JPH0153701B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyphenylene ether resin film with improved heat resistance, solvent resistance and adhesiveness, and a semi-cured polyphenylene ether resin film exhibiting these properties. In recent years, there has been a definite trend towards smaller, lighter, and higher performance electrical equipment, and in response to this, there is a desire to develop insulating materials with excellent heat resistance, and the polymer materials field can meet these demands. Various research efforts are underway to achieve this goal. In particular, heat-resistant insulating films are attracting attention for their mechanical and electrical properties at high temperatures, and are required to have a long service life. Heat-resistant insulating films that meet this requirement are linear condensation polymers such as polyimide and polyamide. However, these materials are expensive, highly hygroscopic, and non-adhesive, and furthermore, it is almost impossible to manufacture a film in a semi-cured state that satisfies certain physical properties. On the other hand, there are also films that utilize thermoplastic resins as heat-resistant insulating films. However, although these materials are cheaper than condensation polymers such as polyimide and polyamide, they are inferior in heat resistance and dimensional stability, and their mechanical properties are highly temperature dependent, severely limiting their fields of application and uses. There is. Polyphenylene ether resin is a thermoplastic resin with excellent mechanical and electrical properties, and is also relatively heat resistant. Attempts have been made to produce a polyphenylene ether resin film focusing on this property (Special Publication No. 25628/1972), but when this material is exposed to high temperatures, the resin deteriorates and its toughness rapidly decreases. Moreover, as the temperature increases, mechanical strength decreases, deformation and weight loss occur. Because of these defects, films using polyphenylene ether resins have not yet been put into practical use. The present invention aims to improve the heat resistance of polyphenylene resin in consideration of these points of view, and even in a semi-cured state (hereinafter referred to as B-stage) film, it can be carried freely and has the performance as a film, and if necessary, B-Cure the stage filmC-
This was completed after intensive study to develop a film that could also be used as a stage film. That is, the present invention provides a mixture of (a) a polyphenylene ether resin and (b) (1) a polyfunctional maleimide and a polyfunctional cyanate ester, or (2) a polyfunctional maleimide and a polyfunctional cyanate ester. 3 to 96% by weight of component (a) and 4 to 96% by weight of component (b) based on the total amount of component (a) and component (b). 97% by weight and polyfunctional maleimides 1 to 70 as component (b)
A semi-cured or cured polyphenylene ether resin film characterized by using a curable resin composition containing a polyfunctional cyanate ester in a range of 3 to 90% by weight, and (a) Polyphenylene ether resin and (b) (1) A mixture of polyfunctional maleimides and polyfunctional cyanic acid esters (2) A mixture of polyfunctional maleimides and polyfunctional cyanic acid esters 3 to 96% by weight of component (a) and 4 to 97% by weight of component (b), based on the total amount of component (a) and component (b); ) component polyfunctional maleimides 1 to 70
A smooth plate, belt or film with releasability is coated with an organic solvent solution having a concentration of 5 to 35% by weight of a curable resin composition containing a polyfunctional cyanate ester in a range of 3 to 90% by weight. A method for producing a semi-cured or cured polyphenylene ether resin film, which is characterized by coating and casting on a B-stage film and forming a film by a dry or wet method. - In addition to being a stage film, polyphenylene ether resins maintain as much of their original properties as possible, while exhibiting particularly excellent heat resistance, solvent resistance, and adhesive properties. Its advantage lies in the fact that it improves upon the drawbacks of resin films. Another feature is that it is an improvement over the fact that it is impossible to directly produce a film from a resin composition comprising a polyfunctional maleimide and a polyfunctional cyanate ester used in the film of the present invention. The polyphenylene ether resin film of the present invention can be taken out as a film even in the B-stage state and can be carried freely, and the B-stage film will not break during transportation or deteriorate in physical properties even if stored for a long time. The film retains its shape and performance semi-permanently. Furthermore, even after this film was thermocompressed between copper foils and placed in a solder bath at 260°C, it did not swell or deform, and had good thermal stability. Furthermore, it realizes improved adhesive strength to copper foil. That is, the adhesive strength is significantly improved compared to when polyphenylene ether resin is used alone. The B-stage film is then cured by an appropriate method as described below to form a C-stage film, and the fact that this film has improved heat resistance will be demonstrated by the following facts. For example, in the composition of the polyphenylene ether resin film of the present invention, 80% by weight of polyphenylene ether resin, 10% by weight of polyfunctional maleimide, and 10% by weight of polyfunctional cyanate ester are blended. The film post-cured for 30 minutes at 220°C was left in an oven at 220°C for 50 hours, and when its tensile strength was measured, the tensile strength retention rate was 100% and there was no decrease in strength. On the other hand, when the polyphenylene ether resin alone was measured under the same conditions, the tensile strength retention rate was about 80%. These facts indicate that the polyphenylene ether resin film of the present invention has improved heat resistance over a polyphenylene ether resin film alone. In addition, in the composition of the polyphenylene ether resin film of the present invention, 80% by weight of polyphenylene ether resin, polyfunctional maleide
A film containing 15% by weight and 5% by weight of a polyfunctional cyanate ester was post-cured at 240°C for 30 minutes. This film was subjected to an extraction test using Soxhlet for 7 hours using chloroform as an extractant. When applied, only 5% of the film weight
is merely extracted. On the other hand, a polyphenylene ether resin single film is substantially extracted under the above extraction conditions, and the extraction residue is only 1% by weight or less. These facts indicate that the solvent resistance of the polyphenylene ether resin alone film is improved. Therefore, the film of the present invention can be used as a B-stage film or a C-stage film, and by taking advantage of its characteristics, it can be applied to various uses such as flexible circuits, flat cables, insulating films, and wire enamel. (a) The polyphenylene resin used in the polyphenylene ether resin film of the present invention has the general formula
of the phenol represented by (1) (Here, R ₄ is a lower alkyl group having 1 to 3 carbon atoms,
R ₃ and R ₅ are a hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms, and a lower alkyl substituent must always be present at the ortho position of at least one of the hydroxyl groups. ) Phenylene ether obtained by polycondensing one or more types of phenylene ether; also refers to a graft copolymer having a polyphenylene ether at its core obtained by graft polymerizing a vinyl aromatic compound to this polyphenylene ether. This polyphenylene ether may be a homopolymer or a copolymer. Examples of the phenol represented by the general formula (1) include 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-dipropylphenol, and 2,6-dimethylphenol.
-Methyl-6-ethylphenol, 2-methyl-
6-propylphenol, 2-ethyl-6-propylphenol, m-cresol, 2,3-dimethylphenol, 2,3-diethylphenol,
2,3-dipropylphenol, 2-methyl-3
-Ethylphenol, 2-methyl-3-propylphenol, 2-ethyl-3-methylphenol, 2-ethyl-3-propylphenol, 2-
Propyl-3-ethylphenol, 2,3,6-
Examples include trimethylphenol, 2,3,6-triethylphenol, 2,3,6-tripropylphenol, 2,6-dimethyl-3-ethyl-phenol, 2,6-dimethyl-3-propylphenol, and the like. Examples of polyphenylene ethers obtained by polycondensation of one or more of these phenols include poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,6-diethyl-
1,4-phenylene)ether, poly(2,6-
Dipropyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-methyl-6-propyl-1,4-phenylene) ether, poly(2- Ethyl-6-propyl-1,4-phenylene)ether, 2,6-dimethylphenol/2,3,6
-Triethylphenol copolymer, 2,6-dimethylphenol/2,3,6-triethylphenol copolymer, 2,6-diethylphenol/
2,3,6-trimethylphenol copolymer,
2,6-dipropylphenol/2,3,6-trimethylphenol copolymer, graft copolymer of styrene grafted onto poly(2,6-dimethyl-1,4-phenylene) ether, 2,6
-Dimethylphenol/2,3,6-trimethylphenol copolymer and a graft copolymer of styrene graft polymerized. In particular, poly(2,6-dimethyl-1,4-phenylene) ether, 2,6-dimethylphenol/2,3,6
-trimethylphenol copolymer and a graft copolymer obtained by graft polymerizing styrene to each of the former two are preferred as the polyphenylene ether resin used in the present invention. These polyphenylene ether resins have a number average of 7000~
It has a molecular weight of 50,000, preferably 10,000 to 40,000. In particular, in a range where the content of polyphenylene resin is small, a high molecular weight resin can be used to obtain a good film, so it may be selected as appropriate depending on the purpose of use. The polyfunctional maleimide which is a component used in the present invention refers to a polymaleimide compound represented by the following general formula (2) having two or more maleimide groups in the molecule, and a polymaleimide compound represented by the following general formula (2). ) [In the formula, R ₁ is a divalent, usually 5 or less, aromatic or alicyclic organic group, X ¹ and X ² are hydrogen, halogen, or an alkyl group, and k is 2 or more, usually 5 It is as follows. ] includes prepolymers derived from. Maleimides represented by the above formula can be produced by a method known per se, in which maleic anhydride and polyamines having 2 to 5 amino groups are reacted to prepare maleamic acid, and then maleamic acid is cyclized by dehydration. Can be done. The polyamines used are preferably aromatic amines in terms of the heat resistance of the final resin, but if the resin is desired to have good repellency or flexibility, alicyclic amines may be used alone or in combination. good. Furthermore, it is particularly desirable that the polyvalent amines be primary amines in terms of reactivity, but secondary amines can also be used. Suitable amines include meta or paraphenylene diamine, meta or para xylylene diamine, 1,4- or 1,3-cyclohexane diamine, hexahydroxylylene diamine, 4,4'-diaminobiphenyl, bis(4 -aminophenyl)methane, bis(4-aminophenyl)ether, bis(4-aminophenyl)sulfone, bis(4-amino-3-methylphenyl)methane, bis(4-amino-3,5-
dimethylphenyl)methane, bis(4-aminophenyl)cyclohexane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-amino-3-methylphenyl)propane, bis(4-aminophenyl)propane,
-amino-3-chlorophenyl)methane, 2,2
-Bis(3,5-dibromo-4-aminophenyl)propane, bis(4-aminophenyl)phenylmethane, 3,4-diaminophenyl-4'-aminophenylmethane, 1,1-bis(4-aminophenyl)- These include 1-phenylethane, melamines having an s-triazine ring, and polyamines made by reacting aniline with formalin and linking benzene rings with methylene bonds. In the present invention, the above-mentioned polyfunctional maleimide can also be used in the form of a prepolymer with the above-mentioned amino, for example, instead of being used in the form of a so-called monomer. The polyfunctional cyanate ester, which is a component used in the present invention, is an organic compound having two or more cyanate ester groups, and a suitable cyanate ester has the following general formula R ₂ (-O-C≡N ) _l ...(3) [l in the formula is an integer greater than or equal to 2 and usually less than or equal to 5.
R ₂ is an aromatic organic group, and the cyanate ester group is bonded to the aromatic ring of the organic group R ₂ . Specific examples include 1,3- or 1,4-dicyanatobenzene,
1,3,5-tricyanatobenzene, 1,3
-, 1,4-, 1,6-1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1,3,6
-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, bis(4-cyanatophenyl)methane, 2,2-bis(4-cyanatophenyl)propane, 2,2-bis(3,5 -dichloro-4-cyanatophenyl)propane, 2,2
-Bis(3,5-dibromo-4-cyanatophenyl)propane, bis(4-cyanatophenyl)ether, bis(4-cyanatophenyl)
Thioether, bis(4-cyanatophenyl)
Sulfone, tris(4-cyanatophenyl) phosphite, tris(4-cyanatophenyl)
These include phosphates, and cyanate esters obtained by the reaction of novolacs with cyanogen halides. In addition to these, Tokuko Sho 41-1928, Tokko Sho
43-18468, Special Publication Showa 44-4791, Special Publication Showa 45-11712,
Special Publication No. 46-41112, Special Publication No. 47-26853, and Special Publication No. 1987-26853
Cyanic acid esters described in 51-63149 and the like can also be used. Further, the above-mentioned polyfunctional cyanate ester is treated in the presence or absence of a mineral acid, a Lewis acid, a salt such as sodium carbonate or lithium chloride, a phosphate ester such as tributylphosphine, or a catalyst such as an epoxy compound. It can be used as a prepolymer obtained by polymerization. These prepolymers generally have a sym-triazine ring in the molecule, which is formed by trimerization of the cyanide group in the cyanate ester. In the present invention, it is preferable to use the prepolymer having an average molecular weight of 400 to 6,000. Furthermore, the polyfunctional cyanate esters described above can also be used in the form of prepolymers with amines. Examples of amines that can be suitably used include those exemplified as the raw material for producing the polyfunctional maleimide. Of course, the polyfunctional cyanate esters mentioned above, their prepolymers, and prepolymers with amines can be used in the form of mixtures. The resin composition of the film of the present invention can also be contained in the form of a preliminary reaction product of the polyfunctional maleimide and the polyfunctional cyanate ester. These preliminary reactants can be produced in the same manner as the method for producing prepolymers of polyfunctional maleimides or polyfunctional cyanate esters. (a) polyphenylene ether resin component, (b) - (1) polyfunctional maleimide component, and (b) explained above.
-(2) The blending ratio with the polyfunctional cyanate ester component is 3 to 96% by weight of the polyphenylene ether resin component and 1 to 1% by weight of the polyfunctional maleimide component, based on the total amount of the three components above. 70% by weight and polyfunctional cyanate ester components account for 3 to 90% by weight, and polyphenylene ether resin
A blending range of 95 to 40% by weight is particularly preferred.
Further, this may be used simply as a mixture, or may be partially pre-reacted in the presence or absence of a catalyst. In producing the film of the present invention, the B-stage film can be obtained by using a mixture of polyphenylene ether resin, (1) polyfunctional maleimide and polyfunctional cyanate ester, or (2) polyphenylene ether resin. The pre-reacted product of functional maleimides and polyfunctional cyanate esters is mixed with aromatic hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as chloroform and trichlene, and mixed solvents thereof.
A resin solution dissolved in weight percent is cast onto a smooth plate belt or film-like material such as stainless steel, Teflon, or Teflon-coated metal sheet that has mold releasability, and is applied to a conventional formulation such as dry, wet, semi-dry, or semi-wet. It can be twisted to form a film. Drying during film formation by the dry method is carried out using a steam pipe, an infrared lamp, a far-infrared lamp, or the like. In actual film formation, the range of film thickness that can be cast is preferably 0.01 to 0.5 mm in view of solvent dissipation. Further, the film can be easily peeled off from a smooth plate, belt, or film-like object by performing the operation in water, hot water, or an organic solvent that does not substantially dissolve the raw materials for film production. All of these operations are carried out in the usual manner and do not require any special operations, and can be carried out either batchwise or continuously. In producing the film of the present invention, a method of obtaining a C-stage film is a method of heating a B-stage film, and generally
Temperatures in the range 400°C are chosen, especially from 150 to 330°C
The heating atmosphere is preferably in the air or in an inert gas such as nitrogen. Although the time required for curing also varies depending on the thickness of the film, it is usually sufficient to select a sufficient time for curing from 30 seconds to 10 hours. The heating method is to place the film formed on a smooth plate, belt, or film-like material into the heating zone and heat it for an arbitrary period of time, or to
Both batch and continuous curing are possible by placing the B-stage film under tension in a thermal heating zone once recovered as a stage film, heating it with rolls, or passing it through a heated atmosphere. Furthermore, a roll or an extruder can also be used in producing the film of the present invention.
In this case, a predetermined amount of each component is added to a mixer such as a Henschel mixer, stirred to obtain a homogeneous composition, and then heated at a temperature in the range of 100 to 350°C, preferably 170 to 330°C. It is also possible to produce the film using conventional methods. The film of the present invention can be used as it is, but it can also be irradiated with ultraviolet rays depending on the purpose. When irradiating ultraviolet rays, if necessary, a known photosensitizer, such as an organic carbonyl compound such as benzoin, benzoin methyl ether, benzathurone, anthraquinone, or benzophenone, or a sensitizing dye such as eosin, erythrosin, or acridine, and various amines may be used. It is also possible to use a combination or the like. The film of the present invention may contain natural, semi-synthetic or synthetic resins in an amount within a range that does not impair the inherent properties of the composition, in order to impart desired performance depending on the intended use. Examples of such resins include drying oils, non-drying oils such as oleosin, rosin, silica, kobal, oil-modified rosin, epoxy resin, acrylic resin, silicone resin, rubber, etc., and one or more of these resins can be used. used in combination. In addition, for the purpose of making the film of the present invention flame retardant, the polyphenylene ether resin may be added with known flame retardants, such as phosphoric acid esters, halogenated organic compounds, a combination of halides and antimony compounds, or halogenated bis Phenol A or a halogenated epoxy compound can also be blended. Furthermore, pigments, mold release agents, stabilizers, plasticizers, softeners,
A known compounding agent such as an anti-static agent may be appropriately blended. Furthermore, a film can also be produced by stretching the film in one or two directions. All of these operations are performed in the usual manner and do not require any special operations. Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples. Parts and percentages herein are by weight unless otherwise specified. Example 1 and Comparative Example 1 Intrinsic viscosity measured in chloroform at 25°C 0.58 dl/
Poly(phenylmethylene) produced by reacting poly(2,6-dimethyl-1,4-phenylene ether), poly(phenylmethylene) polyamines obtained by the reaction of aniline and formaldehyde with maleic anhydride. ) Polymaleimide (having an average of trivalent N-phenylmaleimide residues in the molecule) and 2,2-bis(4-cyanatophenyl)
Propane and propane were each dissolved in toluene in the ratios shown in Table 1 to prepare a toluene solution containing 14% by weight of resin. This toluene solution was cast on a glass plate, dried for 3 minutes with a far-infrared lamp, and then immersed in water to obtain a B-stage film. Obtained B
- The stage film was dried to a fixed length to obtain a film with a thickness of 30μ. Various tests were conducted using this film and the results are shown in Table 1. Table 1 also shows poly(phenylmethylene)polymaleimide and 2,2
For comparison, results are shown for only polyphenylene ether resins excluding bis(4-cyanatophenyl)propane.

[Table] Example 2 Intrinsic viscosity measured in chloroform at 25°C is 0.57
dl/g of phenylene ether copolymer (a random copolymer derived from 95 mol% of 2,6-dimethylphenol and 5 mol% of 2,3,6-trimethylphenol on a monomer basis), 80 parts of bis(4
-50 parts of maleimidophenyl)methane and 50 parts of 2,2-bis(4-cyanatophenyl)propane to 130 parts
The maleimides were reacted at ℃ for 2 hours with stirring,
A prepolymer made of cyanate esters was produced, and 20 parts of the prepolymer and 0.5 parts of di-tert-butyl peroxide were each dissolved in toluene to prepare a 15% by weight toluene solution as a resin content. This toluene solution was preliminarily reacted at 100°C for 1 hour. The pre-reacted toluene solution was cast onto a glass plate using a doctor blade, dried for 2 minutes using a far-infrared lamp, and then immersed in water to obtain a B-stage film. The obtained B-stage film was dried at a constant length to obtain a film with a thickness of 30 μm. The tensile strength of this film is 4.4Kg/ ^mm2 . Example 3 A phenylene ether copolymer (on monomer basis 2,
95 mol% 6-dimethylphenol and 2,3,6-
120 g of a random copolymer derived from trimethylphenol (5 mol%), 60 g of styrene, 110 g of ethylbenzene, and 5 g of di-tert-butyl peroxide were uniformly dissolved with stirring at 100°C, and then nitrogen gas was blown into the reactor. Purge the oxygen gas inside the vessel. Polymerization is carried out for 3 hours while controlling the reactor to be maintained between 145 and 150°C. Remove the contents and dry at 180℃ using a vacuum dryer.
was dried for 10 hours to remove ethylbenzene and unreacted styrene to obtain a graft copolymer. Infrared absorption spectrum analysis of the obtained graft copolymer revealed that the polystyrene content was 10% by weight. 60 parts of this graft copolymer, 20 parts of bis(4-maleimidophenyl)methane, 100 parts of 2,2-bis(4-cyanatophenyl)propane, and 0.2 part of an epoxy resin (trade name: Epicote 152, manufactured by Ciel Chemical Co., Ltd.) were added. A cyanate ester prepolymer was produced by heating and stirring at 150°C for 5 hours.
Dissolve 20 parts of each in toluene to form the resin component.
A 18% by weight toluene solution was prepared. This toluene solution was cast onto a glass plate with a doctor blade, dried with an infrared lamp for 10 minutes, and then immersed in water.
- Obtained a stage film. The obtained B-stage film was dried at a constant length to obtain a film with a thickness of 30 μm. The tensile strength of this film is 3.9Kg/ ^mm2 . Example 4 Intrinsic viscosity measured in chloroform at 25°C is 0.80
dl/g of phenylene ether copolymer (random copolymer derived from 95 mol% of 2,6-dimethylphenol and 5 mol% of 2,3,6-trimethylphenol on monomer basis), 40 parts of bis(4
-maleimidophenyl) methane and 35 parts of the cyanate ester prepolymer used in Example 3 were each dissolved in toluene to prepare a benzene solution having a resin content of 18% by weight. B-
I got a stage film. The obtained B-stage film was dried to a fixed length to obtain a film with a thickness of 35 μm. The tensile strength of this film is 3.3 Kg/mm ² . Examples 5 to 8 and Comparative Example 2 The B-stage films obtained in Examples 1 to 4 and Comparative Example 1 were stacked together, and 35μ copper foil was covered on both sides, and a temperature of 200°C was applied.
It was pressed for 30 minutes to obtain a double-sided copper-clad film. Copper foil peel strength of the double-sided copper-clad film and 260
The solder heat resistance at ℃ was measured and shown in Table 2.

[Table] *1 ○……No blister
×... Blisters Examples 9 to 10 and Comparative Example 3 The polyphenylene ether resin used in Example 4, bis(4-maleimidophenyl)methane, and the cyanate ester prepolymer used in Example 3 were Each of the resins was dissolved in toluene in the proportions shown in Table 3 to prepare a 20% by weight toluene solution as the resin content. This toluene solution was cast on a glass plate, dried with an infrared lamp for 10 minutes, placed in an oven at 250°C for 30 minutes, cured, and then immersed in water.
I got a stage film. The resulting C-stage film was dried to obtain a 30μ film. The film was subjected to a Soxhlet extraction test for 7 hours using chloroform as an extractant, and the results are shown in Table 3.
Shown below. For comparison, Table 3 shows the results for only polyphenylene ether resins excluding the copolymer of bis(4-maleimidophenyl)methane and cyanate ester.

[Table] Examples 11 to 12 and Comparative Example 4 Table shows the polyphenylene ether resin used in Example 2, bis(4-maleimidophenyl)methane, and the cyanate ester prepolymer used in Example 3. Each of the resins was dissolved in toluene at the ratio shown in No. 4 to prepare a toluene solution containing 16% by weight of the resin. This toluene solution was cast on a glass plate, dried for 2 minutes with a far-infrared lamp, placed in an oven at 240°C for 30 minutes, cured, and then immersed in water to obtain a C-stage film. The C-stage film was dried to obtain a 35μ film. The tensile strength of the film and the results of the Soxhlet extraction test are shown in Table 4. For comparison, Table 4 shows the results for only polyphenylene ether resins excluding the copolymer of bis(4-maleimidophenyl)methane and cyanate ester.

[Table] Example 13 and Comparative Example 5 80 parts of polyphenylene ether resin used in Example 2, bis(4-maleimidophenyl)methane
10 parts of the prepolymer and 10 parts of the cyanate ester prepolymer used in Example 3 were each dissolved in toluene to prepare a toluene solution having a resin content of 15% by weight. This toluene solution was cast onto a glass plate using a doctor blade and dried for 3 minutes using a far-infrared lamp.
After hardening after putting it in the oven at 240℃ for 30 minutes,
A C-stage film was obtained by immersing it in water. The resulting C-stage film was dried to obtain a film with a thickness of 30 μm. This film was left in an oven at 220°C for 50 hours and its tensile strength was measured. For comparison, the C-stage film obtained in Comparative Example 4 was also left under the same conditions and its tensile strength was measured in the same manner. The results are shown in Table-5.

【table】

Claims (1)

[Scope of Claims] 1 (a) a polyphenylene ether resin and (b) a mixture of (1) a polyfunctional maleimide and a polyfunctional cyanate ester, or (2) a polyfunctional maleimide and 3 to 96% by weight of component (a) and 4% by weight of component (b) based on the sum of component (a) and component (b). ~97% by weight
and a curable resin composition containing 1 to 70% by weight of a polyfunctional maleimide and 3 to 90% by weight of a polyfunctional cyanate ester as component (b). A polyphenylene ether resin film that is cured or cured. 2 (a) A mixture of polyphenylene ether resin and (b) (1) a polyfunctional maleimide and a polyfunctional cyanic acid ester, or (2) a polyfunctional maleimide and a polyfunctional cyanic acid 3 to 96% by weight of component (a) and 4 to 97% by weight of component (b), based on the sum of component (a) and component (b).
and a curable resin composition containing 1 to 70% by weight of a polyfunctional maleimide and 3 to 90% by weight of a polyfunctional cyanate ester as component (b) has a concentration of 5 to 5%.
Smooth plate with mold releasability from 35% by weight organic solvent solution,
A method for producing a semi-cured or cured polyphenylene ether resin film, which comprises coating and casting onto a belt or film material and forming the film by a dry or wet method.