JPH11262979A - Manufacture of phenolic resin copper-clad laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a fire retardant phenolic resin copper-clad laminated sheet having low variability of fire retardancy without using an organic halogen fire retardant agent. SOLUTION: A fiber base is treated with a water-soluble phenolic resin or melamine resin, and a prepreg and a copper foil obtained by impregnating and drying a phenolic resin varnish are laminated, and applied heat and pressure. In the manufacturing method of the phenolic resin copper-clad laminated sheet, a phosphorus fire retardant agent or nitrogen fire retardant agent having different heat decomposition temperature is blended without using an organic halogen fire retardant agent with the phenolic resin varnish.

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 a phenolic resin-clad laminate having flame retardancy without using a halogen-based flame retardant.

[0002]

2. Description of the Related Art A phenolic resin-clad laminate is manufactured by laminating a predetermined number of fiber base materials impregnated with a phenolic resin and applying heat and pressure. Kraft paper, linter paper, glass-mixed paper, glass nonwoven fabric, glass cloth, and the like are used as the fiber base material. It is well known that a phenol resin modified with a drying oil is used to improve the punching processability of a phenol resin copper-clad laminate. It is also known to incorporate a phosphorus-based flame retardant, a nitrogen-based flame retardant, an organic halogen-based flame retardant, or an inorganic compound-based flame retardant in order to achieve flame retardancy. Examples of the phosphorus-based flame retardant include aromatic phosphate esters, and examples of the halogen-based flame retardant include a brominated phenol compound and a brominated epoxy compound.
Typical examples of the nitrogen-based flame retardant include triazine compounds, and examples of the inorganic compound-based flame retardant include antimony trioxide and aluminum hydroxide. In recent years, materials used for laminates have been increasingly regulated in terms of environmental pollution and toxicity. Among them, the toxicity and carcinogenicity of organic halogen-based flame retardants such as dioxin have become a problem, and organic halogen-based flame retardants have become problems. There is a strong demand for reducing and eliminating fuel. As a method of flame retarding without using an organic halogen-based flame retardant, a method of using a large amount of an aromatic phosphate ester in a phenol resin has been proposed (see Japanese Patent Publication No. 57-19127).

[0003]

However, when an aromatic phosphate ester is blended with a phenol resin, the flame retardancy varies, and UL94V-0 may not be satisfied. The present invention does not use an organic halogen-based flame retardant,
An object of the present invention is to provide a method for producing a phenol resin copper-clad laminate having good flame retardancy.

[0004]

According to the present invention, a prepreg obtained by treating a fiber base material with a water-soluble phenol resin or a melamine resin, impregnating and drying a phenol resin varnish, and a copper foil are laminated and heated. In the method for producing a phenolic resin-clad laminate to be pressed, a phenolic resin-clad laminate containing a phosphorus-based flame retardant or a nitrogen-based flame retardant having a different thermal decomposition temperature without using an organic halogen-based flame retardant in the phenolic resin varnish. It is a manufacturing method. In addition, the present invention provides a water-soluble phenol resin or melamine resin to be pretreated on a fiber base material in an amount of 10 to 30% by weight, and further impregnated with a phenol resin varnish so that the total resin adhesion amount becomes 40 to 60% by weight. This is a preferred method for producing a phenolic resin-clad laminate. Further, the present invention, the phosphorus-based flame retardant,
Manufacture of a phenolic resin-clad laminate selected from the group of triphenyl phosphate, cresyl diphenyl phosphate, trimethyl phosphate, and triethyl phosphate, wherein the nitrogen-based flame retardant is preferably a butylated melamine or a melamine-modified phenol resin. Is the way. In the present invention, by blending a phosphorus-based flame retardant or a nitrogen-based flame retardant having a different thermal decomposition temperature, a substance having a low thermal decomposition temperature is decomposed during combustion, and then a substance having a high thermal decomposition temperature is decomposed. Even if an organic halogen-based flame retardant is not used, the flame-retarding effect can be exhibited, and the flame retardancy can be exhibited without causing variation in the flame retardancy.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The phenolic resin used in the present invention includes a modified phenolic resin such as a dry oil-modified phenolic resin and the like. Polybutadiene or the like is used. As phenols, phenol,
o-cresol, m-cresol, p-cresol, p
-T-butylphenol, nonylphenol, octylphenol, catechol, resorcinol, hydroquinone, bisphenol-F, bisphenol-A and the like. The reaction between tung oil and the above-mentioned phenols is preferably carried out at 50 ° C to 140 ° C, preferably 80 ° C to 120 ° C in the absence of a solvent in the presence of an acidic catalyst such as paratoluenesulfonic acid. At this time, a xylene-formaldehyde resin or a toluene-formaldehyde resin can be reacted to improve the compatibility. Further, as the water-soluble phenol resin or water-soluble melamine resin used in the present invention, a resin generally used in the field of phenol resin laminates can be used as it is. The water-soluble resin preferably has a resin adhesion amount of 10 to 30% by weight when the fiber base material is impregnated and dried in advance. 1
If the content is less than 0% by weight, the electrical characteristics such as insulation resistance are inferior.
If it exceeds 0% by weight, the punching processability and heat resistance are reduced. Preferably, it is 15 to 20% by weight. Further, a phenol resin varnish containing a flame retardant is impregnated and dried after a water-soluble resin is adhered to the fiber base material. At this time, the amount of the resin adhered is preferably 40 to 60% by weight, including the amount of the water-soluble resin adhered. If it is less than 40% by weight, the punching processability and heat resistance are poor, and if it exceeds 60% by weight, the punching processability is poor. Preferably, it is in the range of 48 to 58% by weight. As the phosphorus-based flame retardant or nitrogen-based flame retardant used in the present invention, two or more kinds having different decomposition temperatures are used. , Triethyl phosphate and the like, and it is preferable to use one or more selected from these. Examples of the nitrogen-based flame retardant include butylated melamine or melamine-modified phenol resin. The nitrogen content of these nitrogen-based flame retardants is preferably 5 to 25% by weight. If it is less than 5% by weight, the flame retardant effect is inferior. If it exceeds 25% by weight, the hardness of the obtained laminate becomes high, and in particular, the punching workability such as cracking and peeling becomes poor.

By using a phosphorus-based flame retardant or a nitrogen-based flame retardant having different thermal decomposition temperatures, a flame retardant having a low thermal decomposition temperature is decomposed first during combustion, and then a flame retardant having a high thermal decomposition temperature is decomposed. , The flame-extinguishing effect during combustion increases,
Develops flame retardancy without any variation in flame retardancy.
It is preferable that the difference between the thermal decomposition temperatures is 5 ° C. or more. If the temperature is lower than 5 ° C., no difference is observed in the quenching effect, and the flame retardancy cannot be eliminated. The upper limit of the difference between the thermal decomposition temperatures is preferably 250 ° C. or less,
If the temperature exceeds 50 ° C., the synergistic effect of the quenching effect due to the difference in thermal decomposition temperature is lacking.

[0007] The copper foil used for the phenolic resin-clad laminate of the present invention has a thickness of 5 to 200 µm, which is commonly used for laminates.
Can be used. Further, as the copper foil, a copper foil with an adhesive is preferable in order to secure the adhesiveness to the phenol resin.
Molding conditions for copper clad laminates are usually 150-180 ° C.
In the range of 130 to 200 ° C. in some cases,
The pressure is usually in the range of 1 to 15 MPa, and in some cases in the range of 0.5 to 20 MPa, which is appropriately selected depending on the capacity of the press machine, the thickness of the target laminate, and the like.

[0008]

EXAMPLES (Examples 1 to 3) (Synthesis of Water-Soluble Phenolic Resin Varnish) To 1 mol of phenol, 1.2 mol of formaldehyde was added as 37 wt% formalin, and then a 30 wt% aqueous solution of trimethylamine was added to 0.1 mol of trimethylamine. The reaction was added at 4 mol and reacted at 70 ° C. for 6 hours. A water-soluble phenolic resin varnish was prepared by adjusting the reaction solution to 12% by weight of resin solids with water and methanol (1: 1 mixture by weight).

(Synthesis of Tung Oil-Modified Phenolic Resin) In a 5 liter four-necked flask equipped with a thermometer, a stirrer, and a cooler, 1000 g of tung oil, 1000 g of meta- and para-cresol 1000 were placed.
g, 1000 g of phenol and 1 g of PTS (paratoluenesulfonic acid) were added, and reacted at 110 ° C. for 2 hours to add phenols to tung oil. Further, 1045 g of paraform, 300 g of methanol and 180 g of aqueous ammonia were added to the product and reacted at 80 ° C. 16 of reactants
When the gelation time on a hot plate at 0 ° C. became 5 minutes, the solution was dehydrated and concentrated under reduced pressure. When the gelation time of the reaction product became 3 minutes, the reaction was terminated, and a tung oil-modified resol resin having a tung oil modification rate of 33% by weight was obtained. Tung oil modified resole resin 1
The flame retardant shown in Table 1 was mixed with 00 parts by weight, and dissolved in a mixed solvent of methanol and toluene (1: 1 by weight) to prepare a varnish.

[0010] The water-soluble phenol resin has an adhesion amount of 1 to kraft paper (0.2 mm thick, basis weight 125 g / m ² ).
It was impregnated and dried to 8% by weight, and further impregnated and dried with a tung oil-modified resol resin varnish so that the resin adhesion amount was 52% by weight together with the water-soluble phenol resin to obtain a prepreg. Eight sheets of this prepreg and copper foil with adhesive (thickness of copper foil: 35 μm) are overlapped, and heated and pressed at 170 ° C. and 8 MPa for 90 minutes to form a 1.6 mm-thick phenol resin single-sided copper-clad laminate. Produced.

Comparative Examples 1 and 2 Tung oil modification rate of Example 1 3
A flame retardant shown in Table 1 was blended with 100 parts by weight of a 3% by weight tung oil-modified resole resin, and dissolved in a mixed solvent of methanol and toluene (1: 1 by weight) to form a varnish. Then, a phenol resin single-sided copper-clad laminate was produced in the same manner as in the example.

Using the phenolic resin single-sided copper-clad laminates obtained in Examples 1 to 3 and the phenolic resin single-sided copper-clad laminates obtained in Comparative Examples 1 and 2, the flame retardancy test and the solder heat resistance were measured. The results are shown in Table 1. The flame retardancy test was performed in accordance with the UL vertical method, and the average burning time and the minimum and maximum burning times were measured. Solder heat resistance is J
The laminate was cut into 25 mm squares in accordance with IS C6481 and the time required for floating peeling and blistering in a 260 ° C. solder bath was measured. Table 1 shows the average time, the minimum time, and the maximum time.

[0013]

[Table 1] Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Phosphorus-based flame retardant A 20 45 30 65 0 Phosphorous-based flame retardant B 45 20 30 0 65 Nitrogen-based flame retardant 0 500 0 0 (flame retardation time) Average (second) 1.5 2.0 0.9 3.5 3.0 Minimum to maximum (second) 0 to 40 to 80 to 40 to 180 to 11 (Solder heat resistance) Average (second) 43 45 40 35 38 Minimum to maximum (seconds) 40-47 41-47 38-45 31-37 33-41 *) The flame retardancy test method was based on the UL vertical method. *) Solder heat resistance conformed to J1SC6481. *) Phosphorus flame retardant A: triphenyl phosphate (thermal decomposition temperature 260 to 290 ° C) Phosphorous flame retardant B: cresyl diphenyl phosphate (thermal decomposition temperature 280 to 310 ° C) Nitrogen flame retardant: melamine-modified phenol resin A nitrogen content of 9% by weight (pyrolysis temperature of 350 to 400 ° C.)

As shown in Table 1, in Comparative Examples 1 and 2 in which one kind of flame retardant having the same thermal decomposition temperature was used as the flame retardant, the range of the maximum value and the minimum value of the combustion time varied widely. Is big. On the other hand, in Examples 1 to 3 of the present invention in which two or more phosphorus-based flame retardants or nitrogen-based flame retardants having different thermal decomposition temperatures are used, the dispersion of the burning time is small and the solder heat resistance is good.

[0015]

According to the present invention, by using a phosphorus-based flame retardant or a nitrogen-based flame retardant having different thermal decomposition temperatures, a phenol resin copper-clad laminate having good flame retardancy can be obtained without using a halogen-based flame retardant. You can get a board.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // H05K 1/03 610 H05K 1/03 610Q

Claims (3)

[Claims] 1. A phenolic resin-clad laminate obtained by treating a fiber base material with a water-soluble phenolic resin or melamine resin, further laminating a prepreg obtained by impregnating and drying a phenolic resin varnish with a copper foil, and applying heat and pressure. In the production method, a phenol resin copper-clad laminate is characterized in that a phosphorus-based flame retardant or a nitrogen-based flame retardant having a different thermal decomposition temperature is added to the phenol resin varnish without using an organic halogen-based flame retardant. Method. 2. A water-soluble phenol resin or melamine resin to be pre-processed to a fiber base material is 10 to 30% by weight,
Further, the phenol resin varnish is coated with a total resin adhesion amount of 40 to 60.
2. The method for producing a phenolic resin-clad laminate according to claim 1, wherein the phenolic resin-clad laminate is impregnated and dried so as to have a weight percent. 3. The phosphorus-based flame retardant is selected from the group consisting of triphenyl phosphate, cresyl diphenyl phosphate, trimethyl phosphate, triethyl phosphate,
The method for producing a phenolic resin-clad laminate according to claim 1 or 2, wherein the nitrogen-based flame retardant is a butylated melamine or a melamine-modified phenolic resin.