JP2000327812A - Preparation of prepreg and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a laminate at a low cost which does not cause air pollution and can save natural resources and has stable quality. SOLUTION: A preparation method of a prepreg comprises pre-mixing a thermosetting resin and a curing agent as essential components while being heated, providing mechanical energy to cause mechanochemical reaction to obtain a powdery thermosetting resin composition and rendering the resin composition present at least on the surface of a sheet-like fiber substrate. Preferably, the thermosetting resin and the curing agent are powdery and the heating temperature at which pre-mixing is conducted is equal to or below the fusion temperature of the thermosetting resin. A preparation method of a laminate comprises stacking one or more of the prepregs and compressing the same at elevated temperatures.

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, and more particularly to a method for producing a prepreg and a laminate suitable for a printed circuit board used in electric equipment, electronic equipment, communication equipment and the like. .

[0002]

2. Description of the Related Art As for printed circuit boards, demands for miniaturization and high performance are increasing, but price competition is intense. In particular, multilayer laminated boards, glass cloth base epoxy resin laminated boards, or glass used for printed circuit boards are used. The cost reduction of any laminate using nonwoven fabric as the intermediate layer base material and glass woven fabric as the surface layer base material has been a major issue. Conventionally, a large amount of a solvent has been used in a process for producing a prepreg or a laminate used for these. This is because the preparation of the resin varnish is easy, and the application and impregnation of the resin on the base material is uniform and easy. This solvent evaporates in a drying step after coating and does not exist in the product, and most of the solvent is treated by a combustion device or the like or released to the atmosphere as it is. It has been pointed out that this contributes to global warming and air pollution.
On the other hand, various measures have been taken to reduce the amount of solvent used,
This reduction was difficult due to manufacturing problems such as application and impregnation of the resin to the base material.

[0003] For the production of prepregs and laminates that do not use a solvent, studies have been made to heat and mix a low-melting-point resin or a liquid resin so as to be uniform and apply it to a base material. It is not possible to achieve sufficient production, and there are problems such as resin consolidation in equipment due to a decrease in heating temperature during continuous production, gelling of thermosetting resin during heating, and cleaning of equipment due to this. Was. On the other hand, a method of directly applying a powdery resin has also been proposed (Japanese Patent Application Laid-Open No. 50-14387).
No. 0), however, have problems such as difficulty in uniform mixing and coating, partial curing, and insufficient impregnation of the substrate, and have not been put to practical use. Further, in the conventional powder treatment by the mechanochemical reaction, the surface modification between the resin and the curing agent is not sufficiently performed, and the resin and other components may be separated during application or the like.

[0004]

SUMMARY OF THE INVENTION The present inventor has studied to obtain a prepreg made of a resin that does not use a solvent and a laminate using the prepreg, which has been conventionally difficult to produce. That the uniform powdery composition obtained by performing the mechanochemical reaction while heating the composition containing the agent can be equivalent to the case of the resin using the conventional solvent in the impregnation property to the substrate. Obtained knowledge. Further, since the resin powder has a large surface area during melting and has a passage for air, the resin powder contains no air compared to the solvent type, so that the air can escape well. In addition, there is also a feature that the impregnation property to the base material is excellent. Furthermore, in the prepreg using the conventional solvent, since the solvent does not completely disappear, bubbles are generated due to the solvent in the subsequent pressing step, resulting in voids. The present inventors obtained the knowledge that they can be formed without occurrence of cracks and further advanced various studies based on this knowledge to complete the present invention.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a thermosetting resin and a curing agent as essential components, premixing these components while heating them, and then applying mechanical energy to cause a mechanochemical reaction. The present invention relates to a method for producing a prepreg, characterized in that the obtained powdery thermosetting resin composition is present at least on the surface of a sheet-like fiber base material, wherein the thermosetting resin and the curing agent are preferably in powder form. And a method for producing a prepreg, and
The present invention relates to a method for producing a prepreg in which a heating temperature at the time of premixing is equal to or lower than a melting temperature of a thermosetting resin.
Furthermore, the present invention relates to a method for producing a laminate or a metal foil-clad laminate, which comprises laminating one or more prepregs thus obtained and heating and pressing.

In the present invention, the thermosetting resin used is usually in a powder form, but is preferably an epoxy resin. In addition, a polyimide resin, a polyester resin, a phenol resin and the like can be used. When the thermosetting resin is an epoxy resin, the curing agent is preferably an amine, particularly dicyandiamide and an aromatic amine, and a novolak resin, from the viewpoint of heat resistance and electric characteristics, but acid anhydrides and imidazole compounds are also preferable. Can be used. The curing agent is preferably in the form of a powder, but when the amount is small (for example, 20% by weight or less based on the resin), the curing agent may be in the form of a liquid.
It can be used if it can be pulverized after applying mechanical energy to the mixture with the resin. Preferably, a curing accelerator is used. The curing accelerator is preferably in the form of a powder, but a liquid accelerator can also be used as described above. As such a curing accelerator, an imidazole compound, a tertiary amine, or the like can be used. These components are not limited to those described above.

The particle size of these powders is usually 100
0 μm or less, preferably 0.1 to 500 μm, more preferably 0.1 to 200 μm. This is because if the particle size exceeds 1000 μm, the surface area with respect to the particle weight becomes small, the number of contact points of each component such as a thermosetting resin, a curing agent and a curing accelerator decreases, and uniform dispersion becomes difficult. It may react at a different ratio than the target ratio,
There is a possibility that a uniform reaction is not performed. For the mechanochemical reaction, when the curing agent and / or the curing accelerator is in a powder form, the particle size of the thermosetting resin is preferably 5 to 15 times the particle size of the curing agent and / or the curing accelerator. This is because the curing agent and / or the curing accelerator are easily fused to the thermosetting resin in this range.

[0008] The modification by mechanochemical reaction is "a modification of a solid by a solid, which utilizes the surface activity of particles by grinding, grinding, friction, and contact, and surface appliances. The activity itself is a crystalline form. In some cases, the dissolution or thermal decomposition rate is modified by increasing the transition energy or strain energy, or mechanical strength or magnetic properties are obtained. In other cases, surface activity is used for reaction or adhesion with other substances. Uses mechanical impact energy to perform not only physical modification but also chemical modification such as adhesion by electric charge or magnetism by friction, contact, embedding of modifier in nuclear material, formation of film by melting, etc. ("Overview of Practical Surface Modification Technologies" edited by the Material Technology Research Association, Industrial Technology Service Center, published March 25, 1993, p786)
Things. The present invention utilizes chemical modification by a mechanochemical reaction, but also includes a case where a solid and a liquid are chemically modified by mechanical energy.

[0009] Powder processing methods for applying mechanical energy for the mechanochemical reaction include Raikai machines, Henschel mixers, planetary mixers, ball mills,
Mixing or kneading by a medium stirring mill, a jet mill, an ong mill, a multi-stage mill-type kneading extruder, or the like is available. Among them, Ongmill (Mechanofusion method manufactured by Hosokawa Micron Corporation), multi-stage mill-type kneading extruder (Made by KCK: Mechanochemical dispersion method, etc.), Jet mill (Nara Machinery Co., Ltd .: Hybrid) Tizer method, etc.),
Mixing or kneading with a medium agitating mill (Mitsui Mining Co., Ltd. dry continuous fine pulverizer dynamic mill) is preferable. In particular, in order to efficiently carry out the mechanochemical reaction, a multi-stage mill-type kneading extruder (manufactured by KCK Corporation: Mechanochemical dispersion method) is preferable.

[0010] In order to carry out the mechanochemical reaction, the softening point of the thermosetting resin is preferably 50 ° C or higher, more preferably 70 ° C or higher, and further preferably 80 ° C or higher. This is because heat of about 20 to 50 ° C. is generated due to friction, pulverization, and fusion between the powders or between the powder and the processing apparatus during the above-mentioned processing, so that this influence is minimized. On the other hand, even if the softening point is too high, an effective mechanochemical reaction is difficult to be performed, and it is difficult to impregnate the base material of the resin composition in a later step, so that the temperature is 150 ° C or less, particularly 130 ° C or less. Softening points are preferred.

In the present invention, it is preferable to carry out the reaction while heating in order to carry out the mechanochemical reaction efficiently. This is to cause fusion of resin etc.
This is because reforming can be performed most efficiently when only the powder surface is molten, and powder separation or the like does not occur in a later step. Although the heating temperature varies depending on the melting temperature of the resin, it is preferable that the heating is performed at a temperature lower than the resin melting temperature by 20 ° C. or more, preferably by 50 ° C. or more. Usually, this heating temperature is higher than normal temperature (20 ° C.), preferably 30 ° C.
Or more, more preferably 35 ° C. or more;
Or less, preferably 100 ° C. or less.

In the present invention, in order to sufficiently disperse and mix the respective components such as the thermosetting resin and the curing agent, the powder is pulverized to the above-mentioned particle size before the powder treatment of the mechanochemical reaction, and then heated. It is preferable to perform pre-mixing while mixing as uniformly as possible. The heating temperature during the premixing is preferably equal to or lower than the melting temperature of the thermosetting resin. Heating above the melting point of the resin makes it difficult to mix each component as a powder. As a method of premixing, there are a tumbler, a Henschel mixer, a Raikai machine, and a planetary mixer. By pre-mixing, the main agent and the curing agent can be adhered to each other by the inter-particle force due to electrostatic force or the like, and uniform curing can be achieved.However, even with this inter-particle force alone, there is a possibility of separation due to impact etc. is there. Therefore, by performing pre-mixing while heating, the surfaces of the main agent and the curing agent adhered by the interparticle force were melted to enhance the adhesiveness, thereby enabling more uniform curing. Also, while heating during pre-mixing, epoxy silane,
By adding a coupling agent such as aminosilane, the adhesion between the resins or between the resin and the inorganic filler and the fluidity of the powder during application can be increased.

The thermosetting resin composition used in the present invention may optionally contain an inorganic filler. When an inorganic filler is added, characteristics such as tracking resistance, heat resistance, and a decrease in coefficient of thermal expansion can be imparted. Such inorganic fillers include aluminum hydroxide, magnesium hydroxide, calcium carbonate, talc, wollastonite, alumina, silica, unfired clay, fired clay, barium sulfate and the like. These particle sizes are the same as above.

The particle size of the powder composition subjected to the mechanochemical reaction by the powder treatment is usually 1000 μm or less, preferably 0.1 to 500 μm, more preferably 0.1 to 200 μm. Such a particle size is to improve the fluidity of the powder composition at the time of spraying or application, and to improve the flow and surface smoothness at the time of heating and melting, to improve the resin impregnation property of the base material, It is suitable for stabilizing the distribution of the resin composition.

The powdery thermosetting resin composition is then allowed to exist on at least the surface of the sheet-like fiber base material as it is or by mixing a fine powder additive having an average particle size of 0.01 to 1 μm and mixing uniformly. To obtain a prepreg.

In the present invention, by adding a fine powder additive to the powdery thermosetting resin composition, the uniform dispersibility and flow characteristics of the powdery composition can be greatly improved. By such a technique, uniform distribution can be achieved when the powdery composition is applied to and impregnated on the sheet-like substrate, and uniform impregnation can be achieved by obtaining smoothness of the powder application surface. As the fine powder additive, an inorganic fine powder is desirable, but an organic fine powder can also be used. The average particle size is 0.1.
The thickness is from 0.01 to 1 μm, preferably from 0.01 to 1 μm.
One having a thickness of 0.1 μm (specific surface area: about 50 to 500 m ² / g) is used. Such fine powder additives include silica fine powder and titanium oxide fine powder. Average particle size is 1μm
Exceeding the specific surface area is reduced and the number of particles per unit weight is reduced, and the difference in particle diameter between the powdered resin and the powdered curing agent, which are the main components, is reduced to improve the fluidity. There is a possibility that the bearing effect cannot be sufficiently obtained. The bearing effect in powder means that fine particles are present at the contact points between particles having relatively large particle diameters, so that the movement of particles having large particle diameters becomes more free and the fluidity of the powdery composition as a whole is improved. It is to improve. Further, in the case of the fine powder additive, the particle size is 2 to 10 due to secondary aggregation.
However, there is a sufficient effect if the primary particles have an average particle diameter of 0.01 to 1 μm.

As a treatment method for improving the flowability of the whole powdery composition, any method may be used as long as it can uniformly disperse and mix the fine powder additive. For example, Henschel mixer,
Mixing using a raikai machine, a planetary mixer, a ball mill, or the like is included. In particular, a ball mill or a Henschel mixer having a shearing force is preferably used for the secondary aggregated fine powder.

The powder composition obtained as described above is
It is made to exist on at least the surface of the substrate by spraying or coating. The amount of this powder composition depends on the fiber material of the base material, properties,
Although it depends on the weight (per unit area), it is usually about 40 to 60% of the weight of the substrate. The method of causing the powder composition to be present on the substrate includes a method of sprinkling from the upper surface of the substrate, an electrostatic coating method, a fluid immersion method, a spraying method with a spray, a knife coater, a coating method using various coaters such as a comma coater, and the like. There is no particular limitation. As the substrate, other than glass cloth, glass fiber substrate such as glass non-woven cloth, paper,
Woven fabrics and nonwoven fabrics made of synthetic fibers and the like, metal fibers, carbon fibers, woven fabrics made of mineral fibers and the like, nonwoven fabrics, mats and the like, and the raw material fibers of these substrates may be used alone or in combination. Good.

Although the powder composition may be present on the base material on one side of the base material, the powder composition is preferably provided on both sides of the base material in order to balance the front and back from the aspect of warpage or the like. It is preferred that the substance be present. This operation is usually performed on each side of the substrate. That is, after being made to exist on one surface, the powder composition is heated and adhered to the substrate, and then the same operation is performed on the other surface. With respect to the heating of the substrate, when the powder composition is present on one side (upper surface) of the substrate, when the powder composition is heated only from the opposite surface (lower surface) or when heating from both surfaces, the opposite surface ( It is preferable to set the lower side) to a higher temperature. In this case, air existing in the base material is easily removed from the opposite surface, and the molten resin easily impregnates the base material. The heating temperature of the substrate depends on the softening point of the powder composition, but for the above-described reason, the surface (lower surface) opposite to the surface to which the powder composition has adhered usually has a temperature of 90 to 1.
70 ° C, preferably 110-150 ° C. In addition, on the adhesion surface, usually, at room temperature or when heated, 60 to
150 ° C., preferably at room temperature, or 60 to 140 ° C.
It is.

The resin-impregnated base material may be heated so that the resin composition is more sufficiently impregnated and, if necessary, the resin is in a semi-cured state. This heating temperature is usually 100 to 20
The temperature is 0 ° C., preferably 120 to 190 ° C., but may be different depending on the fluidity and curability of the resin composition. However, the thickness of the substrate is 100 μm or less (10 μm for a glass substrate).
(0 g / m ² or less), or when the powder composition is easily and uniformly melted, a method in which the powder composition is present only on one side may be used. Also in this case, a step of heating and / or heating is usually provided thereafter.

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 or a metal foil-clad laminate. The method for producing a prepreg and a laminate according to the present invention, the performance of the obtained prepreg or laminate, without substantially changing the conventional one,
The production by using the powder composition is facilitated, resource saving by solvent-free, energy saving and reduction of air pollution are achieved, and further cost reduction can be achieved.

The present invention provides an application of mechanochemical reaction,
The obtained resin, using a powder composition consisting of a curing agent, etc., by such technology, each component is uniformly dispersed and bonded, when the obtained powder composition is present in the substrate and impregnated In this case, uniform distribution and smoothness of the coated surface can be obtained, whereby uniform impregnation of the substrate can be achieved. In the method in which the substrate moves in the horizontal direction, the entire apparatus used is a horizontal type. However, the substrate is moved in the vertical direction, and the powder composition is electrostatically sprayed or preheated on a sheet. It is also possible to adopt a method of spraying the air. In this case, a vertical device is employed.

[0023]

Next, examples of the present invention will be specifically described together with comparative examples.

Example 1 (KCK) 100 parts by weight of a powdery epoxy resin having an average particle diameter of 150 μm (brominated epoxy resin Ep5048, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 675), and an average particle diameter of 15 μm
5 parts by weight of a powdery curing agent (dicyandiamide) and a powdery curing accelerator (2-ethyl-
1 part by weight of 4-methylimidazole) was preliminarily mixed at a rotation speed of 200 rpm for 1 minute while heating to 60 ° C. with a Henschel mixer, and then a multi-stage mill-type kneading extruder (manufactured by Co., Ltd.)
KCK made mechanochemical dispersion system
Using KCK-80X2-V (6)), the mixture was treated at a rotation speed of 200 rpm for 1 minute while heating to a temperature of 50 ° C. to obtain a powder composition having an average particle size of 150 μm. This powder composition was uniformly applied to the upper surface of a 100 g / m ² glass cloth using a knife coater so that the resin weight became 50 g / m ² . Then, a panel heater 12 of 150 ° C.
Heated at 0 ° C. for about 1 minute. Then, the glass cloth was turned upside down, and the other side was uniformly coated with a knife coater so that the resin weight became 50 g / m ^2.
Was heated for 1 minute with a hot air heater to obtain a prepreg. 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 2 (Coupling Treatment) 100 parts by weight of a powdery epoxy resin having an average particle diameter of 150 μm (brominated epoxy resin Ep5048, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 675), and an average particle diameter of 15 μm
5 parts by weight of a powdery curing agent (dicyandiamide) and a powdery curing accelerator (2-ethyl-
1 part by weight of 4-methylimidazole) and 1 part by weight of epoxysilane (A-187, manufactured by Nippon Yunika) were added, and the mixture was heated to 60 ° C. with a Henschel mixer while rotating at 200 rpm.
m for 1 minute, and then using a multi-stage mill-type kneading extruder (Mechanochemical Dispersion System KCK-80X2-V (6) manufactured by KCK Co., Ltd.) while rotating to a temperature of 50 ° C. while rotating. The mixture was treated at 200 rpm for 1 minute to obtain a powder composition having an average particle size of 150 μm. This powder composition was uniformly applied to the upper surface of a 100 g / m ² glass cloth using a knife coater so that the resin weight became 50 g / m ² . Thereafter, the panel was heated from the lower surface side by a panel heater at 150 ° C. and 120 ° C. for about 1 minute. Next, the glass cloth was turned upside down, and the other side was uniformly coated with a knife coater so that the resin weight became 50 g / m ^2, and heated with a hot air heater at 170 ° C. for 1 minute to obtain a prepreg. Two prepregs were superimposed, and a copper foil having a thickness of 18 μm was superimposed on and under the prepreg.
It was heated and pressed at 90 ° C. and a pressure of 60 kg / cm ² for 90 minutes to produce a copper-clad laminate having a thickness of 0.22 mm.

Example 3 (Mechanofusion) A powdery epoxy resin having an average particle size of 150 μm (Ep
5048) 100 parts by weight, 5 parts by weight of a powdery curing agent (dicyandiamide) having an average particle diameter of 15 μm, and 1 part by weight of a powdery curing accelerator (2-ethyl-4-methylimidazole) having an average particle diameter of 15 μm 60 with a mixer
Pre-mixing at 200 rpm for 1 minute while heating to 50 ° C., and then using a mechanofusion machine (AM-15F manufactured by Hosokawa Micron Corp.) for 5 minutes at 2000 rpm while heating to 50 ° C. After the treatment, a powder composition having an average particle size of 150 μm was obtained. This powder composition was added to 10
A 60-mesh sieve was passed through one side of a glass cloth of 0 g / m ² , and the mixture was uniformly sprinkled so that the resin weight became 50 g / m ² . Then, the glass cloth was heated for 30 seconds from both sides of the glass cloth with a hot air heater at 170 ° C., then the glass cloth was turned upside down, and the other side was passed through a 60-mesh sieve so that the resin weight became 50 g / m ^2. Sprinkle on
The prepreg was obtained by heating with a hot air heater at 170 ° C. for 3 minutes. Using this prepreg, a copper-clad laminate having a thickness of 0.22 mm was produced in the same manner as in Example 1.

Example 4 (Tumbler premix) 100 parts by weight of a powdery epoxy resin having an average particle size of 150 μm (brominated epoxy resin Ep5048, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 675), and an average particle size of 15 μm
5 parts by weight of a powdery curing agent (dicyandiamide) and a powdery curing accelerator (2-ethyl-
1 part by weight of 4-methylimidazole) is tumbled to 80.
Pre-mixing at 30 rpm for 1 minute while heating to ℃, then multi-stage mill-type kneading extruder (Mechanochemical dispersion system KCK- manufactured by KCK Co., Ltd.)
80X2-V (6)) and heated at a rotation speed of 200 rpm for 1 minute while heating to a temperature of 50 ° C.
A powder composition of 0 μm was obtained. 100 g of this powder composition
/ M ² was uniformly applied to the upper surface of a glass cloth using a knife coater so that the resin weight became 50 g / m ² . Thereafter, the panel was heated from the lower surface side by a panel heater at 150 ° C. and 120 ° C. for about 1 minute. Next, the glass cloth was turned upside down, and the resin weight was adjusted to 50% with a knife coater on the other side.
g / m ² , and the mixture was uniformly heated at 170 ° C. for 1 minute to obtain a prepreg. Two prepregs were superimposed, and a copper foil having a thickness of 18 μm was further superimposed on the prepreg, at a temperature of 165 ° C. and a pressure of 60 kg / cm.
² was heated and pressed for 90 minutes to produce a copper-clad laminate having a thickness of 0.22 mm.

Example 5 (200 μm cloth) The powder composition obtained in Example 1 was applied on one surface of a glass cloth of 210 g / m ^{2 with} a knife coater to a resin weight of 90 g / m 2.
² was applied uniformly. Then, from the bottom side
It was heated by a hot air heater at 20 ° C. for about 1 minute. Then
The glass cloth was turned upside down, and the other side was uniformly coated with a knife coater so that the resin weight became 90 g / m ^2, and heated with a hot air heater at 170 ° C. for 1 minute to obtain a prepreg. Two prepregs were superimposed, and a copper foil having a thickness of 18 μm was superimposed on and under the prepreg.
It was heated and pressed at 90 ° C. and a pressure of 60 kg / cm ² for 90 minutes to produce a copper-clad laminate having a thickness of 0.42 mm.

Example 6 (Novolak curing) Powdered epoxy resin having an average particle diameter of 150 μm (brominated epoxy resin Ep5048 manufactured by Yuka Shell, epoxy equivalent 6)
75) 100 parts by weight of a powdery phenol novolak resin having an average particle diameter of 30 μm (Phenol Novolak PR-51470 manufactured by Sumitomo Durez, phenolic hydroxyl equivalent: 1)
05) 16 parts by weight and 1 part by weight of powdery triphenylphosphine having an average particle diameter of 10 μm are premixed for 1 minute at 200 rpm while being heated to 70 ° C. with a Henschel mixer, and then multi-stage mill-type kneading and extruding. Machine (K Corporation)
CK made mechanochemical dispersion system K
Using CK-80X2-V (6)), the mixture was treated at a rotation speed of 200 rpm for 1 minute while heating to a temperature of 40 ° C. to obtain a powder composition having an average particle size of 150 μm.

This powder composition was coated on the upper surface of a 100 g / m ² glass cloth with a knife coater so that the resin weight was 50 g / m ^2.
m ² . Thereafter, the panel was heated from the lower surface side by a panel heater at 150 ° C. and 120 ° C. for about 1 minute. Next, the glass cloth was turned upside down, and the other side was uniformly coated with a knife coater so that the resin weight became 50 g / m ^2, and heated with a hot air heater at 170 ° C. for 1 minute to obtain a prepreg. The prepreg overlay two further superimposed copper foil having a thickness of 18μm on the upper and lower, temperature 175 ° C., and heated pressing at a pressure 20 kg / cm ² 60 min and a thickness of 0.22mm copper clad laminate A plate was made.

Comparative Example 1 100 parts by weight of a powdery epoxy resin having an average particle diameter of 150 μm (brominated epoxy resin Ep5048, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 675), and a powder having an average particle diameter of 15 μm was cured. 5 parts by weight of an agent (dicyandiamide) and a powdery curing accelerator (2-ethyl-4-methylimidazole) having an average particle size of 15 μm 1
Parts by weight and then using a multi-stage mill-type kneading extruder (Mechanochemical Dispersion System KCK-80X2-V (6) manufactured by KCK Co., Ltd.) at a temperature of 5
The mixture was treated at 200 rpm for 1 minute while heating to 0 ° C. to obtain a powder composition having an average particle size of 150 μm. This powder composition was uniformly applied to the upper surface of a 100 g / m ² glass cloth using a knife coater so that the resin weight became 50 g / m ² . Thereafter, the panel was heated from the lower surface side by a panel heater at 150 ° C. and 120 ° C. for about 1 minute. Next, the glass cloth was turned upside down, and the other side was uniformly coated with a knife coater so that the resin weight became 50 g / m ² .
The prepreg was obtained by heating with a hot air heater at 170 ° C. for 1 minute. The prepreg overlay two further superimposed copper foil having a thickness of 18μm on the upper and lower, temperature 165 ° C., and heated pressing at a pressure 60 kg / cm ² 90 min and a thickness of 0.22mm copper clad laminate A plate was made.

Comparative Example 2 100 parts by weight of a powdery epoxy resin (brominated epoxy Ep5048 manufactured by Yuka Shell)
After mixing 5 parts by weight of a powdery curing agent (dicyandiamide) and 1 part by weight of a powdery curing accelerator (2-ethyl-4-methylimidazole), the powder composition is heated at 100 ° C. and melted. After that, a glass cloth of 100 g / m ² was soaked and impregnated so as to have a resin solid content of 100 g / m ² , and heated at 170 ° C. for 2 minutes to obtain a prepreg. Two prepregs were laminated, and a copper foil having a thickness of 18 μm was laminated on top and bottom of the prepreg.
It was heated and pressed at a pressure of 60 kg / cm ² for 90 minutes to produce a copper-clad laminate having a thickness of 0.22 mm.

Comparative Example 3 100 parts by weight of an epoxy resin (brominated epoxy Ep5048 manufactured by Yuka Shell), 5 parts by weight of a curing agent (dicyandiamide), and a curing accelerator (2-
1 part by weight of ethyl-4-methylimidazole),
This was dissolved in 100 parts by weight of methyl cellosolve. This varnish was added to a resin solid content of 100 g / m ² to obtain a varnish of 10 g / m ^2.
After impregnating by impregnating a glass cloth of 0 g / m ² ,
The prepreg was obtained by heating with a hot air heater at 0 ° C. for 3 minutes.
Two prepregs were superimposed, and a copper foil having a thickness of 18 μm was superimposed on and under the prepreg.
Heat-press molding at 0 kg / cm ² for 90 minutes to give a thickness of 0.
A 22 mm copper-clad laminate was produced.

In the above Examples and Comparative Examples, for the prepreg, the impregnating property of the resin into the glass cloth was measured, and for the copper-clad laminate, the moldability, tensile strength, copper foil peeling strength, and solder heat resistance were measured. Properties and insulation resistance were measured. The results are shown in Tables 1 and 2.

[0035]

[Table 1]

[0036]

[Table 2]

(Measurement method) Impregnating property: The prepreg was observed with a stereoscopic microscope, and the presence or absence of voids between glass fibers was confirmed. 2. Formability: The copper foil of the copper-clad laminate was etched, the presence or absence of the precipitation of a curing agent or the like was visually observed, and the dispersibility of the resin composition was evaluated. 3. Tensile strength: Etching copper foil of copper clad laminate,
After cutting to 10 × 100 mm, the tensile strength was measured with Tensilon. 4. Copper foil peel strength: Measured according to JIS C6481. 5. Solder heat resistance: A laminate of 50 × 50 mm is subjected to 260 ° C.
Was floated in a solder bath for 3 minutes, and the presence or absence of blisters was measured. 6. Insulation resistance: Measured according to JIS C6481.

As for the manufacturing cost, since the method of the embodiment does not use a solvent, the laminated board obtained in the embodiment is reduced in cost by about 30 to 40% as compared with that obtained in the comparative example 3. Was completed. Moreover, about the comparative example 2,
In the step of melting the resin at 100 ° C., the change over time in the curing characteristics of the resin was remarkable, and the resin adhered to the equipment hardened, making cleaning difficult.

[0039]

The method of the present invention comprises a thermosetting resin and a curing agent as essential components, premixing these components while heating them, and then applying mechanical energy to cause a mechanochemical reaction. Since the powdered thermosetting resin composition is used, a laminate having good quality such as electric characteristics and heat resistance can be stably obtained even though an organic solvent is not used. And because no organic solvent is used, resource saving,
Energy saving and reduction of air pollution are achieved, and resource saving and energy saving are also excellent in cost reduction. Thus, the present invention is suitable as an industrial method for producing a prepreg and a laminate.

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Claims (5)

[Claims] 1. A thermosetting resin obtained by premixing a thermosetting resin and a curing agent as essential components while heating these components and then applying mechanical energy to cause a mechanochemical reaction. A method for producing a prepreg, wherein the resin composition is present on at least a surface of a sheet-like fiber substrate. 2. The method for producing a prepreg according to claim 1, wherein the thermosetting resin and the curing agent are in a powder form. 3. The method for producing a prepreg according to claim 1, wherein the heating temperature at the time of pre-mixing is lower than the melting temperature of the thermosetting resin. 4. The method for producing a prepreg according to claim 1, wherein the apparatus for causing the mechanochemical reaction is a jet mill, an ong mill, a medium stirring mill or a multi-stage mill-type kneading extruder. 5. A method for producing a laminate or a metal foil-clad laminate, comprising laminating one or more prepregs obtained by the method according to claim 1, 2, 3 or 4 and heating and pressing. .