JPH0617452B2 - Curable polyphenylene ether-polyepoxide composition and laminates prepared therefrom - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the chemistry of polyphenylene ether-polyepoxide compositions, and more particularly to improving the solvent resistance and solderability of cured composites prepared from such compositions.

A number of polyphenylene ether-polyepoxide compositions are known. Many such compositions generally have high dielectric constants in the form of fiber reinforced prepregs (ie substrates impregnated with uncured or partially cured resin) and, for example, to form printed circuit boards. It is cured to form a material with other properties useful for use as a copper clad laminate suitable for etching. The pending US application No. 92,725 filed Sep. 3, 1987 discloses zinc diketones such as acetylacetone, optionally in the presence of phenolic compounds or basic nitrogen compounds as curing accelerators. Or discloses a group of such compositions that can be cured with aluminum salts.
The product is excellent for use in circuit board laminates. However, the cured product is somewhat deficient in terms of solderability and solvent resistance, particularly the resistance to methylene chloride often used to clean circuit boards.

The present invention provides polyphenylene ether-polyepoxide compositions that are useful in preparing fiber reinforced prepregs. The prepreg may be cured to form a laminate having the properties desired for circuit board applications. Furthermore, it is superior to many previously known laminates in solderability and solvent resistance.

Accordingly, one aspect of the present invention is that (A) a reaction product of at least one polyphenylene ether and at least one unsaturated carboxylic acid or acid anhydride, (B) at least one polyepoxy compound and (C) epoxy. A curable composition comprising a curing catalyst for use.

Polyphenylene ethers useful in the preparation of Reactant A in the curable compositions of the present invention have the formula Consists of many building blocks with. In each of its independent units, each Q ¹ is independently halogen, primary or secondary lower alkyl (ie, alkyl containing up to 7 carbon atoms), phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy. Alternatively, halohydrocarbonoxy in which a halogen atom and an oxygen atom are separated by at least two carbon atoms; each Q ² is independently hydrogen, halogen, primary or secondary lower alkyl, phenyl, haloalkyl,
Hydrocarbonoxy or halohydrocarbonoxy as defined for Q ¹ . Examples of suitable primary lower alkyl groups are methyl, ethyl, n-propyl, n-butyl, isobutyl, n-amyl, isoamyl, 2-methylbutyl, n-hexyl, 2,3-dimethylbutyl, 2-3. -, Or 4-methylpentyl and the corresponding heptyl group. Examples of secondary lower alkyl groups are isopropyl, sec-butyl and 3-pentyl. A straight-chain type is preferable to branched alkyl groups. Most often, each Q ¹ is alkyl or phenyl, especially alkyl having 1 to 4 carbon atoms, and each Q ² is hydrogen. Suitable polyphenylene ethers are disclosed in numerous patents.

Both homopolymer and copolymer type polyphenylene ethers are included. Suitable homopolymers include, for example:
It contains a 2,6-dimethyl-1,4-phenylene ether unit. Suitable copolymers are (for example) 2,
Includes random copolymers containing such units in combination with 3,6-trimethyl-1,4-phenylene ether units. Many suitable random copolymers as well as homopolymers are disclosed in the patent literature.

Also included therein are polyphenylene ethers containing moieties that modify properties such as molecular weight, melt viscosity and / or impact strength. Such polymers are described in the patent literature and include hydroxy-free vinyl monomers such as acrylonitrile and aromatic vinyl compounds (eg styrene) or also hydroxy-free polymers such as polystyrene and elastomers in a known manner. It may be prepared by grafting onto polyphenylene ether. The reaction product is
Typically, it includes both grafted and non-grafted portions. Other suitable polymers are coupled where the coupling agent reacts in a known manner with the hydroxyl groups of the two polyphenylene ether chains to form a high molecular weight polymer containing the reaction product of the hydroxyl groups and the coupling agent. It is polyphenylene ether. Coupling agents are, for example, low molecular weight polycarbonates, quinones, heterocyclic compounds and formal.

For purposes of this invention, polyphenylene ethers are within the range of about 3,000-40,000, preferably at least about 12,000 and most preferably at least about 15, as determined by gel permeation chromatography. Has a number average molecular weight of 000, and is about 20,000-
It has a weight average molecular weight in the range of 80,000. Its intrinsic viscosity is usually about 0.
It is in the range of 35-0.61 d1 / g.

Polyphenylene ethers are typically prepared by oxidative coupling of at least one corresponding aromatic monohydroxy compound. A particularly useful and readily available aromatic monohydroxy compound is 2,6-xylenol (wherein each Q ¹ is methyl and each Q ² is hydrogen) -wherein the polymer is poly (2,6-dimethyl). -1,4-phenylene ether) -and 2,3,6
-Trimethylphenol (in this case each Q ¹ and one Q
² is methyl and the other Q ² is hydrogen).

Various catalyst systems are known for the preparation of polyphenylene ethers by oxidative coupling. There is no particular restriction on the choice of catalyst and any known catalyst can be used. Usually, they contain at least one heavy metal compound such as a copper, manganese or cobalt compound, usually in combination with various other substances.

The first type of catalyst system, which is often preferred, consists of those containing copper compounds. These catalysts are disclosed, for example, in U.S. Pat. Nos. 3,306,874, 3,306,875, 3,914,266 and 4,028,341. They are usually cuprous or cupric ions,
A combination of halide (ie chloride, bromide or iodide) ions and at least one amine.

A catalyst system containing a manganese compound constitutes the second type.
They are usually alkaline systems in which divalent manganese is bound to anions such as halides, alkoxides and phenoxides. Most often manganese is used in dialkylamines, alkanolamines, alkylenediamines, o-hydroxyaromatic aldehydes, o-hydroxyazo compounds, ω-hydroxyoximes (monomeric and polymeric), o-hydroxyaryl oximes and β-diketones. It exists as a complex with one or more of such complexing agents and / or chelating agents. Also useful are the known cobalt-containing catalyst systems. Suitable manganese and cobalt containing catalyst systems for the preparation of polyphenylene ethers are disclosed in numerous patents and publications and are known to those skilled in the art.

Certain commercially available polyphenylene ethers have the formula Comprising a molecule having at least one of the terminal groups represented by, Q ¹ and Q ² are as previously defined, each R ¹
Are independently hydrogen or alkyl provided the total number of carbon atoms in both R ¹ groups is 6 or less, and R
² is independently hydrogen or a primary alkyl group having 1 to 6 carbon atoms. Preferably, each R ¹ is hydrogen and each R ²
Is alkyl, especially methyl or n-butyl.

Polymers containing aminoalkyl-substituted end groups of formula II should incorporate a suitable primary or secondary monoamine as one of the members of the oxidative coupling reaction mixture, especially when copper or manganese containing catalysts are used. May be obtained by Such amines, especially dialkylamines,
Preferably, di-n-butylamine and dimethylamine,
Most often replaces one or more α hydrogen atoms of the Q ¹ group to become chemically bonded to the polyphenylene ether. The main place of reaction is the Q ¹ group adjacent to the hydroxyl group of the terminal unit of the polymer chain. Then, during further processing and / or mixing, the aminoalkyl-substituted end group is probably of the formula Will undergo various reactions involving the quinone methide-type intermediate of.

U.S. Pat. Nos. 4,054,553, 4,092,29
No. 4, No. 4,447, 649, No. 4,477, 651
And No. 4,517,341, the disclosures of which are incorporated herein by reference.

Polymers with 4-hydroxybiphenyl end groups of formula III are typically represented, especially in copper-halide-secondary or tertiary amine systems, by the formula From the reaction mixture in which the by-product diphenoquinone of is present. In this regard, US Pat. No. 4,477,649
No. 4,234,706 is also appropriate.
And No. 4,482,697 are similar, and these descriptions are incorporated herein by reference. In this type of mixture, diphenoquinone is ultimately introduced into the polymer in a much higher proportion, mainly as end groups.

In many polyphenylene ethers obtained under the above conditions, a much higher proportion of the polymer molecules (typically accounting for about 90% of the polymer by weight) have the formula II and
Includes end groups with either III or often both. However, it should be understood that other end groups may be present and the invention is in its broadest sense independent of the molecular structure of the polyphenylene ether end groups. From the foregoing description, it will be apparent to one of ordinary skill in the art that the polyphenylene ethers contemplated for use in the present invention include all those presently known regardless of changes in the building blocks or ancillary chemical features. Will.

For the purposes of the present invention, Reactant A is the reaction product of said polyphenylene ether and at least one unsaturated carboxylic acid or anhydride. Suitable acids and anhydrides include monocarboxylic acids such as acrylic acid and methacrylic acid and dicarboxylic acids such as maleic anhydride, fumaric acid and itaconic acid, and their anhydrides. Maleic anhydride and fumaric acid are preferred, and the latter is particularly preferred because it is readily available and relatively easy to handle.

Reaction conditions for the polyphenylene ether and the unsaturated acid or anhydride generally include temperatures in the range of about 230-390 ° C. Both solution and melt mixing methods may be used, but the melt mixing method is preferred due to its relative simplicity and suitability to readily available equipment for resin processing. The proportion of unsaturated acid or anhydride is most commonly about 0.01-5.0, preferably about 0.1-3.0 parts by weight per 100 parts of polyphenylene ether.

For example, the reaction can be carried out in the presence of a free radical catalyst, as disclosed in Japanese Patent Application Laid-Open No. 59-66452. However, in many cases, since the reaction proceeds efficiently even in the absence of a catalyst, such a catalyst is unnecessary and generally not preferred.

This reaction and its products are disclosed, for example, in European Patent Application No. 121,974, US Pat. No. 4,654,405 and in pending US application No. 885,497 filed Jul. 14, 1986. Claimed.

The preparation of reaction products of polyphenylene ethers with unsaturated carboxylic acids or anhydrides is shown in the examples below. The polyphenylene ethers used in the examples herein are commercially available poly (2,6-diene) having a number average molecular weight of about 20,000 as measured by gel permeation chromatography in comparison with polystyrene. Dimethyl-1,4-phenylene ether).

Examples 1 and 2 A dry blend in which polyphenylene ether and fumaric acid were thoroughly mixed was extruded with a twin-screw extruder in a temperature range of 250 to 300 ° C. The ratio of fumaric acid to 100 parts by weight of polyphenylene ether was as follows: Example 1-1.55 parts Example 2-2.32 parts Reactant B is at least one polyepoxy compound. In its broadest sense, the present invention may use any such compound known in the art. An example is given below.

(1) Polyglycidyl ethers of bisphenol, especially bisphenol A. These are expressions Wherein each of A ¹ and A ² is a monocyclic divalent aromatic group, and Y has one or two carbon atoms A ¹ and A 2.
^A bridging group in which ² is separated, and x is 0 to about 1
It has an average value of up to 5.

Formula (2) An epoxy novolac of the formula: wherein each A ³ is an aromatic group,
y has an average value of at least about 0.1.

(3) N, N-diglycidylaniline, N, N, N ',
Glycidyl adducts with amines and amides exemplified by N'-tetraglycidyl xylylenediamine and triglycidyl isocyanurate.

(4) Glycidyl esters of carboxylic acids such as diglycidyl phthalate and diglycidyl adipate.

(5) Polymers of unsaturated epoxides such as glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether.

(6) Polysiloxanes containing epoxy functionality such as diglycidyl ether of 1,3-bis (3-hydroxypropyl) -tetramityldisiloxane.

(7) Compounds prepared by epoxidation of dienes and polyenes such as bis (2,3-epoxycyclopentyl) ether and vinylcyclohexenedioxide.

Preferred polyepoxy compounds for the purposes of the present invention are:
It is a polyglycidyl ether of bisphenols (particularly bisphenol A) (formula VI), among which x has an average value of up to 1. They can be alone or
4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, vinylcyclohexenedioxide, phenol-formaldehyde novolac polyglycidyl ether (corresponding to formula VII), resorcinol glycidyl ether, tetrakis (glycidyloxyphenyl) ethane, diglycidyl phthalate , Diglycidyl tetrahydrophthalate and diglycidyl hexahydrophthalate, may be used in combination with small amounts of at least one non-bisphenolic polyepoxy compound. Epoxy novolacs of formula VII are often preferred. Also present are aryl monoglycidyl ethers such as phenyl, α-naphthyl and β-naphthyl ethers and substituted derivatives thereof. When they are present, such non-bisphenolic polyepoxy compounds and aryl monoglycidyl ethers usually make up up to 30 weight percent of the total epoxy compounds.

In many cases, if it is contained in the component B, the component B-
The sum of 2 and / or B3 is up to about 30 weight percent. Mixtures of components A and B typically contain component A in the range of 5-90 weight percent, but about 30-85.
Weight percentages are preferred, especially about 60-80 weight percentages.

The particular polyepoxy compound intended to be used in the present invention is (1) in the presence of a catalytic amount of at least one basic reagent at least one aliphatic hydroxy group per molecule on average. Halogen-free bisphenolic polyglycidyl ether, (2) about 15-25% of at least one halogen-free epoxidized novolac, and (3) at least one containing 25-35% bromine as an aryl substituent. Bisphenol (where the percentages of components 2 and 3 are based on the sum of the reactants 1, 2 and 3) of the reaction product obtained by heating.

Such products are disclosed and claimed in pending US Application No. 219,102, filed July 14, 1988, the description of which is incorporated herein by reference. The following examples illustrate the preparation of such compositions.

Example 3 50 parts by weight of diglycidyl ether of bisphenol A,
30 parts by weight of 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, "EP from Ciba Geigy"
N1138 ", a mixture of 20 parts by weight of a commercially available epoxy novolac resin and 0.2 parts by weight of triphenylphosphine, in a nitrogen atmosphere, for 1 hour 165
Heated with stirring at ° C. The product was the expected composition and contained 17.6 percent bromine.

Reactant C is an epoxy cure catalyst. Many such catalysts are known, any of which may be used in accordance with the present invention. They are metal salts of diketones such as tris (acetylacetonate) of aluminum and bis (acetylacetonate) of zinc; diaryls such as tetrafluoroborate, hexafluorophosphate, hexafluoroarsinate and hexafluoroantimonate. Iodonium salt; UV-activated triarylsulfonium salt containing the anion; imidazole, 1,2-dimethylimidazole, 2-methylimidazole, 2-heptadecylimidazole and 1- (2-cyanoethyl) -2 An imidazole such as phenylimidazole; m substituted with diethylmethyl
-And p-phenylenediamine, preferably polyamides of arylenes having a high degree of alkyl substitution on the aromatic ring and mixtures thereof with the imidazoles mentioned above, and a number of those known in the art. Including other species. Metal acetylacetonates, especially zinc and aluminum salts, are generally preferred.

Various substances may also be present in the curable composition of the present invention. For example, curing accelerators may be used. It is a phenolic compound such as bisphenol A, pyrogallol,
It includes dihydroxydiphenyls, hydroxybenzaldehydes such as salicylaldehyde, catechol, resorcinol, hydroquinone, phenol-formaldehyde or resorcinol-formaldehyde condensates and halogenated phenols.

Also useful and usually preferred as cure accelerators are basic nitrogen compounds, especially amines and guanidines. As long as they have low enough volatility that they remain active in the composition during the curing process, it is not particularly important to pinpoint it, especially if it is J-n
Alkylamines having from 4 to 10 carbon atoms, such as -butylamine, tri-n-butylamine and 2-ethylhexylamine, and the generally preferred tetraalkylguanidines, such as tetramethylguanidine. The polyphenylene ethers containing aminoalkyl-substituted end groups of formula II and the free amines generated during the formation of the quinone methide-type intermediates of formula IV thereby also act to some extent as accelerators.

The curable composition of the present invention typically contains a small amount of curing catalyst (component C), usually about 0.5-based on the sum of components A and B.
10.0%, preferably about 1-5%. Where amines or guanidines are used as cure accelerators, they are typically present in an amount that provides about 1000-1500 ppm basic, non-volatile nitrogen relative to the sum of cure accelerators and reactants A, B and C. used. The amount of the promoter added is therefore (if it is usually about 200-1000 pp) if basic nitrogen is present in the polyphenylene ether.
It will be adjusted downward in consideration of that amount (although in the range of m), and will be adjusted upward in consideration of the amount of volatilization. Adjusting for these factors, an amount that provides about 1500-2500 ppm of basic nitrogen is usually adequate.

Also present in the curable composition are substances such as curing agents exemplified by low and relatively high molecular weight phenols (novolak resins as an example of the latter), hydrated alumina, decabromo. Flame retardants such as diphenyl ethers and low or high molecular weight bromine compounds (the latter type eg the product of Example 3), flame retardant synergists such as antimony pentoxide, antioxidants, heat and UV light. Stabilizers, lubricants, antistatic agents, dyes, pigments, etc.
The amount used is a usual amount.

For the preparation of prepregs, the curable compositions of the invention are typically dissolved in an effective amount of an inert organic solvent, for example, with a solute content of about 15-60 weight percent. The solvent is not particularly specified as long as it can be removed by a suitable method such as evaporation.
Aromatic hydrocarbons, especially toluene, are preferred.

Another feature of the present invention, impregnated with the curable composition of the present invention, typically, obtained by removing the solvent by evaporation, glass, quartz, polyester, polyamide, polypropylene, cellulose, A curable material consisting of a fibrous base material (woven and non-woven) such as a fiber made of nylon or acrylic, preferably glass. Such articles (ie prepregs) may be cured by the application of heat, and the resulting cured article is yet another aspect of the invention.

In a typical case, 2 to 20 stacked prepreg laminates are in a temperature range of about 190 to 250 ° C and 20 to 60 kg / cm ^2.
It is pressure molded under moderate pressure. Laminates coated with a conductive metal such as copper and useful in the manufacture of printed circuit boards may be so prepared and cured by methods known to those skilled in the art. Printed circuit board blanks comprising the laminate are characterized by excellent physical dielectric properties. The metallization may then be conventionally patterned.

Although the curing of the epoxy compound will occur at least partially as usual, the exact chemistry of the cured composition of the present invention is not known with certainty. It is believed that Reactant A participates in the curing reaction, at least in part through carboxylic acid or anhydride groups.

The preparation of curable and cured compositions of the present invention is illustrated by the following examples.

Example 4 400 g of the product of Example 1, 230 of the product of Example 2
g, bisphenol A diglycidyl ether 27
0, aluminum tris (acetylacetonate) 2
7 g and tetramethylguanidine 5 g were added to hot toluene 2
Dissolved in 500 ml. A glass cloth is passed through the solution at a speed of 25.4 cm / min to allow the impregnated cloth to reach about 150.
A prepreg material having a resin content of about 50 percent was prepared by drying at 0 ° C. The cured laminate was prepared by pressure molding 10 prepregs at 240 ° C. for 50 minutes.

The laminate was tested for solvent resistance in the following manner: "soak in methylene chloride for 30 minutes-dry in air for 10 minutes-determining percent weight gain". Solder resistance is
It was dipped in a 280-285 ° C solder bath for 30 seconds and then tested by measuring the percent increase in laminate thickness. The results are shown in the following table in the form of a comparison with a control sample in which the products of Examples 1 and 2 have been replaced by untreated polyphenylene ether.

These results clearly show that the present invention improves solvent resistance and solder resistance.

Claims (20)

[Claims] 1. A reaction product of (A) at least one polyphenylene ether and at least one unsaturated carboxylic acid or acid anhydride; (B) at least one polyepoxy compound; and (C) a curing catalyst for epoxy. A curable composition comprising. 2. The composition of claim 1 wherein the polyphenylene ether used to prepare Reactant A has a number average molecular weight of at least 12,000. 3. Reactant B is a polyglycidyl ether of a bisphenol compound and has the formula (In the formula, each of A ¹ and A ² is a monocyclic divalent aromatic group, and Y
Is a bridging group in which one or two atoms separate A ¹ and A ² , and x has an average value of up to 1) and at least one polyglycidyl ether, and said polyglycidyl The composition according to claim 2, which is selected from the group consisting of a combination comprising an ether as a main component and at least one of an aryl monoglycidyl ether and a non-bisphenol-based polyepoxy compound as an accessory component. 4. Reactant A 90 relative to reactants A and B
The composition of claim 3 wherein the unsaturated carboxylic acid or acid anhydride comprising up to weight percent and used to prepare Reactant A is maleic anhydride or fumaric acid. 5. Reactant A from 15,000 to 40,000
A poly (2,6-dimethyl-1,4-phenylene ether) having a number average molecular weight in the range of 0, wherein reactant A comprises 30-85 weight percent of reactants A and B. 4. The composition according to 4. 6. The reaction material B contains the polyglycidyl ether from a bisphenol compound as an essential component.
The composition as described. 7. A composition according to claim 6 wherein each of A ¹ and A ² is p-phenylene, Y is isopropylidene and x is 0. 8. The composition of claim 7 in which reactant C is tris (acetylacetonate) of aluminum or bis (acetylacetonate) of zinc. 9. The composition of claim 8 wherein Reactant C is present in an amount in the range of 0.5-10 percent based on the sum of Reactants A and B. 10. The composition of claim 9 wherein the unsaturated carboxylic acid or anhydride used to prepare Reactant A is fumaric acid. 11. The composition according to claim 7, which contains at least one phenol compound or basic nitrogen compound as a curing accelerator. 12. The promoter is a basic nitrogen compound and is present in an amount to provide 1000-1500 ppm basic, non-volatile nitrogen based on the sum of the promoter and reactants A, B and C. The composition of claim 11. 13. The promoter is tetramethylguanidine and is present in an amount of 1500-2500 ppm, based on the sum of the promoter and reactants A, B and C.
The composition according to 1. 14. A curable article comprising a fibrous substrate impregnated with the composition of claim 1. 15. A curable article comprising a fibrous substrate impregnated with the composition of claim 11. 16. The article according to claim 14, wherein the substrate is glass fiber. 17. The article according to claim 15, wherein the substrate is glass fiber. 18. An article obtained by applying heat to the article according to claim 17 to cure the article. 19. A semi-finished product for a printed circuit board, comprising the article according to claim 18 coated with a conductive metal. 20. The semi-finished product for a printed circuit board according to claim 19, wherein the metal is copper.