TW202300558A - Active polyester, curable resin composition and cured resin - Google Patents

Abstract

An active polyester having the structure shown in formula (I): in formula (1), Y is a single bond, a substituted or unsubstituted C1 to C6 alkylene group, a carbonyl group, an oxygen atom, or a sulfonyl group; Ar is a divalent aromatic group; n1 and n2 are each independently a positive integer and meet the condition: 4 < n1 + n 2 < 26; m is a positive integer from 2 to 50; and R1 is selected from the group consisting of the following formulas:,,, and, wherein R2 is a hydrogen atom, a halogen atom or C1-C6 alkyl group. The active polyester can be used as an epoxy resin curing agent to improve the processability, heat resistance, dielectricity, toughness and flame retardancy of the cured epoxy resin.

Description

Reactive polyester, curable resin composition and cured resin

This disclosure relates to a polyester curing agent, curable resin composition and resin cured product, and more systematically relates to a polyester curing agent with active ester groups, curable resin composition and resin cured product using it.

With the high performance and networking of signal communication equipment, in order to transmit and process a large number of signals at high speed, the operation signal is developing towards high speed and high frequency. In order to achieve the above goals, the printed circuit board (PCB) material in the signal communication equipment must have good dielectric properties (such as low dielectric constant (dielectric constant, Dk) and low loss tangent (dissipation factor, Df)) to meet the signal High-frequency transmission needs, and also need to have good heat resistance and machinability to meet the reliability of printed circuit boards.

Among existing materials for printed circuit boards, cured epoxy resins obtained from epoxy resin compositions mainly composed of epoxy resins and curing agents are widely used. However, if general-purpose curing agents are used, highly polar secondary alcohols are produced during the curing of epoxy resins, which are highly hygroscopic, resulting in high loss tangent, unsatisfactory dielectric properties, and poor heat resistance. also decreased. Therefore, the industry develops active esters as curing agents for epoxy resins, which can avoid the formation of highly polar secondary alcohols.

For example, TWI579332 uses an active ester curing agent (trade name EPICLON HPC-8000-65T) containing a dicyclopentdiene (Dicyclopentdiene, DCPD) structure, epoxy resin and cyanate ester copolymerization to obtain a resin with a dielectric loss of about 8mU. thing.

TWI565750 discloses a novel active ester resin with excellent solubility in various solvents. The resin cured product using it has low dielectric constant and loss tangent, and is also excellent in low hygroscopicity. It can be applied to semiconductor sealing materials and prepregs bodies, circuit substrates, and laminated films. The active ester resin has a structure shown in the following formula, wherein, X is a benzene ring or a naphthalene ring; R ¹ is each independently a methyl group or a hydrogen atom; k is 0 or 1; n is 1 or 2; l is 1 or 2 ; m is the average of repeating units, ie 0.25~1.5.

TWI565750 uses epoxy resin, cyanate resin, active ester and hardening accelerator for curing reaction to obtain a resin composition with low dielectric tangent and excellent bonding strength with conductors after accelerated environmental tests. The active ester used is such as: EXB9460-65T (that is, EPICLON HPC-8000-65T, a product of DIC of DIC, with an active group equivalent of 223), DC808 (the acetylated product of novolac, made by Japan Epoxy Resin, with an active group equivalent of 149) , YLH1026 (a benzoylated product of novolac, manufactured by Japan Epoxy Resin, with an active group equivalent of 200) and the like.

TWI532784 uses dicyclopentadiene type benzoxazine resin, epoxy resin and active ester (HPC-8000-65T) to prepare low dielectric tangent cured products. However, its disadvantage is that the derived epoxy cured product cannot meet the flame retardancy requirements of V-0.

TWI301842 discloses a polyester obtained by reacting xylene ether oligomer and diacyl chloride, which can be formed into a film independently or mixed with polystyrene, and can be laminated with metal foil into layers. Its dielectric constant (10GHz) value is between 2.47~2.72U, and dielectric loss (10GHz) is between 3.8~5.9mU. However, this patent does not mention the application of the crosslinking reaction between active ester and epoxy resin.

CN104761719 proposes an active ester containing 2,6-dimethylphenyl ether structure, which is a double-end multifunctional active ester containing a PPO main bond. Its structure is as follows:

When using 1,3,5-benzenetriformyl chloride and the phenolic oligomer of PPO to react, an oligomer with n3=n4=2 can be obtained. When using 1,2,4,5- pyromellityl chloride to react with PPO phenolic oligomers, n3=n4=3 oligomers can be obtained. However, the active ester group of this patent is only located at the end of the chain, and the derived epoxy resin cured product cannot meet the requirement of high flame retardancy.

TW 106122483 discloses a high-molecular-weight polyester obtained by reacting bisphenol compounds containing 2,6-dimethylphenylene ether oligomers and diacyl chlorides. Its structure is as follows:

The polyester is a reactive polyester and can be cross-linked with epoxy resin. However, the disadvantage of this patent is that the derived epoxy resin cured product cannot meet the requirement of high flame retardancy.

On the other hand, in 2012, Lin et al. (Polym.Chem., 2012, 3, 935-945) performed a curing reaction with a polymer type benzoxazine resin (main-chain type polybenzoxazine), and the obtained cured product ratio was smaller than The cured product obtained from molecular type benzoxazine resin (benzoxazine) has a higher glass transition temperature and good mechanical properties. Lin et al. (Polymer 2013, 54, 1612) in 2013 The cured product obtained by using high molecular weight phenolic curing agent and epoxy resin for curing reaction has a higher glass transition temperature and good mechanical properties than the cured product obtained by using small molecular curing agent.

It can be known from the above documents that the polymer epoxy resin curing agent has the potential to improve the performance of the resin cured product, and different curing agents can be used to obtain a high-performance resin cured product. Since the development of epoxy resin cured products with high solvent resistance, high heat resistance, good dielectric capacity, high toughness and flame retardancy is an urgent goal, it is hoped that the above goals can be achieved with epoxy resin curing agents.

In order to make the product have excellent high processability, high heat resistance, good dielectric capacity, high toughness and flame retardancy, this disclosure provides a kind of active polyester, which has a structure shown in formula (I):

In formula (1), Y is a single bond, substituted or unsubstituted C1 to C6 alkylene, carbonyl, oxygen atom or sulfonyl group,

Ar is a divalent aromatic group,

n1 and n2 are independently positive integers, and 4<n1+n2<26,

m is a positive integer of 2-50, and

_R is selected from the group consisting of:

、

、

及

，其 中，R₂係氫原子、鹵素或C1-C6烷基。

,

,

and

, wherein, R ₂ is a hydrogen atom, halogen or C1-C6 alkyl.

In at least one specific embodiment, Ar in formula (1) is selected from the group consisting of the following formulas:

，其中，X係單鍵、亞甲基、氧原子、羰基、磺醯 基、-C(CH₃)₂-或-C(CF₃)₂-。

, wherein, X is a single bond, methylene, oxygen atom, carbonyl, sulfonyl, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -.

In at least one specific embodiment, Y in formula (1) is a single bond, methylene or isopropylidene, and Ar is 1,4-phenylene or 1,3-phenylene. And in at least one specific embodiment, Y in formula (1) is isopropylene, and Ar is 1,4-phenylene or 1,3-phenylene.

In at least one specific embodiment, the reactive polyester has a structure as shown in formula (II):

In at least one specific embodiment, the reactive polyester has a structure as shown in formula (III):

The present disclosure further provides a curable resin composition, including the above-mentioned reactive polyester and epoxy resin.

In at least one embodiment, the ratio of the epoxy equivalents of the epoxy resin to the active ester equivalents of the reactive polyester is between 0.8 and 1.2.

In at least one specific embodiment, the epoxy resin is selected from bisphenol A type epoxy resin, novolak epoxy resin, methyl novolac epoxy resin, dicyclopentadiene-phenol epoxy resin and naphthalene ring-containing epoxy resin At least one member of the group consisting of epoxy resins.

In at least one embodiment, the curable resin composition further includes a curing accelerator.

In at least one embodiment, the curing accelerator is at least one selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators and organophosphorus-based curing accelerators.

In at least one specific embodiment, the curing accelerator accounts for 0.1 wt % to 1.0 wt % based on the total weight of the epoxy resin.

In at least one specific embodiment, the curing accelerator is selected from the group consisting of imidazole, 2-methylimidazole, 2-methyl-4-ethylimidazole, 4-dimethylaminopyridine and triphenylphosphine at least one of the group.

The present disclosure also provides a cured resin, which is obtained by curing the curable resin composition.

In at least one embodiment, the curing temperature is between 140°C and 240°C.

In at least one specific embodiment, the curing is achieved by stepwise heating and curing, and each stage of curing lasts for more than 1 hour.

The reactive polyester disclosed in this disclosure can be used as a curing agent in a curable resin composition, and the resin used can be an epoxy resin. Since the active polyester has an active ester group, in addition to cross-linking with the epoxy resin, the active polyester can also block the hydroxyl groups generated during the reaction, so that the dielectric constant and loss tangent of the cured resin can be improved. Effectively reduce and improve the heat resistance of cured resin. In addition, the cured resin prepared from the curable resin composition has high processability, high heat resistance, good dielectric capability, high toughness and flame retardancy.

Fig. 1 is the 1H nuclear magnetic resonance (1H NMR) spectrogram of synthesis example 1 active polyester.

Fig. 2 is the 1H nuclear magnetic resonance spectrogram of synthetic example 2 active polyester.

FIG. 3 is the thermomechanical analysis (Thermomechanical analysis, TMA) results of Examples 1 and 2 and Comparative Examples 1 and 2.

Figure 4 is the dynamic mechanical analysis (Dynamic mechanical analysis, DMA) results of Examples 1 and 2 and Comparative Examples 1 and 2.

Fig. 5 is the thermogravimetric analysis (TGA) results of Examples 1 and 2 and Comparative Examples 1 and 2.

The implementation of the present disclosure is described below through specific specific examples, and those skilled in the art to which the present disclosure pertains can easily understand the scope and effect of the present disclosure according to the contents described herein. However, the specific embodiments described herein are not intended to limit the present disclosure, and the listed technical features or solutions can be combined with each other, and the present disclosure can also be implemented or applied through other different implementation modes. The details can also be changed or modified according to different viewpoints and applications without departing from the present disclosure.

When "comprising", "comprising" or "having" specific elements described herein, unless otherwise specified, other elements, components, structures, regions, locations, devices, systems, steps or connection relationships, etc. may be included in addition elements, not to the exclusion of such other elements.

The singular forms "a" and "the" described herein also include plural forms, and "or" and "and/or" described herein may be used interchangeably unless otherwise clearly stated herein.

The numerical ranges described herein are inclusive and combinable, and any value falling within the numerical ranges stated herein can be used as the maximum or minimum value to derive the next range; for example, the numerical range of "0.8 to 1.2" It should be understood as including any sub-range between the minimum value of 0.8 and the maximum value of 1.2, such as: 0.8 to 1.1, 0.9 to 1.2, and 0.9 to 1.1 and other sub-ranges; in addition, if a value falls within the ranges described herein Within (such as between the maximum value and the minimum value), it should be deemed to be included in the scope of the present disclosure.

reactive polyester

The reactive polyester disclosed herein is specifically a reactive polyester comprising 2,6-dimethylphenylene ether repeating units, which may have a structure as shown in formula (I):

In formula (1), Y is a single bond, substituted or unsubstituted C1 to C6 alkylene, carbonyl (carbonyl group), oxygen atom or sulfonyl group (sulfonyl group),

Ar is a divalent aromatic group,

n1 and n2 are independently positive integers, and 4<n1+n2<26,

m is a positive integer from 2 to 50, and

_R is selected from the group consisting of:

、

、

及

，其 中，R₂係氫原子、鹵素或C1-C6烷基。

,

,

and

, wherein, R ₂ is a hydrogen atom, halogen or C1-C6 alkyl.

In at least one embodiment, Y is a single bond, methylene group, or isopropylene group. In at least one embodiment, Ar is the group consisting of:

，其中，X係單鍵、亞甲基、氧原子、羰基、磺醯 基、-C(CH₃)₂-或-C(CF₃)₂-，舉例而言，Ar可為1,4-伸苯基或1,3-伸苯基。

, where X is a single bond, methylene, oxygen atom, carbonyl, sulfonyl, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -, for example, Ar can be 1,4- Phenylylene or 1,3-phenylene.

In at least one specific embodiment, the reactive polyester of the present disclosure has a structure as shown in formula (II) or formula (III):

Preparation method of active polyester

The reactive polyester disclosed herein can be prepared by various methods, and an exemplary preparation method is provided below.

First, a bisphenol compound comprising an oligomer of 2,6-dimethylphenylene ether repeating unit is provided, which has a structure as shown in formula (a):

In general formula (a), Y, n1 and n2 are as defined in formula (I), that is, Y is a single bond, substituted or unsubstituted C1 to C6 alkylene, carbonyl, oxygen atom or sulfonyl group, n1 and n2 are each independently a positive integer and 4<n1+n2<26.

Next, the above-mentioned bisphenol compound and diacyl chloride compound containing an aromatic ring structure are mixed and reacted to obtain the active polyester of the present disclosure.

In at least one embodiment, the molar ratio of the diacid chloride compound to the bisphenol compound is between 0.7 and 1.3, such as 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25 or 1.3.

In at least one specific embodiment, the diacyl chloride compound, for example, includes the following structures shown in formula (b-1) to formula (b-4):

其中，X係單鍵、亞甲基、氧原子、羰基、磺醯基、-C(CH₃)₂-或-C(CF₃)₂-。

Wherein, X is a single bond, a methylene group, an oxygen atom, a carbonyl group, a sulfonyl group, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -.

In at least one specific embodiment, the reaction of the bisphenol compound and the diacyl chloride compound is carried out in the presence of an alkali catalyst, such as the alkali catalyst selected from CsF, KF, CsCl, KCl, K ₂ CO ₃ , At least one member of the group consisting of Na ₂ CO ₃ , KOH and NaOH. In at least one embodiment, the molar ratio of the alkali catalyst to the bisphenol compound is between 0.5 and 1.5, such as 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 , 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, or 1.5.

In at least one embodiment, the ester equivalent weight of the reactive polyester is half of the molecular weight of the repeating unit.

Curable resin composition and resin cured product

The curable resin composition of the present disclosure includes the aforementioned reactive polyester and epoxy resin.

In at least one specific embodiment, the ratio of the epoxy equivalents of the epoxy resin to the active ester equivalents of the reactive polyester is between 0.8 and 1.2, such as 0.8, 0.85, 0.9, 0.95, 1.0 , 1.05, 1.1, 1.15, or 1.2. This ratio range can make the active polyester (as the epoxy resin curing agent) effectively improve the processability, heat resistance, dielectric capacity, toughness and flame retardancy of the curable resin composition.

In at least one specific embodiment, the epoxy resin is selected from bisphenol A type epoxy resin, novolak epoxy resin, methyl novolac epoxy resin, dicyclopentadiene-phenol epoxy resin and naphthalene ring-containing epoxy resin At least one member of the group consisting of epoxy resins.

In at least one specific embodiment, the curable resin composition of the present disclosure further includes a curing accelerator in addition to the aforementioned reactive polyester and epoxy resin. In at least one specific embodiment, the curing accelerator accounts for 0.1% to 1.0% by weight based on the total weight of the epoxy resin, such as 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1.0% by weight.

In at least one specific embodiment, the curing accelerator is at least one selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators and organophosphorus-based curing accelerators, and in at least one specific embodiment , the imidazole-based curing accelerator such as imidazole (imidazole), 2-methylimidazole (2-methylimidazole), 2-methyl-4-ethylimidazole (2-methyl-4-ethylimidazole), the amine-based curing accelerator The agent is, for example, 4-dimethylaminopyridine (4-dimethylaminopyridine, DMAP), and the organophosphorus curing accelerator is, for example, triphenylphosphine.

The cured resin of the present disclosure is obtained by curing the above-mentioned curable resin composition. The curing temperature is, for example, heated to between 140°C and 240°C, such as 140, 150, 160, 170, 180 , 190, 200, 210, 220, 230 or 240°C, it can be cured after heating to a fixed temperature, or it can be cured in a step-by-step manner, for example, it can be cured when the temperature is raised to 180, 200, 220°C, And the curing time of each stage is more than 1 or 2 hours, such as 1, 1.5, 2, 2.5, 3, 3.5, 4 hours.

Example

Synthesis Example 1: Synthesis of Active Polyester 1

Get 5.0g (3.125mmol) of compound (a-1) (the product of Saudi Basic Industries Corporation SABIC, SA90, molecular weight is 1600g/mol), 0.698g (3.125 * 1.1mmol) of isophthaloyl chloride and 22g (20wt %) of o-dichlorobenzene (o-dichlorobenzene) is placed in 100 milliliters of three-necked reactors. Set up a condenser tube and connect it to a vent bottle containing NaOH aqueous solution, stir and react with a magnet at 160° C. for 12 hours in a nitrogen atmosphere. Then, 0.09g (3.125×0.2mmol) of 1-naphthol was added for reaction, after the reaction, it was precipitated with methanol, and then the precipitate was washed with methanol and deionized water, and dried at 60°C to obtain the active polymer as a khaki solid. Ester 1, which has a structure as shown in formula (II), wherein the average value of n1 is 7, the average value of n2 is 7, and m is between 8 and 32. The 1H-NMR spectrum of active polyester 1 is shown in Figure 1.

Synthesis Example 2: Synthesis of Active Polyester 2

Using the method disclosed in Synthesis Example 1, but replacing 1-naphthol with Dopo-AP, the active polyester 2 of khaki solid is obtained, which has a structure as shown in formula (III), wherein the average value of n1 is 7 , the average value of n2 is 7, and m is between 8 and 32. The 1H-NMR spectrum of active polyester 2 is shown in Figure 2.

Reactive Polyester Solubility Test

Take 5mg of the above-mentioned reactive polyester 1, reactive polyester 2, DIC's product HPC-8000-65T and the polyester of the previous technology (TW 106122483) and add them to different solvents to test each in different solvents Solubility, the results are shown in Table 1 below.

[Table 1]

In Table 1, DMAc means dimethylacetamide, Toluene means toluene, NMP means N-methylpyrrolidone, THF means tetrahydrofuran, _CHCl3 means chloroform, Xylene means xylene, and + means soluble at room temperature.

It can be seen from the above that the solubility of reactive polyester 1 and reactive polyester 2 is equivalent to that of the current commercially available and prior art products, soluble in most common solvents, and has high solvent resistance, which is beneficial to various processes in the copper foil substrate manufacturing process. application.

Example 1: Curable resin composition and cured resin

At first, active polyester 1 and epoxy resin (the product of Di Aisheng company DIC, HP7200, epoxy equivalent weight is 260g/eq) that synthetic example 1 gained are dissolved in toluene, and with active polyester 1 The ratio of active ester group equivalents to epoxy resin equivalents is 1:1 to obtain a mixed solution with a solid content of 20% by weight.

Based on the total weight of the epoxy resin, 0.5% by weight of DMAP was added to the mixed solution and completely dissolved to obtain a curable resin composition 1 .

Then, the curable resin composition 1 was coated on the glass substrate with a knife coater, put into a circulation oven, and dried at 80° C. for 12 hours to remove most of the solvent. Afterwards, the temperature was raised to 120° C., 180° C., 200° C., and 220° C. (each for two hours) in a step-by-step manner for curing. Finally, the glass substrate is placed in water to remove the film, so as to obtain the cured resin 1 .

Example 2

Using the method disclosed in Example 1, but using the reactive polyester 2 obtained in Synthesis Example 2 to replace the reactive polyester 1, a curable resin composition 2 and a cured resin 2 were obtained.

Comparative example 1

Using the method disclosed in Example 1, except that EPICLON HPC-8000-65T, a product of DIC of DIC, was used instead of reactive polyester 1 to obtain a curable resin composition and a cured resin.

Comparative example 2

Using the method disclosed in Example 1, but replacing the reactive polyester 1 with the polyester of the prior art (TW 106122483), a curable resin composition and a cured resin were obtained.

Evaluation of Thermal Properties, Dielectric Capability and Flame Retardancy of Cured Resin

The cured resins of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were evaluated for thermal properties and dielectric properties by the following methods, and the results are listed in Table 2 below; the results of flame retardancy are listed in Table 3.

(1) Glass transition temperature Tg, coefficient of thermal expansion CTE

The glass transition temperature of the sample was measured by dynamic mechanical analysis (DMA), as shown in FIG. 4 . The test condition is to use a dynamic mechanical analyzer (model Perkin-Elmer Pyris Diamond) to measure the glass transition temperature Tg of the sample at a heating rate of 5° C./min. In addition, the coefficient of thermal expansion CTE of the sample was measured by thermomechanical analysis (Thermomechanical analysis, TMA), as shown in FIG. 3 .

(2) 5% thermogravimetric loss temperature T _d5% and coke residual rate (Char yield)

Thermogravimetric analysis (thermo-gravimetric analysis, TGA) was used to measure the 5% thermogravimetric loss temperature of the sample and the coke residual rate at 800 °C, as shown in Figure 5. The test condition is to measure the weight change of the sample using a thermogravimetric analyzer (model: Thermo Cahn VersaTherm) under a nitrogen atmosphere at a heating rate of 20° C./min. The 5% thermogravimetric loss temperature refers to the temperature when the weight loss of the sample reaches 5%. The higher the 5% thermogravimetric loss temperature, the better the thermal stability of the sample; The residual weight ratio of the sample at 800°C, the higher the residual weight ratio at 800°C, the better the thermal stability of the sample.

(3) Dielectric constant D _k and loss tangent D _f

At 25°C and 10GHz, the dielectric constant and loss tangent of the sample were measured using Taiwan Rohde Schwartz/Steel/ZNB20.

(4) Flame retardancy

5in×0.5in resin cured film sample, according to the UL-94 test standard, put the fire source in a vertical manner to burn the sample from bottom to top for 10 seconds, remove the fire source and observe the continuous burning time, and observe whether there is The dripping drips into the absorbent cotton below and whether the dripping burns.

[Table 2]

[table 3]

In Table 3, the flame retardancy V2 means that the sample placed vertically stops burning within 30 seconds and drops burning droplets; the flame retardancy V1 means that the samples placed vertically stop burning within 30 seconds and drops non-burning droplets ; and the flame retardancy V0 means that the sample placed vertically stops burning within 10 seconds and drips non-combustible drops.

It can be seen from Table 2 that the glass transition temperatures of the cured resins in Examples 1 and 2 of the present disclosure are both 245°C, much higher than 200°C in Comparative Example 1, and slightly higher than 240°C in Comparative Example 2, which shows that the use of the present disclosure Reactive polyester curing agent can increase the glass transition temperature of cured epoxy resin. and, ben It is disclosed that the 5% thermogravimetric loss temperatures of the cured resins of Examples 1 and 2 are 404°C and 398°C respectively, and the coke residual rates at 800°C are 24% and 32.5% respectively, which shows that the resins obtained by the active polyester curing agent disclosed in this disclosure are obtained The cured epoxy resin has good thermal stability and heat resistance.

Secondly, in the evaluation of the dielectric capacity, the dielectric constants of the cured resins in Examples 1 and 2 of the present disclosure are 2.8U and 2.9U, and the loss tangent is 0.011U, meeting the standards required by the application.

In addition, from the results in Table 3, it can be seen that the cured resins of Examples 1 and 2 of the present disclosure are significantly better than the products of Comparative Examples 1 and 2 in the flame retardancy test, and the flame retardancy can reach the V0 level, which shows that through the present disclosure The cured epoxy resin produced by reactive polyester curing agent has excellent flame retardancy.

In summary, the reactive polyester prepared in the above examples can be used as a curing agent for the epoxy resin composition, and since the reactive polyester has an active ester group, it can not only produce a crosslinking reaction with the epoxy resin, but also The hydroxyl group generated during the reaction is blocked, so it can effectively improve the unsatisfactory dielectric constant and loss tangent problems caused by the high hygroscopicity of the conventional epoxy resin cured product, and can also improve the epoxy resin cured product. Heat resistance and flame retardancy. Therefore, by using the reactive polyester curing agent of the present disclosure, an epoxy resin cured product with high processability, high heat resistance, good dielectric capability, high toughness and flame retardancy can be obtained.

Claims (13)

A kind of active polyester has the structure shown in formula (I):

In formula (1), Y is a single bond, a substituted or unsubstituted C1 to C6 alkylene group, a carbonyl group, an oxygen atom, or a sulfonyl group, Ar series divalent aromatic group, n1 and n2 are independently positive integers, and 4<n1+n2<26, m is a positive integer from 2 to 50, and _R is selected from the group consisting of:

,

,

and

, wherein, R ₂ is a hydrogen atom, halogen or C1-C6 alkyl. Active polyester as described in claim item 1, wherein, Ar is selected from the group consisting of the following formula:

, wherein, X is a single bond, methylene, oxygen atom, carbonyl, sulfonyl, -C(CH ₃ ) ₂ - or -C(CF ₃ ) ₂ -. The reactive polyester as claimed in claim 1, wherein Y is a single bond, methylene or isopropyl, and Ar is 1,4-phenylene or 1,3-phenylene. Active polyester as described in claim item 1, it has the structure shown in formula (II):

Active polyester as described in claim item 1, it has the structure shown in formula (III):

A curable resin composition, comprising reactive polyester and epoxy resin as described in Claim 1. The curable resin composition according to claim 6, wherein the ratio of the epoxy equivalents of the epoxy resin to the active ester equivalents of the reactive polyester is between 0.8 and 1.2. The curable resin composition as described in claim item 7, wherein, the epoxy resin is selected from bisphenol A type epoxy resin, novolak epoxy resin, methyl novolac epoxy resin, dicyclopentadiene-phenol epoxy At least one member of the group consisting of resin and epoxy resin containing naphthalene ring structure. The curable resin composition as described in claim 7 further includes a curing accelerator. The curable resin composition according to Claim 9, wherein the curing accelerator is at least one selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators, and organophosphorus-based curing accelerators. The curable resin composition according to claim 9, wherein the curing accelerator accounts for 0.1% to 1.0% by weight based on the total weight of the epoxy resin. The curable resin composition as described in Claim 9, wherein the curing accelerator is selected from imidazole, 2-methylimidazole, 2-methyl-4-ethylimidazole, 4-dimethylaminopyridine and At least one member of the group consisting of triphenylphosphine. A cured resin obtained by curing the curable resin composition as described in Claim 6.

Images