Bendable or foldable articles as well as methods for the production thereof
AssigneeSchott AG
InventorsMarkus Heiß-Chouquet, Vanessa Hiller
Life of this patent
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Abstract
An article of transparent and brittle material, such as glass, glass ceramic, ceramic or crystals. The article includes at least one exchange layer and at least one bulk layer. The at least one exchange layer includes at least one kind of cation ions with an increased proportion compared to the at least one bulk layer and at least one kind of cation ionR with a reduced proportion compared to the at least one bulk layer. The article is in particularly used as a display cover for flexible displays or flexible protective foils, for example in smartphones or tablets or TV sets. The article can also be used as a substrate for an electronic component such as an OLED or LED.
Claims20
An article of transparent and brittle material having a thickness d of less than 1.2 mm and an article surface, the article comprising:
- at least one exchange layer and at least one bulk layer, the at least one exchange layer includes at least one kind of cation ionI with an increased proportion compared to the at least one bulk layer and at least one kind of cation ionR with a reduced proportion compared to the at least one bulk layer,
- wherein an ion radius of ionI is higher than an ion radius of ionR, a ratio cR,surface of the proportion of ionR at the article surface to the proportion of ionR in the at least one bulk layer and the ratio cR,inner of the proportion of ionR in a depth y of the at least one exchange layer to the proportion of ionR in the at least one bulk layer are such that
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- is higher than 5 μm, and
- wherein the ratio cR,surface of the proportion of ionR at the article surface to the proportion of ionR in the at least one bulk layer and the ratio cR,inner of the proportion of ionR in a depth y of the at least one exchange layer to the proportion of ionR in the at least one bulk layer are such that
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- is higher than 12 μm.
An article of transparent and brittle material having a thickness d of less than 1.2 mm, the article comprising:
- at least one exchange layer and at least one bulk layer, the at least one exchange layer includes at least one kind of cation ions with an increased proportion compared to the at least one bulk layer and at least one kind of cation ionR with a reduced proportion compared to the at least one bulk layer,
- wherein the article has a fracturing behavior in a fracturing test such that when an object falls onto the article from a fracturing height and thereby causes breakage of the article a number of cracks that are formed and that have a length of at least 1000 μm is at most 40, wherein the object has a length of 130 to 150 mm, a weight of 4 to 7 g and a stiffness of 250 to 350 N/mm as well as a tip of tungsten carbide with a diameter of 0.5 to 0.75 mm, wherein the object impinges with the tip of tungsten carbide ahead on the article, wherein on the side of the article being opposite to the object an adhesive PSA layer with a thickness of 2 to 10 μm and a polyethylene layer with a thickness of 200 to 300 μm are present and wherein the adhesive PSA layer is arranged between the article and the polyethylene layer.
A method for increasing at least one of a bending strength and an impact strength, comprising:
- providing an article of transparent and brittle material with a starting thickness dA;
- chemically hardening of the article by ion exchange, wherein on at least one side of the article an exchange layer with a characteristic depth of penetration xc is generated, wherein xc is higher than 12 μm, and
- etching of the chemically hardened article to a final thickness dE, with dE<dA, wherein by the etching more than 5 μm are removed from the exchange layer.
Dependencies are inferred from the claim text.