US-12617887-B2 - Resin composition for stereolithography

Abstract

The present invention provides a resin composition for stereolithography that excels in strength, toughness, and water resistance in the form of a shaped article. The present invention relates to a resin composition for stereolithography that comprises a urethanized (meth)acrylic compound (A), a (meth)acrylate compound (B) containing no urethane bond, and a photopolymerization initiator (C), the compound (A) being a urethanized (meth)acrylic compound (A-1) having a polymer structure, and/or a urethanized (meth)acrylic compound (A-2) having no polymer structure, the compound (A-1) having a weight-average molecular weight of less than 1,000, the compound (A-2) having a molecular weight of less than 1,000, the compound (B) comprising at least one selected from the group consisting of a (meth)acrylate compound (b-I) represented by general formula (I), and a (meth)acrylate compound (b-II) represented by general formula (II).

Inventors

• Kenji Suzuki
• Misaki Ito

Assignees

• KURARAY NORITAKE DENTAL INC.

Dates

Publication Date

20260505

Application Date

20210209

Priority Date

20200210

Claims (16)

1. 1 . A resin composition for stereolithography, comprising: a urethanized (meth)acrylic compound (A), a (meth)acrylate compound (B) containing no urethane bond, a photopolymerization initiator (C), and 0.1 to 100 parts by mass relative to 100 parts by mass of the photopolymerization initiator (C) of a polymerization inhibitor (D), the urethanized (meth)acrylic compound (A) being a urethanized (meth)acrylic compound (A-1) having a polymer structure, the urethanized (meth)acrylic compound (A-1) having a polymer structure having a weight-average molecular weight of less than 1,000, the (meth)acrylate compound (B) containing no urethane bond comprising at least one selected from the group consisting of a (meth)acrylate compound (b-I) represented by the following general formula (I), and a (meth)acrylate compound (b-II) represented by the following general formula (II): wherein R 1 and R 2 are each independently a group represented by the following general formula (i), or a group represented by the following general formula (ii), and X is a C1 to C6 divalent hydrocarbon group, or an oxygen atom, wherein R 3 and R 5 are each independently a C1 to C10 divalent hydrocarbon group, R 4 and R 6 are each independently a hydrogen atom or a methyl group, and k and l are each independently an integer of 0 to 6, and wherein said resin composition for stereolithography further comprises a urethanized (meth)acrylic compound (A-2) having no polymer structure comprising 2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl)dimethacrylate and/or N,N′-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]tetramethacrylate.
2. 2 . The resin composition for stereolithography according to claim 1 , wherein the number of the urethane bonds is three or fewer per molecule in the urethanized (meth)acrylic compound (A-1) having a polymer structure.
3. 3 . The resin composition for stereolithography according to claim 1 , wherein the urethanized (meth)acrylic compound (A- 1 ) having a polymer structure is a (meth)acrylate compound.
4. 4 . The resin composition for stereolithography according to claim 1 , wherein the content of the urethanized (meth)acrylic compound (A-1) having a polymer structure is in the range of 51 to 95 mass % in 100 mass % of polymerizable compounds.
5. 5 . The resin composition for stereolithography according to claim 1 , wherein the polymer structure is a structure selected from the group consisting of a polyester, a polycarbonate, a polyurethane, a polyether, a poly-conjugated diene, and a hydrogenated poly-conjugated diene.
6. 6 . The resin composition for stereolithography according to claim 1 , wherein k and l are each independently an integer of 1 to 4.
7. 7 . The resin composition for stereolithography according to claim 1 , wherein the (meth)acrylate compound (B) containing no urethane bond comprises the (meth)acrylate compound (b-II), and X is an oxygen atom.
8. 8 . The resin composition for stereolithography according to claim 7 , wherein R 2 is a group represented by the general formula (ii).
9. 9 . The resin composition for stereolithography according to claim 1 , wherein the (meth)acrylate compound (B) containing no urethane bond comprises the (meth)acrylate compound (b-I), and R 1 is a group represented by the general formula (i).
10. 10 . The resin composition for stereolithography according to claim 1 , wherein the content of the photopolymerization initiator (C) is in the range of 0.01 to 20 parts by mass relative to total 100 parts by mass of the urethanized (meth)acrylic compound (A) and the (meth)acrylate compound (B) containing no urethane bond.
11. 11 . The resin composition for stereolithography according to claim 1 , wherein a cured product of the resin composition for stereolithography has a flexural strength of 100 MPa or more, and a flexural modulus of 2.1 GPa or more.
12. 12 . A dental material, comprising: a shaped article of the resin composition for stereolithography according to claim 1 .
13. 13 . A denture base material, comprising: a shaped article of the resin composition for stereolithography according to claim 1 .
14. 14 . A dental occlusal splint, comprising: a shaped article of the resin composition for stereolithography according to claim 1 .
15. 15 . A material for treating sleep disorder, comprising: a shaped article of the resin composition for stereolithography according to claim 1 .
16. 16 . A method, comprising: stereolithographically producing a three-dimensional shaped article with the resin composition for stereolithography according to claim 1 .

Description

TECHNICAL FIELD The present invention relates to a resin composition for stereolithography. More specifically, the present invention relates to a resin composition for stereolithography that enables production of a three-dimensional shaped article having excellent strength, toughness, and water resistance. The resin composition of the present invention is particularly suited for denture base materials, dental occlusal splints, and appliances for the treatment of sleep apnea. BACKGROUND ART Patent Literature 1 discloses a photo-solidification technique, a method that produces a three-dimensional shaped article through a repeated procedure whereby a liquid photocurable resin composition is cured into a thin layer under controlled application of necessary amounts of light energy, and another layer of the photocurable resin composition is cured on the cured layer under controlled application of light after supplying another portion of the liquid photocurable resin composition onto the previously formed cured layer. Patent Literature 2 proposes a basic method for practical application of this technique, and, since its proposal, many other photo-solidification techniques have been proposed. Vat stereolithography is a technique typically used for the optical fabrication of a three-dimensional shaped article. In this technique, a computer-controlled ultraviolet laser is selectively applied to draw a desired pattern on the surface of a liquid photocurable resin composition placed in a vat. By being cured, the resin forms a layer of a predetermined thickness, and another cured layer is continuously formed on the cured layer by applying an ultraviolet laser to the liquid photocurable resin composition supplied onto the previously cured layer in the amount necessary to form a single layer. The layering process is repeated to produce a three-dimensional shaped article of the desired shape. This technique has attracted great interest because it enables easy and precision production of the desired three-dimensional shaped article in a relatively short time period, even when the product has a very complex shape. Three-dimensional shaped articles produced by stereolithography are used in an increasingly wider range of applications, from simple concept models to more complex models such as test models and prototypes. This has created a demand for higher shape precision in these three-dimensional shaped articles. In addition to satisfying such properties, these products are also required to have properties that are suited for their intended use. The field of dental materials is thought to greatly benefit from stereolithography because denture bases, dental occlusal splints, and appliances for the treatment of sleep apnea require shapes that vary from patient to patient, aside from being complex in shape. Denture base materials are materials used for the gum as a part of a denture attached to replace missing teeth. The demand for dentures has rapidly increased in recent years because of increasing ageing populations. Some dental splints are fitted to reposition the jaw while others are attached to teeth to reduce tooth wear due to clenching. There are also dental splints that are worn in the mouth to protect the stomatognathic system and the brain by reducing injuries caused when large external forces are applied to teeth and jawbones during sports activities in contact sports. In orthodontics, the use of dental splints has gained wide popularity over the last years because of aesthetics and detachability. Among different types of appliances for the treatment of sleep apnea, of interest in the present invention are appliances (oral appliances, or OA) attached to teeth during sleep for the treatment of obstructive sleep apnea syndrome (OSAS). Such oral appliances have been increasingly used as appliances for the treatment of sleep apnea. Common requirements for denture base materials, dental occlusal splints, and OA include strength, toughness, and water resistance. These are required particularly in what is commonly called non-clasp dentures, which are partial denture bases that do not have metal clasp parts. Low strength creates discomfort by increasing flexure or deformation during biting, whereas a loss of toughness necessitates frequent replacement as it increases susceptibility to breakage due to the impact of biting or deformation occurring upon installation. A loss of water resistance causes a reduction of mechanical properties during use, making the appliance practically useless by making the appliance easily deformable or breakable when it is installed. Another consideration is that fabrication of denture base materials, dental occlusal splints, and appliances for the treatment of sleep apnea typically requires taking an impression of the oral cavity. This is seen as a problem because the procedure involves discomfort, and places a burden on patients, in addition to requiring high technical skills. Recent advances in