Thermosetting resin composition, prepreg made therefrom, laminate clad with metal foil, and high-frequency circuit board

Abstract

Disclosed are a thermosetting resin composition, a prepreg made therefrom, a laminate clad with a metal foil, and a high-frequency circuit board, wherein the thermosetting resin composition contains thermosetting ingredients. The thermosetting ingredients include a phosphorus-containing monomer or a phosphorus-containing resin and another thermosetting resin containing an unsaturated group, and the phosphorus-containing monomer or the phosphorus-containing resin has a structure as shown in formula I. By using the phosphorus-containing monomer or the phosphorus-containing resin as a cross-linking agent of the other thermosetting resin containing an unsaturated group and by means of a cross-linking reaction of a large number of unsaturated double bonds in the resin, the high-frequency dielectric properties and high-temperature-resistance required by a circuit substrate are provided.

Claims

1. A thermosetting resin composition, wherein the thermosetting resin composition comprises thermosetting ingredients which comprise a phosphorus-containing monomer or a phosphorus-containing resin and other thermosetting resins containing unsaturated groups, wherein the phosphorus-containing monomer or the phosphorus-containing resin has a structure as shown in Formula I: ##STR00024## wherein R represents a linear or branched alkyl, ##STR00025## X and Y are independently selected from the group consisting of hydrogen, allyl, linear alkyl, branched alkyl, and a combination of at least two selected therefrom; A is a phosphorus-containing capping group; and n is an integer of 1-20.

2. The thermosetting resin composition of claim 1, wherein: R represents —CH.sub.2—, ##STR00026## n is an integer of 1-20; X and Y are independently selected from the group consisting of hydrogen, allyl, linear alkyl, branched alkyl, and a combination of at least two selected therefrom; and A is a phosphorus-containing capping group.

3. The thermosetting resin composition of claim 1, wherein the phosphorus-containing monomer or the phosphorus-containing resin is prepared by the following method comprising the steps of: (1) a phenolic compound or a phenolic resin of Formula II is reacted with an allylation reagent to obtain an allyl etherified resin of Formula III, wherein the exemplary reaction formula is as follows: ##STR00027## (2) the allyl etherified resin of Formula III is heated under the protection of protective gas, and an intramolecular rearrangement reaction occurs to obtain an allylated phenolic resin of Formula IV: ##STR00028## (3) the allylated phenolic resin of formula IV is reacted with a phosphorus-containing capping reagent to obtain the phosphorus-containing monomer or the phosphorus-containing resin of Formula I: ##STR00029## wherein R.sub.1 is selected from the group consisting of linear or branched alkyl, ##STR00030## R.sub.2 is selected from the group consisting of linear or branched alkyl, ##STR00031## R.sub.3 is selected from the group consisting of linear or branched alkyl, ##STR00032## R is selected from the group consisting of linear or branched alkyl, ##STR00033## X and Y are independently selected from the group consisting of hydrogen, allyl, linear alkyl, branched alkyl, and a combination of at least two selected therefrom; A is a phosphorus-containing capping group; and n is an integer of 1-20.

4. The thermosetting resin composition of claim 1, wherein said other thermosetting resins containing unsaturated groups are thermosetting resins containing double bonds or triple bonds.

5. The thermosetting resin composition of claim 1, wherein the thermosetting resin composition further comprises a powder filler.

6. A prepreg, wherein the prepreg comprises a reinforcing material and the thermosetting resin composition of claim 1 which is adhered thereto after impregnation and drying.

7. A laminate, wherein the laminate comprises at least one prepreg of claim 6.

8. A metal foil-clad laminate, wherein the metal foil-clad laminate comprises one or at least two laminated prepregs of claim 6, and metal foil on one side or both sides of the laminated prepreg.

9. A high-frequency circuit board, wherein the high-frequency circuit board comprises one or at least two laminated prepregs of claim 6.

10. The thermosetting resin composition of claim 1, wherein A is a 9,10-dihydro-9-oxy-10-phosphaphenanthrene-10-oxide (DOPO)-containing group.

11. The thermosetting resin composition of claim 10, wherein A is selected from the group consisting of ##STR00034##

12. The thermosetting resin composition of claim 1, wherein the phosphorus-containing monomer or the phosphorus-containing resin is selected from the group consisting of the compounds having the following structures of Formulae A-D, and a combination of at least two selected therefrom: ##STR00035## ##STR00036## wherein n is an integer of 1-20.

13. The thermosetting resin composition claimed in claim 4, wherein said other thermosetting resins containing unsaturated groups are selected from the group consisting of allyl-terminated polyphenylene ether resin, acrylate-terminated polyphenylene ether resin, vinyl-terminated polyphenylene ether resin, thermosetting polybutadiene resin, a copolymer resin of thermosetting polybutadiene and styrene (styrene-butadiene resin), bismaleimide resin, cyanate resin, allylated phenolic resin, vinyl-terminated siloxane resin, and a combination of at least two selected therefrom.

14. The thermosetting resin composition claimed in claim 1, wherein said other thermosetting resins containing unsaturated groups are thermosetting resins based on polybutadiene or a copolymer resin of polybutadiene and styrene containing 60% or more of vinyl groups, having a molecular weight of 11,000 or less and consisting of carbon and hydrogen.

15. The thermosetting resin composition claimed in claim 1, wherein: the thermosetting ingredients account for 5 to 90% by weight of the thermosetting resin composition; and the phosphorus-containing monomer or the phosphorus-containing resin accounts for 20 to 75% of the total weight of said other thermosetting resins containing unsaturated groups and the phosphorus-containing monomer or the phosphorus-containing resin.

16. The thermosetting resin composition claimed in claim 1, wherein the thermosetting resin composition further comprises a curing initiator.

17. The thermosetting resin composition claimed in claim 1, wherein the thermosetting resin composition further comprises a co-crosslinking agent comprising a monomer or a low-molecular copolymer having unsaturated double bonds or unsaturated triple bonds in the molecular structure.

18. The thermosetting resin composition claimed in claim 17, wherein the co-crosslinking agent is selected from the group consisting of triallyl tripolyisocyanurate, triallyl tripolycyanurate, divinylbenzene, polyfunctional acrylate, bismaleimide, and a combination of at least two selected therefrom.

Description

EMBODIMENTS

(1) The technical solutions of the present invention will be further described below by specific embodiments. It should be understood by those skilled in the art that the examples are merely used for understanding the present invention, rather than any specific limitations to the present invention.

(2) The sources of the components of the resin composition selected in the examples of the present invention are listed in Table 1 as follows:

(3) TABLE-US-00001 TABLE 1 Product name or Manufacturer brand Material contents Sartomer Ricon 100 Styrene-butadiene resin Sartomer Ricon 154 Polybutadiene resin Self-made Phosphorus-containing esterified diallyl bisphenol A Self-made Phosphorus-containing esterified allyl phenolic resin Self-made Phosphorus-containing esterified allyl o-cresol novalac resin Sibelco 525 Silica micropowder Shanghai DCP Dicumyl peroxide Gaoqiao

Preparation Example 1

(4) 188 g of acetone was added to a three-necked reaction flask. 228 g of bisphenol A was then added to the reaction flask, stirred and dissolved, and 106 g of sodium carbonate was added. 153 g of a chloropropene solution was slowly added dropwise, and then the reaction was stopped after raising the temperature for 4 hours. Filtration, removal of most of the solvent and washing were carried out, and then removal of residual solvent and water gave bisphenol A diallyl ether.

(5) 134 g of the prepared bisphenol A diallyl ether was placed in the reaction flask, and subjected to a rearrangement reaction by heating for 6 hours. The mixture was cooled to obtain a brown viscous liquid, i.e. diallyl bisphenol A.

(6) An inert gas was introduced into the three-necked reaction flask for protection. 300 g of dichloromethane was added. 134 g of the prepared diallyl bisphenol A was placed in the reaction flask, stirred and dissolved. 40 g of sodium hydroxide was added, and 152 g of carbon tetrachloride was added. 230 g of 2-(6H-dibenzo(c,e)(1,2)-5-oxa-6-phosphono-6-phenyl-4-phenol was slowly added dropwise, and the reaction was stopped after reacting for 4 hours. An aqueous solution of sodium hydroxide was added to wash to neutrality, then washing was conducted several times to remove residual solvent and water, thereby obtaining phosphorus-containing esterified diallyl bisphenol A, i.e. the low-polarity intrinsic flame-retardant resin having the structure thereof as follows:

(7) ##STR00021##

Preparation Example 2

(8) 300 g of n-butanol was added to a three-necked reaction flask. 114 g of linear phenolic resin was then added to the reaction flask, stirred and dissolved, and 56 g of potassium hydroxide was added. 153 g of a bromopropane solution was slowly added dropwise, and then the reaction was stopped after raising the temperature for 4 hours. Filtration, removal of most of the solvent and washing were carried out, and then removal of residual solvent and water gave an allyl etherified phenolic resin.

(9) 141 g of the prepared allyl etherified phenolic resin was placed in the reaction flask, and subjected to a rearrangement reaction by heating for 4 hours. The mixture was cooled to obtain a brown viscous liquid, i.e. allyl phenolic resin.

(10) An inert gas was introduced into the three-necked reaction flask for protection. 350 g of dichloromethane was added. 141 g of the prepared allyl phenolic resin was placed in the reaction flask, stirred and dissolved. 72 g of triethylamine was added, and 152 g of carbon tetrachloride was added. 230 g of 2-(6H-dibenzo(c,e)(1,2)-5-oxa-6-phosphono-6-phenyl-4-phenol was slowly added dropwise, and the reaction was stopped after reacting for 4 hours. An aqueous solution of sodium hydroxide was added to wash to neutrality, then washing was conducted several times to remove residual solvent and water, thereby obtaining phosphorus-containing esterified allyl phenolic resin, i.e. the low-polarity intrinsic flame-retardant resin having Mn of 1,300 and the structure thereof is as follows:

(11) ##STR00022##

Preparation Example 3

(12) 250 g of toluene was added to a three-necked reaction flask. 118 g of o-cresol novolac resin was then added to the reaction flask, stirred and dissolved, and 100 g of an aqueous solution of sodium hydroxide (having a concentration of 40%) was added, and then 1 g of tetrabutylammonium bromide was further added. After the temperature became constant, 153 g of a chloropropene solution was slowly added dropwise. The reaction was stopped after raising the temperature for 4 hours. Washing and removal of the solvent were carried out to obtain allyl etherified o-cresol novolac resin.

(13) 159 g of the prepared allyl etherified o-cresol novolac resin was placed in the reaction flask, and subjected to a rearrangement reaction by heating for 4 hours. The mixture was cooled to obtain a dark brown semisolid, i.e. allyl o-cresol novolac resin.

(14) An inert gas was introduced into the three-necked reaction flask for protection. 350 g of dichloromethane was added. 159 g of the prepared allyl o-cresol novolac resin was placed in the reaction flask, stirred and dissolved. 103 g of pyridine was added, and 152 g of carbon tetrachloride was added. 230 g of 2-(6H-dibenzo(c,e)(1,2)-5-oxa-6-phosphono-6-phenyl-3-phenol was slowly added dropwise, and the reaction was stopped after reacting for 4 hours. An aqueous solution of sodium hydroxide was added to wash to neutrality, then washing was conducted several times to remove residual solvent and water, thereby obtaining phosphorus-containing esterified allyl o-cresol novolac resin, i.e. the low-polarity intrinsic flame-retardant resin having Mn of 1,200 and the structure thereof is as follows:

(15) ##STR00023##

Example 1

(16) 80 parts by weight of liquid styrene-butadiene resin Ricon 100, 20 parts by weight of phosphorus-containing esterified diallyl bisphenol A prepared in Preparation Example 1, 85 parts by weight of silica (525), and 6.5 parts by weight of an initiator DCP were mixed, adjusted to a suitable viscosity with a solvent of toluene, stirred and uniformly mixed to uniformly disperse the filler in the resin, so as to obtain a varnish. 1080 glass fiber cloth was impregnated with the varnish above, and then dried to remove the solvent to obtain a prepreg. Eight sheets of prepared prepregs were laminated, and pressed on both sides thereof with copper foils having a thickness of 1 oz (ounce), and cured in a press for 2 hours at a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 190° C. The physical property data are shown in Table 2 below.

Example 2

(17) The production process was the same as that in Example 1, except for that the compounding ratio of the thermosetting resin composition was changed. The compounding ratio and the performance data of the prepared copper clad laminate are shown in Table 2 below.

Example 3-4

(18) The production processes were the same as that in Example 1, except for that the co-crosslinking agent bismaleimide was added. The compounding ratio of the resin composition and the performance data of the prepared copper clad laminates are shown in Table 2 below.

Example 5

(19) 80 parts by weight of liquid styrene-butadiene resin Ricon 100, 20 parts by weight of the phosphorus-containing esterified allyl phenolic resin prepared in Preparation Example 2, 85 parts by weight of silica (525), and 6.5 parts by weight of an initiator DCP were mixed, adjusted to a suitable viscosity with a solvent of toluene, stirred and uniformly mixed to uniformly disperse the filler in the resin, so as to obtain a varnish. 1080 glass fiber cloth was impregnated with the varnish above, and then dried to remove the solvent to obtain a prepreg. Eight sheets of prepared prepregs were laminated, and pressed on both sides thereof with copper foils having a thickness of 1 oz (ounce), and cured in a press for 2 hours at a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 190° C. The physical property data are shown in Table 2 below.

Example 6

(20) 80 parts by weight of liquid styrene-butadiene resin Ricon 100, 20 parts by weight of the phosphorus-containing esterified allyl o-cresol novolac resin prepared in Preparation Example 3, 85 parts by weight of silica (525), and 6.5 parts by weight of an initiator DCP were mixed, adjusted to a suitable viscosity with a solvent of toluene, stirred and uniformly mixed to uniformly disperse the filler in the resin, so as to obtain a varnish. 1080 glass fiber cloth was impregnated with the varnish above, and then dried to remove the solvent to obtain a prepreg. Eight sheets of prepared prepregs were laminated, and pressed on both sides thereof with copper foils having a thickness of 1 oz (ounce), and cured in a press for 2 hours at a curing pressure of 50 kg/cm2 and a curing temperature of 190° C. The physical property data are shown in Table 2 below.

Examples 7-8

(21) The production processes were the same as that in Example 1, except for that the compounding ratio of the thermosetting resin composition was changed. The compounding ratio and the performance data of the prepared copper clad laminates are shown in Table 2 below.

Comparison Examples 1-2

(22) The production processes were the same as that in Example 1. The compounding ratio and the performance data of the prepared copper clad laminates are shown in Table 2 below.

(23) TABLE-US-00002 TABLE 2 Example Example Example Example Example Materials and properties 1 2 3 4 5 Ricon 100 80 60 80 35 80 Phosphorus-containing 20 40 20 65 esterified diallyl bisphenol A Phosphorus-containing 20 esterified allyl phenolic resin Phosphorus-containing esterified allyl o-cresol novolac resin 525 85 240 85 85 85 Bismaleimide BM-3000 0 0 10 15 0 DCP 6.5 7.5 5.6 5.3 6.5 1080 glass fiber cloth 80.7 125 78 85 80.7 Dielectric constant (10 GHZ) 3.78 3.86 3.93 3.94 3.80 Dielectric loss tangent (10 GHZ) 0.0053 0.0056 0.0056 0.0057 0.0054 Dip soldering resistance 288° C., (s) >120 >120 >120 >120 >120 Glass transition temperature (° C.) (DSC) 150 163 190 195 160 Flame retardancy V-1 V-0 V-1 V-0 V-1 Glass impregnation operation Good Good Good Good Good

(24) TABLE-US-00003 TABLE 3 Comp. Comp. Example Example Example Example Example Materials and properties 6 7 8 1 2 Ricon 100 80 90 80 80 Ricon 154 60 Phosphorus-containing 10 0 esterified diallyl bisphenol A Phosphorus-containing 40 esterified allyl phenolic resin Phosphorus-containing 20 esterified allyl o-cresol novolac resin Allyl phenolic resin 20 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide 20 525 85 240 85 85 85 Bismaleimide BM-3000 0 0 DCP 6.5 7.5 6 5.8 6.5 1080 glass fiber cloth 80.7 125 86 92 85 Dielectric constant (10 GHZ) 3.79 3.82 3.53 3.5 4.5 Dielectric loss tangent (10 GHZ) 0.0052 0.0051 0.0048 0.004 0.028 Dip soldering resistance, 288° C., (s) >120 >120 20 15 5 Glass transition temperature (° C.) (DSC) 158 220 100 80 130 Flame retardancy V-1 V-0 Combustion Combustion V-1 Glass impregnation operation Good Good Worse Worse Worse

Physical Analysis

(25) From the results of the physical property data in Tables 2 and 3, it can be seen that the circuit boards prepared in Examples 1-4 have better heat resistance and flame retardancy than those in Comparison Examples 1 and 2. It can also be seen that according to the comparisons between Examples 2, 4 and 7 and Examples 1, 3, 5, 6, and 8 that the cooperation between the components is more optimized, which enables the copper clad laminates to obtain better flame retardancy and heat resistance, when the phosphorus-containing monomer or the phosphorus-containing resin accounts for 20-75% by weight of the total weight of said other thermosetting resins containing unsaturated groups and the phosphorus-containing monomer or phosphorus-containing resin.

(26) As can be seen from the results of the physical property data in Table 2, the addition of bismaleimide within the compounding ratio range of the present invention can achieve better heat resistance.

(27) The thermosetting resin composition of the present invention, the prepreg, the metal foil-clad laminate, and the high-frequency circuit board prepared therefrom are described in the above examples. However, the present invention is not limited to the above examples, i.e. it does not mean that the present invention must rely upon the above examples. Those skilled in the art shall know that any modifications of the present invention, equivalent substitutions of the materials selected for use in the present invention, and addition of auxiliary ingredients, and specific manner in which they are selected, all are within the protection scope and disclosure scope of the present invention.