JP3148050B2 - Manufacturing method of flame retardant copper clad laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an inexpensive flame-retardant copper-clad laminate excellent in low-temperature punching workability, solvent resistance and heat resistance.

[0002]

2. Description of the Related Art Heretofore, a flame-retardant paper-phenol resin copper-clad laminate has been punched or contoured by die-cutting. In recent years, in order to reduce the dimensional change of a printed wiring board, there is a tendency to perform punching at room temperature without heating the punching process. Therefore, a flexible phenol resin has been used to improve the punching workability of the laminate. As a method of making the phenolic resin flexible, a method of modifying the phenolic resin by using a phosphoric acid ester such as tung oil or triphenyl phosphate, which is highly reactive and has eryostearic acid as a main component, is generally heavily used. ing. However, since tung oil is a natural product, price fluctuations due to natural disasters such as abnormal weather, floods, earthquakes, etc. and human factors are severe, and in many cases it is difficult to obtain it. In addition, the flexibility by phosphoric acid esters or the like has problems in solvent resistance and electrical characteristics of the laminate, and it has been difficult to realize low-temperature punching workability using only phosphoric acid esters.

[0003] In addition, dry oils and semi-dry oils mainly composed of linoleic acid and linolenic acid, which are easily available and inexpensive alternatives to tung oil, have poor reactivity with phenolic resins. It did not increase, and the degree of curing tended to be insufficient. Therefore, when a flame-retardant copper-clad laminate is added by adding a flame retardant, punching workability and solvent resistance are reduced, and it is difficult to make the flame-retardant. The most effective way to compensate for the lack of reactivity of these drying oils and semi-drying oils is to use a highly reactive bromine-containing epoxy flame retardant.
The pot life of the prepreg was short and it was very difficult to produce it industrially.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a linoleic acid which is easily available as an alternative to phosphoric acid esters and tung oil, which are difficult to achieve the above-mentioned flame retardancy, is inexpensive to supply and stable in price. Using a phenolic resin varnish modified with a drying oil or semi-drying oil containing linolenic acid as a main component, to provide a flame-retardant copper-clad laminate excellent in solvent resistance and low-temperature punching workability. Aim.

[0005]

That is, the present invention relates to a method of impregnating a paper base with a varnish obtained by adding a flame retardant to a modified phenol resin modified with a drying oil or a semi-dry oil containing linoleic acid or linolenic acid as a main component. When a prepreg is formed, a predetermined number of prepregs are stacked, copper foil is stacked on one or both sides of the prepreg, heated and pressed, and when manufacturing a copper-clad laminate, a bromine-containing epoxy compound as a flame retardant and Provided is a method for producing a flame-retardant copper-clad laminate, characterized by adding a reaction product obtained by reacting a compound having an amino group and a hydroxyl group represented by the general formula (1) or (2). Is what you do.

[0006]

Embedded image (Where n represents an integer of 1 to 10).
A reaction product obtained by reacting a bromine-containing epoxy compound and a bromine-containing phenol with a compound having an amino group and a hydroxyl group represented by the above general formula (1) or (2) is added as a flame retardant. The present invention provides a method for producing a flame-retardant copper-clad laminate.

Conventionally, as a phenolic resin flexibilizer,
Tung oil has been widely used. However, as described above, there are problems in price and supply stability, and replacement agents have been studied. Linseed oil, which belongs to the same drying oil as tung oil, is inexpensive and stable, is located closest to tung oil, but is slightly less reactive than tung oil. A problem such as bulging during processing has been pointed out.

According to the present invention, when the linseed oil-modified phenolic resin is made flame-retardant, it has a bromine-containing epoxy compound which reacts with the phenolic resin as a flame retardant to compensate for the poor reactivity of linseed oil, and has a hydroxyl group and an amino group. By blending a reaction product with the compound as an essential component, bulge generation during punching is prevented.

A drying oil or semi-dry oil containing linoleic acid or linolenic acid as a modifier of the modified phenolic resin used in the present invention (hereinafter sometimes referred to as vegetable oil).
Linseed oil, safflower oil, soybean oil, sesame oil,
There are eno oil, thistle oil, rapeseed oil, cottonseed oil and the like, and particularly, linseed oil having a high degree of unsaturation, a low price, and a stable supply amount is preferable.

The phenols which are the raw materials of the modified phenol resin include phenol, ortho-cresol, meta-cresol, para-cresol, xylenol, catechol, resorcin, hydroquinone, octylphenol, tert-butylphenol, nonylphenol,
Bisphenol-A and the like can be mentioned.

Examples of the catalyst for the reaction between vegetable oil and phenols include fluorosulfonic acid, trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid, nonafluorobutanesulfonic acid,
Super strong acids such as perfluoroalkanesulfonic acids such as undecafluoropentanesulfonic acid are preferably used.
Particularly, trifluoromethanesulfonic acid is preferred.

Blend ratio of vegetable oil to phenols (weight ratio)
Is not particularly limited, but vegetable oil: phenols = 2: 8 to 6: 4, particularly 3: 7 to 4: 6, is preferred from the characteristics of the laminate. When the blending ratio of the vegetable oil is more than 6: 4, the curability of the laminated board is reduced, and disadvantages such as a sticky surface appear. If the ratio is less than 2: 8, the reduced punching workability of the laminate cannot be satisfied.

The amount of the catalyst to be added is not particularly limited, either, but is preferably 0.001 to 3 parts by weight, more preferably 0.01 to 0.05 parts by weight, per 100 parts by weight of vegetable oil. If the amount exceeds 3 parts by weight, the electrical properties of the laminate decrease, and if the amount is less than 0.001 part by weight, the reaction becomes slow and the industrial productivity decreases.

The reaction between the vegetable oil and the phenol can be carried out in the absence of a solvent or in a solvent. However, considering the following reaction with formaldehyde, the reaction is preferably carried out without a solvent. The reaction temperature is preferably from 50 to 250 ° C, particularly preferably 100 ° C.
The following is preferred. If the temperature exceeds 250 ° C., the hydrolysis reaction frequently occurs, and the molecular weight is easily reduced, and the properties of the laminate are deteriorated.

Before reacting the vegetable oil with the phenols,
In order to improve the compatibility between the vegetable oil and the phenol resin, a phenol and an aromatic hydrocarbon formaldehyde resin can be reacted in the presence of an acidic catalyst. As the acidic catalyst, paratoluenesulfonic acid, benzenesulfonic acid and the like can be used, but a so-called superacid such as perfluoroalkanesulfonic acid used for the reaction with vegetable oil is preferable. Examples of the aromatic hydrocarbon formaldehyde resin include xylene resins, Nicanol H, Nicanol G, Nicanol L (Mitsubishi Gas Chemical Co., trade name), and Generalite 215.
0, Generalite 2030 (General Petrochemical Co., Ltd., trade name), toluene resin and the like.

After the reaction between the vegetable oil and the phenols is completed, phenol may be added, if necessary, and formaldehyde and a basic catalyst are added, and a usual resolving reaction is carried out to synthesize a resin for a laminate.

A reaction product obtained by reacting the modified phenolic resin thus synthesized as a flame retardant with a bromine-containing epoxy compound and a compound having an amino group and a hydroxyl group represented by the general formula (1) or (2). Is added.

The bromine-containing epoxy compound is not particularly limited as long as it has an epoxy group and a bromine atom in the molecule, but preferably has an aromatic ring substituted with a bromine atom. Specifically, a reaction product of tetrabromobisphenol-A and epichlorohydrin,
That is, ESB-400 (trade name of Sumitomo Chemical Co., Ltd.) which is a glycidyl ether type epoxy resin of tetrabromobisphenol A, YDB-400 (trade name of Toto Kasei Co., Ltd.) and BR-200 which is an epichlorohydrin adduct of polybromophenols. Nippon Kayaku Co., Ltd.), BR-250
(Trade name of Hitachi Chemical), BREN which is an epichlorohydrin adduct of brominated novolak resin (trade name of Nippon Kayaku Co., Ltd.)
And the like.

As the compound having an amino group and a hydroxyl group represented by the general formula (1) or (2), various compounds can be used, and monoethanolamine and diethanolamine are particularly preferably used. The reaction of the bromine-containing epoxy compound with the compound (1) or (2) is, for example, as shown in the following formula. The terminal amino group or hydroxyethyl group of the obtained reaction product reacts with the methylol group, formaldehyde, or vegetable oil of the phenol resin. As a result, the properties are improved, and this has a positive effect on the pot life of prepregs and varnishes.

[0020]

Embedded image(Wherein, Ar ₁Represents an aromatic residue, a represents a bromine atom
Represents an integer of 1 to 5. ) Conversion to a bromine-containing epoxy compound
The reaction ratio of the compounds (1) and (2) is not particularly limited.
80% or more of the epoxy groups of the contained epoxy compound react
Thus, it is preferable to determine the mixing ratio and the reaction conditions.

The use of a reaction product obtained by further adding a bromine-containing phenol to the above reaction system as a flame retardant is preferable in terms of the price of the flame retardant and the increase in bromine content.

Examples of bromine-containing phenols include monobromophenol, dibromophenol, tribromophenol, tetrabromobisphenol-A, and brominated novolak resins.

The reaction proceeds, for example, as follows.

[0024]

Embedded image (However, Ar ₂ and Ar _{3 each} represent an aromatic residue, and b and c each represent an integer of 1 to 5.) These bromine-containing epoxy compounds include other flame retardants such as a phosphorus-based flame retardant and nitrogen. It can also be used in combination with an inorganic flame retardant represented by antimony trioxide or an antimony trioxide.

A varnish obtained by adding the flame retardant thus obtained to a modified phenol resin is impregnated into a paper base, and dried by heating to prepare a prepreg. This is overlaid by a predetermined number,
A copper foil with an adhesive is laminated on one side and heated and pressed at a predetermined pressure and temperature for a predetermined time to produce a flame-retardant copper-clad laminate.

[0026]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

(Synthesis of Flame Retardant A) ESB-400 (trade name of Sumitomo Chemical Co., Ltd.), a reaction product of tetrabromobisphenol-A and epichlorohydrin, was placed in a 1-liter flask equipped with a thermometer, a condenser, and a stirrer. ) 400 g, methyl ethyl ketone (MEK) 200 g and monoethanolamine 15.3 g were charged and reacted for 5 hours. After completion of the reaction, HLC confirmed that unreacted ESB-400 was 15%. This was designated as Flame Retardant A.

(Synthesis of Flame Retardant B) ESB-400 was placed in a 1-liter flask equipped with a thermometer, a condenser, and a stirrer.
(Sumitomo Chemical Co., Ltd.) 400 g, methyl ethyl ketone (MEK) 200 g, monoethanolamine 15.3
g and 13.2 g of diethanolamine, and reacted for 6 hours. After completion of the reaction, unreacted ESB-40 was detected by HLC.
0 was confirmed to be 8%. This was designated as Flame Retardant B.

(Synthesis of Flame Retardant C) ESB-400 was placed in a 1-liter flask equipped with a thermometer, a cooling pipe, and a stirrer.
400 g of Sumitomo Chemical Co., 200 g of methyl ethyl ketone (MEK), 105.2 g of diethanolamine
And reacted for 5 hours. After the reaction, it was confirmed by HLC that unreacted ESB-400 was 2%. This was designated as Flame Retardant C.

[Synthesis of Linseed Oil-Modified Phenolic Resin] In a 2 liter four-necked flask equipped with a thermometer and a condenser stirrer, 50 g of xylene resin (trade name: Nicanol-H, trade name of Mitsubishi Gas Chemical Co., Ltd.), 200 g of phenol, 0.3 g of romethanesulfonic acid was added and reacted at 80 ° C. for 1 hour. Add 200 g of linseed oil and add 2
The reaction was continued for hours. After the reaction, 180 g of phenol, 255 g of paraform, 80 g of methanol, and 3 parts of aqueous ammonia
8 g was added and a resolving reaction was carried out at 80 ° C. 160 ° C
When the gelation time in Step 6 became 6 minutes, the mixture was heated under reduced pressure and concentrated by dehydration. When the gelation time became 3 minutes, the reaction was terminated, and 200 g of toluene and 20 g of methanol were used.
0 g was added to obtain a base varnish.

Examples 1 to 3 Base varnish synthesized by the above method and flame retardants A, B, C
Was blended in the proportions shown in Table 1 to prepare a varnish for a laminate. A methylated melamine resin was used as a nitrogen-based flame retardant, and triphenyl phosphate was used as a phosphorus-based flame retardant.

Comparative Example 1 An epoxy-based flame retardant ESB-400 was used as a flame retardant in a linseed oil-modified phenol resin synthesized in the same manner as in Example.
Was adjusted so that the bromine content was the same as in Example 1, to produce a varnish.

First, the varnish was adjusted to a resin content of 48% by weight, kraft paper impregnated with a water-soluble phenol resin was first impregnated with the varnish, and dried to prepare a vegetable oil-modified phenol resin prepreg. A predetermined number of the prepregs are stacked,
Laminate copper foil with adhesive on one side, 100kg / cm ² ,
A copper-clad laminate was produced by heating and pressing at 160 ° C. for 1 hour. The properties of the laminate were measured according to JIS-6481. Table 1 shows the results.

[0034]

[Table 1]

(Synthesis of Flame Retardant D) ESB-400 was placed in a 2-liter flask equipped with a thermometer, a cooling pipe, and a stirrer.
800 g of Sumitomo Chemical Co., 400 g of methyl ethyl ketone (MEK), 331 g of tribromophenol,
Add 1.2 g of 2-ethyl-4-methylmidazole,
The reaction was performed at the reflux temperature for 10 hours. After confirming that unreacted tribromophenol was 1% or less, 61 g of monoethanolamine was charged and reacted for 5 hours. After completion of the reaction, it was confirmed by HLC that unreacted EBS-400 was 5%. This was designated as Flame Retardant D.

(Synthesis of Flame Retardant E) ESB-400 was placed in a 2-liter flask equipped with a thermometer, a cooling pipe, and a stirrer.
800 g of Sumitomo Chemical Co., 400 g of methyl ethyl ketone (MEK), 497 g of tribromophenol,
1.3 g of 2-ethyl-4-methylmidazole was added,
The reaction was performed at the reflux temperature for 10 hours. After confirming that unreacted tribromophenol became 1% or less, 15.3 g of monoethanolamine and 13.
2 g was charged and reacted for 6 hours. After completion of the reaction, HLC
It was confirmed that the unreacted EBS-400 was 2%. This was designated as Flame Retardant E.

(Synthesis of Flame Retardant F) ESB-400 was placed in a 2-liter flask equipped with a thermometer, a cooling pipe, and a stirrer.
800 g of Sumitomo Chemical Co., 400 g of methyl ethyl ketone (MEK), 331 g of tribromophenol,
54.4 g of tetrabromobisphenol-A and 1.2 g of 2-ethyl-4-methylmidazole were added and reacted at a reflux temperature for 10 hours. Unreacted tribromophenol,
After confirming that tetrabromobisphenol-A has become 1% or less, respectively,
5.2 g was charged and reacted for 5 hours. After the reaction,
LC confirmed that unreacted EBS-400 was 2%. This was designated as Flame Retardant F.

[Synthesis of Linseed Oil-Modified Phenolic Resin] In a 2-liter four-necked flask equipped with a thermometer and a condenser agitator, 50 g of xylene resin (trade name: Nicanol-H, manufactured by Mitsubishi Gas Chemical Company, Inc.), 200 g of phenol, 0.3 g of romethanesulfonic acid was added and reacted at 80 ° C. for 1 hour. Add 200 g of linseed oil and add 2
The reaction was continued for hours. After the reaction, 180 g of phenol, 255 g of paraform, 80 g of methanol, and 3 parts of aqueous ammonia
8 g was added and a resolving reaction was carried out at 80 ° C. 160 ° C
When the gelation time in Step 6 became 6 minutes, the mixture was heated under reduced pressure and concentrated by dehydration. When the gelation time became 3 minutes, the reaction was terminated, and 200 g of toluene and 20 g of methanol were used.
0 g was added to obtain a base varnish.

Examples 4 and 5 Base varnish synthesized by the above method and flame retardants D, E and F
With the composition shown in Table 2 was prepared. A methylated melamine resin was used as a nitrogen-based flame retardant, and triphenyl phosphate was used as a phosphorus-based flame retardant.

Comparative Example 1 An epoxy-based flame retardant ESB-400 was used as a flame retardant in a linseed oil-modified phenol resin synthesized in the same manner as in Example.
Was adjusted so that the bromine content was the same as in Example 4, to produce a varnish.

As described above, a copper-clad laminate was manufactured in the same manner as in Example 1 using the above varnish. Table 2 shows the results.

[0042]

[Table 2]

[0043]

As is clear from Tables 1 and 2, the pot life of prepregs and varnishes, which were disadvantages of epoxy flame retardants, can be improved by reacting the epoxy group of the bromine-containing epoxy compound with linseed oil. Inexpensive vegetable oils that could not be used before can now be used as phenolic resin flexibilizers, low-temperature punching workability, solvent resistance,
An inexpensive flame-retardant copper-clad laminate excellent in heat resistance can be obtained, and its industrial value is great.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Takeshi Horiuchi 1500 Oaza Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Industry Co., Ltd. Inside Shimodate Research Laboratory Co., Ltd. (72) Inventor Yoshiyuki Narabe 1500 Ogawa Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Research Laboratory Co., Ltd. (56) References JP-A-1-138241 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 15/08 H05K 1/03 610

Claims (3)

(57) [Claims] A varnish obtained by adding a flame retardant to a modified phenol resin modified with a drying oil or a semi-dry oil containing linoleic acid or linolenic acid as a main component is impregnated into a paper base and dried to form a prepreg. When a prepreg is laminated, a copper foil is laminated on one or both sides thereof and heated and pressed to produce a copper-clad laminate, a bromine-containing epoxy compound as a flame retardant and the following general formula (1) or (2) A method for producing a flame-retardant copper-clad laminate, characterized by adding a reaction product obtained by reacting a compound having an amino group and a hydroxyl group represented by the following formula: Embedded image (However, n shows the integer of 1-10.) 2. A prepreg made by impregnating and drying a varnish obtained by adding a flame retardant to a modified phenol resin modified with a drying oil or a semi-dry oil containing linoleic acid or linolenic acid as a main component, and forming a prepreg. When a prepreg is laminated, a copper foil is laminated on one or both sides thereof, and heated and pressed to produce a copper-clad laminate, a bromine-containing epoxy compound and a bromine-containing phenol as flame retardants and the following general formula (1) A method for producing a flame-retardant copper-clad laminate, comprising adding a reaction product obtained by reacting a compound having an amino group and a hydroxyl group represented by (2) or (2). Embedded image (However, n shows the integer of 1-10.) 3. The method for producing a flame-retardant copper-clad laminate according to claim 1, wherein the bromine-containing epoxy compound is a glycidyl ether type epoxy resin of tetrabromobisphenol-A.