JP2001310422A - Release film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release film which shows excellence in both releasability and mechanical properties such as tensile elongation and the like, further shows excellence in heat resistance and environmental aptitude and is usable for manufacturing a printed board and the like. SOLUTION: A release film is composed of one or more layers and is 25 to 300 μm thick, wherein at least one surface layer contains a styrene-based polymer having a syndiotactic structure as a major component and its glossiness is less than 100%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release film, and more particularly, to a release film comprising a layer containing a styrene polymer having a syndiotactic structure (hereinafter sometimes abbreviated as "SPS"). The present invention relates to a film which is excellent as a release film and a mechanical property, and is useful as a release film used for manufacturing a printed circuit board.

[0002]

2. Description of the Related Art A release film is a general term for a film having a so-called "peeling function", and includes a release film, a process film, a packaging film and the like. The term "process film" used here means that when manufacturing printed circuit boards, IC chips (wafer molds), ceramic electronic components, thermosetting resin products, decorative boards, etc., metal plates and resins do not adhere to each other. A film sandwiched between the metal plates or between the resins during the molding step. Such a process film is required to have excellent releasability and high mechanical strength such as toughness to withstand the force received during the process.

Conventionally, these process films include a fluororesin film such as Teflon (registered trademark) (PTFE), a poly (4-methylpentene-1) film, and a biaxially stretched polyethylene terephthalate (PET) surface layer. Films coated with a silicon-based material have been used. Also, recently, a release film using SPS has been proposed (Japanese Patent Application Laid-Open No. 11-349703, Japanese Patent Application Laid-Open
000-38461). However, since fluororesin-based films are difficult to incinerate, used ones become industrial waste, and if incinerated, there is a concern about the generation of fluorine-containing dioxins. In addition, the poly (4-methylpentene-1) film has a problem that heat resistance is not sufficient, and thermal adhesion to a stainless steel plate occurs at the time of manufacturing a printed circuit board. Also, biaxially stretched PET itself has a high wetting index, so the releasability is insufficient. For a film in which a silicon-based material is applied to the PET surface layer, silicon is used for printed circuit boards, ceramic electronic components, thermosetting resin products, There was a problem that it adhered to a decorative board or the like. On the other hand, S
Although films using PS have excellent release properties, mechanical properties such as tensile elongation are insufficient, and films using both SPS and thermoplastic resin have both release properties and mechanical properties simultaneously. Satisfactory ones could not be obtained, and all of them were insufficient as process films such as printed circuit boards.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made from the above viewpoint, and has excellent releasability and mechanical properties such as tensile elongation at the same time, and is excellent in heat resistance and environmental suitability. An object of the present invention is to provide a release film used for such purposes.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, at least one
The two release layers containing SPS as a main component and controlling the glossiness of the film to a certain value or less can effectively achieve the object of the present invention,
The present invention has been completed. That is, the gist of the present invention is as follows. <1> 25 to 30 layers consisting of one layer or two or more layers
A release film of 0 μm, wherein at least one surface layer contains a styrene polymer having a syndiotactic structure as a main component, and the surface layer has a glossiness of 1
Release film that is less than 00%. <2> The release film according to <1>, wherein the surface layer contains 85 to 99.9% by mass of a styrene-based polymer having a syndiotactic structure. <3> The surface layer contains 0.1 to 15% by mass of one or more selected from thermoplastic resins and thermoplastic elastomers other than a styrene-based polymer having a syndiotactic structure, and a compatibilizer. The release film according to <1> or <2>, which contains 0 to 10% by mass.

<4> The composition of the surface layer is 85 to 98% by mass of a styrene polymer having a syndiotactic structure, 1 to 15% by mass of a polyolefin polymer, 1 to 15% by mass of a styrene rubber, and a phase. The release film according to <2> or <3>, containing 0 to 10% by mass of a solubilizer. <5> A release film having a thickness of 25 to 300 μm in which the A layer and the C layer are surface layers and one or two or more B layers are present between the two surface layers, and the A layer, each B layer, And a release film in which the C layer has the following composition. A layer: contains a styrenic polymer having a syndiotactic structure as a main component, and has a gloss of 100
% Layer. Each B layer: 30 to 90% by mass of a styrene-based polymer, 10 to 70% by mass of one or more selected from thermoplastic resins and thermoplastic elastomers other than the styrene-based polymer, and 0 to 70% by mass of a compatibilizer. A layer containing 30% by mass. C layer: 70 to 100% by mass of a styrene-based polymer having a syndiotactic structure, and one or two or more selected from thermoplastic resins and thermoplastic elastomers other than the styrene-based polymer having a syndiotactic structure. ~ 30% by weight, and a layer containing 0 to 10% by weight of a compatibilizer. <6> The release film according to <5>, wherein the A layer contains 85 to 99.9% by mass of a styrene-based polymer having a syndiotactic structure. <7> The above <5>, wherein the glossiness of the C layer is less than 100%.
Alternatively, the release film according to <6>. <8> at least one layer of the B layer has 30 to 70% by mass of a styrene polymer having a syndiotactic structure, 0 to 30% by mass of a styrene polymer other than the styrene polymer having a syndiotactic structure, and a polyolefin. 10
<5> to <7> containing 50% by mass, 0 to 30% by mass of a thermoplastic elastomer, and 0 to 30% by mass of a compatibilizer.
The release film according to any one of the above. <9> The release film according to any one of <5> to <8>, wherein the B layer is composed of one layer. <10> The release film according to any one of <5> to <9>, wherein the crystallinity of the styrene-based polymer having a syndiotactic structure present in the release film is 30% or more. <11> Ratio of thickness of each layer, A layer: all B layers: C layer is 1 to 4
The above <5> to <10> which is 9:50 to 98: 1 to 49
The release film according to any one of the above.

[0007]

Embodiments of the present invention will be described below. 1. Physical Properties, Composition and Layer Structure of Release Film The release film of the present invention is a release film having a thickness of 30 to 300 μm comprising one layer or two or more layers, and at least one surface layer has SPS. A release film that contains as a main component and has a glossiness of the surface layer of less than 100%.

That is, the release film of the present invention is characterized in that at least one surface layer has a glossiness of less than 100%. The glossiness of this surface layer is 9
It is more preferably less than 0%, particularly preferably less than 80%. If the glossiness of this layer is 100% or more, sufficient releasability cannot be obtained.

[0009] The glossiness referred to herein is JIS K 7105.
It is sufficient to measure at a measurement angle of 60 ° in accordance with
The glossiness of the glass surface having a refractive index of 1.567 is defined as 100%, and the glossiness of the surface layer is represented.

As for the means for controlling the glossiness of the surface layer to less than 100%, it is necessary to appropriately select the composition of the layer. In some cases, it is effective to appropriately select a method for forming a film.

That is, it is preferable that at least one surface layer of the release film of the present invention contains 85 to 99.9% by mass of SPS. The SPS content is 90-9
8 mass% is more preferable, and 92 to 98 mass% is particularly preferable. When the SPS content exceeds 99.9% by mass, the glossiness becomes 100% or more by a normal molding method,
It is difficult to easily reduce it to less than 100%,
Not economic. On the other hand, even if the content of SPS is less than 85% by mass, sufficient releasability may not be obtained.
Further, the at least one surface layer has an SPS of 85.
0.1 to 15% by mass, preferably 2 to 10% by mass, of one or more selected from thermoplastic resins and thermoplastic elastomers other than SPS.
A layer containing 0 to 10% by mass and a compatibilizer of 0 to 10% by mass is preferable. With such a composition, the glossiness can be maintained at less than 100% and the mechanical properties of the film can be enhanced. In particular, when an olefin-based resin, particularly polyethylene or polypropylene, is used as the thermoplastic resin, not only the mechanical properties are improved, but also the gloss is reduced. This effect becomes even more remarkable when a thermoplastic elastomer, especially a styrene rubber-like elastic material, is used in combination. Also,
The at least one surface layer may contain a compatibilizer, whereby the mechanical properties can be further enhanced, and the effect is greater when a thermoplastic resin or a thermoplastic elastomer is present.

[0012] Therefore, at least one surface layer is composed of 85 to 98% by weight of SPS, 1 to 15% by weight of polyolefin polymer, 1 to 15% by weight of styrene rubbery elastic material and 0 to 10% by weight of compatibilizer. Is a preferred embodiment. In the present invention, various additives can be blended as long as the object of the present invention is not impaired. Hereinafter, SPS, S used in the present invention
The thermoplastic resin and thermoplastic elastomer other than PS, the compatibilizer, and various additives will be described.

(1-1) SPS The syndiotactic structure in the SPS used in the present invention is a syndiotactic structure, that is, phenyl having a side chain with respect to the main chain formed from carbon-carbon bonds. The group has a stereostructure in which the groups are alternately located in opposite directions, and its tacticity is quantified by nuclear magnetic resonance ( ¹³ C-NMR) using isotope carbon. ¹³ C
-Tacticity measured by the NMR method can be represented by an existing ratio of a plurality of continuous structural units, for example, a dyad for two, a triad for three, a pentad for five, S in the present invention
PS is usually 75% or more, preferably 85% or more in racemic diad, or 30% in racemic pentad
Polystyrene, poly (alkylstyrene) having a syndiotacticity of 50% or more, preferably 50% or more,
Poly (halogenated styrene), poly (halogenated alkylstyrene), poly (alkoxystyrene), poly (vinyl benzoate), hydrogenated polymers thereof, mixtures thereof, or copolymers containing these as main components Is referred to. Here, poly (alkylstyrene) includes poly (methylstyrene), poly (ethylstyrene), poly (isopropylstyrene), poly (tertiarybutylstyrene), poly (phenylstyrene), poly (vinylnaphthalene) , Poly (vinylstyrene), and the like, and poly (halogenated styrene) includes poly (chlorostyrene), poly (bromostyrene), poly (fluorostyrene), and the like. As poly (halogenated alkylstyrene), poly (chloromethylstyrene) and the like, and as poly (alkoxystyrene),
Poly (methoxystyrene), poly (ethoxystyrene)
and so on.

Among these, particularly preferred styrene polymers include polystyrene, poly (p-methylstyrene), poly (m-methylstyrene), poly (p-tert-butylstyrene), and poly (p-chlorostyrene). Styrene), poly (m-chlorostyrene), poly (p-fluorostyrene), hydrogenated polystyrene, and copolymers containing these structural units. Such an SPS is
For example, in an inert hydrocarbon solvent or in the absence of a solvent,
It can be produced by polymerizing a styrene-based monomer (a monomer corresponding to the styrene-based polymer) using a titanium compound and a condensation product of water and a trialkylaluminum as a catalyst (Japanese Unexamined Patent Publication No. 187708).
Further, poly (halogenated alkylstyrene) can be obtained by the method described in JP-A-1-46912 and hydrogenated polymers thereof can be obtained by the method described in JP-A-1-178505.

Further, as the comonomer in the styrenic copolymer, in addition to the above-mentioned styrenic polymer monomers, olefin monomers such as ethylene, propylene, butene, hexene and octene; diene monomers such as butadiene and isoprene; Examples include diene monomers and polar vinyl monomers such as methyl methacrylate, maleic anhydride, and acrylonitrile.

In particular, when the styrene repeating unit is 80 to 100
A styrene-based polymer having a mole% of p-methylstyrene repeating units of 0 to 20 mole% is preferably used. The molecular weight of the styrene polymer is not particularly limited, but the weight average molecular weight is 50,000 to 500,0.
00, especially 150,000-30.
More preferably, it is 000. Here, if the mass average molecular weight is less than 50,000, the mechanical properties of the film may be insufficient. Further, regarding the molecular weight distribution, there is no restriction on the width thereof, and various types can be applied, but those having a mass average molecular weight (Mw) / number average molecular weight (Mn) of 1.0 to 3.0 are preferable. preferable.

(1-2) Thermoplastic resin other than styrene-based polymer As the thermoplastic resin other than syndiotactic polystyrene used in the present invention, linear high-density polyethylene, linear low-density polyethylene, high-pressure Density polyethylene,
Isotactic polypropylene, syndiotactic polypropylene, block polypropylene, random polypropylene, polybutene, 1,2-polybutadiene,
Polyolefin resins represented by poly-4-methylpentene, cyclic polyolefins and copolymers thereof, atactic polystyrene, isotactic polystyrene, HIPS, ABS, AS, styrene-methacrylic acid copolymer, styrene-methacrylic acid. Alkyl ester copolymer, styrene-methacrylic acid / glycidyl ester copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid / alkyl ester copolymer, styrene-maleic acid copolymer, styrene-fumaric acid copolymer Representative polystyrene resins, polyester resins such as polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyamide resins such as polyamide 6, polyamide 6,6, and polyphenylene ether It can be selected arbitrarily from those such known PPS. Among these, polyolefin resins, particularly polyethylene and polypropylene, are preferred. In addition, these thermoplastic resins can be used alone or in combination of two or more.

(1-3) Thermoplastic Elastomer Specific examples of the thermoplastic elastomer used in the present invention include natural rubber, polybutadiene, polyisoprene, polyisobutylene, neoprene (registered trademark), polysulfide rubber, thiochol rubber, and acrylic rubber. , Urethane rubber, silicone rubber, epichlorohydrin rubber,
And styrene-butadiene block copolymer (SB
R), hydrogenated styrene-butadiene block copolymer (SEB), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-
Styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), hydrogenated styrene-isoprene block copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS),
Styrene rubber such as hydrogenated styrene-isoprene-styrene block copolymer (SEPS), and olefin rubber such as ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), and linear low density polyethylene elastomer Or butadiene-acrylonitrile-styrene-core-shell rubber (AB
S), methyl methacrylate-butadiene-styrene-
Core shell rubber (MBS), methyl methacrylate-butyl acrylate-styrene-core shell rubber (MA
S), octyl acrylate-butadiene-styrene-
Core shell rubber (MABS), alkyl acrylate-
Core-shell type particle-like elastic materials such as butadiene-acrylonitrile-styrene-core-shell rubber (ABS), butadiene-styrene-core-shell rubber (SBR), and siloxane-containing core-shell rubber such as methyl methacrylate-butyl acrylate-siloxane; Modified rubber and the like can be mentioned. Of these, styrene rubbers are particularly preferred.

(1-4) Compatibilizer The compatibilizer used in the present invention is a copolymer having a styrene structure, and contains a styrene structure in the molecule in an amount of 40 mol% or more, preferably 50 mol% or more. It is a polymer. The polymer having a styrene structure of less than 40 mol% corresponds to a so-called rubber-like elastic body, and enhances the binding between SPS and a thermoplastic resin or a thermoplastic elastomer other than SPS, and further improves the mechanical properties of the film. Inability to function as a compatibilizer. Specific examples of such a compatibilizer include, for example, a styrene-butadiene block copolymer (SBR) and a hydrogenated styrene-butadiene block copolymer (SE
B), styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene block copolymer (SIR), hydrogenated styrene-isoprene block copolymer Copolymer (SEP), styrene-isoprene-styrene block copolymer (SIS), hydrogenated styrene-isoprene-styrene block copolymer (SEPS), and the like. These are all polymers containing a styrene structure in an amount of 50 mol% or more.

(1-5) Various additives Anti-blocking agent (AB agent) Examples of the anti-blocking agent include the following inorganic particles or organic particles. As the inorganic particles, IA
, IIA, IVA, VIA, VIIA, VIII, IB
Oxides, hydroxides, sulfides, nitrides, halides, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylate salts of Group IIB, IIIB, IIIB and IVB elements, Examples thereof include silicates, titanates, borates and hydrates thereof, composite compounds centered on them, and natural mineral particles.

Specifically, compounds of Group IA such as lithium fluoride, borax (sodium borate hydrate), magnesium carbonate, magnesium phosphate, magnesium oxide (magnesia), magnesium chloride, magnesium acetate, magnesium fluoride, titanium Magnesium silicate, magnesium silicate, magnesium silicate hydrate (talc), calcium carbonate, calcium phosphate, calcium phosphite, calcium sulfate (gypsum), calcium acetate, calcium terephthalate, calcium hydroxide, calcium silicate, calcium fluoride, titanate Group IIA compounds such as calcium, strontium titanate, barium carbonate, barium phosphate, barium sulfate, barium sulfite, titanium dioxide (titania), titanium monoxide, titanium nitride, zirconium dioxide (zirconia), dimonoxide Group VIA element compounds such as group IVA element compounds such as conium, molybdenum dioxide, molybdenum trioxide, and molybdenum sulfide; group VIA element compounds such as manganese chloride and manganese acetate; group VIII element compounds such as cobalt chloride and cobalt acetate; Group IB element compounds such as cuprous chloride, group IIB compounds such as zinc oxide and zinc acetate, aluminum oxide (alumina), aluminum hydroxide, aluminum fluoride, alumina silicate (alumina silicate, kaolin, kaolinite), etc. III Group B element compounds, silicon oxide (silica, silica gel), graphite, carbon, graphite, glass, etc., Group IVB element compounds, kernalite, kainite, mica (mica, kinunmo), and particles of natural minerals such as byrose ore. Can be

Examples of the organic particles include Teflon, melamine resin, styrene / divinylbenzene copolymer, acrylic resin silicone, and crosslinked products thereof.

Here, the average particle size of the inorganic particles used is 0.1.
The amount is preferably 1 to 10 μm, and the addition amount is preferably 0.01 to 15% by weight. These inorganic fillers can be used alone or in combination of two or more.

Antioxidant The antioxidant can be arbitrarily selected and used from known ones such as phosphorus-based, phenol-based, and sulfur-based. In addition, these antioxidants may be used alone, or
Two or more can be used in combination. Further, preferably, 2- [1-hydroxy-3,5-di-t-
[Pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate.

Nucleating Agents Nucleating agents include metal salts of carboxylic acids such as aluminum di (pt-butylbenzoate) and phosphoric acids such as sodium methylenebis (2,4-di-t-butylphenol) acid phosphate Any of known metal salts, talc, phthalocyanine derivatives and the like can be used. These nucleating agents can be used alone or in combination of two or more. Plasticizer Any known plasticizer such as polyethylene glycol, polyamide oligomer, ethylene bisstearamide, phthalate ester, polystyrene oligomer, polyethylene wax, or silicone oil can be used. These plasticizers can be used alone or in combination of two or more.

Release Agent The release agent can be arbitrarily selected from known materials such as polyethylene wax, silicone oil, long-chain carboxylic acid, and metal salts of long-chain carboxylic acids. These release agents may be used alone or in combination of two or more.

Process Oil In the present invention, in order to improve elongation, the oil is further heated at 40 ° C.
It is preferable to blend a process oil having a kinematic viscosity of 15 to 600 mm ² / s.

Process oils are roughly classified into paraffinic oils, naphthenic oils, and aroma oils depending on the type of oil. Among them, the number of carbon atoms related to paraffin (straight chain) calculated by the ndM method is particularly preferred. Paraffinic oils having a percentage of 60% Cp or more based on the total carbon number are preferred.

The viscosity of the process oil is preferably from 15 to 600 mm ² / s at 40 ° C.
500 mm ² / s is more preferred. If the kinematic viscosity of the process oil is less than 15 mm ² / s, it has an effect of improving elongation, but it has a low boiling point and may cause melt-kneading with SPS and white smoke, gas burning, and roll adhesion during molding. If the kinematic viscosity exceeds 600 mm ² / s, burning of white smoke gas and the like is suppressed, but the effect of improving elongation is poor. These process oils can be used alone or in combination of two or more.

The above-mentioned various addition amounts are preferably 0 if necessary with respect to 100 parts by mass of SPS, thermoplastic resin other than SPS, thermoplastic elastomer and compatibilizer in total.
What is necessary is just to mix | blend in the range of 1.5 mass parts. In the release film of the present invention, at least one surface layer has the above-described composition and physical properties.
It may be 5 to 300 μm, preferably 40 to 200 μm.
μm, particularly preferably 75 to 150 μm. If the thickness is less than 25 μm, it is difficult to obtain a desired release property. Further, even if the thickness of the film exceeds 300 μm, further improvement in performance is not particularly observed, which is disadvantageous in economical efficiency.

The release film of the present invention comprises one layer or two or more layers. That is, the layer structure of the release film of the present invention may be a single layer, two layers, or three or more layers as long as at least one surface layer satisfies the above conditions. Among these, in the present invention, those having three or more layers are preferable in that both the releasability and the mechanical properties can be significantly improved.

Next, one preferred embodiment when the release film of the present invention has three or more layers will be described. 2. Preferred embodiment when the layer structure of the release film is three or more layers It is composed of an A layer, a B layer, and a C layer, respectively, which will be described later. It is a release film having a total thickness of 25 to 300 μm in which two or more B layers are present.

Hereinafter, the contents (composition and physical properties) of the layer A, the layers B, and the layer C will be described. A Layer As the A layer used in the present invention, a layer having the same composition and physical properties as those described in the above “at least one surface layer” can be used. That is, the layer contains SPS as a main component and has a glossiness of the surface layer of less than 100%. More preferably, the composition is SPS85.
-99.9% by mass, one or two or more selected from thermoplastic resins and thermoplastic elastomers other than SPS.
A layer containing 1 to 15% by mass and 0 to 10% by mass of a compatibilizer, and the layer has a glossiness of less than 100%, and particularly preferably 85 to 99.9% by mass of SPS. %, And 0.1 to 15% by mass of one or more selected from thermoplastic resins and thermoplastic elastomers other than SPS, and 0 to 10% by mass of a compatibilizer. In the A layer, the above-mentioned various amounts of addition are
If necessary, it may be blended in a range of preferably 0 to 1.5 parts by mass with respect to a total of 100 parts by mass of the thermoplastic resin other than PS and SPS, the thermoplastic elastomer, and the compatibilizer.

Each B layer The styrene polymer 30 is used as the B layer used in the present invention.
90 to 90% by mass, preferably 35 to 80% by mass, particularly preferably 40 to 70% by mass, and one or two or more selected from thermoplastic resins and thermoplastic elastomers other than styrene-based polymers. % By mass, preferably 20
A layer containing from 65 to 65% by mass, particularly preferably from 30 to 60% by mass, and from 0 to 30% by mass of a compatibilizer. If the styrene-based polymer is less than 30% by mass or more than 90% by mass, the mechanical properties of the laminated film are all insufficient and the object of the present invention cannot be achieved. The B layer may be a single layer or two or more layers. When two or more B layers are present, the composition of each layer may be the same,
It may be different within the above range. Further, in the present invention, at least one of the B layers has 30 to 70% by mass of SPS, 0 to 30% by mass of a styrene polymer other than SPS, 10 to 50% by mass of polyolefin resin, and 0 to 30% of thermoplastic elastomer. %, Preferably 5 to 30% by mass, and 0 to 30% by mass of the compatibilizer B layer. As described above, it is preferable to use SPS as the styrene-based polymer and use a polyolefin-based resin such as polyethylene or polypropylene as the thermoplastic resin other than SPS, and it is particularly preferable to use a thermoplastic elastomer together. Further, the compatibilizing agent may be blended in the B layer in the same manner as in the A layer, but the blending ratio may be larger than that in the case of the A layer, and may be blended in a range of 30% by mass or less. This is because the ratio of the thermoplastic resin other than the SPS is higher in the layer B than in the case of the layer A. In addition, the B layer, similarly to the case of the A layer, the above-mentioned various addition amounts, styrene-based polymer, a thermoplastic resin other than the styrene-based polymer, a thermoplastic elastomer, and a total of 100 parts by mass of the compatibilizer. If necessary, it may be blended preferably in the range of 0 to 1.5 parts by mass. Hereinafter, the styrene-based polymer, a thermoplastic resin other than the styrene-based polymer, a thermoplastic elastomer, a compatibilizer, and various additives will be described.

(2-1) Styrene-based polymer The styrene-based polymer used in the layer B of the present invention is the above-mentioned (1-)
Not only SPS mentioned in 1) but also atactic polystyrene, isotactic polystyrene, GPPS, HI
A styrene-based polymer having no cysindiotactic structure such as PS is also included. These styrenic polymers can also be used as a component of the layer B because the mechanical properties of the laminated film can be improved and the heat resistance can be maintained. Among these styrene-based polymers, SPS is particularly preferable in that heat resistance is more excellent.

(2-2) Thermoplastic resin other than styrene-based polymer The thermoplastic resin other than styrene-based polymer used in the layer B of the present invention is also mentioned in (1-2) Thermoplastic resin other than SPS. Similar ones can be used. However, thermoplastic resins other than the styrene-based polymer exclude atactic polystyrene, isotactic polystyrene, and HIPS described in (1-2).

Further, (2-3) a thermoplastic elastomer,
As (2-4) the compatibilizer and (2-5) various additives, the same ones as those described in (1-3) to (1-5) can be used.

C Layer As the C layer of the present invention, SPS is 70 to 100% by mass,
Preferably 80 to 100% by mass, one or two selected from thermoplastic resins and thermoplastic elastomers other than SPS
0 to 30% by mass, preferably 0 to 10% by mass,
Particularly preferably, 0 to 5% by mass, and 0 to 10% of the compatibilizer are used.
Layers containing 5% by weight, preferably 0-5% by weight, can be used. If the proportion of SPS is less than 70% by mass, the heat resistance of the release film is lowered, and at the same time, the releasability is insufficient, which is not preferable as the release film.

In particular, the gloss of the surface layer of the layer C is preferably less than 100%, as in the case of the layer A. Further, as in the case of the layer A, the ratio of SPS is 85 to 99.9% by mass. It is preferred that In addition, particularly preferred embodiments include the same compositions as those described for the layer A.

The release film of the present invention comprises A
There are one layer, one layer or two or more layers, B layer and C layer. From the viewpoint of simplifying the manufacturing process, a three-layer release film in which each of A, B, and C layers is one layer is particularly preferable. The thickness of each layer of the release film is preferably 5 μm or more, more preferably 10 μm or more for the A layer and the C layer. Further, the thickness of the layer B is more preferably 30 μm or more, particularly preferably 50 μm or more. In addition, the ratio of the thickness of each layer, A layer: all B layers: C layer, preferably 1 to 49:50 to 98: 1 to 49, more preferably 5 to 30:40 to 90: 5 to 30, Particularly, 10-20: 60-80: 10-20 is preferable. By increasing the ratio of the intermediate B layer as described above, a compounding agent for adding a particularly necessary function or another desired function to the B layer can be added, and the function of the release film can be improved. Further, the thickness of the entire release film is preferably 25 to 300 μm as described above, and more preferably 40 to 20 μm.
0 μm, particularly preferably 75 to 150 μm.

3. Crystallinity of Release Film The crystallinity of SPS in the film used in the present invention, particularly in at least one surface layer, is preferably 30% or more, more preferably 45% or more, and particularly preferably. 50% or more. This is because in the case of SPS having a crystallinity of less than 30%, the releasability may be reduced.

4. Production method of the laminate film The production method of the release film according to the present invention is not particularly limited,
For example, cast molding, inflation molding, biaxial stretching molding, or the like can be used. Furthermore, after performing these moldings, heat treatment or the like may be performed in order to obtain a desired crystallinity. Among them, from the viewpoint of increasing the uniformity of the film thickness and emphasizing productivity, cast molding (3 types 3
(Co-extrusion molding with a layer film molding apparatus).

5. Uses of Laminated Film Since the release film of the present invention has excellent release properties and mechanical properties, it can be used as release films such as release films, process films, and packaging films. That is, as the release film, specifically, for example, an adhesive tape,
It is used in double-sided tapes, masking tapes, labels, seals, stickers, and the like, or a film attached to the surface of a poultice for skin adhering made of nonwoven fabric or the like. Also, as described above, the process film is a printed circuit board, an IC chip (wafer mold),
When manufacturing ceramic electronic parts, thermosetting resin products, decorative boards, etc., it is sandwiched between the metal plates or between the resins during the molding process so that the metal plates and the resins do not adhere to each other. Film, especially when manufacturing laminates
It is suitably used when manufacturing flexible printed circuit boards, manufacturing advanced composite material products, and manufacturing sports and leisure goods. The release film used at the time of manufacturing the laminated board, specifically, for example, in press molding when manufacturing a multilayer printed board, to prevent adhesion between the printed board and the separator plate or other printed board Means a film that exists between the two. The release film used in manufacturing a flexible printed circuit board is, specifically, formed by etching or the like on a base film when manufacturing a deformable flexible printed circuit board incorporated in a movable portion of an electric product. When the cover resin for protecting the formed electric circuit is heated and pressed, the film is used to wrap the cover resin so that the cover resin adheres to the uneven portion of the circuit. The release film used in manufacturing advanced composite material products refers to, for example, films used in manufacturing various products by curing a prepreg composed of glass cloth, carbon fiber or aramid fiber and epoxy resin. The release film used in the production of sports and leisure goods is, for example, a glass cloth, a fishing rod, a golf club shaft, a windsurf pole, and the like.
This is a film used when a prepreg composed of carbon fiber or aramid fiber and epoxy resin is wound in a cylindrical shape, and a film tape is wound thereon and cured in an autoclave.

[0044]

(Physical property evaluation method)

(1) Gloss Using a digital variable-angle glossmeter manufactured by Suga Test Instruments Co., Ltd.
It was measured according to IS K 7105. Measurement angle 60 °
The glossiness of the glass surface having a refractive index of 1.567 is 1
The glossiness of each film was indicated as 00%. (2) Crystallinity The enthalpy of fusion (ΔH) obtained by measuring the temperature of the film with a differential scanning calorimeter at a rate of 20 ° C./min.
f) and the enthalpy of cold crystallization (ΔH _Tcc ) were calculated by the following equation.

Crystallinity (%) = 100 × (ΔHf−ΔH)
_Tcc ) / 53 (J / g) (3) Tensile elongation Measured in accordance with JIS K 7127. Specifically, the test was performed at a test speed of 200 mm / min using the first test piece. (4) Release properties 180 ° C., 4 MPa under the configuration shown in FIG. , And allowed to cool at room temperature, and the peel strength with the copper oxide clad board and the film appearance were measured. [Raw materials used] ・ SPS: Syndiotactic polystyrene Zarek, manufactured by Idemitsu Petrochemical Co., Ltd. Tm = 270 ° C., MI = 3 (300 ° C., 1.2 kgf) ・ LDPE: Low-density polyethylene NUC-8042, manufactured by Nippon Unicar Corporation ・ PP: Polypropylene Idemitsu Petrochemical Co., Ltd. IDEMITU PP E-185G ・ SEBS: SEBS type elastomer Septon 8006, manufactured by Kuraray ・ Compatibilizer: SEBS 8104, manufactured by SEBS Kuraray

Example 1 95% by weight of SPS and 5% by weight of PP for layer A, 55% by weight of SPS for layer B,
15% by weight of PP, 15% by weight of SEBS, and compatibilizer 15
As the A layer, each composition composed of 95% by mass of SPS and 5% by mass of PP was prepared as the A layer. Next, “Irganox1010” (manufactured by Ciba-Geigy), “PEP36” (manufactured by Asahi Denka), and “Sumilyzer GS” (manufactured by Sumitomo Chemical) as antioxidants were added to 100 parts by mass of each composition. 0.1 part by weight was compounded. These were dry-blended and melt-kneaded with a 65 mmφ twin screw extruder to obtain respective pellets. A 500 mm width coat hanger die was attached to a 50 mmφ single screw (full flight type screw) extruder, and co-extruded at an extrusion rate of 20 kg / hr at 300 ° C. The A layer, B layer and C layer each had a thickness of 15 μm. 7
Films having a thickness of 0 μm and 15 μm and a total thickness of 100 μm were obtained. Using a tenter, this film is treated at 200 ° C. for 30 minutes.
The release film of Example 1 was obtained by heat treatment continuously for 2 seconds. This film was evaluated for glossiness, crystallinity, tensile elongation, and releasability. Table 1 shows the obtained results.

[0047]

[Table 1]

[Examples 2 to 9 and Comparative Examples 1 to 5] Using the materials having the respective compositions of the layers A, B and C shown in Table 1, the film thickness of each layer and the total thickness of the film shown in Table 1 were Except for this, each release film was produced in the same manner as in Example 1. However, as in the case of Example 1, each of these layers
0.1 parts by mass of the same antioxidant as in Example 1 was added to 100 parts by mass of the composition therein. These films were evaluated for glossiness, crystallinity, tensile elongation, and releasability. Table 1 shows the obtained results. [Comparative Example 6] The composition and poly (4-methylpentene-1) shown in the column A of Table 1 ("MX0002", manufactured by Mitsui Chemicals, Inc.)
Was performed in the same manner as in Example 1 except that a film was produced by co-extrusion. However, 0.11 parts by mass of the same antioxidant as in Example 1 was added to the composition shown in the column of the A layer. Table 1 shows the results.

[0049]

The release film of the present invention is excellent in heat resistance, environmental suitability and workability, and also excellent in mechanical properties such as release property and tensile elongation. Therefore, it is effective as a release film used for manufacturing a printed circuit board.

[Brief description of the drawings]

FIG. 1 is a schematic diagram in which a stainless steel plate, a test film, and a copper oxide-clad resin plate are stacked for a releasability test.

[Explanation of symbols]

1: Stainless steel plate (surface roughness: 1 μm or less, buffing) 2: Test film 3: Copper oxide-clad resin plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI theme coat ゛ (reference) C08L 9:06) C08L 9:06) F term (reference) 4F100 AK01A AK01B AK01C AK01D AK01E AK03A AK03B AK07 AK11A AK12A AK12B AK12C AK12D AK12E AK73 AL05A AL05B AL05C AL05D AL05E AL09A AL09B AL09C AL09D AL09E AN02A AN02B BA02 BA03 BA04 BA05 BA06 BA07 BA10A BA10B CA30 EH20 EH202 GB43 JA11A JA11B JA11C JA11D JA11E JB16A JB16B JB16C JB16D JB16E JJ03 JL14 JN21A JN21B YY00A YY00B 4J002 AC012 AC032 AC062 AC083 AC092 BB152 BC011 BC031 BC051 BC071 BC111 BG042 BN152 BN162 BN172 BP012 BP013 CH042 CK022 CN022 CP032 FD070 FD160 GF00

Claims (11)

[Claims] (1) a layer comprising one or two or more layers having a thickness of 25
A release film having a glossiness of less than 100%, wherein at least one surface layer contains a styrenic polymer having a syndiotactic structure as a main component, and the surface layer has a glossiness of less than 100%. . 2. The release film according to claim 1, wherein the surface layer contains 85 to 99.9% by mass of a styrene polymer having a syndiotactic structure. 3. The method according to claim 1, wherein the surface layer comprises one or more selected from thermoplastic resins and thermoplastic elastomers other than the styrene polymer having a syndiotactic structure.
The release film according to claim 1, wherein the release film contains 1 to 15% by mass and 0 to 10% by mass of a compatibilizer. 4. The composition of the surface layer is 85 to 98% by mass of a styrene polymer having a syndiotactic structure, 1 to 15% by mass of a polyolefin polymer, and 1
4. The release film according to claim 2, comprising about 15% by mass and 0 to 10% by mass of a compatibilizer. 5. 5. A method according to claim 1, wherein the layer A and the layer C are surface layers, and one or more layers B are present between the surface layers in a thickness of 25 to 30.
A release film of 0 μm, wherein layer A, each layer B, and layer C
A release film in which the layer has the following composition. A layer: contains a styrenic polymer having a syndiotactic structure as a main component, and has a gloss of 100
% Of each layer B: 30 to 90% by mass of a styrene-based polymer, 10 to 70% by mass of one or more selected from thermoplastic resins and thermoplastic elastomers other than the styrene-based polymer, and Layer containing 0 to 30% by mass of compatibilizer Layer C: 70 to 100% by mass of styrene polymer having a syndiotactic structure, thermoplastic resin and thermoplastic elastomer other than styrene polymer having a syndiotactic structure A layer containing 0 to 30% by mass of one or more selected from the group consisting of 6. The release film according to claim 5, wherein the layer A contains 85 to 99.9% by mass of a styrene polymer having a syndiotactic structure. 7. The release film according to claim 5, wherein the glossiness of the layer C is less than 100%. 8. A styrene-based polymer having at least one layer B having a syndiotactic structure in an amount of 30 to 70% by mass, and a styrene-based polymer other than the styrene-based polymer having a syndiotactic structure 0 to 30% by mass. And 10 to 50% by mass of a polyolefin, 0 to 30% by mass of a thermoplastic elastomer, and 0 to 30% by mass of a compatibilizer.
8. The release film according to any one of 7. 9. The release film according to claim 5, wherein the layer B comprises one layer. 10. The styrene polymer having a syndiotactic structure present in the release film has a crystallinity of 30.
% Of the release film according to claim 1. 11. The thickness ratio of each layer, wherein the ratio of A layer: all B layers: C layer is 1-49: 50-98: 1-49.
The release film according to any one of the above.