TW201829562A - Polystylene-based film and multilayer film - Google Patents

Abstract

Provided is a polystyrene-based film ensuring low costs for ginning. To this end, the polystyrene-based film comprises a syndiotactic polystyrene-based resin and a spherical filler, and is biaxially oriented, while having gloss of 30% or less, surface roughness (Ra) of 0.8 [mu]m or more, and tensile elongation of 15% or more. Preferably, the spherical filler is amorphous silica, more preferably the spherical filler is fused silica.

Description

Polystyrene film and multilayer film

The present invention relates to a biaxially oriented syndiotactic polystyrene film having a rough surface. The present invention also relates to a multilayer film including a biaxially oriented syndiotactic polystyrene resin layer having a roughened surface in an outermost layer.

Syndiotactic polystyrene (SPS) -based resins are excellent in heat resistance and chemical resistance, and are used as molded articles or films in various fields. As one of such applications, research has been conducted to prevent the use of SPS-based resins with low surface tension and low wettability in the manufacture of printed substrates, ceramic electronic parts, semiconductor packages, and various other resin molded products. A biaxially-oriented SPS film is used as a release film in which a forming mold or a forming roll is fused with a material to be formed. Patent Documents 1 to 3 describe single-layer or multilayer release films using SPS-based resins.

Moreover, in the said release film, in order to give the surface of a to-be-molded article a matte appearance, the release film may be roughened, and the surface unevenness | corrugation may be transferred to a to-be-molded article. Patent Document 4 and Patent Document 5 describe that while the biaxially oriented SPS film is heated and pressed, it is allowed to pass between a roller having a matt pattern on the surface and other rollers, thereby making the surface of the roller uneven. Transfer to the film surface to roughen the film. Patent Document 6 describes an SPS-based film obtained by melting and kneading an SPS-based resin and polycarbonate, forming a film, performing biaxial stretching, and roughening the film. Patent Document 7 describes an SPS-based film obtained by melting and kneading an SPS-based resin and a styrene-based thermoplastic elastomer, forming a film, performing biaxial stretching, and roughening. [Prior Art Literature] [Patent Literature]

[Patent Literature 1] Japanese Patent Laid-Open No. 2001-168117 [Patent Literature 2] Japanese Patent Laid-Open No. 2001-310428 [Patent Literature 3] Japanese Patent Laid-Open No. 2014-226785 [Patent Literature 4] Japanese Patent Special Japanese Patent Application Publication No. 2013-216779 [Patent Document 5] Japanese Patent Application Publication No. 2013-215989 [Patent Document 6] Japanese Patent Application Publication No. 2016-000467 [Patent Document 7] Japanese Patent Application Publication No. 2011-000468

[Problems to be Solved by the Invention] As described in Patent Literature 4 and Patent Literature 5, a method for roughening by roller transfer requires an alignment step of the film and another roughening step. Therefore, there are manufacturing costs. Room for improvement.

In contrast, the methods described in Patent Literature 6 and Patent Literature 7 that mix SPS with other resins and perform biaxial stretching can reduce manufacturing costs. However, a large degree of surface unevenness by the roller transfer method cannot be obtained. Therefore, even if the gloss is the same as that of the roller transfer method, the texture is subtly different. Some users require adjustment of the texture caused by the increased surface unevenness.

In addition, the present inventors have previously tried to roughen the SPS-based film surface by blending a filler. However, at this time, since the film strength is significantly reduced by blending the filler, the amount of filler added is limited, and it is difficult to enhance the degree of matteness of the film (paragraph 0009 of Patent Document 4).

The present invention has been made in consideration of the above circumstances, and an object thereof is to provide a biaxially oriented SPS-based film having a roughened surface, that is, a film with large surface unevenness and a cheaper film. [Technical means to solve the problem]

In order to solve the problem, in the present invention, the spherical filler is blended in an SPS-based resin and biaxially aligned to roughen the surface.

Specifically, the polystyrene-based film of the present invention contains a syndiotactic polystyrene-based resin and a spherical filler. After biaxial alignment, the gloss is 30% or less, the surface roughness (Ra) is 0.8 μm or more, and the film is stretched. The elongation is 15% or more.

Here, the gloss refers to the 60-degree specular gloss and Gs (60 °) specified in Japanese Industrial Standards (JIS) Z8741: 1997. In addition, in this invention, the glossiness uses the average value of a machine direction (MD) and a transverse direction (TD) value. The surface roughness (Ra) refers to the arithmetic average roughness Ra specified in JISB0601: 1994. The so-called tensile elongation refers to the tensile failure strain (when not accompanied by a drop) or the nominal tensile failure obtained by a tensile test (test piece type 2, test speed 200 mm / min) specified in JISK7127: 1999. Strain (when accompanied by heave). The tensile elongation of the film of the present invention is 15% or more in each of the longitudinal direction (MD) and the transverse direction (TD).

With this configuration, a polystyrene film having surface unevenness and gloss equivalent to those of the conventional roll transfer method can be obtained without excessively impairing the mechanical characteristics of the film.

Preferably, the spherical filler is amorphous silicon dioxide, and further preferably, the spherical filler is fused silica.

In addition, the maximum diameter of the spherical filler is preferably less than the thickness of the polystyrene film, and the median diameter (d50) is preferably 6% or more of the thickness of the polystyrene film. Here, the median particle diameter (d50) is a value on a volume basis.

In addition, it is preferable that the blending amount of the spherical filler is 5 parts by weight or more and 20 parts by weight or less based on 100 parts by weight of the resin component.

The multilayer film of the present invention includes a first layer, a first surface constituting a gloss of 30% or less and a surface roughness (Ra) of 0.8 μm or more, containing a syndiotactic polystyrene resin and a spherical filler, and biaxially Alignment; and at least one resin layer, which is disposed on a side of the first layer opposite to the first surface. When the tensile elongation is 15% or more and the tensile strain is less than 15%, the first layer does not break.

With this configuration, a multilayer film having surface unevenness and gloss equivalent to those of the conventional roll transfer method can be obtained on the first surface. In addition, the first layer and other layers can be used to share and realize various characteristics required for the multilayer film, thereby making it easier to optimize the surface unevenness or the appearance of the first layer.

Preferably, the resin layer adjacent to the first layer contains the same syndiotactic polystyrene resin as the first layer, and the content of the spherical filler is less than that of the first layer or does not contain a spherical shape. filler.

In addition, it is preferable that the second surface on the side opposite to the first surface is made of an antistatic layer. [Inventive effect]

According to the present invention, the syndiotactic polystyrene-based film or the syndiotactic polystyrene-based resin layer is roughened by preparing a filler and performing biaxial alignment, so it can be obtained at a lower cost than the previous roll transfer method. Film with rough surface. Furthermore, the spherical shape of the filler can provide a polystyrene-based monomer with less reduction in the mechanical properties of the film and a surface unevenness and gloss equivalent to those of the conventional roll transfer method while maintaining sufficient tensile elongation. Laminate or multilayer film.

The polystyrene-based film according to the first embodiment of the present invention is a single-layer release formed by roughening a surface by blending a spherical filler in a syndiotactic polystyrene (SPS) -based resin and performing biaxial stretching. membrane.

First, the composition of the film of this embodiment will be described.

The SPS-based resin is a styrene polymer having a syndiotactic structure. The so-called syndiotactic structure refers to a stereo structure in which the stereochemical structure is a syndiotactic structure, that is, a phenyl group or a substituted phenyl group which is a side chain with respect to a main chain formed by a carbon-carbon bond.

The degree of stereoregularity (tacticity) of the SPS-based resin can be quantified by a nuclear magnetic resonance method (13C-NMR method) using isotopic carbon. The stereoregularity of the SPS-based resin measured by the 13C-NMR method can be a chain including a plurality of monomer units, for example, a dyad when two is used, and a triad when three is used. ), When it is five, it is expressed as the proportion of the constituents in the pentad (pentad) whose stereo configuration is the opposite syndiotactic (racemic diad, etc.). The SPS-based resin in the present invention usually has a racemic triad of 75% or more, preferably 85% or more, or a racemic triad of 60% or more, preferably 75% or more, or racemic A styrenic polymer having a syndiotacticity of 30% or more, preferably 50% or more of the pentad.

Examples of the type of the styrene-based polymer as the SPS resin include polystyrene, poly (alkylstyrene), poly (halogenated styrene), poly (halogenated alkylstyrene), and poly (alkoxy). Styrene), poly (vinyl benzoate), these hydrogenated polymers, etc., and mixtures of these, or copolymers containing these as main components. Examples of the poly (alkylstyrene) include poly (methylstyrene), poly (ethylstyrene), poly (isopropylstyrene), poly (tert-butylstyrene), and poly (phenyl) Styrene), poly (vinylnaphthalene), poly (vinylstyrene), and the like. Examples of the poly (halogenated styrene) include poly (chlorostyrene), poly (bromostyrene), and poly (fluorostyrene). Examples of the poly (halogenated alkylstyrene) include poly (chloromethylstyrene). Examples of the poly (alkoxystyrene) include poly (methoxystyrene) and poly (ethoxystyrene).

The weight average molecular weight of the SPS resin constituting the plastic film of the present invention is 10,000 to 3,000,000, preferably 30,000 to 1,500,000, and particularly preferably 50,000 to 500,000. The glass transition temperature of the SPS-based resin is 60 ° C to 140 ° C, and preferably 70 ° C to 130 ° C. The melting point of the SPS-based resin is 200 ° C to 320 ° C, and preferably 220 ° C to 280 ° C. In this specification, the glass transition temperature and melting point of a resin are the values measured based on JISK7121.

The SPS-based resin contained in the film of this embodiment may be a mixture of two or more different SPS-based resins.

The film of this embodiment may contain other resins in a range that does not adversely affect practically the heat resistance, chemical resistance, low surface tension, and the like, which are the characteristics of the SPS film. In this case, the content ratio of the SPS resin to all resin components in the film is preferably 50% by weight or more, more preferably 60% by weight or more, and particularly preferably 75% by weight or more.

For example, the film of this embodiment may contain a styrene-based thermoplastic elastomer (Thermo Plastic Styrene Elastomer (TPS)). TPS is a thermoplastic elastomer (Thermo Plastics Elastomer, TPE) in which the hard segment contains polystyrene. Therefore, when formulated in an SPS film, appearance defects are difficult to occur. By blending TPS, the flexibility of the film is improved. Furthermore, as described in Patent Document 7, TPS is mixed with an SPS-based resin and biaxially aligned to obtain a roughened SPS-based film. Therefore, in this embodiment, the effect of the spherical filler is supplemented. The degree of mattness of the film can be further enhanced.

In the case of formulating TPS, it is preferable to use a hydrogenated one. Thereby, the heat resistance of TPS is improved, and an unexpected reaction can be prevented from occurring in the melting × extrusion step of the SPS-based resin at a high temperature.

As the hydrogenated TPS, polystyrene-poly (ethylene / butene) -polystyrene (TPS-SEBS (Styrene-Ethylene / Butylene-Styrene)), polystyrene-poly (ethylene / propylene) -polystyrene can be used. (TPS-SEPS (Styrene-Ethylene / Propylene-Styrene)), polystyrene-poly (ethylene-ethylene / propylene) -polystyrene (TPS-SEEPS (Styrene-Ethylene-Ethylene / Propylene-Styrene)) and other soft chains Various paragraphs of different kinds.

The TPS contained in the film of this embodiment may be a mixture of two or more different TPS. At this time, all or a part of the TPS may be a soft segment containing a poly (ethylene / propylene) block or a poly (ethylene-ethylene / propylene) random copolymer block. When it is desired to increase the roughening effect of the film, TPS-SEEPS including a random copolymer of poly (ethylene-ethylene / propylene) in a soft segment can be used in all or part of the TPS.

Regarding the blending amount of TPS, the weight of the SPS resin (a) and TPS (b) is preferably set to (a) / (b) = 100/0 to 60/40, and more preferably 100/0. ~ 80/20. The larger the amount of TPS blended, the more roughened or softened. On the other hand, when the blending amount of TPS is too large, characteristics such as heat resistance, chemical resistance, and low surface tension, which are characteristics of SPS-based resins, decrease.

The filler prepared in the film of this embodiment is a spherical filler. Since the filler is spherical, it has good fluidity and can be easily filled into the resin. In addition, since the filler is spherical, it is stable even when a force is applied from any direction. Therefore, there is little reduction in the mechanical properties of the film, and it is difficult to cause the filler to be broken and detach from the film. The sphericity of the spherical filler is preferably 0.80 or more, more preferably 0.90 or more, and particularly preferably 0.95 or more.

The spherical filler is preferably amorphous silicon dioxide. The reason is that the hardness of the amorphous silicon dioxide is not too high, so the screw or die of the extruder is not easy to wear during the production of the film. The amorphous silicon dioxide used as the spherical filler is preferably a non-porous amorphous silicon dioxide. For example, when the amorphous silicon dioxide is derived from a silicon rubber, it is preferable to use an amorphous silicon dioxide that is made non-porous.

Another example of non-porous amorphous silica is fused silica. The reason is that, regarding fused silica, the raw material is melted in a flame and spheroidized by surface tension, so there is no sharp part, the fluidity in the resin is higher, it is more difficult to be damaged, and the mechanical properties of the film are damaged. To a lesser extent. Furthermore, when the film of this embodiment is used as a release film for a semiconductor package, the epoxy resin as the material to be molded may contain fused silicon dioxide, and even if it migrates to the material to be molded, it is not easy to become problem.

The diameter of the largest particle diameter of the spherical filler is preferably the thickness of the underfill film, more preferably 95% or less of the film thickness, and even more preferably 65% or less of the film thickness. The reason is that if a spherical filler is used which is close to the thickness of the film or has a diameter equal to or greater than the thickness of the film, the film is easily broken at this portion, and the degradation of the mechanical properties of the film is increased. In order to provide more textured surface unevenness, the diameter of the largest of the spherical fillers is preferably 40% or more of the film thickness.

In addition, the median particle diameter (d50) of the spherical filler is preferably 6% or more of the film thickness, more preferably 10% or more of the film thickness, and particularly preferably 20% or more of the film thickness. The reason is that if the particle diameter of the filler is too small, sufficient surface irregularities cannot be obtained. On the other hand, the median particle diameter (d50) of the spherical filler is preferably 60% or less of the film thickness, and more preferably 40% or less of the film thickness. The reason is that if the median particle diameter of the filler is too large, the decrease in the mechanical properties of the film becomes large. In order to impart more textured surface irregularities, the median particle diameter (d50) of the spherical filler is preferably in the range of 15% to 35% of the film thickness. In addition, in this specification, a median particle diameter (d50) is a value on a volume basis. If the filler contains a single substance and the density is constant, this value is consistent with the value on a mass basis or a weight basis.

The blending amount of the spherical filler is preferably 5 parts by weight or more with respect to 100 parts by weight of the resin component of the film, and more preferably 10 parts by weight or more. The reason is to obtain a sufficiently large surface asperity. On the other hand, the blending amount of the spherical filler is preferably 20 parts by weight or less based on 100 parts by weight of the resin component of the film. The reason is that if the blending amount is too large, the reduction in the mechanical properties of the film becomes large.

The film according to this embodiment may contain additives such as an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, an antistatic agent, a colorant, a crystal nucleating agent, and a flame retardant in addition to the polymer according to required characteristics. . In particular, it is preferable to add an antioxidant and a lubricant to the film used as the release film. Moreover, it is preferable that the film used as a release film is an antistatic agent, or an antistatic agent, such as surfactant, is apply | coated to the surface of one side.

Next, the characteristics of the film of this embodiment will be described.

The thickness of the film is preferably 10 μm to 100 μm in terms of being able to cope with a large number of uses, and easy to manufacture or handle. The thickness of the biaxially stretched film used as a release film is typically 40 μm to 100 μm, and most typically about 50 μm.

The gloss of the film is represented by 60-degree specular gloss and Gs (60 °) specified in JISZ8741: 1997. The gloss required for the film depends on the application, and is 30% or less, and preferably 20% or less, in order to give a matte appearance to the surface of the molded article that is not "bright". Furthermore, the lower limit value is not particularly significant, but it is usually 1% or more.

The surface roughness (Ra) of the film is represented by an arithmetic average roughness Ra specified in JISB0601: 1994. In order to give the film a matte appearance similar to the texture of the roll transfer method, the surface roughness (Ra) is 0.8 μm or more, and preferably 1.0 μm or more. On the other hand, Ra is preferably 3.5 μm or less, and more preferably 3.0 μm or less. The reason is that if Ra is too large, the resin to be molded cannot completely follow its large irregularities, and a stable molded product surface cannot be obtained. In addition, the reason is that if Ra is too large, the deviation from the texture of the surface by the roll transfer method becomes large.

The tensile elongation of the film refers to a tensile failure strain or a tensile failure nominal strain obtained by a tensile test (test piece type 2, test speed 200 mm / min) specified in JIS K7127: 1999. When the film contains SPS, it is accompanied by a drop in the tensile test, so the tensile elongation refers to the nominal strain at tensile failure. The tensile elongation of the film is 15% or more at normal temperature (23 ° C ± 2 ° C, relative humidity 50% ± 10%) in either of the longitudinal direction (MD) and the transverse direction (TD). More than 20%. On the other hand, even if the tensile elongation of the film is too large, there is no particular problem, but in this embodiment, since SPS is the main component, it usually does not exceed 200%.

Next, the manufacturing method of the film of this embodiment is demonstrated.

The film of this embodiment can be produced by mixing SPS-based resin, spherical filler, and other materials, melting and kneading and extruding to produce a precursor film (stretched front roll film), and then The precursor film is biaxially stretched.

A known method can be adopted as a method for producing the precursor film. For example, a mixture containing a desired component is melted and kneaded by an extruder, and the kneaded material is extruded from a T die and then cooled.

The biaxial stretching step is a step in which the film is stretched with respect to the biaxial direction of the film, and then thermally fixed arbitrarily. Through this biaxial stretching step, the SPS-based resin is crystallized, the glass transition temperature of the film is increased, heat resistance is improved, and mechanical strength is improved. In addition, the film of this embodiment has an uneven surface due to a biaxial stretching step.

Biaxial stretching is performed in the MD and TD directions of the film. The extending method includes a sequential biaxial stretching method and a simultaneous biaxial stretching method. Since the simultaneous biaxial stretching method can further improve heat resistance dimensional stability or tensile elongation, it is preferable. For example, according to the simultaneous biaxial stretching method, the difference between the MD direction and the TD direction of the absolute value of the thermal shrinkage ratio can be easily reduced. When biaxial stretching is performed, conditions suitable for obtaining desired heat-resistant dimensional stability, mechanical properties, and the like can be selected for the stretching ratio, stretching temperature, and stretching speed.

Thermal fixation is a process of fixing the orientation of polymer molecules by holding the stretched film at a temperature equal to or higher than the stretch temperature. The heat treatment temperature, time, and relaxation ratio can be selected as appropriate conditions for obtaining a desired thermal shrinkage rate.

Next, a multilayer film according to a second embodiment of the present invention will be described.

In the first embodiment, the biaxially oriented film containing syndiotactic polystyrene (SPS) resin and spherical filler has a gloss of 30% or less and a surface roughness (Ra) of 0.8 μm or more. The surface characteristics of the axial alignment film, the characteristics of which the tensile elongation is 15% or more, are characteristics of the release film which is the film itself. In the multilayer film, at least one surface has a biaxial alignment film layer containing an SPS-based resin and a spherical filler having a gloss of 30% or less and a surface roughness (Ra) of 0.8 μm or more. In addition, if the tensile elongation of the biaxially oriented film layer is 15% or more, the biaxially oriented film may be used as a single layer, or other layers may be added to be used as a multilayer film. If the tensile elongation of the biaxially oriented film layer is less than 15%, another layer is added to form a multilayer film, and the tensile elongation may be 15% or more. Alternatively, another layer having functions such as antistatic properties may be added to form a multilayer film.

In the example shown in FIG. 1, the multilayer film 10 is composed of two layers, including a first layer 11 constituting a first surface 15 and a second layer 12 adjacent to the first layer and constituting a second surface 16.

The composition and characteristics of the first layer 11 are the same as those of the polystyrene film of the first embodiment. That is, the first layer contains a syndiotactic polystyrene (SPS) -based resin and a spherical filler, and is biaxially aligned. The gloss of the first surface 15 is 30% or less, and the surface roughness (Ra) is 0.8 μm or more. In addition, it is necessary that the first layer does not break when the tensile strain of the multilayer film 10 is less than 15%, and preferably does not break when it is less than 20%. The preferred composition of the SPS-based resin contained in the first layer or the preferred material, particle size, and blending amount of the spherical filler are also the same as those of the first embodiment. Here, the preferable particle diameter of the spherical filler is relatively determined relative to the thickness of the first layer in the same manner as in the first embodiment relative to the thickness of the single-layer film.

The resin forming the second layer 12 is not particularly limited, and may be selected from SPS resins, polyolefin resins such as polyethylene and polypropylene, and polyester resins such as polyethylene terephthalate and polybutylene terephthalate. Among them, those having the desired characteristics are selected for use. When the second layer is used to improve the mechanical properties of the multilayer film 10, the second layer preferably contains an SPS-based resin, and more preferably contains the same SPS-based resin as the first layer. The reason is that, as will be described later, manufacturing by coextrusion is easy. When the second layer contains an SPS-based resin, the content of the spherical filler in the second layer is preferably less than the first layer, and the second layer is more preferably free of a spherical filler. Accordingly, the second layer can be formed into a layer having better mechanical properties than the first layer.

Alternatively, the second layer 12 may be formed as an antistatic layer. The antistatic layer may be formed by blending an antistatic agent into a resin serving as a matrix, or may be a layer containing a conductive resin. The second surface 16 is composed of an antistatic layer. When the multilayer film 10 is used as a resin-molded release film, the first surface 15 is used facing the molding resin side. The glossy appearance, in which the second surface 16 is in contact with the mold, can prevent the electrification of the multilayer film 10.

In the example shown in FIG. 2, the multilayer film 20 is composed of three layers, including a first layer 11 constituting the first surface 15, a second layer 22 adjacent to the first layer, and a third layer 23 constituting the second surface 26. . The first layer in FIG. 2 is the same as the first layer in FIG. 1.

The resin forming the second layer 22 and the third layer 23 is not particularly limited, and those having desired characteristics can be selected and used. As an example, the second layer may be formed as a layer containing the same SPS-based resin as the first layer but not containing a spherical filler, and the third layer may be formed as an antistatic layer. As another example, the second layer is formed as a layer containing the same SPS-based resin as the first layer, but does not contain a spherical filler. If the third layer is composed of the same layer as the first layer, the cross section becomes a symmetrical structure. A multilayer film having the first surface and the second surface similarly roughened can be obtained.

The layer configuration of the multilayer film is not limited to the above. The number of layers can be set to an arbitrary number of 2 or more. The gloss and surface roughness (Ra) of the first surface are achieved by the first layer. Therefore, the composition and function of each layer other than the first layer can be arbitrarily determined.

Next, the manufacturing method of the multilayer film of this embodiment is demonstrated.

The multilayer film of this embodiment may be formed by forming each layer as an independent film, and then bonding the layers through an adhesive layer. For example, the polystyrene film of the first embodiment can be bonded to another film as the first layer 11.

Alternatively, when the softening temperatures or viscosity curves of a plurality of resins are similar, these resins may be co-extruded to form several layers at the same time. For example, when the first layer 11 and the adjacent second layer contain the same SPS-based resin, the respective raw materials can be melted and kneaded to form a two-layer precursor film by coextrusion, and then biaxially processed. It is extended to form the first layer and the second layer at the same time.

Alternatively, a new layer may be formed by applying a resin material to the surface of another film. For example, the thickness of the antistatic layer is usually 0.1 μm or less, and it is difficult to form the thin layer as a separate film. In this case, an antistatic layer may be formed by applying a conductive resin to the second surface of another single-layer or multi-layer film and drying or cross-linking it.

When the film is multilayered as in this embodiment, an effect of increasing the degree of freedom in film design can be obtained. In a single-layer SPS film, if the surface roughness is increased, the tensile elongation tends to decrease. On the other hand, in a multilayer film, the composition of the first layer and the like can be adjusted so as to optimize surface unevenness and texture by realizing required mechanical characteristics and the like with layers other than the first layer. [Example]

An example of the polystyrene film of the first embodiment will be described.

The films of the examples were produced as described below. As the SPS resin, syndiotactic polystyrene (SPS) resin (manufactured by Idemitsu Kosan Co., Ltd., XAREC 142ZE (glass transition temperature: 95 ° C, melting point: 247 ° C)) was used. Predetermined spherical fillers were blended in the SPS at a predetermined ratio, kneaded, and melt-extruded at 290 ° C using an extruder equipped with a T-die at the front end, followed by cooling to obtain a precursor film. This precursor film was simultaneously biaxially stretched at a predetermined magnification at 110 ° C. and an extension speed of about 500% / min. After stretching, heat-fixation was performed at 210 ° C with a relaxation ratio of 0.95 times in the longitudinal direction (MD) and 0.95 times in the transverse direction (TD) to obtain a simultaneous biaxially-stretched SPS system with a thickness of about 50 μm. membrane.

Regarding the film of Comparative Example 1, an SPS-based film was produced by the same method as in the example without preparing a spherical filler. Regarding the film of Comparative Example 2, a spherical filler was blended in the SPS, and an SPS film having a thickness of 50 μm without stretching was prepared by melting × extrusion. Regarding the film of Comparative Example 3, an SPS film was produced in the same manner as in the Example.

Table 1 shows the type, particle size, blending amount, stretching ratio, film thickness, gloss, surface roughness (Ra), and tensile elongation of the spherical filler.

The types, product numbers, and manufacturing companies of the spherical fillers shown by each symbol in Table 1 are as follows. × F5: Silicon dioxide, FB-5SDC, Denka Corporation × F7: Silicon dioxide, FB-7SDC, Denka Corporation × H: Silicon dioxide, HS-207, Nippon Steel Materials Co., Ltd. × FE: Silicon dioxide, FEB25A-SQ, Admatechs Co., Ltd. × K: Silicon dioxide, KSE-2045, Kinseimatec Co., Ltd. × N : Silicon dioxide, NP-100, AGCSI Technology (Tech) Co., Ltd. × S: Aluminosilicate, Shilton JC-50, and Mizusawa Chemical Industry Co., Ltd. All spherical fillers are amorphous. In addition, the spherical fillers "F5", "F7", "H", "FE", and "K" are fused silica, and "N" is obtained by sintering spherical silica gel and making it nonporous.

The gloss in Table 1 is the 60-degree specular gloss and Gs (60 °) specified in JISZ8741: 1997, using a gloss meter (Unigross 60, Konicaminolta Co., Ltd.) To measure. The surface roughness (Ra) is an arithmetic average roughness Ra specified in JIS B0601: 1994, and is measured using a surface roughness tester (Handy Surf, Tokyo Precision Co., Ltd.). The tensile elongation was measured using the method specified in JIS K7127: 1999 with test piece type 2 and test speed of 200 mm / min, and the nominal tensile strain at break was obtained from the obtained stress / strain curve.

[Table 1] ※ The blending amount is 100 parts by weight based on syndiotactic polystyrene

Comparing Comparative Example 1 with Examples 1 to 10, it is understood that the films of Examples have low gloss, large surface roughness (Ra), and roughened film surfaces. In addition, in the films of Examples, it was confirmed by visual observation that the matte feeling was imparted. On the other hand, it was found that, in the films of Examples 1 to 10, the tensile elongation of the film was lower than that of Comparative Example 1. However, in any of the examples, the film was maintained at 15% or more. The reduction in the mechanical properties caused by this is suppressed to a practically sufficient range.

Comparing Comparative Example 2 and Example 6, in Unstretched Comparative Example 2, the gloss was low and the surface roughness (Ra) was large, but the tensile elongation was small. In Example 6 which was biaxially stretched, the gloss became lower, the surface roughness (Ra) became larger, and a practically sufficient tensile elongation was obtained.

Comparing Comparative Example 3 with Examples 1 to 10, Comparative Example 3 using fused silicon dioxide having a large particle diameter obtained a surface roughness (Ra) larger than that of the example, but the tensile elongation was small. The reason is considered to be that the fused silicon dioxide of Comparative Example 3 contained particles having a maximum particle diameter of 67 μm with respect to the film thickness of 50 μm, and therefore the film was broken at a smaller elongation.

Next, examples of the multilayer film of the second embodiment will be described.

The composition of the first layer was the same as that of Example 8. In the second layer, a spherical filler is used without blending in the same SPS as the first layer. The raw materials of the first layer and the second layer were kneaded separately, melt-co-extruded at 290 ° C using a two-layer molding extruder, and then cooled to obtain a precursor two-layer film. The precursor two-layer film was subjected to simultaneous biaxial stretching and thermal fixation under the same conditions as those of Example 1 to Example 10, thereby obtaining a simultaneous biaxially-stretched SPS-based two-layer film of Examples 11 and 12.

Table 2 shows the manufacturing conditions, thickness, gloss, surface roughness (Ra), and tensile elongation of the two-layer film of Example 11 and Example 12.

[Table 2] ※ The blending amount is 100 parts by weight based on syndiotactic polystyrene

It is understood from Table 2 that Examples 11 and 12 have the first surface having the same gloss and surface roughness (Ra) as those of Example 8, and have a tensile elongation greater than that of Example 8. In addition, in the measurement of the tensile elongation in Examples 11 and 12, the first layer did not break until the two-layer film was broken.

The present invention is not limited to the above-mentioned embodiments or examples, and various modifications can be made within the scope of the technical idea. [Industrial availability]

The roughened polystyrene-based film and multilayer film of the present invention are particularly useful as a release film at the time of molding of a printed circuit board made of an epoxy resin or the like, particularly a release film (transfer film) having a transfer function. The use is not limited to this. In addition to its use as a release film, it is also useful for various applications requiring a rough surface. In addition, when used as a release film, the type of plastic constituting the material to be molded is not particularly limited. For example, it can be used for epoxy resin, phenol resin, melamine resin, urea resin, alkyd resin, and polyimide resin. , Polyester resin, polyurethane resin, acrylic resin, etc.

10, 20‧‧‧ multilayer film

11‧‧‧ Level 1

12, 22‧‧‧ Level 2

23‧‧‧Level 3

15‧‧‧ the first surface

16, 26‧‧‧ 2nd surface

FIG. 1 is an example of a cross-sectional configuration diagram of a multilayer film according to a second embodiment of the present invention. 2 is another example of a cross-sectional configuration diagram of a multilayer film according to a second embodiment of the present invention.

Claims (9)

A polystyrene-based film, comprising: a syndiotactic polystyrene-based resin and a spherical filler, biaxially aligned, a gloss of 30% or less, a surface roughness Ra of 0.8 μm or more, and a tensile elongation 15% or more. The polystyrene film according to item 1 of the scope of application, wherein the spherical filler is amorphous silicon dioxide. The polystyrene film according to item 2 of the scope of the patent application, wherein the spherical filler is fused silica. The polystyrene film according to any one of claims 1 to 3, wherein the maximum diameter of the spherical filler is less than the thickness of the polystyrene film, and the median diameter is d50. It is 6% or more of the thickness of the polystyrene film. The polystyrene film according to any one of claims 1 to 3, wherein the amount of the spherical filler is 5 parts by weight or more and 20 parts by weight based on 100 parts by weight of the resin component. the following. The polystyrene-based film according to item 4 of the scope of patent application, wherein the blending amount of the spherical filler is 5 parts by weight or more and 20 parts by weight or less based on 100 parts by weight of the resin component. A multilayer film comprising: a first layer, a first surface constituting a gloss of 30% or less and a surface roughness Ra of 0.8 μm or more, containing a syndiotactic polystyrene resin and a spherical filler, and biaxially oriented; and At least one resin layer is provided on the side of the first layer opposite to the first surface. When the tensile elongation is 15% or more and the tensile strain is less than 15%, the first layer does not occur. fracture. The multilayer film according to item 7 of the scope of patent application, wherein the resin layer adjacent to the first layer contains the same syndiotactic polystyrene resin as the first layer, and the content of the spherical filler is less than The first layer may not contain a spherical filler. The multilayer film according to item 7 or item 8 of the scope of patent application, wherein the second surface on the side opposite to the first surface is composed of an antistatic layer.