JPS60208318A - Production of improved phenolic resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin having improved heat resistance without deteriorating strength, electrical characteristics, adhesive property, processability, etc., by adding or reacting a dialkyl N-alkylaminomethyl phosphonate compound with a phenolic resin. CONSTITUTION:Phenol and formalin are reacted under heating to produce a phenolic resin. In the process, a compound expressed by the formula (R<1> and R<2> are 1-4C alkyl; R<3> is 4-18C alkyl), e.g. diethyl N-octylaminoethyl phosphonate, is added or reacted with the phenolic resin to give the aimed resin. The compound expressed by the formula can be synthesized by reacting a primary amine with formaldehyde or a derivative thereof and a trialkyl phosphite.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for making phenolic resins.

This paper relates to methods for improving the physical properties of phenolic resins, especially flame resistance.

Up until now, the flame retardant of phenol resin has been achieved by adding halogen or phosphorus compounds such as tetrabromobisphenol (AsF') cresyl phosphate, triphenyl phosphate, ammonium phosphate, etc., but it has not been possible to obtain sufficient flame resistance. As its addition increases, various physical properties and processability are unavoidable, such as a decrease in mechanical strength, short-temperature properties, interlayer adhesion, and punching processability.

As a method for improving these, a method of adding and reacting diethyl-N,N-bis(2-hydroxyethyl)amine methylphosphonate (% JP-A-56-49722)
However, the reactivity of this compound with phenols and aldehydes is low, and no fundamental solution has been reached.

The present invention solves the above problems at once by using a phosphorus compound that reacts with phenols and aldehydes, specifically an aminomethyl phosphonate compound containing an -NH group. It is something.

The requirements for the structure of the present invention are that when obtaining a phenolic resin mainly composed of phenols and aldehydes, a phosphorus compound represented by the following formula is reacted with an additive u1 to produce a flame-resistant phenolic resin with excellent physical properties and processability. It's something you get.

Examples of phosphorus compounds used in the present invention include dimethyl-
N-stearylaminomethylphosphonate, diethyl-
Examples include N-stearylaminomethylphosphonate, isopropylbutyl-N-butylaminomethylphosphonate, and diptyl-N-octylaminomethylphosphonate.

Until now, it was thought that it was impossible to economically obtain these phosphorus compounds with high purity and good yield, but the present inventor has developed a method by reacting 1M amine, formaldehyde or its derivatives, and trialkyl phosphite. It has been found that it can be produced extremely easily by removing the by-product alcohol.

The reaction formula is shown below.

The compound of the present invention may be reacted with electric power t1 during the production of the phenol resin, or may be added to the phenol resin face for use.

The amount of phosphorus compound used in the present invention varies depending on the phosphorus content of the phosphorus compound, but it is preferably 5 to 40% by weight. Also,
Other flame retardants can also be used in combination.

Below are production examples and examples of phosphorus compounds used in the present invention,
A comparative example is shown. Note that the parts in the example are based on 31iJt.

[Production Example-1] 66 parts of octylamine was placed in a reaction tank, and 50 to 6 ocK
While maintaining the temperature, 15.8 parts of 95% paraformaldehyde was added and reacted. The time required was 50 minutes.

Next, at the same temperature, 1-83 parts of triethylphosphite was added.
The mixture was added dropwise for about an hour, and stirred at the same temperature for an additional 2 hours.

The product obtained by removing volatile components under water pressure and then under reduced pressure is a nearly colorless liquid with a yield of 140 parts (99%).
It became. The fraction was 24 parts, and as a result of gas chromatography analysis,
It turned out to be ethanol containing some water. Product analysis values are listed in Table-1. The IR spectrum and NMR spectrum of this product are shown in FIG. 1 and FIG. 2, respectively. Analysis results and IR of the product shown in Figure 1.2,
The NMR chart shows that the target product, diethyl-N-octylamine methylphosphonate, was obtained.

[Production Examples-2 to -4] Dimethyl-N-octylaminomethylphosphonate, diethyl-N-stearylaminomethylphosphonate, and dibutyl-N-bunalaminomethylphosphonate were obtained in the same manner as in Production Example-1. .

The manufacturing data and analysis results are summarized in Table 1.

Production of phenol laminate [Example-1] 1 so part of phenol, 156 parts of 3z% formalin, 50 parts of diethyl-N-octylaminomethylphosphonate obtained in Production Example-1, and 6 parts of 26% ammonia were mixed at reflux temperature to 1 part. Allowed time to react.

After dehydration under reduced pressure, the mixture was diluted with methanol to obtain a varnish with a resin content of 50%.

A 0.25 m thick piece of kraft paper was impregnated with this varnish to a ratio of 50% resin and dried.

The obtained 7 sheets of prepreg and 31 sheets of copper rf were laminated to form a 160mm
Pressure was applied at C100 kl/d for 1 hour to obtain a copper-clad MN board with a thickness of 1 and A wx.

The test results for this product are listed in Table-2.

[Examples 2 to 4] [Comparative Example 1] Aminomethyl phosphonate compounds obtained in Production Examples 2 to 4 and a commercially available additive type flame release agent were added to a phenolic resin varnish with a solid content of 50% in a predetermined amount, and diluted with methanol to form a solid. 50%.

Using this varnish, a black-clad laminate was obtained in the same process as in Example-1.

Table 2 shows the combination of the aminomethylphosphonate compound, the additive flame retardant, and the test results of the resulting laminate.

[Brief explanation of drawings]

Figure 1 shows the In spectrum of the chemical compound obtained in Production Example 1,
FIG. 2 is its NMR spectrum. Applicant's agent Kaoru Furuya

Claims (1)

[Claims] A method for producing a flame-resistant phenolic resin, which comprises adding or reacting a compound represented by the following formula to a phenolic resin when producing a phenolic resin.