JP4581599B2 - Resin composition, prepreg and laminate - Google Patents

Description

  The present invention relates to a resin composition, a prepreg, and a laminate.

Thermosetting resins typified by epoxy resins and the like are widely used for electrical and electronic equipment parts because of their excellent characteristics. These thermosetting resins are often given flame retardancy in order to ensure safety against fire. Conventionally, halogen-containing compounds such as brominated epoxy resins have been generally used as a method for making these thermosetting resins flame retardant (see, for example, Patent Document 1).
However, halogen-containing compounds have a high degree of flame retardancy, but have the following problems. For example, aromatic bromine compounds can not only separate corrosive bromine and hydrogen bromide by pyrolysis, but also form highly toxic polybromodibenzofurans and polybromodibenzooxins when decomposed in the presence of oxygen. There is. Also, it is extremely difficult to dispose of obsolete waste containing bromine. For these reasons, flame retardants that replace bromine-containing flame retardants have been studied.

JP 2000-212249 A

  INDUSTRIAL APPLICABILITY The present invention provides a resin composition that can achieve flame retardancy without using a halogen-containing compound, and that can provide a laminate having sufficient solder heat resistance and adhesion, and the same. A prepreg and a laminate are provided.

Such an object is achieved by the present invention described in the following (1) to (6).
A resin composition used for impregnating a base material to form a sheet-like prepreg, an epoxy resin containing a novolac type epoxy resin, dicyandiamide, and an aromatic amino compound having one amino group in the molecule And the phosphine oxide compound , the content of the aromatic amino compound having one amino group in the molecule is 2 to 12 parts by weight with respect to 100 parts by weight of the epoxy resin, and the content of the dicyandiamide is A resin composition characterized by being 2.0 to 4.5 parts by weight based on 100 parts by weight of an epoxy resin .
-Content of the said novolak-type epoxy resin is a resin composition as described in (1) which is 60 to 90 weight% of the whole epoxy resin.
-The resin composition as described in (1) or (2) whose said novolak-type epoxy resin is a cresol novolak-type epoxy resin.
The resin composition according to any one of (1) to (3), wherein the aromatic amino compound having one amino group in the molecule is anisidine.
-A prepreg comprising a substrate impregnated with the resin composition according to any one of (1) to ( 4 ).
-A laminated board formed by molding one or more prepregs according to ( 5 )

The present invention provides a resin composition comprising an epoxy resin containing a novolac-type epoxy resin, dicyandiamide, an aromatic amino compound having one amino group in the molecule, and a flame retardant, and
It is a prepreg and laminate using this, and can achieve flame retardancy without using a halogen-containing compound and can exhibit sufficient solder heat resistance and adhesion as compared with conventional ones.

The resin composition of the present invention is a resin composition used for forming a sheet-like prepreg by impregnating a substrate, an epoxy resin containing a novolac-type epoxy resin, dicyandiamide, and an amino group in the molecule. It includes an aromatic amino compound having one and a flame retardant.
Moreover, the prepreg of the present invention is characterized in that a base material is impregnated with the above-mentioned resin composition.
Moreover, the laminated board of the present invention is formed by molding one or more of the above-described prepregs.
First, the resin composition of the present invention will be described.

The resin composition of the present invention includes a novolac type epoxy resin. Thereby, flame retardance and solder heat resistance of the resin composition and the like can be improved.
Examples of the novolak type epoxy resin include a cresol novolak type epoxy resin, a phenol novolak type epoxy resin, and a bisphenol A novolak type epoxy resin. Among these, a cresol novolac type epoxy resin is preferable. Thereby, a heat absorption can be reduced with a crosslink density increase, and a water absorption rate can be reduced.

  The content of the novolac type epoxy resin is not particularly limited, but is preferably 60 to 90% by weight, particularly preferably 65 to 75% by weight based on the whole epoxy resin. If the content of the novolac epoxy resin is less than the lower limit, the effect of improving the solder heat resistance may be reduced, and if the content exceeds the upper limit, the effect of reducing the water absorption rate may be reduced.

  In addition, in the resin composition of this invention, although it does not specifically limit as epoxy resins other than the said novolak-type epoxy resin, For example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, etc. can be used.

  The resin composition of the present invention contains dicyandiamide. Thereby, adhesiveness can be improved, maintaining heat resistance.

  When dicyandiamide is used as a curing agent for an epoxy resin, the glass transition point of the cured epoxy resin is increased. Further, since nitrogen atoms are contained in dicyandiamide, the adhesion with a conductor circuit metal foil such as a copper foil is improved.

  However, dicyandiamide has low solubility in epoxy resins, particularly novolac type epoxy resins. For this reason, when dicyandiamide is added in an amount necessary to sufficiently cure the novolak epoxy resin, dicyandiamide precipitates in the resin composition and unreacted dicyandiamide remains in the laminate, resulting in poor heat resistance. There is a problem to do. Further, the amount of dicyandiamide that can be dissolved in the novolac type epoxy resin has a problem that the curing is insufficient and the heat resistance is deteriorated.

In contrast, the resin composition of the present invention is characterized by using an aromatic amino compound having one amino group in the molecule together with dicyandiamide. Thereby, adhesiveness can be provided, without reducing heat resistance.
In the resin composition of the present invention, an aromatic amino compound having one amino group in the molecule is used together with dicyandiamide. Therefore, as dicyandiamide, an epoxy resin containing a novolac type epoxy resin (hereinafter simply referred to as “epoxy resin”) A sufficient amount can be used. Thereby, the heat resistant fall by unreacted dicyandiamide depositing can be prevented.
In addition, since the aromatic amino compound having one amino group in the molecule reacts with the epoxy group of the epoxy resin by the amino group, the unreacted epoxy group does not remain in the resin and has sufficient heat resistance. Can be granted.
Furthermore, since one aromatic amino compound having one amino group in the molecule reacts with only two epoxy groups, the resin composition has a feature that the viscosity of the resin composition is hardly increased during the resin curing process. Thereby, the compounded dicyandiamide can be efficiently reacted with the epoxy resin without substantially reducing the solubility of dicyandiamide in the epoxy resin.
Thus, the resin composition of the present invention has not only the single effect each of the dicyandiamide and the aromatic amino compound having one amino group in the molecule, but also the above synergistic effect by using both in combination. It is what you have. Even when a novolak epoxy resin having low solubility of dicyandiamide is used, high adhesion and heat resistance can be imparted to the laminate.

The content of dicyandiamide is not particularly limited, but is preferably 2.0 to 4.5 parts by weight, particularly preferably 2.5 to 4.0 parts by weight with respect to 100 parts by weight of the epoxy resin.
If the content is less than the lower limit, the adhesion may be reduced, and if the content exceeds the upper limit, dicyandiamide may precipitate and heat resistance may be reduced.

The aromatic amino compound having one amino group in the molecule is not particularly limited, and examples thereof include o-anisidine, m-anisidine, p-anisidine, aniline, 2,4-xylidine, 3,4-xylidine, and cresidine. O-toluidine, m-toluidine, p-toluidine, aminobenzaldehyde, aminobenzonitrile, nitroaniline and the like.
Among these, o-anisidine, m-anisidine, and p-anisidine are preferable from the viewpoint of workability because they have a high boiling point.

Although content of the aromatic amino compound which has one amino group in the said molecule | numerator is not specifically limited, 2-12 weight part is preferable with respect to 100 weight part of epoxy resins, and 5-10 weight part is especially preferable.
When the content is less than the lower limit, the epoxy resin is not sufficiently cured, and the heat resistance of the laminate may be lowered. On the other hand, when the upper limit is exceeded, the aromatic amino compound that cannot participate in the curing reaction increases, and the heat resistance may similarly decrease.

The resin composition of the present invention contains a flame retardant.
As the flame retardant, those having no halogen in the molecule can be suitably used, and the kind thereof is not particularly limited. For example, phosphoric flame retardants such as phosphate ester, melamine phosphate, and phosphine oxide, Examples thereof include inorganic flame retardants such as magnesium and aluminum hydroxide, and nitrogen flame retardants such as melamine and melamine cyanurate.
Among these, phosphorus flame retardants are preferable. Thereby, it can be made flame-retardant without using a halogen compound. As the phosphorus-based flame retardant, a phosphine oxide compound is most preferable particularly from the viewpoint of chemical resistance.

Although content of the said flame retardant is not specifically limited, 5-30 weight% of the whole resin composition is preferable, and 10-20 weight% is especially preferable. If the content is less than the lower limit, the effect of improving flame retardancy may be reduced, and if the content exceeds the upper limit, the adhesion with the metal foil may be reduced.

  The resin composition of the present invention contains, as essential components, an epoxy resin containing the above-described novolak epoxy resin, dicyandiamide, an aromatic amino compound having one amino group in the molecule, and a flame retardant. As long as it does not violate the above purpose, other resins, curing accelerators such as imidazole compounds, coupling agents, and other components may be added.

Next, the prepreg will be described.
The prepreg of the present invention is obtained by impregnating a base material with the above resin composition. Thereby, the prepreg excellent in various characteristics, such as heat resistance, can be obtained.
Examples of the base material used in the prepreg of the present invention include glass fiber base materials such as glass fiber cloth and glass non-woven cloth, inorganic fiber base materials such as fiber cloth and non-fiber cloth containing inorganic compounds other than glass, and aromatic polyamide resins. And organic fiber base materials composed of organic fibers such as polyamide resin, aromatic polyester resin, polyester resin, polyimide resin, and fluororesin. Among these base materials, glass fiber base materials represented by glass woven fabric are preferable in terms of strength and water absorption.

  Examples of the method of impregnating the substrate with the resin composition obtained in the present invention include, for example, a method in which a resin varnish is prepared by dissolving the resin composition in a solvent, and the substrate is immersed in the resin varnish. The method of apply | coating a varnish to a base material, the method of spraying a resin varnish on a base material with a spray apparatus, etc. are mentioned. Among these, the method of immersing the base material in the resin varnish is preferable. Thereby, the impregnation property of the resin composition with respect to a base material can be improved. In addition, when a base material is immersed in a resin varnish, a normal impregnation coating device can be used.

The solvent used in the resin varnish desirably has good solubility in the resin composition, but a poor solvent may be used as long as it does not adversely affect the resin varnish. Examples of the solvent exhibiting good solubility include dimethylformamide and dimethylacetamide.
The solid content in the resin varnish is not particularly limited, but the solid content of the resin composition is preferably 40 to 80% by weight, and particularly preferably 50 to 65% by weight. Thereby, the impregnation property to the base material of a resin varnish can further be improved.
A prepreg can be obtained by impregnating the base material with the resin composition and drying at a predetermined temperature, for example, 80 to 200 ° C.

Next, a laminated board is demonstrated.
The laminate of the present invention is formed by molding at least one prepreg described above. Thereby, the laminated board which has the outstanding heat resistance and favorable flame retardance can be obtained.
In the case of a single prepreg, a metal foil or film is stacked on both upper and lower surfaces or one surface.
Two or more prepregs can be laminated. When two or more prepregs are laminated, a metal foil or film is laminated on the outermost upper and lower surfaces or one surface of the laminated prepreg.
Next, a laminate can be obtained by heating and pressurizing a laminate of a prepreg and a metal foil.
Although the temperature to heat is not specifically limited, 120-220 degreeC is preferable and especially 150-200 degreeC is preferable.
Moreover, the pressure to pressurize is not particularly limited, but is preferably 2 to 5 MPa, and particularly preferably 2.5 to 4 MPa.

  Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this.

Example 1
(1) Preparation of resin varnish Cresol novolac type epoxy resin (epoxy equivalent 210, Dainippon Ink & Chemicals N
-690) 72.6 parts by weight, bisphenol A type epoxy resin (epoxy equivalent 190, Dainippon Ink & Chemicals 850) 27.4 parts by weight, dicyandiamide 3.6 parts by weight, p-anisidine 5.8 parts by weight, Dimethylformamide was added to 13.3 parts by weight of triphenylphosphine oxide and 0.1 part by weight of 2-methylimidazole to prepare a resin varnish having a nonvolatile content concentration of 55% by weight.

(2) Production of prepreg Using the above resin varnish, 100 parts by weight of glass fiber cloth (thickness 0.18 mm, manufactured by Nitto Boseki Co., Ltd.) was impregnated with 80 parts by weight of the resin varnish as a solid content. A prepreg having a resin content of 44.4% by weight was prepared by drying in a drying furnace at 150 ° C. for 5 minutes.

(3) Manufacture of laminated board Six sheets of the above prepreg are stacked, and an electrolytic copper foil with a thickness of 35 μm is stacked on the top and bottom, and the pressure is 4 MPa, the temperature is 200 ° C. for 120 minutes, and the temperature is 220 ° C. for 60 minutes. A double-sided copper clad laminate having a thickness of 1.2 mm was obtained.

(Example 2)
A resin varnish was prepared in the same manner as in Example 1 except that the blending amount of dicyandiamide was 2.9 parts by weight and the blending amount of p-anisidine was 9.4 parts by weight to obtain a prepreg and a laminate.

(Example 3)
A resin varnish was prepared in the same manner as in Example 1 except that o-anisidine was used as an aromatic amino compound having one amino group in the molecule to obtain a prepreg and a laminate.

Example 4
The amount of dicyandiamide used is 70.6 parts by weight of phenol novolac epoxy resin (epoxy equivalent 190, N-770 manufactured by Dainippon Ink & Chemicals, Inc.) and 29.4 parts by weight of bisphenol A epoxy resin as novolak epoxy resin. A resin varnish was prepared in the same manner as in Example 1 except that the amount of p-anisidine was 6.2 parts by weight, and a prepreg and a laminate were obtained.

(Comparative Example 1)
A resin varnish was prepared in the same manner as in Example 1 except that an aromatic amino compound having one amino group in the molecule was not used, only dicyandiamide was used as a curing agent, and the blending amounts shown in Table 1 were used. I got a plate.

(Comparative Example 2)
Resin in the same manner as in Example 1 except that the aromatic amino compound having one amino group in the molecule was not used, but 4,4′-diaminodiphenylmethane having two amino groups was used and the blending amounts shown in Table 1 were used. A varnish was prepared to obtain a prepreg and a laminate.

Notes to the table Raw material (1) Cresol novolac type epoxy resin (epoxy equivalent 210, trade name: Dainippon Ink & Chemicals N-690)
(2) Phenol novolac type epoxy resin (epoxy equivalent 190, trade name: N-770 manufactured by Dainippon Ink & Chemicals, Inc.)
(3) Bisphenol A type epoxy resin (epoxy equivalent 190, trade name: 850 manufactured by Dainippon Ink & Chemicals, Inc.)

2. Evaluation methods

  The following evaluation was performed about the laminated board obtained by each Example and the comparative example. Each evaluation is shown below together with the evaluation method. The obtained results are shown in Table 1.

(1) Flame retardancy Flame retardancy was evaluated according to the UL vertical method.

(2) Solder heat resistance The solder heat resistance was measured in accordance with JIS C 6481. In the measurement, after performing a moisture absorption treatment for 2 hours after boiling, it was immersed in a solder bath at 260 ° C. for 120 seconds and then examined for abnormal appearance.

(3) Water absorption The water absorption was measured according to JIS C 6481.

(4) Peel strength The peel strength was measured in accordance with JIS C 6481.

(5) Glass transition temperature The glass transition temperature was determined from the peak temperature of tan δ by a viscoelastic method.

As is apparent from the table, Examples 1-4 include the present invention containing an epoxy resin containing a novolac-type epoxy resin, dicyandiamide, an aromatic amino compound having one amino group in the molecule, and a flame retardant. A laminate using the above resin composition, which was excellent in flame retardancy, solder heat resistance, and adhesion.
On the other hand, Comparative Example 1 used only dicyandiamide as a curing agent, but the solder heat resistance and adhesion were lowered. In Comparative Example 2, an aromatic amino compound having two amino groups in the molecule was used together with dicyandiamide, but the solder heat resistance was lowered.

The present invention relates to a resin composition comprising an epoxy resin containing a novolac-type epoxy resin, dicyandiamide, an aromatic amino compound having one amino group in the molecule, and a flame retardant, and a prepreg and laminate using the same Compared to conventional ones, the plate can achieve flame retardancy without using a halogen-containing compound, and can exhibit sufficient solder heat resistance and adhesion.
Therefore, the present invention can be suitably used for printed wiring boards that require high flame retardancy, heat resistance, and adhesion.

Claims (6)

A resin composition used for impregnating a base material to form a sheet-like prepreg, an epoxy resin containing a novolac type epoxy resin, dicyandiamide, and an aromatic amino compound having one amino group in the molecule The content of the aromatic amino compound containing a phosphine oxide compound and having one amino group in the molecule is 2 to 12 parts by weight with respect to 100 parts by weight of the epoxy resin, and the content of the dicyandiamide is epoxy. A resin composition, which is 2.0 to 4.5 parts by weight with respect to 100 parts by weight of the resin. 2. The resin composition according to claim 1, wherein the content of the novolac-type epoxy resin is 60 to 90% by weight of the entire epoxy resin. The resin composition according to claim 1 or 2, wherein the novolac type epoxy resin is a cresol novolac type epoxy resin. The resin composition according to any one of claims 1 to 3, wherein the aromatic amino compound having one amino group in the molecule is anisidine. Prepreg claims 1 impregnated with a resin composition according to the substrate in any of 4, characterized by comprising. A laminate obtained by molding one or more prepregs according to claim 5 .