EPOXY RESIN COMPOSITION, PREPREG AND LAMINATE USING SAME

Abstract

Provided in the present invention are an epoxy resin composition, prepreg and laminate using the same, the epoxy resin composition comprising the following components: (A) an imide modified epoxy resin; and (B) a crosslinking agent, the imide modified epoxy resin being an epoxy resin having a structure of formula (1) and/or formula (2). The prepreg and laminate prepared from the epoxy resin composition have a high glass-transition temperature, a low dielectric constant, a low dielectric loss factor, a high heat and humidity resistance, a high toughness and a good processability.

Claims

1. An epoxy resin composition, characterized in comprising (A) imide-modified epoxy resin; (B) crosslinking agent; wherein the imide-modified epoxy resin is an epoxy resin having formula (1) and/or (2), ##STR00015## A in Formulae (1) and (2) is independently unsubstituted phenyl or C1-C4 alkyl-substituted phenyl; n.sub.1, n.sub.2 and n.sub.3 all are independently integers which is greater than or equals to 1; R in Formulae (1) and (2) is independently ##STR00016## in Formula (1), R is ##STR00017## wherein R is a single bond, ##STR00018##

2. The epoxy resin composition as claimed in claim 1, characterized in that the imide-modified epoxy resin is an epoxy resin having formula (2).

3. The epoxy resin composition as claimed in claim 1, characterized in that the imide-modified epoxy resin is an epoxy resin having the following structure ##STR00019## wherein A is phenyl; R is ##STR00020##

4. The epoxy resin composition as claimed in claim 1, characterized in that the crosslinking agent is any one selected from the group consisting of active esters, anhydride compounds or novolac resin, or a mixture of at least two selected therefrom.

5. The epoxy resin composition as claimed in claim 1, characterized in that the ratio of the epoxy equivalent of the imide-modified epoxy resin to the active group equivalent in the crosslinking agent is 1:0.9-1.1.

6. The epoxy resin composition as claimed in claim 1, characterized in that the epoxy resin composition further comprises a curing accelerator.

7. The epoxy resin composition as claimed in claim 1, characterized in that the epoxy resin composition further comprises a flame retardant.

8. (canceled)

9. The epoxy resin composition as claimed in claim 1, characterized in that the epoxy resin composition further comprises a filler which is an organic filler or/and inorganic filler.

10. The epoxy resin composition as claimed in claim 9, characterized in that the inorganic filler is any one selected from the group consisting of molten silica, crystalline silica, spherical silica, hollow silica, aluminium hydroxide, alumina, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, calcium silicate, mica or glass fiber powder, or a mixture of at least two selected therefrom.

11. The epoxy resin composition as claimed in claim 9, characterized in that the organic filler is any one selected from the group consisting of polytetrafluoroethylene powder, polyphenylene sulfide and polyether sulfone powder, or a mixture of at least two selected therefrom.

12. The epoxy resin composition as claimed in claim 9, characterized in that the filler is silica having a moderate particle size of 1-15 m.

13. A prepreg comprising a reinforcing material and the epoxy resin composition as claimed in claim 1 and attached thereon after impregnation and drying.

14. A laminate comprising at least one prepreg as claimed in claim 13.

15. (canceled)

16. The epoxy resin composition as claimed in claim 1, characterized in that the crosslinking agent is active esters or/and anhydride compounds.

17. The epoxy resin composition as claimed in claim 16, characterized in that the crosslinking agent is active esters having the following structure: ##STR00021## wherein X is phenyl or naphthyl; j is 0 or 1; k is 0 or 1; n represents a repeating unit of 0.25-1.25.

18. The epoxy resin composition as claimed in claim 6, characterized in that the curing accelerator is added in an amount of 0.05-1 part by weight, based on the sum of the addition amounts of components (A) and (B) which is 100 parts by weight.

19. The epoxy resin composition as claimed in claim 6, characterized in that the curing accelerator is any one selected from the group consisting of 4-dimethylaminopyridine, 2-methylimidazol, 2-methyl-4-ethylimidazol or 2-phenylethylimidazol, or a mixture of at least two selected therefrom.

20. The epoxy resin composition as claimed in claim 7, characterized in that the flame retardant is a bromine-containing flame retardant or/and a halogen-free flame retardant.

21. The epoxy resin composition as claimed in claim 7, characterized in that the flame retardant is added in an amount of 5-50 parts by weight, based on the sum of the addition amounts of components (A) and (B) which is 100 parts by weight.

22. The epoxy resin composition as claimed in claim 20, characterized in that the bromine-containing flame retardant is any one selected from the group consisting of decabrominated diphenyl ethane, brominated polystyrene, ethylene bis-tetrabromo phthalimide and bromine-containing epoxy resin, or a mixture of at least two selected therefrom;

23. The epoxy resin composition as claimed in claim 20, characterized in that the halogen-free flame retardant is any one selected from the group consisting of tri(2,6-dimethylphenyl)phosphine, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2,6-di-(2,6-dimethylphenyl)-phosphinobenzene, 10-phenyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phenoxyphosphazene compound, zinc borate, nitrogen and phosphorus-based intumescent flame retardant, organic polymer flame retardant, phosphorous-containing novolac resin and phosphorous-containing bismaleimide, or a mixture of at least two selected therefrom.

24. The epoxy resin composition as claimed in claim 9, characterized in that the filler is added in an amount of 0-100 parts by weight, excluding 0, based on the sum of the addition amounts of components (A) and (B) which is 100 parts by weight.

Description

PREPARATION EXAMPLE 1

Synthesis of the Epoxy Resin of Formula (1)

[0051] 11 g of aminophenol and 200 g of butanone were added to a round-bottomed flask with a stirrer, a thermometer, a nitrogen gas introduction tube and a reflux condenser, heated in a water bath to speed up the dissolution. Bisphenol A diglycidyl ether dianhydride having a concentration of 20 wt. % (weight percentage) was dropwise added with 130 g of acetone into a reactor. The dropping rate was controlled so as to finish the addition within one hour. The reaction continued at 30 C. for 2 h, and then butanone was removed by evaporation. A mixed solvent of 160 g of DMF and 40 g of toluene was added, and 0.25 g of a catalyst of P-toluenesulfonic acid (P-TSA) was added, to react at 110 C. for 8 h. After the reaction, a part of solvent was removed by evaporation at a reduced pressure. The mixture was then water-washed, filtered, re-crystallized, dried under vacuum to obtain a hydroxyl compound containing benzene ring and imide structures stated as below,

##STR00008##

[0052] Into a four-necked flask were added 80.2 g of the hydroxyl compound containing benzene ring and imide structures obtained above, 18.6 g of 4,4-dihydroxybiphenyl, 6 g of formaldehyde, 0.25 g of P-toluenesulfonic acid and 250 g of a solvent of methyl isobutyl ketone, reacted at 150 C. for 6-8 h. After the reaction, the mixture was water-washed, and the solvent was removed to obtain an intermediate.

[0053] Into a four-necked flask was fed 25 g of the intermediate obtained above. 100 g of epichlorohydrin was weighed and slowly added, dissolved and heated. 1 mol of NaOH solution having a mass fraction of 33% was dropwise added to a dropping funnel, the dropping rate was controlled so as to finish the addition within one hour, and the reaction temperature was controlled at 100 C. After dropping, the mixture was maintained at such temperature for 5 h, cooled and water-washed, then heated to 120 C. and evaporated excessive epichlorohydrin. After the reaction, a part of solvent was removed by evaporation at a reduced pressure, and then water-washing, filtering, re-crystallizing and drying under vacuum were carried out to obtain the following epoxy resin,

##STR00009##

wherein A is benzene ring, R is

##STR00010##

R is

[0054] ##STR00011##

PREPARATION EXAMPLE 2

Synthesis of the Epoxy Resin of Formula (2)

[0055] 11 g of aminophenol and 200 g of butanone were added to a round-bottomed flask with a stirrer, a thermometer, a nitrogen gas introduction tube and a reflux condenser, heated in a water bath to speed up the dissolution. Bisphenol A diglycidyl ether dianhydride having a concentration of 20 wt. % (weight percentage) was dropwise added with 130 g of butanone into a reactor. The dropping rate was controlled so as to finish the addition within one hour. The reaction continued at 30 C. for 2 h, and then butanone was removed by evaporation. A mixed solvent of 160 g of DMF and 40 g of toluene was added, and 0.25 g of a catalyst of P-toluenesulfonic acid (P-TSA) was added, to react at 110 C. for 8 h. After the reaction, a part of solvent was removed by evaporation at a reduced pressure. The mixture was then filtered, re-crystallized, dried under vacuum to obtain a hydroxyl compound containing benzene ring and imide structures stated as below,

##STR00012##

[0056] Into a four-necked flask were added 80.2 g of the hydroxyl compound containing benzene ring and imide structures obtained above, 6 g of formaldehyde, 0.25 g of P-toluenesulfonic acid and 200 g of a solvent of methyl isobutyl ketone, reacted at 150 C. for 6-8 h. After the reaction, the mixture was water-washed, and the solvent was removed to obtain an intermediate.

[0057] Into a four-necked flask was fed 25 g of the intermediate obtained above. 150 g of epichlorohydrin was weighed and slowly added, dissolved and heated. 1 mol of NaOH solution having a mass fraction of 33% was dropwise added to a dropping funnel, the dropping rate was controlled so as to finish the addition within one hour, and the reaction temperature was controlled at 100 C. After dropping, the mixture was maintained at such temperature for 5 h, cooled and water-washed, then heated to 120 C. and evaporated excessive epichlorohydrin, so as to obtain the following epoxy resin,

##STR00013##

wherein A is benzene ring, and R is

##STR00014##

EXAMPLE 1

[0058] 60 parts by weight of A1 was added into a vessel; a suitable amount of MEK, active ester crosslinking ester HPC-8000-65T, and a suitable amount of curing accelerator 4-dimethylaminopyridine were added and continuously stirred. Finally, a solvent was used to adjust the solid content of the liquid to 60%-80% and to prepare a varnish. A glass fiber cloth was impregnated with the aforesaid varnish to control to an appropriate thickness, then dried to remove solvent and obtain a prepreg. Several prepregs were laminated to each other, and covered with a sheet of copper foil on both sides thereof, placed in a hot press and cured to obtain the epoxy resin copper clad laminates. The physical property data are shown in Table 1.

EXAMPLES 2-6

[0059] The preparation processes are the same as that in Example 1, and the composition formulations and the physical indexes are shown in Table 1 below.

COMPARISON EXAMPLES 1-3

[0060] The preparation processes are the same as that in Example 1, and the composition formulations and the physical indexes are shown in Table 1 below.

TABLE-US-00001 TABLE 1 Composition formulations and physical indexes in each Example Substances Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Epoxy resin A1 60 A2 60 60 60 60 60 A3 NC-3000H 7200-3H Crosslinking HPC-8000-65T 1 eq 1 eq 0.9 eq 1.1 eq agent EF40 1 eq 2812 1 eq Accelerator 4-dimethylaminopyridine q.s. q.s. q.s. q.s. q.s. q.s. Performance T.sub.g (DSC)/ C. 178 195 205 190 187 188 Td (5% loss) 390 400 420 430 425 426 CTE 2.00% 1.70% 1.60% 1.80% 1.90% 1.90% D.sub.k (10 GHZ) 3.73 3.8 3.9 3.78 3.8 3.8 D.sub.f (10 GHZ) 0.0065 0.0075 0.0150 0.0068 0.0072 0.0072 PCT water absorption 0.23% 0.32% 0.35% 0.24% 0.25% 0.25% PCT 0/3 0/3 0/3 0/3 0/3 0/3 Phase separation No No No No No No Toughness

TABLE-US-00002 TABLE 2 Composition formulations and physical indexes in each Comparison Example Comparison Comparison Comparison Substances Example 1 Example 2 Example 3 Epoxy resin A1 A2 A3 60 NC-3000H 60 7200-3H 60 Crosslinking HPC-8000-65T 1eq 1eq 1eq agent EF40 2812 Accelerator 4-dimethyl- q.s. q.s. q.s. aminopyridine Performance T.sub.g(DSC)/ C. 180 156 168 Td(5% loss) 392 398 399 CTE 1.90% 2.50% 2.30% D.sub.k(10 GHZ) 3.82 3.7 3.6 D.sub.f(10 GHZ) 0.0064 0.005 0.006 PCT water 0.22% 0.21% 0.20% absorption PCT 2/3 0/3 0/3 Phase Yes No No separation Toughness

[0061] Note: based on parts by weight of solid components.

[0062] The materials listed in Tables 1 and 2 are stated as follows specifically.

[0063] A1: Epoxy resin synthesized in Preparation Example 1

[0064] A2: Epoxy resin synthesized in Preparation Example 2

[0065] A3: Epoxy resin containing naphthalene ring, dicyclopentadiene ring and imide structures

[0066] NC-3000H: Biphenyl phenolic epoxy resin (Product from Nippon Kayaku, having an epoxy equivalent of 288 g/eq)

[0067] 7200-3H: dicyclopentadiene novolac epoxy resin (product form DIC, having an epoxy equivalent of 285 g/eq)

[0068] HPC-8000-65T: active ester crosslinking agent (Product from DIC, having an ester equivalent 223 g/eq)

[0069] EF40: styrene-maleic anhydride (Product from Sartomer, having an anhydride equivalent of 260 g/eq)

[0070] 2812: linear novolac resin (Product from Momentive, having a hydroxyl equivalent of 105 g/eq)

[0071] 4-dimethylaminopyridine: accelerator (Product from Guangrong Chemical)

[0072] The aforesaid properties are tested by the following methods.

[0073] (1) Glass transition temperature (Tg): tested by the DSC method under IPC-TM-6502.4.25 in accordance with Differential scanning calorimetry (DSC).

[0074] (2) Dielectric constant and dielectric loss factor: tested by the method under IPC-TM-650 2.5.5.9 at a testing frequency of 10 GHz.

[0075] (3) PCT-post dip-soldering resistance evaluation: etching copper foils on the surface of copper clad laminates to evaluate the substrate; placing the substrate in a press pan to treat at 120 C. and 105 KPa for 2 h; then impregnating in a tin furnace at 288 C.; recording the corresponding time when the substrate is delaminated and bursted; when there is no bubble or lamination when the substrate is placed in the tin furnace for over 5 min, the evaluation will be ended. If there is bubble or delamination in 0, 1, 2, 3 sheets, it will be recorded as 0/3, 1/3, 2/3 and 3/3.

[0076] (4) Falling dart impact toughness: using the falling Dart Impact tester having a drop height of 40 cm and a falling dart weight of 1 Kg, to evaluate the toughness: if the cross is clear, it shows a better toughness represented by the symbol {circle around ()}; if the cross is vague, it shows a worse toughness and a great brittleness represented by the symbol ; if the cross is between clarity and vague, it shows that the product has a general toughness represented by the symbol .

Analyses on Physical Properties

[0077] According to the physical properties in Tables 1 and 2, it can be seen that, active esters are used in the Comparison Examples to cure biphenyl epoxy resin and dicyclopentadiene epoxy resin, the product has an excellent dielectric performance, a low water absorption, and a lower glass transition temperature. In Comparison Example 1, the epoxy resin containing naphthalene ring, dicyclopentadiene ring and imide structures has a high glass transition temperature, but a worse solubility, and is easy to have phase separation and great brittleness. After adding the imide-modified epoxy resin of the present invention, the cured products in the Examples have not only a high glass transition temperature, a good toughness and PCT moisture proof, but also excellent dielectric properties.

[0078] As stated above, the epoxy circuit boards of the present invention have a high glass transition temperature, a low dielectric constant, a low dielectric loss factor, a high moisture and heat resistance, a high toughness and a good processability, as compared with common laminates.

[0079] The aforesaid examples are only the better examples of the present invention. Those ordinarily skilled in the art can make various corresponding changes and modifications according to the technical solution and technical concept of the present invention. Moreover, all these changes and modifications shall fall within the protection scope of the claims of the present invention.

[0080] The applicant declares that, the present invention discloses the detailed method of the present invention by the aforesaid examples, but the present invention is not limited by the detailed method, i.e. it does not mean that the present invention cannot be fulfilled unless the aforesaid detailed method is used. Those skilled in the art shall know that, any amendment, equivalent change to the product materials of the present invention, addition of auxiliary ingredients, and selection of any specific modes all fall within the protection scope and disclosure scope of the present invention.