JPH0465784B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for continuously manufacturing paper-based synthetic resin laminates, and more particularly to an apparatus for drying paper substrates after preliminary impregnation in the apparatus.

A laminate made of paper as a base material and laminated with a plurality of resin-impregnated base materials impregnated with a resin liquid and cured, and a metal foil-clad laminate made of a laminate with metal foil laminated on one or both sides of the laminate. The board is used as an insulating board and a printed wiring board.

Conventionally, these laminates were manufactured using a batch method in which prepregs obtained by impregnating the base material with resin varnish and drying were stacked and molded by pressurizing and heating. A continuous method has been developed that performs resin impregnation, lamination, curing, etc. while continuously conveying materials, and is attracting attention. For example, see Japanese Patent Application Laid-open Nos. 55-4838 and 56-98136 by the present applicant. When the base material used for continuous production of these laminates is a paper base material mainly composed of cellulose, especially when the resin is an unsaturated polyester resin, to improve the heat resistance and electrical properties of the product when moisture is absorbed. It is common to pre-impregnate paper substrates with methylol compounds such as melamine resins, urea resins, phenolic resins, N-methylol acrylamide and the like. Applicant's Japanese Patent Application Publications No. 55-144159, No. 56-43329, No. 57-
See 57623, 57-131552, etc. For this purpose, the raw paper base material wound into a roll is continuously unwound from the roll, and undergoes preliminary impregnation, drying, impregnation with resin liquid, lamination, etc.
It passes through processes such as curing and cutting while being transported.

In this case, when the pre-impregnated paper base material is dried with hot air using a roll support type device, the paper becomes fluffed, generates paper dust, and adheres to the rotating parts of the device.
It has been found that these lumps tend to get mixed into the laminate and cause problems such as appearance defects such as spots and poor board thickness. In order to avoid such troubles due to the generation of paper dust, the present inventors dried the paper base material after preliminary impregnation by first floating drying and then supporting it on rolls and performing hot air drying. It was found that the generation of paper dust was significantly reduced. In addition, when drying impregnated paper, it is desirable to perform constant rate drying at as low a temperature as possible in terms of quality, and the final moisture content is 1.
% or less. Therefore, it is advantageous to perform constant rate drying efficiently at low temperatures in a short time using a floating method, and to perform high temperature processing for lapse rate drying using a simple roll support system, as this reduces equipment costs and installation space. .

The present invention is based on such knowledge.

In the present invention, a plurality of long paper base materials are individually and continuously conveyed, and each is pre-impregnated with a paper treatment liquid, dried, and impregnated with a curable resin liquid, and then combined, and metal is coated on both sides. In a paper-based synthetic resin laminate continuous manufacturing apparatus equipped with stations for laminating and continuously curing foils and/or cover sheets, a pre-impregnated paper base is transferred to a drying chamber where it is dried while being transported. The gist of this invention is a continuous manufacturing apparatus for paper-based synthetic resin laminates, which is characterized by being equipped with a device for first floating drying and then supporting it on rolls and performing hot air drying.

In the accompanying drawings, FIG. 1 is a schematic view of a specific example of the entire continuous manufacturing apparatus for paper-based synthetic resin laminates, and FIG. 2 is an enlarged view of a part of the interior of the drying chamber.

In FIG. 1, a plurality of long paper base materials 1 are sequentially fed out from respective rolls 2, and are fed into a drying chamber 5.
(the equipment is optional) and passed through a pre-impregnation bath 3. The base material here is JP-A-57-131552.
The paper is pre-impregnated with a paper treatment liquid as described in 1, dried again in the drying chamber 4, and then sufficiently impregnated with a resin liquid in a resin liquid bath 6. A plurality of impregnated base materials 1 are combined by passing between a pair of rolls 7, and a metal foil 9 coated with an adhesive, for example, is placed on the upper surface of the supply roll 11, and a polyester film 8, for example, is placed on the bottom surface of each roll. The sheets are laminated together by laminating rolls 10, cured while passing through a curing furnace 12, and cut into metal foil-clad laminates 16 of predetermined dimensions by cutters 15. In the drawing, the cover sheet 8 is peeled off by a peeling roll 13 and wound up after leaving the curing furnace 12, but a metal foil is used instead of the cover sheet 8, and the bottom surface is also coated with metal foil. If it is not peeled off after laminating and curing, a double-sided metal foil clad laminate can be obtained. Moreover, if the same cover sheet as 8 is laminated on the upper surface instead of the metal foil 9 and peeled off after curing, a laminate that can be used as an insulating substrate can be obtained. Note that the substrate and the like are transported by the take-up device 14 and, if necessary, by driving the rollers 7, 10, etc.

According to the invention, a floating dryer 20 and support rolls 32, 34, 36 are provided in the drying chamber 4 for the pre-impregnated substrate 1. As shown in detail in FIG. 2, floating dryer 2
0 is installed on the entrance side of the drying chamber. The illustrated floating drying device 20 includes boxes 22 and 2 equipped with a plurality of hot air outlets on the side facing the paper base material 1.
4 and 26, which are arranged above and below the paper base material 1 being conveyed, the box 22 blows hot air upward onto the bottom surface of the paper base material 1, and the boxes 24 and 26 blow hot air downward onto the paper base material 1. It is designed to be sprayed onto the top surface. Therefore, the paper base material 1 being conveyed is dried by hot air in a floating state.

Next, the paper substrate 1 is supported on support rolls 32, 34, and 36 on the exit side of the drying chamber 4 and is dried by hot air blown into the entire drying chamber.

By passing the pre-impregnated paper base material 1 through the floating drying section 20 and the roll support drying section 30 in the drying chamber 4,
Initially, it is dried at a relatively high rate in the floating drying section 20. For example, it is possible to dry with high efficiency even in a low temperature range, for example, 40°C to 60°C, preferably around 50°C, and it is preferable to perform constant rate drying using this drying method. Next, the roll drying section 30
It is dried at a relatively slow rate.
For example, it is preferable to dry at 145 to 165°C, preferably around 155°C, and lapse rate drying is preferably performed on the spot. By combining the treatment conditions illustrated in these two drying methods, the water content was reduced to 1% or less in about 2 minutes.
It is believed that drying that combines high and low drying speeds as well as high and low drying temperatures contributes to reducing paper dust generation and equipment costs.

Incidentally, when paper drying was carried out only by a roll support method instead of the present invention, it took about 2 minutes at 160°C to 170°C to obtain a final moisture content of 1% or less.

The invention is not limited to the specific embodiments shown, but may be varied within the scope of the claims. For example, in the floating drying section 20, instead of a box, any device that blows hot air onto both the upper and lower surfaces of the paper base material 1 being conveyed can be used, and between the floating drying section 20 and the roll drying section 30, A partition wall may be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic view of the entire continuous manufacturing apparatus for paper-based synthetic resin laminates, and FIG. 2 is a partially enlarged view of the interior of the drying chamber. 1 is a paper base material, 3 is a preliminary impregnation bath, 4 is a drying chamber, 6
is a resin impregnated bath, 8 is a cover sheet, 9 is a metal foil,
12 is a curing furnace, 14 is a take-up device, 15 is a cutter, 20 is a floating drying section, and 30 is a roll support drying section.

Claims (1)

[Claims] 1 A plurality of long paper base materials are individually and continuously conveyed, pre-impregnated with a paper treatment liquid, dried and impregnated with a curable resin liquid, then combined, and coated with metal foil and/or on both sides. Alternatively, in a paper-based synthetic resin laminate continuous manufacturing device that is equipped with stations for laminating and continuously curing cover sheets, the pre-impregnated paper base material is placed in a drying chamber where it is dried while being transported, in the direction of transport. 1. A continuous manufacturing device for paper-based synthetic resin laminates, characterized in that it is equipped with a device for first floating drying and then supporting on rolls and performing hot air drying.