JP2003191375A - Metallic foil with resin and multi-layer sheet using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper foil with a resin which shows superb strength and impact resistance and is highly adhesive with a metallic foil and further, prevents the resin from falling off in a semi-cured state without an insulation failure. <P>SOLUTION: This metallic foil with a resin is characterized in that it is manufactured by applying a heat-curable resin composition containing a rubber- like polymer with an alkaline metal content of 50 ppm or less of the rubber-like polymer. Especially, the rubber-like polymer contains a monomer having one kind of functional group selected from among an epoxy group, a hydroxyl group, a carboxyl group and an amino group, as a monomer unit constituting the rubber-like polymer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated metal foil used for manufacturing a multilayer printed wiring board and a multilayer board obtained using the resin-coated metal foil.

[0002]

2. Description of the Related Art Conventionally, there is known a method of manufacturing a multilayer printed wiring board by laminating and molding a resin-coated metal foil obtained by applying an insulating resin and then drying and semi-curing it on an inner layer substrate on which a wiring pattern is formed. Has been. In this metal foil with resin,
As disclosed in Japanese Patent Laid-Open No. 5-206647,
Generally, a polyimide resin, an epoxy resin, a fluorine resin, or the like is used as the applied insulating resin. As the method for producing the resin-coated metal foil, an uncured or low-molecular weight resin is dissolved or dispersed in a solvent to be in a liquid state, or a low-molecular weight resin that is liquid at room temperature is selected, and these resins are used as a metal foil. After being applied to the above, it is dried to cure or progress to a semi-cured state to manufacture. The resin-coated metal foil obtained as described above is, for example, subjected to etching on a double-sided copper-clad laminate to form a substrate for an inner layer, and further subjected to a treatment of the inner layer circuit copper foil surface called a blackening treatment to form an inner layer. Put the resin side on both sides of the board
Multi-layer molding is performed by heating and pressing. In addition, one or more prepregs of glass cloth base material are superposed between the resin-coated copper foil and the inner layer substrate, and heated and pressed to perform multi-layer molding.

However, in the above case, the resin-coated metal foil used in the process of manufacturing the multilayer printed wiring board is subject to a resin crack or a resin crack due to an impact at the time of being laminated on the inner layer substrate, a shrinkage at the time of curing or the like. Peeled off, resulting in poor interlayer insulation of the obtained multilayer printed wiring board,
The resin that has peeled off causes bad radish. As a method of improving the above points, an appropriate amount of rubber is added to the insulating resin applied to the metal foil in order to impart flexibility to the insulating resin. Due to impurities such as emulsifiers and coagulants, which are mainly metal ions, contained in the product, there was a problem of poor insulation and corrosion of the coated semiconductor lead wires (mostly aluminum wires). .

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has excellent strength and impact resistance, good adhesion to a metal foil, and resin peeling off in a semi-cured state. It is an object of the present invention to provide a resin-coated copper foil that prevents the above-mentioned problems and has no insulation failure.

[0005]

Means for Solving the Invention As a result of intensive studies to achieve the above object, the present inventors have found that a rubber-like polymer obtained by a special polymerization method is used as a rubber component to improve strength and impact resistance. Excellent, good adhesion with metal foil, prevent resin peeling off in the semi-cured state, and found that a resin-coated copper foil without insulation failure can be obtained,
The present invention has been completed.

That is, the present invention provides the following metal foil with resin and a multilayer board using the same. [1] Content of alkali metal in rubber-like polymer is 50 ppm
A resin-coated metal foil, which is obtained by applying a thermosetting resin composition containing the following rubbery polymer to a metal foil. [2] As the monomer unit constituting the rubber-like polymer,
The metal foil with resin according to the above [1], which is a rubber-like polymer containing a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group. . [3] The resin according to the above [1], wherein the rubber-like polymer is any of rubber-like polymers (1) to (3) composed of the following monomers. Metal foil. (1) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (b) acrylonitrile, (c) ) A rubbery polymer consisting of butadiene and / or isoprene. (2) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (d) an alkyl (meth) A rubbery polymer comprising an acrylate and / or an alkoxyl (meth) acrylate, and (e) another monomer copolymerizable with the above monomer. (3) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (b) acrylonitrile, (c) ) Butadiene and / or isoprene, (d) alkyl (meth) acrylate and /
Alternatively, a rubbery polymer composed of an alkoxy (meth) acrylate. [4] The resin as described in [1] to [3] above, wherein the rubber-like polymer is either a polymer produced by the following method (1) or (2). Metal foil. (1) A coagulant is obtained by using a nonionic activator as an emulsifier, performing emulsion polymerization at a temperature lower than the cloud point of the nonionic activator, and then heating the obtained polymer latex to a temperature of the cloud point or higher. A polymer produced by a method of solidifying without using. (2) After carrying out emulsion polymerization using at least an ionic activator as an emulsifier, the resulting polymer latex is then heated in the presence of a nonionic activator and a metal-free electrolyte to give a rubber-like polymer. A polymer produced by a method of solidifying. [5] The resin according to any one of [1] to [3], wherein the rubber-like polymer is contained in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of a thermosetting resin. With metal foil. [6] A multilayer board obtained by laminating and molding the resin-coated metal foil according to any one of the above [1] to [5] and an inner layer circuit plate.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the resin-coated metal foil of the present invention will be specifically described below. The resin-containing metal foil of the present invention has an alkali metal content of 50 pp in the rubber-like polymer.
A metal foil with a resin obtained by applying a thermosetting resin composition containing a rubber-like polymer of m or less to a metal foil. Hereinafter, each component will be described more specifically.

The rubber-like polymer used in the present invention is not particularly limited, but the rubber-like polymer may be polybutadiene, polyisoprene, butadiene-acrylonitrile copolymer, butadiene-acrylonitrile-acrylic acid ester copolymer. Polymers, butadiene-styrene copolymers, diene polymers such as polychloroprene, acrylic rubber or epoxy groups, hydroxyl groups, carboxyl groups,
And a polymer having at least one functional group selected from the group of amino groups. Specific examples of the polymer having such a functional group include, for example, epoxy group, hydroxyl group,
Monomers having at least one functional group selected from the group of carboxyl group, amino group and alkyl ester group, for example, methacrylic acid, acrylic acid, fumaric acid, itaconic acid, maleic acid, glycidyl (meth) acrylate, glycidyl Allyl ether, glycidyl vinyl ether, hydroxylethyl (meth) acrylate, hydroxylpropyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, diethylaminopropyl (meth) acrylate Etc.

Of these, the rubber-like polymers are preferably rubber-like polymers (1) to (3) composed of the following monomers. (1) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (b) acrylonitrile, (c) ) A rubbery polymer consisting of butadiene and / or isoprene. (2) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (d) an alkyl (meth) A rubbery polymer comprising an acrylate and / or an alkoxyl (meth) acrylate, and (e) another monomer copolymerizable with the above monomer. (3) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (b) acrylonitrile, (c) ) Butadiene and / or isoprene, (d) alkyl (meth) acrylate and /
Alternatively, a rubbery polymer composed of an alkoxy (meth) acrylate. The functional group-containing monomer is usually copolymerized at 1 to 20% by weight. By copolymerizing a monomer having a functional group, the strength, impact resistance and adhesion of the resin-coated metal foil are improved. Examples of the alkyl (meth) acrylate include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and the like, and these can be used alone or in combination of two or more kinds. Further, examples of the alkoxy (meth) acrylate include methoxymethyl acrylate, methoxyethyl acrylate, methoxypropyl acrylate, ethoxymethyl acrylate, ethoxyethyl acrylate, ethoxypropiacrylate and butoxyethyl acrylate. Alternatively, two or more kinds can be used in combination.

Na present in the rubbery polymer of the present invention,
The content of alkali metals such as K and Li is 50 ppm or less, preferably 25 ppm, more preferably 15 ppm or less. The molecular weight of the rubber-like polymer used in the present invention is not particularly limited, and it can be selected from a low molecular weight polymer showing a liquid state to a high molecular weight body as necessary.

Such a polymer can be obtained, for example, by a special emulsion polymerization method exemplified below. (1) After carrying out emulsion polymerization using at least an ionic activator as an emulsifier, the obtained polymer latex is then heated in the presence of a nonionic activator and a metal-free electrolyte to give a rubber-like polymer. Solidify. (2) After emulsion polymerization is performed using an ionic activator and a nonionic activator as an emulsifier, a metal-free electrolyte is subsequently added to the obtained polymer latex and then heated. (3) After emulsion polymerization using an ionic activator as an emulsifier, a nonionic activator and a metal-free electrolyte are added to the obtained polymer latex and then heated. (4) Using a nonionic activator as an emulsifier, emulsion polymerization is carried out at a temperature below the cloud point of the nonionic activator, and then the obtained polymer latex is heated to a temperature above the cloud point.

The ionic activator used as an emulsifier in emulsion polymerization is an anionic activator, a cationic activator or an amphoteric activator. Examples of the anionic activator include soap, funnel oil, emulsified oil, alkylnaphthalene sulfonate, dodecylbenzene sulfonate,
Examples thereof include oleate, alkylbenzene sulfonate, dialkyl sulfosuccinate, lignin sulfonate, alcohol ethoxy sulphate, secondary alkane sulfonate, α-olefin sulfonate and tamol. Examples of the cationic activator include alkyl trimethyl ammonium salt, dialkyl dimethyl ammonium salt, alkyl pyridinium salt and alkyl benzyl dimethyl ammonium salt. Furthermore, examples of the amphoteric activator include alkyl betaine and alkyldiethylene triaminoacetic acid. These ionic activators may be used alone or in combination of two or more.

Next, the nonionic activator used in the emulsion polymerization is one which does not ionize in an aqueous solution among substances exhibiting remarkable surface activity at a low concentration. Specifically, for example, polyoxyethylene alkyl ether. , Polyoxyethylene alkyl allyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene oxypropylene block polymer, alkylsulfinyl alcohol, fatty acid monoglyceride and the like. These nonionic active agents may be used alone or in combination of two or more.

The temperature at which clouding occurs only when the aqueous solution of the nonionic surfactant is heated is called a cloud point, which is a unique phenomenon occurring in the aqueous solution of the nonionic surfactant. The cloud point thermodynamically corresponds to the lower critical solution temperature (LCST). At temperatures above the cloud point, nonionic surfactants become poorly soluble in water and lose their activity as surfactants. For example, anionic surfactants such as acids and polyvalent metal ions reduce water solubility. This corresponds to the conventional separation step of coagulating the polymer latex. That is, if such a nonionic activator is present in at least the polymer latex obtained by emulsion polymerization, coagulation of the polymer can be facilitated by utilizing the phenomenon of cloud point.

The proportion of these activators used is 100% monomer.
0.1-10 parts by weight of ionic activator per part by weight,
Preferably 0.2 to 6 parts by weight, 1 to 1 nonionic activator
15 parts by weight, preferably 2 to 12 parts by weight, and the weight ratio of ionic activator / nonionic activator is 0.01 to.
2, preferably 0.1 to 1.

Examples of the metal-free electrolyte include inorganic salts such as ammonium sulfate, ammonium chloride, ammonium phosphate, ammonium nitrate and ammonium acetate. Such electrolytes containing no metal may be used alone or in combination of two or more. The amount of such an electrolyte used is 5 to 20 per 100 parts by weight of the polymer component in the polymer latex.
Parts by weight, preferably 7 to 15 parts by weight.

Emulsion polymerization is carried out by using a peroxide as a polymerization initiator,
It is carried out by a usual emulsion polymerization method using a polymerization initiator such as a redox compound, an azo compound and a persulfate. In addition, a molecular weight modifier or the like can be used if necessary. The obtained polymer latex is recovered under a reduced pressure or by a usual monomer recovery means such as steam distillation, and then recovered in the polymer latex (when a nonionic activator is not used together during emulsion polymerization). In addition to the nonionic activator, an electrolyte containing no metal is added, and then heated to a predetermined temperature, the ionic activator phase and the nonionic activator phase are phase separated, and The polymer precipitates and can be separated. When a nonionic activator is used during emulsion polymerization,
By utilizing the phenomenon of cloud point, the polymer can be separated without using a coagulant. The polymer obtained by the emulsion polymerization method of the present invention thus obtained has a very small amount of the metal ion content of the alkali metal as compared with the polymer obtained by the usual emulsion polymerization.

The thermosetting resin used in the present invention is not particularly limited, but as the thermosetting resin, epoxy resin, polyimide resin, phenol resin, cyanate resin, unsaturated polyester resin, polycarbodiimide resin, Polyfunctional cyanate ester resin, polyfunctional maleimide-cyanate ester resin, polyfunctional maleimide resin,
Unsaturated group-containing polyphenylene ether resins and the like can be mentioned, and one kind or a combination of two or more kinds is used.
Of these, epoxy resins and polyimide resins are preferable.

Specific examples of the epoxy resin include liquid or solid bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, butadiene, pentadiene. , Vinylcyclohexene, dicyclopentyl ether, and other polyepoxy compounds in which the double bond is epoxidized; polyols, polyglycidyl compounds obtained by the reaction of hydroxyl group-containing silicone resins with epohalohydrin, and the like. These may be used alone or in combination of two or more. As the polyimide resin, specifically,
Examples thereof include reaction products of polyfunctional maleimides and polyamines.

The ratio of the rubber-like polymer of the present invention contained in the thermosetting resin is 0.1 with respect to 100 parts by weight of the thermosetting resin.
-20 parts by weight, preferably 0.2-10 parts by weight.
When it is contained in this proportion, Tg is not lowered and cracking of the resin is reduced, which is preferable.

The thermosetting resin composition of the present invention includes organic,
Various additives such as inorganic fillers, dyes, pigments, thickeners, lubricants, defoamers, dispersants, leveling agents, photosensitizers, flame retardants, brighteners, polymerization inhibitors, thixotropic agents, etc. , Which is appropriately used as desired.

The metal foil used in the present invention is copper,
Aluminum, brass, nickel, iron or the like may be used alone, alloy, or composite foil, and the thickness is preferably 1 to 500 μm.

The thermosetting resin composition is used to form an insulating layer on a metal foil, and an amine solvent such as DMF or dimethylacetamide, MEK, MIBK, or the like so that it can be easily applied on the metal foil. It is dissolved in a ketone solvent such as methyl-n-amyl ketone and liquefied to be used as a resin varnish. Further, if necessary, a filler such as an inorganic powder or fibers can be dispersed at the time of dissolution in a solvent.

As a method for applying the thermosetting resin composition to the metal foil, a comma coater, a transfer coater, a curtain coater or the like is used, and the liquid thermosetting resin composition is applied to the metal foil. Then, it is continuously or discontinuously dried by heating and semi-cured to form a B-staged insulating layer. The insulating layer used is at least one layer, but it is also preferable to apply a plurality of layers.

For example, the thermosetting resin composition applied to the resin-coated metal foil is formed of a first resin layer which is softened at a high temperature and a second resin layer which is melted at a low temperature. When it is formed on the metal foil side, the second resin layer, which is in contact with the inner layer substrate during the laminating and molding, is first melted and the adhesion with the inner layer substrate can be improved. In addition, it is preferable that the insulating layers applied in plural layers are applied by changing the melting points of the respective resin layers, and as they approach the metal foil side,
When the melting point becomes high, when molding a multilayer printed wiring board,
The resin is preferable because it easily flows on the inner layer substrate. Here, it is preferable that the resin layer in contact with the metal foil does not melt at the molding temperature and is softened in order to secure its thickness. This also has the effect of making the surface roughness constant.

The above-mentioned resin-coated metal foil is used as a material for a multilayer printed wiring board. For example, the resin-coated metal foil is laminated on an inner layer substrate having a wiring pattern formed on a glass epoxy copper clad laminate, and heated and pressed. After multi-layer molding, the outer layer circuit is further formed to obtain a multi-layer printed wiring board.

[0027]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Parts and% in the examples and comparative examples are based on weight unless otherwise specified. Further, the synthesis of the rubber-like polymers used in Examples and Comparative Examples and the quantification of metal ions in the polymers were determined as follows. Furthermore, various measurements were based on the following methods.

1) Synthesis of Rubbery Polymer Emulsion polymerization was carried out at 20 ° C. in an autoclave having an internal volume of 20 L. 55 parts by weight of butadiene, 3 acrylonitrile
5 parts by weight, 10 parts by weight of acrylic acid, 220 parts by weight of water, polyoxyethylene nonylphenyl ether (manufactured by Kao Corporation)
5 parts by weight of Emulgen 920 cloud point 82 ° C.), 0.2 parts by weight of tertiary dodecyl mercaptan, 0.25 parts by weight of ammonium persulfate, 0.15 parts by weight of cyanated ether diethanolamine. Polymerization was terminated by adding 0.2 parts by weight of hydroxylamine sulfate per 100 parts by weight of the monomer. Then, after heating and recovering the residual monomer by steam distillation under reduced pressure at about 70 ° C., 2 parts by weight of alkylated phenol as an antiaging agent was added, and then this polymer latex was put in a pressure resistant tube, The latex was coagulated by heating to 110 ° C. The generated crumb was taken out, washed with water, and dried under reduced pressure at 50 ° C. to obtain a rubber-like copolymer evaluation sample (Sample 1). Table 1
Other samples shown in Table 1 were also synthesized by the same formulation. (Samples 2-9)

2) Quantitative determination of metal ion in the polymer The polymer was baked and ashed in a platinum crucible at 700 ° C., and the remaining ash was dissolved in a concentrated hydrochloric acid / concentrated nitric acid = 3/1 mixture to an appropriate concentration. After dilution, the concentration of each metal in the aqueous solution was determined with an atomic absorption spectrometer. Then, the content of the metal ion in the polymer was calculated and calculated from the value of the concentration of each metal.

3) Evaluation of coating property: The state of the coating film was visually confirmed. A film having a smooth coating film was evaluated as OK, and a film having fine wrinkles due to curing shrinkage and poor smoothness was evaluated as NG. 4) Bending test: Each resin-coated copper foil was subjected to a 180-degree bending test using a bending tester with a diameter of 2 mm. If there were no cracks, OK was given; if there were cracks, NG was given. The sex was evaluated. 5) Electrocorrosion resistance test: line / space = 0.2 /
Using a 0.2 (mm) comb pattern, 80 ° C, 1
The copper wiring portion on the substrate surface was observed with an optical microscope after 24 hours under the conditions of 00% RH and DC 100V, and the wiring corrosion was found to be NG, and the wiring without any change in appearance was OK. 6) Adhesion evaluation: Evaluation was performed according to the cross-cut tape method of JIS K5400 (8.5.1). As for the results, the case where the entire surface was peeled off after the test was ×, and a part (50% of the whole)
Below) those that peeled off were marked with Δ, and those that did not peel at all were marked with ◯.

Example 1 First, a wiring pattern was formed on one surface of a FR-4 type double-sided copper clad laminate (laminate thickness 1.0 mm, copper foil thickness 35 μm), and the other surface was formed. The copper foil was removed by etching over the entire surface to produce an inner layer substrate on which a wiring pattern was formed, and the surface of this wiring pattern was subjected to a surface treatment called blackening treatment.

Next, epoxy resin Epicoat 1001
(Product name, manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent: 480) To 100 parts by weight, 3 parts by weight of dicyandiamide, 0.2 parts by weight of 2-ethyl-4-methylimidazole as a catalyst and 200 parts by weight of MIBK as a solvent were added. , A resin varnish was prepared. 5 parts by weight of the above sample 1 was mixed with the above resin varnish and stirred with a stirrer to obtain an epoxy resin varnish. This varnish was applied on an electrolytic copper foil for electrical use (GT-18 μm, manufactured by Furukawa Circuit Co., Ltd.) having a thickness of 18 μm using a comma coater so that the thickness after drying was 50 μm, and the temperature was 130 ° C. It was dried for 20 minutes and semi-cured to obtain a resin-coated copper foil.

Examples 2 to 9 and Comparative Examples 1 to 2 Multilayer printed wiring boards were obtained in the same manner as in Example 1 except that Sample 1 was changed to Samples 2 to 9 as the rubber-like polymer to be added to the resin varnish. It was The characteristics are shown in Table 2. The rubber-like polymer used in Comparative Example 1 is as follows. Acrylonitrile-butadiene copolymer rubber: Product name "N2
30S "manufactured by JRS (bound acrylonitrile amount 35% by weight, ML _{1 + 4} (100 ° C.) = 56, Na content 108 ppm, K content 12 ppm)

[0034]

[Table 1]

[0035]

[Table 2]

As shown in Table 2, it can be seen that the resin-coated copper foil of the present invention is excellent in bending characteristics and also in electrical corrosion resistance.

[0037]

According to the resin-coated copper foil of the present invention, by using a rubber-like polymer having a low alkali metal content as a rubber component, the strength and impact resistance are excellent, and the adhesiveness with the metal foil is excellent. A resin-coated copper foil that prevents resin from peeling off in a cured state and has no insulation failure can be obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 115/00 C09D 115/00 133/06 133/06 133/14 133/14 133/20 133/20 H05K 3/46 H05K 3/46 TF term (reference) 4F100 AB01A AB01B AB17 AB33A AK01B AK25B AK27B AK28B AK29B AK53B AL05B AN00B BA02 BA07 JB13B JK01 JK10 GA01 CH03GA1 01 CH03GA1 CH03 CG08GA1 CH01 KA08 CG08GA1 CH1 CG08GA1 CH1 KA08 CH1 KA08 CH1 KA08 CH1 KA08 CH1 CH1 CH1 CH1 KA08 CH1 CH1 KA08 CH1 CH1 CH1 CH1 CH1 NA12 PC02 4J100 AE18R AJ02R AJ09R AL03P AL08P AL08R AL09R AL10R AM02Q AS02P AS03P BA04P BA05P BA06P BA31R BC54R CA05 CA06 FA20 5E346 AA12 CC09 CC32 DD12 HH08 HH11

Claims (6)

[Claims] 1. A rubbery polymer having an alkali metal content of 50.
A resin-coated metal foil, which is obtained by applying a thermosetting resin composition containing a rubber-like polymer in an amount of ppm or less to a metal foil. 2. A rubber-like polymer containing a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group as a monomer unit constituting the rubber-like polymer. The resin-coated metal foil according to claim 1, which is a united body. 3. The resin according to claim 2, wherein the rubber-like polymer is any of rubber-like polymers (1) to (3) composed of the following monomers. Metal foil. (1) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (b) acrylonitrile, (c) ) A rubbery polymer consisting of butadiene and / or isoprene. (2) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (d) an alkyl (meth) A rubbery polymer comprising an acrylate and / or an alkoxyl (meth) acrylate, and (e) another monomer copolymerizable with the above monomer. (3) As a monomer unit constituting the polymer, (a) a monomer having any one functional group selected from an epoxy group, a hydroxyl group, a carboxyl group and an amino group, (b) acrylonitrile, (c) ) Butadiene and / or isoprene, (d) alkyl (meth) acrylate and /
Alternatively, a rubbery polymer composed of an alkoxy (meth) acrylate. 4. The rubber-like polymer is obtained by the following method (1).
Alternatively, the resin-made metal foil according to any one of claims 1 to 3, which is one of the polymers produced in (2). (1) A coagulant is obtained by using a nonionic activator as an emulsifier, performing emulsion polymerization at a temperature lower than the cloud point of the nonionic activator, and then heating the obtained polymer latex to a temperature of the cloud point or higher. A polymer produced by a method of solidifying without using. (2) After carrying out emulsion polymerization using at least an ionic activator as an emulsifier, the resulting polymer latex is then heated in the presence of a nonionic activator and a metal-free electrolyte to give a rubber-like polymer. A polymer produced by a method of solidifying. 5. The rubber-like polymer is a thermosetting resin 100.
0.1-20 weight part is contained with respect to weight part, The metal foil with resin in any one of Claims 1-4 characterized by the above-mentioned. 6. A multilayer board formed by laminating the resin-coated metal foil according to claim 1 and an inner layer circuit plate.