EPOXY RESIN CURING AGENT AND PREPARATION METHODS AND USES THEREOF

Abstract

The present invention relates to an epoxy resin curing agent having a structure of Formula I and preparation methods and uses thereof. The present invention makes a resin composition formed by the epoxy resin curing agent have good low dielectric properties by using an epoxy resin curing agent having a specific structure, and the cured products of the epoxy resin composition have low dielectric constant and dielectric loss and good heat resistance and are low dielectric materials having great economic properties and being environmental friendly.

Claims

1. An epoxy resin curing agent, characterized in that, it has a molecular structure as shown in Formula I: ##STR00034## wherein, R is independently any organic group according with the chemical environment thereof; R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are independently H or any organic group according with the chemical environment thereof; R.sub.a, R.sub.b are independently aromatic groups; n is an integer greater than or equal to zero.

2. The epoxy resin curing agent of claim 1, characterized in that, R is any one of substituted or unsubstituted straight chain or branched alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkylaryl, substituted or unsubstituted cycloalkylaryl, substituted or unsubstituted alkylheteroaryl or substituted or unsubstituted alkylheteroaryl.

3. The epoxy resin curing agent of claim 1, characterized in that, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are independently any one of H, substituted or unsubstituted straight chain or branched alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkylaryl, substituted or unsubstituted cycloalkylaryl, substituted or unsubstituted alkylheteroaryl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted arylalkoxy, substituted or unsubstituted alkylaryloxy, substituted or unsubstituted heteroarylalkoxy, substituted or unsubstituted alkylheteroaryloxy, substituted or unsubstituted carboxylate group, substituted or unsubstituted carbonate group, substituted or unsubstituted sulfonate group or substituted or unsubstituted phosphonate group.

4. The epoxy resin curing agent of claim 1, characterized in that, R.sub.a, R.sub.b are independently any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenylyl, substituted or unsubstituted phenylalkyl, substituted or unsubstituted alkylphenyl, or substituted or unsubstituted phenylalkylphenyl.

5. The epoxy resin curing agent of claim 1, characterized in that, the epoxy resin curing agent has a molecular structure as shown in the following Formula II: ##STR00035## in Formula II, R is any organic group according with the chemical environment thereof; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8 and R.sub.9 are independently any organic group according with the chemical environment thereof; n is an integer greater than or equal to zero.

6. The epoxy resin curing agent of claim 1, characterized in that, the epoxy resin curing agent has a molecular structure as shown in the following Formula III: ##STR00036## in Formula III, R is any organic group according with the chemical environment thereof; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12 and R.sub.13 are independently H or any organic group according with the chemical environment thereof; X is nothingness or any organic group according with the chemical environment thereof; n is an integer greater than or equal to zero.

7. The epoxy resin curing agent of claim 1, characterized in that, the epoxy resin curing agent has a molecular structure as shown in the following Formula IV: ##STR00037## in Formula IV, R is any organic group according with the chemical environment thereof; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8 and R.sub.9 are independently H or any organic group according with the chemical environment thereof; n is an integer greater than or equal to zero.

8. The epoxy resin curing agent of claim 1, characterized in that, the epoxy resin curing agent has a molecular structure as shown in the following Formula V: ##STR00038## in Formula V, R is independently any organic group according with the chemical environment thereof; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12 and R.sub.13 are independently H or any organic group according with the chemical environment thereof; X is nothingness or any organic group according with the chemical environment thereof; n is an integer greater than or equal to zero.

9. The epoxy resin curing agent of claim 8, characterized in that, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12 and R.sub.13 are independently any one of H, substituted or unsubstituted straight chain or branched alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkylaryl, substituted or unsubstituted cycloalkylaryl, substituted or unsubstituted alkylheteroaryl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted arylalkoxy, substituted or unsubstituted alkylaryloxy, substituted or unsubstituted heteroarylalkoxy, substituted or unsubstituted alkylheteroaryloxy, substituted or unsubstituted carboxylate group, substituted or unsubstituted carbonate group, substituted or unsubstituted sulfonate group or substituted or unsubstituted phosphonate group, or a combination of at least two of them.

10. The epoxy resin curing agent of claim 1, characterized in that, the epoxy resin curing agent is one of compounds having the following structures or a combination of at least two of them: ##STR00039##

11. An epoxy resin composition, characterized in that, the epoxy resin composition comprises an epoxy resin and the epoxy resin curing agent of claim 1.

12. The epoxy resin composition of claim 11, characterized in that, the epoxy resin is any one of liquid bisphenol A epoxy resin, liquid bisphenol F epoxy resin, solid bisphenol A epoxy resin, solid bisphenol F epoxy resin, bisphenol S epoxy resin, cyclopentadiene epoxy resin or biphenyl epoxy resin, or a combination of at least two of them.

13. The epoxy resin composition of claim 11, characterized in that, the epoxy resin composition also comprises a curing accelerator.

14. The epoxy resin composition of claim 13, characterized in that, the curing accelerator is any one of imidazole curing accelerators, organophosphine curing accelerators, tertiary amine curing accelerators, quaternary ammonium salts, DBU and derivatives thereof, pyridines and derivatives thereof, or a mixture of at least two of them.

15. The epoxy resin composition of claim 11, characterized in that, the epoxy resin composition also comprises an inorganic filler.

16. The epoxy resin composition of claim 11, characterized in that, the epoxy resin composition also comprises a flame retardant.

17. A prepreg, characterized in that, it is prepared by impregnating a substrate with the epoxy resin composition of claim 11 or coating the epoxy resin composition of claim 11 onto a substrate.

18. The prepreg of claim 17, characterized in that, the substrate is a glass fiber substrate, a polyester substrate, a polyimide substrate, a ceramic substrate or a carbon fiber substrate.

Description

EMBODIMENTS

[0061] The technical solution of the present invention is further described by the following examples.

[0062] In the following examples, all the raw materials can be obtained through commercial purchase.

Example 1

[0063] The epoxy resin curing agent of the present example has the following structure:

##STR00011##

[0064] The preparation method thereof is:

[0065] 1 mol of 2,6-dimethylhydroquinone was added into a 1000 mL glass reactor equipped with a stirrer using dichloromethane as solvent; the mixture was stirred and dissolved, and then 3 mL of 98% concentrated sulfuric acid was added as a catalyst; then a solution of terephthalic acid (1.1 mol) in dichloromethane was slowly dripped; the mixture was stirred at room temperature for 10 hours after the drip was completed; then 1.1 mol of o-dimethylphenol was added and the mixture was continued to stir for 8 hours; the by-products in the system were removed by physical methods and the solvent were removed by evaporation, and then 100 g of objective product with an ester equivalent of 100 g/eq was obtained; this objective product was named as epoxy resin curing agent A.

[0066] The obtained epoxy resin curing agent A was characterized by nuclear magnetic resonance hydrogen spectrum, and the results are as follows:

[0067] .sup.1H NMR (CDCl.sub.3, 500 MHz): ppm 6.92-6.96 (m, hydrogen on benzene ring in

##STR00012##

6.81-6.83 (m, hydrogen on benzene ring in

##STR00013##

2.32 (s, CH.SUB.3.).

[0068] Characteristic peak positions in infrared spectroscopy: ester carbonyl, 1730-1740 cm.sup.1; COC in ester group, 1200 cm.sup.1; ortho-position substituted benzene ring, 750 cm.sup.1; para-position substituted benzene ring, 860-790 cm.sup.1; absorption peak of methyl, 2995 cm.sup.1.

[0069] An epoxy resin composition is prepared by using the epoxy resin curing agent and other components, and a copper clad laminate is prepared by using the epoxy resin composition, and the steps thereof are as follows:

[0070] 136 g of the above epoxy resin curing agent and 0.1 g of curing accelerator DBU were added into 100 g of bisphenol-A epoxy resin with an epoxide equivalent of 187 g/eq and 100 g of o-cresol novolac epoxy resin with an epoxide equivalent of 120 g/eq. A copper clad laminate meeting the national, UL and other standards is prepared by using the epoxy resin composition according to generally used copper clad laminate production process. The copper clad laminate is named as copper clad laminate a and the properties thereof are measured and the results are shown in table 1.

Example 2

[0071] The epoxy resin curing agent of the present example has the following structure:

##STR00014##

[0072] The preparation method thereof is:

[0073] 1 mol of 2,6-dimethylhydroquinone was added into a 1000 mL glass reactor equipped with a stirrer; the mixture was stirred and dissolved, and then 3 mL of 98% concentrated sulfuric acid was added as a catalyst; then 1.1 mol of 2,3-dimethylterephthalic acid was slowly dripped; the mixture was stirred at room temperature for 15 hours after the drip was completed; then 1.2 mol of o-dimethylphenol was added and the mixture was continued to stir for 6 hours; the by-products in the system were removed by physical methods and the solvent were removed by evaporation, and then 180 g of objective product with an ester equivalent of 180 g/eq was obtained; this objective product was named as epoxy resin curing agent B.

[0074] The obtained epoxy resin curing agent B was characterized by nuclear magnetic resonance hydrogen spectrum, and the results are as follows:

[0075] .sup.1H NMR (CDCl.sub.3, 500 MHz): ppm 7.7-7.9 (m, hydrogen on benzene ring in

##STR00015##

6.91-6.94 (m, hydrogen on benzene ring in

##STR00016##

2.32 (s, CH.SUB.3.).

[0076] Characteristic peak positions in infrared spectroscopy: ester carbonyl, 1730-1740 cm.sup.1; COC in ester group, 1200 cm.sup.1; ortho-position substituted benzene ring, 750 cm.sup.1; para-position substituted benzene ring, 860-790 cm.sup.1; absorption peak of methyl, 2995 cm.sup.1.

[0077] An epoxy resin composition is prepared by using the epoxy resin curing agent and other components, and a copper clad laminate is prepared by using the epoxy resin composition, and the steps thereof are as follows:

[0078] 245 g of the above epoxy resin curing agent and 0.1 g of curing accelerator DBU were added into 100 g of bisphenol-A epoxy resin with an epoxide equivalent of 187 g/eq and 100 g of o-cresol novolac epoxy resin with an epoxide equivalent of 120 g/eq. A copper clad laminate meeting the national, UL and other standards is prepared by using the epoxy resin composition according to generally used copper clad laminate production process. The copper clad laminate is named as copper clad laminate b and the properties thereof are measured and the results are shown in table 1.

Example 3

[0079] The epoxy resin curing agent of the present example has the following structure:

##STR00017##

[0080] The preparation method thereof is:

[0081] 1 mol of 2,6,2,6-tetramethyl bisphenol-A was added into a 1000 mL glass reactor equipped with a stirrer using dichloromethane as solvent; the mixture was stirred and dissolved, and then 3 mL of 98% concentrated sulfuric acid was added as a catalyst; then a solution of 2,3-dimethylterephthalic acid (1.1 mol) in dichloromethane was slowly dripped; the mixture was stirred at room temperature for 10 hours after the drip was completed; then 1.2 mol of o-dimethylphenol was added and the mixture was continued to stir for 8 hours; the by-products in the system were removed by physical methods and the solvent were removed by evaporation, and then 220 g of objective product with an ester equivalent of 220 g/eq was obtained; this objective product was named as epoxy resin curing agent C.

[0082] The obtained epoxy resin curing agent C was characterized by nuclear magnetic resonance hydrogen spectrum, and the results are as follows:

[0083] .sup.1H NMR (CDCl.sub.3, 500 MHz): ppm 7.7-7.9 (m, hydrogen on benzene ring in

##STR00018##

6.4-6.9 (m, hydrogen on benzene ring in

##STR00019##

3.7 (m, hydrogen on methyl in

##STR00020##

2.35 (s, hydrogen on methyl connected to benzene ring), 1.65 (m, hydrogen on methyl which is not connected to benzene ring in

##STR00021##

group).

[0084] Characteristic peak positions in infrared spectroscopy: ester carbonyl, 1730-1740 cm.sup.1; COC in ester group, 1200 cm.sup.1; ortho-position substituted benzene ring, 750 cm.sup.1; skeleton vibration absorption peak of benzene ring in

##STR00022##

1611 cm.sup.1, 1509 cm.sup.1, 1446 cm.sup.1; bending vibration absorption peak of CH.sub.3 in

##STR00023##

1435 cm.sup.1, 1382 cm.sup.1.

[0085] An epoxy resin composition is prepared by using the epoxy resin curing agent and other components, and a copper clad laminate is prepared by using the epoxy resin composition, and the steps thereof are as follows:

[0086] 299 g of the above epoxy resin curing agent and 0.1 g of curing accelerator DBU were added into 100 g of bisphenol-A epoxy resin with an epoxide equivalent of 187 g/eq and 100 g of o-cresol novolac epoxy resin with an epoxide equivalent of 120 g/eq. A copper clad laminate meeting the national, UL and other standards is prepared by using the epoxy resin composition according to generally used copper clad laminate production process. The copper clad laminate is named as copper clad laminate c and the properties thereof are measured and the results are shown in table 1.

Example 4

[0087] The epoxy resin curing agent of the present example has the following structure:

##STR00024##

[0088] The preparation method thereof is:

[0089] 1 mol of bisphenol-B was added into a 1000 mL glass reactor equipped with a stirrer using dichloromethane as solvent; the mixture was stirred and dissolved, and then 3 mL of 98% concentrated sulfuric acid was added as a catalyst; then a solution of terephthaloyl chloride (1.1 mol) in dichloromethane was slowly dripped; the mixture was stirred at room temperature for 10 hours after the drip was completed; then 1.2 mol of o-dimethylphenol was added and the mixture was continued to stir for 8 hours; the by-products in the system were removed by physical methods and the solvent were removed by evaporation, and then 190 g of objective product with an ester equivalent of 190 g/eq was obtained; this objective product was named as epoxy resin curing agent D.

[0090] The obtained epoxy resin curing agent D was characterized by nuclear magnetic resonance hydrogen spectrum, and the results are as follows:

[0091] .sup.1H NMR (CDCl.sub.3, 500 MHz): ppm 8.29 (s, hydrogen on benzene ring in

##STR00025##

7.1-7.2 (m, hydrogen on benzene ring in

##STR00026##

6.8-6.9 (m, 8H, hydrogen on benzene ring in

##STR00027##

3.7 (m, hydrogen on methyl in

##STR00028##

1.91 (m, hydrogen on methylene in

##STR00029##

1.72 (m, hydrogen on methyl connected to quaternary carbon atom in

##STR00030##

1.0 (m, hydrogen on methyl connected to methylene in

##STR00031##

[0092] Characteristic peak positions in infrared spectroscopy: ester carbonyl, 1730-1740 cm.sup.1; COC in ester group, 1200 cm.sup.1; ortho-position substituted benzene ring, 750 cm.sup.1; skeleton vibration absorption peak of benzene ring in

##STR00032##

1641 cm.sup.1, 1500 cm.sup.1, 1446 cm.sup.1; bending vibration absorption peak of CH.sub.3, 1435 cm.sup.1, 1382 cm.sup.1; absorption peak of methyl ether, 2995 cm.sup.1.

[0093] An epoxy resin composition is prepared by using the epoxy resin curing agent and other components, and a copper clad laminate is prepared by using the epoxy resin composition, and the steps thereof are as follows:

[0094] 258 g of the above epoxy resin curing agent and 0.1 g of curing accelerator DBU were added into 100 g of bisphenol-A epoxy resin with an epoxide equivalent of 187 g/eq and 100 g of o-cresol novolac epoxy resin with an epoxide equivalent of 120 g/eq. A copper clad laminate meeting the national, UL and other standards is prepared by using the epoxy resin composition according to generally used copper clad laminate production process. The copper clad laminate is named as copper clad laminate d and the properties thereof are measured and the results are shown in table 1.

Comparative Example 1

[0095] In the present comparative example, a commonly used linear phenolic resin with a phenolic hydroxyl equivalent of 105 g/eq was used to replace the epoxy resin curing agent of the present application as a curing agent, and a method same as that in example 1 was used to prepare a copper clad laminate e. The properties of the copper clad laminate e are measured and the results are shown in table 1.

Comparative Example 2

[0096] 100 g of commercially available MDI-modified epoxy resin with an epoxide equivalent of 380.0 g/eq, 57.9 g of resin compound having a structure of Formula (I) with a ester equivalent of 220 and 0.2 g of pyridine were dissolved in appropriate acetone to form a solution. A copper clad laminate was prepared by using standard glass fiber cloth according to a well-known method. The copper clad laminate is named as copper clad laminate f. The measured properties of the copper clad laminate f are shown in Table 1.

##STR00033##

[0097] The test results of products of examples and comparative examples are shown in table 1 (the specific test methods are not described considering that they are well-known by those skilled in the art).

TABLE-US-00001 TABLE 1 Test Item Copper Copper Copper Copper Copper Copper clad clad clad clad clad clad laminate a laminate b laminate c laminate d laminate e laminate f Tg (DSC) 159 165 158 160 143 146 ( C.) T-peeling 1.97 2.03 2.10 2.0 1.45 1.53 strength (kg/mm.sup.2) Interlaminar 1.65 1.63 1.75 1.62 1.1 0.80 peeling strength (kg/mm.sup.2) Saturated 0.32 0.31 0.34 0.32 0.35 0.58 water absorption (%) Dielectric 3.32 3.25 3.28 3.25 4.68 4.52 constant (1 GHz) Dielectric 0.005 0.006 0.0057 0.0059 0.11 0.12 loss (1 GHz)

[0098] As can be seen from table 1, the copper clad laminates of the present invention prepared by using an resin composition prepared by using a compound having a structure of Formula I as a curing agent have a dielectric constant (1 GHz) of 3.25-3.32, a dielectric loss (1 GHz) of 0.005-0.006, a Tg which can be up to more than 158 C., a T-peeling strength which can be up to more than 1.97 kg/mm.sup.2, an interlaminar peeling strength which can be up to more than 1.62 kg/mm.sup.2 and a saturated water absorption which can be less than 0.34%, which are much better than the properties of the copper clad laminates of comparative examples.

[0099] The applicant states that: the present invention illustrates the epoxy resin curing agent of the present invention and the preparation methods and uses thereof by the above examples, but the present invention is not limited to the above examples, that is, it does not mean that the present invention must be conducted relying on the above examples. Those skilled in the art should understand that any modification to the present invention, any equivalent replacement of each raw material of the product of the present invention and the addition of auxiliary ingredient, the selection of specific embodiment and the like all fall into the protection scope and the disclosure scope of the present invention.