JPH0410909B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a thermoplastic polymer film and a method for producing the same, and more particularly to a base film for magnetic tapes such as audio and video, electrical insulators such as capacitors, and magnetic disks such as floppy disks. The present invention relates to a thermoplastic polymer film suitable for use as a base film for photography, a base film for photography, etc., and a method for producing the same. [Prior Art] Conventionally, magnetic recording media films for audio, video, etc. have been manufactured by coating or vapor depositing a magnetic layer on a base film, slitting the obtained film, and processing it into a tape. However, when such a film is run, the film surface on the side where the magnetic layer is not coated is abraded due to contact with many guide parts, reproducing heads, etc., and powdery film fragments are generated. Not only does it become impossible to read the information stored in the magnetic layer by adhering to the magnetic layer, that is, dropout occurs, but it also becomes difficult to run the tape itself. Therefore, many proposals have been made to improve the runnability and abrasion resistance of such magnetic recording media films. For example, according to Japanese Patent Publication No. 57-34088,
The film contains fine silica particles and calcium carbonate particles with a larger particle size to give the film surface a two-peak unevenness, and by applying the load to each peak, it improves slipperiness and abrasion resistance. I'm doing well. However, there is a contradictory relationship between the particle size of the inorganic fine particles added and the abrasion resistance of the film, and when the particle size is increased to improve the slipperiness and running properties of the film, the particles fall off from the film surface. This results in poor wear resistance and frequent dropouts. On the other hand, if the particle size is small, wear resistance improves, but
The slipperiness and runnability deteriorate, and currently no method has yet been found to solve the problems of slippage, runnability, and dropout at the same time. On the other hand, when a plastic film is used for the insulating layer of an oil-impregnated capacitor impregnated with insulating oil, roughening of the film surface is being considered in order to improve the impregnability of the insulating oil. . Furthermore, when used in the insulating layer of a dry capacitor, the film is thin with a thickness of 0.5 to 15 μm and has a smooth surface, making it difficult to handle. For this reason, roughening of the film surface is being considered in order to make it easier to slide. However, in a film whose surface has been roughened by dispersing inorganic particles, as a result of stretching the film,
A serious drawback was that voids were generated around the particles, making it impossible to avoid deterioration of the dielectric breakdown voltage. Furthermore, in addition to wear-resistant properties, base films for floppy disks, like magnetic tapes, require the information recording position to be confirmed by an optical sensor that uses a specific wavelength, and the film is required to be opaque to light. Therefore, in order to improve the light-shielding properties of the film, it has been proposed to add light-shielding materials such as titanium dioxide or carbon black to the base film, as disclosed in Japanese Patent Laid-Open No. 59-178224. However, by adding titanium dioxide, it is not possible to obtain sufficient light-shielding properties while maintaining surface smoothness. Therefore, if the amount added is increased in order to improve the light-shielding property, the film surface becomes rough and the electromagnetic conversion characteristics deteriorate, and this tendency is particularly strong when carbon black is used as the light-shielding material. [Object of the Invention] The first object of the present invention is to provide a thermoplastic polymer film which has good slip properties, good running properties, excellent abrasion resistance, and is suitable as a base film for magnetic tapes such as audio and video tapes without dropout. The object of the present invention is to provide a manufacturing method thereof. A second object of the present invention is to provide a thermoplastic polymer film that does not easily generate voids even when stretched and is effective as an electrical insulator for capacitors and the like, and a method for producing the same. A third object of the present invention is to provide a thermoplastic polymer film that has excellent light shielding properties, smoothness, and electromagnetic conversion properties and is suitable as a base film for floppy disks, and a method for producing the same. Another object of the present invention is to provide a photographic base film that is white, has a smooth surface, and has good gloss, and a method for producing the same. [Structure of the Invention] The thermoplastic polymer film of the present invention, which achieves the above object, is a film containing inorganic porous microcapsules encapsulating a thermoplastic polymer in a thermoplastic polymer. The wall material of the inorganic porous microcapsule is at least one selected from the group consisting of titanium monoxide, titanium dioxide, silica, calcium carbonate, and barium sulfate. Further, the method for producing a thermoplastic polymer film of the present invention includes dispersing inorganic porous microcapsules in a thermoplastic polymer monomer or a polymerization solvent, and then polymerizing the monomer to produce a thermoplastic polymer. A method of producing a film by extruding a polymer as it is or mixing it with different thermoplastic polymers into a sheet and stretching it,
The wall material of the inorganic porous microcapsule is at least one selected from the group consisting of titanium monoxide, titanium dioxide, silica, calcium carbonate, and barium sulfate. The thermoplastic polymer film of the present invention and its manufacturing method will be explained below. The thermoplastic polymer applied in the present invention exhibits plastic flow when heated, and is mainly a linear polymer in chemical structure, but it also contains low molecular weight oligomers. It may be hot. Typical examples include polyolefins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polybutadiene, polystyrene, and polymethylpentene, polyethylene terephthalate, polybutylene terephthalate,
Polyethylene naphthalate, polyethylene α, β
-bis(2-chlorophenoxy)ethane-4,
Polyesters such as 4'-dicarboxylate and polycarbonate; halogenated polymers such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polyvinyl fluoride; polyhexamethylene adipate (nylon);
66), polyamides represented by polyε-caprolactam (nylon 6), nylon 610, etc., as well as vinyl polymers such as polyacrylonitrile and polyvinyl alcohol, polyacetals, polyethersulfones, polyetherketones, polyphenylene ethers, polysulfones, These include polyphenylene sulfide, copolymers and mixtures thereof, and in the case of the present invention, polyester, polyphenylene sulfide, polyamide, polysulfone, and polyvinylidene fluoride are particularly preferred, and polyester, polyphenylene sulfide, and polyvinylidene fluoride are particularly preferred. id is preferred. Further, if necessary, a thermoplastic polymer containing known additives such as stabilizers, colorants, and antioxidants in a total content of less than 1% by weight based on the thermoplastic polymer can also be used. In addition, the inorganic porous microcapsules (hereinafter simply referred to as microcapsules) used in the present invention are those in which the diameter of one of the particles is from 0.01 μm to 0.01 μm.
As shown in Figure 1, the wall material 1 is a porous, spherical container with an average pore size of 10 to 600 Å, and has a hollow part 2 inside, and the liquid is contained in the hollow part 2. , which can freely enclose and release solids and gases. As a typical manufacturing method, for example,
6251, Japanese Patent Publication No. 57-55454, Japanese Patent Publication No. 55-43404, etc., the "interfacial reaction method" is a method of preparing inorganic powder by an aqueous solution precipitation reaction. In the process, hollow, spherical, and porous inorganic powder particles can be manufactured by using a water-in-oil type (W/O type) emulsion. Inorganic wall materials constituting the microcapsules include alkaline earth metal carbonates such as calcium carbonate, barium carbonate, and magnesium carbonate; alkaline earth metal silicates such as calcium silicate, barium silicate, and magnesium silicate; calcium phosphate;
Alkaline earth metal phosphates such as barium phosphate and magnesium phosphate, alkaline earth metal sulfates such as calcium sulfate, barium sulfate, and magnesium sulfate, silicic anhydride, aluminum oxide, zinc oxide, iron oxide, titanium oxide, oxide Metal oxides such as cobalt, nickel oxide, manganese oxide, antimony oxide, tin oxide, metal hydroxides such as iron hydroxide, nickel hydroxide, aluminum hydroxide, calcium hydroxide, chromium hydroxide, zinc silicate, aluminum silicate Typical examples include metal silicates such as copper silicate, metal carbonates such as zinc carbonate, aluminum carbonate, cobalt carbonate, nickel carbonate, and basic copper carbonate. The size of the microcapsules is variable in the range of 0.01 to 100 μm, and in the case of the present invention, in particular 0.01 to 5 μm.
A spherical material with a sharp average particle size distribution is preferable because it has good compatibility with the thermoplastic polymer and good distribution properties. The pore size on the surface of capsule particles was measured using the BET method.
The range is from 10 to 600 Å, but in the case of the present invention it is from 20 to 100 Å.
A distribution having a main pore size in the range of Å is preferred. Of course, a spherical shape is preferable in terms of dispersibility, fluidity, slipperiness, smoothness, abrasion resistance, runnability, etc. Because these microspheres are porous and have pores, their surface area is extremely large.
It can reach 100 to 1000 m ² /g, and its apparent specific gravity is also small, about 0.1 to 0.4. Furthermore, the thickness of the wall of this microcapsule is also
It can be freely changed to about 0.01 to 5 μm, and this is determined not only by mechanical properties such as deformation and destruction due to external force, but also by the release characteristics of the inclusions to the outside. Next, a method for producing a film, which is an object of the present invention, will be explained. In this production method, the filling rate of the thermoplastic polymer is increased to 90% by volume by adding 0.0001 to 10% by weight of microcapsules during the polymerization step of the thermoplastic polymer.
It is preferable because the above can be achieved. For example, in ethylene glycol, the average particle size is 0.01~
Add and disperse 2 μm inorganic porous microcapsules, replace 90% or more of the air in the microcapsules with ethylene glycol (preferably repeat the vacuum and pressurization state three times), and mix this ethylene glycol dispersion with aromatic dicarbonate. After transesterification or ester reaction with an acid, the polymer obtained by polycondensation is extruded into a sheet as it is, or mixed with other thermoplastic resins such as other polyesters as necessary, and then stretched. Manufactured. Melt extrusion and stretching conditions are not particularly limited. In other words, what is important in achieving the object of the present invention is that the thermoplastic polymer is encapsulated in the hollow part of the microcapsule, and the amount of encapsulation exceeds 40% by volume in terms of filling rate. Preferably, it exceeds 80% by volume, more preferably 90% by volume.
Volume % or more is most preferable. As a result, between the thermoplastic polymer encapsulated in the microcapsules and the thermoplastic polymer surrounding the microcapsules,
A strong bond is formed through the pores on the surface of the microcapsule, and the adhesive force at the microcapsule particle interface is improved. The thermoplastic polymer encapsulated in the microcapsules is usually preferably the same type as the thermoplastic polymer forming the film, but it may be of a different type depending on the purpose of use. . Different types refer to those that are physically and chemically different, such as in molecular weight, content of additives, amount of copolymerization, and the like. Thermoplastic polymer film according to the first object of the present invention To achieve the first object of the present invention, preferably microcapsules with an average particle size of 0.01 to 2 μm are used. If the average particle diameter is less than 0.01, slipperiness and running properties will deteriorate, and if it exceeds 2 μm, electromagnetic conversion characteristics will deteriorate, which is not preferable. Furthermore, the wall material of the microcapsule is not particularly limited and can be selected as appropriate;
For this purpose, for example, silica, titanium oxide, calcium carbonate, barium sulfate, etc. can be mentioned as preferred. The content of microcapsules is preferably 0.0001-0.3% by weight of the thermoplastic polymer. If the content is less than 0.0001% by weight, the resulting film will have poor slip properties, and if it exceeds 0.3% by weight, the surface roughness of the film will increase and the electromagnetic conversion characteristics will deteriorate. In addition, microcapsules may be used alone, but the particle size is 100 to 600 mμ, preferably 140 to 400 mμ.
When used in combination with colloidal silica, the running properties of the film can be further improved. In this case, the amount of colloidal silica added is 0.0001 to 1.0% by weight based on the thermoplastic polymer. The thickness of the film thus obtained is 4~
A material in the 18 μm range is preferable in terms of quality and productivity. In addition, the surface roughness Ra of the film is
A diameter of 0.001 to 0.01 μm is suitable for the purpose of the present invention. The magnetic tape is made by coating or vapor depositing a magnetic recording layer on one side of the thermoplastic polymer film of the present invention with an anchor coat layer.
If necessary, a back coat layer is applied to the opposite side to improve running properties. Thermoplastic Polymer Film as the Second Object of the Invention In achieving the second object, thermoplastic polymers similar to those described above are used, but polyester, polyolefin, and polyphenylene sulfide are particularly preferred. Further, the average particle diameter of the microcapsules is preferably 0.01 to 2 μm, more preferably 0.1 to 1.5 μm, the amount added is also the same as above, and the thermoplastic polymer is encapsulated in the microcapsules in the same manner as above. There is. The content of microcapsules is preferably 0.0001-0.3% by weight of the thermoplastic polymer. If the amount of microcapsules added is less than 0.0001% by weight, slipperiness will deteriorate, and if it exceeds 0.3% by weight, voids will occur due to aggregated particles and the breakdown voltage will deteriorate, which is not preferable. Furthermore, what is important in achieving this second objective is that the hollow part of the microcapsules is filled with a thermoplastic polymer at a filling rate of 90% or more, preferably 95% or more by volume, and that the specific surface area is 200 to 900 m2. ² /
g. When the filling rate is less than 90% by volume, that is, when the porosity exceeds 10%, the breakdown voltage deteriorates. In addition, if the specific surface area is less than 200 m ² /g, the adhesion between the microcapsule particles and the thermoplastic polymer on the film surface will decrease and voids will occur.
If it exceeds 900 m ² /g, microcapsule particles tend to aggregate and voids tend to occur. In addition, the porosity of the microcapsules should be 10% or less,
In order to make it preferably 5% or less, microcapsules can be manufactured by, for example, deaerating the microcapsules under high vacuum, and then processing and enclosing a thermoplastic polymer monomer. A film for achieving the second object of the present invention is also produced by adding microcapsules in the polymerization process of a thermoplastic polymer in the same manner as described above, and in the case of the present invention, the film thickness is particularly preferably 9 μm or less. The effect is remarkable for those with a diameter of 4 μm or less. When the film of the present invention is used for a capacitor, one or both sides of the film may be vapor-deposited with metal, or it may be combined with a thin film of metal such as aluminum, and then wound into a known film capacitor. , if necessary, impregnate it with insulating oil and use it as a capacitor. Thermoplastic polymer film according to the third object of the present invention In this film, the wall material is made of titanium oxide (TiO _x , x=1 or 2) with an average particle size of 0.01
The thermoplastic polymer contains 0.4-10% by weight of porous microcapsules of ~5 μm, preferably 0.1-2 μm. If the amount of microcapsules added is less than 0.4% by weight, light shielding properties will be insufficient, and if it exceeds 10% by weight, coarse protrusions due to aggregated particles will increase, and dropouts will increase when used as a base film for magnetic recording. , and when used as a photographic base film, the surface gloss level decreases. Furthermore, the specific surface area of microcapsules is 200 to 900.
It is preferable that it is ^m2 /g. If the specific surface area is less than 200 m ² /g, the adhesion on the film surface will be reduced and particles will be detached, resulting in drop-out. Moreover, if it exceeds 900 m ² /g, particles will aggregate to form coarse protrusions, leading to deterioration of electromagnetic conversion characteristics. Furthermore, in the case of a magnetic disk, the surface roughness Ra of the thermoplastic polymer film containing the microcapsules is 0.005 to 0.050μ, and the light transmittance at a wavelength of 900 nm is 60% or less, preferably 40%. It is preferably 20% or less, more preferably 20% or less. If Ra is less than 0.005μ, the sliding properties and runnability will be poor, and if it exceeds 0.050μ, the electromagnetic conversion characteristics will deteriorate, which is not preferable. The thermoplastic polymer film, which is the third object of the present invention, can be produced by incorporating microcapsules into the thermoplastic polymer during polymerization in the same manner as described above. Note that the film thickness is not particularly limited, but is 20~
250μ is preferred. In order to form a magnetic disk, a known magnetic layer may be provided on the film of the present invention. [Effects of the Invention] As described above, according to the present invention, the following effects can be achieved. (1) Since microcapsules are added during polymerization of thermoplastic polymers and the polymerization is then completed, the thermoplastic polymer filled in the microcapsules and the thermoplastic polymer surrounding the microcapsules are Strongly bonded through pores. That is, the adhesion to the thermoplastic polymer at the microcapsule particle interface is significantly improved. Therefore, even if the diameter of the added particles is increased in order to improve the running properties (running durability) of the film, the particles will not fall off during running and the film will have excellent abrasion resistance. That is, it is possible to achieve both excellent wear resistance and runnability. In addition, dropouts can be prevented since the microcapsule particles do not fall off during film stretching or during magnetic tape manufacturing and use. Therefore, such thermoplastic polymer films are suitable as base films for audio and video applications. (2) As mentioned above, since the microcapsules encapsulate the thermoplastic polymer, the adhesion between the thermoplastic polymer and the microcapsules is improved, and the surface treatment of the additive particles can improve the adhesion between the thermoplastic polymer and the microcapsules. Even after stretching, the generation of voids is significantly smaller than when the adhesiveness is improved. Therefore, the dielectric breakdown voltage of the film can be improved. In particular, by considering the porosity and specific surface area of the microcapsules, the occurrence of voids can be further reduced. Such thermoplastic polymer films are suitably used as insulating films for oil-impregnated and dry type capacitors. Since the microcapsule wall material is selected from the group consisting of titanium monoxide, titanium dioxide, silica, calcium carbonate, and barium sulfate, it is possible to achieve both running durability and electromagnetic conversion characteristics (silica, calcium carbonate), and It can improve dielectric breakdown voltage and slipperiness (titanium dioxide), and has a larger specific surface area than ordinary titanium oxide particles, so it has a high light reflectance. Therefore, even a thermoplastic polymer film to which a small amount of such microcapsules are added has extremely high light-shielding properties and is suitable as a base film for a floppy disk. Similarly, since the addition of a small amount of microcapsules results in high white turbidity and good gloss, it is preferably used as a base film for photography. Next, the method for measuring physical property values employed in this specification will be explained. (1) Slip property ASTM-D-1894B-63 According to this method,
Static friction coefficient ( _μs ) using a slip tester
Also, the coefficient of dynamic friction (μ _d ) was measured. Generally, the range in which a film is considered to have excellent slipperiness is 1.4 or less for μ _s and 1.2 or less for μ _d . (2) Running durability Using a tape running property tester model TBT-300 [manufactured by Yokohama System Research Institute Co., Ltd.], run the tape 100 times in an atmosphere of 5°C and 50% RH to determine the initial μk and
μk after repeated running 100 times was determined from the following formula, and running durability was expressed as the difference between these two values (μk after repeated running 100 times − initial μk). μk=0.733logT/T where T ₀ is the inlet tension, T ₁ is the outlet tension,
The guide diameter is 8mmφ, and the guide material is
SUS27 (surface roughness 0.2S), wrapping angle 180°, running speed 3.3cm/sec. (3) Surface roughness: Ra (μm) Measured value using a stylus surface roughness meter (cutoff value 0.25 mm, measurement length 4 mm. However, JIS
- In accordance with B-0601. ) (4) Electromagnetic conversion characteristics The following magnetic materials were spread on one side of the biaxially oriented film of the present invention, and dried and hardened to form a magnetic layer. 7000Hz on the magnetic recording medium manufactured in this way.
When viewing the output signal when recording and playing back a single screen, it is good if the output signal is strong and the signal waveform is flat, and if the output signal is weak or the signal waveform is deformed. was determined to be defective. [Magnetic paint] Ferromagnetic alloy powder (Fe-CO) 300 parts by weight Zinc powder (average particle size 2 μm) 25 parts by weight Cellulose acetate butyrate 30 parts by weight Polyisocyanate compound (Dismodule L-75) 180 parts by weight Epoxy Resin 25 parts by weight Silicone oil 4 parts by weight Lecithin 5 parts by weight Toluene (solvent) 200 parts by weight Methyl ethyl ketone (solvent) 200 parts by weight Ethyl acetate (solvent) 100 parts by weight (5) Porosity Dissolve the film with a good solvent for the polymer. The added inert fine particles were separated by centrifugal sedimentation. This separated inert fine particles were removed under a vacuum of 10 torr at a temperature of 100
After sufficiently drying at a temperature of ℃, 1g of the isolated inert fine particles were heated at 800℃ for 4 hours in an air atmosphere based on the ash content test of JIS C2330, and the weight of the isolated inert fine particles obtained at this time was B (unit gr) is 25
Measured at ℃ and 50% RH. Furthermore, the total pore volume A (unit: cc) of the isolated inert fine particles was determined by the permeation method shown below. From these values, the porosity was determined using the following formula (1). Porosity (%) = (1-1-B/ρA) x 100 (1) where ρ is the density (g/cc) of the polymer in the amorphous state at 25°C. The total pore volume (cc) is determined by the above-mentioned infiltration method. After boiling for a period of time, only the particle sample is separated by centrifugal sedimentation. Next, it is dried with hot air at 60 to 70°C for 30 minutes, and the weight D (gr) at this time is measured. From these values, the total pore volume was determined using the following formula (2). Total pore volume (cc) = D-C/1.595...(2) (6) Specific surface area (BET method) (e.g., J.Am.Chem.Soc., 38 , 2219 (1916)
It is described in. ) Nitrogen molecules are adsorbed onto the particle surface, the amount of adsorption is measured, and the volume of adsorbed gas when the entire surface is covered with a monomolecular adsorption layer is calculated using the following formula (1). The number of molecules was determined by dividing by the volume of one.
The specific surface area was obtained by multiplying this number of molecules by the volume σ occupied by one adsorbed molecule on the surface of the following formula (2). V=VmCP/(Ps-P) [1-(C-1)P/Ps]
(1) However, Vm is the volume of adsorbed molecules when the entire surface is covered with single molecule adsorption, V is the volume of adsorbed gas at pressure p, P is the pressure, Ps is the saturated vapor pressure, and C is a constant. be. σ=1.091 (M/NP) (2) Here, σ is the area occupied by one adsorbed molecule on the surface, M is the molecular weight, N is Avogadro's number, and p is the density of the adsorbed molecule layer on the surface. (7) Breakdown voltage (BDV) AC voltage (60Hz) is applied to the capacitor element every second.
The voltage was applied at a rising rate of 100V, and the reading on the voltmeter at the point of complete breakdown (permanent breakdown) was taken as the dielectric breakdown voltage of the capacitor. Also, the capacitance of the capacitor element is 0.5μF
And so. (8) Light transmittance Parallel light transmittance was continuously measured at light wavelengths of 300 nm to 1500 nm using a self-recording spectrometer manufactured by Hitachi, Ltd., and was defined as the light transmittance. Generally, a material with a light transmittance of 60% or less is considered to have excellent light blocking properties. (9) Glossiness In accordance with JIS-Z-8741, values were measured at an incident angle and a reflection angle of 60 degrees using a variable angle gloss meter model VG-107 manufactured by Nippon Denshoku Kogyo Co., Ltd. The evaluation criteria are as follows. GS (60°) = Less than 40% Rank 1 GS (60°) = 40 or more to less than 80% Rank 2 GS (60°) = 80 or more to less than 120% Rank 3 GS (60°) = 120 or more to 160% Less than Rank 4 GS (60°) = 160 or more Rank 5 Generally, if it is rank 3 or higher, it is considered to have excellent gloss. In rank 2, when aluminum or the like is deposited on the film surface, a slight cloudiness is felt. (10) Amount of white powder (evaluation method showing abrasion resistance) After running repeatedly 300 times in an atmosphere of 25℃ and 50RH using a tape runability tester TBT-300 [manufactured by Yokohama System Research Institute Co., Ltd.] , Visually judge the white shaving powder (white powder) attached to the guide part. Here, the guide diameter is 8mmφ, the guide material is SUS27 (surface roughness 0.2S), and the wrapping angle is
180°, tape running speed is 3.3 cm/sec. Criteria for determining the amount of white powder: Very little. ……◎ Not many. ...〇Slightly more. ……△ Very many. ……× (11) Void Stretching ratio: 3.6x vertically, 3.4x horizontally, stretching temperature
A 15 μ thick biaxially oriented film stretched at 85 to 95°C was mounted on a slide glass with liquid paraffin, and the area A of the high brightness area (white area) was measured using an image analyzer (QTM900, Cambridge) using a transmission optical microscope in the dark field. (manufactured by Tsuji Instrument). Next, use a phase-contrast microscope to find the area B of the low-brightness area (gray to black area) in the same location as the high-brightness area using an image analyzer in the same manner as above, and calculate the ratio of their areas (B/A). It was taken as the void ratio. The judgment criteria are as follows. Void ratio Less than 0.1 ◎ 0.13~0.1 〇 0.2~0.13 △ More than 0.2 × (12) Average particle size Capture an image of the particles using a scanning electron microscope, and measure the light density created by the particles using an image analyzer ( For example, the number average diameter φn is connected to QTM900 manufactured by Cambridge Instruments and determined by the following numerical processing: Σdn / Σn = φn where n is the number and d is the actual pore diameter. (13) Pore diameter Using Digisoap 2500 model manufactured by Shimadzu Corporation,
It is determined by analyzing the sorption isotherm curve of the BET method using the BJH method. (14) The content of microcapsules contained in a thermoplastic polymer was determined based on the JIS C2330 ash content test method by heating sample A (gr) in an air atmosphere at 800°C for 4 hours. It is determined from the weight B (Br) of the inert fine particles by B/A x 100 (%) (15) Filling rate The filling rate (volume %) is expressed as [100 - porosity (%)]. (16) Apparent specific gravity The apparent specific gravity is 1g of inorganic microcapsules.
is given by 6/πD ³ from the number average particle diameter D defined in measurement method (12). Examples of the present invention will be described below. [Example] Examples 1 to 7 and Comparative Examples 1 to 9 Porous microcapsules with an average particle size of 1.0 μm were made of polyethylene terephthalate (PET) using two types of wall materials: calcium carbonate and silica. were added separately at the start of polymerization, and the polymerization was completed by a conventional method to produce polyethylene terephthalate containing microcapsules encapsulating PET with an intrinsic viscosity of 0.63 at a filling rate of 98% by volume, and the polymer was further extruded and stretched. A biaxially stretched PET film was produced. The stretching conditions were as follows: the stretching ratio was 3.6 times vertically and 3.4 times horizontally, and the stretching temperature was 85°C vertically and 95°C horizontally.
Heat fixation was performed at 205°C for 10 seconds. Further, the film thickness was 15 μm. When the content of silica microcapsules was changed and when colloidal silica was used in combination (Examples 1 to 4), the wall material was calcium carbonate and the average particle size was
When the amount of microcapsules encapsulating PET of 1.0 μm was changed (Examples 5 to 7), when only colloidal silica was added (Comparative Examples 1 and 2), and when calcium carbonate particles were added The film characteristic evaluation results of (Comparative Examples 3 to 9) were
Shown in Table and Table 2. The evaluation criteria in Tables 1 and 2 are as follows. Slip property (μs): 1.6 or more × 1.0 or more to less than 1.6 △ 0.7 or more to less than 1.0 〇 Less than 0.7 ◎ Running durability (wear resistance): [Difference between μk after 100 repetitions and initial μk] Less than 0.3 ◎ 0.03 or more - less than 0.06 〇 0.06 or more - less than 1.2 △ 1.2 or more × Surface roughness Ra (μm) (c/o0.25mm): 0.10 or more × 0.05 or more - less than 0.10 △ 0.01 or more - less than 0.05 〇 Less than 0.01 ◎ Electromagnetic conversion Properties: As described in the measurement method above Table 1 shows that the thermoplastic resin film of the present invention has excellent running durability and electromagnetic conversion properties, and has excellent properties, especially when used in combination with ultrafine particles such as colloidal silica. It can be seen that results are obtained. On the other hand, when colloidal silica and calcium carbonate are added, it is clear that it is completely impossible to achieve both running durability and electromagnetic conversion characteristics. Examples 8, 9 and Comparative Examples 10 to 15 A thermoplastic material containing microcapsules was prepared in the same manner as in Example 1, except that the wall material was TiO ₂ and 0.1% by weight of microcapsules with an average particle size of 0.7 μm was added. A resin film was produced. The stretching conditions were the same as in Example 1, and the thickness of the obtained film was 2 μm.
It was hot. Tables 3 and 4 below show the evaluation results of film properties when the specific surface area of the microcapsules and the filling rate of the polymer were changed and when only TiO ₂ was added. The evaluation criteria for dielectric breakdown voltage (BVD) are as follows, and the other criteria are the same as in Table 1 above. Less than 250 × 250 or more and less than 300 △ 300 or more and less than 400 〇 400 or more ◎ From Tables 3 and 4, the film of the present invention
When BDV and sliding properties are good, but the porosity or specific surface area is outside the scope of the present invention, and
It can be seen that when only TiO ₂ is added, even if the slipperiness is good, the BVD is worsened. Examples 10 to 13 and Comparative Examples 16 to 20 PET was used as the thermoplastic resin, and the wall material
_TiO2 with an average particle size of 1.0 μm and a filling rate of 93-98 volume%
microcapsules were added and stretched to produce a film. The stretching conditions were the same as in Example 1, and the thickness of the obtained film was 75 μm. Table 5 shows the film evaluation results when the amount of microcapsules added and the specific surface area were changed. The evaluation criteria for light transmittance and amount of white powder are as follows. Light transmittance (%): Over 80% Rank 1 60-80% Rank 2 40-60% Rank 3 20-40% Rank 4 Less than 20% Rank 5 Amount of white powder: Very little ◎ Little 〇 Slightly much △ Very Many x From Table 5, it is clear that the film of the present invention has excellent light shielding properties and electromagnetic conversion properties, and has good gloss. On the other hand, it is clear that when the specific surface area or the amount added is out of the range of the present invention, or when titanium dioxide particles are added, the light shielding properties and electromagnetic conversion properties are reduced, and the gloss is also poor.

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[Table] Example 14 _Inorganic porous microcapsules (average particle size
0.5μm, specific surface area 500m ² /g).
Sufficient ε-caprolactam monomer was encapsulated in microcapsules, followed by polymerization and demonomerization by a known method to obtain nylon 6 (relative viscosity η _r 3.2 in sulfuric acid). The amount of the microcapsules added was 0.15% by weight based on nylon 6, and the microcapsule filling rate of nylon 6 was 90%. The thus obtained nylon 6 was fed to a known extruder and melted at 270°C, then extruded into a sheet from a T-die die, cast onto a mirror roll maintained at 20°C while applying an electrostatic charge, followed by 50
After preheating on a roll heated to 180°C, it was stretched 4 times in the longitudinal direction, and then stretched in an oven heated to 180°C for 50 minutes.
Heat treated for seconds. Furthermore, this stretched film is
After washing in warm water at ℃, dehydration was performed in an oven, and the material was rolled up. Table 6 shows the properties of the uniaxially stretched nylon 6 sheet having a thickness of 100 μm thus obtained. in this way,
The film of the present invention not only has excellent slip properties and running durability, but also has excellent process stability, with no roll staining caused by particles falling off the longitudinal stretching rolls. Comparative Example 21 Example 14 except that the SiO ₂ porous microcapsules used in Example 14 were replaced with colloidal silica (average particle size of 0.5μ), which is SiO ₂ uniform particles.
A uniaxially stretched nylon film with a thickness of 100 μm was obtained in the same manner as above. The properties of the film thus obtained are shown in Table 6, and it can be seen that the running durability was poor and particles easily fell off from the film.

[Table] Examples 15 and 16 TiO (average particle size 0.5 μm, specific surface area 550
m ² /g) and BaSO ₄ (average particle size 0.3 μm, specific surface area 450 m ² /g) were added in an amount of 0.1% by weight, and the respective polymer filling rates were 95% and 85%.
% in the PET polymer, and a PET film containing microcapsules was produced in the same manner as in Example 1. The thickness of the obtained film was 2 μm. Table 7 shows the film properties of the film thus obtained.

[Table] Examples 17, 18 Porous microcapsules made of silica and having an average particle size of 0.6 μm were used as wall materials in polyethylene naphthalate (PEN; Example 17) and polycyclohexane dimethylene terephthalate (PCT; Example 18).
PEN with an intrinsic viscosity of 0.8, PEN with an intrinsic viscosity of 1.0, and PEN with an intrinsic viscosity of 0.8,
PEN and PCT polymers containing microcapsules containing PCT at a filling rate of 95% by volume were manufactured.
The polymer was fed to an extruder in a conventional manner and heated to 295°C.
After stretching the cast sheet melt-extruded in the longitudinal direction in two stages at 115℃ and 80℃ for a total of 5.5 times,
After stretching 4.0 times in the width direction at 85°C, it was heat-set at 210°C for 7 seconds. The thickness of the film thus obtained was 7 μm, and the amount of silica microcapsules added in the film was 0.25% by weight based on the polymer. Table 8 shows the evaluation results of the PEN and PCT films thus obtained.

[Table] In this way, PEN, polyester resin,
It can be seen that even when PCT is used, a film with excellent surface properties can be obtained by incorporating porous microcapsules. Example 19 Wall material made of titanium oxide with average particle size of 0.8 μm
Polyphenylene having microcapsules containing polyphenylene sulfide at a filling rate of 90% by volume was obtained by adding the porous microcapsules of the above into an N-methylpyrrolidone solvent together with dichloromethane and sodium sulfide and polymerizing them by a conventional method. A rufid (5000 poise at 280°C) polymer was produced. The polymer was fed into an extruder in a conventional manner and a cast sheet was melted and extruded at 298°C.
After the double stretching, the film was stretched 3.8 times in the width direction at 103°C, and then heat-set at 255°C for 8 seconds. The thickness of the film thus obtained was 2 μm, and the amount of microcapsules added in the film was 0.4% by weight based on the polymer. The evaluation results of the film are shown in Table 9.

[Table] Example 20 Average particle size of calcium carbonate as wall material
1.5μm porous microcapsules were mixed with dichlorodiphenylsulfone and bisphenol A, and polycondensation was performed using a conventional method to obtain a polysulfone filling rate of 92.
A polysulfone with vol% encapsulated microcapsules was produced. The polymer was supplied to an extruder, melt-extruded at 300°C, and electrostatically cast to obtain a sheet. The thickness of the film thus obtained was 80 μm, and the amount of microcapsules added in the film was 0.75% by weight based on the polymer. The evaluation results of the film were as shown in Table 10.

【table】 [Brief explanation of drawings]

FIG. 1 is an enlarged schematic cross-sectional view of an inorganic porous microcapsule used in the present invention. 1...Wall material, 2...Hollow part.

Claims (1)

[Scope of Claims] 1 A film containing inorganic porous microcapsules encapsulating a thermoplastic polymer in a thermoplastic polymer, the wall material of the inorganic porous microcapsules being titanium monoxide. ,titanium dioxide,
A thermoplastic polymer film characterized by being at least one member selected from the group consisting of silica, calcium carbonate, and barium sulfate. 2 The average particle size of the inorganic porous microcapsules is
The thermoplastic polymer film according to claim 1, which has a thickness of 0.01 to 5 μm. 3. The thermoplastic polymer film according to claim 1, wherein the content of the inorganic porous microcapsules is 0.0001 to 10% by weight of the thermoplastic polymer. 4 The specific surface area of inorganic porous microcapsules is
200 to 900 m ² /g. Thermoplastic polymer film according to claim 1. 5. The thermoplastic polymer film according to claim 1, wherein the thermoplastic polymer is encapsulated in the inorganic porous microcapsules at a filling rate of 90% by volume or more. 6. The thermoplastic polymer film according to claim 1, wherein the wall material of the inorganic porous microfilm is made of titanium dioxide or titanium monoxide. 7. The thermoplastic polymer film according to claim 1, wherein the thermoplastic polymer is polyester. 8. The thermoplastic polymer film according to claim 1, wherein the film has a surface roughness Ra of 0.001 to 0.050μ. 9. The thermoplastic polymer film according to claim 8, wherein the film has a light transmittance of 60% or less. 10 Disperse inorganic porous microcapsules in a thermoplastic polymer monomer or polymerization solvent, then polymerize the monomer to produce a thermoplastic polymer, and use the polymer as it is or with a different thermoplastic polymer. A method of manufacturing a film by mixing, extruding into a sheet, and stretching,
A method for producing a thermoplastic polymer film, characterized in that the wall material of the inorganic porous microcapsule is at least one selected from the group consisting of titanium monoxide, titanium dioxide, silica, calcium carbonate, and barium sulfate. 11. When dispersing the inorganic porous microcapsules in a thermoplastic polymer monomer or a polymerization solvent, the atmosphere is reduced or pressurized at least three times during and/or after the dispersion, as described in claim 10. A method for producing a thermoplastic polymer film. 12. The method for producing a thermoplastic polymer film according to claim 10, wherein the content of the inorganic porous microcapsules is 0.0001 to 10% by weight of the thermoplastic polymer. 13. The method for producing a thermoplastic polymer film according to claim 10, wherein the inorganic porous microcapsules have a specific surface area of 200 to 900 m ² /g. 14. The method for producing a thermoplastic polymer film according to claim 10, wherein the thermoplastic polymer is encapsulated in the inorganic porous microcapsules at a filling rate of 90% by volume or more. 15. The method for producing a thermoplastic polymer film according to claim 10, wherein the wall material of the inorganic porous microcapsules is made of titanium dioxide or titanium monoxide. 16. The method for producing a thermoplastic polymer film according to claim 10, wherein the thermoplastic polymer is polyester. 17. The method for producing a thermoplastic polymer film according to claim 10, wherein the film has a surface roughness Ra of 0.001 to 0.050μ. 18. The method for producing a thermoplastic polymer film according to claim 17, wherein the film has a light transmittance of 60% or less.