A material for pressure gauge diaphragm and a method for preparing the same

Abstract

The application belongs to the technical field of polymer materials, and discloses a material for a pressure gauge diaphragm and a preparation method thereof.The material for the pressure gauge diaphragm comprises polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, a telechelic nanostructured polymer with a three-arm structure, an acrylate-terminated urethane-based PCL polymer, a dispersing agent, glycerol, a crosslinking agent and an antioxidant.The material for the pressure gauge diaphragm uses polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, a telechelic nanostructured polymer with a three-arm structure and an acrylate-terminated urethane-based PCL polymer as reaction raw materials, so that the mechanical properties such as tensile strength and elongation at break of the obtained material for the pressure gauge diaphragm are effectively improved, and the elastic deformation recovery rate is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a material for a pressure detector diaphragm and a preparation method thereof. BACKGROUND

[0002] Hemodialysis, also known as artificial kidney or kidney washing, is a blood purification technology and one of the kidney replacement therapies for patients with acute and chronic renal failure. Hemodialysis machines are the most widely used treatment instruments in blood purification therapy, which are composed of a dialysis liquid supply device and an extracorporeal circulation monitoring device. It mainly includes a blood pump, a dialysis liquid configuration system, a volume control system, and various safety monitoring systems. Among them, the pressure detector is used to monitor the blood pressure in the dialysis blood circuit and is an important part of the safety monitoring system. The existing pressure detector generally introduces blood in the pipeline into the pressure detector, and the pressure detector diaphragm and the pressure sensing device on the dialysis machine are attached. When the blood passes through the pressure detector, the pressure detector diaphragm is inflated and transmitted to the pressure sensing device after being stressed, so as to detect the blood pressure in the blood circuit.

[0003] The existing pressure detector diaphragm uses a silicone flat film which is easy to manufacture, but the price of silicone is rising, and people are looking for alternative materials to replace silicone. The disadvantages of silicone are not only high price, but also complex molding process, non-recyclable, and long molding cycle. Therefore, many enterprises choose to use TPE material and PP material as a substitute. TPE material and PP material have similar hardness and elasticity to silicone, and the hand feeling and environmental performance can be comparable to silicone. In addition, the existing pressure detector diaphragm is not firmly connected with the pressure detector, and is easy to shift. During the deformation process of the diaphragm, wrinkles are easily generated at the edge, which ultimately leads to inaccurate pressure detection.

[0004] Therefore, a pressure detector diaphragm made of TPE material and PP material is needed, which is more closely attached to the pressure detector and improves detection accuracy. Chinese patent CN104231446 discloses a low particle emission medical polypropylene material and its preparation method and application. The material contains polypropylene 50-80 parts, low molecular weight polyolefin wax 1-5 parts, vinyl elastomer 10-35 parts, auxiliary crosslinking elastomer 5-15 parts, modified peroxide 0.005-0.05 parts, and antioxidant 0.01-0.5 parts. However, the material has small tensile strength, is easy to break, has small elongation at break, is easy to have permanent deformation during large or long deformation process, has high permanent deformation rate, and has slow recovery. It is difficult to ensure the accuracy of pressure detection when used as a pressure detector diaphragm. SUMMARY

[0005] The purpose of the present application is to overcome the deficiencies of the above background art, provide a pressure gauge diaphragm material and a preparation method thereof, which uses polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, three-arm structure telechelic nanostructured polymer and acrylate-terminated urethane-based PCL polymer as raw materials for reaction, not only effectively improves the mechanical properties such as tensile strength and elongation at break of the obtained pressure gauge diaphragm material, but also greatly improves the elastic deformation recovery rate.

[0006] To achieve the purpose of the present application, the pressure gauge diaphragm material of the present application comprises polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, three-arm structure telechelic nanostructured polymer, acrylate-terminated urethane-based PCL polymer, dispersant, glycerol, crosslinking agent, antioxidant.

[0007] Further, in some embodiments of the present application, the pressure gauge diaphragm material comprises, by weight fraction, polypropylene 40-55 parts, ethylene-octene copolymer 25-35 parts, hydroxyl-terminated liquid polybutadiene 10-20 parts, three-arm structure telechelic nanostructured polymer 10-20 parts, acrylate-terminated urethane-based PCL polymer 10-20 parts, dispersant 0.5-5 parts, glycerol 1-5 parts, crosslinking agent 0.5-5 parts, antioxidant 0.1-3 parts.

[0008] Further, in some embodiments of the present application, the melt index of the ethylene-octene copolymer is between 0.8-8 g / min.

[0009] Further, in some embodiments of the present application, the number average molecular weight Mn of the hydroxyl-terminated liquid polybutadiene is 2500-3000.

[0010] Further, in some embodiments of the present application, the three-arm structure telechelic nanostructured polymer is selected from one or more of telechelic polyurea TP3, TP4, TP5.

[0011] Further, in some embodiments of the present application, the acrylate-terminated urethane-based PCL polymer is acrylate-terminated urethane-based PCL polymer UPCL-2.

[0012] Further, in some embodiments of the present application, the dispersant is selected from one or more of polyethylene wax, oxidized polyethylene wax, oleic acid amide, stearic acid amide, palmitic acid amide, ethylene bis-stearamide.

[0013] Further, in some embodiments of the present application, the crosslinking agent is selected from one or more of dicumyl peroxide, benzoyl peroxide, dodecanoyl peroxide, and one or more of azobisdimethylvaleronitrile, azobisdimethylvaleronitrile, dimethyl azobis isobutyrate; preferably benzoyl peroxide and azobisdimethylvaleronitrile, and the mass ratio of benzoyl peroxide and azobisdimethylvaleronitrile is 1-2:1-2.

[0014] Further, in some embodiments of the present application, the antioxidant is selected from one or more of BASF-B900, BASF-B225, and BASF-B215.

[0015] In another aspect, the present application also provides a preparation method of the aforementioned material for pressure gauge diaphragm, the method comprising: weighing polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, three-arm structure telechelic nanostructured polymer, acrylate-terminated urethane-based PCL polymer, glycerol, crosslinking agent, and antioxidant according to a proportion, uniformly mixing, and then transferring to an internal mixer for heat mixing to obtain a blend, and then feeding the obtained blend and a dispersing agent into a twin-screw extruder for melt blending, extruding, and granulating.

[0016] Compared with the prior art, the present application has the following advantages:

[0017] (1) In the present application, polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, three-arm structure telechelic nanostructured polymer, and acrylate-terminated urethane-based PCL polymer react under the action of the crosslinking agent to generate soft segments, which not only further improves the mechanical properties such as tensile strength and elongation at break of the obtained material for pressure gauge diaphragm, but also forms a branched and network structure among the components, limits the slippage between molecular chains, and greatly improves the elastic deformation recovery rate of the obtained material.

[0018] (2) The present application uses benzoyl peroxide and azobisdimethylvaleronitrile as a composite crosslinking agent, which can effectively initiate free radicals and promote the crosslinking of each component in the material to form a branched, network, and other three-dimensional crosslinking structure, thereby improving the mechanical properties of the material and improving the elastic deformation of the material.

[0019] (3) The obtained material for pressure gauge diaphragm has high tensile strength and large elongation at break, and the elastic deformation recovery rate is greater than 96%. When used as a material for pressure gauge diaphragm, it will not produce obvious deformation due to the long-term extrusion of blood inside the pressure gauge, and will not affect the pressure measurement results. DETAILED DESCRIPTION

[0020] For purposes of the USPTO rules, the application covers subject matter only to the extent permitted by law. The application may include information that does not meet the requirements of the USPTO rules, but this information can assist in understanding the application. Unless otherwise indicated herein, the materials described herein are not prior art to the claims and are not admitted to be prior art by virtue of their inclusion in this application.

[0021] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a process, a method, an article, or an apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0022] The transitional phrase "consisting of" excludes any element, step, or ingredient not specified. If used in the claims, this phrase shall serve only as a definition of such claim and shall not be construed as a limitation on the claim's scope. When the phrase "consisting of is followed by a listing of elements, the phrase "consisting of shall be interpreted as disclosing only those elements recited in the list and should not be interpreted to preserve any elements not specifically recited.

[0023] When numerical ranges are disclosed, the endpoints of the ranges are included. Unless otherwise indicated, the range is inclusive of both endpoints and all integer and fractional values between the ends of the range. Numerical ranges include all ranges derived from and individually and separately reciting the same upper and lower limits. Where the above ranges using the term "about" are used, this is intended to encompass the range exclusive of the term "about." For example, the recitation of a range "about 1 to about 5" is intended to encompass the range "1 to 5" exclusive.

[0024] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. "Optional" or "any of" means that the subsequently described event or circumstance can or can not occur, and that the description includes instances where the event occurs and instances where it does not.

[0025] Approximating language in the specification and claims can be applied to quantify both the number and range of parameters. Such approximations include the use of "about" or "approximately," with respect to a value or range of values. In some instances, one or more features of the application can constitute an insubstantial change within the meaning of 35 U.S.C. § 103. The mere fact that an element is recited in

[0026] The indefinite articles "a" and "an," as used herein in the specification and in claims, are defined as one or more unless otherwise clearly indicated by context. The inclusion of the indefinite articles "a" and "an" is not to be construed as limiting the claimed application to a single embodiment or to a single instance of the features and / or embodiments otherwise described herein.

[0027] In addition, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," and so forth, as can be used herein throughout the specification, are not necessarily to be construed as specific to the embodiments or examples to which the terms refer. Rather, these terms can be used herein to describe general embodiments or examples that can include, overlap with, or be distinct from other embodiments or examples. Moreover, terms like "first" and "second" are used herein only to describe a difference, and do not connote a limitation on the scope of the application.

[0028] Unless otherwise specified, the preparation method of the material for the pressure transducer diaphragm of the present application is as follows: the polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, three-arm structure telechelic nanostructured polymer, acrylate-terminated urethane-based PCL polymer, glycerol, crosslinking agent and antioxidant (if any) are weighed according to the ratio, uniformly mixed, then transferred into an internal mixer for hot mixing to obtain a blend, and then the dispersing agent is fed into a twin-screw extruder to melt blend, extrude and pelletize.

[0029] Unless otherwise specified, the melt index of the ethylene-octene copolymer described in the present application is between 0.8-8 g / min, the number average molecular weight Mn of the hydroxyl-terminated liquid polybutadiene is 2500-3000, the three-arm structure telechelic nanostructured polymer is telechelic polyurea TP3, the acrylate-terminated urethane-based PCL polymer is acrylate-terminated urethane-based PCL polymer UPCL-2, the dispersing agent is oxidized polyethylene wax, and the antioxidant is BASF-B900.

[0030] Example 1

[0031] A pressure gauge diaphragm material, comprising, by weight fraction, polypropylene 45 parts, ethylene-octene copolymer 30 parts, hydroxyl-terminated liquid polybutadiene 15 parts, three-arm structure telechelic nanostructured polymer 15 parts, acrylate-terminated urethane-based PCL polymer 15 parts, dispersant 2 parts, glycerol 3 parts, crosslinking agent 3 parts, antioxidant 2 parts, wherein the crosslinking agent is benzoyl peroxide and azobisisoheptanenitrile, and the mass ratio of benzoyl peroxide to azobisisoheptanenitrile is 1:1.

[0032] The preparation method of the foregoing pressure gauge diaphragm material is as follows: polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, three-arm structure telechelic nanostructured polymer, acrylate-terminated urethane-based PCL polymer, glycerol, crosslinking agent, and antioxidant are weighed according to the proportions, uniformly mixed, and then transferred to an internal mixer for hot mixing to obtain a blend, and then the dispersant is fed into a twin-screw extruder for melt blending, extrusion, and granulation.

[0033] Example 2

[0034] A pressure gauge diaphragm material, different from example 1, comprises, by weight fraction, polypropylene 40 parts, ethylene-octene copolymer 25 parts, hydroxyl-terminated liquid polybutadiene 10 parts, three-arm structure telechelic nanostructured polymer 10 parts, acrylate-terminated urethane-based PCL polymer 10 parts, dispersant 1 part, glycerol 1 part, crosslinking agent 1 part, and antioxidant 1 part, wherein the crosslinking agent is benzoyl peroxide and azobisisoheptanenitrile, and the mass ratio of benzoyl peroxide to azobisisoheptanenitrile is 1:2.

[0035] Example 3

[0036] A pressure gauge diaphragm material, different from example 1, comprises, by weight fraction, polypropylene 55 parts, ethylene-octene copolymer 35 parts, hydroxyl-terminated liquid polybutadiene 20 parts, three-arm structure telechelic nanostructured polymer 20 parts, acrylate-terminated urethane-based PCL polymer 20 parts, dispersant 5 parts, glycerol 5 parts, crosslinking agent 5 parts, and antioxidant 3 parts, wherein the crosslinking agent is benzoyl peroxide and azobisisoheptanenitrile, and the mass ratio of benzoyl peroxide to azobisisoheptanenitrile is 2:1.

[0037] Example 4

[0038] A pressure gauge diaphragm material, different from example 1, contains, in parts by weight, polypropylene 45 parts, ethylene-octene copolymer 30 parts, telechelic nanostructured polymer with a three-arm structure 15 parts, acrylate-terminated urethane-based PCL polymer 15 parts, dispersing agent 2 parts, glycerol 3 parts, crosslinking agent 3 parts, antioxidant 2 parts, wherein the crosslinking agent is benzoyl peroxide and azobisisoheptane nitrile, and the mass ratio of benzoyl peroxide to azobisisoheptane nitrile is 1:1.

[0039] Example 5

[0040] A pressure gauge diaphragm material, different from example 1, contains, in parts by weight, polypropylene 45 parts, ethylene-octene copolymer 30 parts, hydroxyl-terminated liquid polybutadiene 15 parts, acrylate-terminated urethane-based PCL polymer 15 parts, dispersing agent 2 parts, glycerol 3 parts, crosslinking agent 3 parts, antioxidant 2 parts, wherein the crosslinking agent is benzoyl peroxide and azobisisoheptane nitrile, and the mass ratio of benzoyl peroxide to azobisisoheptane nitrile is 1:1.

[0041] Example 6

[0042] A pressure gauge diaphragm material, different from example 1, contains, in parts by weight, polypropylene 45 parts, ethylene-octene copolymer 30 parts, hydroxyl-terminated liquid polybutadiene 15 parts, telechelic nanostructured polymer with a three-arm structure 15 parts, dispersing agent 2 parts, glycerol 3 parts, crosslinking agent 3 parts, antioxidant 2 parts, wherein the crosslinking agent is benzoyl peroxide and azobisisoheptane nitrile, and the mass ratio of benzoyl peroxide to azobisisoheptane nitrile is 1:1.

[0043] Example 7

[0044] A pressure gauge diaphragm material, different from example 1, contains, in parts by weight, polypropylene 45 parts, ethylene-octene copolymer 30 parts, hydroxyl-terminated liquid polybutadiene 15 parts, telechelic nanostructured polymer with a three-arm structure 15 parts, acrylate-terminated urethane-based PCL polymer 15 parts, dispersing agent 2 parts, glycerol 3 parts, benzoyl peroxide 3 parts, antioxidant 2 parts.

[0045] Example 8

[0046] A pressure gauge diaphragm material, different from example 1, contains, in parts by weight, polypropylene 45 parts, ethylene-octene copolymer 30 parts, hydroxyl-terminated liquid polybutadiene 15 parts, telechelic nanostructured polymer with a three-arm structure 15 parts, acrylate-terminated urethane-based PCL polymer 15 parts, dispersing agent 2 parts, glycerol 3 parts, azobisisoheptane nitrile 3 parts, antioxidant 2 parts.

[0047] Example 9

[0048] A material for pressure gauge diaphragm, different from example 1, comprising, in parts by weight, polypropylene 45 parts, hydroxyl-terminated liquid polybutadiene 15 parts, telechelic nanostructured polymer with three-arm structure 15 parts, acrylate-terminated urethane-based PCL polymer 15 parts, dispersing agent 2 parts, glycerol 3 parts, crosslinking agent 3 parts, antioxidant 2 parts, wherein the dispersing agent is benzoyl peroxide and azobisisoheptanenitrile, and the mass ratio of benzoyl peroxide to azobisisoheptanenitrile is 1:1.

[0049] Effect example

[0050] The tensile strength, elongation at break and elastic deformation recovery rate of the above-mentioned material for pressure gauge diaphragm were tested, and the test results are shown in Table 1.

[0051] Among them, the tensile strength and elongation at break are prepared and detected according to ISO 527, and the elastic deformation recovery rate is tested by DMA (test method: after the sample is heated to 60℃, an external force is applied to make the sample produce 120% deformation, and then the sample is cooled to 0℃ at a temperature gradient of 15K / min under the condition of maintaining mechanical load and keeping for 10min, then the external force is removed, at this time the temporary shape of the sample is fixed, then the sample is heated to 60℃ at a rate of 15K / min and kept for 10min, and the sample returns to the original shape).

[0052] Table 1 Properties of materials obtained in each example

[0053]

[0054]

[0055] From the above test results, it can be seen that polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, telechelic nanostructured polymer with three-arm structure and acrylate-terminated urethane-based PCL polymer in the present application are indispensable, and it is speculated that these components react to form soft segments under the action of the composite crosslinking agent used in the present application, not only the mechanical properties such as tensile strength and elongation at break of the obtained material for pressure gauge diaphragm are further improved, but also the raw materials of each component form a dendritic, network structure, limiting the slip between molecular chains, greatly improving the elastic deformation recovery rate of the material obtained in the present application.

[0056] It is easy for those skilled in the art to understand that the above-mentioned only is the embodiment of the present application, and does not limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A material for pressure gauge diaphragms, characterized by The pressure gauge diaphragm material comprises polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, three-arm telechelic nanostructured polymer, acrylate-terminated urethane-based PCL polymer, dispersant, glycerol, crosslinking agent, antioxidant; the three-arm telechelic nanostructured polymer is selected from one or more of telechelic polyurea TP3, TP4 and TP5; the crosslinking agent is benzoyl peroxide and azobisisheptylnitrile, and the mass ratio of benzoyl peroxide to azobisisheptylnitrile is 1-2:1-2, and the acrylate-terminated urethane-based PCL polymer is acrylate-terminated urethane-based PCL polymer UPCL-2; The pressure gauge diaphragm material comprises, by weight fraction, polypropylene 40-55 parts, ethylene-octene copolymer 25-35 parts, hydroxyl-terminated liquid polybutadiene 10-20 parts, three-arm telechelic nanostructured polymer 10-20 parts, acrylate-terminated urethane-based PCL polymer 10-20 parts, dispersant 0.5-5 parts, glycerol 1-5 parts, crosslinking agent 0.5-5 parts, and antioxidant 0.1-3 parts.

2. The load cell diaphragm material of claim 1, wherein, The ethylene-octene copolymer has a melt index of 0.8-8 g / min.

3. The load cell diaphragm material of claim 1, wherein, The hydroxyl-terminated liquid polybutadiene has a number average molecular weight Mn of 2500-3000.

4. The load cell diaphragm material of claim 1, wherein, The dispersant is selected from one or more of polyethylene wax, oxidized polyethylene wax, oleic acid amide, stearic acid amide, palmitic acid amide and ethylene bis-stearamide.

5. The load cell diaphragm material of claim 1, wherein, The antioxidant is selected from one or more of BASF-B900, BASF-B225 and BASF-B215.

6. The method of producing a pressure sensor diaphragm material according to any one of claims 1 to 5, characterized in that, The method comprises: weighing polypropylene, ethylene-octene copolymer, hydroxyl-terminated liquid polybutadiene, three-arm telechelic nanostructured polymer, acrylate-terminated urethane-based PCL polymer, glycerol, crosslinking agent and antioxidant according to a proportion, uniformly mixing and then transferring to an internal mixer for hot mixing to obtain a blend, and then feeding the dispersant into the obtained blend into a double-screw extruder for melt blending, extruding and granulating.

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