JPH0491947A - Continuous manufacture of laminate for electric use - Google Patents

Abstract

PURPOSE:To prevent a carrier sheet for carrying from peeling-off in preparing a laminate for electric uses by performing corona discharge treatment on a face of a specified carrier sheet which is to be brought into contact with the laminated sheet. CONSTITUTION:A continuous base material 1 such as a nonwoven fabric is taken out of a roll 2, passes through a pre-impregnating bath 3 and a drying a room 4 and enters into an impregnating room 5. In the impregnating room, the base material 1 is impregnated by feeding a thermosetting resin such as unsatd. polyester resins, epoxy resins and epoxy acrylate resins which can be cured without producing any volatile by-product and is liq. at ordinary temp. from a curtain flow coater 16 and it is made in a body by means of a pair of laminating rolls 6. Thereafter, in the case of an unclad sheet, the laminate is covered with release films 8 in a sandwich shape by means of rolls 9. The face of a carrier sheet which is to be brought into contact with the laminate is subjected to a corona discharge treatment. The laminate covered with a metal foil and/or the release film 8 is passed through a preheating oven 10 and is pressed and heated by means of a double belt press 11 and is cured by passing through a postcuring oven 15 to obtain a product 20.

Description

[Detailed Description of the Invention] ■↓-@Murazuki Bunchuu- The present invention relates to a continuous manufacturing method for electrical insulating laminates or metal foil-clad laminates for printed circuits.

The term "electrical insulating laminate board" as used herein refers to a laminate board used as a substrate or support plate for parts or devices for various Shinto shrines.71. Metal foil clad laminates for printed circuits refer to single-sided printed circuit boards used for mounting electronic circuit components, etc. say.

1986-126418 (Patent Publication No. 62-6
513), a thermosetting resin liquid that itself is liquid at room temperature (for example, an unsaturated polyester resin liquid) that does not generate volatile by-products during the curing reaction process is conveyed to a long sheet-like substrate)
A manufacturing method for electrical laminates in which a large number of laminates are impregnated, both sides of the laminate are coated with metal foil and/or a release film, and the laminate is cured continuously under virtually no pressure (wet pressureless continuous method). )
is disclosed.

Also, the present applicant's Japanese Patent Application Laid-Open No. 56-14415 ], (]
In Japanese Patent Publication No. 6O-58031, a laminate is sandwiched between a pair of ends (double belt press) running synchronously with each other, and pressure is applied perpendicularly to the laminate surface while heating is performed. We proposed a curing method (continuous wet pressure method).

-Whether using the wet non-pressure continuous method or the wet pressurized continuous method described above, in order to prevent the uncured resin liquid from adhering to the conveyor roll or its surroundings, the two unclad plates have one side made of metal on both sides. In the case of foil-clad laminates, a release film must be applied on the opposite side of the metal foil and cured. Release films are flexible films, such as polyethylene terephthalate (PET), polyvinyl alcohol (PVA), polyimide, or cellophane, that are unwound from the roll and applied to the uncured laminate prior to the curing oven and cured. After passing through a furnace, it is peeled off 1 and wound into rolls. However, such release films often peel off or sag before the laminate is fully cured due to vibrations during transportation or differences in thermal expansion coefficients between the laminate and the laminate. I can see it. When the release film is peeled off from the laminate before curing, air enters from that part, causing problems such as delaying the curing reaction and impairing the surface smoothness of the product N#Fi.

+i 胛曵澗-丞The present invention proposes a method for preventing peeling of a conveying carrier sheet in manufacturing electrical laminates using a wet no-pressure method or an H continuous force method.

More specifically, the present invention provides a method for transferring a thermosetting resin liquid that is liquid itself at room temperature and does not generate volatile byproducts during the curing reaction process to a plurality of elongated substrates that are continuously conveyed. An electrical laminate comprising: impregnating a material, laminating an impregnated base material, covering at least one side of the laminate with a carrier sheet made of a flexible film, curing by heating, and peeling the carrier sheet from the cured laminate. The present invention relates to a continuous plate manufacturing method, characterized in that the surface of the carrier sheet in contact with the laminate is subjected to a corona discharge treatment.

Although the present invention is equally applicable to a wet pressureless continuous process, we will now discuss the accompanying drawings which schematically show a line applied to a wet pressurized continuous process using a double-held brace. do.

In the drawing, a long base material 1 such as a cellulose base material such as linter paper or kraft paper, glass cloth, glass paper, mixed paper, or non-woven fabric is pulled out from a roll 2, and then passed through a reserve dipping bath 3.
, passes through the drying chamber 4 and enters the impregnation chamber 5-. In the impregnation chamber, the substrate 1 is coated with a thermosetting resin that is liquid at room temperature and hardens without producing volatile by-products, such as unsaturated polyester resin, epoxy resin, or epoxy acrylate resin, from the curtain flow coater 16. impregnated and combined by a pair of laminating rolls 6. The laminate is then coated with a release film 8 in the form of a sandwich in the case of an unclaved board by means of a roll 9. When manufacturing metal foil laminates, a metal foil such as electrolytic copper foil, rolled copper foil or aluminum foil is coated on one side and becomes part of the structure of the final product. A flexible film such as polyethylene terephthalate, polyvinyl alcohol 9 polyimide, cellophane, etc. can be used as the release film, and is peeled off from the laminate after curing.

The laminate coated with metal foil and/or release film 8 passes through a preheating oven 10, is pressed and heated by a double belt press II, and passes through a postcuring oven 15 where it is cured into a product 20.

The double heel brace 11 is made of a roll 13 as shown in the figure.
．． It consists of a pair of upper and lower endless belt devices consisting of steel belts 12 stretched between 13" and 13", with a laminate 20 to be pressurized sandwiched between them and driven synchronously with the conveying speed of the laminate 20.Each endless belt 12 Heat and pressurize the part that is in contact with the laminate on the opposite side of the laminate.
Nox 14 is provided. The pressure applied to the laminate is generally below 20 kg/cd, preferably from 1 to 10 kg/c
It is in the range of tA.

The period during which the molding pressure is applied by the double belt press need not be the entire period of the curing reaction, and the extent of the curing reaction (for example, in the case of unsaturated polyester resin, the conversion rate of crosslinking monomers such as styrene) is 40 to 90%.

Preferably, the double belt press is released when the curing process has progressed to 50 to 80%, and the curing is carried out in the post-curing furnace 15 under no pressure.

This makes it possible to remove at least ~ part of the internal stress of the product. The release film is then peeled off from the cured laminate.

Preferably, a preheating fJ310 using hot air Q is provided on the upstream side of the double helmet breath and adjacent thereto.

Here, due to evaporation of volatile components, blistering, delamination, etc.
Although preheating or partial curing is continued until phenomena such as foaming no longer occur even with subsequent rapid heating, it is not preferable to proceed with curing to such an extent that the impregnating resin liquid no longer exhibits fluidity. Therefore, the reaction rate at this stage is optimally kept at 10% or more and 6% or less.

The line for the continuous wet pressurization method is the same as the line for the continuous wet pressurization method shown in FIG. good.

According to the present invention, the surface of the carrier sheet 8 that comes into contact with the laminate is subjected to a discharge process of 1'-1. The energy of corona discharge is preferably in the range of 1 to 15 watts/yxf; if the energy is too low, it will not be effective, and if it is too high, it will be difficult to peel off the laminate after curing.

The present invention will be described with reference to specific preferred embodiments (7.
It is obvious to those skilled in the art that modifications and modifications may be made within the scope of the claims.

[Brief explanation of the drawing]

The drawing is a schematic view of a specific example in which the present invention is applied to a continuous wet-type laminate manufacturing line. 1 is a base material, 23 is a pre-impregnation chamber, 4 is a drying chamber, 5 is an impregnation chamber, 6 is a lamination chamber, 8 is a carrier film 2.1] is a laminating roll, 10, 11.15 is a curing zone, 20 is a curing It is a laminated board.

Claims (2)

[Claims] (1) A thermosetting resin liquid that is liquid itself at room temperature and does not generate volatile byproducts during the curing reaction process is impregnated into a plurality of long base materials that are continuously conveyed, and the impregnated base material is A continuous manufacturing method for electrical laminates, which comprises laminating materials, covering at least one side of the laminate with a carrier sheet made of a flexible film, curing by heating, and peeling the carrier sheet from the cured laminate, The method described above is characterized in that the surface of the carrier sheet in contact with the laminate is subjected to a corona discharge treatment. (2) The corona discharge treatment is performed at 1 to 15 watts/min/m^
The method of the first term is carried out with an amount of energy of 2.