JP6247913B2 - Corona surface treatment apparatus and release film manufacturing method - Google Patents

Description

The present invention relates to a corona surface treatment apparatus and a method for producing a release film.

  Conventionally, corona surface treatment has been performed for the purpose of imparting hydrophilicity to the surface of an object to be treated such as a film or a substrate to improve wettability.

  A corona surface treatment apparatus that performs such a corona surface treatment includes a discharge electrode and a counter electrode, and passes an object to be processed between the discharge electrode and the counter electrode while moving from the discharge electrode toward the counter electrode. It is configured to discharge and perform a corona surface treatment on the surface of the object to be processed (see, for example, Patent Documents 1 and 2).

  In a conventional corona surface treatment apparatus, an electrode is composed of a pair of discharge electrodes and a counter electrode, and is generally configured to treat the entire surface of an object to be treated. In the case where a part of the surface of the object to be processed is processed, the part not subjected to the surface treatment is masked.

  However, the corona surface treatment using such a mask has a problem that the mask portion is heated by being exposed to the corona surface treatment for a long time, and the workpiece is adversely affected by the heat. . Further, there is a problem that the mask is damaged by being exposed to the corona surface treatment for a long time, and from this damaged portion, the portion not originally subjected to the surface treatment is also processed.

JP 2003-7499 A JP 2003-71925 A

An object of the present invention is to provide a corona surface treatment apparatus capable of easily performing a corona surface treatment on a part of the surface of an object to be treated such as a film or a substrate, and the corona surface treatment apparatus using such a corona surface treatment apparatus. Providing a method for producing a release film that has been subjected to a treatment, and when producing a green sheet, the shrinkage of the edge of the green sheet can be suppressed, and the occurrence of chipping or the like in the green sheet is suppressed. It is in providing the manufacturing method of the peeling film which can be performed.

Such an object is achieved by the present inventions (1) to ( 6 ) below.
(1) a plurality of discharge electrodes;
Have a, a plurality of counter electrodes disposed so as to face the respective discharge electrodes,
A columnar guide roll that guides a workpiece to be subjected to corona surface treatment between the discharge electrode and the counter electrode,
The corona surface treatment apparatus, wherein the plurality of counter electrodes are provided integrally with the guide roll .

(2) the guide roll, a guide roll body, an insulator layer covering the outer peripheral surface of the guide roll itself, and is configured,
The said some counter electrode is a corona surface treatment apparatus as described in said (1) provided on the outer peripheral surface of the said guide roll main body, and being embedded in the said insulator layer.

( 3 ) The said counter electrode is a corona surface treatment apparatus as described in said (1) or (2) which protrudes from the outer peripheral surface of the said guide roll main body.

( 4 ) The object to be subjected to corona surface treatment has a band shape,
The corona surface treatment apparatus according to any one of (1) to ( 3 ), wherein the plurality of discharge electrodes and the plurality of counter electrodes are provided side by side at a predetermined interval in the width direction of the workpiece.

( 5 ) A method for producing a release film , wherein the corona surface treatment is performed using the corona surface treatment apparatus according to any one of (1) to ( 4 ).

( 6 ) It is a manufacturing method of the strip-shaped peeling film used for manufacture of a green sheet,
The release film is a strip-shaped substrate,
A release agent layer formed on the entire surface of one surface of the substrate,
A first region including a widthwise end portion of the green sheet to be formed on the surface of the release agent layer opposite to the base material, in contact with the green sheet to be formed, and the first A second region different from the region,
When the static contact angle for water in the first region is X [°] and the static contact angle for water in the second region is Y [°], the relationship of Y−X ≧ 11 is satisfied,
Peeling characterized in that the first region is formed by subjecting the surface of the release agent layer to corona surface treatment by the corona surface treatment apparatus according to any one of (1) to ( 4 ) above. A method for producing a film.

  ADVANTAGE OF THE INVENTION According to this invention, the corona surface treatment apparatus which can perform a corona surface treatment easily to some surface of to-be-processed objects, such as a film and a board | substrate, can be provided.

Moreover, when manufacturing a green sheet, the shrinkage | contraction of the edge part of a green sheet can be suppressed, and the method of manufacturing the peeling film which can suppress that a chip | tip etc. generate | occur | produce in a green sheet is provided. Is possible.

It is a side view which shows the outline | summary of suitable embodiment of the corona surface treatment apparatus of this invention. It is a longitudinal cross-sectional view which shows arrangement | positioning of the discharge electrode with which the corona surface treatment apparatus of FIG. 1 is equipped, and a counter electrode. It is a permeation | transmission perspective view of the guide roll with which the corona surface treatment apparatus of FIG. 1 is provided. It is a longitudinal cross-sectional view which shows other arrangement | positioning of a discharge electrode and a counter electrode. It is a cross-sectional view showing a preferred embodiment of a release film. It is a top view which shows suitable embodiment of a peeling film.

Hereinafter, the present invention will be described in detail based on preferred embodiments.
1. First, a preferred embodiment of the corona surface treatment apparatus of the present invention will be described.

  FIG. 1 is a side view showing an outline of a preferred embodiment of the corona surface treatment apparatus of the present invention, and FIG. 2 is a longitudinal sectional view showing the arrangement of discharge electrodes and counter electrodes provided in the corona surface treatment apparatus of FIG. 3 is a transparent perspective view of a guide roll provided in the corona surface treatment apparatus of FIG. 1, and FIG. 4 is a longitudinal sectional view showing another arrangement of the discharge electrode and the counter electrode.

  As shown in FIGS. 1 and 2, the corona surface treatment apparatus 1000 includes a discharge electrode 1100, a counter electrode 1200 provided so as to face the discharge electrode 1100, a guide roll 1300, and a strip-like peeling as a workpiece. A film unwinding section 1400 for unwinding the film 1 in the direction of the guide roll 1300 and a film winding section 1500 for winding the release film 1 subjected to the corona surface treatment are included.

  In such a corona surface treatment apparatus 1000, by applying a high-voltage pulse from a high-frequency high-voltage power source (not shown) between the discharge electrode 1100 and the counter electrode 1200, a release film that is an object to be processed from the discharge electrode 1100. Corona discharge occurs toward 1, and the surface of the release film 1 is subjected to corona surface treatment.

  The discharge electrodes 1100 are connected to a high-frequency high-voltage power source (not shown), and four discharge electrodes 1100 are arranged in the width direction of the release film 1 at predetermined intervals. The discharge electrodes 1100 can be attached to and detached from the corona surface treatment apparatus 1000, and the number thereof can be increased or decreased.

  Examples of the material constituting the discharge electrode 1100 include iron, aluminum, and stainless steel.

  The width of one discharge electrode 1100 (the width in the width direction of the release film 1) is not particularly limited, but is preferably about 5 mm to 20 mm.

  Moreover, it is preferable that the distance from the discharge electrode 1100 to the peeling film 1 is about 1.5 mm-2 mm.

  The counter electrode 1200 is connected to a high-frequency high-voltage power supply (not shown), and is arranged in the same number as the discharge electrode 1100 at a position facing the discharge electrode 1100 as shown in FIG.

  The counter electrode 1200 is provided integrally with a guide roll described later, and has a ring shape as shown in FIGS.

  Examples of the material constituting the counter electrode 1200 include iron, aluminum, and stainless steel.

  The width of one counter electrode 1200 (the width in the width direction of the release film 1) is not particularly limited, but is preferably about 5 mm to 20 mm.

  The height of the counter electrode 1200 (the height in the radial direction of a guide roll 1300 described later) is preferably about 5 mm to 20 mm.

  The guide roll 1300 has a function of guiding the release film 1 that is an object to be processed between the discharge electrode 1100 and the counter electrode 1200.

  The guide roll 1300 includes a guide roll body 1310, an insulator layer 1320, and a shaft 1330.

  As shown in FIGS. 1 and 3, the guide roll 1300 has a cylindrical shape whose longitudinal direction is the width direction of the release film 1, and is configured to rotate around a shaft 1330.

The guide roll body 1310 has a cylindrical shape.
Four counter electrodes 1200 described above are provided on the outer peripheral surface of the guide roll body 1310. As shown in FIG. 3, the counter electrode 1200 is configured to protrude from the outer peripheral surface of the guide roll body 1310 in the radial direction. Thereby, corona discharge generated from the discharge electrode 1100 can be directed toward the counter electrode 1200. As a result, unintended spread of corona discharge can be prevented, and corona surface treatment can be performed at a predetermined position.

  Examples of the material constituting the guide roll body 1310 include iron, aluminum, and stainless steel.

  The insulator layer 1320 is formed so as to cover the guide roll body 1310. The insulator layer 1320 is formed so as to embed the counter electrode 1200.

  This insulator layer 1320 is a layer in direct contact with the release film 1. When the insulator layer 1320 has insulating properties, the release film 1 can be subjected to corona treatment.

  The material constituting the insulator layer 1320 is not particularly limited as long as it is an insulating material, and examples thereof include rubber materials such as silicone rubber and ethylene propylene rubber, and ceramics.

  The thickness from the outer peripheral surface of the guide roll body 1310 to the surface of the insulator layer 1320 is preferably about 5 mm to 30 mm.

  The guide roll 1300 is detachable and can be replaced with another guide roll 1300 having a different number of counter electrodes 1200.

  The film unwinding unit 1400 has a function of unwinding (unwinding) the release film 1 from the wound body of the unprocessed release film 1 wound up toward the guide roll 1300.

  The film take-up unit 1500 has a function of taking up the release film 1 subjected to the corona surface treatment sent from the guide roll 1300 side.

  According to the corona surface treatment apparatus 1000 as described above, it is possible to easily perform a corona surface treatment on a part of the surface of an object to be processed such as a film or a substrate. In particular, since no mask is required, the release film 1 is not damaged by unintended heat, and the release film 1 exhibits excellent functions.

  In the above description, the discharge electrode 1100 and the counter electrode 1200 are described as being arranged at a constant interval. However, the interval may not be constant.

  Moreover, in the said description, although the structure which has the four discharge electrodes 1100 and the counter electrodes 1200 was demonstrated, as shown in FIG. 4, the structure which has two each on the edge part side of the peeling film 1, The configuration may include three each, or may include five or more.

  In the above description, one counter electrode 1200 has been described as being continuously provided over the outer periphery of the guide roll body 1310, but may be provided intermittently.

  In the above description, the configuration in which the counter electrode 1200 and the guide roll 1300 are integrated has been described. However, the counter electrode 1200 and the guide roll 1300 may be provided separately.

<Release film>
Next, the release film 1 will be described.
The release film 1 according to this embodiment is used for manufacturing a green sheet.

  FIG. 5 is a cross-sectional view showing a preferred embodiment of the release film, and FIG. 6 is a plan view showing a preferred embodiment of the release film.

  As shown in FIGS. 5 and 6, the release film 1 has a base material 11 and a release agent layer 12 provided on one surface of the base material 11.

Moreover, the peeling film 1 has comprised strip | belt shape.
Moreover, the release film 1 forms the green sheet 20 on the surface of the release agent layer 12, as shown in FIG. 5, FIG.

  Moreover, as shown in FIG. 6, it has the 1st area | region 121 in the width direction both ends of the peeling film 1, and has the 2nd area | region 122 in the center part on the surface of the releasing agent layer 12. FIG.

  In the release film 1 according to the present embodiment, the surface of the release agent layer 12 opposite to the substrate 11 is formed with a first region 121 including the end portion 21 in the width direction of the green sheet 20 to be formed. A second region 122 that is in contact with the green sheet 20 and is different from the first region 121, and the static contact angle with respect to the water in the first region 121 is relative to the water in the second region 122. It is comprised so that it may become smaller than a static contact angle. Specifically, when the static contact angle with respect to water in the first region 121 is X [°] and the static contact angle with respect to water in the second region 122 is Y [°], Y−X ≧ 11 It is configured to satisfy the relationship. The first region 121 is formed by subjecting the surface of the release agent layer 12 to corona surface treatment by the corona surface treatment apparatus 1000 as described above.

  Thereby, contraction of the end portion 21 in the width direction of the green sheet 20 (also simply referred to as end portion contraction) can be suppressed. This is considered to be due to the following reasons. That is, when the static contact angle with respect to the water in the first region 121 is smaller than the static contact angle with respect to the water in the second region 122, the wettability of the ceramic slurry to the release agent layer 12 is reduced to the second. The first area 121 is higher than the area 122. Therefore, shrinkage due to the surface tension of the ceramic slurry is suppressed. As a result, it is possible to prevent the end portion of the formed green sheet 20 from becoming thick.

  Further, the green sheet 20 formed on the release film 1 has a second inner side than the first region 121 (for example, a part indicated by a dashed arrow in FIG. 5 or a part indicated by a one-dot broken line in FIG. 6). Punched in the region 122 and peeled from the release film 1. At this time, since the second region 122 has a lower peeling force than the first region 121, the punched green sheet 20 can be easily peeled off. Further, when the punched green sheet 20 is peeled off, the portion remaining on the peeling film 1 has higher adhesiveness (peeling force) with the release agent layer 12 than the green sheet 20 to be peeled off. It remains reliably on the top and does not hinder the punching of the punched green sheet 20.

Hereinafter, each layer which comprises the peeling film 1 which concerns on this embodiment is demonstrated in detail.
<Base material>
The substrate 11 has a function of imparting physical strength such as rigidity and flexibility to the release film 1. Moreover, the base material 11 has comprised strip | belt shape.

  The substrate 11 may be composed of any material as long as it has physical properties such as appropriate rigidity and flexibility, but is preferably composed mainly of a resin material. Thereby, the base material 11 has sufficient resistance to tearing and breaking, and can have sufficient flexibility.

  The resin material constituting the substrate 11 is not particularly limited, and examples thereof include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, and ethylene-acetic acid. Vinyl copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyetheretherketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polyimide, fluororesin, polyamide, acrylic resin, norbornene resin, cycloolefin resin, etc. 1 type or 2 types or more of them can be used in combination.

  Among these, it is preferable to use polyester as the resin material, and it is particularly preferable to use polyethylene terephthalate.

  Although the average thickness of the base material 11 is not specifically limited, It is preferable that it is 10-150 micrometers, and it is more preferable that it is 20-120 micrometers. Thereby, it is possible to make the release film 1 particularly excellent in resistance to tearing and breaking while making the release film 1 have an appropriate flexibility.

<Release agent layer>
The release agent layer 12 is provided on the entire surface of the substrate 11.

  The release agent layer 12 is mainly composed of a release agent and has a function of imparting peelability to the release film 1.

  The outer surface of the release agent layer 12 (the surface opposite to the base material 11) includes a first region 121 including an end portion 21 in the width direction of the release film 1 of the green sheet 20 to be formed, and the first 2nd area | region 122 inside the area | region 121 of this.

  In the present embodiment, the first region 121 is continuously formed along the longitudinal direction of the release film 1 in the vicinity of the end in the width direction of the release film 1. The second region 122 is formed in a region sandwiched between the first regions 121 at both ends.

  When the static contact angle with respect to water in the first region 121 is X [°] and the static contact angle with respect to water in the second region 122 is Y [°], the relationship of Y−X ≧ 11 is satisfied. However, it is more preferable to satisfy the relationship of YX ≧ 15, and it is further preferable to satisfy the relationship of 45 ≧ YX ≧ 20. By satisfying such a relationship, it is possible to more effectively suppress the occurrence of edge shrinkage in the green sheet 20 to be formed.

  Specifically, the static contact angle of the first region 121 with respect to water is preferably 0 to 95 °, and more preferably 5 to 80 °. Thereby, it can suppress more reliably that edge part shrinkage | contraction generate | occur | produces in the green sheet 20 to form.

  Further, specifically, the static contact angle of the second region 122 with respect to water is preferably 100 to 120 °, and more preferably 100 to 115 °. Thereby, the coating property of a ceramic slurry and the peelability of a green sheet can be made higher.

  In this specification, the static contact angle is a temperature of 23 ° C. and a humidity of 50% by a droplet method using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., fully automatic contact angle meter “DM-701”). The value measured under the conditions of

  The first region 121 and the second region 122 are subjected to corona surface treatment on the region where the first region 121 on the surface of the release agent layer 12 is to be formed, using the corona surface treatment apparatus 1000 as described above. It is formed by. Thereby, the first region 121 and the second region 122 can be easily formed. In addition, the static contact angle of the first region 121 can be adjusted more easily.

Discharge amount when subjected to corona surface treatment is preferably from 150~1000W · min / ^{m 2,} and more preferably 250~600W · min / ^{m 2.} Thereby, sufficient hydrophilicity can be provided, suppressing the unintentional damage with respect to the peeling film 1 surface.

  The ratio of the area of the first region 121 (the total of the first regions 121 at both ends) to the area of the release film 1 when the release film 1 is viewed in plan is preferably 5 to 40%. More preferably, it is -35%. Thereby, the surface of the release agent layer 12 can be effectively used, and the green sheet 20 can be manufactured more efficiently.

The release agent layer 12 is formed using a release agent composition containing a release agent.
Although it does not specifically limit as a release agent composition, It is preferable to use the silicone type release agent composition containing the release agent comprised by the polyorganosiloxane.

  Any polyorganosiloxane may be used as long as it can form the release agent layer 12. For example, addition reaction type or condensation reaction type polyorganosiloxane can be used. Such polyorganosiloxane can undergo a polymerization reaction when energy such as heat and light is applied during the formation of the release agent layer 12. As a result, the silicone release agent is suitably cured and the release agent layer 12 is formed. Among them, it is preferable to use an addition reaction type polyorganosiloxane.

  The addition reaction type polyorganosiloxane is not particularly limited as long as it is a polyorganosiloxane that can undergo an addition reaction at the time of curing of the silicone release agent. Vinyl group, allyl group, propenyl group, hexenyl group, octenyl group, decenyl group are not limited. A polyorganosiloxane having an alkenyl group such as a group can be used.

  As the polyorganosiloxane having an alkenyl group, those having a mass average molecular weight of 20,000 to 1,300,000 having at least two alkenyl groups in one molecule are preferably used.

  The polyorganosiloxane having a mass average molecular weight of 20,000 to 1,300,000 having at least two alkenyl groups in one molecule is represented by the following general formula (I), for example.

R ¹ R ² ₂ SiO (R ₂ SiO) _m (RR ¹ SiO) _n SiR ² ₂ R ¹ (I)
In the formula (I), R is the same or different monovalent hydrocarbon group having no aliphatic unsaturated bond, R ¹ is the same or different alkenyl group, R ² is R or R ¹ , m and n Represents a natural number.

  R in the formula (I) is preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, particularly 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms include alkyl groups such as a methyl group, an ethyl group, and a propyl group, and aryl groups such as a phenyl group and a tolyl group.

Examples of the alkenyl group represented by R ¹ in the formula (I) include those having 2 to 10 carbon atoms such as vinyl group, allyl group, propenyl group, hexenyl group, octenyl group, and decenyl group.

  In the polyorganosiloxane, it is preferable that 80 mol% or more of the monovalent hydrocarbon groups directly bonded to the silicon atom is a methyl group.

  Moreover, it is preferable that a silicone type release agent composition contains a crosslinking agent. By cross-linking the polyorganosiloxane with such a cross-linking agent, the polyorganosiloxane is prevented from transferring from the release agent layer 12 to the green sheet, and the green sheet is reliably prevented from being contaminated. Further, the surface strength of the release agent layer 12 can be made particularly excellent, and the adhesion between the substrate 11 and the release agent layer 12 becomes particularly excellent.

  Examples of the crosslinking agent include polyorganosiloxane having a Si—H bond in the monomer, specifically, dimethylhydrogensiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group endcapped. Examples thereof include dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group end-capped poly (methylhydrogensiloxane), poly (hydrogensilsesquioxane) and the like, and one or a combination of two or more may be used. it can.

  It is preferable that 0.1-100 mass parts is contained with respect to 100 mass parts of polyorganosiloxanes, and, as for the crosslinking agent in a silicone type release agent composition, it is more preferable that 0.3-50 mass parts is contained.

  The silicone release agent composition may contain other components in addition to the components as described above. For example, the silicone release agent composition may contain an adhesion improver, a polymerization initiator, a stabilizer, silica, a dye, a pigment, and the like.

  The thickness of the release agent layer 12 is not particularly limited, but is preferably 0.01 to 3 μm, and more preferably 0.03 to 1 μm.

  In addition, in this specification, a mass average molecular weight (Mw) means what calculated | required each peeling agent by the gel permeation chromatography (GPC) which uses tetrahydrofuran as a developing solvent, and calculated | required as a polystyrene conversion value. The measurement conditions are as follows.

GPC measuring device: HLC-8020 (trade name, manufactured by Tosoh Corporation)
GPC column (passed in the following order): TSK guard column HXL-H, TSK gel GMHXL (× 2), TSK gel G2000HXL (above, trade name, manufactured by Tosoh Corporation)
Measuring solvent: Tetrahydrofuran Measuring temperature: 40 ° C

  As mentioned above, although this invention was demonstrated in detail based on preferred embodiment, this invention is not limited to this.

  For example, in the above-described embodiment, the first region has been described as being continuously formed along the longitudinal direction of the release film. However, the first region is not limited thereto, and may be intermittent.

  Further, for example, the first region 121 and the second region 122 may be formed by using different materials for the release agent layer 12.

  In the above-described embodiment, the boundary between the first region and the second region has been described as clear, but it may not be clear. That is, you may comprise so that the static contact angle with respect to water may become small gradually toward a 1st area | region from a 2nd area | region.

Next, specific examples of the release film will be described.
[1] Production of release film (Example 1)
Addition reaction type polyorganosiloxane solution (solid content 30) containing a polyorganosiloxane having a vinyl group (mass average molecular weight: 11,130,000, vinyl group content: 0.21 mmol / g) and polyorganohydrogensiloxane % By mass, ratio of the number of hydrosilyl groups to the number of vinyl groups: 2.7) 100 parts by mass of a solid solution concentration of 1.5% by mass in a mixed solution of toluene and methyl ethyl ketone (mass ratio 3: 7) Further, 2 parts by mass of a platinum catalyst (manufactured by Dow Corning Toray, SRX-212) was added and mixed to obtain a solution of a release agent composition.

  On the entire surface of a biaxially stretched polyethylene terephthalate base film having a width of 300 mm and a thickness of 31 μm, a solution of the release agent composition was applied on the entire surface so that the thickness after drying was 0.09 μm, and then at 125 ° C. A release agent layer was formed by drying and curing reaction for 30 seconds.

Thereafter, by using a corona surface treatment apparatus as shown in FIGS. 1 to 3, the first region is subjected to corona treatment at a discharge amount of 400 W · min / m ^{2 in} the range from both ends of the release agent layer to 15 mm. And the 2nd area | region was formed and the peeling film wound by roll shape was produced.

  When the obtained release film was viewed in plan, the ratio of the area of the first region to the area of the release film was 10%.

(Example 2)
A release film was produced in the same manner as in Example 1 except that the first region and the second region were formed by performing corona treatment in a range of 30 mm from both ends of the release agent layer. In addition, the ratio of the area of the 1st area | region with respect to the area of a peeling film at the time of planarly viewing the obtained peeling film was 20%.

(Example 3)
A release film was produced in the same manner as in Example 1 except that the first region and the second region were formed by performing corona treatment in a range of 45 mm from both ends of the release agent layer. In addition, the ratio of the area of the 1st area | region with respect to the area of a peeling film in the planar view of the obtained peeling film was 30%.

Example 4
Same as Example 1 except that the first region and the second region were formed by performing corona treatment at a discharge amount of 200 W · min / m ² in the range from both ends of the release agent layer to 15 mm. A release film was prepared.

(Example 5)
Same as Example 1 except that the first region and the second region were formed by performing corona treatment with a discharge amount of 300 W · min / m ² in the range from both ends of the release agent layer to 15 mm. A release film was prepared.

(Comparative Example 1)
A release film was produced in the same manner as in Example 1 except that the corona treatment was not performed.

Table 1 shows the ratio of the area of the first region of each example and comparative example.
Moreover, after producing the peeling film of each Example and each comparative example, after curing for 7 days on the conditions of temperature 23 degreeC and relative humidity 50%, the static contact angle with respect to the water of a 1st area | region and a 2nd area | region is set. It was measured. The results are shown in Table 1. In addition, about the comparative example 1, the static contact angle with respect to the water of the releasing agent layer surface was described in the column of the 2nd area | region.

[2] Evaluation Regarding the release film obtained as described above, the following evaluation was performed.

[2.1] End part shrinkage evaluation Barium titanate (BaTiO ₃ ; manufactured by Sakai Chemical Industry Co., Ltd., BT-02) 100 parts by mass, polyvinyl butyral as a binder (manufactured by Sekisui Chemical Co., Ltd., ESREC B / K BM-2) 8 parts by mass and 4 parts by mass of dioctyl phthalate as plasticizer (manufactured by Kanto Chemical Co., Inc., dioctyl phthalate deer grade 1) 135 parts by mass of a mixed solution of toluene and ethanol (mass ratio 6: 4) are added to a ball mill. The ceramic slurry was prepared by mixing and dispersing.

  On the surface of the release agent layer of the release film (width: 300 mm) that was produced in each example and comparative example and stored at room temperature for 24 hours, the film thickness after drying the ceramic slurry was 3 μm and the width was 290 mm. The film was uniformly coated using a die coater and then dried at 80 ° C. for 1 minute in a dryer. In this way, a 300 m release film with a green sheet was produced.

In 300 m of the obtained release film with a green sheet, whether or not end shrinkage occurred at the end in the width direction was calculated according to the following criteria by calculating the end shrinkage width according to the following formula. The results are shown in Table 1.
Edge shrinkage width = (Ceramic slurry coating width)-(Width of formed green sheet)

○: End shrinkage width is less than 2 mm (good)
Δ: End shrinkage width is 2 mm or more and less than 5 mm (can be used)
×: End shrinkage width is 5 mm or more (defect)

[2.2] Peeling force evaluation The release film with a green sheet obtained in the same manner as the edge shrinkage evaluation was allowed to stand for 24 hours in an atmosphere at a temperature of 23 degrees and a humidity of 50%, A sample having a size of 120 mm × 40 mm was taken from the portion, and a 40 mm long acrylic adhesive tape (manufactured by Nitto Denko Corporation, 31B tape) was attached to the side of 40 mm from the green sheet surface side to obtain a test piece.

  The peeling film surface side of this test piece was fixed to a flat plate, and the edge side to which the acrylic adhesive tape was applied was tilted down to 90 ° and installed in a peeling tester (Shimadzu Corporation, AG-1S 500N). .

  And the peeling film of the edge which stuck the acrylic adhesive tape was peeled from the green sheet, and the acrylic adhesive tape side was attached to the jig | tool of a peeling tester. In this state, the acrylic adhesive tape was pulled vertically upward at a peeling speed of 300 mm / min, and the peeling force (mN / 40 mm) when the green sheet was peeled off from the peeling film was measured.

  Those having a measured peel force of less than 15 mN / 100 mm were evaluated as “◯” (good), and those having a peel strength of 15 mN / 100 mm or more were evaluated as “x” (defective). The results are shown in Table 1.

[3] Evaluation Results As is clear from Table 1, the release films of the examples were able to effectively suppress the edge shrinkage of the green sheet. Moreover, the release film of an Example was excellent in the peelability of the formed green sheet. On the other hand, satisfactory results were not obtained in the comparative example.

DESCRIPTION OF SYMBOLS 1 Release film 11 Base material 12 Release agent layer 121 1st area | region 122 2nd area | region 20 Green sheet 21 End part of the width direction of a green sheet 1000 Corona surface treatment apparatus 1100 Discharge electrode 1200 Counter electrode 1300 Guide roll 1310 Guide roll main body 1320 Insulator layer 1330 Shaft 1400 Film unwinding part 1500 Film winding part

Claims (6)

A plurality of discharge electrodes;
Have a, a plurality of counter electrodes disposed so as to face the respective discharge electrodes,
A columnar guide roll that guides a workpiece to be subjected to corona surface treatment between the discharge electrode and the counter electrode,
The corona surface treatment apparatus, wherein the plurality of counter electrodes are provided integrally with the guide roll . It said guide roll is a guide roll body, an insulator layer covering the outer peripheral surface of the guide roll itself, and is configured,
The corona surface treatment apparatus according to claim 1 , wherein the plurality of counter electrodes are provided on an outer peripheral surface of the guide roll main body and are embedded in the insulator layer. Wherein the counter electrode, a corona surface treatment apparatus according to claim 1 or 2 protrudes from the outer peripheral surface of the guide roll body. The workpiece to be subjected to corona surface treatment has a band shape,
The plurality of discharge electrodes and the plurality of counter electrodes, a corona surface treatment apparatus according to any one of the claims 1 are lined provided at predetermined intervals in the width direction of the workpiece 3. Using a corona surface treatment apparatus according to any one of claims 1 to 4, the production method of the release film characterized in applying a corona surface treatment. A method for producing a strip-shaped release film used for producing a green sheet,
The release film is a strip-shaped substrate,
A release agent layer formed on the entire surface of one surface of the substrate,
A first region including a widthwise end portion of the green sheet to be formed on the surface of the release agent layer opposite to the base material, in contact with the green sheet to be formed, and the first A second region different from the region,
When the static contact angle for water in the first region is X [°] and the static contact angle for water in the second region is Y [°], the relationship of Y−X ≧ 11 is satisfied,
The release film is characterized in that the first region is formed by subjecting the surface of the release agent layer to a corona surface treatment using a corona surface treatment apparatus according to any one of claims 1 to 4. Manufacturing method .

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