TWI747192B - Release film - Google Patents

Abstract

The purpose of the present invention is to provide a release film that does not contaminate the substrate when it is used in the manufacturing step of a flexible circuit substrate. The release film of the present invention has a release layer containing an olefin-based polymer and a phenol-based antioxidant having a melting point of 160°C or higher. In addition, the release film of the present invention has a release layer containing an olefin-based polymer and a metal deactivator, and the nitrogen concentration on the surface of the release layer measured by X-ray photoelectron spectroscopy is 1.5% or less.

Description

Release film

The present invention relates to a release film.

The release film is used in the manufacturing steps of flexible circuit boards such as printed wiring boards, flexible printed wiring boards, and multilayer printed wiring boards. For example, in the manufacturing step of the flexible printed circuit board, a thermosetting adhesive or a thermosetting adhesive sheet is used to heat and press the cover film to the flexible printed circuit board body on which the copper circuit is formed. At this time, in order to prevent the coating film from adhering to the hot platen, a release film is widely used.

For example, Patent Document 1 discloses a release film, which is formed by sequentially stacking a first release layer, an intermediate layer, and a second release layer, and the first release layer and the second release layer consist of 4 -Methyl-1-pentene polymer composition. Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Publication No. 2015-189151

[The problem to be solved by the invention]

It is known that the film containing 4-methyl-1-pentene-based polymer has excellent release properties against pressure hot plates made of stainless steel, coating films composed of polyimide films, etc., and at 170°C The heat resistance in the hot pressing step on the left and right sides is also good. However, when a film containing 4-methyl-1-pentene-based polymer is used as a release film in the manufacturing process of a flexible circuit board, there are the following problems: In the plating process, the plating may not be sufficiently obtained, which may cause the problem of poor plating. It is believed that the surface of the substrate was contaminated due to some reasons. In addition, in the presence of such pollution, it is necessary to use a chemical solution for cleaning, etc., which will increase the environmental load on product manufacturing.

The present invention is based on the above-mentioned current situation, and its purpose is to provide a release film that does not contaminate the substrate when it is used in the manufacturing process of a flexible circuit substrate. [Technical means to solve the problem]

The present invention is a release film, which has a release layer containing an olefin-based polymer and a phenol-based antioxidant with a melting point of 160°C or higher. In addition, the present invention is a release film having a release layer containing an olefin polymer and a metal deactivator, and the nitrogen concentration on the surface of the release layer measured by X-ray photoelectron spectroscopy is 1.5 %the following. Hereinafter, the present invention will be described in detail.

The inventor of the present invention is concerned with the use of a release film having a release layer containing an olefin polymer such as 4-methyl-1-pentene polymer as the release film in the manufacturing process of a flexible circuit board The causes of pollution were studied. As a result, it was found that the cause of the contamination is that low molecular weight components are generated due to the decomposition of the olefin-based polymer. When a release film is used, the low molecular weight components are transferred to the surface of the substrate. In this regard, the present inventors conducted research on preventing contamination by blending a phenolic antioxidant or a metal deactivator into a release layer containing an olefin-based polymer. First, an attempt was made to blend a phenol-based antioxidant in a release layer containing an olefin-based polymer, but the contamination could not be sufficiently prevented. The inventors of the present invention conducted further studies and found that the phenol-based antioxidant itself becomes a new source of pollution. In addition, it has been found that by selecting a phenolic antioxidant with a melting point of 160°C or higher, it is possible to prevent the pollution caused by the low molecular weight components generated by the decomposition of the olefin polymer, and also prevent the pollution caused by the phenolic antioxidant itself. . In addition, the present inventors found that the release layer containing the olefin-based polymer blended with a metal deactivator and the metal deactivator was sufficiently dispersed in the olefin-based polymer to suppress the generation and contamination of low-molecular-weight components. The result is thus completed the present invention.

The release film of the present invention has a release layer containing an olefin-based polymer. The above-mentioned olefin-based polymer is not particularly limited, but preferably contains a 4-methyl-1-pentene-based polymer. When the above-mentioned olefin-based polymer contains the above-mentioned 4-methyl-1-pentene-based polymer, the release film of the present invention becomes a pressurized hot plate made of stainless steel or a coating film composed of a polyimide film It has excellent release properties and good heat resistance in the hot pressing step at about 170°C.

As the aforementioned 4-methyl-1-pentene polymer, in addition to the homopolymer of 4-methyl-1-pentene, 4-methyl-1-pentene and 4-methyl-1-pentene can be used. Copolymer of monomers other than pentene. The monomers other than 4-methyl-1-pentene are not particularly limited, and examples include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1- Dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and other α-olefins with a carbon number of 20 or less. When the 4-methyl-1-pentene polymer is a copolymer, it is derived from the structure of 4-methyl-1-pentene from the viewpoint of exerting higher releasability or heat resistance The content of the unit is preferably 80% by weight, more preferably 90% by weight or more. For the above-mentioned 4-methyl-1-pentene-based polymer, commercially available products such as the trade name TPX (registered trademark) manufactured by Mitsui Chemicals Co., Ltd. can be used, for example.

The content of the 4-methyl-1-pentene-based polymer in the olefin-based polymer is not particularly limited, but from the viewpoint of exhibiting higher releasability or heat resistance, it is preferably 50% by weight, and more Preferably, it is 70% by weight or more. The upper limit of the content of the 4-methyl-1-pentene-based polymer is not particularly limited, and it may be 100% by weight. When the above-mentioned olefin-based polymer contains an olefin-based polymer other than the above-mentioned 4-methyl-1-pentene-based polymer, it shall be regarded as an olefin-based polymer other than the above-mentioned 4-methyl-1-pentene-based polymer It is not particularly limited, and for example, an olefin polymer obtained by using α-olefin having 20 or less carbon atoms can be used. As the above-mentioned α-olefin having a carbon number of 20 or less, specifically, for example, ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, etc.

The content of the olefin polymer in the release layer is not particularly limited. Generally, when the olefin polymer is the main component of the release layer, the lower limit of the content of the olefin polymer is preferably 50% by weight , The preferred upper limit is 99% by weight. If the content of the above-mentioned olefin-based polymer is within this range, release properties or heat resistance can be improved, and contamination of the substrate can be prevented. The lower limit of the content of the olefin-based polymer is more preferably 70% by weight, and the upper limit is more preferably 95% by weight.

In the first aspect of the present invention, the release layer contains a phenolic antioxidant. It is known that olefin-based polymers undergo a radical reaction by light, heat, or the coexistence of metal and oxygen to generate low molecular weight components. The following formula (1) represents a reaction formula of a series of reactions that decompose an olefin-based polymer to produce a low-molecular-weight component. In formula (1), R represents an alkyl chain. It is considered that among olefin polymers, 4-methyl-1-pentene polymers containing many C-H bonds are prone to produce low-molecular-weight components.

The above-mentioned phenol-based antioxidant is in the second reaction of the above formula (1), that is, R· generated from RH reacts with oxygen to produce ROO·, and the ROO· reacts with RH to produce R·, the so-called free radical chain In reaction b, by capturing free radicals, the progress of the reaction that generates a series of low-molecular-weight components can be inhibited, and the contamination of the substrate can be prevented.

In the manufacturing step of the flexible circuit board, the hot pressing is usually performed under the conditions of 160-200°C, 3-10 MPa, and 2-10 minutes. Part of the phenolic antioxidants volatilized during the hot pressing process also became a cause of substrate contamination. In the first aspect of the present invention, a phenolic antioxidant having a melting point of 160° C. or higher (hereinafter, also referred to as "high melting point phenolic antioxidant") is selected as the phenolic antioxidant. By using high melting point phenol antioxidants, it is possible to prevent pollution caused by low molecular weight components generated by the decomposition of olefin polymers, and also prevent pollution caused by phenol antioxidants themselves.

-2,4,6(1H,3H,5H)-三酮、3,3',3'',5,5',5''-六三級丁基-α,α',α''-(對稱三甲苯-2,4,6-三基)三對甲酚等。該等高熔點酚系抗氧化劑可單獨地使用，亦可併用2種以上。 上述受阻酚系抗氧化劑例如可使用：Irganox 1098（熔點160℃，BASF公司製造）、Irganox 3114（熔點221℃，BASF公司製造）、Irganox 1330（熔點240℃，BASF公司製造）等市售品。 上述高熔點酚系抗氧化劑之分子量無特別限定，就充分地分散於上述烯烴系聚合物中之觀點、更進一步防止基板之污染之觀點等而言，較佳之下限為200，較佳之上限為1000，更佳之下限為500，更佳之上限為800。As the above-mentioned high melting point phenol-based antioxidant, if it is a compound having a melting point of 160° C. or higher and having a phenol structure in the molecule, it is not particularly limited, and a hindered phenol-based antioxidant can be used. Furthermore, the so-called hindered phenol structure means that there is a bulky atomic group at the ortho position of the phenolic hydroxyl group. The hindered phenol antioxidant is preferably a compound having a phenolic hydroxyl group and a branched alkyl group at the ortho position of the phenolic hydroxyl group. Specific examples of the hindered phenol-based antioxidant include: N,N'-hexane-1,6-diylbis(3-(3,5-di-tertiarybutyl-4-hydroxyphenyl) Propylamine)), 1,3,5-ginseng (3,5-di-tertiary butyl-4-hydroxybenzyl)-1,3,5-tri

-2,4,6(1H,3H,5H)-Triketone, 3,3',3``,5,5',5''-hexateributyl-α,α',α''- (Symmetric trimethylbenzene-2,4,6-triyl) tri-p-cresol and so on. These high melting point phenol-based antioxidants may be used singly, or two or more of them may be used in combination. As the hindered phenol antioxidant, for example, commercially available products such as Irganox 1098 (melting point 160°C, manufactured by BASF Corporation), Irganox 3114 (melting point 221°C, manufactured by BASF Corporation), and Irganox 1330 (melting point 240°C, manufactured by BASF Corporation), can be used. The molecular weight of the high melting point phenol antioxidant is not particularly limited. From the viewpoint of being sufficiently dispersed in the olefin polymer and the viewpoint of further preventing contamination of the substrate, the preferred lower limit is 200, and the preferred upper limit is 1000 , A more preferable lower limit is 500, and a more preferable upper limit is 800.

The content of the high-melting phenol-based antioxidant in the release layer is not particularly limited. The lower limit is preferably 0.1 parts by weight, and the upper limit is preferably 1.0 parts by weight relative to 100 parts by weight of the olefin-based polymer. If the content of the above-mentioned high-melting phenol-based antioxidant is within this range, it is possible to prevent contamination of the substrate without affecting release properties or heat resistance. The lower limit of the content of the high melting point phenol antioxidant is more preferably 0.3 parts by weight, and the upper limit is more preferably 0.7 parts by weight.

In the first aspect of the present invention, the above-mentioned release layer may further contain a phosphorus-based antioxidant or a sulfur-based antioxidant within a range that does not impair the purpose of the present invention. These antioxidants can decompose the peroxides generated in the series of reactions of the above formula (1), and therefore can further prevent the contamination of the substrate.

In the first aspect of the present invention, the above-mentioned release layer may further contain a metal deactivator within a range that does not impair the purpose of the present invention. The metal deactivator is a compound that can capture and inactivate the metal catalyst by coordinating metal elements. By blending a metal deactivator, in the first reaction of the above formula (1), that is, the cleavage reaction a of generating R from RH, it can capture the metal as a catalyst, inhibit the cleavage reaction a, and further prevent Contamination of the substrate.

In the first aspect of the present invention, it is preferable that the oxygen concentration on the surface of the release layer measured by X-ray photoelectron spectroscopy is 1.2% or less. The above-mentioned olefin-based polymer and the above-mentioned high-melting phenol-based antioxidant generally have low compatibility. Even if only the olefin-based polymer is blended with a high-melting-point phenol-based antioxidant, sometimes the high-melting-point phenol-based antioxidant is not dispersed in the In olefin-based polymers. In such a low-dispersion state, the effect of suppressing the progress of the reaction that produces low-molecular-weight components may not be sufficiently exerted in some cases. In addition, if the above-mentioned high melting point phenolic antioxidant is present on the surface in large amounts, when a release film is used, the high melting point phenolic antioxidant itself may be transferred to the surface of the substrate, causing contamination. The inventors of the present invention have discovered that by implementing the method for producing the release layer described below, the high melting point phenol-based antioxidant can be sufficiently dispersed in the olefin-based polymer, and the contamination can be further suppressed. In this way, the high melting point phenol antioxidant is fully dispersed in the release layer of the olefin polymer, and the high melting point phenol antioxidant will not precipitate on the surface of the release layer. Therefore, by focusing on the oxygen contained in the high melting point phenolic antioxidant and measuring the oxygen concentration on the surface of the release layer by X-ray photoelectron spectroscopy, it is possible to disperse the high melting point phenolic antioxidant in the olefin polymer Status is evaluated. That is, when the oxygen concentration on the surface of the release layer measured by X-ray photoelectron spectroscopy is 1.2% or less, it can be judged that the high-melting phenol-based antioxidant is sufficiently dispersed in the olefin-based polymer. The oxygen concentration on the surface is preferably 0.9% or less, more preferably 0.6% or less.

The oxygen concentration on the surface of the release film can be determined by using an X-ray photoelectron spectrometer (manufactured by ULVAC-PHI, Versa Probe II) in the monochromatic Al Kα ray X-ray source, a detection angle of 45 degrees, and a STEP width of 1 eV. Measured under wide scan conditions. In this measurement, the oxygen concentration in the area about 5 nm from the surface can be measured. The surface oxygen concentration can be calculated using the following calculation formula. Surface oxygen concentration (%)=(IO/SO)/(IC/SC)×100 (IO: photoelectron intensity of oxygen, IC: photoelectron intensity of carbon, SC: relative sensitivity coefficient of carbon, SO: relative sensitivity coefficient of oxygen ) Furthermore, the photoelectron intensity of each element is a value obtained by integrating the photoelectron intensity measured by the wide scan in the following ranges. C _1s : 280-300 eV, O _1s : 520-540 eV In addition, the oxygen concentration in this specification is calculated with SC=0.314 and SO=0.733.

In a second aspect of the present invention, the release layer contains a metal deactivator. As described above, it is known that olefin-based polymers undergo a radical reaction by light, heat, or the coexistence of metal and oxygen to generate low-molecular-weight components. The above-mentioned formula (1), which is a series of reactions in which the olefin-based polymer is decomposed to produce low-molecular-weight components, is again shown below. In formula (1), R represents an alkyl chain.

In particular, the first reaction of the above formula (1), that is, the cleavage reaction a of generating R from RH, uses metal to act as a catalyst. In the release film with a release layer containing an olefin-based polymer, the metal catalysts such as Ti, Zr, Hf, Al, etc. used in the synthesis of the olefin-based polymer exist in the form of residues. It is considered that by heating such a release film during hot pressing, the cleavage reaction a proceeds, and the reaction for generating low molecular weight components is promoted. It is considered that among olefin-based polymers, 4-methyl-1-pentene-based polymers containing a large amount of C-H bonds are likely to produce low-molecular-weight components.

In the second aspect of the present invention, it can be considered that by using the olefin polymer in combination with a metal deactivator, the metal deactivator can capture the metal catalyst, inhibit the above-mentioned cracking reaction a, and inhibit the formation of a series of low molecular weight components. The reaction proceeds to prevent contamination of the substrate.

The aforementioned metal deactivator means a compound that can capture and inactivate the metal catalyst by coordinating metal elements. More specifically, for example, a metal deactivator having a nitrogen atom in the molecule can be cited, and more specifically, for example, a compound having a hydrazine structure or an amide structure in the molecule can be cited. The above-mentioned compound having a hydrazine structure or amide structure in the molecule can capture and inactivate the metal catalyst by coordinating the metal element through the hydrazine structure or amide structure.

-2,4,6-三胺、2',3-雙[[3-[3,5-二三級丁基-4-羥基苯基]丙醯基]]丙醯肼等。 上述於分子內具有醯肼結構之金屬減活劑例如可使用：Adekastab CDA-10（ADEKA公司製造）、Adekastab ZS-27（ADEKA公司製造）、Adekastab ZS-90（ADEKA公司製造）、Adekastab ZS-91（ADEKA公司製造）、IRGANOX MD1024（BASF公司製造）等市售品。As the above-mentioned metal deactivator having a hydrazine structure in the molecule, specifically, for example, N,N'-bis[3-(3,5-ditributyl-4-hydroxyphenyl)propane Amino]hydrazine, 1,3,5-tri

-2,4,6-triamine, 2',3-bis[[3-[3,5-di-tertiarybutyl-4-hydroxyphenyl]propionyl]]propanhydrazine, etc. The above-mentioned metal deactivator having a hydrazine structure in the molecule can be used, for example: Adekastab CDA-10 (manufactured by ADEKA), Adekastab ZS-27 (manufactured by ADEKA), Adekastab ZS-90 (manufactured by ADEKA), Adekastab ZS- 91 (manufactured by ADEKA), IRGANOX MD1024 (manufactured by BASF) and other commercially available products.

As the metal deactivator having an amide structure in the molecule, specifically, for example, hydroxy-N-1H-1,2,4-triazol-3-ylbenzamide, hydroxy-N- 1H-1,2,4-triazol-3-ylbenzamide, N'1,N'12-bis(2-hydroxybenzyl)dodecane dihydrazine, N,N'-diylidene Saluyl-1,2-diaminopropane and so on. The above-mentioned metal deactivator having an amide structure in the molecule can be used, for example: Adekastab CDA-1 (manufactured by ADEKA), Adekastab CDA-1M (manufactured by ADEKA), Adekastab CDA-6 (manufactured by ADEKA), Securis AK- 24M (manufactured by Sanyo Chemical Industry Co., Ltd.), DMD (manufactured by DuPont) and other commercially available products.

The above-mentioned metal deactivator may be used singly, or two or more kinds may be used in combination. Among them, a metal deactivator having a molecular weight of 500 or less is preferred in terms of being relatively easily dispersed in the above-mentioned olefin-based polymer. In addition, in terms of simultaneously imparting antioxidant properties, a metal deactivator having a hindered phenol structure in the molecule is also preferable.

The content of the metal deactivator in the release layer is not particularly limited, but it is preferably 0.1 part by weight or more relative to 100 parts by weight of the olefin-based polymer. If the content of the above-mentioned metal deactivator is less than 0.1 parts by weight, the decomposition of the olefin polymer (the progress of the reaction to produce low molecular weight components) may not be sufficiently suppressed in some cases. The content of the above-mentioned metal deactivator is more preferably 0.3 parts by weight or more. The upper limit of the content of the metal deactivator in the release layer is not particularly limited. From the viewpoint of release properties or heat resistance, it is preferably 1.0 part by weight or less relative to 100 parts by weight of the olefin-based polymer. More preferably, it is 0.7 parts by weight or less.

In the second aspect of the present invention, the nitrogen concentration on the surface of the release layer measured by X-ray photoelectron spectroscopy is 1.5% or less. The above-mentioned olefin-based polymer and the above-mentioned metal deactivator generally have low compatibility. Even if only the olefin-based polymer is blended with the metal deactivator, the metal deactivator may not be dispersed in the olefin-based polymer. And the effect of suppressing the progress of the reaction that produces low-molecular-weight components cannot be fully exhibited. In addition, if the metal deactivator mentioned above is present on the surface in a large amount, when a release film is used, the metal deactivator itself may be transferred to the surface of the substrate, causing contamination. The inventors of the present invention found that by implementing the method for producing the release layer described below, the metal deactivator can be sufficiently dispersed in the olefin-based polymer, and the contamination can be suppressed. In this way, the metal deactivator is fully dispersed in the release layer of the olefin polymer, and the metal deactivator will not be deposited on the surface of the release layer.

The dispersion state of the metal deactivator in the olefin polymer can be evaluated by focusing on the specific atoms contained in the metal deactivator and measuring the surface concentration of the release layer. The concentration of specific atoms in the surface of the release layer can be measured by X-ray photoelectron spectroscopy. For example, when a compound having a hydrazine structure or an amide structure in the molecule is used as a metal deactivator, the evaluation can be made focusing on the nitrogen atom as the above-mentioned specific atom. That is, when the nitrogen concentration on the surface of the release layer measured by X-ray photoelectron spectroscopy is 1.5% or less, the metal deactivator is sufficiently dispersed in the olefin-based polymer. The nitrogen concentration on the surface is preferably 0.9% or less, more preferably 0.7% or less.

The nitrogen concentration on the surface of the release film can be determined by using an X-ray photoelectron spectrometer (manufactured by ULVAC-PHI, Versa Probe II) in the monochromatic Al Kα ray X-ray light source, the detection angle is 45 degrees, and the STEP width is 1 eV. Under the conditions, a wide scan is performed and the measurement is performed. In this measurement, the nitrogen concentration in the area about 5 nm from the surface can be measured. The surface nitrogen concentration can be calculated using the following calculation formula. Surface nitrogen concentration (%)=(IN/SN)/(IC/SC)×100 (IN: photoelectron intensity of nitrogen, IC: photoelectron intensity of carbon, SC: relative sensitivity coefficient of carbon, SN: relative sensitivity coefficient of nitrogen ) Furthermore, the photoelectron intensity of each element is a value obtained by integrating the photoelectron intensity measured by the wide scan in the following ranges. C _1s : 280-300 eV, N _1s : 390-410 eV In addition, the nitrogen concentration in this specification is calculated with SC=0.314 and SN=0.499.

In the second aspect of the present invention, the above-mentioned release layer may further contain an antioxidant within a range that does not impair the purpose and effects of the present invention. For example, phenolic antioxidants can react in the second reaction of the above formula (1), that is, R· generated from RH reacts with oxygen to generate ROO·, and the ROO· reacts with RH to generate the so-called free radicals of R· In chain reaction b, free radicals are captured. Thereby, since the progress of the reaction that generates a series of low molecular weight components can be suppressed, the contamination of the substrate can be further prevented. At this time, by choosing to use a phenol-based antioxidant with a melting point of 160° C. or higher as the phenol-based antioxidant, it is possible to prevent the contamination of the substrate caused by the volatilization of the phenol-based antioxidant itself. In addition, for example, phosphorus-based antioxidants or sulfur-based antioxidants can further prevent the contamination of the substrate by decomposing the peroxide generated in the series of reactions of the above formula (1).

In the first and second aspects of the present invention, the release layer may further contain fibers, inorganic fillers, stabilizers, flame retardants, ultraviolet absorbers, antistatic agents, inorganic substances, higher fatty acid salts, etc., which are previously known additive.

In the first and second aspects of the present invention, the above-mentioned release layer can also be subjected to a release treatment for the purpose of improving release properties. The method of the release treatment is not particularly limited. For example, a method of coating or spraying a silicone-based, fluorine-based release agent on the release layer; a method of heat treatment and other known methods can be used. These release treatments may be used singly or in combination of two or more kinds.

In the first and second aspects of the present invention, the thickness of the release layer is not particularly limited, and the preferred lower limit is 5 μm, and the preferred upper limit is 75 μm. If the thickness of the above-mentioned release layer is within this range, when it is used in the manufacturing steps of a printed wiring board, a flexible printed circuit board, a multilayer printed wiring board, etc., the strength and the conformability to the unevenness of the flexible circuit board can be obtained. The balance of sex. The lower limit of the thickness of the above-mentioned release layer is more preferably 10 μm, and the more preferable upper limit is 30 μm.

In the first and second aspects of the present invention, the method for producing the release layer is not particularly limited, and examples include the following methods: adding the high melting point phenol antioxidant or the metal deactivation to the olefin polymer After mixing and kneading, it is extruded. However, in order to sufficiently disperse the high melting point phenolic antioxidant or metal deactivator in the olefin polymer as described above, for example, it is preferable to adopt (1) the olefin polymer and the high melting point phenol antioxidant or metal The deactivator is heated and kneaded to produce a masterbatch, and the masterbatch is used for extrusion molding. In addition, it is preferable to adopt (2) a method of using a co-rotating twin-screw extruder (double-headed) during extrusion molding to improve kneading properties. Furthermore, it is preferable to adopt (3) a method of improving the kneading property by adjusting the temperature, kneading time, extrusion amount, line speed, etc. during extrusion molding. It is particularly preferable to increase the temperature during the initial stage of extrusion molding (near the exit of the T-die), and to decrease the temperature after a fixed time has passed, and to increase the time until the end of the molding process. More specifically, it is preferable to set the set temperature at a position 20 to 40% away from the inlet side with respect to the full length of the cylinder to approximately 330 to 360°C. In the past, since the olefin-based polymer was decomposed in a high-temperature environment, when the olefin-based polymer was subjected to extrusion molding, the operation of heating to 300°C or higher at which decomposition started was usually not performed. On the other hand, as mentioned above, by deliberately raising the temperature to above 300°C in the initial stage of molding, and then cooling it to below 300°C, the mobility of the molecules can be increased. In addition, it is preferable to reduce the line speed. By making the time spent in extrusion molding longer, the time for the high melting point phenolic antioxidant or metal deactivator to disperse can be ensured. By adjusting the temperature and line speed, the diffusion of high melting point phenol antioxidants or metal deactivators can be promoted. By using at least any one of the methods (1) to (3) above, or using a combination of preferably two or more methods, and more preferably three or more methods, the high melting point phenol antioxidants or metals can be reduced The active agent is sufficiently dispersed in the olefin-based polymer.

The release film of the present invention may have a single-layer structure composed only of the above-mentioned release layer, or may have a two-layer structure composed of the above-mentioned release layer and a substrate layer. In addition, it may have a three-layer structure in which the above-mentioned release layer, intermediate layer (buffer layer), and release layer are sequentially laminated, or may have a multi-layer structure further having other layers. As the aforementioned base layer or intermediate layer, those previously known in the technical field of release films can be used.

The use of the release film of the present invention is not particularly limited, and is particularly suitable for the manufacture of flexible circuit substrates. Specifically, for example, in the manufacturing steps of flexible circuit boards such as printed wiring boards, flexible printed boards, multilayer printed wiring boards, etc., it can be preferably used as a copper clad laminate or The release film when the copper foil is pressed on the substrate. In addition, in the manufacturing process of the flexible printed circuit board, in order to prevent the cover film from being hot-pressed to the flexible printed circuit board body on which the copper circuit is formed by a thermosetting adhesive or a thermosetting adhesive sheet, The cover film is connected to the hot pressing plate and can be preferably used as a release film. Furthermore, in the semiconductor molding step of using a mold to seal a semiconductor wafer with a resin to obtain a molded product, it can be preferably used as a release film for covering the inner surface of the mold to prevent contamination of the mold due to the resin. [Effects of the invention]

According to the present invention, it is possible to provide a release film that does not contaminate the substrate when it is used in the manufacturing step of a flexible circuit substrate. In addition, by using such a release film, it is possible to prevent the occurrence of plating defects or to reduce the cleaning steps, which can help save resources or reduce environmental load.

Hereinafter, embodiments of the present invention will be further described in detail, but the present invention is not limited to these embodiments.

(Example 1) With respect to 100 parts by weight of 4-methyl-1-pentene polymer, 0.1 part by weight of Irganox 1098 (melting point 160°C) was added as a high melting point phenolic antioxidant, and a uniaxial extruder (manufactured by GM Engineering, GM30) was used. -28 (screw diameter 30 mm, L/D28)), extruded with a T-die width of 400 mm to obtain a release film with a thickness of 30 μm. Furthermore, as a condition during extrusion, the full length of the cylinder is divided into 5 equal parts, from the inlet side into 5 zones C1, C2, C3, C4, C5 in sequence, and the set temperature of each zone is set to C1: 300°C, C2: 300°C, C3 to C5: 290°C, the extrusion volume was set to 50 kg/hour, and the line speed was set to 70 m/min.

(Example 2) 0.5 parts by weight of Irganox 3114 (melting point: 221°C) was added as a high melting point phenolic antioxidant, and in the same manner as in Example 1, a release film with a thickness of 30 μm was obtained.

(Example 3) In addition to adding 1.0 part by weight of Irganox 1330 (melting point 240° C.) as a high melting point phenolic antioxidant, in the same manner as in Example 1, a release film with a thickness of 30 μm was obtained.

(Example 4) With respect to 100 parts by weight of 4-methyl-1-pentene polymer, 0.6 parts by weight of Irganox 1098 (melting point 160°C) is added as a high melting point phenolic antioxidant. After mixing with a V-type mixer, use double The shaft extruder performs melt kneading and cutting processing to prepare a pelletized masterbatch of 0.2 g/50 pellets. The obtained masterbatch was extruded with a co-rotating twin-screw extruder (manufactured by Research Laboratory of Plastics Technology, SBTN-92 (screw diameter 92 mm, L/D30)) with a T-die width of 400 mm , A release film with a thickness of 30 μm is obtained. Furthermore, as a condition for extrusion, the full length of the cylinder is divided into 5 equal parts, which are divided into 5 areas C1, C2, C3, C4, and C5 in sequence from the inlet side, and the set temperature of each area is set to C1: 300°C, C2: 350°C, C3 to C5: 290°C, the extrusion volume was set to 25 kg/hour, and the line speed was set to 35 m/min.

(Example 5) In addition to adding 0.3 parts by weight of Irganox 3114 (melting point: 221°C) as a high melting point phenol antioxidant, in the same manner as in Example 4, a release film with a thickness of 30 μm was obtained.

(Example 6) In addition to adding 0.7 parts by weight of Irganox 1330 (melting point 240° C.) as a high melting point phenolic antioxidant, in the same manner as in Example 4, a release film with a thickness of 30 μm was obtained.

(Comparative example 1) Except that no high-melting phenol-based antioxidant was added, in the same manner as in Example 1, a release film with a thickness of 30 μm was obtained.

(Comparative Examples 2 to 5) 0.4-0.7 parts by weight of the phenolic antioxidant shown in Table 1 was added instead of the high melting point phenolic antioxidant, except that the same method as in Example 4 was used to obtain a release film with a thickness of 30 μm. The phenolic antioxidants used are as follows. ・Irganox 1076 (melting point 50°C, manufactured by BASF) ・Irganox 259 (melting point 106°C, manufactured by BASF) ・Irganox 1010 (melting point 115°C, manufactured by BASF) ・Sumilizer GA80 (Melting point 125°C, manufactured by Sumitomo Chemical Co., Ltd.)

(Evaluation 1) The release films obtained in Examples 1 to 6 and Comparative Examples 1 to 5 were evaluated by the following methods. The results are shown in Table 1.

(1) The oxygen concentration on the surface of the release film is measured using an X-ray photoelectron spectrometer (manufactured by ULVAC-PHI, Versa Probe II), with an X-ray source of monochromatic Al Kα rays, a detection angle of 45 degrees, and a STEP width of 1 Perform wide scan measurement under eV conditions. The surface oxygen concentration is calculated using the following calculation formula. Surface oxygen concentration (%)=(IO/SO)/(IC/SC)×100 (IO: photoelectron intensity of oxygen, IC: photoelectron intensity of carbon, SC: relative sensitivity coefficient of carbon, SO: relative sensitivity coefficient of oxygen ) Furthermore, the photoelectron intensity of each element is a value obtained by integrating the photoelectron intensity measured by the wide scan in the following ranges. C _1s : 280-300 eV, O _1s : 520-540 eV Furthermore, the oxygen concentration is calculated with SC=0.314 and SO=0.733.

(2) Evaluation of non-polluting properties Cut the obtained release film into A4, and clamp it with copper foils of the same size to obtain a laminate. The obtained laminate was hot-pressed under the conditions of 180°C, 5 MPa, and 60 minutes. The hot pressing is performed with n=5. After that, a total of 10 copper foils were peeled off from the laminate and collected, and the surface of each of them on the side in contact with the release film was washed with chloroform to obtain an extract. Combine all the obtained extracts and distill off the chloroform, then weigh the remaining amount and use it as the amount of contaminant components transferred from the release membrane. Calculate the amount of pollution components per unit area, and evaluate based on the following criteria. ◎: Contaminant components in an amount of 50 mg / m ² or less ○: Contaminant components of more than 50 mg / m ² and 100 mg / m ² or less △: Contaminant components of more than 100 mg / m ² and 500 mg / m ² or less ×: The amount of pollutants exceeds 500 mg/m ²

[Table 1] Phenolic antioxidants Evaluation type Melting point (℃) Blending amount (parts by weight) Oxygen concentration (%) Non-polluting Example 1 Irganox 1098 160 0.1 1.4 〇 Example 2 Irganox 3114 221 0.5 3.0 〇 Example 3 Irganox 1330 240 1.0 3.6 〇 Example 4 Irganox 1098 160 0.6 0.2 ◎ Example 5 Irganox 3114 221 0.3 0.6 ◎ Example 6 Irganox 1330 240 0.7 1.2 ◎ Comparative example 1 - - - 0.0 X Comparative example 2 Irganox 1076 50 0.5 0.1 △ Comparative example 3 Irganox 259 106 0.4 0.4 △ Comparative example 4 Irganox 1010 115 0.6 0.5 △ Comparative example 5 Sumilizer GA80 125 0.7 1.1 △

(Example 7) With respect to 100 parts by weight of 4-methyl-1-pentene-based polymer, 0.1 parts by weight of Adekastab CDA-1 (molecular weight 204) is added as a metal deactivator. The extruder performs melt kneading and cutting processing to prepare a pelletized masterbatch of 0.2 g/50 pellets. The obtained masterbatch was extruded with a co-rotating twin-screw extruder (manufactured by Research Laboratory of Plastics Technology, SBTN-92 (screw diameter 92 mm, L/D30)) with a T-die width of 400 mm , A release film with a thickness of 30 μm is obtained. Furthermore, as a condition during extrusion, the full length of the cylinder is divided into 5 equal parts, from the inlet side into 5 zones C1, C2, C3, C4, C5 in sequence, and the set temperature of each zone is set to C1: 300°C, C2: 350°C, C3 to C5: 290°C. In addition, the extrusion rate was set to 25 kg/hour, and the line speed was set to 35 m/minute.

(Example 8) Except for using 1.0 part by weight of Adekastab CDA-10 (molecular weight 553) as the metal deactivator, in the same manner as in Example 7, a release film with a thickness of 30 μm was obtained.

(Example 9) Except for using 0.7 parts by weight of Adekastab CDA-1 (molecular weight 204) as the metal deactivator, in the same manner as in Example 7, a release film with a thickness of 30 μm was obtained.

(Example 10) Except for using 0.3 parts by weight of Adekastab CDA-10 (molecular weight 553) as the metal deactivator, in the same manner as in Example 7, a release film with a thickness of 30 μm was obtained.

(Example 11) Except for using 0.5 parts by weight of Adekastab CDA-10 (molecular weight 553) as the metal deactivator, in the same manner as in Example 7, a release film with a thickness of 30 μm was obtained.

(Comparative Example 6) Use 100 parts by weight of 4-methyl-1-pentene polymer using a single-screw extruder (manufactured by GM Engineering, GM30-28 (screw diameter 30 mm, L/D28)) with a T-shaped die width of 400 mm Perform extrusion molding to obtain a release film with a thickness of 30 μm. The extrusion conditions are set as cylinder temperature 260～300℃, cylinder temperature C1: 300℃, C2: 300℃, C3～C5: 290℃, extrusion volume 50 kg/hour, line speed 70 m/min.

(Comparative Example 7) Except for using 1.1 parts by weight of Adekastab CDA-1 (molecular weight 204) as the metal deactivator, in the same manner as in Comparative Example 6, a release film with a thickness of 30 μm was obtained.

(Comparative Example 8) Except for using 1.5 parts by weight of Adekastab CDA-1 (molecular weight 204) as the metal deactivator, in the same manner as in Comparative Example 6, a release film with a thickness of 30 μm was obtained.

(Comparative Example 9) Adekastab CDA-10 (molecular weight 553) 0.5 parts by weight was used as the metal deactivator, and the extrusion conditions were set as cylinder temperature 260～300℃, cylinder temperature C1: 300℃, C2: 300℃, C3～C5: 290 Except for the temperature, the extrusion volume of 50 kg/hour, and the line speed of 70 m/min, in the same manner as in Examples 8 and 10, a release film with a thickness of 30 μm was obtained.

(Comparative Example 10) Adekastab CDA-10 (molecular weight 553) 0.5 parts by weight was used as a metal deactivator, and a single-screw extruder (manufactured by GM Engineering, GM30-28 (screw diameter 30 mm, L/D28)) was used for film formation. Otherwise, in the same manner as in Examples 8 and 10, a release film with a thickness of 30 μm was obtained.

(Comparative Example 11) 0.5 parts by weight of Adekastab CDA-10 (molecular weight 553) was used as the metal deactivator, and raw materials mixed only with a V-type mixer etc. were used, except that it was obtained in the same manner as in Examples 8 and 10 Release film with a thickness of 30 μm.

(Evaluation 2) The release films obtained in Examples 7 to 11 and Comparative Examples 6 to 11 were evaluated by the following methods. The results are shown in Table 2.

(1) The nitrogen concentration on the surface of the release film is measured using an X-ray photoelectron spectrometer (manufactured by ULVAC-PHI, Versa Probe II), with an X-ray source of monochromatic Al Kα rays, a detection angle of 45 degrees, and a STEP width of 1 Perform wide scan measurement under eV conditions. The surface nitrogen concentration is calculated using the following calculation formula. Surface nitrogen concentration (%)=(IN/SN)/(IC/SC)×100 (IN: photoelectron intensity of nitrogen, IC: photoelectron intensity of carbon, SC: relative sensitivity coefficient of carbon, SN: relative sensitivity coefficient of nitrogen ) Furthermore, the photoelectron intensity of each element is a value obtained by integrating the photoelectron intensity measured by the wide scan in the following ranges. C _1s : 280-300 eV, N _1s : 390-410 eV Furthermore, the nitrogen concentration is calculated with SC=0.314 and SN=0.499.

(2) Evaluation of non-polluting properties Cut the obtained release film into A4, and clamp it with copper foils of the same size to obtain a laminate. The obtained laminate was hot-pressed under the conditions of 180°C, 5 MPa, and 60 minutes. The hot pressing is performed with n=5. After that, a total of 10 copper foils were peeled off from the laminate and collected, and the surface of each of them on the side in contact with the release film was washed with chloroform to obtain an extract. Combine all the obtained extracts and distill off the chloroform, then weigh the remaining amount and use it as the amount of contaminant components transferred from the release membrane. Calculate the amount of pollution components per unit area, and evaluate based on the following criteria. ◎: Contaminant components in an amount of 50 mg / m ² or less ○: Contaminant components of more than 50 mg / m ² and 100 mg / m ² or less △: Contaminant components of more than 100 mg / m ² and 500 mg / m ² or less ×: The amount of pollutants exceeds 500 mg/m ²

[Table 2] Metal deactivator Evaluation type Blending amount (parts by weight) Nitrogen concentration (%) Non-polluting Example 7 CDA-1 0.1 0.0 〇 Example 8 CDA-10 1.0 1.1 〇 Example 9 CDA-1 0.7 0.6 ◎ Example 10 CDA-10 0.3 0.6 ◎ Example 11 CDA-10 0.5 0.7 ◎ Comparative example 6 - - 0.0 X Comparative example 7 CDA-1 1.1 2.9 X Comparative example 8 CDA-1 1.5 4.6 X Comparative example 9 CDA-10 0.5 1.6 △ Comparative example 10 CDA-10 0.5 1.8 △ Comparative example 11 CDA-10 0.5 1.9 △ [Industrial availability]

According to the present invention, it is possible to provide a release film that does not contaminate the substrate when it is used in the manufacturing step of a flexible circuit substrate.

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Claims (6)

A release film comprising: a release layer containing a 4-methyl-1-pentene polymer and a phenolic antioxidant with a melting point of 160°C or higher, and the melting point of the release layer is 160°C or higher The content of the phenolic antioxidant is 0.1~1.0 parts by weight relative to 100 parts by weight of the 4-methyl-1-pentene polymer. Antioxidants. The release film of claim 1, wherein the oxygen concentration on the surface of the release layer measured by X-ray photoelectron spectroscopy is 1.2% or less. The release film of claim 1 or 2, wherein the release layer further contains a metal deactivator. A release film, which has: a release layer containing 4-methyl-1-pentene polymer and a metal deactivator, and the nitrogen on the surface of the release layer measured by X-ray photoelectron spectroscopy The concentration is 1.5% or less, the content of the metal deactivator in the release layer is 0.1 parts by weight or more relative to 100 parts by weight of the 4-methyl-1-pentene polymer, and the metal deactivator is in the molecule Compounds with hydrazine structure or amide structure. The release film of claim 4, wherein the content of the metal deactivator in the release layer is 1.0 part by weight or less with respect to 100 parts by weight of the 4-methyl-1-pentene-based polymer. The release film of claim 4 or 5, wherein the metal deactivator is a compound having a hindered phenol structure in the molecule.