Resin composition and pre-preg and laminate using the composition
10858514 ยท 2020-12-08
Assignee
Inventors
- Xianping Zeng (Guangdong, CN)
- Guangbing CHEN (Guangdong, CN)
- Chiji Guan (Guangdong, CN)
- Wenhua Yang (Guangdong, CN)
Cpc classification
B32B2457/08
PERFORMING OPERATIONS; TRANSPORTING
B32B5/26
PERFORMING OPERATIONS; TRANSPORTING
C08L51/08
CHEMISTRY; METALLURGY
C08J2347/00
CHEMISTRY; METALLURGY
C08J5/249
CHEMISTRY; METALLURGY
C08F220/40
CHEMISTRY; METALLURGY
C08J2409/00
CHEMISTRY; METALLURGY
B32B15/20
PERFORMING OPERATIONS; TRANSPORTING
B32B15/14
PERFORMING OPERATIONS; TRANSPORTING
B32B2260/021
PERFORMING OPERATIONS; TRANSPORTING
B32B2307/4026
PERFORMING OPERATIONS; TRANSPORTING
C08L47/00
CHEMISTRY; METALLURGY
C08F220/40
CHEMISTRY; METALLURGY
C08J2447/00
CHEMISTRY; METALLURGY
International classification
B32B5/26
PERFORMING OPERATIONS; TRANSPORTING
C08L51/08
CHEMISTRY; METALLURGY
B32B15/14
PERFORMING OPERATIONS; TRANSPORTING
C08L47/00
CHEMISTRY; METALLURGY
B32B15/20
PERFORMING OPERATIONS; TRANSPORTING
C08J5/24
CHEMISTRY; METALLURGY
Abstract
Copper clad laminates and a resin composition and a pre-preg and a laminate using the composition. The resin composition contains: (A) a prepolymer of vinyl thermosetting polyphenylene ether and a bifunctional maleimide or a multifunctional maleimide; and, (B) a polyolefin resin. Employing the prepolymer of vinyl thermosetting polyphenylene ether and the bifunctional maleimide or the multifunctional maleimide, solves the problem of incompatibility of the bifunctional maleimide or the multifunctional maleimide with the vinyl thermosetting polyphenylene ether and the polyolefin resin. An aqueous glue solution so mixed is uniform and consistent, the prepreg has a uniform expression, and a substrate resin area is free of a phase-separation problem.
Claims
1. A resin composition, comprising: (A) a prepolymer of 70-100 parts of a vinyl thermosetting polyphenylene ether and 5-20 parts of a bifunctional maleimide or trifunctional maleimide; wherein the prepolymer is obtained in the presence of a radical initiator, and the conversion ratio of bifunctional maleimide or trifunctional maleimide is determined by GPC detection and is controlled in the range of 10 to 80%; and (B) 5.25-120 parts of a polyolefin resin which is selected from the group consisting of styrene-butadiene copolymer, polybutadiene, styrene-butadiene-divinylbenzene copolymer, and a mixture of at least two of them; wherein the vinyl thermosetting polyphenylene ether is selected from methyl methacrylate-modified polyphenylene ether and styryl-modified polyphenylene ether.
2. The resin composition of claim 1, wherein the vinyl thermosetting polyphenylene ether has a number average molecular weight from 500 to 10,000 g/mol.
3. The resin composition of claim 1, wherein the polyolefin resin comprises at least one member selected from the group consisting of amino-modified, maleic anhydride-modified, epoxy-modified, acrylate-modified, hydroxy-modified and carboxy-modified.
4. The resin composition of claim 1, wherein the resin composition further comprises an initiator.
5. The resin composition of claim 4, wherein the initiator is a radical initiator that is an organic peroxide initiator.
6. The resin composition of claim 5, wherein the radical initiator comprises at least one member selected from the group consisting of dilauroyl peroxide, dibenzoyl peroxide, cumyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, 1,1-di-(tert-butylperoxy)-3,5,5-trimethylcyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, 2,2-di(tert-butylperoxy)butane, bis(4-tert-butylcyclohexyl)peroxydicarbonate, cetyl peroxydicarbonate, tetradecyl peroxydicarbonate, di-tert amyl peroxide, dicumyl peroxide, bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne, diisopropylbenzene hydroperoxide, isopropylbenzene hydroperoxide, tert-amyl hydroperoxide, tert-butyl hydroperoxide, tert-butyl cumyl peroxide, diisopropylbenzene hydroperoxide, peroxy carbonate-tert-butyl 2-ethylhexanoate, tert-butyl peroxy 2-ethylhexyl carbonate, n-butyl 4,4-di(tert-butylperoxy)valerate, methyl ethyl ketone peroxide and cyclohexane peroxide.
7. The resin composition of claim 4, wherein the weight of the initiator is 1-3 parts by weight, based on 100 parts by weight of the total weight of the prepolymer of vinyl thermosetting polyphenylene ether and bifunctional maleimide or trifunctional maleimide and the polyolefin resin.
8. The resin composition of claim 1, wherein the resin composition further comprises a flame retardant.
9. The resin composition of claim 8, wherein the flame retardant comprises at least one member selected from the group consisting of bromine-containing flame retardant and a phosphorus-containing flame retardant.
10. The resin composition of claim 8, wherein the flame retardant is a phosphorus-containing flame retardant comprising a DOPO structure of molecular formula ##STR00009## wherein n is an integer of 0 to 10.
11. The resin composition of claim 8, wherein the weight of the flame retardant is 2 to 40 parts by weight, based on 100 parts by weight of the total weight of the prepolymer of vinyl thermosetting polyphenylene ether and bifunctional maleimide or trifunctional maleimide, the polyolefin resin and the initiator.
12. The resin composition of claim 1, wherein the resin composition further comprises a filler; and wherein the filler comprises at least one member selected from the group consisting of crystalline silica, amorphous silica, spherical silica, titanium dioxide, silicon carbide, glass fiber, alumina, aluminum nitride, boron nitride, barium titanate and strontium titanate.
13. The resin composition of claim 12, wherein the weight of the filler is 0-150 parts by weight, based on 100 parts by weight of the total weight of the prepolymer of vinyl thermosetting polyphenylene ether and bifunctional maleimide or trifunctional maleimide, the polyolefin resin, the initiator and the flame retardant.
14. A prepreg comprising a substrate and the resin composition of claim 1 which is attached on the substrate after impregnation and drying.
15. A laminate comprising at least one prepreg of claim 14 that is superimposed.
Description
EMBODIMENTS
(1) Technical solutions of the present invention are further described by the following examples.
(2) Raw materials selected for preparing high-speed electronic circuit substrates in examples of the present invention are shown in Table 1 below.
(3) TABLE-US-00001 TABLE 1 Name or trademark Manufacturer of materials Description for materials Sabic MX9000 Methyl methacrylate-modified polyphenylene ether Mitsubishi Chemical St-PPE-1 Styryl-moditied polyphenylene ether Wuhan ZHISHENG Maleimide Monofunctional maleimide Science &Technology K-I Chemical Maleimide Bifunctional maleimide Jinyi Chemical Maleimide Trifunctional maleimide Samtomer R100 Styrene-butadiene copolymer Nippon Soda B-1000 Polybutadiene Samtomer R250 Styrene-butadiene-divinylbenzene copolymer Shanghai Gaoqiao DCP Dicumyl peroxide Petrochemical Corp. Dongguan XINWEI BPO Dibenzoyl peroxide Chemical Industry Sibelco 525 Fused silica powder Albemarle, America BT-93W Bromine-containing flame retardant Albemarle, America XP-7866 Phosphorus-containing flame retardant Shanghai Honghe 2116 Glass fiber cloth
I. Prepolymerization of Vinyl Thermosetting Polyphenylene Ether and Bifunctional Maleimide or Polyfunctional Malcimide
Prepolymerization Example 1
(4) 70 g of vinyl thermosetting polyphenylene ether MX9000 was weighed and dissolved in 70 g of a toluene solvent. 5 g of bifunctional maleimide from K-I Chemical was weighed and dissolved in 20 g of a N,N-dimethylformamide solvent. The solution of vinyl thermosetting polyphenylene ether MX9000 and the solution of bifunctional maleimide from K-I chemical were mixed and stirred uniformly. The mixed solution was heated to 100 C., and then 0.1 g of DCP dissolved in 10 g of toluene was added and the mixture was reacted for 4 hours. Then the heating was stopped and the mixture was cooled for use.
Prepolymerization Example 2
(5) 70 g of vinyl thermosetting polyphenylene ether St-PPE-1 was weighed and dissolved in 70 g of a toluene solvent. 5 g of bifunctional maleimide from K-I Chemical was weighed and dissolved in 20 g of a N,N-dimethylformamide solvent. The solution of vinyl thermosetting polyphenylene ether St-PPE-1 and the solution of bifunctional maleimide from K-I chemical were mixed and stirred uniformly. The mixed solution was heated to 100 C., and then 0.1 g of DCP dissolved in 10 g of toluene was added and the mixture was reacted for 4 hours. Then the heating was stopped and the mixture was cooled for use.
Prepolymerization Example 3
(6) 70 g of vinyl thermosetting polyphenylene ether MX9000 was weighed and dissolved in 70 g of a toluene solvent. 5 g of trifunctional maleimide from Jinyi Chemical was weighed and dissolved in 20 g of a N,N-dimethylformamide solvent. The solution of vinyl thermosetting polyphenylene ether MX9000 and the solution of trifunctional maleimide from Jinyi Chemical were mixed and stirred uniformly. The mixed solution was heated to 100 C., and then 0.1 g of DCP dissolved in 10 g of toluene was added and the mixture was reacted for 4 hours. Then the heating was stopped and the mixture was cooled for use.
II. Preparation of High-Speed Electronic Circuit Substrates
Example 1
(7) A prepolymer prepared by prepolymerization of 70 g parts by weight of vinyl thermosetting polyphenylene ether MX9000 and 5 g parts by weight of bifunctional maleimide from KI Chemical, 25 g parts by weight of butadiene-styrene copolymer R100, 3.0 parts by weight of a curing initiator DCP, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue solution and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 2.
Example 2
(8) A prepolymer prepared by prepolymerization of 70 g parts by weight of vinyl thermosetting polyphenylene ether MX9000 and 5 g parts by weight of bifunctional maleimide from KI Chemical, 25 g parts by weight of polybutadiene B-1000, 3.0 parts by weight of a curing initiator DCP, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue solution and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 2.
Example 3
(9) A prepolymer prepared by prepolymerization of 70 g parts by weight of vinyl thermosetting polyphenylene ether MX9000 and 5 g parts by weight of trifunctional maleimide from Jinyi Chemical, 25 g parts by weight of butadiene-styrene-divinylbenzene copolymer R250, 3.0 parts by weight of a curing initiator BPO, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue solution and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 2.
Example 4
(10) A prepolymer prepared by prepolymerization of 70 g parts by weight of vinyl thermosetting polyphenylene ether MX9000 and 5 g parts by weight of bifunctional maleimide from K-I Chemical, 25 g parts by weight of butadiene-styrene copolymer R100, 3.0 parts by weight of a curing initiator BPO, 30 g parts by weight of a phosphorus-containing flame retardant XP-7866 and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue solution and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 2.
Example 5
(11) A prepolymer prepared by prepolymerization of 100 g parts by weight of vinyl thermosetting polyphenylene ether MX9000 and 5 g parts by weight of bifunctional maleimide from K-I Chemical, 5 g parts by weight of butadiene-styrene copolymer R100, 3.0 parts by weight of a curing initiator DCP, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue solution and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 3.
Example 6
(12) A prepolymer prepared by prepolymerization of 100 g parts by weight of vinyl thermosetting polyphenylene ether St-PPE-1 and 5 g parts by weight of bifunctional maleimide from K-I Chemical, 100 g parts by weight of butadiene-styrene copolymer R100, 3.0 parts by weight of a curing initiator DCP, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue solution and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 3.
Example 7
(13) A prepolymer prepared by prepolymerization of 100 g parts by weight of vinyl thermosetting polyphenylene ether MX9000 and 20 g parts by weight of bifunctional maleimide from K-I Chemical, 5 g parts by weight of butadiene-styrene copolymer R100, 3.0 parts by weight of a curing initiator DCP, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue solution and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 3.
Example 8
(14) A prepolymer prepared by prepolymerization of 100 g parts by weight of vinyl thermosetting polyphenylene ether St-PPE-1 and 20 g parts by weight of bifunctional maleimide from K-I Chemical, 100 g parts by weight of butadiene-styrene copolymer R100, 3.0 parts by weight of a curing initiator DCP, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue solution and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 3.
Comparative Example 1
(15) 70 g parts by weight of vinyl thermosetting polyphenylene ether MX9000 dissolved in toluene, 5 g parts by weight of bifunctional maleimide from KI Chemical dissolved in N,N-dimethylformamide, 25 g parts by weight of butadiene-styrene copolymer R100, 3.0 parts by weight of a curing initiator DCP, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 2.
Comparative Example 2
(16) 70 g parts by weight of vinyl thermosetting polyphenylene ether MX9000 dissolved in toluene, 5 g parts by weight of monofunctional maleimide from Wuhan ZHISHENG Science &Technology dissolved in N,N-dimethylformamide, 25 g parts by weight of butadiene-styrene copolymer R100, 3.0 parts by weight of a curing initiator DCP, 30 g parts by weight of a bromine-containing flame retardant BT-93 W and 50 g of fused silica powder 525 were dissolved in a toluene solvent and the solution was adjusted to a suitable viscosity. A 2116 fiberglass cloth was impregnated in the resulting glue and was controlled to a suitable weight by a clamp shaft, and was dried in an oven to remove the toluene solvent, and then a 2116 bonding sheet was obtained. Four 2116 bonding sheets were superimposed, and copper foils having a thickness of 1 OZ overlaid at the upper and lower surfaces of the superimposed bonding sheets, and then they were laminated and cured in a press machine in vacuum for 90 min with a curing pressure of 50 kg/cm.sup.2 and a curing temperature of 200 C. to obtain a high-speed electronic circuit substrate. Physical properties thereof are shown in Table 2.
(17) TABLE-US-00002 TABLE 2 Raw materials Comparative Comparative and Properties Example 1 Example 2 Example 3 Example 4 Example 1 Example 2 MX9000 70 0 70 70 70 70 St-PPE-1 0 70 0 0 0 0 R100 25 0 0 25 25 25 B-1000 0 25 0 0 0 0 R250 0 0 25 0 0 0 Bifunctional 5 5 0 5 5 0 maleimide Monofunctional 0 0 0 0 0 5 maleimide Trifunctional 0 0 5 0 0 0 maleimide DCP 3 3 0 3 3 3 BPO 0 0 3 0 0 0 BT-93W 30 30 30 0 30 30 XP-7866 0 0 0 30 0 0 525 0 50 50 50 50 50 Glass transition 210.0 210.0 220.0 210.0 210.0 190.0 temperature ( C.) Thermal 420.0 420.0 430.0 440.0 420.0 390.0 decomposition temperature ( C.) Thermal >60 min >60 min >120 min >60 min >60 min <60 min stratification time T288 Thermal 1.8% 1.8% 1.6% 1.8% 1.8% 2.7% expansion coefficient 50-260 C. Flame Grade V-0 Grade V-0 Grade V-0 Grade V-0 Grade V-0 Grade V-0 retardancy Dielectric 3.90 3.90 3.90 3.90 3.90 3.90 constant (10 GHz) Dielectric loss 0.0048 0.0048 0.0048 0.0048 0.0048 0.0048 tangent (10 GHz) Appearance of Good Good Good Good Poor Poor prepreg appearance appearance appearance appearance appearance appearance No crack No crack No crack No crack with cracks with cracks Whether the No phase No phase No phase No phase Phase Phase substrate resin area separation separation separation separation separation separation has a phase occurs occurs separation
(18) TABLE-US-00003 TABLE 3 Raw materials and Properties Example 5 Example 6 Example 7 Example 8 MX9000 100 0 100 0 St-PPE-1 0 100 0 100 R100 5.25 105 6 120 B-1000 0 0 0 0 R250 0 0 0 0 Bifunctional 5 5 20 20 maleimide Monofunctional 0 0 0 0 maleimide Trifunctional 0 0 0 0 maleimide DCP 3 3 3 3 BPO 0 0 0 0 BT-93W 30 30 30 0 XP-7866 0 0 0 0 525 50 50 50 50 Glass transition 200.0 200.0 225.0 230.0 temperature ( C.) Thermal 425.0 410.0 430.0 425.0 decomposition temperature ( C.) Thermal >60 min >60 min >60 min >60 min stratification time T288 Thermal expansion 1.6% 2.8% 1.5% 2.2% coefficient 50-260 C. Flame retardancy Grade V-0 Grade V-0 Grade V-0 Grade V-0 Dielectric constant 4.10 3.70 4.20 4.00 (10 GHz) Dielectric loss 0.0055 0.0045 0.0060 0.0058 tangent (10 GHz) Appearance of Good Good Good Good prepreg appearance appearance appearance appearance No crack No crack No crack No crack Whether the No phase No phase No phase No phase substrate resin area separation separation separation separation has a phase separation
(19) Physical Properties Analysis:
(20) As can be seen from Table 2 and Table 3, by prepolymerization of vinyl thermosetting polyphenylene oxide and bifunctional maleimide or polyfunctional maleimide, the problem of incompatibility of vinyl thermosetting polyphenylene ether, polyolefin resin and maleimide is solved; the prepared prepreg has a good appearance and the prepared substrate resin has no phase separation and an excellent overall performance such as dielectric properties and heat resistance.
(21) As can be seen from Comparative Example 1, when vinyl thermosetting polyphenylene oxide and bifunctional maleimide are not subjected to prepolymerization, the prepreg has a poor appearance with defect of cracks, and there is a phase separation in the substrate resin area.
(22) As can be seen from Comparative Example 2, when monofunctional maleimide is used and is not prepolymerized with vinyl thermosetting polyphenylene oxide, the prepreg has a poor appearance with defect of cracks, and there is a phase separation in the substrate resin area. In addition, heat resistance of the product is inferior to that of a product prepared by using bifunctional maleimide.
(23) The examples of the present invention are described above and they are not intended to limit the present invention. Any changes and modifications made to the present invention according to the technical concept of the present invention fall within the protection scope of the present invention.
(24) The applicant states that: the present application describes detailed means of the present invention by the aforesaid examples, but the present invention is not limited to the aforesaid detailed means. That is to say, it does not mean that the present invention cannot be fulfilled unless relying on the aforesaid detailed means. Those skilled in the art shall know that, any modification to the present invention, any equivalence 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.