JPS6026036A - Production of laminated sheet - Google Patents

Abstract

PURPOSE:To provide a laminated sheet which has improved punchability and ply adhesion and can retain a substrate treating effect, by treating a substrate for laminated sheets with a phenolic resin precondensate contg. PVA. CONSTITUTION:A substrate for laminated sheets is treated with a mixture obtd. by adding polyvinyl alcohol (PVA) having a degree of saponification of 70-80% to a phenolic resin precondensate. The treated substrate is impregnated with a thermosetting resin and dried. The obtained laminating materials are laminated. It is desirable that PVA has a low degree of saponification, pref. 70-80% to dissolve the phenolic resin precondensate in an aq. methanol soln. When the degree of saponification exceeds 80%, the precondensate can not be dissolved in the aq. methanol soln, while when it is less than 70%, effects of improving the substrate treating effect and ply adhesion are insufficient.

Description

[Detailed description of the invention]

The present invention relates to a manufacturing method that improves the punching processability of a phenolic resin laminate using a base material such as paper. In recent years, printed circuit patterns have become larger and more dense. With the automation of the component mounting process, improvements in dimensional accuracy and punching workability for densely packed small holes are required. Due to the requirement for a high degree of dimensional accuracy, the punching temperature for circuit boards is reduced, and in some cases, circuit boards are punched at room temperature. In that case, it is necessary that the laminate plate serving as the substrate is plasticized in a low temperature range and at the same time has strong adhesion between the eyebrows. When producing a laminated material by applying a two-stage coating of resin varnish, such as an undercoat and a topcoat, the purpose is to obtain high electrical properties, moisture resistance, and water resistance. Therefore, from the viewpoint of the permeability of the resin varnish into the base material, conventionally, a phenol resin initial condensate is often used as an undercoat. These have a low molecular weight and have a certain degree of water solubility, so they have a great effect on treating substrates. This tendency is particularly noticeable in paper substrates. On the other hand, most of the lubricants currently used for topcoating are made of natural drying oil-modified phenolic resins such as tung oil, so they have strong lipophilicity and have an affinity for paper base materials or base materials after the above-mentioned undercoat treatment. 'flt-1 of the contact between the holes during punching.
In addition, in order to plasticize the coating resin, the content of natural drying oils such as tung oil or phosphorous If such a compound is used, the compatibility with the base material will be reduced.In this case, if an alkyl-modified phenol resin such as nonylphenol is used as the undercoat resin, interlayer adhesion will be reduced.
However, there is a limit because as the alkylphenol content increases, water solubility is lost and the treatment effect on the substrate is reduced. In order to solve the above-mentioned problems, the present invention has been developed by pre-treating a base material, especially a paper base material, with a mixture in which polyvinyl alcohol (hereinafter abbreviated as PVA) is added to a phenolic resin cutting condensate. The purpose is to improve the punching workability of the laminate by maintaining the effect, improving interlayer adhesion, and maintaining plasticization at low temperatures. PVA has conventionally been widely used as a paper treatment agent and a water-soluble adhesive, and is expected to have compatibility with substrates, especially paper substrates, due to the hydroxyl groups in its molecular structure. In addition, it can be expected to have a surfactant effect due to the action of the residual acetate group and the C--C bond, and it can also be expected to have a 411 degree of affinity with coating resins. Furthermore, by dispersing PVA of a certain degree of high molecular weight between the layers of the laminated material, it is possible to plasticize the laminated plate at low temperatures. The degree of saponification of the PVA used in the present invention is desirably low, and is suitably 70 to 80% in order to dissolve the phenolic resin initial condensate in water and methanol. If it exceeds 80%, the phenolic resin initial condensate will not dissolve in a water-methanol solution, and if it is less than 70%,
The treatment effect of the base material and the improvement of interlayer adhesion are insufficient. Furthermore, since the PVA used in the present invention is not involved in the curing reaction in the laminated material, it is preferable to have a relatively high molecular weight.
Approximately 0 to 1700 is appropriate. The amount of PVA added is in a weight ratio (PVA/phenol resin initial condensate solid) -5/95 to 20/8.
0 or desirable. If the amount of P'VA added is small, the desired effect will be small; if it is added in a large amount, curing of the undercoat resin will be inhibited and the viscosity of the undercoat resin mixture will increase, making it impractical. Example 1 will be specifically explained below. Example 1 Phenol 1000j 1.86'% formaldehyde 74 was added to a 3-day flask equipped with stirring, vorticity, and condenser.
Add 50y of 0P, l-lyntylamine, react at 80°C, and gel the product on a 160°C heating plate for about 8 minutes.
At this point, it was cooled and the resin content was adjusted to 50% with methanol (referred to as varnish A).Varnish A was oooy, saponification degree 75%, molecular weight 1500.
PVA 50F, water '175F. 776 methanol was blended to obtain a resin mixture for undercoating (referred to as varnish B). Next, add 80 flask = λμ oil 720y% m-cresol 580p, PTS acid 074F,
After reacting for 1 hour at °C, phenol 5-500y, 86% formaldehyde 450), 25
Add 35y of ammonia water and continue the reaction at 80℃.
When the gelation time of the product on a 160°C heating plate reaches 6 minutes, it is dehydrated and then methanol is added to reduce the resin content to 50%.
adjusted to

[7. Obtained phenolic resin modified with tung oil (varnish C
). Kraft paper was immersed in varnish B, (adhesive resin amount/laminated material weight after soaking) = 20 inches, dried at 140°C for 5 minutes, and then varnish C was added so that the total resin amount was 50%. Apply and dry. Eight laminated materials obtained in this way and three
Copper foil with adhesive of 5μ thickness is overlapped and heated to 160~1
Heat and pressurize for 60 minutes at 65°C and a pressure of xookV/m, 1. A copper-clad laminate with a fimm thickness was obtained. Example 2 Nonylphenol 220y, 3 was added to the same apparatus as Example 1.
7% formalin 60y, 86% paraformaldehyde 8
After 2 hours of reaction at 81)''O, 600y of phenol and 450y of 8F1% paraform were added, and the reaction was continued at 80''O. hot plate 1
．． After reacting until the gelation time reached 3 minutes, the mixture was cooled and the methanol resin content was adjusted to 50 g (referred to as varnish D).
. Varnish D 900), degree of saponification 70% 1 molecule 11000
1) V, A 50y, water 'I' 159° methanol 7
75y to obtain a resin mixture for undercoating (Varnish E
). Kraft paper was immersed in varnish E in the same manner as in Example 17 below to obtain a copper-clad laminate having a thickness of 1.61 mm. Comparative Example 1 Varnish A 1000F, water 7505E, methanol 75
Kraft paper was immersed in the solution containing No. 09, and the same method as in Example 1 was carried out to obtain a 1.6-thick laminate. Comparative Example 2 Varnish DIE: ]000p, water 750. Kraft paper was immersed in a solution containing 750 g of methanol, and a 1.6 mm thick copper-clad laminate was obtained in the same manner as in the examples. The properties of these feed laminates are shown in Table 1. Table 1 (→Punch diameter 0.8+nJ21, 1.6rtan pitch As is clear from Table 1, according to the present invention, the base material is pretreated with a solution containing phenolic resin initial condensate I and PVA and dried. One of the advantages of this method is that it can reduce the interlayer adhesion during the punching process of laminates and reduce the punching humidity by 1 m, making it possible to handle high-density punching patterns, and its industrial value is extremely great. Yes. Patent applicant 9-1

Claims (1)

[Claims] 1. The base material for the laminate is prepared by adding polyvinyl alcohol with a degree of saponification of 70 to 80% to a phenol resin initial condensate + JII
1. A method for producing a laminate, which comprises treating the substrate with a mixture of L. and then impregnating the treated substrate with a thermosetting resin and drying it to form a laminate material. 2. The method for producing a copper-clad laminate according to claim 1, characterized in that the initial bonding power t of phenol resin is a phenol-small luminaldehyde resin initial condensate or an alkylphenol-formaldehyde initial condensate.