Dental adhesive as well as preparation method and application thereof

Abstract

The invention relates to a dental adhesive as well as a preparation method and application thereof. The dental adhesive comprises polyurethane prepolymer grafted epoxy resin, a defoaming agent and a curing agent, compared with a traditional dental adhesive, the dental adhesive has better adhesive capacity, mechanical property and anti-seepage performance, and the possibility of breeding bacteria in the oral cavity can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and in particular to a dental adhesive and a preparation method and application thereof. Background Art

[0002] Dental restorative materials are mainly divided into resin-based composite materials, porcelain and alloy materials according to their chemical composition. Resin-based composite materials are composed of organic resin matrix, inorganic filler and initiator system, and have good toughness, aesthetics and clinical operability. However, resin-based adhesive materials will undergo a series of physical and chemical changes when exposed to water, including swelling, micro-cracking, softening, etc., which will affect the bonding strength of the material, reduce mechanical properties and shorten the service life.

[0003] At present, the dental bonding technology is indirect bonding technology, which is divided into traditional indirect bonding and resin indirect bonding. The concept of indirect bonding technology was jointly proposed by Silvernan and Cohen in 1972. Through the intraoral impression or scanning impression, the bracket is positioned and pasted on the impression, and the bracket is transferred to the intraoral crown. Based on this, dental adhesives need to have reliable bonding strength, anti-leakage and good mechanical properties.

[0004] Traditional dental adhesives usually contain a large amount of organophosphorus. Due to the difficulty of synthesis and purification, the market price of organophosphorus is about 30,000 yuan / kg, which greatly reduces the cost-effectiveness of the product. In addition, dentin contains a large amount of collagen, and organophosphorus does not have a good bonding ability to collagen. In addition, the structure of adhesive promoters containing phosphorus is relatively simple, which does not meet market needs, and there is a serious rejection reaction with other monomers. Therefore, it is urgent to develop a dental adhesive with good bonding ability, mechanical properties and anti-leakage performance. Summary of the invention

[0005] The present application provides a dental adhesive and a preparation method and application thereof. Compared with traditional dental adhesives, the dental adhesive has better bonding ability, mechanical properties and anti-leakage properties, and can reduce the possibility of bacterial growth in the oral cavity.

[0006] In a first aspect of the present application, a dental adhesive is provided, comprising an epoxy resin grafted with a polyurethane prepolymer, a defoaming agent and a curing agent.

[0007] In some embodiments, based on the mass of the dental adhesive, the mass fraction of the epoxy resin grafted with the polyurethane prepolymer is 50% to 89.5%, the mass fraction of the defoaming agent is 0.5% to 5%, and the mass fraction of the curing agent is 10% to 49.5%.

[0008] In some embodiments, the polyurethane prepolymer grafted epoxy resin comprises a polyurethane prepolymer structural unit and an epoxy resin structural unit, and the mass ratio of the epoxy resin structural unit to the polyurethane prepolymer structural unit is 1:(0.2~1.2).

[0009] In some embodiments, the weight average molecular weight of the epoxy resin grafted with the polyurethane prepolymer is 100-350.

[0010] In some embodiments, the dental adhesive further comprises a solvent. Optionally, the solvent comprises water.

[0011] In some embodiments, the polyurethane prepolymer structural unit includes at least one of a polyurethane prepolymer structural unit containing a blocking group, a hydroxyl-terminated polyurethane prepolymer structural unit, and an isocyanate-terminated polyurethane prepolymer structural unit.

[0012] In some embodiments, the epoxy resin structural unit includes at least one of a bisphenol A type epoxy resin structural unit and an aliphatic type epoxy resin structural unit.

[0013] In some embodiments, the defoaming agent includes at least one of a polyether defoaming agent, a silicone defoaming agent, and a vegetable oil defoaming agent.

[0014] In some embodiments, the curing agent includes a water-based curing agent. Optionally, the water-based curing agent includes at least one of F0705 curing agent, NX-8401 curing agent and S-161 curing agent.

[0015] In some embodiments, the polyurethane prepolymer structural unit includes a terminal hydroxyl polyurethane prepolymer structural unit, the epoxy resin structural unit includes a bisphenol A epoxy resin structural unit, the defoaming agent includes an organosilicon defoaming agent, and the curing agent includes F0705 curing agent.

[0016] The second aspect of the present application provides a method for preparing a dental adhesive, comprising the following steps:

[0017] The solution containing epoxy resin and defoamer is heated, and polyurethane prepolymer is added to make the epoxy resin and the polyurethane prepolymer undergo grafting reaction to form polyurethane prepolymer grafted epoxy resin, thereby obtaining an intermediate product;

[0018] The intermediate product, a solvent and a curing agent are mixed to obtain the dental adhesive.

[0019] In some embodiments, based on the mass of the dental adhesive, the mass fraction of the epoxy resin grafted with the polyurethane prepolymer is 50% to 89.5%, the mass fraction of the defoaming agent is 0.5% to 5%, and the mass fraction of the curing agent is 10% to 49.5%.

[0020] In some embodiments, the heating temperature is 70°C to 80°C.

[0021] In some embodiments, the reaction time of the grafting reaction is 1.5 h to 2.5 h.

[0022] In some embodiments, the step of mixing the intermediate product, the solvent and the curing agent comprises: first mixing the intermediate product and the solvent, stirring at a speed of 200 r / min to 300 r / min for 0.5 min to 1.5 min, and then adding the curing agent.

[0023] In some embodiments, the mass ratio of the epoxy resin to the polyurethane prepolymer is 1:(0.2~1.2).

[0024] In some embodiments, the polyurethane prepolymer includes at least one of a polyurethane prepolymer containing a blocking group, a hydroxyl-terminated polyurethane prepolymer, and an isocyanate-terminated polyurethane prepolymer.

[0025] In some embodiments, the epoxy resin includes at least one of a bisphenol A type epoxy resin and an aliphatic type epoxy resin.

[0026] In some embodiments, the solvent includes water.

[0027] The third aspect of the present application provides the use of the dental adhesive described in the first aspect of the present application and the dental adhesive prepared by the preparation method described in the second aspect of the present application in the preparation of dental filling and restorative materials.

[0028] Compared with traditional technologies, the above dental adhesives have at least the following advantages:

[0029] The polyurethane prepolymer grafted epoxy resin in the above dental adhesive has excellent antibacterial properties and can reduce the possibility of bacterial growth in the oral cavity. It uses the polyurethane prepolymer structural unit as a reinforcing resin structural unit to form an interpenetrating network structure with the epoxy resin structural unit, which can improve the bonding performance, mechanical properties and anti-leakage performance of the dental adhesive. The polyurethane prepolymer grafted epoxy resin, defoamer and curing agent are used in combination to reduce bubbles in the dental adhesive and make the surface of the adhesive smoother, which is conducive to further improving the bonding effect. After curing, the adhesive has higher strength and hardness and can maintain a stable bonding effect. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0031] In this application, "first aspect", "second aspect", "third aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0032] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0033] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0034] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0035] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application. The terms used in this application and in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this application includes any and all combinations of one or more related listed items. The term "multiple" in this application means at least two, such as two, three, etc., unless otherwise clearly and specifically limited.

[0036] One embodiment of the present application provides a dental adhesive, comprising an epoxy resin grafted with a polyurethane prepolymer, a defoaming agent, and a curing agent.

[0037] The polyurethane prepolymer grafted epoxy resin in the above dental adhesive has excellent antibacterial properties and can reduce the possibility of bacterial growth in the oral cavity. It uses the polyurethane prepolymer structural unit as a reinforcing resin structural unit to form an interpenetrating network structure with the epoxy resin structural unit, which can improve the bonding performance, mechanical properties and anti-leakage performance of the dental adhesive. The polyurethane prepolymer grafted epoxy resin, defoamer and curing agent are used in combination to reduce bubbles in the dental adhesive and make the surface of the adhesive smoother, which is conducive to further improving the bonding effect. After curing, the adhesive has higher strength and hardness and can maintain a stable bonding effect.

[0038] In some embodiments, based on the mass of the dental adhesive, the mass fraction of the epoxy resin grafted with the polyurethane prepolymer is 50% to 89.5%, the mass fraction of the defoamer is 0.5% to 5%, and the mass fraction of the curing agent is 10% to 49.5%. Controlling the mass fraction of each component in the dental adhesive to the above range is conducive to further improving the bonding performance and mechanical properties of the dental adhesive. Specifically, the mass fraction of the epoxy resin grafted with the polyurethane prepolymer includes but is not limited to: 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 89.5% or any range between the foregoing, the mass fraction of the defoamer includes but is not limited to: 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% or any range between the foregoing, and the mass fraction of the curing agent includes but is not limited to: 10%, 20%, 30%, 40%, 49.5% or any range between the foregoing.

[0039] In some embodiments, the epoxy resin grafted with the polyurethane prepolymer comprises a polyurethane prepolymer structural unit and an epoxy resin structural unit, and the mass ratio of the epoxy resin structural unit to the polyurethane prepolymer structural unit is 1:(0.2-1.2). Controlling the mass ratio of the epoxy resin structural unit to the polyurethane prepolymer structural unit within the above range can further improve the bonding performance and mechanical properties of the dental adhesive. Specifically, the above mass ratio includes but is not limited to: 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1, 1:1.2 or a range between any two of the foregoing.

[0040] In some embodiments, the weight average molecular weight of the epoxy resin grafted with the polyurethane prepolymer is 100 to 350. By controlling the weight average molecular weight of the epoxy resin grafted with the polyurethane prepolymer to be within the above range, it is more conducive to improving the bonding performance and mechanical properties of the dental adhesive. Specifically, the above weight average molecular weight includes but is not limited to: 100, 150, 200, 250, 300, 350 or a range between any two of the foregoing.

[0041] In some embodiments, the dental adhesive further comprises a solvent comprising water.

[0042] In some embodiments, the polyurethane prepolymer structural unit includes at least one of a polyurethane prepolymer structural unit containing a blocking group, a hydroxyl-terminated polyurethane prepolymer structural unit, and an isocyanate-terminated polyurethane prepolymer structural unit.

[0043] In some embodiments, the epoxy resin structural unit includes at least one of a bisphenol A type epoxy resin structural unit and an aliphatic type epoxy resin structural unit.

[0044] In some embodiments, the defoaming agent includes at least one of a polyether defoaming agent, a silicone defoaming agent, and a vegetable oil defoaming agent.

[0045] In some embodiments, the curing agent includes a water-based curing agent. In some embodiments, the water-based curing agent includes at least one of F0705 curing agent, NX-8401 curing agent, and S-161 curing agent.

[0046] In some embodiments, the polyurethane prepolymer structural unit includes a hydroxyl-terminated polyurethane prepolymer structural unit, the epoxy resin structural unit includes a bisphenol A epoxy resin structural unit, the defoamer includes an organosilicon defoamer, and the curing agent includes an F0705 curing agent. The above components are used in combination to further improve the bonding performance and mechanical properties of the dental adhesive.

[0047] Another embodiment of the present application provides a method for preparing a dental adhesive, comprising the following steps:

[0048] The solution containing epoxy resin and defoamer is heated, and polyurethane prepolymer is added to make the epoxy resin and polyurethane prepolymer undergo grafting reaction to form polyurethane prepolymer grafted epoxy resin, thereby obtaining an intermediate product;

[0049] The intermediate product, the solvent and the curing agent are mixed to obtain a dental adhesive.

[0050] The epoxy resin grafted with polyurethane prepolymer in the above-mentioned dental adhesive has excellent antibacterial properties, can reduce the possibility of bacterial growth in the oral cavity, and uses polyurethane prepolymer structural units as reinforcing resin structural units to form an interpenetrating network structure with epoxy resin structural units, which can improve the bonding performance, mechanical properties and anti-leakage performance of the dental adhesive, and the epoxy resin grafted with polyurethane prepolymer, defoamer and curing agent are used in combination to reduce bubbles in the dental adhesive, so that the surface of the adhesive is relatively smooth, which is conducive to further improving the bonding effect, and the adhesive has higher strength and hardness after curing, and can maintain a stable bonding effect. In addition, the above-mentioned preparation method is easy to operate, which is conducive to the mass production of dental adhesives, and is also conducive to the reduction of the production cost of dental adhesives.

[0051] In some embodiments, based on the mass of the dental adhesive, the mass fraction of the epoxy resin grafted with the polyurethane prepolymer is 50% to 89.5%, the mass fraction of the defoamer is 0.5% to 5%, and the mass fraction of the curing agent is 10% to 49.5%. Controlling the mass fraction of each component in the dental adhesive to be within the above range is conducive to further improving the bonding performance and mechanical properties of the dental adhesive.

[0052] In some embodiments, the heating temperature is 70°C to 80°C.

[0053] In some embodiments, the reaction time of the grafting reaction is 1.5 h to 2.5 h.

[0054] Controlling the heating temperature and the reaction time of the grafting reaction within the above range is conducive to the full grafting reaction between the epoxy resin and the polyurethane prepolymer. Specifically, the heating temperature includes but is not limited to: 70°C, 72°C, 74°C, 76°C, 78°C, 80°C or a range between any two of the foregoing, and the reaction time of the grafting reaction includes but is not limited to: 1.5h, 1.7h, 2h, 2.2h, 2.5h or a range between any two of the foregoing.

[0055] In some embodiments, the step of mixing the intermediate product, the solvent and the curing agent comprises: first mixing the intermediate product and the solvent, stirring at a speed of 200 r / min to 300 r / min for 0.5 min to 1.5 min, and then adding the curing agent. This is conducive to uniform mixing of the intermediate product, the solvent and the curing agent.

[0056] In some embodiments, the mass ratio of epoxy resin to polyurethane prepolymer is 1:(0.2-1.2). When the mass ratio of epoxy resin to polyurethane prepolymer is 1:0.2, the mass ratio of epoxy resin structural units to polyurethane prepolymer structural units in the prepared polyurethane prepolymer grafted epoxy resin is about 1:0.2; when the mass ratio of epoxy resin to polyurethane prepolymer is 1:1.2, the mass ratio of epoxy resin structural units to polyurethane prepolymer structural units in the prepared polyurethane prepolymer grafted epoxy resin is about 1:1.2.

[0057] In some embodiments, the polyurethane prepolymer includes at least one of a polyurethane prepolymer containing a blocking group, a hydroxyl-terminated polyurethane prepolymer, and an isocyanate-terminated polyurethane prepolymer.

[0058] In some embodiments, the epoxy resin includes at least one of a bisphenol A type epoxy resin and an aliphatic type epoxy resin.

[0059] In some embodiments, the solvent includes water.

[0060] By adjusting the process parameters of the above preparation method, the dental adhesive in one embodiment of the present application can be obtained.

[0061] Conventional dental adhesives contain organophosphorus, which is highly toxic. However, the dental adhesive described above or the dental adhesive prepared by the above preparation method does not contain organophosphorus. Therefore, compared with conventional dental adhesives, the dental adhesive described above is safer and more environmentally friendly.

[0062] Another embodiment of the present application provides the use of the dental adhesive mentioned above and the dental adhesive prepared by the preparation method mentioned above in the present application in the preparation of dental filling and restorative materials.

[0063] In order to further illustrate the present application, the technical scheme of the present application is described in detail below in conjunction with specific examples. If no specific technology or conditions are specified in the examples, the technology or conditions described in the literature in the field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0064] Example 1

[0065] The dental adhesive was prepared as follows:

[0066] Pour 4g of bisphenol A epoxy resin into a three-necked flask, add 0.2g of silicone defoamer, put the three-necked flask into a water bath, gradually heat the water bath to 75°C, slowly pour 2g of hydroxyl-terminated polyurethane prepolymer into the three-necked flask, react for 1h, and obtain an intermediate product, which includes bisphenol A epoxy resin grafted with polyurethane prepolymer (polyurethane prepolymer grafted epoxy resin) and defoamer, the weight average molecular weight of the polyurethane prepolymer grafted epoxy resin is 233.69, and the mass ratio of epoxy resin structural units to polyurethane prepolymer structural units in the polyurethane prepolymer grafted epoxy resin is 2:1;

[0067] Weigh 1 g of deionized water (solvent), mix the deionized water with all the intermediate products, stir on a magnetic stirrer at a speed of 250 r / min for 1 min, and finally add 3 g of F0705 curing agent to obtain a dental adhesive;

[0068] The dental adhesive includes bisphenol A epoxy resin grafted with polyurethane prepolymer, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the bisphenol A epoxy resin grafted with polyurethane prepolymer, the defoamer and the curing agent are 58.82%, 1.96% and 29.41%, respectively, and the balance is water.

[0069] Embodiment 2~6

[0070] The preparation method of the dental adhesive is substantially the same as that of Example 1, except that the type and / or quality of the raw materials are changed, as described in Table 1;

[0071] In Example 2, the dental adhesive includes aliphatic epoxy resin grafted with polyurethane prepolymer, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the aliphatic epoxy resin grafted with polyurethane prepolymer, the defoamer and the curing agent are 58.82%, 1.96% and 29.41%, respectively, and the remainder is water; wherein the weight average molecular weight of the aliphatic epoxy resin grafted with polyurethane prepolymer is 182.75.

[0072] In Example 3, the dental adhesive includes a bisphenol A epoxy resin grafted with a polyurethane prepolymer, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the bisphenol A epoxy resin grafted with a polyurethane prepolymer, the defoamer and the curing agent are 57.69%, 3.85% and 28.85%, respectively, and the remainder is water; wherein the weight average molecular weight of the epoxy resin grafted with a polyurethane prepolymer is 229.19.

[0073] In Example 4, the dental adhesive includes a bisphenol A epoxy resin grafted with a polyurethane prepolymer, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the bisphenol A epoxy resin grafted with a polyurethane prepolymer, the defoamer and the curing agent are 59.41%, 0.99% and 29.7%, respectively, and the remainder is water; wherein the weight average molecular weight of the epoxy resin grafted with a polyurethane prepolymer is 160.38.

[0074] In Example 5, the dental adhesive includes a bisphenol A epoxy resin grafted with a polyurethane prepolymer, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the bisphenol A epoxy resin grafted with a polyurethane prepolymer, the defoamer and the curing agent are 53.57%, 1.79% and 35.71%, respectively, and the remainder is water; wherein the weight average molecular weight of the epoxy resin grafted with a polyurethane prepolymer is 212.82.

[0075] In Example 6, the dental adhesive includes a bisphenol A epoxy resin grafted with a polyurethane prepolymer, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the bisphenol A epoxy resin grafted with a polyurethane prepolymer, the defoamer and the curing agent are 65.22%, 2.17% and 21.74%, respectively, and the remainder is water; wherein the weight average molecular weight of the epoxy resin grafted with a polyurethane prepolymer is 259.09.

[0076] Embodiments 7 to 10

[0077] The preparation method of the dental adhesive is substantially the same as that of Example 1, except that: the mass of the hydroxyl-terminated polyurethane prepolymer is changed, as specifically described in Table 1;

[0078] In Example 7, the mass of the hydroxyl-terminated polyurethane prepolymer is 4.4 g, the mass ratio of the epoxy resin structural unit to the polyurethane prepolymer structural unit in the obtained polyurethane prepolymer-grafted epoxy resin is 1:1.1, and the weight average molecular weight of the polyurethane prepolymer-grafted epoxy resin is 270.7; the dental adhesive includes a polyurethane prepolymer-grafted bisphenol A epoxy resin, a defoamer and a curing agent, and based on the mass of the dental adhesive, the mass fractions of the polyurethane prepolymer-grafted bisphenol A epoxy resin, the defoamer and the curing agent are 66.67%, 1.59% and 23.81%, respectively.

[0079] In Example 8, the mass of the terminal hydroxyl polyurethane prepolymer is 1.5 g, the mass ratio of the epoxy resin structural unit to the polyurethane prepolymer structural unit in the obtained polyurethane prepolymer grafted epoxy resin is 1:0.375, and the weight average molecular weight of the polyurethane prepolymer grafted epoxy resin is 223.67; the dental adhesive includes a polyurethane prepolymer grafted bisphenol A type epoxy resin, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the polyurethane prepolymer grafted bisphenol A type epoxy resin, the defoamer and the curing agent are 56.70%, 2.06% and 30.93%, respectively, and the balance is water.

[0080] In Example 9, the mass of the hydroxyl-terminated polyurethane prepolymer is 6 g, the mass ratio of the epoxy resin structural unit to the polyurethane prepolymer structural unit in the obtained polyurethane prepolymer-grafted epoxy resin is 1:1.5, and the weight average molecular weight of the polyurethane prepolymer-grafted epoxy resin is 279.98; the dental adhesive includes a polyurethane prepolymer-grafted bisphenol A type epoxy resin, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the polyurethane prepolymer-grafted bisphenol A type epoxy resin, the defoamer and the curing agent are 70.42%, 1.41% and 21.13%, respectively, and the balance is water.

[0081] In Example 10, the mass of the hydroxyl-terminated polyurethane prepolymer is 0.4 g, the mass ratio of the epoxy resin structural unit to the polyurethane prepolymer structural unit in the obtained polyurethane prepolymer-grafted epoxy resin is 1:0.1, and the weight average molecular weight of the polyurethane prepolymer-grafted epoxy resin is 197.53; the dental adhesive includes a polyurethane prepolymer-grafted bisphenol A type epoxy resin, a defoamer and a curing agent. Based on the mass of the dental adhesive, the mass fractions of the polyurethane prepolymer-grafted bisphenol A type epoxy resin, the defoamer and the curing agent are 51.16%, 2.33% and 34.88%, respectively, and the remainder is water.

[0082] Comparative Example 1

[0083] The dental adhesive was prepared as follows:

[0084] Pour 4 g of aliphatic epoxy resin into a three-necked flask, add 0.2 g of silicone defoamer, put the three-necked flask into a water bath, gradually heat the water bath to 75° C., and keep the temperature for 1 hour to obtain an intermediate product, which contains aliphatic epoxy resin and defoamer;

[0085] 1 g of deionized water (solvent) was weighed, and the deionized water was mixed with all the intermediate products, and stirred at a speed of 250 r / min for 1 min on a magnetic stirrer, and finally 3 g of F0705 curing agent was added and mixed to obtain a dental adhesive.

[0086] Comparative Example 2

[0087] The dental adhesive was prepared as follows:

[0088] Pour 4 g of bisphenol A epoxy resin into a three-necked flask, put the three-necked flask into a water bath, gradually heat the water bath to 75° C., slowly pour 2 g of hydroxyl-terminated polyurethane prepolymer into the three-necked flask, react for 1 hour, and obtain an intermediate product, which includes bisphenol A epoxy resin grafted with polyurethane prepolymer;

[0089] 1 g of deionized water (solvent) was weighed, and the deionized water was mixed with all the intermediate products, and stirred on a magnetic stirrer at a speed of 250 r / min for 1 min. Finally, 3 g of F0705 curing agent was added and mixed to obtain a dental adhesive; the weight average molecular weight of the epoxy resin grafted with the polyurethane prepolymer was 323.96.

[0090] Comparative Example 3

[0091] The dental adhesive was prepared as follows:

[0092] Pour 4 g of bisphenol A epoxy resin into a three-necked flask, add 0.2 g of silicone defoamer, put the three-necked flask into a water bath, gradually heat the water bath to 75° C., slowly pour 2 g of hydroxyl-terminated polyurethane prepolymer into the three-necked flask, react for 1 hour, and obtain an intermediate product, which includes bisphenol A epoxy resin grafted with polyurethane prepolymer and defoamer;

[0093] 1 g of deionized water (solvent) was weighed, the deionized water was mixed with all the intermediate products, and the mixture was stirred on a magnetic stirrer at a speed of 250 r / min for 1 min to obtain a dental adhesive; the weight average molecular weight of the epoxy resin grafted with the polyurethane prepolymer was 331.06.

[0094] The raw materials for preparing the dental adhesives of each embodiment and each comparative example can be obtained from commercial sources.

[0095] Table 1

[0096]

[0097] Test Case

[0098] (1) Adhesion test

[0099] The metal bonding test was conducted using a tooth-specific cobalt-chromium alloy. Cow teeth were selected as the base surface for tooth bonding. The age of the cows was 2 to 3 years old. Before the test, the enamel contact surface of the bonding needed to be treated with acid, and the dentin contact surface did not need to be treated. Before the test, the surface of the test metal needed to be sandblasted. After the bonding was completed, the bonding surface was immersed in 37°C water for 24 hours, and then the bonding test was conducted.

[0100] (2) Microleakage test

[0101] The microleakage test was conducted according to ISO11405-2015 standard. The tracking liquid was dropped into the interface. The samples were subjected to staining tests under 5℃ cold cycle treatment and 55℃ hot cycle treatment respectively. The level of microleakage was determined according to the staining conditions:

[0102] Level 0: No penetration of the essential surface;

[0103] Level 1: penetration depth is less than 1 / 2;

[0104] Level 2: Large area penetration;

[0105] Grade 3: The sample penetrates into the pulp.

[0106] (3) Mechanical properties

[0107] The prepared tooth adhesive is quickly coated on a foam board with a length and width of approximately 40 mm to 60 mm, a height of approximately 10 mm to 30 mm, and a coating thickness of approximately 0.2 mm to 0.5 mm. After thorough curing, its compressive strength is tested. When the compressive strain reaches 80% to 90%, the compressive stress value it is subjected to is the compressive strength. The larger the value, the better the mechanical properties of the tooth adhesive.

[0108] The test results of each embodiment and each comparative example are shown in Table 2 and Table 3.

[0109] Table 2

[0110]

[0111] It can be seen from Table 2 that, compared with Comparative Examples 1 to 3, the dentin bonding force and enamel bonding force of the dental adhesives of Examples 1 to 10 are relatively high, and the microleakage level of the dental adhesives of Examples 1 to 10 is all level 0, indicating that the dental adhesives of Examples 1 to 10 have good bonding ability and anti-leakage performance.

[0112] Table 3

[0113]

[0114] It can be seen from Table 3 that, compared with Comparative Examples 1-2, the compressive strength of the dental adhesives of Examples 1-2 is higher, indicating that the dental adhesives of Examples 1-2 have higher strength and hardness, better mechanical properties, and thus can maintain a more stable bonding effect.

[0115] In addition, the compressive strength of the dental adhesives of Examples 3 to 10 was tested, and the test results showed that the compressive strength of the dental adhesives of Examples 3 to 10 was higher than that of the dental adhesives of Comparative Examples 1 to 2. Therefore, the bonding effect of the dental adhesives of Examples 3 to 10 was more stable than that of Comparative Examples 1 to 2.

[0116] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims, and the description may be used to interpret the content of the claims.

Claims

1. A dental adhesive, characterized in that The invention comprises epoxy resin grafted with polyurethane prepolymer, defoaming agent and curing agent.

2. The dental adhesive according to claim 1, characterized in that Based on the mass of the dental adhesive, the mass fraction of the epoxy resin grafted with the polyurethane prepolymer is 50% to 89.5%, the mass fraction of the defoamer is 0.5% to 5%, and the mass fraction of the curing agent is 10% to 49.5%.

3. The dental adhesive according to claim 1, characterized in that The dental adhesive has at least one of the following characteristics (1) to (2): (1) The epoxy resin grafted with the polyurethane prepolymer comprises a polyurethane prepolymer structural unit and an epoxy resin structural unit, and the mass ratio of the epoxy resin structural unit to the polyurethane prepolymer structural unit is 1:(0.2-1.2); (2) The weight average molecular weight of the epoxy resin grafted with the polyurethane prepolymer is 100-350.

4. The dental adhesive according to any one of claims 1 to 3, characterized in that Also included is a solvent, which includes water.

5. The dental adhesive according to claim 3, characterized in that The dental adhesive has at least one of the following characteristics (1) to (4): (1) The polyurethane prepolymer structural unit comprises at least one of a polyurethane prepolymer structural unit containing a blocking group, a terminal hydroxyl group polyurethane prepolymer structural unit and a terminal isocyanate group polyurethane prepolymer structural unit; (2) the epoxy resin structural unit comprises at least one of a bisphenol A type epoxy resin structural unit and an aliphatic type epoxy resin structural unit; (3) The defoamer comprises at least one of a polyether defoamer, a silicone defoamer and a vegetable oil defoamer; (4) The curing agent includes a water-based curing agent; optionally, the water-based curing agent includes at least one of F0705 curing agent, NX-8401 curing agent and S-161 curing agent.

6. The dental adhesive according to claim 3, characterized in that The polyurethane prepolymer structural unit includes a terminal hydroxyl polyurethane prepolymer structural unit, the epoxy resin structural unit includes a bisphenol A type epoxy resin structural unit, the defoaming agent includes an organosilicon defoaming agent, and the curing agent includes an F0705 curing agent.

7. A method for preparing a dental adhesive, characterized in that: The steps include: The solution containing epoxy resin and defoamer is heated, and polyurethane prepolymer is added to make the epoxy resin and the polyurethane prepolymer undergo grafting reaction to form polyurethane prepolymer grafted epoxy resin, thereby obtaining an intermediate product; The intermediate product, a solvent and a curing agent are mixed to obtain the dental adhesive.

8. The preparation method according to claim 7, characterized in that: Based on the mass of the dental adhesive, the mass fraction of the epoxy resin grafted with the polyurethane prepolymer is 50% to 89.5%, the mass fraction of the defoamer is 0.5% to 5%, and the mass fraction of the curing agent is 10% to 49.5%.

9. The preparation method according to claim 7, characterized in that: The preparation method satisfies at least one of the following conditions (1) to (2): (1) The heating temperature is 70°C to 80°C; (2) The reaction time of the grafting reaction is 1.5h~2.5h.

10. The preparation method according to any one of claims 7 to 9, characterized in that: The step of mixing the intermediate product, the solvent and the curing agent comprises: firstly mixing the intermediate product and the solvent, stirring at a speed of 200 r / min to 300 r / min for 0.5 min to 1.5 min, and then adding the curing agent.

11. The preparation method according to any one of claims 7 to 9, characterized in that The preparation method satisfies at least one of the following conditions (1) to (4): (1) The mass ratio of the epoxy resin to the polyurethane prepolymer is 1:(0.2-1.2); (2) the polyurethane prepolymer comprises at least one of a polyurethane prepolymer containing a blocking group, a hydroxyl-terminated polyurethane prepolymer and an isocyanate-terminated polyurethane prepolymer; (3) The epoxy resin comprises at least one of a bisphenol A epoxy resin and an aliphatic epoxy resin; (4) The solvent includes water.

12. Use of the dental adhesive according to any one of claims 1 to 6 and the dental adhesive prepared by the preparation method according to any one of claims 7 to 11 in preparing dental filling and restorative materials.

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