Modified silicon nitride prepolymer for light-cured resin and light-cured resin

Abstract

The invention discloses a modified silicon nitride prepolymer for light-cured resin and the light-cured resin. The modified silicon nitride prepolymer is prepared from the following substances according to a mass ratio: 0.95-0.98 of a prepolymer; 0.02 to 0.05 part of nano silicon nitride; 0.001 to 0.004 part of a surface active agent; 0.001 to 0.005 part of fumed silica; and 0.002 to 0.005 part of a polymerization inhibitor. The preparation method has the beneficial effects that the pretreated silicon nitride modified prepolymer can form an effective filling system in the resin, so that the surface wear resistance of the resin is improved, meanwhile, the stable silicon nitride modified prepolymer can ensure the printing stability of the resin, and the conditions of particle precipitation and precipitation cannot occur after continuous printing for 48 hours for a long time; the light-cured resin has the advantages of good storage stability, difficult precipitation and particle precipitation, simple post-curing mode, no need of heating post-curing, curing only through ultraviolet light waterproof irradiation, and excellent wear resistance of a molded model, and can be used for structural members and vulnerable parts.

Description

Technical Field

[0001] The invention relates to the technical field of photocurable resins, in particular to a modified silicon nitride prepolymer for photocurable resins and the photocurable resins. Background Art

[0002] Photocurable resin is a material that can be quickly cured after being irradiated with ultraviolet light or visible light. In digital light processing (DLP) technology, photocurable resin is widely used in rapid prototyping and precision manufacturing. However, the existing photocurable resin has problems such as poor scratch resistance and easy scratching after molding, especially in the application of structural parts and assemblies, which limits its application in the industrial field.

[0003] In order to improve the wear resistance of photocurable resin, researchers often choose to add inorganic powders and other additives to ensure that the resin surface is wear-resistant;

[0004] However, simply adding inorganic powders can easily lead to many problems. For example, the resin surface cannot be made very wear-resistant after 3D printing, and it is easy to have problems such as increased viscosity and powder agglomeration. It cannot be directly applied to the 3D printing process. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a modified silicon nitride prepolymer for a photocurable resin, which is composed of the following substances in a mass ratio:

[0006] Prepolymer: 0.95-0.98;

[0007] Nano silicon nitride: 0.02-0.05;

[0008] Surfactant: 0.001-0.004;

[0009] Fumed silica: 0.001-0.005;

[0010] Inhibitor: 0.002-0.005.

[0011] To further supplement the technical solution, the prepolymer is one or more of epoxy acrylic resin, epoxy methacrylic resin, aliphatic polyurethane methacrylic resin, and aliphatic polyurethane acrylic resin, and the aliphatic polyurethane acrylic resin is preferably one or more of CN981NS, CN1963NS, and CN8895NS.

[0012] To further supplement the technical solution, the surfactant is one or more of Lutensol TO-3, TO-5, and TO-7; the fumed silica is Evonik R 711, The polymerization inhibitor is one or more of hydroquinone and tert-butylcatechol.

[0013] A method for preparing a modified silicon nitride prepolymer for a photocurable resin comprises the following steps:

[0014] S1: Add prepolymer to the reactor, heat to 60°C, keep constant temperature, then add fumed silica, disperse with a high-speed 3000 rpm homogenizer, test the fumed silica particle size after dispersion to reach 40um (scraper fineness meter test), continue to keep constant temperature at 60°C and continue stirring, add surfactant and polymerization inhibitor while stirring, after adding, heat to 80°C, keep constant temperature at 80°C and stir at 3000 rpm for 30 minutes, then add nano silicon nitride while stirring, and continue stirring for 2 hours;

[0015] S2: The prepolymer is further heated to 100°C and stirred at 1000 rpm for 10 min;

[0016] S3: After stirring is completed, take a sample to test its particle size. The scraper fineness meter needs to reach 30um. If it does not meet the standard, continue stirring at 100℃ and 1000 rpm for 10min;

[0017] S4: After the particle size reaches the standard, stir at a constant temperature of 40 degrees for 30 minutes, slowly cool to room temperature, and after the room temperature reaches the standard, pass the high viscosity prepolymer through a three-roll grinder for 3 times, re-measure the particle size, and keep the particle size stable at 20um.

[0018] A photocurable resin comprises the following components in parts by weight: 25-55 parts by weight of the modified silicon nitride prepolymer according to any one of claims 1 to 3, 25-70 parts by weight of a reactive diluent, and 0.1-8 parts by weight of a free radical initiator.

[0019] Further supplementing the technical solution, the active diluent is one or more of 2-phenoxyethyl acrylate (SR339NS), tricyclodecane dimethanol diacrylate (SR833), tri(2-hydroxyethyl) isocyanuric acid triacrylate (SR368), isobornyl methacrylate (SR423), dipropylene glycol diacrylate (SR508), (4) ethoxylated bisphenol A diacrylate (SR601NS), tricyclodecane dimethanol methacrylate (SR834), and trimethylolpropane triacrylate (SR351).

[0020] As a further supplement to the technical solution, the free radical initiator is one or more of diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide and phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide.

[0021] As a further supplement to the technical solution, the photocurable resin further comprises 0.05-0.5 parts by weight of a leveling agent, wherein the leveling agent is an organic silicone leveling agent and / or an acrylic leveling agent, preferably one or more of BYK330, BYK306, and BYK323.

[0022] As a further supplement to the technical solution, the photocurable resin further comprises 0.06-0.2 parts by weight of a defoamer, wherein the defoamer is a silicone defoamer and / or an acrylate defoamer, preferably one or more of BYK054, BYK054T, and BYK057.

[0023] As a further supplement to the technical solution, the photocurable resin also includes 0.02-0.2 parts by weight of UV color concentrate.

[0024] The beneficial effect is that the pretreated silicon nitride modified prepolymer can form an effective filling system in the resin, thereby improving the wear resistance of the resin surface. At the same time, the stable silicon nitride modified prepolymer can ensure the stability of resin printing, and there will be no particle precipitation and sedimentation during long-term 48-hour continuous printing. The photocurable resin of the present invention has good storage stability and is not easy to precipitate and precipitate particles. At the same time, the post-curing method is simple, and no heating is required for post-curing. It can be cured by ultraviolet light water-proof irradiation. The molded model has excellent wear resistance and can be used for structural parts and vulnerable parts. DETAILED DESCRIPTION

[0025] In order to make the technical solution more clear to those skilled in the art, the technical solution of the present invention will be described in detail below in conjunction with embodiments:

[0026] A modified silicon nitride prepolymer for a photocurable resin, comprising the following substances in a mass ratio:

[0027] Prepolymer: 0.95-0.98;

[0028] Nano silicon nitride: 0.02-0.05;

[0029] Surfactant: 0.001-0.004;

[0030] Fumed silica: 0.001-0.005;

[0031] Inhibitor: 0.002-0.005.

[0032] The prepolymer is one or more of epoxy acrylic resin, epoxy methacrylic resin, aliphatic polyurethane methacrylic resin, and aliphatic polyurethane acrylic resin, and the aliphatic polyurethane acrylic resin is preferably one or more of CN981NS, CN1963NS, and CN8895NS.

[0033] Wherein, the surfactant is one or more of Lutensol TO-3, TO-5, and TO-7; the fumed silica is Evonik R 711, The polymerization inhibitor is one or more of hydroquinone and tert-butyl catechol. A method for preparing a modified silicon nitride prepolymer for a photocurable resin comprises the following steps:

[0034] S1: Add prepolymer to the reactor, heat to 60°C, keep constant temperature, then add fumed silica, disperse with a high-speed 3000 rpm homogenizer, test the fumed silica particle size after dispersion to reach 40um (scraper fineness meter test), continue to keep constant temperature at 60°C and continue stirring, add surfactant and polymerization inhibitor while stirring, after adding, heat to 80°C, keep constant temperature at 80°C and stir at 3000 rpm for 30 minutes, then add nano silicon nitride while stirring, and continue stirring for 2 hours;

[0035] S2: The prepolymer is further heated to 100°C and stirred at 1000 rpm for 10 min;

[0036] S3: After stirring is completed, take a sample to test its particle size. The scraper fineness meter needs to reach 30um. If it does not meet the standard, continue stirring at 100℃ and 1000 rpm for 10min;

[0037] S4: After the particle size reaches the standard, stir at a constant temperature of 40 degrees for 30 minutes, slowly cool to room temperature, and after the room temperature reaches the standard, pass the high viscosity prepolymer through a three-roll grinder for 3 times, re-measure the particle size, and keep the particle size stable at 20um.

[0038] A photocurable resin comprises the following components in parts by weight: 25-55 parts by weight of the modified silicon nitride prepolymer according to any one of claims 1 to 3, 25-70 parts by weight of a reactive diluent, and 0.1-8 parts by weight of a free radical initiator.

[0039] Among them, the active diluent is one or more of 2-phenoxyethyl acrylate (SR339NS), tricyclodecane dimethanol diacrylate (SR833), tri(2-hydroxyethyl) isocyanurate triacrylate (SR368), isobornyl methacrylate (SR423), dipropylene glycol diacrylate (SR508), (4) ethoxylated bisphenol A diacrylate (SR601NS), tricyclodecane dimethanol methacrylate (SR834), and trimethylolpropane triacrylate (SR351).

[0040] Wherein, the free radical initiator is one or more of diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide and phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide.

[0041] The photocurable resin further comprises 0.05-0.5 parts by weight of a leveling agent, wherein the leveling agent is an organic silicon leveling agent and / or an acrylic leveling agent, preferably one or more of BYK330, BYK306 and BYK323.

[0042] The photocurable resin further comprises 0.06-0.2 parts by weight of a defoamer, wherein the defoamer is a silicone defoamer and / or an acrylate defoamer, preferably one or more of BYK054, BYK054T, and BYK057.

[0043] The photocurable resin further comprises 0.02-0.2 parts by weight of UV color concentrate.

[0044] Example 1

[0045] This embodiment provides a method for preparing a silicon nitride modified prepolymer, comprising the following steps:

[0046] S1: Prepare according to the following ratio:

[0047]

[0048] The prepolymer is CN981NS, the surfactant is Lutensol TO-3, and the fumed silica is R 711, the inhibitor is hydroquinone;

[0049] The specific process is as follows: add prepolymer to the reactor, heat to 60°C, keep constant temperature, then add fumed silica, disperse with a high-speed 3000 rpm homogenizer, after dispersion, test the fumed silica particle size to reach 40um (scraper fineness meter test), continue to keep constant temperature at 60°C and continue stirring, add surfactant and polymerization inhibitor while stirring, after adding, heat to 80°C, keep constant temperature at 80°C and stir at 3000 rpm for 30 minutes, then add nano silicon nitride while stirring, and continue stirring for 2 hours;

[0050] S2: The prepolymer is further heated to 100°C and stirred at 1000 rpm for 10 min;

[0051] S3: After stirring is completed, take a sample to test its particle size. The scraper fineness meter needs to reach 30um. If it does not meet the standard, continue stirring at 100℃ and 1000 rpm for 10min;

[0052] S4: After the particle size reaches the standard, stir at a constant temperature of 40 degrees for 30 minutes, slowly cool to room temperature, and after the room temperature reaches the standard, pass the high viscosity prepolymer through a three-roll grinder for 3 times, re-measure the particle size, and keep the particle size stable at 10um.

[0053] Example 2

[0054] This embodiment provides a method for preparing a silicon nitride modified prepolymer, comprising the following steps:

[0055] S1: Prepare according to the following ratio:

[0056]

[0057] The prepolymer is CN1963NS, the surfactant is Lutensol TO-3, and the fumed silica is R 711, the inhibitor is hydroquinone;

[0058] The specific process is as follows: add prepolymer to the reactor, heat to 60°C, keep constant temperature, then add fumed silica, disperse with a high-speed 3000 rpm homogenizer, after dispersion, test the fumed silica particle size to reach 40um (scraper fineness meter test), continue to keep constant temperature at 60°C and continue stirring, add surfactant and polymerization inhibitor while stirring, after adding, heat to 80°C, keep constant temperature at 80°C and stir at 3000 rpm for 30 minutes, then add nano silicon nitride while stirring, and continue stirring for 2 hours;

[0059] S2: The prepolymer is further heated to 100°C and stirred at 1000 rpm for 10 min;

[0060] S3: After stirring is completed, take a sample to test its particle size. The scraper fineness meter needs to reach 30um. If it does not meet the standard, continue stirring at 100℃ and 1000 rpm for 10min;

[0061] S4: After the particle size reaches the standard, stir at a constant temperature of 40 degrees for 30 minutes, slowly cool to room temperature, and after the room temperature reaches the standard, pass the high viscosity prepolymer through a three-roll grinder for 3 times, re-measure the particle size, and keep the particle size stable at 20um.

[0062] Example 3

[0063] This embodiment provides a method for preparing a silicon nitride modified prepolymer, comprising the following steps:

[0064] S1: Prepare according to the following ratio:

[0065]

[0066] The prepolymer is CN8895NS, the surfactant is Lutensol TO-3, and the fumed silica is R 711, the inhibitor is hydroquinone;

[0067] The specific process is as follows: add prepolymer to the reactor, heat to 60°C, keep constant temperature, then add fumed silica, disperse with a high-speed 3000 rpm homogenizer, after dispersion, test the fumed silica particle size to reach 40um (scraper fineness meter test), continue to keep constant temperature at 60°C and continue stirring, add surfactant and polymerization inhibitor while stirring, after adding, heat to 80°C, keep constant temperature at 80°C and stir at 3000 rpm for 30 minutes, then add nano silicon nitride while stirring, and continue stirring for 2 hours;

[0068] S2: The prepolymer is further heated to 100°C and stirred at 1000 rpm for 10 min;

[0069] S3: After stirring is completed, take a sample to test its particle size. The scraper fineness meter needs to reach 30um. If it does not meet the standard, continue stirring at 100℃ and 1000 rpm for 10min;

[0070] S4: After the particle size meets the standard, stir at a constant temperature of 40 degrees for 30 minutes, slowly cool to room temperature, and after the room temperature meets the standard, pass the high-viscosity prepolymer through a three-roll grinder for 3 times, re-measure the particle size, and keep the particle size stable at 15um.

[0071] Example 4

[0072] This embodiment provides a method for preparing a photocurable resin, comprising the following steps:

[0073] 45 parts by weight of the silicon nitride prepolymer prepared in Example 1, 25 parts by weight of tricyclodecane dimethanol diacrylate (SR833), 30 parts by weight of tris(2-hydroxyethyl)isocyanurate triacrylate (SR368), 1 part by weight of free radical initiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 0.2 parts by weight of leveling agent BYK330, 0.1 parts by weight of defoamer BYK054, and 0.1 parts by weight of UV color concentrate were added into a container and mixed thoroughly to obtain a resin composition;

[0074] The resin composition is injected into the DLP light curing device, and the light emitted by the light source is controlled by the micromirror array to cure to obtain the light curing resin; the DLP device uses a wavelength of 385nm, an exposure time of 3s / layer, a layer thickness of 50μm, and a post-curing method of light energy density of 10mw / cm 2 Curing box watertight curing for 10 minutes.

[0075] Example 5

[0076] This embodiment provides a method for preparing a photocurable resin, comprising the following steps:

[0077] 40 parts by weight of the silicon nitride prepolymer prepared in Example 2, 10 parts by weight of 2-phenoxyethyl acrylate (SR339NS), 10 parts by weight of isobornyl methacrylate (SR423), 40 parts by weight of tricyclodecane dimethanol methacrylate (SR834), 1.2 parts by weight of free radical initiator phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide, 0.1 parts by weight of leveling agent BYK306, 0.05 parts by weight of defoamer BYK054T, and 0.1 parts by weight of UV color concentrate were added into a container and mixed thoroughly to obtain a resin composition;

[0078] The resin composition was injected into the DLP light curing device, and the light emitted by the light source was controlled by the micromirror array to cure the light-curing resin. The DLP device used a wavelength of 385 nm, an exposure time of 3 s / layer, a layer thickness of 50 μm, and a post-curing method of light energy density of 10 mw / cm 2 Curing box watertight curing for 10 minutes.

[0079] Example 6

[0080] This embodiment provides a method for preparing a photocurable resin, comprising the following steps:

[0081] 35 parts by weight of the silicon nitride prepolymer prepared in Example 3, 30 parts by weight of dipropylene glycol diacrylate (SR508), 25 parts by weight of tris(2-hydroxyethyl)isocyanurate triacrylate (SR368), 10 parts by weight of isobornyl methacrylate (SR423), 3 parts by weight of free radical initiator diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, 0.1 parts by weight of leveling agent BYK323, 0.2 parts by weight of defoamer BYK057, and 0.1 parts by weight of UV color concentrate were added into a container and mixed thoroughly to obtain a resin composition;

[0082] The resin composition was injected into the DLP light curing device, and the light emitted by the light source was controlled by the micromirror array to cure the light-curing resin. The DLP device used a wavelength of 385 nm, an exposure time of 3 s / layer, a layer thickness of 50 μm, and a post-curing method of light energy density of 10 mw / cm 2 Curing box watertight curing for 10 minutes.

[0083] Example 7

[0084] This embodiment provides a method for preparing a photocurable resin, comprising the following steps:

[0085] 35 parts by weight of the silicon nitride prepolymer prepared in Example 1, 20 parts by weight of dipropylene glycol diacrylate (SR508), 10 parts by weight of (4) ethoxylated bisphenol A diacrylate (SR601NS), 5 parts by weight of trimethylolpropane triacrylate (SR351), 30 parts by weight of tricyclodecane dimethanol methacrylate (SR834), 0.5 parts by weight of free radical initiator diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, 0.2 parts by weight of leveling agent BYK306, 0.2 parts by weight of defoamer BYK054T, and 0.1 parts by weight of UV color concentrate were added into a container and mixed thoroughly to obtain a resin composition;

[0086] The resin composition was injected into the DLP light curing device, and the light emitted by the light source was controlled by the micromirror array to cure the light-curing resin. The DLP device used a wavelength of 385 nm, an exposure time of 3 s / layer, a layer thickness of 50 μm, and a post-curing method of light energy density of 10 mw / cm 2 Curing box watertight curing for 10 minutes.

[0087] Comparative Example 1

[0088] This comparative example provides a method for preparing a photocurable resin, which is different from Example 4 only in that the untreated nano silicon nitride powder used in Examples 1-3 is directly used.

[0089] Comparative Example 2

[0090] This comparative example provides a method for preparing a photocurable resin, which is different from Example 5 only in that the untreated nano silicon nitride powder used in Examples 1-3 is directly used.

[0091] Comparative Example 3

[0092] This comparative example provides a method for preparing a photocurable resin, which is different from Example 6 only in that the untreated nano silicon nitride powder used in Examples 1-3 is directly used.

[0093] Effect example

[0094] This effect example tests the tensile strength, impact resistance, surface hardness and wear resistance of the photocurable resin prepared in Examples 4-7 and Comparative Examples 1-3, wherein: the tensile strength is measured by printing Type 1 (American Standard) specimens with photocurable resin using the ASTM-D638 test method on a universal tensile testing machine, the impact resistance is measured by using the ASTM-D256 test method on an impact tester using notched impact specimens, and the surface hardness is measured by printing a 20*20*10 rectangular block with the prepared photocurable resin, and the post-curing method is a light energy density of 10mw / cm 2After 10 minutes of water-proof curing in a curing box, fix the pencil at a 45° angle and apply a load of 750g, then push at least 7mm at a speed of 0.5mm / s to 1mm / s, gradually increase the hardness until defects appear on the coating surface. For the wear resistance, use a 9H hardness pencil, apply a load of 500g, and quickly wear the resin surface 100 times at 5mm / s, and record the number of scratches to determine the wear resistance.

[0095] Table 1 Performance test results of photocurable resins prepared in Examples 4-7 and Comparative Example 1

[0096]

[0097] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made to certain parts thereof by technicians in this technical field all reflect the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. A modified silicon nitride prepolymer for photocurable resin, characterized in that: It is composed of the following substances in mass ratio: Prepolymer: 0.95-0.98; Nano silicon nitride: 0.02-0.05; Surfactant: 0.001-0.004; Fumed silica: 0.001-0.005; Inhibitor: 0.002-0.

005.

2. The modified silicon nitride prepolymer for photocurable resin according to claim 1, characterized in that: The prepolymer is one or more of epoxy acrylic resin, epoxy methacrylic resin, aliphatic polyurethane methacrylic resin, and aliphatic polyurethane acrylic resin. The aliphatic polyurethane acrylic resin is preferably one or more of CN981NS, CN1963NS, and CN8895NS.

3. The modified silicon nitride prepolymer for photocurable resin and the photocurable resin according to claim 2, characterized in that: The surfactant is one or more of Lutensol TO-3, TO-5, and TO-7; the fumed silica is Evonik R 711, The polymerization inhibitor is one or more of hydroquinone and tert-butylcatechol.

4. The method for preparing a modified silicon nitride prepolymer for a photocurable resin according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Add prepolymer to the reactor, heat to 60°C, keep constant temperature, then add fumed silica, disperse with a high-speed 3000 rpm homogenizer, test the fumed silica particle size after dispersion to reach 40um (scraper fineness meter test), continue to keep constant temperature at 60°C and continue stirring, add surfactant and polymerization inhibitor while stirring, after adding, heat to 80°C, keep constant temperature at 80°C and stir at 3000 rpm for 30 minutes, then add nano silicon nitride while stirring, and continue stirring for 2 hours; S2: The prepolymer is further heated to 100°C and stirred at 1000 rpm for 10 min; S3: After stirring is completed, take a sample to test its particle size. The scraper fineness meter needs to reach 30um. If it does not meet the standard, continue stirring at 100℃ and 1000 rpm for 10min; S4: After the particle size reaches the standard, stir at a constant temperature of 40 degrees for 30 minutes, slowly cool to room temperature, and after the room temperature reaches the standard, pass the high-viscosity prepolymer through a three-roll grinder for 3 times, re-measure the particle size, and keep the particle size stable at 20um.

5. A photocurable resin, characterized in that: The invention comprises the following components in parts by weight: 25-55 parts by weight of the modified silicon nitride prepolymer according to any one of claims 1 to 3, 25-70 parts by weight of a reactive diluent, and 0.1-8 parts by weight of a free radical initiator.

6. A photocurable resin according to claim 5, characterized in that: The active diluent is one or more of 2-phenoxyethyl acrylate (SR339NS), tricyclodecane dimethanol diacrylate (SR833), tri(2-hydroxyethyl) isocyanurate triacrylate (SR368), isobornyl methacrylate (SR423), dipropylene glycol diacrylate (SR508), (4) ethoxylated bisphenol A diacrylate (SR601NS), tricyclodecane dimethanol methacrylate (SR834), and trimethylolpropane triacrylate (SR351).

7. A photocurable resin according to claim 6, characterized in that: The free radical initiator is one or more of diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide and phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide.

8. The photocurable resin according to claim 7, characterized in that: The photocurable resin further comprises 0.05-0.5 parts by weight of a leveling agent, wherein the leveling agent is an organic silicon leveling agent and / or an acrylic leveling agent, preferably one or more of BYK330, BYK306 and BYK323.

9. The photocurable resin according to claim 8, characterized in that: The photocurable resin further comprises 0.06-0.2 parts by weight of a defoamer, wherein the defoamer is a silicone defoamer and / or an acrylate defoamer, preferably one or more of BYK054, BYK054T, and BYK057.

10. The photocurable resin according to claim 9, characterized in that: The photocurable resin further comprises 0.02-0.2 parts by weight of UV color concentrate.

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