact ratio of a length L G to a length L from 40% or more where the length L G is an outer periphery in a cross-section along a thickness direction in contact with the glass substrate of one particle in the plurality of particles and the length L is an entire outer periphery in a cross-section along a thickness direction of the one particle, the average glass contact ratio being obtained by a cross-section observation method, the method comprising:

obtaining a cross section near the first face of the functional glass article by cutting out and finely polishing performed by an ion milling method using a focused ion beam (FIB) or a method obtained a smooth surface equivalent to a smooth surface obtained by the ion milling method;

observing the cross section by using an electron microscope at a magnification of 100,000;

measuring the length L G and the length L for 10 sample particles partly positioned inside the glass substrate among the plurality of particles; and

obtaining the average glass contact ratio by using the length L G and the length L of each of the 10 sample particles.

10 . The functional glass article according to claim 6 ,

wherein the plurality of particles have a value of an average glass contact ratio of a length L G to a length L from 40% or more where the length L G is an outer periphery in a cross-section along a thickness direction in contact with the glass substrate of one particle in the plurality of particles and the length L is an entire outer periphery in a cross-section along a thickness direction of the one particle, the average glass contact ratio being obtained by a cross-section observation method, the method comprising:

obtaining a cross section near the first face of the functional glass article by cutting out and finely polishing performed by an ion milling method using a focused ion beam (FIB) or a method obtained a smooth surface equivalent to a smooth surface obtained by the ion milling method;

observing the cross section by using an electron microscope at a magnification of 100,000;

measuring the length L G and the length L for 10 sample particles partly positioned inside the glass substrate among the plurality of particles; and

obtaining the average glass contact ratio by using the length L G and the length L of each of the 10 sample particles.

11 . The functional glass article according to claim 1 ,

wherein the plurality of particles are α alumina particles.

12 . The functional glass article according to claim 4 ,

wherein the plurality of particles are α alumina particles.

13 . The functional glass article according to claim 4 ,

wherein the Martens hardness of the first face is higher than 3000 N/mm 2 .

14 . A method for producing a functional glass article, comprising;

preparing a coating solution comprising a plurality of particles having a melting point higher than a softening point of the glass substrate, each of the plurality of particles having an average particle diameter of 1 nm or more and 300 nm or less;

preparing a glass substrate;

coating a surface of the glass substrate with the coating solution; and

performing a heat treatment on the glass substrate coated with the coating solution.

15 . The method for producing a functional glass article according to claim 14 ,

wherein the plurality of particles are made of a material having a Mohs hardness of 7 or higher.

16 . The method for producing a functional glass article according to claim 14 ,

wherein hydrogen fluoride is brought into contact with the surface of the glass substrate to treat the surface, and then the treated surface is coated with the coating solution.

17 . The method for producing a functional glass article according to claim 14 ,

wherein the heat treatment keeps the glass substrate coated with the coating solution at a temperature higher than an annealing point of the glass substrate.