CN116082605A - A modified epoxy resin and its preparation method and its application in halogen-free high-speed copper-clad laminates - Google Patents

Abstract

The invention relates to the technical field of epoxy resin for electronic circuits, and provides modified epoxy resin, a preparation method thereof and application thereof in halogen-free high-speed copper-clad plates. The modified epoxy resin provided by the invention comprises a material A and a material B; the preparation method of the material A comprises the following steps: mixing novolac epoxy resin, a reactive flame retardant DOPO and a catalyst for reaction; mixing the obtained reaction liquid with tetrafunctional glycidyl ether and an organic solvent to obtain a material A; the preparation method of the material B comprises the following steps: and mixing the BPA benzoxazine resin, dicyandiamide and an organic solvent to obtain a material B. The modified epoxy resin is obtained through the combination of a plurality of resin systems, the obtained modified epoxy resin does not contain halide, the modified epoxy resin is suitable for preparing halogen-free high-speed copper-clad plates, and the copper-clad plates prepared by using the modified epoxy resin have low dielectric loss and low expansion coefficient, and are good in heat resistance and flame retardance.

Description

A modified epoxy resin and its preparation method and its application in halogen-free high-speed copper-clad laminates

technical field

The invention relates to the technical field of epoxy resins for electronic circuits, in particular to a modified epoxy resin, a preparation method thereof and an application in halogen-free high-speed copper-clad laminates.

Background technique

5G communication, the full name of the fifth-generation mobile phone mobile communication standard, also known as the fifth-generation mobile communication technology. Regardless of the air domain, frequency domain, or time domain, the speed, capacity, density, and delay of 5G communication signal transmission have undergone earth-shaking improvements. With the official landing of 5G commercialization, the market development of printed circuit board (PCB) has brought explosive growth, and new requirements have been put forward for product upgrading or technological innovation. In addition, in recent years, the rise of new technologies such as wearable devices, Internet of Things, artificial intelligence, AR/VR, as well as the improvement of automotive electronics and the increase in demand for new energy vehicles have all made the related technologies and high-speed PCB boards The market has risen further.

With the increasing demand for high confidentiality and high-quality transmission and the development of 4G mobile communication technology, the high-frequency and high-speed field has become a hot spot pursued by copper-clad laminate (CCL) manufacturers, PCB industry and terminal manufacturers. Build basic general-purpose services with core basic capabilities, highly integrate with vertical industries, penetrate into various application scenarios, and promote digital transformation in the real world.

Copper clad laminate (CCL) is one of the key materials of PCB substrate. Copper-clad laminate is a plate-shaped material made by impregnating the reinforcing material with resin, then covering one or both sides with copper foil, and hot pressing; ordinary epoxy resin EP-based CCL (FR-4 or FR-5, etc.) It is difficult to meet the high-speed performance requirements. This is because EP itself and the related curing agent molecular structure contain a large number of polar groups (such as hydroxyl, amino, carboxyl, etc.), and there are still a large number of them after curing. The existence of these groups It will affect the dielectric properties of copper clad laminates.

At the same time, with the development of science and information technology in various countries, various electronic products have been produced and used worldwide, and the core part of electronic equipment is the circuit board, but the circuit board and its components will have many harmful effects during the production process. substance. At present, in order to improve the flame retardant coefficient of circuit boards and reduce production costs in the production of many circuit boards in our country, bromine compounds will still be contained in them; the halides will release a large amount of corrosive and harmful gases during the combustion process, not only It pollutes the environment and endangers human health.

Therefore, there is an urgent need to provide an epoxy resin that does not contain halides and is suitable for high-speed copper clad laminates.

Contents of the invention

In view of this, the present invention provides a modified epoxy resin, a preparation method thereof, and an application in halogen-free high-speed copper-clad laminates. The modified epoxy resin provided by the invention does not contain halides, and when it is applied to high-speed copper-clad laminates, the obtained board has low dielectric loss and low expansion coefficient, and can meet the use requirements of high-speed copper-clad laminates.

In order to achieve the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A kind of preparation method of modified epoxy resin, described modified epoxy resin comprises A material and B material; The preparation method of described A material comprises the following steps:

Mix novolac epoxy resin, reactive flame retardant DOPO and catalyst for reaction; mix the obtained reaction liquid with tetrafunctional glycidyl ether and organic solvent to obtain material A;

The preparation method of the B material comprises the following steps: mixing BPA type benzoxazine resin, dicyandiamide and an organic solvent to obtain the B material.

Preferably, the mass ratio of the novolac epoxy resin to the reactive flame retardant DOPO is 1:0.2 to 0.5;

The catalyst includes one or more of triphenylsulfone, tetramethylammonium chloride and ethyltriphenylphosphorus iodide; the quality of the catalyst is 0.8% to 10% of the mass of the reactive flame retardant DOPO;

The mass of the tetrafunctional glycidyl ether is 5-20% of the mass of the novolac epoxy resin.

Preferably, the organic solvent used in the A material and the B material independently includes one or more of butanone, propylene glycol methyl ether and propylene glycol methyl ether acetate; the quality of the organic solvent used in the A material is 20-40% of the total mass of novolac epoxy resin and tetrafunctional glycidyl ether.

Preferably, the temperature of the reaction is 155-160°C; the reaction is carried out in a protective atmosphere.

Preferably, the reaction of mixing the novolac epoxy resin, the reactive flame retardant DOPO and the catalyst specifically includes: heating the novolac epoxy resin to 110-120°C, and then adding the first part of the reactive flame retardant DOPO, After the reactive flame retardant DOPO is dissolved, add the catalyst, raise the temperature to 155-160°C, and keep warm for the first stage of reaction. After the first stage of reaction is completed, add the second part of the reactive flame retardant DOPO. Insulate and carry out the second stage reaction; the time of the first stage reaction is 40-100 minutes, and the time of the second stage reaction is 120-200 minutes.

Preferably, the mass ratio of the BPA-type benzoxazine resin to dicyandiamide is 4:0.5-2.

Preferably, the mixing of the BPA-type benzoxazine resin, dicyandiamide and an organic solvent specifically includes: dissolving the BPA-type benzoxazine resin and dicyandiamide in an organic solvent respectively to obtain the BPA-type benzoxazine resin solution and dicyandiamide solution, and then the BPA type benzoxazine resin solution and dicyandiamide solution are mixed.

The present invention also provides the modified epoxy resin prepared by the preparation method described in the above scheme, including material A and material B which are separately packaged.

The present invention also provides the application of the modified epoxy resin described in the above proposal in a halogen-free high-speed copper-clad laminate.

Preferably, during the application, the mass ratio of material A and material B in the modified epoxy resin is 4:0.8-1.5.

The present invention provides a kind of preparation method of modified epoxy resin, described modified epoxy resin comprises A material and B material; The preparation method of described A material comprises the following steps: novolak epoxy resin, reaction The fuel DOPO and the catalyst are mixed for reaction; the obtained reaction liquid is mixed with tetrafunctional glycidyl ether and organic solvent to obtain material A; the preparation method of material B comprises the following steps: mixing BPA type benzoxazine resin, dicyandiamide The amine is mixed with an organic solvent to obtain material B. The present invention adopts novolac epoxy resin and four-functional glycidyl ether as the main raw materials to prepare material A, each resin has good compatibility and good wettability with glass fiber; the present invention adopts reactive flame retardant DOPO modified novolac epoxy resin to improve flame retardancy; in addition, the present invention adopts BPA type benzoxazine resin and dicyandiamide as curing agent, the combination of BPA type benzoxazine resin and tetrafunctional glycidyl ether It can form a network-like stable structure in the system, combined with the combined curing of dicyandiamide, it can further stabilize the structure of the cured product; and the BPA type benzoxazine resin has a low expansion coefficient and high heat resistance The four-functional glycidyl ether has a symmetrical structure and can reduce the overall polarity. In summary, the present invention adopts the combination of various resin systems to obtain modified epoxy resin, and the resin system does not contain halides, and has good fluidity at room temperature. The modified epoxy resin of the present invention is applied to high-speed Among copper clad laminates, it can meet the technical requirements of copper clad laminates, and the obtained board meets the requirements of ROSH and REACH.

In addition, the raw materials used in the present invention are all domestically produced, easy to obtain, and low in cost.

The results of the examples show that the copper-clad laminates prepared by the modified epoxy resin of the present invention have lower dielectric loss and lower expansion coefficient, can meet the requirements of high-speed boards, and the heat resistance and flame retardancy of the boards good.

Detailed ways

The invention provides a method for preparing a modified epoxy resin. The modified epoxy resin includes material A and material B.

The preparation methods of material A and material B are described in detail below.

Unless otherwise specified, all raw materials used in the present invention are commercially available.

In the present invention, the preparation method of described A material comprises the following steps:

Mix novolak epoxy resin, reactive flame retardant DOPO and catalyst for reaction; mix the obtained reaction liquid with tetrafunctional glycidyl ether and organic solvent to obtain material A.

The invention mixes the novolak epoxy resin, the reactive flame retardant DOPO and the catalyst for reaction. In the present invention, the functionality of the novolac epoxy resin is preferably 2, and the epoxy equivalent is preferably 170 to 180 g/eq. In a specific embodiment of the present invention, the model of the novolac epoxy resin is preferably 638S; the mass ratio of the novolac epoxy resin to the reactive flame retardant DOPO is preferably 1:0.2 to 0.5, more preferably 1:0.3 to 0.4; the chemical name of the reactive flame retardant DOPO is 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; the catalyst preferably includes one or Various; the mass of the catalyst is preferably 0.8-10% of the mass of the reactive flame retardant DOPO, more preferably 1-6%.

In the present invention, the temperature of the reaction is preferably 155-160°C, more preferably 156-158°C; the reaction is preferably carried out in a protective atmosphere, and the protective atmosphere is preferably nitrogen.

In the present invention, the novolak epoxy resin, the reactive flame retardant DOPO and the catalyst are mixed and reacted specifically comprising: heating the novolac epoxy resin to 110-120°C, preferably 113-115°C, and then adding the second Part of the reactive flame retardant DOPO, after the reactive flame retardant DOPO is dissolved, add the catalyst, raise the temperature to 155-160°C, keep warm for the first stage of reaction, after the first stage of reaction is completed, add the second part of the reactive flame retardant DOPO, heat preservation at 155-160°C for the second-stage reaction; the time for the first-stage reaction is preferably 40-100 minutes, more preferably 50-80 minutes, and the time for the second-stage reaction is preferably 120-200 minutes, More preferably 150～180min; In the present invention, the mass ratio of the first partially reactive flame retardant DOPO and the second partially reactive flame retardant DOPO is preferably 2:2～4; DOPO and novolac epoxy react The heat release is relatively large, and the high temperature will affect the quality of the finished product. In the present invention, the reactive flame retardant DOPO is added in two parts, which can avoid excessive heat release during the reaction process and ensure product quality; the present invention uses the reactive flame retardant Introduced into epoxy resin, the epoxy resin itself can directly exert flame retardant properties and heat resistance.

After the reaction is completed, the present invention mixes the obtained reaction liquid with tetrafunctional glycidyl ether and an organic solvent to obtain material A. In the present invention, the mass of the tetrafunctional glycidyl ether is preferably 5-20% of the mass of the novolac epoxy resin, more preferably 10-15%. In the present invention, the structure of the tetrafunctional glycidyl ether is shown in formula I; in a specific embodiment of the present invention, the model of the tetrafunctional glycidyl ether is AG80, purchased from Hubei Zhenzhengfeng New Material Co., Ltd. company.

In the present invention, the organic solvent used in the A material preferably includes one or more of butanone, propylene glycol methyl ether and propylene glycol methyl ether acetate, more preferably butanone; the organic solvent used in the A material The mass of the solvent is preferably 20-40% of the total mass of the novolac epoxy resin and the tetrafunctional glycidyl ether, more preferably 25-35%; the organic solvent plays a role of dilution.

In the present invention, the mixing of the reaction solution, the tetrafunctional glycidyl ether and the organic solvent specifically includes: after the reaction is completed, keeping the reaction solution warm, adding the tetrafunctional glycidyl ether into the reaction reaction solution, and stirring for 30 ~60min, then add organic solvent, stir evenly, then cool down and discharge.

In the present invention, the preparation method of the B material includes the following steps: mixing BPA type benzoxazine resin, dicyandiamide and an organic solvent to obtain the B material. In the present invention, the mass ratio of the BPA-type benzoxazine resin to dicyandiamide is preferably 4:0.5-2, more preferably 4:1-1.5; the organic solvent used in the B material preferably includes butane One or more of ketone, propylene glycol methyl ether and propylene glycol methyl ether acetate; the mixing of BPA type benzoxazine resin, dicyandiamide and organic solvent specifically includes: mixing BPA type benzoxazine resin and bis Cyanamide is dissolved in organic solvent respectively, obtains BPA type benzoxazine resin solution and dicyandiamide solution, then described BPA type benzoxazine resin solution and dicyandiamide solution are mixed; In the present invention, dissolving all The organic solvent for the BPA type benzoxazine resin is more preferably butanone, and the organic solvent for dissolving dicyandiamide is more preferably propylene glycol methyl ether; the mass fraction of the BPA type benzoxazine resin solution is preferably 80%, so The mass fraction of above-mentioned dicyandiamide solution is preferably 10%.

In the present invention, the material B is a curing agent, the material A and material B are packaged separately, and the material A and material B are mixed when used, and will be described in detail later.

The present invention also provides the modified epoxy resin prepared by the preparation method described in the above scheme, including material A and material B which are separately packaged.

The present invention also provides the application of the modified epoxy resin described in the above scheme in halogen-free high-speed copper-clad laminates; high-speed copper-clad laminates refer to substrate materials for high-speed digital circuit boards with low transmission signal loss (DF lower than 0.01) characteristics The present invention has no special requirements for the high-speed copper-clad laminate, and is a high-speed copper-clad laminate well-known to those skilled in the art, and can be specifically a single-sided copper-clad laminate or a double-sided copper-clad laminate; in the present invention, during the application, the modified The mass ratio of material A and material B in the epoxy resin is preferably 4:0.8-1.5, more preferably 4:1-1.2.

In a specific embodiment of the present invention, the preparation method of the high-speed copper-clad laminate preferably includes the following steps: mixing material A and material B uniformly and then aging, coating the aging material on glass fiber cloth and baking, Then the obtained prepreg is cut and laminated to obtain a dielectric layer; the single or double-sided copper foil of the dielectric layer is then pressed together to obtain a copper clad board. In the present invention, the temperature of the slaking is preferably room temperature, and the time is preferably 1.5h; the coating amount of the slaking material on the glass fiber cloth is preferably 0.02g/cm ² ; , Folding and pressing have no special requirements, and methods well known to those skilled in the art can be used.

The technical solutions in the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the following examples, the novolac epoxy resin was purchased from Shandong Deyuan Epoxy Technology Co., Ltd., the model is 638S, DOPO was purchased from Sanhiro, Japan, and the BPA type benzoxazine resin was purchased from Weilin New Material Technology Co., Ltd. Tetrafunctional glycidyl ether was purchased from Hubei Zhenzhengfeng New Material Co., Ltd., model AG80.

Example 1

Under the protection of nitrogen, put 500g of novolac epoxy resin into a four-neck bottle, raise the temperature to 120°C, put in 45g of DOPO, after it is completely dissolved, put in 1g of catalyst triphenylphosphine, raise the temperature to 155-160°C, and keep it warm 1h, then put in DOPO 78g, continue to control the temperature between 155-160°C, keep warm for 3h, put in 50g of tetrafunctional glycidyl ether, stir evenly, put in 220g of methyl ethyl ketone, stir evenly, cool down and discharge to obtain material A.

Example 2

Under the protection of nitrogen, put 513g of novolac epoxy resin into a four-neck bottle, raise the temperature to 120°C, put in 48g of DOPO, after it is completely dissolved, put in 1g of catalyst triphenylphosphine, raise the temperature to 155-160°C, and keep it warm. 1h, put in DOPO75g, continue to control the temperature between 155-160°C, keep warm for 3h, put in 52g of tetrafunctional glycidyl ether, stir evenly, put in 226g of methyl ethyl ketone, stir evenly, cool down and discharge to obtain material A.

Example 3

Under the protection of nitrogen, put 503g of novolac epoxy resin into a four-neck bottle, raise the temperature to 120°C, put in 44g of DOPO, after it is completely dissolved, put in 1g of catalyst triphenylphosphine, raise the temperature to 155-160°C, and keep it warm. 1h, put in DOPO78g, continue to control the temperature between 155-160°C, keep warm for 3h, put in 50g of tetrafunctional glycidyl ether, stir evenly, put in 220g of methyl ethyl ketone, stir evenly, cool down and discharge to obtain material A.

Example 4

Under the protection of nitrogen, put 498g of novolac epoxy resin into a four-neck bottle, raise the temperature to 120°C, put in 44g of DOPO, after it is completely dissolved, put in 1.1g of catalyst triphenylphosphine, raise the temperature to 155-160°C, Keep warm for 1 hour, add 73g of DOPO in the second stage, continue to control the temperature between 155 and 160°C, keep warm for 3 hours, add 52g of four-functional glycidyl ether, stir evenly, add 219g of methyl ethyl ketone, stir evenly, cool down and discharge, and obtain material A.

Example 5

Under the protection of nitrogen, put 523g of novolac epoxy resin into a four-necked bottle, raise the temperature to 120°C, put in 47g of DOPO, after it is completely dissolved, put in 1.2g of catalyst triphenylene, and raise the temperature to between 155-160°C. Keep warm for 1 hour, put in 80g of DOPO, continue to control the temperature between 155-160°C, keep warm for 3 hours, put in 51g of tetrafunctional glycidyl ether, stir evenly, put in 231g of methyl ethyl ketone, stir evenly, then cool down and discharge to obtain material A.

The physical parameters of material A obtained in Examples 1-5 were characterized, and the results are shown in Table 1.

The physical parameter characterizing result of embodiment 1～5 gained A material

According to the data in Table 1, it can be seen that introducing the reactive flame retardant DOPO into the epoxy resin can make the epoxy resin itself directly exert its flame retardant properties and heat resistance. At the same time, it can be found that the resin has good fluidity at 25°C, which is suitable for the process system of copper clad laminates.

Application example

Preparation of material B: Dissolving BPA type benzoxazine resin in butanone solvent to obtain a BPA type benzoxazine resin solution with a mass fraction of 80%, dissolving dicyandiamide in propylene glycol methyl ether solution to obtain mass A dicyandiamide solution with a fraction of 10% is mixed with a BPA type benzoxazine resin solution and a dicyandiamide solution to obtain material B, wherein the mass ratio of the BPA type benzoxazine resin to dicyandiamide is 4:1.

Copper-clad laminates were prepared by using material A prepared in Examples 1-5 and material B prepared by the above method; the specific plate making process is as follows: mix resin material A and material B according to the mass ratio of 4:1.2, mix evenly and then mature for 1.5h, And evenly coated on the glass fiber cloth (avoid air bubbles when coating, based on the weight of the prepreg, the coating amount of the cured material is 0.02g/cm ² ), after baking in the oven, cut, laminate, and coat on one side Copper lamination makes single-sided copper clad laminate.

Bismalimide resin was used as a comparative example, and a copper clad laminate was prepared by the same method.

Perform performance test on the prepared copper clad laminate, the specific test method is as follows:

Glass transition temperature (T _g ): DSC differential scanning calorimeter (Q20 type, American TA Company) was used to test, the heating rate was 30°C/min, and the temperature range was 30-160°C;

Thermal stability (5% T _d ): use a thermogravimetric analyzer (4000 type, American PE company) to test, nitrogen atmosphere, raise the temperature from 30°C to 850°C at a heating rate of 10°C/min, and keep it at 850°C 5min;

Flame retardancy: Use a plastic combustion tester (TZ5061A type, UL-94 standard), mainly to investigate the flame duration in the vertical combustion test;

Heat resistance: using MD-C150 tin melting furnace, the test temperature is 288°C, mainly to investigate the stability of the copper clad laminate under T288 thermal shock, and record the holding time of the plate without cracking or warping at 288°C.

In addition, the DK value and DF value of the copper clad laminate are tested.

The test results are shown in Table 2.

Table 2 Copper Clad Laminate Performance Test Results

Test items Example 1 Example 2 Example 3 Example 4 Example 5 comparative example <![CDATA[T_g/℃]]> 223.7 219.5 226.4 225.1 222.6 216.5 <![CDATA[5%T_d/°C]]> 349 351 351 348 349 347 flame retardant V0 V0 V0 V0 V0 V0 heat resistance/sec 75 73 80 79 76 65 DK (1GHZ) 3.96 3.94 3.96 3.90 3.94 4.1 DF (1GHZ) 0.009 0.007 0.007 0.008 0.007 0.019

According to the data in Table 2, it can be concluded that the dielectric constant, dielectric loss and heat resistance of the copper-clad laminate prepared by the modified epoxy resin of the present invention are better than those of similar comparative examples in the market, and have excellent flame retardancy and Higher glass transition temperature; the modified epoxy resin of the present invention is suitable for high-speed copper-clad laminates, and all raw materials are from domestic manufacturers, which is easy to obtain and has broad application prospects.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. a preparation method of modified epoxy resin, is characterized in that, described modified epoxy resin comprises A material and B material; The preparation method of described A material comprises the following steps: Mix novolak epoxy resin, reactive flame retardant DOPO and catalyst for reaction; mix the obtained reaction solution with tetrafunctional glycidyl ether and organic solvent to obtain material A; The preparation method of the B material comprises the following steps: mixing BPA type benzoxazine resin, dicyandiamide and an organic solvent to obtain the B material. 2. preparation method according to claim 1, is characterized in that, the mass ratio of described novolac epoxy resin and reactive flame retardant DOPO is 1:0.2～0.5; The catalyst includes one or more of triphenylsulfone, tetramethylammonium chloride and ethyltriphenylphosphorus iodide; the quality of the catalyst is 0.8% to 10% of the mass of the reactive flame retardant DOPO; The mass of the tetrafunctional glycidyl ether is 5-20% of the mass of the novolac epoxy resin. 3. preparation method according to claim 1, is characterized in that, the organic solvent used in described A material and B material independently comprises one or more in butanone, propylene glycol methyl ether and propylene glycol methyl ether acetate ; The quality of the organic solvent used in the A material is 20% to 40% of the total mass of novolac epoxy resin and tetrafunctional glycidyl ether. 4. The preparation method according to claim 1, characterized in that, the temperature of the reaction is 155-160° C.; and the reaction is carried out in a protective atmosphere. 5. according to the described preparation method of claim 1 or 4, it is characterized in that, said novolac epoxy resin, reactive flame retardant DOPO and catalyst are mixed and reacted specifically comprising: novolac epoxy resin is heated to 110 ~120°C, then add the first part of the reactive flame retardant DOPO, add the catalyst after the reactive flame retardant DOPO dissolves, raise the temperature to 155-160°C, keep warm for the first stage of reaction, after the first stage of reaction is completed, add the second The two-part reaction flame retardant DOPO is kept at 155-160° C. for the second-stage reaction; the time for the first-stage reaction is 40-100 minutes, and the time for the second-stage reaction is 120-200 minutes. 6. The preparation method according to claim 1, characterized in that, the mass ratio of the BPA-type benzoxazine resin to dicyandiamide is 4:0.5-2. 7. The preparation method according to claim 1 or 6, wherein the mixing of BPA type benzoxazine resin, dicyandiamide and organic solvent specifically comprises: mixing BPA type benzoxazine resin and dicyandiamide The amines are respectively dissolved in the organic solvent to obtain a BPA type benzoxazine resin solution and a dicyandiamide solution, and then the BPA type benzoxazine resin solution and the dicyandiamide solution are mixed. 8. The modified epoxy resin prepared by the preparation method according to any one of claims 1 to 7, comprising independently packaged A material and B material. 9. The application of the modified epoxy resin according to claim 8 in halogen-free high-speed copper-clad laminates. 10. The application according to claim 9, characterized in that, during the application, the mass ratio of material A and material B in the modified epoxy resin is 4:0.8-1.5.