JP2001200157A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin composition having a low dielectric constant. SOLUTION: This thermosetting resin composition is prepared by compounding (1) 100 pts.wt. of a polyfunctional cyanic ester compound or its prepolymer with both of (2) 0.1-1,000 pts.wt. of a polyimide having an imide ring closure rate of 95-100 mol% and (3) 0.005-5 pts.wt. of a heat curing catalyst as essential components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The thermosetting resin composition of the present invention comprises:
It has a low dielectric constant and excellent heat resistance, electrical insulation and chemical resistance, and is used for printed wiring board substrates (laminates and metal-clad laminates) and metal foil with resin.

[0002]

2. Description of the Related Art Examples of resin compositions containing polyimide are disclosed in JP-A-55-66927 and JP-A-56-9082.
No. 4 public information.

However, the above resin composition has a high dielectric constant and cannot be used for low dielectric constant applications.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a low dielectric constant thermosetting resin composition having excellent heat resistance, moisture absorption and electric insulation after pressure cooker treatment, and excellent chemical resistance. This is to greatly reduce the dielectric constant, which has been a problem with conventional thermosetting resin compositions, while maintaining the properties, electrical properties, chemical resistance, and operability.

The present invention has been intensively studied to solve the above-mentioned problems, and as a result, it has been found that a polyfunctional cyanate ester compound has an imide ring closure ratio of 95 mol% or more and 100 mol or more.
By using a resin composition containing polyimide and a thermosetting catalyst of less than 1% as an essential component, it has a low dielectric constant, heat resistance, moisture absorption and electric insulation after pressure cooker treatment, chemical resistance, operation. It has been found that a thermosetting resin composition having excellent properties and the like can be obtained, and the present invention has been completed.

That is, the present invention relates to (1) a polyfunctional cyanate ester compound or 100 parts by weight of the cyanate ester prepolymer, and (2) an imide ring closure rate of 95 mol.
1% or more and 100 mol% or less of polyimide 0.1 to
1000 parts by weight, and (3) thermosetting catalyst 0.005 to 5
It is a thermosetting resin composition in which parts by weight are added as an essential component.

Hereinafter, the configuration of the present invention will be described. First, the (1) polyfunctional cyanate compound of the present invention is an aromatic organic compound having usually 2 to 5 cyanato groups in a molecule, and the cyanato group is an aromatic organic compound. It is directly bonded to the aromatic ring of an organic compound. Specific examples include 1,3- or 1,4-dicyanatobenzene, 1,3,5-
Tricyanatobenzene, 1,3-, 1,4-, 1,6-, 1,8-, 2,6-
Or 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, bis (4-dicyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane , Bis (4-cyanatophenyl) ether,
Reaction of bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) sulfone, tris (4-cyanatophenyl) phosphite, tris (4-cyanatophenyl) phosphate, and novolak with cyanogen halide And the like.

In addition to these, Japanese Patent Publication Nos. 41-4928, 43-18468, 44-4791, and 45-117
12, 46-1112, 47-26853, and JP-A-51-63149. These can be used alone or 2
Used in combination of more than one species. Among these ingredients,
The impurity content of hydrolyzable Cl, Na, and the like is extremely small, and when incorporated as a component of the present invention, the total amount of impurities is reduced, making the semiconductor peripheral material optimal.

Further, a prepolymer having a molecular weight of 200 to 6000 having a triazine ring formed by trimerization of a cyanato group of these polyfunctional cyanate compounds is used. This prepolymer is obtained by polymerizing the above-mentioned polyfunctional cyanate ester monomer with a catalyst such as a mineral acid, a Lewis acid; a base such as sodium alcoholate and tertiary amine; and a salt such as sodium carbonate. This prepolymer contains some monomers and is in the form of a mixture of monomers and polymers,
Such a raw material is suitably used for the purpose of the present invention.

The polyimide (2) used in the present invention has an imide ring ring closure of 95 mol% or more and 100 mol% or less, and is hereinafter simply referred to as “component (2)”. Ingredient (2)
Is an organic compound in which the ratio of the imide group to the total of the imide group and the amic acid group is 95 mol% to 100 mol%, preferably 97 mol% to 100 mol%, more preferably 99 mol% to 100 mol%. The imide ring closure rate was analyzed using infrared spectroscopy.

The polymerization of the component (2) can be carried out by a known polyimide polymerization method such as a diamine method using an acid anhydride and a diamine compound as raw materials, or an isocyanate method using an acid anhydride and a diisocyanate compound as raw materials. However, the isocyanate polymerization method is preferable because the imide ring closure ratio can be easily increased to 95 mol% or more.

The component (2) is produced by reacting a tetracarboxylic dianhydride with a diisocyanate compound. Tetracarboxylic dianhydride is a compound represented by the following general formula.

Embedded image (In the formula, Ar ₁ represents a tetravalent aromatic group or an aliphatic group.)

Specific examples of the aromatic tetracarboxylic dianhydride include the following, but are not limited thereto. Further, two or more compounds can be used in combination.

Embedded image

The diisocyanate compound used for producing the component (2) is a compound represented by the following general formula.

Embedded image O ＝ C ＝ N—R ₂ —N ＝ C ＝ O (wherein R ₂ represents a divalent aromatic group or an aliphatic group)

Specific examples thereof include the following, but are not limited thereto. In addition, two or more compounds can be used as a mixture.

Embedded image

Embedded image

The imide ring closure rate of the component (2) is 95 mol.
% Is not preferable because the dielectric constant of the resin composition increases. Component (2) is added in an amount of 0.1 to 1000 parts by weight, preferably 5 to 500 parts by weight.

The (3) thermosetting catalyst used in the present invention is:
It is mainly used to promote the reaction of the cyanato group of the component (1). Examples of the catalyst include organic acid metal salts such as zinc octylate, tin octylate, zinc naphthenate, and cobalt naphthenate. The amount used is 0.005-5
Parts by weight, preferably 0.01 to 3 parts by weight.

Various additives can be added to the photosensitive thermosetting resin composition containing the above-mentioned components as required as long as the inherent properties of the composition are not impaired.
Examples of these additives include polyfunctional liquid or solid epoxy resins; polyfunctional maleimides; polyimides; polymerizable double bond-containing monomers such as unsaturated polyesters and (meth) acrylates, and prepolymers thereof; polybutadiene. Low molecular weight to high molecular weight rubbers such as epoxidized butadiene, maleated butadiene, butadiene-acrylonitrile copolymer, polychloroprene, butadiene-styrene copolymer, isoprene rubber, fluorine rubber, etc .; polyethylene, polypropylene, polybutene, poly -4-methylpentene, polystyrene, AS resin, ABS
Resins, polyethylene-polypropylene copolymers; high-molecular polymers such as polycarbonate, polyphenylene ether, polysulfone, polyesters, and polyphenylene sulfite; and low-molecular prepolymers or oligomers thereof; polyurethane; and the like are used as appropriate.

Other known inorganic and organic fillers, pigments, paints, thickeners, lubricants, defoamers, dispersants, leveling agents, coupling agents, flame retardants, brighteners, polymerization inhibitors, etc. The various additives described above can be used in an appropriate combination as required. The photosensitive thermosetting resin composition of the present invention can be used in any state such as a liquid non-solvent, a solution dissolved in a solvent, or a solution dispersed in a suspension. As the solvent, a generally known organic solvent can be used.

When the resin composition of the present invention is used as a laminate or a metal-clad laminate, the composition is dissolved in a solvent such as methyl ethyl ketone or dimethylformamide to form a varnish, and a known glass or quartz woven or nonwoven fabric is used. A method of impregnating and drying a substrate such as a synthetic quartz fiber woven fabric, an aramid fiber cloth or a nonwoven fabric by a sol-gel method to form a prepreg, laminating and forming the prepreg, the composition of the present invention at 80 to 200 ° C. Then, a method is used in which the prepreg is heated and melted, placed on a reinforcing substrate, and cooled to form a prepreg. Further, a method of applying and drying a solution of the present composition on a release sheet or film to form a film with a release sheet or film, and applying and drying a surface of a metal foil or the like to form a metal foil with a resin And the like.

The conditions for curing the composition of the present invention by the above method are usually 60 to 250 ° C, preferably 80 to 2 ° C.
At a temperature of 00 ° C., a metal foil with a resin, a sheet or a film under no pressure, and when laminating and molding, 0.1 to 1000 k
g / cm ² , preferably 3 to 500 kg / cm ² . The time varies depending on the amount of the thermosetting catalyst, but is generally 30 seconds to 30 hours, preferably 3 minutes to 1 hour.
0 hours. For drying, a general device such as a heating and pressing molding machine and a hot air drying furnace can be used.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. Examples 1 to 3 and Comparative Examples 1 to 3 The components described below were appropriately blended as shown in Table 1 to prepare a photosensitive resin composition of the present invention and a resin composition for comparison. In addition, “parts” means parts by weight unless otherwise specified.

Component (a): Synthesis of polyfunctional cyanate ester prepolymer Synthesis Example 1 2,2-bis (4-cyanatophenyl) propane 10
0 g was melted at 150 ° C. and reacted for 6 hours with stirring to obtain a solid prepolymer (component a-1). Synthesis Example 2 100 g of 1,4-dicyanatobenzene was melted at 140 ° C. and reacted for 2 hours with stirring to obtain a viscous prepolymer (component a-2).

Component (b): imide ring closure rate is 95 mol
Synthesis of polyimide with l% or more and 100 mol% or less Synthesis Example 1 N-methylpyrrolidone 100 ml
21.8 g of water, 22.2 g of isophorone diisocyanate
g into an eggplant flask connected to a curved tube packed with silica gel
Preparation, heating at 90 ° C for 1 hour, and further at 160 ° C for 3 hours
Stirred. After cooling to room temperature, pour the reaction solution into methanol.
Then, the mixture was stirred and a brown precipitate was obtained. Suction filtration and
After washing with methanol, solid polyimide (component b-
1) 35.2 g was obtained. Imide ring closure using infrared spectroscopy
When the ring ratio was measured, it was 99.9%. Imide closed
FTIR-5300 (manufactured by JASCO Corporation) is used to calculate the ring ratio
Then, the spectrum of the sample prepared by the KBr method (a)
Absorption by C = O stretching vibration of mid ring: 1780cm^{- 1}, And Ami
Absorption by C = O stretching vibration of C-group: 1670cm^-1Use
Was. Create a calibration curve based on the absorbance of the aforementioned spectrum,
The imide ring closure was calculated. Synthesis Example 2 Instead of pyromellitic dianhydride, benzophenone tet
As in Synthesis Example 1, using 32.2 g of lacarboxylic dianhydride.
To obtain 45.6 g of a polyimide (component b-2).
Was. The imide ring closure rate was 99.9%. Comparative Example As a comparison, an existing polyimide (trade name: THERMI)
D 600 Gulf Oil Chemical) (Component b-3)
Was. The imide ring closure was 43.3%.

Component (c): heat curing catalyst Zinc octylate (component c-1) was used. As an additional component other than the above, a cresol novolak type epoxy resin (trade name: ESCN-22) as an epoxy resin
0F, manufactured by Sumitomo Chemical Co., Ltd.) (component d-1), and methyl ethyl ketone (component e-1) and dimethylformamide (e-2) as solvents.

[0026]

[Table 1]

The resulting resin composition was 0.18 mm thick.
Impregnated into a plain weave E glass cloth of 203 g / m ² ,
Baked for 6 minutes at ℃ to make B-stage prepreg,
Four such prepregs were stacked, and an electrolytic copper foil having a thickness of 12 μm was stacked on both sides, and laminated and formed at a temperature of 200 ° C. and a pressure of 30 kg / cm ² for 2 hours to produce a copper-clad laminate of 0.65 mm in thickness.

Further, the properties of the obtained copper-clad laminate were evaluated by the following methods. Dielectric constant and dielectric loss tangent: 1 MHz by the transformer bridge method, 2
The value at 5 ° C. was measured. Copper foil peeling strength: A test piece was cut at 1 cm intervals, a copper foil peeling test was performed, and the strength was measured. Solder heat resistance: After dipping in a solder bath at 260 ° C. for 10 minutes, the presence or absence of abnormality in the coating film was visually observed. Glass transition temperature: measured by DSC.

[0029]

[Table 2]

Effects of the Invention The thermosetting resin composition of the present invention has a low dielectric constant, and is excellent in heat insulation, electrical absorption after moisture absorption and pressure cooker treatment, chemical resistance, operability and the like. It is suitable for use as a substrate for printed wiring boards (laminates and metal-clad laminates), metal foil with resin, and the like.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Hibiki Ikeda 22nd Wadai, Tsukuba, Ibaraki Pref.

Claims (2)

[Claims] (1) An imide ring closure rate of 95 mol% or more and 100 m / (100) parts by weight of (1) a polyfunctional cyanate compound or 100 parts by weight of the cyanate ester prepolymer.
0.1 to 1000 parts by weight of polyimide,
And (3) a thermosetting resin composition obtained by adding 0.005 to 5 parts by weight of a thermosetting catalyst as an essential component. 2. The thermosetting resin composition according to claim 1, which has a low dielectric constant.