阅读说明：本技术 无卤树脂组合物及其制备方法、半固化片及其制备方法、层压板及其制备方法 (Halogen-free resin composition and preparation method thereof, prepreg and preparation method thereof, and laminated board and preparation method thereof ) 是由 邓瑞景 许红卫 窦伟 于 2019-09-27 设计创作，主要内容包括：本发明提供一种无卤树脂组合物,包括如下组分：按照重量份计：环氧树脂300-400份,固化剂A 40-70份,固化剂B 10-30份,无机填料130-200份,固化促进剂0.1-0.8份,偶联剂0.7-1.5份,溶剂150-210份,其中,溶剂以外的组分的含量为60％-75％。采用本发明的无卤树脂组合物,制备的半固化片表面外观平整光滑,加工操作窗口极宽。使用该固化片制备的层压板表面外观缺陷少,尺寸稳定性高,电绝缘性能优异,能够满足高性能印制线路板基材的要求。(The invention provides a halogen-free resin composition, which comprises the following components: the weight portions are as follows: 400 portions of epoxy resin, 40-70 portions of curing agent A, 10-30 portions of curing agent B, 200 portions of inorganic filler, 0.1-0.8 portion of curing accelerator, 0.7-1.5 portions of coupling agent and 210 portions of solvent, wherein, the content of the components except the solvent is 60-75 percent. The prepreg prepared by adopting the halogen-free resin composition has a flat and smooth surface appearance and a very wide processing operation window. The laminated board prepared by using the curing sheet has the advantages of less surface appearance defects, high dimensional stability and excellent electrical insulation performance, and can meet the requirements of high-performance printed circuit board base materials.)

1. A halogen-free resin composition is characterized by comprising the following components:

the weight portions are as follows:

300 portions and 400 portions of epoxy resin,

40-70 parts of a curing agent A,

10-30 parts of a curing agent B,

130 portions and 200 portions of inorganic filler,

0.1 to 0.8 portion of curing accelerator,

0.7 to 1.5 portions of coupling agent,

150 portions of 225 portions of solvent,

wherein, the content of the components except the solvent is 60 to 75 percent.

2. The halogen-free resin composition according to claim 1,

comprises the following components:

the weight portions are as follows:

354 parts of epoxy resin, namely 354 parts of epoxy resin,

41 parts of a curing agent A, namely,

29 parts of a curing agent B, namely,

182 parts of an inorganic filler, namely an inorganic filler,

0.45 part of a curing accelerator,

1.5 parts of a coupling agent,

224 parts of a solvent, namely 224 parts of,

wherein, the content of the components except the solvent is 60 to 75 percent;

preferably, the epoxy resin includes one or a combination of two or more of bisphenol a type epoxy resin, phenol novolac type epoxy resin, bisphenol a phenol novolac type epoxy resin, o-methyl phenol novolac type epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, isocyanate type epoxy resin, tetrafunctional epoxy resin, or phosphorus-containing phenol novolac epoxy resin; further preferably, the phosphorus-containing novolac epoxy resin comprises one or a combination of more than two of DOPO modified novolac epoxy resin, DOPO-HQ modified novolac epoxy resin or DOPO-NQ modified novolac epoxy resin;

preferably, the curing agent A comprises one or a combination of more than two of diaminodiphenyl sulfone, diaminodiphenylmethane, diaminodiphenyl ether, p-xylidine, dicyandiamide, phenol-formaldehyde novolac resin, bisphenol A type phenol-formaldehyde resin or phosphorus-containing phenol-formaldehyde resin; further preferably, the phosphorus-containing phenolic resin comprises one or more of DOPO modified phenolic resin, DOPO-HQ modified phenolic resin or DOPO-NQ modified phenolic resin;

preferably, the curing agent B is an organic phosphorus curing agent, and the structural formula of the curing agent B is as follows:

wherein R1 is an aliphatic group, R2 is an aliphatic group;

preferably, the inorganic filler comprises one or a combination of more than two of silica, magnesium hydroxide, mica powder, kaolin, talcum powder, calcium carbonate or aluminum hydroxide; preferably, the inorganic filler is an inorganic filler subjected to surface treatment by a silane coupling agent;

preferably, the halogen-free resin composition further comprises a flame retardant, wherein the weight part of the flame retardant is less than 20 parts, preferably less than 10 parts; preferably, the flame retardant comprises one or the combination of more than two of triphenyl phosphate, ammonium polyphosphate, condensed phosphate, phosphazene, aluminum hypophosphite, aluminum diethylphosphinate, melamine polyphosphate or melamine cyanurate;

preferably, the curing accelerator comprises an imidazole accelerator and/or an organometallic salt; further preferably, the imidazole-based accelerator comprises 2-ethyl-4-methylimidazole or 2-methylimidazole; further preferably, the organometallic salt comprises aluminum acetylacetonate or cobalt acetylacetonate;

preferably, the coupling agent is a silane coupling agent;

preferably, the solvent comprises one or a combination of more than two of acetone, butanone, dimethylformamide, propylene glycol methyl ether acetate or cyclohexanone.

3. A method for preparing a halogen-free resin composition, characterized in that the halogen-free resin composition according to any of claims 1-3 is used, comprising the steps of:

mixing the solid components in the epoxy resin and the curing agent in the halogen-free resin composition with a part of solvent, and stirring to completely dissolve the solid components in the solvent;

adding the liquid components, and stirring until the liquid components are uniformly mixed; and

adding the solid flame retardant, the inorganic filler and the residual solvent, and stirring until the mixture is uniformly mixed to obtain the halogen-free resin composition;

preferably, if the halogen-free resin composition comprises a solid curing agent and a solid epoxy resin, the method of mixing the epoxy resin in the halogen-free resin composition and the solid component in the curing agent with a part of the solvent and stirring to completely dissolve the solid component in the solvent comprises: firstly, the solid component in the curing agent is dissolved, and then the solid component in the epoxy resin is dissolved.

Preferably, the order of addition of the liquid components is: epoxy resin, a curing agent A, a curing agent B, a flame retardant, a curing accelerator and a coupling agent;

preferably, the gel time of the halogen-free resin composition obtained by mixing is 250-300 s.

4. A prepreg comprising a glass cloth, the halogen-free resin composition according to claim 1 or 2 attached to the surface of the glass cloth and the grain of the glass cloth;

preferably, the thickness of the prepreg is 0.18 to 0.24mm, preferably 0.20 to 0.22 mm.

5. The preparation method of the prepreg is characterized by comprising the following steps:

preparing a halogen-free resin composition using the method of claim 3;

and (3) soaking the glass fiber cloth in the halogen-free resin composition, and baking to obtain a prepreg.

6. The method for preparing a prepreg according to claim 5, wherein the baking temperature is 150-180 ℃;

preferably, the baking time is 3-8 min.

7. A laminate comprising two metal foils and the prepreg according to claim 4 sandwiched between the two metal foils.

8. The laminate of claim 7, wherein the prepreg is one or more than two sheets, and when the prepreg is two or more than two sheets, the prepreg has a laminated structure;

preferably, the metal foil is a copper foil;

preferably, the thickness of the metal foil is 12-105 μm, preferably 18-70 μm, further preferably 35 μm.

9. A method of making a laminate, comprising the steps of:

preparing a prepreg using the method according to claim 5 or 6;

stacking two metal foils on the upper surface and the lower surface of a prepreg; and

and laminating the metal foil and the prepreg to obtain the laminated board.

10. The method of making the laminate of claim 9, wherein the lamination is performed in a vacuum environment;

preferably, the heating rate of the lamination is 1.1-2.5 ℃/min;

preferably, the maximum pressure is applied to the metal foil and the prepreg when the temperature of the prepreg reaches 90 to 120 ℃; further preferably, the maximum pressure is 350-;

preferably, the temperature of the prepreg is controlled at 195-210 ℃ during curing, and the temperature is kept for 90-140 min.

Technical Field

The invention relates to the technical field of electronic materials, in particular to a halogen-free epoxy resin composition, and a prepreg and a laminated board prepared from the halogen-free epoxy resin composition.

Background

In recent years, with the rapid development of computers, communication equipment and communication technologies, the integration level of electronic components is higher and higher, and electronic products are developed towards being light, thin, short and small, so that higher requirements are put forward on the fineness of printed circuit board processing and the circuit accuracy.

The traditional laminated board for the printed circuit mainly adopts brominated epoxy resin, tetrabromobisphenol A and other bromine-containing flame retardants to realize the flame retardant property of the board. However, the bromine-containing flame retardant generates harmful substances such as hydrogen bromide, dioxin, dibenzofuran and the like during combustion, seriously pollutes the environment and harms human health. Therefore, research on halogen-free flame retardant laminates has become a hot spot in the electronics industry.

As a substitute for the bromine-containing flame retardant, a resin mainly containing flame retardant elements such as nitrogen, phosphorus, silicon and the like, and an inorganic filler containing crystal water (such as aluminum hydroxide, magnesium hydroxide and the like) are introduced to improve the flame retardancy of the board, but the surface appearance of the prepreg and the wettability of the resin in the glass fiber cloth are affected.

Moreover, the conventional formula of the halogen-free flame-retardant copper-clad plate is usually cured by matching epoxy resin containing a DOPO structure with phenolic resin containing the DOPO structure, the two substances containing the DOPO structure have higher molecular weight and molecular structure steric hindrance and poorer wettability, and the cured surface has rough and uneven appearance. The prepreg prepared by the conventional halogen-free resin formula is used for preparing the copper-clad plate, the processing operation window is narrow, the appearance defects of the copper-clad plate surface are more, the dimensional stability is poor, the short circuit and open circuit defects are easy to occur in the subsequent circuit board processing process, and the high standard and high requirement of the high-performance printed circuit board on the processing fineness and the circuit accuracy can not be met.

Disclosure of Invention

Aiming at one or more problems in the prior art, the invention aims to provide a halogen-free resin composition, and a prepreg and a laminated board prepared by using the halogen-free resin composition. The halogen-free resin composition can realize halogen-free flame retardance, and the flame retardance can reach UL 94V-0 level; the composition has excellent wettability in glass fiber cloth, so that the surface of a prepreg prepared from the composition is flat and smooth in appearance, and the processing operation window is extremely wide. The laminated board prepared by using the epoxy resin composition has the advantages of less surface appearance defects, high dimensional stability and excellent electrical insulation performance, and can meet the requirements of high-performance printed circuit board base materials.

The invention adopts the following technical scheme:

the invention provides a halogen-free resin composition, which comprises the following components:

the weight portions are as follows:

300 portions and 400 portions of epoxy resin,

40-70 parts of a curing agent A,

10-30 parts of a curing agent B,

130 portions and 200 portions of inorganic filler,

0.1 to 0.8 portion of curing accelerator,

0.7 to 1.5 portions of coupling agent,

150 portions of solvent and 210 portions of solvent,

wherein, the content of the components except the solvent is 60 to 75 percent.

Preferably, the following components are included:

the weight portions are as follows:

354 parts of epoxy resin, namely 354 parts of epoxy resin,

41 parts of a curing agent A, namely,

29 parts of a curing agent B, namely,

182 parts of an inorganic filler, namely an inorganic filler,

0.45 part of a curing accelerator,

1.5 parts of a coupling agent,

224 parts of a solvent, namely 224 parts of,

wherein, the content of the components except the solvent is 60 to 75 percent.

According to an aspect of the present invention, the epoxy resin includes one or a combination of two or more of a bisphenol a type epoxy resin, a phenol novolac type epoxy resin, a bisphenol a novolac type epoxy resin, an o-methyl novolac type epoxy resin, a dicyclopentadiene type epoxy resin, a biphenyl type epoxy resin, an isocyanate type epoxy resin, a tetrafunctional epoxy resin, or a phosphorous novolac epoxy resin.

Preferably, the phosphorus-containing novolac epoxy resin comprises one or more of DOPO modified novolac epoxy resin, DOPO-HQ modified novolac epoxy resin or DOPO-NQ modified novolac epoxy resin.

DOPO is 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; DOPO-HQ is 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; DOPO-NQ is 10- (2, 5-dihydroxynaphthyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

The structural formulas of the DOPO and the DOPO derivatives are as follows:

DOPO structural formula:

9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide

DOPO-HQ structural formula:

10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide

DOPO-NQ structural formula:

10- (2, 5-dihydroxynaphthyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide

According to one aspect of the present invention, the curing agent a includes one or a combination of two or more of diaminodiphenyl sulfone, diaminodiphenylmethane, diaminodiphenyl ether, p-xylidine, dicyandiamide, phenol novolac resin, bisphenol a type phenol resin, or phosphorus-containing phenol resin.

Preferably, the phosphorus-containing phenolic resin comprises one or more of DOPO modified phenolic resin, DOPO-HQ modified phenolic resin or DOPO-NQ modified phenolic resin.

DOPO is a flame retardant intermediate, DOPO and derivatives thereof can be used as reactive and additive flame retardants, DOPO and derivatives thereof can be used for synthesizing epoxy resin containing a DOPO structure and phenolic resin containing the DOPO structure, and the DOPO and derivatives thereof are mainly used in the conventional halogen-free flame-retardant copper-clad plate formula at present, the two substances containing the DOPO structure have larger molecular weight and molecular structure steric hindrance, poorer wettability, and rough and uneven surface appearance after curing.

The reaction formula of DOPO and DOPO-NQ and the epoxy resin is as follows:

reaction formula of DOPO and epoxy resin

Reaction formula of DOPO-NQ and epoxy resin

According to one aspect of the invention, the curing agent B is an organic phosphorus curing agent, and the structural formula of the curing agent B is as follows:

wherein R1 is an aliphatic group and R2 is an aliphatic group. The aliphatic space structure is relatively small, the wettability of the halogen-free resin composition can be better by reacting with the epoxy resin, and the reaction formula of the curing agent B and the epoxy resin is shown as follows. The better the wettability, the more the resin components in the grains of the glass fiber cloth, the more excellent the electrical insulation performance, and the less the defects of open circuit, short circuit and the like in the later PCB processing process such as drilling, copper deposition, electroplating and the like.

Reaction formula of curing agent B and epoxy resin

According to one aspect of the invention, the inorganic filler comprises one or a combination of two or more of silica, magnesium hydroxide, mica powder, kaolin, talc, calcium carbonate or aluminum hydroxide.

Preferably, the inorganic filler is an inorganic filler surface-treated with a silane coupling agent.

According to an aspect of the present invention, the halogen-free resin composition further comprises a flame retardant in an amount of 20 parts by weight or less, preferably 10 parts by weight or less.

In the formula of the halogen-free resin composition, phosphorus is mainly used for flame retardance, and if the phosphorus-containing epoxy resin or the phosphorus-containing curing agent in the formula contains more phosphorus, the phosphorus content reaches a certain amount, the flame retardance grade can meet the requirement, and a flame retardant is not needed. If the phosphorus-containing epoxy resin and the phosphorus-containing curing agent are less in component and the phosphorus content is insufficient, the flame retardant needs to be supplemented to meet the requirement of flame retardant grade.

According to one aspect of the invention, the flame retardant comprises one or a combination of two or more of triphenyl phosphate, ammonium polyphosphate, condensed phosphate, phosphazene, aluminum hypophosphite, aluminum diethylphosphinate, melamine polyphosphate or melamine cyanurate. The flame retardant is added additionally according to the requirement of the flame retardant property of the material.

According to one aspect of the invention, the cure accelerator comprises an imidazole accelerator and/or an organometallic salt.

Preferably, the imidazole-based accelerator comprises 2-ethyl-4-methylimidazole or 2-methylimidazole.

Preferably, the organometallic salt comprises aluminum acetylacetonate or cobalt acetylacetonate.

According to one aspect of the invention, the coupling agent is a silane coupling agent.

According to one aspect of the invention, the solvent comprises one or a combination of two or more of acetone, butanone, dimethylformamide, propylene glycol methyl ether acetate or cyclohexanone.

The invention also provides a preparation method of the halogen-free resin composition, which adopts the components of the halogen-free resin composition and comprises the following steps:

mixing solid components in epoxy resin and curing agent in the halogen-free resin composition with partial solvent, and stirring to completely dissolve the solid components in the solvent;

adding the liquid components, and stirring until the liquid components are uniformly mixed; and

then adding the solid flame retardant, the inorganic filler and the residual solvent, and stirring until the mixture is uniformly mixed to obtain the halogen-free resin composition.

In the halogen-free resin composition, some of the epoxy resin, the curing agent and the flame retardant are in a liquid state and some are in a solid state. The solid is dissolved first, so that the dissolution degree of the solid is convenient to observe.

According to an aspect of the present invention, if the halogen-free resin composition includes a solid curing agent and a solid epoxy resin, the method of mixing the epoxy resin in the halogen-free resin composition and the solid component in the curing agent with a partial solvent and stirring to completely dissolve the solid in the solvent comprises: firstly, the solid component in the curing agent is dissolved, and then the solid component in the epoxy resin is dissolved. Because the viscosity of the epoxy resin is relatively high, if the epoxy resin is dissolved together with the curing agent, whether the curing agent is completely dissolved is not easy to distinguish.

According to one aspect of the invention, the order of adding the liquid components is: epoxy resin, a curing agent A, a curing agent B, a flame retardant, a curing accelerator and a coupling agent.

According to one aspect of the present invention, the gel time of the halogen-free resin composition obtained by mixing is 250-300 s.

The invention also provides a prepreg, which comprises glass fiber cloth and the halogen-free resin composition attached to the surface and the lines of the glass fiber cloth.

According to one aspect of the invention, the thickness of the prepreg is 0.18 to 0.24mm, preferably 0.20 to 0.22 mm.

The halogen-free resin composition contains the organic phosphorus curing agent, has good wetting property, and can be immersed into the lines of the glass fiber cloth to ensure that the surface of the prepreg is smooth.

The invention also provides a preparation method of the prepreg, which comprises the following steps:

preparing a halogen-free resin composition by using the preparation method of the halogen-free resin composition;

and (3) soaking the glass fiber cloth in the halogen-free resin composition, and baking to obtain a prepreg.

According to one aspect of the invention, the temperature of the baking is 150-.

According to one aspect of the invention, the baking time is 3-8 min.

The invention also provides a laminated board which comprises two metal foils and the prepreg sandwiched between the two metal foils.

According to an aspect of the present invention, the number of the prepregs is one or two or more, and when the number of the prepregs is two or more, the prepregs have a laminated structure.

According to one aspect of the invention, the metal foil is a copper foil.

According to one aspect of the invention, the thickness of the metal foil is 12-105 μm, preferably 18-70 μm, and more preferably 35 μm.

The invention also provides a preparation method of the laminated plate, which comprises the following steps:

preparing a prepreg by adopting the preparation method of the prepreg;

stacking two metal foils on the upper surface and the lower surface of a prepreg; and

and laminating the metal foil and the prepreg to obtain the laminated board.

According to one aspect of the invention, the lamination is performed in a vacuum environment.

According to one aspect of the invention, the heating rate of the lamination is 1.1-2.5 ℃/min.

According to an aspect of the invention, the maximum pressure is applied to the metal foil and the prepreg when the temperature of the prepreg reaches 90-120 ℃.

Preferably, the maximum pressure is 350-.

According to one aspect of the invention, the temperature of the prepreg is controlled at 195-210 ℃ and the temperature is kept for 90-140min during curing.

The lamination process is to melt and then cure the resin. And the pressure of the semi-solidified sheet and the metal foil is increased in a step-type manner. The maximum pressure is applied to the metal foil and the prepreg one third to one half of the maximum pressure before the temperature reaches 90 c, and the maximum pressure is applied when the temperature reaches 90-120 c. The applied pressure needs to be strictly controlled, and if the maximum pressure is applied prematurely, the resin in the prepreg can be lost due to the excessive pressure; if the maximum pressure is applied too late, the resin in the prepreg is easily cured, and the resin in the prepreg has poor fluidity, which may cause defects in the finally prepared laminate.

The invention has the beneficial effects that:

1. the halogen-free resin composition does not contain halogen, and according to the synergistic effect of the epoxy resin, the phosphorus element, the inorganic filler and the flame retardant, the epoxy resin provides a carbon source, the phosphorus element provides an acid source, and the nitrogen element provides a gas source for synergistic flame retardance. The inorganic filler is heated to decompose water vapor and oxides, the concentration of combustible gas and oxygen is reduced while the temperature is reduced, the decomposed oxides can adsorb particles and reduce smoke density, low-smoke halogen-free flame retardance is realized, and the flame retardance reaches UL 94V-0 grade.

2. The novel organic phosphine curing agent with the micromolecule structure with good heat resistance replaces a substance containing a DOPO structure, the organic phosphine curing agent can perform a curing reaction with epoxy resin, the steric hindrance of the molecular structure is small, the halogen-free resin composition has good wettability, the surface of the prepared prepreg is flat and smooth, and the processing operation window is improved; the laminated board has the advantages of few surface appearance defects, high dimensional stability and excellent electrical insulation performance, and can meet the high standards and high requirements of high-performance printed circuit boards on the processing fineness and the circuit accuracy.

3. The phenolic resin curing agent is selected to enable the epoxy resin composition to have excellent moist heat resistance and heat resistance.

4. The addition of more inorganic filler gives epoxy resin compositions having a low coefficient of expansion.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a pictorial representation of a prepreg according to example 1B;

FIG. 2 is a schematic representation of a prepreg according to example 2B;

FIG. 3 is a pictorial view of a prepreg according to example 3B;

FIG. 4 is a pictorial view of a prepreg according to example 4B;

FIG. 5 is a pictorial view of a prepreg according to example 5B;

fig. 6 is a physical diagram of a prepreg of comparative example 6B.

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or uses of other materials.

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.