Electronic-grade cyanate ester prepolymer as well as preparation method and application thereof

Abstract

The invention discloses an electronic-grade cyanate ester prepolymer as well as a preparation method and application thereof. The preparation method comprises the following steps: in a protective atmosphere, melting a cyanate ester monomer at 140-160 DEG C, adding a catalyst, continuously stirring and reacting for 6-10 hours, cooling to 110-120 DEG C, or cooling to 60-75 DEG C, and adding a low-boiling-point solvent to prepare an electronic-grade cyanate ester prepolymer; wherein the catalyst comprises polyhydroxy alkyl melamine and / or polyhydroxy alkyl cyanuric acid. The cyanate ester prepolymer with excellent performance can be prepared under mild conditions, and the cyanate ester prepolymer has wide application prospects in the fields of electronic packaging substrates, copper-clad plates and aerospace.

Description

Technical Field

[0001] This invention belongs to the field of thermosetting resins and their preparation and application technology, specifically relating to an electronic-grade cyanate ester prepolymer and its preparation method and application. Background Technology

[0002] Cyanate ester resins, with their excellent dielectric properties, heat resistance, excellent hydrothermal properties, mechanical properties, and processability, have been widely used in electronic packaging circuit boards and aerospace wave-transparent composite materials. They are high-performance thermosetting resins for manufacturing next-generation high-performance electronic products.

[0003] Commonly used cyanate monomers contain two or more cyanate functional groups (-OCN). High-purity cyanate monomers are difficult to polymerize and generally require very high temperatures (greater than 200°C) or the addition of catalysts to polymerize. Several processes for preparing cyanate ester monomer prepolymers have been reported. Patent CN103145983B reports a method for preparing bisphenol A cyanate ester prepolymers. This method involves heating under negative pressure, controlling the reaction temperature at 120°C for a period of time, and then polymerizing to obtain the prepolymer. This method assumes that although the material temperature is controlled at 120°C, it is equivalent to atmospheric pressure (150°C), allowing the monomer to react. When the reaction reaches its endpoint, the pressure is changed to positive, and the material temperature remains at 120°C, essentially ceasing further reaction. However, for batch prepolymer preparation, maintaining a negative pressure system increases energy consumption, and the increased volatility of cyanate ester monomers under negative pressure damages equipment. Patent CN102993438B reports a method using hydroxyl-terminated polyphenylene ether to catalyze the preparation of bisphenol A cyanate ester prepolymers. Currently, hydroxyl-terminated polyphenylene ether resin is not fully domestically produced, and import substitution is difficult. Patent CN111848952B reports a method using hexa(o-,p-hydroxymethylphenoxy) Cyclotriphosphazene is used to catalyze the production of prepolymers from bisphenol A cyanate monomers. However, the cyclotriphosphazene structure has poor heat resistance, with a thermal decomposition temperature of around 248°C, which leads to a loss in the heat resistance of the cyanate resin. Furthermore, the cyclotriphosphazene structure has a high polarity compared to the triazine ring structure, thus also affecting the dielectric properties of the cyanate resin. Patents CN107722265A and CN102199289B report the use of nonylphenol, dimethylimidazole, or transition metal ion promoters to catalyze the production of bisphenol A cyanate monomers. The method of obtaining prepolymers from cyanate monomers and tetramethylbisphenol F cyanate monomers involves the use of compounds such as nonylphenol and dimethylimidazole, which are highly environmentally hazardous or toxic and unfavorable for downstream manufacturing and processing. Patent CN101450994B reports a method of preparing a prepolymer with a refractive index of 1.580-1.585 by heating the bisphenol A cyanate monomer at 140-150℃ for 15-20 hours. However, the reaction time is too long and the monomer conversion rate is low, which needs to be further improved.

[0004] Therefore, developing a production method for preparing cyanate prepolymers that is highly efficient, yields no or minimal loss to the excellent properties of cyanate ester resins, and does not introduce environmentally harmful or toxic compounds during the prepolymerization process is of great practical significance. Thus, this invention has very important application value. Summary of the Invention

[0005] The main objective of this invention is to provide an electronic-grade cyanate prepolymer, its preparation method, and its application, in order to overcome the shortcomings of the prior art: high reaction temperature and high energy consumption; in order to reduce energy consumption, catalysts are introduced to lower the reaction temperature, but the introduction of active catalysts such as nonylphenol, dimethylimidazole, or transition metal ions is harmful to the environment or highly toxic, which is detrimental to environmental protection and health; while the introduction of other substances improves the monomer conversion efficiency, it also leads to a loss of the original cyanate resin performance.

[0006] To achieve the aforementioned objectives, the technical solution adopted by this invention includes: This invention provides a method for preparing an electronic-grade cyanate prepolymer, comprising: melting cyanate monomers at 140-160°C in a protective atmosphere, adding a catalyst and continuing to stir the reaction for 6-10 hours, then cooling to 110-120°C, or cooling to 60-75°C and adding a low-boiling-point solvent to obtain the electronic-grade cyanate prepolymer; wherein the catalyst comprises polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid.

[0007] The present invention also provides an electronic-grade cyanate prepolymer prepared by the aforementioned preparation method, wherein the color grade of the electronic-grade cyanate prepolymer is ≥6.

[0008] The present invention also provides a modified cyanate ester prepolymer, which is prepared by mixing the aforementioned electronic-grade cyanate ester prepolymer with at least one resin selected from epoxy resin, bismaleimide resin, benzoxazine resin, and phenolic resin.

[0009] The present invention also provides a cyanate ester cured product, which is obtained by curing the aforementioned electronic-grade cyanate ester prepolymer.

[0010] The embodiments of the present invention also provide the application of the aforementioned electronic-grade cyanate prepolymer, modified cyanate prepolymer, and cyanate cured product in electronic packaging substrates, copper-clad laminates, or aerospace fields.

[0011] This invention also provides a composite material, which is obtained by pre-impregnating fibers with the aforementioned electronic-grade cyanate prepolymer or modified cyanate prepolymer using a hot-melt or solvent method, followed by cutting, layering, and curing; wherein the fibers include any one or more combinations of glass fibers, quartz fibers, polyimide fibers, and polyethylene fibers.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In this invention, the active hydroxyl groups in the structure of polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid can effectively catalyze the polymerization of cyanate ester monomers at a lower temperature (140~160℃). The introduction of this catalyst effectively solves the problems of excessively high prepolymerization temperature, long reaction cycle, low production efficiency and low monomer conversion rate of cyanate ester monomers. It avoids the environmental hazards or high toxicity of active catalysts such as nonylphenol, dimethylimidazole or transition metal ions, which are not conducive to environmental protection and health. (2) The polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid used in this invention contain the same triazine ring structure as the cyanate ester prepolymer, thereby avoiding the influence on the thermal properties, electrical properties, mechanical properties and other properties of the cyanate ester prepolymer resin, and retaining the original excellent properties of the cyanate ester resin. (3) The polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid used in this invention can achieve prepolymerization of cyanate monomers at a lower temperature (140~160℃). The lower the prepolymerization temperature, the lighter the color of the prepolymer. Moreover, polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid are white powders themselves, which have no effect on the color of the prepolymer itself. (4) The polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid used in this invention are soluble in low-boiling-point solvents commonly used in cyanate ester prepolymers, while avoiding the defects such as bubbles that are easily generated in high-boiling-point solvents such as toluene, xylene, DMF, and DMAc during the resin molding process, which is beneficial to the stability control of product quality during the laminate molding process. (5) The preparation method of the present invention has the characteristics of wide adaptability, simple operation process, short prepolymerization time and no solvent in the prepolymerization process. It is applicable to bisphenol A type cyanate monomer, bisphenol E type cyanate monomer, bisphenol M type cyanate monomer, bisphenol F type cyanate monomer, dicyclopentadiene type cyanate monomer, phenolic type cyanate monomer, etc. (6) The present invention uses cyanate monomer as the main body and polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid as catalysts to prepare prepolymer resin through a prepolymerization process. After the prepolymer resin is heated and cured at 180℃ / 1~2h+220℃ / 2~4h, the dielectric constant of the cyanate resin cured at 1GHz frequency is ≤2.9, the dielectric loss is ≤0.006, the glass transition temperature is ≥280℃, and the 5% thermogravimetric temperature is ≥420℃. The prepolymer resin is suitable for various molding processes such as compression molding, autoclave molding or RTM molding, and has broad application prospects in the fields of high frequency circuit copper clad laminates or advanced aerospace resin-based composite materials. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figures 1a-1b These are appearance diagrams of the prepolymers prepared in Comparative Example 1 and Example 1 of this invention; Figure 2 This is the DMA diagram of the prepolymer prepared in Example 1 of this invention; Figure 3 This is a schematic diagram of the polymerization reaction of cyanate ester monomers in a typical embodiment of the present invention; Figure 4 This is the infrared spectrum of the prepolymer and its cured product prepared in Example 1 of the present invention. Detailed Implementation

[0015] In view of the deficiencies of the prior art, the inventors of this case, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0016] Specifically, as one aspect of the technical solution of this invention, the preparation method of an electronic-grade cyanate prepolymer includes: melting cyanate monomers at 140~160℃ in a protective atmosphere, adding a catalyst and continuing to stir the reaction for 6~10h, then cooling to 110~120℃, or cooling to 60~75℃ and adding a low-boiling-point solvent to obtain an electronic-grade cyanate prepolymer; wherein, the catalyst includes polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid.

[0017] This invention utilizes the principle that active hydrogen can catalyze the polymerization of cyanate ester monomers. By designing the molecular structure of compounds containing active hydrogen, it is necessary to avoid excessively active and strong catalytic ability, which is not conducive to the large-scale production of cyanate ester monomers and is prone to the risk of explosive polymerization (such as amino and imidazole compounds), and excessively active and weak catalytic ability, which is economically inefficient (such as phenolic compounds). A catalyst with moderate catalytic activity is selected to achieve the catalytic reaction of cyanate ester monomers while maintaining the excellent performance of cyanate ester resin. (1) The relatively active alkyl hydroxyl groups in the structure of polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid can effectively catalyze the polymerization of cyanate ester monomers at lower temperatures (140~160℃). The polymerization reaction of cyanate ester monomers is as follows: Figure 3 As shown, the introduction of this catalyst effectively solves the problems of excessively high prepolymerization temperature of cyanate ester monomer, long reaction cycle, low production efficiency and low monomer conversion rate; (2) Polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid contain the same triazine ring structure as cyanate ester prepolymer, thereby avoiding the influence on the thermal properties, electrical properties, mechanical properties and other properties of cyanate ester prepolymer resin.

[0018] In some preferred embodiments, the preparation method specifically includes: melting the cyanate monomer in a reaction apparatus at 140-160°C under a protective atmosphere, then adding a catalyst and continuing the reaction for 6-10 hours with a stirring rate of 50-500 r / min until the refractive index of the resin reaches between 1.583 and 1.589, then cooling to 110-120°C for discharge and packaging, or cooling to 60-75°C and adding a low-boiling-point solvent to achieve a cyanate prepolymer content between 70-75%, and then discharging and packaging.

[0019] In some preferred embodiments, the mass ratio of the cyanate monomer to the catalyst is 100:1~6.

[0020] In some preferred embodiments, the polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid have any one or a combination of structures such as formula (I), formula (II), and formula (III):

[0021] Equation (I) Equation (II) Equation (II)

[0022] R1, R2, and R3 are all independently selected from alkylene groups having 1 to 10 carbon atoms.

[0023] Furthermore, R1, R2, and R3 are all independently selected from alkylene groups having 1 to 4 carbon atoms.

[0024] Among them, formula (I) and formula (II) are polyhydroxyalkyl melamine, and formula (III) is polyhydroxyalkyl cyanuric acid.

[0025] In some preferred embodiments, the polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid includes any one or more combinations of trimethylol melamine, hexamethylol melamine, hexaethylol melamine, hexaisopropylol melamine, triethylol melamine, hexabutylol melamine, tripropylol melamine, trimethylol melamine, triethylol melamine, tripropylol melamine, and triisopropylol melamine, and is not limited thereto.

[0026] In some preferred embodiments, the cyanate monomer includes any one or more combinations of bisphenol A cyanate monomer, bisphenol E cyanate monomer, bisphenol M cyanate monomer, tetramethylbisphenol F cyanate monomer, hexafluorobisphenol A cyanate monomer, dicyclopentadiene cyanate monomer, and phenolic cyanate monomer, and is not limited thereto.

[0027] In some preferred embodiments, the low-boiling solvent includes any one or more combinations of acetone, butanediol, ethyl acetate, dioxane, and dichloromethane, but is not limited thereto.

[0028] In some more specific embodiments, the method for preparing the electronic-grade cyanate prepolymer specifically includes: Using cyanate ester monomers as the main component and polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid as catalysts, it is composed of the following components by weight: 100 parts cyanate ester monomers and 1-6 parts polyhydroxyalkyl melamine. The preparation process is as follows: By weight, 100 parts of cyanate monomer are placed in a reactor at 140-160°C. After complete melting, 1-6 parts of polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid are added. The resin is stirred at a stirring rate of 50-500 r / min and the reaction continues for 6-10 hours. When the refractive index of the resin reaches 1.583-1.589, the temperature is lowered to 110-120°C for direct discharge and packaging, or the temperature is lowered to 60-75°C and a low-boiling-point solvent is added to the resin to make the cyanate prepolymer content between 70-75%. Then the resin is discharged and packaged. The color grade of the cyanate prepolymer is ≥6 (the higher the value, the lighter the color). The entire reaction process is under nitrogen protection. The low-boiling-point solvent is any one of acetone, butanone, ethyl acetate, dioxane, dichloromethane, etc.

[0029] Another aspect of the present invention provides an electronic-grade cyanate prepolymer prepared by the aforementioned preparation method, wherein the color grade of the electronic-grade cyanate prepolymer is ≥6.

[0030] Another aspect of the present invention provides a modified cyanate ester prepolymer, which is prepared by mixing the aforementioned electronic-grade cyanate ester prepolymer with at least one resin selected from epoxy resin, bismaleimide resin, benzoxazine resin, and phenolic resin.

[0031] Another aspect of the present invention provides a cyanate ester cured product, which is obtained by curing the aforementioned electronic-grade cyanate ester prepolymer.

[0032] In some preferred embodiments, the curing process specifically includes: curing the electronic-grade cyanate prepolymer sequentially at 180°C for 1-2 hours and at 220°C for 2-4 hours to obtain a cyanate cured product.

[0033] In some preferred embodiments, the cyanate ester cured product has a dielectric constant ≤2.9 and a dielectric loss ≤0.006 at 1 GHz.

[0034] In some preferred embodiments, the glass transition temperature of the cyanate ester cured product is ≥280°C.

[0035] In some preferred embodiments, the 5% thermogravimetric temperature of the cyanate ester cured product is ≥420°C.

[0036] Another aspect of the present invention provides the application of the aforementioned electronic-grade cyanate prepolymer, modified cyanate prepolymer, and cyanate cured product in electronic packaging substrates, copper-clad laminates, or aerospace applications.

[0037] Another aspect of the present invention provides a composite material, which is obtained by pre-impregnating fibers with the aforementioned electronic-grade cyanate prepolymer or modified cyanate prepolymer using a hot-melt method or a solvent method, followed by cutting, layering, and curing; wherein the fibers include any one or more combinations of glass fibers, quartz fibers, polyimide fibers, and polyethylene fibers.

[0038] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides detailed implementation methods and specific operation processes. However, the protection scope of the present invention is not limited to the following embodiments.

[0039] Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0040] In the following examples, the Fourier transform infrared (FTIR) spectroscopy test conditions for the electronic-grade cyanate prepolymer and its cured products were as follows: number of scans: 32, resolution: 4 cm⁻¹ -1 Scanning range: 4000~400cm-1 ; In the following comparative examples and embodiments, the gel time test conditions for electronic grade cyanate ester prepolymer resin at 180°C were as follows: the test was conducted according to the national military standard GJB1059.4. In the following examples and comparative examples, the viscosity performance test conditions for electronic grade cyanate ester prepolymers were as follows: a high-temperature extended rheometer in oscillation mode was used, the temperature was room temperature, the strain was 1.0%, the angular frequency was 10.0 rad / s, and the atmosphere was air.

[0041] In the following examples and comparative examples, the test conditions for the glass transition temperature of the electronic grade cyanate ester prepolymer resin cured products were: DMA test, single cantilever beam mode, frequency 1Hz, heating rate 5℃ / min. In the following comparative examples and embodiments, the room temperature storage conditions for the electronic grade cyanate prepolymer were: test temperature 23±2℃, and the time required for the resin viscosity to double or for the resin to become cloudy at this temperature. In the following comparative examples and embodiments, the color scale number of the electronic grade cyanate prepolymer is: The color system created by Munsell at room temperature is a method of representing color using a color solid model. It uses the visual characteristics of color to formulate a color classification and labeling system, and represents the characteristics of various surface colors in a way that is equally spaced according to visual color perception. In the following examples and comparative examples, the test conditions for the 5% thermogravimetric temperature of the cured electronic grade cyanate ester prepolymer resin were: heating rate 10℃ / min, temperature range 40~800℃, air atmosphere; In the following examples and comparative examples, the impact strength of the cured electronic-grade cyanate ester prepolymer resin was tested according to the national standard GB / T2567-2008.

[0042] The dielectric properties of the electronic-grade cyanate ester prepolymer resin cured products were tested under the following conditions in the comparative examples and embodiments: Agilent Technologies E5071C radio frequency vector network analyzer was used to test the samples using the cylindrical cavity perturbation method. The radio frequency range was 1 GHz, and polytetrafluoroethylene was used for calibration. The test environment temperature was 23 ± 2 °C and the humidity was ≤ 40%.

[0043] Example 1

[0044] The electronic-grade cyanate prepolymer resin is prepared from the following components in parts by weight: 100 parts of bisphenol A cyanate monomer and 3 parts of catalyst (trimethylolmelamine).

[0045] The preparation method of electronic-grade bisphenol A cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of bisphenol A cyanate monomer were placed in a reactor at 150°C. After complete melting, 3 parts of trimethylol melamine were added. The resin was stirred at 100 r / min and the reaction continued for 7 hours. When the refractive index of the resin reached 1.585, the temperature was lowered to 110°C for direct packaging, or the temperature was lowered to 70°C and butanone solvent was added to the resin to make the solid content of the bisphenol A cyanate prepolymer 72%. Then the prepolymer was packaged. The color grade of the cyanate prepolymer was 7. The entire reaction process was under nitrogen protection. The appearance of the prepared prepolymer is as follows. Figure 1b As shown, the DMA graph is as follows Figure 2 As shown.

[0046] The bisphenol A type cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1MPa for 30 minutes. Then, it was cured by heating at 180°C / 2h + 220°C / 2h to obtain the cured bisphenol A type prepolymer resin.

[0047] The infrared spectra of the prepolymer and its cured product prepared in this embodiment are as follows: Figure 4 As shown.

[0048] The properties of bisphenol A cyanate prepolymer and its solution are shown in Table 1, and the properties of bisphenol A cyanate resin cured products are shown in Table 2.

[0049] Example 2

[0050] The electronic-grade cyanate prepolymer resin is prepared from the following components in parts by weight: 100 parts of tetramethylbisphenol F cyanate monomer and 4 parts of catalyst (trihydroxyethyl cyanuric acid).

[0051] The preparation method of electronic-grade cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of tetramethylbisphenol F cyanate monomer were placed in a reactor at 145°C. After complete melting, 4 parts of trihydroxyethyl cyanuric acid were added. The resin was stirred at a stirring rate of 150 r / min and the reaction was continued for 6 hours. When the refractive index of the resin reached 1.586, the temperature was lowered to 120°C and the material was directly discharged and packaged, or the temperature was lowered to 65°C and a mixture of acetone and butanone (acetone:butanone mass ratio of 1:2) was added to the resin to make the cyanate prepolymer content 71%. Then the material was discharged and packaged. The color grade of the cyanate prepolymer was 6. The entire reaction process was protected by nitrogen.

[0052] The tetramethylbisphenol F cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1 MPa for 30 minutes. Then, it was cured by heating at 180°C / 2h + 220°C / 3h to obtain the cured tetramethylbisphenol F prepolymer resin.

[0053] The properties of tetramethylbisphenol F prepolymer and its solution are shown in Table 1, and the properties of the cured tetramethylbisphenol F cyanate resin are shown in Table 2.

[0054] Example 3

[0055] The electronic-grade cyanate prepolymer resin is prepared from the following components in parts by weight: 60 parts of bisphenol A cyanate monomer, 20 parts of bisphenol M cyanate monomer, 20 parts of hexafluorobisphenol A cyanate monomer, and 3 parts of catalyst (hexahydroxymethyl melamine).

[0056] The preparation method of electronic-grade cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of cyanate monomer were placed in a reactor at 140°C. After complete melting, 3 parts of hexamethylol melamine were added. The resin was stirred at a stirring rate of 200 r / min and the reaction was continued for 6 hours. When the refractive index of the resin reached 1.585, the temperature was lowered to 110°C and the material was directly discharged and packaged, or the temperature was lowered to 75°C and butanone was added to the resin to make the cyanate prepolymer content 73%. Then the material was discharged and packaged. The color grade of the cyanate prepolymer was 8. The entire reaction process was protected by nitrogen.

[0057] The cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1 MPa for 30 minutes. Then, it was cured by heating at 180°C / 1h + 220°C / 2h to obtain the cured cyanate prepolymer resin.

[0058] The properties of the cyanate prepolymer and its solution are shown in Table 1, and the properties of the cured cyanate prepolymer resin are shown in Table 2.

[0059] Example 4

[0060] The electronic-grade cyanate prepolymer resin is prepared from the following components in parts by weight: 90 parts of bisphenol A type cyanate monomer, 10 parts of dicyclopentadiene type cyanate monomer, and 5 parts of catalyst (hexahydroxyisopropylmelamine to trihydroxyethyl cyanuric acid mass ratio 1:2).

[0061] The preparation method of electronic-grade cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of cyanate monomer were placed in a reactor at 155°C. After complete melting, 5 parts of catalyst were added. The resin was stirred at a stirring rate of 250 r / min and the reaction was continued for 8 hours. When the refractive index of the resin reached 1.586, the temperature was lowered to 110°C and the material was directly discharged and packaged, or the temperature was lowered to 65°C and a mixed solvent of butanone and dioxane (mass ratio of 2:1) was added to the resin to make the cyanate prepolymer content 74%. Then the material was discharged and packaged. The color grade of the cyanate prepolymer was 6. The entire reaction process was protected by nitrogen.

[0062] The cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1 MPa for 30 minutes. Then, it was cured by heating at 180°C for 2 hours and then at 220°C for 3 hours to obtain the cured cyanate prepolymer resin.

[0063] The properties of the cyanate prepolymer and its solution are shown in Table 1, and the properties of the cured cyanate prepolymer resin are shown in Table 2.

[0064] Example 5

[0065] The electronic-grade cyanate prepolymer resin is prepared from the following components calculated by weight: 80 parts of bisphenol E type cyanate monomer, 10 parts of dicyclopentadiene type cyanate monomer, 10 parts of phenolic type cyanate monomer, and 3 parts of catalyst (the mass ratio of trihydroxypropylmelamine to trihydroxymethyl cyanuric acid is 1:1).

[0066] The preparation method of electronic-grade cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of cyanate monomer were placed in a reactor at 160°C. After complete melting, 3 parts of catalyst were added. The resin was stirred at a stirring rate of 300 r / min and the reaction was continued for 7 hours. When the refractive index of the resin reached 1.588, the temperature was lowered to 120°C and the material was directly discharged and packaged, or the temperature was lowered to 75°C and a mixed solvent of butanone and dichloromethane (mass ratio of 2:1) was added to the resin to make the cyanate prepolymer content 70%. Then the material was discharged and packaged. The color grade of the cyanate prepolymer was 6. The entire reaction process was protected by nitrogen.

[0067] The cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1 MPa for 30 minutes. Then, it was cured by heating at 180°C / 1h + 220°C / 4h to obtain the cured cyanate prepolymer resin.

[0068] The properties of the cyanate prepolymer and its solution are shown in Table 1, and the properties of the cured cyanate prepolymer resin are shown in Table 2.

[0069] Example 6

[0070] The electronic-grade cyanate prepolymer resin is prepared from the following components in parts by weight: 10 parts of dicyclopentadiene cyanate monomer, 80 parts of bisphenol A cyanate monomer, 10 parts of tetramethylbisphenol F cyanate monomer, and 5 parts of catalyst (hexahydroxyethyl melamine).

[0071] The preparation method of electronic-grade cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of cyanate monomer were placed in a reactor at 150°C. After complete melting, 5 parts of hexahydroxyethyl melamine were added. The resin was stirred at a stirring rate of 400 r / min and the reaction was continued for 6 hours. When the refractive index of the resin reached 1.585, the temperature was lowered to 120°C and the material was directly discharged and packaged, or the temperature was lowered to 65°C and butanone was added to the resin to make the cyanate prepolymer content between 72% and then discharged and packaged. The color grade of the cyanate prepolymer was 6. The entire reaction process was protected by nitrogen.

[0072] The cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1 MPa for 30 minutes. Then, it was cured by heating at 180°C / 1.5h + 220°C / 3h to obtain the cured cyanate prepolymer resin.

[0073] The properties of the cyanate prepolymer and its solution are shown in Table 1, and the properties of the cured cyanate prepolymer resin are shown in Table 2.

[0074] Example 7

[0075] The electronic-grade cyanate prepolymer resin is prepared from the following components by weight: 60 parts of bisphenol A cyanate monomer, 20 parts of hexafluorobisphenol A cyanate monomer, 20 parts of tetramethylbisphenol F cyanate monomer, and 2 parts of catalyst (the mass ratio of trihydroxyisopropyl cyanuric acid to trihydroxypropyl melamine is 3:1).

[0076] The preparation method of electronic-grade cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of cyanate monomer were placed in a reactor at 158°C. After complete melting, 2 parts of catalyst were added. The resin was stirred at a stirring rate of 150 r / min and the reaction was continued for 8 hours. When the refractive index of the resin reached 1.588, the temperature was lowered to 110°C and the material was directly discharged and packaged. Alternatively, the temperature was lowered to 70°C and a mixed solvent of butanone and ethyl acetate (mass ratio of 4:1) was added to the resin to make the cyanate prepolymer content 73%. Then the material was discharged and packaged. The color grade of the cyanate prepolymer was 7. The entire reaction process was protected by nitrogen.

[0077] The cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1 MPa for 30 minutes. Then, it was cured by heating at 180°C / 2h + 220°C / 2.5h to obtain the cured cyanate prepolymer resin.

[0078] The properties of the cyanate prepolymer and its solution are shown in Table 1, and the properties of the cured cyanate prepolymer resin are shown in Table 2.

[0079] Example 8

[0080] The electronic-grade cyanate prepolymer resin is prepared from the following components calculated by weight: 50 parts of hexafluorobisphenol A cyanate monomer, 50 parts of tetramethylbisphenol F cyanate monomer, and 1 part of catalyst (hexamethylolmelamine to trimethylolmelamine in a mass ratio of 1:2).

[0081] The preparation method of electronic-grade cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of cyanate monomer were placed in a reactor at 160°C. After complete melting, 1 part of catalyst was added. The resin was stirred at a stirring rate of 500 r / min and the reaction was continued for 9 hours. When the refractive index of the resin reached 1.589, the temperature was lowered to 110°C and the material was directly discharged and packaged, or the temperature was lowered to 65°C and butanone was added to the resin to make the cyanate prepolymer content 75%. Then the material was discharged and packaged. The color grade of the cyanate prepolymer was 6. The entire reaction process was protected by nitrogen.

[0082] The cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1 MPa for 30 minutes. Then, it was cured by heating at 180°C / 2h + 220°C / 2h to obtain the cured cyanate prepolymer resin.

[0083] The properties of the cyanate prepolymer and its solution are shown in Table 1, and the properties of the cured cyanate prepolymer resin are shown in Table 2.

[0084] Comparative Example 1

[0085] The difference between this comparative example and Example 1 is that no polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid catalysts were added, and the reaction temperature was 220°C.

[0086] The electronic-grade cyanate prepolymer resin is prepared from the following components calculated by weight: 100 parts of bisphenol A type cyanate monomer.

[0087] The preparation method of electronic-grade bisphenol A cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of bisphenol A cyanate monomer were placed in a reactor at 220°C. After complete melting, the resin was stirred at 100 r / min and the reaction continued for 10 hours. When the refractive index of the resin reached 1.585, the temperature was lowered to 110°C for direct packaging, or the temperature was lowered to 70°C and butanone solvent was added to the resin to make the solid content of the bisphenol A cyanate prepolymer 72%. Then the prepolymer was packaged. The color grade of this cyanate prepolymer is 4. The entire reaction process was under nitrogen protection. The appearance of the prepared prepolymer is as follows. Figure 1a As shown.

[0088] The bisphenol A type cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1MPa for 30 minutes. Then, it was cured by heating at 180°C / 2h + 220°C / 2h to obtain the cured bisphenol A type prepolymer resin.

[0089] The properties of bisphenol A cyanate prepolymer and its solution are shown in Table 1, and the properties of bisphenol A cyanate resin cured products are shown in Table 2.

[0090] Comparative Example 2

[0091] The difference between this comparative example and Example 1 is that no polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid catalysts were added, and the reaction temperature was maintained at 150°C.

[0092] The electronic-grade cyanate prepolymer resin is prepared from the following components calculated by weight: 100 parts of bisphenol A type cyanate monomer.

[0093] The preparation method of electronic-grade bisphenol A cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of bisphenol A cyanate monomer were placed in a reactor at 150°C. After complete melting, the resin was stirred at 100 r / min. The reaction was continued for 100 h. When the refractive index of the resin reached 1.585, the temperature was lowered to 110°C and the material was directly discharged and packaged, or the temperature was lowered to 70°C and butanone solvent was added to the resin to make the solid content of the bisphenol A cyanate prepolymer 72%. Then the material was discharged and packaged. The color grade of the cyanate prepolymer was 7. The entire reaction process was protected by nitrogen.

[0094] The bisphenol A type cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1MPa for 30 minutes. Then, it was cured by heating at 180°C / 2h + 220°C / 2h to obtain the cured bisphenol A type prepolymer resin.

[0095] The properties of bisphenol A cyanate prepolymer and its solution are shown in Table 1, and the properties of bisphenol A cyanate resin cured products are shown in Table 2.

[0096] Comparative Example 3

[0097] The difference between this comparative example and Example 1 is that instead of adding polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid catalyst, nonylphenol and cobalt acetylacetonate (mass ratio 50:1) are added.

[0098] The electronic-grade cyanate prepolymer resin is prepared from the following components calculated by weight: 100 parts of bisphenol A cyanate monomer and 3 parts of nonylphenol and cobalt acetylacetone (mass ratio of 50:1).

[0099] The preparation method of electronic-grade bisphenol A cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of bisphenol A cyanate monomer were placed in a reactor at 150°C. After complete melting, a catalyst was added, and the resin was stirred at a stirring rate of 100 r / min. The reaction was continued for 7 hours. When the refractive index of the resin reached 1.585, the temperature was lowered to 110°C and the material was directly discharged for packaging, or the temperature was lowered to 70°C and butanone solvent was added to the resin to make the solid content of the bisphenol A cyanate prepolymer 72%. Then the material was discharged for packaging. The color grade of the cyanate prepolymer was 5. The entire reaction process was protected by nitrogen.

[0100] The bisphenol A type cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1MPa for 30 minutes. Then, it was cured by heating at 180°C / 2h + 220°C / 2h to obtain the cured bisphenol A type prepolymer resin.

[0101] The properties of bisphenol A cyanate prepolymer and its solution are shown in Table 1, and the properties of bisphenol A cyanate resin cured products are shown in Table 2.

[0102] Comparative Example 4

[0103] The difference between this comparative example and Example 1 is that dimethylimidazole is added instead of polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid catalyst.

[0104] The electronic-grade cyanate prepolymer resin is prepared from the following components in parts by weight: 100 parts of bisphenol A cyanate monomer and 3 parts of dimethylimidazole.

[0105] The preparation method of electronic-grade bisphenol A cyanate prepolymer is carried out according to the following steps: By weight, 100 parts of bisphenol A cyanate monomer were placed in a reactor at 150°C. After complete melting, a catalyst was added, and the resin was stirred at a stirring rate of 100 r / min. The reaction was continued for 4 hours. When the refractive index of the resin reached 1.585, the temperature was lowered to 110°C and the material was directly discharged for packaging, or the temperature was lowered to 70°C and butanone solvent was added to the resin to make the solid content of the bisphenol A cyanate prepolymer 72%. Then the material was discharged for packaging. The color grade of the cyanate prepolymer was 4. The entire reaction process was protected by nitrogen.

[0106] The bisphenol A type cyanate prepolymer was heated to 100°C, placed in a mold at 100°C, and degassed under a vacuum pressure of -0.1MPa for 30 minutes. Then, it was cured by heating at 180°C / 2h + 220°C / 2h to obtain the cured bisphenol A type prepolymer resin.

[0107] The properties of bisphenol A cyanate prepolymer and its solution are shown in Table 1, and the properties of bisphenol A cyanate resin cured products are shown in Table 2.

[0108] Table 1: Performance data of electronic-grade cyanate prepolymers and their solutions in Comparative Examples 1-2 and Examples 1-8

[0109] Table 2: Performance data of electronic-grade cyanate ester resin cured products in Comparative Examples 1-2 and Examples 1-8

[0110] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0111] It should be understood that the technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made to the technical solutions of the present invention without departing from the spirit and scope of the claims are within the scope of protection of the present invention.

Claims

1. A method for preparing an electronic-grade cyanate prepolymer, characterized in that, include: In a protective atmosphere, cyanate monomers are melted at 140-160°C, then a catalyst is added and the reaction is continued with stirring for 6-10 hours. The temperature is then lowered to 110-120°C, or to 60-75°C, and a low-boiling-point solvent is added to obtain an electronic-grade cyanate prepolymer. The catalyst includes polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid.

2. The preparation method according to claim 1, characterized in that, Specifically, it includes: In a protective atmosphere, the cyanate monomer is melted in a reaction apparatus at 140-160°C. Then, a catalyst is added and the reaction continues for 6-10 hours with a stirring rate of 50-500 r / min. When the refractive index of the resin reaches between 1.583 and 1.589, the temperature is lowered to 110-120°C for discharge and packaging, or the temperature is lowered to 60-75°C and a low-boiling-point solvent is added to make the cyanate prepolymer content between 70-75% before discharge and packaging.

3. The preparation method according to claim 1, characterized in that: The mass ratio of the cyanate monomer to the catalyst is 100:1~6.

4. The preparation method according to claim 1, characterized in that: The polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid have any one or a combination of structures of formula (I), formula (II), and formula (III): ； Equation (I) Equation (II) Equation (II); R1, R2, and R3 are all independently selected from alkylene groups having 1 to 10 carbon atoms, preferably alkylene groups having 1 to 4 carbon atoms; And / or, the polyhydroxyalkyl melamine and / or polyhydroxyalkyl cyanuric acid includes any one or more combinations of trimethylol melamine, hexamethylol melamine, hexaethylol melamine, hexaisopropylol melamine, triethylol melamine, hexabutylol melamine, tripropylol melamine, trimethylol melamine, triethylol melamine, tripropylol melamine, and triisopropylol melamine; And / or, the cyanate monomer includes any one or more combinations of bisphenol A cyanate monomer, bisphenol E cyanate monomer, bisphenol M cyanate monomer, tetramethylbisphenol F cyanate monomer, hexafluorobisphenol A cyanate monomer, dicyclopentadiene cyanate monomer, and phenolic cyanate monomer; And / or, the low-boiling solvent includes any one or more combinations of acetone, butanone, ethyl acetate, dioxane, and dichloromethane.

5. The electronic-grade cyanate prepolymer prepared by any one of claims 1-4, characterized in that: The color grade of the electronic-grade cyanate prepolymer is ≥6.

6. A modified cyanate ester prepolymer, characterized in that: The modified cyanate prepolymer is prepared by mixing the electronic-grade cyanate prepolymer of claim 5 with at least one resin selected from epoxy resin, bismaleimide resin, benzoxazine resin, and phenolic resin.

7. A cyanate ester cured product, characterized in that: The cured product is obtained by curing the electronic-grade cyanate prepolymer according to claim 5. Preferably, the curing process specifically includes: curing the electronic-grade cyanate prepolymer sequentially at 180°C for 1-2 hours and at 220°C for 2-4 hours to obtain a cyanate cured product.

8. The cyanate ester cured product according to claim 7, characterized in that: The cyanate ester cured product has a dielectric constant ≤2.9 and a dielectric loss ≤0.006 at 1 GHz; And / or, the glass transition temperature of the cyanate ester cured product is ≥280°C; And / or, the 5% thermal weight loss temperature of the cyanate ester cured product is ≥420°C.

9. The application of the electronic-grade cyanate prepolymer of claim 5, the modified cyanate prepolymer of claim 6, and the cyanate cured product of claim 7 in electronic packaging substrates, copper-clad laminates, or aerospace fields.

10. A composite material, characterized in that: The composite material is obtained by pre-impregnation of fibers with the electronic-grade cyanate prepolymer of claim 5 or the modified cyanate prepolymer of claim 6 using a hot-melt or solvent method, followed by cutting, layering, and curing; wherein the fibers include any one or more combinations of glass fibers, quartz fibers, polyimide fibers, and polyethylene fibers.

Images