JPH0153699B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a semi-cured film and a cured film of a novel polyphenylene ether resin. In recent years, electrical equipment has become smaller, lighter, and more sophisticated, which is a definite trend, and in response to this trend, there is a demand for the development of insulating materials with excellent heat resistance. Various studies are underway to meet these requirements. 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, non-adhesive, and moreover, it is almost impossible to produce 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. 25628/1973), 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 ether resin in consideration of the above points, and also achieves the performance of a film that can be carried freely even in a semi-cured state (hereinafter referred to as B-stage), and as needed. This was completed as a result of intensive research to develop a film that could be used as a C-stage film by curing a B-stage film. That is, the present invention comprises (a) a polyphenylene ether resin and (b) a polyfunctional maleimide represented by the following general formula and/or a prepolymer thereof, the (a) component and the (b) component. 99 to 30% by weight of component (a), 1 to 70% by weight of component (b), based on the sum of
A semi-cured or cured polyphenylene ether resin film characterized by using a curable resin composition containing the following formula: (In the formula, R ₁ is an aromatic or alicyclic organic group with a valence of 2 or less, usually 5 or less, X ₁ and X ₂ are hydrogen, halogen, or an alkyl group, and m is 2 or more and usually 5
below). and (a) a polyphenylene ether resin and (b) a polyfunctional maleimide represented by the following general formula and/or a prepolymer thereof, and the sum of the components (a) and (b) is As a standard, the component (a) is 99 to 30% by weight, and the component (b) is 1 to 70% by weight.
The concentration of the curable resin composition blended in the range of 5
A semi-cured or hardened polyphenylene produced by coating and casting a ~35% by weight organic solvent solution on a smooth plate belt or film-like material with mold releasability, and forming a film by a dry or wet method. Manufacturing method of ether resin film Formula (In the formula, R ₁ is an aromatic or alicyclic organic group with a valence of 2 or less, usually 5 or less, X ₁ and X ₂ are hydrogen, halogen, or an alkyl group, and m is 2 or more and usually 5
below). The film can be a B-stage film or a C-stage film, and it also maintains the various properties inherent to polyphenylene ether resin as much as possible, and has particularly excellent heat resistance. Its advantage is that it exhibits solvent resistance and improves the drawbacks of films made solely of polyphenylene ether resin. Another feature of the present invention is that it is not possible to directly produce a film from the polyfunctional maleimides 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. There is no deterioration and the film retains its shape and performance semi-permanently. Furthermore, even after this film was placed between copper foils and bonded under heat and pressure, no blistering deformation occurred even when the film was placed in a solder bath at 260°C, and the film had good thermal stability. Furthermore, measurements of peel strength with copper foil revealed that the material has higher strength than polyphenylene ether resin alone and has excellent adhesion to copper foil, making these materials suitable for film carrier materials. It is also a powerful one. The B-stage film is then cured by a suitable 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 polyphenylene ether resin film composition of the present invention, a film containing 15% by weight of polyfunctional maleimide is placed in an oven at 220°C for 50 minutes.
When the tensile strength was measured after standing for a period of time, the tensile strength retention rate was 100%, with no decrease in strength. On the other hand, when polyphenylene ether resin alone was measured under the same conditions, the tensile strength retention rate was approximately 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. Furthermore, in the polyphenylene ether resin film composition of the present invention, the film is post-cured at 250°C for 30 minutes with 10% by weight of polyfunctional maleimide compounded.
When this film was subjected to a Soxhlet extraction test for 7 hours using chloroform as an extractant, only 15% of the film's weight was extracted, and an additional 15% by weight of polyfunctional maleimides was extracted.
With the above combination, nothing is extracted at all by chloroform. 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 polyphenylene ether resin film of the present invention has significantly improved solvent resistance than the polyphenylene ether resin film alone. Therefore, the film of the present invention can be used as a B-stage film or a C-stage film.
Taking advantage of its properties, it can be applied to a variety of applications 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 is a phenol represented by the general formula (1). (Here, R ₃ is a lower alkyl group having 1 to 3 carbon atoms,
R ₂ and R ₄ are hydrogen atoms or lower alkyl groups 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. ) Polyphenylene ether obtained by polycondensing one or more types of polyphenylene ether; also refers to a graft copolymer having a polyphenylene ether as a base 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,
2-Methyl-6-ethylphenol, 2-methyl-6-propylphenol, 2-ethyl-6-propylphenol, m-cresol, 2,3-dimethylphenol, 2,3-diethylphenol, 2,3-dimethylphenol Propylphenol, 2-methyl-3-ethylphenol, 2-methyl-3-propylphenol, 2-ethyl-3-methylphenol, 2-ethyl-3-propylphenol, 2
-Propyl-3-ethylphenol, 2,3,6
-trimethylphenol, 2,3,6-triethylphenol, 2,3,6-tripropylphenol, 2,6-dimethyl-3-ethyl-phenol, 2,6-dimethyl-3-propylphenol and the like. Polyphenylene ethers obtained by polycondensation of one or more of these phenols include, for example, poly(2,6-dimethyl-1,4-phenylene) ether, 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
-Trimethylphenol 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 the polyphenylene ether 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 another component used in the polyphenylene resin film of the present invention, is a polymaleimide compound represented by the following general formula (2) having two or more maleimide groups in the molecule, (In the formula, R ₁ is a divalent, usually pentavalent or less aromatic or alicyclic organic group, X ₁ and X ₂ are hydrogen, halogen, or an alkyl group, and m is 2 or more, usually 5 ) and prepolymers derived from this polymaleimide compound. The maleimide represented by the above formula has maleic anhydride and an amino group of 2 to 2.
It can be produced by a method known per se, in which maleamic acid is prepared by reacting with a polyamine having five polyamines, and then the maleamic acid is cyclized by dehydration. It is preferable that the polyamines used are aromatic amines in terms of the heat resistance of the final resin, but if flexibility and flexibility of the resin are desired, 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-amino-
3-chlorophenyl)methane, 2,2-bis(3,5-dipromo-4-aminophenyl)propane, bis(4-aminophenyl)phenylmethane, 3,4-diaminophenyl-4'-aminophenylmethane, 1, These include 1-bis((4-aminophenyl)-1-phenylethane, melamines with an s-triazine ring, and polyamines made by reacting aniline with formalin and linking benzene rings with methylene bonds. In the present invention, Instead of using the above-mentioned polyfunctional maleimide in the form of a monomer, it can also be used, for example, in the form of a prepolymer with the amine exemplified above. (a) in the polyphenylene ether resin film of the present invention The blending ratio of the polyphenylene ether resin component and (b) polyfunctional maleimide component is as follows:
Based on the sum of the polyphenylene ether resin component and the polyfunctional maleimide, the polyphenylene ether resin component accounts for 99 to 30% by weight, and the polyphenylene ether resin component accounts for 95% by weight.
Particular preference is given to formulations accounting for ~40% by weight. Further, these may be used simply as a mixture, or may be partially pre-reacted in the presence or absence of a catalyst. The method for producing the B-stage or C-stage film of the present invention using the above components is most preferably a solution casting method, but before the component (b) is used in the crosslinking reaction, it is used plastically. Extrusion methods, roll methods, etc. can also be used. The solution casting method uses a resin in which 5 to 35% by weight of the above components (a) and (b) are dissolved in an aromatic hydrocarbon such as benzene or toluene, a halogenated hydrocarbon such as chloroform or trichlene, or a mixed solvent thereof. A film can be formed by casting the solution onto a smooth plate belt or film-like material having mold releasability, such as stainless steel, Teflon, or Teflon-coated metal sheet, and using a conventional method such as a dry-wet method or a semi-dry-semi-wet method. During dry process film production, drying is done using steam pipes,
This is done using an infrared lamp or a far-infrared lamp. 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, peeling of the film from a smooth plate, belt or film-like object can be facilitated by carrying out 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 can be carried out either batchwise or continuously, without requiring any special operations. In producing the film of the present invention, the C-stage film is obtained by heating the B-stage film, generally at a temperature in the range of 100 to 400°C, particularly in the range of 150 to 330°C.
The temperature range is preferably 0.degree. C., and the heating atmosphere is preferably air or 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 or belt film-like material into the heating zone and heat it for an arbitrary time, or
- After being collected as a stage film, the B-stage film is put into a heating zone under tension and cured either batchwise or continuously by heating it with a roll or passing it through a heated atmosphere. . Further, 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 form a homogeneous composition, and then heated to a temperature of 100 to 350°C, preferably
It is also possible to produce films in a conventional manner at temperatures ranging from 170°C to 340°C. 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, photosensitizers known per se, such as organic carbonyl compounds such as benzoin, benzoin methyl ether, benzathurone, anthraquinone, and benzophenone, sensitizing dyes such as eosin, erythrosine, and acridine, and various amines are used. It is also possible to use a combination with. 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, copal, 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 order to make 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 Bisphenol 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 axes. All of these operations are performed in the usual manner and do not require any special operations. As described above, the present invention can exhibit excellent heat resistance and solvent resistance while maintaining the various properties of polyphenylene ether resin as much as possible, and furthermore, This device exhibits a novel feature of being able to provide a film in the same condition. The present invention will be specifically explained below using Examples and Comparative Examples. Unless otherwise specified herein, parts and percentages are by weight. Examples 1 to 2 and Comparative Example 1 Intrinsic viscosity measured in chloroform at 25°C 0.58 dl/
g poly(2,6-dimethyl-1,4-phenylene ether) and bis(4-maleimidophenyl)
Methane and methane were dissolved in toluene in the proportions shown in Table 1, respectively, to prepare a toluene solution containing 14% by weight of the resin. This toluene solution was cast onto a glass plate using a doctor blade, dried for 3 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. Various tests were conducted using this film and the results are shown in Table 1.
Shown below. Table 1 also shows bis(4-maleimidophenyl)
The results for only polyphenylene ether resin excluding methane are shown for comparison.

[Table] Phenylene ether copolymer (2,6- on monomer basis) with an intrinsic viscosity of 0.40 dl/g measured in chloroform at 25° C.
120 g of a random copolymer derived from 95 mol% of dimethylphenol and 5 mol% of 2,3,6-trimethylphenol, 60 g of styrene, 110 g of ethylbenzene, and 5 g of di-tert-butyl peroxide were charged and stirred at 100°C. After uniformly dissolving the mixture, nitrogen gas was sucked in to purge the oxygen gas in the reaction system. Polymerization was carried out for 3 hours while controlling the temperature inside the reactor to be maintained between 145 and 150°C. Remove the contents and use a vacuum dryer.
Ethylbenzene and unreacted styrene were removed by drying at 180°C for 10 hours to obtain a graft copolymer. Infrared absorption spectrum analysis of the obtained graft copolymer revealed that the polystyrene content was 10% by weight.
It was hot. This graft copolymer and bis(4-maleimidophenyl)methane were each dissolved in a toluene solution in the proportions shown in Table 2 to prepare a toluene solution containing 17% by weight of the resin. This toluene solution was cast onto a glass plate using a doctor blade, dried for 10 minutes using an 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 40 μm. The tensile strength of this film was measured.

[Table] Examples 4-5 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) and bis(4-maleimidophenol). (enyl) methane and dissolved in toluene solution in the proportions shown in Table 3 respectively to form a resin component.
Toluene solutions of 15% and 19% by weight were prepared.
This toluene solution was cast onto a glass plate with a doctor blade while keeping it at 80℃, and then heated with a far-infrared lamp.
After drying for a minute, it was immersed in water to obtain a B-stage film. The obtained B-stage films were dried to a fixed length to obtain films with thicknesses of 30μ and 20μ. The tensile strength of this film was measured.

[Table] Examples 6-7 Intrinsic viscosity measured in chloroform at 25°C 0.80 dl/
g of phenylene ether copolymer (95 mol% of 2,6-dimethylphenol and 2,6-dimethylphenol on a monomer basis)
A random copolymer derived from 5 mol% of 3,6-trimethylphenol) and bis(4-maleimidophenyl)methane were dissolved in toluene in the proportions shown in Table 4, and 18% by weight of toluene was obtained as a resin content. A solution was prepared. This toluene solution was cast onto a glass plate using a doctor blade while maintaining the temperature at 80°C, dried for 2 minutes using a far-infrared lamp, and then immersed in hot 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 20 μm. The tensile strength of this film was measured.

[Table] Example 8 Intrinsic viscosity measured in chloroform at 25°C is 0.34
dl/g of poly(phenylmethylene) polyamines obtained by reacting 92 parts of poly(2,6-dimethyl-1,4-phenylene ether) with aniline and formaldehyde with maleic anhydride. 8 parts of (phenylmethylene)polymaleimide (having an average of 3 N-phenylmaleimide residues in the molecule) and 0.5 parts of di-tert-butyl peroxide are each dissolved in toluene to give a resin content of 20% by weight of toluene. A solution was prepared. 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 3 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 40 μm. The tensile strength of this film was 3.8 Kg/mm ² . Examples 9 to 15 and Comparative Example 2 Two B-stage films obtained in Examples 1 to 7 and Comparative Example 1 were stacked and copper foil was covered on both sides.
A double-sided copper-clad film was obtained by pressing at a temperature of 200°C for 30 minutes. The copper foil peel strength and solder heat resistance of this double-sided copper-clad film were measured and are shown in Table 5.

【table】

[Table] *1 ○…No blister
×...Blistering Examples 16 to 22 and Comparative Example 3 Intrinsic viscosity measured in chloroform at 25°C 0.57 dl/
g of phenylene ether copolymer (0.5 mol% of 2,6-dimethylphenol and 2,6-dimethylphenol on monomer basis)
A random copolymer derived from 5 mol% of 3,6-trimethylphenol) and bis(4-maleimidophenyl)methane were dissolved in toluene in the proportions shown in Table 6 to obtain a resin content of 13% by weight or more.
A 20% by weight toluene solution was prepared. This toluene solution was cast onto a glass plate using a doctor blade, dried for 3 minutes using 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 obtained C-stage film was dried to obtain a film with a size of 20μ to 40μ. This film was subjected to a Soxhlet extraction test for 7 hours using chloroform as an extractant, and the results are shown in Table 6. Table 6 also shows screws (4
-Maleimidophenyl) The results for only polyphenylene ether resins excluding methane are shown for comparison.

[Table] Example 23 and Comparative Example 4 The C-stage film obtained in Example 18 was heated at 220°C.
It was left in an oven for 50 hours and its tensile strength was measured. For comparison, the C-stage film obtained in Comparative Example 3 was also left under the same conditions and its tensile strength was measured in the same manner. The results are shown in Table 7.

【table】

Claims (1)

[Scope of Claims] 1 Contains (a) a polyphenylene ether resin and (b) a polyfunctional maleimide represented by the following general formula and/or a prepolymer thereof, the component (a) and (b) ) 99 to 30% by weight of component (a), 1 to 70% by weight of component (b), based on the sum of component (a)
A semi-cured or cured polyphenylene ether resin film characterized by using a curable resin composition containing the following. formula (R ₁ in the formula is an aromatic or alicyclic organic group with a valence of 2 or less, usually 5 or less, X ₁ and X ₂ are hydrogen, halogen, or an alkyl group, and m is 2 or more and usually 5 or less. ). 2 Contains (a) a polyphenylene ether resin and (b) a polyfunctional maleimide represented by the following general formula and/or its prepolymer, and the sum of the components (a) and (b) is (a) as a criterion
The concentration of the curable resin composition is 5 to 30% by weight of component (b) and 1 to 70% by weight of component (b).
A semi-cured or hardened polyphenylene ether characterized by coating and casting a 35% by weight organic solvent solution onto a smooth plate, belt, or film-like material with mold releasability and forming a film by a dry or wet method. A method for producing a resin film. formula (R ₁ in the formula is an aromatic or alicyclic organic group with a valence of 2 or less, usually 5 or less, X ₁ and X ₂ are hydrogen, halogen, or an alkyl group, and m is 2 or more and usually 5 or less. ).