A prepreg, its method of manufacture and use

Abstract

The present application relates to a prepreg, a method for preparing the same and an application thereof, the prepreg comprising a reinforcing material and a resin composition arranged on the reinforcing material; the resin composition comprising a first resin composition and a second resin composition; the first resin composition comprising the following components: phenolic resin, nitrogen-containing flame retardant and phosphorus-containing flame retardant; the second resin composition comprising the following components: epoxy resin, curing agent, halogen-containing flame retardant and antimony-containing flame retardant. The copper-clad laminate prepared from the prepreg has excellent heat resistance, punching property and flame retardancy, and has excellent comprehensive performance.

Description

Technical Field

[0001] This invention relates to the field of copper clad laminate technology, and in particular to a prepreg, its preparation method, and its application. Background Technology

[0002] CEM-1 copper-clad laminate is made by impregnating electronic-grade fiberglass cloth and bleached wood pulp paper with a resin composition for copper-clad laminates to form the face material and core material, which are then covered with copper foil and hot-pressed. With the increasing complexity of circuits in end products becoming more integrated and lead-free, higher demands are placed on the heat resistance and perforation properties of CEM-1 copper-clad laminates. Flame retardancy is one of the essential performance characteristics that CEM-1 copper-clad laminates must meet. Traditional flame retardant methods for halogenated CEM-1 mainly involve adding large amounts of antimony halogen flame retardants. However, this large amount of antimony halogen flame retardants degrades the heat resistance and perforation properties of CEM-1 copper-clad laminates, making it difficult to improve the overall performance of halogenated CEM-1 copper-clad laminates.

[0003] CN113088061A discloses a thermosetting resin composition and prepregs, laminates, and foil-coated laminates using the same. The disclosed thermosetting resin composition comprises the following components in parts by weight: component A, aminosilane, 1-8 parts by weight; component B, modified or unmodified polyolefin resin, 20-70 parts by weight; component C, resin containing at least two maleimide functional groups, 5-50 parts by weight; and component D, acrylic or methacrylic acid-terminated resin, 0-70 parts by weight. The total amount of components A, B, C, and D is 100 parts by weight. However, the laminates made from this composition have poor heat resistance and perforation properties.

[0004] CN111806001A discloses a method for preparing a highly flexible CEM-1 copper-clad laminate with solderability resistance, including steps such as preparing a surface prepreg adhesive, preparing a first-stage resin adhesive for the inner material, preparing a second-stage resin adhesive for the inner material, preparing a prepreg, and hot pressing. A phosphorus-containing flame retardant is added to the first-stage resin adhesive for the inner material, and phosphorus-containing epoxy, nitrogen-containing phenolic resin, and phosphorus- and nitrogen-containing flame retardants are added to the second-stage resin adhesive. Although the first-stage resin adhesive treats the wood pulp paper with phosphorus-containing flame retardant, there is no synergistic effect between phosphorus and nitrogen. The second-stage resin adhesive employs a synergistic effect between phosphorus and nitrogen. Compared with the synergistic effect of bromine and antimony in halogenated systems, the amount of flame retardant added is large, resulting in poor heat resistance and poor solderability of the board, with only 24″-26″ at 288℃.

[0005] In the existing technology, in order to achieve good flame retardancy, a large amount of antimony halogen flame retardant is added to CEM-1 copper clad laminate, which makes it difficult to improve the overall performance of CEM-1 copper clad laminate in terms of heat resistance and perforation.

[0006] In conclusion, developing a prepreg that enables the manufactured copper-clad laminate to possess excellent heat resistance, perforation properties, and flame retardancy, resulting in superior overall performance, is of paramount importance. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a prepreg, its preparation method and application. The copper-clad laminate made from the prepreg has excellent heat resistance, perforation and flame retardancy, and excellent overall performance.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a prepreg comprising a reinforcing material and a resin composition disposed on the reinforcing material;

[0010] The resin composition includes a first resin composition and a second resin composition;

[0011] The first resin composition comprises the following components: phenolic resin, nitrogen-containing flame retardant, and phosphorus-containing flame retardant;

[0012] The second resin composition comprises the following components: epoxy resin, curing agent, halogenated flame retardant, and antimony-containing flame retardant.

[0013] In this invention, phenolic resin, a nitrogen-containing flame retardant, and a phosphorus-containing flame retardant form a first resin composition. The nitrogen-containing flame retardant and the phosphorus-containing flame retardant work synergistically in the phenolic resin to improve the flame retardancy of the first resin composition. Epoxy resin, a curing agent, a halogenated flame retardant, and an antimony-containing flame retardant form a second resin composition. The halogenated flame retardant and the antimony-containing flame retardant work synergistically in the epoxy resin to improve the flame retardancy of the second composition. The first resin composition and the second resin composition work together to form a prepreg. The copper-clad laminate made from this prepreg exhibits excellent heat resistance, perforation properties, and flame retardancy, resulting in superior overall performance.

[0014] Preferably, the first resin composition and the second composition are sequentially disposed on the reinforcing material.

[0015] Preferably, the mass ratio of the first resin composition to the second resin composition is 1:(8-12), wherein 8-12 can be 9, 10, 11, etc.

[0016] Preferably, the reinforcing material comprises wood pulp paper and / or cotton pulp paper.

[0017] In this invention, the first resin composition and the second resin composition, in a system using wood pulp paper and / or cotton pulp paper as reinforcing materials, can achieve excellent flame retardancy without compromising the perforation and heat resistance of the copper-clad laminate produced.

[0018] Preferably, the first resin composition comprises the following components in parts by weight:

[0019] 100 parts of phenolic resin

[0020] 5-10 parts of nitrogen-containing flame retardant

[0021] 10-20 parts of phosphorus-containing flame retardant.

[0022] In this invention, nitrogen-containing flame retardants and phosphorus-containing flame retardants are used in combination at specific addition amounts in the first resin composition. With a small addition amount, the two can replace a large amount of halogenated flame retardants and antimony-containing flame retardants, thus avoiding the loss of perforation and heat resistance of the copper-clad laminate due to excessive addition of flame retardants.

[0023] In this invention, the nitrogen-containing flame retardant is present in 5-10 parts by weight, such as 6 parts, 7 parts, 8 parts, 9 parts, etc.

[0024] The phosphorus-containing flame retardant is present in parts by weight of 10-20, such as 12, 14, 16, or 18 parts.

[0025] Preferably, the second resin composition comprises the following components in parts by weight:

[0026]

[0027] In this invention, halogenated flame retardants and antimony-containing flame retardants are used in combination at specific addition amounts in the second resin composition, which further improves the overall performance of the copper-clad laminate made from the prepreg.

[0028] In this invention, the curing agent is in the form of 30-80 parts by weight, such as 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, etc.

[0029] The halogenated flame retardant is present in parts by weight of 10-30, such as 15, 20, or 25 parts.

[0030] The antimony-containing flame retardant is present in parts by weight of 5-15, such as 6, 8, 10, 12, or 14 parts.

[0031] Preferably, the phenolic resin includes an aqueous phenolic resin.

[0032] Preferably, the number average molecular weight of the phenolic resin is 1000-2000 g / mol, such as 1200 g / mol, 1400 g / mol, 1600 g / mol, 1800 g / mol, etc.

[0033] Preferably, the nitrogen-containing flame retardant includes nitrogen-containing flame retardants.

[0034] Preferably, the nitrogen-containing flame retardant includes any one or a combination of at least two of vinyl isocyanate, melamine-glyoxal resin, melamine-formaldehyde resin, methylated melamine resin, butylated melamine resin, triisocyanate-modified melamine resin, or silicone-modified melamine resin. Typical but non-limiting combinations include: combinations of vinyl isocyanate, melamine-glyoxal resin, and melamine-formaldehyde resin; combinations of methylated melamine resin, butylated melamine resin, triisocyanate-modified melamine resin, and silicone-modified melamine resin; and combinations of vinyl isocyanate, melamine-glyoxal resin, melamine-formaldehyde resin, methylated melamine resin, butylated melamine resin, triisocyanate-modified melamine resin, and silicone-modified melamine resin, etc.

[0035] Preferably, the phosphorus-containing flame retardant includes a water-based phosphorus-containing flame retardant.

[0036] Preferably, the phosphorus-containing flame retardant includes any one or a combination of at least two of alkoxycyclotriphosphazene, phenoxycyclotriphosphazene, hexa-p-aldehyde phenoxycyclotriphosphazene, hexa(4-DOPO hydroxymethylphenoxy)cyclotriphosphazene, (2-allylphenoxy)pentaphenoxycyclotriphosphazene, or hexa(4-nitrophenoxy)cyclotriphosphazene. Typical but non-limiting combinations include: a combination of alkoxycyclotriphosphazene and phenoxycyclotriphosphazene; a combination of hexa-p-aldehyde phenoxycyclotriphosphazene, hexa(4-DOPO hydroxymethylphenoxy)cyclotriphosphazene, and (2-allylphenoxy)pentaphenoxycyclotriphosphazene; a combination of hexa(4-DOPO hydroxymethylphenoxy)cyclotriphosphazene, (2-allylphenoxy)pentaphenoxycyclotriphosphazene, and hexa(4-nitrophenoxy)cyclotriphosphazene, etc.

[0037] Preferably, the epoxy resin includes any one or a combination of at least two of the following: biphenyl / pyrrolidone type phenolic epoxy resin, phenol linear phenolic epoxy resin, o-cresol linear phenolic epoxy resin, melamine tricyanate epoxy resin, p-aminophenol epoxy resin, and diaminodiphenylmethane epoxy resin. Typical but non-limiting combinations include: a combination of biphenyl / pyrrolidone type phenolic epoxy resin and phenol linear phenolic epoxy resin; a combination of o-cresol linear phenolic epoxy resin, melamine tricyanate epoxy resin, p-aminophenol epoxy resin, and diaminodiphenylmethane epoxy resin; and a combination of biphenyl / pyrrolidone type phenolic epoxy resin, phenol linear phenolic epoxy resin, o-cresol linear phenolic epoxy resin, melamine tricyanate epoxy resin, p-aminophenol epoxy resin, and diaminodiphenylmethane epoxy resin, etc.

[0038] Preferably, the curing agent comprises any one or a combination of at least two of vegetable oil-modified phenolic resin, linear phenolic resin, or thermosetting phenolic resin, wherein typical but non-limiting combinations include: a combination of vegetable oil-modified phenolic resin and linear phenolic resin, a combination of linear phenolic resin and thermosetting phenolic resin, a combination of vegetable oil-modified phenolic resin, linear phenolic resin, and thermosetting phenolic resin, etc.

[0039] Preferably, the halogenated flame retardant includes any one or a combination of at least two of tetrabromobisphenol A, tribromophenol, decabromodiphenyl ethane, or octabromodiphenyl ethane, wherein typical but non-limiting combinations include: a combination of tetrabromobisphenol A and tribromophenol, a combination of tribromophenol, decabromodiphenyl ethane, and octabromodiphenyl ethane, a combination of tetrabromobisphenol A, tribromophenol, decabromodiphenyl ethane, and octabromodiphenyl ethane, etc.

[0040] Preferably, the antimony-containing flame retardant is any one or a combination of at least two of antimony oxide, antimony halide, or antimonate, wherein typical but non-limiting combinations include: a combination of antimony oxide and antimony halide, a combination of antimony halide and antimonate, a combination of antimony oxide, antimony halide, and antimonate, etc.

[0041] Preferably, the second resin composition further includes a curing accelerator.

[0042] Preferably, the curing accelerator comprises any one or a combination of at least two of tertiary amines, tertiary phosphines, organometallic complexes, quaternary ammonium salts, or imidazole compounds. Typical but non-limiting combinations include: combinations of tertiary amines and tertiary phosphines, combinations of organometallic complexes, quaternary ammonium salts, and imidazole compounds, and combinations of tertiary amines, tertiary phosphines, organometallic complexes, quaternary ammonium salts, and imidazole compounds, etc.

[0043] Preferably, the curing accelerator is ≤1 part by weight, for example, 0.8 parts, 0.6 parts, 0.4 parts, 0.2 parts, etc.

[0044] In a second aspect, the present invention provides a method for preparing the prepreg described in the first aspect, the method comprising the following steps:

[0045] The reinforcing material is impregnated in a liquid containing the resin composition and dried to obtain the prepreg.

[0046] Preferably, the preparation method specifically includes:

[0047] (1) Phenolic resin, nitrogen-containing flame retardant and phosphorus-containing flame retardant are mixed in a solvent to form a first adhesive solution;

[0048] Epoxy resin, curing agent, halogenated flame retardant and antimony-containing flame retardant are mixed in a solvent to form a second adhesive solution;

[0049] (2) The reinforcing material is immersed in the first adhesive solution and dried to obtain the first adhesive sheet;

[0050] (3) The first adhesive sheet is immersed in the second adhesive solution and dried to obtain the prepreg.

[0051] In this invention, the first resin composition and the second resin composition work together to directly flame-retardant the reinforcing material, and the resulting prepreg copper-clad laminate has excellent heat resistance, perforation and flame retardancy, and excellent overall performance.

[0052] Preferably, the solvents used in the first and second adhesive solutions each independently include acetone and / or methyl ethyl ketone.

[0053] Preferably, the solid content of the first adhesive is 10%-30%, such as 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, etc.

[0054] Preferably, the solid content of the second adhesive is 50%-70%, such as 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, etc.

[0055] Preferably, the drying temperatures in steps (2) and (3) are each independently 150℃-220℃ and 120℃-190℃, for example 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, etc.

[0056] Preferably, the drying times in steps (2) and (3) are 3 min-5 min (e.g., 3.5 min, 4 min, 4.5 min, etc.) and 2 min-4 min (e.g., 2.5 min, 3 min, 3.5 min, etc.), respectively.

[0057] Thirdly, the present invention provides a copper-clad laminate comprising at least one (e.g., 2, 4, 6, 8, etc.) prepreg as described in the first aspect and copper foil covering one or both sides of the prepreg after stacking.

[0058] Fourthly, the present invention provides a printed circuit board comprising at least one (e.g., 2, 4, 6, 8, etc.) copper-clad laminate as described in the third aspect.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] (1) The copper-clad laminate made from the prepreg described in this invention has excellent heat resistance, perforation and flame retardancy, and excellent overall performance.

[0061] (2) Within the preferred range, the thermal stress (288°C, floating solder) of the copper-clad laminate formed by the prepreg material of the present invention is above 125s, the perforation meets level 5, and the flame retardancy can reach level V-0. Detailed Implementation

[0062] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0063] In this invention, the procurement information of some raw materials in each embodiment is as follows:

[0064] A: Waterborne phenolic resin, named waterborne phenol-formaldehyde resin, with a number-average molecular weight of 300-500 g / mol, purchased from Shandong Shengquan New Material Co., Ltd., brand name SQ-9322;

[0065] B1: Nitrogen-containing flame retardant, named melamine-formaldehyde resin, purchased from Dalian Jinxin Chemical Co., Ltd., brand name JX-2533;

[0066] B2: Nitrogen-containing flame retardant, named vinyl isocyanate, purchased from Hubei Jusheng Technology Co., Ltd., brand name JS-5634;

[0067] B3: Nitrogen-containing flame retardant, named methylated melamine resin, purchased from Foshan Weng Kai'er, brand name CYMEL303LF;

[0068] C1: Phosphorus-containing flame retardant, named phenoxycyclotriphosphazene, purchased from Hubei Yuancheng Saichuang Technology Co., Ltd., brand name SPB-100;

[0069] C2: Phosphorus-containing flame retardant, named hexa-para-aldehyde phenoxycyclotriphosphazene, purchased from Jiangsu Tiancheng Chemical Co., Ltd., brand name TC-130;

[0070] C3: Phosphorus-containing flame retardant, named hexa(4-DOPO hydroxymethylphenoxy)cyclotriphosphazene, purchased from Wuhan Haishan Technology Co., Ltd., brand name GC-PNP;

[0071] D1: Epoxy resin, named biphenyl phenolic epoxy resin, purchased from Hongchang Electronic Materials Co., Ltd., brand name GELR134;

[0072] D2: Epoxy resin, named phenolic linear phenolic epoxy resin, purchased from Jinan Kangyu New Materials Co., Ltd., brand name BN-57;

[0073] D3: Epoxy resin, named o-cresol linear phenolic epoxy resin, purchased from Wuhan Jiyesheng Chemical Co., Ltd., grade LP-39;

[0074] E: Curing agent, named linear phenolic resin, purchased from Zhangjiagang Yarui Chemical Co., Ltd., brand name ZP150;

[0075] F1: Halogenated flame retardant, named decabromodiphenyl ethane, purchased from Chengdu Jiaye Biotechnology Co., Ltd., brand name ZK-500;

[0076] F2: Halogenated flame retardant, named tetrabromobisphenol A, purchased from Laizhou Dilong Chemical Co., Ltd., brand name BC-52;

[0077] F3: Halogenated flame retardant, named tribromophenol, purchased from Qianyan Chemical Technology (Wuhan) Co., Ltd., brand name ZX-45;

[0078] G1: Antimony-containing flame retardant, named antimony pentoxide, purchased from Wuhan Xinghe Chemical Co., Ltd., brand name SD-405;

[0079] G2: Antimony-containing flame retardant, named antimony pentoxide, purchased from Zhangjiagang Yarui Chemical Co., Ltd., brand name ZP530;

[0080] G3: Antimony-containing flame retardant, named sodium antimonate, purchased from Hubei Yongcheng Industrial Co., Ltd., brand name YC-278;

[0081] H: Curing accelerator, named 2-methylimidazole, purchased from Hubei Xingyinhe Chemical Co., Ltd., brand name TD-230.

[0082] Examples 1-16 and Comparative Examples 1-6

[0083] Examples 1-16 and Comparative Examples 1-6 provide a prepreg comprising a reinforcing material and a resin composition disposed on the reinforcing material; the resin composition comprises a first resin composition and a second resin composition, formulated in parts by weight as shown in Tables 1-3.

[0084] Table 1

[0085]

[0086]

[0087] Table 2

[0088]

[0089]

[0090] Table 3

[0091]

[0092]

[0093] The prepregs described in Examples 1-16 and Comparative Examples 1-6 were obtained by the following preparation method, which includes the following steps:

[0094] (1) Phenolic resin, nitrogen-containing flame retardant and phosphorus-containing flame retardant are mixed, and the solid content of the solution is adjusted to 20% by using acetone as solvent to form the first adhesive solution;

[0095] Epoxy resin, curing agent, halogenated flame retardant and antimony-containing flame retardant are mixed, and the solid content of the solution is adjusted to 60% using acetone as a solvent to form a second adhesive solution.

[0096] (2) The reinforcing material is immersed in the first adhesive solution, and the drying temperature and time are 200℃ and 4min to obtain the first adhesive sheet;

[0097] (3) The first adhesive sheet is immersed in the second adhesive solution and dried at 180°C for 3 minutes to obtain the prepreg as the CEM-1 core adhesive sheet. The mass ratio of the first resin composition and the second resin composition is 1:10.

[0098] Example 17

[0099] The difference between this embodiment and Example 1 is that the first resin composition and the second resin composition are directly mixed and then impregnated and dried once; the rest is the same as in Example 1.

[0100] The prepreg is obtained by the following preparation method, which includes the following steps:

[0101] (1) Phenolic resin, nitrogen-containing flame retardant and phosphorus-containing flame retardant are mixed, and the solid content of the solution is adjusted to 20% by using acetone as solvent to form the first adhesive solution;

[0102] Epoxy resin, curing agent, halogenated flame retardant and antimony-containing flame retardant are mixed, and the solid content of the solution is adjusted to 60% using acetone as a solvent to form a second adhesive solution.

[0103] (2) The reinforcing material is immersed in a mixture of the first adhesive and the second adhesive, and dried to obtain the prepreg, which is used as the CEM-1 core bonding sheet.

[0104] Example 18

[0105] The difference between this embodiment and Embodiment 1 lies in the impregnation sequence, as detailed below:

[0106] (1) Phenolic resin, nitrogen-containing flame retardant and phosphorus-containing flame retardant are mixed, and the solid content of the solution is adjusted to 20% by using acetone as solvent to form the first adhesive solution;

[0107] Epoxy resin, curing agent, halogenated flame retardant and antimony-containing flame retardant are mixed, and the solid content of the solution is adjusted to 60% using acetone as a solvent to form a second adhesive solution.

[0108] (2) The reinforcing material is immersed in the second adhesive solution and dried to obtain the first adhesive sheet;

[0109] (3) The first adhesive sheet is immersed in the first adhesive solution and dried to obtain the prepreg, which is used as the CEM-1 core adhesive sheet.

[0110] The resin compositions described in Examples 1-18 and Comparative Examples 1-6 were prepared into copper-clad laminates, which were prepared by the following method:

[0111] The resin composition is mixed with the solvent methyl ethyl ketone (MEK), and then the adhesive solution is impregnated with wood pulp paper. After drying in an oven, a core material semi-cured sheet is obtained. The core material semi-cured sheet is placed on the inner side and the fabric is placed on the outer side. Five core material bonding sheets are then stacked together. Copper foil is then placed on the outer side of the fabric semi-cured sheet. The sheets are hot-pressed at 160°C and 5 MPa for 120 minutes to obtain a 1.6 mm thick copper-clad laminate.

[0112] Performance testing

[0113] The copper-clad laminates made from the prepregs described in Examples 1-18 and Comparative Examples 1-6 were subjected to the following tests:

[0114] (1) Thermal stress: The thermal stress test method specified in GT / T 4722-2017 shall be used for determination;

[0115] (2) Punching performance: The punching performance shall be determined in accordance with the punching performance test method specified in GT / T 4722-2017;

[0116] (3) Flame retardancy: Tested according to UL94 “50W (20mm) vertical burning test: V-0, V-1 and V-2” test method.

[0117] The test results are summarized in Table 4.

[0118] Table 4

[0119]

[0120]

[0121] Analysis of the data in Table 4 shows that the thermal stress (288℃, floating solder) of the copper-clad laminate formed by the prepreg of the present invention is above 65s, the perforation performance meets level 4, and the flame retardancy reaches level V-1 or above. Within the preferred range, the thermal stress (288℃, floating solder) of the copper-clad laminate formed by the prepreg of the present invention is above 124s, the perforation performance meets level 5, and the flame retardancy reaches level V-0. The copper-clad laminate made from the prepreg of the present invention possesses excellent heat resistance, perforation performance, and flame retardancy, exhibiting superior overall performance.

[0122] Analysis of Examples 1-8 and Comparative Examples 1-2 shows that the flame retardancy of Comparative Example 1 is only comparable to that of Examples 1-8 after a significant increase in the amount of bromine-antimony flame retardant, and its thermal stress is significantly worse; the flame retardancy of Comparative Example 2 is even worse than that of Examples 1-8, and its thermal stress is significantly worse; this proves that in the prepreg of the present invention, the combined use of the first resin composition and the second resin composition results in better overall performance.

[0123] Analysis of Example 1 and Comparative Examples 3-4 shows that the performance of Comparative Examples 3-4 is not as good as that of Example 1, proving that the combination of nitrogen-containing flame retardant and phosphorus-containing flame retardant in the first resin composition has a better overall performance due to their synergistic effect.

[0124] Analysis of Example 1 and Comparative Examples 5-6 shows that the performance of Comparative Examples 5-6 is not as good as that of Example 1, proving that the combination of halogenated flame retardant and antimony-containing flame retardant in the second resin composition results in a better overall performance of the prepreg formed by their synergistic effect.

[0125] Analysis of Examples 1 and 9-10 shows that the flame retardancy or heat resistance of Examples 9-10 is not as good as that of Example 1, proving that the performance of the nitrogen-containing flame retardant in the prepreg of the present invention is better when the weight part of the nitrogen-containing flame retardant is in the range of 5-10 parts.

[0126] Analysis of Examples 3 and 11-12 shows that the flame retardancy or heat resistance of Examples 11-12 is not as good as that of Example 3, proving that the performance of the phosphorus-containing flame retardant in the prepreg of the present invention is better when the weight part of the phosphorus-containing flame retardant is in the range of 10-20 parts.

[0127] Analysis of Examples 4 and 13-14 shows that the flame retardancy or heat resistance of Examples 13-14 is not as good as that of Example 4, proving that the performance of the prepreg containing bromine flame retardant is better when the weight part is in the range of 10-30 parts.

[0128] Analysis of Examples 5 and 15-16 shows that the flame retardancy or perforation properties of Examples 13-14 are not as good as those of Example 5, proving that the performance of the prepreg containing antimony flame retardant is better when the weight part is in the range of 5-15 parts.

[0129] Analysis of Examples 1 and 17-18 shows that the flame retardancy or heat resistance of Examples 17-18 is not as good as that of Example 1, proving that the prepreg of the present invention has better performance when the first resin composition and the second resin composition are impregnated in sequence, that is, when the first resin composition and the second composition are sequentially disposed on the reinforcing material.

[0130] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A prepreg, characterized in that, The prepreg includes a reinforcing material and a resin composition disposed on the reinforcing material; The resin composition includes a first resin composition and a second resin composition; The first resin composition comprises the following components in parts by weight: 100 parts of phenolic resin, 5-10 parts of nitrogen-containing flame retardant, and 10-20 parts of phosphorus-containing flame retardant; The second resin composition comprises the following components in parts by weight: 100 parts epoxy resin, 30-80 parts curing agent, 10-30 parts halogenated flame retardant and 5-15 parts antimony-containing flame retardant; The first resin composition and the second composition are sequentially disposed on the reinforcing material; The mass ratio of the first resin composition to the second resin composition is 1:(8-12). The prepreg is prepared by the following method, the method comprising: (1) Phenolic resin, nitrogen-containing flame retardant and phosphorus-containing flame retardant are mixed and a first adhesive solution is formed in a solvent; Epoxy resin, curing agent, halogenated flame retardant and antimony-containing flame retardant are mixed in a solvent to form a second adhesive solution; (2) The reinforcing material is immersed in the first adhesive solution and dried to obtain the first adhesive sheet; (3) The first adhesive sheet is immersed in the second adhesive solution and dried to obtain the prepreg.

2. The prepreg according to claim 1, characterized in that, The reinforcing material includes wood pulp paper and / or cotton pulp paper.

3. The prepreg according to claim 1, characterized in that, The phenolic resin includes water-based phenolic resin.

4. The prepreg according to claim 1, characterized in that, The number average molecular weight of the phenolic resin is 1000-2000 g / mol.

5. The prepreg according to claim 1, characterized in that, The nitrogen-containing flame retardant includes any one or a combination of at least two of the following: vinyl isocyanate, melamine-glyoxal resin, melamine-formaldehyde resin, methylated melamine resin, butylated melamine resin, triisocyanurate-modified melamine resin, or organosilicon-modified melamine resin.

6. The prepreg according to claim 1, characterized in that, The phosphorus-containing flame retardant includes any one or a combination of at least two of alkoxycyclotriphosphazene, phenoxycyclotriphosphazene, hexa-p-aldehyde phenoxycyclotriphosphazene, hexa(4-DOPO hydroxymethylphenoxy)cyclotriphosphazene, (2-allylphenoxy)pentaphenoxycyclotriphosphazene, or hexa(4-nitrophenoxy)cyclotriphosphazene.

7. The prepreg according to claim 1, characterized in that, The epoxy resin includes any one or a combination of at least two of the following: biphenyl-type phenolic epoxy resin, pyromellitic phenolic epoxy resin, linear phenolic epoxy resin, o-cresol linear phenolic epoxy resin, triglycidylamine cyanurate epoxy resin, p-aminophenol epoxy resin, and diaminodiphenylmethane epoxy resin.

8. The prepreg according to claim 1, characterized in that, The curing agent includes any one or a combination of at least two of vegetable oil-modified phenolic resins, linear phenolic resins, or thermosetting phenolic resins.

9. The prepreg according to claim 1, characterized in that, The halogenated flame retardant includes any one or a combination of at least two of tetrabromobisphenol A, tribromophenol, decabromodiphenyl ethane, or octabromodiphenyl ethane.

10. The prepreg according to claim 1, characterized in that, The antimony-containing flame retardant is any one or a combination of at least two of antimony oxide, antimony halide, or antimonate.

11. The prepreg according to claim 1, characterized in that, The second resin composition also includes a curing accelerator.

12. The prepreg according to claim 11, characterized in that, The curing accelerator includes any one or a combination of at least two of the following: tertiary amines, tertiary phosphines, organometallic complexes, quaternary ammonium salts, or imidazole compounds.

13. The prepreg according to claim 11, characterized in that, The curing accelerator is ≤1 part by weight.

14. A method for preparing the prepreg according to any one of claims 1-13, characterized in that, The preparation method includes the following steps: (1) Phenolic resin, nitrogen-containing flame retardant and phosphorus-containing flame retardant are mixed and a first adhesive solution is formed in a solvent; Epoxy resin, curing agent, halogenated flame retardant and antimony-containing flame retardant are mixed in a solvent to form a second adhesive solution; (2) The reinforcing material is immersed in the first adhesive solution and dried to obtain the first adhesive sheet; (3) The first adhesive sheet is immersed in the second adhesive solution and dried to obtain the prepreg.

15. A copper-clad laminate, characterized in that, The copper-clad laminate comprises at least one stacked prepreg as described in any one of claims 1-13 and copper foil covering one or both sides of the stacked prepreg.

16. A printed circuit board, characterized in that, The printed circuit board includes at least one copper-clad laminate as described in claim 15.

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