3D printing photocuring aesthetic resin material and preparation method thereof

Abstract

The invention relates to the technical field of materials, and discloses a 3D printing light-cured aesthetic resin material and a preparation method thereof.The 3D printing light-cured aesthetic resin material is formed by taking an acrylate preform as a main raw material and matching with auxiliary materials such as an active crosslinking monomer and an inorganic reinforcing agent to be mixed, and in the subsequent light curing process, the curing time is shortened, and the curing time is shortened. The active cross-linking monomer and the inorganic reinforcing agent can participate in the photocuring process of the photocuring resin material, so that the resin material can present a cross-linked network structure, on one hand, the active cross-linking monomer structure contains stable adamantane heterocyclic rings and rigid benzene rings, the mechanical strength of the resin material can be effectively improved, and on the other hand, the active cross-linking monomer structure can be used for preparing the photocuring resin material; moreover, the density of the material can be higher by virtue of the cross-linked structure, so that the impact strength of the resin material is improved, the effects of transferring load and dispersing stress can be effectively exerted by virtue of the existence of the wollastonite, and the mechanical strength of the resin material is further enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and particularly to a 3D printing photocurable aesthetic resin material and a preparation method thereof. Background Art

[0002] 3D printing is an additive manufacturing technology that uses a computer to create a digital model and then constructs complex three-dimensional structures by layer-by-layer stacking for manufacturing various complex structures or solid parts. With the rapid development of technology, 3D printing technology has gradually penetrated into various industries, especially prominent in the field of stomatology. As an innovative oral restoration material and technology, 3D printing photocurable aesthetic resin can produce highly realistic anterior tooth restorations according to the patient's oral model and aesthetic needs. After restoration, the tooth shape and color of the patient are indistinguishable from natural teeth. Therefore, 3D printing technology is leading a new trend in oral aesthetic restoration with its advantages of high precision, personalization, and rapid manufacturing.

[0003] 3D printing photocurable resin material is also known as photosensitive resin, which generally consists mainly of a preform (or oligomer), an active diluent, a photoinitiator, and a small amount of additives. Among them, the preform is the main component of the photocurable resin, which is a multi-functional oligomer that can rapidly polymerize and cure under the initiation of a photoinitiator. The preform determines important mechanical properties such as the viscosity of the liquid resin, the curing shrinkage rate, the curing speed, and the hardness and strength of the cured resin. The active diluent is an organic small molecule with polymerizable functional groups, mainly used to adjust the resin viscosity. The photoinitiator is a key component of the resin curing system, which can absorb light sources such as ultraviolet light or laser beams, release free radicals or cations after being excited, and thus initiate a polymerization reaction. It is related to whether the preform and the active diluent can rapidly crosslink and cure when the resin system is irradiated with light. According to the different absorbed energies, photoinitiators are divided into ultraviolet photoinitiators and visible light photoinitiators; according to the different generated activities, they are divided into free radical photoinitiators and cationic photoinitiators.

[0004] At present, the preform is mainly a free radical preform. Common free radical preforms include epoxy acrylate, polyurethane acrylate, unsaturated polyester, and polyester acrylate, etc. Among them, the curing speed of unsaturated polyester is slow and it is difficult to meet the requirements of rapid curing. Although the curing speed of epoxy acrylate is relatively fast, it is brittle and easy to damage. Although the toughness of polyurethane acrylate is acceptable, its mechanical properties are poor, and there are large defects in practical applications.

[0005] With the continuous development of 3D printing technology, high-performance photocurable resin materials have gradually become a research hotspot, and their mechanical properties such as tensile strength have gradually become a new standard for measuring themselves. Especially in oral aesthetic restoration, higher-strength photocurable resin materials are significantly more reliable. Obviously, the currently used 3D printing photocurable resin materials are gradually unable to meet the needs of consumers. Therefore, it is of great significance to develop photocurable resin materials with higher mechanical strength. Summary of the Invention

[0006] (I) Technical problems to be solved

[0007] In view of the deficiencies of the prior art, the present invention provides a 3D printing photocurable aesthetic resin material and a preparation method thereof.

[0008] (II) Technical solutions

[0009] A preparation method of a 3D printing photocurable aesthetic resin material, wherein the resin material is made of the following raw materials measured by weight parts:

[0010]

[0011] The preparation method of the 3D printing photocurable aesthetic resin material comprises the following steps:

[0012] First step, weigh each raw material according to the weight parts for standby;

[0013] Second step, transfer the acrylate preform, active crosslinking monomer, photoinitiator, diluent and inorganic reinforcing agent into a high-speed mixer, control the stirring temperature at 50-60 °C, and mechanically stir and mix at a stirring rate of 500-1000 r / min for 20-40 min to obtain the resin material;

[0014] The active crosslinking monomer is an adamantane derivative containing two equivalents of unsaturated alkenyl substituents in the structure.

[0015] As a further scheme of the present invention, the acrylate preform is at least one of polyurethane acrylate or epoxy acrylate.

[0016] As a further scheme of the present invention, the preparation method of the active crosslinking monomer is as follows:

[0017] Add 2,2-bis(4-hydroxyphenyl)adamantane and tetrahydrofuran to a reaction kettle filled with nitrogen. After adding, start stirring until a uniform reaction solution is formed. Then place the reaction kettle in an ice bath environment, and continue to add an acyl chloride modifier to the reaction kettle. After adding, remove the ice bath, then add an acid-binding agent to the reaction kettle. After adding, stir at room temperature for 2-4 h, evaporate to remove the solvent, and collect the product to obtain the active crosslinking monomer.

[0018] As a further solution of the present invention, the acyl chloride modified body is methacryloyl chloride or acryloyl chloride.

[0019] As a further solution of the present invention, the acid-binding agent is pyridine or triethylamine.

[0020] As a further solution of the present invention, the molar ratio of 2,2-bis(4-hydroxyphenyl)adamantane to the acyl chloride modified body is 1:2.

[0021] In the above technical solution, using 2,2-bis(4-hydroxyphenyl)adamantane as a reactant, with the use of an acyl chloride modified body, under the action of an acid-binding agent, the active hydroxyl groups and acyl chloride substituents react with each other by condensation reaction. By controlling the dosage ratio of the reactants, an adamantane derivative containing two equivalents of unsaturated alkenyl substituents in its structure, that is, an active crosslinking monomer, can be prepared.

[0022] As a further solution of the present invention, the photoinitiator is any one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, and benzophenone; the diluent is any one of polyethylene glycol dimethacrylate, cyclohexane dimethanol diacrylate, or trimethylolpropane formal acrylate.

[0023] As a further solution of the present invention, the preparation method of the inorganic reinforcing agent is as follows:

[0024] Ultrasonically disperse wollastonite in an anhydrous toluene solvent to form a uniform dispersion liquid, and then continue to add an olefinated surface modification reagent to the dispersion liquid, while adding dibutyltin dilaurate for catalysis. After adding, start heating, maintain the temperature at 70-80 °C, stir and react for 6-9 h under nitrogen protection, then stop heating, cool down and discharge, centrifuge out the solid material, and after washing and vacuum drying treatment, the inorganic reinforcing agent can be prepared.

[0025] As a further solution of the present invention, it is characterized in that the olefinated surface modification reagent is ethyl isocyanate acrylate or isocyanatoethyl methacrylate.

[0026] In the above technical solution, by using dibutyltin dilaurate for catalysis, the isocyanate group in the structure of the olefinated surface modification reagent is used to perform surface modification on wollastonite, and an inorganic reinforcing agent with a large number of polymerizable unsaturated alkenyl substituents on its surface is prepared.

[0027] A 3D printing photocurable aesthetic resin material is prepared by using the above preparation method.

[0028] (III) Beneficial technical effects

[0029] (1) The present invention prepares an adamantane derivative containing two equivalents of unsaturated alkenyl substituents in its structure as an active crosslinking monomer, which participates in the photocuring process of the photocurable resin material, enabling the resin material to exhibit a crosslinked network structure. On the one hand, the active crosslinking monomer structure contains a stable adamantane heterocycle and a rigid benzene ring, which can effectively improve the mechanical strength of the resin material, and the crosslinked structure can make the material more dense, thereby improving the impact strength of the resin material, etc.

[0030] (2) The present invention prepares an inorganic reinforcing agent by subjecting wollastonite to surface alkenylation modification. Since the unsaturated alkenyl functional group can participate in the photocuring process of the resin material, the interfacial bonding force between wollastonite and the resin material can be greatly improved, and then a crosslinked network with wollastonite as the crosslinking core point is formed, enabling wollastonite to more effectively exert its effect of transferring load and dispersing stress, and further enhancing the mechanical strength of the resin material. Brief Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for describing the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 It is an infrared analysis test chart of the active crosslinking monomer. Detailed Embodiments

[0033] To facilitate the understanding of the present invention, the following will describe the present invention more comprehensively. The following gives the preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present invention more thorough and comprehensive.

[0034] Preparation Example 1

[0035] Preparation of the active crosslinking monomer:

[0036] Add 0.3 g of 2,2-bis(4-hydroxyphenyl)adamantane and tetrahydrofuran to a reaction kettle filled with nitrogen. After adding, start stirring until a homogeneous reaction solution is formed. Then place the reaction kettle in an ice bath environment and continue to add 0.17 g of acryloyl chloride to the reaction kettle. After adding, remove the ice bath, and then add triethylamine to the reaction kettle. After adding, stir at room temperature for 3 h, evaporate to remove the solvent, and collect the product to obtain the active crosslinking monomer.

[0037] Figure 1This is the infrared analysis test chart of active cross-linking monomers. After analysis, we know that 3089cm -1 3057cm -1 The characteristic absorption peak at 3310 cm is the characteristic absorption peak of carbon and hydrogen on the benzene ring. -1 The characteristic absorption peak at 1753 cm is the characteristic absorption peak of carbon-hydrogen on the unsaturated carbon-carbon double bond. -1 The characteristic absorption peak appearing at is the characteristic absorption peak of the ester group C=O. Obviously, the ester group is formed by the condensation reaction of the hydroxyl group in the 2,2-bis(4-hydroxyphenyl)adamantane structure and the acyl chloride group in the acryloyl chloride structure.

[0038] Preparation Example 2

[0039] Preparation of inorganic reinforcing agent:

[0040] 2.8 g of wollastonite is ultrasonically dispersed in anhydrous toluene solvent to form a uniform dispersion, and then 0.5 g of ethyl isocyanate acrylate is added to the dispersion, and 0.01 g of dibutyltin dilaurate is added for catalysis. After the addition is completed, heating is turned on and the temperature is maintained at 75°C. After stirring and reacting for 8 hours under nitrogen protection, heating is stopped, the temperature is lowered and the material is discharged. The solid material is centrifuged out, and the inorganic reinforcing agent can be obtained after washing and vacuum drying.

[0041] Example 1

[0042] A 3D printing light-curing aesthetic resin material is made of the following raw materials measured in parts by weight:

[0043]

[0044] The preparation method comprises the following steps:

[0045] The first step is to weigh each raw material according to the weight portion for use;

[0046] In the second step, the acrylate preform, the active cross-linking monomer, 2-hydroxy-2-methyl-1-phenyl-1-propanone, polyethylene glycol dimethacrylate and the inorganic reinforcing agent are transferred into a high-speed mixer, the stirring temperature is controlled to be 50° C., and the mixture is mechanically stirred and mixed at a stirring rate of 500 r / min for 40 minutes to obtain a resin material.

[0047] The acrylate preform is polyurethane acrylate purchased from BASF with the model number of Laromer PR9000; the active cross-linking monomer is the active cross-linking monomer prepared in Preparation 1; the inorganic reinforcing agent is the active cross-linking monomer prepared in Preparation Example 2, and the rest are the same.

[0048] Example 2

[0049] A 3D printing light-curing aesthetic resin material is made of the following raw materials measured in parts by weight:

[0050]

[0051]

[0052] The preparation method comprises the following steps:

[0053] The first step is to weigh each raw material according to the weight portion for use;

[0054] In the second step, the acrylate preform, active cross-linking monomer, 1-hydroxycyclohexyl phenyl ketone, cyclohexanedimethanol diacrylate and inorganic reinforcing agent are transferred into a high-speed mixer, the stirring temperature is controlled to be 60° C., and the mixture is mechanically stirred and mixed at a stirring rate of 800 r / min for 30 minutes to obtain a resin material.

[0055] Example 3

[0056] A 3D printing light-curing aesthetic resin material is made of the following raw materials measured in parts by weight:

[0057]

[0058] The preparation method comprises the following steps:

[0059] The first step is to weigh each raw material according to the weight portion for use;

[0060] In the second step, the acrylate preform, active cross-linking monomer, 1-hydroxycyclohexyl phenyl ketone, cyclotrimethylolpropane formal acrylate and inorganic reinforcing agent are transferred into a high-speed mixer, the stirring temperature is controlled to be 60° C., and the mixture is mechanically stirred and mixed at a stirring rate of 800 r / min for 30 minutes to obtain a resin material.

[0061] Example 4

[0062] A 3D printing light-curing aesthetic resin material is made of the following raw materials measured in parts by weight:

[0063]

[0064]

[0065] The preparation method comprises the following steps:

[0066] The first step is to weigh each raw material according to the weight portion for use;

[0067] Step 2: Transfer the acrylate preform, reactive crosslinking monomer, 1-hydroxycyclohexyl phenyl ketone, trimethylolpropane formal acrylate, and inorganic reinforcing agent into a high-speed mixer. Control the stirring temperature at 60 °C and mechanically stir and mix for 30 min at a stirring rate of 800 r / min to obtain the resin material.

[0068] Example 5

[0069] A 3D printing photocurable aesthetic resin material is prepared from the following raw materials measured by weight parts:

[0070]

[0071] The preparation method includes the following steps:

[0072] Step 1: Weigh each raw material according to the weight parts for standby.

[0073] Step 2: Transfer the acrylate preform, reactive crosslinking monomer, 1-hydroxycyclohexyl phenyl ketone, trimethylolpropane formal acrylate, and inorganic reinforcing agent into a high-speed mixer. Control the stirring temperature at 60 °C and mechanically stir and mix for 20 min at a stirring rate of 1000 r / min to obtain the resin material.

[0074] Comparative Example 1

[0075] A 3D printing photocurable aesthetic resin material is prepared from the following raw materials measured by weight parts:

[0076]

[0077] The preparation method includes the following steps:

[0078] Step 1: Weigh each raw material according to the weight parts for standby.

[0079] Step 2: Transfer the acrylate preform, reactive crosslinking monomer, 1-hydroxycyclohexyl phenyl ketone, trimethylolpropane formal acrylate, and wollastonite into a high-speed mixer. Control the stirring temperature at 60 °C and mechanically stir and mix for 30 min at a stirring rate of 800 r / min to obtain the resin material.

[0080] Comparative Example 2

[0081] A 3D printing photocurable aesthetic resin material is prepared from the following raw materials measured by weight parts:

[0082]

[0083] The preparation method includes the following steps:

[0084] Step 1: Weigh each raw material according to the weight parts and set aside for use;

[0085] Step 2: Transfer the acrylate preform, active crosslinking monomer, 1-hydroxycyclohexyl phenyl ketone, and trimethylolpropane formal acrylate into a high-speed mixer, control the stirring temperature at 60 °C, and mechanically stir and mix for 20 minutes at a stirring rate of 1000 r / min to obtain the resin material.

[0086] Comparative Example 3

[0087] A 3D printing photocurable aesthetic resin material is made from the following raw materials measured by weight parts:

[0088]

[0089] The preparation method includes the following steps:

[0090] Step 1: Weigh each raw material according to the weight parts and set aside for use;

[0091] Step 2: Transfer the acrylate preform, 1-hydroxycyclohexyl phenyl ketone, trimethylolpropane formal acrylate, and inorganic reinforcing agent into a high-speed mixer, control the stirring temperature at 60 °C, and mechanically stir and mix for 20 minutes at a stirring rate of 1000 r / min to obtain the resin material.

[0092] Test Example

[0093] The resin materials in the examples and comparative examples were formed by 3D printing and cut into test samples that meet the specifications for various performance tests. The results are recorded in the following table:

[0094] Tensile strength / MPa <![CDATA[Impact strength / kJ / m 2 > Flexural strength / MPa Example 1 139.4 67.7 145.1 Example 2 139.5 67.8 145.3 Example 3 139.8 68.0 145.8 Example 4 139.7 68.0 145.5 Example 5 139.5 67.5 145.6 Comparative Example 1 124.1 58.4 138.3 Comparative Example 2 110.7 49.1 125.9 Comparative Example 3 106.3 43.8 120.8

[0095] Among them, the tensile strength test refers to the standard GB / T 1040.1-2018; the impact strength test refers to the standard GB / T1843-2008; the flexural strength test refers to the standard GB / T 9341-2008.

[0096] Analyzing the test results, it can be seen that using the active crosslinking monomer prepared in Preparation Example 1 and the inorganic reinforcing agent prepared in Preparation Example 2 of the present invention as additives can make the finally formed resin material have more excellent mechanical strength.

[0097] After replacing the inorganic reinforcing agent with unmodified wollastonite, on the one hand, there may be agglomeration problems, and on the other hand, due to the interfacial incompatibility between wollastonite and the resin material groups, the reinforcing effect of wollastonite cannot be efficiently exerted, so the mechanical properties of the resin material are relatively poor. After removing the inorganic reinforcing agent, the mechanical strength of the resin material is significantly further reduced.

[0098] After removing the active crosslinking monomer, the crosslinking density of the molecular chains of the resin material decreases, the material density decreases, and the mechanical strength decreases significantly.

[0099] In this article, specific examples are used to elaborate on the principles and implementation modes of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those of ordinary skill in the art in the technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of the present invention patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that have no substantial difference from the literal description of the claims, then these other embodiments should also be included within the scope of the claims.

[0100] Enlightened by the ideal embodiments of the present invention, through the above description, relevant personnel can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing a 3D printing light-curing aesthetic resin material, characterized in that: The resin material is made of the following raw materials measured in parts by weight: The preparation method comprises the following steps: The first step is to weigh each raw material according to the weight portion for use; The second step is to move the acrylate preform, active cross-linking monomer, photoinitiator, diluent and inorganic reinforcing agent into a high-speed mixer, control the stirring temperature to 50-60°C, and mechanically stir and mix at a stirring rate of 500-1000r / min for 20-40min to obtain a resin material; The active cross-linking monomer is an adamantane derivative containing two equivalents of unsaturated alkenyl substituents in the structure.

2. The method for preparing a 3D printing light-curing aesthetic resin material according to claim 1, characterized in that: The acrylate preform is at least one of polyurethane acrylate or epoxy acrylate.

3. The method for preparing a 3D printing light-curing aesthetic resin material according to claim 1, characterized in that: The preparation method of the active cross-linking monomer is as follows: Add 2,2-bis(4-hydroxyphenyl)adamantane and tetrahydrofuran to a reactor filled with nitrogen. After the addition is completed, start stirring until a uniform reaction liquid is formed. Then place the reactor in an ice bath environment and continue to add the acyl chloride modifier to the reactor. After the addition is completed, remove the ice bath, then add the acid binding agent to the reactor. After the addition is completed, stir at room temperature for 2-4 hours, evaporate to remove the solvent, collect the product, and the active cross-linking monomer can be obtained.

4. According to the method for preparing a 3D printing light-curing aesthetic resin material according to claim 3, the acyl chloride modified body is methacryloyl chloride or acryloyl chloride.

5. According to the method for preparing a 3D printing light-curing aesthetic resin material according to claim 3, the acid binding agent is pyridine or triethylamine.

6. According to the method for preparing a 3D printing light-curing aesthetic resin material according to claim 3, the molar ratio of the 2,2-bis(4-hydroxyphenyl)adamantane to the acyl chloride modified product is 1:

2.

7. According to the method for preparing a 3D printing light-curing aesthetic resin material according to claim 1, the photoinitiator is any one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, and benzophenone; the diluent is any one of polyethylene glycol dimethacrylate, cyclohexanedimethanol diacrylate, or cyclotrimethylolpropane formal acrylate.

8. According to the method for preparing a 3D printing light-curing aesthetic resin material according to claim 1, the preparation method of the inorganic reinforcing agent is as follows: The wollastonite is ultrasonically dispersed in anhydrous toluene solvent to form a uniform dispersion, and then the olefination surface modification agent is continuously added to the dispersion, and dibutyltin dilaurate is added for catalysis. After the addition is completed, the heating is turned on and the temperature is maintained at 70-80°C. After stirring and reacting for 6-9 hours under nitrogen protection, the heating is stopped, the temperature is lowered and the material is discharged, the solid material is centrifuged out, and the inorganic reinforcing agent can be obtained after washing and vacuum drying.

9. The method for preparing a 3D printing light-curing aesthetic resin material according to claim 8, characterized in that: The olefinic surface modification agent is ethyl isocyanate acrylate or isocyanoethyl methacrylate.

10. A 3D printing light-curing aesthetic resin material, characterized in that: The method is prepared according to claim 1.

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