JPS6185444A - Production of flame-retardant phenolic resin laminate - Google Patents

Abstract

PURPOSE:To obtain laminate having improved soldering resistance and heat resistant in gases, by impregnating a paper substrate with phenolic resin varnish containing a reaction product of a phosphoric ester and a halogen-containing aromatic alcohol and molding the paper substrate under heating. CONSTITUTION:A phosphoric ester is reacted with a halogen-containing aromatic alcohol to give a reaction product, which is used as a flame-retardant and added to phenolic resin varnish, and a given amount of the phenolic resin varnish is impregnated into a paper substrate, which is molded under heating. A phosphoric ester such as tricresyl phosphate, etc. containing an aromatic ring is used as the phosphoric ester. 2,4,6-Tribromophenyl-B-hydroxyethyl ether, 2,4,6-tribromobenzyl alcohol, etc. may be used as the alcohol. The reaction is carried out at 80-250 deg.C, preferably 130-170 deg.C, and a catalyst such as K2CO3, etc., is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing flame-retardant paper-phenolic resin laminates (including copper-clad laminates).

[Conventional technology]

Recently, insulating materials, especially laminates used for communication equipment and electronic equipment, are required to be punchable at room temperature or slightly higher temperature from the viewpoint of automation of processing equipment and energy saving. Normally, the resin for low-temperature punchable laminates uses alkylphenols of each type in combination with phenol.
Phenol 4tJ fat plasticized with drying oil is used.

However, there is a growing demand for flame retardancy for laminating machines used for insulating materials from the perspective of safety, and from the perspective of flame retardancy, drying oil used to improve punching processability is becoming more and more important. These plasticizers make flame retardation even more difficult and complicated.

A method of making laminates flame retardant is to add a flame retardant to phenolic resin. The flame retardant contains Sb as a flame retardant element,
Compounds containing As, B, N, halogen, P, etc. are often used. Sometimes important elements include phosphorus, which is effective in blocking oxygen, carbonizing organic matter, and forming a carbonized film, and halogen, which is effective in trapping highly reactive radicals. Furthermore, since these compounds exhibit a synergistic effect with each other, compounds containing phosphorus and halogen in the molecule are desired.

Halogen-containing phosphorus flame retardants include tris(β-chloroethyl)phosphate) and tris(-dibromopropyl).
There are halogen-containing phosphate esters such as phosphate, tris-(dichloropropyl) phosphate, tris-(2°3-dibromopropyl) phosphate, and tris-(bromochloropropyl) phosphate. but.

These halogen-containing phosphate esters have halogens bonded to aliphatic hydrocarbons, so when used in laminates or copper-clad laminates, they may cause a decrease in heat resistance such as solder heat resistance and air heat resistance. Cause.

[Problem that the invention seeks to solve]

The present invention aims to provide a flame-retardant paper-phenolic resin laminate with excellent heat resistance.

[Next method to solve the problem]

The present invention is characterized in that a paper base material impregnated with a predetermined amount of phenolic resin varnish containing a reaction product obtained by reacting phosphoric acid esters and halogen-containing aromatic alcohols as a flame retardant is heat-formed. It is something to do.

Considering the transesterification reaction between phosphoric acid esters and halogen-containing aromatic alcohols, the former has 3 reaction points, and the latter has only 1 reaction point, so transesterification is possible up to 3 moles. Yes, and the halogen content can be varied. By using an alcohol in which a halogen is bonded to an aromatic ring, it is possible to prevent a decrease in heat resistance, which is a drawback of the above-mentioned halogen-containing phosphate ester. Furthermore, it is possible to uniformly distribute phosphorus atoms and halogen atoms in a constant ratio in the phenol resin, which is effective in effectively improving flame retardancy.

To explain the present invention in more detail, in the presence of a basic catalyst such as a phosphoric acid ester and a halogen-containing lid group 4i alcohol, transesterification is caused by heating in a bath medium or without a bath medium to generate a flame retardant reaction. get something As the phosphoric acid ester, a compound represented by the general formula (1) is used.

Phosphate esters that can be used in the present invention (1,1 include tricresyl phosphate (TCP), cresyl diphenyl phosphatide) (CDP), toIJ phenyl phosphate (
TPP), enyl octyl phosphate, tributyl phosphate.

xyleldiphenylphosn-A) (XDP).

Tris(-β-chloroethyl)phos 2ate, tris-
(dibromopropyl)phosa h,) lis(-bromochloropropyl)phosphate.

Triethyl phosphate, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, triptoxyethyl phosphate, trilauryl phosphate, triceyl phosphate, tristearyl phosphate, trixylenyl phosphate, etc.

As the halogen-containing aromatic alcohol, general formula (II
) and (III) are used alone or in combination.

For halogen-containing aromatic alcohol m11.11).

2.4.6-tribromophenyl-β-hydroxyethyl ether, 2,4.6-tribromophenyl-β-hydroxypropyl ether, 2゜4-dibromophenyl-β-hydroxyethyl ether, 2.4- Dibromophenyl-β-hydroxyglobyl ether, 2.6-
Dibucumophenyl-β-hydroxyethyl ether.

2.6-Dibromophenyl-β-hydroxypropyl ether, monobromophenyl-β-hydroxyethyl ether, monobromophenyl-β-hydroxypropyl ether, diethylene glycol-mono-2,4-6
- dolibromophenyl ether, cyfropylene glycol-mono-2,4,6-dolibromophenyl ether,
2,4゜6-trichlorophenyl-β-hydroxyethyl ether, λ4,6-)dichlorophenyl-β-hydroxyethyl ether, dichlorophenyl-β-hydroxyethyl ether, monochlorophenyl-β-hydroxyethyl ether, etc. ) for 2.4.6
-Dolipromobenzyl alcohol, 2,4-Schif'romopenzyl alcohol, 2,6-dibromobenzyl alcohol, monobromobenzyl alcohol, 2,4.6-)
Dichlorobenzyl alcohol, 2,4-dichlorobenzyl alcohol, 2,6-dichlorobenzyl alcohol, monochlorobenzyl alcohol, β-2,4,6-
ToIJ Bromophenyl-ethanol, β-dibromophenylethanol, β-monobromophenylethanolnatocal.

The reaction temperature may be at least the temperature at which compounds (1), [...], (1113) are uniformly dissolved, and is approximately 80 to 250°C, preferably 130 to 170°C. Below 80°C, the mineral reaction is slow, so the reaction It takes longer.

On the other hand, if the temperature exceeds 250°C, this is likely due to (1) or [■] because the secondary decomposition reaction also proceeds at the same time.

Catalysts used in the ester matasho reaction of (1) and (If) (fit) above include KxCOs, NazCOs,
Carbonates such as CaCO5, MgQ)s, organic basic compounds such as triethylamine, diethylamine, and benzyldimethylamine, and fluorides such as KF, NaF, and CsF are used.

The catalytic amount is the reaction compound CI), (n) or (IID
(preferably 101 to 2%, 0.01% to the total weight of
If it is less than 2%, the reaction will be slow, and if it exceeds 2%, the properties of the base resin will deteriorate due to the catalyst.

Any solvent may be used as long as it dissolves compound (1), (It) or (III), but it is better to proceed with the reaction as solvent-free as possible. This is because alcohols, which are by-produced from phosphoric esters during or after the reaction, are
This is to make it easier to distill off phenols under reduced pressure.

CI) / (It) or [■] =
1/Q, 3 to 115 (mole ratio) is preferred, and can be changed as appropriate in consideration of the flame retardant method of the paper-phenol laminate and the properties of the laminate.

The phenolic resin for paper-phenol laminates to which a halogen- and phosphorus-containing flame retardant synthesized by the method described above is added can be used as long as it is normally used for paper-phenol laminates. For example, drying oil-modified phenolic resins, drying oils and aromatic hydrocarbons to improve cold punchability.

Examples include formaldehyde resin-modified phenol resin, polybutiene-modified phenol resin, alkylphenol-modified phenol resin, and epoxidized vegetable oil-modified phenol resin.

In addition, flaming agents containing halogens and phosphorus are
It can also be used in combination with inorganic flame retardants such as halogen flame retardants, phosphorus fiber flame retardants, nitrogen flame retardants, and antimony trioxide and boron trioxide.

The flame retardant is preferably added in an amount of 30 to 200 parts by weight based on 100 parts by weight of the raw material phenol for the laminated metal layer phenolic fat. There is no particular restriction on the timing of adding the flame retardant.

For products in which phenols are by-produced from phosphoric acid esters, fJ≦ should be added during the synthesis of the phenol side for laminates, while leaving phenol in the reaction system.

Resol formation eliminates the step of distilling off phenol under reduced pressure, which is advantageous in terms of cost.

A paper base material impregnated with a predetermined amount of phenolic resin varnish containing this reaction product as a flame release agent is heat-formed together with copper foil as necessary to form a paper-phenolic resin laminate.

〔Example〕

Hereinafter, B51 will be explained in detail by showing examples.

Flame retardant stand preparation example 1 21 three-turn flasks K equipped with stirrer, thermometer, condensing tube, 750 g (2 mol) of 2,4.6-) lipcumophenyl-β-hydroxyethyl ether, ) liphenyl phosphene) 652g (2 mol), anhydrous KzCO37,01
g was added, the temperature was raised to 150°C, and the reaction was carried out for 8 hours. The temperature was raised to 170° C. and the pressure was reduced to distill off the by-produced phenol. Next, the product was poured from the flask into a vat, cooled, and crushed to obtain flame retardant (2).

Bromine-containing 1ji39.5i [i% Zarin-containing 35.1f
Synthesis Example 2 of i amount % flame retardant 888 g (3 moles) of dibromophenyl-β-hydroxyethyl ether and 652 g (2 moles) of triphenyl phosphate were added to anhydrous 2CO37,7 in the same flask as above.
g was added thereto and reacted at 170°C for 10 hours. While maintaining the temperature, the by-produced phenol was distilled off under reduced pressure. When the distillation of phenol stopped, the reaction product in the flask was poured into a vat and cooled. The solidified product was pulverized to obtain flame retardant (2). Bromine content: 3aO wt% Phosphorus content: 4.9% by weight Flame retardant synthesis example 6 In a flask similar to synthesis example 1, triethylene glycol mo/-2,4,6-)lipromophenyl ether (AJ
926 (2 mol), cresyl diphenyl phosphate
) CB] 3411 g k 1 mol) CsF 1.2
7 g was added and reacted at 150°C for 8 hours. The reaction mixture was used as flame retardant ■. The reaction rate of (A) was 98%, and the reaction rate of (B) was 100%.

The flame retardant ■ is the reaction mixture used to synthesize the phenolic resin for the laminated board next to the tile. Bromine content f37°9% by weight Phosphorus content 2.4Mk% Phenol resin synthesis example 1 (phenol thin wire ■) Stirrer, cooling 100 tung oil in 51 flasks equipped with a thermometer and a thermometer.
2,000 g of p-cresol and 51 g of PT were placed in a m pot and reacted at 100° C. for 2 hours. Then paraform 8
33g, methanol 250g, ammonia water 120g
was added and reacted at 80°C. The reaction was monitored by the gelation time on a hot plate at 160°C, and when the gelation time reached No. 6, the mixture was dehydrated and concentrated under reduced pressure. By the way, after finishing the reaction, add 250 g of toluene and 250 g of methanol.
g was added to make a varnish. Resin content 7070 Gelation time 2
It was minutes and 45 seconds.

Synthesis example 2 of phenol resin (phenol resin ■) 250 ml of tung oil was added to 24 flasks equipped with a stirrer, cooler, and thermometer.
g, 500 g of nrp-cresol, and 25 g of PTSα were added and reacted at 100° C. for 2 hours. Next, flame retardant synthesis example 3
617g of flame retardant ■ synthesized with
, add 70g of methanol and 30g of ammonia water and bring to 80°C.
I reacted with When the gelation time reached 6 minutes, the mixture was dehydrated and concentrated under reduced pressure. The reaction was terminated when the reaction solution became clear to i1, and 130 g of toluene and 130 g of methanol were added to the reactor. The resin content was 69.5% and the gelation time was 2 minutes and 40 seconds.

A phenolic resin varnish for laminates was prepared using the above-mentioned flame retardant and phenolic resin in the formulation shown in Table 1.

Then, kraft paper impregnated with a water-soluble phenolic resin in advance was impregnated with the varnish shown in Table 1 after the resin content was adjusted to 50%, and dried for two hours to prepare a prepreg.

A predetermined number of sheets of the prepreg were stacked, adhesive copper foil was layered on one side, and pressure was applied at 150° C. and 100 kg/an' for 70 minutes to produce a copper-clad laminate having a thickness of 1.6 mm.

As a comparative example, a varnish was prepared by adding trischloroethyl phosphate to a phenolic resin, and a Gripreg and a copper-clad laminate were prepared in the same manner.

Copper clad laminate t';jJ l5-C-6481,0L-9
The characteristics were measured according to the measurement method described in 4. The results are shown in Table 1.

〔Effect of the invention〕

The paper-phenolic steel Vc laminate obtained in the present invention has improved heat resistance and in-air resistance.

Claims (1)

[Claims] 1. A paper base material impregnated with a predetermined amount of a phenolic resin varnish containing a flame retardant containing a reaction product obtained by reacting a phosphoric acid ester and a halogen-containing aromatic alcohol is heated and formed. A method for producing a flame-retardant paper-phenolic resin laminate, characterized by: 2. The method for producing a flame-retardant paper-phenolic resin laminate according to claim 1, wherein the phosphoric acid ester is a phosphoric acid ester having an aromatic ring.