JP2008024805A - Epoxy adhesive, cover lay, prepreg, metal-clad laminated plate and printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy adhesive that is excellent in flame retardancy without halogen flame retardants as well as in adhesive properties, electric insulation and flexibility (pliability), and to provide a cover lay, a prepreg, a metal-clad laminated plate and a printed wiring board that are flexible using the epoxy adhesive. <P>SOLUTION: The epoxy adhesive comprises 100 pts.mass of an epoxy resin containing a phosphorus atom in the skeleton and, incorporated therewith, at least 20 but at most 40 pts.mass of a phenol novolak resin having a triazine structure, at least 40 but at most 80 pts.mass of a carboxylated rubber, and at least 40 but at most 100 pts.mass of a metal hydrate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

 The present invention relates to an epoxy adhesive excellent in electrical characteristics and heat resistance, and a flexible cover lay, prepreg, metal-clad laminate, and printed wiring board using the epoxy adhesive.

In recent years, with the miniaturization of electronic devices, a flexible printed circuit board (FPC = Flexible Printed Circuit) that is light and can be three-dimensionally mounted has been widely used.
In this flexible printed circuit board, a wiring layer is formed on a flexible substrate via an adhesive layer, and an insulating coverlay film is bonded to the surface for the purpose of protecting the wiring layer. ing.
As the flexible substrate, for example, a polyimide film is used, and the wiring layer is formed of a metal foil such as a copper foil.
A flexible insulating film such as a polyimide film is used for the coverlay film.

As an adhesive for adhering them, an epoxy adhesive is used in which a polymer component such as acrylonitrile butadiene rubber (NBR) or acrylic rubber and a curing agent are added to an epoxy resin.
In order to make a flexible printed circuit board highly functional, such an adhesive is required to improve adhesiveness and flexibility and to be excellent in flame retardancy.
Conventionally, in order to impart flame retardancy to an adhesive, a halogen-based flame retardant has been added to the adhesive (see, for example, Patent Document 1 and Patent Document 2).
Japanese Patent Publication No. 7-33501 Japanese Patent Laid-Open No. 10-081858

 However, when a flexible printed circuit board using an adhesive containing a halogen-based flame retardant is incinerated, there is a possibility that dioxins resulting from the halogen-based flame retardant are generated.

 The present invention has been made to solve the above-described problems, and is excellent in flame retardancy without containing a halogen-based flame retardant, and has adhesiveness, electrical insulation, and flexibility (flexibility). It is an object of the present invention to provide an epoxy adhesive having excellent resistance, and a flexible cover lay, prepreg, metal-clad laminate, and printed wiring board using the epoxy adhesive.

 In the epoxy adhesive according to claim 1 of the present invention, 100 parts by mass of an epoxy resin having a phosphorus atom in the skeleton, 20 parts by mass or more and 40 parts by mass or less of a phenol novolac resin having a triazine structure, and a carboxylated rubber 40 parts by mass or more and 80 parts by mass or less, and 40 to 100 parts by mass of metal hydrate is added.

 The epoxy adhesive according to claim 2 of the present invention is the epoxy adhesive according to claim 1 of the present invention, wherein the phenol novolac resin having a triazine structure is a cresol type phenol novolac resin. .

 The cover lay according to claim 3 of the present invention is a cover lay in which an adhesive layer is provided on one side of an insulating film, and the adhesive constituting the adhesive layer has an epoxy resin having a phosphorus atom in the skeleton of 100 mass. 20 parts by mass or more and 40 parts by mass or less of a phenol novolak resin having a triazine structure, 40 parts by mass or more and 80 parts by mass or less of a carboxylated rubber, and 40 parts by mass or more and 100 parts by mass or less of a metal hydrate It is characterized by becoming.

 The prepreg according to claim 4 of the present invention is a prepreg obtained by impregnating a glass cloth with an epoxy adhesive, and the epoxy adhesive has a triazine structure on 100 parts by mass of an epoxy resin having a phosphorus atom in the skeleton. A phenol novolac resin having 20 to 40 parts by mass, a carboxylated rubber of 40 to 80 parts by mass, and a metal hydrate of 40 to 100 parts by mass. And

 The metal-clad laminate according to claim 5 of the present invention is a metal-clad laminate in which an adhesive layer is provided between a base film and a metal foil, and the adhesive constituting the adhesive layer contains phosphorus atoms. 20 parts by mass or more and 40 parts by mass or less of phenol novolak resin having a triazine structure, 40 parts by mass or more and 80 parts by mass or less of carboxylated rubber, and 40 parts by mass of metal hydrate, with 100 parts by mass of epoxy resin in the skeleton It is characterized by being added in an amount of not less than 100 parts and not more than 100 parts by mass.

 A printed wiring board according to claim 6 of the present invention is characterized in that the coverlay according to claim 3 of the present invention is bonded to the metal foil surface of the metal-clad laminate according to claim 5 of the present invention. And

According to the epoxy adhesive of the present invention, 20 parts by mass or more and 40 parts by mass or less of phenol novolac resin having a triazine structure and 40 parts by mass of carboxylated rubber are added to 100 parts by mass of epoxy resin having phosphorus atoms in the skeleton. As described above, 80 parts by mass or less and metal hydrate are added by 40 parts by mass or more and 100 parts by mass or less. In addition, an adhesive layer excellent in flexibility (flexibility) can be formed.
Therefore, according to the epoxy adhesive of the present invention, it is possible to provide a printed wiring board such as an FPC that requires a narrow pitch wiring. As a result, downsizing, high functionality and long life of various electronic devices It can contribute to the conversion.

 Hereinafter, the present invention will be described in detail.

 The epoxy adhesive of the present invention is 100 parts by mass of an epoxy resin having a phosphorus atom in the skeleton, 20 parts by mass or more and 40 parts by mass or less of a phenol novolac resin having a triazine structure, 40 parts by mass or more of carboxylated rubber, It is an adhesive formed by adding 80 parts by mass or less and 40 parts by mass or more and 100 parts by mass or less of metal hydrate.

  When the addition amount of the phenol novolac resin having a triazine structure is less than 20 parts by mass with respect to 100 parts by mass of the epoxy resin, the epoxy adhesive is not sufficiently cured and the adhesiveness is lowered. On the other hand, when the addition amount of the phenol novolac resin having a triazine structure exceeds 40 parts by mass with respect to 100 parts by mass of the epoxy resin, the phenol novolac resin having a triazine structure becomes excessive and the insulation resistance is lowered.

When the addition amount of the carboxylated rubber is less than 40 parts by mass with respect to 100 parts by mass of the epoxy resin, the flexibility (flexibility) of the adhesive layer formed using this epoxy adhesive cannot be sufficiently obtained. On the other hand, when the addition amount of the carboxylated rubber exceeds 80 parts by mass with respect to 100 parts by mass of the epoxy resin, the electrical resistance value of the adhesive layer formed using this epoxy-based adhesive is lowered, and sufficient insulation is achieved. Can't get.
By setting the amount of rubber to be in the above range, an adhesive layer excellent in both flexibility (flexibility) and insulation can be formed.

 When the addition amount of the metal hydrate is less than 40 parts by mass with respect to 100 parts by mass of the epoxy resin, the epoxy adhesive is inferior in flame retardancy. On the other hand, when the addition amount of the metal hydrate exceeds 100 parts by mass with respect to 100 parts by mass of the epoxy resin, the adhesiveness of the epoxy adhesive decreases.

 As the epoxy resin, an epoxy resin having a phosphorus atom in the skeleton is used. Examples of the epoxy resin having a phosphorus atom in the skeleton include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, glycidyl ester type epoxy resin, Examples include glycidylamine type epoxy resins, hydantoin type epoxy resins, isocyanurate type epoxy resins, acrylic acid-modified epoxy resins (epoxy acrylates) and the like having a phosphorus atom in the skeleton. These epoxy resins may be used independently and may use 2 or more types together. Moreover, since an acrylic acid modified epoxy resin (epoxy acrylate) has photosensitivity, it is effective for imparting photocurability to the epoxy resin composition. These epoxy resins can also be used together with a novolak type phenol resin, a vinyl phenol resin, a brominated vinyl phenol resin, or the like that undergoes a crosslinking reaction.

The phenol novolak resin having a triazine structure is used as a curing agent for the epoxy adhesive of the present invention. Among these phenol novolak resins having a triazine structure, a cresol type phenol novolak resin is preferable.
The cresol type phenol novolac resin is a resin in which phenol of a phenol novolac resin obtained by addition / condensation of phenol and formaldehyde is replaced with cresol (methylphenol).
Examples of the cresol type phenol novolak resin include o-cresol novolak resin and aminotriazine cresol novolak resin.

The carboxylated rubber is not particularly limited as long as it is dispersed in the epoxy resin and imparts flexibility to the epoxy resin, but carboxylated acrylonitrile butadiene rubber (carboxylated NBR), carboxylated ethylene acrylic rubber, and the like are used. . In particular, carboxylated acrylonitrile butadiene rubber is suitable.
Carboxylated acrylonitrile butadiene rubber (carboxylated NBR) is obtained by modifying acrylonitrile butadiene rubber (NBR), which is a copolymer of acrylonitrile and butadiene, to introduce a carboxy group. As a method for introducing a carboxy group, (1) when copolymerizing acrylonitrile and butadiene, further copolymerizing a monomer having a carboxy group; (2) after copolymerizing acrylonitrile and butadiene, And a method of graft-reacting the monomer possessed. This carboxylated acrylonitrile butadiene rubber is dispersed in an epoxy resin and imparts flexibility to the epoxy resin.

 Examples of the metal hydrate include aluminum hydroxide, magnesium hydroxide, calcium hydroxide and the like.

Moreover, you may mix | blend a filler, another additive, etc. with the epoxy adhesive of this invention as needed.
Examples of the filler include silica, mica, clay, talc, titanium oxide, calcium carbonate and the like.

 Examples of other additives include a silane coupling agent and imidazole that are used to improve the adhesion to the circuit.

Next, the usage method of the epoxy adhesive of this invention is demonstrated.
As a method for using the epoxy adhesive of the present invention, a predetermined amount of a constituent material such as epoxy resin, cresol type phenol novolac resin, carboxylated rubber and an organic solvent is blended, and a pot mill, a ball mill, a homogenizer, a super mill, etc. A method of preparing an adhesive solution by stirring and mixing, and applying the adhesive solution to an object is used.

 The epoxy adhesive of the present invention can be used to bond or seal an object by applying the above adhesive solution to the object, drying and curing. The drying and curing of the adhesive solution can be performed at a temperature of about 20 to 200 ° C., for example.

 Examples of the organic solvent used for preparing the adhesive solution include methanol, acetone, methyl ethyl ketone, toluene, dimethylformamide, 2-methoxyethanol and the like. The solid content concentration in the adhesive solution is preferably in the range of 5 to 70 mass%, more preferably 10 to 50 in consideration of the suppression of coating unevenness and the solubility of the epoxy adhesive. It is in the range of mass%.

 The epoxy-based adhesive of the present invention can be suitably used for various applications, but exhibits excellent effects when applied to various materials used for flexible printed circuit boards (FPC). Examples of the FPC material include a cover-lay (CL), a prepreg, a metal-clad laminate such as a copper foil-clad laminate (CCL), a printed wiring board, and the like.

 The epoxy adhesive of the present invention is 100 parts by mass of an epoxy resin having a phosphorus atom in the skeleton, 20 parts by mass or more and 40 parts by mass or less of a phenol novolac resin having a triazine structure, 40 parts by mass or more of carboxylated rubber, 80 parts by weight or less, metal hydrate is added by 40 parts by weight or more and 100 parts by weight or less, so it is excellent in flame retardancy without containing a halogen-based flame retardant, and has adhesiveness, electrical insulation and flexibility. Excellent in flexibility (flexibility).

FIG. 1 is a schematic cross-sectional view showing an embodiment of a cover lay of the present invention.
The cover lay 1 of this embodiment is formed by providing an adhesive layer 3 made of the epoxy adhesive of the present invention on one surface 2a of an insulating film (film base material) 2. In a flexible printed circuit board, It is used to insulate and protect the circuit or the like by being laminated on the circuit or the like formed on the substrate.

As the insulating film 2, for example, a film made of polyimide resin, polyethylene terephthalate resin, aramid resin or the like and having a thickness of about 1 μm to 150 μm can be used.
The thickness (after drying) of the adhesive layer 3 can be, for example, about 1 μm to 100 μm.
As described above, the method of forming the adhesive layer from the epoxy adhesive of the present invention can be performed by a method such as coating.

 The CCL to which the cover lay of the present invention is applied is not particularly limited. For example, a three-layer CCL formed by bonding a copper foil (metal foil) with an adhesive to a base film made of polyimide or the like. A two-layer CCL (CCL having no adhesive layer) formed by applying a polyimide varnish to one side of a copper foil (metal foil) and drying can be used.

According to the coverlay of the present invention, since the adhesive layer is formed by the epoxy adhesive of the present invention, it is excellent in flame retardancy, adhesiveness, electrical insulation and flexibility (flexibility). .
Therefore, according to the coverlay of the present invention, it is possible to provide a printed wiring board such as an FPC that requires a narrow pitch wiring. As a result, it is possible to reduce the size, increase the functionality, and extend the life of various electronic devices. Can contribute. Moreover, since the coverlay of this invention has flexibility, if this is applied to a printed wiring board, a printed wiring board will also have flexibility.

 The prepreg of the present invention is obtained by impregnating a glass cloth with the epoxy adhesive of the present invention. In the metal-clad laminate, the adhesive is provided between the base film and the metal foil and adheres to both. Used as an adhesive constituting the layer.

 The glass cloth is not particularly limited, and examples thereof include an MS cloth manufactured by Asahi Schwer.

According to the prepreg of the present invention, since the glass cloth is impregnated with the epoxy adhesive of the present invention, it is excellent in flame retardancy, adhesiveness, electrical insulation and flexibility (flexibility). Yes.
Therefore, according to the prepreg of the present invention, it is possible to provide a printed wiring board such as an FPC that requires a narrow pitch wiring. As a result, it contributes to miniaturization, high functionality and long life of various electronic devices. can do. In addition, since the prepreg of the present invention has flexibility, when this is applied to a printed wiring board, the printed wiring board also has flexibility.

FIG. 2 is a schematic cross-sectional view showing an embodiment of the metal-clad laminate of the present invention.
In the metal-clad laminate 4 of this embodiment, an adhesive layer 6 made of the prepreg of the present invention is provided between a base film 5 and a metal foil 7.

As the base film 5, a resin film having electrical insulation and flexibility is used, and examples thereof include films made of resins such as polyimide, polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, and polyethersulfone.
The metal foil 7 is made of copper foil or the like and forms a predetermined circuit pattern.

According to the metal-clad laminate of the present invention, since the adhesive layer made of the prepreg of the present invention is provided between the base film and the metal foil, flame retardancy, adhesiveness, electrical insulation And excellent in flexibility (flexibility).
Therefore, according to the metal-clad laminate of the present invention, it is possible to provide a printed wiring board such as an FPC that requires a narrow pitch wiring. As a result, downsizing, high functionality, and long life of various electronic devices are provided. It can contribute to the conversion. In addition, since the metal-clad laminate of the present invention has flexibility, when this is applied to a printed wiring board, the printed wiring board also has flexibility.

FIG. 3 is a schematic cross-sectional view showing an embodiment of the printed wiring board of the present invention.
In the printed wiring board 10 of this embodiment, the cover lay 1 is attached to the surface (metal foil surface) on which the metal foil 7 of the metal-clad laminate 4 is provided, and the cover lay 1 and the metal-clad laminate 4 Are laminated and integrated.

The printed wiring board 10 can be manufactured by a method in which, for example, the metal foil 7 of the metal-clad laminate 4 is etched to form a wiring, and then the coverlay 1 is attached to the metal foil surface. .
The cover lay 1 is attached so that the adhesive layer 3 of the cover lay 1 and the metal foil surface of the metal-clad laminate 4 face each other and are integrated by hot pressing or the like. As hot press conditions, for example, the heating temperature can be about 140 to 200 ° C., and the heating time can be about 0.1 to 3 hours.

According to the printed wiring board of the present invention, the cover lay of the present invention is adhered to the surface of the metal-clad laminate of the present invention on which the metal foil 7 is provided, and the cover lay of the present invention and the metal tension of the present invention are adhered. Since the laminated board is laminated and integrated, it is excellent in flame retardancy, adhesiveness, electrical insulation and flexibility (flexibility).
Therefore, according to the printed wiring board of the present invention, it is possible to provide a printed wiring board such as an FPC that requires a narrow pitch wiring. As a result, various electronic devices can be miniaturized, enhanced in function and extended in life. Can contribute. In addition, the printed wiring board of the present invention has flexibility because the coverlay having flexibility and the metal-clad laminate are laminated and integrated.

 EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples.

"Example 1"
(Preparation of epoxy adhesive)
An epoxy adhesive according to Example 1 was prepared according to the formulation shown in Table 1.
An epoxy resin A, a phenol novolac resin A, a carboxylated rubber A and a metal hydrate A are dissolved and dispersed in methyl ethyl ketone to obtain a solid content (epoxy resin A, phenol novolac resin A, carboxylated rubber A, metal hydrate A An adhesive solution having a concentration of 30) by mass was prepared.
As epoxy resin A, an epoxy resin having a phosphorus atom in its skeleton (manufactured by Dainippon Ink and Chemicals, trade name: EXA-9710, solid content: 70% by mass), as phenol novolac resin A, a cresol type phenol novolac having a triazine structure As a resin (Dainippon Ink Chemical Co., Ltd., trade name: LA-3018-50P, solid content 50% by mass), as carboxylated rubber A, carboxylated acrylonitrile butadiene rubber (manufactured by Nippon Zeon Co., Ltd., trade name: Nipol 1072), As the metal hydrate A, aluminum hydroxide (manufactured by Showa Denko KK, trade name: Hygielite H-43S) was used.
In Table 1, each compounding ratio of phenol novolac resin A, phenol novolac resin B, carboxylated rubber A, and metal hydrate A was expressed in parts by mass with epoxy resin A being 100 parts by mass.

(Evaluation of flame retardancy)
Underwriters Laboratories Inc. of the United States. (UL) The flame retardant test standard for polymer materials is evaluated by a method based on the V test of UL94, and the sample satisfying the V-0 level is accepted (O), and the sample not satisfying the V-0 level is rejected. It was evaluated as a pass (x).

(Adhesive evaluation)
An adhesive solution is applied to a polyimide film having a thickness of 25 μm (product name: Kapton 100H, manufactured by Toray DuPont Co., Ltd.) so that the thickness after drying is 25 μm, and further dried at 150 ° C. for 10 minutes to obtain a coverlay. It was.
Next, a rolled copper foil having a thickness of 35 μm was adhered to the adhesive surface of the adhesive layer of this coverlay.
Next, the cover lay on which the rolled copper foil was adhered was pressed at 170 ° C. and a pressure of 40 kg / cm ^{2 for} 40 minutes to obtain a single-sided plate for adhesion evaluation.
PI pulling was performed from this single-sided plate, and the peel strength at 90 degrees was measured.
The results are shown in Table 1.

(Evaluation of flexibility)
An adhesive layer is applied by applying an adhesive solution to a polyimide film having a thickness of 25 μm (trade name: Kapton 100H, manufactured by Toray Du Pont Co., Ltd.) so that the thickness after drying is 25 μm, and further drying at 150 ° C. for 10 minutes. A coverlay formed was obtained.
Next, two coverlays were prepared, the adhesive layer surfaces of each other were superposed, and pressed at 170 ° C. and a pressure of 40 kg / cm ^{2 for} 40 minutes to prepare a sample for flexibility evaluation.
After bending the obtained flexibility evaluation sample by 180 degrees, the adhesive layer was cracked and whitening did not occur (O), and the adhesive layer was cracked and whitened was rejected (X). It was evaluated.
The results are shown in Table 1.

(Measurement of insulation resistance)
An adhesive solution is applied to a polyimide film (trade name: Kapton 100H, manufactured by Toray DuPont Co., Ltd.) having a thickness of 25 μm so that the thickness after drying is 10 μm, and this adhesive solution is dried to form an adhesive layer. Formed.
Subsequently, a rolled copper foil having a thickness of 35 μm was adhered to the adhesive surface of the adhesive layer formed on the polyimide film to obtain a single-sided plate.
Next, a copper circuit pattern as shown in FIG. 4 was formed on the copper foil of this single-sided plate. The unit of the dimension shown in FIG. 4 is μm.
Next, an adhesive solution is applied to another polyimide film having a thickness of 25 μm (trade name: Kapton 100H, manufactured by Toray DuPont Co., Ltd.) so that the thickness after drying is 25 μm, and this adhesive solution is dried to obtain an adhesive. A layer was formed.
Next, the adhesive layer formed on the polyimide film is bonded to the adhesive surface of the single-sided board on which the copper circuit pattern is formed, and pressed at 170 ° C. and a pressure of 40 kg / cm ^{2 for} 40 minutes to measure insulation resistance. A printed wiring board was prepared.
Under normal conditions, a DC voltage of 500 V was applied to the printed wiring board and held for 1 minute, and the insulation resistance between the copper circuit patterns shown in FIG. 4 was measured.
The results are shown in Table 1.

"Example 2"
An epoxy adhesive according to Example 2 was prepared in the same manner as in Example 1 with the formulation shown in Table 1.
Using this epoxy-based adhesive, in the same manner as in Example 1, a single-sided board for adhesion evaluation was prepared to evaluate adhesion, a sample for flexibility evaluation was prepared to evaluate flexibility, and insulation resistance A printed wiring board for measurement was produced and the insulation resistance was measured.
The results are shown in Table 1.

"Example 3"
An epoxy adhesive according to Example 3 was prepared in the same manner as in Example 1 with the formulation shown in Table 1.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 1.

Example 4
An epoxy adhesive according to Example 4 was prepared in the same manner as in Example 1 with the formulation shown in Table 1.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 1.

"Example 5"
Table 1 except that phenol novolak resin B (phenol novolak resin having a triazine structure, manufactured by Dainippon Ink & Chemicals, trade name: LA-7054, solid content 60% by mass) was used in place of phenol novolak resin A. The epoxy adhesive according to Example 5 was prepared in the same manner as in Example 1 with the formulation shown in FIG.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 1.

"Example 6"
An epoxy adhesive according to Example 6 was prepared in the same manner as in Example 1 with the formulation shown in Table 1.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 1.

"Example 7"
An epoxy adhesive according to Example 7 was prepared in the same manner as in Example 1 with the formulation shown in Table 2.
In Table 2, each compounding ratio of phenol novolak resin A, carboxylated rubber A, carboxylated rubber B, metal hydrate A, and metal hydrate B is 100 parts by mass of epoxy resin A. Expressed in
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 2.

"Example 8"
An epoxy adhesive according to Example 8 was prepared in the same manner as Example 1 with the formulation shown in Table 2.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 2.

"Example 9"
The same as in Example 1 except that carboxylated rubber B (carboxylated ethylene acrylic rubber, manufactured by Mitsui DuPont Chemical Co., Ltd., trade name: Baymac HVG) was used instead of carboxylated rubber A. Thus, an epoxy adhesive according to Example 9 was prepared.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 2.

"Example 10"
An epoxy adhesive according to Example 10 was prepared in the same manner as in Example 1 with the formulation shown in Table 2.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 2.

"Example 11"
With the formulation shown in Table 2, an epoxy adhesive according to Example 11 was prepared in the same manner as in Example 1.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 2.

"Example 12"
With the formulation shown in Table 2, an epoxy adhesive according to Example 12 was prepared in the same manner as Example 1.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 2.

"Example 13"
Except for using Metal Hydrate B (magnesium hydroxide, manufactured by Kyowa Chemical Industry Co., Ltd., trade name: Kisuma 5P) instead of Metal Hydrate A, the same procedure as in Example 1 was performed with the formulation shown in Table 2. Thus, an epoxy adhesive according to Example 13 was prepared.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 2.

"Comparative Example 1"
Implemented according to the formulation shown in Table 3 except that epoxy resin B (epoxy resin having no phosphorus atom in the skeleton, Japan Epoxy Resin, trade name: Epicoat 828EL) was used instead of epoxy resin A In the same manner as in Example 1, an epoxy adhesive according to Comparative Example 1 was prepared.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 3.

"Comparative Example 2"
According to the formulation shown in Table 3, except that phenol novolak resin C (phenol novolak resin not having a triazine structure, manufactured by Gunei Chemical Industry Co., Ltd., trade name: PSM-4357) was used instead of phenol novolak resin A. In the same manner as in Example 1, an epoxy adhesive according to Comparative Example 2 was prepared.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 3.

“Comparative Example 3”
With the formulation shown in Table 3, an epoxy adhesive according to Comparative Example 3 was prepared in the same manner as Example 1.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 3.

“Comparative Example 4”
An epoxy adhesive according to Comparative Example 4 was prepared in the same manner as in Example 1 with the formulation shown in Table 3.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 3.

“Comparative Example 5”
An epoxy adhesive according to Comparative Example 5 was prepared in the same manner as in Example 1 with the formulation shown in Table 3.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 3.

“Comparative Example 6”
An epoxy adhesive according to Comparative Example 6 was prepared in the same manner as in Example 1 with the formulation shown in Table 3.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 3.

“Comparative Example 7”
An epoxy adhesive according to Comparative Example 7 was prepared in the same manner as in Example 1 with the formulation shown in Table 3.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 3.

"Comparative Example 8"
An epoxy adhesive according to Comparative Example 8 was prepared in the same manner as in Example 1 with the formulation shown in Table 3.
Using this epoxy adhesive, in the same manner as in Example 1, flame retardancy was evaluated, a single-sided plate for adhesion evaluation was prepared to evaluate adhesion, and a sample for flexibility evaluation was prepared to be flexible. The printed wiring board for insulation resistance measurement was produced, and the insulation resistance was measured.
The results are shown in Table 3.

 From the result of Table 1 and Table 2, Examples 1-13 are 20 mass parts or more and 40 mass parts or less of the phenol novolak resin which has a triazine structure to 100 mass parts of epoxy resins which have a phosphorus atom in frame | skeleton. 40 parts by weight or more and 80 parts by weight or less of rubber and 40 parts by weight or more and 100 parts by weight or less of metal hydrate are added, so that it has excellent flame retardancy, adhesiveness, flexibility and electrical insulation. Was confirmed.

On the other hand, from the results of Table 3, in Comparative Example 1, it was confirmed that the epoxy resin having no phosphorus atom in the skeleton was used, so that it was inferior in flame retardancy.
In Comparative Example 2, since a phenol novolac resin having no triazine structure was used, it was confirmed that the flame retardancy was poor.
In Comparative Example 3, since the blending ratio of the phenol novolak resin having a triazine structure was 15 parts by mass, it was confirmed that the epoxy adhesive was not sufficiently cured and the adhesiveness was lowered.
In Comparative Example 4, since the blending ratio of the phenol novolac resin having a triazine structure was 50 parts by mass, it was confirmed that the phenol novolac resin having a triazine structure was excessive and the insulation resistance was lowered.
In Comparative Example 5, since the compounding ratio of the carboxylated rubber was 35 parts by mass, it was confirmed that the inflexibility was poor.
In Comparative Example 6, since the compounding ratio of the carboxylated rubber was 85 parts by mass, it was confirmed that the insulation resistance was lowered.
In Comparative Example 7, since the compounding ratio of the metal hydrate was 35 parts by mass, it was confirmed that the incombustibility was poor.
In Comparative Example 8, since the compounding ratio of the metal hydrate was 105 parts by mass, it was confirmed that the adhesiveness was lowered.

 The epoxy adhesive of the present invention can also be applied to coverlays, prepregs, metal-clad laminates, and printed wiring boards.

It is a schematic sectional drawing which shows one Embodiment of the coverlay of this invention. It is a schematic sectional drawing which shows one Embodiment of the metal-clad laminated board of this invention. It is a schematic sectional drawing which shows one Embodiment of the printed wiring board of this invention. In the Example and comparative example of this invention, it is a top view which shows the copper circuit pattern for measuring the insulation resistance of a printed wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Coverlay, 2 ... Insulating film, 3 ... Adhesive layer, 4 ... Metal-clad laminate, 5 ... Base film, 6 ... Adhesive layer, 7 ... Metal foil, 10 ... printed wiring board.

Claims (6)

 20 parts by mass or more and 40 parts by mass or less of phenol novolac resin having a triazine structure, 100 parts by mass of epoxy resin having a phosphorus atom in the skeleton, 40 parts by mass or more and 80 parts by mass or less of carboxylated rubber, metal hydrate 40 parts by mass or more and 100 parts by mass or less of an epoxy adhesive.  The epoxy adhesive according to claim 1, wherein the phenol novolac resin having a triazine structure is a cresol type phenol novolac resin. In the coverlay that is provided with an adhesive layer on one side of the insulating film,
The adhesive constituting the adhesive layer is composed of 100 parts by mass of an epoxy resin having a phosphorus atom in the skeleton, 20 parts by mass or more and 40 parts by mass or less of phenol novolac resin having a triazine structure, and 40 parts by mass of carboxylated rubber. As described above, a cover lay comprising 80 parts by mass or less and a metal hydrate added by 40 parts by mass or more and 100 parts by mass or less. In a prepreg formed by impregnating an epoxy adhesive into a glass cloth,
The epoxy adhesive has 100 parts by mass of an epoxy resin having a phosphorus atom in the skeleton, 20 parts by mass or more and 40 parts by mass or less of a phenol novolac resin having a triazine structure, 40 parts by mass or more and 80 parts by mass of a carboxylated rubber. Prepreg characterized by adding 40 parts by weight or more and 100 parts by weight or less of metal hydrate. In the metal-clad laminate in which an adhesive layer is provided between the base film and the metal foil,
The adhesive constituting the adhesive layer is composed of 100 parts by mass of an epoxy resin having a phosphorus atom in the skeleton, 20 parts by mass or more and 40 parts by mass or less of phenol novolac resin having a triazine structure, and 40 parts by mass of carboxylated rubber. The metal-clad laminate obtained by adding 80 parts by mass or less and 40 parts by mass or more and 100 parts by mass or less of metal hydrate. A printed wiring board comprising the coverlay according to claim 3 attached to a metal foil surface of the metal-clad laminate according to claim 5.

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