KR101797721B1 - Thermoplastic polyimide resin for flexible metal laminate, flexible metal laminate, and preparation method of flexible metal laminate - Google Patents

Abstract

The present invention relates to a glass transition temperature (T 2) which contains specific repeating units at a predetermined molar ratio and has a second transition temperature (T ₂ ) at which the rate of change of the ratio of the increment of the length to the increment of the temperature at the glass transition temperature And a thermoplastic polyimide resin layer containing the thermoplastic polyimide resin, wherein the difference between the transition temperatures (Tg) is 30 占 폚 or less, and a method for producing the flexible metal laminate .

Description

TECHNICAL FIELD The present invention relates to a thermoplastic polyimide resin, a flexible metal laminate, and a method for producing the flexible metal laminate,

The present invention relates to a thermoplastic polyimide resin for flexible metal laminate, a flexible metal laminate, and a method for producing the flexible metal laminate, and more particularly, to a method for producing a flexible metal laminate, A flexible metal laminate including the thermoplastic polyimide resin for a flexible metal laminate, and a method for producing the flexible metal laminate. The thermoplastic polyimide resin for a flexible metal laminate can have a high adhesive strength to a polymer resin.

In recent years, signal transmission speed within the electronic device or signal transmission speed to the outside of the electronic device has been accelerating in accordance with the trend of miniaturization and high speed of electronic devices and the combination of various functions. Accordingly, a printed circuit board using an insulator having a dielectric constant and a dielectric loss coefficient lower than that of an existing insulator is required.

As reflected in this tendency, there is a tendency to apply LCP (Liquid Crystalline Polymer), which is an insulator less susceptible to moisture absorption, than a conventional polyimide even in a flexible printed circuit board. However, even when the LCP is applied, the degree of improvement due to application is insignificant because the dielectric constant (Dk = 2.9) of LCP is substantially not different from that of polyimide (Dk = 3.2) substantially and the heat resistance of the LCP becomes a problem in the soldering process And since the LCP has thermoplasticity, there is a problem that compatibility with the PCB manufacturing process using the conventional polyimide is inferior in the laser hole processing using the laser.

Accordingly, efforts have been made to lower the dielectric constant of polyimide used as an insulator of conventional flexible circuit boards. For example, U.S. Patent No. 4,816,516 discloses a method of molding a molded article by mixing polyimide and a fluorine-based polymer. However, the above patent does not relate to a product for an electronic device requiring a low dielectric constant but relates to a molded product, and polyimide having a large coefficient of thermal expansion and a low glass transition temperature is used. In addition, in order to be used for a printed circuit board, a polyimide resin must be processed in the form of a thin film. The US patent does not disclose a thin-film-type copper-clad laminate.

Further, U.S. Patent No. 7026032 discloses a method of lowering the dielectric constant of a product produced by dispersing a fine powder of a fluorine-based polymer in polyimide. The US patent discloses that the fluorine-based polymer fine powder is more distributed on the outer surface than the inner core of the insulator. However, since the content of the fluorinated polymer is large in the outermost layer of the insulator as described in the above-mentioned U.S. patent, moisture permeation and absorption are lowered by the fluorinated polymer on the outer surface, and the overall water absorption rate can be lowered. However, There is a problem that the copper clad laminate does not exist.

For example, the polyimide resin described in the U.S. patent may weaken the adhesive force with the coverlay or the adhesion with the prepreg, and the adhesive force with the ACF may be lowered, and the coefficient of thermal expansion (CTE) of the polyimide resin disclosed in the above- Since the fluoropolymer is present in excess on the surface of the polyimide resin, the fluoropolymer can be melted at a temperature of about 380 ° C, which is applied to the holding process during the PCB manufacturing process There is a risk that the copper foil circuit will peel off from the insulator.

On the other hand, the flexible metal laminate may further include a thermoplastic polyimide resin in addition to a polyimide resin containing a component such as fluorine. Such a thermoplastic polyimide resin is applied to a metal thin film by applying a high temperature condition of a glass transition temperature (Tg) or more and is applied as a flexible metal laminate. Accordingly, in the manufacturing process of the conventional flexible metal laminate, high temperature conditions of about 300 ° C or higher are applied. When the metal thin film and the thermoplastic polyimide resin are laminated at a temperature of about 300 ° C or so, Can not be secured.

When a high temperature of 100 캜 or more is applied to the glass transition temperature (Tg) of the thermoplastic polyimide resin, a certain degree of adhesion between the metal thin film and the thermoplastic polyimide resin can be secured. However, There has been a problem of lowering the structure and mechanical properties of the laminate itself or lowering the physical properties of polymers or fluorine-based components contained in the flexible metal laminate.

Therefore, there is a need to develop a method that can improve the adhesion between the components of the soft metal laminate while applying a lower process temperature than the previously known lamination temperature conditions.

(Prior Art Document 001) U.S. Patent No. 4,816,516 (Prior Art Document 002) United States Patent No. 7026032

The present invention is to provide a thermoplastic polyimide resin for a flexible metal laminate capable of having high adhesion to a metal or other polymer resin even at a temperature of 300 DEG C or less while having excellent mechanical properties and elasticity.

The present invention also provides a flexible metal laminate comprising the thermoplastic polyimide resin for a flexible metal laminate.

The present invention also provides a method for producing the flexible metal laminate.

In the present specification, a resin composition comprising a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2) in a molar ratio of 2:10 to 7:10 and having a ratio of the increment of the length to the increment of the temperature at or above the glass transition temperature Wherein the difference between the second transition temperature (T ₂ ) and the glass transition temperature (Tg) at which the rate of change of the glass transition temperature (Tg) is the maximum is 30 ° C or less.

[Chemical Formula 1]

In Formula 1, Y ₁ is a tetravalent aromatic organic functional group, and X ₁ is an aromatic organic functional group containing a divalent functional group represented by Formula 11 below.

(11)

(2)

In Formula 2, Y ₂ is a tetravalent aromatic organic functional group, and X ₂ is a divalent aromatic organic functional group including a divalent functional group represented by Formula 12 below.

[Chemical Formula 12]

또는

or

In the above Formulas (11) and (12), '*' means a bonding point.

Further, in the present specification, a thermoplastic polyimide resin layer containing the thermoplastic polyimide resin; A composite polyimide resin layer containing a fluorine resin and a polyimide resin; And a metal thin film.

Also, in the present specification, there is provided a method for producing a flexible metal laminate, which comprises laminating a thermoplastic polyimide resin layer containing the thermoplastic polyimide resin and a metal thin film at a temperature of 250 캜 to 300 캜.

Hereinafter, a method for producing a thermoplastic polyimide resin, a flexible metal laminate, and a flexible metal laminate for a flexible metal laminate according to a specific embodiment of the present invention will be described in detail.

According to one embodiment of the present invention, the glass transition temperature (Tg) of the glass transition temperature (Tg) and the glass transition temperature Wherein the difference between the second transition temperature (T ₂ ) and the glass transition temperature (Tg) at which the rate of change of the rate of increase of the rate of increase of the rate of increase of the rate of increase of the rate of increase of the rate of increase of the rate of increase is not more than 30 ° C.

Previously known thermoplastic polyimide resins failed to exhibit sufficient adhesion with the metal thin film near the glass transition temperature and could be firmly bonded to the metal thin film at a high temperature of about 400 ° C near the melting point (Tm).

On the contrary, the thermoplastic polyimide resin for a flexible metal laminate according to one embodiment of the present invention has a repeating unit of the formula (1) and a repeating unit of the formula (2) in a molar ratio of 2:10 to 7:10, or 2.5: 10 to 6:10 , The difference between the second transition temperature (T ₂ ) and the glass transition temperature (Tg) at which the rate of change of the ratio of the increment of the length to the increment of the temperature at the temperature above the glass transition temperature (Tg) Or 10 占 폚 or lower, or 1 占 폚 to 5 占 폚, and can have a high bonding force with the metal thin film even at a relatively low temperature, for example, 300 占 폚 or lower, or 200 占 폚 to 270 占 폚.

This is because, as the thermoplastic polyimide resin for a flexible metal laminate of this embodiment contains the repeating unit of the above formula (1) and the repeating unit of the above formula (2) in the above-mentioned specific molar ratio, the crystallinity of the polymer is lowered, The adhesion to the metal thin film can be greatly increased at the second transition temperature (T ₂ ) or higher at which the crystallinity of the polymer or the melting property at a high temperature starts to change.

The repeating unit of Formula 1 is derived from a polyamic acid or a polyimide precursor formed by reacting 4,4'-oxydianiline and an aromatic tetracarboxylic acid or an acid anhydride thereof.

The repeating unit of Formula 2 is derived from a polyamic acid or a polyimide precursor formed by reacting bis (4-aminophenoxy) benzene and an aromatic tetracarboxylic acid or an acid anhydride thereof.

As described above, the thermoplastic polyimide resin for a flexible metal laminate according to one embodiment of the present invention has a molar ratio of the repeating unit represented by the formula (1) and the repeating unit represented by the following formula (2) in the range of 2:10 to 7:10, or 2.5: 10 to 6:10 Rate.

If the molar ratio of the repeating unit represented by the formula (2) to the repeating unit represented by the formula (2) is less than 2:10, the thermoplastic polyimide resin for the flexible metal laminate of the embodiment can not have a high adhesion to the thin metal film A high bonding temperature (high lamination temperature), which results in poor process efficiency, and a relatively flexible repeating unit may cause a phenomenon such as deterioration of surface characteristics during high-temperature lamination.

When the molar ratio of the repeating unit represented by the formula (1) to the repeating unit represented by the formula (2) exceeds 7:10, the thermoplastic polyimide resin for the flexible metal laminate of the embodiment can not have a high adhesion to the metal thin film, The temperature (lamination temperature) of the thermoplastic polyimide resin also increases and the process efficiency is lowered. Also, the relatively low rigidity of the repeating units lowers the adhesive force even at high temperature lamination, and the thermoplastic polyimide resin is likely to brittle .

On the other hand, as described above, the thermoplastic polyimide resin for a flexible metal laminate has a second transition temperature (T ₂ ) at which the rate of change of the ratio of the increment of the length to the increment of the temperature at the temperature of the glass transition temperature (Tg) The difference between the glass transition temperatures (Tg) may be 30 占 폚 or lower, or 10 占 폚 or lower, or 1 占 폚 to 5 占 폚.

The second transition temperature (T ₂ ) means a temperature at which the rate of change of the ratio of the increment of the length to the increment of the temperature becomes maximum in the range of the glass transition temperature (Tg) or more of the thermoplastic polyimide resin for the flexible metal laminate. The 'second' is used for distinguishing or specifying terms, and is not interpreted as indicating a sequence or importance.

The ratio of the increment of the length to the temperature increment means the rate at which the thermoplastic polyimide resin for soft metal laminate is linearly expanded in accordance with the change in temperature. For example, in the thermomechanical analysis (TMA) Lt; / RTI >

The rate of change of the rate of the increment of the length with respect to the increment of the temperature means the rate of change of the rate of the increment of the length with respect to the temperature increment according to the temperature. For example, in the thermomechanical analysis (TMA) May be the rate of change of the slope.

If the difference between the second transition temperature (T ₂ ) and the glass transition temperature (Tg) of the thermoplastic polyimide resin for a flexible metal laminate exceeds 30 ° C, even if the polyimide crystallites are in a temperature range higher than the glass transition temperature It is necessary to apply a higher temperature and pressure condition to increase the flowability of the thermoplastic polyimide resin, so that the processability is deteriorated. On the surface of the copper foil after lamination of the thermoplastic polyimide resin, Failure may occur.

The crystallinity of the polymer is lowered or the melting property at a high temperature is higher in a temperature range of the thermoplastic polyimide resin for a flexible metal laminate lower than the melting point (Tm) or higher than the second transition temperature (T ₂ ) The thermoplastic polyimide resin for the flexible metal laminate can be firmly bonded to the metal thin film with high adhesive force.

The second transition temperature (T ₂ ) of the thermoplastic polyimide resin for a flexible metal laminate may be 270 ° C. or less, 250 ° C. or less, or 200 ° C. to 240 ° C. Accordingly, the thermoplastic polyimide resin for a flexible metal laminate The mid resin can be firmly bonded to the metal thin film at a high adhesive force at a temperature of 300 DEG C or less, 270 DEG C or less, or 250 DEG C or less.

The glass transition temperature (Tg) of the thermoplastic polyimide resin for a flexible metal laminate may be determined by differential scanning calorimetry (DSC).

The second transition temperature (T ₂ ) of the thermoplastic polyimide resin for the flexible metal laminate may be determined by thermomechanical analysis (TMA). For example, by applying a load of 0.1 N / cm in a thermomechanical analysis (TMA), the change of dimension is measured while raising the temperature from 30 ° C to 460 ° C at a heating rate of 10 ° C / min, and the glass transition temperature Tg ), The inflection point at which the rate of change of the ratio of the increment of the length to the increment of the temperature becomes the maximum can be defined as the second transition temperature (T ₂ ).

On the other hand, in order for the thermoplastic polyimide resin for a flexible metal laminate of one embodiment to have the above-described action and effect, the Y ₁ And Y ₂ in Formula 2 are each preferably an aromatic tetravalent organic group, and each preferably contains a tetravalent aromatic organic functional group represented by Formula 3 below.

(3)

In the above formula (3), '*' means a bonding point.

More specifically, Y ₁ of Formula ₁ And Y ₂ in Formula 2 may include 10 mol% to 100 mol% of the tetravalent aromatic organic functional group of Formula 3, respectively.

The Y < 1 _> And the Y ₂ in the formula (2) may be included in each of the tetravalent aromatic organic functional groups other than the tetravalent aromatic organic functional group represented by the above formula (3).

[Chemical Formula 21]

[Chemical Formula 22]

In Formula 22, Y ₁ represents -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -CONH-, -COO- _{, - (CH 2) n1 -} , -O (CH 2) n2 O-, or -OCO (CH _{2) n3} a OCO-, wherein n1, n2 and n3 is an integer of 1 to 10, respectively.

 (23)

Y ₂ and Y ₃ may be the same or different and each represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C _{(CF 3) 2 -, -CONH-} , -COO-, - (CH 2) n1 - _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} OCO-, wherein n1, n2, and and n3 is an integer of 1 to 10, respectively.

≪ EMI ID =

In the above formula (24), Y ₄ , Y ₅ And Y ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 -, -C (CH 3) 2 -, -C (CF 3) 2 -, _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} a OCO-, wherein n1, n2 and n3 is 1 to 10 - -CONH-, -COO-, - (CH 2) n1 It is an integer.

(25)

(26)

(27)

In the above Formulas 21 to 27, '*' means a bonding point.

The thermoplastic polyimide resin for a flexible metal laminate may be a block copolymer or a random copolymer containing the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) in the molar ratio described above. That is, in the thermoplastic polyimide resin for a flexible metal laminate, the repeating unit of the formula (1) and the repeating unit of the repeating unit of the formula (2) may be sequentially bonded or may be bonded in a specific order, They may be combined.

The thermoplastic polyimide resin for a flexible metal laminate may have a weight average molecular weight of 15,000 to 400,000. If the weight average molecular weight of the thermoplastic polyimide resin is too small, mechanical properties and the like can not be sufficiently secured. If the weight average molecular weight of the thermoplastic polyimide resin is too large, the elasticity and mechanical properties of the resin itself or the film or polymer layer formed therefrom may be deteriorated.

On the other hand, the thermoplastic polyimide resin for a flexible metal laminate includes a diamine compound containing 4,4'-oxydianiline and bis (4-aminophenoxy) benzene in a molar ratio of 2:10 to 7:10; And an aromatic tetracarboxylic acid or an acid anhydride thereof; and curing the polyamic acid resin composition formed at 200 to 400 ° C or 230 to 350 ° C.

The bis (4-aminophenoxy) benzene may be 1,3-bis (4-aminophenoxy) benzene or 1,4-bis (4-aminophenoxy) benzene.

More specifically, after the polyamic acid resin composition is coated on a predetermined substrate, it is thermally cured at a temperature of 200 ° C to 400 ° C, or 230 ° C to 350 ° C to form a thermoplastic polyimide resin layer containing the thermoplastic polyimide resin Can be formed.

As described above, the thermoplastic polyimide resin for a flexible metal laminate can be firmly bonded to the metal thin film at a high adhesive strength at a temperature of 300 ° C or lower, 270 ° C or 250 ° C, and more specifically, IPC-TM- 650 2.4.8 The peel strength measured as a 180 degree peel as a standard may be 0.5 kgf / cm or more, or 0.7 kgf / cm or more, or 0.5 kgf / cm to 2.0 kgf / cm.

According to another embodiment of the present invention, there is provided a thermoplastic polyimide resin composition comprising the thermoplastic polyimide resin; A composite polyimide resin layer containing a fluorine resin and a polyimide resin; And a metal thin film, may be provided.

The soft metal laminate can secure a high elasticity and an optimized thermal expansion coefficient while having a lower dielectric constant and a lower water absorption rate, and can also have a relatively high bonding force or peel strength between the respective layers.

The thermoplastic polyimide layer may comprise a thermoplastic polyimide resin for a flexible metal laminate of one embodiment described above. That is, in the thermoplastic polyimide layer, the thermoplastic polyimide resin for a flexible metal laminate of the embodiment may have a repeating unit represented by Formula 1 and a repeating unit represented by Formula 2 at a ratio of 2:10 to 7:10, or 2.5: 10 to 6: 10, and the difference between the second transition temperature (T ₂ ) and the glass transition temperature (Tg) at which the rate of change of the ratio of the length increment to the increment of the temperature at the temperature above the glass transition temperature (Tg) 30 占 폚 or lower, or 10 占 폚 or lower, or 1 占 폚 to 5 占 폚.

Accordingly, the thermoplastic polyimide layer can have a high bonding strength with the metal thin film even at a relatively low temperature, for example, at a temperature of 300 ° C or less, or 200 ° C to 270 ° C. Specifically, the thermoplastic polyimide layer may have a peel strength of 0.5 kgf / cm or more, or 0.7 kgf / cm or more, or 0.5 kgf / cm or less, measured as a 180 degree peel based on IPC-TM- To 2.0 kgf / cm.

The specific content of the thermoplastic polyimide resin includes all of the contents described above with respect to the thermoplastic polyimide resin for a flexible metal laminate of the embodiment.

The thermoplastic polyimide resin layer may have a thickness of 0.1 占 퐉 to 200 占 퐉, or 1 占 퐉 to 150 占 퐉.

The composite polyimide resin layer may have a thickness of 0.1 to 200 탆, or 1 to 150 탆.

The metal thin film may be laminated on at least one side of the thermoplastic polyimide resin layer. In addition, the thermoplastic polyimide resin layer may have the metal thin film formed on one side and the composite polyimide resin layer on the other side.

The soft metal laminate may include one metal thin film. The soft metal laminate may include two metal thin films facing each other. In this case, the thermoplastic polyimide resin layer and the composite poly And a middle resin layer may be stacked on each other.

When at least one or more of the thermoplastic polyimide resin layer and the composite polyimide resin layer are laminated between the two mutually facing metal thin films, the thermoplastic polyimide resin layer and the composite polyimide resin layer are alternately and sequentially Or may be laminated in a different order.

The composite polyimide resin layer may include a fluorine resin and a polyimide resin.

The specific characteristics of the polyimide resin contained in the composite polyimide resin layer are not limited, and a polyimide resin known to be usable for the flexible metal laminate can be used without any limitation.

For example, the polyimide resin included in the composite polyimide resin layer may have a weight average molecular weight of 1,000 to 300,000, or 10,000 to 300,000. If the weight average molecular weight of the polyimide resin is too small, it is impossible to sufficiently secure the mechanical properties required in the application of the flexible metal laminate or the like. If the weight average molecular weight of the polyimide resin is too large, the elasticity and mechanical properties of the composite polyimide resin layer may be deteriorated.

Specifically, the polyimide resin may include a repeating unit represented by the following formula (46).

 (46)

In Formula 46, Y is a tetravalent aromatic organic functional group, X is a divalent aromatic organic functional group, and n is an integer of 1 to 300.

Y may include a tetravalent functional group selected from the group consisting of the following formulas (31) to (37).

(31)

(32)

In Formula 32, Y ₁ represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -CONH-, _{-COO-, - (CH 2) n1} -, -O (CH 2) n2 O-, or -OCO (CH _{2) n3} a OCO-, wherein n1, n2 and n3 is an integer of 1 to 10, respectively.

 (33)

Y ₂ and Y ₃ may be the same or different and each represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C _{(CF 3) 2 -, -CONH-} , -COO-, - (CH 2) n1 - _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} OCO-, wherein n1, n2, and and n3 is an integer of 1 to 10, respectively.

(34)

In the above formula (34), Y ₄ , Y ₅ And Y ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 -, -C (CH 3) 2 -, -C (CF 3) 2 -, _{a, -O (CH 2) n2 O-} , or -OCO (CH _{2) n3} a OCO-, wherein n1, n2 and n3 is 1 to 10 - -CONH-, -COO-, - (CH 2) n1 It is an integer.

(35)

(36)

(37)

In the above Formulas 31 to 37, '*' means a bonding point.

In order for the composite polyimide resin layer to have an optimized thermal expansion coefficient with a high elasticity while having a lower dielectric constant and a low moisture absorption rate, it is preferable that Y in the formula (46) is a tetravalent group selected from the group consisting of the following formulas Functional group. The Y may be the same or different in each of the repeating units of the formula (1).

(38)

[Chemical Formula 39]

(40)

In the above formulas 38 to 40, '*' means a bonding point.

In formula (46), X may be a divalent functional group selected from the group consisting of the following formulas (41) to (44).

(41)

Wherein R ₁ is hydrogen, -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , or - CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

(42)

Wherein L ₁ represents a single bond, -O-, -CO-, -S-, -SO ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -CONH-, _{-COO-, - (CH 2) n1} -, -O (CH 2) and _{n2 O-, -OCH 2 -C (CH} 3) 2 -CH 2 O- , or -OCO (CH _{2) n3} OCO-, wherein n1, n2 and n3 is an integer from 1 to 10, R ₁ and R ₂ may be the same or different from one another, each _{hydrogen, -CH 3, -CH 2 CH 3} , -CH 2 CH 2 CH 2 CH 3, -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , or -CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

(43)

In Formula 43, L ₂ and L ₃ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 -, -C (CH 3) 2 -, -C _{(CF 3) 2 -, -CONH-} , -COO-, - (CH 2) n1 -, -O (CH 2) n2 O-, -OCH 2 -C (CH 3) 2 -CH 2 O- or - a OCO (CH _{2) n3} OCO-, wherein n1, n2 and n3 is an integer from 1 to 10, R _1, R ₂ and R ₃ may be the same or different from one another, each hydrogen, -CH _3, -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , or -CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

(44)

In the above formula (44), L ₄ , L ₅ And L ₆ may be the same or different from each other, and respectively a single bond, -O-, -CO-, -S-, -SO 2 -, -C (CH 3) 2 -, -C (CF 3) 2 -, _{-CONH-, -COO-, - (CH 2} ) n1 -, -O (CH 2) n2 O-, -OCH 2 -C (CH 3) 2 -CH 2 O- , or -OCO (CH _{2) n3} OCO -, and wherein n1, n2 and n3 is an integer from 1 to 10, R _1, R _2, R ₃ and R ₄ may be the same or different from one another, each _{hydrogen, -CH 3, -CH 2 CH 3} , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , or -CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

In particular, when X in the above formula (3) is a divalent functional group of the following formula (45), the composite polyimide resin layer can have a lower dielectric constant and a lower water absorption rate, and also can secure an optimized thermal expansion coefficient have. X may be the same or different in each of the repeating units of the formula (1).

 [Chemical Formula 45]

In the above formula (45), R ₁ and R ₂ may be the same or different from each other and each represents -CH ₃ , -CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ CH ₃ , -CF ₃ , -CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₃ , -CF ₂ CF ₂ CF ₂ CF ₃ Lt; / RTI >

On the other hand, the composite polyimide resin layer may contain 10 to 60 wt% of fluorine resin particles having the longest diameter of 0.05 to 20 탆, or 0.1 to 10 탆.

If the content of the fluorine resin is too small, the soft metal laminate finally produced may not have a sufficiently low dielectric constant or water absorption rate. If the content of the fluorine resin is too large, the mechanical properties of the flexible metal laminate may be deteriorated to easily tear or break, and the coefficient of thermal expansion of the polymer resin layer included in the flexible metal laminate may be Can greatly increase.

The shape of the fluororesin particles is not limited to a specific one, and may be a circular shape, a spherical shape, a truncated cone, a polygonal prism, or a three-dimensional shape having a plurality of internal angles.

The fluororesin particles may be selected from the group consisting of polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene May comprise at least one compound selected from the group consisting of copolymer resin (ETFE), tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE / CTFE) and ethylene-chlorotrifluoroethylene resin (ECTFE) .

Meanwhile, the flexible metal laminate of one embodiment may further include a dispersant dispersed in the composite polyimide resin layer. Specific examples of the dispersing agent include a polyester-based polymer, a polyether-modified polydimethylsiloxane, a polyester / polyamine condensation polymer, or a mixture of two or more thereof.

The metal thin film may include at least one metal selected from the group consisting of copper, iron, nickel, titanium, aluminum, silver, gold, and two or more alloys thereof.

The ten point average roughness Rz of the surface of the metal thin film may be 0.5 탆 to 2.5 탆. If the 10-point average roughness of the surface of the metal thin film is too small, the adhesion to the polymer resin layer may be lowered. If the average roughness of the 10-point average of the surface of the metal thin film is too large, surface roughness may increase and transmission loss may be increased in a high frequency range.

The metal thin film may have a thickness of 0.1 탆 to 50 탆.

On the other hand, the method for producing the above-described flexible metal laminate is not particularly limited, and a commonly known method for synthesizing a polyimide resin and a method for producing a flexible metal laminate can be used.

According to another embodiment of the present invention, there is provided a method of manufacturing a flexible metal laminate, which comprises laminating a thermoplastic polyimide resin layer containing the thermoplastic polyimide resin and a metal foil at a temperature of 250 ° C to 300 ° C .

As described above, the soft metal laminate produced using the thermoplastic polyimide resin layer containing the thermoplastic polyimide resin can secure a high elasticity and an optimized thermal expansion coefficient while having a lower dielectric constant and a lower moisture absorption rate , And the bonding strength or peel strength between the respective layers included therein may be relatively high.

The specific contents of the thermoplastic polyimide resin and the thermoplastic polyimide resin layer all include the above-mentioned contents regarding the thermoplastic polyimide resin for the flexible metal laminate of the embodiment and the flexible metal laminate of the other embodiment.

The thermoplastic polyimide layer may have a high bonding strength with the metal thin film even at a relatively low temperature, for example, at a temperature of 300 DEG C or less, or 270 DEG C or less, or 250 DEG C or less. Specifically, the thermoplastic polyimide layer may have a peel strength of 0.5 kgf / cm or more, or 0.7 kgf / cm or more, or 0.5 kgf / cm or less, measured as a 180 degree peel based on IPC-TM- To 2.0 kgf / cm.

The lamination method is not limited to a specific method. For example, a polyamic acid, which is a precursor of the thermoplastic polyimide layer, is coated on the surface of the polyimide resin layer and then cured, followed by roll lamination at a pressure of 2 Tonf Lt; / RTI >

Meanwhile, the manufacturing method of the flexible metal laminate includes a diamine compound containing 4,4'-oxydianiline and bis (4-aminophenoxy) benzene in a molar ratio of 2:10 to 7:10; And an aromatic tetracarboxylic acid or an acid anhydride thereof; And applying the polyamic acid composition on at least one surface of the metal thin film and curing the metal thin film at a temperature of 200 ° C to 400 ° C.

The bis (4-aminophenoxy) benzene may be 1,3-bis (4-aminophenoxy) benzene or 1,4-bis (4-aminophenoxy) benzene.

The aromatic tetracarboxylic acid or an acid anhydride thereof may include a tetravalent aromatic organic functional group represented by the following formula (3).

(3)

In the above formula (3), '*' means a bonding point.

More specifically, the aromatic tetracarboxylic acid or an acid anhydride thereof may include from 10 mol% to 100 mol% of an aromatic tetracarboxylic acid or an acid anhydride thereof containing a tetravalent aromatic organic functional group of Formula 3.

Examples of the aromatic tetracarboxylic acid having a tetravalent aromatic organic functional group of Formula 3 or an acid anhydride thereof include aromatic tetracarboxylic acids or tetracarboxylic acid anhydrides thereof having the tetravalent aromatic organic functional groups of the above formulas 21 to 27 have.

More specifically, after the polyamic acid resin composition is coated on at least one surface of the metal thin film, the thermoplastic polyimide resin composition is thermally cured at a temperature of 200 to 400 캜, or 230 to 350 캜, A mid resin layer can be formed.

Meanwhile, the manufacturing method of the flexible metal laminate of the embodiment may further include cooling the laminated thermoplastic polyimide resin layer and the metal thin film.

According to the present invention, there is provided a thermoplastic polyimide resin for a flexible metal laminate capable of having a high adhesive strength to a metal or other polymer resin at a temperature of 300 DEG C or less while having excellent mechanical properties and elasticity, a thermoplastic polyimide resin for a flexible metal laminate And a method of manufacturing the flexible metal laminate.

In addition, the flexible metal laminate may have high heat resistance, excellent chemical resistance, and dimensional stability required in an electric / electronic device or a printed circuit board, and may have a thinner thickness of an electric / electronic element or a printed circuit board, And it is possible to remarkably reduce the defective rate in the production of an electric / electronic element or a printed circuit board.

Fig. 1 shows the thermomechanical analysis (TMA) results of the thermoplastic polyimide resins of Examples 1 to 3 and Comparative Example 2.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Example  And Comparative Example  : Polyamic acid  Solutions and soft metals Of the laminate  Produce]

One. Polyamic acid  Preparation of solution

A 2 L glass container was filled with nitrogen and charged with 870 g of N-methylpyrrolidinone, 74.8 g of BPDA (3,3'4,4'-biphenyl-tetracarboxylic acid dianhydride) and 4,4'-oxydianiline The diamine compound in which the bis (4-aminophenoxy) benzene was mixed in the ratio shown in Table 1 was added in an amount of 1 equivalent relative to BPDA, and the mixture was allowed to react at 50 DEG C for 10 hours while stirring using a stirrer to give a viscosity of 3,000 cps Of polyamic acid solution was obtained.

2. Soft metal Of the laminate  Produce

Using the polyamic acid obtained above, a 25 μm thick PI film was coated on both sides of the substrate in a coma coater, followed by sequential double-side coating of 4 μm each, and dried at 100 ° C. for 5 minutes.

The dried film was cured in an oven at 280 ° C for 10 minutes to prepare a PI film to which TPI was bonded on both sides. The produced PI film was subjected to roll-lamination of a copper foil on the upper and lower surfaces at a pressure of 2 Tonf to prepare a flexible metal laminate.

[ Experimental Example ]

One. Experimental Example 1 Thermomechanical Analysis of Thermoplastic Polyimide Resin TMA )

The polyamic acid solution obtained in each of the Examples and Comparative Examples was cured on one side of the copper foil, followed by bar coating to a thickness of 20 μm, drying at 100 ° C for 5 minutes, and curing in an oven at 280 ° C for 20 minutes. The resultant copper foil-thermoplastic polyimide resin laminate was immersed in a copper foil etching solution to remove the copper foil, thereby separating only the thermoplastic polyimide layer.

The glass transition temperature (Tg) of the separated thermoplastic polyimide layer was determined by differential scanning calorimetry (DSC), and the separated thermoplastic polyimide layer was subjected to thermomechanical analysis (TMA) at a load of 0.1 N / cm The change in dimension was measured while raising the temperature from 30 ° C to 460 ° C at a heating rate of 10 ° C / min, and another inflection point generated after the glass transition temperature (Tg) was defined as a second transition temperature (T ₂ ) .

2. Experimental Example 2 : Soft metal Of the laminate  Peel strength test

The peel strength of the copper foil-thermoplastic polyimide resin laminate obtained in Experimental Example 1 was measured as a 180 degree peel based on IPC-TM-650 2.4.8.

Diamine
Composition ratio The second transition temperature (T ₂ ) The glass transition temperature (Tg) │Tg-T ₂ Melting point (Tm) Peel strength Example 1 0.3 213 211 2 388 One Example 2 0.4 214 215 One 410 0.8 Example 3 0.5 222 220 2 - 0.7 Comparative Example 1 0 376 205 171 393 ≪ 0.1 Comparative Example 2 0.1 365 217 148 381 ≪ 0.1 Comparative Example 3 0.75 385 236 149 431 ≪ 0.1 Comparative Example 4 0.9 402 254 148 442 ≪ 0.1 Comparative Example 5 One 403 266 137 453 ≪ 0.1

* Diamine composition ratio is the ratio of 4,4'-oxydianiline to bis (4-aminophenoxy) benzene.

As shown in Table 1, the thermoplastic polyimide resins of Examples 1 to 3 had a difference between the second transition temperature (T ₂ ) and the glass transition temperature (Tg) of 30 ° C or less, or 5 ° C or less, It was confirmed that the difference between the second transition temperature (T ₂ ) and the glass transition temperature (Tg) of the thermoplastic polyimide resin of Examples 1 to 5 exceeded 100 ° C.

In addition, the thermoplastic polyimide resins of Examples 1 to 3 can have high adhesion to the metal thin film even at a temperature of 300 ° C or less, while the thermoplastic polyimide resins of Comparative Examples 1 to 5 are relatively low Adhesive strength.

Claims (15)

A repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2) in a molar ratio of 2.5: 10 to 6:10,
Wherein the difference between the second transition temperature (T ₂ ) and the glass transition temperature (Tg) at which the rate of change of the ratio of the increment of the length to the increment of the temperature at the glass transition temperature (Tg)
Thermoplastic polyimide resin for flexible metal laminate:
[Chemical Formula 1]

Wherein Y ₁ is a tetravalent aromatic organic functional group, X ₁ is an aromatic organic functional group containing a divalent functional group represented by the following formula (11)
(11)

(2)

In Formula 2, Y ₂ is a tetravalent aromatic organic functional group, X ₂ is a divalent aromatic organic functional group including a divalent functional group represented by the following Formula 12,
[Chemical Formula 12]

or

In the above Formulas (11) and (12), '*' means a bonding point.
delete The method according to claim 1,
And the second transition temperature (T ₂ ) is 270 ° C or lower.
The method according to claim 1,
Wherein the second transition temperature (T ₂ ) is determined by thermomechanical analysis (TMA).
The method according to claim 1,
The Y < 1 _> And, a thermoplastic polyimide resin for Y ₂ in the formula 2 is a 4 of the formula 3, each containing 10 mol% to 100 mol% aromatic organic functional groups:
(3)

In the above formula (3), '*' means a bonding point.
The method according to claim 1,
Wherein the thermoplastic polyimide resin has a weight average molecular weight of 15,000 to 400,000.
A thermoplastic polyimide resin layer comprising the thermoplastic polyimide resin of claim 1;
A composite polyimide resin layer containing a fluorine resin and a polyimide resin; And
And a metal thin film.
8. The method of claim 7,
Wherein each of the thermoplastic polyimide resin layer and the composite polyimide resin layer has a thickness of 0.1 占 퐉 to 200 占 퐉.
8. The method of claim 7,
Wherein the metal thin film is laminated on at least one surface of the thermoplastic polyimide resin layer.
8. The method of claim 7,
Wherein at least one of the thermoplastic polyimide resin layer and the composite polyimide resin layer is laminated between two metal thin films facing each other.
8. The method of claim 7,
Wherein the composite polyimide resin layer comprises 10 wt% to 60 wt% of fluoric resin particles having the longest diameter of 0.05 mu m to 20 mu m.
8. The method of claim 7,
And a dispersing agent dispersed in the composite polyimide resin layer.
8. The method of claim 7,
Wherein the metal thin film has a thickness of 0.1 占 퐉 to 50 占 퐉.
A process for producing a flexible metal laminate, comprising the steps of: laminating a thermoplastic polyimide resin layer containing the thermoplastic polyimide resin of claim 1 and a metal thin film at a temperature of 250 캜 to 300 캜.
15. The method of claim 14,
A diamine compound containing 4,4'-oxydianiline and bis (4-aminophenoxy) benzene in a molar ratio of 2:10 to 7:10; And an aromatic tetracarboxylic acid or an acid anhydride thereof; And
Applying the polyamic acid composition on at least one side of the metal thin film and curing at a temperature of 200 ° C to 400 ° C.

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