JPS61220A - Flame-retarding epoxy resin composition - Google Patents

Abstract

PURPOSE:To flame-retarding epoxy resin composition excellent in heat, moisture, impact, and solvent resistance and low in curing shrinkage, prepared by mixing an epoxy resin with a high-purity brominated novolak resin and an epoxy cure accelerator. CONSTITUTION:The titled composition is obtained by mixing an epoxy resin having at least two epoxy groups in the molecule (e.g., bisphenol A-derived epoxy resin) with a high-purity brominated novolak resin of the formula (wherein R is H or methyl, n has an average of 0-15, and x and y are each 0-2) (having a bromine content of 5-60% and a free brominated monomer content of, preferably, 0.3% or below and being added preferably in such an amount that the phenolic hydroxyl groups of the brominated novolak resin are present in an amount of 0.7-1.1 equivalent per equivalent of the epoxy groups of the epoxy resin) and an epoxy cure accelerator comprising a urea derivative, preferably, in an amount of 0.5-5pts.wt. per pt.wt. epoxy resin.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a flame-retardant epoxy resin composition having excellent heat resistance, moisture resistance, solvent resistance, and low curing shrinkage.

B. Prior Art 1 Poxy resin has excellent electrical and mechanical properties, so it can be used to seal elements such as individual semiconductors, coils, insulators, printed wiring boards, or LSIs, and to provide electrical and mechanical properties. Used for manufacturing electronic parts.

Recently, there has been a demand for high reliability and high density in electrical and electronic components, and to meet these demands, heat resistance, impact resistance,
There is a demand for the development of a 1-poxy resin composition that has excellent solvent resistance and is flame retardant.

Problems to be solved by the C0 invention Conventionally, flame-retardant epoxy resins have been divided into additive-type ones in which a flame retardant is added to the resin, reactive-type flame retardants that react with the epoxy resin, and resins themselves. Self-extinguishing resins having flame retardant properties are known.

For example, resin compositions in which epoxy resins are blended with flame retardants (such as tetrabromobisphenol A), phenol-novolak type resins, dicyandiamide, imidazole-based hardening agents, etc. are used as electrical/electronic insulating materials. The cured product obtained from this composition has a low crosslinking density, and has the disadvantage that it cannot be obtained in terms of heat resistance, impact resistance, solvent resistance, etc.

In addition, in systems where dicyandiamide is used as a curing agent for epoxy resins and brominated epoxy resins, it has poor compatibility with resins in laminates, and the curing agent may precipitate during the production of polypregs, resulting in uneven reactions. This has the disadvantage of decreasing heat resistance, solvent resistance, measling resistance, etc.

Means for Solving Problem D9 In order to solve the above-mentioned conventional drawbacks, the present inventors have developed various compounds as curing agents.
As a result of physical property evaluation, high purity brominated novola “′□□
We discovered that when Tsuku-type resin is used as a curing agent for epoxy resin, the curing speed is faster than that of conventional novolac-type resin, and it has excellent performance such as flame resistance, heat resistance, impact resistance, and solvent resistance. This is what led to his invention.

10 actions and effects The present invention will be explained in more detail below.

In the present invention, 1 poxy resin is 2 per molecule.
Any epoxy resin having more than 2 epoxy groups can be used. Such epoxy resins include bisphenol A epoxy resins, brominated bisphenol A epoxy resins, novolac epoxy resins, and epoxidized polyolefin resins, and they can be used alone or in combination.

The high-purity brominated novolak resin in the present invention has the general formula [wherein R represents hydrogen or a methyl group, and n represents an average value of 0 to 15]. It is a resin represented by Cobolin is a homopolymer resin obtained by

Also, novolac type resin (copolymer~, small mobolymer type)
It can also be obtained by dissolving this in a solvent that does not react with bromine and brominating it.

In particular, the high purity brominated novolak type resin of the present invention can be obtained by the method previously proposed by the applicant (Japanese Patent Application No. 1986-67986).
That is, it can be advantageously obtained by dissolving a novolac type resin in a solvent and brominating it in the dark in the presence of a radical inhibitor.

Compared to conventional phenol novolac type resins, the high purity brominated novolac type resin in the C1 invention has a high nucleophilicity to epoxy groups, and therefore has a high curing speed.

In addition, in the high purity brominated novolac type resin of the present invention, alkylphenols are used as the component (a), and by co-condensing them, the resin has excellent fluidity and is flame retardant with excellent moisture resistance and impact resistance. It has the characteristics of providing a synthetic resin composition.

Furthermore, it is possible to adjust the degree of co-condensation of novolak depending on the desired physical properties.

Also, regarding flame resistance, the degree of bromination can be adjusted and used.

The bromine content of the high-purity brominated novolac type resin in the present invention is 5 to 60%, and the free bromination content is 0.
, 3% or less, is a high purity brominated novolak type resin.

A high content of free monones is undesirable because it lowers the crosslinking density and reduces heat resistance and solvent resistance.In addition, in the case of a molding phase composition, it is undesirable because it causes contamination of the mold, etc. .

Polymerization degree of high purity brominated novolac type resin [1 is 0 to 15
If it exceeds 15 in the range, the compatibility with the resin decreases, the flowability of the resin decreases, and the moldability deteriorates. In addition, the strength of the obtained cured product decreases, which is not preferable. When n is less than or equal to O (binary), heat resistance decreases. Among the above, those with a degree of C polymerization of 1 to 8 and a softening point of about 40 to 130°C are preferred 1
゜Next, the amount of high purity brominated novolak type resin added to the epoxy resin is such that the phenolic hydroxyl group of the high purity brominated novolac type resin is 0.7 to 1.1 to the epoxy group of the epoxy resin. A range of equivalents is desirable. When the amount exceeds 1.1 equivalents, the brominated novolac type resin remains unreacted, and when the amount is less than -0.7 equivalents, the epoxy resin remains unreacted, resulting in a decrease in heat resistance. Among the above ranges, particularly preferably 0.8 to 1.0 equivalents.

Generally, curing agents for epoxy resins include dicyandiamide, diaminosif-[nylsulfone, diaminosif-1
Aromatic curing agents such as nilmethane, acid anhydride curing agents, etc. are used.

As curing accelerators, tertiary amines such as benzyldimethylamine and trimethylamine, and imidazoles such as 2-methylimidazole and )l-nylimidazole are generally used. There are drawbacks such as reduced heat resistance and water resistance.

The inventors of the present invention have investigated various epoxy curing accelerators in order to overcome the above-mentioned drawbacks of conventional epoxy curing accelerators, and have developed a curing accelerator that has excellent heat resistance and moisture resistance and is compatible with high-purity brominated novolac resins. reached. As the curing accelerator, 3-phenyl-1,1-dimethylurea, 3-(4bromphenyl)-i,i-dimethylurea, 1,1'
Examples include urea derivatives such as -phenylenebis(3,3-dimethylurea). The amount of the curing accelerator added to the epoxy resin composition is desirably in the range of 0.05 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on the epoxy resin.

If it is less than 0.05 parts by weight, the curing accelerating effect will be low, and if it is more than 10 parts by weight, curing will proceed rapidly and shrinkage will increase.

In addition, various additives such as curing accelerators, diluents, fillers, pigment flame retardants, etc. may be added to this as necessary. An example of an experiment conducted for this purpose will be explained.

[Examples 1 to 5] EOCN, which is a cresol novolak type 1-4 resin
-4023 (Nippon Kayaku Co., Ltd., epoxy equivalent 210.
~230), highly brominated epoxy resin EBOTO hYDB
-400 (Kyoto Kasei Co., Ltd.), a high-purity brominated cresol/phenol novolac type co-condensation resin and a curing accelerator were blended according to the formulation in Table 1, and methyl ethyl ket [.
was added to prepare an epoxy resin varnish. This varnish is impregnated and coated on a base material made of 0.18 mm thick glass cloth (Nitto Boseki E P F 18A) treated with Konipogishiran, and dried at a temperature of 160°C to reduce the resin content to 40%.
A prepreg was created. Eight sheets of this prepreg were laminated, and copper foil with a thickness of 35μ was placed on both sides of the prepreg, and the temperature was set at 160°C for 60 minutes.
Hot pressure molded for 60 minutes using OSG/CTI, and the plate thickness is 'I'.
, a 6 mm copper-clad laminate was produced. .

The heat resistance of the copper-clad laminate of the example obtained in this way,
When the retardancy, flame resistance, measling property, moldability, hardness, and water absorption were examined, the results shown in Table 1 were obtained.

[Comparative Example 1] As shown in Table 1, the high-purity brominated cresol/phenol novolak type cocondensation resin of Examples 1 to 5 was changed to dicyandiamide, and benzyldimethylamine was blended as a curing accelerator. The same conditions as in Examples 1 to 5 were used to produce double-sided copper foil laminates. Examples 1-5
Table 1 shows the results of a performance test conducted in the same manner as above.

[Examples 6 to 7] The composition described in (g) was sufficiently kneaded at a temperature of 90 to 110°C, then cooled and pulverized to obtain a molding material.

E'CON 1
00 parts (manufactured by Nippon Kayaku Co., Ltd., Ebogishi equivalent weight 210-230)
High purity brominated cresol/phenol novolac type resin 3 = F1-1,1-dimethylurea 4
Part: Fuse Rex RD-8 (manufactured by Rei Tatsumori) 350 parts Carnauba wax 2 parts Carbon black 1 part Milano Copper 0.5 part Curing conditions were 100°C for 2 hours plus 170°C for 6 hours. Create a.

Bending strength of cured product, glass transition temperature, shear-1D strength,
The curing shrinkage properties are shown in Table 2.

[Comparative Example 2] As shown in Table 2, the high purity brominated cresol/phenol novolac type resin blended in Examples 6 to 7 was changed to a phenol/novolak resin random type with a softening point of 85°C, and flame retardant 1 poxy resin BREN was obtained. (manufactured by Nippon Kayakusha Co., Ltd., epoxy weight M 280-300) was added to prepare a molding material,
Cured products were produced in the same manner as in Examples 6 and 7, and their physical properties were evaluated.

Procedural Amendment (Import) July 121, 1982 1. Indication of the case 1988 Patent side No. 120159 2. Name of the invention Flame retardant epoxy resin composition 3. Person making the amendment Relationship to the case Patent applicant Address: 1-4-5 Marunouchi, Chiyoda-ku, Tokyo
(234) Sanyo Kokusaku Valve Co., Ltd. 101
3rd floor, 5th floor of the British Building, Contents of the amendment 1, the 7th character ``in relation to laminates'' on page 8, line 9 of the specification was omitted by l'Jll.

2. Mei 18, page 6, lines 3-4 It says "Novolac's" "Novolak type - resinous" and 8] Correct.

3. In line 10 of the same page, add 1,'' between ``1-7 nomer'' and ``0.3% or less''.

4. On page 8 of the specification, lines 1 to 2 "Pigment flame retardant J" "Pigments, flame retardants" and a seal.

5. Statement box page 11, line 4 It says [Milan Cutting Agent] "Silanka-1 ring agent" and 6T [.

6. On the same page, lines 7-8 It says "Shear-1D strength" Corrected to "Shore D Koumaro."

7. On page 13 of the specification, in the bottom left column of Table 2, the phrase ``Shear U Sandness'' has been corrected to ``1 Shore 1 Hardness''.

Claims (1)

[Claims] Epoxy resin has the following general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (In the formula, R represents hydrogen or a methyl group, n represents an average value of 0 to 15, x and y are each represents an integer of 0 to 2.] A flame-retardant epoxy resin composition characterized by adding a high-purity brominated novolac type resin represented by these and an epoxy curing accelerator.