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EP-4741430-A2 - PHOTOCURABLE COMPOSITION AND SHAPED PRODUCT FORMED FROM THE SAME

EP4741430A2EP 4741430 A2EP4741430 A2EP 4741430A2EP-4741430-A2

Abstract

An object of the present invention is to provide a photocurable composition from which a molded product having excellent mechanical properties is obtained. The present invention provides a photocurable composition containing a urethane (meth)acrylate oligomer and a vinyl monomer, wherein the vinyl monomer includes a first monomer having a glass transition temperature (Tg) of-100 °C or more and 20 °C or less, and a second monomer having a glass transition temperature (Tg) of more than 20 °C and 150 °C or less, an amount of the urethane (meth)acrylate oligomer ranges from 20 mass % to 80 mass %, an amount of the first monomer ranges from 15 mass % to 75 mass %, an amount of the second monomer ranges from 5 mass % to 65 mass %, and a total amount of the urethane (meth)acrylate oligomer and the vinyl monomer is 100 mass %.

Inventors

  • KURODA, KENICHI
  • FUJIWARA, TAKAHIRO

Assignees

  • Sumitomo Rubber Industries, Ltd.

Dates

Publication Date
20260513
Application Date
20220812

Claims (13)

  1. A photocurable composition for stereolithography containing a urethane (meth)acrylate oligomer and a vinyl monomer, wherein the vinyl monomer includes a first monomer whose homopolymer has a glass transition temperature (Tg) of -100 °C or more and 20 °C or less, and a second monomer whose homopolymer has a glass transition temperature (Tg) of more than 20 °C and 150 °C or less, an amount of the urethane (meth)acrylate oligomer ranges from 20 mass % to 80 mass %, an amount of the first monomer ranges from 15 mass % to 75 mass %, an amount of the second monomer ranges from 5 mass % to 65 mass %, a total amount of the urethane (meth)acrylate oligomer and the vinyl monomer is 100 mass %, and a compression set of the cured product obtained by curing the photocurable composition is 5% or less, when measured as follows: the cured product is compressed in a compression rate of 25% at a temperature of 23 °C for 22 hours based on the method prescribed in JIS K6262: 2013, and the compression set is measured in 0.5 hour later after removing the compression.
  2. The photocurable composition according to claim 1, wherein the urethane (meth)acrylate oligomer has a (meth)acryloyl group.
  3. The photocurable composition according to claim 1 or 2, wherein the urethane (meth)acrylate oligomer has a glass transition temperature (Tg) ranging from -100 °C to 50 °C.
  4. The photocurable composition according to any one of claims 1 to 3, wherein the vinyl monomer includes at least one member selected from the group consisting of a monofunctional vinyl monomer, a difunctional vinyl monomer, a trifunctional vinyl monomer, and a tetrafunctional vinyl monomer.
  5. The photocurable composition according to any one of claims 1 to 4, wherein the vinyl monomer includes (meth)acrylate.
  6. The photocurable composition according to any one of claims 1 to 5, wherein the first monomer includes 2-ethylhexyl acrylate and/or (2-methyl-2-ethyl-1 ,3-dioxolane-4-yl) methacrylate.
  7. The photocurable composition according to any one of claims 1 to 6, wherein the second monomer includes isobornyl acrylate.
  8. The photocurable composition according to any one of claims 1 to 7, wherein the photocurable composition has a viscosity of 100 mPa·s or more and 6,000 mPa·s or less as measured at a temperature of 25 °C and a shear rate of 100 s -1 .
  9. A cured product of the photocurable composition according to any one of claims 1 to 8, wherein the cured product has a glass transition temperature (Tg) measured as specified in the description and of 20 °C or less.
  10. A method for producing an object in a three dimensional shape by stereolithography, comprising a step of irradiating light to a photocurable composition to cure the photocurable composition, and forming the cured photocurable composition into an object in a three dimensional shape, wherein the photocurable composition contains a urethane (meth)acrylate oligomer and a vinyl monomer, the vinyl monomer includes a first monomer whose homopolymer has a glass transition temperature (Tg) of -100 °C or more and 20 °C or less, and a second monomer whose homopolymer has a glass transition temperature (Tg) of more than 20 °C and 150 °C or less, an amount of the urethane (meth)acrylate oligomer ranges from 20 mass % to 80 mass %, an amount of the first monomer ranges from 15 mass % to 75 mass %, an amount of the second monomer ranges from 5 mass % to 65 mass %, a total amount of the urethane (meth)acrylate oligomer and the vinyl monomer is 100 mass %, and a compression set of the cured product obtained by curing the photocurable composition is 5% or less, when measured as follows: the cured product is compressed in a compression rate of 25% at a temperature of 23 °C for 22 hours based on the method prescribed in JIS K6262: 2013, and the compression set is measured in 0.5 hour later after removing the compression.
  11. The method for producing the object in the three dimensional shape according to claim 10, wherein the urethane (meth)acrylate oligomer has a (meth)acryloyl group.
  12. The method for producing the object in the three dimensional shape according to claim 10 or 11, wherein the first monomer includes 2-ethylhexyl acrylate and/or (2-methyl-2-ethyl-1,3-dioxolane-4-yl) methacrylate.
  13. The production method of the molded product according to any one of claims 10 to 12, wherein the second monomer includes isobornyl acrylate.

Description

FIELD OF THE INVENTION The present invention relates to a photocurable composition, and more specifically relates to a photocurable composition suitable for stereolithography. DESCRIPTION OF THE RELATED ART In recent years, a three-dimensionally laminating and shaping apparatus (so-called 3D printer) for producing a three-dimensional structure by laminating and curing a resin based on design data of the three-dimensional structure has been put into practical use. As the three-dimensional structure produced by the three-dimensionally laminating and shaping apparatus, a three-dimensional structure made of a resin is well known. For example, WO 2017/154335 A discloses a rubber composition for three-dimensionally laminating and shaping, wherein the rubber composition comprises a liquid rubber. The rubber composition is suitably used to produce an elastic molded product by the three-dimensionally laminating and shaping apparatus. JP 2021-75044 A discloses a polymer composition for stereolithography comprising a liquid polymer and a monomer, wherein the polymer composition for stereolithography has a viscosity of 3,000 mPa·s or less as measured using an E type viscometer under conditions of a cone plate diameter: 25 mm and a shear rate: 100 s-1 in an environment of a temperature: 25 °C and a relative humidity: 50%. SUMMARY OF THE INVENTION The cured product of the conventional photocurable composition used for stereolithography does not have adequate mechanical properties. The present invention has been achieved in view of the above circumstances, and an object of the present invention is to provide a photocurable composition providing a shaped product having excellent mechanical properties. The present invention provides a photocurable composition containing a urethane (meth)acrylate oligomer and a vinyl monomer, wherein the vinyl monomer includes a first monomer having a glass transition temperature (Tg) of -100 °C or more and 20 °C or less, and a second monomer having a glass transition temperature (Tg) of more than 20 °C and 150 °C or less, an amount of the urethane (meth)acrylate oligomer ranges from 20 mass % to 80 mass %, an amount of the first monomer ranges from 15 mass % to 75 mass %, an amount of the second monomer ranges from 5 mass % to 65 mass %, and a total amount of the urethane (meth)acrylate oligomer and the vinyl monomer is 100 mass %. The cured product (shaped product) obtained by curing the photocurable composition according to the present invention has a low glass transition temperature (Tg), and shows excellent mechanical properties. The photocurable composition according to the present invention is suitable for stereolithography. The shaped product formed from the photocurable composition according to the present invention has excellent mechanical strength. DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention provides a photocurable composition containing a urethane (meth)acrylate oligomer and a vinyl monomer, wherein the vinyl monomer includes a first monomer having a glass transition temperature (Tg) of -100 °C or more and 20 °C or less, and a second monomer having a glass transition temperature (Tg) of more than 20 °C and 150 °C or less, an amount of the urethane (meth)acrylate oligomer ranges from 20 mass % to 80 mass %, an amount of the first monomer ranges from 15 mass % to 75 mass %, an amount of the second monomer ranges from 5 mass % to 65 mass %, and a total amount of the urethane (meth)acrylate oligomer and the vinyl monomer is 100 mass %. 1. Urethane (meth)acrylate oligomer The urethane (meth)acrylate oligomer is an oligomer having a (meth)acryloyl group and a urethane bond in the molecule. The (meth)acryloyl group means a methacryloyl group and/or an acryloyl group. The oligomer is a molecule of multiple compounds bonded. The oligomer is, for example, preferably a polymer of about 3 to 100 compounds bonded, more preferably a polymer of about 3 to 50 compounds bonded, and even more preferably a polymer of about 3 to 40 compounds bonded. Examples of the urethane (meth)acrylate oligomer include a product obtained by a reaction between a urethane prepolymer having an isocyanate group and a (meth)acrylate monomer having a hydroxy group; a product obtained by a reaction between a urethane prepolymer having a hydroxy group and a (meth)acrylate monomer having an isocyanate group; and a product obtained by a reaction between a urethane prepolymer having an amino group and a (meth)acrylate monomer having an isocyanate group. In the present invention, the (meth)acrylate means acrylate and/or methacrylate. The urethane prepolymer is preferably a product formed by a reaction between a polyisocyanate and a polyol. The molecular chain of the urethane prepolymer has a urethane bond formed by the reaction between the polyisocyanate and the polyol. The urethane prepolymer has an isocyanate group or a hydroxy group at the terminal of the molecular chain. In addition, the urethane prepol