WO2018120564A1 - Phosphorus-containing active ester, halogen-free composition and copper-clad foil substrate thereof - Google Patents

Abstract

Provided in the present invention are a phosphorus-containing active ester, a halogen-free resin composition thereof, and a prepreg and a laminate using the same. The halogen-free resin composition comprises: (A) a thermosetting resin; (B) a phosphorus-containing active ester resin. Prepregs and laminates which are made using said halogen-free resin composition have a low dielectric loss factor and may achieve halogen-free flame retardance.

Description

Phosphorus-containing active ester and halogen-free composition thereof and copper-clad substrate Technical field

The invention belongs to the technical field of copper clad laminates, and particularly relates to a phosphorus-containing active ester and a halogen-free resin composition thereof, and a prepreg, a laminate and a printed circuit board using the same.

Background technique

With the development of electronic components in the direction of small size, light weight, high performance, and multi-function, high-frequency, high-speed signal transmission is brought about. This requires that the dielectric constant and dielectric loss of the electronic material are relatively low, which is related to the structure of the material, and the low dielectric constant and low dielectric loss resin generally have a structure of large free volume and low polarization. , low water absorption, low dielectric constant structure exists and so on. In addition, on July 1, 2006, the EU's two environmental protection directives, the Waste Electrical and Electronic Equipment Directive and the Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment, were officially implemented, and the halogen-free flame-retardant copper foil layer was officially implemented. The development of pressure plate has become a hot spot in the industry. Each copper-clad laminate manufacturer has launched its own halogen-free flame-retardant copper-clad laminate.

The introduction of a phosphorus-containing compound into the resin matrix of the copper clad laminate is the main technical route for the halogen-free flame retardant of the copper clad laminate. At present, phosphorus-based flame retardants widely used in the field of copper clad laminates are mainly classified into two types: reactive type and additive type. The reaction type is mainly a DOPO compound, and the phosphorus-containing epoxy resin and the phosphorus-containing phenolic resin are mainly used, and the phosphorus content is between 2% and 10%. However, in practical applications, it has been found that DOPO-based compounds have a large water absorption rate and poor dielectric properties, and the sheet has poor heat and humidity resistance. The addition type is mainly a phosphazene and a phosphonate compound, and the added flame retardant has a low flame retardancy efficiency, and it is necessary to add more amount to achieve the flame retardant requirement. At the same time, due to its lower melting point (generally lower than 150 ° C), it is easy to migrate to the surface of the sheet during the processing of the laminate, which affects the performance of the sheet.

Summary of the invention

In view of the problems of the prior art, an object of the present invention is to provide a novel phosphorus-containing active ester which is incorporated into a thermosetting resin to prepare a halogen-free resin composition and a prepreg and a laminate using the same, using the same The reactive group with the specific thermosetting resin does not produce secondary hydroxyl groups, which can meet the requirements of low dielectric loss factor of high-speed substrate materials and meet the requirements of halogen-free flame retardant, so that the high-frequency high-speed substrate material is halogen-free. become possible.

In order to achieve the above object, the present invention adopts the following technical solutions:

One of the objects of the present invention is to provide a phosphorus-containing active ester comprising a component of the structure shown in formula (I):

Where R is

R ₁ is

m represents the average degree of polymerization, m is any number between 0.25 and 3, such as 0.25, 0.5, 1, 1.2, 1.8, 2.05, 2.8 or 3, and the specific point value between the above values, limited to length and for conciseness For the consideration of the present invention, the specific point values included in the scope are not exhaustive.

Another object of the present invention is to provide a halogen-free resin composition comprising the following components:

(A) a thermosetting resin;

(B) a phosphorus-containing active ester resin;

The phosphorus-containing active ester resin has a structure as shown in the formula (I):

Where R is

R ₁ is

m represents the average degree of polymerization, m is any number between 0.25 and 3, such as 0.25, 0.5, 1, 1.2, 1.8, 2.05, 2.8 or 3, and the specific point value between the above values, limited to length and for conciseness For the consideration of the present invention, the specific point values included in the scope are not exhaustive.

The invention introduces a phosphorus-containing structural active ester into a thermosetting resin, and utilizes an active ester to react with an epoxy resin or the like without generating a secondary hydroxyl group; it can satisfy the halogen-free flame retardant requirement and can improve the electrical properties of the system (reducing the dielectric loss factor) ) to achieve halogen-free high-frequency high-speed substrate materials.

According to the present invention, the thermosetting resin is an epoxy resin, a benzoxazine resin, a cyanate resin, an unsaturated polyester resin, a vinyl resin, a bismaleimide resin, a BT resin, a phenol resin, a polyurethane resin. Any one or a mixture of at least two of a thermosetting polyimide, an aryl acetylene resin or a furan resin, wherein a typical but non-limiting mixture is: an epoxy resin and a benzoxazine resin, a cyanate resin And unsaturated polyester resins, vinyl resins and bismaleimide resins.

In the present invention, the epoxy resin is any one of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a dicyclopentadiene epoxy resin, a biphenyl epoxy resin or a naphthol epoxy resin. Or a mixture of at least two, wherein the typical but non-limiting mixture is: bisphenol A type epoxy resin and bisphenol F type epoxy resin, bisphenol F type epoxy tree and dicyclopentadiene epoxy resin, Benzene epoxy resin and naphthol epoxy resin.

Preferably, the epoxy resin is a biphenolic epoxy resin or/and a DCPD novolac epoxy resin, which has both heat resistance and dielectric properties and low water absorption.

In the present invention, the epoxy equivalent of the epoxy resin and the ester group equivalent ratio of the phosphorus-containing active ester resin are 1: (0.9 to 1.1), for example, 1:0.9, 1:0.95, 1:1, 1:1.05 or 1 : 1.1, and the specific point values between the above values, limited to the length and for the sake of brevity, the present invention will not exhaustively enumerate the specific point values included in the range, preferably 1: (0.95 - 1.05).

In the present invention, the halogen-free resin composition may further contain a component (C) curing accelerator which cures the resin and accelerates the curing speed of the resin.

Preferably, the curing accelerator is added in an amount of 0.05 to 1 part by weight, such as 0.05 part by weight, 0.08 part by weight, or 0.1, based on 100 parts by weight of the sum of the components (A) and the component (B). Parts by weight, 0.15 parts by weight, 0.2 parts by weight, 0.25 parts by weight, 0.3 parts by weight, 0.35 parts by weight, 0.4 parts by weight, 0.45 parts by weight, 0.5 parts by weight, 0.55 parts by weight, 0.6 parts by weight, 0.65 parts by weight, 0.7 parts by weight 0.75 parts by weight, 0.8 parts by weight, 0.85 parts by weight, 0.9 parts by weight or 1 part by weight, and the specific point values between the above values, which are limited in scope and for the sake of brevity, the present invention is not exhaustively enumerated. The specific point value.

Preferably, the curing accelerator is any one of a mixture of 4-dimethylaminopyridine, 2-methylimidazole, 2-methyl 4-ethylimidazole or 2-phenylimidazole or a mixture of at least two thereof, wherein Typical but non-limiting mixtures are: 4-dimethylaminopyridine and 2-methylimidazole, 2-methylimidazole and 2-methyl 4-ethylimidazole, 2-methyl 4-ethylimidazole and 2- Phenyl imidazole.

In the present invention, the halogen-free resin composition may further comprise a component (D) flame-retardant compound which is a halogen-free flame retardant.

Preferably, the flame retardant compound is added in an amount of from 0 to 50 parts by weight, such as 1 based on 100 parts by weight of the sum of the addition amounts of the component (A), the component (B) and the component (C). Parts by weight, 5 parts by weight, 10 Parts by weight, 15 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight or 50 parts by weight, and the specific values between the above values, are limited in length and for the sake of brevity. The present invention is no longer exhaustive of the specific point values included in the scope.

Preferably, the flame retardant compound is a phosphorus-containing phenolic resin, a phosphorus-containing bismaleimide, a phosphinate, an aryl phosphate type compound, a nitrogen-phosphorus-based intumescent flame retardant, and a phosphazene type resist. Any one or a mixture of at least two of a flammable or organic polymer flame retardant, wherein a typical but non-limiting mixture is: a phosphorus-containing phenolic resin and a phosphorus-containing bismaleimide, a phosphorus-containing double horse Imide and phosphinates, nitrogen-phosphorus-based intumescent flame retardants and phosphazene-type flame retardants.

Preferably, the halogen-free resin composition may further comprise a component (E) filler, which is an organic or/and inorganic filler, which is mainly used to adjust some physical properties of the composition, such as lowering the coefficient of thermal expansion (CTE). , reduce water absorption, improve thermal conductivity, and so on.

Preferably, the filler is added in an amount of from 0 to 100 parts by weight based on 100 parts by weight of the sum of the components (A), the component (B), the component (C) and the component (D). It is preferably 0 to 50 parts by weight. The filler is added in an amount of, for example, 0.5 parts by weight, 1 part by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, and 45 parts by weight. Parts, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, 90 parts by weight, 95 parts by weight or 100 parts by weight, and the above values The specific point values are limited, and for the sake of brevity, the present invention will not exhaustively enumerate the specific point values included in the scope.

Preferably, the inorganic filler is fused silica, crystalline silica, spherical silica, hollow silica, aluminum hydroxide, alumina, talc, aluminum nitride, boron nitride, silicon carbide Any one or a mixture of at least two of barium sulfate, barium titanate, barium titanate, calcium carbonate, calcium silicate, mica or fiberglass powder, wherein a typical but non-limiting mixture is: fused silica a mixture with crystalline silica, a mixture of spherical silica and hollow silica, aluminum hydroxide and oxidation a mixture of aluminum, a mixture of talc and aluminum nitride, a mixture of boron nitride and silicon carbide, a mixture of barium sulfate and barium titanate, a mixture of barium titanate and calcium carbonate, calcium silicate, mica and glass fiber powder Mixture, fused silica, a mixture of crystalline silica and spherical silica, hollow silica, a mixture of aluminum hydroxide and alumina, a mixture of talc, aluminum nitride and boron nitride, silicon carbide a mixture of barium sulfate and barium titanate, a mixture of barium titanate, calcium carbonate, calcium silicate, mica and fiberglass powder.

Preferably, the organic filler is any one of a polytetrafluoroethylene powder, a polyphenylene sulfide or a polyethersulfone powder or a mixture of at least two, wherein a typical but non-limiting mixture is: polytetrafluoroethylene powder a mixture with polyphenylene sulfide, a mixture of polyethersulfone powder and polytetrafluoroethylene powder, a mixture of polyphenylene sulfide and polyethersulfone powder, a mixture of polytetrafluoroethylene powder, polyphenylene sulfide and polyethersulfone powder .

Preferably, the filler is silica, and the filler has a median particle diameter of 1 to 15 μm, and preferably the filler has a median particle diameter of 1 to 10 μm.

The term "comprising" as used in the present invention means that it may contain, in addition to the components, other components which impart different characteristics to the halogen-free resin composition. In addition, the "comprising" described in the present invention may also be replaced by a closed "for" or "consisting of".

For example, the halogen-free resin composition may further contain various additives, and specific examples thereof include an antioxidant, a heat stabilizer, an antistatic agent, an ultraviolet absorber, a pigment, a colorant, a lubricant, and the like. These various additives may be used singly or in combination of two or more kinds.

The preparation method of the halogen-free resin composition of the present invention is a conventional technical means in the art, which is: firstly, the solid matter is put in, then the liquid solvent is added, and the mixture is stirred until the solid matter is completely dissolved, and then the liquid resin is added and promoted. Continue to stir evenly.

The solvent in the present invention is not particularly limited, and specific examples thereof include alcohols such as methanol, ethanol, and butanol, ethyl cellosolve, butyl cellosolve, ethylene glycol methyl ether, carbitol, and butyl. Kika An ether such as an alcohol, a ketone such as acetone, methyl ethyl ketone, methyl ethyl ketone or cyclohexanone; an aromatic hydrocarbon such as toluene or xylene; an ester such as ethyl acetate or ethoxyethyl acetate; A nitrogen-containing solvent such as N,N-dimethylformamide or N,N-dimethylacetamide. The above solvents may be used singly or in combination of two or more. Preference is given to ketones such as acetone, methyl ethyl ketone, methyl ethyl ketone and cyclohexanone. The amount of the solvent to be added is selected by those skilled in the art based on his own experience, so that the resin glue can reach a viscosity suitable for use.

A third object of the present invention is to provide a prepreg comprising a reinforcing material and a halogen-free resin composition as described above adhered thereto by dampening and drying.

Exemplary reinforcing materials are nonwoven fabrics and/or other fabrics such as natural fibers, organic synthetic fibers, and inorganic fibers.

The prepreg is obtained by using the glue-impregnated reinforcing material such as a fabric or an organic fabric such as glass cloth, and drying the infiltrated reinforcing material in an oven at 155 ° C for 5 to 10 minutes.

A fourth object of the present invention is to provide a laminate comprising at least one prepreg as described above.

The laminate of the present invention comprises a laminate produced by bonding together one or two or more prepregs by heat and pressure, and a metal foil bonded to one or both sides of the laminate. The laminate is obtained by curing in a hot press at a curing temperature of 150 to 250 ° C and a curing pressure of 10 to 60 kg/cm ² . The metal foil is copper foil, nickel foil, aluminum foil, SUS foil, etc., and the material thereof is not limited.

A fifth object of the present invention is to provide a printed circuit board comprising at least one prepreg as described above.

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

(1) By introducing a novel phosphorus-containing active ester into a thermosetting resin, it can react with an epoxy resin or the like without generating a secondary hydroxyl group, thereby satisfying the halogen-free flame retardant requirement and improving the electrical properties of the system (reducing dielectric properties) Loss factor), making high-frequency high-speed substrate materials halogen-free possible;

(2) A prepreg, a laminate, and a metal foil-clad laminate produced by using the halogen-free resin composition of the present invention have a low dielectric loss factor and a Df value of between 0.0076 and 0.0097, and Halogen-free flame retardant, reaching UL94V-0.

detailed description

The technical solution of the present invention will be further described below by way of specific embodiments.

The following is a specific embodiment of the embodiments of the present invention. It should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the embodiments of the present invention. And retouching is also considered to be the scope of protection of the embodiments of the present invention.

The embodiments of the present invention are further described below in various embodiments. The embodiments of the present invention are not limited to the specific embodiments below. Modifications can be made as appropriate without departing from the scope of the claims.

Synthesis Example 1

0.3 mol of DOPO was heated to 160 ° C to melt, 0.1 mol of 4,4 '-dihydroxybenzophenone was added to the molten DOPO, water was formed during the reaction, and the generated water was distilled off under reduced pressure to promote the positive movement of the reaction. . After 4 h of reaction, the temperature was lowered to 100 ° C, 100 ml of toluene was added, and the excess DOPO was dissolved in toluene, and the product was precipitated as a white powder. The product was filtered and purified by washing with tetrahydrofuran to give 2DOPO-2PhOH.

628.5 g (1 mol) of 2DOPO-2PhOH and 816 g of methyl isobutyl ketone (MIBK) were placed in a flask equipped with a thermometer, a dropping funnel, a condenser, a fractionation tube, and a stirrer, and the system was replaced with nitrogen under reduced pressure in the system. It dissolves. Next, 182.7 g (0.9 mol) of terephthalic acid chloride was charged and reacted for 2 h, and the temperature in the system was controlled to be below 60 ° C; then, 114 g (1.2 mol) of phenol was added to the system, and the reaction was continued for 1 h; 189 g of a 20% aqueous sodium hydroxide solution were added dropwise; stirring was continued for 1 h under the conditions. After the reaction was completed, the aqueous layer was removed by static liquid separation. Water was added to the MIBK phase in which the reactant was dissolved, stirred and mixed, and the liquid layer was statically separated to remove the aqueous layer. Repeat the above operation until the pH of the water layer reaches about 7.0. Then pass The water was removed by a decanter, and then MIBK was removed by distillation under reduced pressure to obtain a phosphorus-containing active ester resin A1.

Synthesis Example 2

0.3 mol of DOPO was heated to 160 ° C to melt, 0.1 mol of 4,4 '-dihydroxybenzophenone was added to the molten DOPO, water was formed during the reaction, and the generated water was distilled off under reduced pressure to promote the positive movement of the reaction. . After 4 h of reaction, the temperature was lowered to 100 ° C, 100 ml of toluene was added, and the excess DOPO was dissolved in toluene, and the product was precipitated as a white powder. The product was filtered and purified by washing with tetrahydrofuran to give 2DOPO-2PhOH.

628.5 g (1 mol) of 2DOPO-2PhOH and 816 g of methyl isobutyl ketone (MIBK) were placed in a flask equipped with a thermometer, a dropping funnel, a condenser, a fractionation tube, and a stirrer, and the system was replaced with nitrogen under reduced pressure in the system. It dissolves. Next, 182.7 g (0.9 mol) of terephthalic acid chloride was added and reacted for 2 h, and the temperature in the system was controlled to be below 60 ° C; then, 172.8 g (1.2 mol) of naphthol was added to the system, and the reaction was continued for 1 h; 189 g of a 20% aqueous sodium hydroxide solution was slowly added dropwise; stirring was continued for 1 hour under the conditions. After the reaction was completed, the aqueous layer was removed by static liquid separation. Water was added to the MIBK phase in which the reactant was dissolved, stirred and mixed, and the liquid layer was statically separated to remove the aqueous layer. Repeat the above operation until the pH of the water layer reaches about 7.0. Then, the water was removed by a decanter, and then MIBK was removed by distillation under reduced pressure to obtain a phosphorus-containing active ester resin A2.

The tables are all based on the weight of the solid components, and the materials listed in Tables 1-2 are as follows:

627: bisphenol A type phenolic epoxy resin (Hexion, USA)

7200-3H: Dicyclopentadiene type novolac epoxy resin (Japan DIC trade name)

NC-3000H: Biphenyl type phenolic epoxy resin (Japanese chemical product trade name)

HP8000: Dicyclopentadiene type active ester (Japan DIC trade name)

CE-01PS: Bisphenol A type cyanate (Yangzhou Tianqi trade name)

Filler: spherical silicon micro powder DQ1040 (Jiangsu Lianrui product name)

Flame retardant: DOPO structure flame retardant XP-7866 (Albemarle product name)

A1: The phosphorus-containing structural active ester described in Synthesis Example 1

A2: The phosphorus-containing structural active ester described in Synthesis Example 2

DMAP: 4-dimethylaminopyridine, accelerator (Guangrong Chemical Trade Name)

Example 1

Take a container, add 60 parts by weight of 627, add an equivalent of A1 active ester and continue to stir, add an appropriate amount of curing accelerator 4-dimethylaminopyridine, continue to stir evenly, and finally adjust the liquid solid content to 60% to 80% with solvent. And made into a glue. The above glue is impregnated with a glass fiber cloth to form a glue. The above glue was impregnated with a glass fiber cloth and controlled to a suitable thickness, and then the solvent was removed by drying to obtain a prepreg. The prepregs obtained by using a plurality of sheets were laminated on each other, and a copper foil was respectively pressed on both sides thereof and placed in a heat press to be cured to form the epoxy resin copper clad laminate. The physical property data is shown in Table 1.

Examples 2-9

The production process was the same as in Example 1, and the formulation composition and physical property index are shown in Tables 1-2.

Comparative examples 1 to 6

The manufacturing process was the same as that of Example 1, and the formulation composition and physical property index are shown in Table 2.

Table 1

substance	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Example 7
627	60
7200-3H		60
NC-3000H			60	60	60	60	60
A1	1eq	1eq	1eq	0.9eq	1.1eq		1eq
A2						1eq
CE-01PS
filler							20
DMAP	0.05	0.06	0.07	0.08	0.08	0.08	0.07
Tg(DSC)/°C	178	175	165	162	164	168	170
Dk (10GHz)	3.96	3.85	3.95	3.95	3.93	3.93	4.03
Df (10GHz)	0.0097	0.0092	0.0089	0.0089	0.0088	0.0088	0.0086

Flame retardant properties

94V-0

94V-0

94V-0

94V-0

94V-0

94V-0

94V-0

Table 2

substance	Example 8	Example 9	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5	Comparative example 6
NC-3000H	60	60	60	60	60	60	60	60
A1	20	20
A2
HP8000			1eq	1eq	1eq	20	20	20
CE-01PS	20	20				20	20	20
filler		20			20			20
Flame retardant				15	15		15	15
DMAP	0.05	0.05	0.07	0.08	0.07	0.08	0.05	0.08
Tg(DSC)/°C	187	190	155	148	150	182	175	178
Dk (10GHz)	3.98	4.05	3.95	3.96	4.02	4.02	4.08	4.06
Df (10GHz)	0.078	0.076	0.0095	0.0010	0.0098	0.0086	0.0089	0.0087
Flame retardant properties	94V-0	94V-0	94V-2	94V-0	94V-0	94V-2	94V-0	94V-0

The test methods for the above characteristics are as follows:

(1) Glass transition temperature (Tg): It was measured by differential scanning calorimetry (DSC) according to the DSC method specified in IPC-TM-6502.4.25.

(2) Dielectric constant and dielectric loss factor: The test was carried out in accordance with the method specified in IPC-TM-650 2.5.5.9, and the test frequency was 10 GHz.

(3) Flame retardancy: It was carried out in accordance with the UL 94 standard method.

Physical property analysis:

It can be seen from Examples 1 to 9 in Tables 1 and 2 that after the introduction of the phosphorus-containing active ester curing agent, the system has a low dielectric loss factor and can meet the UL94V-0 flame retardant requirement; as can be seen from Example 7, After the introduction of the silica filler, the system has a lower dielectric loss factor; as can be seen from Example 8 and Example 9, the ternary system has a lower ternary system due to the introduction of a free-volume and symmetrical annular DOPO structure. Dielectric loss factor and higher glass transition temperature.

It can be seen from Comparative Example 1 and Comparative Example 2 of Table 2 that after the introduction of the dicyclopentadiene type active curing agent, the body Has a lower dielectric loss factor, but can not meet the flame retardant requirements of UL94, and even after adding flame retardant, although the UL94 flame retardant requirements can be met, the dielectric loss factor is slightly increased; and from Examples 3-6 It can be seen that, compared with Comparative Example 1 and Comparative Example 2, while satisfying the UL94V-0 flame retardant requirement, the system has a lower dielectric loss factor and has a lower dielectric loss factor due to the introduction of a free-volume and symmetrical annular DOPO structure. High glass transition temperature.

Comparing Comparative Example 3 of Table 2 with Example 7, and Comparative Example 5, as compared with Example 8, it is understood that the phosphorus-containing active ester curing of the present invention is replaced by a mixture of a DOPO structural flame retardant and a dicyclopentadiene type active ester. Agent, system heat resistance and dielectric properties are poor; from the comparison of 4, the introduction of cyanate ester can reduce the dielectric loss factor of the system, but still can not meet the UL94V-0 flame retardant requirements; from Comparative Example 5 and the comparative example 6 It can be seen that the introduction of the flame retardant can improve the flame retardant performance, but the dielectric loss factor is increased, even if the dielectric loss factor of the system is lowered by adding the filler, it is still higher than the dielectric loss of the system of the embodiment 8 and the embodiment 9. factor.

As described above, the circuit substrate material made of the halogen-free composition of the present invention has a low dielectric loss factor and can realize halogen-free flame retardancy as compared with a general laminate.

The above is only a preferred embodiment of the present invention, and various other changes and modifications can be made in accordance with the technical solutions and technical concept of the present invention, and all such changes and modifications will be made to those skilled in the art. Modifications are intended to fall within the scope of the claims of the present invention.

The Applicant declares that the present invention is described by the above-described embodiments, but the present invention is not limited to the above detailed methods, that is, it does not mean that the present invention must be implemented by the above detailed methods. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitution of the various materials of the products of the present invention, addition of auxiliary components, selection of specific means, and the like, are all within the scope of the present invention.

Claims (9)

1. A phosphorus-containing active ester characterized in that it comprises a component of the structure shown in formula (I):

   

   Where R is

   

   R ₁ is

   

   m represents the average degree of polymerization, and m is an arbitrary number between 0.25 and 3.
2. A halogen-free resin composition characterized in that the halogen-free resin composition comprises the following components:

   (A) a thermosetting resin;

   (B) a phosphorus-containing active ester resin;

   The phosphorus-containing active ester resin has a structure as shown in the formula (I):

   

   Where R is

   

   R ₁ is

   

   m represents the average degree of polymerization, and m is an arbitrary number between 0.25 and 3.
3. The halogen-free resin composition according to claim 2, wherein the thermosetting resin is an epoxy resin, a benzoxazine resin, a cyanate resin, an unsaturated polyester resin, a vinyl resin, and a double horse. Any one or a mixture of at least two of an imide resin, a BT resin, a phenol resin, a polyurethane resin, a thermosetting polyimide, an aryl acetylene resin or a furan resin;

   Preferably, the epoxy resin is any one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene epoxy resin, biphenyl epoxy resin or naphthol epoxy resin or a mixture of at least two, preferably a biphenolic epoxy resin or/and a dicyclopentadiene novolac epoxy resin;

   Preferably, the epoxy equivalent of the epoxy resin and the ester group equivalent ratio of the phosphorus-containing active ester resin are 1: (0.9 to 1.1), preferably 1: (0.95 to 1.05).
4. The halogen-free resin composition according to claim 2 or 3, wherein the halogen-free resin composition further comprises a component (C) curing accelerator;

   Preferably, the curing accelerator is added in an amount of 0.05 to 1 part by weight based on 100 parts by weight of the sum of the components (A) and the component (B);

   Preferably, the curing accelerator is any one of 4-dimethylaminopyridine, 2-methylimidazole, 2-methyl 4-ethylimidazole or 2-phenylimidazole or a mixture of at least two.
5. The halogen-free resin composition according to any one of claims 2 to 4, wherein the halogen-free resin composition further comprises a component (D) flame-retardant compound;

   Preferably, the flame retardant compound is added in an amount of from 0 to 50 parts by weight based on 100 parts by weight of the sum of the components (A), the component (B) and the component (C);

   Preferably, the flame retardant compound is a phosphorus-containing phenolic resin, a phosphorus-containing bismaleimide, a phosphinate, an aryl phosphate type compound, a nitrogen-phosphorus-based intumescent flame retardant, and a phosphazene type resist. Any one or a mixture of at least two of a flammable or organic polymer flame retardant.
6. A halogen-free resin composition according to any one of claims 2 to 5, wherein said halogen-free tree The fat composition further comprises a component (E) filler;

   Preferably, the filler is an organic or/and inorganic filler;

   Preferably, the filler is added in an amount of from 0 to 100 parts by weight based on 100 parts by weight of the sum of the components (A), the component (B), the component (C) and the component (D). , preferably 0 to 50 parts by weight;

   Preferably, the inorganic filler is fused silica, crystalline silica, spherical silica, hollow silica, aluminum hydroxide, alumina, talc, aluminum nitride, boron nitride, silicon carbide Any one or a mixture of at least two of barium sulfate, barium titanate, barium titanate, calcium carbonate, calcium silicate, mica or fiberglass powder;

   Preferably, the organic filler is any one of a polytetrafluoroethylene powder, a polyphenylene sulfide or a polyethersulfone powder or a mixture of at least two;

   Preferably, the filler is silica, and the filler has a median particle diameter of from 1 to 15 μm, preferably from 1 to 10 μm.
7. A prepreg comprising a reinforcing material and a halogen-free resin composition according to any one of claims 2 to 6 adhered thereto by impregnation and drying.
8. A laminate comprising at least one prepreg according to claim 7.
9. A printed circuit board comprising at least one prepreg according to claim 7.