JPS59136251A - Manufacture of paper base material phenol resin laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a single paper-based phenolic resin laminate, and to improving its punching processability.

In recent years, printed circuit boards obtained by processing metal/metal foil-covered laminates have become larger in circuit pattern, higher in density, and automated in the single-component mounting process. Improved workability is required. Due to the requirement for a high degree of dimensional accuracy, the punching temperature for each circuit board has been lowered and the circuit board is punched out at room temperature. There are also examples. In that case, it is necessary that the laminate is plasticized in a low temperature range and at the same time has strong interlayer adhesion.

Conventionally, paper-based phenolic resin laminates are produced by laminating coated paper coated with resin in two stages: undercoating and topcoating, on one paper base, in order to obtain high electrical properties and moisture and water resistance. is being carried out. Conventionally, a phenol initial condensate is used as the undercoat resin due to its permeability into the base material, and especially when obtaining a flame-retardant laminate, a melamine initial fastener is also used. These have a low molecular weight and a certain degree of water solubility, so they have a great effect on treating a single paper base material. However, even if the top coat resin was plasticized, its effect would be diminished.

In addition, plasticized topcoat resins or natural drying oil-modified phenolic resins such as tung oil in many cases have strong oil properties, reducing their affinity with the paper base material or with the undercoat resins, resulting in poor compatibility with the laminate. During the punching process, the adhesion between layers decreases, and phenomena such as hole-to-hole rack and delamination often occur.

Therefore, the more the content of natural drying oil such as tung oil is increased in order to plasticize the coating resin, the further the affinity with the paper base material and the undercoating resin decreases.

In order to solve these problems in a laminate made by laminating and molding coated paper using two-stage coating, the undercoat resin must have hydrophilicity for treating the paper base material and lipophilicity for the upper finishing resin. Moreover, it is necessary that the material itself be plasticized.

The present invention is.

By using a polyvinyl alcohol (hereinafter abbreviated as PVA) modified phenolic resin as an undercoat resin, the processing effect of the paper base material is maintained.

The purpose is to improve the interlayer adhesion of the laminate and improve the punching processability by plasticizing itself and compatibility with the one-coat resin.

PVA has conventionally been widely used as a paper treatment agent and a water-soluble adhesive, and is expected to have affinity with paper base materials due to the hydroxyl group in its molecular structure.

In addition, a surfactant effect can be expected due to the action of the residual acetate group and the C--C bond, and affinity with the top coating resin can also be expected. The present invention aims to plasticize the phenolic resin at low temperatures by using PVA in combination with a normal phenolic resin to ensure the above characteristics and by dispersing a certain amount of high molecular weight PVA in the system. be.

What dissolves PVA is water or a warm water tank, and it does not dissolve in a phenol resin solution, so it is usually difficult to use PVA and phenol resin together. However, a small amount of phenol is used as a viscosity stabilizer and solubilizer for PVA.

So, we focused on this point and first dissolved water and PVA, then added Tamouse's phenol, heated and dissolved it, and then added Taisha's methanol.

No separation or precipitation of PVA occurred, and a uniform solution state could be maintained. By adding formalde, do, and a basic catalyst to accelerate the curing reaction, a homogeneous solution of PV is produced.
It became possible to obtain A-modified phenol resin. Since no reaction between PVA and formaldehyde is expected under basic conditions, it is desirable to add PVA to PVA/phenol (weight ratio) of 5/95 to 20/80. Further, since PVA is only dispersed in the system, it is preferable to use a polymer with a certain degree of molecular weight, but in view of the viscosity when dissolved, a molecular weight of about 1700 is suitable for practical use. And 1.
I: Depending on the characteristics of the coating resin, those having a molecular weight of 88 to 100% can be used.

As a basic catalyst, ammonia, )! J)'? Amines commonly used in phenolic resins such as amine, dimethylamine, etc. can be used, and are not necessarily limited to those used in the examples. Moreover, the ratio of phenol to formaldehyde used can also be varied widely depending on the desired properties.

This will be specifically explained below using examples.

Example: 400g of water in a flask and 8896° molecule m17
00(7) Add PVA100F and stir. Next, add phenol 90 (Ml', 800 g of methanol, and 70 jl of trimethylamine) and heat to 80°C to dissolve. After dissolving, 8696 rose formaldehyde 5ooIi
was added and allowed to react for 4 hours. When the gelation time on a 160° C. hot plate reaches 3 minutes, it is dehydrated and the resin content is adjusted to 50% (referred to as undercoat varnish A).

Next, add 720 f of tung oil, 5 sop of m-cresol, and 0.749 of p'rs acid to the same flask and add 80 f of tung oil.
500g of phenol after reacting at ℃ for 1 hour! , 80% paraformaldehyde 450f.

Add 35 f of 2596 ammonia water and proceed with the reaction at 80°C, dehydrate when the gelation time on a 160°C hot plate reaches 6 minutes, then add methanol to adjust the resin content to 50% and make tung oil modified phenol. A resin was obtained (made into a varnish to be applied with L).

20% of the above-mentioned undercoat varnish A (adhesive resin amount/coated paper weight pupil =) is applied to kraft paper, and after drying, a topcoat varnish is further applied and dried so that the total resin is Q5096. 8 sheets of this coated paper and 35 μ thick black copper foil with adhesive were layered at a temperature of 160 to 1
The product was heated and pressed for 60 minutes under the conditions of 65° C. and 100 Kp/C to obtain a copper-clad laminate with a thickness of 7 tB.

In a comparative flask, phenol 1000 and 86% formaldehyde 74011 were added. After adding 50 g of trimethylamine and reacting at 80°C for 4 hours, it was cooled when the gelation time on a 160°C hot plate reached 3 minutes, and the methanol resin content was 5096.
(referred to as undercoat varnish B).

After adhering resin m2096 to the undercoat varnish B+kraft paper in the same manner as in the examples, the E-coating varnish in the examples was coated six times and dried to give a total resin of Q 5 Q 96. This coated paper was used to obtain a laminate similar to that of the example.

Table 1 shows the characteristics of the laminates of Examples and Comparative Examples.

Table 1 As is clear from Table 1, the use of 8PVA modified phenolic resin as an undercoat resin lowers the punching temperature of the laminate, and also improves the density at low temperatures due to the increased adhesion between layers. The industrial value of the present invention is extremely great in that it makes it possible to perform die-cutting.

Claims (1)

[Claims] 1. In a method for manufacturing a laminate in which coated paper is coated with resin on a paper base material in two stages of undercoating and L coating, a polyvinyl alcohol-modified phenol resin is used as the undercoat resin. Characteristic manufacturing method for paper-based phenolic resin laminates. 2. The paper base phenolic resin according to claim 1, wherein the polyvinyl alcohol-modified phenolic resin is obtained by dissolving polyvinyl alcohol in water and phenol, adding formaldehyde, and reacting under a basic catalyst. Method of manufacturing laminates.