WO2017092471A1 - Thermosetting alkyl polyol glycidyl ether resin composition and application thereof - Google Patents

Abstract

Provided is a thermosetting alkyl polyol glycidyl ether resin composition and application thereof. The resin composition is composed of epoxy resin as the main resin component. The epoxy resin comprises alkyl polyol glycidyl ether, which accounts for 50-100% by mass percent of the main resin component. The composition is useful in the preparation of prepregs, laminates and printed circuit boards, etc. By using the epoxy resin having the alkyl polyol glycidyl ether molecular structure as the main resin component, the laminates prepared exhibit a low dielectricity while maintaining good thermal property and bonding property. The preparation cost is low, the preparation method is simple, and the prospect of application is broad.

Description

[Invention name established by ISA according to Rule 37.2] Thermosetting alkyl polyol glycidyl ether resin composition and application thereof Technical field

The present invention is an epoxy resin composition and relates to a thermosetting alkyl polyol glycidyl ether resin composition and use thereof.

Background technique

With the rapid development of wireless transmission products and the leap forward of high-frequency transmission technology, higher requirements are placed on the dielectric properties of materials. The materials of existing epoxy resin and phenolic resin systems are unable to meet advanced applications, especially Meet the requirements of high frequency printed circuit boards. As a substrate material of a printed circuit board having a low dielectric loss, there is a fluorine-based resin, but such a resin is expensive and difficult to process, and its application is limited to the military and aerospace fields. In addition, polyphenylene ether resin has good mechanical properties and excellent dielectric properties, and is increasingly becoming the resin material of choice for high-frequency printed circuit board substrates. However, polyphenylene ether with double bonds is currently used to manufacture high-frequency high-speed sheets. Through the free radical reaction, special production equipment must be used, and the prepreg has a short shelf life, and the production process conditions are difficult to adjust and the cost is high.

CN101684191B proposes that a composite cured epoxy resin using benzoxazine, styrene-maleic anhydride or a phosphorus-containing curing agent can obtain a cured product having a lower dielectric constant and dielectric loss, but only styrene-Malay. Anhydrides to reduce the dielectric properties of materials inevitably have many other problems, especially for the adhesion, because the non-polar styrene structural units in the styrene-maleic anhydride (SMA) molecular structure are reduced. The polarity of the modified matrix resin weakens the interaction between the resin and the copper foil; at the same time, because the large amount of benzene ring structure in the SMA increases the brittleness of the resin crosslinked network, and also the bonding properties under dynamic conditions. Adverse effects are produced, thereby reducing the bond strength between the substrates and the substrate to the copper foil.

CN100523081C proposes the use of benzoxazine, styrene-maleic anhydride and other curing agents Curing a phosphorus-containing and halogen-free phosphorus-free epoxy composition can obtain a cured product having a lower dielectric constant and dielectric loss, but using a phosphorus-containing epoxy resin as a host resin, although excellent flame retardancy can be achieved, The excessive introduction of phosphorus will inevitably have a great influence on the water absorption of the substrate, which will inevitably have a negative impact on many other properties of the sheet.

Japanese Patent Laid-Open No. 2003-252958 discloses a biphenyl type epoxy resin and an active ester composition which has excellent dielectric constant and dielectric loss tangent after curing, but is a bifunctional group. The benzene epoxy resin and the active ester have a low crosslink density, and have a disadvantage that the cured product has a low glass transition temperature and low heat resistance.

CN 102689463 A discloses a soft copper clad laminate comprising an adhesive layer, a polyimide substrate and a copper foil layer, the adhesive layer being composed of the following components, by weight of the raw material : 30-40 parts of solvent-based epoxy resin, 10-20 parts of solvent-based epoxy toughening agent, 6 to 25 parts of halogen-free flame retardant, 1-3 parts of radiation protection agent, 1-3 parts of additive, solvent I 20 - 40 parts, the solvent-type epoxy toughening agent in the invention may be a polypropylene glycol glycidyl ether, however, the polypropylene glycol glycidyl ether in the invention is used only as a toughening agent, and its application amount is low.

At present, most of the research focuses on improving the properties of the thermosetting epoxy resin composition by using a curing agent or a toughening agent to improve the performance of the resin composition, and improving the performance of the composition by selecting and modifying the main resin component. There are few reports.

Accordingly, it is desirable in the art to be able to prepare a resin composition by selection of a host resin component such that a sheet prepared from the resin composition has a low dielectric constant as well as good thermal properties and bonding properties.

Summary of the invention

In view of the deficiencies of the prior art, it is an object of the present invention to provide a thermosetting alkyl polyol glycidyl ether resin composition and use thereof. The resin composition can effectively reduce the dielectric constant of the sheet while maintaining Good thermal properties and bonding properties.

To this end, the present invention employs the following technical solutions:

In a first aspect, the present invention provides a thermosetting alkyl polyol glycidyl ether resin composition comprising an epoxy resin as a main resin component, the epoxy resin comprising an alkyl polyol having the following structure shrinkage Any one or a combination of at least two of glyceryl ethers:

Wherein n=1-10 (eg 2, 3, 4, 5, 6, 7, 8, or 9), m=1-10 (eg 2, 3, 4, 5, 6, 7, 8, or 9), q=2, 4 or 6, R=H, CH ₃ - or CH ₃ -CH ₂ -;

The alkyl polyol glycidyl ether accounts for 50-100% by mass of the main resin component.

In the present invention, the main resin component means a toughening agent, a curing agent or the like as a resin component in the resin composition, not as a resin component. In the present invention, only an epoxy resin is used as a main resin component, and if a resin other than an epoxy resin is contained, the other resin is used as a component other than the main resin component, for example, as a toughening agent or Curing agent, etc.

The main resin component of the resin composition of the present invention is selected from the group consisting of alkyl polyol glycidyl ether, alkyl group The polyol glycidyl ether has an alkane segment, which can give it a low dielectric advantage, and the cost is relatively low, and at the same time, the length of the flexible chain between the epoxy groups in the network can be increased after curing, thereby improving the resin composition. Flexibility, lower cost and better bonding performance than fluororesin; superior processing performance compared with polyphenylene ether resin, easy production equipment and production process, and at the same time The resin composition of the present invention is characterized by low dielectric properties.

Preferably, the alkyl polyol glycidyl ether of the present invention is

Any of them;

Where q = 2, 4 or 6.

In the thermosetting alkyl polyol glycidyl ether resin composition of the present invention, the alkyl polyol glycidyl ether accounts for 50-100% by mass of the main resin component, for example, 53%, 55%, 58%. %, 60%, 64%, 68%, 70%, 73%, 75%, 78%, 80%, 84%, 88%, 90%, 93%, 95% or 98%, preferably 50-70% . The excessive or too small mass percentage of the alkyl polyol glycidyl ether in the main resin component affects the dielectric properties and thermal properties.

In the thermosetting alkyl polyol glycidyl ether resin composition of the present invention, the main resin component further contains an epoxy resin other than the alkyl polyol glycidyl ether, here the alkyl polyol glycidyl ether That is, the alkyl polyol glycidyl ether of the first aspect of the invention.

Preferably, the other epoxy resin is selected from the group consisting of a phenol novolak type epoxy resin, a methyl phenol novolak type epoxy resin, a bisphenol A type novolac epoxy resin, a dicyclopentadiene epoxy resin, a biphenyl epoxy resin, Naphthalene epoxy resin, glycidyl ether epoxy resin, alicyclic epoxy resin, polyethylene glycol epoxy resin, tetraphenolethane tetraglycidyl ether resin or trisphenol methane epoxy resin Any one or at least two mixture. For example, the mixture may be, but not limited to, a mixture of a phenol novolak type epoxy resin and a methyl phenol novolak type epoxy resin, a mixture of a bisphenol A type novolac epoxy resin and a dicyclopentadiene epoxy resin, bisphenol A Mixture of novolac epoxy resin, dicyclopentadiene epoxy resin and biphenyl epoxy resin, mixture of biphenyl epoxy resin, naphthalene epoxy resin and glycidyl ether epoxy resin, glycidyl ether epoxy a mixture of a resin and an alicyclic epoxy resin, a composition of an alicyclic epoxy resin, a polyethylene glycol type epoxy resin, and a tetraphenolethane tetraglycidyl ether resin, tetraphenol ethane tetraglycidyl ether A composition of a resin and a trisphenol methane type epoxy resin.

Preferably, the other epoxy resin may be a phosphorus-containing epoxy resin and/or a silicon-containing epoxy resin.

In the thermosetting alkyl polyol glycidyl ether resin composition of the present invention, the thermosetting resin composition further includes a curing agent.

Preferably, the curing agent is selected from any one or a mixture of at least two of an acid anhydride curing agent, an active ester curing agent or a benzoxazine resin.

Preferably, the acid anhydride curing agent is selected from the group consisting of styrene maleic anhydride, methyl vinyl ether-maleic anhydride copolymer, methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, phenyl succinic anhydride, succinic anhydride, and oxyic anhydride , dimethyl maleic anhydride, glutaric anhydride, 2-methyl succinic anhydride, phthalic anhydride, norbornene dianhydride, pyromellitic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 4-fluorine Phthalic anhydride, 3-fluorophthalic anhydride, 2,2-dimethylsuccinic anhydride, 1,1-cyclohexyldiacetic anhydride, phenyl maleic anhydride, citraconic anhydride, 1,8-naphthalene Anhydride, 4,4'-diphenyl ether dianhydride, 3,3'4,4'-biphenyltetracarboxylic dianhydride, phthalic anhydride, 3,3'4,4'-dianhydride diphenyl ether, 4 , 4'-(hexafluoroisopropene) dicarboxylic anhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 3,3'4,4'-benzophenonetetracarboxylic dianhydride, 1 , 4,5,8-benzenetetracarboxylic anhydride, hydrazine-1,4,9,10-tetracarboxylic acid acetic anhydride, 3,4,5,6-tetrahydrophthalic anhydride or cis-1,2,3,6- Any one or a mixture of at least two of tetrahydrophthalic anhydride.

Preferably, the active ester curing agent is a curing reaction of a phenolic compound linked by an aliphatic cyclic hydrocarbon structure, a difunctional carboxylic aromatic compound or an acidic halogenated product and a monohydroxy compound. The difunctional carboxylic acid aromatic compound or acid halide is used in an amount of 1 mol, the phenolic compound is bonded in an aliphatic cyclic hydrocarbon structure in an amount of 0.05 to 0.75 mol, and the monohydroxy compound is used in an amount of 0.25 to 0.95 mol.

Preferably, the structural formula of the active ester curing agent is as follows:

Wherein X is phenyl or naphthyl, j is 0 or 1, k is 0 or 1, and n is 0.25-1.25.

Preferably, the thermosetting alkyl polyol glycidyl ether resin composition of the present invention further comprises a catalyst.

Preferably, the catalyst is an imidazole or pyridine compound.

Preferably, the imidazole compound is selected from the group consisting of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole Any one of 2-heptadecylimidazole, 2-isopropylimidazole, 2-phenyl-4-methylimidazole, 2-dodecylimidazole or 1-cyanoethyl-2-methylimidazole Kind or a mixture of at least two.

Preferably, the pyridine compound is 4-dimethylaminopyridine.

The amount of the catalyst used in the present invention depends on the type of the epoxy resin, the type of the curing agent, and the type of the catalyst. One principle of using the catalyst is that the gelation time of the glue should not be less than 120 s.

Preferably, the catalyst is used in an amount of 0.001 to 5.0%, for example, 0.002%, 0.005%, 0.01%, 0.015%, 0.02%, 0.04%, 0.06% by mass of the thermosetting alkyl polyol glycidyl ether resin composition. , 0.08%, 0.1%, 1%, 1.5%, 1.8%, 2%, 2.3%, 2.5%, 2.8%, 3%, 3.3%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.7 % or 4.9%, preferably 0.02-4.0%, further preferably 0.005-3.0%. Excessive use of the catalyst (more than 5.0%) will result in too much reactivity of the thermosetting composition, which will increase the formation of by-products and adversely affect the uniformity of the conversion rate of the curing reaction; If the amount of the catalyst used in the composition is less than 0.001%, the reactivity is too slow, which is disadvantageous for the preparation of the prepreg.

Preferably, the resin composition further contains a flame retardant.

Preferably, the flame retardant is selected from the group consisting of organic flame retardants and/or inorganic flame retardants.

The organic flame retardant of the present invention may be an organophosphorus flame retardant, for example, a substituted or unsubstituted alkylphosphonic acid, such as a dialkylphosphonic acid (the alkyl group described herein is preferably a C1-10 alkyl group). ), including but not limited to dimethylphosphonic acid, methyl ethylphosphonic acid, diethylphosphonic acid, ethyl (n-, iso- or tert-)butylphosphonic acid, di-n-propylphosphonic acid, two Isopropylphosphonic acid, di-n-butylphosphonic acid, diisobutylphosphonic acid, di-tert-butylphosphonic acid, dipentylphosphonic acid, dioctylphosphonic acid, etc.; hydroxyl group-containing dialkylphosphonic acid, for example (hydroxymethyl)methylphosphonic acid, (hydroxyethyl)methylphosphonic acid, bis(hydroxymethyl)phosphonic acid, bis(hydroxyethyl)phosphonic acid, etc.; a carboxyl group-containing dialkylphosphoric acid, for example (2) -carboxyethyl)methylphosphonic acid or the like; alkoxy-containing dialkylphosphonic acid, such as (methoxymethyl)methylphosphonic acid, etc.; arylphosphonic acid, for example, C6-10 arylphosphonic acid (such as phenylphosphonic acid), di-C6-10 arylphosphonic acid (such as diphenylphosphonic acid), alkyl arylphosphonic acid (for example, C1-4 alkyl-C6-10 aryl-phosphonic acid, Such as methyl phenylphosphonic acid, etc., as well as salts of these organic phosphonic acids.

The organic flame retardant may also be a substituted or unsubstituted alkylene phosphonic acid (preferably C3-8 alkylene phosphonic acid, etc.), such as 1-hydroxy-1H-phosphorane-1-oxide, 2- Carboxy-1-hydroxy-1H-phosphorane-1-oxide; substituted or unsubstituted alkenylene phosphonic acid (preferably C3-8 alkenylenephosphonic acid), such as 1-hydroxyphosphorane-1-oxide Et.; cycloalkylphosphonic acid (preferably C4-10 cycloalkylenephosphonic acid), such as 1,3-cyclopentylene phosphonic acid, 1,3-cyclopentylphosphonic acid, 1,4-cyclo ring Octylphosphonic acid, 1,5-cyclooctylene phosphonic acid, etc.; or a salt thereof.

Preferably, the organic flame retardant is selected from the group consisting of tris(2,6-dimethylphenyl)phosphine, resorcinol bis[bis(2,6-dimethylphenyl)phosphate], isophthalic acid Phenol tetraphenyl diphosphate, triphenyl phosphate, bisphenol A bis(diphenyl phosphate), phosphazene flame retardant, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9- Oxa-10-phosphinophen-10-oxide, 10-(2,5-dihydroxynaphthyl)-10-hydro-9-oxa-10-phosphinophen-10-oxide or 9,10-di Hydrogen-9-oxa-10-phosphine Any one or a mixture of at least two of the phenanthrene-10-oxide flame retardants. For example, the mixture may be, but is not limited to, a mixture of tris(2,6-dimethylphenyl)phosphine and resorcinol bis[bis(2,6-dimethylphenyl)phosphate], three ( a mixture of 2,6-dimethylphenyl)phosphine, resorcinol bis[bis(2,6-dimethylphenyl)phosphate] and resorcinol tetraphenyl diphosphate, isophthalic acid Mixture of phenol tetraphenyl diphosphate, triphenyl phosphate and bisphenol A bis(diphenyl phosphate), phosphazene flame retardant, 10-(2,5-dihydroxyphenyl)-10-hydrogen- 9-oxa-10-phosphinophen-10-oxide, 10-(2,5-dihydroxynaphthyl)-10-hydro-9-oxa-10-phosphinophen-10-oxide and 9,10 a mixture of dihydro-9-oxa-10-phosphaphenanthrene-10-oxide flame retardant, tris(2,6-dimethylphenyl)phosphine, resorcinol double [2 (2,6) -Dimethylphenyl)phosphate], a mixture of resorcinol tetraphenyl diphosphate and triphenyl phosphate and bisphenol A bis(diphenyl phosphate), resorcinol double [2 (2 ,6-dimethylphenyl)phosphate], resorcinol tetraphenyl diphosphate, triphenyl phosphate, bisphenol A bis(diphenyl phosphate), phosphazene flame retardant and 10-( 2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphine -10- mixture of oxides.

Preferably, the inorganic flame retardant is selected from any one or a mixture of at least two of red phosphorus, aluminum hydroxide, magnesium hydroxide or antimony trioxide. The mixture may be, but not limited to, a mixture of red phosphorus and aluminum hydroxide, a mixture of aluminum hydroxide and magnesium hydroxide, a mixture of red phosphorus, aluminum hydroxide and magnesium hydroxide, aluminum hydroxide, magnesium hydroxide and trioxide. a mixture of cockroaches.

Preferably, the resin composition further comprises a filler.

Preferably, the filler is selected from the group consisting of silica, kaolin, talc, magnesium hydroxide, aluminum hydroxide, boehmite, hydrotalcite, titanium oxide, calcium silicate, cerium oxide, boron nitride, glass powder, boric acid. Zinc, aluminum nitride compound, silicon nitride, silicon carbide, magnesium oxide, zirconium oxide, mullite, titanium dioxide, potassium titanate, hollow glass microspheres, polytetrafluoroethylene powder, polystyrene powder, potassium titanate fiber Any one or a mixture of at least two of silicon carbide single crystal fibers, silicon nitride fibers, alumina single crystal fibers, or glass short fibers. For example, the mixture may be, but not limited to, a mixture of silica and kaolin, a mixture of talc, magnesium hydroxide and aluminum hydroxide, a mixture of magnesium hydroxide, aluminum hydroxide and boehmite, kaolin, a mixture of talc, magnesium hydroxide and aluminum hydroxide, a mixture of silica, kaolin, talc, magnesium hydroxide and aluminum hydroxide, silica, kaolin, talc, magnesium hydroxide, aluminum hydroxide and bo a mixture of mashi.

The silica of the present invention may be crystalline silica, molten silica or spherical silica.

Preferably, the resin composition further contains a curing accelerator. One skilled in the art can select a suitable curing accelerator as needed.

As a preferred embodiment of the present invention, the thermosetting alkyl polyol glycidyl ether resin composition of the present invention comprises the alkyl polyol glycidyl ether of the structure of the first aspect of the invention, other epoxy resins and a curing agent, wherein The alkyl polyol glycidyl ether accounts for 50% by mass or more of the main resin component.

The alkyl polyol glycidyl ether of the present invention can be used in combination with the other epoxy resins and curing agents to synergistically impart a low dielectric property to the product and to ensure thermal properties and bonding properties.

"Comprising" as used herein means that in addition to the components, it may include other components which impart different characteristics to the epoxy resin composition. In addition, the "include" of the present invention may also be replaced by a closed "for" or "consisting of". Regardless of the composition of the thermosetting alkyl polyol glycidyl ether resin composition of the present invention, the resin composition, in addition to the solvent, the sum of the mass percentages of the components is 100%.

In a second aspect, the present invention provides a resin glue obtained by dissolving or dispersing a thermosetting alkyl polyol glycidyl ether resin composition according to the present invention in a solvent.

Preferably, the solvent is one or a combination of at least two of a ketone, a hydrocarbon, an ether, an ester or an aprotic solvent, preferably acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene , xylene, methanol, ethanol, primary alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol methyl ether acetate, acetic acid One or a mixture of at least two of esters, N,N-dimethylformamide or N,N-diethylformamide. The solvent may be used singly or in combination. The amount of the solvent to be added can be determined by a person skilled in the art according to the viscosity of the resin to be selected, so that the viscosity of the obtained thermosetting alkyl polyol glycidyl ether resin composition is moderate, which is convenient for curing, which is not limited in the present invention.

In a third aspect, the present invention provides a prepreg produced using the thermosetting alkyl polyol glycidyl ether resin composition as described in the first aspect. The alkyl polyol glycidyl ether resin composition of the present invention is attached to a reinforcing material by impregnation and drying to form a prepreg.

The method for producing a prepreg using the alkyl polyol glycidyl ether resin composition of the present invention is as follows, but the method of producing the prepreg is not limited thereto. The thermosetting alkyl polyol glycidyl ether resin composition glue (here, solvent-adjusted viscosity has been used) is impregnated on the reinforcing material, and the prepreg impregnated with the resin composition is dried by heating to make the prepreg The epoxy resin composition is in a semi-cured stage (B-Stage) to obtain a prepreg. The heating temperature of the prepreg is 80-250 ° C, such as 90 ° C, 100 ° C, 110 ° C, 120 ° C, 130 ° C, 140 ° C, 150 ° C, 160 ° C, 170 ° C, 180 ° C, 190 ° C, 200 ° C, 210 ° C, 220 ° C, 230 ° C or 240 ° C, time 1-30 min, such as 3 min, 5 min, 7 min, 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min or 29 min. The reinforcing material used therein may be an inorganic or organic material. Examples of the inorganic material include woven fabrics such as glass fibers, carbon fibers, boron fibers, and metals, or nonwoven fabrics or paper. The glass fiber cloth or the nonwoven fabric may be E-glass, Q-type cloth, NE cloth, D-type cloth, S-type cloth, high-silicone cloth or the like. Organic fibers such as polyester, polyamine, polyacrylic acid, polyimide, aramid, polytetrafluoroethylene, syndiotactic polystyrene, etc., or nonwoven fabric or paper, however, the reinforcing material is not limited thereto, and the others The reinforcing material which can be used for resin reinforcement can also realize the present invention. The resin content in the prepreg is between 30 and 80% by weight, for example 32%, 35%, 38%, 40%, 45%, 48%, 50%, 53%, 55%, 58%, 60%, 63%, 65%, 68%, 70%, 72%, 75%, 78% or 79%.

In a fourth aspect, the present invention provides a laminate for a printed circuit comprising one or at least two laminated prepregs according to the third aspect.

The printed circuit board laminate of the present invention comprises one or at least two laminated prepregs, and a metal foil on one side or both sides of the laminated prepreg, each prepreg comprising a reinforcing material and adhering after being impregnated and dried. The alkyl polyol glycidyl ether resin composition of the present invention on a reinforcing material.

The resin composition of the present invention can also be used as a resin sheet or prepreg, a resin composite metal copper foil, a laminate, and a printed wiring board. The laminate, the copper clad laminate, and the printed wiring board can be produced using the above-described resin sheet, resin composite metal foil, and prepreg. This production method will be described by taking a copper clad laminate as an example, but is not limited thereto. When a copper-clad laminate is produced using a prepreg, one or more of the prepregs are cut into a certain size, laminated, and fed into a laminating apparatus for lamination, while the metal foil is placed on one side or both sides of the prepreg through Hot press forming will be semi-cured to form a metal foil laminate. As the metal foil, copper, brass, aluminum, nickel, and an alloy of these metals or a composite metal foil can be used. As the pressing conditions of the laminate, suitable lamination curing conditions should be selected in accordance with the actual conditions of the resin composition of the present invention. If the pressing pressure is too low, there will be voids in the laminate, and the electrical properties will be lowered. Excessive lamination pressure will cause excessive internal stress in the laminate, which will reduce the dimensional stability of the laminate. The molding pressure is met to compress the sheet to achieve the desired requirements. The general guidelines for conventional pressed laminates are lamination temperatures of 130-250 ° C, pressures of 3-50 kgf/cm ² and hot press times of 60-240 min. For example, the hot pressing temperature may be 140 ° C, 150 ° C, 160 ° C, 170 ° C, 180 ° C, 190 ° C, 200 ° C, 210 ° C, 220 ° C, 230 ° C or 240 ° C. The pressure may be ^{5kgf / cm 2, 8kgf / cm} 2, 11kgf / cm 2, 14kgf / cm 2, 17kgf / cm 2, 24kgf / cm 2, 28kgf / cm 2, 32kgf / cm 2, 37kgf / cm 2, 42 kgf/cm ² , 45 kgf/cm ² or 48 kgf/cm ² . The hot pressing time may be 70 min, 90 min, 110 min, 130 min, 150 min, 170 min, 190 min, 210 min, 230 min or 240 min.

A printed wiring board or a complicated multilayer circuit board is produced by a layering method or a subtractive layer method using a resin sheet, a resin composite metal foil, a prepreg, or a metal-clad laminate.

The thermosetting resin composition of the present invention can be used for making an adhesive, in addition to being used as a resin sheet, a resin composite metal copper foil, a prepreg, a laminate, a copper clad laminate, a printed wiring board, Paints or composites can also be used in the construction, aerospace, marine or automotive industries.

Compared with the prior art, the present invention has the following beneficial effects:

In the resin composition of the present invention, an epoxy resin is used as a main resin component, and an alkyl polyol glycidyl ether structure having a molecular structure of the present invention in a mass percentage of 50 to 100% by using a main resin component is used. The epoxy resin has low dielectric properties while maintaining good thermal properties and bonding properties, and has low cost and simple preparation method. This well overcomes the drawbacks of the prior art, such as the low adhesion of fluororesin, the disadvantage of high cost, and the disadvantages of difficult production process conditions of polyphenylene ether resin. In the invention, the alkyl polyol glycidyl ether epoxy resin is used as the main resin component, and the active ester or acid anhydride is used as the curing agent, and the active ester and the acid anhydride curing agent are fully utilized to react with the epoxy resin without generating a polar group. The characteristics of the group make the cured product have excellent dielectric constant and dielectric loss factor. The present invention utilizes an alkyl polyol glycidyl ether as a main resin component, so that the prepreg, the laminate, and the printed circuit board produced by the resin composition of the present invention have a low dielectric constant (10 GHz, ≤ 3.64) and a low dielectric loss factor. (10GHz, ≤0.0083), better glass transition temperature (151.1-165.5 °C), thermal decomposition temperature (361.5-382.3 °C) and peel strength (0.81-0.93N/mm), and have good processing properties and obvious The cost advantage has broad application prospects.

detailed description

The technical solution of the present invention will be further described below by way of specific embodiments. It should be understood by those skilled in the art that the present invention is not to be construed as limited.

Example 1

Add 27 parts of 1,4-butanediol diglycidyl ether (Cragmar reagent) and 73 parts of EF40 (styrene maleic anhydride copolymer, American Sartomer) to the beaker, add 50 parts of MEK (butanone) Or the solvent mentioned in the present invention dissolves the above compound, and an appropriate amount of 2E4MI (2-ethyl-4-methylimidazole, Japan's four countries) is used as a curing accelerator to prepare a gum having a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Example 2

Add 18 parts of 1,4-butanediol diglycidyl ether, 18 parts of HP7200H (dicyclopentadiene epoxy resin, Japan DIC) and 64 parts of EF40 to the beaker, add 50 parts of MEK or any solvent mentioned in the present invention. Dissolve, use a proper amount of 2E4MI as a curing accelerator to prepare a glue with a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Example 3

Adding 23 parts of 1,4-butanediol diglycidyl ether, 10 parts of NC3000H (biphenyl epoxy resin, Japan DIC) and 67 parts of EF40 to a beaker, adding 50 parts of MEK or any solvent mentioned in the present invention to dissolve the above The compound was prepared by using an appropriate amount of 2E4MI as a curing accelerator to prepare a glue having a solid content of 60-70%. Use The 2116 glass cloth was impregnated with the glue, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Example 4

31 parts of 1,4-butanediol diglycidyl ether and 69 parts of HPC-8000-65T (active ester crosslinking agent, Japan DIC) were added to a beaker, and 50 parts of MEK or any solvent mentioned in the present invention was added to dissolve the above. The compound was prepared by using an appropriate amount of DMAP (4-dimethylaminopyridine, Guangrong Chemical) as a curing accelerator to prepare a glue having a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Example 5

Add 30 parts of 1,6-hexanediol diglycidyl ether (Cragmar reagent) and 70 parts of EF40 to the beaker, add 50 parts of MEK or any solvent mentioned in the invention to dissolve the above compound, and promote the curing with an appropriate amount of 2E4MI. The agent is made into a glue with a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and remains This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Example 6

20 parts of 1,6-hexanediol diglycidyl ether, 20 parts of HP7200H and 58 parts of EF40 are added to the beaker, 60 parts of MEK or any solvent mentioned in the invention is added to dissolve the above compound, and an appropriate amount of 2E4MI is used as a promoter. A glue with a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Example 7

Adding 22 parts of 1,6-hexanediol diglycidyl ether, 15 parts of NC3000H and 63 parts of EF40 to a beaker, adding 50 parts of MEK or any solvent mentioned in the invention to dissolve the above compound, and using an appropriate amount of 2E4MI as a promoter. A glue with a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Example 8

Add 25 parts of ethylene glycol diglycidyl ether (Cragmar reagent) to 75 parts of EF40 (styrene maleic anhydride copolymer, American Sartomer) to a beaker, add 50 parts of MEK (butanone) or any of the inventions The solvent mentioned dissolves the above compound in an appropriate amount of 2E4MI (2-ethyl-4-methylimidazole, Japan's four countries) As a curing accelerator, it is made into a glue with a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Example 9

Add 43 parts of polyethylene glycol diglycidyl ether (Cragmar reagent) and 57 parts of EF40 (styrene maleic anhydride copolymer, American Sartomer) to the beaker, add 50 parts of MEK (butanone) or any The solvent mentioned in the invention dissolves the above compound, and an appropriate amount of 2E4MI (2-ethyl-4-methylimidazole, formed by the Japanese four countries) is used as a curing accelerator to prepare a gum having a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 1.

Comparative example 1

52 parts of HP7200H and 48 parts of EF40 were added to a beaker, 50 parts of MEK or any solvent mentioned in the invention was added to dissolve the above compound, and an appropriate amount of 2E4MI was used as a curing accelerator to prepare a glue having a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on each of the upper and lower sides, and pressed by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 2.

Comparative example 2

53 parts of NC3000H and 47 parts of EF40 were added to the beaker, 50 parts of MEK or any solvent mentioned in the present invention was added to dissolve the above compound, and an appropriate amount of 2E4MI was used as a curing accelerator to prepare a glue having a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 2.

Comparative example 3

Add 56 parts of HP7200H and 44 parts of HPC-8000-65T to the beaker, add 50 parts of MEK or any solvent mentioned in the invention to dissolve the above compound, and use appropriate amount of DMAP as curing accelerator to make glue with solid content of 60-70%. liquid. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 2.

Comparative example 4

Add 12 parts of 1,4-butanediol diglycidyl ether, 30 parts of HP7200H (dicyclopentadiene epoxy resin, Japan DIC) and 58 parts of EF40 to the beaker, add 50 parts of MEK or any solvent mentioned in the present invention. Dissolve, use a proper amount of 2E4MI as a curing accelerator to prepare a glue with a solid content of 60-70%. The glue was wetted using a 2116 glass cloth, and the solvent was removed in an oven at 155 ° C to obtain a prepreg sample.

Four sheets of 2116 prepreg laminates were used, one 0.5 ounce of electrolytic copper foil on the top and bottom, and laminated by a hot press to obtain a double-sided copper clad laminate. The lamination conditions are as follows: (1) when the temperature of the material is 80-120 ° C, the heating rate is controlled at 1.0-3.0 ° C / min; (2) the pressure is set to 20 kg / cm ² ; (3) the curing temperature is 200 ° C, and kept This temperature is 90 minutes. The corresponding performance is shown in Table 2.

The test criteria or methods for the parameters involved in Table 1 are as follows:

(1) Glass transition temperature (Tg): The DSC test was used, and the measurement was carried out in accordance with the DSC test method specified in IPC-TM-6502.4.25.

(2) Dielectric constant and dielectric loss factor: The test was carried out in accordance with the method of IPC-TM-6502.5.5.13, and the test frequency was 10 GHz.

(3) Evaluation of solder resistance: The copper-clad laminate was immersed in a tin furnace at a temperature of 288 ° C until the sheet was layered and foamed, and the time of layering and foaming of the sheet was recorded. Sexual limit.

(4) Peel strength (N/mm): The test was carried out in accordance with the method of IPC-TM-6502.4.8.

(5) Thermal decomposition temperature (Td): Measured according to the TGA method specified in IPC-TM-6502.4.24 by thermogravimetric analysis (TGA).

Table 1

Table 2

As can be seen from Table 1, the resin compositions of Examples 1 to 7 of the present invention have a low dielectric constant and a low dielectric loss factor, have excellent low dielectric properties, and have a good glass transition temperature Tg and thermal decomposition. Temperature Td and peel strength. In the first embodiment, when the other epoxy resin is not added, it is also ensured that the laminate prepared by the resin composition has a dielectric constant and a low dielectric loss factor while maintaining a good glass transition. Temperature and thermal decomposition temperature, Example 2 compared with Comparative Example 1, or Example 3 compared with Comparative Example 2, it can be explained that the addition of the alkyl polyol glycidyl ether to the system greatly reduces the thermosetting resin composition. The dielectric constant and dielectric loss factor while maintaining good thermal performance and adhesion. It can also be seen from the comparison of Examples 1, 2, 3, 4 and Examples 5, 6, 7, and 8, respectively, that the longer the alkyl segment of the alkyl polyol, the better the dielectric properties. As can be seen from the comparison of Examples 1, 2, 3, and 4 with Comparative Example 4, the present invention utilizes an alkyl polyol glycidyl ether as a main resin component and controls the content thereof to 50-100% of the main resin component. In the range, the dielectric constant and the dielectric loss factor of the thermosetting resin composition can be effectively lowered to maintain good thermal properties and adhesion, but if the content is less than 50%, the dielectric properties and thermal properties of the resin composition are obtained. And the bonding properties are far less than the performance of the resin composition at a content of 50-100%.

The applicant claims that the present invention describes the thermosetting alkyl polyol glycidyl ether resin composition of the present invention and the use thereof by the above examples, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above. The embodiment can be implemented. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitution of the various materials of the products of the present invention, addition of auxiliary components, selection of specific means, and the like, are all within the scope of the present invention.

Claims (10)

1. A thermosetting alkyl polyol glycidyl ether resin composition characterized in that the resin composition comprises an epoxy resin as a main resin component, and the epoxy resin comprises an alkyl polyol glycidyl ether having the following structure Any one or combination of at least two:

   

   Wherein n=1-10, m=1-10, q=2, 4 or 6, R=H, CH ₃ - or CH ₃ -CH ₂ -;

   The alkyl polyol glycidyl ether accounts for 50-100% by mass of the main resin component.
2. The thermosetting alkyl polyol glycidyl ether resin composition according to claim 1, wherein the alkyl polyol glycidyl ether is:

   

   

   Any one or a combination of at least two;

   Where q = 2, 4 or 6.
3. The thermosetting alkyl polyol glycidyl ether resin composition according to claim 1 or 2, wherein the alkyl polyol glycidyl ether accounts for 50 to 70% by mass of the main resin component.
4. The thermosetting alkyl polyol glycidyl ether resin composition according to any one of claims 1 to 3, wherein the main resin component further contains an epoxy other than the alkyl polyol glycidyl ether Resin

   Preferably, the other epoxy resin is selected from the group consisting of a phenol novolak type epoxy resin, a methyl phenol novolak type epoxy resin, a bisphenol A type novolac epoxy resin, a dicyclopentadiene epoxy resin, a biphenyl epoxy resin, Naphthalene epoxy resin, glycidyl ether epoxy resin, alicyclic epoxy resin, polyethylene glycol epoxy resin, tetraphenolethane tetraglycidyl ether resin or trisphenol methane epoxy resin Any one or a mixture of at least two;

   Preferably, the other epoxy resin is a phosphorus-containing epoxy resin and/or a silicon-containing epoxy resin.
5. The thermosetting alkyl polyol glycidyl ether resin composition according to any one of claims 1 to 4, wherein the thermosetting resin composition further comprises a curing agent;

   Preferably, the curing agent is selected from any one or a mixture of at least two of an acid anhydride curing agent, an active ester curing agent or a benzoxazine resin;

   Preferably, the acid anhydride curing agent is selected from the group consisting of styrene maleic anhydride, methyl vinyl ether-maleic anhydride copolymer, methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, phenyl succinic anhydride, succinic anhydride, and oxyic anhydride , dimethyl maleic anhydride, glutaric anhydride, 2-methyl succinic anhydride, phthalic anhydride, norbornene dianhydride, pyromellitic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 4-fluorine Phthalic anhydride, 3-fluorophthalic anhydride, 2,2-dimethylsuccinic anhydride, 1,1-cyclohexyldiacetic anhydride, phenyl maleic anhydride, citraconic anhydride, 1,8-naphthalene Anhydride, 4,4'-diphenyl ether dianhydride, 3,3'4,4'-biphenyltetracarboxylic dianhydride, phthalic anhydride, 3,3'4,4'-dianhydride diphenyl ether, 4 , 4'-(six Fluoroisopropene) Diphthalic anhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 3,3'4,4'-benzophenonetetracarboxylic dianhydride, 1,4,5,8 - benzoic anhydride, hydrazine-1,4,9,10-tetracarboxylic acid acetic anhydride, 3,4,5,6-tetrahydrophthalic anhydride or cis-1,2,3,6-tetrahydrophthalic acid Any one or a mixture of at least two;

   Preferably, the active ester curing agent is a curing agent obtained by reacting a phenolic compound linked by an aliphatic cyclic hydrocarbon structure, a difunctional carboxylic aromatic compound or an acidic halogenated product, and a monohydroxy compound. The amount of the difunctional carboxylic acid aromatic compound or acid halide is 1 mol, the amount of the phenolic compound linked by the aliphatic cyclic hydrocarbon structure is 0.05-0.75 mol, and the amount of the monohydroxy compound is 0.25-0.95 mol;

   Preferably, the structural formula of the active ester curing agent is as follows:

   

   Wherein X is phenyl or naphthyl, j is 0 or 1, k is 0 or 1, and n is 0.25-1.25.
6. The thermosetting alkyl polyol glycidyl ether resin composition according to any one of claims 1 to 5, wherein the resin composition further comprises a catalyst;

   Preferably, the catalyst is an imidazole or a pyridine compound;

   Preferably, the imidazole compound is selected from the group consisting of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole Any one of 2-heptadecylimidazole, 2-isopropylimidazole, 2-phenyl-4-methylimidazole, 2-dodecylimidazole or 1-cyanoethyl-2-methylimidazole Or a mixture of at least two;

   Preferably, the pyridine compound is 4-dimethylaminopyridine;

   Preferably, the catalyst is used in an amount of 0.001 to 5.0%, preferably 0.02 to 4.0%, further preferably 0.005 to 3.0% by mass based on the mass of the thermosetting alkyl polyol glycidyl ether resin composition;

   Preferably, the resin composition further comprises a flame retardant;

   Preferably, the flame retardant is selected from the group consisting of organic flame retardants and/or inorganic flame retardants;

   Preferably, the organic flame retardant is selected from the group consisting of tris(2,6-dimethylphenyl)phosphine, resorcinol bis[bis(2,6-dimethylphenyl)phosphate], isophthalic acid Phenol tetraphenyl diphosphate, triphenyl phosphate, bisphenol A bis(diphenyl phosphate), phosphazene flame retardant, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9- Oxa-10-phosphinophen-10-oxide, 10-(2,5-dihydroxynaphthyl)-10-hydro-9-oxa-10-phosphinophen-10-oxide or 9,10-di Any one or a mixture of at least two hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide flame retardants;

   Preferably, the inorganic flame retardant is selected from any one or a mixture of at least two of red phosphorus, aluminum hydroxide, magnesium hydroxide or antimony trioxide;

   Preferably, the resin composition further comprises a filler;

   Preferably, the filler is selected from the group consisting of silica, kaolin, talc, magnesium hydroxide, aluminum hydroxide, boehmite, hydrotalcite, titanium oxide, calcium silicate, cerium oxide, boron nitride, glass powder, boric acid. Zinc, aluminum nitride compound, silicon nitride, silicon carbide, magnesium oxide, zirconium oxide, mullite, titanium dioxide, potassium titanate, hollow glass microspheres, polytetrafluoroethylene powder, polystyrene powder, potassium titanate fiber Any one or a mixture of at least two of silicon carbide single crystal fibers, silicon nitride fibers, alumina single crystal fibers, or glass short fibers;

   Preferably, the resin composition further contains a curing accelerator.
7. A resin glue obtained by dissolving or dispersing a thermosetting alkyl polyol glycidyl ether resin composition according to any one of claims 1 to 6 in a solvent.
8. A prepreg produced by using the thermosetting alkyl polyol glycidyl ether resin composition according to any one of claims 1 to 7.
9. A laminate for printed circuit board, characterized in that the laminate for printed circuit board comprises one or at least two prepregs according to claim 8.
10. A printed circuit board characterized in that the printed circuit board comprises one or at least two prepregs according to claim 8.