JPH11226950A - Manufacture of prepreg and laminated plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a good and stable quality laminated plate which is manufactured without atmospheric pollution, and with the saving of natural resources and energy at a low manufacturing cost. SOLUTION: This manufacturing method is for prepregs formed of a sheetlike fiber base material, on at least, the surface of which, a powder like resin composition obtained by kneading and uniformly dispersing a resin and other components with the help of a kneading machine and then grinding the kneaded product is present. Preferably the prepreg manufacturing method is to knead the components which form the resin composition prior to kneading and are either solid or at least, one of which is liquid. The method for manufacturing the laminated plate is to thermally press one piece of the prepreg thus obtained or laminate plural pieces of the prepreg and thermally press these laminated pieces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a prepreg and a laminate which are particularly suitable for a printed circuit board used for electric equipment, electronic equipment, communication equipment and the like.

[0002]

2. Description of the Related Art As for printed circuit boards, demands for downsizing and high functionality are becoming stronger, but price competition is fierce. In particular, multilayer laminated boards, glass cloth base epoxy resin laminated boards, and glass nonwoven fabrics used for printed circuit boards are particularly important. Is a middle layer base material and a glass woven fabric is used as a surface layer base material, and a laminated board formed by impregnating with epoxy resin and heating and pressing (hereinafter referred to as a composite laminated board) is a major issue in terms of cost reduction. ing. In recent years, measures against global warming and reduction of environmental pollution have been required. Conventionally, a large amount of solvent has been used in a process of manufacturing a prepreg or a laminated board used for these in view of resin impregnation of the base material and uniformity of the resin. On the other hand, this large amount of solvent evaporates in the coating and drying step and is released to the atmosphere as it is without being present in the product, or it is treated by a combustion treatment device and released to the atmosphere as carbon dioxide gas or the like. Therefore, there is a problem that causes air pollution and global warming. On the other hand, it has been difficult to reduce the amount of solvent and thereby reduce the cost due to manufacturing problems such as resin impregnation of the base material.

[0003] As a technique for eliminating the solvent, studies have been made on heating and mixing a low-melting-point resin or a liquid resin to uniformly mix and apply the solution. However, the heating temperature during continuous production is not sufficient. In addition, there is a problem that solidification of the thermosetting resin during heating and gelation of the thermosetting resin due to a decrease in the temperature, and difficulty in cleaning the facility due to the consolidation, make continuous production difficult. On the other hand, when the powdery resin is applied as it is, there is a problem that uniform mixing and application cannot be performed, and partial curing occurs and impregnation of the substrate cannot be performed.

[0004]

SUMMARY OF THE INVENTION The present invention has been studied to obtain a prepreg or a laminate using a solventless resin, which has been conventionally difficult to produce. As a result, the resin and the curing agent are kneaded by a specific method. , Using uniformly dispersed and powdered, especially using powdered resin and hardener, or non-solvent liquid resin and hardener, etc. It was found that the uniform impregnation of the base material was the same as that of a resin using a conventional solvent by heating and melting the base material by spraying or applying it evenly on the base material. The present invention has been completed to complete the present invention.

[0005]

According to the present invention, a powdery resin composition obtained by kneading a resin and other components with a kneading machine, uniformly dispersing the mixture, and then pulverizing the mixture is at least one of a sheet-like fiber base material. A method for producing a prepreg, characterized in that it is present on the surface, and preferably, each component constituting the resin composition is solid before kneading, or at least one of the components is in a liquid state before kneading. The present invention relates to a method for producing a prepreg in which these components are kneaded, and to a method for producing a laminate, comprising laminating one or more of the obtained prepregs and heating and pressing.

[0006] In the present invention, the resin used is generally a thermosetting resin, such as an epoxy resin,
Polyimide resin, polyester resin, phenol resin,
Melamine resins and their modified resins are preferably used, but other resins such as thermoplastic resins and natural resins are also used, and are not limited thereto. As the thermosetting resin, an epoxy resin is desirable, but in addition, a polyimide resin, a polyester resin, a phenol resin, or the like can be used. When the thermosetting resin is an epoxy resin, the curing agent in the form of powder is preferably an aromatic amine-based resin or a novolak resin-based resin, but may be an acid anhydride-based resin. Further, it is preferable to use a curing accelerator. As such curing accelerators, imidazole-based, third
Secondary amines, phosphines and the like can be used. These components are not limited to those described above.

The components constituting these resin compositions are as follows:
The mixture is kneaded by a kneader and uniformly dispersed. It is taken out of the kneader and crushed. The kneading conditions of the kneading machine are appropriately determined depending on the softening point of the resin, the viscosity in the case of a liquid, the type of other components such as a curing agent, the amount of the resin, and the like. As a condition for raising the temperature to about 10 to 30 ° C. higher than the softening point, the resin is taken out in a state where the resin viscosity is low, the curing agent and the like are easily dispersed uniformly in the resin, and the pot life is maintained.

In the present invention, other components such as a resin, a curing agent, and a filler in the resin composition are not made into a low-viscosity solution with a solvent or the like, but are solid or non-solvent liquid. used. The solid is preferably in the form of flakes, granules or powder. It is preferable that the block-like material is ground before use. The liquid is not particularly limited as long as it does not use a solvent. It should be avoided that the solvent disappears due to evaporation at the stage of the prepreg or the laminate, such as a solvent. These are used as solids, liquids or a combination thereof.

In the present invention, the powdery resin composition is kneaded by a kneader, uniformly dispersed, then taken out, cooled and pulverized. This powdery resin composition is uniformly dispersed or spread on a sheet fiber base material. Although present by application, a method of causing the powdery resin composition to be present on the sheet-like substrate is a method of sprinkling from the upper surface of the sheet-like fiber substrate, an electrostatic coating method,
There are a fluid immersion method, a spraying method using a spray, a coating method using various coaters, and the like. At this time, the particle size of the powdery resin composition to be sprayed or applied is usually 1000 μm or less, preferably 0.1 to 500 μm, and more preferably 0.1 to 200 μm. Such a particle size can be used to improve the flowability of powder during spraying or application, the flowability during heating and melting, the smoothness of the surface, the improvement of impregnation of resin into the sheet-like fiber base material, and the stabilization of weight distribution and the like. Suitable for In addition, if the sheet-like fiber base material is previously heated to about 60 to 100 ° C., the powder-like resin composition adheres well to the base material when the sheet-like fiber base material is present in the sheet-like fiber base material, and the subsequent heating is performed. Thereby, it penetrates well into the inside of the base material, and a good prepreg is obtained. Although the resin powder used in the present invention can be used as it is, an inorganic filler can be added to impart heat resistance, flame resistance, tracking resistance and the like.

The kneading machine is a two-roll, three-roll, single-screw extruder (single-screw kneader), twin-screw extruder (two-screw kneader), kneader, co-kneader, KCK (Kishihiro Continuous Kneader).
der (continuous kneading extruder)), Henschel mixer and the like. In addition, it is generally desirable to perform pre-mixing before processing in a kneading machine. Examples of such a mixing machine include a Henschel mixer, a Raikai machine, a ribbon blender, a planetary mixer, a ball mill, a mechanochemical processing machine, a homomixer, and a disperser. And a stirring pot.
A combination of these may be used.

In the present invention, examples of the sheet-like fiber base material include glass fiber base materials such as glass cloth, glass non-woven cloth and glass paper, as well as woven and non-woven fabrics made of paper and synthetic fibers, metal fibers, and carbon fibers. And woven fabrics, nonwoven fabrics, mats and the like made of mineral fibers, etc., and these base materials may be used alone or in combination.

The prepreg obtained as described above is
One or more of the sheets are laminated with a metal foil such as a copper foil as necessary, and heated and pressed by a usual method to form a laminate. The method for producing a prepreg and a laminate according to the present invention, without substantially changing the performance of the obtained prepreg or laminate, resource saving and air pollution are reduced by using no solvent, and the solvent is evaporated. Thermal energy for burning is also unnecessary. During the production of the pre-flag and the laminate, the reaction is fast because there is no solvent originally, the drying and the molding time are shortened, and the cost can be reduced. The concept of the present invention is that a solid component (resin, curing agent, etc.) or a solventless liquid component (resin,
Kneading and uniform dispersion using a kneading machine using a curing agent, etc., enables uniform bonding and dispersion of each component, uniform impregnation of the sheet-like substrate, and uniform reaction of the impregnated resin composition. It has become. When prepregs and laminates are manufactured using ordinary resin varnishes, the non-volatile content of the resin and the like is about 40 to 60% by weight and the solvent is 60 to 40% by weight. Therefore, it can be said that the above-mentioned effect by using a powdery resin and not using a solvent is very large.

[0013]

Next, examples of the present invention will be specifically described together with comparative examples. The present invention is not limited by these examples.

Example 1 100 parts by weight of a powdery epoxy resin (brominated epoxy resin Ep5048, oil equivalent shell, epoxy equivalent: 675), 5 parts by weight of a powdery curing agent (dicyandiamide), powdery curing accelerator (2-ethyl-
4-methylimidazole) mixed at a ratio of 1 part by weight, using two rolls having a diameter of 12 inches, and rotating at a high speed side of 20 rpm.
Treated 30 times at a high-speed roll temperature of 60 ° C., a low-speed roll temperature of 30 ° C., and a rotation ratio of 1.5: 1, took out a sheet, cooled with cold air, and pulverized with a fine pulverizer to an average particle size of 200 μm. . 100 g / m of the treated powdery resin composition
50g with a sieve 60 mesh on one side of ² of the glass cloth
/ M ² . Then 170 ° C
After heating with a dryer for 30 seconds, the glass cloth was turned upside down, and the other surface was sifted through a 60-mesh sieve to 50 g / m ^2.
And dried with a dryer at 170 ° C. for 3 minutes to obtain a prepreg. Two prepregs are laminated, and a copper foil having a thickness of 18 μm is laminated on the upper and lower sides of the prepreg, and is heated and pressed at a temperature of 165 ° C. and a pressure of 60 kg / cm ² for 90 minutes to form a copper-clad laminate having a thickness of 0.22 mm. A plate was made.

Example 2 100 parts by weight of a solid epoxy resin (brominated epoxy resin Ep5048, oil equivalent shell, epoxy equivalent: 675), 5 parts by weight of a powdery curing agent (dicyandiamide), powdery curing accelerator (2-ethyl-
4-Methylimidazole) 1 part by weight of the mixture was melted and liquefied at a temperature of 100 ° C., treated with a Henschel mixer at a rotation speed of 500 rpm for 20 minutes, taken out into a vat in a plate shape, and cooled with cold air. And pulverized to an average particle size of 200 μm with a fine pulverizer. The treated powdery resin composition was uniformly sprayed on one surface of a 100 g / m ² glass cloth with a 60-mesh sieve to 50 g / m ² . Then, after heating in a dryer at 170 ° C. for 30 seconds, the glass cloth was turned upside down, and uniformly sprayed on the other surface with a 60-mesh sieve to 50 g / m ^2.
The prepreg was dried by drying at 0 ° C. for 3 minutes. Two prepregs are stacked, and a thickness of 1
8μm copper foil is superimposed, temperature 165 ℃, pressure 60k
g / cm ² for 90 minutes under heat and pressure.
mm copper-clad laminate was prepared.

Example 3 100 parts by weight of a powdery epoxy resin (brominated epoxy resin Ep5048 manufactured by Yuka Shell, epoxy equivalent: 675), 5 parts by weight of a powdery curing agent (dicyandiamide), powdery curing accelerator (2-ethyl-
4-methylimidazole), mixed at a ratio of 1 part by weight, using a single screw extruder, cylinder temperature 50 ° C., L / D = 20,
The material was processed at a rotation speed of 100 rpm, and the extruded material was cooled by cold air and then pulverized by a fine pulverizer to an average particle diameter of 200 μm. 100 g / m ^{2 of} this treated powdery resin composition
60g sieve on one side of a glass cloth of 50g /
m ² . Then, after heating with a dryer at 170 ° C. for 30 seconds, the glass cloth was turned upside down, and evenly sprayed on the other surface with a 60-mesh sieve to 50 g / m ^2. After drying for a minute, a prepreg was obtained. Two prepregs are laminated, and a copper foil having a thickness of 18 μm is laminated on the upper and lower sides of the prepreg, and is heated and pressed at a temperature of 165 ° C. and a pressure of 60 kg / cm ² for 90 minutes to form a copper-clad laminate having a thickness of 0.22 mm. A plate was made.

Comparative Example 1 A powdery epoxy resin having an average particle size of 150 μm (brominated epoxy Ep50 manufactured by Yuka Shell Co., Ltd.)
48) 100 parts by weight, 5 parts by weight of a powdery curing agent (dicyandiamide) having an average particle diameter of 15 μm, and an average particle diameter of 15 μm
After mixing by hand for 5 minutes, the mixture was mixed at a ratio of 1 part by weight of a powdery curing accelerator, and the powder was heated at 100 ° C. to dissolve, and then the resin solid content was reduced to 100 g / m ² . A 100 g / m ² glass cloth was soaked and impregnated to obtain a prepreg by drying at 170 ° C. for 2 minutes. Two prepregs are laminated, and a copper foil having a thickness of 18 μm is laminated on the upper and lower sides of the prepreg, and is heated and pressed at a temperature of 165 ° C. and a pressure of 60 kg / cm ² for 90 minutes to form a copper-clad laminate having a thickness of 0.22 mm. A plate was made.

Comparative Example 2 A powdery epoxy resin having an average particle size of 150 μm (brominated epoxy Ep50 manufactured by Yuka Shell Co., Ltd.)
48) 100 parts by weight, 5 parts by weight of a powdery curing agent (dicyandiamide) having an average particle diameter of 15 μm, and an average particle diameter of 15 μm
Was mixed with 100 parts by weight of methylcellosolve. This varnish was added to 100 g / m ² so that the solid content of the varnish became 100 g / m ^2.
After impregnating with impregnating a glass cloth of m ^2, the glass cloth was dried with a dryer at 170 ° C. for 3 minutes to obtain a prepreg. Two prepregs are stacked, and a thickness of 18 μm
165 ° C, pressure 60kg / c
It was heated and pressed at m ² for 90 minutes to produce a copper-clad laminate having a thickness of 0.22 mm.

For the prepregs obtained in the above Examples and Comparative Examples, the impregnating property of the glass cloth with the resin was measured. For the copper-clad laminate, the moldability, tensile strength, and copper foil peeling strength were measured. , And solder heat resistance were measured. Table 1 shows the results.

[0020]

[Table 1]

(Measurement method) Impregnating property: The presence or absence of voids between glass fibers was confirmed with a prepreg under a stereoscopic microscope. 2. Formability: The copper foil of the copper-clad laminate is etched, and the presence or absence of precipitation of a curing agent or the like is visually observed to evaluate the dispersibility. 3. Tensile strength: Etching copper foil of copper clad laminate,
After cutting to 10 × 100 mm, the tensile strength was measured with Tensilon. 4. 4. Copper foil peel strength: according to JIS C6481 Solder heat resistance: A laminate of 50 × 50 mm square was converted to 260
The sample was floated in a solder bath at a temperature of 3 ° C. for 3 minutes, and the presence or absence of blister was measured.

As for the manufacturing cost, since the method of the embodiment does not use a solvent, the cost of the laminate obtained in the embodiment is reduced by about 30 to 40% as compared with that obtained in the comparative example 2. Was completed. Further, in Comparative Example 1, the resin adhering matter to the equipment hardened and cleaning became difficult.

[0023]

According to the method of the present invention, since no organic solvent is used, there is no air pollution, resources can be saved, and thermal energy for evaporating and burning the solvent is not required. In the production of pre-flags and laminates, the reaction is fast because no solvent is originally present, and the drying and molding time are reduced. A powdery resin composition obtained by kneading and uniformly dispersing each component with a kneading machine, preferably using a solid component (resin, curing agent, etc.) or a solventless liquid component (resin, curing agent, etc.) By using, the sheet fibrous base material can be uniformly impregnated, and the impregnated resin composition can be uniformly reacted. Therefore, the quality of the obtained prepregs and laminates is stable and has good characteristics.
It is excellent in terms of cost reduction, and is suitable as an industrial method for manufacturing a laminate.

Claims (4)

[Claims] 1. A powdery resin composition obtained by kneading and uniformly dispersing a resin and other components in a kneading machine, and then pulverizing the resin and the powdered resin composition to be present at least on the surface of a sheet-like fiber base material. Prepreg manufacturing method. 2. The method for producing a prepreg according to claim 1, wherein the components constituting the resin composition are solid before kneading, and these solid components are melt-kneaded. 3. The method of claim 1, wherein at least one of the components constituting the resin composition is in a liquid state before kneading, and the components are kneaded. 4. A method for producing a laminate, comprising laminating one or more prepregs obtained by the method according to claim 1, 2, or 3 and heating and pressing.