JP2014180846A - Transparent flexible metal-clad laminate and flexible printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible metal-clad laminate and a flexible printed wiring board each endowed simultaneously with excellent heat resistance, flexibility, and low hygroscopicity.SOLUTION: A flexible metal-clad laminate wherein a polyesterimide resin including, among structural units thereof, a structure expressed by the following general formula (1) is laminated on at least one surface of a metal foil is manufactured: general formula (1) (in the formula, R1 expresses a divalent linear aliphatic group, divalent alicyclic group, or divalent aromatic group, whereas R2 expresses a divalent linear aliphatic group, divalent alicyclic group, or divalent aromatic group).

Description

The present invention relates to a flexible metal-clad laminate having excellent heat resistance, flexibility, low hygroscopicity, and sufficient colorless transparency, and a flexible printed wiring board.

  In device substrates for display devices such as liquid crystal display elements, plasma displays, and organic EL displays, with the development of foldable paper displays, the need for transparent film substrates to replace current glass substrates is increasing. In the fields of smart phones and tablet terminal devices, electronic devices are becoming smaller, lighter and lighter, and the glass and ceramic substrates used are required to be lighter, more flexible, and more flexible. ing. In recent years, as an alternative to these glass substrates and ceramic substrates, application of a flexible printed wiring board using a transparent film substrate and a transparent coverlay excellent in heat resistance and flexibility has been promoted.

In order to apply the flexible printed wiring board to these uses, a flexible film-like material having colorless transparency similar to that of glass is required. Of course, since it is applied as a mounting substrate, heat resistance and dimensional stability are required. In particular, with the recent advancement of IC packaging technology and higher density, film substrate materials require higher heat resistance, thermal dimensional stability, hygroscopic dimensional stability, low hygroscopicity, and the like.

A flexible printed wiring board is manufactured by laminating a cover lay on a circuit after processing an etching circuit of a flexible metal-clad laminate by a subtractive method or the like. Conventionally, as a flexible metal-clad laminate, a) a three-layer flexible metal-clad laminate in which a metal foil and a wholly aromatic polyimide film are bonded together with an adhesive (Patent Document 1), b) an aromatic without using an adhesive Two-layer flexible metal-clad laminate in which polyimide film is laminated on metal foil (Patent Document 2), c) Metal such as Cr is directly deposited on an aromatic polyimide film by sputtering, etc., and copper is electrolessly and / or electrolyzed. There is a metalizing type two-layer flexible metal-clad laminate (Patent Document 3) that is manufactured by plating.

However, all flexible metal laminates use wholly aromatic polyimide films that form charge transfer complexes within and between molecules as substrate materials. For this reason, visible light is absorbed and it is colored pale yellow-reddish brown, and it was difficult to apply to the use which needs colorless transparency. In addition, a molecular structure composed of an imide group via an aromatic ring can exhibit high heat resistance, but has a drawback of large polarization and high affinity with water molecules. That is, the moisture absorption rate is high, and the circuit has problems such as swelling and peeling during high temperature mounting such as solder reflow due to the influence of moisture. Furthermore, due to the highly polar molecular structure, the flexibility is inferior, and it has been difficult to cope with downsizing and thinning of electronic devices such as smart phones and tablet terminal devices.

The cover lay material is the same, and the current situation is that it is laminated on the pattern by laminating a polyimide film with an adhesive that has been punched in advance according to the pattern shape, or by screen printing of an inked polyimide. In some cases, wholly aromatic polyimide is used. For this reason, it is difficult to apply to applications requiring colorless transparency, and the same applies to low hygroscopicity and flexibility, and the performance is not always sufficient.

As a transparent heat-resistant resin material, a polyimide that suppresses the formation of charge transfer complexes within and between molecules by using an alicyclic diamine or an aliphatic diamine as a diamine component has been proposed. For example, Patent Document 4 discloses an aromatic acid dianhydride such as pyromellitic dianhydride or 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and trans-1,4-diaminocyclohexane. A polyimide obtained by imidizing a polyimide precursor (polyamic acid) to be formed has been proposed. However, although the polyimide exhibits high heat resistance and high transparency, the polyimide main chain skeleton has high rigidity and linearity, so there are problems of low elongation, lack of flexibility, and high moisture absorption. .

In Patent Document 5, a highly flexible alicyclic diamine such as 4,4′-methylenebis (cyclohexylamine) and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, A colorless and transparent copolymer polyimide formed from a specific aromatic dianhydride such as 4,4′-diphenylsulfonetetracarboxylic dianhydride has been proposed. However, it is difficult to say that the heat resistance is sufficiently satisfied, and there are problems in flexibility and moisture absorption characteristics.

In addition, the polyimides proposed in Patent Documents 4 and 5 have poor solubility, and must be heat-treated at a high temperature after molding (after coating) in the form of a precursor polyamic acid. In order to continuously produce a film or the like using, there is a problem that productivity is lowered or expensive equipment is required, which basically increases the manufacturing cost.

Further, Patent Document 6 proposes a colorless and transparent modified polyimide resin formed from cyclohexanetricarboxylic acid anhydride and aromatic diamine.

JP 2000-273430 A JP 2010-150552 A JP 2012-186307 A Japanese Patent No. 3972600 Japanese Patent Laid-Open No. 7-10993 WO08 / 072495 Pamphlet

The present invention has been made against the background of the problems of the prior art. That is, an object of the present invention is to provide a flexible metal-clad laminate having excellent flexibility, low hygroscopicity, and sufficient colorless transparency while maintaining the characteristics of polyimide such as heat resistance, low thermal expansion, and thermal dimensional accuracy. The body and the flexible printed wiring board are to be manufactured at low cost.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have reached the present invention. That is, this invention consists of the following structures.

(Claim 1)
A flexible metal-clad laminate, wherein a polyesterimide resin containing a structure represented by the following general formula (1) in a structural unit is laminated on at least one surface of a metal foil.

(Wherein R1 represents a divalent chain aliphatic group, a divalent cycloaliphatic group or a divalent aromatic group, and R2 represents a divalent chain aliphatic group or a divalent cycloaliphatic group. An aromatic group or a divalent aromatic group.)
(Section 2)
The flexible metal-clad laminate according to Item 1, wherein the polyesterimide resin further contains a structure represented by the general formula (2) in the structural unit.

(Wherein R2 ′ represents a divalent chain aliphatic group, a divalent cycloaliphatic group or a divalent aromatic group.)
(Section 3)
Item 3. The flexible metal-clad laminate according to Item 1 or 2, wherein R1 is a structure represented by the following General Formula (3) in General Formula (1).

(Here, R represents a chain aliphatic compound having a divalent hydroxyl group, a cyclic aliphatic compound having a divalent hydroxyl group, or an OH group derived from an aromatic compound having a divalent hydroxyl group) The plurality of R may be the same or different from each other, and m is a positive integer of 1 or more.)
(Section 4)
Item 4. The flexible metal-clad laminate according to any one of Items 1 to 3, wherein in the general formula (1), R1 is constituted by the following general formula (4) and / or general formula (5).


(R3 and R4 represent a direct bond, an alkylene group, a perfluoroalkylene group, an ether bond, an ester bond, a carbonyl group, a sulfonyl group, a sulfinyl group, a sulfenyl group, a carbonate group, or a fluorenylidene group. X1 to X8 and X1 ′ to X 8 ′ may be the same or different and each represents a group selected from hydrogen, halogen, and an alkyl group.)
(Section 5)
In general formula (1), R2 is comprised by following General formula (6), The flexible metal-clad laminated body in any one of Claims 1-4 characterized by the above-mentioned.

(R5 represents a direct bond, an alkylene group, a perfluoroalkylene group, an ether bond, an ester bond, a carbonyl group, a sulfonyl group, a sulfinyl group, or a sulfenyl group. X9 to X16 may be the same or different. Well each represents a group selected from hydrogen, halogen and alkyl groups.)
(Claim 6)
Item 6. The flexible metal-clad laminate according to any one of Items 2 to 5, wherein in the general formula (2), R2 'is constituted by the following general formula (7).

(R5 ′ represents a direct bond, an alkylene group, a perfluoroalkylene group, an ether bond, an ester bond, a carbonyl group, a sulfonyl group, a sulfinyl group, or a sulfenyl group. X9 ′ to X16 ′ may be the same or different. And each represents a group selected from hydrogen, halogen, and an alkyl group.)
(Claim 7)
When the total structural unit constituting the polyesterimide resin is 100 mol%, the structure represented by the general formula (1) and the general formula (2) is contained in a total of 20 mol% or more,
The molar ratio between the structure represented by the general formula (1) and the structure represented by the general formula (2) is configured in the range of the general formula (1) / general formula (2) = 99/1 to 1/99. Item 7. The flexible metal-clad laminate according to any one of Items 2 to 6, which is characterized.
(Section 8)
Item 8. A flexible printed wiring board obtained from the flexible metal-clad laminate according to any one of Items 1 to 7.

The flexible metal-clad laminate and the flexible printed wiring board of the present invention have excellent heat resistance, flexibility, low hygroscopicity, and sufficient colorless transparency. Thereby, device mounting boards for display devices such as liquid crystal displays, plasma displays, organic EL displays, inter-board connection wiring boards such as smart phones, tablet terminal devices, digital cameras, portable game machines, operation switch unit boards, etc. It can be widely used as a substrate material for mounting ICs in electronic devices that are becoming smaller, lighter, and thinner.

  The present invention is described in detail below.

The colorless transparency in the present invention refers to a base film prepared by etching and removing a copper foil from a flexible metal-clad laminate or a flexible printed wiring board according to the present invention at 40 ° C. using a 35% cupric chloride solution. When the film thickness is 5 μm or more when measured under the following measurement conditions, the total light transmittance (%) is 80% or more.
<Measurement conditions>
Measurement sample: A copper foil of a flexible metal-clad laminate or a flexible printed wiring board was etched using a 35% cupric chloride solution at 40 ° C. to completely remove the copper foil.
Measurement method: According to JISK7105.
Measurement device: Measured with a haze meter (trade name “NDH2000”, manufactured by Nippon Denshoku Industries Co., Ltd., lamp type D65), and the value of Tt, which is one of the result items, was defined as the total light transmittance.

<< Polyesterimide resin >>
The polyesterimide resin of this invention contains the structure shown by General formula (1) in a structural unit.

In general formula (1), R1 represents a divalent chain aliphatic group, a divalent cycloaliphatic group or a divalent aromatic group, and R2 represents a divalent chain aliphatic group, a divalent aromatic group. A cycloaliphatic group or a divalent aromatic group is shown.

As an example of the structure of the general formula (1), a halide of cyclohexanetricarboxylic anhydride and a diol are reacted to obtain an ester group-containing tetracarboxylic dianhydride, and then the ester group-containing tetracarboxylic acid. It can be obtained by condensation reaction (polyimidization) of acid dianhydride and diamine or diisocyanate.

  The polyesterimide resin of the present invention preferably further contains the structure represented by the general formula (2) in the structural unit.

In the general formula (2), R2 ′ represents a divalent chain aliphatic group, a divalent cycloaliphatic group or a divalent aromatic group.

  When all the structural units constituting the polyesterimide resin are 100 mol%, the structure represented by the general formula (1), or the total structure represented by the general formula (1) and the general formula (2) Is preferably contained in an amount of 20 mol% or more, more preferably 50 mol% or more, and even more preferably 70 mol% or more. Resin having both flexibility and low hygroscopicity when the structure represented by the general formula (1) and the general formula (2) is less than 20 mol% when all the structural units constituting the polyesterimide resin are 100 mol% Production of the composition becomes difficult.

  In the polyesterimide resin of the present invention, the molar ratio of the structure represented by the general formula (1) and the structure represented by the general formula (2) is general formula (1) / general formula (2) = 99/1 to 1/99. The general formula (1) / the general formula (2) = 90/10 to 10/90 is more preferable, and the general formula (1) / the general formula (2) = 80/20 to 20 / It is more preferable that it is 80, and it is especially preferable that it is general formula (1) / general formula (2) = 70 / 30-30 / 70.

When the structure represented by the general formula (1) exceeds 99, heat resistance and thermal dimensional accuracy may be impaired depending on the chemical structure of the R1 component. Moreover, when the molar ratio of the structure represented by the general formula (2) exceeds 99, depending on the R2 component and / or R2 'component, the low hygroscopicity and flexibility are generally deteriorated. Also, the solubility is lowered.

<R1 of general formula (1)>
R1 in the general formula (1) is not particularly limited as long as it is a divalent chain aliphatic group, a divalent cycloaliphatic group, or a divalent aromatic group. These “divalent chain aliphatic group”, “divalent cycloaliphatic group”, and “divalent aromatic group” can be used alone or in combination of two or more.

R1 in the general formula (1) is preferably “chain aliphatic compound having a divalent hydroxyl group” or “cycloaliphatic having a divalent hydroxyl group” because of balance of heat resistance, flexibility, low hygroscopicity, and the like. A residue derived from “a compound” or “an aromatic compound having a divalent hydroxyl group” or the like is desirable. Further, R1 in the general formula (1) represents “a chain aliphatic compound having a divalent hydroxyl group”, “a cycloaliphatic compound having a divalent hydroxyl group”, and “an aromatic compound having a divalent hydroxyl group”. It may be a residue derived from a “polycarbonate diol compound” that can be polymerized from a compound selected from the group consisting of carbonates, phosgene and the like.
That is, R 1 in the general formula (1) of the present invention is preferably a residue derived from a “diol compound”, “a chain aliphatic compound having a divalent hydroxyl group”, “a ring having a divalent hydroxyl group”. Residues derived from "formula aliphatic compounds", "aromatic compounds having a divalent hydroxyl group", and "polycarbonate diol compounds" that can be polymerized therefrom are preferred.
These “chain aliphatic compounds having a divalent hydroxyl group”, “cycloaliphatic compounds having a divalent hydroxyl group”, “aromatic compounds having a divalent hydroxyl group”, and “polycarbonates” that can be polymerized therefrom The “diol compound” can be used alone or in combination of two or more.

  As the “chain aliphatic compound having a divalent hydroxyl group”, a branched or linear diol compound having two hydroxyl groups can be used. Examples thereof include an alkylene diol compound, a polyoxyalkylene diol compound, a polyester diol compound, a polycaprolactone diol compound, and the like. Examples of the branched or straight chain diol compound having two hydroxyl groups that can be used as the “chain aliphatic compound having a divalent hydroxyl group” are listed below.

  Examples of the alkylene diol compound include ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 3-methyl-1,5-pentanediol. 1,6-hexanediol, 1,8-octanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanediol, 1,4- And cyclohexanedimethanol.

  Examples of the polyoxyalkylene diol compound include dimethylolpropionic acid (2,2-bis (hydroxymethyl) propionic acid), dimethylolbutanoic acid (2,2-bis (hydroxymethyl) butanoic acid), polyethylene glycol, polyoxy Examples include tetramethylene glycol, polypropylene glycol, polytetramethylene glycol, and a random copolymer of tetramethylene glycol and neopentyl glycol. Polyoxytetramethylene glycol is preferable.

  As a polyester diol compound, the polyester diol compound etc. which are obtained by making the polyhydric alcohol and polybasic acid which are illustrated below react, for example are mentioned.

Any "polyhydric alcohol" can be used as the "polyhydric alcohol component" used in the polyester diol compound. For example, ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5 -Pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanemethanol, Neopentyl hydroxypiparic acid ester, ethylene oxide adduct and propylene oxide adduct of bisphenol A, ethylene oxide adduct and propylene oxide adduct of water-added bisphenol A, 1,9-nonanediol, 2-methyloctanedi Lumpur, 1,10-dodecane diol, 2-butyl-2-ethyl-1,3-propanediol, tricyclodecane methanol, polyethylene glycol, polypropylene glycol, polyether polyol such as polytetramethylene glycol may be used.

  As the “polybasic acid component” used in the polyester diol compound, any of various polybasic acids can be used. For example, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, 4,4′-diphenyldicarboxylic acid, 2,2′-diphenyldicarboxylic acid, 4,4′-diphenyletherdicarboxylic Acid, adipic acid, sebacic acid, azelaic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, dimer acid, etc. Aliphatic and alicyclic dibasic acids can be used.

  As a commercially available polyester diol compound that can be used in the present invention, specifically, OD-X-688 (DIC Corporation, aliphatic polyester diol: adipic acid / neopentyl glycol / 1,6-hexanediol, number average Molecular weight of about 2,000), Vylon 220 (polyester diol manufactured by Toyobo Co., Ltd., number average molecular weight of about 2,000), and the like.

  Examples of polycaprolactone diol compounds include polycaprolactone diol compounds obtained by ring-opening addition reaction of lactones such as γ-butyllactone, ε-caprolactone, and δ-valerolactone.

The above-mentioned “chain aliphatic compound having a divalent hydroxyl group” can be used alone or in combination of two or more.

  Examples of the “cycloaliphatic compound having a divalent hydroxyl group” or “the aromatic compound having a divalent hydroxyl group” include “a compound having two hydroxyl groups in an aromatic ring or cyclohexane ring”, “two phenols or fats” A compound in which a cyclic alcohol is bonded with a divalent functional group, a “compound having one hydroxyl group in both nuclei of the biphenyl structure”, a “compound having two hydroxyl groups in the naphthalene skeleton”, and the like are used.

  As "a compound having two hydroxyl groups in an aromatic ring or cyclohexane ring", hydroquinone, 2-methylhydroquinone, resorcinol, catechol, 2-phenylhydroquinone, cyclohexanedimethanol, tricyclodecanemethanol, 1,4-dihydroxycyclohexane, 1, 3-dihydroxycyclohexane, 1,2-dihydroxycyclohexane, 1,3-adamantanediol, dicyclopentadiene dihydrate, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid A carboxyl group-containing diol compound such as acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and 3,5-dihydroxybenzoic acid can be used.

  “A compound in which two phenols or alicyclic alcohols are bonded with a divalent functional group” or “a compound having one hydroxyl group at both nuclei of a biphenyl structure” is represented by the following general formula (4), general formula A compound from which the residue of (5) is derived is preferred.

R3 and R4 are a direct bond, an alkylene group (—C _n H _2n —), a perfluoroalkylene group (—C _n F _2n —), an ether bond (—O—), an ester bond (—COO—), a carbonyl group ( -CO-), a sulfonyl group (-S (= O) _2- ), a sulfinyl group (-SO-), a sulfenyl group (-S-), a carbonate group (-OCOO-), or a fluorenylidene group. n is a positive integer of 1 or more. X1 to X8 and X1 ′ to X8 ′ may be the same or different, and each represents a group selected from hydrogen, halogen, and an alkyl group. Here, the upper limit of n is not particularly limited, but is preferably 10 or less, more preferably 5 or less, and still more preferably 3 or less.

Examples of “a compound in which two phenols or alicyclic alcohols are bonded with a divalent functional group” include 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenylsulfone, 4,4 ′-( 9-fluorenylidene) diphenol, 4,4'-dihydroxydicyclohexyl ether, 4,4'-dihydroxydicyclohexylsulfone, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, ethylene oxide adduct of bisphenol A, bisphenol A propylene oxide adduct of A, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct and the like can be used.
Preferably, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, 4,4 ′-(9-fluorenylidene) diphenol, 4,4′-dihydroxydicyclohexyl ether, 4,4′-dihydroxydicyclohexyl sulfone An ethylene oxide adduct of bisphenol A is preferred. More preferably, 4,4′-dihydroxydiphenyl ether and an ethylene oxide adduct of bisphenol A are used.

Examples of “compound having one hydroxyl group in both nuclei of biphenyl structure” are 4,4′-biphenol, 3,4′-biphenol, 2,2′-biphenol, 3,3 ′, 5,5 ′. -Tetramethyl-4,4'-biphenol or the like can be used.

  Examples of the “compound having two hydroxyl groups in the naphthalene skeleton” include 2,6-naphthalenediol, 1,4-naphthalenediol, 1,5-naphthalenediol, 1,8-naphthalenediol, and the like.

The above-mentioned “cycloaliphatic compound having a divalent hydroxyl group” and “aromatic compound having a divalent hydroxyl group” can be used alone or in combination of two or more.

  In the present invention, as R1 of the general formula (1), in addition to the residues derived from the various “diol compounds” described above, the above-mentioned various “chain aliphatic compounds having a divalent hydroxyl group”. ”,“ Cycloaliphatic compound having a divalent hydroxyl group ”or“ Aromatic compound having a divalent hydroxyl group ”, etc. and a residue derived from a“ polycarbonate diol compound ”that can be polymerized from carbonates, phosgene, etc. It may be.

Specifically, as R1 in the general formula (1), the above-mentioned various “chain aliphatic compounds having a divalent hydroxyl group”, “cycloaliphatic compounds having a divalent hydroxyl group” or “divalents”. It may be a compound that can be polymerized from an “aromatic compound having a hydroxyl group” or the like and in which a residue of the following general formula (3) is derived.

Here, R is a chain aliphatic compound having a divalent hydroxyl group, a cycloaliphatic compound having a divalent hydroxyl group, or an OH group derived from an aromatic compound having a divalent hydroxyl group. Residue. A plurality of R may be the same as or different from each other. m is a positive integer of 1 or more.

R represents the aforementioned various diol compounds, “chain aliphatic compounds having a divalent hydroxyl group”, “cycloaliphatic compounds having a divalent hydroxyl group”, “aromatic compounds having a divalent hydroxyl group”, etc. And an alkylene group or a bisphenol residue is preferable. m is a positive integer of 1 or more. Here, although the upper limit of m is not specifically limited, Preferably it is 25 or less, More preferably, it is 20 or less, More preferably, it is 10 or less. When it exceeds 25, the heat resistance tends to decrease.

Examples of the method for producing the polycarbonate diol include transesterification between a raw material diol and a carbonic acid ester, and a dehydrochlorination reaction between the raw material diol and phosgene. Examples of the carbonic acid ester as a raw material include dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; diaryl carbonates such as diphenyl carbonate; and alkylene carbonates such as ethylene carbonate and propylene carbonate.

  As a polycarbonate diol compound, the polycarbonate diol (copolymerization polycarbonate diol) which has the multiple types of alkylene group mentioned above in the frame | skeleton may be sufficient. For example, a combination of 2-methyl-1,8-octanediol and 1,9-nonanediol, a combination of 2-methyl-1,8-octanediol and 1,9-nonanediol, 3-methyl-1,5- A combination of pentanediol and 1,6-hexanediol, a combination of 3-methyl-1,5-pentanediol and 1,6-hexanediol, a combination of 1,5-pentanediol and 1,6-hexanediol, 1, Examples thereof include a copolymerized polycarbonate diol that can be synthesized by a combination of 5-pentanediol and 1,6-hexanediol, a combination of 1,5-pentanediol and 1,6-hexanediol, and the like. A copolymer polycarbonate diol that can be synthesized from a combination of 2-methyl-1,8-octanediol and 1,9-nonanediol is preferable.

  Examples of commercially available polycarbonate diol compounds that can be used in the present invention include Kuraray Kuraray Polyol C Series, Asahi Kasei Chemicals Duranol Series, and the like. For example, Kuraray polyol C-1015N, Kuraray polyol C-1065N (Kuraray Co., Ltd. carbonate diol: 2-methyl-1,8-octanediol / 1,9-nonanediol, number average molecular weight about 1,000), Kuraray Polyol C-2015N, Kuraray polyol C2065N (Kuraray Co., Ltd. carbonate diol: 2-methyl-1,8-octanediol / 1,9-nonanediol, number average molecular weight of about 2,000), Kuraray polyol C-1050, Kuraray polyol C-1090 (Kuraray Co., Ltd. carbonate diol: 3-methyl-1,5-pentanediol / 1,6-hexanediol, number average molecular weight of about 1,000), Kuraray polyol C-2050, Kuraray polyol C -2090 (Kuraray Co., Ltd.) : 3-methyl-1,5-pentanediol / 1,6-hexanediol, number average molecular weight of about 2,000), DURANOL-T5650E (polycarbonate diol manufactured by Asahi Kasei Chemicals Corporation: 1,5-pentanediol / 1, 6-hexanediol, number average molecular weight of about 500), DURANOL-T5651 (polycarbonate diol manufactured by Asahi Kasei Chemicals Corporation: 1,5-pentanediol / 1,6-hexanediol, number average molecular weight of about 1,000), DURANOL- T5652 (Asahi Kasei Chemicals Corporation polycarbonate diol: 1,5-pentanediol / 1,6-hexanediol, number average molecular weight of about 2,000). Kuraray polyol C-1015N is preferable.

  The number average molecular weight of the “diol compound” as R1 of the general formula (1) that can be used in the present invention is preferably 100 or more and 30000 or less, more preferably 200 or more and 20000 or less, and further preferably 200 or more and 10,000. It is as follows. If the average molecular weight is less than 100, low hygroscopicity and flexibility cannot be sufficiently exhibited, and if it is more than 30000, depending on the composition and structure of the “diol compound” and the composition and structure of the diamine component (or isocyanate component) described later. , Phase separation, mechanical properties and colorless transparency may not be fully exhibited.

These “diol compounds” can be used in combination of two or more.

Among the “diol compounds”, “polyoxyalkylene diol compounds”, “compounds in which two phenols or alicyclic alcohols are bonded with a divalent functional group”, and “polycarbonate diol compounds” are preferable,
As the “polyoxyalkylene diol compound”, polyoxytetramethylene glycol is good,
As “a compound in which two phenols or alicyclic alcohols are bonded with a divalent functional group”, 4,4′-dihydroxydiphenyl ether, an ethylene oxide adduct of bisphenol A may be used.
The “polycarbonate diol compound” is preferably a copolymerized polycarbonate diol that can be synthesized from a combination of 2-methyl-1,8-octanediol and 1,9-nonanediol.

<R2 ′ in General Formula (1) and R2 ′ in General Formula (2)>
The diamine component of R2 in the general formula (1) and R2 ′ in the general formula (2) or the diisocyanate component corresponding thereto may be the same or different. If based on the preferable manufacturing method mentioned later, it is preferable to be the same.
The diamine component of R2 in the general formula (1) and R2 ′ in the general formula (2) that can be used in the present invention or the diisocyanate component corresponding thereto will be described below.

As the diamine component of R2 in the general formula (1) and R2 ′ in the general formula (2) or a diisocyanate component corresponding thereto, a divalent chain aliphatic group, a divalent cyclic aliphatic group, or a divalent component If it is an aromatic group, it will not specifically limit. Derived from “aromatic diamine or corresponding aromatic diisocyanate”, “cycloaliphatic diamine or corresponding cycloaliphatic diisocyanate” and “chain aliphatic diamine or corresponding chain aliphatic diisocyanate”. It is desirable that it is a residue.

In the present invention, the “aromatic diamine or the corresponding aromatic diisocyanate” of R2 in the general formula (1) is the balance of the following general formula (6) from the balance of heat resistance, flexibility, low hygroscopicity, and the like. Preferred are diamines from which the groups are derived or the corresponding diisocyanates.

R5 is a direct bond, an alkylene group (—C _n H _2n —), a perfluoroalkylene group (—C _n F _2n —), an ether bond (—O—), an ester bond (—COO—), a carbonyl group (—CO -), A sulfonyl group (—S (═O) ₂ —), a sulfinyl group (—SO—) or a sulfenyl group (—S—). n is a positive integer from 1 to 10. X9 to 16 may be the same or different and each represents a group selected from hydrogen, halogen, and an alkyl group. Here, n is preferably 1 or more and 10 or less, preferably 1 or more and 5 or less, and more preferably 1 or more and 3 or less.

In the present invention, the “aromatic diamine or aromatic diisocyanate corresponding to R2 ′” in the general formula (2) is represented by the following general formula (7) in view of the balance of heat resistance, flexibility, low hygroscopicity, and the like. Preferred are diamines from which the residues are derived or their corresponding diisocyanates.

R5 ′ is a direct bond, an alkylene group (—C _n H _2n —), a perfluoroalkylene group (—C _n F _2n —), an ether bond (—O—), an ester bond (—COO—), a carbonyl group (— CO-), a sulfonyl group (—S (═O) ₂ —), a sulfinyl group (—SO—) or a sulfenyl group (—S—). n is a positive integer from 1 to 10. X9 ′ to 16 ′ may be the same or different and each represents a group selected from hydrogen, halogen, and an alkyl group. Here, n is preferably 1 or more and 10 or less, preferably 1 or more and 5 or less, and more preferably 1 or more and 3 or less.

  Specific examples of the “aromatic diamine or the corresponding aromatic diisocyanate” include 2,2′-bis (trifluoromethyl) benzidine, p-phenylenediamine, m-phenylenediamine, , 4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, 4,4′-diaminodiphenylmethane, 4,4′-methylenebis (2-methylaniline), 4, 4'-methylenebis (2-ethylaniline), 4,4'-methylenebis (2,6-dimethylaniline), 4,4'-methylenebis (2,6-diethylaniline), 4,4'-diaminodiphenyl ether, 3 , 4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 2,4 ′ Diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenylsulfide, 3, 3 ' -Diaminodiphenyl sulfide, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminobenzanilide, P-xylenediamine, m-xylenediamine, 1,4-naphthalenediamine, 1 , 5-naphthalenediamine, 2,6-naphthalenediamine, 2,7-naphthalenediamine, benzidine, 3,3′-dihydroxybenzidine, 3,3′-dimethoxybenzidine, 3,3′-dimethyl-4, 4′- Diaminobiphenyl, 3,3'-diethyl 4,4′-diaminobiphenyl, 2,2′-dimethyl-4, 4′-diaminobiphenyl, 2,2′-diethyl-4, 4′-diaminobiphenyl, 3,3′-dimethoxy-4, 4′- Diaminobiphenyl, 3,3′-diethoxy-4, 4′-diaminobiphenyl, o-tolidine, m-tolidine, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) Benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4- Aminophenoxy) phenyl) sulfone, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phene Le) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, diamino terphenyl, and the like. These can be used in combination of two or more.

The “cycloaliphatic diamine or the corresponding cycloaliphatic diisocyanate” is exemplified by a diamine compound such as trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-diamino. Cyclohexane (trans / cis mixture), 1,3-diaminocyclohexane, 4,4'-methylenebis (cyclohexylamine) (tonthane, cis, trans / cis mixture), isophoronediamine, 1,4-cyclohexanebis (methylamine) ), 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 3,8-bis (aminomethyl) tricyclo [5.2.1.0] decane, 1,3-diaminoadamantane, 4,4′-methylenebis 2-methylcyclohexylamine), 4,4′-methylenebis (2-ethylcyclohexylamine), 4,4′-methylenebis (2,6-dimethylcyclohexylamine), 4,4′-methylenebis (2,6-diethylcyclohexyl) Amine), 2,2-bis (4-aminocyclohexyl) propane, 2,2-bis (4-aminocyclohexyl) hexafluoropropane, and the like. These can be used in combination of two or more.

Examples of the “chain aliphatic diamine or the corresponding chain aliphatic diisocyanate” include 1,3-propanediamine, 1,4-tetramethylenediamine, 1,5-pentamethylenediamine, 1, Examples include 6-hexamethylene diamine, 1,7-heptamethylene diamine, 1,8-octamethylene diamine, and 1,9-nonamethylene diamine. These can be used in combination of two or more.

In view of the balance of heat resistance, flexibility, low hygroscopicity, etc., preferred components as the diamine component of R2 in general formula (1) and R2 ′ in general formula (2) or the corresponding diisocyanate component are exemplified as diamine compounds. Then, p-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 1,5-naphthalenediamine, o-tolidine, diaminoterphenyl, 4, 4'- It is a residue derived from methylene bis (cyclohexylamine), isophoronediamine, and the like.
More preferred are 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 1,5-naphthalenediamine, o-tolidine, and more preferred is 4,4′-diaminodiphenylmethane, 4,4 ′. -Diaminodiphenyl ether, o-tolidine. Most preferred is a residue derived from 4,4′-diaminodiphenylmethane, o-tolidine.

<< Manufacture of polyesterimide resin >>
If an example of the manufacturing method of the polyesterimide resin of this invention is given, the halide of cyclohexane tricarboxylic anhydride and diol will be made to react, and ester group containing tetracarboxylic dianhydride will be obtained, and then the ester group containing tetra It can be obtained by condensation reaction (polyimidation) of carboxylic dianhydride and diamine or diisocyanate. Hereinafter, although the manufacturing method of the polyesterimide resin of this invention is illustrated, this invention is not limited by this.

  For example, an ester group-containing tetracarboxylic dianhydride can be synthesized from a chloride of anhydrous-1,2,4-cyclohexanetricarboxylic acid chloride and the above-mentioned “diol compound” by a known reaction method. For example, it can be produced by esterifying an anhydrous cyclohexanetricarboxylic acid chloride chloride and a “diol compound” in a solvent such as tetrahydrofuran, diethyl ether, acetone, cyclopentanone, cyclohexanone, ethyl acetate, gamma butyrolactone. The molar ratio is usually anhydrous cyclohexanetricarboxylic acid chloride / diol compound = 2/1 mol, and the reaction is carried out, for example, at 50 to 200 ° C. for 0.1 to 10 hours. In this case, a catalyst such as antimony, titanium, tin, zinc, cobalt, germanium, or aluminum may be used. Further, since hydrochloric acid or the like is produced as a reaction byproduct, the product is usually filtered and purified after completion of the reaction.

  Using ester group-containing tetracarboxylic dianhydride obtained as described above as a monomer and polymerizing with various diamines (diamine method) or diisocyanate (diisocyanate method), heat resistance, flexibility, low moisture absorption It is possible to produce a polyesterimide resin that is soluble in an organic solvent that has both the properties and sufficient colorless transparency.

From the viewpoint of production cost and the like, a particularly preferred production method is a diisocyanate method in which a polymer is obtained by a decarboxylation reaction.

In the case of the diisocyanate method, the ester group-containing tetracarboxylic dianhydride obtained by the reaction of the chloride of anhydrous cyclohexanetricarboxylic acid chloride and the “diol compound” and the diisocyanate are approximately stoichiometric amounts in an organic solvent, 100 The resin composition used in the present invention can be obtained by heat polycondensation at ˜200 ° C. Examples of the polymerization solvent include N-methyl-2-pyrrolidone, N, N′-dimethylformamide, N, N′-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, tetramethylurea, sulfolane, and dimethyl. Sulfooxide, γ-butyrolactone, cyclohexanone, cyclopentanone and the like, preferably N-methyl-2-pyrrolidone, N, N′-dimethylacetamide and 1,3-dimethyl-2-imidazolidinone. When these solvents are used as polymerization solvents, they can be used as solutions for producing polyesterimide films and sheets described later. Some of these can be replaced with hydrocarbon organic solvents such as toluene and xylene, ether organic solvents such as diglyme, triglyme and tetrahydrofuran, and ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone.

As long as the object of the present invention is not impaired, the acid component exemplified above may be replaced with anhydrous cyclohexanetricarboxylic acid chloride or a part thereof may be replaced with the following tricarboxylic acid anhydride.

a) Tricarboxylic acid; diphenyl ether-3,3 ′, 4′-tricarboxylic acid, diphenylsulfone-3,3 ′, 4′-tricarboxylic acid, benzophenone-3,3 ′, 4′-tricarboxylic acid, naphthalene-1,2 , 4-tricarboxylic acid, butane-1,2,4-tricarboxylic acid, cyclohexanetricarboxylic acid, dicyclohexyl ether-3,3 ′, 4′-tricarboxylic acid, dicyclohexylsulfone-3,3 ′, 4′-tricarboxylic acid, dicyclohexyl A monoanhydride such as tricarboxylic acid such as methane-3,3 ′, 4′-tricarboxylic acid, an esterified compound or the like, or a mixture of two or more.

The anhydrous cyclohexanetricarboxylic acid chloride has cis and trans isomers, which can be separated and purified according to known methods such as distillation and recrystallization. These mixing ratios are not particularly limited, but if the content of the trans isomer decreases, the glass transition temperature tends to decrease and the coefficient of thermal expansion tends to increase. Therefore, the trans isomer is preferably 50% by weight or more, more preferably 90 wt. It is recommended to use at least% cyclohexanetricarboxylic acid chloride.

In addition to the tricarboxylic acid anhydrides exemplified above, the following tetracarboxylic acid anhydrides, dicarboxylic acids and the like can be used as the acid component as long as the object of the present invention is not impaired.

b) Tetracarboxylic acid; pyromellitic acid, benzophenone-3,3 ′, 4,4′-tetracarboxylic acid, diphenyl ether-3,3 ′, 4,4′-tetracarboxylic acid, biphenyl-3,3 ′, 4 , 4′-tetracarboxylic acid, diphenylsulfone-3,3 ′, 4,4′-tetracarboxylic acid, naphthalene-2,3,6,7-tetracarboxylic acid, naphthalene-1,2,4,5-tetra Monoanhydrides such as carboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, cyclopentane-1,2,3,4-tetracarboxylic acid , Dianhydrides, esterified compounds, etc., or a mixture of two or more.
c) Dicarboxylic acid; adipic acid, azelaic acid, sebacic acid, cyclohexane-4,4′-dicarboxylic acid, terephthalic acid, isophthalic acid, diphenyl ether dicarboxylic acid, diphenylsulfone dicarboxylic acid, benzophenone dicarboxylic acid, dicarboxylic acid of biphenyl dicarboxylic acid.

  The molecular weight of the polyesterimide resin used in the present invention corresponds to a logarithmic viscosity of 0.1 to 2.5 dl / g in N-methyl-2-pyrrolidone (polymer concentration 0.5 g / dl) at 30 ° C. Those having a molecular weight are preferred, more preferably those having a molecular weight corresponding to 0.3 to 1.5 dl / g. If the logarithmic viscosity is less than 0.1 dl / g, the mechanical properties of the flexible metal-clad laminate and the flexible printed wiring board may be insufficient, and if it exceeds 2.5 dl / g, the solution viscosity becomes high. Forming processing when processing into a flexible metal-clad laminate becomes difficult.

A powdery polymer sample prepared by reprecipitation and purification of a solution containing the polyesterimide resin with a large amount of acetone is dissolved in N-methyl-2-pyrrolidone so that the polymer concentration is 0.5 g / dl. The solution viscosity and solvent viscosity of the solution are measured at 30 ° C. with an Ubbelohde-type viscosity tube, and calculated by the following formula.
Logarithmic viscosity (dl / g) = [ln (V1 / V2)] / V3
In the above formula, V1 represents the solution viscosity measured with an Ubbelohde type viscosity tube, V2 represents the solvent viscosity measured with an Ubbelohde type viscosity tube, and V1 and V2 represent a polymer solution and a solvent (N-methyl-2-pyrrolidone). Is determined from the time it passes through the capillary of the viscosity tube. V3 is the polymer concentration (g / dl).

<< Polyesterimide resin composition >>
If necessary, the polyester of the present invention may be used to improve various properties of the flexible metal-clad laminate and flexible printed wiring board, such as transparency, mechanical properties, electrical properties, slipperiness, and flame retardancy. Another resin, an organic compound, and an inorganic compound may be mixed or reacted with a resin solution containing an imide resin to obtain a resin composition.
For example, lubricant (silica, talc, silicone, etc.), adhesion promoter, flame retardant (phosphorus, triazine, aluminum hydroxide, etc.), stabilizer (antioxidant, UV absorber, polymerization inhibitor, etc.), plating activity Agents, organic and inorganic fillers (talc, titanium oxide, fluoropolymer fine particles, pigments, dyes, calcium carbide, etc.), silicone compounds, fluorine compounds, isocyanate compounds, blocked isocyanate compounds, acrylic resins, urethane resins, Resin or organic compound such as polyester resin, polyamide resin, epoxy resin, phenol resin, polyimide resin, or these curing agents, inorganic compounds such as silicon oxide, titanium oxide, calcium carbonate, iron oxide, etc. It can be used in combination as long as it is not.
The content of the polyesterimide resin in the resin composition is preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 80% by weight or more in the total solid content of the resin composition. Although there is no restriction | limiting in particular about an upper limit, What is necessary is just 99.0 mass% or less. When the content of the polyesterimide resin in the resin composition is 50% by weight or more based on the total solid content, the production of the film described below is particularly easy.

<< Flexible metal-clad laminate >>

A flexible metal-clad laminate can be obtained by laminating with a metal foil using the polyesterimide resin or the polyesterimide resin composition of the present invention.

<Metal foil>
As the metal foil used in the present invention, a copper foil, an aluminum foil, a steel foil, a nickel foil, and the like can be used. A composite metal foil obtained by combining these can also be used, but preferably a copper foil. is there. On the surface of the copper foil, organic rust prevention treatment (benzothiazole, benzotrizole, imidazole, etc.), inorganic rust prevention treatment (zinc, chromate, zinc alloy, etc.), silane coupling agent treatment (epoxy silane coupling agent, amino Silane coupling agents, mercapto-based silane coupling agents, etc.), surface plating treatment such as overlay plating treatment and burn plating treatment may be applied.

The surface roughness (Rz) of the surface on which the polyesterimide resin layer is laminated (so-called M-plane) is 5.0 μm or less, preferably 2.0 μm or less, and most preferably 1.0 μm or less. If it exceeds 5 μm, the patterning property is inferior, and the transparency of the resin film layer after the copper foil is removed by etching is deteriorated. The lower limit of the surface roughness is not limited as low as possible, but the object of the present invention can be achieved as long as it is about 0.1 μm.

More preferably, regarding the M-plane, the glossiness is 300 or more, preferably 400 or more, and more preferably 600 or more. The glossiness is measured according to JIS Z 8741-1997, and is usually irradiated at an incident angle of 60 °, and the reflected light at 60 ° is measured. The higher the glossiness is, the lower the surface roughness is, and there are few undulations that are not reflected in the surface roughness (Rz), indicating that the surface is smoother. Therefore, the higher the value is, the better the transparency is, but if it is about 800, the object of the present invention can be achieved. More practically, in addition to the above-mentioned glossiness, selection of copper foil for making a flexible printed wiring board with better transparency when the substrate is irradiated with visible light of about 400 nm to 800 nm vertically. In the present invention, it is more preferably at least 20%, more preferably at least 25%, still more preferably at least 30% in the visible light region of 400 nm to 800 nm. If it is less than 20%, the transparency is poor. The higher the reflectivity, the better. However, if it is about 80%, the object of the present invention can be achieved.

Although there is no limitation in particular about the thickness of metal foil, For example, 3-50 micrometers metal foil can be used suitably. The metal foil is usually in the form of a ribbon, and its length is not particularly limited. Also, the width of the ribbon-like metal foil is not particularly limited, but is generally about 25 to 300 cm, particularly about 50 to 150 cm.

As the copper foil as described above, a commercially available electrolytic foil or a rolled foil can be used as it is. For example, “HLS” manufactured by Nippon Electrolytic Co., Ltd., “F0-WS”, “U-WZ” manufactured by Furukawa Circuit Foil Co., Ltd., or “NA-VLP”, “DFF” manufactured by Mitsui Mining & Smelting Co., Ltd. ”,“ CF-T9D-SVR ”,“ CF-TGD-SV ”, etc.

<Method for producing flexible metal-clad laminate>
The method for producing a flexible metal-clad laminate using the polyesterimide resin or the polyesterimide resin composition of the present invention is not particularly limited. For example, a polyesterimide resin solution is applied to one side of a metal foil, and then initially dried. And can be manufactured by heat treatment.

The coating method is not particularly limited, and conventionally well-known methods can be applied. Can be applied onto metal foil after adjusting the viscosity of the coating solution with a roll coater, knife coater, doctor blade coater, gravure coater, die coater, multilayer die coater, reverse coater, reverse roll coater, etc.

In the present invention, the initial drying conditions after coating are not particularly limited, but in general, the initial drying is performed at a temperature 70 ° C. to 130 ° C. lower than the boiling point (Tb (° C.)) of the solvent used in the polyesterimide resin solution. . When the initial drying temperature is higher than (Tb-70) ° C., foaming occurs on the coated surface, and when the drying temperature is lower than (Tb-130) ° C., the drying time becomes longer and the productivity is lowered. The initial drying temperature varies depending on the type of solvent, but is generally about 60 to 150 ° C, preferably about 80 to 120 ° C. The time required for the initial drying is generally an effective time for the solvent remaining rate in the coating film to be about 5 to 40% under the above temperature conditions, but generally about 1 to 30 minutes, especially 2 ~ 15 minutes. It is preferable to further dry (secondary drying) at a temperature near the boiling point of the solvent or at a temperature equal to or higher than the boiling point.

The heat treatment conditions are not particularly limited, and may be dried at a temperature near the boiling point of the solvent or at a temperature equal to or higher than the boiling point, but is generally 120 ° C to 500 ° C, preferably 200 ° C to 400 ° C. If it is less than 120 degreeC, drying time will become long and productivity will fall, and if it exceeds 500 degreeC, a degradation reaction will advance depending on resin composition, and a base resin film layer may become weak, or transparency may fall. The time required for the heat treatment may be an effective time that generally eliminates the solvent remaining rate in the coating film under the above temperature conditions, but is generally about several minutes to several tens of hours.

In the present invention, the initial drying and heat treatment may be performed under an inert gas atmosphere or under reduced pressure. Examples of the inert gas include nitrogen, carbon dioxide, helium, and argon, but it is preferable to use easily available nitrogen. Moreover, when it carries out under reduced pressure, it is preferable to carry out under the pressure of about 10 < ^-5 > -10 < ³ > Pa, preferably about 10 < ^-1 > -200 Pa.

In the present invention, there are no particular limitations on the drying method for both initial drying and secondary drying, but it can be performed by a conventionally known method such as a roll support method or a floating method. Further, the heat treatment may be continuous heat treatment in a heating furnace such as a tenter type, wound in a wound state, and heat treated in a batch type oven. In the case of a batch type, it is preferable to wind up so that a coating surface and a non-coating surface do not contact.

Although the thickness of the polyesterimide base material layer of the flexible metal-clad laminate can be selected from a wide range, it is generally about 3 to 300 μm, preferably about 10 to 100 μm, after being completely dried. When the thickness is less than 3 μm, mechanical properties such as film strength and handling properties are inferior. On the other hand, when the thickness exceeds 300 μm, characteristics such as flexibility and workability (drying properties, coating properties) are deteriorated. Tend. Moreover, you may perform a surface treatment as needed. For example, surface treatment such as hydrolysis, corona discharge, low temperature plasma, physical roughening, and easy adhesion coating treatment can be performed.

The double-sided flexible metal-clad laminate having metal foils on both sides of the present invention is a conventionally known method such as heating lamination of the resin surfaces of the metal-clad laminate in which the metal foil is laminated only on one side molded as described above. Can be produced by a method such as pasting together, or pasting together by a conventionally known method via an adhesive layer. The method of laminating is not particularly limited, and conventionally known methods such as roll laminating, press laminating, and belt press laminating can be adopted, and the laminating temperature is usually equal to or higher than the Tg of the resin, and 200 ° C to 500 ° C. Is preferable, more preferably 250 ° C. to 450 ° C., and still more preferably 330 ° C. to 400 ° C. If it is less than 200 degreeC, adhesiveness is inadequate, and if it exceeds 500 degreeC, degradation of a resin layer will arise and mechanical characteristics, transparency, etc. will fall. The lamination time is not particularly limited, but is usually 10 seconds to 10 hours, preferably 1 minute to 1 hour, more preferably 3 minutes to 30 minutes. If it is less than 10 seconds, the adhesiveness is insufficient, and if it exceeds 10 hours, the resin layer is deteriorated and the mechanical properties, transparency and the like tend to be lowered.

The adhesive composition in the case of laminating through the adhesive layer is not particularly limited, and acrylonitrile butadiene rubber (NBR) adhesive, polyamide adhesive, polyester adhesive, polyester urethane adhesive, epoxy resin , Acrylic resin, polyimide resin, polyamideimide resin, polyesterimide resin, etc. can be used as flexible printed wiring boards with heat resistance, adhesiveness, flexibility, low moisture absorption, transparency, etc. In view of the balance of the characteristics of the resin, a polyimide resin system, a polyamideimide resin system, a polyesterimide resin system, or a resin composition in which an epoxy resin is blended with these resins is preferable, and more preferably, the polyesterimide resin composition of the present invention. It is.

As for the thickness of an adhesive bond layer, about 1-30 micrometers is preferable. The thickness of the adhesive is not particularly limited as long as it does not hinder the performance of the flexible printed circuit board, but if the thickness is too thin, sufficient adhesiveness may not be obtained. If the thickness is too thick, processability (drying property, coating property) and the like may be deteriorated.

<< Flexible printed wiring board >>
Using the flexible metal-clad laminate of the present invention, a flexible printed wiring board can be produced by a conventionally known process, for example, by a method such as a subtractive method. When covering the circuit surface for the purpose of protecting from the solder resist of the conductor circuit or dirt and scratches, the heat-resistant film is bonded to the wiring board (base substrate on which the conductor circuit is formed) with an adhesive. A method or a method of applying a liquid coating agent to a wiring board by a screen printing method can be applied.

As the heat-resistant film, polyimide resin-based, polyamide-imide resin-based, polyester-imide resin-based films, etc. can be used, but as a flexible printed wiring board such as heat resistance, adhesiveness, flexibility, low moisture absorption, transparency, etc. A film obtained from the polyesterimide resin of the present invention is preferable from the viewpoint of balance of characteristics.

Adhesives include acrylonitrile butadiene rubber (NBR) adhesive, polyamide adhesive, polyester adhesive, polyester urethane adhesive, epoxy resin, acrylic resin, polyimide resin, polyamideimide resin, polyesterimide Resin-based adhesives can be used, but polyimide resin-based, polyamide-imide resin-based, polyester due to the balance of characteristics as flexible printed wiring boards such as heat resistance, adhesiveness, flexibility, low hygroscopicity, and transparency An imide resin system or a resin composition in which an epoxy resin is blended with these resins is preferable, and the polyesterimide resin composition of the present invention is more preferable.

As the liquid coating agent, conventionally known epoxy-based or polyimide-based inks can be used, but the balance of characteristics as a flexible printed wiring board such as heat resistance, adhesiveness, flexibility, low moisture absorption, transparency, etc. From the above, preferably a polyimide system such as polyimide resin, polyamideimide resin, polyesterimide resin, or a resin composition in which an epoxy resin is blended with these resins, more preferably the polyesterimide resin composition of the present invention, or these It is a resin composition in which an epoxy resin is blended with a resin.

It is also possible to directly bond an epoxy or polyimide adhesive sheet to the wiring board. In this case, the polyesterimide resin composition of the present invention or a resin composition in which an epoxy resin is blended with these resins is also used. preferable.

An arbitrary pattern can be formed as the circuit wiring pattern. In particular, the flexible printed wiring board of the present invention exhibits a high level of performance even in a circuit provided with a fine wiring pattern. Therefore, the flexible printed wiring board of the present invention is particularly advantageous in a circuit provided with a fine wiring pattern.

Specifically, the wiring thickness of the circuit can be 50 μm or less, the wiring thickness can be 30 μm or less, and the wiring thickness can be 20 μm or less. It is also possible to make the thickness of the wiring 10 μm or less. The interval between the wirings can be 50 μm or less, can be 30 μm or less, can be 20 μm or less, and can be 10 μm or less.

The flexible printed wiring board manufactured in this way is a device mounting substrate for a display device such as a liquid crystal display, a plasma display, and an organic EL display, and a substrate such as a smartphone, a tablet terminal device, a digital camera, and a portable game machine. It can be widely used as a substrate material for IC mounting of electronic devices that are becoming smaller, lighter, and thinner, such as relay cables and operation switch board.

  In order to describe the present invention in more detail, examples are given below, but the present invention is not limited to the examples. In addition, the measured value described in the Example is measured by the following method. In the examples, “parts” means “parts by mass”. Moreover, the film used for the measurement and the method for producing the printed wiring board are also shown.

<Method for producing flexible metal-clad laminate>
The resin solutions obtained in Examples and Comparative Examples described later were applied to a copper foil having a thickness of 12 μm (NA-VLP of Mitsui Kinzoku Mining Co., Ltd.) with a knife coater so that the thickness after drying was 20 μm. Next, after drying to a transparent and tack-free state at a temperature of 50 ° C. to 100 ° C., the ends of the upper and lower surfaces and the left and right surfaces are fixed to a stainless steel frame, and 200 ° C. 60 minutes, 220 ° C. 60 under vacuum. The heat treatment was performed at 260 ° C. for 10 hours.

<Flexible printed wiring board (FPC) fabrication method>
A photosensitive resist is laminated on the copper foil surface of the flexible copper-clad laminate obtained in each of the examples and comparative examples described later, and is exposed, baked and developed with a mask film, and is defined in JIS C 5016. Solder heat resistance and chemical resistance wiring was prepared. Subsequently, the copper foil was removed by etching using a 35% cupric chloride solution at 40 ° C., and the resist used for circuit formation was removed with an alkali.

<Method for manufacturing FPC with coverlay>
Knife coater on the circuit surface of the FPC obtained above with a resin solution obtained in each of the examples and comparative examples described later (resins having the same composition as the base film layer) so that the thickness after drying is 10 μm. It was applied with. After drying to a transparent and tack-free state at a temperature of 50 ° C. to 100 ° C., heat treatment was performed under vacuum at 200 ° C. for 30 minutes, 220 ° C. for 30 minutes, and 250 ° C. for 3 hours.

<Preparation method of base film>
The flexible metal-clad laminates obtained in Examples and Comparative Examples described later were prepared by completely etching away the copper foil using a 35% cupric chloride solution at 40 ° C.

<Measurement of logarithmic viscosity>
The polymer solution obtained in each Example and Comparative Example was reprecipitated and purified with a large amount of acetone, and a powdery polymer sample was prepared so that the polymer concentration was 0.5 g / dl. Dissolved in pyrrolidone. The solution viscosity and solvent viscosity of the solution were measured at 30 ° C. with an Ubbelohde type viscosity tube and calculated according to the following formula.
Logarithmic viscosity (dl / g) = [ln (V1 / V2)] / V3
In the above formula, V1 represents the solution viscosity measured with an Ubbelohde type viscosity tube, V2 represents the solvent viscosity measured with an Ubbelohde type viscosity tube, and V1 and V2 represent a polymer solution and a solvent (N-methyl-2-pyrrolidone). Was determined from the time taken to pass through the capillary of the viscosity tube. V3 is the polymer concentration (g / dl).

<Thermal dimensional change rate: index of heat resistance>
A film (base film) produced by etching and removing the metal layer of the flexible metal-clad laminate obtained in each of Examples and Comparative Examples was obtained by IPC-TM-650, 2.2.4 (c) (Method C; The dimensional change rate before and after heat treatment was measured in the MD direction at 150 ° C. for 30 minutes.

<Solder heat resistance: index of heat resistance>
FPCs prepared using the resin solutions obtained in each Example and Comparative Example and FPC with coverlay were conditioned at 25 ° C. and 65% (humidity) for 24 hours, and flux washed. Next, it was immersed in a jet solder bath at 260 ° C. for 20 seconds, and the presence or absence of deformation, discoloration, peeling, and swelling was observed with a microscope. “Yes” means “No” and “No” means “Good”. Note that the solder heat resistance and humidified solder heat resistance of the flexible metal-clad laminate are usually measured with a test pattern (FPC, FPC with coverlay).

<Gurley-type flexibility: index of flexibility>
As an index of flexibility of flexible metal-clad laminates and flexible printed wiring boards, a film (base film) produced by etching away the metal layer of the flexible metal-clad laminate obtained in each Example and Comparative Example was used as a JIS L According to 1096, the Gurley method was used under the following conditions.
Measuring device: manufactured by Toyo Seisakusho Co., Ltd. Sample size: 25.4 mm (width) x 88.9 mm (length) x 20 μm (thickness)
Arm rotation speed: 2 rpm

<Humidification solder heat resistance: index of hygroscopicity>
FPC and FPC with coverlay prepared using the resin solutions obtained in each Example and Comparative Example were conditioned at 40 ° C. and 90% (humidity) for 24 hours, and flux washed. Next, it was immersed in a jet solder bath at 260 ° C. for 20 seconds, and the presence or absence of deformation, discoloration, peeling, and swelling was observed with a microscope. When any of deformation, discoloration, peeling, and swelling was observed by visual observation, “Yes” was given and “No” was given.

<Total light transmittance: index of colorless transparency>
Measurement was performed under the following conditions, and the value of Tt, which is one of the result items, was defined as the total light transmittance.
Measurement sample: A film (base film) produced by etching away the metal layer of the flexible metal-clad laminate obtained in each of Examples and Comparative Examples.
Measurement method: According to JISK7105.
Measuring device: Haze meter (trade name “NDH2000”, manufactured by Nippon Denshoku Industries Co., Ltd., lamp type D65)

Example 1
95.22 g (0.07 mol) of diester tetracarboxylic dianhydride obtained by reacting anhydrous cyclohexanetricarboxylic acid chloride with PTMG1000 (manufactured by Sanyo Chemical Industries, Ltd., molecular weight 1000) as a diol compound in a reaction vessel, anhydrous cyclohexane 1.95 g (0.03 mol) of tricarboxylic acid chloride, 25.03 g (0.1 mol) of 4,4′-diphenylmethane diisocyanate as diisocyanate and 0.1 g of potassium fluoride were added, and 1,3-dimethyl-2-imidazo After dissolving in 249.46 g of lysinone, a transparent and viscous polyesterimide solution was obtained by reacting at 80 ° C. to 190 ° C. for 8 hours with stirring in a nitrogen stream. The logarithmic viscosity of the obtained polyesterimide was 0.95 dl / g as shown in Table 1. Using the obtained resin solution, a flexible metal-clad laminate, a printed wiring board (FPC), an FPC with a coverlay, and a substrate film were prepared, and the characteristics were evaluated according to the contents shown in Table 2, Table 3, and Table 4. Table 1 shows resin characteristics, Table 2 shows printed wiring board (FPC) characteristics, Table 3 shows FPC characteristics with coverlay, and Table 4 shows base film characteristics.

(Examples 2 to 5, Comparative Example 1)
A resin solution was prepared in the same manner as in Example 1 except that the components such as “diol compound” and the diisocyanate component were changed to those shown in Table 1. The logarithmic viscosity of each polyesterimide obtained is shown in Table 1. Using the obtained resin solution, a flexible metal-clad laminate, a printed wiring board (FPC), an FPC with a coverlay, and a substrate film were prepared, and the characteristics were evaluated according to the contents shown in Table 2, Table 3, and Table 4. Table 1 shows resin characteristics, Table 2 shows printed wiring board (FPC) characteristics, Table 3 shows FPC characteristics with coverlay, and Table 4 shows base film characteristics.

(Example 6)
136.03 g (0.1 mol) of diester tetracarboxylic dianhydride obtained by reacting anhydrous cyclohexanetricarboxylic acid chloride with C1015 (manufactured by Kuraray Co., Ltd., molecular weight 1000) as a diol compound in a reaction vessel, and o- After adding 26.43 g (0.1 mol) of tolidine diisocyanate and 0.1 g of potassium fluoride and dissolving in 326.53 g of 1,3-dimethyl-2-imidazolidinone, the mixture was stirred at 80 ° C. under a nitrogen stream. By reacting at ˜190 ° C. for 8 hours, a transparent and viscous polyesterimide solution was obtained. The logarithmic viscosity of the obtained polyesterimide was 0.86 dl / g as shown in Table 1. Using the obtained resin solution, a flexible metal-clad laminate, a printed wiring board (FPC), an FPC with a coverlay, and a substrate film were prepared, and the characteristics were evaluated according to the contents shown in Table 2, Table 3, and Table 4. Table 1 shows resin characteristics, Table 2 shows printed wiring board (FPC) characteristics, Table 3 shows FPC characteristics with coverlay, and Table 4 shows base film characteristics.

Abbreviations in Table 1 are shown below.
Abbreviation
PTMG1000; Sanyo Chemical Industries, Ltd. Polyoxytetramethylene glycol
BPE-20; Sanyo Chemical Industry Co., Ltd. New Pole BPE-20 (Bisphenol A
Ethylene oxide adduct)
C-1015; carbonate diol manufactured by Kuraray Co., Ltd .: 2-methyl-1,8-octane
Diol / 1,9-nonanediol, number average molecular weight of about 1000
DHDE; 4,4'-dihydroxydiphenyl ether
MDI: 4,4'-diphenylmethane diisocyanate
TODI: o-tolidine diisocyanate

The flexible metal-clad laminate and the flexible printed wiring board of the present invention have excellent flexibility, low hygroscopicity, and sufficient colorless transparency. Thereby, device mounting boards for display devices such as liquid crystal displays, plasma displays, organic EL displays, inter-board connection wiring boards such as smart phones, tablet terminal devices, digital cameras, portable game machines, operation switch unit boards, etc. It can be widely used as a substrate material for mounting ICs in electronic devices that are becoming smaller, lighter, and thinner.

Claims (8)

A flexible metal-clad laminate, wherein a polyesterimide resin containing a structure represented by the following general formula (1) in a structural unit is laminated on at least one surface of a metal foil.

(Wherein R1 represents a divalent chain aliphatic group, a divalent cycloaliphatic group or a divalent aromatic group, and R2 represents a divalent chain aliphatic group or a divalent cycloaliphatic group. An aromatic group or a divalent aromatic group.) 2. The flexible metal-clad laminate according to claim 1, wherein the polyesterimide resin further contains a structure represented by the general formula (2) in the structural unit.

(Wherein R2 ′ represents a divalent chain aliphatic group, a divalent cycloaliphatic group or a divalent aromatic group.) The flexible metal-clad laminate according to claim 1 or 2, wherein in the general formula (1), R1 has a structure represented by the following general formula (3).

(Here, R represents a chain aliphatic compound having a divalent hydroxyl group, a cyclic aliphatic compound having a divalent hydroxyl group, or an OH group derived from an aromatic compound having a divalent hydroxyl group) The plurality of R may be the same or different from each other, and m is a positive integer of 1 or more.) The flexible metal-clad laminate according to any one of claims 1 to 3, wherein in the general formula (1), R1 is constituted by the following general formula (4) and / or the general formula (5).


(R3 and R4 represent a direct bond, an alkylene group, a perfluoroalkylene group, an ether bond, an ester bond, a carbonyl group, a sulfonyl group, a sulfinyl group, a sulfenyl group, a carbonate group, or a fluorenylidene group. X1 to X8 and X1 ′ to X 8 ′ may be the same or different and each represents a group selected from hydrogen, halogen, and an alkyl group.) In general formula (1), R2 is comprised by following General formula (6), The flexible metal-clad laminated body in any one of Claims 1-4 characterized by the above-mentioned.

(R5 represents a direct bond, an alkylene group, a perfluoroalkylene group, an ether bond, an ester bond, a carbonyl group, a sulfonyl group, a sulfinyl group, or a sulfenyl group. X9 to X16 may be the same or different. Well each represents a group selected from hydrogen, halogen and alkyl groups.) In general formula (2), R2 'is comprised by following General formula (7), The flexible metal-clad laminate in any one of Claims 2-5 characterized by the above-mentioned.

(R5 ′ represents a direct bond, an alkylene group, a perfluoroalkylene group, an ether bond, an ester bond, a carbonyl group, a sulfonyl group, a sulfinyl group, or a sulfenyl group. X9 ′ to X16 ′ may be the same or different. And each represents a group selected from hydrogen, halogen, and an alkyl group.) When the total structural unit constituting the polyesterimide resin is 100 mol%, the structure represented by the general formula (1) and the general formula (2) is contained in a total of 20 mol% or more,
The molar ratio between the structure represented by the general formula (1) and the structure represented by the general formula (2) is configured in the range of the general formula (1) / general formula (2) = 99/1 to 1/99. The flexible metal-clad laminate according to any one of claims 2 to 6.   A flexible printed wiring board obtained from the flexible metal-clad laminate according to claim 1.