Acoustic matching material and preparation method thereof, ultrasonic transducer, ultrasonic probe and ultrasonic imaging device

Abstract

The application relates to the technical field of acoustic materials, in particular to a sound matching material, a preparation method thereof, an ultrasonic transducer, an ultrasonic probe and an ultrasonic imaging device. The sound matching material comprises a polystyrene telechelic polymer with a chemical structure as shown in formula I: wherein n1 and n2 are positive integers; X comprises at least one of halogen atoms, hydroxyl groups, carboxyl groups, amino groups, propargyl groups, methoxyl groups, azido groups, pyrimidyl groups and malonate groups. The sound matching material has not only good low sound attenuation characteristics, but also good bonding performance, can improve the stable reliability of sound transmission, and has a good application prospect in medical ultrasonic probes.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of acoustic materials, and particularly relates to a sound matching material and a preparation method thereof, an ultrasonic transducer, an ultrasonic probe and an ultrasonic imaging device. BACKGROUND

[0002] Medical ultrasonic technology is a diagnostic technology that uses the characteristics of high-frequency sound waves propagating and reflecting in the internal tissues of the human body to obtain images. With its non-invasive and real-time characteristics, it has become an important branch of modern medical imaging diagnosis. Its working principle is based on the Doppler effect and echo positioning. By emitting ultrasonic waves of a specific frequency into the body, it utilizes the difference in the reflection of sound waves by different tissues, receives and converts them into electrical signals through the ultrasonic probe, and finally forms images that can be used for diagnosis. The medical ultrasonic probe, as the core of the ultrasonic equipment, is responsible for the emission and reception of ultrasonic waves. The piezoelectric crystal built into the ultrasonic probe can vibrate to produce ultrasonic waves under the action of an electric field, and generate an electric signal when receiving echoes. The application of the ultrasonic probe runs through the entire medical diagnosis process, from routine physical examinations to complex surgical navigation, and its high-precision imaging capability provides doctors with intuitive and real-time anatomical information.

[0003] In order to achieve the best imaging effect of the ultrasonic probe, the ultrasonic waves produced by the vibration of the piezoelectric unit need to be acoustically matched with the human body, so a matching layer is needed between the piezoelectric unit and the human body to adjust the acoustic matching degree. The acoustic matching layer of the medical ultrasonic probe is a key medium. The acoustic matching layer is usually composed of materials with specific acoustic impedance, and the acoustic impedance of such materials is between that of the piezoelectric crystal and the human tissue. The acoustic matching layer not only enhances the quality of the ultrasonic image, but also improves the sensitivity and resolution of the probe. It helps to reduce artifacts and improve the accuracy of imaging, thereby providing doctors with clearer diagnostic information.

[0004] Common acoustic matching layer materials include ceramic materials and polymers such as epoxy resin. These materials are widely used in the manufacture of acoustic matching layers of medical ultrasonic probes due to their good acoustic properties and easy processing properties. The acoustic impedance of a material is proportional to the density of the material and the speed of sound in the material, so adding fillers of different specific gravities can obtain acoustic materials of different impedance. Epoxy resin can undergo ring-opening polymerization with multifunctional curing agents under appropriate reaction conditions, and can also be mixed with different fillers in proportion to obtain epoxy resin composites, so it is often used as the base material of the acoustic matching layer. Polystyrene (PS) is a thermoplastic polymer made from styrene monomers through polymerization.

[0005] Currently, the epoxy resin used in the acoustic matching layer has a high acoustic attenuation coefficient, but polystyrene with low acoustic attenuation characteristics has poor adhesion, and as a matching layer material, it has low reliability. SUMMARY

[0006] The application aims to provide a sound matching material, a preparation method thereof, an ultrasonic transducer, an ultrasonic probe and an ultrasonic imaging device, and aims to solve the technical problem of how to provide a sound matching material with low sound attenuation and good adhesion.

[0007] To achieve the above application purposes, the technical scheme adopted by the application is as follows:

[0008] In a first aspect, the application provides a sound matching material, which comprises a polystyrene telechelic polymer with a chemical structure as shown in Formula I:

[0009]

[0010] wherein n1 and n2 are positive integers; X comprises at least one of halogen atoms, hydroxyl groups, carboxyl groups, amino groups, propargyl groups, methoxyl groups, azido groups, pyrimidyl groups and malonate groups.

[0011] In some embodiments, n1 and n2 are the same, or n1 = n2 = 100-400.

[0012] And / or, X is a carboxyl group or an amino group.

[0013] In some embodiments, the sound matching material has a sound impedance ranging from 2.5 to 2.9 MRayl, a sound attenuation of 11-13 dB / cm at 20 MHz, and / or an adhesion of 0.36-0.66 KN / m.

[0014] In a second aspect, the application provides a preparation method of a sound matching material, comprising:

[0015] The styrene monomer is subjected to a polymerization reaction in an initiation system containing p-dicumyl chloride, and then 1,3-butadiene is added for end-capping treatment to generate a polystyrene telechelic polymer with a chemical structure as shown in Formula Ia, thereby obtaining the sound matching material.

[0016]

[0017] wherein n1 and n2 are positive integers.

[0018] In some embodiments, the chlorine atoms in the polystyrene telechelic polymer shown in Formula Ia are subjected to substitution treatment, so that the chlorine atoms in the chemical structure of Formula Ia are replaced by X; wherein X comprises at least one of non-chlorine halogen atoms, hydroxyl groups, carboxyl groups, amino groups, propargyl groups, methoxyl groups, azido groups, pyrimidyl groups and malonate groups.

[0019] In some embodiments, X is a bromine atom, and the substitution treatment of the chlorine atoms comprises: reacting the polystyrene telechelic polymer shown in Formula Ia with lithium bromide at a temperature of 70-90°C.

[0020] Alternatively, the X is hydroxyl, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer represented by Formula Ia with lithium bromide at 70-90°C, and then reacting with a quaternary ammonium base at 20-30°C;

[0021] Alternatively, the X is amino, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer represented by Formula Ia with lithium bromide at 70-90°C, and then sequentially reacting with phthalimide potassium salt and hydrazine hydrate at 60-80°C;

[0022] Alternatively, the X is malonate, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer represented by Formula Ia with lithium bromide at 70-90°C, and then reacting with malonate at 50-70°C;

[0023] Alternatively, the X is carboxyl, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer represented by Formula Ia with lithium bromide at 70-90°C, and then sequentially reacting with malonate and alkali metal hydroxide at 50-70°C.

[0024] In some embodiments, the initiation system in the polymerization reaction further comprises a co-initiator, and the co-initiator comprises at least one of TiCl4, BCl3, and AlCl3;

[0025] And / or, the conditions of the polymerization reaction comprise: a temperature of -80 to -60°C, and a time of 10-20 min;

[0026] And / or, the molar ratio of the 1,3-butadiene to the styrene monomer in the end-capping treatment is 1:(100-400);

[0027] And / or, the conditions of the end-capping treatment comprise: a temperature of -80 to -60°C, and a time of 2-8 min.

[0028] In a third aspect, the present application provides an ultrasonic transducer comprising the acoustic matching material provided in the first aspect of the present application and / or the acoustic matching material prepared by the preparation method provided in the second aspect of the present application.

[0029] In a fourth aspect, the present application provides an ultrasonic probe comprising the ultrasonic transducer provided in the third aspect of the present application, or comprising a piezoelectric crystal and an acoustic matching layer, wherein the acoustic matching layer comprises the acoustic matching material provided in the first aspect of the present application and / or the acoustic matching material prepared by the preparation method provided in the second aspect of the present application.

[0030] In a fifth aspect, the present application provides an ultrasonic imaging device, comprising the ultrasonic transducer provided in the third aspect of the present application or the ultrasonic probe provided in the fourth aspect of the present application.

[0031] The sound matching material provided in the first aspect of the present application comprises a polystyrene telechelic polymer with a chemical structure as shown in Formula I, which has a polystyrene main structure and a functionalization of allyl containing X at the end. Such polystyrene telechelic polymer not only has good low acoustic attenuation characteristics, but also has good bonding properties. As a sound matching material, it can well improve the stable reliability of material sound transmission and has good application prospects in medical devices such as medical ultrasonic probes.

[0032] The preparation method provided in the second aspect of the present application polymerizes styrene monomers in an initiation system containing p-cumyl chloride, and then adds 1,3-butadiene for end-capping treatment. In this way, a sound matching material with low acoustic attenuation characteristics and high bonding properties can be obtained. The preparation method is simple and easy to synthesize, and the obtained sound matching material has good application.

[0033] The ultrasonic transducer provided in the third aspect of the present application comprises the sound matching material provided in the first aspect of the present application and / or the sound matching material prepared by the preparation method provided in the second aspect of the present application. Based on the characteristics of the sound matching material used therein, which has low acoustic attenuation characteristics and high bonding properties, the ultrasonic transducer has good stable reliability in terms of acoustic-electric conversion and electric-acoustic conversion performance.

[0034] The ultrasonic probe provided in the fourth aspect of the present application uses the sound matching material provided in the first aspect of the present application and / or the sound matching material prepared by the preparation method provided in the second aspect of the present application. Based on the characteristics of the sound matching material used therein, which has low acoustic attenuation characteristics and high bonding properties, the ultrasonic probe has good reliability for ultrasonic signal detection.

[0035] The ultrasonic imaging device provided in the fifth aspect of the present application comprises the ultrasonic transducer provided in the third aspect of the present application or the ultrasonic probe provided in the fourth aspect of the present application. Therefore, it has good medical image diagnosis reliability. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0037] Figure 1 Some preparation method flowcharts of the sound matching material provided in the embodiments of the present application. DETAILED DESCRIPTION

[0038] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application and not intended to limit the present application.

[0039] In the present application, the term "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it.

[0040] In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one" or similar expressions mean any combination of these items, including any combination of single or multiple items.

[0041] It should be understood that in various embodiments of the present application, the size of the sequence number of the above processes does not mean the order of execution, and part or all of the steps can be executed in parallel or in sequence, and the execution order of the processes should be determined according to their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0042] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0043] The weight of the related components mentioned in the specification of the embodiments of the present application can not only refer to the specific content of each component, but also represent the weight ratio relationship between each component, therefore, as long as the content of the related components in the specification of the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass mentioned in the specification of the embodiments of the present application can be μg, mg, g, kg and other mass units commonly known in the chemical field.

[0044] The terms "first", "second" are only used for description purposes, to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX can also be referred to as the second XX, and similarly, the second XX can also be referred to as the first XX. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more of the features.

[0045] An ultrasonic transducer is an "electrical-acoustical" signal converter that converts electrical signals into ultrasonic waves, and a device that converts ultrasonic wave reverse signals received from a detected object into electrical signals, and is widely used in the field of medical ultrasonic diagnosis.

[0046] An ultrasonic probe, also called an ultrasonic wave probe, is a device that transmits and receives ultrasonic waves in an ultrasonic wave detection process. The probe used in ultrasonic detection is a transducer that converts electrical energy and acoustic energy by using the piezoelectric effect of a material. The key component in the probe is a wafer, which is a single crystal or polycrystalline sheet having a piezoelectric effect, and functions to convert electrical energy and acoustic energy. A medical ultrasonic probe is built-in with a piezoelectric crystal that can vibrate to generate ultrasonic waves under the action of an electric field, and generate an electrical signal when receiving an echo.

[0047] An acoustic matching material refers to a medium material having a certain acoustic impedance and capable of adjusting acoustic matching degree, and can be used as an acoustic matching layer of an ultrasonic transducer or an ultrasonic probe. Whether it is an ultrasonic transducer or an ultrasonic probe, it needs an acoustic matching material to adjust the acoustic matching degree.

[0048] Epoxy resin has the advantages of cast molding and being a high-quality adhesive, and can be prepared into a composite material with a plurality of fillers, and has a wide application space in the field of ultrasonic probes. The density of epoxy resin is usually in the range of 1.1-1.25 g / cm 3 , and the acoustic impedance is about 3.0-3.6 MRayl, and the acoustic attenuation at 20 MHz is 120 dB / cm, so the acoustic attenuation coefficient is large, and generally needs to be modified to obtain an epoxy resin composite material with good acoustic performance.

[0049] Polystyrene can be obtained by free radical polymerization, cationic polymerization, anionic polymerization and other ways of styrene monomer, has good mechanical properties, easy processing and other advantages, and is mainly used in the fields of packaging materials, shell materials and disposable medical supplies. The density of polystyrene is 1.05 g / cm 3 , has a low acoustic attenuation characteristic, the acoustic impedance is 2.43 MRayl, and the acoustic attenuation at 20 MHz is only 12 dB / cm, which is much smaller than the 120 dB / cm acoustic attenuation of epoxy resin. However, due to the difficulty of bonding of polystyrene, its application in the field of matching layer materials is limited.

[0050] Therefore, the polystyrene is modified in the embodiments of the present application to form a polystyrene telechelic polymer with styrene as a basic unit, copolymerization with other structural units and a functional group at the end, which is used as an acoustic matching material. It not only has excellent low acoustic attenuation characteristics, but also has the characteristics of high bonding force, and can effectively replace epoxy resin as an acoustic matching material. The specific technical solutions are as follows.

[0051] In a first aspect, the embodiments of the present application provide an acoustic matching material. Specifically, the acoustic matching material of the embodiments of the present application comprises a polystyrene telechelic polymer with a chemical structure as shown in Formula I:

[0052]

[0053] wherein n1 and n2 are positive integers; and X comprises at least one of a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a propargyl group, a methoxyl group, an azido group, a pyrimidyl group, and a malonate group.

[0054] In the embodiments of the present application, the polystyrene telechelic polymer as shown in Formula I has a polystyrene main structure, and at the end, there is a functional group of an allyl group containing X, i.e., a double-end telechelic polystyrene with various functional groups. Such a polystyrene telechelic polymer not only has good low acoustic attenuation characteristics, but also has good bonding properties. Therefore, the polystyrene telechelic polymer of the embodiments of the present application used as an acoustic matching material can well improve the stable reliability of material acoustic transmission, and has a good application prospect in medical devices such as medical ultrasonic probes, and can be used to replace epoxy resin for the preparation of acoustic matching layer acoustic transmission materials.

[0055] In some embodiments, n1 and n2 can be the same or different. Specifically, n1 and n2 are the same.

[0056] In some embodiments, n1 = n2 = 100-400. Exemplarily, n1 and n2 can be 100, 120, 150, 200, 220, 250, 280, 300, 350, 400, etc.

[0057] In some embodiments, X is on the terminal allyl group of polystyrene, and X can comprise at least one of a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a propargyl group, a methoxyl group, an azido group, a pyrimidyl group, and a malonate group. The halogen atom can be fluorine, chlorine, bromine, etc.; the malonate group can be -2-dimethyl malonate group or -2-diethyl malonate group or -2-dipropyl malonate group. The above X group at the end can make the polystyrene telechelic polymer have good adhesion. 1-3 The carbonyl carbon of malonic acid in the malonate group is connected with the terminal allyl group of the polystyrene telechelic polymer, and specifically, it can be -2-dimethyl malonate group or -2-diethyl malonate group or -2-dipropyl malonate group. The above X group at the end can make the polystyrene telechelic polymer have good adhesion.

[0058] Further, X is a carboxyl group or an amino group. The polystyrene telechelic polymer corresponding to the two groups makes it have better adhesion when used as an acoustic matching material.

[0059] Further, the sound matching material provided by the embodiments of the present application is a polystyrene telechelic polymer with high molecular weight and narrow molecular weight distribution after cationic polymerization. For the polystyrene telechelic polymer shown in Formula I, the number average molecular weight can be 20000-80000. Specifically, it can be 20000, 25000, 30000, 35000, 40000, 45000, 50000, 60000, 70000, 80000, etc. The polystyrene telechelic polymer with the above number average molecular weight range can be formed according to the type of X group, the value range of n1 and n2.

[0060] The sound matching material provided by the embodiments of the present application has a polystyrene telechelic polymer with a sound impedance range of 2.5-2.9 MRayl, and the sound attenuation is only 11-13 dB / cm at 20 MHz. At the same time, the peel adhesion strength can be improved from 0.03 KN / m of polystyrene to 0.36-0.66 KN / m, which has good adhesion, and the sound attenuation coefficient is significantly lower than that of epoxy resin.

[0061] The adhesion test of the above sound matching material is to use epoxy adhesive to bond and cure the sound matching material and aluminum plate as the base material, and then perform 90° peel test adhesion strength.

[0062] In a second aspect, the embodiments of the present application provide a preparation method of the sound matching material. The preparation method of the sound matching material of the embodiments of the present application includes the following steps:

[0063] The styrene monomer is subjected to polymerization reaction in an initiation system containing p-di-cumyl chloride, and then 1,3-butadiene is added for end capping treatment to generate a polystyrene telechelic polymer with a chemical structure as shown in Formula Ia, thereby obtaining the sound matching material.

[0064]

[0065] wherein n1 and n2 are positive integers.

[0066] The embodiments of the present application subject the styrene monomer to polymerization reaction in an initiation system containing p-di-cumyl chloride, and then add 1,3-butadiene for end capping treatment, so as to obtain a sound matching material with low sound attenuation characteristics and high adhesion performance. The preparation method is simple in process, easy to synthesize, and the obtained sound matching material has good application.

[0067] The initiation system containing p-dicumyl chloride (DCC) is a cationic double-end initiation system, and can initiate polymerization of the styrene monomer at both ends. 1,3-Butadiene is added in the later stage of the polymerization reaction to copolymerize at the end of the polystyrene, and after the reaction is completed, the obtained polystyrene telechelic polymer shown in formula Ia is a double-end allyl chloride functionalized polystyrene telechelic polymer (DPSCl). Then, the DPSCl can be subjected to a series of functionalization reactions to obtain polystyrene telechelic polymers including but not limited to polystyrene telechelic polymers with X as a non-chlorine halogen atom (such as bromine), a hydroxyl group, a carboxyl group, an amino group, a propargyl group, a methoxy group, an azido group, a pyrimidyl group, a malonate group, etc. as a telechelic group, to obtain corresponding various acoustic matching layer materials provided in the first aspect of the application. Compared with epoxy resin-based and polystyrene matching layer materials, the polystyrene telechelic polymer prepared in the application has good forming process, good adhesion, good mechanical properties and low acoustic attenuation characteristics, and can be processed into a matching layer film, and can effectively replace epoxy resin to be applied to the matching layer material of a medical ultrasonic probe.

[0068] In some embodiments, the initiation system containing p-dicumyl chloride further includes a co-initiator in addition to the p-dicumyl chloride, and the co-initiator includes at least one of TiCl4, BCl3 and AlCl3; in this way, cationic double-end initiation polymerization of the styrene monomer can be better promoted. In the application, the initiation system is selected to be a combination of p-dicumyl chloride and TiCl4.

[0069] In some embodiments, the conditions for the polymerization reaction of the styrene monomer under the above initiation system include a temperature of -80 to -60°C and a time of 10 to 20 min; in this way, the styrene monomer can be fully polymerized.

[0070] In some embodiments, after the polymerization of the styrene monomer under the above initiation system, 1,3-butadiene is added for end-capping treatment, that is, end-capping polymerization with 1,3-butadiene. In the end-capping treatment, the 1,3-butadiene is added in a molar ratio of 1: (100-400) of 1,3-butadiene to the styrene monomer; in this way, the both ends can be functionalized as allyl chloride.

[0071] In some embodiments, the conditions for the end-capping treatment by adding 1,3-butadiene include a temperature of -80 to -60°C and a time of 2 to 8 min; in this way, the both ends can be fully functionalized as allyl chloride.

[0072] Further, after the end-capping treatment, ethanol can be added to terminate the polymerization.

[0073] In some embodiments, after the synthesis of the allyl chloride functionalized polystyrene telechelic polymer (DPSCl) is completed, the chlorine atoms in the polystyrene telechelic polymer of Formula Ia can be further substituted to replace the chlorine atoms in the chemical structure of Formula Ia with X; wherein X includes at least one of a non-chlorine halogen atom, a hydroxyl group, a carboxyl group, an amino group, a propargyl group, a methoxy group, an azido group, a pyrimidinyl group, and a malonate group.

[0074] As shown in Figure 1 , the styrene monomer is polymerized under the condition of a p-di-cumyl chloride / TiCl4initiation system, and then 1,3-butadiene is added for end-capping to generate a double-end allyl bromine functionalized telechelic polystyrene (DPSBr) having a chemical structure as shown in Formula Ia, and then various reactions are sequentially performed to obtain various functionalized polystyrene telechelic polymers.

[0075] For example, taking the synthesis of a double-end allyl bromine functionalized telechelic polystyrene (DPSBr) as an example, the double-end allyl chloride functionalized polystyrene telechelic polymer of Formula Ia is reacted with lithium bromide at a temperature of 70-90°C, so that the chlorine atoms in the double-end allyl chloride functionalized polystyrene telechelic polymer are replaced with bromine atoms to obtain a double-end allyl bromine functionalized telechelic polystyrene. Exemplarily, the reaction process can be carried out in a mixed solvent system of toluene and acetone.

[0076] For example, taking the synthesis of a double-end allyl bromine functionalized telechelic polystyrene (DPSBr) as an example, the double-end allyl chloride functionalized polystyrene telechelic polymer of Formula Ia is reacted with lithium bromide at a temperature of 70-90°C, so that the chlorine atoms in the double-end allyl chloride functionalized polystyrene telechelic polymer are replaced with bromine atoms to obtain a double-end allyl bromine functionalized telechelic polystyrene. Exemplarily, the reaction process can be carried out in a mixed solvent system of toluene and acetone.

[0077] For example, taking the synthesis of the double-allyl amino-functionalized telechelic polystyrene (DPSNH2) as an example, the double-allyl chloride-functionalized polystyrene telechelic polymer represented by formula Ia is reacted with lithium bromide at 70-90°C, so that the chlorine in the double-allyl chloride-functionalized polystyrene telechelic polymer is replaced by bromine to obtain a double-allyl bromide-functionalized telechelic polystyrene (exemplarily, the reaction process can be carried out in a mixed solvent system of toluene and acetone); then, the double-allyl bromide-functionalized telechelic polystyrene is first reacted with potassium phthalimide at 60-80°C (exemplarily, the reaction process can be carried out in a mixed solvent system of tetrahydrofuran and N-methylpyrrolidone), and then reacted with hydrazine hydrate (exemplarily, the reaction process can be carried out in a mixed solvent system of tetrahydrofuran and ethanol) to obtain a double-allyl amino-functionalized telechelic polystyrene.

[0078] For example, taking the synthesis of the double-allyl propionamide-functionalized telechelic polystyrene (DPSNH2) as an example, the double-allyl chloride-functionalized polystyrene telechelic polymer represented by formula Ia is reacted with lithium bromide at 70-90°C, so that the chlorine in the double-allyl chloride-functionalized polystyrene telechelic polymer is replaced by bromine to obtain a double-allyl bromide-functionalized telechelic polystyrene (exemplarily, the reaction process can be carried out in a mixed solvent system of toluene and acetone); then, the double-allyl bromide-functionalized telechelic polystyrene is reacted with dimethyl malonate at 50-70°C to obtain a double-allyl propionamide-functionalized telechelic polystyrene. In this process, the dimethyl malonate can be mixed with K2CO3 and added to the reaction system, and further, the reaction can be carried out in an acetonitrile solvent system.

[0079] For example, taking the synthesis of the double-allyl propionamide-functionalized telechelic polystyrene (DPSNH2) as an example, the double-allyl chloride-functionalized polystyrene telechelic polymer represented by formula Ia is reacted with lithium bromide at 70-90°C, so that the chlorine in the double-allyl chloride-functionalized polystyrene telechelic polymer is replaced by bromine to obtain a double-allyl bromide-functionalized telechelic polystyrene (exemplarily, the reaction process can be carried out in a mixed solvent system of toluene and acetone); then, the double-allyl bromide-functionalized telechelic polystyrene is reacted with dimethyl malonate at 50-70°C to obtain a double-allyl propionamide-functionalized telechelic polystyrene. In this process, the dimethyl malonate can be mixed with K2CO3 and added to the reaction system, and further, the reaction can be carried out in an acetonitrile solvent system.

[0080] In some embodiments, the above preparation method further comprises a purification process after the synthesis of the various polystyrene telechelic polymers. For example, the polystyrene telechelic polymer is dissolved in a mixed solvent of hexane and dichloromethane, ethanol is added to the solution to precipitate the product, and impurities and oligomers are washed away. The product is dried to a constant weight, and then molded into a plate using a mold in a flat plate vulcanizer to obtain a sound-transmitting material with an acoustic impedance range of 2.5-2.9 MRayl.

[0081] In a third aspect, the embodiments of the present application provide an ultrasonic transducer. Specifically, the ultrasonic transducer of the embodiments of the present application comprises the acoustic matching material provided in the first aspect of the embodiments of the present application and / or the acoustic matching material prepared by the preparation method provided in the second aspect of the embodiments of the present application. The acoustic matching material used in the ultrasonic transducer of the embodiments of the present application has both low acoustic attenuation characteristics and high bonding performance, so that the ultrasonic transducer has good stability and reliability in terms of acoustic-electric conversion and electric-acoustic conversion performance.

[0082] In a fourth aspect, the embodiments of the present application provide an ultrasonic probe. Specifically, the ultrasonic probe of the embodiments of the present application is a medical ultrasonic probe. Specifically, it comprises the ultrasonic transducer provided in the third aspect of the embodiments of the present application, or comprises a piezoelectric crystal and an acoustic matching layer, and the acoustic matching layer comprises the acoustic matching material provided in the first aspect of the embodiments of the present application and / or the acoustic matching material prepared by the preparation method provided in the second aspect of the embodiments of the present application. The acoustic matching material used in the ultrasonic probe of the embodiments of the present application has both low acoustic attenuation characteristics and high bonding performance, so that such an ultrasonic probe has good reliability for ultrasonic signal detection.

[0083] In a fifth aspect, the embodiments of the present application provide an ultrasonic imaging device. Specifically, the ultrasonic imaging device of the embodiments of the present application comprises the ultrasonic transducer provided in the third aspect of the embodiments of the present application or the ultrasonic probe provided in the fourth aspect of the embodiments of the present application. The ultrasonic imaging device of the embodiments of the present application has good medical image diagnosis reliability.

[0084] The following will be described in conjunction with specific embodiments.

[0085] Embodiment 1

[0086] An acoustic matching material, i.e., a double-end allyl chloride functionalized telechelic polystyrene (DPSCl).

[0087] The preparation method comprises: using a p-dicumyl chloride / TiCL4 cationic double-end initiation system to initiate cationic polymerization of 10 g of styrene, and polymerizing at-80℃ for 15 min, then adding 1,3-butadiene, and end-capping at-80℃ for 5 min, wherein the molar ratio of 1,3-butadiene to styrene monomer is 1:300. After the end-capping reaction is completed, 3 mL of anhydrous ethanol is added to the system to terminate the polymerization. After the polymerization is terminated, ethanol is added to the reaction system to precipitate the polymerization product, and the polymerization product is fully dissolved in a mixed solvent (hexane and dichloromethane in equal weight) again, ethanol is added to the solution to precipitate the product, and the impurities and oligomers are repeatedly washed off, and finally a double-end allyl chloride functionalized telechelic polystyrene (DPSCl) with a number average molecular weight of about 60,000 can be obtained.

[0088] The obtained DPSCl is molded by using a mold in a flat vulcanization instrument, and the tested density is 1.07 g / cm 3 , the acoustic impedance is 2.59 MRayl, and the 20MHz acoustic attenuation is 12.64 dB / cm. After being bonded with an aluminum plate, the 90° peeling test is performed, and the anti-peeling bonding strength is 0.36 KN / m.

[0089] Example 2

[0090] An acoustic matching material, namely, a double-end allyl bromine functionalized telechelic polystyrene (DPSBr).

[0091] The preparation method comprises: dissolving the DPSCl prepared in Example 1 in a mixed solvent of toluene and acetone, adding anhydrous lithium bromide to react, the reaction system is protected under high-purity nitrogen, and the reaction is carried out at 80℃ for 14 h. After the reaction is completed, the impurities in the product are washed away with deionized water, and after rotary evaporation and drying, the double-end allyl bromine functionalized telechelic polystyrene (DPSBr) is obtained, and then the hexane-dichloromethane mixed solvent and ethanol are used for re-precipitation and purification.

[0092] The obtained DPSBr is molded by using a mold in a flat vulcanization instrument, and the tested density is 1.08 g / cm 3 , the acoustic impedance is 2.71 MRayl, and the 20MHz acoustic attenuation is 12.07 dB / cm. After being bonded with an aluminum plate, the 90° peeling test is performed, and the anti-peeling bonding strength is 0.40 KN / m.

[0093] Example 3

[0094] An acoustic matching material, namely, a double-end allyl bromine functionalized telechelic polystyrene (DPSBr).

[0095] The preparation method comprises: dissolving the DPSBr prepared in Example 2 in tetrahydrofuran, adding a tetrabutylammonium hydroxide aqueous solution for reaction, protecting the reaction system under high-purity nitrogen, and reacting at 25 DEG C for 2 hours. After the reaction is completed, impurities in the product are washed away with deionized water, and after rotary evaporation and drying, a double-allyl hydroxyl functional telechelic polystyrene (DPSOH) is obtained. Subsequently, hexane-dichloromethane mixed solvent and ethanol are used for reprecipitation and purification.

[0096] The obtained DPSOH is molded by pressing in a flat vulcanization instrument using a mold, and the tested density is 1.06 g / cm 3 , the acoustic impedance is 2.60 MRayl, and the 20MHz acoustic attenuation is 11.67 dB / cm. After being bonded with an aluminum plate, 90 DEG peeling test is performed, and the anti-peeling bonding strength is 0.52 KN / m.

[0097] Example 4

[0098] An acoustic matching material, namely a double-allyl malonic acid dimethyl ester functional telechelic polystyrene (DPSME).

[0099] The preparation method comprises: dissolving the DPSBr prepared in Example 2 in tetrahydrofuran, adding a tetrabutylammonium hydroxide aqueous solution for reaction, protecting the reaction system under high-purity nitrogen, and reacting at 25 DEG C for 2 hours. After the reaction is completed, impurities in the product are washed away with deionized water, and after rotary evaporation and drying, a double-allyl hydroxyl functional telechelic polystyrene (DPSOH) is obtained. Subsequently, hexane-dichloromethane mixed solvent and ethanol are used for reprecipitation and purification.

[0100] The obtained DPSME is molded by pressing in a flat vulcanization instrument using a mold, and the tested density is 1.06 g / cm 3 , the acoustic impedance is 2.52 MRayl, and the 20MHz acoustic attenuation is 13.04 dB / cm. After being bonded with an aluminum plate, 90 DEG peeling test is performed, and the anti-peeling bonding strength is 0.52 KN / m.

[0101] Example 5

[0102] An acoustic matching material, namely a double-allyl carboxylic acid functional telechelic polystyrene (DPSCOOH).

[0103] The preparation method comprises: dissolving the DPSME prepared in Example 4 in tetrahydrofuran, sequentially adding deionized water and potassium hydroxide for reaction, and protecting the reaction system under high-purity nitrogen; reacting at 60 DEG C for 24 hours; acidifying the mixture with concentrated hydrochloric acid to pH = 3, and evaporating the excess tetrahydrofuran under reduced pressure; washing the product with ethanol, then dissolving it in pyridine, adding water, refluxing and stirring for 40 hours, stopping the reaction, and adding the mixture into an aqueous hydrochloric acid solution; separating the residue and dissolving it in a mixed solvent of hexane and dichloromethane, and then obtaining a double-allyl carboxylic acid functionalized telechelic polystyrene (DPSCOOH) after rotary evaporation and drying, and subsequently reprecipitating and purifying the product with a mixed solvent of hexane and dichloromethane and ethanol.

[0104] The obtained DPSCOOH is molded by pressing in a mold in a flat vulcanization instrument, and the tested density is 1.06 g / cm 3 , the acoustic impedance is 2.64 MRayl, and the 20MHz acoustic attenuation is 12.66 dB / cm. After bonding with an aluminum plate, the 90 DEG peeling test is performed, and the anti-peeling bonding strength is 0.64 KN / m.

[0105] Example 6

[0106] An acoustic matching material, namely a double-allyl amino functionalized telechelic polystyrene (DPSNH2).

[0107] The preparation method comprises: dissolving the DPSBr prepared in Example 2 in a mixed solvent of tetrahydrofuran and N-methylpyrrolidone, adding potassium phthalimide for reaction, protecting the reaction system under high-purity nitrogen, and reacting at 70 DEG C for 16 hours to obtain an intermediate product of double-allyl phthalimide functionalized polystyrene; washing the intermediate product with deionized water three times to remove impurities; dissolving the intermediate product in a mixed solvent of tetrahydrofuran and ethanol, adding hydrazine hydrate for reaction, protecting the reaction system under high-purity nitrogen, and reacting at 70 DEG C for 36 hours; and then obtaining the double-allyl amino functionalized telechelic polystyrene (DPSNH2) after rotary evaporation and drying, and subsequently reprecipitating and purifying the product with a mixed solvent of hexane and dichloromethane and ethanol.

[0108] The obtained DPSNH2 is molded by pressing in a mold in a flat vulcanization instrument, and the tested density is 1.06 g / cm 3 , the acoustic impedance is 2.64 MRayl, and the 20MHz acoustic attenuation is 12.81 dB / cm. After bonding with an aluminum plate, the 90 DEG peeling test is performed, and the anti-peeling bonding strength is 0.66 KN / m.

[0109] Comparative Example 1

[0110] An acoustic matching material: an epoxy resin cured product.

[0111] Preparation method: 50 g of epoxy resin was added into a 250 ml flask, 14 g of curing agent was added, stirred at 25°C for 3 min, vacuum degassed by a degassing machine for 3.5 min after mixing, poured into a mold for casting, and cured at 60°C for 16 h to obtain an epoxy resin cured product (EP).

[0112] The tested density was 1.16 g / cm 3 , the acoustic impedance was 3.14 MRayl, and the 20 MHz acoustic attenuation was 122.5 dB / cm. After bonding with an aluminum plate, the 90° peeling test was performed, and the anti-peeling bonding strength was 0.67 KN / m.

[0113] Comparative Example 2

[0114] An acoustic matching material: polystyrene.

[0115] Preparation method: polystyrene (PS) product was obtained by active cationic polymerization under the action of isotonous salt n-Bu4NBr using C6H5CH(CH3)Br / SnCl4 initiation system.

[0116] The obtained polystyrene product was pressed and formed in a flat plate curing instrument using a mold, and the tested density was 1.05 g / cm 3 , the acoustic impedance was 2.43 MRayl, and the 20 MHz acoustic attenuation was 11.64 dB / cm. After bonding with an aluminum plate, the 90° peeling test was performed, and the anti-peeling bonding strength was 0.03 KN / m.

[0117] The test structure is shown in Table 1.

[0118] Table 1

[0119] The density was measured by a solid density tester. The specific steps included: first, the sample was placed on the measuring table of the tester to measure the mass of the sample in the air, and the memory key was pressed. Then, the sample was placed on the water measuring table of the tester, and the corresponding memory key was pressed. The instrument directly displayed the density result.

[0120] The acoustic performance was tested by the water immersion insertion method. The specific steps included: the transmitting probe and the receiving probe were inserted into the water tank, both of which were 20 MHz single-element transducers. The pulse signal generator excited the transmitting probe to generate ultrasonic signals, which were transmitted in water to the receiving probe and displayed on the oscilloscope. First, the waveform and amplitude of the pulse signal of pure water without the sample were measured and recorded. Then, the waveform and amplitude of the pulse signal after the sample was measured and recorded. According to the data imported into the test software, the acoustic velocity, acoustic impedance, and acoustic attenuation data of the material were automatically calculated.

[0121] The peel strength is tested according to GBT 7760-2003. The specific steps include: using epoxy glue to bond the sample and the standard aluminum plate, the glue layer thickness is 3 μm, the size of the sample strip is 125*25*6 mm. A universal testing machine is used to test with a special 90° peeling clamp. The clamp is designed to swing left and right to ensure that the peeling force is always 90° to the bonding surface. The sample is fixed on the testing machine, and the sample strip is peeled off along the 90° direction with the standard aluminum plate by applying external force. The maximum peeling force, minimum peeling force and average peeling force are recorded, and the peel strength is calculated according to the test results.

[0122] From the data in Table 1 above, compared with the cured product of the epoxy resin of Comparative Example 1, the Examples 1-6 of the present application have a lower sound attenuation coefficient, and compared with polystyrene of Comparative Example 2, the Examples 1-6 of the present application have better bonding performance, and the bonding strength of Examples 5 and 6 is stronger.

[0123] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An acoustic matching material, characterized by, The acoustic matching material comprises a polystyrene telechelic polymer with a chemical structure as shown in formula I: Formula I wherein n1 and n2 are positive integers; X includes at least one of a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a propargyl group, a methoxy group, an azido group, a pyrimidine group, a malonate group, the malonate group being -2-propandioic acid diC 1-3 alkyl ester group.

2. The acoustic matching material of claim 1, wherein, n1 and n2 are the same, or n1 = n2 = 100-400; And / or, the X is a carboxyl group or an amino group.

3. The acoustic matching material of claim 1 or 2, wherein, The acoustic impedance of the acoustic matching material ranges from 2.5 to 2.9 MRayl, and the acoustic attenuation is 11-13 dB / cm at 20 MHz; and / or, the adhesive force of the acoustic matching material is 0.36-0.66 KN / m.

4. A method of preparing an acoustic matching material, characterized by, Comprise: The polystyrene telechelic polymer with a chemical structure as shown in formula Ia is obtained by polymerizing styrene monomers in an initiation system containing p-dicumyl chloride, and then adding 1,3-butadiene for end-capping treatment to generate the polystyrene telechelic polymer with a chemical structure as shown in formula Ia, thereby obtaining the acoustic matching material; Formula Ia Wherein, n1 and n2 are positive integers.

5. The production method according to claim 4, wherein Also comprise: substituting the chlorine atom in a polystyrene telechelic polymer represented by Formula Ia, such that the chlorine atom in the chemical structure of Formula Ia is substituted with X; wherein X comprises at least one of a non-chlorine halogen atom, a hydroxyl group, a carboxyl group, an amino group, an acetylene group, a methoxy group, an azido group, a pyrimidinyl group, a malonate group, the malonate group being -2-propandioic acid diC 1-3 alkyl ester group.

6. The production method according to claim 5, wherein The X is a bromine atom, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer as shown in formula Ia with lithium bromide under the condition of 70-90°C; Or, the X is a hydroxyl group, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer as shown in formula Ia with lithium bromide under the condition of 70-90°C, and then reacting with a quaternary ammonium base under the condition of 20-30°C; Or, the X is an amino group, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer as shown in formula Ia with lithium bromide under the condition of 70-90°C, and then sequentially reacting with phthalimide potassium salt and hydrazine hydrate under the condition of 60-80°C; Or, the X is a malonate group, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer as shown in formula Ia with lithium bromide under the condition of 70-90°C, and then reacting with malonate under the condition of 50-70°C; Or, the X is a carboxyl group, and the substitution treatment of the chlorine atom comprises: reacting the polystyrene telechelic polymer as shown in formula Ia with lithium bromide under the condition of 70-90°C, and then sequentially reacting with malonate and alkali metal hydroxide under the condition of 50-70°C.

7. The production method according to any one of claims 4 to 6, wherein The initiation system in the polymerization reaction further comprises a co-initiator, and the co-initiator comprises at least one of TiCl4, BCl3, and AlCl3; And / or, the conditions of the polymerization reaction comprise: a temperature of -80 to -60°C, and a time of 10-20 min; And / or, the molar ratio of the 1,3-butadiene to the styrene monomers in the end-capping treatment is 1: (100-400); And / or, the conditions of the end-capping treatment comprise: a temperature of -80 to -60°C, and a time of 2-8 min.

8. An ultrasonic transducer, characterized by, The acoustic matching material of any one of claims 1-3 and / or the acoustic matching material prepared by the preparation method of any one of claims 4-7.

9. An ultrasound probe, characterized by, The ultrasonic transducer of claim 8; or, comprising a piezoelectric crystal and an acoustic matching layer, and the acoustic matching layer comprises the acoustic matching material of any one of claims 1-3 and / or the acoustic matching material prepared by the preparation method of any one of claims 4-7.

10. An ultrasound imaging apparatus, characterized by An ultrasonic transducer as claimed in claim 8 or an ultrasonic probe as claimed in claim 9.

Images