DE3931809A1 - Curable formulation based on reaction prod. of polyphenylene ether - with unsatd. carboxylic acid or anhydride, polyepoxide cpd. and epoxy cure catalyst - Google Patents

Abstract

Curable formation consists of (a) a reaction prod. (I) of polyphenylene ether(s) (II) with unsatd. carboxylic acid(s) (IIIA) or unsatd. anhydride(s) (IIIB), (b) polyepoxide cpd(s). (IV) and (c) epoxy hardening catalysts (V). (II) has Mn = min. ca. 12000. (IV) consists of polyglycidyl ether(s) of a bisphenolic cpd., of formula (IVA) Glyc-O-A1-Y-A2- (OCH2CH(OH)O-A1-Y-A2)x-O-Glyc (IVA) Glyc = the glycidyl gp.; A1 and A2 independently = a monocyclic divalent aromatic gp.; esp. p-phenylene; Y = a bridging gp. with 1 or 2 atoms sepg. A1 from A2; esp. propylidene; x has an average value to up 1; esp. 0, either alone or mixed with a smaller amt. of aryl monoglycidyl ether(s) and non-bisphenolic polyepoxy cpd(s). The formulation contains up to 90 (wt)% (I) w.r.t. (I)-(IV) and (III) is maleic anhydride or fumaric acid. In particular, (II) is a poly(2,6-dimethyl-1,4-phenylene ether) (IIA) with MN = ca. 15000-40000 in an amt. of ca, 30-85% w.r.t. (I) + (IV). (V) is Al tris(acetylacetonate) (VA) or Zn bis(acetylacetonate) and is used in an amt. of 0.5-10% w.r.t. (I) + (IV). The formulation pref. also contains phenolic cpd(s). (VIA) or basic N cpd(s). (VIB) as hardening accelerator, pref. (VIB) an amt. equiv. to ca. 1000-15000 ppm basic, involatile N w.r.t. (I) + (IV) + (V), esp. ca. 1500-2500 ppm tetramethylguanidine. USE/ADVANTAGE - The formulation is claimed for use in curable materials with a substrate of fibre, esp. glass fibre, the prods. obtd. by thermal cure of these and PCBs consisting of these prods. covered with a conductive metal, esp. Cu. The cured composites (laminates) have improved solvent resistance and solderability.

Description

The invention relates to polyphenylene ether / polyepoxide preparations, and it concerns more particularly an improved one Resistance to solvents and improved solderability for hardened composites made from such preparations were manufactured.

It is a number of polyphenylene ether / polyepoxide preparations known. Many such preparations, in general in the form of fiber reinforced prepregs (i.e. substrates, those with uncured or partially cured resins are impregnated), harden to form materials with high dielectric constant and others for your Use favorable properties, e.g. B. as copper-clad Laminates used for etching to form printed circuits are suitable.

The older US application Ser. No. 92 725 dated September 3 1987 discloses a class of such preparations that using a zinc or aluminum salt of a diketone, such as acetylacetone, optionally in the presence of a phenolic Compound or a basic nitrogen compound  are curable as a curing accelerator. The products are excellent for use in circuit board laminates. The hardened products are however regarding solderability and resistance to solvents, especially methylene chloride, which is often used for Cleaning printed circuit boards is in need of improvement.

The present invention provides polyphenylene ether / polyepoxide preparations which are useful for production fiber reinforced prepregs. Such prepregs can be found under Formation of laminates can be hardened to the desired Properties for use as printed circuits exhibit. They are also better than many so far known laminates in terms of solderability and Resistance to solvents.

In one of its aspects, the present invention closes therefore preparations containing (A) the reaction product at least one polyphenylene ether with at least one unsaturated carboxylic acid or an unsaturated anhydride, (B) at least one polyepoxy compound and (C) an epoxy curing catalyst include.

The polyphenylene ether used in the preparation of the ingredient (A) the curable preparations of the present Invention are useful include a variety of structural Units of the formula

wherein in each of these units independently each Q¹ is independently halogen, primary or secondary lower alkyl (ie alkyl of up to 7 carbon atoms), phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy or halohydrocarbonoxy, with at least 2 carbon atoms separating the halogen and oxygen atoms and each Q² is independently hydrogen, halogen, primary or secondary lower alkyl, phenyl, haloalkyl, hydrocarbonoxy or halohydrocarbonoxy, as defined for Q¹. 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 groups. Examples of secondary lower alkyl groups are isopropyl, sec-butyl and 3-pentyl. All alkyl radicals are preferably straight-chain rather than branched. Most commonly, each Q¹ is alkyl or phenyl, especially C _1-4 alkyl, and each Q² is hydrogen. Suitable polyphenylene ethers are described in a large number of patents.

They are both homo- and copolymeric polyphenylene ethers locked in. Suitable homopolymers are those that e.g. B. 2,6-dimethyl-1,4-phenylene ether units. Suitable copolymers include random copolymers one, such units in combination with, e.g. B. 2,3,6- Trimethyl-1,4-phenylene ether units included. Lots suitable random copolymers and homopolymers are disclosed in the patent literature.  

Polyphenylene ethers, the groups, are also included contain that modify properties such as molecular weight, the melt viscosity and / or the impact strength. Such polymers are in the patent literature described, and they can by grafting hydroxyl-free Vinyl monomers such as acrylonitrile and vinyl aromatic Compounds (e.g. styrene) or hydroxyl-free polymers, such as polystyrenes and elastomers, on the polyphenylene ether can be obtained in a known manner. The product usually contains both grafted and ungrafted Components. Other suitable polymers are those coupled polyphenylene ether, in which the coupling agent in a known manner with the hydroxyl groups of two polyphenylene ether chains is converted to a higher molecular weight Obtain polymer that is the reaction product contains the hydroxyl groups and the coupling agent. Exemplary coupling agents are low molecular weight Polycarbonates, quinones, heterocycles and formals.

For the purposes of the present invention, the polyphenylene ether a number average molecular weight in Range from about 3000 to 40,000, preferably at least about 12,000 and most preferably at least 15,000 and one Weight average molecular weight in the range of about 20,000 to 80,000 as determined by gel permeation chromatography. Its intrinsic viscosity most often is in the range of about 0.35 to 0.6 dl / g, measured in chloroform at 25 ° C.

The polyphenylene ethers are usually produced by oxidative coupling at least one corresponding monohydroxyaromatic compound. Particularly useful and readily available monohydroxyaromatic compounds  are 2,6-xylenol, (wherein each Q¹ is methyl and Q² Is hydrogen), whereupon the polymer as poly (2,6- dimethyl-1,4-phenylene ether) can be characterized and 2,3,6-trimethylphenol (wherein each Q¹ and Q² Methyl and the other Q² is hydrogen).

It is a variety of catalyst systems for manufacturing known from polyphenylene ethers by oxidative coupling. There is no particular limitation on it the catalyst selection, and it can be any of the known Catalysts are used. Mostly they contain at least one heavy metal compound, such as a copper, Manganese or cobalt compound, usually in combination with various other materials.

A first class of catalyst systems that are common is preferred, consists of those that have a copper compound contain. Such catalysts are e.g. Tie U.S. Patents 33 06 874, 33 06 875, 39 14 266 and 40 28 341 disclosed. They are usually combinations of copper (I) or copper (II) ions, halide (i.e. Chloride, bromide or iodide) ions and at least one Amine.

Catalyst systems containing manganese compounds form a second class. They are generally alkaline systems in which divalent manganese is combined with such anions as halide, alkoxide or phenoxide. Most often, the manganese is present as a complex with one or more complexing and / or chelating agents, such as dialkylamines, alkanolamines, alkylenediamines, o-hydroxyaromatic aldehydes, o-hydroxyazo compounds, ω- hydroxyoximes (monomers and polymers), o-hydroxyaryloximes and β -Diketones. Known cobalt-containing catalyst systems are also useful. Suitable manganese and cobalt-containing catalyst systems for the production of polyphenylene ether are known from disclosure in many patents and publications.

Certain commercial polyphenylene ethers include molecules with at least one end group of the formula

wherein Q¹ and Q² are as defined above, each R¹ is independently hydrogen or alkyl, provided that the total number of carbon atoms in both R¹ groups is 6 or less and each R² is independently hydrogen or a primary C _1-6 alkyl group . Preferably each R1 is hydrogen and each R2 is alkyl, especially methyl or n-butyl.

Polymers having the aminoalkyl-substituted end groups of formula II can be obtained by employing a suitable primary or secondary monoamine as one of the components of the reaction mixture in the oxidative coupling, especially when a copper- or manganese-containing catalyst is used. Such amines, especially the dialkylamines and preferably di-n-butylamine and dimethylamine, are often chemically bound to the polyphenylene ether, most often by replacing one of the α -hydrogen atoms on one or more Q¹ radicals. The principal reaction site is the Q¹ residue adjacent to the hydroxy group at the end unit of the polymer chain. During further processing and / or mixing, the aminoalkyl-substituted end groups can undergo various reactions, which are likely to include a quinone methide-like intermediate of the following formula

Reference is made to the US patents 40 54 553, 40 92 294, 44 77 649, 44 77 651 and 45 17 341.

Polymers with 4-hydroxybiphenyl end groups of the formula III are usually obtained from reaction mixtures,  in which as a by-product diphenoquinone the following Formula is present

especially in a copper halide secondary or tertiary amine system. In this context is the revelation the US-PS 44 77 649 of importance as well as the U.S. Patent Nos. 4,234,706 and 4,482,697, to which reference is hereby made. In mixtures of this type The diphenoquinone is finally used in considerable proportions, mainly incorporated as an end group in the polymer.

In many polyphenylene ethers, among the above Conditions obtained contain a considerable amount Proportion of polymer molecules, usually around 90 Make up wt .-% of the polymer, end groups with one or often two groups of formulas II and III. However, it is to point out that there are also other end groups can be, and that the invention in its broadest Does not make sense of the molecular structure of the end groups of the May depend on polyphenylene ether.

The specialist is due to the above statements clear that for use in the present invention suitable polyphenylene ether all currently known polyphenylene ether include, regardless of variations in the structural units or subordinate chemical  Characteristics.

For the purposes of the present invention, the reagent is or the reactant A the reaction product of mentioned polyphenylene ether with at least one unsaturated Carboxylic acid or an unsaturated carboxylic acid hydride. Close suitable acids and anhydrides Monocarboxylic acids such as acrylic acid and methacrylic acid as well as dicarboxylic acids and their anhydrides, including Maleic anhydride, fumaric anhydride and itaconic acid. Maleic anhydride and fumaric anhydride are preferred, the latter because of availability and the relatively easy handling is particularly preferred is.

The conditions for the implementation of the polyphenylene ether with the unsaturated acid or the unsaturated anhydride generally close temperatures in the range from about 230 to 290 ° C. Both a solution as well as melt mixing, wherein the melt mixing because of its relative simplicity and the Adaptability to equipment used for resin processing are readily available, is preferred. The amount is due to unsaturated acid or unsaturated anhydride often in the range of about 0.01 to 5.0 parts, and preferably in the range of about 0.1 to 3 parts by weight, to 100 parts of the polyphenylene ether.

It is possible to implement in the presence of a free Execute radical initiators such. B. in Japanese Kokai publication 84/66 452 discloses. Mostly such initiators are not required, and they are generally not preferred because of the implementation  progress effectively even in their absence. These Implementation and the products obtained are e.g. B. in EP-A-1 21 974, US-PS 46 54 405 and the US application Ser. No. 8 85 497 of July 14, 1986.

The production of the reaction products of polyphenylene ethers with unsaturated carboxylic acids or anhydrides is illustrated by the following examples. The polyphenylene ether used in these examples a commercially available poly (2,6-dimethyl-1,4-phenylene ether) with a number average molecular weight of about 20,000 as determined by gel permeation chromatography with respect to polystyrene.

Example 1-2

Intimate dry mixes of polyphenylene ether and fumaric acid were in a twin screw extruder at temperatures extruded in the range of 250 to 300 ° C. The Proportions of fumaric acid per 100 parts by weight of polyphenylene ether cheat:

Example 1 - 1.55 parts
Example 2 - 2.32 parts

Reagent B is at least one polyepoxy compound. In In its broadest sense, the invention closes the use any such connection that is known. The The following connections are examples:

• (1) Polyglycidyl ether of bisphenols, especially bisphenol-A. These include compounds of the formula wherein each A¹ and A² is a monocyclic aromatic radical, Y is a bridging radical in which one or two carbon atoms separate A¹ from A² and x has an average of 0 to about 15.
• (2) Epoxy novolaks of the formula wherein each A³ is an aromatic residue and y has an average of at least 0.1.
• (3) Glycidyl adducts of amines and amides by N, N-diglycidylaniline, N, N, N ′, N′-tetraglycidylxylylenediamine 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 with functional epoxy groups, such as the Diglycidyl ether of 1,3-bis (3-hydroxypropyl) tetramethyldisiloxane.
• (7) Compounds by epoxidation of dienes or Polyenes are obtained, such as bis (2,3-epoxycyclopentyl) ether and vinylcyclohexene dioxide.

The preferred polyepoxy compounds for the purposes of the present invention are the polyglycidyl ethers of bisphenols (which have the formula VI), especially bisphenol-A, and most particularly those in which x has an average of up to 1. They can be used alone or in combination with minor amounts of at least one non-bisphenolic polyepoxy compound, illustrated by alicyclic polyepoxy compounds, such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, vinylcyclohexene dioxide, phenolformaldehyde novolak polyglycidyl ether, which correspond to formula VII, Resorcing glycidyl ether, tetrakis (glycidyloxyphenyl) ethane, diglycidyl phthalate, diglycidyl tetrahydrophthalate and diglycidyl hexahydrophthalate. Epoxy novolaks of formula VII are often preferred. Aryl monoglycidyl ethers can also be present, such as the phenyl, α- naphthyl and β- naphthyl ethers and their substituted derivatives. If present, such non-bisphenolic polyepoxy compounds and aryl monoglycidyl ethers usually make up up to about 30% by weight of the total epoxy compounds.

For the most part, component B is no more than about Contain 30% by weight of components B-2 and / or B-3, if any. The mixtures of components A and B contains component A usually in proportions of 5 to 90 % By weight, with 30 to 85% preferred and 60 to 80% particularly are preferred.

A specific class of polyepoxy compounds for Use in the present invention consists of reaction products which you get by heating the following mixture in the presence of a catalytic amount of at least one basic reagent receives:

• (1) at least one halogen-free bisphenol polyglycidyl ether with an average of at most one aliphatic hydroxy group per molecule;
• (2) about 15 to 25% of at least one halogen-free epoxidized Novolaks and
• (3) 25 to 35% of at least one bisphenol, the bromine as Contains aryl substituents,

the percentages of components (2) and (3) the total amount of reagents (1), (2) and (3) based. Such products are in the older application P 39 22 741.2 discloses and claims to the hereby Reference is made. The following example illustrates the preparation of such preparations.

Example 3

A mixture of 50 parts by weight of bisphenol A diglycidyl ether; 30 parts of 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane; 20 parts of an epoxy novolak resin sold under the trade name EPN 1138 is available from Ciba-Geigy and 0.2 parts of triphenylphosphine were added in one hour Heated nitrogen atmosphere to 165 ° C with stirring. The Product was the desired preparation and contained 17.6% Bromine.

Reagent C is an epoxy curing catalyst. There are many Types of such catalysts are known, and each of them can be used in the present invention. they include metal salts of diketones, such as aluminum tris (acetylacetonate) and zinc bis (acetylacetonate); Diaryliodonium salts, like the tetrafluoborates, hexafluophosphates, Hexafluoroarsenates and hexafluoantimonates; UV activated  Triarylsulfonium salts with the same anions; Imidazole, such as imidazole, 1,2-dimethylimidazole, 2-methylimidazole, 2-heptadecylimidazole and 1- (2-cyanoethyl) -2-phenylimidazole; Arylene polyamide, preferably those with a high degree of alkyl substitution on the aromatic ring, illustrated by the diethylmethyl-substituted m- and p-phenylenediamines and their mixtures with the aforementioned imidazoles and numerous other types of compounds one known in the art. The metal acetylacetonates and especially zinc and Aluminum is generally preferred.

Various other materials can also be used in the curable Preparations of the present invention are present be. So hardening accelerators can be used. These include phenolic compounds such as bisphenol-A, Pyrogallol, dihydroxydiphenyls, hydroxybenzaldehydes, such as Salicylaldehyde, pyrocatechol, resorcinol, hydroquinone, Phenol-formaldehyde or resorcinol-formaldehyde condensates and halogenated phenols.

Basic nitrogen compounds, in particular amines and guanidines, are also useful and are usually preferred as hardening accelerators. Their exact identity is not critical, provided they are sufficiently volatile to remain in the preparation and be active during curing. C _4-10 alkylamines, such as di-n-butylamine, tri-n-butylamine and 2-ethylhexylamine, and tetraalkylguanidines, such as tetramethylguanidine, which are generally preferred, are particularly effective. Polyphenylene ethers with aminoalkyl-substituted end groups of the formula II and to a certain extent the free amines formed in the formation of the quinone methide-like intermediates of the formula IV can also act as accelerators.

The curable preparations of the present invention usually contain the curing catalyst (component C) in small amounts, usually about 0.5 to 10% and preferably about 1 to 5%, based on the total amount A and B. Will use an amine or guanidine as an accelerator used, then usually in a lot, which are about 1000 to 1500 ppm, based on the total amount from accelerators and reagents A, B and C. basic, non-volatilized nitrogen. The The amount of accelerator added is therefore reduced adjusted below, for example in the polyphenylene ether to compensate for basic nitrogen, which is usually is in the range of 200 to 1000 ppm or them is set up to volatilize compensate. If you balance these factors, then there is Usually an amount of accelerator suitable, such as 1500 to 2500 ppm of basic nitrogen results.

There may also be materials, such as hardeners, those caused by phenols both low and relatively high Molecular weight are illustrated, an example for the latter are novolak resins; further flame retardants, such as hydrated aluminum oxide, decabromodiphenyl ether and bromine compounds low or high Molecular weight (the latter type is due to the product Example 3); Anti-inflammatory synergists, such as antimony pentoxide; Antioxidants, thermal and UV stabilizers, lubricants, antistatic agents, Dyes, pigments and the like Ä., all in usual Shares.  

The curable preparations are used to form prepregs of the present invention usually in an effective amount of an inert organic solvent dissolved, typically up to a salary from 15 to 60% by weight of solute. The identity of the solvent is not critical, provided it can appropriately removed, such as by evaporation. Aromatic hydrocarbons, especially toluene, are prefers.

Another aspect of the present invention are curable Objects made of a fibrous substrate (woven or non-woven), such as glass, quartz, polyester, polyamide, Polypropylene, cellulose, nylon or acrylic fibers, preferably comprise glass fibers which are compatible with the curable Preparations of the present invention impregnated and usually by removing the solvent from it, such as by evaporation. Such items (i.e. prepregs) can be heat cured, and the hardened objects obtained are still another aspect of the present invention.

2 to 20-layer prepreg laminates are usually used at temperatures in the range of about 190 to 250 ° C and under pressures in the order of 20 to 60 kg / cm² shaped. Laminates covered with a conductive metal, such as Copper, are clad, usable for printed circuit boards, can be made in this way and after known methods are cured. Printed circuit boards, which comprise these laminates are distinguished by characterized dielectric properties. The metal lamination can be patterned in the usual way  will.

The exact chemical nature of the hardened preparations the present invention is not exactly known, though at least curing the epoxy compound is likely partly takes place in the usual way. It will assuming that Reagent A takes part in the curing reaction, probably at least in part, by means of the carboxylic acid or anhydride groups.

The production of curable and hardened preparations The present invention is illustrated in the following example.

Example 4

A solution of 400 g of the product according to Example 1 230 g of the product according to Example 2, 270 g of bisphenol A diglycidyl ether, 27 g aluminum tris (acetylacetonate) and 5 g of tetramethylguanidine in 2500 ml of hot toluene prepared. Glass fabric was removed by the solution with a Speed of 25.4 cm / min and the impregnated Fabric dried at about 150 ° C to form a prepreg material to give, whose resin content was about 50%. After further drying for 15 minutes at 165 ° C a hardened laminate by printing 10 plates of the prepreg for 50 minutes at 240 ° C.

The laminate was tested for solvent resistance Immerse in methylene chloride for 30 minutes, dry for 10 minutes in air and measure the percentage weight gain examined. It was made on solder resistance by immersing in a solder bath for 30 seconds  at 280 to 285 ° C and measuring the percentage increase the laminate thickness examined. The results are in the following table given together with a comparative sample, in which the products of Examples 1 and 2 by untreated polyphenylene ether were replaced.

These results clearly show the improvement in terms solvent resistance and solder resistance of the preparations of the present invention.

Claims (20)

1. Comprehensive curable preparation

• (A) the reaction product of at least one polyphenylene ether with at least one unsaturated carboxylic acid or an unsaturated anhydride,
• (B) at least one polyepoxy compound and
• (C) an epoxy curing catalyst.

2. Preparation according to claim 1, wherein the preparation of the reactant (A) used polyphenylene ether a number average molecular weight of at least has about 12,000.   3. Preparation according to claim 2, wherein the reactant (B) is selected from the group consisting of at least one polyglycidyl ether of a bisphenolic compound, this polyglycidyl ether having the following formula: wherein A¹ and A² are each a monocyclic divalent aromatic radical, Y is a bridging radical in which one or two atoms separate A¹ from A² and x has an average value up to 1 and (B) is further selected from combinations of a majority of a polyglycidyl ether with a minor amount of at least one aryl monoglycidyl ether and at least one non-bisphenolic polyepoxy compound. 4. Preparation according to claim 3, comprise up to 90 wt .-% of the reactant (A), based on the reactants (A) and (B), wherein the for the preparation of the Reactant (A) used unsaturated carboxylic acid or the unsaturated anhydride maleic anhydride or is fumaric acid. 5. The preparation of claim 4, wherein the reactant (A) is a poly (2,6-dimethyl-1,4-phenylene ether), which is a number average molecular weight in the range from about 15,000 to 40,000 and about 30 to 85 percent by weight  to the reactants (A) and (B). 6. The preparation according to claim 5, wherein the reactant (B) essentially from the polyglycidyl ether mentioned bisphenolic compound. 7. A preparation according to claim 6, wherein A¹ and A² are each p-phenylene, Y is isopropylidene and x has a value of 0. 8. The preparation according to claim 7, wherein the reagent (C) Aluminum tris (acetylacetonate) or zinc bis (acetylacetonate) is. 9. The preparation according to claim 8, wherein reagent (C) in is present in an amount in the range of 0.5 to 10% on the total amount of reagents (A) and (B). 10. A preparation according to claim 9, wherein the preparation of the reagent (A) used unsaturated carboxylic acid or unsaturated anhydride is fumaric acid. 11. Preparation according to claim 7, the at least one phenolic Compound or a basic nitrogen compound as a curing accelerator. 12. A preparation according to claim 11, wherein the accelerator is a basic nitrogen compound in an amount the approximately 1000 to 1500 ppm basic, not volatilized Nitrogen gives, based on the total Accelerator and reagents (A), (B) and (C).   13. A preparation according to claim 11, wherein the accelerator Tetramethylguanidine in an amount of about 1500 to Is 2500 ppm based on the total amount of accelerator and reagents (A), (B) and (C). 14. A curable article comprising a fibrous Substrate impregnated with the preparation according to claim 1 is. 15. A curable article comprising a fibrous Substrate impregnated with the preparation according to claim 11 is. 16. The article of claim 14, wherein the substrate is made of Glass fibers exist. 17. The article of claim 15, wherein the substrate is made of Glass fibers exist. 18. Hardened object made by heating of the article according to claim 17. 19. Printed circuit board comprising an object according to claim 18, laminated with a conductive metal is. 20. A printed circuit board according to claim 19, wherein the metal is copper.