Composite film comprising thermoplastic polyimide layer and non-thermoplastic polyimide layer, and method for manufacturing same

Abstract

The present invention provides a thermoplastic polyimide film comprising a thermoplastic polyimide (TPI) including polymerization units of a dianhydride monomer and a diamine monomer, and having surface oxygen concentration of 2.5 to 8.5% as measured by depth XPS analysis, and provides a composite film comprising the thermoplastic polyimide film on one or both surfaces of a non-thermoplastic polyimide layer and having surface oxygen concentration of 2.5 to 8.5% as measured by depth XPS analysis, and a method for manufacturing the composite film.

Description

Composite film comprising a thermoplastic polyimide layer and a non-thermoplastic polyimide layer and a method for manufacturing the same

[0001] The present invention relates to a composite film with improved adhesion by applying a thermoplastic polyimide layer on a non-thermoplastic polyimide layer, and a method for manufacturing the same. More specifically, the invention relates to a composite film with improved adhesion in which an optimal oxygen ratio is achieved on the surface of a thermoplastic polyimide layer, and a method for manufacturing the same.

[0002] Polyimide (PI) is a polymer material based on an imide ring with excellent chemical stability and a rigid aromatic main chain, and possesses the highest level of heat resistance, chemical resistance, electrical insulation, chemical resistance, and weather resistance among organic materials.

[0003] Generally, polyimide (PI) film refers to a polyimide resin formed into a film. Polyimide resin refers to a high-heat-resistant resin produced by solution polymerizing an aromatic dianhydride with an aromatic diamine or an aromatic diisocyanate to produce a polyamic acid derivative, and then dehydrating it at high temperatures to form an imid.

[0004] Among the important applications of polyimide films, for example, PCB materials or electrical insulation films are commonly used as prepreg materials manufactured by bonding with copper foil via adhesive, coating with adhesive, or bonding with fluoropolymer; therefore, their adhesive strength has emerged as a critical issue.

[0005] Generally, conventional post-treatment methods such as sandblasting and alkali treatment have been used to impart adhesion to polyimide films. However, these methods are for post-treating commercially available films, making it difficult to apply them during the film manufacturing process. Consequently, issues regarding the stability of the post-treatment method, the homogeneity of the treated film, and changes in film adhesion prior to post-treatment have persisted, and it has been difficult to reliably manufacture films with improved adhesion. Furthermore, post-treatment methods aimed at improving film adhesion inevitably led to increased manufacturing costs.

[0006] Therefore, there is a need to develop a polyimide film with improved adhesion that does not require a post-processing method, and a method for manufacturing the same.

[0007] The present invention aims to provide a thermoplastic polyimide film with improved adhesion by having oxygen present at an optimal concentration on the surface of the thermoplastic polyimide layer.

[0008] In addition, the present invention aims to provide a composite film with excellent heat resistance and mechanical properties due to a low coefficient of thermal expansion, and a method for manufacturing the same, comprising a non-thermoplastic polyimide layer and a thermoplastic polyimide layer formed on one or both sides of the non-thermoplastic polyimide layer, wherein oxygen is present at an optimal concentration on the surface of the thermoplastic polyimide layer to improve adhesion, and comprising an Ultra Low CTE PI, a non-thermoplastic polyimide having isotropic thermal and mechanical properties.

[0009] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are to be illustrated and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0010] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0011] Where in this specification, when a quantity, concentration, or other value or parameter is given as an enumeration of a range, a preferred range, a preferred upper limit, and a preferred lower limit, it should be understood that any pair of any upper range limit or preferred value and any lower range limit or preferred value are specifically disclosed, regardless of whether the range is disclosed separately.

[0012] Where a range of numerical values ​​is mentioned in this specification, unless otherwise stated, the range and the scope of the parent invention within that range are not intended to be limited to the specific value mentioned when defining the range.

[0013] In this specification, "dianhydride" is intended to include its precursor or derivative, and is also referred to as "dianhydric acid," "dianhydride," or "acid dianhydride." Although these may not technically be dianhydrides, they will nevertheless react with a diamine to form a polyamic acid, which can then be converted into a polyimide.

[0014] In this specification, "diamine" is intended to include its precursors or derivatives, which may not technically be diamines but nevertheless will react with dianhydrides to form polyamic acids, which can then be converted into polyimides.

[0015] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application. Specific details for the implementation of the above invention are described below.

[0016] The present invention relates to a composite film with improved adhesion in the form of a laminated non-thermoplastic polyimide layer and a thermoplastic polyimide layer, and a method for manufacturing the same.

[0017] Thermoplastic polyimide film

[0018] The present invention provides a thermoplastic polyimide film having a surface oxygen concentration of 2.5 to 8.5% when analyzed by Depth XPS (X-ray Photoelectron Spectrocopy).

[0019] Specifically, the present invention provides a thermoplastic polyimide film comprising a thermoplastic polyimide (TPI) and having a surface oxygen concentration of 2.5 to 8.5% when analyzed by Depth XPS (X-ray Photoelectron Spectrocopy).

[0020] Preferably, the surface oxygen concentration may be 3.0 to 8.0%, more preferably 3.5 to 7.5%, and even more preferably 4.0 to 7.0%. If the oxygen concentration is less than 2.5% or exceeds 8.5%, the adhesion is low and therefore undesirable.

[0021] In addition, when analyzing the Depth XPS (X-ray Photoelectron Spectroscopy) above, the surface carbon concentration may be 87.5 to 93.0%, preferably 87.8 to 92%, more preferably 87.9 to 91.95%, and even more preferably 87.9 to 91%.

[0022] The above-mentioned Depth XPS (X-Ray Photoelectron Spectroscopy) is an instrument that enables the determination of the composition and chemical bonding state of a sample surface by irradiating the surface with X-rays and measuring the energy of the emitted photoelectrons.

[0023] The above surface oxygen concentration and the above surface carbon concentration may be measured by irradiating the surface of the thermoplastic polyimide film with X-rays for 20 to 30 seconds using Depth XPS.

[0024] The thermoplastic polyimide film may further include a metal layer on one or both sides, and the metal layer may include one or more selected from the group consisting of Ni, Cr, and Cu.

[0025] In addition, the thermoplastic polyimide film may have an adhesion strength of 0.8 kgf / cm or more to the metal layer. For example, the lower limit of the adhesion strength may be 0.9 kgf / cm or more, 1.0 kgf / cm or more, 1.05 kgf / cm or more, or 1.08 kgf / cm or more, and the upper limit is not particularly limited but may be 2.0 kgf / cm or less.

[0026] More specifically, the surface oxygen concentration and the surface carbon concentration may be formed by hydroxyl groups (-OH) and carboxyl groups (-COOH), which are functional groups on the surface of the thermoplastic polyimide film, and these functional groups may be formed depending on the amount of heat required to manufacture the thermoplastic polyimide film.

[0027] Specifically, when manufacturing the thermoplastic polyimide film, the manufacturing process is performed under an oxygen atmosphere, and depending on the amount of heat required, the imide ring within the thermoplastic polyimide molecule is rearranged to form a functional group including a hydroxyl group (-OH) and a carboxyl group (-COOH), and the imide ring can be rearranged into an amide group.

[0028] In addition, the hydroxyl group (-OH) and carboxyl group (-COOH), which are functional groups on the surface of the thermoplastic polyimide film, and the metal ions of the metal layer are coordinately bonded, thereby strengthening the interaction between the thermoplastic polyimide film and the metal layer and improving adhesion.

[0029] The above caloric value is 70 to 180 kcal / m² 2 It may be, for example, the lower limit of the above calorific value is 75 Kcal / m² 2 Above, 80 kcal / m² 2 Above, 85 Kcal / m² 2 Above, 90 Kcal / m² 2 Above, 95 Kcal / m² 2 Above, 100 Kcal / m² 2 Above, 105 Kcal / m² 2 Above, 110 Kcal / m² 2 Above, 115 Kcal / m² 2 120 Kcal / m² or more 2 It may be higher, and the upper limit is 175 Kcal / m² 2 Below, 173 Kcal / m² 2 Below, 170 Kcal / m² 2 Below, 168 Kcal / m² 2 Below, 165 Kcal / m² 2Below, 163 Kcal / m² 2 Below, 160 Kcal / m² 2 Below, 158 Kcal / m² 2 Below, 155 Kcal / m² 2 Below, 153 Kcal / m² 2 Below, 150 Kcal / m² 2 Below, 148 Kcal / m² 2 Below, 145 Kcal / m² 2 Below, 140 Kcal / m² 2 Below, 138 Kcal / m² 2 135 Kcal / m² or less 2 It may be less than.

[0030] The above caloric value is 70 Kcal / m² 2 Less than or 180 Kcal / m² 2 If it exceeds a certain amount, the adhesive strength is low, which is undesirable.

[0031] Here, the above heat quantity can be calculated by the following Equations 1 and 2. Specifically, the output value can be obtained using Equation 1 below, and the heat quantity consumed during film manufacturing can be calculated by substituting the output value into Equation 2 below.

[0032] [Equation 1]

[0033]

[0034] [Equation 2]

[0035]

[0036] The above thermoplastic polyimide may comprise polymerization units of a dianhydride monomer and a diamine monomer.

[0037] Specifically, the dianhydride monomer may comprise one or more compounds selected from the group consisting of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3',4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA), and 4,4'-oxydiphthalic anhydride (ODPA), and preferably may comprise one or more compounds selected from the group consisting of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA).

[0038] Specifically, the diamine monomer may comprise one or more compounds selected from the group consisting of 4,4'-oxydianiline, 3,4'-oxydianiline, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)benzidine (TFMB), p-phenylenediamine (PPD), and m-phenylenediamine (MPD), and preferably may comprise one or more compounds selected from the group consisting of 4,4'-oxydianiline, 1,3-bis(4-aminophenoxy)benzene, and 1,4-bis(4-aminophenoxy)benzene.

[0039] Composite film

[0040] The present invention provides a composite film comprising: a non-thermoplastic polyimide layer; and a thermoplastic polyimide layer located on one surface of the non-thermoplastic polyimide layer, wherein the surface oxygen concentration of the thermoplastic polyimide layer is 2.5 to 8.5% when analyzed by Depth XPS (X-ray Photoelectron Spectrocopy).

[0041] Preferably, the surface oxygen concentration may be 3.0 to 8.0%, more preferably 3.5 to 7.5%, and even more preferably 4.0 to 7.0%. If the oxygen concentration is less than 2.5% or exceeds 8.5%, the adhesion is low and therefore undesirable.

[0042] In addition, when analyzing the Depth XPS (X-ray Photoelectron Spectroscopy) above, the surface carbon concentration may be 87.5 to 93.0%, preferably 87.8 to 92%, more preferably 87.9 to 91.95%, and even more preferably 87.9 to 91%.

[0043] The above-mentioned Depth XPS (X-Ray Photoelectron Spectroscopy) is an instrument that enables the determination of the composition and chemical bonding state of a sample surface by irradiating the surface with X-rays and measuring the energy of the emitted photoelectrons.

[0044] The above surface oxygen concentration and the above surface carbon concentration may be measured by irradiating the surface of the thermoplastic polyimide film with X-rays for 20 to 30 seconds using Depth XPS.

[0045] The above composite film may further include a metal layer on one or both sides of the thermoplastic polyimide layer, and the metal layer may include one or more selected from the group consisting of Ni, Cr, and Cu.

[0046] In addition, when a metal layer is formed on one or both sides of the thermoplastic polyimide layer, the adhesive strength to the metal layer may be 0.8 kgf / cm or more. For example, the lower limit of the adhesive strength may be 0.9 kgf / cm or more, 1.0 kgf / cm or more, 1.05 kgf / cm or more, 1.08 kgf / cm or more, or 1.1 kgf / cm or more, and the upper limit is not particularly limited but may be 2.0 kgf / cm or less.

[0047] More specifically, the surface oxygen concentration and the surface carbon concentration may be formed by hydroxyl groups (-OH) and carboxyl groups (-COOH), which are functional groups on the surface of the thermoplastic polyimide film, and these functional groups may be formed depending on the amount of heat required to manufacture the thermoplastic polyimide film.

[0048] Specifically, when manufacturing the thermoplastic polyimide film, the manufacturing process is performed under an oxygen atmosphere, and depending on the amount of heat required, the imide ring within the thermoplastic polyimide molecule is rearranged to form a functional group including a hydroxyl group (-OH) and a carboxyl group (-COOH), and the imide ring can be rearranged into an amide group.

[0049] In addition, the hydroxyl group (-OH) and carboxyl group (-COOH), which are functional groups on the surface of the thermoplastic polyimide layer, and the metal ions of the metal layer are coordinately bonded, thereby strengthening the interaction between the thermoplastic polyimide film and the metal layer and improving adhesion.

[0050] The above caloric value is 70 to 180 kcal / m² 2 It may be, for example, the lower limit of the above calorific value is 75 Kcal / m² 2 Above, 80 kcal / m² 2 Above, 85 Kcal / m² 2 Above, 90 Kcal / m² 2 Above, 95 Kcal / m² 2 Above, 100 Kcal / m² 2 Above, 105 Kcal / m² 2 Above, 110 Kcal / m² 2 Above, 115 Kcal / m² 2 120 Kcal / m² or more 2 It may be higher, and the upper limit is 175 Kcal / m² 2 Below, 173 Kcal / m² 2 Below, 170 Kcal / m² 2 Below, 168 Kcal / m² 2 Below, 165 Kcal / m²2 Below, 163 Kcal / m² 2 Below, 160 Kcal / m² 2 Below, 158 Kcal / m² 2 Below, 155 Kcal / m² 2 Below, 153 Kcal / m² 2 Below, 150 Kcal / m² 2 Below, 148 Kcal / m² 2 Below, 145 Kcal / m² 2 Below, 140 Kcal / m² 2 Below, 138 Kcal / m² 2 135 Kcal / m² or less 2 It may be less than.

[0051] The above caloric value is 70 Kcal / m² 2 Less than or 180 Kcal / m² 2 If it exceeds a certain amount, the adhesive strength is low, which is undesirable.

[0052] Here, the above heat quantity can be calculated by the following Equations 1 and 2. Specifically, the output value can be obtained using Equation 1 below, and the heat quantity consumed during film manufacturing can be calculated by substituting the output value into Equation 2 below.

[0053] [Equation 1]

[0054]

[0055] [Equation 2]

[0056]

[0057] The thermal expansion coefficient in the width direction (TD) of the composite film measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min may be -12 to 12 ppm / °C, and preferably -10 to 10.0 ppm / °C.

[0058] The mechanical transport direction (MD) thermal expansion coefficient of the composite film measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min may be -12 to 12 ppm / °C, and preferably -10 to 10.0 ppm / °C.

[0059] The thermal expansion coefficient in the width direction (TD) of the non-thermoplastic polyimide layer measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min may be -7 to 7 ppm / °C, and preferably -5 to 5 ppm / °C.

[0060] The mechanical transport direction (MD) thermal expansion coefficient of the non-thermoplastic polyimide layer measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min may be -7 to 7 ppm / °C, and preferably -5 to 5 ppm / °C.

[0061] The thermal expansion coefficients in the width direction (TD) and the thermal expansion coefficients in the machine conveying direction (MD) were each measured using a TA company TMA device (Q400) at 50 mN per 10 ℃ / min in the 50 to 200 ℃ range.

[0062] The above non-thermoplastic polyimide layer comprises a non-thermoplastic polyimide, and the non-thermoplastic polyimide may be a block copolymer having two or more blocks. The block copolymer may be composed of a first block in which a dianhydride monomer composed of pyromellitic dianhydride (PMDA) and a diamine monomer composed of m-tolydine (m-TD) are copolymerized; and a second block in which a dianhydride monomer composed of pyromellitic dianhydride (PMDA) and a diamine monomer composed of 4,4'-diaminodiphenyl ether (ODA) are copolymerized.

[0063] Specifically, the content of m-tolydine (m-TD) among the total diamine monomers of the block copolymer may be 40 to 80 mol%, and the content of 4,4'-diaminodiphenyl ether (ODA) among the total diamine monomers of the block copolymer may be 20 to 60 mol%.

[0064] In one embodiment, the non-thermoplastic polyimide layer may include pyromellitic dianhydride (PMDA), 2,2'-dimethyl-4,4'-diaminobiphenyl (m-tolidine), and 4,4'-diaminodiphenyl ether (ODA) as polymerization units.

[0065] Specifically, the thickness of the non-thermoplastic polyimide layer may be 1 to 100 μm, and the thickness of the thermoplastic polyimide layer may be 0.5 to 50 μm.

[0066] A thermoplastic polyimide layer may be additionally included on the other side of the non-thermoplastic polyimide layer of the above composite film.

[0067] Specifically, the thickness of the composite film can be appropriately selected considering the application, usage environment, physical properties, etc. of the composite film. For example, the thickness of the composite film may be 1 to 150 μm, 15 to 100 μm, 25 to 70 μm, or 30 to 60 μm, but is not limited thereto.

[0068] Specifically, the non-thermoplastic polyimide layer may have a modulus of 6 GPa or more. For example, the lower limit of the modulus may be 9 GPa or more, 9.5 GPa or more, or 10 GPa or more. In addition, the upper limit of the modulus is not specifically limited but may be 18 GPa or less, 17 GPa or less, 16 GPa or less, or 15 GPa or less. The modulus was measured using an INSTRON Instron 5564 UTM instrument at a speed of 20 mm / min on samples with a length of 80 mm and a width of 15 mm, and the average of 10 samples was calculated.

[0069] Another embodiment of the present invention provides a multilayer film comprising a thermoplastic polyimide layer on the other side of the non-thermoplastic polyimide layer of the composite film.

[0070] Another embodiment of the present invention provides a flexible metal foil laminate comprising the composite film and an electrically conductive metal foil.

[0071] Another embodiment of the present invention provides an electronic component comprising the flexible metal foil laminate.

[0072] Another embodiment of the present invention provides a display element comprising the composite film.

[0073] Method for manufacturing a thermoplastic polyimide film

[0074] The present invention provides a method for manufacturing a thermoplastic polyimide film comprising: (a) a step of preparing a solution containing a thermoplastic polyimide precursor by mixing a dianhydride monomer and a diamine monomer in a solvent; and (b) a step of preparing a thermoplastic polyimide film containing the thermoplastic polyimide by applying the solution containing the thermoplastic polyimide precursor, drying, and curing, wherein the surface oxygen concentration of the thermoplastic polyimide film is 2.5 to 8.5% when analyzed by Depth XPS.

[0075] Preferably, the surface oxygen concentration may be 3.0 to 8.0%, more preferably 3.5 to 7.5%, and even more preferably 4.0 to 7.0%. If the oxygen concentration is less than 2.5% or exceeds 8.5%, the adhesion is low and therefore undesirable.

[0076] In addition, the surface carbon concentration during the above Depth XPS (X-ray Photoelectron Spectrocopy) analysis may be 87.5 to 93.0%, preferably 87.8 to 92%, more preferably 87.9 to 91.95%, and even more preferably 87.9 to 91%.

[0077] The above-mentioned Depth XPS (X-Ray Photoelectron Spectroscopy) is an instrument that enables the determination of the composition and chemical bonding state of a sample surface by irradiating the surface with X-rays and measuring the energy of the emitted photoelectrons.

[0078] The above surface oxygen concentration and the above surface carbon concentration may be measured by irradiating the surface of the thermoplastic polyimide film with X-rays for 20 to 30 seconds using Depth XPS.

[0079] The thermoplastic polyimide film may further include a metal layer on one or both sides, and the metal layer may include one or more selected from the group consisting of Ni, Cr, and Cu.

[0080] In addition, the thermoplastic polyimide film may have an adhesion strength of 0.8 kgf / cm or more to the metal layer. For example, the lower limit of the adhesion strength may be 0.9 kgf / cm or more, 1.0 kgf / cm or more, 1.05 kgf / cm or more, 1.08 kgf / cm or more, or 1.1 kgf / cm or more, and the upper limit is not particularly limited but may be 2.0 kgf / cm or less.

[0081] More specifically, drying and curing of step (b) may be performed, and an optimal oxygen concentration and an optimal carbon concentration may be formed on the surface of the thermoplastic polyimide layer by the amount of heat applied, and the adhesive force may be formed by the surface oxygen concentration.

[0082] Here, the drying and curing conditions include speed, temperature gradient, time, etc., and preferably, the optimal oxygen concentration may be formed by the drying and curing speed / temperature conditions, more preferably by the drying and curing temperature conditions.

[0083] Specifically, the drying can be performed at a temperature of 50 to 200°C at a speed of 5 to 10 mpm, and the curing can be performed at a temperature of 250 to 350°C at a speed of 5 to 10 mpm.

[0084] Preferably, the curing can be performed at 260 to 340°C, and more preferably at 270 to 330°C.

[0085] By performing the above curing at a temperature of 250 to 350°C, preferably 260 to 340°C, and more preferably 270 to 330°C, a thermoplastic polyimide film having a desired surface oxygen concentration during Depth XPS analysis can be produced.

[0086] More specifically, the surface oxygen concentration and the surface carbon concentration may be formed by hydroxyl groups (-OH) and carboxyl groups (-COOH), which are functional groups on the surface of the thermoplastic polyimide film, and these functional groups may be formed depending on the amount of heat required to manufacture the thermoplastic polyimide film.

[0087] Specifically, when manufacturing the thermoplastic polyimide film, the manufacturing process is performed under an oxygen atmosphere, and depending on the amount of heat required, the imide ring within the thermoplastic polyimide molecule is rearranged to form a functional group including a hydroxyl group (-OH) and a carboxyl group (-COOH), and the imide ring can be rearranged into an amide group.

[0088] In addition, the hydroxyl group (-OH) and carboxyl group (-COOH), which are functional groups on the surface of the thermoplastic polyimide film, and the metal ions of the metal layer are coordinately bonded, thereby strengthening the interaction between the thermoplastic polyimide film and the metal layer and improving adhesion.

[0089] The above caloric value is 70 to 180 kcal / m² 2 It may be, for example, the lower limit of the above calorific value is 75 Kcal / m² 2Above, 80 kcal / m² 2 Above, 85 Kcal / m² 2 Above, 90 Kcal / m² 2 Above, 95 Kcal / m² 2 Above, 100 Kcal / m² 2 Above, 105 Kcal / m² 2 Above, 110 Kcal / m² 2 Above, 115 Kcal / m² 2 120 Kcal / m² or more 2 It may be higher, and the upper limit is 175 Kcal / m² 2 Below, 173 Kcal / m² 2 Below, 170 Kcal / m² 2 Below, 168 Kcal / m² 2 Below, 165 Kcal / m² 2 Below, 163 Kcal / m² 2 Below, 160 Kcal / m² 2 Below, 158 Kcal / m² 2 Below, 155 Kcal / m² 2 Below, 153 Kcal / m² 2 Below, 150 Kcal / m² 2 Below, 148 Kcal / m² 2 Below, 145 Kcal / m² 2 Below, 140 Kcal / m² 2 Below, 138 Kcal / m² 2 135 Kcal / m² or less 2 It may be less than.

[0090] The above caloric value is 70 Kcal / m² 2 Less than or 180 Kcal / m² 2 If it exceeds a certain amount, the adhesive strength is low, which is undesirable.

[0091] Here, the above heat quantity can be calculated by the following Equations 1 and 2. Specifically, the output value can be obtained using Equation 1 below, and the heat quantity consumed during film manufacturing can be calculated by substituting the output value into Equation 2 below.

[0092] [Equation 1]

[0093]

[0094] [Equation 2]

[0095]

[0096] Specifically, the dianhydride monomer of step (a) may comprise one or more compounds selected from the group consisting of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3',4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA), and 4,4'-oxydiphthalic anhydride (ODPA), and preferably comprises one or more compounds selected from the group consisting of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA). It could be.

[0097] Specifically, the diamine monomer of step (a) may comprise one or more compounds selected from the group consisting of 4,4'-oxydianiline, 3,4'-oxydianiline, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)benzidine (TFMB), p-phenylenediamine (PPD), and m-phenylenediamine (MPD), and preferably may comprise one or more compounds selected from the group consisting of 4,4'-oxydianiline, 1,3-bis(4-aminophenoxy)benzene, and 1,4-bis(4-aminophenoxy)benzene.

[0098] In step (a), the solution may include one or more selected from the group consisting of a dehydrating agent, an imidizing agent, and a sublimable inorganic filler.

[0099] Specifically, the dehydrating agent may include one or more selected from the group consisting of aliphatic acid anhydrides (acetic anhydride, propionic anhydride, lactic anhydride, etc.), aromatic acid anhydrides, N,N'-dialkylcarbodiimide, halogenated lower aliphatic halides, halogenated lower fatty acid anhydrides, arylphosphonic acid dihalides, and thionyl halides, and preferably may include one or more selected from the group consisting of aliphatic acid anhydrides, more preferably acetic anhydride, propionic anhydride, and lactic anhydride.

[0100] The above imidizing agent may include one or more selected from the group consisting of heterocyclic tertiary amines (β-picoline, quinoline, isoquinoline, pyridine, etc.), aliphatic tertiary amines, and aromatic tertiary amines, and preferably may include one or more selected from the group consisting of heterocyclic tertiary amines, more preferably β-picoline, quinoline, isoquinoline, and pyridine.

[0101] The above sublimable inorganic filler may include one or more selected from the group consisting of silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, dicalcium phosphate, calcium carbonate, barium sulfate, and mica.

[0102] Method for manufacturing a composite film

[0103] The present invention provides a method for manufacturing a composite film comprising: (1) a step of manufacturing a non-thermoplastic polyimide layer by applying a solution containing a non-thermoplastic polyimide precursor, drying, and curing; and (2) a step of manufacturing a composite layer in which a thermoplastic polyimide layer is formed on one side of the non-thermoplastic polyimide layer by applying a solution containing a thermoplastic polyimide precursor, drying, and curing; wherein the thermoplastic polyimide layer has a surface oxygen concentration of 2.5 to 8.5% when analyzed by Depth XPS (X-ray Photoelectron Spectrocopy).

[0104] Preferably, the surface oxygen concentration may be 3.0 to 8.0%, more preferably 3.5 to 7.5%, and even more preferably 4.0 to 7.0%. If the oxygen concentration is less than 2.5% or exceeds 8.5%, the adhesion is low and therefore undesirable.

[0105] In addition, when analyzing the Depth XPS (X-ray Photoelectron Spectroscopy) above, the surface carbon concentration may be 87.5 to 93.0%, preferably 87.8 to 92%, more preferably 87.9 to 91.95%, and even more preferably 87.9 to 91%.

[0106] The above-mentioned Depth XPS (X-Ray Photoelectron Spectroscopy) is an instrument that enables the determination of the composition and chemical bonding state of a sample surface by irradiating the surface with X-rays and measuring the energy of the emitted photoelectrons.

[0107] The above surface oxygen concentration and the above surface carbon concentration may be measured by irradiating the surface of the thermoplastic polyimide film with X-rays for 20 to 30 seconds using Depth XPS.

[0108] The above composite film may further include a metal layer on one or both sides of the thermoplastic polyimide layer, and the metal layer may include one or more selected from the group consisting of Ni, Cr, and Cu.

[0109] In addition, when a metal layer is formed on one or both sides of the thermoplastic polyimide layer, the adhesive strength to the metal layer may be 0.8 kgf / cm or more. For example, the lower limit of the adhesive strength may be 0.9 kgf / cm or more, 1.0 kgf / cm or more, 1.05 kgf / cm or more, 1.08 kgf / cm or more, or 1.1 kgf / cm or more, and the upper limit is not particularly limited but may be 2.0 kgf / cm or less.

[0110] Specifically, the surface oxygen concentration may be formed by the amount of heat applied during drying and curing performed after applying a thermoplastic polyimide precursor to one or both sides of a non-thermoplastic polyimide layer when manufacturing the composite film, and the adhesion strength may be improved by the surface oxygen concentration.

[0111] Here, the drying and curing conditions include speed, temperature gradient, time, etc., and preferably, an optimal oxygen concentration may be formed according to the drying and curing speed / temperature conditions, more preferably the drying and curing temperature conditions.

[0112] Specifically, the drying can be performed at a temperature of 50 to 200°C at a speed of 5 to 10 mpm, and the curing can be performed at a temperature of 250 to 350°C at a speed of 5 to 10 mpm.

[0113] Preferably, the curing can be performed at 260 to 340°C, and more preferably at 270 to 330°C. By performing the curing at a temperature of 250 to 350°C, preferably 260 to 340°C, and more preferably 270 to 330°C, a thermoplastic polyimide layer having a desired surface oxygen concentration for Depth XPS analysis can be formed on one or both sides of a non-thermoplastic polyimide layer.

[0114] More specifically, the surface oxygen concentration and the surface carbon concentration may be formed by hydroxyl groups (-OH) and carboxyl groups (-COOH), which are functional groups on the surface of the composite film, and these functional groups may be formed depending on the amount of heat required when manufacturing the composite film.

[0115] Specifically, when manufacturing the composite film, the manufacturing process is performed under an oxygen atmosphere, and depending on the amount of heat required, the imide ring within the thermoplastic polyimide molecule is rearranged to form a functional group including a hydroxyl group (-OH) and a carboxyl group (-COOH), and the imide ring can be rearranged into an amide group.

[0116] In addition, the hydroxyl group (-OH) and carboxyl group (-COOH), which are functional groups on the surface of the thermoplastic polyimide layer, and the metal ions of the metal layer are coordinately bonded, thereby strengthening the interaction between the thermoplastic polyimide film and the metal layer and improving adhesion.

[0117] The above caloric value is 70 to 180 kcal / m² 2 It may be, for example, the lower limit of the above calorific value is 75 Kcal / m² 2 Above, 80 kcal / m² 2 Above, 85 Kcal / m² 2 Above, 90 Kcal / m² 2 Above, 95 Kcal / m² 2 Above, 100 Kcal / m² 2 Above, 105 Kcal / m² 2 Above, 110 Kcal / m² 2 Above, 115 Kcal / m² 2 120 Kcal / m² or more 2 It may be higher, and the upper limit is 175 Kcal / m² 2 Below, 173 Kcal / m² 2 Below, 170 Kcal / m² 2 Below, 168 Kcal / m² 2 Below, 165 Kcal / m² 2 Below, 163 Kcal / m² 2Below, 160 Kcal / m² 2 Below, 158 Kcal / m² 2 Below, 155 Kcal / m² 2 Below, 153 Kcal / m² 2 Below, 150 Kcal / m² 2 Below, 148 Kcal / m² 2 Below, 145 Kcal / m² 2 Below, 140 Kcal / m² 2 Below, 138 Kcal / m² 2 135 Kcal / m² or less 2 It may be less than.

[0118] The above caloric value is 70 Kcal / m² 2 Less than or 180 Kcal / m² 2 If it exceeds a certain amount, the adhesive strength is low, which is undesirable.

[0119] Here, the above heat quantity can be calculated by the following Equations 1 and 2. Specifically, the output value can be obtained using Equation 1 below, and the heat quantity consumed during film manufacturing can be calculated by substituting the output value into Equation 2 below.

[0120] [Equation 1]

[0121]

[0122] [Equation 2]

[0123]

[0124] Specifically, a solution containing the thermoplastic polyimide precursor can be prepared by mixing a dianhydride monomer and a diamine monomer in a solvent to prepare a polyamic acid solution, and then mixing a dehydrating agent, an imidizing agent, a sublimable inorganic filler, and a solvent into the polyamic acid solution.

[0125] Specifically, the dianhydride monomer may comprise one or more compounds including 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3',4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA), and 4,4'-oxydiphthalic anhydride (ODPA), and preferably, may comprise one or more compounds selected from the group consisting of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA).

[0126] Specifically, the diamine monomer may comprise one or more compounds including 4,4'-oxydianiline, 3,4'-oxydianiline, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)benzidine (TFMB), p-phenylenediamine (PPD), and m-phenylenediamine (MPD), and preferably, may comprise one or more compounds selected from the group consisting of 4,4'-oxydianiline, 1,3-bis(4-aminophenoxy)benzene, and 1,4-bis(4-aminophenoxy)benzene.

[0127] Specifically, the dehydrating agent may include one or more selected from the group consisting of aliphatic acid anhydrides (acetic anhydride, propionic anhydride, lactic anhydride, etc.), aromatic acid anhydrides, N,N'-dialkylcarbodiimide, halogenated lower aliphatic halides, halogenated lower fatty acid anhydrides, arylphosphonic acid dihalides, and thionyl halides, and preferably may include one or more selected from the group consisting of aliphatic acid anhydrides, more preferably acetic anhydride, propionic anhydride, and lactic anhydride.

[0128] The above imidizing agent may include one or more selected from the group consisting of heterocyclic tertiary amines (β-picoline, quinoline, isoquinoline, pyridine, etc.), aliphatic tertiary amines, and aromatic tertiary amines, and preferably may include one or more selected from the group consisting of heterocyclic tertiary amines, more preferably β-picoline, quinoline, isoquinoline, and pyridine.

[0129] The above sublimable inorganic filler may include one or more selected from the group consisting of silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, dicalcium phosphate, calcium carbonate, barium sulfate, and mica.

[0130] The above step (a) may comprise: (a-1) a step of polymerizing a dianhydride monomer comprising pyromellitic dianhydride (PMDA) and a diamine monomer comprising m-tolydine (m-TD) to produce a first block; and (a-2) a step of polymerizing a dianhydride monomer comprising pyromellitic dianhydride (PMDA) and a diamine monomer comprising 4,4'-diaminodiphenyl ether (ODA) to produce a second block.

[0131] The thermal expansion coefficient in the width direction (TD) of the composite film measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min may be -12 to 12 ppm / °C, and preferably -10 to 10.0 ppm / °C.

[0132] The mechanical transport direction (MD) thermal expansion coefficient of the composite film measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min may be -12 to 12 ppm / °C, and preferably -10 to 10.0 ppm / °C.

[0133] The thermal expansion coefficient in the width direction (TD) of the non-thermoplastic polyimide layer measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min may be -7 to 7 ppm / °C, and preferably -5 to 5 ppm / °C.

[0134] The mechanical transport direction (MD) thermal expansion coefficient of the non-thermoplastic polyimide layer measured under conditions of a measurement temperature range of 50 to 200°C and a heating rate of 10°C / min may be -7 to 7 ppm / °C, and preferably -5 to 5 ppm / °C.

[0135] The thermal expansion coefficients in the width direction (TD) and the thermal expansion coefficients in the machine conveying direction (MD) were each measured using a TA company TMA device (Q400) at 50 mN per 10 ℃ / min in the 50 to 200 ℃ range.

[0136] Specifically, the modulus of the non-thermoplastic polyimide layer may be 6 GPa or higher. For example, the lower limit of the modulus may be 9 GPa or higher, 9.5 GPa or higher, or 10 GPa or higher. In addition, the upper limit of the modulus is not specifically limited but may be 18 GPa or lower, 17 GPa or lower, 16 GPa or lower, or 15 GPa or lower. The modulus was measured using an INSTRON Instron 5564 UTM instrument at a speed of 20 mm / min on samples with a length of 80 mm and a width of 15 mm, and the average of 10 samples was calculated.

[0137] In the step of generating the first block, the content of the diamine monomer containing m-tolydine (m-TD) may be greater than the content of the dianhydride monomer containing pyromellitic dianhydride (PMDA).

[0138] More specifically, in the step of generating the first block, the content of the diamine monomer containing m-tolydine (m-TD) is 40 to 80 mol%, the content of the dianhydride monomer containing pyromellitic dianhydride (PMDA) is 20 to 70 mol%, and the content of the dianhydride monomer containing pyromellitic dianhydride (PMDA) (M 1st PMDA The content of the diamine monomer containing the above m-toluidine (m-TD) relative to ) (M m-TD ) ratio(M m-TD / M 1st PMDA ) may be greater than 1 and less than 2.

[0139] The above ratio (M m-TD / M 1st PMDA If ) is 1 or less, or 2 or more, it is difficult to form a block copolymer of the desired shape, which is undesirable.

[0140] In the step of producing the second block, the content of the diamine monomer containing the 4,4'-diaminodiphenyl ether (ODA) may be less than the content of the dianhydride monomer containing the pyromellitic dianhydride (PMDA).

[0141] More specifically, in the step of generating the second block, the content of the diamine monomer containing the 4,4'-diaminodiphenyl ether (ODA) is 20 to 60 mol%, the content of the dianhydride monomer containing the pyromellitic dianhydride (PMDA) is 30 to 80 mol%, and the content of the dianhydride monomer containing the pyromellitic dianhydride (PMDA) (M 2nd PMDA The content of the diamine monomer containing the 4,4'-diaminodiphenyl ether (ODA) relative to ) (M ODA ) ratio(M ODA / M 2nd PMDA ) may be greater than 0 and less than 1.

[0142] The above ratio (M ODA / M 2nd PMDAIf ) is 0 or 1 or more, it is difficult to form a block copolymer of the desired shape, which is undesirable.

[0143] Each of the above first block and second block can be produced in the presence of a solvent.

[0144] The above solvent may include one or more selected from the group consisting of N,N'-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), N,N'-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), diethylacetamide (DEAc), N-ethyl-2-pyrrolidone (NEP), N,N'-diethylformamide (DEF), dimethylpropanamide (DMPA), and gamma-butyrolactone (GBL), and preferably N,N'-dimethylformamide (DMF) may be used.

[0145] Another embodiment of the present invention provides a multilayer film comprising a thermoplastic polyimide layer on the other side of a non-thermoplastic polyimide layer of a composite film manufactured by the method for manufacturing the composite film above.

[0146] Another embodiment of the present invention provides a flexible metal foil laminate comprising a composite film manufactured by the method for manufacturing the composite film and an electrically conductive metal foil.

[0147] Another embodiment of the present invention provides an electronic component comprising the flexible metal foil laminate.

[0148] Another embodiment of the present invention provides a display element comprising a composite film manufactured by the method for manufacturing the composite film.

[0149] The composite film comprising a thermoplastic polyimide layer and a non-thermoplastic polyimide layer according to the present invention and the method for manufacturing the same have the effect of improving adhesion by forming oxygen at an optimal concentration on the surface of the thermoplastic polyimide, and have relatively higher price competitiveness and excellent productivity and process efficiency by not using paraphenylenediamine (p-phenylenediamine, PPD).

[0150] In addition, the composite film according to the present invention includes Ultra Low CTE PI (GW Type), a non-thermoplastic polyimide having isotropic thermal and mechanical properties, and has a low coefficient of thermal expansion, which has the effect of excellent heat resistance and mechanical properties.

[0151] Examples are provided to aid in understanding the present invention. The following examples are provided merely to facilitate a better understanding of the invention, and the scope of the invention is not limited by these examples.

[0152] <Preparation Example>

[0153] Preparation Example 1. Preparation of a non-thermoplastic polyimide film

[0154] A solution containing a first block (m-TD / PMDA block) was prepared by mixing 80 mol% of the diamine monomer m-tolydine (m-TD) and 60 mol% of the dianhydride monomer pyromellitic dianhydride (PMDA) with 100 mol% of dimethylformamide (DMF) and polymerizing them.

[0155] 20 mol% of the diamine monomer 4,4'-diaminodiphenyl ether (ODA) and 37 mol% of the dianhydride monomer pyromellitic dianhydride (PMDA) were mixed in the above solution and polymerized to form a second block (ODA / PMDA block).

[0156] Finally, 3 mol% of PMDA was added to produce a polyamic acid containing a first block (m-TD / PMDA block) and a second block (ODA / PMDA block).

[0157] The above polyamic acid was mixed with a catalyst and the degassed polyamic acid was coated onto a glass plate. Subsequently, the solvent-to-solid ratio was calculated using an applicator and the mixture was pushed to uniformly distribute the surface. Afterward, the polyimide film was obtained by curing under a nitrogen atmosphere at 130°C (4 min) → 280°C (4 min) → 420°C (4 min). At this time, the film thickness was prepared to be 33.5 μm.

[0158] For the non-thermoplastic polyimide film of Preparation Example 1, the slope in the range of 50 to 200 ℃ was measured in the mechanical transport direction (MD) and width direction (TD) using a TA TMA equipment (Q400) under conditions of 10 ℃ / min 50 mN. It was confirmed that the thermal expansion coefficient of the non-thermoplastic polyimide layer in the mechanical transport direction (MD) was -5 to 5 ppm / ℃ and the thermal expansion coefficient in the width direction (TD) was -5 to 5 ppm / ℃.

[0159] For the non-thermoplastic polyimide film of Preparation Example 1, samples with a length of 80 mm and a width of 15 mm were prepared and measured at a speed of 20 mm / min using an INSTRON Instron 5564 UTM instrument, and the average of 10 samples was calculated. The non-thermoplastic polyimide film was confirmed to have a modulus of 6 GPa or higher.

[0160] According to the results of the coefficient of thermal expansion (CTE) and modulus of the above non-thermoplastic polyimide film, since it possesses isotropic mechanical and thermal properties, there is minimal dimensional change due to the mounting process temperature, and pattern design is facilitated regardless of the circuit orientation and film surface.

[0161] Preparation Example 2. Preparation of a solution containing a thermoplastic polyimide precursor

[0162] Preparation Example 2-1

[0163] 217.5 g of dimethylformamide was added to a reactor as a solvent, and the temperature was set to 20°C. 13.2 g of 4,4'-oxydianiline (ODA) was added as a diamine monomer, followed by the addition of 19.3 g of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA) as a dianhydride monomer to prepare a polyamic acid solution with a viscosity of 10,000 cP. Subsequently, 23.2 g of acetic anhydride as a dehydrating agent, 3.0 g of β-picoline as an imidizing agent, 0.09 g of calcium phosphate (average particle size (D50): 1.5 μm) as a sublimable inorganic filler, and 18.6 g of dimethylformamide as a solvent were mixed with the prepared polyamic acid solution to prepare a solution containing a thermoplastic polyimide precursor.

[0164] Preparation Examples 2-2 to 2-9

[0165] Solutions containing thermoplastic polyimide precursors according to Preparation Examples 2-2 to 2-9 were prepared in the same manner as Preparation Example 2-1, except that the type and content of the dianhydride monomer and the type and content of the diamine monomer were controlled as shown in Table 1 below.

[0166] Table 1 below describes the type and content of the dianhydride monomer and the type and content of the diamine monomer when preparing a solution containing a thermoplastic polyimide precursor according to Preparation Examples 2-1 to 2-9.

[0167] Classification Anhydrous Monomer Diamine Monomer Type Content (g) Type Content (g) Preparation Example 2-1 BPDA 19.3 ODA 13.2 Preparation Example 2-2 BPDA 16.3 TPE-R 16.2 Preparation Example 2-3 BPDA 16.3 TPE-Q 16.2 Preparation Example 2-4 BTDA 20.0 ODA 12.5 Preparation Example 2-5 BTDA 17.0 TPE-R 15.5 Preparation Example 2-6 BTDA 17.0 TPE-Q 15.5 Preparation Example 2-7 BPADA 23.5 ODA 9.0 Preparation Example 2-8 BPADA 20.8 TPE-R 11.7 Preparation Example 2-9 BPADA 20.8 TPE-Q 11.7

[0168] The abbreviations listed in Table 1 above are as follows.

[0169] BPDA: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride

[0170] BTDA: 3,3',4,4'-Benzophenonetetracarboxylic acid dianhydride

[0171] BPADA: 4,4'-(4,4'-isopropylidene diphenoxy)diphthalic anhydride

[0172] ODA: 4,4'-Oxidianiline

[0173] TPE-R: 1,3-Bis(4-aminophenoxy)benzene

[0174] TPE-Q: 1,4-Bis(4-aminophenoxy)benzene

[0175] <Example>

[0176] Example: Preparation of a composite film according to the amount of heat required during the formation of a thermoplastic polyimide film

[0177] Example 1

[0178] A solution containing a thermoplastic polyimide precursor according to Preparation Example 2-1 was applied to one surface of a non-thermoplastic polyimide film according to Preparation Example 1, and dried at 50 to 200°C for 3 to 5 minutes.

[0179] After drying, cure at a temperature of 273°C for 3 to 5 minutes under an oxygen atmosphere to 84 Kcal / m² 2 A composite film treated with the heat of was manufactured.

[0180] Examples 2 to 7, Comparative Examples 1 to 4

[0181] Composite films according to Examples 2 to 7 and Comparative Examples 1 to 4 were prepared in the same manner as Example 1, except that the amount of heat was controlled as shown in Table 2 below.

[0182] Table 2 below lists the amount of heat required during the step of forming a thermoplastic polyimide film when manufacturing composite films according to Examples 1 to 7 and Comparative Examples 1 to 4. The amount of heat was calculated using Equation 1 and Equation 2 below. Specifically, an output value was obtained using Equation 1 below, and the amount of heat was calculated by substituting the output value into Equation 2 below. In this case, 1 kW is 860 kcal / h.

[0183] [Equation 1]

[0184]

[0185] [Equation 2]

[0186]

[0187] Classification Caloric Value (Kcal / m²) 2 Example 184 Example 2117 Example 3147 Example 4172 Example 5128 Example 6134 Example 7155 Comparative Example 139 Comparative Example 247 Comparative Example 349 Comparative Example 4188

[0188] <Experimental Example>

[0189] Experimental Example 1. Evaluation of adhesion strength according to film surface oxygen concentration

[0190] The adhesion results according to the surface carbon and oxygen concentrations of the composite films of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 3 below.

[0191] At this time, the adhesion strength was measured by forming a metal layer on the film through a sputter process and then measuring the adhesion strength of the film to the metal layer. Specifically, a polyimide film was sputtered / electroplated, then etched and developed to produce a sample with a width of 2 mm and a length of 100 mm, and the adhesion strength was measured by peeling one side at a 90° angle at a speed of 25 mm / min using an Instron UTM machine.

[0192] Classification Caloric Value (Kcal / m²) 2)Depth XPSSputter Adhesion Strength (kgf / cm) Carbon (%) Oxygen (%) Example 18 49 2.57 3.17 1.08 Example 2 11 79 1.92 4.49 1.17 Example 3 14 79 0.815 1.15 Example 4 17 29 0.745 64 1.12 Example 5 12 89 0.116 76 1.25 Example 6 13 48 7.927 28 1.23 Example 7 15 58 8.317 79 1.17 Comparative Example 13 99 5.40 0.66 0.51 Comparative Example 2 4 79 4.79 1.53 0.54 Comparative Example 3 4 99 3.80 2.08 0.62 Comparative Example 418887.309.210.71

[0193] According to Table 3 above, 84 to 172 Kcal / m² 2 Examples 1 to 7, prepared according to the calorific value, were found to have excellent adhesive strength of 1.08 kgf / cm or higher by satisfying a surface oxygen concentration of 2.5 to 8.5%. Among them, Example 5 (surface oxygen concentration 6.76%) showed the best adhesive strength at 1.25 kgf / cm, followed by Example 6 (surface oxygen concentration 7.28%) at 1.23 kgf / cm. On the other hand, Comparative Examples 1 to 4, which had a surface oxygen concentration of less than 2.5% or more than 8.5%, were found to have low adhesive strength of 0.71 kgf / cm or lower.

[0194] From these results, it was found that adhesion is improved by having a surface oxygen concentration within a specific range.

[0195] Specifically, it can be seen that the thermoplastic polyimide is manufactured under an oxygen atmosphere, and depending on the amount of heat required, the imide rings within the thermoplastic polyimide molecule are rearranged, forming functional groups including hydroxyl groups (-OH) and carboxyl groups (-COOH) on the surface of the thermoplastic polyimide layer, and the imide rings are rearranged into amide groups, and the metal ions (Ni, Cr, Cu) of the metal layer are coordinately bonded with the formed functional groups, namely hydroxyl groups (-OH) and carboxyl groups (-COOH), thereby strengthening the interaction between the thermoplastic polyimide layer and the metal layer and improving adhesion.

[0196] Experimental Example 2. Coefficient of Thermal Expansion (CTE) of Composite Film

[0197] For each of the composite films of Examples 1 to 7 above, the slope in the range of 50 to 200 ℃ was measured in the machine transport direction (MD) and width direction (TD) using a TA TMA equipment (Q400) under conditions of 10 ℃ / min 50 mN.

[0198] The composite films according to Examples 1 to 7 of the present invention have a coefficient of thermal expansion CTE in the machine transport direction (MD). MD and coefficient of thermal expansion in the width direction (TD) CTE TD It can be confirmed that all of them have excellent thermal properties of 10.0 ppm / ℃ or less.

[0199] The specification omits detailed descriptions of matters that can be sufficiently recognized and inferred by those skilled in the art of the present invention, and various modifications are possible within the scope of not altering the technical concept or essential configurations of the present invention, in addition to the specific examples described in this specification. Accordingly, the present invention may be implemented in a manner different from that specifically described and exemplified in this specification, and this is a matter that can be understood by those skilled in the art.

Claims

1. A thermoplastic polyimide film having a surface oxygen concentration of 2.5 to 8.5% upon depth XPS analysis.

2. In Paragraph 1, The thermoplastic polyimide film is a thermoplastic polyimide film having an adhesion strength of 0.8 kgf / cm or more to the metal layer when a metal layer is formed on one or both sides.

3. In Paragraph 1, The above thermoplastic polyimide comprises polymerization units of a dianhydride monomer and a diamine monomer, and The above dianhydride monomer comprises one or more compounds including 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3',4-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA), and 4,4'-oxydiphthalic anhydride (ODPA). A thermoplastic polyimide film wherein the diamine monomer comprises one or more compounds including 4,4'-oxydianiline, 3,4'-oxydianiline, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)benzidine (TFMB), p-phenylenediamine (PPD), and m-phenylenediamine (MPD).

4. Non-thermoplastic polyimide layer; and A thermoplastic polyimide layer located on one surface of the above-mentioned non-thermoplastic polyimide layer; comprising A composite film having a surface oxygen concentration of 2.5 to 8.5% in the thermoplastic polyimide layer upon Depth XPS analysis.

5. In Paragraph 4, The above composite film is a composite film having an adhesion strength of 0.8 kgf / cm or more to the metal layer when a metal layer is formed on one or both sides of the thermoplastic polyimide layer.

6. In Paragraph 4, The coefficient of thermal expansion (CTE) in the width direction (TD) of the above composite film measured under conditions of a measurement temperature range of 50–200℃ and a heating rate of 10℃ / min. TD The value is -12 to 12 ppm / ℃, and Coefficient of thermal expansion (CTE) of the above composite film in the machine-transport direction (MD) measured under conditions of a measurement temperature range of 50–200℃ and a heating rate of 10℃ / min MD A composite film having a temperature of -12 to 12 ppm / ℃.

7. In Paragraph 4, The above non-thermoplastic polyimide layer comprises non-thermoplastic polyimide, and A composite film in which the above-mentioned non-thermoplastic polyimide is a block copolymer having two or more blocks.

8. In Paragraph 7, The above block copolymer, A first block copolymerized with a dianhydride monomer composed of pyromellitic dianhydride (PMDA) and a diamine monomer composed of m-toluidine (m-TD); and A composite film comprising a second block copolymerized with a dianhydride monomer composed of pyromellitic dianhydride (PMDA) and a diamine monomer composed of 4,4'-diaminodiphenyl ether (ODA).

9. In Paragraph 8, The content of m-tolydine (m-TD) among the total diamine monomers of the block copolymer is 40 to 80 mol%, and A composite film having a 4,4'-diaminodiphenyl ether (ODA) content of 20 to 60 mol% among the total diamine monomers of the block copolymer.

10. In Paragraph 4, The thickness of the above non-thermoplastic polyimide layer is 1 to 100 μm, and A composite film having a thermoplastic polyimide layer with a thickness of 0.5 to 50 μm.

11. In Paragraph 4, A composite film comprising a thermoplastic polyimide layer additionally included on the other side of the non-thermoplastic polyimide layer of the above composite film.

12. (a) a step of preparing a solution containing a thermoplastic polyimide precursor by mixing a dianhydride monomer and a diamine monomer in a solvent; and (b) a step of applying a solution containing the thermoplastic polyimide precursor and drying and curing to produce a thermoplastic polyimide film containing the thermoplastic polyimide; comprising, A method for manufacturing a thermoplastic polyimide film in which the surface oxygen concentration of the thermoplastic polyimide film is 2.5 to 8.5% when analyzed by Depth XPS.

13. In Paragraph 12, A method for manufacturing a thermoplastic polyimide film, wherein drying and curing of step (b) are performed and an optimal oxygen concentration is formed on the surface of the thermoplastic polyimide layer by the amount of heat applied.

14. In Paragraph 13, The above caloric value is 70 to 180 kcal / m² 2 A method for manufacturing a thermoplastic polyimide film.

15. (1) A step of preparing a non-thermoplastic polyimide layer by applying a solution containing a non-thermoplastic polyimide precursor, drying, and curing; and (2) a step of applying a solution containing a thermoplastic polyimide precursor to one surface of the non-thermoplastic polyimide layer, drying and curing to produce a composite film having a thermoplastic polyimide layer formed on one surface of the non-thermoplastic polyimide layer; and A method for manufacturing a composite film in which the surface oxygen concentration of the thermoplastic polyimide layer is 2.5 to 8.5% when analyzed by Depth XPS.

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