JP2001315261A - Release film - Google Patents

Abstract

(57) [Problem] To provide a release film excellent in abrasion resistance, heat resistance, chemical resistance, release property and the like. A release film comprising a support base material and a release layer, wherein the support base material is a film containing a liquid crystal polymer exhibiting optical anisotropy when melted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear-resistant, heat-resistant, chemical-resistant, and mold-releasing material having a liquid crystal polymer film as a supporting substrate and having a release layer as a protective film on its surface. It relates to a release film excellent in quality.

[0002]

2. Description of the Related Art A so-called release film having good releasability from a pressure-sensitive adhesive tape, a molten resin, an adhesive or a thermoplastic resin is used in various industrial fields. In particular, the demand has been increasing, and higher performance has been required. In recent years, a release film having excellent heat resistance has been required. For example, in the manufacture of printed wiring boards, a multi-layering technique is used for the purpose of enabling high-density mounting. Release films are widely used in the hot pressing process when manufacturing this multilayer printed circuit board. In the manufacturing process of a multilayer substrate, first, two single-sided copper-clad laminates are bonded to both sides of an inner layer plate having a circuit formed by an etching process via a prepreg by a hot press. In order to prevent the resin of the prepreg flowing out during the heating press from contaminating the stainless steel flat surface of the press machine, the release film is heated and pressed between the stainless steel flat surface and the surface of the laminated wiring board. In this case, the properties required for the release film are sufficient heat resistance at the temperature at which the prepreg resin is cured, and good release properties for the resin that has flowed out on the copper foil surface of the multilayer board after molding and around the product. is there. For such uses, polymethylpentene resin films and polyvinyl fluoride films are mainly used as release films. However, these films have poor releasability from a prepreg resin in contact with the film, and when the release film used is to be peeled off after curing, a sufficient force may be required to deform or break the film. In addition, in a process that requires a processing temperature higher than the melting temperature of the resin forming each film, the release film shrinks or deforms, and cannot be used for a resin that requires processing at a higher temperature. There is a limit.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a release film excellent in abrasion resistance, heat resistance, chemical resistance, release property and the like.

[0004]

According to the present invention, there is provided a release film comprising a support substrate and a release layer, wherein the support substrate comprises a film containing a liquid crystal polymer exhibiting optical anisotropy when melted. A release film is provided.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The release film of the present invention includes a support base material and a release layer, and the support base material is a film containing a liquid crystal polymer exhibiting optical anisotropy when melted (hereinafter, may be simply referred to as a liquid crystal polymer). is there. Examples of the liquid crystalline polymer that exhibits optical anisotropy when melted include, for example, a wholly aromatic or semi-aromatic, polyester, polyesterimide, polyesteramide, and the like, and a liquid crystal resin composition containing these. . As such a liquid crystalline polymer, a liquid crystal polyester or a composition containing the liquid crystal polyester as one component is preferably used. From the viewpoint of molding processability and performance of the obtained film, (A) a liquid crystal polyester is used as a continuous phase,
It is more preferable to use a liquid crystal polyester resin composition containing (B) a copolymer containing a functional group reactive with liquid crystal polyester (hereinafter sometimes referred to as (B) copolymer) as a dispersed phase.

The liquid crystal polyester is a polyester called a thermotropic liquid crystal polymer. Specifically, (1) those obtained by reacting an aromatic dicarboxylic acid, an aromatic diol and an aromatic hydroxycarboxylic acid,
(2) one obtained by reacting two or more aromatic hydroxycarboxylic acids, (3) one obtained by reacting an aromatic dicarboxylic acid with a nucleus-substituted aromatic diol, (4) polyethylene terephthalate, etc. Examples thereof include those obtained by reacting an aromatic hydroxycarboxylic acid with a polyester, and those that form an anisotropic melt at a temperature of 400 ° C. or lower are preferable. In addition, instead of these aromatic dicarboxylic acids, aromatic diols and aromatic hydroxycarboxylic acids, their ester derivatives can also be used.

The repeating structural unit of the liquid crystalline polyester (A) is a repeating structural unit derived from an aromatic dicarboxylic acid, a repeating structural unit derived from an aromatic diol, or an aromatic hydroxycarboxylic acid represented by the following structural formula. Examples thereof include a repeating structural unit derived from, but are not limited to, these.

A repeating structural unit derived from an aromatic dicarboxylic acid:

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A repeating structural unit derived from an aromatic diol:

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[0010]

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A repeating structural unit derived from an aromatic hydroxycarboxylic acid:

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In view of the balance among heat resistance, mechanical properties and workability, a particularly preferred liquid crystalline polyester (A) includes those containing a repeating structural unit represented by the following structural formula.

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More preferably, (A) the liquid crystalline polyester contains at least 30 mol% or more of the repeating structural unit, and a combination of the following repeating units (I) to (VI) is preferable. Can be

[0014]

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[0015]

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Of these, (I), (II) and (I)
V), more preferably (I)
Or the combination shown by (II) is mentioned. (I) to (V
Examples of the method for producing the liquid crystal polyester represented by I) include JP-B-47-47870 and JP-B-63-38.
No. 88, JP-B-63-3891, JP-B-56
-18016, JP-A-2-51523 and the like.

In the field where high heat resistance is required in the above-mentioned (A) liquid crystal polyester, the following are preferred: 30 to 80 mol% of the repeating unit (a) and 0 to 1 of the repeating unit (b).
A liquid crystal polyester comprising 0 mol%, the repeating unit (c) of 10 to 25 mol%, and the repeating unit (d) of 10 to 35 mol% is preferably used.

[0018]

Embedded image (In the formula, Ar is a divalent aromatic group.)

The functional group of the copolymer (B) has only to be reactive with the liquid crystal polyester.
Oxazolyl group, epoxy group, amino group and the like,
It preferably has an epoxy group. The epoxy group or the like may be present as a part of another functional group, and such an example includes, for example, a glycidyl group.

The copolymer (B) preferably contains 0.1 to 30% by mass of an unsaturated carboxylic acid glycidyl ester unit and / or an unsaturated glycidyl ether unit. In order to improve heat resistance and flexibility, the copolymer (B) has a heat of fusion of crystal of 3%.
It is preferably less than J / g. Further, the copolymer (B) preferably has a Mooney viscosity of 3 to 70, and more preferably 3 to 30.
Are more preferable, and those having 4 to 25 are particularly preferable. Here, the Mooney viscosity is 10 according to JIS K6300.
A value measured using a large rotor at 0 ° C.

In the copolymer (B), the method for introducing a functional group reactive with the liquid crystal polyester into the copolymer is not particularly limited, and it can be carried out by a known method. For example, a method of introducing a monomer having such a functional group by copolymerization at the stage of synthesizing the copolymer, a method of graft-copolymerizing a monomer having such a functional group on the copolymer, and the like can be mentioned. As the monomer having such a functional group, among others, a monomer having a glycidyl group, specifically,
Unsaturated carboxylic acid glycidyl esters and / or unsaturated glycidyl ethers are preferably used.

The unsaturated carboxylic acid glycidyl ester is
Preferably, a compound represented by the following formula or the like is used.

Embedded image (In the formula, R has 2 to 2 carbon atoms having an ethylenically unsaturated bond.
And 13 hydrocarbon groups. ) Further, as the unsaturated glycidyl ether, a compound represented by the following formula is preferably used.

Embedded image (In the formula, R ′ has 2 to 2 carbon atoms having an ethylenically unsaturated bond.
18 represents a hydrocarbon group, X represents a group -CH ₂ -O- or the following structure. )

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The unsaturated carboxylic acid glycidyl ester includes, for example, glycidyl acrylate, glycidyl methacrylate, diglycidyl itaconate,
Butene tricarboxylic acid triglycidyl ester, p-styrene carboxylic acid glycidyl ester and the like.
Examples of the unsaturated glycidyl ether include vinyl glycidyl ether, allyl glycidyl ether,
-Methylallyl glycidyl ether, methacryl glycidyl ether, styrene-p-glycidyl ether and the like.

Examples of the copolymer (B) include rubbers and / or thermoplastic resins having the above-mentioned functional groups. In particular, it is preferable to use a rubber capable of imparting excellent thermal stability and flexibility. Here, the rubber corresponds to a polymer substance having rubber elasticity at room temperature according to a new edition of Polymer Dictionary (edited by the Society of Polymer Science, published in 1988, Asakura Shoten), for example, natural rubber, butadiene polymer , Butadiene-styrene copolymer (including random copolymer, block copolymer (including SEBS rubber or SBS rubber, etc.), graft copolymer, etc.) or hydrogenated product thereof, isoprene polymer, chlorobutadiene polymer Coal, butadiene-acrylonitrile copolymer, isobutylene polymer, isobutylene-butadiene copolymer rubber, isobutylene-isoprene copolymer, acrylate-ethylene copolymer rubber, ethylene-propylene copolymer rubber, ethylene-butene Copolymer rubber, ethylene-propylene-styrene copolymer rubber, styrene-
Isoprene copolymer rubber, styrene-butylene copolymer, styrene-ethylene-propylene copolymer rubber, perfluoro rubber, fluoro rubber, chloroprene rubber, butyl rubber, silicone rubber, ethylene-propylene-non-conjugated diene copolymer rubber, Examples thereof include thiol rubber, polysulfide rubber, polyurethane rubber, polyether rubber (for example, polypropylene oxide and the like), epichlorohydrin rubber, polyester elastomer, polyamide elastomer and the like. Among them, acrylate-ethylene copolymers are preferably used, and (meth) acrylate-
Ethylene copolymer rubber is more preferred. These rubber-like substances may be prepared by any production method (e.g., emulsion polymerization method, solution polymerization method, etc.) and any catalyst (e.g., peroxide, trialkylaluminum, lithium halide, nickel-based catalyst, etc.). .

The rubber-like substance (B) as the copolymer includes, for example, (meth) acrylate-ethylene-
Rubbers having an epoxy group such as (unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether) copolymer rubber are preferred. The (meth) acrylic acid ester is an ester obtained from acrylic acid or methacrylic acid and an alcohol. As the alcohol, an alcohol having 1 to 8 carbon atoms is preferable.
Examples of the (meth) acrylate include methyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-
Examples include ethylhexyl acrylate and 2-ethylhexyl methacrylate. As the (meth) acrylic acid ester, one kind thereof may be used alone, or two or more kinds may be used in combination.

Preferred examples of the rubber having an epoxy group include more than 40% by mass of (meth) acrylate units and less than 97% by mass in order to improve the thermal stability and mechanical properties of the obtained laminated film. More preferably 4
5 to 70% by mass, 3 to 50% by mass, more preferably 10 to 49% by mass of ethylene units, and 0.1 to 30% by mass of unsaturated carboxylic acid glycidyl ether units and / or unsaturated glycidyl ether units. And more preferably 0.5 to 20% by mass.

The method for introducing the functional group such as an epoxy group into the rubber-like substance is not particularly limited, and can be performed by a known method. For example, a method of introducing a monomer having such a functional group by copolymerization at the stage of synthesizing rubber, a method of graft-copolymerizing a monomer having such a functional group on rubber, and the like can be mentioned. The copolymerization of rubber is carried out in the usual way,
For example, it can be produced by bulk polymerization, emulsion polymerization, solution polymerization or the like using a free radical initiator. Typical polymerization methods are described in JP-B-46-45085 and JP-B-61-45085.
Based on the method described in -127709 and the like,
Pressure of 5 in the presence of a free radical generating polymerization initiator
It can be carried out under conditions of at least 00 kg / cm ² and a temperature of 40 to 300 ° C.

As the rubber as the copolymer (B),
Other examples include an acrylic rubber or a vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer rubber having such a functional group. The acrylic rubber is preferably an acrylic rubber containing at least one monomer selected from the compounds represented by formulas (1) to (3) as a main component.

[0029]

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In the formula (1), R ¹ represents an alkyl group having 1 to 18 carbon atoms or a cyanoalkyl group. In the formula (2), R ²
Represents an alkylene group having 1 to 12 carbon atoms, and R ³ represents an alkyl group having 1 to 12 carbon atoms. In the formula (3), R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents an alkylene group having 3 to 30 carbon atoms, R ⁶ represents an alkyl group having 1 to 20 carbon atoms or a derivative thereof, and n represents 1 to Indicates an integer of 20.

The alkyl acrylate represented by the general formula (1) includes, for example, methyl acrylate,
Ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, actyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate,
Dodecyl acrylate, cyanoethyl acrylate and the like can be mentioned. Examples of the alkoxyalkyl acrylate represented by the general formula (2) include methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, and ethoxypropyl acrylate. The compounds represented by the above general formulas (1) to (3) can be used as a main component of the acrylic rubber by using one or more kinds at the time of polymerization.

As components for producing such an acrylic rubber, in addition to the compounds represented by the above general formulas (1) to (3), if necessary, unsaturated monomers copolymerizable therewith can be used. Can also be used. Examples of such unsaturated monomers include styrene, α-methylstyrene, acrylonitrile, halogenated styrene, methacrylonitrile,
Acrylamide, methacrylamide, vinylnaphthalene, N-methylolacrylamide, vinyl acetate, vinyl chloride, vinylidene chloride, benzyl acrylate, methacrylic acid, itaconic acid, fumaric acid, maleic acid, and the like.

The preferred constituent ratio of the acrylic rubber is the above-mentioned formula (1) in order to improve the moldability of the layer (A) and the heat resistance and impact resistance of the resulting film.
40.0 to 99.9% by mass of at least one monomer unit selected from the compounds represented by formulas (1) to (3), an unsaturated glycidyl ester unit and / or an unsaturated glycidyl ether unit of 0.1 to 30. 0 mass%, the above general formula
The ratio is preferably 0.0 to 30.0% by mass of an unsaturated monomer unit copolymerizable with at least one of the compounds represented by (1) to (3).

The method for producing the acrylic rubber is not particularly limited, and examples thereof include JP-A-59-113010, JP-A-62-64809, JP-A-3-160008, and WO95 / 04764. The polymerization can be carried out by emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization in the presence of a radical initiator.

The vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer rubber includes a block copolymer composed of a structural unit mainly composed of a vinyl aromatic hydrocarbon compound and a structural unit mainly composed of a conjugated diene compound. A rubber obtained by epoxidizing a polymer, a rubber obtained by epoxidizing a hydrogenated product of the block copolymer, and the like can be given. Such a vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer or a hydrogenated product thereof,
For example, Japanese Patent Publication No. 40-23798, Japanese Patent Application Laid-Open No.
It can be manufactured by a well-known method described in, for example, JP-A-133203.

Examples of the above-mentioned vinyl aromatic hydrocarbon compound include styrene, vinyl toluene, divinylbenzene, α-methylstyrene, p-methylstyrene, vinylnaphthalene and the like, with styrene being preferred. Examples of the conjugated diene compound include butadiene, isoprene, pyrrylene, 1,3-pentadiene,
Examples thereof include 3-butyl-1,3-octadiene and the like, with butadiene or isoprene being preferred.

The rubber as the copolymer (B) may be vulcanized as required and used as a vulcanized rubber. The vulcanization of the (meth) acrylic acid ester-ethylene- (unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether) copolymer rubber is carried out using a polyfunctional organic acid, a polyfunctional amine compound, an imidazole compound, or the like. This is achieved by, but not limited to.

As the thermoplastic resin having an epoxy group as the copolymer (B), (a) 50 units of ethylene units are used.
To 99% by mass, (b) 0.1 to 30% by mass, preferably 0.5 to 20% by mass of unsaturated carboxylic acid glycidyl ester units and / or unsaturated glycidyl ether units.
(c) Epoxy group-containing ethylene copolymers containing 0 to 50% by mass of an ethylenically unsaturated ester compound unit. Examples of the ethylenically unsaturated ester compound (c) include, for example, vinyl carboxylate such as vinyl acetate, vinyl propionate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate Esters, α, β-unsaturated carboxylic acid alkyl esters, and the like. Particularly, vinyl acetate, methyl acrylate and ethyl acrylate are preferred.

The epoxy group-containing ethylene copolymer includes, for example, a copolymer composed of ethylene units and glycidyl methacrylate units, a copolymer composed of ethylene units, glycidyl methacrylate units and methyl acrylate units, and a copolymer composed of ethylene units. Copolymers composed of glycidyl methacrylate units and ethyl acrylate units, and copolymers composed of ethylene units, glycidyl methacrylate units and vinyl acetate units are exemplified. The melt index of the epoxy group-containing ethylene copolymer (hereinafter referred to as MF
Sometimes called R. This MFR is based on JIS K6760.
(Measured at 190 ° C. under a load of 2.16 kg) is preferably 0.5 to 100 g / 10 min, more preferably 2 to 50 g.
/ 10 minutes. The MFR may be outside this range, but the MF
If R exceeds 100 g / 10 minutes, it is not preferable in terms of mechanical properties of the resin composition, and if R is less than 0.5 g / 10 minutes, compatibility with the liquid crystal polyester (A) is inferior. The epoxy group-containing ethylene copolymer preferably has a flexural rigidity in the range of 10 to 1300 kg / cm ^{2 in} order to improve the mechanical properties of the obtained film,
Those having ^{20 to} 1100 kg / cm ² are more preferable.

The method for preparing the above-mentioned epoxy group-containing ethylene copolymer is usually carried out by reacting an unsaturated epoxy compound with ethylene in the presence of a radical generator at 500 to 4000 atm.
A high-pressure radical polymerization method in which copolymerization is carried out at a temperature of up to 300 ° C. in the presence or absence of a suitable solvent or chain transfer agent. Further, a method of mixing an unsaturated epoxy compound and a radical generator with polyethylene and performing melt graft copolymerization in an extruder can also be mentioned. As the above liquid crystal polyester resin composition, a resin composition having the above (A) liquid crystal polyester as a continuous phase and the above (B) copolymer as a dispersed phase is preferable. (A) When the liquid crystal polyester is not a continuous phase, the heat resistance and the like of a film using the liquid crystal polyester resin composition may be reduced.

Although the details of the mechanism of such a liquid crystal polyester resin composition are unknown, a reaction occurs between the components of the composition, and (A) the liquid crystal polyester forms a continuous phase and (B) ) It is considered that the copolymer is finely dispersed, so that the moldability of the composition is improved and the performance of the film using the composition is excellent.

As one embodiment of the liquid crystal polyester resin composition, (A) liquid crystal polyester 56.0 to 99.
9% by weight, preferably 65.0 to 99.9% by weight, more preferably 70 to 98% by weight, and (B) copolymer 4
It is a resin composition containing 4.0 to 0.1% by weight, preferably 35.0 to 0.1% by weight, more preferably 30 to 2% by weight. (A) 56.0% by weight of liquid crystal polyester
If it is less than this, the heat resistance of the obtained film may decrease, which is not preferable. (A) The liquid crystal polyester is 9
If the content exceeds 9.9% by weight, the molding processability of the composition may decrease, which is not preferable.

The liquid crystal polyester resin composition can be prepared, for example, by mixing the components of the composition in a solution state and evaporating the solvent or precipitating it in the solvent. From an industrial point of view, a method of kneading each component in a molten state is preferred. For the melt kneading, kneading apparatuses such as a single-screw or twin-screw extruder and various kneaders which are generally used can be used. In particular, a biaxial high kneader is preferred. During the melt kneading, the cylinder set temperature of the kneading apparatus is 200
The range is preferably from 360 to 360 ° C, more preferably from 230 to 350 ° C. At the time of kneading, each component may be uniformly mixed in advance with a device such as a tumbler or a Henschel mixer, or, if necessary, mixing may be omitted and a method of separately supplying each component to the kneading device may be used. be able to.

In the present invention, an organic filler, an antioxidant, a heat stabilizer, a light stabilizer,
Various additives such as flame retardants, lubricants, inorganic or organic colorants, rust inhibitors, crosslinking agents, foaming agents, fluorescent agents, surface smoothing agents, surface gloss improvers, release improvers such as fluororesins, etc. It can also be added during the manufacturing process or in a subsequent processing step.

In the present invention, as the film of the supporting substrate, for example, a film obtained by using the above-mentioned liquid crystal polyester resin composition or the like can be employed. Such a film is obtained by, for example, a T-die method of extruding and winding a molten resin from a T-die, or an inflation film forming method of extruding a molten resin into a cylindrical shape from an extruder provided with an annular die, cooling and winding the same. Use of a film or sheet, a film or sheet obtained by a hot press method or a solvent casting method, or a film or sheet obtained by further uniaxially or biaxially stretching a sheet obtained by an injection molding method or an extrusion method. Can be.

In the T-die method, a uniaxially stretched film or a biaxially stretched film obtained by winding a molten resin extruded from the T-die while stretching it in the winder direction (longitudinal direction) can be produced. The setting conditions of the extruder at the time of forming the uniaxially stretched film can be appropriately set according to the composition of the composition, but the cylinder set temperature is preferably in the range of 200 to 360 ° C, and more preferably in the range of 230 to 350 ° C. If it is outside this range, thermal decomposition of the composition occurs,
Film formation may be difficult, which is not preferable. The slit interval of the T-die in the T-die method is preferably from 0.2 to 2.0 mm, more preferably from 0.2 to 1.2 mm. The draft ratio of the uniaxially stretched film is preferably in the range of 1.1 to 40, more preferably 10 to 40, and particularly preferably 15 to 35. Here, the draft ratio refers to a value obtained by dividing the cross-sectional area of the T-die slit by the cross-sectional area of the film perpendicular to the longitudinal direction. If the draft ratio is less than 1.1, the film strength is insufficient, and if the draft ratio exceeds 40, the surface smoothness of the film may be insufficient, which is not preferable. The draft ratio depends on the setting conditions of the extruder,
The winding speed and the like can be controlled and set.

For the biaxially stretched film, the same extruder setting conditions as those for forming the uniaxially stretched film, that is, the cylinder set temperature is preferably in the range of 200 to 360 ° C., more preferably 230 to 350 ° C. The composition is melt-extruded in a slit interval of preferably 0.2 to 1.2 mm, and the melt sheet extruded from the T-die is simultaneously stretched in the longitudinal direction and in the direction perpendicular to the longitudinal direction (lateral direction). First, the melt sheet extruded from the T-die is stretched in the longitudinal direction, and then the stretched sheet is stretched in a transverse direction from the tenter at a high temperature of 100 to 300 ° C. in the same process. Can be When obtaining a biaxially stretched film, the stretching ratio is 1.2 to 2 in the longitudinal direction.
The range is preferably 0 times and 1.2 to 20 times in the lateral direction. If the stretching ratio is outside the above range, the strength of the obtained film may be insufficient, or it may be difficult to obtain a film having a uniform thickness, which is not preferable.

An inflation film obtained by forming a melt sheet extruded from a cylindrical die by inflation is also preferably used. In the inflation method, a liquid crystal polymer is supplied to a melt extruder equipped with a die having an annular slit, and a cylinder set temperature of 200 to 36 is set.
The melt-kneading is performed at 0 ° C., preferably at 230 to 350 ° C., and the molten resin is extruded upward or downward from the annular slit of the extruder. The annular slit interval is usually 0.1 to 5 mm, preferably 0.2 to 2 mm, and the diameter of the annular slit is usually 20 to 1000 mm, preferably 2
5 to 600 mm. The melt-extruded molten resin film is stretched in the longitudinal direction (MD), and air or an inert gas, for example, nitrogen gas, is blown from the inside of the cylindrical film so that the transverse direction is perpendicular to the longitudinal direction.
The film can be expanded and stretched to (TD). In the inflation method, a preferable blow ratio is 1.5 to
10. The preferred MD stretching ratio is 1.5 to 40. Here, the blow ratio refers to a value obtained by dividing the diameter of the molten resin discharged and expanded from the die opening by the diameter of the annular slit. If the setting conditions during the inflation film formation are outside the above range, it may be difficult to obtain a high-strength liquid crystal polyester resin composition film having a uniform thickness and no wrinkles, which is not preferable. The expanded film is usually air-cooled or water-cooled on its circumference, and then passed through a nip roll and taken up. Upon inflation film formation, conditions can be selected according to the composition of the liquid crystal polyester resin composition such that the cylindrical melt film expands to a uniform thickness and a smooth surface state.

In the present invention, the thickness of the film layer containing the liquid crystal polymer as the supporting base material is not particularly limited.
Preferably 3 to 1000 μm, more preferably 5 to 5 μm
0 μm. In the present invention, it is preferable that the film containing the liquid crystalline polymer, which is the supporting base material, has a heat resistance of 140 ° C. or higher at a normal heat resistance temperature.

In the present invention, the release layer is a resin layer having a peeling action, a paper or a film having the resin layer, or the like.
The release layer preferably has a water contact angle of more than 80 degrees. The resin forming the resin layer is not particularly limited as long as it is a commonly used resin such as a silicone resin, a polyolefin, an alkyd resin, a long-chain alkyl group-containing resin, and a fluororesin. Particularly, a silicone resin-based resin is preferable because of easy adjustment.

As the silicone resin, any one of a solvent type, an emulsion type, and a non-solvent type or a combination of a plurality of types can be used. , Condensation type,
Any one of an addition type, an ultraviolet ray, and an electron beam curing type, or a combination of a plurality of them can be used. In particular, in the curing reaction, no heat energy is required, processing can be performed without using a solvent, and as a result, a solvent-free type is preferable because it can reduce the economic load for preserving the working environment. An electron beam curing type is preferred.

The ultraviolet curing reaction may be of a cationic polymerization type, a radical polymerization type, a radical addition type or the like, and any one or a combination of a plurality of them may be used. The cationic polymerization type is particularly preferred because of the absence of such a component.

In the present invention, since the liquid crystal polymer film as the supporting substrate is also excellent in solvent resistance, as a component of the release layer, a reactive silicone polymer for exhibiting releasability, a peel resistance, a peel resistance, Additives to control the rate dependence, and crosslinking agents, reaction retarders, solvents,
A catalyst or the like may be appropriately added. As a catalyst,
For the purpose of accelerating the crosslinking reaction of the solventless silicone resin, a curing catalyst such as a photocationic catalyst may be used.

The solventless silicone resin has a linear siloxane structure having -SiOR- as a repeating unit in the main chain. Here, R includes, for example, a hydrogen atom, an alkyl group, a phenyl group, a halogen group, an alkoxy group, a carboxyl group, a carbinol group, a mercapto group, an aralkyl group, a fluoroalkyl group, an amino group, an acyloxy group, and the like. R may be a functional group capable of causing a crosslinking reaction by ultraviolet rays or electron beams, such as a vinyl group, a mercapto group, an acryl group, an epoxy group, and a methacryl group. R in the resin may be the same or different.

In order to prepare the release film of the present invention, a method in which a paper or a film, which has already been provided with a release property by the above-described release layer or the like, is bonded to the above-mentioned support substrate using an adhesive, A method of directly applying a substance having a mold-releasing property to the above-mentioned support substrate, and then curing the substance by an appropriate method, a solution in which the substance having a mold-releasing property is dissolved or dispersed in an appropriate solvent or The dispersion can be produced by, for example, a method of directly applying the dispersion onto the above-mentioned supporting substrate. Among them, a method in which a release layer is directly provided on a supporting base material is preferable because processing is easy, the number of film components is reduced, and the film can be thinned and homogenized. The release film of the present invention thus obtained is at a temperature of 180 ° C. or more and 250 ° C. or less,
After heat treatment in air for 30 minutes, it is preferable to have dimensional stability such that the vertical and horizontal dimensional change rate is ± 5% or less.

[0056]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples, but the present invention is not limited thereto. Each measurement and test in the examples was performed according to the following methods. <Thickness measurement> DIGIMATIC Model MG-4 manufactured by Topro Planning
It measured using. Five points were measured on a sample piece having a size of 20 mm x 50 mm, and the average value was taken as the sample film thickness. <Peeling load measurement test> A sample was 250 mm x 500 m.
m, fixed on a glass plate with the silicone processing surface up, a bar coater (clearance 200 μm,
Using a pressure-sensitive adhesive (Olivine BPS-
8170). Then, after drying at 70 ° C. for 5 minutes, it is bonded to high quality paper (80 g / m ² ). The obtained bonded product was cut out to a size of 100 mm × 500 mm, sandwiched between glass plates (250 mm × 500 mm), and 20 g / cm 2
Under a load of ² , it was heated in a hot air oven at 70 ° C. for 20 hours. Then, it is left at room temperature for 1 hour, cut out to a width of 25 mm, and a test piece is prepared. The obtained test piece was subjected to a peeling speed of 5.0 m /
Measured at an angle of 180 ° in minutes.

<Measurement of Residual Adhesion Ratio>
A stainless steel plate specified in G-4305 polished with # 280 water-resistant abrasive paper specified in JIS R-6253 is used. As a Teflon (registered trademark) plate, a Nitoflon # 923 is used as the standard plate.
Before use, wipe the surface with acetone and wipe with ethyl alcohol, and use the following formula to calculate the basic adhesive strength (fo) and residual adhesive strength (f) according to the following formula. Calculate the residual adhesion rate. Residual adhesion rate (%) = (f) / (fo) × 100 The measurement of the basic adhesive force (fo) was performed by first measuring 25 m on a Teflon plate.
Paste m width polyester tape so that air bubbles do not enter,
After one reciprocating pressure-bonding using a 2 kg rubber roller, it was sandwiched between glass plates (15 cm × 30 cm), and 20 g / cm ²
After heating in a hot-air oven at 70 ° C. for 20 hours, the polyester tape was peeled off from the Teflon plate by allowing to stand at room temperature for 1 hour. The peeled polyester tape is stuck on a standard plate so as to prevent air bubbles from entering, using a 2 kg rubber roller for one reciprocating pressure, and allowed to stand at room temperature for 20 to 40 minutes. This was done by measuring the peel strength at 180 °. Residual adhesive strength (f)
First, a test piece was sampled to a size of 340 mm x 250 mm, and a 50 mm wide polyester tape (Nitto Lumilar 31B) was bubbled on the silicone-processed surface in a lengthwise direction at right, middle, and left in three places, 200 mm in length. Paste so that it does not enter. Next, using a rubber roller weighing 2 kg, after pressing back and forth one time, sandwiching between glass plates (15 cm × 30 cm), applying a load of 20 g / cm ² , and heating in a hot air oven at 70 ° C. for 20 hours And let stand at room temperature for 20 to 40 minutes to peel off the polyester tape from the silicone surface. The peeled polyester tape is adhered to a standard plate so that air bubbles do not enter, and one round-trip compression is performed using a rubber roller weighing 2 kg. After standing for 30 minutes in a standard state, the peeling rate was set to 0.
The measurement was performed by measuring the peel strength at 3 m / min and a peel angle of 180 °.

<Measurement of Water Contact Angle of Release Layer> Water was measured using a FACE contact angle measuring device (CA-A type, manufactured by Kyowa Interface Science Co., Ltd.). <Measurement method of heat resistance of film>
Place in a circulating oven maintained at 0 ° C, 150 ° C, 200 ° C, 250 ° C, take out every 500 hours from 0 hours to 2500 hours, and leave it in a constant temperature and humidity room (23 ° C, 55% RH) for one day. The tensile strength in the MD direction is measured to obtain a time-dependent curve of the strength. From there, the time at which the intensity becomes half the intensity at 0 hours at each temperature was obtained, and then the obtained time (half-life) was plotted against the temperature to obtain a curve,
The temperature in the case of a half life of 40,000 hours was defined as a normal heat-resistant temperature. <Dimension change rate> A test piece is cut into a rectangle having a length of 50 mm and a width of 20 mm. The test piece was sandwiched between aluminum foils having a thickness of 15 μm and placed in a hot air oven heated to a predetermined temperature,
Heat treatment. The length and width of the sample piece after the heat treatment was measured, and the obtained area was defined as S (mm ² ). The dimensional change rate was obtained by dimensional change rate = (S / 1000) × 100.

Production Example 1 Production of Liquid Crystal Polyester A-1 8.3 kg (60 mol) of p-acetoxybenzoic acid, 2.49 kg (15 mol) of terephthalic acid, 0.83 of isophthalic acid
kg (5 mol) and 5.45 kg (20.2 mol) of 4,4′-diacetoxydiphenyl were charged into a polymerization tank equipped with a comb-shaped stirring blade, and the mixture was heated to 330 ° C. while stirring under a nitrogen gas atmosphere. For 1 hour. During this time, polymerization was carried out under strong stirring while liquefying and collecting and removing acetic acid gas produced as a by-product in a cooling tube. Thereafter, the system was gradually cooled, and the polymer obtained at 200 ° C. was taken out of the system. The obtained polymer was ground with a hammer mill manufactured by Hosokawa Micron Co., Ltd.
mm or less. This was further treated in a rotary kiln under a nitrogen gas atmosphere at 280 ° C. for 3 hours to obtain a particulate wholly aromatic polyester having a flow start temperature of 324 ° C. and comprising the following repeating structural units. Here, the flow start temperature refers to a resin heated and melted at a heating rate of 4 ° C./min using a Shimadzu Flow Tester Model CFT-500 manufactured by Shimadzu Corporation under a load of 100 kgf / cm ² and an inner diameter of 1 mm. , A temperature (° C.) at which the melt viscosity shows 48,000 poise when extruded from a nozzle having a length of 10 mm. Hereinafter, the obtained liquid crystal polyester is abbreviated as A-1. This A-1 showed optical anisotropy at 340 ° C. or higher under pressure.

[0060]

Embedded image

Production Example 2 (B) Production of Rubber as Copolymer Methyl acrylate / ethylene / glycidyl methacrylate = 59.0 / according to the method described in Example 5 of JP-A-61-127709. A rubber having a 38.7 / 2.3 (mass ratio) and a Mooney viscosity of 15 was obtained. Hereinafter, the obtained rubber is abbreviated as B-1.

Production Example 3 Nippon Steel Corp. was prepared by mixing 85% by mass of A-1 produced in Production Example 1 and 15% by mass of B-1 produced in Production Example 2.
Using a TEX-30 twin screw extruder, melt kneading was performed at a cylinder set temperature of 350 ° C. and a screw rotation speed of 250 rpm to obtain liquid crystal polyester resin composition pellets. This pellet showed optical anisotropy at 340 ° C. or higher under pressure. The obtained pellets were subjected to a cylinder set temperature of 3 using a 60 mmφ single screw extruder equipped with a cylindrical die.
Melt extrusion at 50 ° C., screw rotation speed 60 rpm,
Diameter 50mm, lip interval 1.0mm, die set temperature 3
The molten resin was extruded upward from a cylindrical die at 48 ° C., dry air was injected into the hollow portion of the obtained cylindrical film, expanded, cooled, and then passed through a nip roll to obtain a film. The blow ratio is 4, the drawdown ratio is 10,
The measured average thickness of the film was 26 μm, and the ordinary heat resistance temperature was 165 ° C. Hereinafter, the obtained film as a supporting substrate is abbreviated as F-1.

Example 1 The inside of the cylindrical film F-1 produced in Production Example 3 is designated as A side, and the outside is designated as B side. UV-curable silicone paint (Ricoh Poulin Co., Siliconely POLY20)
0) to 100 parts by mass of a boron-based cationic polymerization initiator (Diaryl Iodonium, Tetrakis (Penta, Rhodia)
fliuoro Phenyl) Borate) was added in an amount of 2.5 parts by mass to prepare a release layer material. The release layer material was coated on the side A of the above F-1 at a line speed of 30 m / min using an offset gravure coater. Thereafter, the coating liquid was cured by irradiating ultraviolet rays (120 watts / cm) with a high-pressure mercury lamp to form a release layer, thereby obtaining a release film. The basis weight of the release layer of the obtained release film is 2
g / m ² . The thickness of the obtained release film, the peel load value, the residual contact rate and the water contact angle on the release layer side, the dimensional change rate, the thickness of the release film after the dimensional change rate measurement, the peel load value and The residual adhesion ratio was measured. The predetermined temperatures in the dimensional change rate measurement were 230 ° C. and 200 ° C.
Table 1 shows the results.

Example 2 A release film was prepared in the same manner as in Example 1 except that the coating of the release layer material was changed to the B side of F-1. Was. Table 1 shows the results.

Comparative Example 1 A commercially available polyvinyl fluoride film was used as a release film.
Using Tedlar TMR10SM3 (manufactured by DuPont), the film thickness and the water contact angle on the release layer side were measured. In addition, the predetermined temperature of the dimensional change rate measurement was set to 230 ° C. and 200 ° C., the dimensional change rate was measured, and the film thickness after this heat treatment and the water contact angle on the release layer side were measured. Table 1 shows the results.

Comparative Example 2 Each measurement was carried out in the same manner as in Comparative Example 1, except that a commercially available polymethylpentene resin film (Opulan X-44B, manufactured by Mitsui Chemicals, Inc.) was used as the release film. Table 1 shows the results. The predetermined temperature for measuring the dimensional change rate is 2
At 30 ° C., the sample melted.

[0067]

[Table 1]

[0068]

The release film of the present invention is excellent in heat resistance, release property and chemical resistance since a liquid crystal polymer film is used as a supporting substrate. Therefore, the release film of the present invention is suitable as a release film used in the manufacture of composite materials such as aircraft parts and sports goods, printed wiring boards and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 5/18 CFD C08J 5/18 CFD // C08L 67:00 C08L 67:00 (72) Inventor Noboru Yamaguchi 6 Kitahara, Tsukuba, Ibaraki Prefecture Sumitomo Chemical Co., Ltd. (72) Inventor Makoto Tamaki 10-11 Nihonbashi Kodenma-cho, Chuo-ku, Tokyo Kite Chemical Industry Co., Ltd. (72) Tokuyoshi Sato, Chuo-ku, Tokyo 10-11, Nihonbashi Kodenmacho K-term Chemical Industry Co., Ltd. F-term (reference) 4F071 AA48 AA69 AF12 BB07 BB08 BC01 4F100 AK01A AK52B AK71A AL01A AL05A AN02A AR00A AT00A BA02 EH17 EH172 EH46 EJ54 GB43 JA06AJABJJBJJBJJBJJBJ JL14B JN10A YY00A YY00B 4J029 AA06 AB01 AB07 AD09 AE03 BB04A BB05A BB05B BB10A BB12A BB13A BC05A BC06A BE05A BF14A BG05X BG05Y BH0 2 DB07 DB13 EB04A EB05A EB05B EE05 JE152 4J031 AA06 AA12 AA13 AA14 AA20 AA29 AA34 AA38 AA47 AA49 AA53 AA55 AA56 AA58 AA59 AC03 AC04 AC07 AC09 AD01 AE19 AF30 CD02 4J011 AK09 AK02 AK09 AK02

Claims (20)

[Claims] 1. A release film comprising a support substrate and a release layer, wherein the support substrate is a film containing a liquid crystal polymer exhibiting optical anisotropy when melted. 2. The release film according to claim 1, wherein the water contact angle of the release layer exceeds 80 degrees. 3. The release film according to claim 1, wherein the film containing a liquid crystal polymer exhibiting optical anisotropy when melted has a normal heat resistance temperature of 140 ° C. or higher. 4. The method according to claim 2, wherein after a heat treatment in air at a temperature of 180 ° C. or more and 250 ° C. or less for 30 minutes, a vertical and horizontal dimensional change rate is ± 5% or less. 3. The release film according to 3. 5. The release film according to claim 1, wherein the liquid crystal polymer exhibiting optical anisotropy upon melting is a liquid crystal polyester. 6. A liquid crystal polymer exhibiting optical anisotropy upon melting, wherein (A) a liquid crystal polyester is used as a continuous phase and (B) a copolymer containing a functional group reactive with the liquid crystal polyester is used as a dispersed phase. The release film according to any one of claims 1 to 5, which is a liquid crystal polyester resin composition. 7. A liquid crystal polyester exhibiting optical anisotropy when melted comprises (A) 56.0 to 99.9% by mass of a liquid crystal polyester.
And (B) 44.0 to 0.1% by mass of a copolymer containing a functional group reactive with the liquid crystal polyester, which is a liquid crystal polyester resin composition obtained by melt-kneading. Item 7. The release film according to any one of Items 1 to 5. 8. The functional group of the copolymer containing a functional group reactive with the liquid crystal polyester (B) contains at least one of an oxazolyl group, an epoxy group and an amino group. 8. The release film according to 7. 9. The copolymer (B) containing a functional group reactive with the liquid crystal polyester, containing 0.1 to 30% by mass of an unsaturated carboxylic acid glycidyl ester unit and / or an unsaturated glycidyl ether unit. The release film according to any one of claims 6 to 8, wherein the release film is a polymer. 10. The copolymer (B) containing a functional group reactive with a liquid crystal polyester has a crystal having a heat of fusion of 3J.
/ G of a copolymer.
10. The release film according to any one of 9. 11. The copolymer according to claim 6, wherein the Mooney viscosity of the copolymer (B) containing a functional group reactive with the liquid crystal polyester is in the range of 3 to 70. Release film. 12. The method according to claim 6, wherein (B) the copolymer containing a functional group reactive with the liquid crystal polyester is a rubber having an epoxy group and / or a thermoplastic resin having an epoxy group. 12. The release film according to any of 11. 13. The rubber having an epoxy group may be a (meth) acrylate-ethylene- (unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether).
13. The release film according to claim 12, comprising a copolymer rubber. 14. A thermoplastic resin having an epoxy group,
(a) 50 to 99% by mass of ethylene units, (b) 0.1 to 30% by mass of unsaturated carboxylic acid glycidyl ester units and / or unsaturated glycidyl ether units, and (c) 0 to 50 of ethylenically unsaturated ester compound units. 13. The release film according to claim 12, which is an epoxy group-containing ethylene copolymer in an amount of 1% by mass. 15. The release film according to claim 6, wherein (A) the liquid crystal polyester contains at least 30 mol% of the following repeating structural units. Embedded image 16. The mold release according to claim 6, wherein (A) the liquid crystal polyester is a reaction product of an aromatic dicarboxylic acid, an aromatic diol, and an aromatic hydroxycarboxylic acid. the film. 17. The release film according to claim 6, wherein (A) the liquid crystal polyester is a reaction product of two or more aromatic hydroxycarboxylic acids. 18. The release film according to claim 1, wherein the release layer has a silicone resin layer obtained by reacting a reactive silicone resin. 19. The release film according to claim 18, wherein the reactive silicone resin is of a solventless type and is of an ultraviolet or electron beam curing type. 20. The film containing a liquid crystal polymer exhibiting optical anisotropy when melted is a film obtained by an inflation film forming method.
The release film according to any one of the above.