JP2020139128A - Halogen-free flame-retardant thermosetting resin composition, resin rubber liquid, prepreg for printed circuit, insulation plate, metal-clad laminate, and printed wiring board - Google Patents

Abstract

To provide a halogen-free flame-retardant thermosetting resin composition, a prepreg for printed circuit, and a metal-clad laminate.SOLUTION: The halogen-free flame-retardant thermosetting resin composition contains a modified bismaleimide prepolymer, a benzoxazine resin, a phosphorus-containing epoxy resin, an acid anhydride compound, and a curing accelerator. By using the halogen-free flame-retardant thermosetting resin composition, the manufactured metal-clad laminate has at least one of characteristics such as good adhesion, high heat resistance, high glass transition temperature (Tg), flame retardancy, low dielectric constant and low loss.SELECTED DRAWING: None

Description

The present invention relates to the technical field of a printed wiring board. Specifically, the present invention relates to a resin rubber liquid, a prepreg for a printed circuit, an insulating plate, a metal-clad laminate, and a printed wiring board.

A metal-clad laminate is a plate-like material produced by impregnating an electronic glass fiber cloth (also called glass fiber cloth) or another reinforcing material with a resin liquid, covering one or both sides with a metal foil, and hot-pressing. , Metal foil-clad laminate, and abbreviated as metal-clad laminate or metal-clad plate, for example, copper-clad laminate or copper-clad plate (CPL). A metal-clad laminate, for example, a copper-clad plate, is a base laminate material for manufacturing a printed wiring board (abbreviated as PCB), and PCB is one of the important parts in the electronic industry. In almost every electronic device, from small electronic watches and calculators to large computers, communication electronic devices, and military weapon systems, as long as there are electronic components such as integrated circuits, all of them are for electrical connections between the electronic components. It is necessary to use a printed board. The metal-clad laminate has three main functions of conductivity, insulation, and support in the entire printed wiring board.

With the rapid progress of electronic technology, wireless communication and networks have spread to every corner of society, and in order to meet people's demands for faster information acquisition and larger capacity, communication equipment, base stations, servers, routers, etc. Signal transmission in network infrastructure, large computers, etc. is developing at higher speeds and larger capacities. Along with this, the printed wiring board mounted on these electronic devices needs to have characteristics of high frequency transmission and low transmission loss, so that the corresponding substrate material needs to have a low dielectric constant and a low dielectric loss tangent. .. Further, as the performance and miniaturization of electronic information devices are increasing, the PCB lines are becoming denser and more multi-layered, so that the plate material needs to have high reflow solder heat resistance and through-hole reliability. As a performance index of the material, the glass transition temperature needs to be 190 ° C. or higher, and thus the thermal expansion coefficient needs to be lower. Below Tg, the Z-axis CTE needs to be 45 ppm / ° C. or lower, and thus 40 ppm / ° C. or lower. .. Considering the issue of environmental protection, such product development tends to eventually develop into halogen-free.

Conventionally, as a resin composition used for printed wiring boards that require low transfer loss, patent CN103131131A discloses a method of blending a styrene maleic acid anhydride copolymer with an epoxy resin and a benzoxazine resin, but it is produced. The vitrification temperature of the plate material is only 170 ° C., the thermal expansion rate (CTE) is large, the water absorption of the plate material is large, and the heat resistance of the multilayer plate is not good. In CN104725781A (Application No .: CN201510106304), the combination of amine-modified bismaleimide, benzoxazine resin, and epoxy resin utilized the advantages of bismaleimide to obtain the effects of high vitrification temperature and low CTE. The dielectric constant is rather high, which is disadvantageous for signal transmission in PCB at high frequencies.

CN103131131A CN104725781A

One object of the present invention is to provide a halogen-free flame-retardant thermosetting resin composition. A prepreg for a printed circuit obtained by impregnating a reinforcing material, for example, glass fiber cloth, with the halogen-free flame-retardant thermosetting resin composition, and a metal-clad laminate containing the prepreg for the printed circuit. The metal-clad laminate has at least one of properties such as good adhesiveness, high heat resistance, high glass transition temperature (Tg), flame retardancy, low dielectric constant and low loss.

Another object of the present invention is to provide an insulating plate including the prepreg for a printed circuit, and a printed wiring board including the prepreg for a printed circuit, the insulating plate or the metal-clad laminate. The insulating plate or metal-clad laminate has one of the characteristics such as good adhesiveness, high heat resistance, high glass transition temperature (Tg), flame retardancy, low dielectric constant and low loss.

In order to achieve this object, the following technical forms are adopted in the present invention.
In the first aspect, the present invention provides a halogen-free flame-retardant thermosetting resin composition containing a modified bismaleimide prepolymer, a benzoxazine resin, a phosphorus-containing epoxy resin, an acid anhydride compound, and a curing accelerator. ..

Specifically, the present invention
Modified bismaleimide prepolymer formed by prepolymerizing maleimide having at least two N-substituted maleimide groups in its molecular structure, aromatic diamine, and hydroxy-containing aromatic amine: 10 to 50 parts by weight.
Benzoxazine resin: 5 to 50 parts by weight,
Phosphorus-containing epoxy resin: 30 to 90 parts by weight,
Acid anhydride compounds: 10 to 50 parts by weight,
Hardening accelerator: 0.01 to 1 part by weight,
Provided is a halogen-free flame-retardant thermosetting resin composition containing.

In the second aspect, the present invention provides a resin rubber liquid containing the halogen-free flame-retardant thermosetting resin composition according to the first aspect and a solvent.

In the third aspect, the present invention provides a prepreg for a printed circuit containing the reinforcing material and the halogen-free flame-retardant thermosetting resin composition according to the first aspect, which is attached to the reinforcing material by impregnation and drying. To do.

In the fourth aspect, the present invention provides an insulating plate containing the prepreg for a printed circuit according to the third aspect.

In a fifth aspect, the present invention provides a metal-clad laminate comprising the printed circuit prepreg according to the third aspect and a metal foil covering one or both sides of the outer side of the prepreg.

In the sixth aspect, the present invention comprises at least one printed circuit prepreg according to the third aspect, or an insulating plate according to the fourth aspect, or a metal-clad laminate according to the fifth aspect. Provide printed wiring board including.

According to the present invention, (1) a halogen-free flame-retardant thermosetting resin composition contains a modified bismaleimide prepolymer, and by taking advantage of the feature of having a highly rigid molecular chain after the bismaleimide is cured, a high Tg is obtained. And heat resistance is obtained, and since the active phenolic hydroxyl group can react with the epoxy resin, higher toughness and adhesiveness can be obtained. (2) Since the halogen-free flame-retardant thermosetting resin composition contains a phosphorus-containing epoxy resin, not only good adhesiveness can be provided, but also a flame-retardant effect can be obtained. (3) Since the halogen-free flame-retardant thermosetting resin composition contains an acid anhydride compound, good dielectric properties can be given to the system. Further, preferably, (4) since the halogen-free flame-retardant thermosetting resin composition contains an inorganic filler, the expansion rate of the halogen-free flame-retardant thermosetting resin composition can be significantly reduced and the cost is increased. It can also be lowered to improve flame retardancy. Therefore, the copper-clad foil laminates produced with the composition and applied to halogen-free high-multilayer printed wiring boards have good adhesiveness, high heat resistance, high glass transition temperature (Tg), flame retardancy, low dielectric constant and It has characteristics such as low loss.

Therefore, according to the present invention, it is possible to provide a halogen-free flame-retardant thermosetting resin composition. A prepreg for a printed circuit obtained by impregnating a reinforcing material with the halogen-free flame-retardant thermosetting resin composition, a metal-clad laminate or an insulating plate containing the prepreg for the printed circuit, the prepreg for the printed circuit, and the insulating material. By the plate or the printed wiring board including the metal-clad laminate, the metal-clad laminate has characteristics such as good adhesiveness, high heat resistance, high glass transition temperature (Tg), flame retardancy, low dielectric constant and low loss. It preferably has at least one and at least two of these properties, more preferably all of these properties.

Hereinafter, the technical embodiments in the examples of the present invention will be clearly and entirely described based on the specific embodiments of the present invention. It is self-evident that the embodiments and / or embodiments described are merely some embodiments and / or embodiments of the present invention, not all embodiments and / or embodiments. Based on the embodiments and / or examples in the present invention, any other embodiment and / or any other embodiment obtained by those skilled in the art without exhausting creative labor shall be within the scope of the invention. enter.

In the present invention, all numerical features are within the error range of the measurement, for example, within 10%, within 5%, or within 1% of the limited numerical value.

The term "containing" or "containing" described in the present invention means that other components may be contained in addition to the above-mentioned components, and these other components give different characteristics to the prepreg. .. Further, the "containing" or "containing" described in the present invention may include "substantially consisting of ..." and can be replaced with "is" or "consisting of".

In the present invention, unless otherwise specified, the content, ratio, etc. are calculated by weight.

In the present invention, the term "halogen-free flame retardant" means that it does not contain a halogen-containing flame retardant that is significantly added to the composition of the present invention.

As mentioned above, the present invention
Modified bismaleimide prepolymer formed by prepolymerizing maleimide having at least two N-substituted maleimide groups in its molecular structure, aromatic diamine, and hydroxy-containing aromatic amine: 10 to 50 parts by weight.
Benzoxazine resin: 5 to 50 parts by weight,
Phosphorus-containing epoxy resin: 30 to 90 parts by weight,
Acid anhydride compounds: 10 to 50 parts by weight,
Hardening accelerator: 0.01 to 1 part by weight,
Provided is a halogen-free flame-retardant thermosetting resin composition containing.

Modified Bismaleimide Prepolymer As described above, the modified bismaleimide prepolymer is obtained by prepolymerizing maleimide, aromatic diamine, and hydroxy-containing aromatic amine having at least two N-substituted maleimide groups in the molecular structure. It may be.
An example of a maleimide having at least two N-substituted maleimide groups in its molecular structure is represented by the following formula (I) or (II).

R ₁ and R ₂ are independently alkyl groups of H or C _{1 to} C ₄ , respectively. In Equation II, n is an integer of 1-8.
The hydroxy-containing aromatic amine is any one selected from the following, or a combination of any two or more.

However, R ₁ and R ₂ are independently alkyl groups of H or C _{1 to} C ₄ , respectively.
Examples of alkyl groups C _{1 to} C ₄ may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and t-butyl.

In the present invention, there is no limitation on the substitution positions of the substituents R ₁ and R ₂ . For example, if one benzene ring has one substituent, namely R ₁ or R ₂ , R ₁ or R ₂ may be in any possible position. If one benzene ring has two substituents, namely R ₁ and R ₂ , then R ₁ and R ₂ may be in any possible position and at the o-, m- or p-positions of each other. May be. It can also be applied to the case of naphthalene ring.

The aromatic diamine may be an aromatic diamine having two or more and four or less aromatic rings. Examples of the aromatic diamines are 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone. , 1,5-Diaminonaphthalene, 2,6-diaminonaphthalene, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-dimethyl -5,5'-diethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 4,4'-diamino-3,3', 5,5'-tetraethyldiphenylmethane, 4,4-diaminobiphenyl , 4-Diaminoanisol, 3,3'-dimethoxybiphenylamine and 3,3'-dimethylbiphenylamine, or any combination of two or more.

The modified bismaleimide prepolymer may be prepared by the following prepolymerization method. Maleimide having at least two N-substituted maleimide groups in the molecular structure, hydroxy-containing aromatic amine, aromatic diamine, and organic solvent are mixed according to a certain ratio, and gradually heated and stirred while raising the temperature to form a solution. Then, the mixture was continuously stirred in a nitrogen gas atmosphere and subjected to a reflux reaction while keeping the reaction temperature at about 100 to 150 ° C., the reaction time was about 0.5 to 8 hours, and after the reaction was completed, heating was completed and cooled. A modified bismaleimide prepolymer solution having a structure containing an amino group and a phenolic hydroxyl group is obtained.

In the modified bismaleimide prepolymer, the structural unit derived from maleimide having at least two N-substituted maleimide groups in the molecular structure, the structural unit derived from the aromatic diamine, and the hydroxy-containing aromatic amine. The weight ratio of the structural units is about (6 to 12) :( 0.5 to 3) :( 0.5 to 3).

The modified bismaleimide prepolymer has a molecular weight of about 500 to 2500, with a preferred lower limit of molecular weight of 600, 750, 900, 1000 or 1200. By controlling the charging weight ratio, the end capping in the prepolymerization reaction is controlled to obtain the modified bismaleimide prepolymer. When the molecular weight is less than about 500, the fluidity of the halogen-free flame-retardant thermosetting resin composition becomes large, and the uniformity of the thickness of the metal-clad laminate becomes poor. When the molecular weight exceeds about 2500, the impregnation property of the prepreg is deteriorated, and the insulation reliability of the insulating layer, the metal-clad laminate or the printed wiring board is deteriorated. The molecular weight can be measured by the measuring method specified in "GB / T 21863-2008 gel permeation chromatography (GPC) using tetrahydrofuran as an elution solvent".

Benzoxazine Resin Examples of the benzoxazine resin are bisphenol A type benzoxazine resin, bisphenol F type benzoxazine resin, diamine type benzoxazine resin, phenolphthaline type benzoxazine resin, dicyclopentadiene type benzoxazine resin, and bisphenol fluorene. It may contain any one or a mixture of two or more kinds selected from the type benzoxazine resin, preferably the bisphenol F type benzoxazine resin, the diamine type benzoxazine resin, the phenolphthaline type benzoxazine resin, and the bisphenol fluorene type. Includes any one or a mixture of two or more selected from benzoxazine resins.

In the present invention, benzoxazine acts as a curing agent and opens at high temperatures to produce hydroxy. The hydroxy can react with the modified bismaleimide and epoxy resin to form a crosslinked network, which can give the corresponding cured product good overall performance.

Phosphorus-Containing Epoxy Resin An example of the phosphorus-containing epoxy resin is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide structure, 10- (2,5-dihydroxyphenyl) -9,10-dihydro. Many containing -9-oxa-10-phosphaphenanthrene-10-oxide structure and 10- (2,5-dihydroxynaphthyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide structure It may be any one or a mixture of two or more selected from functional epoxy resins.

The phosphorus-containing epoxy resin has a molecular weight of about 800 to 2500. The molecular weight can be measured by the measuring method specified in "GB / T 21863-2008 gel permeation chromatography (GPC) using tetrahydrofuran as an elution solvent".

According to the present invention, the halogen-free flame-retardant thermosetting resin composition may contain other polyfunctional epoxy resins in addition to the phosphorus-containing epoxy resin. As a result, the crosslink density of the resin composition can be further improved and the Tg can be increased. Examples of other polyfunctional epoxy resins include naphthalene skeletons such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, and naphthol aralkyl type epoxy resin. Examples thereof include a containing type epoxy resin, a biphenyl aralkyl type epoxy resin, a dicyclopentadiene type epoxy resin, and a dihydroanthracene type epoxy resin. These may be used alone or in combination of two or more. From the viewpoint of high frequency characteristics, heat resistance, thermal expansion characteristics and flame retardancy, it is preferable to use a naphthalene skeleton-containing epoxy resin or a biphenyl aralkyl type epoxy resin.

Acid anhydride compounds The acid anhydride compounds include compounds having two or more acid anhydride groups in their molecular structures.
Examples of the acid anhydride compounds include styrene-maleic anhydride copolymer, phenylpropylene-maleic anhydride copolymer, 3,3', 4,4'-diphenyl ether tetracarboxylic dianhydride, 2 , 3,3', 4'-diphenyl ether tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride With any one or a mixture of two or more selected from anhydrides, 3,3', 4,4'-benzophenonetetracarboxylic dianhydrides, and 1,2,4,5-pyromellitic dianhydrides. There may be.
In the styrene-maleic anhydride copolymer and the phenylpropylene-maleic anhydride copolymer, the copolymerization ratio of styrene or phenylpropylene and maleic anhydride is about 1:10 to 10: 1 in mole. It may be preferably about 1: 5 to 5: 1, more preferably about 1: 2 to 2: 1.

Curing Accelerator Examples of curing accelerators are t-amines, imidazoles, 4-dimethylaminopyridine, triphenylphosphine, or boron trifluoride monoethylamine, whichever is one or a mixture of two or more.
Examples of t-amines include triethylamine, benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol and salts thereof.
Examples of imidazoles include 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methyl. Examples thereof include imidazole and 1-cyanoethyl-2-phenylimidazole.

The halogen-free flame-retardant thermosetting resin composition may further contain an inorganic filler.
The inorganic filler accounts for 30% to 70% of the total weight of the halogen-free flame-retardant thermosetting resin composition.
The inorganic fillers include silica, soft glass powder, talc, kaolin, mica powder, boehmite, hydrotalcite, zinc borate, aluminum hydroxide, magnesium hydroxide, alumina, boron nitride, aluminum nitride, barium sulfate, and wallast. Any one or a mixture of two or more selected from knights. The silica is any one or a mixture of spherical silica, molten silica, and crystalline silica.
The particle size of the inorganic filler is limited, and an inorganic filler having a particle size of preferably about 0.01 to 30 μm, more preferably about 0.1 to 15 μm is used.
When the particle size of the inorganic filler is less than about 0.01 μm, the fluidity of the halogen-free flame-retardant thermosetting resin composition is lowered, so that the moldability at the time of manufacturing the prepreg and the metal-clad laminate is deteriorated. Since voids are likely to be generated or the surface area thereof is increased, the adhesive area between the metal and the resin is reduced, which is not preferable because the peeling strength of the printed wiring board is lowered. On the other hand, if the particle size exceeds about 30 μm, the insulation reliability between the wirings of the printed wiring board or the insulating layer is lowered, which is not preferable.

In the present invention, in order to further improve the flame retardant effect, other flame retardants having a phosphorus-containing structure, for example, phosphorus-containing phenol resin, phosphazene compound, ammonium polyphosphate, tris (2-carboxyethyl) phosphine, tris (chloroisopropyl). ) Phosphate, trimethyl phosphate, dimethyl-methyl phosphate, resorcinol bisxylenyl phosphate, melamine polyphosphate, melamine cyanurate, and trihydroxyethyl isocyanurate may be introduced in any one or a combination of two or more.
When a flame retardant having another phosphorus-containing structure is contained, the content of the flame retardant having another phosphorus-containing structure in the halogen-free flame-retardant thermosetting resin composition may be about 1 to 60% by weight. It is preferably 2 to 40% by weight.

The halogen-free flame-retardant thermosetting resin composition may further contain a solvent. Examples of solvents are one or two selected from acetone, butanone, cyclohexanone, N, N-dimethylformamide, N, N-dimethylacetamide, ethylene glycol methyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, and dimethyl sulfone. It may be a mixture of seeds or more. When a solvent is contained, the content of the solvent in the halogen-free flame-retardant thermosetting resin composition may be 10 to 99.5% by weight, preferably about 20 to 99% by weight.
The halogen-free flame-retardant thermosetting resin composition containing a solvent may be referred to as a resin rubber liquid in the present invention. The resin rubber liquid is obtained by dissolving or dispersing the above halogen-free flame-retardant thermosetting resin composition in a solvent.

Further, the halogen-free flame-retardant thermosetting resin composition may further contain various auxiliaries. Specific examples of the auxiliary agent include filler dispersants, antifoaming agents, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, lubricants and the like. These auxiliaries may be used alone or in combination of any two or more.

The halogen-free flame-retardant thermosetting resin composition of the present invention is prepared by a known method, for example, a modified bismaleimide prepolymer, a benzoxazine resin, a phosphorus-containing epoxy resin, an acid anhydride compound, a curing accelerator, and the like. Any one or two selected from solvents, fillers, flame retardants, dispersants, defoaming agents, antioxidants, heat stabilizers, antistatic agents, UV absorbers, pigments, colorants and lubricants as needed. It can be prepared by blending, stirring, and mixing with a mixture of seeds or more.
A halogen-free flame-retardant thermosetting resin composition is prepared in a resin rubber solution by mechanical stirring, emulsification, or ball mill dispersion, and then the reinforcing material is impregnated with the resin rubber solution and further dried to obtain a prepreg. A metal-clad laminate can be manufactured by hot-pressing the prepreg with a metal foil, for example, a copper foil or an aluminum foil with a vacuum press.

Examples of reinforcing materials include glass fiber cloth, glass fiber non-woven fabric, and organic non-woven fabric.

In order to reduce the viscosity of the resin rubber liquid, it can be impregnated while heating. The temperature of the resin rubber liquid when heated and impregnated so that the temperature of the resin rubber liquid is lower than the boiling point of the solvent is preferably about 20-90 ° C, more preferably about 25-55 ° C.

On the other hand, the present invention can further provide a prepreg for a printed circuit containing the reinforcing material and the halogen-free flame-retardant thermosetting resin composition adhered to the reinforcing material by impregnation / drying.

On the other hand, the present invention can further provide an insulating plate or a metal-clad laminate including at least one prepreg for a printed circuit described above. For example, the metal-clad laminate may include at least one prepreg for a printed circuit described above and a metal foil covering one or both sides of the outside of the prepreg.

On the other hand, the present invention comprises at least one prepreg for a printed circuit as described above, or at least one insulating plate as described above, or at least one printed wiring board including the above-mentioned metal-clad laminate. Can be further provided.

According to the present invention, a halogen-free flame-retardant thermosetting resin composition can be provided. A prepreg for a printed circuit obtained by impregnating a reinforcing material with the halogen-free flame-retardant thermosetting resin composition, a metal-clad laminate or an insulating plate containing the prepreg for the printed circuit, the prepreg for the printed circuit, and the insulating material. By the plate or the printed wiring board including the metal-clad laminate, the metal-clad laminate has characteristics such as good adhesiveness, high heat resistance, high glass transition temperature (Tg), flame retardancy, low dielectric constant and low loss. Have at least one.

Hereinafter, the technical embodiment of the present invention will be further described with reference to specific embodiments. However, these examples are for explaining the present invention by way of examples, and do not limit the present invention.

Preparation Example Preparation of Modified Bismaleimide Prepolymer (1) Preparation of Prepolymer A-1, 4,4'-bismaleimide diphenylmethane, m-aminophenol, 4,4'-diamino-3,3'-dimethyl-5, 5'-diethyldiphenylmethane in a weight ratio of 10: 1: 1 (ie, 10 parts by weight of 4,4'-bismaleimide diphenylmethane, 1 part by weight of m-aminophenol, 4,4'-diamino-3,3'-dimethyl -5,5'-diethyldiphenylmethane (1 part by weight), put in a three-necked flask, add 12 parts by weight of dimethylformamide as a solvent, stir and disperse, let nitrogen flow, and gradually raise the temperature while stirring. The solution is obtained by refluxing for 4 hours and cooling while keeping the temperature at 150 ° C. to obtain a solution of the modified bismaleimide prepolymer A-1. The color of the solution was brownish black, the solid content of the solution was 50%, and the viscosity of the solution was 52.5 cP.
Viscosity is measured with an LVDV-E type digital viscometer, and when measuring, fill the conical plate with the solution until the rotor liquid level mark (tank on the rotor rod) is flush with the liquid level. Continued to increase.
The molecular weight of A-1 was 500 to 2500 as measured by the measuring method specified in "GB / T 21863-2008 gel permeation chromatography (GPC) using tetrahydrofuran as an elution solvent".

(2) Preparation of prepolymer A-2 4,4'-bismaleimide diphenylmethane, 4-aminonaphthol, and 4,4'-diaminodiphenyl sulfone in a weight ratio of 10: 1: 1 (that is, 4,4'-. Add 10 parts by weight of bismaleimide diphenylmethane, 1 part by weight of 4-aminonaphthol, 1 part by weight of 4,4'-diaminodiphenyl sulfone), put in a three-necked flask, add 12 parts by weight of dimethylformamide as a solvent, and stir. Disperse, flow nitrogen, gradually raise to a higher temperature with stirring to further dissolve, reflux reaction for 4 hours at a temperature of 150 ° C., and cool to obtain a solution of modified bismaleimide A-2. The color of the solution was brownish black, the solid content of the solution was 50%, and the viscosity of the solution was 55.4 cP.
Viscosity is measured with an LVDV-E type digital viscometer, and when measuring, fill the conical plate with the solution until the rotor liquid level mark (tank on the rotor rod) is flush with the liquid level. Continued to increase.
The molecular weight of A-2 was 500 to 2500 as measured by the measuring method specified in "GB / T 21863-2008 gel permeation chromatography (GPC) using tetrahydrofuran as an elution solvent".

Examples 1-9 and Comparative Examples 1-5
The composition and solid amount of the thermosetting resin compositions of Examples 1 to 9 and Comparative Examples 1 to 5 are shown in Table 1 or Table 2.

Preparation of Copper Clad Plate According to the composition and amount (parts by weight) shown in Table 1 or 2, the components of each thermosetting resin composition of Examples 1 to 9 and Comparative Examples 1 to 5 are placed in a container and stirred. Mix uniformly to prepare each thermosetting resin composition of Examples 1 to 9 and Comparative Examples 1 to 5, add butanone as a solvent and mix uniformly, and rubber so that the solid content becomes 60%. Liquids were prepared, and as a result, the resin rubber liquids of Examples 1 to 9 and Comparative Examples 1 to 5 were obtained. The 2116 electronic grade glass fiber cloth is immersed in a resin rubber solution and baked in an oven at 150 ° C. to obtain 2116 prepregs of Examples 1 to 9 and Comparative Examples 1 to 5. Six pieces of each of the 2116 prepregs of Examples 1 to 9 and Comparative Examples 1 to 5 were taken, both sides of each of the 2116 prepregs were further covered with an electrolytic copper foil having a thickness of 18 μm, laminated in a vacuum by a hot press machine, and the curing temperature was 200. The copper-clad plates of Examples 1 to 9 and Comparative Examples 1 to 5 were prepared at ° C. and a time of 120 min.

Performance measurement 1) Glass transition temperature Tg: According to the DMA measurement method specified in IPC-TM-650 2.4.24 by dynamic thermomechanical analysis (DMA) measurement.
2) Peeling strength: Follow the measuring method specified in GB / T 4722-2017 7.2.1.
3) Combustibility: Measured according to the UL94 "50W (20mm) vertical combustion test: V-0, V-1 and V-2" measurement method, and certified as flame-retardant V-0.
4) Immersion-resistant soldering time with copper foil: Take three 100 mm x 100 mm size plate samples with copper foil on both sides, immerse them in solder at 288 ° C, and calculate the average time for which delamination and swelling do not occur. adopt.
5) Z-axis expansion (adopts coefficient of thermal expansion α1 before Tg): Measurements are made with a static thermal analyzer (TMA) and measurements are made according to reference IPC-TM-650 2.4.24. Here, the Z axis represents the thickness direction of the laminated plate sample.
6) PCT pressure vessel thermal stress test: Three plates of 100 mm x 100 mm size removed by etching copper foil are taken, steamed in a high-pressure pan at a pressure of 105 ± 3 KPa for 2 hours, and the removed plates are soldered at 288 ° C. The average value of the time during which delamination and swelling do not occur is adopted.
7) Water absorption: Three plates of 100 mm x 100 mm, which were removed by etching copper foil, were weighed, steamed in a high-pressure pan at a pressure of 105 ± 3 KPa for 2 hours, and the removed plates were weighed again and weighed. Calculate the rate of increase.
8) Electrical performance Measured at Dk / Df: 1 GHz by the parallel plate method, and performed according to the standard IPC-TM-650 2.5.5.9.
9) Molecular weight: Perform according to the measurement method specified in "GB / T 21863-2008 gel permeation chromatography (GPC) using tetrahydrofuran as an elution solvent".

The components used in the examples and comparative examples are as follows in detail.
A. Modified Bismaleimide Prepolymer (A-1) Prepolymer A-1 prepared in the above preparation example.
(A-2) Prepolymer A-2 prepared in the above preparation example.
(A-3) BMI Resin (4,5'-Bismaleimide Diphenylmethane, Honghu Souma Resin Company)

B. Epoxy resin (B-1) KDP-555MC80 (DOPO-HQ modified epoxy resin, Korea Metropolitan Chemical Company)
(B-2) HP-7200H (DCPD-phenol type epoxy resin, DIC Corporation, Japan)
(B-3) NC-3000H (biphenyl-phenol type epoxy resin, Nippon Kayaku Co., Ltd.)

C. Benzoxazine resin (C-1) D125 (diamine type benzoxazine resin, Sichuan East Materials Technology Co., Ltd.)
(C-2) LZ8270 (Phenolphthalein-type benzoxazine resin, Huntsman Advanced Materials, USA)

D. SMA-EF40 (Styrene-Maleic anhydride oligomer, CrayVary, USA)

E. XZ92741 (phosphorus-containing novolac resin, OLIN Chemical Company, USA)

F. SPB-100 (phosphazene resin, Otsuka Chemical Co., Ltd.)

G. 2E4MZ (2-ethyl-4-methylimidazole, Shikoku Chemicals Corporation, Japan)

H. MEGASIL 525 (Fused silica, Sibelco company, particle size D50 is 2.6 μm, D100 is less than 15 μm)

Examples 1 to 5 and 6 to 9 used different prepolymers, and in Examples 1 to 5, prepolymer A-1 was used, but in Examples 6-9, prepolymer A-2 was used.
In Example 2, based on Example 1, the amounts of the inorganic filler and the phosphorus-containing epoxy resin were reduced, and the phosphorus-containing novolak resin was introduced.
In Examples 3, 4 and 5, based on the prepolymer A-1, a non-different type of epoxy resin and a non-different type of benzoxazine resin were used.
In Example 6, based on Example 1, prepolymer A-2 was used instead of prepolymer A-1.
In Examples 7, 8 and 9, based on the prepolymer A-2, a non-different type of epoxy resin and a non-different type of benzoxazine resin were used.
In Comparative Example 1, the unmodified bismaleimide monomer was used. In Comparative Example 2, the amount of the styrene maleic anhydride copolymer used was reduced, and the amount of the diamine-type benzoxazine resin used was increased. In Comparative Example 3, the amount of the modified bismaleimide prepolymer used was reduced, and the amount of the diamine-type benzoxazine resin used was increased. In Comparative Example 4, the amount of the bismaleimide prepolymer used was increased without using the benzoxazine resin. In Comparative Example 5, the phosphorus content was increased by using a phosphazene resin instead of using a phosphorus-containing epoxy resin.
The performances of Examples and Comparative Examples are shown in Tables 3 and 4, respectively.

From Examples 1 and 6 and Comparative Example 1, after the prepolymerization modification, the bismaleimide becomes highly compatible with the resin mixture, the reactivity is improved, and the performance is clearly improved, while the prepolymerization is performed. It can be seen that the missing bismaleimide monomer has poor compatibility, easily precipitates in the resin mixture, has poor plate material performance, and some performance indexes cannot be measured.
In Example 2, a phosphorus-containing novolak was introduced to reduce the content of the inorganic filler, and as a result, the Tg and the dielectric properties were slightly lowered.
In Examples 3, 4 and 5, based on the prepolymer A-1, different types of epoxy resin and benzoxazine resin are adopted, and the results are compared. Example 4 using the phenolphthalein-type benzoxazine resin 8270 has a slightly higher Tg (DMA) than Example 3 using the diamine-type benzoxazine resin D125, but the dielectric properties are not as good as those of Example 3. Example 5 using the biphenyl epoxy resin NC-3000H obtained better dielectric properties than Example 4 using the DCPD epoxy resin HP-7200H, but the cost of the biphenyl epoxy was relatively high.
Examples 7, 8 and 9 are carried out based on the prepolymer A-2, and the design concept is the same as that of the examples using the prepolymer A-1. Since the hydroxy-containing aromatic amine used when prepolymerizing to prepare A-2 has a naphthalene ring structure, the Tg of Examples 7, 8 and 9 is higher than that of Examples 3, 4 and 5. In terms of dielectric properties, Examples 3, 4 and 5 are more excellent, and there is no large difference in other performances such as PCT, water absorption rate, immersion resistance soldering and the like.
In Comparative Example 2, as a result of reducing the styrene maleic anhydride oligomer SMA-EF40 to 5 parts by weight and increasing the amount of the diamine-type benzoxazine resin D125 used, the dielectric properties were clearly lowered. In Comparative Example 3, as a result of reducing the modified bismaleimide prepolymer to 5 parts by weight and increasing the amount of the diamine-type benzoxazine resin D125 used, the plate material Tg decreased to 178 ° C., and delamination and swelling occurred in the PCT measurement. It happened, and at the same time, the Z-axis α1 became high. In Comparative Example 4, as a result of increasing the modified bismaleimide prepolymer and the styrene-maleic anhydride oligomer without using the benzoxazine resin, the water absorption rate of the plate material was increased, and delamination and swelling occurred in the PCT measurement. In Comparative Example 5, flame retardancy was achieved by introducing 20 parts by weight of phosphazene to improve the phosphorus content of the system without using a phosphorus-containing epoxy resin, but the plate material had a reduced Tg and a high water absorption rate. It improved, and delamination and swelling occurred in the PCT measurement.

Therefore, according to the present invention, (1) the halogen-free flame-retardant thermosetting resin composition contains a modified bismaleimide prepolymer, and by taking advantage of the feature of having a highly rigid molecular chain after the bismaleimide is cured. High Tg and heat resistance can be obtained, and since the active phenolic hydroxyl group can react with the epoxy resin, higher toughness and adhesiveness can be obtained. (2) Since the halogen-free flame-retardant thermosetting resin composition contains a phosphorus-containing epoxy resin, not only good adhesiveness can be provided, but also a flame-retardant effect can be obtained. (3) Since the halogen-free flame-retardant thermosetting resin composition contains an acid anhydride compound, good dielectric properties can be given to the system. Further, preferably, (4) since the halogen-free flame-retardant thermosetting resin composition contains an inorganic filler, the expansion rate of the halogen-free flame-retardant thermosetting resin composition can be significantly reduced and the cost is increased. It can also be lowered to improve flame retardancy. Therefore, the copper-clad foil laminates produced with the composition and applied to halogen-free high-multilayer printed wiring boards have good adhesiveness, high heat resistance, high glass transition temperature (Tg), flame retardancy, low dielectric constant and It has characteristics such as low loss.

According to the present invention, a halogen-free flame-retardant thermosetting resin composition can be provided. A prepreg for a printed circuit obtained by impregnating a reinforcing material with the halogen-free flame-retardant thermosetting resin composition, a metal-clad laminate or an insulating plate containing the prepreg for the printed circuit, the prepreg for the printed circuit, and the insulating material. By the plate or the printed wiring board including the metal-clad laminate, the metal-clad laminate has characteristics such as good adhesiveness, high heat resistance, high glass transition temperature (Tg), flame retardancy, low dielectric constant and low loss. It preferably has at least one and at least two of these properties, more preferably all of these properties.

It is self-evident to those skilled in the art that embodiments of the present invention may be modified or modified as long as they do not exceed the gist and scope of the present invention. As described above, the present invention also includes these modifications and modifications as long as these modifications and modifications of the present invention are within the scope of the claims of the present invention and the equivalent technology thereof.

Claims (10)

Modified bismaleimide prepolymer formed by prepolymerizing maleimide having at least two N-substituted maleimide groups in its molecular structure, aromatic diamine, and hydroxy-containing aromatic amine: 10 to 50 parts by weight.
Benzoxazine resin: 5 to 50 parts by weight,
Phosphorus-containing epoxy resin: 30 to 90 parts by weight,
Acid anhydride compounds: 10 to 50 parts by weight,
Hardening accelerator: 0.01 to 1 part by weight,
Halogen-free flame-retardant thermosetting resin composition containing. The halogen-free flame-retardant thermosetting resin composition according to claim 1, wherein the maleimide having at least two N-substituted maleimide groups in the molecular structure is represented by the following formula (I) or (II).

The halogen-free flame-retardant thermosetting resin composition according to claim 1, wherein the hydroxy-containing aromatic amine is any one selected from the following, or a combination of any two or more.

However, R ₁ and R ₂ are independently alkyl groups of H or C _{1 to} C ₄ , respectively.
Preferably, the aromatic diamine is an aromatic diamine having two or more and four or less aromatic rings.
Preferably, the aromatic diamine is 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenyl. Pulmonate, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, 4,4'-diamino-3,3'- Dimethyl-5,5'-diethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 4,4'-diamino-3,3', 5,5'-tetraethyldiphenylmethane, 4,4-diamino One or a combination of any two or more selected from biphenyl, 4-diaminoanisol, 3,3'-dimethoxybiphenylamine and 3,3'-dimethylbiphenylamine. In the modified bismaleimide prepolymer, the structural unit derived from maleimide having at least two N-substituted maleimide groups in the molecular structure, the structural unit derived from the aromatic diamine, and the hydroxy-containing aromatic amine. The halogen-free flame-retardant thermosetting resin composition according to claim 1, wherein the weight ratio of the structural units is (6 to 12) :( 0.5 to 3) :( 0.5 to 3). The benzoxazine resin is composed of bisphenol A type benzoxazine resin, bisphenol F type benzoxazine resin, diamine type benzoxazine resin, phenolphthaline type benzoxazine resin, dicyclopentadiene type benzoxazine resin, and bisphenol fluorene type benzoxazine resin. Includes any one or a mixture of two or more selected.
Preferably, the phosphorus-containing epoxy resin has a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide structure, 10- (2,5-dihydroxyphenyl) -9,10-dihydro-9-. Polyfunctional epoxy resin containing an oxa-10-phosphaphenanthrene-10-oxide structure and a 10- (2,5-dihydroxynaphthyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide structure Any one or a mixture of two or more selected from.
Preferably, the acid anhydride compound contains a compound having two or more acid anhydride groups in its molecular structure.
Preferably, the acid anhydride compound is a styrene-maleic anhydride copolymer, a phenylpropylene-maleic anhydride copolymer, 3,3', 4,4'-diphenyl ether tetracarboxylic dianhydride, and the like. 2,3,3', 4'-diphenyl ether tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic acid Any one or a mixture of two or more selected from dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, and 1,2,4,5-pyromellitic dianhydride. Is.
Preferably, the curing accelerator is one or a mixture of t-amine, imidazoles, 4-dimethylaminopyridine, triphenylphosphine, or boron trifluoride monoethylamine.
Preferably, the halogen-free flame-retardant thermosetting resin composition further contains an inorganic filler.
Preferably, the inorganic filler accounts for 30% to 70% of the total weight of the halogen-free flame-retardant thermosetting resin composition.
Preferably, the inorganic filler is silica, soft glass powder, talc, kaolin, mica powder, boehmite, hydrotalcite, zinc borate, aluminum hydroxide, magnesium hydroxide, alumina, boron nitride, aluminum nitride, barium sulfate, and the like. And any one or a mixture of two or more selected from talcite.
The halogen-free flame-retardant thermosetting resin composition according to claim 1, wherein the silica is preferably one or a mixture of two or more of spherical silica, molten silica, and crystalline silica. A resin rubber liquid containing the halogen-free flame-retardant thermosetting resin composition according to any one of claims 1 to 5 and a solvent. A prepreg for a printed circuit containing a reinforcing material and the halogen-free flame-retardant thermosetting resin composition according to any one of claims 1 to 5, which is attached to the reinforcing material by impregnation and drying. An insulating plate containing at least one prepreg for a printed circuit according to claim 7. A metal-clad laminate comprising at least one prepreg for a printed circuit according to claim 7 and a metal foil covering one or both sides of the outer side of the prepreg. A printed wiring board including at least one prepreg for a printed circuit according to claim 7, or at least one insulating plate according to claim 8, or at least one metal-clad laminate according to claim 9.