JPS6341526A - Flame-retardant epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition suitable for sealing semiconductor devices, having excellent heat resistance and mechanical properties, by blending an epoxy resin with a curing agent and halognated phenol polycondensate. CONSTITUTION:The aimed composition is obtained by blending (A) an epoxy resin (e.g. resin containing >=2 epoxy groups in one molecule, preferably cresol novolak type epoxy resin etc., containing an epoxy resin having <=300 epoxy equivalents in an amount of >=50wt% in the total epoxy resin) with (B) a curing agent (preferably phenol novolak or cresol novolak) and (C) a halogenated phenol polycondensate (preferably tribromophenol polycondensate). The chemical equivalent ratio of the components (B) to (A) is preferably 0.8-1.2 and the amount of the component (C) is preferably 7-40pts.wt. based on 100pts.wt. component (A).

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a flame-retardant epoxy resin composition with excellent heat resistance and mechanical properties.

<Conventional technology> Epoxy resins have excellent heat resistance, moisture resistance, electrical properties, adhesive properties, etc., and can be given various properties depending on the formulation, so they are used as industrial materials such as paints, adhesives, and electrical insulation materials. has been done.

For example, as methods for encapsulating electronic circuit components such as semiconductor devices, hermetic seals using metals and ceramics, and resin encapsulation using phenolic resins, epoxy resins, etc., have been proposed. Resin sealing using epoxy resin has become the main method in terms of balance.

These industrial materials are strongly required to have flame retardancy as well as general chemical and physical properties.

Methods for making epoxy resin flame retardant: (i) Method using halogenated epoxy resin (ii)
Method using a halogen-containing curing agent (iii) A method using an additive flame retardant such as a phosphorus compound or a halogen compound is known (CMC Technical Report No.
35 High functionality and application development of epoxy resins P, 187, (
1983).

Methods (i) and (11) are methods of directly incorporating halogen atoms into the network structure of the epoxy resin using a reactive flame retardant. According to this method, by using a flame retardant with an appropriate structure, it is possible to make the epoxy resin flame retardant without significantly reducing its physical properties. It has become mainstream.

The method (ii) is characterized in that flame retardation can be easily achieved and flame retardants can be combined relatively easily.

<Problems to be Solved by the Invention> Although the conventional flame retardant technology for epoxy resins has the above-mentioned characteristics, the heat resistance and mechanical properties are insufficient.

For example, if the flame retardant is not exposed to a high-temperature atmosphere for a long time, such as in an automobile engine compartment, it will thermally decompose and generate gas, causing molded products to swell and crack. In addition, it was pointed out that repeated rapid temperature changes would cause molded products to crack, so it was necessary to reduce stress and improve breaking strength and elongation.

The present invention was made to solve the above-mentioned problems and to provide a flame-retardant epoxy resin composition with excellent heat resistance and mechanical properties.

Means for Solving the Problems> As a result, the above object of the present invention is to provide a flame retardant material which is obtained by blending an epoxy resin (A) with a curing agent (B) and a halogenated phenol polycondensate (C). It has been found that this can be achieved by using an epoxy resin composition.

The configuration of the present invention will be described in detail below.

The epoxy resin (A) in the present invention is not particularly limited as long as it has two epoxy groups in one molecule.

Examples include Talesol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol A type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, polycyclic epoxy resin, and halogenated epoxy resin.

Depending on the application, two or more types of epoxy resins may be used together, or for semiconductor device encapsulation, epoxy resins with an epoxy equivalent of 500 or less, especially 300 or less, such as Talesol novolac type epoxy resin, are recommended from the viewpoint of heat resistance and moisture resistance. It is preferable that the total epoxy resin contains 50% by weight or more of the epoxy resin.

Further, it is preferable to use a material from which impurities such as Na, CI, and others have been removed as much as possible.

The curing agent (B) in the present invention is an epoxy resin (A
) is not particularly limited as long as it is cured by reacting with the material.

For example, novolac resins such as phenol novolac and cresol novolac, tetrabromo bisphenol A
Examples include bisphenol compounds such as maleic anhydride, phthalic anhydride, acid anhydrides such as pyromellitic anhydride, aromatic amines such as metaphenylene diamine, diaminodiphenylmethane, and diaminodiphenylsulfone. For encapsulating semiconductor devices, phenol novolak and cresol novolak are preferably used from the viewpoint of heat resistance and storage stability. Depending on the application, two or more types of curing agents may be used together.

-4 In the present invention, the blending ratio of epoxy resin (A) and curing agent (B) to (A) is determined from the viewpoint of mechanical properties and moisture resistance.
The chemical equivalent ratio of B) is from 0.5 to 1.5, especially from 0.8 to 1.
It is preferable that it is in the range of 2. Further, in the present invention, a curing catalyst may be used to promote the curing reaction between the epoxy resin (A) and the curing agent (B). The curing catalyst is not particularly limited as long as it promotes the curing reaction. For example, 2-
Methylimidazole, 2,4-dimethylimidazole,
2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole,
imidazoles such as 2-heptadecyl imidazole,
Triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 2-(dimethylaminomethyl)phenol, 2.4.6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4
,, O) Tertiary amines such as undecene-7, zirconium tetramethoxide, zirconium tetrapropoxide, tetrakis(acetylacetonato)zirconium,
Organic metals such as tri(acetylacetonato)aluminum, triphenylphosphine, triethylphosphine, tributylphosphine, trimethylphosphine, 1-
Examples include organic bosphines such as p-methylphenyl phosphine and tri(nonylphenyl) phosphine. Depending on the application, two or more types of curing catalysts may be used together. Addition value of curing catalyst is epoxy resin (A) 100
It is preferably 0.1 to 10 parts by weight.

As the halogenated phenol polycondensate (C) used as a flame retardant in the present invention, for example, the following general formula (1) is used.
Examples include those obtained by polycondensing one or more of the halogenated phenols represented by, for example, in the presence of a caustic alkaline earth metal catalyst (eg, an iron catalyst, a copper catalyst, etc.) in a solvent or without a solvent.

(In the above formula (I), R represents a lower alkyl group or hydrogen, X represents bromine or chlorine, m represents an integer of O to 4,
n represents an integer of 1 to 5. ) Preferred specific examples of the halogenated phenol of the above formula (1) include monobromophenol, dibromophenol,
1-ribromophenol, tetrachlorophenol, pentabromophenol, dibromocresol, monochlorophenol, dichlorophenol, trichlorophenol, tetrachlorophenol, pentabromophenol, etc., and mixtures thereof, with tribromophenol being most preferred.

The degree of polymerization of the halogenated phenol polycondensate (C) is 3 to 1
A range of 00 is preferred, and a range of 5 to 50 is particularly preferred. Further, the halogen content in the halogenated phenol polycondensate (C) is preferably 30% by weight or more, particularly 50% by weight or more. If it is less than 30%, it is necessary to add a large amount of halogenated phenol polycondensate (C) to make it flame retardant.
Formability becomes insufficient.

The halogenated phenol polycondensate (C) may have a terminal hydroxyl group, or the terminal hydroxyl group may be capped with a bifunctional or higher functional metal compound or a monofunctional or higher functional organic compound that can react with the terminal hydroxyl group.

Examples of such metal compounds include aluminum, magnesium, calcium, strontium, barium,
Examples include halides such as antimony and tin, and specific examples include aluminum bromide, magnesium chloride, calcium chloride, strontium chloride, barium chloride, antimony chloride, and stannous chloride.

Examples of organic compounds include alkyl cybarides, acyl halides, acyl cybalides, haloacyl halides, haloacyl cybalides, dihalodate phosphates, cyanuric halides and other organic compounds containing active halogens, and polyepoxy compounds. , more specifically dibromoethylene, dichloroethylene, dichlorodiethyl ether, maleic acid dichloride, -0-benzoic acid chloride, toluic acid chloride, terephthalic acid dichloride, tetrabromophthalic acid dichloride, phenylphosphoric acid dichloride, phenyl phosphonic acid dichloride,
Diglomucresyl phosphate dichloride, chlorphenylphosphonic acid dichloride, cyanuric chloride and the following general formula (
These include compounds represented by II) to (■).

Br4CH2CH20-Ar-0), CH2CH2Br
, , , , , (I engineering) C9,4
CH2CH20CH2CH20-Ar-0+-TCL
, , , , , (III)C9,+C-
0-Ar-O+TCC9,0019, (■) 1-C9° (in the above formulas (n) to (■), an integer from 1 to 50,
R1-R5 each represent hydrogen, chlorine or bromine. Also A
r is a compound represented by the following general formulas (IX> and (X).) (In the above formulas (IX) and (X), R1 to R4 each represent hydrogen, chlorine, or bromine. Alkylene group, alkylidene group, -802-1-SO-1-S-1
-〇-1-C〇- or indicates a chemical bond. ) Among these, benzoic acid chloride, terephthalic acid dichloride, isophthalic acid dichloride, and compounds of the formula (VI>) can be preferably used.

The reaction when blocking the terminal hydroxyl group of a polycondensate of halogenated phenol with the above metal compound or organic compound is to react with the polycondensate of halogenated phenol by adding one or more of the above compounds to the polycondensate of halogenated phenol (a) in the presence of caustic alkali, etc. The following methods include reacting in a solvent or without a solvent, or (b) reacting in a nonpolar solvent using a Lewis-11 acid (for example, BF3).

The amount of the halogenated phenol polycondensate (C) added is preferably 3 to 60 parts by weight, particularly 7 to 10 parts by weight, per 100 parts by weight of the epoxy resin (A).

If the width is less than 3, the flame retardance will be insufficient, and if it exceeds 60 width, the moldability will deteriorate significantly, which is not preferable.

Further, two or more of these halogenated phenol polycondensates (C) may be used in combination.

The flame retardant effect of the halogenated phenol polycondensate (C) is significantly enhanced by the combined addition of antimony trioxide. The amount added is preferably 1 to 30 parts by weight, particularly 2 to 30 parts by weight, based on the epoxy resin (A). If it is less than 1 part by weight, the flame retardant improvement effect by the combined addition of antimony trioxide will not be sufficient, and if it exceeds 30 parts by weight, the mechanical properties will deteriorate significantly. More preferably, it is added in a ratio of 1 antimony atom in antimony trioxide to 0.2 to 5 halogen atoms in the added halogenated phenol polycondensate (C). At the same time, flame retardant adjuvants such as boron oxide, zirconium oxide, iron oxide, etc. may be used in combination.

The flame retardant epoxy resin composition of the present invention includes fillers such as fused silica, crystalline silica, quartz glass, calcium carbonate, magnesium carbonate, alumina, clay,
Tartar, calcium silicate, titanium oxide, asbestos,
Glass fiber, carbon fiber, Kevlar, etc. can be blended. In addition, we also use colorants such as carbon black and iron oxide, silicone rubber, silicone oil, modified nitrile rubber, and modified polybutadiene rubber.
Coupling agents such as polymers, silane coupling agents, titanate coupling agents, long chain fatty acids, metal salts of long chain fatty acids, esters of long chain fatty acids, bisamide waxes, paraffin waxes, etc. can be optionally used. Can be added.

The flame-retardant epoxy resin composition of the present invention is preferably melt-kneaded, and the melt-kneading can be carried out by any known method. For example, Banbury mixer, kneader,
The resin composition can be prepared using a roll, -screw or twin-screw extruder, kneader, etc., usually at a temperature of 50 to 150'C.

<Example> Hereinafter, the present invention will be specifically explained with reference to Examples.

The numbers in the examples mean parts by weight.

Examples 1 to 5, Comparative Examples 1 to 3 Using the reagents shown in Table 1, the reagents were triblended using a mixer at the composition ratio of the formulation shown in Table 2, and then
5 using a mixing roll with a roll surface temperature of 90'C.
After heating and kneading for a minute, the mixture was cooled and pulverized to produce an epoxy resin composition.

Using this composition, 1
A combustion test piece (5″ x 1/
2"X1/16"), disk (2"φX1/8"t)
, a bending test piece (5# x 1/2" x 1/4") and an ASTM No.
Time post cured. After post-curing, the physical properties of each composition were measured using the following physical property measuring method.

O physical property measurement method The physical properties measurement methods of Examples and Comparative Examples are as follows.

Flammability: A vertical combustion test was conducted using a combustion test piece according to the Ul 94 standard.

Glass transition temperature: Measured using a portion of a combustion test piece by DSC at a heating rate of 40'C for 7 minutes.

Water absorption rate: 121°C 1100%R using a disk
A prenchure cooker test 1 to 1 was conducted under the conditions of H, and the water absorption rate after 1,000 hours was determined.

Flexural modulus: Measured using a bending test piece according to the ASTM D-790 standard.

To -1 - Breaking strength: Measured using ASTM1@dumbbell according to ASTM D-638 standard.

Heating loss: 10% at 250'C using a combustion test piece
The weight loss rate after heat treatment for 0 hours was measured.

These results are shown in Table 2.

As seen in Examples 1 to 5, the epoxy resin composition of the present invention using a halogenated phenol polycondensate as a flame retardant is endowed with flame retardancy, and has a small loss on heating and excellent heat resistance. It can also be seen that the fracture strength is large and the mechanical properties are excellent.

As seen in Comparative Example 1, flame retardancy is not imparted unless a flame retardant is used.

As seen in Comparative Example 2.3, it can be seen that when a brominated epoxy resin is used as a flame retardant, flame retardancy is imparted, but the loss on heating is large, the breaking strength is low, and the heat resistance and mechanical properties are inferior. .

<Effects of the Invention> According to the present invention, a flame-retardant epoxy resin composition having excellent heat resistance and mechanical properties can be obtained by blending an epoxy resin with a curing agent and a halogenated phenol polycondensate.

Claims (2)

[Claims] (1) A flame-retardant epoxy resin composition prepared by blending an epoxy resin (A) with a curing agent (B) and a halogenated phenol polycondensate (C). (2) A flame-retardant epoxy resin composition according to claim (1), wherein the composition is used for encapsulating a semiconductor device.