JP5621435B2 - Biaxially oriented polyarylene sulfide film for mold release and molding method - Google Patents

Description

  The present invention relates to a release film composed of a biaxially oriented polyarylene sulfide film, and relates to a release film that is suitably used for production by mold press molding. More specifically, the present invention relates to a release film that can be used for the production of mold press molding of an epoxy prepreg molded into a three-dimensional shape.

  Fiber reinforced composite materials made by impregnating and curing an uncured matrix resin such as epoxy resin on a reinforcing fiber substrate such as glass cloth, carbon fiber, and aramid fiber are moldable, thin-walled, lightweight, high-rigidity, productivity, economic efficiency It is frequently used for electrical / electronic parts and casings such as electrical / electronic equipment parts, automobile equipment parts, personal computers, OA equipment, AV equipment, mobile phones, telephones, facsimiles, home appliances, toy products.

  As a typical method for producing a fiber-reinforced composite material, there is a method of laminating and arranging a fiber-reinforced prepreg obtained by impregnating a continuous reinforcing fiber with an uncured resin, and heating and pressing to cure. In some cases, release films are used.

  Fluorine films, silicon-coated polyethylene terephthalate films, polymethylpentene films, polypropylene films and the like have been used as release films used for these applications. However, the fluorine-based film conventionally used as a release film is excellent in heat resistance and releasability, but is expensive and difficult to burn in waste incineration treatment after use. There is a problem of generating poisonous gas, and when it is used as a release film for epoxy prepreg, there is a problem that mold mold contamination is likely to occur and productivity is deteriorated. Further, the silicon-coated polyethylene terephthalate film has a risk of impairing mold stains and prepreg quality due to migration of the silicon component. In addition, the polymethylpentene film is excellent in releasability, but has a problem that the film is easily wrinkled during molding. Further, the polypropylene film was inferior in heat resistance and insufficient in releasability.

  On the other hand, biaxially stretched polyphenylene sulfide films are known to be used for mold release because they are excellent in heat resistance and chemical resistance. (1) Polyphenylene sulfide provided with a coating layer made of silicone resin A film has been proposed (see Patent Document 1). Further, (2) polyphenylene sulfide films with few surface defects and excellent workability and surface smoothness have been proposed (see Patent Documents 2 and 3). However, when these polyphenylene sulfide films for mold release are used as mold release films for epoxy prepreg molding having a three-dimensional shape, there is a problem that wrinkles are likely to occur during molding.

JP-A-5-286084 JP 2007-152761 A JP 2008-110549 A

  An object of the present invention is to solve the above-mentioned problems, that is, to provide a release film for molding an epoxy prepreg having a three-dimensional shape, and is biaxially oriented for release excellent in wrinkle suppression and release properties. It is to provide a polyarylene sulfide film.

In order to solve the above problems, the biaxially oriented polyarylene sulfide film for mold release of the present invention mainly has the following constitution. That is,
(1) A biaxially oriented polyarylene sulfide film substantially consisting only of a polyarylene sulfide resin (A) and particles (B), which is at 160 ° C. for 10 minutes in either the longitudinal direction or the width direction of the film The heat shrinkage rate is 1.6% or more, the heat shrinkage rate when treated at the other 160 ° C. for 10 minutes is 0.5% or more, and the minute endothermic peak temperature (Tmeta) just below the melting point is 230 ° C. or more. Biaxially oriented polyarylene sulfide film for mold release , which is 255 ° C. or less and contains 0.5 to 3% by mass of the particles (B) ,
( 2) The biaxially oriented polyarylene sulfide film for mold release according to (1 ) , wherein the particles (B) are vaterite-type calcium carbonate,
( 3) The biaxially oriented polyarylene sulfide film for release according to (1) or (2) , which is for three-dimensional molding,

  According to the present invention, it is possible to obtain a release biaxially oriented polyarylene sulfide film that has excellent mold releasability, and can be suitably used as a release film for a three-dimensional molding epoxy prepreg. Can be used.

It is a schematic diagram which shows the example of the state of the wrinkles which generate | occur | produce on a prepreg after press molding. It is a figure explaining the installation state of a release film.

  Hereinafter, the biaxially oriented polyarylene sulfide film for mold release according to the present invention will be described. The polyarylene sulfide referred to in the present invention is a homopolymer or copolymer having a repeating unit of-(Ar-S)-. Examples of Ar include groups represented by the following formulas (A) to (K).

(R1 and R2 are substituents selected from hydrogen, an alkyl group, an alkoxy group, and a halogen group, and R1 and R2 may be the same or different.)
As the repeating unit of polyarylene sulfide used in the present invention, those adopting the repeating unit represented by the above formula (A) are preferable, and representative examples thereof include polyphenylene sulfide (hereinafter referred to as PPS). And polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers thereof, block copolymers, and mixtures thereof. A particularly preferred polyarylene sulfide is preferably PPS from the viewpoint of film properties and economy. In the present invention, the repeating unit of the polyarylene sulfide preferably contains paraphenylene sulfide units represented by the following structural formula, preferably 95 mol% or more, more preferably 98 mol% or more (consisting of paraphenylene sulfide). PPS is referred to as p-PPS). When the paraphenylene sulfide unit is less than 95 mol%, the crystallinity and heat transition temperature of the polymer are low, and the heat resistance and releasability may be impaired as a release film.

  The melt viscosity of polyarylene sulfide is not particularly limited as long as melt kneading is possible, but it may be in the range of 100 to 2000 Pa · s at a temperature of 300 ° C. and a shear rate of 1,000 (1 / sec). Preferably, it is in the range of 200 to 1,000 Pa · s.

  The polyarylene sulfide resin can be obtained by various methods, for example, a method for obtaining a polymer having a relatively low molecular weight described in JP-B-45-3368, or JP-B-52-12240 and JP-A-61-7332. It can be produced by a method for obtaining a polymer having a relatively large molecular weight described in the publication.

  The polyarylene sulfide resin obtained in the present invention is crosslinked / high molecular weight by heating in air, heat treatment in an inert gas atmosphere such as nitrogen or under reduced pressure, washing with an organic solvent, hot water, an acid aqueous solution, etc., acid anhydride It can also be used after various treatments such as activation with functional group-containing compounds such as products, amines, isocyanates and functional group disulfide compounds.

  The biaxially oriented polyarylene sulfide film for mold release of the present invention is substantially composed of only the polyarylene sulfide resin and the particles. The term “substantially” as used herein refers to the polyarylene sulfide resin and the particles in the film. It means that the mass per unit area occupies 99 mass% or more, desirably 99.5 mass% or more with respect to the mass per unit area of the film. When a resin or additive other than polyarylene sulfide resin and particles is contained, the releasability may be deteriorated.

The biaxially oriented polyarylene sulfide film for mold release of the present invention is a biaxially oriented film containing particles (B) and may contain 0.5 to 3% by mass of particles (B) with respect to the film mass. It is necessary from the viewpoint of releasability at the time of epoxy prepreg molding and suppression of wrinkles , and is preferable from the viewpoint of suppression of epoxy prepreg surface defects. When the content of the particles (B) is less than 0.5% by mass, the air releasing property with the epoxy prepreg may be deteriorated, and the remaining bubbles may be transferred to the prepreg and become a surface defect. When the content of the particles exceeds 5% by weight, the elongation at break of the film may be lowered, the molding followability at the time of three-dimensional molding may be deteriorated, and the releasability may be deteriorated. . The content of the particles (B) is more preferably 0.5% by mass to 2% by mass.

  Examples of such particles (B) include inorganic particles such as calcium carbonate, silica, titanium oxide, alumina, kaolin, calcium phosphate, barium sulfate, talc, and zinc oxide, and organic materials that do not melt up to 300 ° C. such as crosslinked styrene particles. Particles. As the inorganic particles, calcium carbonate is preferable from the viewpoint of affinity with the polymer, and vaterite type calcium carbonate is particularly preferable from the viewpoint of releasability.

  The average particle diameter of the particles (B) used in the present invention is preferably 0.5 μm or more and 5 μm or less, and more preferably 0.5 to 3 μm. When the particle size is less than 0.5 μm, the air release property between the epoxy prepreg is deteriorated, and the remaining bubbles may be transferred to the prepreg to cause surface defects. If it exceeds 5 μm, coarse protrusions are likely to be formed, the film may be cleaved due to particle dropping, and the releasability from the prepreg may be deteriorated. Moreover, the elongation at break of the film may be reduced, and the molding followability may be deteriorated.

  The biaxially oriented polyarylene sulfide film for mold release of the present invention needs to have a heat shrinkage rate of 1.6% or more in either the longitudinal direction or the width direction of the film when treated at 160 ° C. for 10 minutes. It is. More preferably, it is 1.7% or more. When the heat shrinkage rate in either the longitudinal direction or the width direction of the film when treated at 160 ° C. for 10 minutes is smaller than 1.6%, the prepreg and the release film are formed at the time of molding the epoxy prepreg having a three-dimensional shape. In some cases, wrinkles are generated in between, and the shape of the wrinkles is transferred to the prepreg. Although there is no particular upper limit on the heat shrinkage rate of the film, the upper limit is about 5% in view of the film formability of the film. Here, 160 ° C. is a representative temperature for thermoforming an epoxy prepreg. In the present invention, an epoxy having a three-dimensional shape is obtained by setting the thermal shrinkage rate of the film at the temperature to be within the range specified in this application. The present inventors have found that wrinkles of a film generated after prepreg molding can be suppressed.

  When the biaxially oriented polyarylene sulfide film for mold release according to the present invention is treated at 160 ° C. for 10 minutes, the thermal shrinkage rate in either the longitudinal direction or the width direction of the film satisfies the above range. Is important, but the heat shrinkage rate when treated at 160 ° C. for 10 minutes in the other direction, ie, the width direction for the longitudinal direction and the longitudinal direction for the width direction, is 0.5% or more. It is necessary to be. More preferably, it is 1.0% or more. When the heat shrinkage rate when treated at 160 ° C. for 10 minutes is less than 0.5%, wrinkles are likely to occur between the prepreg after mold molding at 160 ° C. and the release film due to thermal expansion of the film, The shape of the ridge may be transferred to the prepreg. Although there is no particular upper limit on the heat shrinkage rate of the film, the upper limit is about 5% in view of the film formability of the film.

  The biaxially oriented polyarylene sulfide film for mold release according to the present invention can be appropriately installed in a mold. For example, when wrinkles occur in parallel with the width direction of the film (FIG. 1), From the viewpoint of wrinkle suppression, it is important to install the film in such a way that the thermal shrinkage of the film is 1.5% or more so as to be vertical (FIG. 2). That is, in the present invention, it has been found that wrinkles can be suppressed by aligning the direction in which the film has a high thermal shrinkage rate with the direction perpendicular to the wrinkle generation direction, which is a typical mold molding temperature of 160. It has been found that wrinkles can be suppressed by setting the thermal shrinkage rate to 1.5% or more when treated at 10 ° C. for 10 minutes. Of course, when wrinkles occur in the longitudinal direction of the film, wrinkles are suppressed by setting the thermal shrinkage rate in the width direction of the film to 1.5% or more.

Small endothermic peak temperature just below the melting point of the releasing biaxially oriented polyarylene sulfide film of the present invention (Tmeta) is wrinkle suppression is at 255 ° C. or less 230 ° C. or higher is required in terms of releasability, preferably Is 240 ° C. or more and 255 ° C. or less. When the endothermic peak temperature just below the melting point is less than 230 ° C, the releasability may be deteriorated. When it exceeds 255 ° C, wrinkles may occur due to a decrease in the thermal shrinkage rate, and the releasability is deteriorated. There is a case.

  The minute endothermic peak temperature (Tmeta) just below the melting point is a minute endothermic peak that appears before crystal melting by differential scanning calorimetry (DSC) measurement, and is observed at a temperature corresponding to the heat treatment temperature of the film. This is because an incomplete part of the structure melts.

  The thickness of the biaxially oriented polyarylene sulfide film for mold release according to the present invention is not particularly limited, but is preferably 10 μm or more and 300 μm, more preferably 20 μm or more and 200 μm or less, more preferably from the viewpoint of mold release and economy. Preferably it is the range of 20-100 micrometers.

  The biaxially oriented polyarylene sulfide film for mold release according to the present invention is suitably used for a mold release film. Specifically, a release film for prepreg molding, a release film for FPC manufacturing, a release film for ACM materials used for aircraft parts, a release film for manufacturing rigid printed boards, a release film for semiconductor sealing materials, Examples include rubber sheet curing release films and special adhesive tape release films.

  Among them, the biaxially oriented polyarylene sulfide film for release of the present invention is a prepreg obtained by impregnating and curing an uncured matrix resin such as an epoxy resin on a reinforcing fiber base material such as glass cloth, carbon fiber, or aramid fiber. It is particularly preferably used for curing the material in a press mold or in an autoclave and preventing adhesion between the mold and the prepreg.

  Examples of the prepreg suitable for molding using the release biaxially oriented polyarylene sulfide film of the present invention include carbon fiber, glass cloth, and aramid fiber as reinforcing fibers. As the matrix resin impregnated in these reinforcing fibers, a thermosetting resin or a thermoplastic resin can be used. Specific examples thereof include an epoxy resin, an unsaturated polyester resin, an allyl resin, a phenol resin, and a polyamide resin. be able to. In the present invention, it can be suitably used as a release film for a prepreg using an epoxy resin as a matrix resin.

  The biaxially oriented polyarylene sulfide film for mold release according to the present invention is preferably used for molding a two-dimensional flat plate shape, but is particularly preferably used for molding a prepreg having a three-dimensional curved surface shape. It is.

  As a measure of releasability of the polyarylene sulfide film for mold release according to the present invention, the film breaks even if it is superposed on an epoxy prepreg and applied at a pressure of 1 MPa at 160 ° C. for 3 to 5 minutes and then cooled to room temperature. It is a preferable aspect that the mold can be released without performing.

  Next, a method for producing a polyarylene sulfide film for mold release according to the present invention will be described with reference to an example of a method for producing a biaxially oriented polyphenylene sulfide film using p-PPS as a polyarylene sulfide. There is no difficulty in obtaining it with reference to the following, and the same effect as when p-PPS is used can be expected. That is, it goes without saying that the present invention is not limited to the following description.

(1) Polymerization method of polyphenylene sulfide p-PPS can be prepared by various methods, for example, a method of obtaining a polymer having a relatively small molecular weight described in JP-B-45-3368, or JP-B-52-12240. It can be produced by a method for obtaining a polymer having a relatively large molecular weight described in JP-A-63-1332.

  Although the manufacturing method of p-PPS resin is illustrated, it is not limited to this in this invention. For example, sodium sulfide and p-dichlorobenzene are reacted in an amide polar solvent such as N-methyl-2-pyrrolidone (NMP) at high temperature and high pressure. If necessary, a copolymer component such as trihalobenzene can be included. Caustic potash or alkali metal carboxylate is added as a polymerization degree adjusting agent, and a polymerization reaction is performed at 230 to 280 ° C. After the polymerization, the polymer is cooled, and the polymer is filtered as a water slurry through a filter to obtain a granular polymer. This is stirred in an aqueous solution such as calcium acetate at 30 to 100 ° C. for 10 to 60 minutes, washed several times with ion exchange water at 30 to 80 ° C. and dried to obtain a PPS powder. The powder polymer is washed with NMP at an oxygen partial pressure of 10 torr or less, preferably 5 torr or less, then washed several times with ion exchange water at 30 to 80 ° C., and dried under a reduced pressure of 5 torr or less. If necessary, an inorganic or organic additive or the like is added to the polymer obtained above to the extent that the object of the present invention is not hindered to obtain a p-PPS resin.

(2) Production method of polyphenylene sulfide film After p-PPS obtained as described above was dried under reduced pressure, the melting part of the extruder was heated to a temperature of 300 to 350 ° C, preferably 310 to 340 ° C. Put into the extruder. Thereafter, the molten polymer passed through the extruder is passed through a filter, and the molten polymer is discharged into a sheet form using a die of a T die. The set temperature of the filter part and the die is preferably 3 to 20 ° C higher than the temperature of the melting part of the extruder, more preferably 5 to 15 ° C. This sheet-like material is brought into close contact with a cooling drum having a surface temperature of 20 to 70 ° C. to be cooled and solidified to obtain a substantially non-oriented unstretched film.

  Next, this unstretched film is biaxially stretched and biaxially oriented. Stretching methods include sequential biaxial stretching methods (stretching methods that combine stretching in each direction, such as a method of stretching in the width direction after stretching in the longitudinal direction), and simultaneous biaxial stretching methods (in the longitudinal direction and the width direction). The method of extending | stretching simultaneously), or the method which combined them can be used. Here, an example using a sequential biaxial stretching method in which stretching in the longitudinal direction and then in the width direction is performed first will be described.

  After heating the unstretched polyphenylene sulfide film with a heating roll group, it is 3.2 to 4.2 times, preferably 3.6 to 4.0 times, more preferably, from the viewpoint of wrinkle suppression in the longitudinal direction (MD direction). The film is stretched in multiple stages of 3.8 to 4.0 times in one or more stages (MD stretching). The stretching temperature is in the range of Tg (glass transition temperature of PPS) to (Tg + 40) ° C., preferably (Tg + 5) to (Tg + 30) ° C. Thereafter, it is cooled by a cooling roll group of 20 to 50 ° C.

As a stretching method in the width direction (TD direction) following MD stretching, for example, a method using a tenter is common. The both ends of this film are gripped with clips, guided to a tenter, and stretched in the width direction (TD stretching). The stretching temperature is preferably Tg to (Tg + 40) ° C., more preferably (Tg + 5) to (Tg + 30) ° C. The draw ratio is 3.2 to 4 times, preferably 3.4 to 3.8 times, more preferably 3.5 to 3.8 times from the viewpoint of suppressing wrinkles, and is drawn in one or more stages. (TD stretching).
Next, this biaxially stretched film is heat-set under tension. In the present invention, from the viewpoint of achieving the heat shrinkage rate specified in the present application, it is preferable to perform heat setting at two or more different temperatures, and the heat setting temperature in the first step is 160 to 200 ° C, preferably 180 to 200 ° C. The maximum temperature of the subsequent heat setting and / or relaxation heat treatment to be performed subsequently is 230 to 255 ° C, preferably 240 to 255 ° C. From the viewpoint of achieving the thermal shrinkage of the present invention, it is preferable to perform a relaxation treatment in the range of 0 to 5% in the film width direction, more preferably 0 to 3%, still more preferably 0%, that is, heat treatment at a constant length. To do.

  Further, the film is cooled to room temperature and wound up to obtain a target biaxially oriented polyphenylene sulfide film.

  The characteristic value measurement method and effect evaluation method of the present invention are as follows.

(1) Thermal contraction rate A straight line is drawn on a sample sampled to a width of 10 mm and a length of 200 mm so as to have an interval of about 100 mm, and the length of the interval is measured by a universal projector to be L0 (mm). Next, the sample was held in a gear oven heated to 160 ° C. under a load of 2.5 g for 10 minutes, and then cooled at room temperature for 2 hours. Measure to L (mm). From this measurement result, heat shrinkage rate = ((L0−L) / L0) × 100) (%), and an average value of n number of 5 samples was adopted for each of the film longitudinal direction and width direction. In addition, when the sign of the heat shrinkage rate is “− (negative)”, it indicates elongation.

(2) Minute endothermic peak temperature (Tmeta) just below the melting point
In accordance with JIS K7121-1987, a differential scanning calorimeter is used as a differential scanning calorimeter DSC (RDC220), and a data analyzer is a disk station (SSC / 5200) manufactured by Seiko Instruments Inc. The temperature was increased at a rate of temperature increase of 20 ° C./min. At that time, the observed minute endothermic peak just below the melting point was defined as Tmeta.

(3) Wrinkles and releasability by a mold molding test A film roll product wound up with a width of 600 mm is cut into a width of 500 mm and a length of 900 mm, and a release film and an epoxy prepreg are overlapped to form a curved surface. After applying a pressure of 160 ° C. and 1 MPa for 5 minutes with a press molding machine provided with a mold, the sample was taken out and cooled sufficiently to room temperature, and then the epoxy prepreg and the release film were peeled off by hand. The following criteria were used to determine releasability, air biting, wrinkles, and mold contamination. ○ and △ are acceptable levels (○ is better than △).

Releasability ○: The film was easily peeled off from the prepreg without breaking. Δ: The film was partially broken but peeled off from the prepreg. X: The film was not peeled off from the prepreg. ×: Film wrinkle transferred to product part of prepreg

  In the following examples, PPS as polyarylene sulfide and calcium carbonate as particles are described as specific examples. However, when preparing polyarylene sulfide, it can be obtained by the same method as described below. Even when other particles are used, it goes without saying that a predetermined effect can be obtained if a film according to the present invention is produced with reference to the following examples.

(1) Preparation of polyphenylene sulfide A 50 L autoclave (manufactured by SUS316) was charged with 56.25 mol of sodium hydrosulfide (NaSH), 54.8 mol of sodium hydroxide, 16 mol of sodium acetate, and 170 mol of N-methylpyrrolidone (NMP). . Next, dehydration was performed by raising the internal temperature to 220 ° C. while stirring under a nitrogen gas stream. After dehydration, the system was cooled to 170 ° C., and 55 mol of p-dichlorobenzene (p-DCB) and 0.055 mol of 1,2,4, -trichlorobenzene (TCB) were added together with 2.5 L of NMP. The system was pressurized and sealed to 2.0 kg / cm ² under a nitrogen stream. After heating under stirring at 235 ° C. for 1 hour and further at 270 ° C. for 5 hours, the system was cooled to room temperature, the obtained polymer slurry was put into 200 mol of water, and stirred at 70 ° C. for 30 minutes. Separate the polymer. The polymer was further washed 5 times with stirring at about 70 ° C. ion-exchanged water (9 times the polymer weight), and then stirred for about 1 hour under a nitrogen stream with a 1% by weight aqueous solution of calcium acetate at about 70 ° C. . Furthermore, after washing with ion-exchanged water at about 70 ° C. three times, it was separated and dried in an atmosphere of 120 ° C. and 1 torr for 20 hours to obtain a white polyphenylene sulfide powder.

  Next, this polyphenylene sulfide powder was stirred twice for 0.5 hours in NMP (3 times the weight of polyphenylene sulfide polymer) at 90 ° C. in a commercially available nitrogen gas atmosphere. The polyphenylene sulfide powder was further washed four times with ion-exchanged water at about 70 ° C. and then separated and dried as described above to obtain a white polyphenylene sulfide powder. The polyphenylene sulfide powder had a melt viscosity of 5000 poise at 300 ° C.

(2) Preparation of pellet [Particle pellet 1]
A slurry was prepared in which 50% by weight of vaterite-type calcium carbonate particles having an average particle size of 1.2 μm was dispersed in ethylene glycol. The slurry was filtered with a filter, and then mixed with the PPS powder obtained in (1) using a Henschel mixer so that the content of calcium carbonate was 7% by weight. The obtained mixture was supplied to a vent extruder having a 30 mm diameter biaxial screw and melted at a temperature of 320 ° C. This melt was filtered through a filter made of metal fibers with a 95% cut hole diameter of 10 μm, and then extruded from a 2 mm hole diameter die to obtain a gut-like resin composition. Further, the composition was cut into a length of about 3 mm to obtain particle pellets 1 having a particle content of 7% by weight.

[Particle pellet 2]
A heavy calcium carbonate (calcite-type calcium carbonate) fine powder with an average particle size of 1.2 μm, classified with a sieve after pulverization, is added to the PPS powder obtained in (1) with a calcium carbonate content of 20 wt. It mixed so that it might become%. The obtained mixture was supplied to a vent extruder having a 30 mm diameter biaxial screw and melted at a temperature of 320 ° C. This melt was filtered through a filter made of metal fibers with a 95% cut hole diameter of 10 μm, and then extruded from a 2 mm hole diameter die to obtain a gut-like resin composition. Further, the composition was cut into a length of about 3 mm to obtain particle pellets 2 having a particle content of 20% by weight.

[No particle pellet]
Except that only the polymer obtained in (1) was used and no particles were added, melt extrusion was performed in the same manner as the above particle pellets to obtain particle-free pellets containing no particles.

Example 1
After mixing the particle pellet 1 with the particle-free pellet obtained above so that the content of calcium carbonate is 0.5% by mass, the temperature is 180 ° C. under a reduced pressure of 3 mmHg using a rotary vacuum dryer. And dried for 4 hours. The obtained dried chip was supplied to a full flight single screw extruder whose melting part was heated to 310 ° C., filtered through a filter set at a temperature of 320 ° C., and then from a die of a T die set at a temperature of 310 ° C. It was melt-extruded and closely cooled and solidified while applying an electrostatic charge to a cast drum having a surface temperature of 25 ° C. to produce an unstretched film.

  This unstretched film is subjected to 4.0 times in the longitudinal direction of the film at a film temperature of 101 ° C. at a film temperature of 101 ° C. by using a difference in peripheral speed of the roll after preheating using a longitudinal stretching machine comprising a plurality of heated roll groups. Stretched at a magnification. Thereafter, both ends of the film are gripped with clips, guided to a tenter, stretched in the width direction of the film at a stretching temperature of 101 ° C. and a stretching ratio of 3.5 times, and subsequently heat treated at a temperature of 200 ° C. for 5 seconds (1 (Stage heat treatment), followed by heat treatment at a constant length in the horizontal direction at 250 ° C. for 15 seconds (second stage heat treatment), after cooling to room temperature, the film edge was removed, and the thickness was 25 μm. A biaxially oriented PPS film was prepared.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. This biaxially oriented PPS film was excellent in wrinkle and releasability.

(Example 2)
A biaxially oriented PPS film was produced in the same manner as in Example 1 except that the second stage heat treatment temperature was 230 ° C. in Example 1.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. This biaxially oriented PPS film was excellent in wrinkle and releasability.

( Comparative Example 5 )
A biaxially oriented PPS film was prepared in the same manner as in Example 1 except that the second stage heat treatment temperature was 210 ° C. in Example 1.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. In the biaxially oriented PPS film, a close contact portion was generated at the time of peeling from the prepreg.

Example 4
A biaxially oriented PPS film was produced in the same manner as in Example 1 except that the draw ratio in Example 1 was 3.8 times in the longitudinal direction.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. This biaxially oriented PPS film was excellent in wrinkle and releasability.

(Example 5)
A biaxially oriented PPS film was produced in the same manner as in Example 1 except that the content of calcium carbonate in Example 1 was changed to 3% by weight.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. This biaxially oriented PPS film was excellent in wrinkle and releasability.

(Example 6)
A biaxially oriented PPS film was produced in the same manner as in Example 1 except that the content of calcium carbonate was 1% by weight in Example 1.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. This biaxially oriented PPS film was excellent in wrinkle and releasability.

( Comparative Example 6 )
A biaxially oriented PPS film was produced in the same manner as in Example 1 except that the content of calcium carbonate in Example 1 was changed to 5% by weight.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. In the biaxially oriented PPS film, a close contact portion was generated at the time of peeling from the prepreg.

(Example 8)
Biaxial orientation was performed in the same manner as in Example 1 except that the particle pellet 2 was used instead of the particle pellet 1 used in Example 1 and the calcium carbonate content was 0.5% by mass as in Example 1. A PPS film was prepared.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. This biaxially oriented PPS film was excellent in wrinkle and releasability.

(Comparative Example 1)
A biaxially oriented PPS film was produced in the same manner as in Example 1 except that the second stage heat treatment temperature was 265 ° C. in Example 1.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. This biaxially oriented PPS film was wrinkled in the product portion.

(Comparative Example 2)
A biaxially oriented PPS film was produced in the same manner as in Example 1 except that the first-stage heat treatment temperature was 250 ° C. and the second-stage heat treatment temperature was 250 ° C. in Example 1.

  The measurement and evaluation results for the structure and properties of the obtained biaxially oriented PPS film are as shown in Table 1, and this biaxially oriented PPS film has a close contact portion when peeled from the prepreg, A wrinkle occurred in the product part.

(Comparative Example 3)
A biaxially oriented PPS film was produced in the same manner as in Example 1 except that the draw ratio in Example 1 was changed to 3.4 times in the vertical direction and 3.4 times in the horizontal direction.

  The measurement and evaluation results for the structure and properties of the obtained biaxially oriented PPS film are as shown in Table 1, and this biaxially oriented PPS film has a close contact portion when peeled from the prepreg, A wrinkle occurred in the product part.

(Comparative Example 4)
In Example 1, a biaxially oriented PPS film was produced in the same manner as in Example 1 except that 7% was applied in the lateral direction in the relaxation treatment zone.

  The measurement and evaluation results for the configuration and properties of the obtained biaxially oriented PPS film are as shown in Table 1. This biaxially oriented PPS film was wrinkled in the product portion.

  The polyarylene sulfide film for mold release of the present invention is excellent in wrinkle suppression and mold release properties, and can be suitably used as an epoxy prepreg mold release film for three-dimensional molding.

1. 1. Prepreg after press molding皺 3. Release film

Claims (3)

A biaxially oriented polyarylene sulfide film substantially consisting only of a polyarylene sulfide resin (A) and particles (B), which has a heat shrinkage of 160 ° C. for 10 minutes in either the longitudinal direction or the width direction of the film. Is 1.6% or more, the heat shrinkage rate is 0.5% or more when treated at the other 160 ° C. for 10 minutes, and the minute endothermic peak temperature (Tmeta) just below the melting point is 230 ° C. or more and 255 ° C. or less. A biaxially oriented polyarylene sulfide film for mold release containing 0.5 to 3% by mass of the particles (B) . The biaxially oriented polyarylene sulfide film for mold release according to claim 1, wherein the particles (B) are vaterite type calcium carbonate. The biaxially oriented polyarylene sulfide film for mold release according to claim 1 or 2 , which is used for three-dimensional molding.

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