GB2103621A - Thermosetting resin composition - Google Patents

Abstract

A thermosetting resin composition comprising a copolymer of an isopropenylphenol and at least one polymerizable monomer, an epoxy resin and, if necessary, an acidic substance. The above thermosetting resin composition has good hardenability and moldability and affords hardened products which are excellent in heat resistance, adhesiveness and dimensional stability.

Description

SPECIFICATION Thermosetting resin composition This invention relates to a thermosetting resin composition usable for a wide variety of applications such as molding materials, laminated materials, paint, adhesive, etc.

It is particularly desirable to have a thermosetting resin composition which has good curing ability and exhibits excellent work efficiency in its molding work and affords cured products having excellent heat resistance, adhesiveness and dimensional stability.

Epoxy resins have heretofore been used extensively, in combination with a variety of curing agents, for laminated materials, molding materials, paints, adhesives and the like. Various improvements and modifications have been incorporated in such epoxy resins to meet everincreasing demands for higher quality in various application fields thereof. However, it is considered to be rather difficult to fulfill both industrial and economical demands in a well-balanced way.

Epoxy resin compositions, which contain an amine-type curing agent, have excellent curing ability and have found wide-spread commercial utility. They are however accompanied by such drawbacks that they involve a problem in work efficiency as their pot lives are short and they must be formulated right before their actual application; they carry a safety problem since the amine-type hardening agent is said to give deleterious influence to human bodies when working on them; and resulting cured products will be poor in heat resistance. They have found only limited utility in an application field where a high degree of reliability is required, for example, in the field of electronic materials.

Acid anhydride-type curing agents have also been used for epoxy resins with a view toward improving their thermal stability. Although the thermal stability of curing products can be improved, such compositions have poor curing and requires a long time period for curing them. To compensate this shortcoming, curing accelerators such as tertiary amines have been incorporated together with acid anhydride-type curing agents. This has however resulted in another problem that their pot lives have become too short. Here again, the epoxy resin compositions have obviously been limited in their utility.

With a view toward overcoming the above-mentioned drawbacks, i.e., with a view toward obtaining epoxy resin compositions which have a suitably prolonged pot life and are excellent in curing ability further compositions have been developed by incorporating the so-called latent catyst such as dicyanamide or BF3-amine complex in epoxy resins. Although such compositions have a suitably prolonged potlife and exhibit excellent curing ability, their cured products are insufficient in thermal stability and their use is considerably limited in any application field where long-term reliability is required. In addition, such compositions involve some problems stemming from the use of such a curing agent, i.e., such problems that the curing agent has a high degree of hygroscopicity and gives off corrosive gases upon curing the compositions.

Under the above-mentioned circumstances, it has recently been attempted to improve the thermal stability of thermosetting resin compositions by means of curing agents of the phenol resin type. Principally, it has been attempted to cure epoxy resins through the incorporation of one or more novolac phenol resins thereinto.

For example, thermosetting resin compositions obtained by compounding a novolac phenol resin with epoxy resins are used in such fields as molding materials, laminated materials, paint and the like. However, their cured products are poor in dimensional stability and they are accompanied by a drawback that they are not suited for use in electronic materials and the like because the dimensional stability of cured products are poor whereas the electronic materials require a high degree of dimensional accuracy. Furthermore, their heat resistance, particularly, their heat distortion temperatures are as low as 1 00 C or so and it has been difficult to use them for electric parts, mechanical parts, automobiles, airplanes, other vehicles and the like, in other words, as so-called engineering plastics.

As special phenol resins having far better thermal stability, there have recently been developed thermosetting resin compositions which comprise a para-isopropenylphenol polymer, para-vinylphenol polymer and epoxy resin. Cured products, which resulted from the above resin compositions, are superior in heat resistance and dimensional stability to cured products resulting from conventional resin compositions of an epoxy resin and a novolac phenol resin, but they are subjected to limitations in their application for the following drawbacks. Namely, they are poor in adhesiveness and, when they are used, for example, in copperclad laminates having glass cloths as base materials, no sufficient adhesive strength is available and the interlaminar peeling between glass cloths arises.Furthermore, it is also necessary to additionally apply an adhesive between a copper cladding and its corresponding laminated material. With respect to the heat resistance of such thermosetting resin compositions, they can maintain sufficiently various physical properties such as mechanical strength as long as they are used at temperatures below 200"C. However, at elevated temperatures above 300"C, their cured products are susceptible to thermal decomposition and undergo deterioration in physical properties. Thus, they cannot be used in any application field where they are used under such high temperature conditions. This is another drawback of the aforementioned thermo-setting resin compositions.

In addition, the curing reaction between a compound having one or more phenolic hydroxyl radicals, such as the above-mentioned novolac phenol resin, para-isopropenylphenol polymer or para-vinylphenol polymer, and an epoxy resin is very slow and, in most instances, a curing accelerator is required. To cope with this problem, curing accelerators such as tertiary amines are generally employed to shorten the curing time. Use of a curing accelerator can certainly promote a hardening reaction but it results in a shortened pot life and deteriorated work efficiency.When a curing accelerator, for example, a tertiary amine is incorporated, a part of the amine evaporates upon proportioning the resin composition or carrying out its molding work, thereby raising such working problems that odor is given off and dermatitis may be developed if brought into contact with the thus-evaporated amine vapor. Use of such a curing accelerator creates another problem with respect to the physical properties of the resulting hardened products, since such cured products become poor in adhesiveness.

Another problem, which also arises from the use of an amine, is that the resulting thermosetting compositions have poor storage stability and, when stored for a long period of time, they undergo a viscosity increase or gelation and are thus not suitable from the standpoint of quality control for producing molding materials, laminated materials, paint or the like.

Accordingly, it has also been attempted to make use of a latent catalyst to prolong the pot life when a curing accelerator such as tertiary amine is incorporated. However, use of BF3-amine complex, which is a representative latent catalyst, orthe like is not satisfactory in terms of working efficiency as such a latent catalyst involves a problem due to its hygroscopicity. As a common drawback which is encountered upon using such phenol resin-type hardening agents, insufficient adhesive strength may be mentioned. This drawback has been pointed out with respect to using a resultant resin composition in composite materials.

As one of possible causes for such a drawback, the high concentration of phenolic hydroxyl groups in each phenol resin-type curing agent (i.e., a high hydroxyl value) may be mentioned, because it makes the crosslinking density greater and induces mold shrinkage.

Furthermore, it is difficult to remove unreacted phenols from novolac phenol resins, p-vinylphenol polymers or p-isopropenylphenol polymers. Thus, it has been pointed out that these resins or polymers tend to develop swelling when used at elevated temperatures. Accordingly, resin compositions making use of such phenol resin-type curing agents cannot be free from restrictions with respect to their application range.

Use of such curing agents are also limited from an economical viewpoint because it requires an additional costforthe removal of unreacted phenols or expensive starting materials.

It is therefore desirable to provide a thermosetting resin composition having good curing ability and excellent work efficiency upon molding the same as well as capable of affording cured products having excellent heat resistance, adhesiveness and dimensional stability.

It is also desirable to provide a thermosetting resin composition which can afford molded products having excellent heat resistance and a high degree of dimensional accuracy as well as having a high degree of rigidity under heat, thereby facilitating their removal from molds after molding work and improving their molding efficiency further.

A further useful aim is to provide a thermosetting resin composition which, when used in laminated materials, provides a large adhesive strength and, in the case of copperclad laminates, provides an extremely high degree of resistance agains interlaminar peeling between base materials such as paper or glass sheets and also provides an extremely high anti-peeling strength for copper cladding.

A still further desirable aim is to provide a thermosetting resin composition which, without need for any curing accelerator such as tertiary amine or the like, provides a satisfactory curing speed equivalent to or even faster than that available from the use of such a curing accelerator, satisfactorily meets the demand for achieving curing work at low temperatures in a short time period, as well as are easy to handle and process as it is completely free from the odor problem and skin trouble due to evaporation of the amine.

Moreover, it is desirable to provide a thermosetting resin composition which has excellent storage stability and does not develop any viscosity increase or gellation even when stored for a long period of time.

According to the present invention there is provided a thermosetting resin composition which is obtained by incorporating, in an epoxy resin, a copolymer of at least one polymerizable monomer and a isopropenylphenol.

Athermosetting resin composition according to this invention has been found to produce cured products having a wide range of heat distortion temperatures and an extensive range of rigidity including those having a high flexibility to those having a high rigidity may be obtained at will by changing the content of the isopropenylphenol component in the copolymer. It also has an excellent advantage of heat resistance that, particularly taking its initiation temperature of thermal decomposition as an example, it always has a value as high as 350on or higher irrespective of the content of the alkenylphenol component.

Furthermore, a thermosetting resin composition to be obtained by incorporating an acidic substance in the aforementioned composition can have good curing stability and storage ability, provide excellent work efficiency when molding and afford curing products excellent in heat resistance, adhesiveness and dimensional stability.

As has been described, the thermosetting resin composition according to this invention can have excellent work efficiency and curing ability and provide hardened products excellent in thermal stability and adhesiveness. Accordingly, it can be used in a wide variety of application fields, including the electronic material field and automobile-related field where a high degree of reliability is required. For example, when the composition of this invention is used as a molding material, its adhesion with a filler such as silica or alumina may be enhanced, thereby making it possible to improve, for example, the sealing ability of semiconductor parts. When it is used in a copperclad laminate the adhesiveness between the resin composition and its corresponding metal or glass may be improved.Thus, a satisfactory adhesive strength can be obtained without using any special adhesive between a copper cladding and its corresponding laminated material. In addition, use of the composition according to this invention can give better resistance to interlaminar peeling between glass cloths. Therefore, it is possible to obtain copperclad laminates having a high value from an industrial viewpoint.

Another characteristic feature of this invention resides in that, as mentioned above, the resin composition may be formed into a curing product having desired mechanical properties by suitably adjusting the content of the iso-propenylphenol in the copolymer. A further characteristic feature of this invention resides in that, although the isopropenylphenol monomer is a expensive material from the industrial viewpoint, its amount has been lowered by using it in the form of a copolymer with a relatively inexpensive polymerizable monomer.

Detailed description of the preferred embodiments The term "a copolymer of an isopropenylphenol and at least one polymerizable monomer" usable in the thermosetting resin composition according to this invention means a copolymer to be obtained by copolymerizing at least one monomer selected from the following polymerizable monomers and a isopropenylphenol.As exemplary polymerizable monomers which are useful in the practice of this invention, may be mentioned the following monomers: (A) Copolymerizable monomers including, for example, styrenes such as styrene, chlorostyrene, bromostyrene, a-methylstyrene, vinyltoluene and vinylxylene; acrylic esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate; methacrylic esters such as methyl methacrylate, ethyl methacrylate and n-butyl methacrylate; acrylonitrile; methacrylonitrile; fumaronitrile; acrylic acid; methacrylic acid; maleic anhydride; acrylic amide; methacrylic amide; isoprene; butadiene; dicyclopentadiene; etc.; and (B) Polymerizable monomers containing one or more basic groups including, for example, Nalkylaminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate, N,N-dimethyalaminopropyl acrylate and N,N-dimethylaminoethyl acryalte;N-alkylaminoalkyl methacrylates such as N,N-dimethylaminoethyl methacrylate, N,N-dimethylaminoethyl methacylate and N,N-dimethylaminopropyl methacylate; vinyl aniline; isopropenyl aniline; N-vinyldimethylamine; N-vinyldiethylamine; N-vinyldiphenylamine; Nvinylpyrrole; N-vinylindole; N-vinylcarbazole; N-vinylimidazole; N-vinylpyrrolidone; 2-methyl-Nvinylimidazole; 2-vinylquinoline; 3-vinylpiperidine; N-methyl-3-vinylpiperidine; vinylpyrazine; 2vinylpyridine; 3-vinylpyridine; 4-vinylpyridine; 2-methyl-5-vinylpryidine; 5-ethyl-2-vinylpyridine; N-(2dimethylaminomethyl)acrylamide; N-(2-dimethylaminoethyl)acrylamide; N-(3dimethylaminopropyl)acrylamide; N-(2-diethylaminoethyl)acrylamide; N-(2-morpholinoethyl)acrylamide; N-(2-dimethylaminomethyl)methacrylamide; N-(2-diethylaminoethy)methacrylamide; and N-(2dibutylaminomethyl)methacrylamide.

The above copolymerizable and polymerizable monomers (A) and (B) may be used solely in or in combination.

The ortho-, meta- and para-isomers of ispropenylphenol may be used alone or in combination.

Para-isopropenylphenol is particularly preferred.

In the copolymer usable in the composition according to this invention, particularly in the copolymer of one or more of the polymerizable monomers (A) and isopropenylphenol (hereinafter abbreviated as "PA-copolymer"), the polymerizable monomers (A) and isopropenylphenol may be used in the following content ranges. Namely, the polymerizable monomer or monomers (A) amount to 10 - 95 wt.%, and preferably 20 -90 wt.% of the PA-copolymer while isopropenylphenol may account for 5 - 90 wt.%, and preferably 10 - 80 wt.% of the PA-copolymer; Among the above polymerizable monomers (A), acrylonitrile is particularly preferred. A composition of this invention, which contains a copolymer of acrylonitrile and isopropenylphenol, has a variety of excellent properties.

In a copolymer of acrylonitrile and isopropenylphenol, the contents of acrylonitrile and isopropenylphenol may vary in the following ranges. Regarding acrylonitrile, it may be contained in an amount within a range of 20 - 40 wt.%, and preferably, 20 - 35 wt.% of the copolymer. When acrylonitrile is used within a range of 20-40 wt.%, cured products of particularly excellent adhesiveness can be obtained. On the other hand, with respect to isopropenylphenol, its content ranges 20 - 80 wt.%, and preferably 25 - 75 wt.% of the copolymer. When isopropenylphenol is used within the former range, the resulting resin composition will have particularly excellent curing ability and can afford hardened products of good thermal stability.

Among compositions according to this invention, thermosetting resin composition comprising a copolymer of 20 - 40 wt.% acrylonitrile and 20 - 80 wt.% isopropenylphenol and an epoxy resin are excellent in work efficiency and hardenability as well as can afford cured products having excellent thermal stability and adhesiveness. They can also solve the problems of conventional resin compositions although they are resin systems similar to conventional resin compositions making use of a phenol resin-type curing agent, and they may be used for a variety of applications without adversely affecting the characteristic meritorious features of conventional hardened epoxy resin products.

In other words, the copolymer may fall within the phenol resin-type hardening agents if one dares to classify same. However, contrary to the above-mentioned compositions making use of a phenol resin-type curing agent, it exhibits a suitable degree of curing speed when reacted with an epoxy resin without need for any additional hardening accelerator. In a resin composition according to this invention, BF3,amine complex which has heretofore been used as a latent catalyst acts as a curing retarder rather than latent catalyst. It has already been known that the BF,amine complex serves to accelerate the curing reaction of an epoxy resin when used in combination with any curing agent. However, it has not been known at all that the BF3-amine complex has a curing retarding effect.This serves as an indication that the compositions of this invention are completely novel resin systems. The compositions of this invention can provide a sufficinetly high curing speed without any curing accelerators which have heretofore been employed, and is capable of affording cured products of intended properties. However, such a curing aid may be employed without causing any problem or inconvenience in view of work cycle. Such a hardening aid may also be incorporated to retard the hardening of each resin composition according to this invention, as mentioned above.

A still further feature of the composition according to this invention resides in that the problems of molding shrinkage and poor adhesion due to an excessively high cross-linking density or poor moisture resistance probably stemming from unreacted phenolic hydroxyl groups due to suppression to their crosslinking, which problems are encountered when the aforementioned phenol resin-type curing agents are used, have been solved. Namely, the above-mentioned problems can be practically solved by adjusting the proportions of the copolymerizable components in the copolymer in accordance with the type of an epoxy resin to be compounded and the number of epoxy groups contained therein so as to permit its curing reaction to proceed to an extent to be determined depending on the end use of cured products.Further adhesiveness may also be brought about by the cyano radical of acrylonitrile copolymerized as an essential component into the copolymer, whereby improving its adhesion with fillers or composite base materials such as silica, glass, alumina and metals.

On the other hand, in a copolymer of one or more of the polymerizable monomers (B) and isopropenylphenol (hereinafter abbreviated as "PB-copolymer"), the polymerizable monomer or monomers containing one or more basic radicals and isopropenylphenol may preferably contained within the following ranges.

Namely, the polymerizable monomer containing one or more basic groups may be contained within a range of 0.01 - 20 wt.%, and preferably, 0.1 - 10 wt.%. When the polymerizable monomer containing one or more basic radicals is contained in any amounts less than 0.01 wt.%, the curing ability of the resultant resin composition will be poor while any amounts beyond 20 wt.% will lead to insufficient heat resistance, adhesiveness and dimensional stability.

In the above copolymer, isopropenylphenol may be contained within a range of 5 - 90 wt.%, and preferably, 10 - 80 wt.%. Any isopropenylphenol contents lower than 5 wt.% will result in deteriorated heat resistance and dimensional stability, whereas adhesiveness will be lowered if isopropenylphenol is used beyond 90 wt.%.

A composition according to this invention, which contains the PB copolymer, may be adjusted in curing ability at will by varying the content a basic monomer contained in the PB copolymer. Its curing time may be shortened to a considerably extent without need for any curing aid. A commonly used curing aid such as tertiary amine or the like induces such handling and working problem as the generation of odor and dermatitis due to amine vapor as a part of the amine is caused to evaporate during proportioning or molding work. It also induces problems with respect to quality control when the composition is used to produce molding material, laminated materials, paint and the like, since the resultant resin composition is deteriorated in storage stability and develops a viscosity increase or gellation when stored for a prolonged time period.Accordingly, obviation of such a curing aid has centainly improved these problems to a considerable extent.

The composition according to this invention, which contains the PB copolymer, does not require any latent catalyst such as BF3-amine complex to improve its curing ability. The problems of water and moixture resistance, which have arisen from the use of such a complex, have thus been eliminated.

The above-mentioned monomers (A) and (B) may be employed in combination. Any of the polymerizable monomers may be used in any contents so long as the principal polymerizable monomer, isopropeny Iphenyl, in the copolymer is contained within the above-specified range.

For preparing the copolymer, the monomers may be polymerized by any method such as radical polymerization, ionic polymerization, charge-transfer polymerization or the like. Radical polymerization, which uses a radical polymerization initiator, is particularly preferred in view of its ease in controlling the polymerization reaction. Exemplary radical polymerization initiators include azo-type initiators such as azobisisobutylonitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexane carbonitrile, azobis-2 amidinopropaneHCI and the like; peroxide-type initiators such as benzoyl peroxide, lauroyl peroxide, acetyl peroxide, cumenhydroxyperoxide, t-butyl hydroxyperoxide, di-t-butyl hydroperoxide, etc.; and redox initiators such as benzoyl peroxide-N,N-dimethylaniline, peroxo-bis-sulfate-sodium hydrogensulfite, and the like. It is suitable to use such an initiator in an amount of 0.01 - 10 wt.% based on the total weight of various monomers which are used as raw materials of the copolymer. The copolymer can be readily prepared by a known method, namely, applying the solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization or the like.

The molecular weight of the PA-copolymer or PB-copolymer ranges 300 - 200,000, and preferably 500 50,000. If the molecular weight is smaller than 300 or exceeds 200,000, it is impossible to obtain any thermosetting resin composition having excellent curing ability and capable of affording cured products having excellent heat resistance, adhesiveness and dimensional stability, which thermosetting resin composition is an objective of this invention.

Particularly, the molecular weight of the PA-copolymer, which contains acrylonitrile as its essential component, may range 500 - 50,000, and preferably 1,000 - 30,000. If its molecular weight is smaller than 500 or greater than 50,000, it is unfeasible to obtain cured products having excellent thermal stability, adhesiveness and moisture resistance, the provision of which cured product is an objective of this invention.

On the other hand, the epoxy resin which is useful in the thermosetting resin composition of this invention may be any epoxy resin so long as it contains at least two epoxy groups per molecule. As exemplary epoxy resins, may be mentioned a variety of epoxy resins such as epoxy resins produced from bisphenol A, halogenated bisphenol, resorcin, bisphenol F, tetradhydroxyphenylmethane, novolac, polygylcol, glycerine, triether or polyoelfinic, epoxylated soybean oil, and alicyclic epoxy resins.

The thermosetting resin composition according to this invention is prepared by compounding the aforementioned copolymer and epoxy resin. They may be compounded in various proportions as needed.

However, the copolymer is used in such an amount that the number ratio of the phenolic hydroxyl groups in the copolymer to the epoxy groups in the epoxy resin (i.e., the number ratio of OH groups to epoxy groups) ranges 0.2 - 5, and preferably 0.5 - 2. If the number ratio of OH groups to epoxy groups is smaller than 0.2 or greater than 5, it is impossible to obtain cured products of good thermal stability, adhesiveness and dimensional stability which are characteristic features of this invention.

In order to improve the storage stability of the thermosetting resin composition according to this invention, an acidic substance may also be incorporated as mentioned above. Such an acidic substance may also be either Lewis acid or Brönsted acid. As exemplary Lewis acids, may be mentioned aluminum chloride, antimony pentachloride, boron trifluoride, boron trifluoride-ethyl ether complex, boron trichloride, ferric chloride, ferric bromide, stannic chloride, titanium tetrachloride, zirconium chloride, zinc chloride, nickel chloride, etc.Among brönsted acids useful for the practice of this invention, there are inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, chiorosulfonic acid, fluorosulfonic acid, polyphosphoric acid, boric acid, hydrogen fluoride, hydrogen bromide, hydrogen iodide, perchloric acid, sulfurous acid, thiosulfuric acid, sulfinic acid, phosphinous acid, phosphonous acid, phophorous acid, phosphinic acid, phosphonic acid, arsenic acid and the like; as well as organic acids such as acetic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, methanesulfonic acid, ethanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, para-toluenesulfonic acid, benzoic acid, salicylic acid, phthalic acid, maleic acid, trimellitic acid, pryomellitic acid, etc.Such an acid substance may be incorporated in an amount of 0.01 - 10 wt.%, and preferably 0.05 - 5 wt.% per hundred parts of the mixture of the copolymer and epoxy resin. By choosing suitable acidic substance and a suitable amount within the above range, it is possible to change at will the curing speed of the thermosetting resin composition according to this invention and to improve its storage stability to a considerable extent.

Furthermore, the thermosetting resin composition of this invention may further contain a curing aid as needed. As exemplary curing aids, may be mentioned tertiary amines such as N,N-dimethylbenzylamine, triethylamine, triethanolamine and the like, nitrogen-containing heterocyclic compounds such as pyridine, piperidine, imidazole, etc.; complexes of Lewis acids and amines such as BF3-pyridine, BF3.piperidine, BF3.monoethylamine and the like; and carboxylic acid salts of amines such as N,N-dimethylbenzylamine acetate, piperidine acetate and the like. It is preferable to use such a curing aid in an amount of 0.1 - 1 0wt.% of the composition.

It is feasible to replace a part of the copolymer in the composition of this invention with another curing agent for epoxy resins, for example, an amine, acid anhydride, dicyandiamine, or novolac phenol. Here, it is obviously required to adjust the chemical equivalent of the functional group of the curing agent which takes part in the curing reaction of epoxy groups.

The thermosetting resin composition according to this invention may be prepared in the following manner. Namely, it can be prepared by mixing the copolymer and epoxy resin together and then grinding them. Alternatively, the thermosetting resin composition of this invention may also be formulated into a varnish-like state for neat application by using a solvent common to both of the copolymer and epoxy resin, for example, one or more solvents selected from the group consisting of alcohols such as methanol, ethanol, propanol, benzyl alcohol, diacetone alcohol and the like; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; ethers such as dioxane, tetrahydrofuran, methycellosolve, ethylcellosolve, and the like; esters such as ethyl acetate, butyl acetate and the like; nitrogen-containing solvents such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidine, etc; hydrocarbons such as benzene, toluene, xylene and the like; dimethylsufoxide; and the like solvents.

Exemplary use of the thermosetting resin composition according to this invention will hereinafter be described separately use by use.

For producing molding materials, a proportioned powdery composition or proportioned and partialiy hardened powdery composition may be molded at temperature of 80 - 250"C by pressure molding transfer molding, or injection molding same. Here, it is possible to add silica, calcium carbonate, talc, clay, wood flour, asbestos, glass powder, glass fibers or the like as a filler.

To obtain laminated products, the composition of this invention is dissolved in a solvent to form a varnish.

Paper or glass fibers are then impregnated with the varnish. The solvent is thereafter caused to evaporate, thereby forming prepregs. Several to several tens of such prepegs are superposed and formed into a laminate at 100 - 200"C and 20 - 100 Kg/cm2. The thus-obtained laminate may be subjected to post curing at 160 - 250"C for several hours if necessary.

In order to use the composition of th is invention as paint, a varnish or the like formulation of the composition according to this invention are coated on a substrate and then dried by heating same at 100 200"C. Alternatively, a proportioned and ground composition or a partially cured composition is applied to a steel sheet by means of an electrostatic coating machine or the like and then baked at 100 - 200"C so as to obtain a coating film of a uniform thickness.

The composition of this invention may also be employed as adhesive by optionally adding a reactive diluent such as phenyl glycidyl ether and/or a filler such as silica or asbestos to the composition of this invention, coating the resultant formation onto a material to be adhered, bringing the material into contact with its counterpart material, and heating them to 80 - 200C so as to harden the composition and adhere them together.

The composition of th is invention and its properties will hereinafter be described in the following preparation examples, formulation examples, comparative examples and test examples. It should however be understood that the present invention will not be limited to the following examples. In the following examples, all designations of part, % and ratio will mean parts by weight, % by weight and weight ratio unless otherwise specified.

Preparation Example 1 In a flask equipped with a stirrer and condenser, were charged as a mixture 15 parts of paraisopropenylphenol (hereinafter abbreviated as "PIPE"), 85 parts of styrene (hereinafter shortened to "St"), 67 parts of methyl ethyl ketone (hereinafter called "MEK") and 4.8 parts of azobisisobutylonitrile (hereinafter abbreviated as "AIBN"). They were reacted for 4 hours while heating and refluxing them under stirring.

Then, 2.4 parts of AIBN were added further and the heating and refluxing were continued for further 4 hours.

A copolymer solution of a solid content of 51.0 /O was resulted. This solution was dried under reduced pressures for 2 hours at 1700C and for further 2 hours at 200"C. Then, the residue was ground to obtain 83.0 parts of a powdery copolyer (1). According to gel permeation chromatography (hereinafter abbreviated as "GPC"), the weight average molecular weight of the copolymer (1) was 5,600 while its hydroxyl value was found to be 70mg KOH/g in accordance with the acetylation method.

Preparation Example 2 A flask equipped with a stirrer and condenser was charged with a mixture of 30 parts of PIPE, 70 parts of methyl methacrylate (hereinafter called "MMA"), 100 parts of MEK and 4.8 parts of AIBN. They were caused to undergo polymerization for 4 hours while being heated and refluxed under stirring. Then, 2.4 parts of AIBN were added further, followed by heating and refluxing the resultant reaction mixture for 4 hours. A copolymer solution was obtained with a solid content of 43.0%. This solution was dried under reduced pressures for 2 hours at 170"C and then for further 2 hours at 200"C. The residue was thereafter ground to give 84.5 parts of a powdery copolymer (2). A GPC analysis indicated that the copolymer had a weight average molecular weight of 6,200.Its hydroxyl value was found to be 137mg KOH/g by the acetylation method.

Preparation Example 3 In a flask equipped with a stirrer and condenser, were placed as a mixture 50 parts of PIPE, 50 parts of methyl acrylate (hereinafter abbreviated as "MA"), 233 parts of MEK and 4.8 parts of AIBN. They were allowed to undergo polymerization while being heated and refluxed under stirring. Thereafter, 2.4 parts of AIBN were added further, followed by heating and refluxing the resultant mixture for 4 hours. A copolymer solution of a solid content of 28.5% was resulted. The solution was dried under reduced pressures for 2 hours at 170"C and then for further 2 hours at 200"C. The residue was comminuted to give 93.0 parts of a powdery copolymer (3). The weight average molecular weight of the copolymer was determiend to be 9,400 by GPC, while its hydroxyl value was found to be 231 mg KOH/g by the acetylation method.

Preparation Example 4 A flask, which was equipped with a stirrer and condenser, was charged with a mixture of 70 parts of PIPE, 30 parts of MA, 233 parts of MEK and 4.8 parts of AIBN. They were caused to undergo polymerization for 4 hours while being heated and refluxed under stirring. Then, 2.4 parts of AIBN were added further, followed by heating and refluxing the resultant mixture for 4 hours. A copolymer solution of a solid content of 27.9% was obtained. The solution was dried under reduced pressures for2 hours at 1700C and then forfurther2 hours at 200"C. The residue was pulverised to obtain 91.5 parts of a powdery copolymer (4). A GPC analysis indicated that the copolymer had a weight average molecular weight of 9,000. Its hydroxyl value was found to be 273 mg KOH/g by the acetylation method.

Preparation Example 5 One hundred (100) parts of cyclohexanone (hereinafter called "CH") were charged into a flask equipped with a stirrer and condenser and heated and refluxed under stirring. To the CH, were dropped over 3 hours a solution mixture consisting of 25 parts of PIPE, 33 parts of AN, 42 parts of St, 50 parts of CH and 3.5 parts of AIBN to carry out polymerization. The resulting mixture was heated for 1 hour under refluxing, resulting in a copolymer solution having a solid content of 39.4%. The thus-obtained solution was dried under reduced pressures for 2 hours at 170 C and then a further 2 hours at 200"C. The residue was ground to obtain 94.0 parts of a powdery copolymer (5). The weight average molecular wieght of the copolymer was determined to be 10,000 by GPC.Its hydroxyl value was 99 mg KOH/g according to the acetylation method.

Preparation Example 6 Into a flask equipped with a stirrer and condenser, were charged as a mixture of 30 parts of PIPE, 33 parts of AN, 37 parts of St, 233 parts of MEK and 4.8 parts of AIBN. They were allowed to undergo polymerization for 4 hours while being heated and refluxed under stirring. Thereafter, 2.4 parts of AIBN were added further, followed by heating and refluxing the resultant mixture for 4 hours. A copolymer solution of a solid content of 29.4% was resulted. This solution was dried under reduced pressures for 2 hours at 170C and then for further 2 hours at 200"C. The residue was comminuted to obtain 95.5 parts of a powdery copolymer (6). A GPC analysis indicated that the copolymer had a weight average molecular weight of 8,800.Its hydroxyl value was found to be 117 mg KOH/g bytheacetylation method.

Preparation Example 7 A flask equipped with a stirrer and condenser was charged with a mixture of 40 parts of PIPE, 25 parts of AN, 25 parts of St, 10 parts of MA, 233 parts of MEK and 4.8 parts of AIBN. They were caused to undergo polymerization for 4 hours while heated and refluxed, thereby obtaining a copolymer solution of a solid content of 28.6%. This solution was dried under reduced pressures for 2 hours at 1700C and then for a further 2 hours at 200"C. The residue was ground to give 93.0 parts of a powdery copolymer (7). The weight average molecular weight of the copolymer was found to be 8,200 by GPC while its hydroxyl value was determined to be 159 mg KOH/g by the acetylation method.

Preparation Example 8 One hundred (100) parts of methyl isobutyl ketone (hereinafter shortened to "MIBK") were charged into a flask equipped with a stirrer and condenser. It was heated and refluxed under stirring, to which a solution mixture of 50 parts of PIPE, 32 parts of AN, 18 parts of St, 50 parts of MIBK and 6 parts of AIBN was added dropwise in the course of 3 hours, thereby allowing them to undergo polymerization. The resulting mixture was heated for further 1 hour under refluxing, thereby obtaining a copolymer solution having a solid content of 37.5%. The solution was dried under reduced pressures for 2 hours at 1700C and then for further 2 hours at 200"C. The residue was comminuted to give 93.0 parts of a powdery copolymer (8).Its weight average molecular weight was 8,300 according to a GPC analysis carried out on the copolymer. Its hydroxyl value by the acetylation method was 196 mg KOH/g.

Preparation Example 9 Into a flask equipped with a stirrer and condenser, were charged as a mixture 60 parts of PIPE, 25 parts of AN, 5 parts of St, 10 parts of MA, 233 parts of MEK and 4.8 parts of AIBN. They were heated and refluxed under stirring for 4 hours, thereby undergoing polymerization. A copolymer solution having a solid content of 28.3% was resulted. This solution was dried under reduced pressures for 2 hours at 170"C and then for a further 2 hours at 2000C. The residue was ground to give 92.7 parts of a powdery copolymer (9). A GPC analysis indicated that the copolymer had a weight average molecular weight of 8,900. Its hydroxyl value was found to be 240 mg KOH/g by the acetylation method.

Preparation Example 10 One hundred (100) parts CH was charged into a flask equipped with a stirrer and condenser and then heated and refluxed, which which a solution mixture consisting of 70 parts of PIPE, 30 parts of AN, 50 parts of CH and 3.2 parts of AIBN was dropped over 3 hours to undergo polymerization. The resultant mixture was heated under refluxing for further 1 hour, thereby obtaining a copolymer solution of a solid content of 38.3%.

This solution was dried under reduced pressures for 2 hours at 170"C and then for further 2 hours at 200do.

The residue was comminuted to give 93.5 parts of a powdery copolymer (10). According to a GPC analysis, its weight average molecular weight was 8,500. It was found by the acetylation method to have a hydroxyl value of 273 mg KOH/g.

Preparation Example ii Into a flask, were added 1 part of 2-vinylpyridine, 50 parts of PIPE, 30 parts of MMA, 20 parts of AN, 200 parts of MEK and 3.6 parts of AIBN. They were caused to undergo polymerization at their refluxing temperature, thereby obtaining a copolymer solution having a solid content of 31%. The thus-obtained solution was dried for 4 hours in vacuo at 170"C and the residue was ground, resulting in 93 parts of a powdery copolymer (11). The content of 2-vinylpyridine in the copolymer was 0.8% when determined by a non-aqueous titration in a dioxane solvent using the standard perchloric acid solution. Its weight average molecular weight was 10,000 according to a GPC analysis.

Preparation Example 12 Into a flask, were charged 3 parts of N-(2-diethylaminoethyl)acrylamide, 50 parts of PIPE, 30 parts of MMA, 20 parts of AN, 200 parts of MEK and 3.6 parts of AIBN. They were caused to undergo polymerization at their refluxing temperature for 10 hours, resulting in a copolymer solution having a solid content of 31%. This solution was dried in vacuo at 170"C for 4 hours and the residue was comminuted to obtain 92 parts of a powdery copolymer (12). The content of N-(2-diethyaminoethyl)acrylamide in the copolymerwas determined to be 2.6% when measured in the same manner as that employed in Preparation Example 11. Its GPC analysis indicated that the copolymer had a weight average molecular weight of 10,000.

Preparation Example 13 A flask was charged with 1.5 parts of N,N-diethylaminoethyl acrylate, 70 parts of PIPE, 30 parts of AN, 200 parts of MEK and 4 parts of AIBN. They were polymerized at their refluxing temperature for 10 hours, resulting in a copolymer solution having a solid content of 32%. This solution was dried in vacuo at 170"Cfor 4 hours and the residue was ground to give 97 parts of a powdery copolymer (13). An analysis of the content of dimethylaminoethyl acrylate in the copolymer by the same method as in Preparation Example 11 indicated that the content was 1.4%. Its weight average molecualr weight was determined to be 8,000 by GPC.

Preparation Example 14 Into a flask, were charged 0.5 parts of N,N-dimethylaminoethyl methacrylate, 30 parts of PIPE, 30 parts of AN, 40 parts of St, 200 parts of MEK and 4.6 parts of AIBN. They were polymerized for 10 hours at their refluxing temperature, resulting in a copolymer solution having a solid content of 33%. This solution was dried in vacuo at 170"C for 4 hours and the residue was ground to give 98 parts of a powdery copolymer (14).

The content of dimethylaminoethyl methacrylate in the copolymer was determined in accordance with the same method as that used in Preparation Example 11. It was found to be 0.5%. The weight average molecular weight of the copolymer was 5,000 according to GPC.

Preparation Example 15 A flask was charged with 1 part of 3-vinyl piperidine, 20 parts of PIPE, 50 parts of a-methylstyrene, 30 parts of AN, 200 parts of MEK and 4.6 parts of AIBN. They were allowed to undergo polymerization for 10 hours at their refluxing temperature, thereby obtaining a copolymer solution having a solid content of 32%. This solution was dried in vacuo at 170"C for 4 hours and the residue was comminuted to give 95 parts of a powdery copolymer (15). The content of 3-vinylpiperidine in the copolymer was determined in accordance with the same method as that used in Preparation Example 11. It was found to be 0.8%. According to a GPC analysis, the weight average molecular weight of the copolymer was 6,000.

Preparation Example 16 Into a flask, were charged 1 part of para-isopropenylaniline, 50 parts of PIPE, 50 parts of MA, 200 parts of MEK and 4.6 parts of AIBN. They were polymerized for 10 hours at their refluxing temperature, leading to a copolymer solution having a solid content of 29%. The solution was dried in vacuo at 1 70"C for 4 hours and the residue was pulverised to give 90 parts of a powdery copolymer (16). The content of paraisopropenylaniline in the copolymer was determined by the same method as in Preparation Example 11. It was found to be 0.9%. A GPC analysis indicated that the copolymer had a weight average molecular weight of 4,500.

Formulation Example 1 In 100 parts of acetone, were dissolved 80 parts of the powdery copolymer (1) and 20 parts of an epoxy resin of the bisphenol a type ("EPICOAT 828", a product of Shell Chemical Co. Ltd.,; chemical equivalent of epoxy radicals: 190; will be abbreviated as "EPICOAT 828") to form a uniform solution. This solution was dried in vacuo for 24 hours at room temperature to drive off most of the acetone, resulting in the provision of 101 parts of a thermosetting resin composition.

Formulation Example 2 Sixty eight (68) parts of the powdery copoiymer (2) and 32 parts of "EPICOAT 828" were dissolved in 100 parts of acetone to give a homogeneous solution. The solution was thereafter dried in vacuo at room temperature for 24 hours so as to drive off most of the acetone, thereby providing 101 parts of a thermosetting resin composition.

Formulation Example 3 Fifty six (56) parts of the powdery copolymer (3) 44 parts of "EPICOAT 828" were fused and mixed together at 90"C. The resultant mixture was ground to give 95 parts of a thermosetting resin composition.

Formulation Example 4 Fifty two (52) parts of the powdery copolymer (4) and 48 parts of "EPICOAT 828" were fused and mixed together at 900C. The resultant mixture was comminuted to provide 96 parts of a thermosetting resin composition.

Comparative Example 1 Fourty (40) parts of poly-para-isopropenylphenol (weight average molecular weight: 2,500) and 60 parts of "EPICOAT 828" were fused and mixed together at 90"C. The resultant mixture was ground to give 98 parts of a thermosetting resin composition.

Formulation Example 5 In 400 parts of acetone, were dissolved into a homegeneous solution 282 parts of the powdery copolymer (5), 100 parts of "EPICOAT 828" and 1 part of BF3.piperidine complex as a hardening aid. The solution was dried under reduced pressures for 24 hours at room temperature to drive off most of the acetone, thereby obtaining 385 parts of a thermosetting resin composition.

Formulation Example 6 In 300 parts of acetone, were dissolved into a homogeneous solution 235 parts of the powdery copolymer (6) and 94 parts of a novolac epoxy resin ("EPICOAT 154", product of Shell Chemical Co., Ltd.; chemical equivalent of epoxy radicals: 178). The solution was dried under reduced pressures for 24 hours at room temperature so as to drive off most of the acetone, resulting in 335 parts of a thermosetting resin composition.

Formulation Example 7 In 320 parts of acetone, were dissolved into a uniform solution 235 parts of the powdery copolymer (6), 100 parts of "EPICOAT 828" and, as a hardening aid, 1 part of BF3.piperidine complex. The solution was dried under reduced pressures for 24 hours at room temperature so as to drive off most of the acetone, thereby obtaining 340 parts of a thermosetting resin composition.

Formulation Example 8 In 170 parts of acetone, were dissolved into a homogeneous solution 176 parts of the powdery copolymer (70 and 100 parts of "EPICOAT 828". The solution was dried under reduced pressures for 24 hours at room temperature so as to drive off most of the acetone, leading to 282 parts of a thermosetting resin composition.

Formulation Example 9 In 190 parts of acetone, were dissolved into a uniform solution 95 parts of the powdery copolymer (8), 30 parts of "EPICOAT 828", 70 parts of YDB-340 (a brominated epoxy resin produced by Tohto Chemical Co., Ltd; chemical equivalent of epoxy radicals: 355) and, as a hardening aid, 1 part of BF3,piperidine complex.

The solution was dried under reduced pressures at room temperature so as to remove most of the acetone, resulting in 204 parts of a thermosetting resin composition.

Formulation Example 10 In 350 parts of acetone, were dissolved into a uniform solution 118 parts of the powdery copolymer (9) and 250 parts of an epoxy resin of the bisphenol A type ("EPICOAT 1001"), product of Shell Chemical Co. Ltd.; chemical equivalent of epoxy radicals: 475; will hereinafter be abbreviated as "EPICOAT 1001"). This solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, resulting in 380 parts of a thermosetting resin composition.

Formulation Example 11 In 180 parts of acetone, were dissolved into a homogeneous solution 100 parts of the powdery copolymer (10) and 100 parts of "EPICOAT 828". This solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, leading to 205 parts of a thermosetting resin composition.

Formulation Example 12 In 180 parts of acetone, were dissolved into a uniform solution 100 parts of the powdery copolymer (10), 100 parts of "EPICOAT 828" and, as a curing aid, 1 part of BF3.piperidine complex. The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 207 parts of a thermosetting resin composition.

Comparative Example 2 In 45 parts of acetone, were dissolved 33 parts of 4,4-diaminodiphenylsulfone, 100 parts of "EPICOAT 828" and, as a hardening accelerator, BF3.monoethylamine complex to obtain a uniform solution. This solution was then dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 135 parts of a thermosetting resin composition.

Comparative Example 3 Four (4) parts of dicyandiamide, 100 parts of "EPICOAT 1001" and, as a curing accelerator, 0.2 part of dimethylbenzylamine were fused and mixed together at 90"C. The resulting mixture was ground, resulting in 103 parts of a thermosetting resin composition.

Comparative Example 4 In 100 parts of acetone, were dissolved into a uniform solution 55 parts of a phenol novolac resin, #1000 HS (phenol resin produced by Mitsui Toatsu Chemicals Incorporated; hydroxyl value: 540 mg KOH/g; will hereinafter be abbreviated as "#1000 HS") and 100 parts of "EPICOAT 828". The solution was dried under reduced pressures at room temperature for 24 hours to drive off most of the acetone, leading to the provision of 157 parts of a thermosetting resin composition.

Comparative Example 5 In 100 parts of acetone, were dissolved into a uniform solution 55 parts of "#1000 HS", 100 parts of "EPICOAT 828" and, as a curing accelerator, 1 part of BF3-piperidine complex. The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 158 parts of a thermosetting resin composition.

Comparative Example 6 Sixty four (64) parts of poly-para-vinylphenol (product of Maruzen Petroleum Co., Ltd.; hydroxyl value: 467 mg KOH/g; will hereinafter be abbreviated as "PPVP") and 100 parts of "EPICOAT 828" were dissolved in 150 parts of acetone to form a homogeneous solution. The solution was then dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, leading to 167 parts of a thermosetting resin composition.

Comparative Example 7 In 50 parts of acetone, were dissolved into a uniform solution 64 parts of PPVP, 100 parts of "EPICOAT 828" and, as a curing accelerator, BF3-piperidine complex. The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 168 parts of a thermosetting resin composition.

Formulation Example 13 In 100 parts of acetone, were dissolved into a uniform solution 59 parts of the powdery copolymer (11), and 41 parts of "EPICOAT 828". The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 101 parts of a thermosetting resin composition.

Formulation Example 14 Fifty nine (59) parts of the powdery copolymer (12) and 41 parts of "EPICOAT 828" were dissolved in 100 parts of acetone to form a uniform solution, which was then dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone. One hundred (100) parts of a thermosetting resin composition were resulted.

Formulation Example 15 In 100 parts of acetone, were dissolved into a uniform solution 50 parts of the powdery copolymer (13) and 50 parts of "EPICOAT 828". The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 100 parts of a thermosetting resin composition.

Formulation Example 16 Seventy (70) parts of the powdery copolymer (14) and 30 parts of "EPICOAT 828" were fused and mixed together at 60"C. The mixture was comminuted in a pulverizer, thereby obtaining 96 parts of a thermosetting resin composition.

Formulation Example 17 In 100 parts of acetone, were dissolved into a uniform solution 78 parts of the powdery copolymer (15) and 22 parts of "EPICOAT 828". The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 101 parts of a thermosetting resin composition.

Formulation Example 18 In 100 parts of acetone, were dissolved into a uniform solution 59 parts of the powdery copolymer (16) and 41 parts of "EPICOAT 828". The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, leading to 102 parts of a thermosetting resin position.

Comparative Example 8 In 100 parts of acetone, were dissolved into a homogeneous solution 35 parts of a multi-purpose novolac phenol resin having a softening point in the range of 92-98"C ("NOVOLAC 2000", product of Mitsui Toatsu Chemicals Incorporated), 65 parts of "EPICOAT 828" and, as a hardening accelerator, 0.7 part of N,N-dimethylbenzylamine. The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, resulting in 99 parts of a thermosetting resin composition.

Comparative Example 9 In 100 parts of acetone, were dissolved into a uniform solution 59 parts of a para-isopropenylphenol polymer having a weight average molecular weight of 10,000,41 parts of "EPICOAT 828" and, as a hardening accelerator, 0.5 part oftriethanolamine. The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby leading to 103 parts of a thermosetting resin composition.

Comparative Example 10 In 100 parts of acetone, were dissolved into a uniform solution 59 parts of a powdery copolymer, which had a weight average molecular weight of 4,500 and had been obtained in the same manner as in Preparation Example 16 except for the omitting of 1 part of para-isopropenylaniline as a polymerizable monomer, 41 parts of "EPICOAT 828" and, as a curing accelerator,0.5 part of aniline. The soltion was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 102 parts of a thermosetting resin composition.

Formulation Example 19 In 100 parts of acetone, were dissolved into a uniform solution 59 parts of the powdery copolymer (11), 41 parts of "EPICOAT 828" and 1 part of para-toluenesulfonic acid. The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, leading to 102 parts of a thermosetting resin composition.

Formulation Example 20 In 100 parts of acetone, were dissolved into a homegeneous solution 59 parts of the powdery copolymer (12), 41 parts of "EPICOAT 828" and 1.0 part of methanesulfonic acid. The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 103 parts of a thermosetting resin composition.

Formulation Example 21 In 100 parts of acetone, were dissolved into a uniform solution 50 parts of the powdery copolymer (13), 50 parts of "EPICOAT 828" and 0.6 part of boron trifluoride-ethyl ether complex. The solution was dried under reduced pressures at room temperature for 24 hours so as to drive off most of the acetone, thereby obtaining 101 parts of a thermosetting resin composition.

Formulation Example 22 Seventy (70) parts of the copolymer (14), 30 parts of "EPICOAT 828" and 0.3 part of aluminum chloride were fused and mixed together at 90"C. The resultant mixture was then ground to obtain 96 parts of a thermosetting resin composition.

Formulation Example 23 In 100 parts of acetone, were dissolved into a homogeneous solution 78 parts of the copolymer (15), 22 parts of "EPICOAT 828" and 0.5 part of trichloroacetic acid. The solution was dried under reduced pressures at room temperature for 24 hours so as to remove most of the acetone, thereby obtaining 102 parts of a thermosetting resin composition.

Formulation Example 24 In 100 parts of acetone, were dissolved into a uniform solution 59 parts of the powdery copolymer (16), 41 parts of "EPICOAT 828" and 0.5 part of chlorosulfonic acid. The solution was dried under reduced pressures at room temperature for 24 hours to drive off most of the acetone, resulting in 102 parts of a thermosetting resin composition.

Comparative Example 11 The procedure of Formulation Example 24 was exactly followed exceptforthe omitting of chlorosulfonic acid, resulting in the provision of 102 parts of a thermosetting resin composition.

The following physical properties were measured with respect to the thermosetting resin compositions obtained in Formulation Examples 1 - 24 and Comparative Examples 1 - 11.

Performance testing procedure A) Gelation time: According to the procedure prescribed in JIS K6910, each composition was placed on a hot plate of 150"C or 160"C and time was measured until no stringiness occurred.

B) Amine odor: Each composition was placed in an amount of 10 g in a testing tube of 20 cc. The testing tube with the composition was immersed in a constant-temperature bath of 100 C. Amine odor was checked at a point above the testing tube 30 minutes later.

C Heat resistance of copperclad laminate to hot solder and anti-peeling strength of copper cladding: (1) Preparation ofcoppercladlaminates: One hundred (100) g of each composition were dissolved in 100 g of methyl ethyl ketone to form a uniform solution. Glass cloths ("WE18K104BZ-2", product of Nitto Boseki Co., Ltd., 0.18 mm thick) were soaked in the above solution, i.e., a varnish. The varnish-impregnated glass cloths were taken out of the solution and dried in air for 10 minutes. They were then dried for 5 minutes in a drier maintained at 140"C to obtain prepregs.

Eight sheets of the thus-obtained prepregs were superposed, sandwiched by copper claddings having a thickness of 35 um and pressure formed for 20 minutes under the conditions of 160'C and 30 Kglcm2 by means of a press. Thereafter, the temperature and pressure were increased respectively to 170"C and 70 Kg/cm2 and the heating and pressing operation was carried out for further 3 hous under such conditions. A double copperclad laminate of 16 mm thick was resulted.

(2) Resistance to hot solder: Following the procedure prescribed under JIS C6481, each copperclad laminate was allowed to float on a hot solder bath. There was measured the highest temperature at which the copper cladding does not develop swelling or peeling.

(3) Anti-peeling strength of copper cladding: The procedure prescribed under JIS C6481 was followed.

(4) Interlaminar adhesive strength between glass cloths: Each laminate, which had been obtained in C)-(1), was immersed for 30 minutes in a 40% aqueous solution of ferric chloride maintained at 20-40"C to subject it to an etching treatment, thereby removing the copper claddings. Then, the thus-obtained laminate was cut into strips, each, having a width of 1 cm. Each strip was burned at one end to remove its resin component. The glass cloths thus exposed at one end of the strip were peeled off to a suitable length and the adhesive force between glass cloths was measured by a tensile strength testing machine while applying a peeling force at 50 mm/min. in a direction perpendicular to the laminate.

(5) Thermal stability of laminate {weight loss under heating): To investigate the thermal stability of each laminate, its copper claddings were subjected to an etching treatment in the same manner as in C)-(4). The resulting laminate was heat-treated for a predetermined time period in a hot-air recirculation drier maintained at 250"C. Then, its weight loss due to the heat treatment was determined.

D) Molding shrinkage rate: (1) Preparation ofmoldingpowder: Two hundred (200) grams of silica powder and 1 gram of magnesium stearate were added to 100 g of each composition. The resulting mixture was fused and kneaded for 4 minutes by hot rolls of 100 C.

Then, the thus-kneaded mixture was ground by a grinding machine to 20 mesh or smaller, thereby providing molding powder.

(2) Molding shrinkage rate: The above molding powder was employed. Each molding shrinkage rate was determined in accordance with the procedure prescribed underJlS K6911.

E) Initiation temperature of thermal decomposition: Each composition was heated and hardened for 5 hours in a drier maintained at 170"C. The thus-heated product was subjected to a thermogravimetric analysis (TGA) using a thermobalance T-B1OB (manufactured by Shimazu Seisakusho K.K.) in an air atmosphere with a heating rate of 10 C/min. so as to determine its initiation temperature of thermal decomposition (5% weight loss temperature).

F) Storage stability of varnish Each of the above compositions was dissolved in methyl ethyl ketone to form varnish having a solid content of 50%. This solution was allowed to stand for 3 months and its viscosity was determined to find out whether any viscosity increase had taken place. Test results are shown in Table 6, in which each circle mark indicates no viscosity increase and each cross mark means a viscosity increase.

Table 1 With respect to the thermosetting resin compositions obtained in Formulation Examples 1 through 4 and Comparative Example 1, performance tests were conducted in accordance with the testing procedures A) and C). Test results are shown in Table 1.

TABLE 1 Gelation Time Anti-peeling Strength (sec./160 C) of Copper Cladding (Kg/cm) Formulation Example 1 758 1.88 Formulation Example 2 535 1.94 Formulation Example 3 394 2.16 Formulation Example4 288 2.07 Comparative Example 1 1,345 1.25 Test2 The solution of the thermosetting resin composition obtained in each of Formulation Examples 5 to 12 and Comparative Examples 4 though 7 was subjected to drying under reduced pressures to drive off most of its solvent. The gelation time of the residue was measured on a hot plate of 160"C in accordance with the testing procedure A). Test results are shown in Table 2.

TABLE 2 Formulation Example No. 5 6 7 8 9 10 11 12 Gelation Time 552 225 386 225 367 348 154 185 (sec./160OC) Comparative Example No. 4 5 6 7 Gelation Time > 1800 812 1254 607 (sec.l1 60"C) Test3 A weight loss under heating was determined by the testing procedure C)-(5) on each of the thermosetting resin compositions obtained in Formulation Examples 5,7,8, 10 and 12 as well as Comparative Examples 2 and 3. Test results are tabulated in Table 3.

The good thermal stability of the hardened product obtained from each of the compositions according to this invention will be understood from the table.

TABLE 3 Weight Loss (%) under Heating (at 250"C) 100 hrs 200 hrs 400 hrs 600 hrs 800 hrs No. 5 2.30 3.00 3.82 4.70 5.60 No.7 2.12 2.75 3.46 4.18 5.00 No. 8 2.03 2.65 3.38 4.20 5.13 No. 10 1.94 2.70 3.48 4.23 5.08 * No.12 1.74 2.49 3.35 4.12 5.06 No.4 2.04 4.07 6.97 10.93 15.13 No. 3 2.59 3.74 4.86 6.00 7.32 Note: * Formulation Example ** Comparative Example Formulation Example Test4 Using the thermosetting resin compositions obtained in Formulation Examples 5 to 12 as well as Comparative Examples 6 and 7, double copperclad laminates were prepared in accordance with the testing method C)-(1 ). The laminate resulted from the thermosetting resin composition of Comparative Example 6 was also subjected to a post-hardening treatment at 200"C and for 3 hours in a hot-air recirculation drier. To investigate the adhesiveness of each of the laminates, the anti-peeling strength of its copper cladding and the interlaminar adhesive strength between its glass cloths were measured respectively in accordance with the testing method C)-(3) and C)-(4). Test results are given in Table 4.

TABLE 4 Anti-peeling Strength Interlaminar Adhesive of Copper Cladding Strength (Kg/cm) (Kg/cm) Formulation Example 5 2.05 1.0* Formulation Example 6 2.07 1.0* Formulation Example 7 2.13 1.0* Formulation Example 8 2.09 1.0* Formulation Example9 2.10 1.0* Formulation Example 10 2.06 1.0* Formulation Example 11 1.95 0.80 Formulation Example 12 1.98 0.80 Comparative Example 6 1.14 0.32 Comparative Example 7 1.61 0.45 Note: * Glass cloths were broken off since the interlaminar adhesive strength was extremely high.

Test 5 With respect to the thermosetting resin compositions obtained in Formulation Examples 13 to 24 and Comparative Example 8 to 11, their various performances were tested. Test results are summarized in Tables 5 and 6.

TABLE 5 Formulation Example Comp. Ex.

No.13 No.14 No.15 No.16 No.17 No.18 No.8 No.10 Gelation Time (sec./150"C) 300 210 120 200 210 290 150 320 Amine Odor none none none none none none sensed sensed 20 sec. 370 370 390 380 380 370 340 360 Resistance to Hot Solder ( C) 180 sec. 330 330 350 340 340 330 310 330 Anti-Peeling Strength of Copper Cladding (Kg/cm) 2.0 2.0 2.0 2.0 1.8 1.1 1.4 Molding Shrinkage Rate (%) 0.39 0.40 0.40 0.38 0.35 0.46 0.85 0.50 Initiation Temperature of Thermal Decomposition ("C) 360 360 385 370 370 360 330 350 (5% Weight Loss Temperature) TABLE 6 Formulation Example Comp. Ex.

No.19 No.20 No.21 No.22 No.23 No.24 No.9 No.11 GelationTime(sec./150 C) 420 360 300 420 420 300 420 180 Amine Odor none none none none none none sensed none Storage Stability of Varnish 0 0 0 0 0 O X X 20 sec. 370 370 390 380 380 370 320 370 Resistance to Hot Solder ( C) 180 sec. 330 330 350 340 340 330 290 330 Anti-Peeling Strength of Copper Cladding (Kg/cm) 2.0 2.0 2.0 2.0 2.0 1.8 1.2 1.8 Molding Shrinkage Rate (%) 0.39 0.40 0.40 0.38 0.35 0.46 0.64 0.46 Initiation Temperature of Thermal Decomposition ("C) 360 360 385 370 370 360 305 360 (5% Weight Loss Temperature)

Claims (19)

1. Athermosetting resin composition comprising a copolymer of an isopropenylphenol and at least one polymerizable monomer and an epoxy resin.

2. The thermosetting resin composition according to Claim 1, wherein the polymerizable monomer contains one or more basic groups.

3. The thermosetting resin composition according to Claim 1, wherein the polymerizable monomer is selected from styrenes, acrylic esters, methacrylic esters, acrylonitrile, methacrylonitrile, fumaronitrile, acrylic acid, methacrylic acid, maleic anhydride, acrylic amide, isoprene, butadiene and dicyclopentadiene.

4. The thermosetting resin composition according to Claim 1, wherein the polymerizable monomer is acrylonitrile.

5. The thermosetting resin composition according to Claim 1, further comprising an acidic substance.

6. The thermosetting resin composition according to Claim 1, wherein the isopropenylphenol is para-isopropenylphenol.

7. The thermosetting resin composition according to Claim 2, wherein the basic group containing polymerizable monomer is selected from N-alkylaminoalkyl acrylates and N-alkylamino methacrylates.

8. The thermosetting resin composition according to Claim 2, wherein the basic radial-containing polymerizable monomer is selected from isopropenyl radical-containing amines, N-vinylalkylamines, N-vinylarylamines, N-vinyl heterocyclic compounds, N-alkylaminoalkyl acrylamides and N-alkylaminoalkyl methacrylamides.

9. The thermosetting resin composition according to Claim 1, wherein the copolymer contains 0.01 - 20 wt.% of the polymerizable monomer and 5 - 90 wt.% of the isopropenylphenol.

10. The thermosetting resin composition according to Claim 1, wherein the copolymer 0.1 - 10 wt.% of the polymerizable monomer and 10 - 80 wt.% of the isopropenylphenol.

11. The thermosetting resin composition according to Claim 3, wherein the copolymer contains 10 - 95 wt.% of the polymerizable monomer and 5 - 90 wt.% of the isopropenylphenol.

12. The thermosetting resin composition according to Claim 4, wherein the copolymer contains 20 - 40 wt.% of acrylonitrile and 20 - 80 wt.% of the isopropenylphenol.

13. The thermosetting resin composition according to Claim 1,wherein the molecular weight of the copolymer is within a range of 300 - 200,000.

14. The thermosetting resin composition according to Claim 12, wherein the molecular weight of the copolymer is within a range of 500 - 50,000.

15. The thermosetting resin composition according to Claim 1, wherein the number ratio of the phenolic hydroxyl groups in the copolymer to the epoxy groups in the epoxy resin is within a range of 0.5 - 2.

16. The thermosetting resin composition according to Claim 5, wherein the acidic substance is a Lewis acid or Br6nsted acid.

17. The thermosetting resin composition according to Claim 5, wherein the acidic substance is contained in an amount of 0.01 - 10 parts by weight per hundred parts of the mixture of the epoxy resin and copolymer.

18. The thermosetting resin composition according to Claim 12, further comprising a BF3 amine complex in an amount of 0.01 - 10 wt.% based on the composition.

19. A thermosetting resin composition according to claim 1 substantially as described herein.