阅读说明：本技术 脱模膜 (Mold release film ) 是由 川原良介 小屋原宏明 六车有贵 前川博亮 于 2020-03-06 设计创作，主要内容包括：本发明的目的在于提供一种在用于柔性电路基板的制造工序时不会污染基板的脱模膜。本发明是一种脱模膜,其具有脱模层,所述脱模层含有烯烃系聚合物和熔点为160℃以上的酚系抗氧化剂。另外,本发明是一种脱模膜,其具有脱模层,所述脱模层含有烯烃系聚合物和金属钝化剂,所述脱模层的通过X射线光电子能谱法测定的表面的氮浓度为1.5％以下。(The invention aims to provide a release film which does not pollute a substrate when used in a manufacturing process of a flexible circuit substrate. The present invention is a release film having a release layer containing an olefin polymer and a phenol antioxidant having a melting point of 160 ℃ or higher. The present invention is a release film having a release layer containing an olefin polymer and a metal deactivator, wherein the surface nitrogen concentration of the release layer as measured by X-ray photoelectron spectroscopy is 1.5% or less.)

1. A release film comprising a release layer containing an olefin polymer and a phenol antioxidant having a melting point of 160 ℃ or higher.

2. The release film according to claim 1, wherein the content of the phenolic antioxidant having a melting point of 160 ℃ or higher in the release layer is 0.1 to 1.0 part by weight based on 100 parts by weight of the olefin polymer.

3. The release film according to claim 1 or 2, wherein the surface of the release layer has an oxygen concentration of 1.2% or less as measured by X-ray photoelectron spectroscopy.

4. The release film according to claim 1, 2 or 3, wherein the phenol antioxidant having a melting point of 160 ℃ or higher is a hindered phenol antioxidant.

5. The release film according to claim 1, 2, 3 or 4, wherein the olefin polymer contains a 4-methyl-1-pentene polymer.

6. A release film comprising a release layer containing an olefin polymer and a metal deactivator, wherein the surface of the release layer has a nitrogen concentration of 1.5% or less as measured by X-ray photoelectron spectroscopy.

7. The release film of claim 6, wherein the metal deactivator is a metal deactivator having a nitrogen atom in a molecule.

8. The release film according to claim 6 or 7, wherein the content of the metal deactivator in the release layer is 0.1 parts by weight or more based on 100 parts by weight of the olefin-based polymer.

9. The release film according to claim 6, 7 or 8, 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 olefin-based polymer.

10. The release film according to claim 6, 7, 8 or 9, wherein the metal deactivator is a compound having a hydrazide structure or an amide structure in a molecule.

11. The release film according to claim 6, 7, 8, 9 or 10, wherein the metal deactivator is a compound having a hindered phenol structure in a molecule.

12. The release film according to claim 6, 7, 8, 9, 10 or 11, wherein the olefin-based polymer contains a 4-methyl-1-pentene-based polymer.

Technical Field

The present invention relates to a release film.

Background

A mold release film is used in a process of manufacturing a flexible circuit board such as a printed wiring board, a flexible printed board, and a multilayer printed wiring board. For example, in a process for manufacturing a flexible printed circuit board, a thermosetting adhesive or a thermosetting adhesive sheet is used to thermally press-bond a cover film to a flexible printed circuit board main body on which a copper circuit is formed. In this case, a release film is widely used to prevent the cover film from adhering to the hot press plate.

For example, patent document 1 discloses a release film in which a first release layer, an intermediate layer, and a second release layer are stacked in this order, and the first release layer and the second release layer contain a 4-methyl-1-pentene polymer.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-189151

Disclosure of Invention

Problems to be solved by the invention

It is known that a film containing a 4-methyl-1-pentene polymer is excellent in mold release from a press hot plate made of stainless steel, a cover film made of a polyimide film, and the like, and is also excellent in heat resistance in a hot pressing step at about 170 ℃.

However, when a film containing a 4-methyl-1-pentene polymer is used as a release film in a process for producing a flexible circuit board, there is a problem that plating cannot be sufficiently performed even if a plating treatment is performed on the resulting board, and a plating failure may occur. This is considered to be because the surface of the substrate is contaminated for some reason.

In addition, when such contamination occurs, cleaning with a chemical solution or the like is necessary, which increases the environmental load on product production.

In view of the above-described situation, an object of the present invention is to provide a release film that does not contaminate a substrate when used in a process for manufacturing a flexible circuit substrate.

Means for solving the problems

The present invention is a release film having a release layer containing an olefin polymer and a phenol antioxidant having a melting point of 160 ℃ or higher. The present invention is a release film comprising a release layer containing an olefin polymer and a metal deactivator, wherein the surface of the release layer has a nitrogen concentration of 1.5% or less as measured by X-ray photoelectron spectroscopy.

The present invention is described in detail below.

The present inventors have studied the cause of contamination when a release film having a release layer containing an olefin polymer such as 4-methyl-1-pentene polymer is used as a release film in a process for producing a flexible circuit board. As a result, the following factors were found to cause contamination: the olefin-based polymer is decomposed to generate a low molecular weight component, and the low molecular weight component is transferred to the surface of the substrate when the release film is used. In contrast, the present inventors have studied to prevent contamination by incorporating a phenolic antioxidant or a metal deactivator in a release layer containing an olefin polymer.

First, attempts have been made to incorporate a phenolic antioxidant into a release layer containing an olefin polymer, but contamination cannot be sufficiently prevented. The present inventors have further studied and found that the phenolic antioxidant itself is a new source of pollution. Further, it has been found that by selecting and using a phenol-based antioxidant having a melting point of 160 ℃ or higher, contamination by low molecular weight components generated by decomposition of an olefin-based polymer can be prevented, and contamination by the phenol-based antioxidant itself can also be prevented. The present inventors have also found that the formation of low molecular weight components and the generation of contamination can be suppressed by blending a metal deactivator in a release layer containing an olefin polymer and sufficiently dispersing the metal deactivator in the olefin polymer, and have completed the present invention.

The release film of the present invention has a release layer containing an olefin polymer.

The olefin polymer is not particularly limited, but preferably contains 4-methyl-1-pentene polymer. By including the 4-methyl-1-pentene polymer in the olefin polymer, the release film of the present invention has excellent releasability from a hot press plate made of stainless steel, a cover film made of a polyimide film, and the like, and has good heat resistance in a hot press step at about 170 ℃.

As the 4-methyl-1-pentene polymer, a copolymer of 4-methyl-1-pentene and a monomer other than 4-methyl-1-pentene may be used in addition to a homopolymer of 4-methyl-1-pentene.

The monomer other than 4-methyl-1-pentene is not particularly limited, and examples thereof include α -olefins having not more than 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene.

In the case where the 4-methyl-1-pentene polymer is a copolymer, the content of the structural unit derived from 4-methyl-1-pentene is preferably 80% by weight or more, more preferably 90% by weight or more, from the viewpoint of achieving higher mold releasability and heat resistance.

As the above-mentioned 4-methyl-1-pentene polymer, a commercially available polymer such as TPX (registered trademark) manufactured by Mitsui chemical Co., Ltd. can be used.

The content of the 4-methyl-1-pentene polymer in the olefin polymer is not particularly limited, but is preferably 50% by weight or more, more preferably 70% by weight or more, from the viewpoint of achieving higher mold releasability and heat resistance. The upper limit of the content of the 4-methyl-1-pentene polymer is not particularly limited, and may be 100% by weight.

When the olefin-based polymer contains an olefin-based polymer other than the 4-methyl-1-pentene-based polymer, the olefin-based polymer other than the 4-methyl-1-pentene-based polymer is not particularly limited, and for example: an olefin polymer obtained by using an alpha-olefin having 20 or less carbon atoms or the like. Specific examples of the α -olefin having 20 or less carbon atoms include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene.

The content of the olefin-based polymer in the release layer is not particularly limited, and usually, the olefin-based polymer is a main component of the release layer, and the preferable lower limit and the preferable upper limit of the content of the olefin-based polymer are 50 wt% and 99 wt%, respectively. When the content of the olefin polymer is within this range, the releasability and 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 1 st aspect of the present invention, the releasing layer contains a phenolic antioxidant.

It is known that olefin polymers undergo radical reaction by light, heat or coexistence of metal and oxygen to generate low molecular weight components. The following formula (1) shows a reaction formula of a series of reactions in which an olefin polymer is decomposed to produce a low molecular weight component.

In the formula (1), R represents an alkyl chain.

Among olefin polymers, 4-methyl-1-pentene polymers containing a large number of C-H bonds are considered to be likely to generate low molecular weight components.

[ chemical formula 1]

The phenolic antioxidant can inhibit progress of a series of reactions for producing low molecular weight components by trapping radicals in the so-called radical chain reaction b in which ROO is generated by reacting R.generated from RH with oxygen and R.is generated by reacting the ROO.with RH in the 2 nd reaction of the formula (1), thereby preventing contamination of a substrate.

In the manufacturing process of the flexible circuit board, hot pressing is generally performed at 160 to 200 ℃ under 3 to 10MPa for about 2 to 10 minutes. In this hot pressing, a part of the phenol-based antioxidant volatilizes and causes contamination of the substrate.

In embodiment 1 of the present invention, a phenolic antioxidant having a melting point of 160 ℃ or higher (hereinafter, also referred to as "high-melting phenolic antioxidant") is selected and used as the phenolic antioxidant. By using the high-melting-point phenol-based antioxidant, contamination by low-molecular-weight components generated by decomposition of the olefin-based polymer can be prevented, and contamination by the phenol-based antioxidant itself can also be prevented.

The high-melting-point phenol antioxidant is not particularly limited as long as it is a compound having a melting point of 160 ℃ or higher and a phenol structure in the molecule, and a hindered phenol antioxidant can be used. The hindered phenol structure means that a bulky atomic group is present in the ortho position to the phenolic hydroxyl group. The hindered phenol antioxidant is preferably a compound having a phenolic hydroxyl group and a branched alkyl group in the ortho-position to the phenolic hydroxyl group. Specific examples of the hindered phenol antioxidant include N, N '-hexane-1, 6-diylbis (3- (3, 5-di-tert-butyl-4-hydroxyphenylpropionamide)), 1, 3, 5-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) -1, 3, 5-triazine-2, 4, 6(1H, 3H, 5H) -trione, 3', 5, 5 '-hexa-tert-butyl-alpha, alpha' - (mesitylene-2, 4, 6-triyl) tri-p-cresol, and the like. These high-melting-point phenol antioxidants may be used alone or in combination of 2 or more.

As the hindered phenol antioxidant, commercially available products such as Irganox1098 (melting point 160, manufactured by BASF Co., Ltd.), Irganox3114 (melting point 221, manufactured by BASF Co., Ltd.), and Irganox1330 (melting point 240, manufactured by BASF Co., Ltd.) can be used.

The molecular weight of the high-melting-point phenol antioxidant is not particularly limited, and from the viewpoint of sufficient dispersion in the olefin polymer, the viewpoint of further preventing contamination of the substrate, and the like, a preferred lower limit is 200, a preferred upper limit is 1000, a more preferred lower limit is 500, and a more preferred upper limit is 800.

The content of the high-melting-point phenolic antioxidant in the release layer is not particularly limited, and the lower limit is preferably 0.1 part by weight and the upper limit is preferably 1.0 part by weight with respect to 100 parts by weight of the olefinic polymer. When the content of the high-melting-point phenol antioxidant is within this range, contamination of the substrate can be prevented without affecting the releasability and heat resistance. The lower limit of the content of the high-melting-point phenol antioxidant is more preferably 0.3 part by weight, and the upper limit is more preferably 0.7 part by weight.

In the 1 st aspect of the present invention, the release layer may further contain a phosphorus antioxidant or a sulfur antioxidant within a range not to impair the object of the present invention. These antioxidants decompose peroxides generated in the series of reactions of formula (1) above, and thus can further prevent contamination of the substrate.

In the 1 st aspect of the present invention, the release layer may further contain a metal deactivator within a range not to impair the object of the present invention. The metal deactivator is a compound capable of trapping and deactivating a metal catalyst by coordinating with a metal element. By incorporating a metal deactivator, the metal serving as a catalyst can be trapped in the cracking reaction (suns: open reaction) a, which is the particularly initial reaction of formula (1), i.e., the generation of R · by RH, thereby suppressing the cracking reaction a and further preventing contamination of the substrate.

In the 1 st aspect of the present invention, the surface of the release layer preferably has an oxygen concentration of 1.2% or less as measured by X-ray photoelectron spectroscopy.

The olefin polymer and the high-melting-point phenol antioxidant are generally low in compatibility, and even if the high-melting-point phenol antioxidant is simply blended with the olefin polymer, the high-melting-point phenol antioxidant may not be dispersed in the olefin polymer. In such a low dispersion state, the effect of suppressing the progress of the reaction for producing the low molecular weight component may not be sufficiently exhibited. Further, if the high-melting-point phenol antioxidant is present in a large amount on the surface, the high-melting-point phenol antioxidant itself may be transferred to the surface of the substrate when the release film is used, which may cause contamination. The present inventors have found that by carrying out the above-described method for producing a release layer, which will be described later, a high-melting-point phenol-based antioxidant can be sufficiently dispersed in an olefin-based polymer, and staining can be further suppressed.

In the release layer in which the high-melting-point phenol antioxidant is dispersed in the olefin polymer sufficiently in this manner, the high-melting-point phenol antioxidant is not precipitated on the surface of the release layer in a concentrated manner. Therefore, focusing attention on oxygen contained in the high-melting-point phenol antioxidant, the dispersion state of the high-melting-point phenol antioxidant in the olefin polymer can be evaluated by measuring the oxygen concentration on the surface of the release layer by X-ray photoelectron spectroscopy. 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-point 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 at the surface of the release film can be measured by: an X-ray photoelectron spectrometer (Versa Probe II, manufactured by ULVAC-PHI) was used to perform a wide scan under conditions of an X-ray source for monochromatizing Al K.alpha.rays, a detection angle of 45 degrees, and a STEP width of 1 eV. In this measurement, the oxygen concentration in a region of about 5nm from the surface can be measured. The surface oxygen concentration can be calculated by 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)

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：280-300eV，O_1s：520-540eV

The oxygen concentration in the present specification was calculated under the conditions of SC 0.314 and SO 0.733.

In the 2 nd aspect of the present invention, the releasing layer contains a metal deactivator.

As described above, it is known that olefin polymers undergo radical reaction by light, heat or coexistence of metal and oxygen to generate low molecular weight components. The reaction formula of the series of reactions in which the olefin polymer is decomposed to produce low molecular weight components, that is, the formula (1), will be described again below.

In the formula (1), R represents an alkyl chain.

[ chemical formula 2]

The first reaction, in particular, the cleavage reaction a of RH to R · is catalyzed by the metal in the above formula (1). In a release film having a release layer containing an olefin polymer, a metal catalyst such as Ti, Zr, Hf, Al, or the like used in synthesizing the olefin polymer is present as a residue. It is considered that the cleavage reaction a proceeds and the reaction to generate the low molecular weight component proceeds because such a release film is heated at the time of hot pressing. Among olefin polymers, 4-methyl-1-pentene polymers containing a large number of C-H bonds are considered to be likely to generate low molecular weight components.

In the 2 nd aspect of the present invention, it is considered that the metal deactivator is used in combination with the olefin polymer, whereby the metal deactivator traps the metal catalyst, the above-mentioned cleavage reaction a is suppressed, the progress of a series of reactions for producing low molecular weight components is suppressed, and contamination of the substrate can be prevented.

The metal deactivator is a compound capable of capturing and deactivating a metal catalyst by coordinating with a metal element. More specifically, for example, a metal deactivator having a nitrogen atom in the molecule, and more specifically, for example, a compound having a hydrazide structure or an amide structure in the molecule. The compound having a hydrazide structure or an amide structure in the molecule can coordinate to a metal element via the hydrazide structure or the amide structure, thereby trapping and deactivating the metal catalyst.

Specific examples of the metal deactivator having a hydrazide structure in the molecule include N, N '-bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine, 1, 3, 5-triazine-2, 4, 6-triamine, and 2', 3-bis [ [3- [3, 5-di-tert-butyl-4-hydroxyphenyl ] propionyl ] propionylhydrazine.

As the metal deactivator having a hydrazide structure in the molecule, commercially available products such as ADKSTAB CDA-10 (manufactured by ADEKA), ADKSTAB ZS-27 (manufactured by ADEKA), ADKSTAB ZS-90 (manufactured by ADEKA), ADKSTAB ZS-91 (manufactured by ADEKA) and IRGANOX MD1024 (manufactured by BASF) can be used.

Specific examples of the metal deactivator having an amide structure in the molecule include hydroxy-N-1H-1, 2, 4-triazol-3-ylbenzamide, N ' 1, N ' 12-bis (2-hydroxybenzoyl) dodecyldihydrazine (Japanese: N ' 1, N ' 12- ビス (2- ヒドロキシベンゾル) ドデ force ンジヒドラジン), and N, N ' -disalicylidene-1, 2-diaminopropane.

As the metal inactivator having an amide structure in the molecule, commercially available products such as ADKSTAB CDA-1 (manufactured by ADEKA), ADKSTAB CDA-1M (manufactured by ADEKA), ADKSTAB CDA-6 (manufactured by ADEKA), セクリス AK-24M (manufactured by Sanyo chemical industries, Ltd.), DMD (manufactured by DuPont) and the like can be used.

The metal deactivators may be used alone or in combination of 2 or more.

Among them, the metal deactivator having a molecular weight of 500 or less is preferable because it can be dispersed in the olefin polymer relatively easily.

Further, since oxidation resistance can be simultaneously provided, 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, and is preferably 0.1 part by weight or more based on 100 parts by weight of the olefin-based polymer. If the content of the metal deactivator is less than 0.1 parts by weight, the decomposition of the olefin polymer (the progress of the reaction to form low molecular weight components) may not be sufficiently suppressed. The content of the 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, but is preferably 1.0 part by weight or less, more preferably 0.7 part by weight or less, based on 100 parts by weight of the olefin-based polymer, from the viewpoint of releasability and heat resistance.

In the 2 nd aspect of the present invention, the surface of the release layer has a nitrogen concentration of 1.5% or less as measured by X-ray photoelectron spectroscopy.

The olefinic polymer and the metal deactivator are generally low in compatibility, and even if the metal deactivator is simply added to the olefinic polymer, the metal deactivator is not dispersed in the olefinic polymer, and the effect of suppressing the progress of the reaction for producing the low-molecular-weight component may not be sufficiently exhibited. Further, if the metal deactivator is present in a large amount on the surface, the metal deactivator itself may be transferred to the surface of the substrate when the release film is used, which may cause contamination. The present inventors have found that by carrying out the above-described method for producing a release layer, a metal deactivator can be dispersed in an olefin polymer sufficiently, and staining can be further suppressed. In the release layer in which the metal deactivator is dispersed in the olefin polymer sufficiently in this manner, the metal deactivator is not precipitated on the surface of the release layer in a concentrated manner.

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

The nitrogen concentration at the surface of the release film can be measured as follows: an X-ray photoelectron spectrometer (Versa Probe II, manufactured by ULVAC-PHI) was used to perform a wide scan under conditions of an X-ray source for monochromatizing Al K.alpha.rays, a detection angle of 45 degrees, and a STEP width of 1 eV. In this measurement, the nitrogen concentration in a region of about 5nm from the surface can be measured. The surface nitrogen concentration can be calculated by 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)

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：280-300eV，N_1s：390-410eV

The nitrogen concentration in the present specification was calculated under the conditions of SC 0.314 and SN 0.499.

In the 2 nd aspect of the present invention, the release layer may further contain an antioxidant within a range that does not impair the object and effect of the present invention.

For example, the phenolic antioxidant can trap radicals in the 2 nd reaction of the above formula (1), that is, the so-called radical chain reaction b in which R.produced from RH reacts with oxygen to produce ROO.and the ROO.reacts with RH to produce R.. This can suppress the progress of a series of reactions for generating low molecular weight components, and thus can further prevent contamination of the substrate. In this case, by selecting a phenol antioxidant having a melting point of 160 ℃ or higher as the phenol antioxidant, contamination of the substrate due to volatilization of the phenol antioxidant itself can be prevented.

Further, for example, the phosphorus-based antioxidant and the sulfur-based antioxidant can further prevent contamination of the substrate by decomposing the peroxide generated in the series of reactions of the above formula (1).

In the embodiments 1 and 2 of the present invention, the release layer may further contain conventionally known additives such as fibers, inorganic fillers, stabilizers, flame retardants, ultraviolet absorbers, antistatic agents, inorganic substances, higher fatty acid salts, and the like.

In the 1 st and 2 nd aspects of the present invention, the release layer may be subjected to a release treatment for the purpose of improving the releasability. The method of the release treatment is not particularly limited, and for example, the following may be used: a method of applying or spreading a silicone-based or fluorine-based release agent on the release layer, a method of performing heat treatment, and the like. These mold release treatments may be used alone, or 2 or more kinds may be used in combination.

In the 1 st and 2 nd aspects of the present invention, the thickness of the release layer is not particularly limited, and the lower limit is preferably 5 μm and the upper limit is preferably 75 μm. When the thickness of the release layer is within this range, the strength, the ability to follow the irregularities of the flexible circuit board, and the like can be balanced when the release layer is used in a manufacturing process of a printed wiring board, a flexible printed board, a multilayer printed wiring board, and the like. A more preferable lower limit and a more preferable upper limit of the thickness of the release layer are 10 μm and 30 μm, respectively.

In the 1 st and 2 nd aspects of the present invention, the method for producing the release layer is not particularly limited, and examples thereof include: and a method in which the high-melting-point phenolic antioxidant or the metal deactivator and, if necessary, additives are added to the olefinic polymer, kneaded, and then extruded.

However, in order to sufficiently disperse the high-melting-point phenolic antioxidant or metal deactivator in the olefinic polymer as described above, for example, it is preferable to use: (1) a method in which an olefin polymer is heated and kneaded with a high-melting-point phenol antioxidant or a metal deactivator to produce a master batch, and the master batch is subjected to extrusion molding. In addition, it is preferable to employ: (2) in the extrusion molding, a co-rotating twin-screw extruder (double flight) is used to improve kneading property. Further, it is preferable to employ: (3) a method of improving the kneading property by adjusting the temperature, kneading time, extrusion amount, line speed, and the like at the time of extrusion molding. In particular, it is preferable to increase the temperature at the initial stage of extrusion molding (in the vicinity of the T-die exit), decrease the temperature after a certain period of time, and increase the time until the molding is completed. More specifically, the set temperature at a position 20 to 40% of the total length of the cylinder from the inlet side is preferably set to about 330 to 360 ℃. Conventionally, since the decomposition of olefin polymers proceeds in a high-temperature environment, when the olefin polymers are extrusion molded, the olefin polymers are not generally heated to 300 ℃ or higher from which the decomposition starts. On the other hand, as described above, the mobility of molecules can be increased by specifically raising the temperature to 300 ℃ or higher in the initial stage of molding and then lowering the temperature to 300 ℃ or lower. In addition, the linear velocity is preferably reduced. By extending the time taken for extrusion molding, the time for dispersing the high-melting-point phenolic antioxidant or the metal deactivator can be ensured. By adjusting the temperature and the line speed, the diffusion of the high-melting-point phenol-based antioxidant or the metal deactivator can be promoted.

By using at least any one of the methods (1) to (3) above, or preferably 2 or more in combination, and more preferably 3 or more in combination, the high-melting-point phenolic antioxidant or metal deactivator can be sufficiently dispersed in the olefinic polymer.

The release film of the present invention may have a single-layer structure composed only of the release layer, or may have a 2-layer structure composed of the release layer and a base material layer. The above-mentioned release layer, intermediate layer (buffer layer), and release layer may be stacked in this order to form a 3-layer structure, or may be a multilayer structure further including other layers.

As the substrate layer and the intermediate layer, those conventionally known in the art 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 production of a flexible circuit board. Specifically, for example, in a process for producing a flexible circuit board such as a printed wiring board, a flexible printed board, or a multilayer printed wiring board, the release film can be suitably used as a release film in hot-pressing a copper-clad laminate or a copper foil on a substrate via a prepreg or a heat-resistant film. In the production process of a flexible printed circuit board, when a cover film is thermally pressure-bonded to a flexible printed circuit board main body on which a copper circuit is formed with a thermosetting adhesive or a thermosetting adhesive sheet, the cover film can be suitably used as a release film in order to prevent the cover film from being bonded to a hot-press plate. In addition, in a semiconductor molding process in which a molded article is obtained by sealing a semiconductor chip with a resin using a mold, the resin composition can be suitably used as a mold release film for covering the inner surface of the mold to prevent contamination of the mold with the resin.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a mold release film that does not contaminate a substrate when used in a process for manufacturing a flexible circuit substrate can be provided. Further, by using such a release film, occurrence of plating failure can be prevented, reduction in cleaning process can be realized, and resource saving and reduction in environmental load can be facilitated.

Detailed Description

The mode of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

(example 1)

Irganox1098 (melting point 160 ℃ C.) as a high-melting phenolic antioxidant was added in an amount of 0.1 part by weight based on 100 parts by weight of the 4-methyl-1-pentene polymer, and extrusion molding was carried out using a single-screw extruder (GM 30-28 (screw diameter 30mm, L/D28, manufactured by GM Engineering Co.) with a T-die width of 400mm to obtain a mold release film having a thickness of 30 μm. As conditions for extrusion, the total length of the barrel was divided into 5 equal parts, which were divided into 5 regions of C1, C2, C3, C4, and C5 in this order from the inlet side, and the set temperatures of the respective regions were C1: 300. c2: 300. C3-C5: 290. the extrusion amount was 50kg/hr and the linear velocity was 70 m/min.

(example 2)

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 1 except that 0.5 parts by weight of Irganox3114 (melting point 221 ℃ C.) as a high-melting-point phenol antioxidant was added.

(example 3)

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 1 except that 1.0 part by weight of Irganox1330 (melting point 240 ℃ C.) as a high-melting-point phenolic antioxidant was added.

(example 4)

Irganox1098 (melting point 160 ℃ C.) as a high-melting-point phenol antioxidant was added in an amount of 0.6 part by weight per 100 parts by weight of the 4-methyl-1-pentene polymer, and the mixture was mixed by a V-type mixer or the like, and then melt-kneaded and cut by a twin-screw extruder to prepare a granulated master batch having 0.2g/50 pellets. The resulting master batch was extruded at a T die width of 400mm using a co-rotating twin-screw extruder (SBTN-92 (screw diameter 92mm, L/D30, manufactured by Plastic engineering research Co., Ltd.) to give a mold release film having a thickness of 30 μm. As conditions for extrusion, the total length of the barrel was divided into 5 equal parts, which were divided into 5 regions of C1, C2, C3, C4, and C5 in this order from the inlet side, and the set temperatures of the respective regions were C1: 300. c2: 350 ℃, C3-C5: 290. the extrusion amount was 25kg/hr and the linear velocity was 35 m/min.

(example 5)

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 4 except that 0.3 part by weight of Irganox3114 (melting point 221 ℃ C.) as a high-melting-point phenol antioxidant was added.

(example 6)

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 4 except that 0.7 part by weight of Irganox1330 (melting point 240 ℃ C.) as a high-melting-point phenol antioxidant was added.

Comparative example 1

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 1, except that the high-melting-point phenol antioxidant was not added.

Comparative examples 2 to 5

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 4 except that 0.4 to 0.7 parts by weight of the phenolic antioxidant shown in Table 1 was added instead of the high-melting phenolic antioxidant. The phenolic antioxidants used were as follows.

Irganox1076 (melting point 50 ℃, manufactured by BASF corporation)

Irganox259 (melting point 106, manufactured by BASF corporation)

Irganox1010 (melting point 115 ℃, manufactured by BASF corporation)

Sumilizer GA80 (melting point 125 ℃, 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) Measurement of oxygen concentration on surface of mold Release film

The measurement was performed by a wide scan under conditions of an X-ray source for monochromating Al K.alpha.rays, a detection angle of 45 degrees, and a STEP width of 1eV using an X-ray photoelectron spectrometer (Versa Probe II, manufactured by ULVAC-PHI Co.). The surface oxygen concentration was calculated by 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)

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：280-300eV，O_1s：520-540eV

The SC is 0.314 and the SO is 0.733.

(2) Evaluation of non-staining

The obtained release film was cut into a4, and sandwiched between copper foils of the same size to obtain a laminate. The obtained laminate was hot-pressed at 180 ℃ under 5MPa for 60 minutes. Hot pressing was performed with n-5.

Then, 10 pieces of copper foil in total were peeled off from the laminate and collected, and the surface of the side in contact with each release film was cleaned with chloroform to obtain an extract. All the obtained extracts were combined, chloroform was distilled off, and the remaining amount was weighed as the amount of the contaminant transferred from the mold release film. The amount of the contaminant component per unit area was calculated and evaluated according to the following criteria.

Very good: the amount of the stain component was 50mg/m²The following

O: the amount of the pollutant component exceeds 50mg/m²And is 100mg/m²The following

Δ: the content of pollutant components exceeds 100mg/m²And 500mg/m²The following

X: the content of pollutant components exceeds 500mg/m²

[ Table 1]

(example 7)

To 100 parts by weight of 4-methyl-1-pentene polymer, 0.1 part by weight of ADKSTAB CDA-1 (molecular weight: 204) as a metal deactivator was added, and the mixture was mixed by a V-type mixer or the like, and then melt-kneaded and cut by a twin-screw extruder to prepare a granulated master batch having 0.2g/50 pellets. The resulting master batch was extruded at a T die width of 400mm using a co-rotating twin-screw extruder (SBTN-92 (screw diameter 92mm, L/D30, manufactured by Plastic engineering research Co., Ltd.) to give a mold release film having a thickness of 30 μm. As conditions for extrusion, the total length of the barrel was divided into 5 equal parts, which were divided into 5 regions of C1, C2, C3, C4, and C5 in this order from the inlet side, and the set temperatures of the respective regions were C1: 300 ℃, C2: 350 ℃, C3-C5: 290 deg.c. The extrusion amount was 25kg/hr, and the linear velocity was 35 m/min.

(example 8)

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 7 except that 1.0 part by weight of ADKSTAB CDA-10 (molecular weight 553) as a metal deactivator was used.

(example 9)

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 7 except that 0.7 parts by weight of ADKSTAB CDA-1 (molecular weight: 204) as a metal deactivator was used.

(example 10)

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 7 except that 0.3 part by weight of ADKSTAB CDA-10 (molecular weight 553) as a metal deactivator was used.

(example 11)

A mold release film having a thickness of 30 μm was obtained in the same manner as in example 7 except that 0.5 part by weight of ADKSTAB CDA-10 (molecular weight 553) as a metal deactivator was used.

Comparative example 6

Using a single-screw extruder (GM 30-28 (screw diameter 30mm, L/D28), 100 parts by weight of 4-methyl-1-pentene polymer was extruded with a T-die width of 400mm to give a mold release film having a thickness of 30 μm. The extrusion conditions are set as follows, wherein the cylinder temperature is 260-300 ℃, and the cylinder temperature is C1: 300 ℃, C2: 300 ℃, C3-C5: the extrusion rate was 50kg/hr at 290 ℃ and the linear velocity was 70 m/min.

Comparative example 7

A mold release film having a thickness of 30 μm was obtained in the same manner as in comparative example 6, except that 1.1 parts by weight of ADKSTAB CDA-1 (molecular weight: 204) as a metal deactivator was used.

Comparative example 8

A mold release film having a thickness of 30 μm was obtained in the same manner as in comparative example 6, except that 1.5 parts by weight of ADKSTAB CDA-1 (molecular weight: 204) as a metal deactivator was used.

Comparative example 9

0.5 part by weight of ADKSTAB CDA-10 (molecular weight 553) as a metal deactivator was used, and extrusion conditions were set to 260 to 300 ℃ in barrel temperature, C1 in barrel temperature: 300 ℃, C2: 300 ℃, C3-C5: a mold release film having a thickness of 30 μm was obtained in the same manner as in examples 8 and 10, except that the extrusion rate was 50kg/hr at 290 ℃ and the linear velocity was 70 m/min.

Comparative example 10

A mold release film having a thickness of 30 μm was obtained in the same manner as in examples 8 and 10 except that 0.5 part by weight of ADKSTAB CDA-10 (molecular weight 553) as a metal deactivator was used to form a film by means of a single screw extruder (GM 30-28 (screw diameter 30mm, L/D28, manufactured by GM Engineering Co.).

Comparative example 11

A mold release film having a thickness of 30 μm was obtained in the same manner as in examples 8 and 10 except that 0.5 part by weight of ADKSTAB CDA-10 (molecular weight 553) as a metal deactivator was used and that the starting materials were mixed by only a V-type mixer or the like.

(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) Measurement of Nitrogen concentration on surface of mold Release film

The measurement was performed by a wide scan under conditions of an X-ray source for monochromating Al K.alpha.rays, a detection angle of 45 degrees, and a STEP width of 1eV using an X-ray photoelectron spectrometer (Versa Probe II, manufactured by ULVAC-PHI Co.). The surface nitrogen concentration was calculated by 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)

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：280-300eV，N_1s：390-410eV

The SC was determined under the conditions of 0.314 and SN was 0.499.

(2) Evaluation of non-staining

The obtained release film was cut into a4, and sandwiched between copper foils of the same size to obtain a laminate. The obtained laminate was hot-pressed at 180 ℃ under 5MPa for 60 minutes. Hot pressing was performed with n-5.

Then, 10 pieces of copper foil in total were peeled off from the laminate and collected, and the surface of the side in contact with each release film was cleaned with chloroform to obtain an extract. All the obtained extracts were combined, chloroform was distilled off, and the remaining amount was weighed as the amount of the contaminant transferred from the mold release film. The amount of the contaminant component per unit area was calculated and evaluated according to the following criteria.

Very good: the amount of the stain component was 50mg/m²The following

O: the amount of the pollutant component exceeds 50mg/m²And is 100mg/m²The following

Δ: the content of pollutant components exceeds 100mg/m²And 500mg/m²The following

X: the content of pollutant components exceeds 500mg/m²

[ Table 2]

Industrial applicability

According to the present invention, a mold release film that does not contaminate a substrate when used in a process for manufacturing a flexible circuit substrate can be provided.