JPH04258658A - Flame-retardant thermosetting resin composition - Google Patents

Abstract

PURPOSE:To improve both flame retardance and heat resistance by compounding a specific polybutadiene, a halogenated bismaleimide compd. and, if necessary, a nonhalogenated bismaleimide compd. CONSTITUTION:The title compsn. is prepd. by mixing or reacting 90-10wt.% polybutadiene (deriv.) having double bonds in the side chains and contg. 20wt.% or higher 1,2-polybutadiene as butadiene units with 10-90wt.% halogenated bismaleimide compd. of formula I (wherein Z is a divalent group of formula II; at least one of X1 to X4 is Cl or Br; R1 and R2 are each H, CH3, C2H5, trifluoromethyl, or trichloromethyl; and (n) is 0-3) {e.g. 2,2-bis[3,5-dibromo-4-(4- maleimidophenoxy)phenyl]propane} and, if necessary, a nonhalogenated maleimide compd.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a flame-retardant thermosetting resin composition with excellent electrical properties, and is particularly suitable for substrate resins and heat-resistant adhesives for printed circuit boards for electronic devices that require a low dielectric constant. The present invention relates to a flame-retardant thermosetting resin composition.

0002

[Prior Art] Glass fabric epoxy resin laminates using epoxy resin as a binder have been widely used for printed circuit boards for electronic devices, but as electronic components become smaller and wiring becomes more dense, Printed circuit boards are required to have improved heat resistance. Furthermore, in recent years, in order to improve data processing speed, it has become necessary to lower the dielectric constant of resin for substrates.

[0003] Resins with low dielectric constants include hydrocarbon polymers such as polybutadiene, and 1,2-polybutadiene having double bonds in side chains is known as a thermosetting resin. When such a butadiene resin is required to have high heat resistance as a resin for printed circuit boards, a resin copolymerized with maleimide or the like is used. However, when hydrocarbon polymers such as polybutadiene are applied to resins for printed circuit boards, it is necessary to make them flame retardant, and bromine-containing compounds that react with double bonds such as polybutadiene are usually used. There is.

Examples of methods for imparting flame retardancy to polybutadienes include methods using acrylic acid esters such as tribromophenol, as shown in Japanese Patent Publication No. 53-21433, and Japanese Patent Publication No. 57-43162. Tetrabromobisphenol A as shown in
Method using acrylic ester such as and JP-A-62
A method using an acrylic acid ester of a tetrabromobisphenol A ethylene oxide derivative disclosed in Japanese Patent Publication No. 167309 or JP-A No. 61-243844
As shown in the above publication, there is a method using an acrylic acid ester of a brominated polyhydroxystyrene oligomer.

[0005] In addition, as a method for improving flame retardancy and further improving heat resistance of polybutadiene, Japanese Patent Publication No. 55-1682
As shown in the above-mentioned JP-A-62-167309 and JP-A-1-121356, there is a method of reacting an acrylic acid ester with a maleimide compound in addition to a bromine-containing compound.

[0006]

[Problems to be Solved by the Invention] The conventional method of using a bromine-containing compound of acrylic acid ester has the problem that although this compound is reactive with polybutadienes and can impart flame retardancy, There was a problem that the heat resistance of the composition decreased. The present invention provides a thermosetting resin composition that is excellent in both flame retardancy and heat resistance.

[0007]

[Means for solving the problem] A polybutadiene or a derivative thereof containing 20% by weight or more of 1,2-polybutadiene having a double bond in the side chain as a butadiene unit, and a compound of the general formula [I]

[C3] (In the formula, Z is

It is a divalent group having the structure: [Image Omitted] In the divalent group, at least one of X1 to X4 represents chlorine or bromine, and they may be the same or different from each other. R1 and R2 represent hydrogen, a methyl group, an ethyl group, a trifluoromethyl group, or a trichloromethyl group, and may be the same or different. n is 0~
Indicates an integer of 3. ) A flame-retardant thermosetting resin composition characterized by mixing or reacting a bismaleimide compound containing a halogen atom represented by It is.

The flame-retardant thermosetting resin composition of the present invention, unlike conventional flame-retardant components, can improve the heat resistance of polybutadiene by polymerizing with 1,2-polybutadiene. The bismaleimide compound containing a halogen atom represented by the above general formula [I] and polybutadiene or a derivative thereof can be polymerized by heating without a catalyst or in the presence of a catalyst.

In addition to the halogen atom-containing bismaleimide compound represented by the general formula [I] in the flame-retardant thermosetting resin composition of the present invention, other maleimide compounds may be mixed or reacted to improve heat resistance. can be done. As the bismaleimide compound containing a halogen atom represented by the general formula [I], 2,2-bis[3,5-dibromo-4
-(4-maleimidophenoxy)phenyl]propane,
2,2-bis{3,5-dibromo-4-[β-(4-maleimidophenoxy)ethoxy]phenyl}propane is preferably used.

The required amount of the bismaleimide compound of the present invention as a flame retardant component varies depending on the amount of polybutadiene, which is a combustible component. When the amount of polybutadiene blended is large, it is necessary to increase the blended amount of the bismaleimide compound of the present invention. The amount of the bismaleimide compound of the present invention as a heat-resistant component is preferably in the range of 10 to 90% by weight based on all resin components including itself. 1
If it is less than 0% by weight, sufficient heat resistance cannot be obtained, and if it exceeds 90% by weight, the cured product becomes brittle although it has high heat resistance.

From the viewpoint of heat resistance, the halogen atom-containing bismaleimide compound of the present invention has a lower thermal decomposition temperature than other maleimide compounds. Therefore, when particularly high heat resistance is required, the bismaleimide compound of the present invention is blended so that the amount of halogen atoms added as a flame retardant component satisfies the required amount, and the amount of maleimide compound necessary to improve heat resistance is added. It is desirable to ensure this by blending other maleimide compounds.

The polybutadiene component containing 20% by weight or more of 1,2-polybutadiene having a double bond in the side chain as a butadiene unit in the flame-retardant thermosetting resin composition of the present invention may be a polybutadiene homopolymer or Various polymers having a double bond in the side chain and having a polybutadiene as a basic skeleton can be used, such as epoxidized polybutadiene, maleated polybutadiene, hydroxyl-terminated polybutadiene, terminal carboxy-modified polybutadiene, and acrylic-terminated polybutadiene. These polybutadienes preferably contain 20% by weight or more of 1,2-polybutadiene having double bonds as butadiene units. In the case of polybutadiene containing less than 20% by weight of 1,2-polybutadiene as butadiene units, the reactivity with the bismaleimide compound containing a halogen atom, which is another component of the present invention, decreases, making it difficult to obtain sufficient heat resistance and flame retardancy. can't get it.

In the flame retardant thermosetting resin composition of the present invention, examples of other maleimide compounds used to further improve heat resistance include paraphenylene bismaleimide, 4,4'-diphenylmethane bismaleimide, , 4'-diphenyl ether bismaleimide, 4,
There are bismaleimide compounds such as 4'-diphenylsulfone bismaleimide and xylylene bismaleimide, polyamine compounds, and polymaleimide compounds in which an amino group is converted to maleimide, such as aniline-formaldehyde resin.

[0014] 1,2-polybutadiene or its derivative, the halogen atom-containing bismaleimide compound represented by the general formula [I], and other maleimide compounds are prepared in a composition without a solvent or by dissolving both in a suitable solvent. be able to. In addition, a composition can be obtained by thermally polymerizing without a solvent or by dissolving it in an appropriate solvent, or by adding a small amount of organic peroxide or imidazole and reacting by radical polymerization or anionic polymerization. can.

The flame-retardant thermosetting resin composition thus produced is once dissolved in an organic solvent, and a curing catalyst such as an organic peroxide or imidazole is added thereto to prepare an impregnating varnish, which is applied to glass fibers. A prepreg sheet is obtained by impregnating and drying the prepreg sheet, and several sheets are stacked on top of each other to maintain a predetermined temperature and temperature.
A laminate is produced by lamination molding under pressure.

An organic peroxide or an anionic polymerization initiator is used as a curing catalyst for the flame-retardant thermosetting resin composition of the present invention. Examples of organic peroxides include benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, and t-butyl perbenzoate, and are preferably added in an amount of 0.1 to 10% by weight based on the resin composition. Examples of anionic polymerization initiators include imidazoles such as 2-methylimidazole, 2-ethyl-4methylimidazole, and 2-phenylimidazole, amines such as benzyldimethyldiamine, triethylenediamine, and DBU, dicyandiamide, triphenylphosphine, and organic metals. There are compounds, etc., which are preferably added in an amount of 0.1 to 10% by weight to the resin composition.

[0017]

[Function] The flame-retardant thermosetting resin composition of the present invention comprises polybutadiene or a derivative thereof containing 20% by weight or more of 1,2 polybutadiene having a double bond in the side chain as a butadiene unit, and a bismaleimide compound having a halogen atom. It is a resin composition made by mixing or reacting with and other maleimide compounds as necessary, and since the flame retardant component is a highly heat-resistant bismaleimide compound, it has the flame retardancy of polybutadiene without impairing its heat resistance. It is possible to improve

[0018]

EXAMPLES The flame retardant resin composition of the present invention will be specifically explained in the following examples. Example 1 NISSO-PB, B-1000 (atactic 1, 2
-Polybutadiene, Nippon Soda Co., Ltd. trade name, 1,2
- Contains 85% by weight of polybutadiene as a butadiene unit) into N,N'-dimethylformamide (hereinafter referred to as DMF)
A 40% by weight polybutadiene solution was prepared. Dissolve 2,2-bis[3,5-dibromo-4-(4-maleimidophenoxy)phenyl]propane in DMF and add 4
A 0% by weight bismaleimide solution was prepared. Weight mixing ratio of polybutadiene solution and bismaleimide solution is 40:60.
The mixture was mixed and reacted by heating at 160° C. for 2 hours. Then,
Dicumyl peroxide was added at a concentration of 1.5% by weight to obtain an impregnating varnish.

A glass cloth (0.1 mm thick, manufactured by Nittobo) was impregnated and coated with this varnish, and then dried at 170° C. for 3 minutes to remove the solvent, thereby obtaining a prepreg with a resin content of 55% by weight. 12 sheets of this prepreg were layered with 35 μm electrolytic copper foils on top and bottom, and laminated and molded under conditions of a pressure of 40 kgf/cm 2 , a temperature of 200° C., and a molding time of 2 hours to produce a 1.6 mm thick copper-clad laminate.

Regarding this copper-clad laminate, the dielectric constant, dielectric loss tangent, soldering heat resistance, and copper foil peel strength (JIS-C-6
481) and flame retardancy (UL-94-vertical method) were measured. The results are shown in Table 1. The obtained copper clad laminate has voids,
There was no fading, and it had excellent dielectric constant, dielectric loss tangent, solder heat resistance, copper foil peel strength, and flame retardancy.

Example 2 During the production of bismaleimide solution, 2,2-bis{3,
A copper-clad laminate was prepared in the same manner as in Example 1 except that 5-dibromo-4-[β-(4-maleimidophenoxy)ethoxy]phenyl}propane was used, and its properties were measured. The results are shown in Table 1. The obtained copper-clad laminate had no voids or scratches, and was excellent in dielectric constant, dielectric loss tangent, solder heat resistance, copper foil peel strength, and flame retardancy.

Example 3 During the production of bismaleimide solution, 2,2-bis[3,
Example 1 except that 5-dibromo-4-(4-maleimidophenoxy)phenyl]propane and 4,4'-diphenylmethane bismaleimide were used at a weight mixing ratio of 70:30.
A copper-clad laminate was prepared in the same manner as above, and its properties were measured. The results are shown in Table 1. The obtained copper clad laminate has voids,
There was no fading, and it had excellent dielectric constant, dielectric loss tangent, solder heat resistance, copper foil peel strength, and flame retardancy.

Example 4 During the production of polybutadiene solution, NISSO-PB
C-1000 (terminal carboxy modified atactic 1,
2-Polybutadiene, Nippon Soda Co., Ltd. trade name, 1,
90% by weight of 2-polybutadiene as butadiene units
A copper-clad laminate was produced in the same manner as in Example 1 except that a copper-clad laminate was used, and its properties were measured. The results are shown in Table 1. The obtained copper-clad laminate has no voids or scratches, and has a good dielectric constant and
It had excellent dielectric loss tangent, soldering heat resistance, copper foil peel strength, and flame retardancy.

Example 5 During the production of bismaleimide solution, Polybd R
-15HT (terminal hydroxyl-modified polybutadiene, 1,
A copper-clad laminate was produced in the same manner as in Example 1, except that 20% by weight of 2-polybutadiene units (trade name, manufactured by Idemitsu Petrochemical Co., Ltd.) was used, and its properties were measured. The results are shown in Table 1. The obtained copper-clad laminate had no voids or scratches, and was excellent in dielectric constant, dielectric loss tangent, solder heat resistance, copper foil peel strength, and flame retardancy.

Comparative Example 1 In the production of a bismaleimide solution, 4,4'-diphenylmethane bismaleimide was used, and after reacting with a polybutadiene solution, D-5001, a commercially available flame retardant, was added together with dicumyl peroxide. (TBA methacrylate, Daiichi Kogyo Seiyaku brand name) was added so that the bromine content of the resin composition was 20% by weight to prepare a varnish for impregnation. A copper-clad laminate was produced using this varnish in the same manner as in Example 1, and its properties were measured. The results are shown in Table 1. The obtained copper-clad laminate had no voids or scratches, but had poor solder heat resistance.

Comparative Example 2 Similar measurements were carried out using a commercially available polyimide copper clad laminate. The results are shown in Table 1.

[0027]

[Table 1]

[0028]

[Effects of the Invention] According to the present invention, by using a bismaleimide compound having a halogen atom, it is possible to impart flame retardancy to polybutadienes and improve heat resistance, which is of great industrial value. .

Claims (3)

[Claims] Claim 1: Polybutadiene or a derivative thereof containing 20% by weight or more of 1,2-polybutadiene having a double bond in the side chain as a butadiene unit, and a compound of the general formula [I] [Chemical formula 1] (wherein Z is [Chemical formula 1]) 2] A divalent group having the structure, at least one of X1 to X4 represents chlorine or bromine, and may be the same or different from each other.R1 and R2 are hydrogen, methyl group, ethyl group , represents a trifluoromethyl group or a trichloromethyl group, and may be the same or different from each other. n is 0 to
Indicates an integer of 3. ) A flame-retardant thermosetting resin composition, characterized in that it is formed by mixing or reacting a bismaleimide compound containing a halogen atom represented by the following formula with a maleimide compound not containing a halogen atom, if necessary. Claim 2: The bismaleimide compound represented by the general formula [I] is 2,2-bis[3,5-dibromo-4-(4
The flame-retardant thermosetting resin composition according to claim 1, which is -maleimidophenoxy)phenyl]propane. 3. The bismaleimide compound represented by the general formula [I] is 2,2-bis{3,5-dibromo-4-[β
-(4-maleimidophenoxy)ethoxy]phenyl}
The flame-retardant thermosetting resin composition according to claim 1, which is propane.