A phosphorus-containing benzoxazine resin composition and its application

Abstract

The present invention provides a phosphorus-containing benzoxazine resin composition and its application. The resin composition, measured by weight, comprises the following components: 10-60 parts of a benzoxazine composition, 10-60 parts of an epoxy resin, 0-40 parts of a curing agent, 0.01-10 parts of an accelerator, and 0-100 parts of an inorganic filler; the benzoxazine composition comprises a benzoxazine resin A, which comprises at least one of the compounds represented by formula (1) to (2), wherein R is H or a C1-C6 alkane. The present invention utilizes the inherent flame retardancy of the phosphorus-containing benzoxazine resin, which has advantages such as good flame retardant properties and a high glass transition temperature, reduces the use of additive flame retardants, and solves problems such as decreased heat resistance of the curing system. #imgabs0#

Description

Technical Field

[0001] The present invention relates to the technical field of electronic materials, and in particular to a phosphorus-containing benzoxazine resin composition and applications thereof. Background Art

[0002] Copper-clad laminates (CCLs) are the substrate for electronic circuits. The resins used in CCLs are often flammable, making them susceptible to ignition and fires in situations such as electrical short circuits. Therefore, flame retardants, such as halogen flame retardants, phosphorus-containing flame retardants, nitrogen-containing flame retardants, and metal hydrates, are often incorporated into resin formulations to achieve flame retardancy.

[0003] Although halogen flame retardants exhibit good flame retardant effects, the gases such as hydrogen halides they release are harmful to the human body, and most halogen flame retardants are not environmentally friendly, so their use has gradually been restricted.

[0004] Phosphorus-containing flame retardants also exhibit good flame retardant effects, but commonly used additive flame retardants often exhibit poor compatibility, easy agglomeration, sedimentation and other problems. Due to the large amount of addition, it will also lead to a decline in the mechanical properties and mechanical properties of the material.

[0005] Commonly used phosphorus-containing epoxy resins must maintain a high phosphorus content (3±0.05%) to meet UL94-V0 flame retardancy requirements. This reduces the reactive functional groups in the epoxy resin and imposes significant structural limitations. Furthermore, these products suffer from high water absorption, poor heat resistance, susceptibility to moisture absorption, and poor heat resistance to tin immersion. Benzoxazine resins, containing nitrogen, possess certain flame retardancy. Upon curing, they form a phenolic-like structure. Phosphorus-modified benzoxazine resins do not reduce the crosslink density of the system, allowing for flexible curing with epoxy resins. They maintain excellent heat resistance while retaining many of the epoxy resin's excellent properties.

[0006] Therefore, there is an urgent need to develop a phosphorus-containing benzoxazine resin composition that can balance the flame retardancy, heat resistance, dielectric properties, water absorption and other requirements of the resin curing system, so as to achieve good application in the copper clad laminate field. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a phosphorus-containing benzoxazine resin composition and its application.

[0008] According to a first aspect of the present invention, a phosphorus-containing benzoxazine resin composition is provided, comprising the following components, in parts by weight: 10-60 parts of a benzoxazine composition A, 10-60 parts of an epoxy resin, 0-40 parts of a curing agent, 0.01-10 parts of an accelerator, and 0-100 parts of an inorganic filler;

[0009] The benzoxazine composition comprises a benzoxazine resin A, wherein the benzoxazine resin A comprises at least one of the compounds represented by formula (1) to formula (2), wherein the compounds represented by formula (1) to formula (2) are specifically as follows:

[0010]

[0011] Wherein, R is H or C1-C6 alkane.

[0012] In some embodiments, the benzoxazine composition A is prepared as follows:

[0013] (1) reacting a phosphorus-containing raw material and p-hydroxybenzaldehyde in a molar ratio of 1:1 in an inert solvent for 2-5 hours, adding a phenolic substance in an amount of 1-5 times the amount of the phosphorus-containing raw material, and adding an acidic catalyst, and reacting for 2-10 hours to obtain a suspension; adding an alkaline solution to neutralize the suspension to neutrality, adding clean water for washing, and separating the solid and liquid to obtain a phosphorus-containing bisphenol compound;

[0014] (2) The phosphorus-containing bisphenol compound is mixed with formaldehyde and a primary amine in a molar ratio of hydroxyl:formaldehyde:amine = 1:2:1, and an inert solvent is added at a molar ratio of 2-8 times that of the phosphorus-containing bisphenol compound. The temperature is raised to 80-150° C. to react for 2-10 hours, and the solvent is refluxed to separate water until no water is produced. The solvent is evaporated under reduced pressure to obtain the phosphorus-containing benzoxazine.

[0015] In some embodiments, the phosphorus-containing raw material is at least one of DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) or DPO (diphenylphosphine oxide).

[0016] In some embodiments, the phenolic substance is phenol.

[0017] In some embodiments, the acidic catalyst is at least one of oxalic acid, boron trifluoride, p-toluenesulfonic acid, sulfuric acid or hydrochloric acid; and / or the molar ratio of the acidic catalyst to the phosphorus-containing raw material is (0.01-0.2):1.

[0018] In some embodiments, the primary amine is at least one of aniline, p-methylaniline, or p-tert-butylaniline.

[0019] In some embodiments, the inert solvent is at least one of toluene, xylene, methyl isobutyl ketone, butanone, or acetone.

[0020] Benzoxazine composition A inherently contains phosphorus, and its DOPO or DPO structure exhibits superior heat resistance compared to typical phosphorus-containing structures (such as phosphates). This results in superior flame retardancy and reduces the need for additional phosphorus flame retardants. The addition of additive flame retardants typically reduces the heat resistance and Tg of the cured system and increases water absorption. Compared to conventional benzoxazine, Benzoxazine composition A possesses a greater steric hindrance, which helps reduce the dielectric constant.

[0021] In some embodiments, the benzoxazine composition further comprises a benzoxazine resin B, wherein the weight proportion of the benzoxazine resin B is 0-40 parts; and / or, the benzoxazine resin B is one or more of bisphenol A benzoxazine, bisphenol F benzoxazine, MDA benzoxazine, ODA benzoxazine or diallyl bisphenol A benzoxazine.

[0022] In some embodiments, the epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, bisphenol A novolac epoxy resin, DCPD phenol type epoxy resin, biphenyl phenol type epoxy resin, tetraphenol ethane epoxy resin, trisphenol methane epoxy resin, tetramethyl biphenyl epoxy resin, MDI modified epoxy resin, DOPO modified epoxy resin, DOPO-HQ modified epoxy resin, DOPO-NQ modified epoxy resin, alicyclic epoxy, aliphatic epoxy, hydantoin epoxy or epoxidized soybean oil resin.

[0023] In some embodiments, the epoxy equivalent weight of the epoxy resin is 100-800 g / eq.

[0024] In some embodiments, the curing agent includes one or more of dicyandiamide, 4,4-diaminodiphenyl sulfone, phenolic resin, cyanate resin, acid anhydride, or styrene maleic anhydride copolymer.

[0025] In some embodiments, the accelerator includes one or more of imidazole, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, triphenylphosphine, bicyclic amidine, or substituted urea.

[0026] In some embodiments, the inorganic filler includes one or more of silicon dioxide, aluminum hydroxide, magnesium hydroxide, aluminum oxide, titanium oxide, barium sulfate, aluminum borate, and calcium carbonate.

[0027] In some embodiments, the resin composition further comprises an organic solvent.

[0028] In some embodiments, the organic solvent is selected from one or more of toluene, xylene, trimethylbenzene, acetone, butanone, methyl isobutyl ketone, cyclohexanone, ethylene glycol methyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, ethanol, butanol, N,N'-dimethylformamide, N,N'-dimethylacetamide, ethyl acetate or butyl acetate.

[0029] According to a second aspect of the present invention, a prepreg is provided, which is prepared from the resin composition according to the first aspect of the present invention.

[0030] According to a third aspect of the present invention, a laminate is provided, comprising the prepreg according to the second aspect of the present invention.

[0031] The present invention also proposes the use of the resin composition described in the first aspect, the prepreg described in the second aspect, or the laminate described in the third aspect in the preparation of a printed circuit board.

[0032] According to one embodiment of the present invention, there are at least the following beneficial effects:

[0033] (1) The composition can achieve V0 flame retardancy without the need for additional flame retardants, thus avoiding the decrease in the glass transition temperature (Tg) of the curing system and the increase in water absorption caused by the addition of additional flame retardants.

[0034] (2) The composition introduces a large steric hindrance structure, and its glass transition temperature (Tg) is higher than that of ordinary bisphenol A type benzoxazine resin, its heat resistance is better, and the dielectric loss is slightly reduced. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments so as to fully understand the purpose, characteristics and effects of the present invention.

[0036] Example 1

[0037] A phosphorus-containing benzoxazine resin composition comprises the following components, measured by weight: 50 parts of a phosphorus-containing benzoxazine resin (Formula 1), 40 parts of a phenol novolac epoxy resin, 10 parts of a phenolic resin, 0.5 parts of 2-methylimidazole, and 50 parts of silicon dioxide. The above components are dissolved in a butanone solution and stirred thoroughly to prepare a resin solution with a solid content of 50%.

[0038] A prepreg is prepared by impregnating the resin solution with 7628 fiberglass cloth and baking it at 170°C for 4 minutes. The prepreg has a glue content of 55±5%.

[0039] A laminated board is prepared by stacking five sheets of the above-mentioned semi-cured sheets neatly, covering both sides with copper foil, placing them between stainless steel plates, and then placing them in a vacuum press and hot pressing them at 200±3°C and 35kgf / cm2 for 180 minutes to form a double-sided copper-clad board (laminated board).

[0040] The phosphorus-containing benzoxazine resin (Formula 1) is prepared as follows:

[0041] (1) 1 mol of a phosphorus-containing raw material, DOPO, and p-hydroxybenzaldehyde are reacted in a 1:1 molar ratio in 500 g of an inert solvent, toluene, for 4 hours. 2 mol of phenol and 0.05 mol of p-toluenesulfonic acid are added, and the reaction is continued for 6 hours to obtain a suspension. 50% sodium hydroxide solution is added to neutralize the suspension, and the suspension is washed with clean water. After solid-liquid separation, the solid obtained is a phosphorus-containing bisphenol compound.

[0042] (2) 1 mol of a phosphorus-containing bisphenol compound is mixed with formaldehyde and aniline in a molar ratio of hydroxyl:formaldehyde:amine = 1:2:1, 200 g of an inert solvent, toluene, is added, and the temperature is raised to 110°C for reaction for 6 hours. The solvent is refluxed to separate water until no water is produced. The solvent is evaporated under reduced pressure to obtain a phosphorus-containing benzoxazine resin (Formula 1).

[0043] Example 2

[0044] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 50 parts of a phosphorus-containing benzoxazine resin (Formula 2), 40 parts of a phenol novolac epoxy resin, 10 parts of a phenolic resin, 0.5 parts of 2-methylimidazole, and 50 parts of silica.

[0045] The phosphorus-containing benzoxazine resin (Formula 2) is prepared as follows:

[0046] (1) 1 mol of phosphorus-containing raw material DPO and p-hydroxybenzaldehyde are reacted in 400 g of an inert solvent, toluene, at a molar ratio of 1:1 for 6 hours, 3 mol of phenol are added, and 0.04 mol of hydrochloric acid are added, and the reaction is continued for 4 hours to obtain a suspension; 50% sodium hydroxide solution is added to neutralize the suspension, and the suspension is washed with clean water. After solid-liquid separation, the solid obtained is a phosphorus-containing bisphenol compound;

[0047] (2) The phosphorus-containing bisphenol compound is mixed with formaldehyde and p-tert-butylaniline in a molar ratio of hydroxyl:formaldehyde:amine = 1:2:1, 300 g of an inert solvent, toluene, is added, and the temperature is raised to 120° C. to react for 5 hours. The solvent is refluxed to separate water until no water is produced. The solvent is evaporated to dryness under reduced pressure to obtain a phosphorus-containing benzoxazine resin (Formula 2).

[0048] Example 3

[0049] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 50 parts of a phosphorus-containing benzoxazine resin (Formula 1), 30 parts of a phenol novolac epoxy resin, 10 parts of an isocyanate-modified epoxy resin, 10 parts of a phenolic resin, 0.5 parts of 2-methylimidazole, and 40 parts of silica.

[0050] Example 4

[0051] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 40 parts of a phosphorus-containing benzoxazine resin (Formula 1), 30 parts of a phenol novolac epoxy resin, 30 parts of an isocyanate-modified epoxy resin, 0.5 parts of 2-methylimidazole, and 40 parts of silica.

[0052] Example 5

[0053] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 40 parts of a phosphorus-containing benzoxazine resin (Formula 1), 30 parts of a phenol novolac epoxy resin, 30 parts of an isocyanate-modified epoxy resin, 2 parts of dicyandiamide, 0.5 parts of 2-methylimidazole, and 40 parts of silica.

[0054] Example 6

[0055] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 40 parts of a phosphorus-containing benzoxazine resin (Formula 1), 30 parts of a phenol novolac epoxy resin, 20 parts of a phosphorus-modified epoxy resin (phosphorus content 3.0%), 2 parts of dicyandiamide, 0.5 parts of 2-methylimidazole, and 40 parts of silica.

[0056] Example 7

[0057] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 40 parts of a phosphorus-containing benzoxazine resin (Formula 1), 10 parts of a bisphenol A benzoxazine resin, 30 parts of a phenol novolac epoxy resin, 20 parts of a bisphenol A novolac epoxy resin, 1 part of dicyandiamide, 0.5 parts of 2-methylimidazole, and 40 parts of silica.

[0058] Example 8

[0059] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 40 parts of a phosphorus-containing benzoxazine resin (Formula 1), 10 parts of a bisphenol F benzoxazine resin, 30 parts of a phenol novolac epoxy resin, 20 parts of a bisphenol A novolac epoxy resin, 1 part of dicyandiamide, 0.5 parts of 2-methylimidazole, and 40 parts of silica.

[0060] Example 9

[0061] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 30 parts of a phosphorus-containing benzoxazine resin (Formula 1), 40 parts of a phenol novolac epoxy resin, 10 parts of a bisphenol A novolac epoxy resin, 20 parts of a phosphorus-containing phenolic resin, 0.4 parts of 2-methylimidazole, and 40 parts of silica.

[0062] Example 10

[0063] The only difference from Example 1 is that the phosphorus-containing benzoxazine resin composition comprises the following components, by weight: 40 parts of a phosphorus-containing benzoxazine resin (Formula 1), 20 parts of a diallyl bisphenol A benzoxazine resin, 30 parts of a biphenyl phenol epoxy resin, 10 parts of a styrene-maleic anhydride copolymer, 0.5 parts of 2-methylimidazole, and 60 parts of spherical silica.

[0064] Comparative Example 1

[0065] The only difference from Example 1 is that the resin composition, by weight, comprises the following components: 50 parts of bisphenol A benzoxazine resin, 40 parts of phenol novolac epoxy resin, 10 parts of phenolic resin, 0.5 parts of 2-methylimidazole

[0066] And 50 parts of silicon dioxide.

[0067] Comparative Example 2

[0068] The only difference from Example 1 is that the resin composition, calculated in parts by weight, comprises the following components: 60 parts of bisphenol A epoxy resin, 20 parts of phenolic resin, 1 part of dicyandiamide, 0.5 parts of 2-methylimidazole and 50 parts of silicon dioxide.

[0069] Comparative Example 3

[0070] The only difference from Example 1 is that the resin composition, in parts by weight, comprises the following components: 50 parts of bisphenol A benzoxazine resin, 30 parts of phenol novolac epoxy resin, 30 parts of isocyanate-modified epoxy resin, 0.5 parts of 2-methylimidazole and 50 parts of silica.

[0071] Comparative Example 4

[0072] The only difference from Comparative Example 1 is that the resin composition further comprises the following components in parts by weight: 20 parts of triphenyl phosphate.

[0073] The compositions of the phosphorus-containing benzoxazine resin compositions of Examples 1-10 and Comparative Examples 1-3 are shown in Table 1.

[0074] Table 1 Composition of phosphorus-containing benzoxazine resin composition

[0075]

[0076]

[0077] Test example

[0078] The double-sided copper clad laminates prepared in Examples 1-10 and Comparative Examples 1-4 were subjected to performance tests. The test results are shown in Table 2, wherein the detection methods of the parameters involved are as follows:

[0079] Glass transition temperature (Tg): DMA test is used to measure the glass transition temperature according to the DMA test method specified in IPC-TM-650 2.4.24.4.

[0080] Water absorption is tested according to IPC-TM-650 2.6.2.1 method.

[0081] The coefficient of thermal expansion CET is tested according to IPC-TM-650 2.4.41 method.

[0082] Dielectric constant and dielectric loss factor: Tested in accordance with IPC-TM-650 2.5.5.9, with a test frequency of 5 GHz.

[0083] Flame retardancy: measured according to the flammability test method specified in UL94.

[0084] Table 2 Performance test data

[0085]

[0086]

[0087] No curing agent was added in Example 4, phosphorus-modified epoxy resin was used in Example 6, and phosphorus-containing phenolic resin was used in Example 9, resulting in the glass transition temperature of the prepared copper clad laminate being lower than that in the other examples.

[0088] Comparative Examples 1-3 did not add phosphorus-containing benzoxazine resin, and the copper clad laminates obtained were not flame retardant; Comparative Example 4 added a phosphorus-containing flame retardant, and compared with Examples 1-3, 5, 7-8, and 10, the glass transition temperature was lower, the water absorption was increased, the dielectric constant was higher, and the dielectric loss was also greater.

Claims

1. A phosphorus-containing benzoxazine resin composition, characterized in that The composition is composed of the following components in parts by weight: 10-60 parts of benzoxazine composition, 10-60 parts of epoxy resin, 0-40 parts of curing agent, 0.01-10 parts of accelerator and 0-100 parts of inorganic filler; The benzoxazine composition comprises a benzoxazine resin A, and the benzoxazine resin A comprises a compound represented by formula (2). The compound represented by formula (2) is specifically as follows: Wherein, R is tert-butyl; The weight portion of the benzoxazine resin A is 40-60 parts; The preparation method of the benzoxazine resin A is as follows: (1) reacting diphenylphosphine oxide and p-hydroxybenzaldehyde in a molar ratio of 1:1 in an inert solvent for 2-5 hours, adding phenolic substances 1-5 times the amount of diphenylphosphine oxide, and adding an acidic catalyst, and reacting for 2-10 hours to obtain a suspension; adding alkali solution to neutralize to neutrality, adding clean water for washing, and separating the solid and liquid to obtain a phosphorus-containing bisphenol compound; (2) The phosphorus-containing bisphenol compound is mixed with formaldehyde and a primary amine in a molar ratio of hydroxyl:formaldehyde:amine = 1:2:1, and an inert solvent is added at a molar ratio of 2-8 times that of the phosphorus-containing bisphenol compound. The temperature is raised to 80-150° C. to react for 2-10 hours, and the solvent is refluxed to separate water until no water is produced. The solvent is evaporated under reduced pressure to obtain the phosphorus-containing benzoxazine.

2. The resin composition according to claim 1, wherein The benzoxazine composition further comprises a benzoxazine resin B, wherein the weight proportion of the benzoxazine resin B is 0-40 parts; and / or the benzoxazine resin B is one or more of bisphenol A benzoxazine, bisphenol F benzoxazine, MDA benzoxazine, ODA benzoxazine or diallyl bisphenol A benzoxazine.

3. The resin composition according to claim 1, wherein The epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, bisphenol A novolac epoxy resin, DCPD phenol type epoxy resin, biphenyl phenol type epoxy resin, tetraphenol ethane epoxy resin, trisphenol methane epoxy resin, tetramethyl biphenyl epoxy resin, MDI modified epoxy resin, DOPO modified epoxy resin, DOPO-HQ modified epoxy resin, DOPO-NQ modified epoxy resin, alicyclic epoxy, aliphatic epoxy, hydantoin epoxy or epoxy soybean oil resin.

4. The resin composition according to claim 3, characterized in that The epoxy equivalent of the epoxy resin is 100-800 g / eq.

5. The resin composition according to claim 1, wherein The curing agent includes one or more of dicyandiamide, 4,4-diaminodiphenyl sulfone, phenolic resin, cyanate resin, acid anhydride or styrene maleic anhydride copolymer.

6. The resin composition according to claim 1, characterized in that The accelerator includes one or more of imidazole, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, triphenylphosphine, bicyclic amidine or substituted urea.

7. A prepreg, characterized in that: The invention is prepared from the resin composition according to any one of claims 1 to 6.

8. The prepreg according to claim 7, characterized in that: The prepreg comprises a reinforcing material and the resin composition attached to the reinforcing material after being impregnated and dried.

9. A laminated board, characterized in that: The present invention comprises the prepreg according to any one of claims 7 to 8.

10. Use of the resin composition according to any one of claims 1 to 6, the prepreg according to any one of claims 7 to 8, or the laminate according to claim 9 in the preparation of a printed circuit board.

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