TWI451959B - Solvent release film and laminates made of polyphenylene sulfide resin - Google Patents

Description

Release film and laminate of polyphenylene sulfide resin

The present invention relates to a release film of a polyphenylene sulfide resin and a laminate of the release film using the polyphenylene sulfide resin. More specifically, it relates to a technique for improving the releasability of a release film of a polyphenylene sulfide resin.

The circuit board is one of the main components of an electrical product for fixing electronic components for wiring, and is roughly classified into a rigid substrate using an insulating substrate having no flexibility and a thin and flexible insulating substrate. Flexible substrate. On the other hand, in the process of manufacturing a circuit board and the process of mounting and sealing a semiconductor device on a circuit board, it is intended to fix and protect a substrate material such as a prepreg, and to prevent leakage of a sealant. After the end of the step, a peelable release film was used.

The release film for a circuit board is subjected to heat and pressure, chemical liquid infiltration, etc., in a state of being attached to a substrate material such as a prepreg, and is then peeled off, so that not only the adhesion to the substrate material is obtained. Various properties such as heat resistance, chemical resistance, and peelability are also required. Therefore, in recent years, as a release film for a circuit board, a polyphenylene sulfide (PPS) film having excellent heat resistance and chemical resistance has been used.

In addition to heat resistance and chemical resistance, the PPS film is excellent in moisture resistance and various electrical properties, and various evaluations have been made in order to improve other properties (see Patent Documents 1 to 4). For example, in Patent Documents 1 and 2, in order to improve moldability, a polyarylene sulfide resin composition in which a styrene polymer having a syndiotactic structure is mixed is disclosed.

On the other hand, as a manufacturing use of a circuit board, Patent Document 3 proposes a laminated film for mold release, which is laminated on both sides of a resin composition layer (layer B) having a heat distortion temperature of 70 to 150 ° C. The ratio of the thickness of the layer A of the biaxially stretched film (layer A) which consists of the resin composition of the benzene sulfide as a main component, and the thickness of the A layer of the whole thickness is the range of 0.05-0.5.

Further, Patent Document 4 also proposes a composite sheet in which the polyphenylene sulfide layer forming the release surface has an average surface roughness of 5 nm or more and a thickness of 0.1 to 200 μm by using a polyphenylene sulfide layer and The other resin layer is coextruded to laminate a substantially unstretched composite sheet.

Patent Document 1: Japanese Patent Laid-Open No. 2-70754

Patent Document 2: Japanese Patent Publication No. 2-172528

Patent Document 3: Japanese Laid-Open Patent Publication No. 2006-21372

Patent Document 4: Japanese Laid-Open Patent Publication No. 2007-216627

However, the conventional PPS film is excellent in heat resistance and chemical resistance, but has high adhesion to a substrate material and has a problem that it is difficult to peel off. On the other hand, the biaxially stretched film composed of the polyphenylene sulfide resin composition described in Patent Document 2 is particularly excellent in moldability, but the peeling property with the substrate material is not examined.

Further, since the film described in Patent Document 3 has a laminated structure, it is easy to cause curling due to a difference in thermal expansion coefficient between the resin constituting the layer A and the resin constituting the layer B, and further, the PPS is disposed in the outermost layer. Since the film has a large adhesion strength to the substrate material, there is a problem that it is difficult to peel off. Further, in the film described in Patent Document 4, the PPS film is not stretched, and if it is heated, it becomes brittle, and there is a problem that it cannot withstand the stress at the time of peeling and is broken.

As described above, the conventional PPS film has various problems in order to be used as a release film for a circuit board. Therefore, it is necessary to provide a PPS film having a good balance between adhesion and releasability of the substrate material, and specifically, it is necessary to adhere to the substrate material during the treatment such as drug infiltration, and to surely protect the substrate, and then do not need to protect the substrate. The PPS film can be easily peeled off from the substrate material.

Therefore, a main object of the present invention is to provide a release film and a laminate of a polyphenylene sulfide resin which are excellent in heat resistance, chemical resistance, and adhesion to a substrate material, and are processed from a substrate material. The peelability is also excellent.

The release film of the polyphenylene sulfide resin of the present invention is a release film formed by stretching a polyphenylene sulfide resin composition, and the polyphenylene sulfide resin composition contains 0.1 to 30 volumes of syndiotactic polystyrene. %, the thickness of the film is in the range of 20 to 100 μm.

Further, the content (% by volume) of the inter-polystyrene specified herein is a conversion value obtained by the amount and density of the syndiotactic polystyrene.

In the present invention, since a specific amount of inter-polystyrene is contained, the peeling property of the substrate material is improved, and since the film has a specific thickness, the workability is good, and the elongation strength is also improved. Thereby, the peeling property of the substrate material after the treatment is improved. As a result, in addition to the heat resistance and chemical resistance of the PPS resin and the appropriate adhesion to the substrate material, it is also possible to provide a release film which is excellent in easy peelability.

The release film preferably has a ratio (C/S) of carbon (C) to sulfur (S) on the surface of the film, which is larger than a central portion in the thickness direction, in particular, in a polyphenylene sulfide resin composition. The inter-polystyrene content is 1.0% by volume or more, and the element ratio (C/S) of carbon (C) to sulfur (S) on the surface of the film is 7.5 or more. Further, the surface of the film in the present invention means a region having a depth of several nm from the surface of the film.

In addition, the polyphenylene sulfide resin composition may contain 25 parts by mass or less of the saturated hydrocarbon copolymer based on 100 parts by mass of the syndiotactic polystyrene.

In addition, the polyphenylene sulfide resin composition may contain calcium carbonate: 0.3 parts by mass or less and calcium stearate: 0.2 parts by mass or less based on 100 parts by mass of the syndiotactic polystyrene.

These release films can be used, for example, in the process of a rigid substrate.

The laminate of the present invention is applied to at least one surface of a rigid substrate, and is adhered to the above-mentioned release film of a polyphenylene sulfide resin, or a release film made of the polyphenylene sulfide resin, and laminated. Hard substrate.

According to the present invention, since the polyphenylene sulfide contains a specific amount of inter-polystyrene, and the film thickness is in a specific range, and is formed by stretching, it is possible to achieve not only adhesion to the substrate material but also resistance. A release film and a laminate which are excellent in peelability from a substrate material after the treatment, in addition to chemical properties and heat resistance.

Hereinafter, the form for carrying out the invention will be described in detail. In order to solve the above problems, the inventors of the present invention have conducted experimental investigations and found that (1) polystyrene sulfide (hereinafter, abbreviated as PPS) is added with a specific amount of polystyrene (hereinafter, simply referred to as The PPS resin composition of s-PS) is stretched, and (2) the thickness of the film after stretching is in a specific range, and a release film of a PPS resin excellent in peeling property with a substrate material can be obtained, and the present invention has been completed.

Further, the present inventors have found that the release film of the PPS resin is composed of (3) adjusting the element ratio (C/S) of carbon (C) to sulfur (S) on the surface of the film, and (4) composition of the PPS resin. The elastomer is blended with the elastomer component (saturated hydrocarbon copolymer) to control the peelability from the substrate material. Further, the present inventors have found that even if a filler such as calcium carbonate or calcium stearate is blended in a PPS resin composition, the properties such as peelability are not lowered, and the release film of the PPS resin is particularly suitable for a rigid substrate. Process.

In other words, the release film of the PPS resin of the present invention is a film formed by stretching a PPS resin composition containing 0.1 to 30% by volume of s-PS, and has a thickness of 20 to 100 μm. Further, in the release film of the PPS resin of the present invention, the element ratio (C/S) of carbon (C) to sulfur (S) on the surface of the film is preferably larger than the center portion in the thickness direction, more preferably, PPS resin. The s-PS content in the composition was 1.0% by volume or more, and the element ratio (C/S) of carbon (C) to sulfur (S) on the surface of the film was 7.5 or more.

Further, the PPS resin composition constituting the release film of the PPS resin of the present invention is preferably a saturated hydrocarbon copolymer: 25 parts by mass or less per 100 parts by mass of s-PS, and 100 parts by mass per PPS, as needed. Calcium carbonate can be blended: 0.3 parts by mass or less and calcium stearate: 0.2 parts by mass or less. According to these configurations, it is possible to obtain a release film which is excellent not only in adhesion to the substrate material, chemical resistance, and heat resistance but also in peelability from the substrate material after the treatment.

Further, the peeling property of the release film for a substrate depends on the chemical and physical properties of the substrate material to be bonded. The release film of the PPS resin of the present invention is used as a prepreg to be adhered, and is a type of substrate material which is obtained by impregnating a substrate with a resin. The base material to be used at this time may, for example, be an inorganic fiber base material such as a glass woven fabric (glass cloth) or a glass nonwoven fabric, an aromatic polyamide woven fabric, an aromatic polyamide woven fabric, an organic fiber base such as paper fiber or carbon fiber. material. Further, as the matrix resin impregnated with the base materials, for example, an epoxy resin, a phenol resin, an acrylic resin, an amine resin, an olefin resin, an ethylene resin, a quinone imine resin, or a guanamine system can be used. Various thermosetting resins or thermoplastic resins such as a resin, an ester resin, an ether resin, a fluorine resin, a cyanate resin, and an isocyanate resin. In such a prepreg, a copper clad or the like is processed into a substrate-attached copper laminate, and used as a circuit board.

<About PPS>

First, the PPS which is a main component of the release film of the PPS resin of the present invention will be described. PPS is a polymer having p-phenylene sulfide as a repeating unit represented by the following Chemical Formula 1, and the release film of the PPS resin of the present invention is used for ensuring adhesion to a substrate material, heat resistance and chemical resistance. An important ingredient.

Further, the PPS used in the present invention preferably contains 70 mol% or more of p-phenylene sulfide unit as a repeating unit in the polymer. When the content of the p-phenylene sulfide unit is less than 70 mol%, the crystallinity of the polymer and the glass transition point are lowered, so that the heat resistance of the polymer film having the PPS as a main component cannot be sufficiently exhibited. The reason for the mechanical strength. Further, the p-phenylene sulfide unit is more preferably contained in an amount of 90 mol% or more.

Further, the PPS may contain, in addition to the p-phenylene sulfide unit, a repeating unit having a polymerizable thioether bond as long as it is less than 30 mol%, preferably less than 10 mol%, of the repeating unit of the polymer. unit. The repeating unit having a polymerizable thioether bond is not particularly limited, and particularly preferably an aromatic thioether bond unit represented by the following Chemical Formula 2. Further, in the following Chemical Formula 2, Ar is an aryl group, and examples thereof include each of the functional groups represented by the following Chemical Formulas 3 to 10. In particular, when PPS having an aromatic thioether unit having a functional group represented by the above Chemical Formula 9 and/or an aromatic thioether unit having a functional group represented by the following Chemical Formula 10 is used, excellent heat resistance can be obtained. Further, in the following Chemical Formula 6, Q represents a halogen atom or a methyl group, and m represents an integer of 1 to 4. Further, the PPS in the present invention may contain one or a combination of two or more of the above-mentioned repeating units.

On the other hand, when the PPS system contains a copolymer of a monomer unit represented by the above Chemical Formula 2, the form of the polymer may be either a random polymer or a block polymer. Further, a monomer unit other than the above Chemical Formula 1 may be present at or near the end of the polymer.

The PPS of the present invention can be obtained, for example, by the method described in the specification of U.S. Patent No. 4,645,826, that is, an alkali metal sulfide and dichlorobenzene in a polar solvent such as N-methyl 2-pyrrolidone. In the presence of water, it is obtained by a specific two-stage temperature polymerization method. By using this polymerization method, a substantially linear high molecular weight PPS can be obtained. Further, by adding a small amount of an aromatic halogen compound having three or more halogen substituents during the polymerization, PPS having a branched or crosslinked structure may be introduced. In addition, as a method of producing a block polymer, for example, a method described in JP-A No. 2-225535 or JP-A-4-213328 can be used.

Further, the melt viscosity of the PPS is preferably from 20 to 2,000 Pa s when measured at a temperature of 310 ° C and a shear rate of 1,200 / sec. When the melt viscosity is less than 20 Pa ‧ , the mechanical properties and heat resistance of the film are lowered, and the characteristics of the PPS film may not be obtained. Further, if the melt viscosity exceeds 2000 Pa ‧ , the manufacturing device such as an extruder or a filter device The additional increase will cause a bad situation. The melt viscosity of the PPS is preferably from 30 to 1800 Pa‧s. Further, the shear speed herein is defined as the value of the gradient velocity of the viscous fluid passing between the flat plates.

<About s-PS>

Next, the s-PS added to the PPS resin composition which forms the release film of the PPS resin of the present invention will be described. s-PS is a styrene-based polymer mainly having a styrene structure represented by the following Chemical Formula 11 in a repeating unit. The syndiotactic structure refers to a three-dimensional structure in which the phenyl group or the substituted phenyl group of the side chain is alternately located in the opposite direction with respect to the main chain formed by the carbon-carbon bond.

Further, s-PS can be obtained, for example, by the method described in JP-A-62-187708, that is, a titanium compound and water and a trialkyl aluminum in an inert hydrocarbon solvent or in the absence of a solvent. The condensation product is used as a catalyst to polymerize a styrene monomer.

On the other hand, when the s-PS is blended in the PPS resin composition, the effect of improving the peeling property with the substrate material is obtained. However, if the s-PS content in the PPS resin composition is less than 0.1 volume, the effect of addition thereof cannot be obtained, and the adhesion due to PPS acts, and it is difficult to peel off from the substrate material. In addition, when the s-PS content is more than 30% by volume, the amount of PPS in the composition is reduced, so that the adhesion to the substrate material, heat resistance, and chemical resistance are lowered, and the practicality as a release film is lowered. Further, when the s-PS content exceeds 30% by volume, the moldability is lowered, so that cracking occurs in the lateral direction. Therefore, the s-PS content in the PPS resin composition is from 0.1 to 30% by volume.

On the other hand, the s-PS content in the PPS resin composition is preferably from 0.3 to 25% by volume, more preferably from 0.5 to 20% by volume. Thereby, the peeling property to the substrate material can be further improved. Here, the volume % referred to herein is a value obtained by the amount (mass) and density of s-PS. Further, at this time, the density of PPS was calculated at a density of 1.35 g/cm ³ and s-PS at 1.04 g/cm ³ .

<About film thickness>

The thickness of the film after stretching affects the workability as a release film. Specifically, when the substrate material is peeled off, a strong force is applied to the film. Therefore, when the thickness is less than 20 μm, the film is easily broken and workability is lowered. On the other hand, when the thickness exceeds 100 μm, it is difficult to uniformly conduct heat to the entire film during stretching, and it is difficult to form a film. Therefore, the film thickness is set to 20 to 100 μm. Further, the film thickness is preferably 22.5 to 80 μm, more preferably 25 to 70 μm. Thereby, the workability can be improved.

<About the element ratio of carbon to sulfur>

In the release film of the PPS resin of the present invention, it is preferred to satisfy the above-described respective constituent elements and to have an element ratio of carbon (C) to sulfur (S) in the surface of the film (hereinafter referred to as C/S ratio). The C/S ratio is larger than the center portion in the thickness direction. Thus, by biasing the carbon on the surface of the film, it is possible to obtain a good peeling property of the substrate material from stability. Here, the surface of the film means a region having a depth of several nm from the surface of the film.

Particularly, the s-PS content in the PPS resin composition is 1.0% by volume or more, and the C/S ratio of the surface of the film is 7.5 or more, whereby the peeling property of the surface of the film can be improved. Specifically, the peel strength of the general-purpose multilayer printed wiring board material (FR-4) can be made 200 N/m or less. Here, the s-PS content in the PPS resin composition is 1.0% by volume or more because the C/S ratio of the film surface may be less than 7.5 when the s-PS content is less than 1.0% by volume.

Further, the C/S ratio in the film surface and the central portion of the thickness can be measured by XPS (X-ray photoelectron spectroscopy). Further, the C/S ratio in the surface of the film can be adjusted by the amount of s-PS in the PPS resin composition, the production conditions described later, and the like.

1 and 2 are cross-sectional TEM (Transmission Electron Microscope) photographs of a release film made of PPS resin. Further, Fig. 1 is a photograph of a film formed by using a PPS resin composition containing 7.7% by volume of s-PS and a saturated hydrocarbon copolymer and 6.0% by volume of an s-PS content, and Fig. 2 is a volume of 7.5 containing s-PS. A photograph of a film formed from a PPS resin composition of %. As shown in Fig. 1 and Fig. 2, in the release film of the PPS resin of the present invention, the s-PS phase of the bulk is dispersed throughout the film, and the C/S ratio (theoretical value) is about 6.6, and the surface C is The /S ratio is about 10 to 13. Therefore, it is presumed that the low molecular weight s-PS or the elastomer component (saturated hydrocarbon copolymer) is biased on the surface.

<About Saturated Hydrocarbon Copolymer>

Further, the PPS resin composition constituting the release film of the PPS resin of the present invention may be blended with a saturated hydrocarbon copolymer as an elastomer. In general, the compatibility of PPS with s-PS is low, and by the blending of the PPS resin with the elastomer component (saturated hydrocarbon copolymer), the saturated hydrocarbon copolymer acts as a phase solvent to improve the compatibility. Thereby, variations in the peel strength in the surface of the film and between the batches can be suppressed.

Further, by blending the saturated hydrocarbon copolymer, since the composition of the substance present on the surface of the film changes, the peeling property of the release film of the PPS resin and the substrate material also changes. That is, in the release film of the PPS resin of the present invention, the releasability to the substrate material can be controlled by adjusting the blending amount of the saturated hydrocarbon copolymer to the PPS resin composition.

However, when the amount of the saturated hydrocarbon copolymer is more than 25 parts by mass relative to s-PS: 100 parts by mass, the thermal stability is lowered, and it is decomposed when formed into a sheet by extrusion molding (unstretched film). Therefore, when a saturated hydrocarbon copolymer is added to the PPS resin composition, the saturated hydrocarbon copolymer is preferably 25 parts by mass or less based on 100 parts by mass of s-PS.

<About calcium carbonate and calcium stearate>

Further, the release film of the PPS resin of the present invention may contain calcium carbonate and calcium stearate. Calcium carbonate and calcium stearate act as lubricants. However, when the amount of the calcium carbonate is more than 0.3 parts by mass based on 100 parts by mass of the PPS, aggregation occurs and the elongation at break is lowered to make it difficult to extend. Further, when the amount of calcium stearate is more than 0.2 parts by mass, extrusion failure occurs. Therefore, when the PPS resin composition is blended with the above, it is preferred that the calcium carbonate: 0.3 parts by mass or less and calcium stearate: 0.2 parts by mass or less with respect to 100 parts by mass of the PPS.

Next, a method for producing a release film of a PPS resin of the present invention will be described. The release film of the PPS resin of the present invention can be produced by the following method: an elastomer component such as a saturated hydrocarbon copolymer or a calcium carbonate which is s-PS: 0.1 to 30% by volume, and optionally quantitatively as required. The PPS resin composition of an additive such as calcium stearate is melted to form an unstretched film, and the film is stretched and obtained.

In the present invention, the film is formed by stretching to impart strength to the film. In the release film, it is necessary to withstand the strength of the force applied when the substrate material is peeled off, and the unstretched film is brittle due to heating, so that the strength at the time of peeling cannot be withstood, and the film is broken. Therefore, the film is formed by stretching.

When manufacturing the release film of the PPS resin of the present invention, first, weigh the PPS particles and the s-PS particles so that the s-PS content is 0.1 to 30% by volume (converted value), and further, if necessary, cooperate The particles of the saturated hydrocarbon copolymer are metered and dry blended and supplied to an extruder (hereinafter, this method is referred to as dry blending). Alternatively, the PPS powder may be blended so that the s-PS is 0.1 to 30% by volume (converted value), and if necessary, a predetermined amount of the saturated hydrocarbon copolymer particles are blended, and then mixed and remelted to the pellets. The granulator is supplied to an extruder (hereinafter, this method is referred to as a compound method).

In this case, calcium carbonate and calcium stearate may be blended, and as a substitute for the PPS particles, a resin composition in which PPS is blended with calcium carbonate and calcium stearate may be used as the granules. Similarly, as an alternative to s-PS particles, it is also possible to use s-PS with a resin composition of a saturated hydrocarbon copolymer to form a granule. Further, the PPS particles or PPS are compounded with resin particles of a predetermined amount of calcium carbonate and calcium stearate, and resin particles of a saturated hydrocarbon copolymer in s-PS particles or s-PS, and may also be blended with a lubricant, Various additives such as plasticizers, antioxidants and impact inhibitors.

Thereafter, each of the supplied resins is melted at 280 to 340 ° C, and is formed into a film shape for molding into a die, and is ejected. At this time, if the melting temperature is less than 280 ° C, the PPS may not be sufficiently melted, or if it exceeds 340 ° C, a decomposition product of the resin may be formed during extrusion. Therefore, the melting temperature is set to 280 to 340 °C. Further, in this step, it is preferred to filter the molten resin composition using a filter or the like to remove a large foreign matter such as dust or agglomerates of the additive. The film ejected from the die is extruded onto a cooling body such as a metal barrel, and solidified by cooling to obtain an unstretched film.

Next, the unstretched film thus obtained is given strength to the film by stretching. The release film of the PPS resin of the present invention may be a stretched film, but a biaxially stretched film is preferred. Here, the biaxial stretching is an extension for imparting molecular alignment in the longitudinal direction and the lateral direction. The extension may be performed by extending the two directions separately (hereinafter, referred to as sequential biaxial stretching), or may be extended in both directions at the same time. Further, it can be extended in the longitudinal direction and/or the lateral direction.

Hereinafter, an example of a method of producing a release film of a PPS resin by sequential biaxial stretching will be described. First, the extension of the longitudinal direction will be explained. The extension of the longitudinal direction is usually performed by the circumferential speed difference of the rolls. This extension can be carried out in one stage, or it can be carried out in multiple stages using a plurality of roller pairs. The surface temperature of the film when extending in the longitudinal direction is preferably 80 to 110 °C. If the surface temperature of the film at the time of stretching is less than 80 ° C, it will become below the glass transition temperature of PPS, so that it is difficult to uniformly extend the film. Further, when the surface temperature of the film at the time of stretching exceeds 110 ° C, the film is intermittently adhered to the stick-slip of the stretching roll, and it is difficult to uniformly extend. Further, the film temperature when extending in the longitudinal direction is preferably 85 to 105 °C. Further, the surface temperature of the film at the time of stretching can be appropriately adjusted by changing the temperature of the roll.

Further, the stretching ratio in the longitudinal direction is set to be 2.0 to 5.0 times. When the stretching ratio is less than 2.0 times, it is difficult to obtain sufficient strength and heat resistance in the longitudinal direction. On the other hand, if the stretching ratio exceeds 5.0, the magnification which can be extended in the lateral direction is lowered, and the balance of the physical properties in the longitudinal direction and the lateral direction is impaired. Further, the stretching ratio in the longitudinal direction is preferably 2.5 to 4.0 times.

Next, the film extending in the longitudinal direction by the above method and conditions is introduced into a tenter stretching machine, and is stretched in the lateral direction by stretching the both ends of the film with a jig. The surface temperature of the film when extending in the transverse direction is preferably 80 to 110 °C. When the surface temperature of the film at the time of stretching is less than 80 ° C, it is difficult to uniformly extend, and it is difficult to obtain good planarity. On the other hand, when the surface temperature of the film exceeds 110 ° C, it is difficult to sufficiently carry out the crystallization, and the elastic modulus or heat resistance tends to be insufficient. Further, the surface temperature of the film when extending in the transverse direction is preferably 85 to 105 °C.

The stretching ratio in the lateral direction is set to be 2.0 to 5.0 times. When the stretching ratio is less than 2.0 times, it is difficult to uniformly extend, and it becomes a cause of poor planarity. On the other hand, when the stretching ratio exceeds 5.0, the frequency of occurrence of cracking increases, and the productivity tends to be lowered.

After the lateral stretching, it is preferred to shorten the distance between the jigs holding the film by 0.1 to 10%, preferably about 0.5 to 7%, thereby relaxing the film formed in the tenter stretching machine. The heat setting treatment is performed at a temperature above the extension temperature and below the melting point. Thereby, the heat resistant size can be stabilized. The temperature of the heat setting treatment is preferably 240 to 290 °C. When the heat setting temperature is less than 240 ° C, the lateral relaxation efficiency is lowered, and it is difficult to obtain a film excellent in dimensional stability at a high temperature, and if the heat setting temperature exceeds 290 ° C, the melting point of the PPS film is higher, and film formation is performed. difficult. Further, the heat setting treatment temperature is preferably from 250 to 285 °C.

The film after the heat setting treatment was cooled to room temperature at the outlet portion of the tenter stretching machine, and then wound up by a winder to obtain a biaxially stretched PPS resin release film.

As described above, the release film of the PPS resin of the present invention is formed of a PPS resin composition containing 0.1 to 30% by volume of s-PS, and therefore has superior peelability from the substrate material as compared with the conventional PPS film. Further, in the release film of the PPS resin of the present invention, since the thickness of the film obtained by stretching is in the range of 20 to 100 μm, excellent workability and strength as a release film can be obtained. As a result, the chemical resistance and heat resistance of the PPS are not lowered, and the adhesion to the substrate material such as the prepreg can be maintained, and the peeling property of the substrate material after the treatment can be improved.

Further, the release film of the PPS resin of the present invention can control the peel strength with the substrate material by adjusting the C/S ratio of the surface of the film. The C/S ratio of the surface of the film can be adjusted, for example, by changing the amount of s-PS compounded in the PPS resin composition or the mixing method and conditions at the time of preparation of the PPS resin composition. Further, in the release film of the PPS resin of the present invention, the peeling strength of the general-purpose multilayer printed wiring board material (FR-4) can be made 200N by setting the C/S ratio of the surface of the film to 7.5 or more in such a manner. /m below. Thereby, good peelability to the substrate material can be obtained by stability.

Further, in the release film of the PPS resin of the present invention, since the composition of the substance present on the surface of the film can be changed by blending the PPS resin composition with the saturated hydrocarbon copolymer, by adjusting the amount of the saturated hydrocarbon copolymer, The peelability to the substrate material can be controlled.

The above-mentioned PPS resin release film of the present invention is suitable for a process of a rigid substrate, for example, a release film of the PPS resin of the present invention is adhered to at least one side of a rigid substrate, or is made of the PPS resin of the present invention. The release film is laminated with a plurality of hard substrates. On the other hand, in the treatment, the release film of the PPS resin in the treatment is adhered to the substrate, and when the film is not required, the release film of the PPS resin can be easily peeled off from the substrate.

[Examples]

Hereinafter, examples and comparative examples of the present invention will be described to specifically illustrate the effects of the present invention. Further, the present invention is not limited to the embodiments shown below.

<First Embodiment>

According to the first embodiment of the present invention, the films of Examples 1 to 8 and Comparative Examples 1 to 4 in which the amount of s-PS, the thickness of the film, and the film formation method are different are produced by the method described below, and the substrate materials are compared. Peelability.

(Example 1)

In the present embodiment, first, resin particles (hereinafter, referred to as PPS resin particles) in which PPS is blended with calcium carbonate and calcium stearate are prepared. Specifically, 100 parts by mass of the PPS powder was added with calcium carbonate having an average particle diameter of 0.7 μm: 0.3 parts by mass and calcium stearate: 0.2 parts by mass, and the obtained mixed powder was pelletized to prepare PPS resin particles. Next, the PPS resin pellets and the s-PS pellets were weighed so as to have a volume ratio of 95:5, and then mixed using a blender to obtain a PPS resin composition. In addition, the volume ratio here is such that the density of PPS is 1.35 g/cm ³ and the density of s-PS is 1.04 g/cm ³ , which is converted from the mass and density of PPS and s-PS, and the following The examples and comparative examples shown are also the same.

Next, the PPS resin composition was heated to 310 ° C using an extruder having a diameter of 50 mm to be melted, and filtered through a disk filter having a mesh size of 10 μm. Next, the molten PPS resin composition was extruded from a die having a linear slit having a length of 560 mm and a gap of 1.1 mm, and cast on a metal barrel having a surface maintained at 40 ° C to be cooled to have a thickness of 380 μm unstretched film.

Next, the unstretched film was preheated in contact with a metal roll whose surface temperature was adjusted to about 85 ° C, and then the metal film was adjusted to a surface temperature of about 90 ° C so that the length of the longitudinal direction was 3.4 times. Perform roll extension. Next, the film extending in the longitudinal direction was introduced into a tenter stretching machine and extended laterally by 2.8 times in an ambient atmosphere of 93 °C. Immediately after stretching, the film was thermally relaxed at about 4% in the lateral direction and fixed at 250 ° C for about 90 seconds to obtain a biaxially stretched film having a thickness of about 40 μm.

(Example 2)

In the same manner as in the above-mentioned Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 93:7 was used, and extruded under the same conditions as in Example 1 to obtain a thickness. It is an unstretched film of 380 μm. Next, the unstretched film was stretched in the longitudinal direction and the transverse direction under the same conditions as in Example 1, and then relaxed to obtain a biaxially stretched film having a thickness of about 40 μm.

(Example 3)

In the same manner as in the above-mentioned Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 90:10 was used, and extruded under the same conditions as in Example 1 to obtain a thickness. It is an unstretched film of 380 μm. Next, the unstretched film was stretched in the longitudinal direction and the transverse direction under the same conditions as in Example 1, and then relaxed to obtain a biaxially stretched film having a thickness of about 40 μm.

(Example 4)

In the same manner as in the above-mentioned Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 90:10 was used, and extruded under the same conditions as in Example 1 to obtain a thickness. It is an unstretched film of 300 μm. Next, the unstretched film was stretched in the longitudinal direction and the transverse direction under the same conditions as in Example 1, and then relaxed to obtain a biaxially stretched film having a thickness of about 32 μm.

(Example 5)

In the same manner as in the above-mentioned Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 90:10 was used, and extruded under the same conditions as in Example 1 to obtain a thickness. It is an unstretched film of 500 μm. Then, the unstretched film was stretched in the longitudinal direction and the transverse direction under the same conditions as in Example 1, and then relaxed to obtain a biaxially stretched film having a thickness of about 53 μm.

(Example 6)

In the same manner as in the above-mentioned Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 80:20 was used, and extruded under the same conditions as in Example 1 to obtain a thickness. It is an unstretched film of 380 μm. Next, the unstretched film was stretched in the longitudinal direction and the transverse direction under the same conditions as in Example 1, and then relaxed to obtain a biaxially stretched film having a thickness of about 40 μm.

(Example 7)

In the same manner as in the above-mentioned Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 99.8:0.2 was used, and extrusion was carried out under the same conditions as in Example 1 to obtain a thickness. It is an unstretched film of 380 μm. Next, the unstretched film was stretched in the longitudinal direction and the transverse direction under the same conditions as in Example 1, and then relaxed to obtain a biaxially stretched film having a thickness of about 40 μm.

(Example 8)

In the same manner as in the above-mentioned Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 75:25 was used, and extrusion was carried out under the same conditions as in Example 1 to obtain a thickness. It is an unstretched film of 380 μm. Next, the unstretched film was stretched in the longitudinal direction and the transverse direction under the same conditions as in Example 1, and then relaxed to obtain a biaxially stretched film having a thickness of about 40 μm.

(Comparative Example 1)

In Comparative Example 1 of the present invention, in the same manner as in the above Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed in a ratio of 50:50 by volume was used in the same manner as in Example 1. The conditions were extruded to obtain an unstretched film having a thickness of 380 μm. Next, the unstretched film was stretched in the longitudinal direction and the transverse direction under the same conditions as in Example 1, and then relaxed to obtain a biaxially stretched film having a thickness of about 40 μm. However, in this comparative example, many fractures occurred during lateral stretching, making it difficult to perform continuous film formation.

(Comparative Example 2)

In Comparative Example 2 of the present invention, a release film made of a PPS resin to which s-PS was not added was produced. Specifically, resin pellets containing PPS prepared in the same manner as in the above Example 1 as a main component were melted and filtered in the same manner as in Example 1 and then cast to prepare an unstretched film having a thickness of 440 μm.

Next, the unstretched film was preheated in contact with a metal roll whose surface temperature was adjusted to about 85 ° C, and then the metal film was adjusted to a surface temperature of about 90 ° C so that the length of the longitudinal direction was 3.4 times. Perform roll extension. Next, the film extending in the longitudinal direction was introduced into a tenter stretching machine, and after extending 3.2 times in the lateral direction in an ambient atmosphere of 93 ° C, it was immediately relaxed toward the lateral direction by about 3%. Thereafter, it was heat-set at 260 ° C for about 50 seconds to obtain a biaxially stretched film having a thickness of about 40 μm.

(Comparative Example 3)

In Comparative Example 3 of the present invention, in the same manner as in the above Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 90:10 was used in the same manner as in Example 1. The conditions were extruded to obtain an unstretched film having a thickness of 200 μm. Next, the unstretched film was stretched 3.4 times in the longitudinal direction and 3.6 times in the lateral direction, and then relaxed to obtain a biaxially stretched film having a thickness of about 16 μm.

(Comparative Example 4)

In Comparative Example 4 of the present invention, in the same manner as in the above Example 1, a PPS resin composition in which PPS resin particles and s-PS particles were mixed at a volume ratio of 90:10 was used, and extrusion was carried out to cool. The barrel was wound at a high speed to obtain an unstretched film having a thickness of 40 μm.

Next, the peeling property was evaluated about each film of the Example and the comparative example produced by the said method. Specifically, the prepreg (the prepreg FR-4 (product number: EI-6765) for the epoxy multilayer printed wiring board made by Sumitomo Co., Ltd.) was held on each of the films of the examples and the comparative examples. After the glass was semi-hardened by using a press machine at 125 ° C for 30 minutes, it was pressed at 175 ° C and 2.2 MPa (22.5 kgf / cm ² ) for 45 minutes to harden the prepreg.

Thereafter, each film of the prepreg was thermocompression-bonded and peeled off by hand, and the ease of peeling was evaluated. As a result of the evaluation, the film was not broken and was easily peeled off by the prepreg, and the film was peeled off from the prepreg, but the peel strength was rated as Δ, and the film strength was low. And the adhesion strength with the prepreg is large and the film cannot be peeled off and is rated as ×. The above results are shown in Table 1.

As shown in the above Table 1, the films of Examples 1 to 8 in which s-PS was added to the PPS within the scope of the present invention were easily peeled off, and in particular, the s-PS content was in the range of 0.5 to 20% by volume. The films of Examples 1 to 6 showed excellent peeling properties which were not conventionally obtained.

On the other hand, the film of Comparative Example 1 having an s-PS content of 50% by volume caused a lot of breakage during lateral stretching, making film formation difficult. Further, the film of Comparative Example 2 in which s-PS was not added had a high degree of adhesion to the prepreg and could not be peeled off. Further, in the film of Comparative Example 3 having a film thickness of 16 μm, the film was easily broken at the time of peeling due to the thin thickness, and was not suitable as a release film. Further, the unstretched film of Comparative Example 4 was low in strength and brittle due to heating, so that the film was easily cracked at the time of peeling.

As described above, the PPS resin is added to the PPS within the scope of the present invention, and the film thickness is within the scope of the present invention, and the release film of the PPS resin of the present embodiment is formed by extending the film, and the present invention is beyond the present invention. In comparison with the film of the comparative example outside the range, it was confirmed that the peeling property and the heat resistance were excellent.

<Second embodiment>

In the second embodiment of the present invention, the films of Examples Nos. 11 to 19 having different C/S ratios on the surface of the film were produced by the methods and conditions shown below, and the peel strength against the substrate material was measured. In the present embodiment, first, a PPS resin composition is prepared by blending PPS with s-PS by a dry blending method (D) or a synthesis method (P).

Specifically, the film of No. 11 to 16, 19 prepared by dry blending is a PPS pellet of PPS pellet (No. 11) or granulated with calcium carbonate and calcium stearate in PPS. (No. 12 to 16, 19), s-PS particles were blended, and a part of the samples (No. 15 to 19) were also dry blended with saturated hydrocarbon copolymer particles, and supplied to an extruder. On the other hand, synthetically prepared No. 17, 18 is a PPS powder mixed with s-PS particles and saturated hydrocarbon copolymer particles, and the film No. 17 is also blended with calcium carbonate and calcium stearate. After that, it will be remelted and granulated, and supplied to the extruder.

In this case, the s-PS system uses three kinds of particles having different molecular weights (s-PS type: A to C), and the s-PS content in the PPS resin composition is 0.1 to 30% by volume (converted value). . Further, the saturated hydrocarbon copolymer is a styrene ethylene butylene styrene block copolymer, and the compounding amount thereof is 25 parts by mass based on 100 parts by mass of the s-PS. In addition, the amount of calcium carbonate is 0.3 parts by mass per 100 parts by mass of the PPS, and the amount of calcium stearate is 0.2 parts by mass per 100 parts by mass of the PPS.

Next, the PPS resin composition was heated to 310 ° C using an extruder having a diameter of 50 mm to be melted, and filtered through a disk filter having a mesh size of 10 μm. Next, the molten PPS resin composition was extruded from a die having a linear slit having a length of 560 mm and a gap of 1.1 mm, and cast on a metal barrel having a surface maintained at 40 ° C to be cooled, thereby producing an unstretched film.

Next, the unstretched film was preheated in contact with a metal roll whose surface temperature was adjusted to about 85 ° C, and then placed on a metal roll having a surface temperature of about 90 ° C so that the length of the longitudinal direction became 3.4 times or 3.5. The method of multiple times is performed to extend between rolls separately. Next, the film extending in the longitudinal direction was introduced into a tenter stretching machine, and was extended 2.9 times or 3.0 times in the lateral direction in an ambient atmosphere of 93 ° C, respectively. Immediately after stretching, the film was gently relaxed to about 3%, 4%, or 4.7%, and thermally fixed at a temperature of 250 ° C or 260 ° C for 40 seconds or 100 seconds to obtain a biaxially stretched film having a thickness of about 40 μm.

Further, as a comparative example of the present invention, a film of No. 20 which was not blended with s-PS was produced. Specifically, PPS: 100 parts by mass of calcium carbonate: 0.3 parts by mass and calcium stearate: 0.2 parts by mass and granulated PPS resin particles are melted and filtered in the same manner as in Example 1 and then cast. An unstretched film having a thickness of 380 μm was produced.

Next, the unstretched film was preheated by contact with a metal roll whose surface temperature was adjusted to about 85 ° C, and then the metal film was adjusted to a surface temperature of about 90 ° C so that the length of the longitudinal direction was 3.5 times. Perform roll extension. Next, the film extending in the longitudinal direction was introduced into a tenter stretching machine, and after extending 2.9 times in the lateral direction in an ambient atmosphere of 93 ° C, it was immediately relaxed toward the lateral direction by about 4%. Thereafter, it was heat-set at 250 ° C for about 100 seconds to obtain a biaxially stretched film having a thickness of about 40 μm.

Next, the peel strength was measured about each film of the Example and the comparative example produced by the said method. Specifically, the prepreg (the prepreg FR-4 (product number: EI-6765) for the epoxy multilayer printed wiring board made by Sumitomo Co., Ltd.) was held on each of the films of the examples and the comparative examples. After the glass was semi-hardened by using a press machine at 125 ° C for 30 minutes, it was pressed at 175 ° C and 2.2 MPa (22.5 kgf / cm ² ) for 45 minutes to harden the prepreg.

From the laminate of the film and the prepreg, a rectangular test piece having a width of 15 mm was cut. On the test piece, the prepreg was placed in a horizontal state, and the film was pulled up in the vertical direction, and the 90 peel strength was measured. At this time, the tensile tester was a TENSILON RTC-1210A manufactured by A&D Co., Ltd., and the test speed was 50 mm/min, and the test environment was 23 ° C and 50% RH. Further, in the measurement of the peel strength, nine test pieces were measured and averaged.

Further, for each of the films of the examples and the comparative examples, XPS (Quantera SX manufactured by ULVAC-PHI Co., Ltd.) was used to analyze the types of elements having a depth of about several nm from the surface, the existence ratio thereof, and the chemical state, and the surface C was determined. /S ratio. At this time, the X-ray source used a monochromatic Al line (1486.6 eV). Further, the detection area was 100 μm Φ, and the detection depth was about 4 to 5 nm (the extraction angle was 45°). The above results are shown in Table 2 below. Further, in the following Table 2, the measurement conditions of each film and the measurement (theoretical value) of the C/S ratio at the center of the film were also shown.

As shown in the above Table 2, the film prepared this time had a higher C/S ratio on the surface of the film than the center portion in the thickness direction, and it was confirmed that C was on the surface. In particular, the films of Examples Nos. 11 to 18 having a C/S ratio of 7.5 or more on the surface of the film were excellent in peelability as compared with the film of No. 19 having a C/S ratio of less than 7.5, and the peel strength of the substrate. Both are reduced to below 200N/m. Further, the film of No. 20 which was not blended with s-PS had a C/S ratio of less than 6, and the peel strength was high, and the film was broken when peeled off from the substrate, and the peel strength could not be measured. From the above results, it was confirmed that the peeling property of the substrate material can be improved by setting the C/S ratio of the surface of the film to 7.5 or more.

Fig. 1 (a) and (b) are cross-sections of a release film of a PPS resin formed by using a PSS resin composition containing 7.7% by volume and a s-PS content of 6.0% by volume in total of s-PS and a saturated hydrocarbon copolymer. TEM photo.

2(a) and 2(b) are cross-sectional TEM photographs of a release film made of a PPS resin formed using a PPS resin composition containing 7.5% by volume of s-PS.

Claims (7)

A release film made of a polyphenylene sulfide resin, which is a release film formed by stretching a polyphenylene sulfide resin composition, wherein the polyphenylene sulfide resin composition contains syndiotactic polystyrene 0.1~ 30% by volume, the film thickness is 20 to 100 μm, and the element ratio (C/S) of carbon (C) to sulfur (S) on the surface of the film is larger than the central portion in the thickness direction. The release film of the polyphenylene sulfide resin according to claim 1, wherein the polyphenylene sulfide resin composition has a polystyrene content of 1.0 to 30% by volume, and the carbon on the surface of the film ( C) The elemental ratio (C/S) to sulfur (S) is 7.5 or more. The release film of a polyphenylene sulfide resin according to the first or second aspect of the invention, wherein the polyphenylene sulfide resin composition contains 25 parts by mass of a saturated hydrocarbon copolymer with respect to 100 parts by mass of the syndiotactic polystyrene. the following. The release film of a polyphenylene sulfide resin according to the first or second aspect of the invention, wherein the polyphenylene sulfide resin composition contains calcium carbonate: 0.3 parts by mass or less based on 100 parts by mass of the syndiotactic polystyrene. And calcium stearate: 0.2 parts by mass or less. A release film of a polyphenylene sulfide resin as claimed in claim 1 or 2, which is used in a process of a rigid substrate. A laminate comprising a release film of a polyphenylene sulfide resin according to any one of claims 1 to 4 on at least one side of a rigid substrate. A laminate comprising a release film of a polyphenylene sulfide resin according to any one of claims 1 to 4, wherein a plurality of rigid substrates are laminated.