Glass filler and method for producing the same

1. A glass filler comprising glass having a composition comprising iron oxide, wherein

for the content of the iron oxide in mass %, the following are satisfied:

0.005≤FeO≤0.30; and

0.01≤T-Fe 2 O 3 <0.50, wherein T-Fe 2 O 3 represents total iron oxide calculated as Fe 2 O 3 ,

for the iron oxide in the composition, Fe 2+ /(Fe 2+ +Fe 3+ ) is 0.45 or more and 1.00 or less, wherein Fe 2+ /(Fe 2+ +Fe 3+ ) represents the proportion by mass of Fe 2+ to total iron;

the composition further comprises the following components, in mass %:

50≤SiO 2 ≤60,

2≤B 2 O 3 ≤15,

10≤Al 2 O 3 ≤20,

15≤CaO≤30, and

0≤(Li 2 O+Na 2 O+K 2 O)≤2; and

the glass filler is a glass flake.

2. A glass filler comprising glass having a composition comprising iron oxide, wherein

for the content of the iron oxide in mass %, the following are satisfied:

0.005≤FeO≤0.30; and

0.01≤T-Fe 2 O 3 <0.50, wherein T-Fe 2 O 3 represents total iron oxide calculated as Fe 2 O 3 , for the iron oxide in the composition, Fe 2+ /(Fe 2+ +Fe 3+ ) is 0.45 or more and 1.00 or less, wherein Fe 2+ /(Fe 2+ +Fe 3+ ) represents the proportion by mass of Fe 2+ to total iron;

the composition further comprises the following components, in mass %:

57≤SiO 2 ≤65,

0≤B 2 O 3 ≤2,

8≤Al 2 O 3 ≤15,

1≤MgO≤5,

15≤CaO≤30, and

0≤(Li 2 O+Na 2 O+K 2 O)≤4; and

the glass filler is a glass flake.

3. A glass filler comprising glass having a composition comprising iron oxide, wherein

for the content of the iron oxide in mass %, the following are satisfied:

0.005≤FeO≤0.30; and

0.01≤T-Fe 2 O 3 <0.50, wherein T-Fe 2 O 3 represents total iron oxide calculated as Fe 2 O 3 ,

for the iron oxide in the composition, Fe 2+ /(Fe 2+ +Fe 3+ ) is 0.45 or more and 1.00 or less, wherein Fe 2+ /(Fe 2+ +Fe 3+ ) represents the proportion by mass of Fe 2+ to total iron;

the composition further comprises the following components, in mass %:

65<SiO 2 ≤70,

5≤Al 2 O 3 ≤15,

1≤MgO≤10,

10≤CaO≤25, and

0≤(Li 2 O+Na 2 O+K 2 O)≤4; and

the glass filler is a glass flake.

4. A glass filler comprising glass having a composition comprising iron oxide, wherein

for the content of the iron oxide in mass %, the following are satisfied:

0.005≤FeO≤0.30; and

0.01≤T-Fe 2 O 3 ≤0.50, wherein T-Fe 2 O 3 represents total iron oxide calculated as Fe 2 O 3 ,

for the iron oxide in the composition, Fe 2+ /(Fe 2+ +Fe 3+ ) is 0.45 or more and 1.00 or less, wherein Fe 2+ /(Fe 2+ +Fe 3+ ) represents the proportion by mass of Fe 2+ to total iron;

the composition further comprises the following components, in mass %:

50≤SiO 2 ≤75,

0≤B 2 O 3 ≤2,

15≤Al 2 O 3 ≤30,

5≤MgO≤25, and

0≤(Li 2 O+Na 2 O+K 2 O)≤4; and

the glass filler is a glass flake.

5. The glass filler according to claim 2 , wherein a visible transmittance, as calculated for a thickness of 15 μm of the glass filler, is 87% or more.

6. The glass filler according to claim 2 , wherein a light transmittance T 750nm at a wavelength of 750 nm, as calculated for a thickness of 1 mm of the glass filler, is 71 to 91%.

7. The glass filler according to claim 2 , wherein a light transmittance T 350nm at a wavelength of 350 nm, as calculated for a thickness of 1 mm of the glass filler, is 5 to 84%.

8. A coated glass filler comprising the glass filler according to claim 2 and a coating formed on a surface of the glass filler, wherein

the coating contains a metal or a metal oxide as a main component.

9. A resin composition comprising the glass filler according to claim 2 and a matrix resin.

10. A paint comprising the glass filler according to claim 2 and at least one selected from the group consisting of (a) a matrix resin and (b) at least one component selected from the group consisting of a thermosetting resin, a thermoplastic resin, and a curing agent.

11. An ink composition comprising the glass filler according to claim 6 and a vehicle in which is dispersed at least one selected from the group consisting of a pigment and a dye.

12. A cosmetic comprising the glass filler according to claim 2 and a cosmetic additive.

13. A method for producing the glass filler according to claim 2 ,

the method comprising controlling glass raw materials and/or an atmosphere where the glass filler is formed, thereby controlling, for the iron oxide in the composition of glass, the content of FeO, the content of T-Fe 2 O 3 , and Fe 2+ /(Fe 2+ +Fe 3+ ) representing the proportion by mass of Fe 2+ to total iron to obtain the glass filler having a desired color.

14. A resin composition comprising the coated glass filler according to claim 8 and a matrix resin.

15. A paint comprising the coated glass filler according to claim 8 and at least one selected from the group consisting of (a) a matrix resin and (b) at least one component selected from the group consisting of a thermosetting resin, a thermoplastic resin, and a curing agent.

16. An ink composition comprising the coated glass filler according to claim 8 and a vehicle in which is dispersed at least one selected from the group consisting of a pigment and a dye.

17. A cosmetic comprising the coated glass filler according to claim 8 and a cosmetic additive.

18. A method for producing the coated glass filler according to claim 8 ,

the method comprising controlling glass raw materials and/or an atmosphere where the glass filler is formed, thereby controlling, for the iron oxide in the composition of glass, the content of FeO, the content of T-Fe 2 O 3 , and Fe 2+ /(Fe 2+ +Fe 3+ ) representing the proportion by mass of Fe 2+ to total iron to obtain the glass filler having a desired color.