# US 2024/0199472 A1 · Lithium disilicate glass-ceramic with high strength and high transparency and preparation method and use thereof

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- Number: US 2024/0199472 A1
- Document ID: US20240199472A1
- Status: Published application
- Kind: A1
- Application number: 17/802,757
- Filed: 2022-07-08
- Published: 2024-06-20
- Earliest claimed: 2021-08-06
- Assignees: Aidite (Qinhuangdao) Technology Co., Ltd.
- Applicants: Aidite (Qinhuangdao) Technology Co., Ltd.
- Inventors: Jiaxin ZHANG; Quanyi NIE; Lijia ZHAO; Shenggang ZHOU; Yong YU; Xiaojun WANG
- Web page: https://patentgrep.com/patent/US20240199472A1

## CPC

- C03C 10/00: Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
- C03C 10/0027: {containing SiO2, Al2O3, Li2O as main constituents}
- A61K 6/833: Glass-ceramic composites
- C03B 5/18: Stirring devices; Homogenisation {(mixing in general B01F)}
- C03B 19/02: by casting {molten glass, e.g. injection moulding}
- C03B 25/02: in a discontinuous way
- C03B 32/02: Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)}
- C03C 3/097: containing phosphorus, niobium or tantalum
- C03C 4/0021: {for dental use}
- C03C 2204/00: Glasses, glazes or enamels with special properties
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES

## Abstract

The present disclosure discloses a lithium disilicate glass-ceramic with high strength and high transparency and a preparation method and use thereof. A raw material composition of the lithium disilicate glass-ceramic comprises: 63-75 wt % of SiO2, 13-18 wt % of Li2O, 1-6 wt % of Al2O3, 1-10 wt % of K2O, 2-6 wt % of P2O5, 0-4 wt % of an additive and 0-10 wt % of a colorant; a main crystal phase of the lithium disilicate glass-ceramic is lithium disilicate crystals, and an impurity phase of the lithium disilicate glass-ceramic is any one or a combination of at least two selected from the group consisting of lithium metasilicate, lithium phosphate and quartz; the lithium disilicate crystal has a size larger than 700 nm and a length-diameter ratio not less than 3.

## Claims

### Claim 1

A lithium disilicate glass-ceramic with high strength and high transparency, wherein a raw material composition of the lithium disilicate glass-ceramic comprises: 63-75 wt % of SiO2, 13-18 wt % of Li2O, 1-6 wt % of Al2O3, 1-10 wt % of K2O, 2-6 wt % of P2, O5, 0-4 wt % of an additive and 0-10 wt % of a colorant;
a main crystal phase of the lithium disilicate glass-ceramic is lithium disilicate crystals, and an impurity phase of the lithium disilicate glass-ceramic is any one or a combination of at least two selected from the group consisting of lithium metasilicate, lithium phosphate and quartz; the lithium disilicate crystal has a size larger than 700 nm and a length-diameter ratio not less than 3.

### Claim 2 (depends on 1)

The lithium disilicate glass-ceramic according to claim 1, wherein the raw material composition of the lithium disilicate glass-ceramic comprises: 65-70 wt % of SiO2, 14-16 wt % of Li2O, 2-5 wt % of Al2O3, 2-8 wt % of K2O, 3-5 wt % of P2O5, 1-3 wt % of an additive and 2-5 wt % of a colorant.

### Claim 3 (depends on 1)

The lithium disilicate glass-ceramic according to claim 1, wherein the raw material composition of the lithium disilicate glass-ceramic further comprises any one or a combination of at least two selected from the group consisting of 0-6 wt % of CaO, 0-5 wt % of BaO, 0-10 wt % of B2O3 and 0-10 wt % of ZrO2 or HfO2, excluding 0 wt % for each.

### Claim 4 (depends on 1)

The lithium disilicate glass-ceramic according to claim 1, wherein the additive comprises a monovalent metal oxide and a divalent metal oxide;
the monovalent metal oxide comprises any one or a combination of at least two selected from the group consisting of Na2O, Rb2O and Cs2O;
the divalent metal oxide comprises any one or a combination of at least two selected from the group consisting of MgO, SrO and ZnO.

### Claim 5 (depends on 1)

The lithium disilicate glass-ceramic according to claim 1, wherein the colorant comprises any one or a combination of at least two selected from the group consisting of Fe2O3, TiO2, CeO2, CuO, Cr2O3, MnO, SeO2, V2O5, In2O3 and a rare earth oxide;
the rare earth oxide comprises any one or a combination of at least two selected from the group consisting of La2O3, Nd2O3, Tb2O3, Pr6O11 and Er2O3.

### Claim 6 (depends on 1)

The lithium disilicate glass-ceramic according to claim 1, wherein the lithium disilicate crystal is fusiform;
the lithium disilicate crystal has a microstructure with three-dimensional interweaving and crystal grain interlocking.

### Claim 7 (depends on 1)

The lithium disilicate glass-ceramic according to claim 1, wherein a light transmittance of a sample of the lithium disilicate glass-ceramic with a thickness of 1 mm at 550 nm is within a range of 10%-40%, provided that the lithium disilicate crystal has a size larger than 700 nm and smaller than 1200 nm and a length-diameter ratio within a range of 3-5.

### Claim 8 (depends on 1)

The lithium disilicate glass-ceramic according to claim 1, wherein a light transmittance of a sample of the lithium disilicate glass-ceramic with a thickness of 1 mm at 550 nm is within a range of 40%-80%, provided that the lithium disilicate crystal has a size not smaller than 1200 nm and a length-diameter ratio not less than 5.

### Claim 9 (depends on 1)

A method for preparing the lithium disilicate glass-ceramic according to claim 1, comprising:
(1) mixing raw materials of the lithium disilicate glass-ceramic in proportion, followed by melting to obtain a basic glass liquid; and
(2) subjecting the basic glass liquid obtained in step (1) to a molding annealing treatment and a heat treatment in sequence to obtain the lithium disilicate glass-ceramic.

### Claim 10 (depends on 9)

The method according to claim 9, wherein in step (1),
the mixing is performed on a mixer;
in step (1), the mixing is performed for 30-300 min.

### Claim 11 (depends on 9)

The method according to claim 9, wherein in step (1), the melting is performed at a temperature within a range of 1300-1600° C.; in step (1), the melting is performed for 1-10 h.

### Claim 12 (depends on 9)

The method according to claim 9, wherein in step (2), the molding annealing treatment comprises: pouring the basic glass liquid into a mold for annealing to obtain a substrate glass;
the mold is preheated to a temperature within a range of 200-500° C.;
the annealing is performed for 0.1-24 h;
after the molding annealing treatment, the treated substrate glass is cooled to room temperature.

### Claim 13 (depends on 9)

The method according to claim 9, wherein the heat treatment comprises at least a first heat treatment and a last heat treatment; the first heat treatment is performed at a temperature within a range of 500-600° C.; the first heat treatment is performed for 60-240 min; the last heat treatment is performed at a temperature within a range of 800-860° C.; the last heat treatment is performed for 1-30 min.

### Claim 14 (depends on 13)

The method according to claim 13, wherein the heat treatment further comprises an intermediate heat treatment; the intermediate heat treatment is performed at a temperature within a range of 600-700° C.; the intermediate heat treatment is performed for 30-240 min.

### Claim 15 (depends on 13)

The method according to claim 13, wherein the substrate glass or an intermediate product before the last heat treatment is subjected to CAD/CAM machining to be formed into the shape of a tooth to be repaired.

### Claim 16 (depends on 13)

The method according to claim 13, wherein the substrate glass or an intermediate product before the last heat treatment is formed into the shape of a tooth to be repaired by a hot pressing process or a lost wax process.

### Claim 17 (depends on 1)

A method for using the lithium disilicate glass-ceramic according to claim 1, wherein the lithium disilicate glass-ceramic is used for making an oral restoration.

### Claim 18 (depends on 17)

The method according to claim 17, wherein the oral restoration comprises any one of dental veneers, inlays, onlays, abutment teeth, single crowns, anterior multi-unit pontic and posterior multi-unit pontic.

### Claim 19 (depends on 3)

The lithium disilicate glass-ceramic according to claim 3, wherein the raw material composition of the lithium disilicate glass-ceramic comprises: 65-70 wt % of SiO2, 14-16 wt % of Li2O, 2-5 wt % of Al2O3, 2-8 wt % of K2O, 3-5 wt % of P2, O5, 1-3 wt % of an additive and 2-5 wt % of a colorant.

### Claim 20 (depends on 6)

The lithium disilicate glass-ceramic according to claim 6, wherein the raw material composition of the lithium disilicate glass-ceramic comprises: 65-70 wt % of SiO2, 14-16 wt % of Li2O, 2-5 wt % of Al2O3, 2-8 wt % of K2O, 3-5 wt % of P2O5, 1-3 wt % of an additive and 2-5 wt % of a colorant.