JPS629422B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polyester laminated films.
More specifically, excellent mechanical properties, electrical properties,
This invention relates to a polyester laminated film for printed circuits that has various properties such as heat resistance, chemical resistance, and dimensional stability. Conventionally, laminated films in which a conductive metal layer is laminated on an electrically insulating film have been used for applications such as flexible printed circuits and tape carriers, and as electronic devices become smaller, lighter, and more precise. Its importance is increasing. At present, polyester films, polyimide films, glass-epoxy films, etc. are mainly used as electrically insulating films. Polyester films, especially polyethylene terephthalate films, have excellent mechanical and electrical properties, but they do not have sufficient heat resistance; for example, stretched polyethylene terephthalate films shrink even at temperatures below their melting point, such as 230°C. The range of use is severely limited due to the high rate of use, and the chemical resistance and dimensional stability are also inferior compared to, for example, thermosetting resins. Although polyimide film has excellent mechanical properties and heat resistance, it has a high equilibrium moisture content, does not have good dimensional stability and electrical properties, and must be molded from a solution. The disadvantage is that it is very expensive. Furthermore, glass-epoxy film is a thermosetting resin and has the disadvantage of low elongation and lack of flexibility. The inventor of the present invention has developed an extremely unique method of using a film that has the melt moldability and excellent electrical properties of saturated linear polyester as a substrate film for a laminated film for printed circuits, and also has heat resistance comparable to that of a curable resin. As a result of intensive research to solve difficult technical problems, linear polyester made by copolymerizing and/or blending compounds with specific reactivity has been developed by melt molding and irradiation with actinic rays such as ultraviolet rays. The present invention was achieved based on the discovery that it forms strong crosslinks, has appropriate elongation and flexibility at room temperature, and has strength and dimensional stability sufficient to withstand use at high temperatures. That is, the present invention provides a laminated film for printed circuits in which a conductive metal layer is laminated on at least one side of an electrically insulating film, wherein the electrically insulating film is a substantially saturated linear polyester film formed by the following formula: The degree of crosslinking measured using a mixed solution of phenol/tetrachloroethane (weight ratio 60/40) crosslinked using a compound having an unsaturated group represented by (i) is 70% or more, and the degree of swelling is 30
The present invention relates to a polyester laminated film for printed circuits, characterized in that it is a crosslinked polyester film having the following properties and an elongation at room temperature of 10% or more. [However, in the formula, R ₁ , R ₂ and R ₃ are the same or different and each represents a member selected from the group consisting of a hydrogen atom and a C ₁ to _{C 6} alkyl. ] Copper, aluminum, etc. are used as the conductive metal layer in the present invention, and copper foil is particularly preferably used. Further, there are two types of copper foil: electrolytic copper foil and rolled copper foil, and electrolytic copper foil is generally used. Particularly when flexibility is required, rolled copper foil is preferably used. These copper foils are bonded to the crosslinked polyester film described below using an adhesive as will be described in detail later. In this case, it is preferable to use a surface-oxidized copper foil with good adhesive properties. As a method for forming a conductive metal layer, especially a copper layer, on a crosslinked polyester film, a method using a combination of electroless copper plating and electrolytic copper plating is also preferably used. Next, regarding the crosslinked polyester film of the present invention, this film is obtained by crosslinking a substantially saturated linear polyester after molding. Examples of the acid component constituting the substantially saturated linear polyester include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid,
Aromatic dicarboxylic acids such as diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, methyl terephthalic acid, and methyl isophthalic acid; Aliphatic dicarboxylic acids such as succinic acid, adipic acid, and sebacic acid; Alicyclic acids such as hexahydroterephthalic acid Group dicarboxylic acids: Oxycarboxylic acids such as ε-oxycaproic acid, oxybenzoic acid, and hydroxyethoxybenzoic acid are mentioned, and aromatic dicarboxylic acids, particularly terephthalic acid and isophthalic acid, are preferable. Examples of the glycol component of polyester include ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentylene glycol, cyclohexane dimethylol, etc. In particular, ethylene glycol, tetramethylene glycol, neo Pentylene glycol and cyclohexane dimethylol are preferred. Note that polyfunctional compounds such as pentaerythritol, trimethylolpropane, pyromellitic acid, and ester-forming derivatives thereof may be copolymerized within the range where the polyester is substantially linear. The crosslinked polyester film in the present invention is
It is necessary that the degree of crosslinking measured using a mixed solution of phenol/tetrachloroethane (weight ratio 60/40) is 70% or more, and the degree of swelling is 30 or less. If the degree of crosslinking is less than 70% or the degree of swelling is more than 30, the crosslinking will be insufficient and it will be unsuitable for the intended use, such as flexible printed circuits, in terms of heat resistance. The degree of crosslinking herein refers to the weight percent of the insoluble portion when 100 mg of crosslinked polyester film is stirred and dissolved at 140° C. for 30 minutes in 10 ml of a phenol/tetrachloroethane mixed solution (weight ratio 60/40). Therefore, a degree of crosslinking of 70% means that the insoluble portion is 70 mg. Also, the degree of swelling is phenol/
Tetrachloroethane mixed solution (weight ratio 60/40) 10
100mg of cross-linked polyester film in ml at 140℃ for 30
When the weight of the phenol/tetrachloroethane mixed solution adhering to the film surface after wiping off after processing for a minute is W mg, and the weight of the film after washing and drying is G mg, it is expressed by the following formula. Swelling degree = W-G/G The crosslinked polyester film in the present invention needs to have a degree of crosslinking of at least 70%, preferably 80% or more, more preferably 85%.
It is particularly desirable that it be 90% or more. Further, the degree of swelling needs to be at least 30 or less, preferably 20 or less, more preferably 10 or less, particularly preferably 5 or less. Furthermore, regarding the elongation at room temperature,
10 when measured at a tensile rate of 100%/min.
% or more, preferably 20% or more, more preferably
It is 30% or more, particularly preferably 50% or more. If the elongation at room temperature is less than 10%, the desired performance in terms of flexibility cannot be achieved. The film in the present invention desirably has a thickness of 1000μ or less, preferably 500μ or less, more preferably 300μ or less, particularly preferably 200μ or less, and is preferably transparent. The compound used to crosslink the saturated linear polyester in the present invention is a compound having an unsaturated group represented by the following formula (i). [However, in the formula, R ₁ , R ₂ and R ₃ are the same or different and each represents a member selected from the group consisting of a hydrogen atom and a C ₁ to _{C 6} alkyl. ] Preferred alkyls for R ₁ , R ₂ and R ₃ in formula (i) include C ₁ to C ₆ alkyls. Among the unsaturated groups represented by formula (i), ie, allyl or substituted allyl, allyl, metaallyl and crotyl are preferred, and allyl is particularly preferred. Such allyls or substituted allyls are substantially stable under the melting conditions of the polyester, e.g.
Even if the polyester is maintained at a high temperature in an inert gas for, for example, 15 minutes, no reaction occurs between the unsaturated groups or between the unsaturated groups and the polyester. Incorporation of such an unsaturated group into the polyester can be achieved by copolymerizing and/or mixing a compound having the aliphatic unsaturated group (hereinafter sometimes referred to as compound (A)) with the polyester. When copolymerizing the compound (A) with a polyester, the compound (A) must be stable under the copolymerization conditions without decomposition, and it must be a stable fat under the copolymerization conditions. In addition to group-based unsaturated groups, ester-forming functional groups (e.g. carboxyl groups,
It is necessary to have at least one, preferably two, functional groups that form the ester-forming functional group under the polymerization conditions of the polyester. An example of the latter functional group is an epoxy group. In addition, when compounding compound (A) with polyester, not only the unsaturated group in compound (A) is stable under melt-kneading with polyester, but also the compound (A) itself is stable. Therefore, when compound (A) is melt-blended, there is substantially no insoluble matter that does not dissolve in the phenol/tetrachloroethane mixed solution at 35°C in the resulting composition, and the polyester It is preferable that the intrinsic viscosity [η] of Therefore, compounds that decompose or gasify at the melting temperature of polyester are not preferred as blending compounds. Therefore, from the point of view of gasification, the vapor pressure is 100% at the melting temperature of polyester.
Preferably, the compound has a temperature of not more than mmHg, more preferably not more than 50 mmHg, particularly not more than 10 mmHg. Compound (A) containing a group represented by the above general formula (i)
A specific example is given below. [] First, regarding the case where it is copolymerized with polyester, the preferred compound is the general formula (iii). Examples include compounds represented by and ester-forming derivatives of the compounds. In the general formula (ii), R ₁ , R ₂ and R ₃ are hydrogen atoms or C ₁ to _{C 6} alkyl groups, and Q is an organic group. In the above general formula (iii), n and m are 0 or a number of 1 or more, and (n+m)≧1, and l is a number of 1 or more. Such compounds include, for example, allyloxy (or meta-allyloxy, or crotyloxy)
Benzoic acid, 4-allyl-3-oxybenzoic acid,
N-allyl (or metaallyl, or crotyl)
Carboxylic acids and oxycarboxylic acids such as trimellitic acid imide, and ester-forming derivatives thereof (for example, lower alkyl esters such as methyl, ethyl, and propyl; aryl esters such as phenyl ester; acid anhydrides, etc.); 4- Allyloxyphenyl, 2,5-diallyl (or dimethallyl, or dicrotyl)
-1,4-dioxybenzene, 2,2-bis[3-allyl (or metaallyl, or crotyl)-4-hydroxyphenyl]propane, bis(3-allyl-4-hydroxyphenyl)sulfone, 2, 2-bis[3-allyl (or metaallyl, or crotyl)-4-hydroxyethoxyphenyl]propane, bis(3-allyl-
4-hydroxyethoxyphenyl) sulfone,
Hydroxy compounds such as allyl-bis(β-hydroxyethyl) isocyanurate, N·N-diallyl-4-hydroxybenzamide, etc.
and ester-forming derivatives thereof (for example, lower fatty acid esters). Further, compounds other than the above general formula (ii) having an epoxy group as an ester-forming inducing group are preferred, and examples of such compounds include the following. [] Diallylglycidyl cyanurate, diallylglycidyl isocyanurate, allyl diglycidyl cyanurate, allyl diglycidyl isocyanurate, and the allyl groups of the above compounds are replaced with crotyl or methallyl groups, and the glycidyl groups are replaced with 2,3-epoxy-2- Cyanuric acid or isocyanuric acid derivatives substituted with methylpropyl group, 2,3-epoxybutyl group, 2,3-epoxy-2-methyl-butyl group, etc. [] N-allylglycidyloxybenzamide, N・N-diallylglycidyloxybenzamide, N・N′-diallylglycidyloxyiso(or tele)phthalamide, N・N・N′・
N'-tetraallylglycidyloxyiso(or tele)phthalamide, N・N-diallyl 2,3
-(or 3,4-)epoxycyclohexanecarboxamide, N/N'-diallyl (or N,N,N',N'-tetraallyl)-3,4-
(or 4.5-)epoxycyclohexane 1.
2-dicarboxamide, N・N′-diallyl (or N・N・N′・N′-tetraallyl)-2・
3-(or 3.3-)epoxycyclohexane 1.1-dicarboxamide, N.N'-diallyl (or N.N.N'.N'-tetraallyl)-
2,3-epoxycyclohexane 1,4-dicarboxamide, N/N'-diallyl 2,3-
(or 3,4-)epoxyhexane 1,6-dicarboxamide, N,N'-diallyl (or N,N,N',N'-tetraallyl)-2,3-epoxybutane 1,4-dicarboxy Amide, N
-Allyl-glycidyloxyphthalimide and the allyl group of the above compound to a crotyl group or methallyl group, or the glycidyl group to a 2,3-epoxy-2-methylpropyl group, 2,3-epoxybutyl group, 2,3-epoxy- Amide or imide compounds substituted with 2-methylbutyl group etc., [] 2,2-bis(3-allyl-4-glycidyloxyphenyl)propane, 1,1-bis(3-allyl-4-glycidyloxyphenyl) ) Cyclohexane, (2-allylphenyl)-
Glycidyl ether, (2,6-diallylphenyl)glycidyl ether, 1,4-diglycidyloxy-2,6-diallylbenzene, 2.
2-bis(3.5-diallyl-4-glycidyloxyphenyl)propane, (2.4.6-triallylphenyl)glycidyl ether, 3.
3'-diallyl-4,4'-diglycidyloxybenzophenone, bis(3-allyl-4-glycidyloxyphenyl) ether, bis(3,5
-diallyl-4-glycidyloxyphenyl)
The allyl group of the sulfone and the above compounds is replaced with a crotyl group or metaallyl group, and the glycidyl group is replaced with a 2,3-epoxy-2-methylpropyl group,
Compounds substituted with 2,3-epoxybutyl group, 2,3-epoxy-2-methyl-butyl group, etc., N-glycidyl-4-cyclohexene-
Examples include 1,2-dicarboxamide. [] Furthermore, preferred examples of compounds that change to the compound represented by formula (ii) above under the polyester polymerization conditions and become copolymerizable compounds include bisallyloxy (or methalyloxy or methacrotyloxy)benzene, 2・2-bis [4
-Allyloxy (or meta-allyloxy or crotyloxy) phenyl]propane, 1.1-
Bis(4-allyloxyphenyl)cyclohexane, bis(4-allyloxyphenyl)sulfone and the like can be mentioned. Next, as compounds having an unsaturated group that can be blended with polyester, those having two or more groups represented by the general formula (i) above can be used to form a stronger crosslinked structure in the actinic ray treatment described below. It is preferable because it can be obtained in a molded body. Examples of such compounds include the following compounds. [] A compound having an amide bond and/or an imide bond. Examples of such compounds include the following compounds. N・N′-diallyl (or dimethallyl or dicrotyl) adipamide, N・N′-diallyl (or dimethallyl or dicrotyl) sebacaramide, N・N′-diallyl (or dimethallyl or dicrotyl) decanedicarboxamide, N・N′- Diallyl (or dimethallyl or dicrotyl) terephthalamide, N·N′-diallyl (or dimethallyl or dicrotyl) isophthalamide, N·N′-diallyl (or dimethallyl or dicrotyl) naphthalene dicarboxamide, N·N′-diallyl (or dimethallyl or dicrotyl) dicrotyl) hexahydroterephthalamide, N・N′-diallyl (or dimethallyl or dicrotyl) diphenoxyethanedicarboxamide, N・N′・N″-triallyl (or trimetaallyl or tricrotyl) trimesic acid amide, N・N′-diallyl (or trimetaallyl or tricrotyl) trimesic acid amide N′・N′-tetraallyl (or tetramethallyl or tetracrotyl)
Adipoamide, N・N・N′・N′-tetraallyl (or tetramethallyl or tetracrotyl) sebacaramide, N・N・N′・N′-tetraallyl (or tetramethallyl or tetracrotyl) decanedicarboxamide, N・N・
N', N'-tetraallyl (or tetramethallyl or tetracrotyl) terephthalamide, N'-
N・N′・N′-tetraallyl (or tetramethallyl or tetracrotyl) isophthalamide,
N・N・N′・N′-tetraallyl (or tetramethallyl or tetracrotyl) naphthalene dicarboxamide, N·N-diallyl (or dimethallyl or dicrotyl) benzamide,
N・N・N′・N′-tetraallyl (or tetramethallyl or tetracrotyl) hexahydroterephthalamide, N・N・N′・N′-tetraallyl (or tetramethallyl or tetracrotyl) diphenoxyethanedicarboxamide ,
N・N・N′・N′・N″・N″-hexaallyl (or hexamethallyl or hexacrotyl) trimesic acid amide, N・N・N′・N′・N″・N″−
Hexaallyl (or hexamethallyl or hexacrotyl) trimellitic acid amide, N・N・
N′・N′・N″・N″・N・N-octaallyl (or octamethallyl or octacrotyl)
Pyromellitic acid amide, N/N'-diallyl (or dimethallyl or dicrotyl) pyromellitimide, N/N'-diallyl (or dimethallyl or dicrotyl) benzophenone-3.
4,3',4'-tetracarboxylic acid bisimide,
N・N′-diallyl (or dimethallyl or dicrotyl)butane-1,2,3,4-tetracarboxylic acid bisimide, N・N′-diallyl (or dimethallyl or dicrotyl)cyclobentane-1,2,3,4- Tetracarboxylic acid bisimide, ethylene bis[N-allyl (or N-methallyl or N-crotyl) trimellitic acid imide] amide, tetramethylene bis[N-allyl (or N-methallyl or N-crotyl) trimellitic acid imide] amide, Hexamethylenebis[N-allyl (or N-methallyl or N
-crotyl) trimellitic acid imide] amide,
Decamethylene bis[N-allyl (or N-methallyl or N-crotyl) trimellitic acid imide] amide, dodecamethylene bis[N-allyl (or N-methallyl or N-crotyl) trimellitic acid imide] amide, (However, A: allyl or metaallyl or crotyl), N/N'-diallyl (or dimethallyl or dicrotyl) trimellitic acid amide imide,
N・N・N'-triallyl (or trimethallyl or tricrotyl) trimellitic acid amide imide, ethylene (or trimethylene or tetramethylene or hexamethylene or docamethylene) bis(2-propylenecarboxamide), ethylene (or trimethylene or tetramethylene or hexamethylene) or decamethylene)bis[2-(or 3-)butenecarboxamide], ethylene(or trimethylene or tetramethylene or hexamethylene or decamethylene)bis[2-(or 3-or 4-)benzenecarboxamide], ethylene(or trimethylene or tetramethylene or hexamethylene or decamethylene) bis[2-(or 3- or 4- or 5-)hexenecarboxamide],
N-allyl (or crotyl or metaallyl)2
-propylenecarboxamide, N-allyl (or crotyl or metaallyl) 2-(or 3
-) butenecarboxamide, N-allyl (or crotyl or metaallyl) 2-(or 3- or 4-) propanecarboxamide, N-allyl (or crotyl or metaallyl) 2-(or 3- or 4- or 5-) ) hexenecarboxamide, N/N-diallyl (or dicrotyl or dimethallyl) 2-propylenecarboxamide, N/N-diallyl (or dicrotyl or dimethallyl) 2-(or 3-butenecarboxamide, N/N-diallyl (or dicrotyl or dimethallyl) 2-(or 3- or 4-) propenecarboxamide, N.N-diallyl (or dicrotyl or dimethallyl) 2-(or 3- or 4- or 5-) hexenecarboxamide, N.N' -diallyl (or dicrotyl or dimethallyl) 3-(or 2-)hexene 1,6-dicarboxamide, N.N'-diallyl (or dicrotyl or dimethallyl) 2-
Butene 1,4-dicarboxamide, N・N・
N', N'-tetraallyl (or tetracrotyl or tetramethallyl) 3-(or 2-)hexene 1,6-dicarboxamide, N.N.
N'/N'-tetraallyl (or tetracrotyl or tetramethallyl) 2-butene 1,4-dicarboxamide, ethylene (or trimethylene or tetramethylene or hexamethylene or decamethylene) bis-2-(or 3-)cyclohexenecarboxamide, ethylene (or trimethylene or tetramethylene or hexamethylene or decamethylene) bis3-(or 4-)cyclohexene 1,2-dicarboximide N-allyl (or crotyl or metaallyl) 2-(or 3-)cyclohexenecarboxamide, N
-Allyl (or crotyl or metaallyl) 3-
(or 4-)cyclohexene 1,2-dicarboximide, N-allyl (or crotyl or metaallyl) bicyclo[2,2,1]-5-hebutene 2,3-dicarboximide, N,N-diallyl (or dicrotyl or dimethallyl)2
-(or 3-)cyclohexenecarboxamide, N・N・N'-tetraallyl (or tetracrotyl or tetramethallyl) 3-(or 4)
-) Cyclohexene 1,2-dicarboxamide, N/N/N'/N'-tetraallyl (or tetracrotyl or tetramethallyl) 2-(or 3-)cyclohexene 1,1-dicarboxamide, N/N/N ′・N′-tetraallyl (or tetracrotyl or tetramethallyl) 2-
cyclohexene 1,4-dicarboxamide,
N・N・N′・N′-tetraallyl (or tetracrotyl or tetramethallyl) bicyclo[2.2.1]-5-hebutene 2,3-dicarboxamide, N・N′-diallyl (or dicrotyl or dimethallyl) ) 2-cyclohexene 1,4-dicarboxamide, [] Compound having an ester bond Examples of such compounds include the following compounds. Diallyl terephthalate, diallyl isophthalate, diallyl naphthalenedicarboxylate, diallyl diphenyldicarboxylate, diallyl diphenylsulfonedicarboxylate, diallyl diphenoxyethanedicarboxylate, diallyl diphenyl ether dicarboxylate, diallyl benzophenonedicarboxylate, methyl terephthal acid diallyl,
Diallyl methylisophthalate, diallyl hexahydroterephthalate, triallyl trimellitate, triallyl trimesate, triallyl naphthalenetricarboxylate, tetraallyl naphthalenetetracarboxylate, triallyl diphenyltricarboxylate, tetraallyl diphenyltetracarboxylate, triallyl diphenylsulfonetricarboxylate, Tetraallyl diphenylsulfonetetracarboxylate, triallyl diphenoxyethanetricarboxylate, tetraallyl diphenoxyethanetetracarboxylate, triallyl benzophenonetricarboxylate, tetraallyl benzophenonetetracarboxylate, [] Cyanuric acid is a derivative of isocyanuric acid. Examples of such compounds include the following compounds. triallyl (or tricrotyl or trimetaallyl) isocyanurate, diallyl (or dicrotyl or dimethallyl) methyl isocyanurate, diallyl (or dicrotyl or dimethallyl) ethyl isocyanurate, diallyl (or dicrotyl or dimethallyl) decyl isocyanurate, diallyl (or dichlor or dimethallyl) dodecyl isocyanurate,
diallyl (or dicrotyl or dimethallyl)
Silistyl isocyanurate, diallyl (or dicrotyl or dimethallyl) cetyl isocyanurate, diallyl (or dicrotyl or dimethallyl) stearyl isocyanurate, ethylene bis [diallyl (or dicrotyl or dimethallyl) isocyanurate], tetramethylene bis [diallyl (or dicrotyl or dimethallyl) dimethallyl) isocyanurate], hexamethylenebis[diallyl (or dicrotyl or dimethallyl) isocyanurate], decamethylenebis[diallyl (or dicrotyl or dimethallyl) isocyanurate], oxydiethylenebis[diallyl (or dicrotyl or dimethallyl) isocyanurate] Dioxytriethylene bis[diallyl (or dicrotyl or dimethallyl) isocyanurate] Polyethylene allyl (or metaallyl or crotyl) isocyanurate whose terminal end is a diallyl isocyanurate residue, polytetramethylene allyl whose terminal end is a diallyl isocyanurate residue ( or meta-allyl or crotyl) isocyanurate, polyhexamethylene allyl (or meta-allyl or crotyl) isocyanurate whose terminal end is a diallyl isocyanurate residue, polydecamethylene allyl (or meta-allyl or crotyl) isocyanurate whose terminal end is a diallyl isocyanurate residue Nurate, triallyl (or trimetaallyl or tricrotyl) cyanurate, diallyl (or dimethallyl or dicromethyl) methyl cyanurate, diallyl (or dimethallyl or dicrotyl) ethyl cyanurate, diallyl (or dimethallyl or dicrotyl) decyl cyanurate, diallyl (or dimethallyl or dicrotyl) ) dodecyl cyanurate, diallyl (or dimethallyl or dicrotyl) myristyl cyanurate, diallyl (or dimethallyl or dicrotyl) cetyl cyanurate, diallyl (or dimethallyl or dicrotyl) stearyl cyanurate, tetramethylene bis[diallyl (or dimethallyl or dicrotyl) cyanurate] ], hexamethylenebis[diallyl (or dimethallyl or dicrotyl) cyanurate],
decamethylene bis [diallyl (or dimethallyl or dicrotyl) cyanurate], oxydiethylene bis [diallyl (or dicrotyl or dimethallyl) cyanurate], dioxytriethylene bis [diallyl (or dicrotyl or dimethallyl) cyanurate], terminal end with diallyl cyanurate residue polytetramethylene allyl (or meta-allyl or crotyl) cyanurate which is a group, polyhexamethylene allyl (or meta-allyl or crotyl) cyanurate whose terminal end is a diallyl cyanurate residue, polydecamethylene allyl (or meta-allyl or crotyl) cyanurate whose terminal end is a diallyl cyanurate residue or metaallyl or crotyl) cyanurate. These compounds include, for example, Zh Orgao Khim,
2 (10) p1742-3 (1965) (Russ), or J.Am,
soc, 73 p3003 (1951). Next, examples of compounds having intermediate performance between the copolymerization type and the mixed type include the epoxy-containing compounds [ ], [ ], and [ ] mentioned above as the copolymerization type. Even if this product partially reacts with polyester during melt blending and/or molding, it does not cause a decrease in the overall degree of polymerization and can be used. Alternatively, a method of accelerating the reaction by adding a small amount of an acid anhydride such as succinic anhydride (for example, 5 mol % or less based on the polyester) is also preferably recommended. As the compound having an unsaturated group, a mixed type compound is preferable, and further the above-mentioned [], [], []
or [] compounds are preferred, especially []
Compounds [] are preferred. Furthermore, among [ ], compounds having four or more unsaturated groups are preferred. As the crosslinking agent, the above-mentioned unsaturated group-containing compounds are preferred, but it is preferable to use a reaction initiator, particularly a photoreaction initiator, such as aromatic ketones, benzyl and its derivatives, benzoin and its derivatives, Preferred examples include polynuclear quinones. Examples of such compounds include benzophenone, 4-methylbenzophenone, 4-nitrobenzophenone, 3-methylbenzophenone,
4,4'-dimethylbenzophenone, 3,3'-dimethylbenzophenone, 3,4'-dimethylbenzophenone, 4-phenylbenzophenone, 3-phenylbenzophenone, 3,3' -Dinitrobenzophenone, 4,4'-Dinitrobenzophenone, 3-
Nitrobenzophenone, 4-methoxybenzophenone, 3-methoxybenzophenone, 4,4'-dimethoxybenzophenone, bis(4-diphenyl)ketone, bis(3-diphenyl)ketone,
3,4-dimethylbenzophenone, 3,4,3'.
4'-tetramethylbenzophenone, Michler's ketone, anthraquinone, nitroanthraquinone,
Phenanthraquinone, acetophenone, propiophenone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin butyl ether, benzoin phenyl ether, α-methylbenzoin methyl ether, α-phenylbenzoin ethyl ether, α-Benzylbenzoin ethyl ether, benzyl methyl ketal, benzyl diethyl ketal, benzyl dipropyl ketal, benzyl ethylene ketal, benzyl trimethylene ketal, benzyl neopentylene ketal, benzyl bis(2-methoxyethyl) ketal, naphthylphenyl ketone, bis Naphthyl ketone, ethylene bis(benzoylbenzamide),
Tetramethylenebis(benzoylbenzamide), hexamethylenebis(benzoylbenzamide), decamethylenebis(benzoylbenzamide), dodecamethylenebis(benzoylbenzamide), hexamethylenebis(4-acetylbenzamide), hexamethylenebis(4-methyl benzoyl)benzamide], ethylenebis[(4
-Nitrobenzoyl)benzamide], dodecamethylene bis[(4-methoxybenzoyl)benzamide], dibenzoylbenzene, bis(4-methylbenzoyl)benzene, ethylene bis(benzoyl phenyl ether), bis(benzoylmethyl) ether, Tris (benzoylphenoxy)benzene, bis(4-methoxybenzoylmethyl ether), and the like. Also, German published patent specification no.
No. 1769168, No. 1769853, No. 1807297, No.
Among the photoreaction initiators listed in No. 1807301, No. 1919078, and No. 1949010, those that are substantially stable when the polyester is melted can be used as appropriate. Further, for example, benzophenone-4,4'-dicarboxylic acid or the like may be copolymerized with the polyester.
Among these photoreaction initiators, benzyl and its derivatives are preferred, and benzyl derivatives are particularly preferred because of their high activity. Further, among aromatic ketones, compounds having two or more benzophenone residues are also preferred since they have high activity. In the case of compounds containing unsaturated groups, the amount of the crosslinking agent added is 0.01 to 0.5 as unsaturated groups per 100 g of polymer.
about an equivalent, more preferably about 0.03 to 0.4 equivalent,
Particularly preferably, it is about 0.06 to 0.3 equivalent, and the amount of photoreaction initiator added is about 0.01 to 20 parts by weight, preferably 0.05 to 10 parts by weight, per 100 parts by weight of polyester.
The amount is preferably about 0.1 to 5 parts by weight, particularly preferably about 0.1 to 3 parts by weight. Further, a compound having both the functions of an unsaturated group and a photoreaction initiating function can also be used as a preferred crosslinking agent. Examples of the compound having such two functions include N-allyl (or crotyl or metaallyl). ) Benzoylbenzamide, N
-Allyl (or crotyl or metaallyl) anthraquinone carboxamide, N-allyl (or crotyl or metaallyl) benzoyl phthalimide, N·N-diallyl (or dicrotyl or dimethallyl) benzoylbenzamide, N·N'-
Examples include diallyl (or dicrotyl or dimethallyl) benzophenone tetracarboximide. The crosslinked polyester film used in the present invention is produced by, for example, copolymerizing and/or blending a predetermined unsaturated group and a photoreaction initiator.
melting the polyester into a desired film;
It is then obtained by subjecting the film to crosslinking treatment. When an unsaturated group or a photoinitiator is incorporated into a polyester by copolymerization, the above-mentioned acid component, glycol component, and the compounds exemplified above are usually reacted by a conventionally known method. In this case, a so-called masterbatch method is also used, in which a polyester copolymerized with an excess of unsaturated groups and/or a photoinitiator is prepared in advance, and this is melt-blended with a polyester containing no unsaturated groups and/or a photoinitiator. Preferably used. In addition, when blending an unsaturated group and/or a photoreaction initiator into a polyester, it is common to mix the polyester with a compound having an unsaturated group and/or a photoreaction initiator.
or a photoinitiator, for example, in an S-type blender, V
The polyester is mixed using a mechanical mixing means such as a mold blender, and then mixed using a kneading machine such as an extruder at or above the temperature at which the polyester becomes molten, preferably at or about 60° C. higher than the melting point of the polyester. Blend evenly over a range of temperatures. Then, it is melted and can be easily formed into a film-like molded product by continuous injection molding, extrusion molding, or other conventional thermoplastic resin molding methods. The crosslinking treatment is carried out between the stage of forming the film and the stage of laminating the conductive metal layer. As a crosslinking treatment method, irradiation with actinic rays such as ultraviolet rays, electron beams, and radiation is preferable, and irradiation with ultraviolet rays is particularly preferable. The ultraviolet irradiation conditions are room temperature to a temperature lower than the decomposition temperature of polyester (°C), preferably the secondary transition point (Tg) to the melting point (Tm) of polyester.
(℃), more preferably (Tg+10) to Tm
(℃), more preferably (Tg+10) to (Tm−10)
at a temperature of 1 second to 10 hours, preferably 2 seconds to 1 hour, more preferably 5 seconds to 30 minutes, particularly preferably
10 seconds to 10 minutes. The crosslinked polyester film used in the present invention is
It is also possible to contain reinforcing agents such as glass fiber, mica, and talc. In this case, the purpose can be easily achieved by mixing the reinforcing agent with the crosslinking agent and initiator, and performing the crosslinking treatment as described above after melt extrusion. It is also preferable to melt and impregnate glass cloth with a polyester resin mixed with a crosslinking agent and an initiator, and then perform crosslinking treatment to obtain a crosslinked polyester film on a glass cloth substrate.A film with excellent dimensional stability and heat resistance can be obtained. It will be done. The polyester laminated film of the present invention can be obtained by laminating a conductive metal layer on at least one side of the crosslinked polyester film. Various methods can be considered for lamination, including a method in which conductive metal foil is laminated on a crosslinked polyester film by adhering it, and a method in which a conductive metal layer is deposited on a crosslinked polyester film by electroless plating. It can be broadly classified. The lamination method by adhesion is a generally widely used method, and is also applied to the polyester laminated film of the present invention. As an adhesive, it not only has good adhesion to cross-linked polyester film and conductive metal foil, but also has good electrical properties and
Those with excellent heat resistance are preferred, and in the polyester laminated film of the present invention, adhesives generally used as polyester adhesives can be used as they are, but urethane-modified polyester adhesives, polyester-modified epoxy adhesives, etc. are preferably used. In particular, urethane-modified polyester adhesives are preferably used. Adhesion is carried out by continuously applying a solution of the adhesive to the crosslinked polyester film using a roll coater or the like, and after drying the solvent by heating, pressing the conductive metal foil with a heated roller. The polyester laminate film of the present invention can be industrially advantageously produced by the method described above. Further, in the polyester laminate film of the present invention, it is also possible to form a conductive metal layer by electroless plating. In this case, the surface of the crosslinked polyester film is subjected to a surface activation treatment using a conventionally known method, and then an electroless plating solution is applied to the crosslinked polyester film.
In particular, a copper layer is formed on a crosslinked polyester film by immersing it in an electroless copper plating solution. If the copper layer thickness is approximately 10μ or less, electroless plating alone can achieve the purpose, but if a thicker copper layer is required, electroless plating must be performed followed by electrolytic plating. A thick copper layer can be easily obtained by this method. Further, in order to improve adhesion to the copper foil, it is preferable to perform soft etching such as amine treatment beforehand. As described above, since the polyester laminated film of the present invention uses a cross-linked polyester film as a substrate, it has the excellent electrical properties of a polyester film, and also has 260
It has sufficient heat resistance to be used at high temperatures ranging from 300°C to 300°C. Furthermore, since it has appropriate flexibility, it can be bent freely, has a low shrinkage rate, and has excellent dimensional stability. The laminated film of the present invention can be effectively applied to materials that require heat resistance and flexibility, such as flexible printed circuits, tape carriers, and the like. The present invention will be explained in more detail below with reference to Examples. In the Examples, "part" means "part by weight", and the intrinsic viscosity is a value measured at 35°C in a mixed solution of phenol/tetrachloroethane (weight ratio 60/40). The elongation and peel strength were measured using an Instron tensile tester, and the elongation was 100%/
The peel strength was measured at a tensile rate of 1 cm/min. Soldering heat resistance was measured according to JIS-C-6481 (Test method for copper-clad laminates for printed circuits), and bendability was determined by visual inspection of the bent state with a radius of curvature of 0.4 mm. Examples 1 to 3 and Comparative Example 1 Cyclohexane-1.
100 parts of polyethylene terephthalate (intrinsic viscosity 0.65) copolymerized with 15% 4-dimethanol was thoroughly mixed with a predetermined amount of crosslinking agent (A) and photoinitiator (B) using an S-type blender, and then melted using a T-die. A transparent amorphous film with a thickness of about 100 μm was obtained by extrusion. The film was irradiated with a 2KW high-pressure mercury lamp (30W/cm) at 130°C for 3 minutes from a position 20cm away to obtain a photocrosslinked film. Next, the cross-linked film RV-300 (Toyobo) 100 parts Epikote 828 (Ciel Chemical) 10 parts Coronate L (Nippon Polyurethane Industries) 10 parts toluene 300 parts was coated with a bar on one side of the cross-linked film prepared by degreasing an adhesive having the following composition with acetone. It was applied uniformly using a coater (No. 20) and subjected to an open treatment at 170°C for 5 minutes to remove toluene. 35μ thick cross-linked film coated with adhesive
Electrolytic copper foil was thermocompressed between two rollers heated to 150°C, and then heated to 170°C to harden the adhesive layer.
Heat treatment was performed for 10 minutes. Table 1 shows the crosslinking degree, swelling degree, elongation at room temperature of the crosslinked film, heat resistance of the laminated film, and peel strength of the copper foil.

[Table] As a comparative example, Table 1 also shows the results of a laminated film using a stretched polyethylene terephthalate film. As shown in Table 1, the polyester laminated film of the present invention uses a highly crosslinked polyester crosslinked film for the substrate, so it has excellent soldering heat resistance and has sufficient elongation. It has good flexibility. Example 4 100 parts of polybutylene terephthalate having an intrinsic viscosity (0.70), 20 parts of ethylene bis(diallyl isocyanurate) as a crosslinking agent, and 1 part of benzyl dimethyl ketal as a photoreaction initiator were thoroughly mixed in an S-type blender. A transparent film with a thickness of about 120 μm was obtained by melt extrusion through a T-die and quenching. The film was heated with a 2KW high pressure mercury lamp (30W/
cm) was irradiated from a position 10 cm away to obtain a crosslinked film. After degreasing the crosslinked film with acetone, apply an adhesive with the following composition to one side using a bar coater (No. 20), RV-300 100 parts Coronate L (Nippon Polyurethane Industries) 12 parts Toluene 250 parts 170°C After treatment for 5 minutes, it was heat-pressed at 170°C with a 35μ thick surface oxidized copper foil. The substrate film, a polybutylene terephthalate crosslinked film, had a degree of crosslinking of 98%, a degree of swelling of 1, and an elongation of 30% at room temperature. The peel strength of the copper foil in the 180° direction was 15 kg/cm, and the soldering heat resistance was normal at 260°C for 30 seconds, and there was no abnormality at all when immersed in trichlorethylene for 5 minutes. Example 5 Isophthalic acid is 15% of the total acid component, and neopentylene glycol is 30% of the total glycol component.
% copolymerized polyethylene terephthalate (intrinsic viscosity 0.78), 5 parts of diallylglycidyl isocyanurate and 15 parts of hexamethylene bis(diallylisocyanurate) as a crosslinking agent, and 2 parts of benzyl ethylene ketal as a photoinitiator in an S-type blender. The mixture was mixed well and melt-extruded through a T-die to obtain a transparent amorphous film with a thickness of about 50 μm.
The film was irradiated with a 2KW high-pressure mercury lamp at 130°C for 5 minutes to obtain a crosslinked film with a degree of crosslinking of 88%, a degree of swelling of 3.5, and an elongation of 1120% at room temperature. The crosslinked film
It was immersed in a 50% monoethylamine aqueous solution for 1 minute, washed with water, dried, and degreased with acetone. Next, apply an adhesive with the following composition using a bar coater (No. 20) and dry at 170°C for 5 minutes. RV-300 100 parts Epicote 815 (Ciel Chemical) 10 parts Coronate L (Nippon Polyurethane Industries) 5 parts After adding 300 parts of toluene, it was heat-pressed at 150°C with an electrolytic copper foil having a thickness of 35μ. The peel strength of copper foil is 1.8Kg/cm, and the peel strength at 260℃30
A laminated film with good flexibility was obtained, with no abnormality in the second soldering heat resistance test and no change even after immersion in acetone or trichlorethylene for 5 minutes. Example 6 Polybutylene terephthalate (intrinsic viscosity 0.70)
is melted in an extruder, and a triallyl cyanurate/benzophenone mixture (weight ratio 6/1) is introduced into the extruder from a side pipe provided in the extruder for crosslinking agent blending. Nurate and benzophenone were mixed and then extruded through a T-die and rapidly cooled to obtain a transparent film with a thickness of about 100 μm. The film was irradiated with a 2KW high-pressure mercury lamp (30W/cm) at 130℃ for 5 minutes from a position 20cm away to determine the degree of crosslinking.
A crosslinked film with a swelling degree of 95%, a swelling degree of 1.5, and a room temperature of 50% was obtained. The crosslinked film was immersed in a 50% monoethylamine aqueous solution for 1 minute at room temperature and washed with water. Next, it was immersed in Hitachi Chemical Co., Ltd.'s sensitizer for electroless copper plating HS-101B for 10 minutes and then washed with water, and similarly in the adhesion promoter ADP-201 for 5 minutes and washed with water. Next, apply the same electroless copper plating solution CUST-201 at 25℃.
After soaking for 15 minutes and washing with water, electrolytic copper plating was performed using a copper sulfate bath to obtain a double-sided copper-clad laminated film with a copper foil thickness of approximately 30 μm. In this laminated film, the peel strength of the copper foil in the 180° direction was 0.9 kg/cm, and the results of a soldering heat resistance test at 260° C. for 30 seconds showed no abnormality at all.

Claims (1)

[Scope of Claims] 1. A laminated film for printed circuits in which a conductive metal layer is laminated on at least one side of an electrically insulating film, the electrically insulating film comprising a substantially saturated linear polyester film. The degree of crosslinking measured using a mixed solution of phenol/tetrachloroethane (weight ratio 60/40) crosslinked using a compound having an unsaturated group represented by the following formula:
1. A polyester laminated film for printed circuits, characterized in that it is a crosslinked polyester film having a swelling degree of 70% or more, a swelling degree of 30 or less, and an elongation at room temperature of 10% or more. [However, in the formula, R ₁ , R ₂ and R ₃ are the same or different and each represents a member selected from the group consisting of a hydrogen atom and a C ₁ to _{C 6} alkyl. ]