DE3931809C2 - Curable polyphenylene ether / polyepoxide preparations and their use - Google Patents

Description

The invention relates to curable preparation tions according to claims 1 to 11 and their use. Hardened composites made from such preparations have improved solvent resistance and solderability.

It is a number of polyphenylene ether / polyepoxide preparations tion known (see Derwent-Abstr. 52 972 K / 22 to JP 58 069 052). 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 a copper liner te laminates used for etching to form printed scarf 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 pheno or a basic nitrogen compound  are curable as a curing accelerator. The products are excellent for use in circuit boards laminates. However, the hardened products are respectable Lich solderability and resistance to solutions means, especially methylene chloride, which is often used for Cleaning printed circuits is used, verbes in need of maintenance.

The present invention provides the curable Preparations according to claim 1 which are useful for manufacture 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. In addition, they are better than many so far known laminates in terms of solderability and Resistance to solvents.

The polyphenylene ethers useful in the preparation of component (A) of the curable preparations of the present invention include a variety of structural units of the formula

wherein in each of these units independently each Q ^{1 is} independently halogen, primary or secondary lower alkyl (ie alkyl having up to 7 carbon atoms), phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy or halogenated hydrocarbons, at least 2 carbon atoms separating the halogen and oxygen atoms from one another and each Q ^{2 is} independently hydrogen, halogen, primary or secondary lower alkyl, phenyl, haloalkyl, hydrocarbon oxy 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 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 Q ^{1 is} alkyl or phenyl, especially C _1-4 alkyl, and each Q ² 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 like the mole specular weight, melt viscosity and / or 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, like polystyrenes and elastomers, on the polyphenylene ether can be obtained in a known manner. The product usually contains both grafted and ungrafted grafted ingredients. Other suitable polymers are those coupled polyphenylene ether, where the coupling medium in a known manner with the hydroxyl groups of two polyphenylene ether chains is implemented to one higher to obtain molecular polymer that the reaction pro product of the hydroxyl groups and the coupling agent holds. Exemplary coupling agents are low molecular weight lare polycarbonates, quinones, heterocycles and formals.

For the purposes of the present invention, the poly phenylene ether a number average molecular weight in Range from 3,000 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 20,000 to 80,000, determined by gel permeation tography. 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 of at least one corresponding monohydroxyaromatic compound. Particularly useful and readily available monohydroxyaromatic compounds are 2,6-xylenol (where each Q ^{1 is} methyl and each Q ^{2 is} hydrogen), whereupon the polymer can be characterized as poly (2,6-dimethyl-1,4-phenylene ether) and 2,3,6-trimethylphenol (wherein each Q ¹ and one Q ^{2 is} methyl and the other Q ^{2 is} hydrogen).

It is a variety of catalyst systems to manufacture development of polyphenylene ethers through oxidative coupling knows. 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 a combination nation with various other materials.

A first class of catalyst systems that are common is preferred, consists of those that a copper ver binding included. Such catalysts are e.g. Tie U.S. Patents 3,306,874, 3,306,875, 3,914,266 and 4,028,341. 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 alka systems in which divalent manganese with such Anions such as halide, alkoxide or phenoxide combined is. The most common is the manganese as a complex with one or more complexing and / or chelating the agents present, such as dialkylamines, alkanolamines, Alkylene diamines, o-hydroxyaromatic aldehydes, o-hydroxy azo compounds, ω-hydroxyoximes (monomers and polymers),  o-hydroxyaryloximes and β-diketones. Known cobalt Catalyst systems are also useful. Suitable Catalyst systems containing manganese and cobalt for the manufacturer position of polyphenylene ether are by revelation known in many patents and publications.

Certain commercially available polyphenylene ethers comprise molecules with at least one end group of the formula

wherein Q ¹ and Q ² are as defined above, each R ^{1 is} independently hydrogen or alkyl, provided that the total number of carbon atoms in both R ¹ groups is 6 or less and each R ² is independently hydrogen or a primary one C _1-6 alkyl group. Each R ¹ is preferably hydrogen and each R ^{2 is} alkyl, in particular methyl or n-butyl.

Polymers having the aminoalkyl-substituted end groups of formula II can be obtained by using 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 an α-hydrogen atom on one or more Q ¹ radicals. The principal reaction site is the Q ¹ residue adjacent to the hydroxy group on 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 4 054 553, 4 092 294, 4 477 649, 4 477 651 and 4,517,341.

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

Especially in a copper halide secondary or tertiary amine system. In this context, it is open definition of US-PS 4,477,649 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 quantities share, mainly as an end group, in the polymer builds.

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. It is ever but to point out that other end groups also 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 person skilled in the art is familiar with the foregoing clear that for use in the present invention suitable polyphenylene ether all included in claim 1 poly Include phenylene ether, regardless of variations in the structural units or subordinate chemical  Characteristics.

For the purposes of the present invention the reactant A the reaction product of the mentioned polyphenylene ether with at least one saturated carboxylic acid or an unsaturated carbon acid hydride. Close suitable acids and anhydrides Monocarboxylic acids such as acrylic acid and methacrylic acid as well as dicarboxylic acids and their anhydrides Lich maleic anhydride, fumaric anhydride and itacon acid. Maleic anhydride and fumaric anhydride are preferred, the latter because of availability and the relatively easy handling especially before is moving.

The conditions for the implementation of the polyphenylene ether with the unsaturated acid or the unsaturated type hydrides generally close temperatures in the range from about 230 to 290 ° C. Both a solution as well as melt mixing, the melt mix because of its relative simplicity and the Adaptability to equipment used for resin processing tion 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 above 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 Japan African Kokai publication 84/66452 disclosed. Size Such initiators are sometimes not required, and they are generally not preferred because of the implementation  progresses effectively even in their absence. This Implementation and the products obtained are e.g. B. in EP 121 974 A1, US 4,654,405 and US application dung Ser. No. 885,497 of July 14, 1986.

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

Examples 1-2

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

Example 1 - 1.55 parts
Example 2 - 2.32 parts

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

• 1. Polyglycidyl ether of bisphenols, especially bisphenol A. These include compounds of the formula
  wherein each A ¹ and A ^{2 is} a monocyclic aromatic radical, Y is a bridging radical in which one or two carbon atoms separate A ¹ from A ² and x has an average value from 0 to about 15.
• 2. Epoxy novolaks of the formula
  wherein each A ^{3 is} an aromatic radical and y has an average of at least 0.1.
• 3. Glycidyl adducts of amines and amides light through N, N-diglycidylaniline, N, N, N ', N'-tetraglyci dylxylylenediamine 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) tetramethyl disiloxane.
• 7. Compounds made 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 present invention are the polyglycidyl ethers of Bisphenols (which have the formula VI), especially of Bisphenol-A and most especially those in which x is one Has mean of up to 1. You can go alone or in Combination with minor quantities of at least one non-bisphenolic polyepoxy compound can be used, illustrated by alicyclic polyepoxy compounds, such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxy lat, vinylcyclohexene dioxide, phenol formaldehyde novolak poly glycidyl ether corresponding to formula VII, resorcinol glycidyl ether, tetrakis (glycidyloxyphenyl) ethane, diglyci dylphthalate, diglycidyltetrahydrophthalate and diglycidyl hexahydrophthalate. Epoxy novolaks of formula VII often preferred. It can also use aryl monoglycidyl ether be present, such as the phenyl, α-naphthyl and β-naphthyl ether and their substituted derivatives. If available, then make such non-bisphenolic polyepoxyverbin and aryl monoglycidyl ether usually 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 mixture 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 who are preferred.

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

• 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 epoxy dated novolaks and
• 3. 25 to 35% of at least one bisphenol which contains bromine as aryl substituent,
  where the percentages of components (2) and (3) are based on the total amount of reagents (1), (2) and (3). Such products are disclosed and claimed in the earlier application P 39 22 741.2, to which reference is made here. 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 designation EPN 1138 is available from Ciba-Geigy and 0.2 parts of triphenylphosphine was 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 selected from Metal salts of diketones, such as aluminum tris (acetylacetonate) and zinc bis (acetylacetonate); Diaryl iodonium salts, such as tetrafluoborates, hexafluophosphates, Hexafluoroarsenates and hexafluoantimonates; UV activated  Triarylsulfonium salts with the same anions; Imidazoles, such as imidazole, 1,2-dimethylimidazole, 2-methylimidazole, 2-heptadecylimidazole and 1- (2-cyanoethyl) -2-phenylimi dazol; Arylene polyamides preferably those with a high degree of alkyl substitution on the aromatic ring, illustrated by the Diethylmethyi-substituted m- and p-phenylenediamines and their mixtures with the aforementioned imidazoles and numerous other verbin types of extensions known in the art. The metal acetylacetonates and especially zinc and Aluminum is generally preferred.

Various other materials can also be used in the hardens present preparations of the present invention 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 that they are sufficiently low in volatility to remain in the preparation and be active during curing. Be particularly effective are C _4-10 alkylamines, such as di-n-butylamine, tri-n-butylamine and 2-ethylhexylamine, and tetraalkylguanidines, such as tetramethylguanidine, which are generally preferred. Polyphenylene ether 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 (compo nente C) in small amounts, usually about 0.5 to 10% and preferably about 1 to 5%, based on the Ge total amount A and B. If an amine or guanidine as Be accelerator, then usually in a lot, which is about 1,000 to 1,500 ppm, based on the total amount of 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 existing nitrogen to compensate, the more common example is in the range of 200 to 1,000 ppm or she is set up to volatilize compensate. If you balance these factors, then Usually an amount of accelerator suitable, such as 1,500 to 2,500 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, with a case play for the latter are novolak resins; further Ent flame retardants such as hydrated alumina, deca Bromodiphenyl ether and bromine compounds low or high Molecular weight (the latter type is by the Pro product of Example 3); Flame retardant mer synergists such as antimony pentoxide; Antioxidants, thermal and UV stabilizers, lubricants, anti statics, dyes, pigments and the like Ä., all in usual Shares.  

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

Another aspect of the present invention is the use of the curable preparation for hardness bare objects that have a fibrous substrate (woven or non-woven), such as glass, quartz, polyester, poly amide, 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.

2- to 20-layer prepreg laminates are usually molded at temperatures in the range from approximately 190 to 250 ° C. and under pressures in the range from 20 to 60 kg / cm ² . Laminates laminated with a conductive metal such as copper, useful for printed circuit boards, can be made in this manner and cured by known methods. Printed circuit boards comprising these laminates are characterized by excellent dielectric properties. The metal lamination can be patterned in the usual way.

The exact chemical nature of the hardened preparations it is not known exactly whether probably hardening of the epoxy compound at least partially takes place in the usual way. It will assumed that Reagent A participated in the curing reaction takes, probably at least partially, namely ver by means of the carboxylic acid or anhydride groups.

The preparation of the curable preparations the present invention and its use is ver in the following example vividly.

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 2,500 ml of hot toluene prepared. Glass fabric was removed by the solution with a Speed of 25.4 cm / min. managed and the imprint nier tissue dried at about 150 ° C to a prepreg to give material 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 by immersion in methylene chloride for 30 minutes, air drying for 10 minutes, and measuring the percent weight gain. It was examined for solder resistance by immersing in a solder bath for 30 seconds at 280 to 285 ° C and measuring the percentage increase in the laminate thickness. The results are shown in the following table together with a comparison sample in which the products of Examples 1 and 2 were replaced by untreated polyphenylene ether.

These results clearly show the improvement Lich the resistance to solvents and the solder Persistence of the preparations of the present invention.

Claims (14)

1. Curable preparation, comprehensive

• A) the reaction product of at least one polyphenylene ether which has a number average molecular weight in the range from 3,000 to 40,000 and a weight average molecular weight from 20,000 to 80,000, with at least one unsaturated carboxylic acid or an unsaturated anhydride,
• B) at least one polyepoxy compound selected from
• C) Polyglycidyl ether of bisphenol ~ A of the formula
  wherein each A ¹ and A ^{2 is} a monocyclic aromatic radical, Y is a bridging radical in which one or two carbon atoms separate A ¹ from A ² and x has an average value from 0 to 15,
• D) Epoxy novolaks of the formula
  wherein each A ^{3 is} an aromatic radical and y has an average of at least 0.1,
• E) glycidyl adducts of amines and amides,
• F) glycidyl esters of carboxylic acids,
• G) polymers of unsaturated epoxides,
• H) polysiloxanes with functional epoxy groups,
• I) compounds obtained by epoxidation of dienes or polyenes and
• J) an epoxy curing catalyst selected from metal salts of diketones, diaryliodonium salts, UV-activatable triarylsulfonium salts, imidazoles and arylene polyamides.

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 12,000.   3. A preparation according to claim 2, wherein the reaction part taker (B) is further selected from station wagon nations of a major amount of a polyglycidyl ether with a minor amount of at least one aryl monoglycidyl ether and at least one non-bisphenolic poly epoxy compound. 4. Preparation according to claim 3, comprising up to 90 wt .-% of the reactant (A), based on the reaction Participants (A) and (B), wherein the for the preparation of the Reactant (A) used unsaturated carbon acid or the unsaturated anhydride maleic anhydride or is fumaric acid. 5. A preparation according to claim 4, wherein the reaction part recipient (A) is a poly (2,6-dimethyl-1,4-phenylene ether), which is a number average molecular weight in the range from 15,000 to 40,000 and 30 to 85% by weight, be  drew on the reactants (A) and (B). 6. A preparation according to claim 1, wherein A ¹ and A ^{7 are} each p-phenylene, Y is isopropylidene and x has a value of 0. 7. The preparation according to claim 6, wherein the reagent (C) Aluminum tris (acetylacetonate) or zinc bis (acetylacetonate) is. 8. The preparation according to claim 7, wherein reagent (C) in is present in an amount in the range of 0.5 to 10%, be drew on the total amount of reagents (A) and (B).   9. Preparation according to claim 6, the at least one phenolic compound selected from bisphenol A, pyro gallol, dihydroxydiphenylene, hydroxybenzaldehydes, pyrocatechol, resorcinol, hydroquinone, and phenol-formaldehyde and resorcinol-formaldehyde condensates and halogenated phenols, or a basic nitrogen compound selected from amines and guanidines, in particular C _4-10 alkylamines and tetraalkylguanidines, and also polyphenylene ethers with aminoalkyl-substituted end groups of formula II
as a curing accelerator, wherein Q1 is independently halogen, primary or secondary lower alkyl of up to 7 carbon atoms, phenyl, haloalkyl, aminoalkyl, hydrocarbonoxy or halogenated hydrocarbonoxy, with at least 2 carbon atoms separating the halogen and oxygen atoms and each Q ² independently being hydrogen, Halogen, primary or secondary Nie deralkyl having up to 7 carbon atoms, phenyl, halogen alkyl, hydrocarbonoxy or halogenated hydrocarbons, and each R ^{1 is} independently hydrogen or alkyl, with the condition that the total number of carbon atoms in both R ¹ radicals Is 6 or less and each R ^{2 is} independently hydrogen or a primary C _1-6 alkyl group. 10. A preparation according to claim 9, wherein the accelerator is a basic nitrogen compound in an amount the 1,000 to 1,500 ppm basic, not cursed yields nitrogen; based on the whole Accelerator and reagents (A), (B) and (C). 11. The preparation of claim 9, wherein the accelerator Tetramethylguanidine in an amount of 1,500 to Is 2,500 ppm, based on the total amount of acceleration niger and reagents (A), (B) and (C). 12. Use of the preparation after one or more of claims 1 to 11 for the preparation of a curable An article comprising a fibrous substrate comprising the preparation according to claim 1 is impregnated. 13. Use according to claim 12, characterized in that the fibrous substrate with the preparation according to claim 9 is impregnated. 14. Use according to claim 12 or 13, wherein the substrate consists of glass fibers.