Modified maleimide prepolymer, resin composition and application thereof

Abstract

The present invention provides a thermosetting resin composition, which comprises a modified maleimide prepolymer and oxazoline modified polystyrene, the modified maleimide prepolymer is generated by a prepolymerization reaction of a maleimide compound, an allyl phenol compound and a tetra-substituted aromatic diamine compound, the weight ratio of the maleimide compound to the allyl phenol compound to the tetra-substituted aromatic diamine compound is (40-70): (1-40): (5-30). The tetra-substituted aromatic diamine compound is applied to the modification process of maleimide and is matched with the oxazoline modified polystyrene compound, so that the problems that the water absorption rate of a cured product is increased and the dielectric property is reduced due to inherent phenolic hydroxyl groups in an allyl phenol compound can be reduced; the prepreg and the laminated board prepared from the composition have the advantages of excellent heat resistance, heat and humidity resistance, low water absorption rate, good dielectric property and good board thickness uniformity.

Description

Technical Field

[0001] The invention relates to the technical field of electronic materials, and in particular to a modified maleimide prepolymer, a resin composition and applications thereof. Background Art

[0002] Bismaleimide has excellent heat resistance, moisture and heat resistance, low thermal expansion coefficient, and good dielectric properties, making it a commonly used resin matrix in high-performance copper-clad laminates. Among them, diaminodiphenylmethane-type bismaleimide is particularly representative. However, unmodified bismaleimide has poor solubility and toughness, and cannot be used alone. It can only be used after modification. It is generally modified with aromatic diamine compounds or allyl compounds. Aromatic diamine compounds are used to modify bismaleimide through Michael addition reaction, and the modified products have a certain degree of improvement in solubility, toughness, etc. However, traditional aromatic diamine compounds are more toxic, and the modified products can only be dissolved in high-boiling polar solvents such as DMAC, DMF, and NMP. The products modified by allyl compounds (represented by allyl bisphenol A) are further improved in toughness, adhesion, and solubility than aromatic diamine compounds, and are currently the main methods used for bismaleimide modification. However, the inherent phenolic hydroxyl groups in allylphenol compounds inevitably lead to an increase in the water absorption of the cured product and a decrease in the dielectric properties. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art. The present invention proposes a modified maleimide prepolymer, a resin composition and applications thereof. The resin composition is prepared with the modified maleimide prepolymer to obtain a semi-cured sheet and a laminated board with uniform thickness, excellent heat resistance, moisture and heat resistance, low water absorption and good dielectric properties.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a modified maleimide prepolymer, which is prepared by prepolymerizing a maleimide compound, an allylphenol compound and a tetrasubstituted aromatic diamine compound; wherein the weight ratio of the maleimide compound, the allylphenol compound and the tetrasubstituted aromatic diamine compound is 40-70:1-40:5-30;

[0005] The maleimide compound is a compound containing two or more imide ring groups as shown in the following formula 1 in one molecular structure:

[0006]

[0007] In the structure shown in Formula 1, R1 is H or an alkyl group having 1 to 3 carbon atoms;

[0008] The allylphenol compound is a mixture of one or both of diallyl bisphenol A and allyl phenolic resin;

[0009] The tetra-substituted aromatic diamine compound is one of tetramethyldiaminodiphenylmethane, tetraethyldiaminodiphenylmethane and 3,3'-dimethyl-5,5'-diethyldiaminodiphenylmethane, preferably tetraethyldiaminodiphenylmethane.

[0010] Furthermore, the maleimide compound is at least one of the following structures:

[0011]

[0012] In the structure shown in Formula 5, R2 is any one of hydrogen or methyl, and n is 0-10.

[0013] Furthermore, the reaction temperature of the prepolymerization reaction is 80-200° C., and the reaction time is 0.5-6 h.

[0014] Furthermore, the equivalent ratio of the double bond in the maleimide compound to the double bond in the allyl compound and the primary amino group in the tetrasubstituted diamine is 2-0.5. If the equivalent ratio is lower than 0.5, the heat resistance decreases; if the equivalent ratio is higher than 2, the prepolymer is easily precipitated.

[0015] Furthermore, a thermosetting resin composition comprises 60 to 95 parts of a modified maleimide prepolymer and 5 to 30 parts of oxazoline-modified polystyrene, based on 100 parts by mass, wherein the structure of the oxazoline-modified polystyrene is shown in the following formula:

[0016]

[0017] In the structure shown in Formula 6, m is 50-1000, and n is 5-50.

[0018] Furthermore, a semi-cured sheet is prepared by the following method: after impregnating the composition into glass fiber cloth, baking at 100-200° C. for 1-10 min.

[0019] Furthermore, a laminate is prepared by the following method: metal foil is coated on both sides of the semi-cured sheet, and pressed at a pressure of 2.0-3.0 MPa and a temperature of 180-250° C. for 2-4 hours.

[0020] Compared with the prior art, the beneficial effects of the present invention include:

[0021] 1) By applying the tetrasubstituted aromatic diamine compound to the modification process of maleimide, the prepolymerization process of the allylphenol compound and maleimide can be effectively adjusted, and the secondary amine or tertiary amine structure is generated after curing, which is beneficial to improve the peel strength. At the same time, it can also effectively dilute the inherent phenolic hydroxyl content in the allylphenol compound, thereby reducing the water absorption rate of the cured product and improving the dielectric properties.

[0022] 2) By introducing oxazoline to modify polystyrene, on the one hand, the oxazoline group can further react with the phenolic hydroxyl group in the system to form a relatively low-polarity amide bond, and at the same time, due to the low hygroscopicity and excellent dielectric properties of polystyrene itself, the water absorption rate and dielectric properties of the system can be further improved. On the other hand, the reactivity of the oxazoline group with the phenolic hydroxyl group or secondary amine, and the high molecular weight of the polystyrene main chain can significantly improve the problem of excessive fluidity of the resin system during heating and pressurization. DETAILED DESCRIPTION

[0023] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the present invention.

[0024] A resin composition, based on 100 parts by mass, comprising:

[0025] 60-95 parts of modified maleimide prepolymer;

[0026] 5-30 parts of oxazoline-modified polystyrene.

[0027] The maleimide compound, the allylphenol compound and the tetrasubstituted aromatic diamine compound are prepolymerized to generate a modified maleimide prepolymer. The weight ratio of the maleimide compound, the allylphenol compound and the tetrasubstituted aromatic diamine compound is 40-70:1-40:5-30. The equivalent ratio of the double bond in the maleimide compound to the double bond in the allyl compound and the primary amino group in the tetrasubstituted diamine is 2-0.5. If the equivalent ratio is lower than 0.5, the heat resistance decreases; if the equivalent ratio is higher than 2, the prepolymer is easy to precipitate.

[0028] A semi-cured sheet made of a resin composition is prepared by impregnating a glass fiber cloth with the composition and then baking it at 100-200°C for 1-10 minutes.

[0029] A laminate made of a resin composition is formed by covering both sides of a semi-cured sheet with metal foils and pressing at a pressure of 2.0-3.0 MPa and a temperature of 180-250° C. for 2-4 hours.

[0030] The present invention is described in detail below in conjunction with embodiments:

[0031] Synthesis Example 1: 80 parts of allyl bisphenol A, 40 parts of tetraethyldiaminodiphenylmethane, and 200 parts of bis(4-maleimidophenyl)methane were added into a beaker, reacted at 140° C. for 60 minutes, and cooled to obtain prepolymer P1.

[0032] Synthesis Example 2: 140 parts of allyl bisphenol A and 200 parts of bis(4-maleimidophenyl)methane were added into a beaker, reacted at 130° C. for 60 minutes, and cooled to obtain prepolymer P2.

[0033] Embodiment 1:

[0034] 180 parts of prepolymer P of Synthesis Example 1 and 20 parts of oxazoline-modified polystyrene (Japan Catalyst RP-37) were dissolved in a mixed solvent of acetone and toluene to prepare a 65% solid content adhesive solution, and then 7628 glass fiber cloth was impregnated with the above adhesive solution and baked in an oven at 170°C for 3 minutes to obtain a semi-cured sheet.

[0035] The 8 prepregs are neatly stacked, and a 35um electrolytic copper foil is placed on each side, and then pressed in a vacuum hot press to obtain a copper clad laminate with a core thickness of 1.57mm. The specific pressing process is to press at a pressure of 2-3.0Mpa and a temperature of 220℃ for 4 hours.

[0036] The properties of the obtained copper clad laminate are shown in Table 1.

[0037] Embodiment 2:

[0038] 90 parts of prepolymer P1 of Synthesis Example 1 and 10 parts of oxazoline-modified polystyrene (Japan Catalyst RPS-1005) were dissolved in a mixed solvent of acetone and toluene to prepare a 65% solid content glue solution, and then 7628 glass fiber cloth was impregnated with the above glue solution and baked in an oven at 170°C for 3 minutes to obtain a semi-cured sheet.

[0039] The hot pressing process is the same as in Example 1, and the properties of the obtained copper clad laminate are shown in Table 1.

[0040] Comparative Example 1: 1100 parts of the prepolymer P1 of Synthesis Example 1 were dissolved in acetone solvent to prepare a glue solution with a solid content of 65%, and then 7628 glass fiber cloth was impregnated with the above glue solution and baked in an oven at 170°C for 3 minutes to obtain a semi-cured sheet.

[0041] The hot pressing process is the same as in Example 1, and the properties of the obtained copper clad laminate are shown in Table 1.

[0042] Comparative Example 2: 100 parts of the prepolymer P2 of Synthesis Example 2 were dissolved in acetone solvent to prepare a glue solution with a solid content of 65%, and then 7628 glass fiber cloth was impregnated with the above glue solution and baked in an oven at 170°C for 3 minutes to obtain a semi-cured sheet.

[0043] The hot pressing process is the same as in Example 1, and the properties of the obtained copper clad laminate are shown in Table 1.

[0044] Comparative Example 3: 190 parts of the prepolymer P of Synthesis Example 1 and 10 parts of non-oxazoline-modified polystyrene (Mw 150,000) were dissolved in butanone and toluene solvents to prepare a 65% solid content glue solution, and then 7628 glass fiber cloth was impregnated with the above glue solution and baked in an oven at 170°C for 3 minutes to obtain a semi-cured sheet.

[0045] The hot pressing process is the same as in Example 1, and the properties of the obtained copper clad laminate are shown in Table 1.

[0046] Comparative Example 4: 180 parts of the prepolymer P of Synthesis Example 1 and 20 parts of phenoxy resin (JER1256) were dissolved in butanone solvent to prepare a glue solution with a solid content of 65%. Then 7628 glass fiber cloth was impregnated with the above glue solution and baked in an oven at 170°C for 3 minutes to obtain a semi-cured sheet.

[0047] The hot pressing process is the same as in Example 1, and the properties of the obtained copper clad laminate are shown in the following table.

[0048]

[0049]

[0050] As can be seen from the above table, Comparative Example 1 does not contain oxazoline modified polystyrene components, and moisture and heat resistance decreases, water absorption increases, and thickness consistency deteriorates. Comparative Example 2 does not contain tetrasubstituted diaminodiphenylmethane and oxazoline modified polystyrene components, and its moisture and heat resistance is poor, water absorption is high, and thickness consistency is the worst. In Comparative Example 3, polystyrene without oxazoline is used, and there is a compatibility problem, copper foil adhesion seriously decreases, and water absorption increases; In Comparative Example 4, phenoxy resin is used, dielectric properties deteriorate, water absorption increases, and glass transition temperature decreases significantly.

[0051] The technical scope of the present invention is not limited to the contents in the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of ​​the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A modified maleimide prepolymer, characterized in that: Prepolymerizing a maleimide compound, an allylphenol compound and a tetrasubstituted aromatic diamine compound to generate the modified maleimide prepolymer; wherein the weight ratio of the maleimide compound, the allylphenol compound and the tetrasubstituted aromatic diamine compound is 40-70:1-40:5-30; The maleimide compound is a compound containing two or more imide ring groups as shown in the following formula 1 in one molecular structure: In the structure shown in Formula 1, R1 is H or an alkyl group having 1 to 3 carbon atoms; The allylphenol compound is a mixture of one or both of diallyl bisphenol A and allyl phenolic resin; The tetra-substituted aromatic diamine compound is one of tetramethyldiaminodiphenylmethane, tetraethyldiaminodiphenylmethane and 3,3'-dimethyl-5,5'-diethyldiaminodiphenylmethane.

2. The modified maleimide prepolymer according to claim 1, characterized in that The maleimide compound is at least one of the following structures: In the structure shown in Formula 5, R2 is any one of hydrogen or methyl, and n is 0-10.

3. The modified maleimide prepolymer according to claim 1, characterized in that: The reaction temperature of the prepolymerization reaction is 80-200° C., and the reaction time is 0.5-6 h.

4. The modified maleimide prepolymer according to claim 1, characterized in that The equivalent ratio of the double bond in the maleimide compound to the double bond in the allyl compound and the primary amino group in the tetrasubstituted diamine is 2-0.

5.

5. A thermosetting resin composition, characterized in that: Based on 100 parts by mass, it includes 60 to 95 parts of modified maleimide prepolymer and 5 to 30 parts of oxazoline modified polystyrene, and the structure of the oxazoline modified polystyrene is shown in the following formula: In the structure shown in Formula 6, m is 50-1000, and n is 5-50.

6. A prepreg, characterized in that: The preparation method is as follows: After impregnating the thermosetting resin composition described in claim 5 into glass fiber cloth, the glass fiber cloth is baked at 100-200° C. for 1-10 minutes.

7. A laminated board, characterized in that: The preparation method is as follows: metal foil is coated on both sides of the prepreg described in claim 6, and pressed at a pressure of 2.0-3.0 MPa and a temperature of 180-250° C. for 2-4 hours.

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