JPS6410020B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a composition containing a bismaleimide-triazine polymer. The compositions of the invention are particularly suitable as matrix materials for printed circuit boards. More specifically, the present invention relates to solutions containing bismaleimide triazine polymers and solvents that exhibit remarkable stability properties. BACKGROUND OF THE INVENTION Circuit boards are used extensively in the electrical industry in areas such as radios, televisions, appliances, and various electrical devices. A widely used technique for forming circuit boards is woven fiberglass.
The method involves impregnating a sheet with a resin composition and laminating a copper sheet on one or both sides of the resin-impregnated fiberglass sheet. Electrical circuits can then be etched into the copper sheet to form a circuit board, and electrical connections can be brazed to the circuit board when used. Various resins have been proposed in the past for impregnating fiberglass to form circuit boards.
For example, polyimide resins are used for such purposes. When polyimide resins are used, high quality circuit boards are obtained that have good electrical properties, including high resistance to high temperatures, low thermal expansion, and high electrical resistance. However, circuit boards formed from polyimide resin are relatively expensive compared to circuit boards formed from fiberglass sheets impregnated with epoxy resin. Fiberglass sheet circuit boards impregnated with epoxy resin are significantly less expensive than circuit boards formed using polyimide resin; , are not particularly resistant to high temperatures, have lower electrical properties and higher thermal expansion. Additionally, other types of resin systems have also been proposed for this purpose. For example, the combination of certain epoxy resins and certain specific bismaleimide materials is disclosed in U.S. Pat.
It is proposed in the specifications of No. 4294877 and No. 4294743. Additionally, bismaleimide triazine resins have been proposed as bonding or matrix materials that may be used for printed circuit boards. However, such materials do not form stable solutions in various low boiling point solvents. When using them to form printed circuit boards, it is desirable to use low boiling point solvents to aid in rapid application of the resins. One method that has been proposed to prevent such resins from separating from solution is to add a solvent such as dimethyl formamide or N-methyl pyrrolidone.
Regarding these, please refer to the High
HeatResistant PPlyimide Resin BT Resin
(Bismaleimide Triazine) (3rd edition), page 11. The resin composition desirably should exhibit a relatively high glass transition temperature and exhibit high resistance to high temperatures when cured. Therefore, compositions that are suitable as matrix materials for integrated circuit boards have a relatively high glass transition temperature when cured, solubility and stability in low-boiling solvents, and adhesion to fiberglass sheets. It must have a number of diverse properties such as hardness, low thermal expansion, and high electrical resistance. SUMMARY OF THE INVENTION The present invention provides compositions that exhibit remarkable stability properties in low boiling solvents. Furthermore, the compositions according to the invention have very high resistance to high temperatures and have very low thermal expansion properties when cured. Compositions according to the present invention contain from about 70 to about 80% by weight bismaleimide triazine polymer and from about 20 to about 30% by weight brominated epoxy polymer. Their amount depends on the amount of bismaleimide present in the composition.
Based on the total weight of triazine polymer and brominated epoxy polymer. The composition according to the invention also comprises:
It contains from about 10 to about 70% by weight solvent, based on the total weight of bismaleimide triazine polymer, brominated epoxy polymer, and solvent present in the composition. The brominated epoxy polymer contains at least about 45% by weight bromine and is a tetrabrominated diglycidyl ether of phenol. The composition according to the invention is impregnated into a fibrous substrate together with a curing agent to form a product. Examples of the Invention The composition according to the invention comprises a bismaleimide-triazine polymer as the main solid content of the composition. The bismaleimide triazine polymer is a commonly available resin such as BT resin (trade name) manufactured by Mitsubishi Gas Chemical Co., Ltd. Bismaleimide triazine resins are described in the following literature. High Heat Resistant Resin BT Resin
(Bismaleimide Triazine), Mitsubishi Gas Chemical Co., Ltd. High Heat Resistant Resin BT Resin
(Bismaleimide Triazine), (2nd edition) Mitsubishi Gas Chemical Co., Ltd. High Heat Resistant Polyimide Resin BT
Resin (Bismaleimide Triazine) (3rd edition) Mitsubishi Gas Chemical Co., Ltd. Chemical Economy and Engineering Review,
March 1978, Volume 10, No. 3 (No. 115),
Triazine Chemistry and Its Application
Development―Triazine and BT Resins as
High Performance Materials Ayano. Technical Bulletin BT Resin (Bismaleimide)
Triazine ReSin) BT-2420, Mitsubishi Gas Chemical Co., Ltd. Technical Bulletin BT Resin (Bismaleimide)
Triazine Resin) BT-2120A, Mitsubishi Gas Chemical Co., Ltd. The bismaleimide/triazine polymer used in the present invention is an addition polymerization type thermosetting polyimide resin containing triazine and bismaleide. Bismaleimide triazine is a polymer of bisphenol-A-dicyanate and the bisimide of 4,4'-diaminodiphenyl methane and maleic anhydride. The following formula is bismaleimide
A representative model of a triazine polymer is shown. Those preferred resins used in the present invention are solid and available as the BT-2000 series (trade names) manufactured by Mitsubishi Gas Chemical, most preferably BT-2170 and BT-2120A.
(product name). These preferred resins are obtained from mixtures containing at least about 50% by weight bisphenol A-dicyanate. Other important polymeric materials present in the compositions of the present invention are brominated epoxy polymers. The brominated epoxy polymer must have at least 45% by weight bromine, preferably at least about 50% by weight, and must be a tetrabrominated diglycidyl ether of phenol. These phenols are polynuclear divalent phenols and are represented by the following formula. In the above formula, Ar is a divalent aromatic hydrocarbon such as naphthylene and preferably phenylene, and A and A ₁ which are the same or different are preferably alkyl groups having 1 to 4 carbon atoms;
a halogen atom of fluorine, chlorine, bromine and iodine; or preferably an alkoxy group having 1 to 4 carbon atoms, and x and y are hydrogen atoms in an aromatic group (Ar) which may be substituted with a substituent is an integer from zero to a maximum value corresponding to the number of R ¹ is a bond between adjacent carbon atoms, as in dihydroxydiphenyl, or

[Formula] -O-, -S-, -SO-, -SO ₂ - and -S-S-; Alicyclic groups such as alkylene, alkylidene, for example cycloalkylene and cycloalkylidene,
Divalent hydrocarbon radicals such as halogenated or substituted with alkoxy or aryloxy alkylene, alkylidene and cycloaliphatic radicals, and alkalylene; and halogenated or substituted with alkyl, alkoxy or aryloxy. a substituted aromatic group and an aromatic group such as a ring fused to an Ar group; R ¹ is also a divalent group such as polyalkoxy; polysiloxy; or an aromatic ring,
It can be an amino group, an ether linkage, a carbonyl group, or two or more alkylidene groups separated by a sulfur-containing group such as a sulfoxide group. Examples of specific polynuclear divalent phenols include 2,
2-bis(4-hydroxyphenyl)propane, 2,4'-dihydroxydiphenylmethane,
Bis(2-hydroxyphenyl)methane, bis(4-hydroxyphenyl)methane, bis(4
-Hydrooxy-2,6-dimethyl-3-methoxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 1,2-bis(4-hydroxyphenyl)ethane, 1,1 -Bis(4)
-hydroxy-2-chlorophenyl)ethane,
1,1-bis(3-methyl-4-hydroxyphenyl)ethane, 1,3-bis(3-methyl-4
-hydroxyphenyl)propane, 2,2-bis(2-isopropyl-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxynaphthyl)propane, 2,2-bis(4-hydro oxyphenyl)pentane, 3,3-bis(4-
hydroxyphenyl)pentane, 2,2-bis(4-hydroxyphenyl)heptane, bis(4-hydroxyphenyl)phenylmethane,
Bis(4-hydroxyphenyl)cyclohexylmethane, 1,2-bis(4-hydroxyphenyl)-1,2-bis(phenyl)propane, and 2,2-bis(4-hydroxyphenyl) ―
Bis(hydroxyphenyl)alkanes such as 1-phenylpropane; bis(4-hydroxyphenyl)sulfone, 2,4'-dihydroxydiphenyl sulfone, 5'-chloro-2,4'-dihydro di(hydroxyphenyl) sulfones such as oxydiphenyl sulfone and 5'-chloro-4,4'-dihydroxydiphenyl sulfone; and bis(4-hydroxyphenyl) ether, 4,3' -, 4,2'-, 2,2'-, 2,3'-dihydroxydiphenyl ether, 4,4'-dihydroxy-2,6-dimethyldiphenyl ether, bis(4-hydroxy- 3-isobutylphenyl) ether, bis(4-hydroxy-3-isopropylphenyl) ether, bis(4-hydroxy-3-chlorophenyl) ether, bis(4-hydroxy-3-fluorophenyl) ether, bis( 4-hydroxy-3
-bromphenyl) ether, bis(4-hydroxynaphthyl) ether, bis(4-hydroxy-3-chlornaphthyl) ether, bis(2
-hydroxydiphenyl)ether, and 4,
Di(hydroxyphenyl) ethers such as 4'-dihydroxy-2,5-diethoxydiphenyl ether; and the like. A preferred polynuclear divalent phenol is represented by the following formula. In the above formula, A and A ₁ are defined as above, x and y have values of 0 to 4, and R ¹ is a divalent saturated aliphatic hydrocarbon group, especially Alkylene and alkylidene radicals having 1 to 3 carbon atoms, and cycloalkylene radicals having up to 10 carbon atoms. most preferred 2
The valent phenol is bisphenol-A, i.e. 2,
2-bis(p-hydroxyphenyl)propane. A preferred brominated epoxy polymer for use in the present invention has a bromine content of at least about 45% by weight and is Araldite LT-8049 manufactured by Ciba-Geigy.
It is generally available as (trade name) etc. This brominated epoxy polymer has a melting point of about 55°C, an epoxy number (eq/100g) of 0.26, and a weight per epoxide of about 385. Additionally, to achieve all of the necessary properties obtained by the compositions of the present invention, the relative amounts of bismaleimide triazine polymer and brominated epoxy polymer should be about 70 to 80% by weight and about 20 to 20% by weight, respectively. about
Must be 30% by weight. The above relative amounts are based on the total weight of bismaleimide triazine polymer and brominated epoxy polymer present in the composition. When larger amounts of brominated epoxy polymer are used, the cured product tends to have significantly lower glass transition temperatures. This is harmful when used as an impregnating agent to form printed circuit boards. Furthermore, as described later,
If an epoxy polymer containing less than 45% bromine by weight is used, the combination of properties so important in this invention will not be obtained. Furthermore, preferred compositions according to the invention preferably have a temperature of at least about 175°C.
It is substantially free of other polymeric materials, such as non-brominated epoxy polymers, which would disadvantageously lower the glass transition temperature of the cured composition. Furthermore, it has been found that the stability of the bismaleimide triazine resin is particularly significant when the solids content of the composition is about 65% or more by weight of the bismaleimide triazine resin. If a low percentage of bismaleimide triazine resin is used, no solubility properties are obtained. Compositions of the invention also include organic solvents. The solvent is preferably a low boiling point solvent, most preferably a ketone such as acetone or methyl ethyl ketone. In a preferred embodiment of the invention, the solvent contains no or very little solvent other than the ketone. The solvent is present in an amount of about 10 to about 70% by weight, based on the total weight of bismaleimide triazine polymer, brominated epoxy polymer, and solvent present in the composition. While stored prior to use, the composition generally contains from about 10 to about 60% by weight solvent. When the composition is used, the amount of solvent generally ranges from about 20 to about
It is 70% by weight. Most preferably, the relative amount of solvent during storage is about 30% by weight and then diluted to about 45% by weight of solvent just before use. Furthermore, to facilitate curing of the composition, a catalyst is generally added to the composition of the invention immediately before use. The catalyst used is a type of catalyst that initiates an oxidation reaction. Suitable catalysts are, for example, metal salts of carboxylic acids, such as the salts of octylic and naphthenic acids, such as zinc octoate, stannic octoate, zinc naphthenate and cobalt naphthenate; Metal salts of acetylacetone such as feriacetylacetone and copper acetylacetone; butyl titanate; propylaluminum; metal powders such as zinc powder and iron powder; dicumyl peroxide, benzoyl peroxide, cyclohexanone peroxide, t-butyl hydroperoxide, peroxide Decanoyl and diisopropyl peroxydicarbonates; amines such as triethylene diamine, N,N-dimethylbenzylamine, N-methylmorpholine, tri-N-butylamine and N,N, _N1 , _N1 -tetramethylbutanediamine;2 - imidazoles such as methylimidazole, 2-undecylimidazole, 2-phenylimidazole and 2-ethyl-4-methylimidazole; and chlorides such as stannic chloride, ammonium chloride, ferric chloride and ferrous chloride. etc. Additionally, mixtures of curing agents may be used if desired. The catalysts are generally used in amounts of about 0.01 to about 5 parts per 100 parts of resin in the composition. The preferred catalyst used in the present invention is zinc octoate. The compositions of the present invention are preferably used to form printed circuit boards. In forming a circuit board, a fibrous substrate is coated and impregnated with the composition of the present invention. Conventional coating equipment can be used. The coated and impregnated substrate is heated at a temperature of about 100°C to about 200°C.
The substrate is cured for about 10 minutes to form a hard substrate. The compositions of the present invention can be used to coat and/or impregnate fibrous substrates such as fiberglass, polyimide, graphite, and the like. After the rigid substrate is formed, a sheet of copper or other conductive material is deposited at about 3.5 to about 28 Kg/cm ² , about 50
It can be laminated to the substrate using lamination conditions such as from 300° C. to about 30 to about 300 minutes. Circuits can then be etched into the conductive layer using well known techniques for forming circuit boards. Next, to show the present invention in more detail,
Example 1 is shown together with some comparative examples, but the present invention is not limited thereto. Example 1 About 345.6 parts by weight of a bismaleimide-triazine composition, available as BT-2120A, comprising about 280 parts by weight of bismaleimide-triazine resin and about 65.6 parts by weight of methyl ethyl ketone;
Araldite LT—with a bromine content of 50% by weight
About 120 parts by weight of a brominated epoxy resin, available as 8049; additionally about 98.4 parts by weight of methyl ethyl ketone; and about 164 parts by weight of acetone were combined. This composition is stable for at least 9 months at room temperature. Further, the composition comprises a solution of about 8% zinc octylate in petroleum spirits.
Mixed with 0.2% by weight. Then, the above composition is impregnated into the glass fiber and about 14Kg/cm ² and about
Cured at 175℃. The result is good nonflammability and an excellent glass transition temperature of about 200°C. Comparative Example 1 Comprising about 176 parts by weight of bismaleimide triazine resin and about 44 parts by weight of methyl ethyl ketone,
about 220 parts by weight of a bismaleimide triazine composition, available as BT-2120A;
Ciba-Geigy containing 38% bromine by weight.
about 76 parts by weight of a brominated epoxy resin available as Araldite LT-8052;
49 parts by weight of methyl ethyl ketone; about 82 parts by weight of acetone were mixed. The above composition had a sufficient glass transition temperature when cured, but was flammable because it contained a lower amount of bromine. It was also not very stable. Precipitation occurred within about one month. This example shows that even though the relative amounts of brominated epoxy resin and bismaleimide triazine resin are the same, it is still possible to use the specific type of brominated epoxy polymer required in the present invention. It shows that it is extremely important. Comparative Example 2 The relative amounts of bismaleimide triazine resin and brominated epoxy resin were adjusted to have a bromine content of about 15% by weight based on their total solids content as in Example 1, and the like. A composition is formed in the same manner as in Comparative Example 1. Its composition is approximately
199 parts by weight of BT-2120A and about 93 parts by weight
Araldite LT-8052 and also about 52 parts by weight of methyl ethyl ketone and about 82 parts by weight of acetone. The composition of this example does not have a sufficient glass transition temperature when cured. Its glass transition temperature is about 160°C. Comparative Example 3 Comprising about 176 parts by weight of bismaleimide triazine resin and about 44 parts by weight of methyl ethyl ketone,
about 220 parts by weight of a bismaleimide triazine composition, available as BT-2120A; Araldite from Ciba-Geigy, containing about 20% by weight bromine;
About 76 parts by weight of a brominated epoxy resin, available as LT-8047; additionally about 49 parts by weight of methyl ethyl ketone; and about 82 parts by weight of acetone are admixed. This composition contains the same relative amounts of bismaleimide triazine resin and brominated epoxy resin as in Example 1. However, the percentage of bromine based on their total solids is about 6% by weight and the cured resins are not non-flammable as in Example 1. Comparative Example 4 The relative amounts of bismaleimide triazine resin and brominated epoxy resin were adjusted to have a bromine content of about 15% by weight based on their total solids content as in Example 1, and the like. A composition is formed in the same manner as in Comparative Example 3. Its composition is approximately
81% by weight of BT-2120A and about 187 parts by weight
Araldite LT-8047 and also about 71 parts by weight of methyl ethyl ketone and about 82 parts by weight of acetone. The above composition contains about 26% by weight of bismaleimide.
Contains triazine resin. The glass transition temperature of the cured composition is only about 140°C. Therefore, as shown by the Examples and Comparative Examples above, in order to achieve the combination of properties obtained by the compositions of the present invention, it is necessary to use certain relative amounts of materials and certain types of brominated epoxides. is necessary. The present invention achieves compositions with nonflammable properties, storage stability, and high glass transition temperatures when cured. It is not possible to obtain a combination of all these properties when working outside the scope of the compositions of the invention.

Claims (1)

[Scope of Claims] 1. A bismaleimide-triazine polymer, and a brominated epoxy polymer containing at least 45% by weight of bromine, which is a tetrabrominated diglycidyl ether of phenol, and comprising: a bismaleimide-triazine polymer; The relative amounts of the polymer and the brominated epoxy polymer are 70 to 80% by weight of the bismaleimide triazine polymer and 30 to 20% by weight of the brominated epoxy polymer; 10 to 70 of total weight including
A bismaleimide triazine composition comprising % by weight. 2 The bismaleimide/triazine polymer is
Bisphenol-A-dicyanate and 4,4′-
The composition according to claim 1, which is a polymer of diaminodiphenyl methane and maleic anhydride with bisimide. 3. The composition of claim 1, wherein the brominated epoxy polymer is a tetrabrominated diglycidyl ether of bisphenol-A. 4. The composition according to claim 1, wherein the solvent is a ketone.