阅读说明：本技术 一种oca声学薄膜及其制备方法 (OCA acoustic film and preparation method thereof ) 是由 夏超华 于 2019-10-08 设计创作，主要内容包括：本发明公开了一种OCA声学薄膜,其特征在于,自上而下依次包括第一外层,第一胶粘层,芯层,第二胶粘层,第二外层；所述第一胶黏层和第二胶粘层相互独立地由OCA光学胶形成；所述芯层为2,6-萘二硫酚/4,4’-二巯基二苯硫醚双甲基丙烯酸甲酯缩聚物,所述第一外层和第二外层相互独立地为聚苯硫醚树脂形成。本发明还提供了所述OCA声学薄膜的制备方法。本发明公开的OCA声学薄膜综合性能优异,机械力学性能、耐热性、耐候性、抗紫外老化性佳,各层之间粘结力大,不易出现脱层现象,高频下介电常数和介电损耗小,能有效改善信号传输质量,提升信号传输速度,经济价值和社会价值高。(The invention discloses an OCA acoustic film which is characterized by sequentially comprising a first outer layer, a first adhesive layer, a core layer, a second adhesive layer and a second outer layer from top to bottom; the first adhesive layer and the second adhesive layer are formed by OCA optical cement independently; the core layer is a 2, 6-naphthalene dithiol/4, 4' -dimercaptodiphenyl sulfide dimethyl methacrylate polycondensate, and the first outer layer and the second outer layer are formed by polyphenylene sulfide resin independently. The invention also provides a preparation method of the OCA acoustic film. The OCA acoustic film disclosed by the invention has the advantages of excellent comprehensive performance, good mechanical property, heat resistance, weather resistance and ultraviolet aging resistance, large bonding force among layers, difficulty in delaminating, small dielectric constant and dielectric loss at high frequency, capability of effectively improving the signal transmission quality and increasing the signal transmission speed, and high economic value and social value.)

1. The OCA acoustic film is characterized by sequentially comprising a first outer layer, a first adhesive layer, a core layer, a second adhesive layer and a second outer layer from top to bottom; the first adhesive layer and the second adhesive layer are formed by OCA optical cement independently; the core layer is a 2, 6-naphthalene dithiol/4, 4' -dimercaptodiphenyl sulfide dimethyl methacrylate polycondensate, and the first outer layer and the second outer layer are formed by polyphenylene sulfide resin independently.

2. The OCA acoustic film of claim 1, wherein the core layer has a thickness of 1-40 μ ι η; the thickness of the first outer layer is 3-30 μm; the thickness of the second outer layer is 3-30 μm.

3. The OCA acoustic film of claim 1, wherein the OCA optical cement comprises the following components in parts by mass: 100 parts of acrylate adhesive, 20-30 parts of hyperbranched polyurethane acrylate, 1-3 parts of [ (3,3, 3-trifluoro-1-propenyl) thio ] benzene, 1-3 parts of methyl vinyl bis (butanone oximino) silane, 0.5-1.6 parts of bis (triethoxysilyl) ethylene, 10-15 parts of butanone, 0.1-0.3 part of nano praseodymium oxide and 0.8-1.2 parts of initiator.

4. The OCA acoustic membrane of claim 3, wherein the initiator is at least one of azobisisobutyronitrile, azobisisoheptonitrile, and lauroyl peroxide.

5. The OCA acoustic film of claim 3, wherein the acrylic adhesive has a weight average molecular weight in the range of 400 to 900 ten thousand and a glass transition temperature of-60 to-30 ℃.

6. The OCA acoustic membrane of claim 3, wherein the preparation method of the OCA optical cement comprises the following steps: mixing the components in proportion, deoxidizing for 15-25 minutes by using inert gas, and stirring for 30-50 minutes at the temperature of 30-50 ℃ to obtain the prime OCA optical cement.

7. The OCA acoustic membrane of claim 6, wherein the inert gas is one of helium, neon, and argon.

8. The OCA acoustic film according to claim 1, wherein the method for preparing the 2, 6-naphthalene dithiol/4, 4' -dimercaptodiphenylsulfide methylmethacrylate polycondensate comprises the steps of: adding 2, 6-naphthalene dithiol, 4 '-dimercaptodiphenyl sulfide dimethyl methacrylate and a catalyst into a high boiling point solvent, stirring and reacting for 18-22 hours at 90-110 ℃ under the nitrogen atmosphere, then precipitating in water, washing the product with ethanol for 3-5 times, and then placing the product in a vacuum drying oven at 80-90 ℃ to dry to constant weight to obtain the 2, 6-naphthalene dithiol/4, 4' -dimercaptodiphenyl sulfide dimethyl methacrylate polycondensate.

9. The OCA acoustic membrane of claim 8, wherein the mass ratio of 2, 6-naphthalene dithiol, 4' -dimercaptodiphenylsulfide bis-methyl methacrylate, catalyst, high boiling point solvent is 1:2 (0.2-0.4): (10-15); the catalyst is at least one of sodium ethoxide, sodium hydride, sodium amide and potassium tert-butyl alkoxide; the high boiling point solvent is at least one of dimethyl sulfoxide, N-dimethylformamide and N-methylpyrrolidone.

10. The OCA acoustic film of any one of claims 1-9, wherein the preparation method of the OCA acoustic film comprises the steps of: melting and extruding polyphenylene sulfide resin at the temperature of 220-240 ℃, cooling and solidifying, and rolling by a roller to obtain a first outer layer; melting and extruding the polyphenylene sulfide resin at the temperature of 220-240 ℃, cooling and solidifying, and rolling by a roller to obtain a second outer layer; melting and extruding the 2, 6-naphthalene dithiol/4, 4' -dimercapto diphenyl sulfide dimethyl methacrylate polycondensate at the temperature of 230-250 ℃, cooling and solidifying, and rolling by a roller to obtain a core layer; uniformly coating OCA optical cement on the upper surface and the lower surface of the core layer, then respectively superposing the first outer layer and the second outer layer on the upper surface and the lower surface of the core layer coated with the OCA optical cement, pressing, and performing hardening treatment to obtain an OCA acoustic film; the hardening treatment specifically comprises the following steps: hardening at 60-80 deg.C for 20-30 min, and then at room temperature for 15-20 hr.

Technical Field

The invention relates to the technical field of membrane materials, in particular to an OCA acoustic membrane and a preparation method thereof.

Background

The sound wave is a mechanical wave generated by the vibration of a sound source, and the space for the sound wave to propagate is a sound field. When the sound waves are transmitted by the air, the density of the air is changed, and the air pressure is changed periodically; the pressure change of the air can be utilized to effectively detect sound waves, sound vibration is converted into an electric signal or an optical signal through the transduction of the film, and the purpose of detecting the sound signal is achieved through detecting the electric signal or the optical signal. Therefore, a good quality transducing film is crucial to improve the detection sensitivity and accuracy of the acoustic wave.

The conventional transduction membrane used in the acoustic device is a capacitive or voltage type membrane, which has capacitive or piezoelectric properties, has high selectivity to materials, and is expensive and cannot be used in high magnetic field and high electromagnetic field. Microphone films of the acoustic sensing technology based on FP interference developed in recent years do not require piezoelectricity or capacitance, so that more materials are suitable for the acoustic films, the production cost is effectively reduced, and the application range of the acoustic films is widened. The acoustic membranes in the prior art are commonly used as silicone acoustic membranes and polyether ether ketone acoustic membranes, and the membrane materials are different from each other in thousands of autumn, so that the defects that the heat resistance and the weather resistance are required to be further improved, and the dielectric constant at high frequency is required to be further reduced are generally existed.

In order to further improve the overall performance of the acoustic membrane, manufacturers of micro-speakers often use multifunctional layered membranes as the acoustic thin-film material, for example, WO 2008/056286 discloses a multi-layered membrane for an acoustic device, in which a thermoplastic material is used. The outer membrane facing the surface is preferably a softer material which can be melted and used to establish a direct connection with other components of the acoustic device. Preferably, one layer is rigid, for example polycarbonate, and the other layer is a softer material, for example PU, thermoplastic elastomers being considered particularly suitable. However, these materials are often not laminated well by gluing and are prone to delamination.

The OCA optical cement is a special adhesive used for cementing transparent optical elements (such as lenses and the like). The acoustic multilayer film has the advantages of high light transmittance, low haze, ultraviolet resistance, high adhesion, high temperature resistance, no yellowing after long-time use and the like, can meet the use requirements of the acoustic multilayer film, has huge market application potential in the field of acoustic films, is expected to become a 'new favorite' in the future acoustic film consumption market, and has poor aging resistance and short service life in the prior art.

Therefore, the development of an OCA acoustic film with excellent comprehensive performance and long service life is very important, and the OCA acoustic film has very important significance for promoting high-quality sound transmission of an acoustic device.

Disclosure of Invention

The invention mainly aims to provide an OCA acoustic film and a preparation method thereof, wherein the preparation method has the advantages of short process flow, convenient operation, low preparation cost, high preparation efficiency and high qualification rate of finished products, and is suitable for continuous large-scale production; the prepared OCA acoustic film has excellent comprehensive performance, good mechanical property, heat resistance, weather resistance and ultraviolet aging resistance, large bonding force among layers, difficult delamination phenomenon, small dielectric constant and dielectric loss under high frequency, effective improvement of signal transmission quality, improvement of signal transmission speed and high economic value and social value.

In order to achieve the above purpose, the invention provides an OCA acoustic film, which is characterized by sequentially comprising a first outer layer, a first adhesive layer, a core layer, a second adhesive layer and a second outer layer from top to bottom; the first adhesive layer and the second adhesive layer are formed by OCA optical cement independently; the core layer is a 2, 6-naphthalene dithiol/4, 4' -dimercaptodiphenyl sulfide dimethyl methacrylate polycondensate, and the first outer layer and the second outer layer are formed by polyphenylene sulfide resin independently.

Further, the thickness of the core layer is 1 to 40 μm, preferably 1 to 20 μm, more preferably 2 to 15 μm.

Further, the thickness of the first outer layer is 3 to 30 μm, preferably 1 to 10 μm, more preferably 2 to 8 μm.

Further, the thickness of the second outer layer is 3 to 30 μm, preferably 1 to 10 μm, more preferably 2 to 8 μm.

Further, the OCA optical cement comprises the following components in parts by mass: 100 parts of acrylate adhesive, 20-30 parts of hyperbranched polyurethane acrylate, 1-3 parts of [ (3,3, 3-trifluoro-1-propenyl) thio ] benzene, 1-3 parts of methyl vinyl bis (butanone oximino) silane, 0.5-1.6 parts of bis (triethoxysilyl) ethylene, 10-15 parts of butanone, 0.1-0.3 part of nano praseodymium oxide and 0.8-1.2 parts of initiator.

Further, the initiator is at least one of azobisisobutyronitrile, azobisisoheptonitrile and lauroyl peroxide.

Furthermore, the weight average molecular weight of the acrylic adhesive is 400-900 ten thousand, and the glass transition temperature is-60-30 DEG C

Further, the preparation method of the OCA optical cement comprises the following steps: mixing the components in proportion, deoxidizing for 15-25 minutes by using inert gas, and stirring for 30-50 minutes at the temperature of 30-50 ℃ to obtain the prime OCA optical cement.

Preferably, the inert gas is one of helium, neon and argon.

Further, the preparation method of the 2, 6-naphthalene dithiol/4, 4' -dimercaptodiphenyl sulfide dimethyl methacrylate polycondensate comprises the following steps: adding 2, 6-naphthalene dithiol, 4 '-dimercaptodiphenyl sulfide dimethyl methacrylate and a catalyst into a high boiling point solvent, stirring and reacting for 18-22 hours at 90-110 ℃ under the nitrogen atmosphere, then precipitating in water, washing the product with ethanol for 3-5 times, and then placing the product in a vacuum drying oven at 80-90 ℃ to dry to constant weight to obtain the 2, 6-naphthalene dithiol/4, 4' -dimercaptodiphenyl sulfide dimethyl methacrylate polycondensate.

Preferably, the mass ratio of the 2, 6-naphthalene dithiol, the 4,4' -dimercaptodiphenyl sulfide dimethyl methacrylate, the catalyst and the high boiling point solvent is 1:2 (0.2-0.4) to (10-15).

Preferably, the catalyst is at least one of sodium ethoxide, sodium hydride, sodium amide and potassium tert-butyl alkoxide; the high boiling point solvent is at least one of dimethyl sulfoxide, N-dimethylformamide and N-methylpyrrolidone.

Further, the preparation method of the OCA acoustic film comprises the following steps: melting and extruding polyphenylene sulfide resin at the temperature of 220-240 ℃, cooling and solidifying, and rolling by a roller to obtain a first outer layer; melting and extruding the polyphenylene sulfide resin at the temperature of 220-240 ℃, cooling and solidifying, and rolling by a roller to obtain a second outer layer; melting and extruding the 2, 6-naphthalene dithiol/4, 4' -dimercapto diphenyl sulfide dimethyl methacrylate polycondensate at the temperature of 230-250 ℃, cooling and solidifying, and rolling by a roller to obtain a core layer; and uniformly coating the OCA optical cement on the upper surface and the lower surface of the core layer, then respectively superposing the first outer layer and the second outer layer on the upper surface and the lower surface of the core layer coated with the OCA optical cement, pressing, and performing hardening treatment to obtain the OCA acoustic film.

Preferably, the hardening treatment is specifically: hardening at 60-80 deg.C for 20-30 min, and then at room temperature for 15-20 hr.

Due to the application of the technical scheme, the invention has the following beneficial effects:

(1) the OCA acoustic film disclosed by the invention is short in process flow, convenient to operate, low in preparation cost, high in preparation efficiency and finished product qualification rate, and suitable for continuous large-scale production.

(2) The OCA acoustic film disclosed by the invention overcomes the defects that the heat resistance and weather resistance of the traditional acoustic film are required to be further improved and the dielectric constant under high frequency is required to be further reduced, also overcomes the problems that multilayer films in the prior art are not firmly bonded and easily delaminate, fully utilizes the advantages of OCA, avoids the problem of easy aging through reasonable selection and configuration of components, and has the advantages of excellent comprehensive performance, excellent mechanical property, heat resistance, weather resistance and ultraviolet aging resistance, large bonding force among layers, difficulty in delaminating, small dielectric constant and dielectric loss under high frequency, capability of effectively improving signal transmission quality and signal transmission speed, and high economic value and social value.

(3) The invention discloses an OCA acoustic film, belonging to multilayer film, wherein each layer is bonded by OCA optical cement, the OCA optical adhesive comprises acrylate adhesives, hyperbranched polyurethane acrylate, [ (3,3, 3-trifluoro-1-propenyl) thio ] benzene, methyl vinyl di (butanone oxiyl) silane, bis (triethoxy silicon-based) ethylene, butanone, nano praseodymium oxide, an initiator and the like, wherein firstly, the acrylate adhesives, the hyperbranched polyurethane acrylate, [ (3,3, 3-trifluoro-1-propenyl) thio ] benzene, the methyl vinyl di (butanone oxiyl) silane and the bis (triethoxy silicon-based) ethylene can be crosslinked and cured under the action of the initiator to form a three-dimensional network structure, so that the performance stability and other comprehensive performances of the film are improved, and the service life of the film is prolonged; due to the introduction of the hyperbranched polyurethane acrylate structure, the hyperbranched polyurethane acrylate has excellent performance of hyperbranched molecules, has good solubility in molecular treatment, reduces the stacking of molecular chains due to the easy stretching of the molecular chains, and reduces the dielectric constant and dielectric loss of the whole film layer; the advantages of polyurethane and acrylate adhesives are combined, the adhesive strength is higher, the weather resistance and the aging resistance are better, and the substance also plays a role of a cross-linking agent; reaction sites and a foundation are provided for rapid and efficient molding in a curing stage; the [ (3,3, 3-trifluoro-1-propenyl) sulfenyl ] benzene introduces a fluorine structure, the stability of a carbon-fluorine bond is high, so that the performance stability of the material is better, and the introduced thiophenoxide ether structure has similar structural units with an outer layer and a core layer, so that the compatibility is enhanced, and the bonding strength is favorably improved; the methyl vinyl di (butanone oxime) silane can improve the bonding strength, and a silicon structure is introduced, so that the methyl vinyl di (butanone oxime) silane has the advantages of fluorine silicon organic matters, and the comprehensive performance is improved.

(4) The OCA acoustic film disclosed by the invention has the advantages that the outer layer is made of thermoplastic PPS resin, the inner layer is made of 2, 6-naphthalene dithiol/4, 4' -dimercapto diphenyl sulfide dimethyl methacrylate polycondensate, and the advantages of the two are combined, so that the OCA acoustic film has excellent heat resistance, thermal stability, weather resistance, corrosion resistance and chemical resistance, and also has very low dielectric constant and excellent insulativity in a high-temperature and high-humidity environment; the nanometer praseodymium oxide improves the hardness and mechanical property of the film.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art.

In the embodiment of the invention, the raw materials are all purchased commercially; the hyperbranched polyurethane acrylate is prepared in advance, and the preparation method refers to the following steps: the synthesis of the photocuring hyperbranched polyurethane acrylate and the performance of a curing film thereof are Xiaowenqing, Spirodela dela, college chemical engineering journal, Vol 23, No. 2 of 2009; the polyphenylene sulfide resin is linear polyphenylene sulfide resin with the molecular weight of 20000.