TWI776557B - Active polyester, curable resin composition and cured resin - Google Patents

Abstract

An active polyester having the structure shown in formula (I):

, in formula (1), R₁ and R₂ is a hydrogen atom, a substituted or unsubstituted C1 to C6 alkyl group or phenyl group; Ar is a divalent aromatic group; n is a positive integer from 5 to 200; and R₃ is selected from the group consisting of the following formulas:

,

,

, and

, wherein R₄ 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 resin cured product

The present disclosure relates to a polyester curing agent, a curable resin composition and a cured resin product, and more particularly to a polyester curing agent having an active ester group, a curable resin composition and a cured resin product using the same.

Among polymer materials, epoxy resin materials have a long development. Epoxy resin has excellent solvent resistance and easy processing characteristics, and suitable curing agent can be selected to form curable epoxy resin composition and epoxy resin cured product, because epoxy resin cured product exhibits excellent heat resistance and insulation Therefore, it is widely used in electronic parts such as semiconductors or multilayer printed circuit boards (PCBs). 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 purpose, the material of the printed circuit substrate in the signal communication equipment needs to have good dielectric properties (such as low dielectric constant (Dk) and low loss tangent (Df)) to meet the high frequency transmission of signals It also needs to have good heat resistance and machinability to meet the reliability of printed circuit boards.

Existing curable epoxy resin compositions for printed circuit substrates will produce highly polar secondary alcohols during the curing process, which have high hygroscopicity, resulting in high loss tangent, dielectric energy The force is not ideal, and the heat resistance is also reduced. Therefore, active esters have been developed in the industry as curing agents for epoxy resins, which can avoid the disadvantages of traditional phenolic or amine curing agents that produce highly polar secondary alcohols during curing. Among the resin curing agents, the structure of Dicyclopentadiene (DCPD) has the characteristics of high boiling point, easy separation of high-purity products and relatively low cost. Ultraviolet light, good electrical properties, mechanical properties and other properties make it a great potential for resin curing agents.

For example, in 2006, Hwang scholars et al. (Polymer, 55 [7] 1666-1673, (2014)), synthesized bismaleimide containing dicyclopentadiene and limonene (Dipentene) structures , and compared the cured product with the cured product of bismaleimide containing aromatic structure, it was found that the dielectric constants of DCPDBMI, DPBMI and DDMBMI were 3.01, 3.03 and 4.03 at 1MHz, respectively, indicating that the bicyclic ring was introduced into the structure. The non-polar aliphatic structure of pentadiene can effectively reduce the dielectric constant of the material.

TW I579332 uses an active ester hardener containing a dicyclopentadiene structure (trade name EPICLON HPC-8000-65T), which reacts with epoxy resin and cyanate ester to obtain a cured product with a dielectric loss of about 8 mU.

TW I565750 discloses a novel active ester resin with excellent solubility in various solvents, low dielectric constant and loss tangent of hardened products, and excellent low hygroscopicity. An epoxy resin composition, its cured product, a semiconductor sealing material, a prepreg, a circuit board, and a laminate film. The above-mentioned active ester resin has a molecular structure represented by the following structural formula. In the structural formula, X is a benzene ring or a naphthalene ring; R1 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.

TW I565750 uses epoxy resin, cyanate ester resin, active ester and hardening accelerator for curing reaction to obtain a resin composition with low dielectric tangent and excellent adhesion strength to conductors after accelerated environmental test. The active esters used are such as: EXB9460-65T (ie DIC product EPICLON HPC-8000-65T of Diaisheng Company, active group equivalent 223), DC808 (novolac acetylation product, Japanese epoxy resin system, active group equivalent 149) , YLH1026 (benzylation product of novolac, Japan epoxy resin system, active group equivalent 200) and so on.

TW I532784 uses dicyclopentadiene benzoxazine resin, epoxy resin and active ester (HPC-8000-65T) to prepare low dielectric tangent cured products, but its disadvantage lies in the thermal stability of the derived epoxy cured products , Insufficient heat resistance, and can not meet the requirements of high flame retardancy.

TW I658060 discloses a high molecular polyester obtained by reacting a bisphenol compound containing dicyclopentadiene with diacyl chloride, the structure of which is as follows:

The polyester is a reactive polyester and can undergo a cross-linking reaction with epoxy resin. However, the disadvantage of this patent is that the dielectric capacity of the derived epoxy resin cured product is limited and cannot meet the requirement of high flame retardancy.

It can be seen from the above literature that the polymer epoxy resin curing agent has the potential to improve the properties of the cured resin. By making the curing agent have a dicyclopentadiene structure, the electrical properties of the cured resin can be obtained. Improves and can enhance processability. Since the development of epoxy resin cured products with high solvent resistance, high heat resistance, good dielectric ability, high toughness, mechanical strength and flame retardancy is an urgent goal at present, it is hoped that a ring with a dicyclopentadiene structure will be used. Oxygen resin curing agent achieves the above objects.

In order to make the product have excellent high processability, high heat resistance, good dielectric ability, high toughness and flame retardancy, the present disclosure provides a reactive polyester having the structure shown in formula (I):

、

、

及

，其中，R₄係氫原子、鹵素或C1-C6烷基。 In formula (1), R ₁ and R ₂ are hydrogen atoms, substituted or unsubstituted C1 to C6 alkyl groups or phenyl groups, Ar is a divalent aromatic group, n is a positive integer from 5 to 200, and _R3 is selected from the group consisting of:

,

,

and

, wherein R ₄ is a hydrogen atom, halogen or C1-C6 alkyl group.

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

、

、

及

,

,

and

，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 embodiment, R ₁ and R ₂ in formula (1) are hydrogen atoms or methyl groups, and Ar is 1,4-phenylene or 1,3-phenylene. In at least one embodiment, R ₁ and R ₂ in formula (1) are methyl groups, and Ar is 1,4-phenylene or 1,3-phenylene. In at least one embodiment, R ₁ and R ₂ are C1 to C6 alkyl substituted with at least one halogen atom, such as -CF ₃ .

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

The reactive polyester according to claim 1, which has the structure shown in formula (III):

The present disclosure further provides a curable resin composition comprising the reactive polyester and the epoxy resin.

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

In at least one embodiment, the epoxy resin is selected from the group consisting of bisphenol A epoxy resin, novolac epoxy resin, methyl novolac epoxy resin, dicyclopentadiene-phenol epoxy resin and naphthalene ring-containing structure. At least one 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 organic phosphorus-based curing accelerators.

In at least one 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 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 groups.

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 the curing time of each step is more than 1 hour.

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

Fig. 1 shows the 1H nuclear magnetic resonance (1H NMR) spectrum of the reactive polyester of Synthesis Example 1.

Figure 2 is a 1H nuclear magnetic resonance spectrum of the reactive polyester in Synthesis Example 2.

3 shows the results of thermomechanical analysis (TMA) of Examples 1 and 2 and Comparative Examples 1 and 2.

FIG. 4 shows the results of dynamic mechanical analysis (DMA) of Examples 1 and 2 and Comparative Examples 1 and 2.

FIG. 5 shows the results of thermogravimetric analysis (TGA) of Examples 1 and 2 and Comparative Examples 1 and 2.

The embodiments of the present disclosure will be described below through specific specific embodiments, and those with ordinary knowledge in the technical field of the present disclosure can easily understand the scope and effect of the present disclosure based on the contents described herein. However, the specific embodiments described herein are not intended to limit the present disclosure. The listed technical features or solutions can be combined with each other. The present disclosure can also be implemented or applied through other different embodiments. The details can also be given different changes or modifications according to different viewpoints and applications without departing from the present disclosure.

When "comprising", "comprising" or "having" a specific element described herein, unless otherwise specified, other elements, components, structures, regions, parts, devices, systems, steps or connection relationships, etc. may be further included requirements, but not the exclusion of such other requirements.

Unless the context clearly dictates otherwise, the singular forms "a" and "the" mentioned herein also include the plural forms, and "or" and "and/or" are used interchangeably herein.

Numerical ranges recited herein are inclusive and combinable, and any number falling within a numeric range recited herein may be taken as the maximum or minimum value to derive the following range; for example, a numerical range of "0.8 to 1.2" It should be understood to include any sub-range between a minimum value of 0.8 and a maximum value of 1.2, such as: 0.8 to 1.1, 0.9 to 1.2, and 0.9 to 1.1, etc. sub-ranges; furthermore, if a value falls within each range described herein (eg, between the maximum value and the minimum value), shall be deemed to be included in the scope of the present disclosure.

reactive polyester

The reactive polyester of the present disclosure is specifically a reactive polyester comprising dicyclopentadiene repeating units, which can have a structure as shown in formula (I):

In formula (I), R ₁ and R ₂ are hydrogen atoms, substituted or unsubstituted C1 to C6 alkyl groups or phenyl groups,

Ar is a divalent aromatic group,

n is a positive integer from 5 to 200, and

_R3 is selected from the group consisting of:

、

、

及

，其中，R₄係氫原子、鹵素或C1-C6烷基。

,

,

and

, wherein R ₄ is a hydrogen atom, halogen or C1-C6 alkyl group.

In at least one embodiment, R ₁ and R ₂ are hydrogen atoms, methyl or -CF ₃ . In at least one embodiment, Ar is the group consisting of the following formula:

，其中，X係單鍵、亞甲基、氧原子、羰基、磺醯基、-C(CH₃)₂-或-C(CF₃)₂-。於至少一具體實施例中，R₁及R₂係甲基且Ar為1,4-伸苯基或1,3-伸苯基。

, 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 embodiment, R ₁ and R ₂ are methyl and Ar is 1,4-phenylene or 1,3-phenylene.

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

Preparation method of reactive polyester

The reactive polyesters of the present disclosure can be prepared by various methods, and an exemplary preparation method is provided below.

First, a bisphenol compound comprising a dicyclopentadiene structure is provided, which has the structure shown in formula (a):

In the general formula (a), R ₁ and R ₂ are as defined in the formula (I), ie, a hydrogen atom, a substituted or unsubstituted C1 to C6 alkyl group or a phenyl group.

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

In at least one embodiment, the molar ratio of the diacyl 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 includes, for example, the structures represented by the following formulae (b-1) to (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, for example, the alkali catalyst is selected from CsF, KF, CsCl, KCl, K ₂ CO ₃ , At least one of the group consisting of Na ₂ CO ₃ , KOH and NaOH. In at least one embodiment, the molar ratio of the base 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 embodiment, the ratio of the epoxy group equivalents of the epoxy resin to the reactive 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 enable the reactive polyester (as epoxy resin curing agent) to effectively improve the processability, heat resistance, dielectric ability, toughness and flame retardancy of the curable resin composition.

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

In at least one 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 embodiment, the curing accelerator accounts for 0.1 wt % to 1.0 wt % 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 embodiment, the curing accelerator is at least one selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators and organic phosphorus-based curing accelerators, and in at least one embodiment , the imidazole-based curing accelerator is such as imidazole, 2-methylimidazole, 2-methyl-4-ethylimidazole, the The amine-based curing accelerator is, for example, 4-dimethylaminopyridine (DMAP), and the organic phosphorus-based curing accelerator is, for example, triphenylphosphine.

The resin cured product of the present disclosure is obtained by curing the above-mentioned curable resin composition. , 190, 200, 210, 220, 230 or 240 ℃, can be heated to a fixed temperature and then cured, or can also be cured in a step-by-step manner, such as curing at 180, 200, 220 ℃ in stages, 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 Reactive Polyester 1

Take 2.4674g (0.0197×0.665mol) of compound DCPD-2,6-DP (molecular weight is 376.69g/mol), 0.9514g (0.0197×0.335mol) of 1-naphthol and 2.99g (0.0197×1.5mol) of Triethylamine and 50 mL of toluene were placed in a 100 mL three-neck reactor. A condenser tube was set up and a vent bottle containing an aqueous NaOH solution was connected, and the reaction was stirred and reacted with a magnet at 0° C. in a nitrogen atmosphere for 0.5 hours. Next, 2 g (0.0197 mol) of isophthalic chloride was added to react for 6 hours. After the reaction was completed, the salts were filtered, and then extracted with acid and deionized water until neutral. The solvent was removed by a vacuum concentrator and dried at 60° C. to obtain a khaki-yellow solid reactive polyester 1 having the structure shown in formula (II), wherein n is a positive integer from 5 to 200. The 1H-NMR spectrum of reactive polyester 1 is shown in Figure 1.

Synthesis Example 2: Synthesis of Reactive Polyester 2

Using the method as disclosed in Synthesis Example 1, except that 2.312 g (0.0197*0.335 mol) of Dopo-AP was used in place of 1-naphthol, reactive polyester 2 was obtained as a khaki solid with the formula (III) structure, where n is a positive integer from 5 to 200. The 1H-NMR spectrum of reactive polyester 2 is shown in FIG. 2 .

Reactive Polyester Solubility Test

5mg of the above reactive polyester 1, reactive polyester 2, product HPC-8000-65T of DIC of Diaisheng Company and polyester DCPD-2,6-DP-ICl of the prior art (TW I658060) were respectively added to different solvents , to test the solubility of each in different solvents, and the results are shown in Table 1 below.

[Table 1]

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

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

Example 1: Curable resin composition and resin cured product

First, the reactive polyester 1 obtained in Synthesis Example 1 and the epoxy resin (product of DIC, HP7200, epoxy equivalent of 260 g/eq) were dissolved in toluene, and the reactive ester group equivalent of reactive polyester 1 was used. The number and the epoxy group equivalent number of the epoxy resin were prepared in a ratio of 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, and placed in a circulating oven, and dried at 80° C. for 12 hours to remove most of the solvent. After that, the temperature was raised to 120° C., 180° C., 200° C., and 220° C. (two hours each) in order to cure. Finally, the glass substrate was placed in water to be released from the mold to obtain a resin cured product 1 .

Example 2: Curable resin composition and resin cured product

Using the method disclosed in Example 1, except that the reactive polyester 2 obtained in the synthesis example 2 was used in place of the reactive polyester 1, the curable resin composition 2 and the resin cured product 2 were obtained.

Comparative Example 1

The method as disclosed in Example 1 was used, except that the reactive polyester 1 was replaced by EPICLON HPC-8000-65T, a product of DIC from Diessen, to obtain a curable resin composition and a cured resin.

Comparative Example 2

Using the method disclosed in Example 1, except that the polyester DCPD-2,6-DP-IC1 of the prior art (TW I658060) was used instead of the reactive polyester 1, a curable resin composition and a cured resin were obtained.

Evaluation of thermal properties, dielectric properties and flame retardancy of resin cured products

The thermal properties and dielectric properties of the cured resins of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were evaluated 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, thermal expansion coefficient CTE

The glass transition temperature Tg of the samples was measured using dynamic mechanical analysis (DMA), and the results are shown in Figure 4. The test conditions were to measure the glass transition temperature Tg of the sample using a dynamic mechanical analyzer (model Perkin-Elmer Pyris Diamond) at a heating rate of 5°C/min. In addition, thermomechanical analysis (TMA) was used to measure the thermal expansion coefficient CTE of the sample, and the results are shown in FIG. 3 .

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

Thermo-gravimetric analysis (TGA) was used to measure the 5% thermogravimetric loss temperature and the coke residual rate at 800° C. of the samples, and the results are shown in FIG. 5 . The test conditions were 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% TGA loss temperature refers to the temperature at which the weight loss of the sample reaches 5%. The higher the 5% TGA loss temperature, the better the thermal stability of the sample; and the coke residual rate of 800℃ refers to the heating temperature reaching 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

The dielectric constant and loss tangent of the samples were measured at 25°C and 10GHz using Taiwan Rohde Schwarz/Steel/ZNB20.

(4) Flame retardancy

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

[Table 2]

[table 3]

In Table 3, flame retardancy V2 means that the vertically placed sample stops burning within 30 seconds, and dripping dripping drops; flame retardancy V1 means that the vertically placed sample stops burning within 30 seconds, and drips non-burning dripping ; And the flame retardancy V0 represents that the vertically placed sample stops burning within 10 seconds, and drips droplets that do not burn.

It can be seen from Table 2 that the thermal expansion coefficient CTE, glass transition temperature Tg and 5% thermogravimetric loss temperature T _d5% of the resin cured products of Examples 1 and 2 of the present disclosure are maintained at the same level as those of Comparative Examples 1 and 2, which meet the needs of the industry. . In terms of coke residual rate at 800°C, Comparative Example 1 is obviously at a disadvantage, only 6.2%, while Comparative Example 2 can reach 14.1%; in contrast, the 800°C coke residual rate of Example 1 and Example 2 is higher In Comparative Example 2, the ratios are 14.9% and 16.9%, respectively, indicating that the thermal stability and heat resistance of the cured resin product of the present disclosure are better.

Secondly, in the evaluation of dielectric capability, although the thermal-related properties of Comparative Example 2 are better than those of Comparative Example 1, due to the presence of hydroxyl groups, the dielectric capability of Comparative Example 2 is relatively poor. . As for the resin cured products of Examples 1 and 2 of the present disclosure, the dielectric constants are 2.5 U and 2.6 U, which are at the same level as those of Comparative Examples 1 and 2, and the loss tangents are 0.012 U and 0.015 U, which are between Comparative Examples 1 and 2 between. It can be seen that, in addition to better thermal properties, the cured resin product of the present disclosure can also block hydroxyl groups and exhibit good dielectric properties, thereby improving the conventional problem of low dielectric properties caused by hydroxyl groups.

In addition, the results in Table 3 show that the cured resin of Example 2 is significantly better than others in the flame retardancy test, and the flame retardancy can reach the V0 level.

To sum up, the reactive polyesters prepared in the above examples can be used as curing agents for epoxy resin compositions, and since reactive polyesters have reactive ester groups, in addition to cross-linking reaction with epoxy resins, they can also be used as curing agents for epoxy resin compositions. The hydroxyl groups generated in the reaction process are blocked, so it can effectively improve the problems of unsatisfactory dielectric constant and loss tangent caused by the high hygroscopicity of hydroxyl groups in the conventional epoxy resin cured products, and can also improve the epoxy resin cured products. 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 property, high toughness and flame retardancy can be obtained.

Claims (12)

A reactive polyester having the structure shown in formula (I):

In formula (1), R ₁ and R ₂ are hydrogen atoms, C1 to C6 alkyl groups, phenyl groups or -CF ₃ groups, and Ar is selected from the group consisting of the following formulas:

,

,

and

, 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 - n is a positive integer from 5 to 200, and R ₃ is selected from the group consisting of:

,

,

and

, wherein R ₄ is a hydrogen atom, halogen or C1-C6 alkyl group. The reactive polyester according to claim 1, wherein R ₁ and R ₂ are methyl groups, and Ar is 1,4-phenylene or 1,3-phenylene. The reactive polyester according to claim 1, which has the structure shown in formula (II):

The reactive polyester according to claim 1, which has the structure shown in formula (III):

A curable resin composition comprising the reactive polyester and epoxy resin according to claim 1. The curable resin composition as claimed in claim 5, wherein the ratio of the equivalent number of epoxy groups of the epoxy resin to the equivalent number of active ester groups of the reactive polyester is between 0.8 and 1.2. The curable resin composition according to claim 6, wherein the epoxy resin is selected from the group consisting of bisphenol A epoxy resin, novolac epoxy resin, methyl novolac epoxy resin, and dicyclopentadiene-phenol epoxy resin At least one of the group consisting of resin and epoxy resin containing naphthalene ring structure. The curable resin composition according to claim 6, further comprising a curing accelerator. The curable resin composition according to claim 8, wherein the curing accelerator is at least one selected from the group consisting of imidazole-based curing accelerators, amine-based curing accelerators, and organic phosphorus-based curing accelerators. The curable resin composition according to claim 8, wherein the curing accelerator accounts for 0.1% by weight to 1.0% by weight based on the total weight of the epoxy resin. The curable resin composition according to claim 8, wherein the curing accelerator is selected from imidazole, 2-methylimidazole, 2-methyl-4-ethylimidazole, 4-dimethylaminopyridine and At least one of the group consisting of triphenylphosphine. A resin cured product obtained by curing the curable resin composition according to claim 5.

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