JP7271146B2 - Dimer diamine composition, method for producing the same, and resin film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dimer-diamine composition containing dimer-diamine as a main component, a method for producing the same, and a resin film.

In recent years, with the progress of miniaturization, weight reduction, and space saving of electronic devices, flexible printed circuit boards (FPCs) that are thin, lightweight, flexible, and have excellent durability even after repeated bending have been developed. Circuits are in increasing demand. Since FPCs can be mounted three-dimensionally and at high density even in a limited space, their applications are expanding, for example, to the wiring of moving parts of electronic devices such as HDDs, DVDs, and smartphones, as well as components such as cables and connectors. I'm doing it.

In addition, due to the further development of high-performance electronic equipment, it is necessary to deal with higher frequency transmission signals. 2. Description of the Related Art When transmitting a high-frequency signal, if the transmission loss in the transmission path is large, problems such as the loss of the electrical signal and the increase in signal delay time occur. Therefore, reduction of transmission loss will be important for FPC in the future. There is a demand for FPCs and adhesives that can handle high frequencies.

By the way, as a technique related to an adhesive layer containing polyimide as a main component, it is obtained by reacting a polyimide containing a diamine component containing dimer diamine as a raw material with an amino compound having at least two primary amino groups as functional groups. It has been proposed to apply a crosslinked polyimide resin to an adhesive layer such as a coverlay film (for example, Patent Document 1).
In addition, it has been proposed to apply a resin composition in which a polyimide using dimer diamine as a diamine component, a thermosetting resin such as an epoxy resin, and a cross-linking agent in combination is applied to a copper-clad laminate (for example, patent Reference 2).

Dimer acid is obtained by Diels-Alder reaction using natural fatty acids such as soybean oil fatty acid, tall oil fatty acid, rapeseed oil fatty acid, and refined oleic acid, linoleic acid, linolenic acid, erucic acid, etc. as raw materials. It is a dimerized fatty acid (eg, Patent Document 3). Polybasic acid compounds containing dimer acids are known to be obtained as mixtures of starting fatty acids and fatty acids of trimers or higher. Therefore, commercially available dimer diamines are actually mixtures containing monoamines, triamines, etc. derived from fatty acids as raw materials, in addition to diamine components. In the present invention, such a mixture is sometimes referred to as a "dimer diamine composition".

Japanese Unexamined Patent Application Publication No. 2013-1730 JP 2017-119361 A JP 2017-137375 A

When a commercially available dimer diamine is used as the diamine component to produce a polyimide resin film, there is a problem that the transparency of the film is lowered and the film is colored.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resin film having high transparency and a low degree of coloring while using dimer diamine.

As a result of intensive research, the present inventors have found that in the production of a resin film from a polyimide using a dimer diamine composition as a diamine component, the amount of double bonds derived from the fatty acid, which is the raw material of the dimer diamine composition, is the same as that of the resin film. coloration, storage stability, and filling properties between circuit wirings. Then, the present inventors have found that by controlling the amount of double bonds contained in the dimer diamine composition, it is possible to stably produce a resin film with high transparency and a low degree of coloring, thereby completing the present invention.

That is, the dimer-diamine composition of the present invention is a dimer-diamine composition mainly composed of a dimer-diamine obtained by substituting a primary aminomethyl group or ^an amino group for two terminal carboxylic acid groups of a dimer acid, Aliphatic double bonds quantified by H-NMR are 1.0 mol % or less per 1 mol of CH ₂ groups (--CH ₂ --) in primary aminomethyl groups (NH ₂ CH ₂ --). characterized by

The dimer diamine composition of the present invention contains the following components (a) to (c) in terms of area percent of a chromatogram measured using gel permeation chromatography for the dimer diamine composition;
(a) a dimer diamine;
(b) a monoamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms;
(c) an amine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms (wherein the dimer diamine except for);
The component (c) in may be 2% or less.

In the method for producing a dimer-diamine composition of the present invention, a fat The dimer diamine composition is obtained by performing a treatment to reduce the content of group double bonds.

The resin film of the present invention is a resin film obtained by forming a polyimide into a film,
The polyimide is obtained by reacting a tetracarboxylic anhydride component and a diamine component containing 40 mol% or more of the dimer diamine composition according to claim 1 or 2 with respect to the total diamine component, And when the thickness is 30 μm, the following conditions i) to iii);
i) the transmittance of light with a wavelength of 400 nm is 70% or more;
ii) a YI value of 5 or less;
iii) The total light transmittance (T.T.) is 90% or more.

According to the dimer diamine composition of the present invention, since the amount of double bonds is controlled, by using this, a polyimide resin film with high transparency and low degree of coloring can be stably produced. Is possible. Therefore, it is possible to stabilize the quality and improve the yield in the production of the resin film.

An embodiment of the present invention will be described in detail.
The dimer-diamine composition of the present embodiment contains, as a main component, a dimer-diamine obtained by substituting two terminal carboxylic acid groups of a dimer acid with a primary aminomethyl group or an amino group. In this dimer _diamine composition _{, the} proportion of aliphatic double bonds determined by ¹ H-NMR _is is 1.0 mol % or less, preferably 0.8 mol % or less. The dimer diamine composition is a polyimide resin film having high transparency, low coloration, and improved visibility because the proportion of aliphatic double bonds is suppressed to 1.0 mol % or less. can be stably manufactured. Furthermore, by suppressing the proportion of aliphatic double bonds to 1.0 mol % or less, it is possible to improve the storage stability of the resin film and the filling properties between circuit wirings. If the ratio of the aliphatic double bonds exceeds 1.0 mol %, the resin film produced using dimer diamine as a raw material is colored yellow to yellowish brown, and the transparency is lowered. In addition, the storage stability of the resin film and the fillability between the circuit wirings are also deteriorated.

A dimer diamine is an aliphatic diamine that is liquid at room temperature, and a polyimide obtained by using this as a diamine component has an aliphatic chain (or alicyclic) structure. This aliphatic chain (or alicyclic) structure reduces interactions such as π-π stacking between polymer chains, improves solubility in solvents, and makes it difficult for charge transfer to occur due to its chemical structure. Originally, polyimide should be made nearly colorless and transparent. However, the polyimide obtained from the commercially available dimer diamine composition has low transparency and is colored. Moreover, even if a commercially available dimer diamine composition having a low YI value is selected, the YI value of the obtained polyimide cannot always be reduced.
As described above, the commercially available dimer-diamine composition is a mixture containing, in addition to the diamine component, monoamines and triamines derived from the raw material fatty acid, and is rich in double bonds. In the present embodiment, the amount of double bonds, particularly aliphatic double bonds, contained in the dimer diamine composition can reduce the transparency and coloration of the resin film, further improve storage stability and fill between circuit wirings. The amount of aliphatic double bonds is controlled based on the knowledge that it is involved in the decrease in sex. The amount of aliphatic double bonds is determined by ¹ H-NMR relative to the integrated value of ^{the 1} H peak of the CH ₂ group (CH ₂ in NH ₂ CH ₂ ) to which the amino group is attached at 2.6-2.9 ppm. , ^4.6 to 5.7 ppm.
Aliphatic double bond ratio [mol%] = (X/Y) x 100
[Where X means the integrated value of ^{the 1} H peak from 4.6 to 5.7 ppm and Y means the integrated value of ^{the 1} H peak from 2.6 to 2.9 ppm. ]

Commercially available dimer-diamine compositions contain double bonds derived from aromatic rings in addition to aliphatic double bonds. It is intended for The ratio of aromatic rings determined by ¹ H-NMR is preferably 20 mol % or less with respect to 1 mol of amino groups.

The dimer diamine composition of the present embodiment preferably contains the following component (a), and the amounts of components (b) and (c) are controlled.
Component (a) is a dimer diamine. In the dimer diamine of component (a), the two terminal carboxylic acid groups (--COOH) of the dimer acid are substituted with primary aminomethyl groups ( _--CH.sub.2 -- _NH.sub.2 ) or amino groups ( _--NH.sub.2 ). means a diamine. Dimer acid is a known dibasic acid obtained by an intermolecular polymerization reaction of unsaturated fatty acids, and its industrial production process is almost standardized in the industry. It is obtained by dimerization with Etc. Industrially obtained dimer acids are mainly composed of dibasic acids with 36 carbon atoms obtained by dimerizing unsaturated fatty acids with 18 carbon atoms such as oleic acid, linoleic acid and linolenic acid. To some extent, it contains any amount of monomeric acid (18 carbon atoms), trimer acid (54 carbon atoms), other polymerized fatty acids of 20 to 54 carbon atoms.

The dimer-diamine composition of the present embodiment is obtained by subjecting the starting dimer-diamine composition to a purification method such as molecular distillation so that the dimer-diamine content of component (a) is reduced to 96% by weight or more, preferably 97% by weight or more, more preferably It is preferable that the content is increased to 98% by weight or more. By setting the dimer diamine content of the component (a) to 96% by weight or more, it is possible to suppress the spread of the molecular weight distribution of the polyimide. If technically possible, it is best that all (100% by weight) of the dimer diamine composition is composed of the component (a) dimer diamine.

Component (b) is a monoamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms. The monobasic acid compound having 10 to 40 carbon atoms is a monobasic unsaturated fatty acid having 10 to 20 carbon atoms derived from the dimer acid raw material, and a by-product during the production of dimer acid. is a mixture of monobasic acid compounds within the range of 21 to 40 carbon atoms. A monoamine compound is obtained by substituting the terminal carboxylic acid group of these monobasic acid compounds with a primary aminomethyl group or an amino group.

The monoamine compound of component (b) is a component that suppresses an increase in the molecular weight of polyimide. When polyamic acid or polyimide is polymerized, the monofunctional amino group of the monoamine compound reacts with the terminal acid anhydride group of polyamic acid or polyimide to seal the terminal acid anhydride group, thereby reducing the molecular weight of polyamic acid or polyimide. restrain the increase.

Component (c) is an amine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms ( However, the dimer diamine mentioned above is excluded). The polybasic acid compound having a hydrocarbon group having 41 to 80 carbon atoms is mainly composed of a tribasic acid compound having 41 to 80 carbon atoms, which is a by-product of dimer acid production. It is a polybasic acid compound that Polymerized fatty acids other than dimer acids having 41 to 80 carbon atoms may also be included. Amine compounds are obtained by substituting the terminal carboxylic acid groups of these polybasic acid compounds with primary aminomethyl groups or amino groups.

The amine compound of component (c) is a component that promotes an increase in the molecular weight of polyimide. A trifunctional or higher functional amino group whose main component is a triamine derivative derived from trimer acid reacts with the terminal acid anhydride group of polyamic acid or polyimide to rapidly increase the molecular weight of polyimide. Amine compounds derived from polymerized fatty acids other than dimer acids having 41 to 80 carbon atoms also increase the molecular weight of polyimide and cause gelation of polyamic acid or polyimide.

In the present embodiment, the components (a) to (c) include those whose degree of unsaturation is lowered by the double bond reduction treatment described later.

Quantification of components (a) to (c) can be performed on the dimer diamine composition by measurement using gel permeation chromatography (GPC). In order to facilitate confirmation of the peak start, peak top and peak end of each component of the dimer diamine composition, a sample of the dimer diamine composition treated with acetic anhydride and pyridine was used, and cyclohexanone was used as an internal standard substance. preferably. Samples prepared in this manner can be used to quantify each component by area percent of the GPC chromatogram. The peak start and peak end of each component are the minimum values of each peak curve, and the area percentage of the chromatogram can be calculated based on this.

The dimer diamine composition preferably contains component (c) in an area percentage of 2% or less, more preferably 1% or less in a chromatogram obtained by GPC measurement. By setting it to such a range, the number of aliphatic double bonds in the dimer diamine composition can be effectively reduced. In addition, the component (c) may not be contained in the dimer diamine composition.

Also, the area percentage of the chromatogram of component (b) is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less. By setting it in such a range, it is possible to suppress the decrease in the molecular weight of the polyimide, and further to widen the range of the molar ratio of the tetracarboxylic anhydride component and the diamine component. In addition, the component (b) may not be contained in the dimer diamine composition.

Also, the total content of components (b) and (c) is 4% or less, preferably less than 4%. By setting the total content of components (b) and (c) to 4% or less, the number of aliphatic double bonds in the dimer diamine composition can be effectively reduced, and broadening of the polyimide molecular weight distribution can be suppressed. .

[Method for producing dimer diamine composition]
The dimer-diamine composition of the present embodiment is prepared by subjecting a raw material dimer-diamine composition containing the dimer-diamine of component (a) (for example, a commercially available dimer-diamine composition) to a treatment such as hydrogenation or distillation (" It can be produced by performing a double bond reduction treatment" to reduce the content of aliphatic double bonds. When distillation is performed as the double bond reduction treatment, it is also possible to reduce the components (b), (c), etc. at the same time.
Here, distillation for reducing the content of aliphatic double bonds is preferably carried out by vacuum distillation, vacuum distillation, steam distillation, or the like.
Hydrogenation for reducing the content of aliphatic double bonds is preferably carried out using a catalyst such as nickel, platinum, palladium, copper, chromium or sodium formate.

Raw material dimer diamine compositions before double bond reduction treatment are commercially available, for example, PRIAMINE 1073 (trade name), PRIAMINE 1074 (trade name), and PRIAMINE 1075 (trade name) manufactured by Croda Japan. is mentioned.

[Manufacturing of polyimide]
Next, a method for producing polyimide using the dimer diamine composition of the present embodiment will be described. Polyimide is obtained by imidizing a precursor polyamic acid obtained by reacting a tetracarboxylic anhydride component and a diamine component.

Examples of tetracarboxylic anhydrides that can be used in the production of polyimide include 3,3′,4,4′-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 1,4-phenylenebis(tri mellitic acid monoester) dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 2,3',3,4'-biphenyltetra Carboxylic dianhydride, 2,2',3,3'-, 2,3,3',4'- or 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3' ,3,4'-diphenyl ether tetracarboxylic acid dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, 3,3'',4,4''-,2,3,3'', 4″- or 2,2″,3,3″-p-terphenyltetracarboxylic dianhydride, 2,2-bis(2,3- or 3,4-dicarboxyphenyl)-propane anhydride, bis(2,3- or 3.4-dicarboxyphenyl)methane dianhydride, bis(2,3- or 3,4-dicarboxyphenyl)sulfone dianhydride, 1,1-bis(2 ,3- or 3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride 2,3,6,7-anthracenetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1 ,4,5,8-tetracarboxylic dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene-1,4,5,8- (or 2,3 ,6,7-)tetracarboxylic dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene- tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4, 5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, 2,2- Bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, p-phenylene bis(trimellitic acid monoester anhydride) , ethylene glycol bisanhydrotrimellitate, and 2,2′-bis(4-(3,4-dicarboxyphenoxy)phenyl)hexafluoropropane dianhydride. Among these, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, ethylene glycol bis-anhydrotrimellitate, 2,2' are preferred from the viewpoint of producing a polyimide with high transparency and low coloring. Acid dianhydrides such as -bis(4-(3,4-dicarboxyphenoxy)phenyl)hexafluoropropane dianhydride are preferred. When using 2,2',3,3'-, 2,3,3',4'- or 3,3',4,4'-benzophenonetetracarboxylic dianhydride, the molecular skeleton The existing ketone group may react with the amino group of the component (b) or (c) to form a C=N bond, which is preferable because a polyimide having a high molecular weight can be easily obtained.

As the diamine component, the dimer diamine composition of the present embodiment can be used as part or all of it. By using the dimer diamine composition of the present embodiment in an amount of 40 mol % or more, preferably 60 to 100 mol %, based on the total diamine component, the transparency of the resin film obtained from the polyimide is increased and the degree of coloring is reduced. can be reduced and visibility improved. Furthermore, it is possible to improve storage stability and filling properties between circuit wirings. If the amount of the dimer-diamine composition is less than 40 mol % with respect to the total diamine component, the effect of enhancing the transparency of the resin film is not sufficiently obtained, and the effect of improving the storage stability and filling between circuit wirings is also obtained. can't get enough.

Examples of diamine components other than the dimer diamine composition that can be used in the production of polyimide include aromatic diamine compounds and aliphatic diamine compounds. Specific examples thereof include 1,4-diaminobenzene (p-PDA; paraphenylenediamine), 2,2′-dimethyl-4,4′-diaminobiphenyl (m-TB), 2,2′-n- Propyl-4,4'-diaminobiphenyl (m-NPB), 4-aminophenyl-4'-aminobenzoate (APAB), 2,2-bis-[4-(3-aminophenoxy)phenyl]propane, bis[ 4-(3-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy)phenyl]methane , bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)]benzophenone, 9,9-bis[4-(3-aminophenoxy)phenyl]fluorene, 2,2- Bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 3,3'-dimethyl-4,4'- diaminobiphenyl, 4,4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 3,3'-diaminodiphenylethane, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, bis(p-aminocyclohexyl)methane, bis(p-β-amino-t-butylphenyl) ether, bis(p-β -methyl-δ-aminopentyl)benzene, p-bis(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,5-diaminonaphthalene, 2 ,6-diaminonaphthalene, 2,4-bis(β-amino-t-butyl)toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m -xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, 2'-methoxy-4, 4'-diaminobenzanilide, 4,4'-diaminobenzanilide, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 6-amino-2-(4-aminophenoxy)benzo oxazole, 1,3-bis(3-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-bbis(2-(trifluoromethyl) -4-aminophenoxy)biphenyl, 2,2-bis(4-(2-(trifluoromethyl)-4-aminophenoxy)phenyl)hexafluoropropane, 4,4'-bis(3-(trifluoromethyl) -4-aminophenoxy)biphenyl, 4,4′-bis(3-(trifluoromethyl)-4-aminophenoxy)biphenyl, p-bis(2-trifluoromethyl)-4-aminophenoxy]benzene and other diamines compound. Among these, from the viewpoint of producing a polyimide with high transparency and a low degree of coloring, 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 9,9-bis[4- (3-aminophenoxy)phenyl]fluorene, 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl, 4,4′-b bis(2-(trifluoromethyl)-4-aminophenoxy )biphenyl, 2,2-bis(4-(2-(trifluoromethyl)-4-aminophenoxy)phenyl)hexafluoropropane, 4,4′-bis(3-(trifluoromethyl)-4-aminophenoxy ) biphenyl, 4,4′-bis(3-(trifluoromethyl)-4-aminophenoxy)biphenyl, p-bis(2-trifluoromethyl)-4-aminophenoxy]benzene and the like are preferred.

A polyimide can be produced by reacting the above tetracarboxylic anhydride and a diamine component in a solvent to form a polyamic acid, followed by heating and ring closure. For example, a tetracarboxylic dianhydride and a diamine component are dissolved in an organic solvent in approximately equimolar amounts, and stirred at a temperature within the range of 0 to 100° C. for 30 minutes to 24 hours for a polymerization reaction to form a polyimide precursor. A polyamic acid is obtained. In the reaction, the reaction components are dissolved in the organic solvent so that the resulting precursor is within the range of 5 to 50% by weight, preferably within the range of 10 to 40% by weight. Examples of organic solvents used in the polymerization reaction include N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), 2 -butanone, dimethylsulfoxide (DMSO), hexamethylphosphoramide, N-methylcaprolactam, dimethyl sulfate, cyclohexanone, dioxane, tetrahydrofuran, diglyme, triglyme, cresol and the like. Two or more of these solvents can be used in combination, and aromatic hydrocarbons such as xylene and toluene can also be used in combination. The amount of such an organic solvent to be used is not particularly limited, but the amount used is adjusted so that the concentration of the polyamic acid solution obtained by the polymerization reaction is about 5 to 50% by weight. is preferred.

It is usually advantageous to use the synthesized polyamic acid as a reaction solvent solution, but if necessary, it can be concentrated, diluted, or replaced with another organic solvent. Polyamic acid is also advantageously used because it is generally excellent in solvent solubility. The viscosity of the polyamic acid solution is preferably in the range of 500 cps to 100,000 cps. If the thickness is out of this range, defects such as thickness unevenness and streaks are likely to occur in the film during the coating operation using a coater or the like.

The method of imidizing the polyamic acid to form a polyimide is not particularly limited, for example, a heat treatment such as heating for 1 to 24 hours under a temperature condition within the range of 80 to 400 ° C. in the solvent is preferably employed. be done. Moreover, the temperature may be heated under constant temperature conditions, or the temperature may be changed during the process.

The weight average molecular weight of the polyimide is preferably in the range of 10,000 to 200,000, for example. Within this range, the weight average molecular weight of the polyimide can be easily controlled. Further, when applied as an adhesive for FPC, for example, the weight-average molecular weight of polyimide is more preferably in the range of 40,000 to 150,000. When the weight average molecular weight of the polyimide is less than 40,000, the flow resistance tends to deteriorate. On the other hand, if the weight-average molecular weight of the polyimide exceeds 150,000, the viscosity increases excessively and the polyimide becomes insoluble in the solvent, which tends to cause defects such as uneven thickness of the adhesive layer and streaks during coating. Become.

[Resin film]
The resin film is produced by reacting a tetracarboxylic anhydride component and a diamine component containing 40 mol % or more, preferably 60 to 100 mol %, of the dimer diamine composition of the present embodiment with respect to the total diamine component. It is a resin film formed from polyimide. The resin film of the present embodiment satisfies the following conditions i) to iii) when the thickness is 30 μm.

i) Transmittance of light with a wavelength of 400 nm is 70% or more.
Transparency of the resin film can be ensured by having a transmittance of 70% or more for light having a wavelength of 400 nm. If the transmittance of light with a wavelength of 400 nm is less than 70%, the transparency is low and the visibility of the resin film is lowered.

ii) a YI value of 5 or less;
When the YI value is 5 or less, preferably 4 or less, the resin film can be made nearly colorless. When the YI value exceeds 5, yellow to yellowish brown coloring becomes strong, and the visibility of the resin film is lowered.

iii) Total light transmittance (T.T.) is 90% or more.
When the total light transmittance (T.T.) is 90% or more, white turbidity due to reflection and scattering of light in the resin film is suppressed, resulting in excellent transparency. If the total light transmittance (T.T.) is less than 90%, the turbidity increases and the transparency of the resin film decreases.

The form of the resin film of the present embodiment is not particularly limited, and may be a film (sheet). For example, copper foil, glass plate, polyimide film, polyamide film, polyester film, etc. It may be in a state of being laminated on a substrate.

In addition, the thickness of the resin film can be appropriately set according to the purpose of use. It can range from ˜50 μm.

The method for forming the resin film of the present embodiment is not particularly limited, but for example, [1] a method of applying a polyamic acid solution to a supporting substrate, drying it, and then imidating it to produce a resin film (hereinafter referred to as cast method), and [2] a method in which a polyamic acid solution is applied to a supporting substrate and dried, then the polyamic acid gel film is peeled off from the supporting substrate and imidized to produce a resin film. Further, when the resin film produced in the present embodiment is composed of a plurality of polyimide resin layers, the production method may include, for example, [3] a support substrate, a solution of polyamic acid is applied and dried. After repeating this several times, imidization is performed (hereinafter referred to as sequential coating method), [4] The support substrate is simultaneously coated and dried with a polyamic acid laminate structure by multilayer extrusion, and then imidized. (hereinafter referred to as multilayer extrusion method). The method of applying the polyimide solution (or polyamic acid solution) onto the substrate is not particularly limited, and it can be applied, for example, by a comma, die, knife, lip coater, or the like. When forming a multi-layered polyimide layer, a method of repeating the operation of applying a polyimide solution (or a polyamic acid solution) to a base material and drying the solution is preferred.

Since the resin film of the present embodiment has improved storage stability and filling properties between circuit wirings, it can be used for various applications such as an insulating resin layer, an adhesive layer, and a protective layer in electronic devices. . Important properties of dimer diamine include the ability to impart low elastic modulus, flexibility, and adhesiveness to polyimide, and the improvement of dielectric properties of polyimide (lower dielectric constant and lower dielectric loss tangent). As such, it has been confirmed that these properties are hardly affected by the use of those with a reduced amount of aliphatic double bonds. Therefore, the resin film of the present embodiment can be preferably used for applications such as circuit boards such as FPC, adhesive layers in coverlay films, bonding sheets in multilayer circuit boards, and the like.
Further, the resin sheet of the present embodiment is excellent in transparency and has a low elastic modulus and can suppress residual stress. , a material for transparent electrode substrates, light-receiving devices such as thin-film solar cells, and the like.

[Metal clad laminate]
A metal-clad laminate has an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer. In such a metal-clad laminate, the insulating resin layer has a single-layer or multiple-layer polyimide layer. At least one of the polyimide layers (preferably an adhesive layer) may have the same structure as the resin film of the present embodiment. Preferably, the adhesiveness between the insulating resin layer and the metal layer is increased. Therefore, the adhesive layer in the insulating resin layer, which is in contact with the metal layer, preferably has the same structure as the resin film of this embodiment. The material of the metal layer in the metal-clad laminate is not particularly limited, but examples include copper, stainless steel, iron, nickel, beryllium, aluminum, zinc, indium, silver, gold, tin, zirconium, tantalum, titanium, lead, Examples include magnesium, manganese and alloys thereof. Among these, copper or a copper alloy is particularly preferable. The material of the wiring layer in the circuit board, which will be described later, is also the same as that of the metal layer. A preferred specific example of the metal-clad laminate is a copper-clad laminate (CCL).

The metal-clad laminate is prepared by, for example, preparing an insulating resin film containing the resin film of the present embodiment, sputtering metal onto this to form a seed layer, and then forming a metal layer by, for example, plating. good too.

Alternatively, the metal-clad laminate may be prepared by preparing an insulating resin film containing the resin film of the present embodiment and laminating a metal foil thereon by a method such as thermocompression bonding.

Furthermore, the metal-clad laminate is obtained by casting a polyamic acid coating solution using a diamine component containing a predetermined amount of the dimer diamine composition of the present embodiment on a metal foil, and drying to form a coating film. may be prepared by heat treatment to imidize and form a polyimide layer.

[Circuit board]
The circuit board has an insulating resin layer and a wiring layer formed on the insulating resin layer. In the circuit board of this embodiment, the insulating resin layer can have a single layer or multiple layers of polyimide layers. In this case, at least one polyimide layer (preferably an adhesive layer) should have the same structure as the resin film of the present embodiment. Moreover, in order to improve the adhesiveness between the insulating resin layer and the wiring layer, it is preferable that the adhesive layer in the insulating resin layer in contact with the wiring layer has the same structure as the resin film of the present embodiment.

The method for producing the circuit board does not matter. For example, a subtractive method in which a metal-clad laminate composed of an insulating resin layer including a polyimide layer having the same configuration as the resin film of the present embodiment and a metal layer is prepared, and the metal layer is etched to form wiring. It's okay. Further, after forming a seed layer on an insulating resin layer including a polyimide layer having a structure similar to that of the resin film of the present embodiment, resist is patterned, and metal is pattern-plated to form wiring. A semi-additive method may be used.

EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited to these examples. In the following examples, unless otherwise specified, various measurements and evaluations are as follows.

[Calculation of Aliphatic Double Bond Ratio and Aromatic Ring Ratio]
The aliphatic double bond ratio and the aromatic ring ratio of the dimer diamine composition were calculated by the following procedure. First, about 50 μl of the dimer diamine composition was dissolved in 550 μl of THF-d8 to prepare a sample. Liquid ¹ H-NMR measurement was performed on the prepared sample at room temperature using an FT-NMR device (JNM-ECA400 manufactured by JEOL). ¹ H peaks derived from aliphatic _double bonds found at 4.6-5.7 ppm compared to the integrated values of ¹ H peaks derived from CH _groups directly attached to NH groups found at 2.6-2.9 ppm From the ratio of the integrated value of the peak and the integrated value of the ¹ H peak derived from the aromatic ring observed at 6.6 to 7.2 ppm, the ratio of the aliphatic double bond and the ratio of the aromatic ring were calculated according to the following equations.
Aliphatic double bond ratio [mol%] = (X/Y) x 100
Aromatic ring ratio [mol%] = (Z / Y) × 100
[Wherein, X means the integrated value of ^{the 1} H peak at 4.6-5.7 ppm, Y means the integrated value of ^{the 1} H peak at 2.6-2.9 ppm, and Z is 6.6- Means the integrated value of the ¹ H peak (derived from the aromatic ring) at 7.2 ppm. ]

[Calculation of area percent of GPC and chromatogram]
(a) a dimer diamine;
(b) a monoamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms;
(c) an amine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms (wherein the dimer diamine except for);

[Calculation of area percent of GPC and chromatogram]
For GPC, 20 mg of the dimer diamine composition was pretreated with 200 μL of acetic anhydride, 200 μL of pyridine and 2 mL of THF, and 100 mg of the solution was diluted with 10 mL of THF (containing 1000 ppm of cyclohexanone) to prepare samples. The prepared sample is manufactured by Tosoh Corporation, trade name; using HLC-8220GPC, column: TSK-gel G2000HXL, G1000HXL, G1000HXL, flow rate: 1 mL / min, column (oven) temperature: 40 ° C., injection volume: 50 μL was measured under the conditions of In addition, cyclohexanone was treated as a standard substance for correction of effluent time.

At this time, the peak top of the main peak of cyclohexanone is adjusted so that the retention time is 27 minutes to 31 minutes, and the peak end is 2 minutes from the peak start of the main peak of cyclohexanone, and the peak of cyclohexanone is excluded. Each component (a) to (c);
(a) the component represented by the main peak;
(b) A component represented by a GPC peak detected at a time later than the minimum value on the time side with a slow retention time in the main peak;
(c) A component represented by a GPC peak detected at an earlier time than the minimum value on the time side where the retention time in the main peak is early;
detected.

[Calculation of light transmittance (400 nm transmittance), b ^* , and YI]
The light transmittance (400 nm transmittance), b ^* , and YI of the dimer diamine composition were measured using a UV-3600 Plus UV-VIS-NIR SPECTROPHOTOMETER manufactured by Shimadzu Corporation and a quartz standard cell with an optical path length of 1 cm, using xylene as a blank, according to JIS Z. 8722 standard.
The light transmittance (400 nm transmittance), b ^* , and YI of the film were measured according to JIS Z 8722 using a UV-3600 Plus UV-VIS-NIR SPECTROPHOTOMETER manufactured by Shimadzu Corporation.

[Calculation of total light transmittance (TT) and HAZE (turbidity)]
The total light transmittance (T.T.) and HAZE (turbidity) of the film were measured according to JIS K 7136 with a HAZE METER NDH5000 manufactured by Nippon Denshoku.

[Measurement of weight average molecular weight (Mw) of polyimide]
The weight average molecular weight was measured by gel permeation chromatography (manufactured by Tosoh Corporation, using HLC-8220GPC). Polystyrene was used as a standard substance, and tetrahydrofuran was used as a developing solvent.

The abbreviations used in the examples represent the following compounds. In addition, "%" of component (b) and component (c) means the area percent of the chromatogram in GPC measurement.
BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride

[DDA1-5]
DDA1: manufactured by Croda Japan Co., Ltd., trade name; PRIAMINE 1075 distilled and purified (component (a): 96.1% by weight, component (b): 2.4%, component (c): 1.5%)
DDA2: manufactured by Croda Japan Co., Ltd., trade name: PRIAMINE 1075 distilled and purified (component (a): 97.8% by weight, component (b): 0.3%, component (c): 1.9%)
DDA3: manufactured by Croda Japan Co., Ltd., trade name: PRIAMINE 1075 distilled and purified (component (a): 98.5% by weight, component (b): 0.2%, component (c): 1.3%)
DDA4: manufactured by Croda Japan Co., Ltd., trade name; PRIAMINE 1075 distilled and purified (component (a); 98.8% by weight, component (b): 0.2%, component (c); 1.0%)
DDA5: manufactured by Croda Japan Co., Ltd., trade name; PRIAMINE 1075 distilled and purified (component (a): 98.9% by weight, component (b): 0.2%, component (c): 0.9%)
NMP: N-methyl-2-pyrrolidone Purification by distillation was carried out under reduced pressure.

Table 1 below shows the calculation of the aliphatic double bond ratio, aromatic ring ratio, light transmittance (transmittance at 400 nm), b ^* and YI of DDA1 to DDA5.

[Example 1]
A 1000 ml separable flask was charged with 56.22 g of BTDA (0.174 mol), 93.78 g of DDA1 (0.176 mol), 210 g of NMP and 140 g of xylene and mixed well at 40° C. for 1 hour. Then, a polyamic acid solution was prepared. The polyamic acid solution was heated to 190° C., heated and stirred for 4 hours, and 140 g of xylene was added to complete the imidation. prepared. The resulting polyimide solution 1 was applied to one side of a release-treated PET film and dried at 80° C. for 15 minutes to prepare a resin film 1 (thickness: 22 μm). Table 2 shows the thickness, light transmittance (400 nm transmittance), b ^* , YI, total light transmittance (TT), and HAZE (turbidity) of Resin Film 1.

[Examples 2 to 5]
Polyimide solutions 2 to 5 were prepared in the same manner as in Example 1, except that the DDA shown in Table 1 was used. Thickness, light transmittance (400 nm transmittance), b ^* , YI, total light transmittance (TT), HAZE (turbidity) of resin films 2 to 5 obtained using polyimide solutions 2 to 5 Table 2 shows.

[DDA6-8]
DDA6: Croda Japan Co., Ltd., trade name: PRIAMINE 1075 (component (a): 97.0% by weight, component (b): 0.7%, component (c): 2.3%)
DDA7: Croda Japan Co., Ltd., trade name: PRIAMINE 1075 (component (a): 95.8% by weight, component (b): 0.2%, component (c): 4.0%)
DDA8: Croda Japan Co., Ltd., trade name: PRIAMINE 1075 (component (a): 97.3% by weight, component (b): 0.2%, component (c): 2.5%)

Table 3 shows the aliphatic double bond ratio, aromatic ring ratio, light transmittance (400 nm transmittance), b ^* and YI of DDA6-8.

[Comparative Examples 1 to 3]
Polyimide solutions 6 to 8 were prepared in the same manner as in Example 1, except that DDA 6 to 8 shown in Table 3 were used. Thickness, light transmittance (400 nm transmittance), b ^* , YI, total light transmittance (TT), HAZE (turbidity) of resin films 6 to 8 obtained using polyimide solutions 6 to 8 were measured. Table 4 shows.

From a comparison between Tables 1 and 2 and Tables 3 and 4, in Examples 1 to 5, by using a dimer diamine composition with a reduced proportion of aliphatic double bonds, transparency was high and It was confirmed that a polyimide resin film having a low degree of coloring and good visibility was obtained. On the other hand, in Comparative Examples 1 to 3 using a diamine component in which the proportion of aliphatic double bonds was not controlled, the resin film yield was lower than in Examples 1 to 5, although the YI value of the raw material itself was low. The transparency was low, the coloring was deepened, and the visibility was poor.

Although the embodiments of the present invention have been described in detail for purposes of illustration, the present invention is not limited to the above embodiments.

Claims (7)

A dimer-diamine composition mainly comprising a dimer-diamine in which two terminal carboxylic acid groups of a dimer acid are substituted with primary aminomethyl groups or amino groups,
Aliphatic double bonds quantified by ¹ H-NMR are 1.0 mol% or less with respect to 1 mol of CH ₂ groups (—CH ₂ —) in primary aminomethyl groups (NH ₂ CH ₂ —) together with the following components (a) to (c) in area percent of the chromatogram as measured using gel permeation chromatography;
(a) a dimer diamine;
(b) a monoamine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a monobasic acid compound having 10 to 40 carbon atoms;
(c) an amine compound obtained by substituting a primary aminomethyl group or an amino group for the terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group within the range of 41 to 80 carbon atoms (wherein the dimer diamine except for);
wherein the component (b) is 2% or less, the component (c) is 2% or less, and the total of the component (b) and the component (c) is less than 4%. diamine composition. A method for producing the dimer diamine composition according to claim 1,
A raw material dimer-diamine composition containing a dimer-diamine in which two terminal carboxylic acid groups of a dimer acid are substituted with primary aminomethyl groups or amino groups is subjected to a treatment to reduce the content of aliphatic double bonds. A method for producing a dimer diamine composition, characterized in that the dimer diamine composition is obtained by carrying out. A resin film formed by filming polyimide,
The polyimide is obtained by reacting a tetracarboxylic anhydride component and a diamine component containing 40 mol % or more of the dimer diamine composition according to claim 1 with respect to the total diamine component, and
When the thickness is 30 μm, the following conditions i) to iii);
i) the transmittance of light with a wavelength of 400 nm is 70% or more;
ii) a YI value of 5 or less;
iii) A resin film having a total light transmittance (T.T.) of 90% or more. 4. The resin film according to claim 3 , which is an adhesive layer in a circuit board or a coverlay film or a bonding sheet in a multilayer circuit board. 4. The resin film according to claim 3 , which is a touch panel material, a TFT substrate material, a transparent electrode substrate material, or a light receiving device material. A metal-clad laminate having an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer,
5. A metal-clad laminate, wherein the insulating resin layer has a single or multiple polyimide layers, and at least one of the polyimide layers is the resin film according to claim 3 or 4 . A circuit board having an insulating resin layer and a wiring layer formed on the insulating resin layer,
5. A circuit board, wherein the insulating resin layer has a single layer or a plurality of polyimide layers, and at least one of the polyimide layers is the resin film according to claim 3 or 4 .