Resin block and process for producing the same

• US 10,639,131 B2
• Filed: 10/25/2016
• Issued: 05/05/2020
• Est. Priority Date: 10/26/2015
• Status: Active Grant

• Current Assignee: Tokuyama Dental Corporation (Tokuyama Corporation)
• Original Assignee: Tokuyama Dental Corporation (Tokuyama Corporation)
• Inventors: Yamagawa, Junichiro, Shimizu, Tomonao, Nagasawa, Yuko
• Primary Examiner(s): Yi, Stella K
• Application Number:
  US15/770,220
• Publication Number:
  US 20180303587A1
• Time in Patent Office: 1,288 Days
• CPC Class Codes: A61C 13/0004 Computer-assisted sizing or machining of dental prostheses
• CPC Class Codes: A61C 13/0022 Blanks or green, unfinished dental restoration parts
• CPC Class Codes: A61C 13/081 Making teeth by casting or moulding
• CPC Class Codes: A61C 13/087 Artificial resin teeth A61C13/081 takes precedence; preparations A61K6/80
• CPC Class Codes: A61C 13/09 Composite teeth, e.g. front and back section A61C13/0835, A61C13/1023 take precedence; Multilayer teeth
• CPC Class Codes: A61C 13/206 Injection moulding
• CPC Class Codes: A61K 6/831 comprising non-metallic elements or compounds thereof, e.g. carbon
• CPC Class Codes: A61K 6/844 Noble metals
• CPC Class Codes: A61K 6/853 Silicates
• CPC Class Codes: A61K 6/891 Compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: B29C 45/0001 characterised by the choice of material
• CPC Class Codes: B29C 45/0055 Shaping
• CPC Class Codes: B29K 2101/12 Thermoplastic materials
• CPC Class Codes: B29K 2105/16 Fillers
• CPC Class Codes: B29L 2031/7532 Artificial members, protheses
• CPC Class Codes: C08J 2371/10 from phenols
• CPC Class Codes: C08J 5/00 Manufacture of articles or shaped materials containing macromolecular substances manufacture of semi-permeable membranes B01D67/00 - B01D71/00
• CPC Class Codes: C08K 2003/2241 Titanium dioxide
• CPC Class Codes: C08K 3/00 Use of inorganic substances as compounding ingredients
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/36 : Silica
• CPC Class Codes: C08L 101/00 : Compositions of unspecified macromolecular compounds

Abstract

A resin block that can be favorably used for obtaining dental prosthetics through the milling work, containing very little voids, having excellent property for being cut, exhibiting excellent appearance and mechanical strength, and without permitting the formation of defective products. The resin block contains a thermoplastic resin having a fluidizing temperature in a range of 310 to 500° C. and inorganic particles in an amount of 30 to 150 parts by mass per 100 parts by mass of said thermoplastic resin. The inorganic particles are at least one kind of inorganic oxide particles selected from the group consisting of silica particles, silica composite particles of silica and other metal oxides, titania particles, and titania composite particles of titania and other metal oxides. The resin block has a thick portion of a thickness of at least not less than 5 mm, and does not contain any void whose length is not less than 1.0 mm.

Claims

1. A process for producing a resin block that contains a thermoplastic resin and inorganic particles, that does not contain any void whose length is not less than 1.0 mm, that has a thick portion of a thickness of at least 5 mm, and that can be used as a material for producing a dental prosthetic through milling work:

by providing a thermoplastic resin composition that contains a thermoplastic resin having a fluidizing temperature in a range of 310 to 500°

C. and at least one kind of inorganic oxide particles selected from the group consisting of silica particles, silica composite particles of silica and other metal oxides, titania particles, and titania composite particles of titania and other metal oxides in an amount of 30 to 150 parts by mass per 100 parts by mass of the thermoplastic resin, and comprising the steps of;

injecting and filling a melt of said thermoplastic resin composition in a cavity of an injection-molding machine that has a projection mechanism;

exerting a pressure on the thermoplastic resin composition;

pushing a projecting member into one side surface of the cavity filled with the thermoplastic resin composition over a contact area of not more than 50% on the basis of the contact area of the whole one side surface before the thermoplastic resin composition is completely solidified; and

taking out the thermoplastic resin composition after it has been cooled down.

2. The process for producing the resin block according to claim 1, wherein a portion in one side surface of the cavity filled with the thermoplastic resin composition with which the projecting member comes in contact is formed being protruded toward an outer side of the cavity, and the projecting member is pushed so that the one side surface of the cavity filled with the thermoplastic resin composition becomes nearly flat.

4. The process for producing the resin block according to claim 1, wherein the thermoplastic resin is a crystalline thermoplastic resin.

5. The process for producing the resin block according to claim 1, wherein the thick portion has a thickness of 10 to 50 mm.

6. The process for producing the resin block according to claim 1, wherein the resin block does not contain any void whose length is not less than 0.2 mm.

7. The process for producing the resin block according to claim 1, wherein the milling work is executed by using a CAD/CAM (computer aided design⋅

manufacturing) system.

3. A process for producing a resin block that contains a thermoplastic resin and inorganic particles, that does not contain any void whose length is not less than 1.0 mm, that has a thick portion of a thickness of at least 5 mm, and that can be used as a material for producing a dental prosthetic through milling work:

by providing a thermoplastic resin composition that contains a thermoplastic resin having a fluidizing temperature in a range of 310 to 500°

C. and at least one kind of inorganic oxide particles selected from the group consisting of silica particles, silica composite particles of silica and other metal oxides, titania particles, and titania composite particles of titania and other metal oxides in an amount of 30 to 150 parts by mass per 100 parts by mass of the thermoplastic resin, and comprising the steps of;

injecting and filling a melt of said thermoplastic resin composition in a cavity of an injection-molding machine that has a projection mechanism;

exerting a pressure on the thermoplastic resin composition;

pushing a projecting member into one side surface of a compression chamber that has a pushing portion, over a contact area of not more than 50% on the basis of the contact area of said whole one side surface before the thermoplastic resin composition is completely solidified, the compression chamber having a volume which is 0.2 to 80% the volume of the cavity and, further, having a space continuous to an interior of the cavity; and

taking out the thermoplastic resin composition after it has been cooled down.