JPS6017413B2 - Manufacturing method of thermosetting resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a thermosetting resin that is effective for manufacturing laminates that require high properties such as punching workability, flame retardance, arc resistance, chemical resistance, and heat resistance. Regarding manufacturing.

As a method for imparting the above-mentioned protective properties to a high degree, a technique has been adopted in which a plasticizer is added to a resin obtained by co-condensing a phenol resin with an amino compound containing a triazine ring such as melamine.

However, this conventional method has problems with co-condensation, requires strict pH control during resin production, lacks storage stability of the condensate, tends to precipitate unreacted amino compounds, and is difficult to co-dip into the base material. The properties when made into a laminate do not satisfy the above properties. That is, if a triazine compound is used, flame retardancy and arc resistance are improved, but there is a tendency for the material to become hard. Therefore, in order to obtain punching workability in an appropriate temperature range, a large amount of plasticizer is required, which has the drawback of significantly lowering chemical resistance and heat resistance. In addition, considering the need to combine such processability with chemical resistance and heat resistance, it is also possible to use an alkylphenol, such as a nonylphenol-formaldehyde reaction product, in place of the conventional plasticizer. However, stable co-condensation with triazine compounds such as melamine and compatibility between melamine and formaldehyde do not occur sufficiently, and the storage stability of the resin varnish is poor, so when made into a laminate, the above-mentioned properties cannot be fully satisfied. There wasn't. The present invention provides a stable resin varnish by reacting nylphenol, phenol, and melamine-formaldedehyde initial condensate in the same reaction system by the method described below. The aim is to provide a thermosetting resin that can maintain various properties when molded, especially the flexibility of Noel phenol to improve punching processability, and the combined use of phenol to improve the melamine-formaldehyde initial condensate in resin varnish. Stabilization and chemical resistance when laminated,
Further, by adding arc resistance and flame retardance by using a melamine resin in combination, the present invention aims to provide a laminate that is required in the recent electronic field.

That is, in the present invention, after nonylphenol and formaldehyde are reacted in the presence of an alkali catalyst, phenol is added in an amount of 50 to 20% by weight based on the nonylphenol to this reaction system, and the reaction is caused to occur. The reaction is controlled such that the molecular weight product (molecular weight 400-800) is in the range of 5-2% by weight in the product. Then,
The desired thermosetting resin can be obtained by adding 20 to 100% by weight of a melamine-formaldehyde initial condensate to the nonylphenol and dehydrating it under reduced pressure. In carrying out the present invention, the reaction between nonylphenol and formaldehyde can be carried out using either acidic or alkaline catalysts, as is well known, but when a melamine-formaldehyde initial condensate is used in combination, it is preferable from the viewpoint of stability of the resin varnish. Alkalinity is suitable, and suitable catalysts include ethylenediamine, diethylamine, trimethylamine, etc.

In addition, in the first step of reacting nonylphenol and formaldehyde, it is desirable to use an amount of formaldehyde that includes the formaldehyde that is condensed with nonylphenol and the formaldehyde necessary for condensation with phenol that is added later. . The molar ratio may generally be in the range of 1.1 to 1.5 moles for each mole of nonylphenol and phenol, which is the molar ratio that produces resol. Nonylphenol is less reactive than phenol, and it is necessary to condense nonylphenol and formaldehyde before adding phenol. Paraformaldehyde and 37% formalin can be used as formaldehyde. The extent of the reaction between nonylphenol and formaldehyde is allowed to proceed until formaldehyde consumption reaches equilibrium at reflux temperature. When a melamine-formaldehyde initial condensate is directly added to a reaction product of nonylphenol and formaldehyde to cause a reaction, storage instability occurs due to insufficient compatibility of the resin varnish, resulting in precipitation of a gel-like substance and a gelation phenomenon in the reaction system. Therefore, by using phenol together,
It is possible to stabilize the melamine-formaldehyde initial condensate and allow it to participate in the reaction without causing gelation.
If the amount of phenol used is less than 5% by weight based on nonyl phenol, the above-mentioned effect will not be obtained and the chemical resistance will be poor when made into a laminate. On the other hand, if it exceeds 20% by weight, the hardness of the laminate increases and the punching workability decreases. Furthermore, when phenol is added to the reaction system of nonylphenol and formaldehyde to cause a reaction, the high molecular weight substances (molecular weight 400 to 800) in the reaction product are
It is necessary to control the amount within a range of 2% by weight. In addition, in order to facilitate reaction control, the reaction of phenol was carried out at 80%
It is preferable to carry out at a low temperature of ~90 qo. When the amount of high molecular weight substances in the product is less than 5% by weight, there is a large amount of unreacted phenol. When made into a laminate, chemical resistance decreases.
On the other hand, if the amount exceeds 2% by weight, the stability of the reaction system will not be maintained, especially when the melamine-formaldehyde initial condensate is added, and a gelled product will be formed or the resulting resin varnish will become cloudy. The melamine-formaldehyde initial condensate is an integrated product whose main component is trimethylolmelamine, which is obtained by condensing melamine and formaldehyde at pH 8 to 10, and is commercially available, for example, under the trade name Nicaresin S-3.
05 S-260 (manufactured by Nippon Carbide Kogyo ■) can be used.

When the initial condensate is added to the reaction system, the pH is 6.8~
A value of about 7.5 is preferable from the viewpoint of compatibility. The amount of the initial condensate added is suitably 20 to 10% by weight based on nonylphenol. If the amount is less than 2% by weight, the desired arc resistance and flame retardance cannot be obtained.

Moreover, if it exceeds 10% by weight, the stability of the resin varnish decreases, and when it is made into a laminate, it becomes hard and the punching process deteriorates. Further, the degree of reaction is adjusted to a degree suitable for coating by measuring gelation time. Finally, methanol, acetone, etc. are added as a solvent to be removed under reduced pressure to obtain a resin varnish. The thermosetting resin thus obtained is treated with a suitable amount of a key fuel additive, such as a phosphate ester compound or the like.

After adding a genified epoxy compound and the like and dipping it into a paper base material by a conventional method and heating and drying to obtain a prepreg, a predetermined number of sheets of the prepreg are stacked, and if necessary, copper foil or the like is stacked and laminated by heating and pressing. Examples will be described below.

Example 1 / 500 parts of nylphenol (purity 99.5%) (hereinafter referred to as “
"parts" indicate parts by weight), 85% paraformaldehyde 3
3 anchor parts, 37% formalin 8 loose parts, ethylenediamine 3 parts
The mixture was placed in a reaction vessel equipped with a Takayoso-do, a counterflow condenser, and a thermometer, and reacted at reflux temperature for 4 hours.

At this stage, 50% of phenol was added and the reaction proceeded at a temperature of 80qo, and when the high molecular weight substance with a number average molecular weight of 400 to 800 was 1% by weight in the reactant (gas chromatography analysis), the pH was confirmed to be 7.1. After that, 25 parts of melamine-formaldehyde initial condensate (Nicaresin S-305) were added and mixed, the reaction was allowed to proceed at reflux temperature, and when the gelation time of the reaction product reached 3 minutes, dehydration was performed under reduced pressure. , 80 parts of methanol was added to obtain a resin varnish with a solid content of 50%. The varnish had good stability without forming turbidity or precipitate even when left alone at room temperature. The gelation time is expressed as the time it takes for the resin to change into a gel after 10 minutes of the resin is placed in a 50cc beaker and heated at a temperature of 160 quarts.

A coating varnish is prepared by blending phosphate ester as a flame retardant additive into the above varnish at the solid content ratio (parts) shown in Table 1,
Impregnated into linter paper with a thickness of 10 mils and dried to a resin amount of 5
0% prepreg, 9 sheets of the prepreg were stacked and inserted into a lamination press, temperature 16 to 0, pressure 100k9/ground,
Heat and pressure was applied for 60 minutes to obtain a laminate with a skin thickness of 1.6.

The properties of the laminate were as shown in Table 2. Example 2 35 parts of nonylphenol, 337 parts of 85% paraformaldehyde, 8 parts of 37% formalin, and 3 parts of ethylenediamine were reacted at reflux temperature for 4 hours.

In this step, 65 parts of phenol was added, and the reaction was carried out in the same manner as in Example 1. When the amount of high molecular weight substances with a number average molecular weight of 400 to 800 was 15% by weight in the reaction product, the melamine-formaldehyde initial condensate ( 25 parts of Nikaresin S-305) was added and reacted, gelling time of the reaction product was 3 minutes, dehydration was started under reduced pressure with 2 silica sand, and after completion of dehydration, 8 parts of methanol was added.
A resin varnish with a solid content of 50% was obtained by adding 0.05%. Even when the varnish was left at room temperature for one month, there was no turbidity or precipitation of solid content. The above-mentioned varnish was used as a coating varnish in the formulation shown in Table 1, and a laminate having a thickness of 1.6 mm was obtained in the same manner as in Example 1.

The properties of the laminate were as shown in Table 2. Comparative Example 1 When the melamine-formaldehyde initial condensate was directly added to the nonylphenol-formaldehyde reaction product in Example 1 without using phenol, the reaction system became cloudy and a gel-like substance precipitated, which could be provided to the laminate. Resin varnish could not be manufactured.

Comparative Example 2 In Example 1, the melamine-formaldehyde initial condensate (Nicaresin S-305) was not used;
The first experiment was carried out using a resin varnish in which the reaction proceeded only by adding phenol to the nylphenol-formaldehyde reaction system.
A coating varnish was prepared using the formulation shown in the table, and a laminate having a thickness of 1.6 mm was obtained in the same manner as in Example 1 except for the following.

The properties of the laminate were as shown in Table 2. Comparative Example 3 In Example 2, 40 parts of melamine-formaldehyde initial condensate (Nicaresin S-305) was added to proceed with the reaction, and after 3 minutes of gelation time of the reaction product, dehydration began under reduced pressure and methanol was added after completion of dehydration. 950 parts of were added to obtain a resin varnish with a solid content of 50%.

The varnish became cloudy after 2 hours at room temperature and formed a precipitate after 3 days. Table 2 shows the properties of the laminate using this varnish. Table 1 (Note) C. D. P: Cresyl diphenyl phosphate (phosphate ester compound) Generally used as a flame retardancy improver.

Table 2 The method for the above characteristic test is as follows.

'1} Optimum punching temperature: Temperature at which a Ve od rating can be obtained according to the ASTM method (targeting 60 qo or less) {2
) Flame retardancy: By UL manufacturing method (targeting V-○) (V-0 average 5 seconds or less, maximum 1 sand or less) [3} Arc resistance: AS
By TM method (targeting 10 or higher) {4) Chemical resistance:
Judging by appearance (out if spots are formed) As is clear from Table 2, the laminate using the thermosetting resin produced by the method of the present invention has excellent punching workability, flame retardancy, arc resistance, and chemical resistance. It maintains both properties of heat resistance and heat resistance.

Claims (1)

[Claims] 1. After reacting nonylphenol and formaldehyde in the presence of an alkali catalyst, 50 to 200% by weight of phenol based on the nonylphenol is added to the reaction system to remove high molecular weight substances (molecular weight 400 to 800) in the reaction product.
The reaction is allowed to proceed until it accounts for 5 to 20% by weight in the product, and then 20 to 100% by weight of the melamine-formaldehyde initial condensate is added to the nonylphenol and reacted. Method of manufacturing resin.