Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/62218—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products obtaining ceramic films, e.g. by using temporary supports
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/28—Web or sheet containing structurally defined element or component and having an adhesive outermost layer
  • Y10T428/2839—Web or sheet containing structurally defined element or component and having an adhesive outermost layer with release or antistick coating
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31551—Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
  • Y10T428/31598—Next to silicon-containing [silicone, cement, etc.] layer
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31652—Of asbestos
  • Y10T428/31663—As siloxane, silicone or silane
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31855—Of addition polymer from unsaturated monomers
  • Y10T428/31938—Polymer of monoethylenically unsaturated hydrocarbon

Definitions

• the present invention relates to a casting film for producing a ceramic green sheet. More particularly, it is concerned with a casting film which is used in the production process of a ceramic green sheet in producing ceramic electronic part items, and which has excellent wettability of ceramic slurry and moderate releasability for the ceramic green sheet.
• a ceramic electronic part item such as a capacitor, a laminated inductor element, a piezo-part, a thermistor and a varister is produced by a method comprising the steps of forming a green sheet by coating a casting film with ceramic slurry which is suited to the aforesaid electronic part items, which is used in high dielectric constant, magnetism and the like, and which is composed of ceramic powders, organic binders, plasticizers, solvents (an organic solvent or water) and the like (Step ⁇ circle over (1) ⁇ ); equipping the resultant green sheet with an electrode made of palladium, silver, nickel or the like by means of screen printing (Step ⁇ circle over (2) ⁇ ); thereafter peeling off the green sheet from the casting film and laminating the green sheets in multi-layer (Step ⁇ circle over (3) ⁇ ); forming ceramic green chips through a step of press cutting (Step ⁇ circle over (4) ⁇ ); baking the chips thus obtained (Step ⁇ circle over (5) ⁇
• an object of the present invention is to provide a casting film which is used in the production of a ceramic green sheet to be employed in a ceramic electronic part items, and which is free from repelling on ceramic slurry coating and also free from lifting and/or peeling off on repeated coating of ceramic slurry.
• the present invention provides:
• a casting film which is used for producing a ceramic green sheet and which comprises a substrate film and a releasing layer formed on at least either side thereof, wherein said releasing layer comprises a mixture of a silicone based releasing agent and a cellulose derivative;
• the casting film for producing a ceramic green sheet as set forth in the preceding item(1) wherein the cellulose derivative is at least one member selected from the group consisting of ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose and hydroxypropyl cellulose;
• the silicone based releasing agent to be used as an either component of the releasing agent in the present invention which is a conventional well known addition reaction type silicone based releasing agent, comprises an addition reaction type silicone resin as the principal component, a crosslinking agent and a catalyst, both being incorporated in the silicone resin, and may be incorporated as desired, with an addition reaction inhibitor, a release modifier and an adhesion improver. It may further be incorporated with a photosensitizer in the case of carrying out ultraviolet ray irradiation in addition to a heat treatment in a curing step after coating a releasing agent.
• the type of the silicone based releasing agent may be any of a solvent type, an emulsion type and a solventless (solvent free) type provided that the silicone resin is of an addition reaction type.
• a solvent type releasing agent is suitable from the aspect of quality and easiness of handling.
• the above-mentioned addition reaction type silicone resin is not specifically limited, but may be selected for use for instance, from those that have heretofore been customarily used as a releasing agent composed of a heat curable addition reaction type silicone resin, which is exemplified by at least one member selected from polyorganosiloxanes having an alkenyl group as a functional group in a molecule.
• a heat curable addition reaction type silicone resin which is exemplified by at least one member selected from polyorganosiloxanes having an alkenyl group as a functional group in a molecule.
• Preferable examples of the above-mentioned polyorganosiloxanes having an alkenyl group as a functional group in a molecule include polydimethylsiloxane having a vinyl group as a functional group, polydimethylsiloxane having a hexenyl group as a functional group and the mixture of the two.
• the crosslinking agent is exemplified by polyorganosiloxane having in its one molecule, at least two hydrogen atoms each bonded to a silicon atom, specifically by dimethylsiloxane/methylhydrogen-siloxane copolymer the end of which is hindered with dimethylhydrogen-siloxy group, dimethylsiloxane/methylhydrogen-siloxane copolymer the end of which is hindered with trimethylsiloxy group, poly(methylhydrogen-siloxane) the end of which is hindered with trimethylsiloxy group and poly (hydrogen silsequioxane).
• the amount of the exemplified crosslinking agent to be used is selected in the range of 0.1 to 100 parts by weight, preferably 0.3 to 50 parts by weight based on 100 parts by weight of the addition reaction type silicone resin.
• a catalyst there is usually employed as a catalyst, a platinum base catalyst, palladium base catalyst and rhodium base catalyst each in a proper amount to accelerate polymerization reaction.
• Examples of the release modifier include dimethylpolysiloxane and silicone resin.
• the aforesaid addition reaction inhibitor is a component used for the purpose of imparting shelf life stability at room temperature to the silicone resin, and is specifically exemplified by 3,5-dimethyl-1-hexyne-3-ol, 3-methyl-1-pentene-3-ol, 3-methyl-3-pentene-1-in, 3,5-dimethyl-3-hexene-1-in, cyclic tetravinylsiloxane and benzotriazole.
• the aforesaid photosensitizer is not specifically limited, but may be properly optionally selected for use from those that have heretofore been customarily used in ultraviolet curable resin.
• examples thereof include benzoins, benzophenones, acetophenones, ⁇ -hydroxy ketones, ⁇ -amino ketones, ⁇ -diketones, ⁇ -diketone dialkyl acetals, anthraquinones, thioxanthones and the other compounds.
• any of the above-exemplified photosensitizers may be used alone or in combination with at least one other.
• the amount thereof to be used is selected in the range of usually 0.01 to 30 parts by weight, preferably 0.05 to 20 parts by weight based on 100 parts by weight of total amount of the addition reaction type silicone resin and the crosslinking agent.
• the cellulose derivative to be used as an other component of the releasing agent in the present invention it is suitable to employ at least one member selected from the group consisting of ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose and hydroxypropyl cellulose.
• the dissolvability of the cellulose derivative in an organic solvent or water is different from one another depending upon the type thereof, it is preferable to select a cellulose derivative which is more prone to be dissolved in an organic solvent such as toluene and ethyl acetate for a solvent type silicone based releasing agent, and to select a cellulose derivative which is more prone to be dissolved in water for an emulsion type silicone based releasing agent.
• a solvent type silicone based releasing agent to combine ethyl cellulose, methyl cellulose or hydroxyethyl cellulose and in the case of an emulsion type silicone based releasing agent to combine carboxy cellulose, hydroxyethyl cellulose or hydroxypropyl cellulose.
• the above-mentioned cellulose derivative may be subjected in advance to silane coupling treatment or silicone treatment.
• a solventless type silicone based releasing agent is preferably combined with a cellulose derivative which has been subjected in advance to such a treatment.
• the proportion of the silicone based releasing agent to the cellulose derivative that are used in the present invention is different depending upon the type of the ceramic slurry to be used, but the solid content ratio by weight (silicone based releasing agent: cellulose derivative) is preferably 90:10 to 3:97, particularly preferably 87:13 to 40:60.
• the ratio of the silicone based releasing agent to be used therein when being more than the foregoing range, brings about a decrease in wettability accompanying a decrease in critical surface tension of the releasing layer surface, thus causing repelling, whereby favorable coating is made impossible to form.
• the ratio of the cellulose derivative to be used therein when being less than the foregoing range, gives rise to insufficiency in releasing performance, thus making it difficult to peel off the green sheet from the casting film in the foregoing Step ⁇ circle over (3) ⁇ .
• the releasing agent is used for producing a green sheet in which use is made of ceramic slurry of the type being difficult to peel off from the casting film, it is suitable to increase the ratio of the silicone resin within the above-mentioned range, whereas the releasing agent is used for producing a green sheet in which use is made of ceramic slurry of the type being easy to peel off from the casting film, it is suitable to increase the ratio of the cellulose derivative within aforesaid range.
• the substrate film to be used in the present invention is not specifically limited, but may be properly optionally selected for use from any of the well known films which have heretofore been usable as a substrate film for a casting film for producing a ceramic green sheet.
• examples of such films include a polyester film made of polyethylene terephthalate, polyethylene naphthalate or the like, a polyolefin film made of polypropylene, polymethylpentene or the like, a polycarbonate film and polyvinyl acetate film.
• a polyester film is preferable and a biaxially oriented polyethylene terephthalate film is preferable in particular from the aspects of smoothness, heat resistance and cost.
• a coating solution is prepared at first which contains the aforesaid silicone based releasing agent and the cellulose derivative at a prescribed ratio.
• a coating solution having a viscosity which enables coating is prepared by using as a diluent, any of toluene, hexane, ethyl acetate, methyl ethyl ketone, heptane and a mixture thereof in a system of solvent type silicone based releasing agent/cellulose derivative, or by generally using water as a diluent in a system of emulsion type silicone based releasing agent/cellulose derivative.
• the coating solution may be incorporated at need, with a filler, antistatic agent, dye, pigment, other additive, etc.
• the coating solution thus prepared is applied to either or both sides of the aforesaid substrate film by means of, for instance, gravure coat method, bar coat method, spray coat method, spin coat method, multi-roll coat method or the like.
• the coating amount expressed in terms of solid content is in the range of suitably 0.01 to 1.0 g/m 2 , preferably 0.03 to 0.5 g/m 2 in particular.
• the coating amount when being less than 0.01 g/m 2 , brings about poor releasability, whereas the coating amount, when being more than 1.0 g/m 2 , gives rise to possibility of causing repelling at a time of ceramic slurry coating.
• the amount of the cellulose derivative to be used is increased to suppress the repelling, desirable releasability sometimes fails to be assured.
• any of a heating treatment with an oven of a coating machine and the combination of a heating treatment with subsequent ultraviolet ray radiation are preferable from the viewpoints of thermal shrinkage or wrinkle to be prevented, curability of silicone resin and adhesiveness of the releasing agent to the substrate film.
• heating treatment alone, the conditions thereof is not specifically limited provided that a period of time for sufficient curing is assured at a temperature in the range of 70 to 160° C., and it is usually suitable to carry out the heating treatment for 5 to 120 seconds thereat.
• the coated substrate film is firstly heat-treated at a temperature in the range of 40 to 120° C. to preliminarily cure the coating solution.
• the heating temperature when being lower than 40° C., causes a fear of insufficiency in drying or preliminary curing, whereas the heating temperature, when being higher than 120° C., causes thermal shrinkage or wrinkle, thereby sometimes failing to attain the objects of the the present invention.
• the heating temperature is preferably in the range of 50 to 100° C. The heating time can be shortened as compared with the case of the heating treatment alone.
• the coating solution layer which has been preliminarily cured by the heat treatment is subjected to inline ultraviolet ray radiation to completely cure the layer.
• Usable ultraviolet lamps are available from previously well known lamps such as high pressure mercury vapor lamp, metal halide lamp, high power metal halide lamp, non-electrode ultraviolet lamp. Of these, non-electrode ultraviolet lamp is preferable from the viewpoints of less thermal damage to the substrate film and favorable curability of the silicone resin due to suitable ultraviolet emission efficiency, amount of infrared ray irradiation, etc.
• the foregoing lamp is available from D bulb, H bulb, H+ bulb, V bulb and the like manufactured by Fusion Corporation, of which H bulb and H+ bulb are particularly preferable.
• the ultraviolet irradiation output is in the range of usually 30 W/cm to 600 W/cm, preferably 50 W/cm to 360 W/cm.
• the substrate film may in advance, be subjected to a adhesiveness enhancing treatment such as corona discharge treatment, ozone treatment, flame treatment, anchor coat agent coating and the like.
• a adhesiveness enhancing treatment such as corona discharge treatment, ozone treatment, flame treatment, anchor coat agent coating and the like.
• the releasing agent may be applied to the entire surface of the substrate film or to part of the surface thereof, for instance, pattern coating in which a non-coating portion is placed at both the ends so as to regulate the releasability and adhesiveness.
• the casting film thus obtainable according to the present invention is used for producing ceramic green sheets, and is well suited for producing ceramic green sheets which has a thickness of preferably 20 ⁇ m or less, more preferably 10 ⁇ m or less, particularly preferably 4 ⁇ m or less.
• the casting film according to the present invention is characterized by favorable adhesiveness among the sheets in the case where ceramic green sheets are laminated in multi-layer because of less migration of the silicone based releasing agent to the ceramic slurry.
• the ceramic slurry for electronic part items which is used for the production of ceramic green sheet is broadly classified into solvent system and aqueous system, to both of which is applicable the casting film according to the present invention.
• the casting film is imparted with excellent wettability of ceramic slurry and moderate releasability for ceramic green sheets and besides, prevents the occurrence of repelling even in the case of the ceramic slurry being applied in a small thickness, and also the occurrence of lifting or peeling off of the green sheets even in the case of repeatedly carrying out the steps of coating ceramic slurry and printing electrode.
• a blend of 100 parts by weight of barium titanate powder, 5 parts by weight of an acrylic resin, 40 parts by weight of methylene chloride, 25 parts by weight of acetone and 6 parts by weight of mineral spirit was prepared, and mixed for 24 hours with a pot stand by the use of zirconia beads having a diameter of 10 mm to produce ceramic slurry having a high dielectric constant.
• the resultant ceramic slurry was applied to releasing surfaces of a casting film with a slot die coater so that the thickness of the coating after dryness was made to be 3 ⁇ m, followed by drying treatment to prepare a green sheet.
• the wettability (repelling, unevenness of coating being present or not) of the ceramic slurry was visually observed, and the result was evaluated in accordance with the following criterion.
• the resultant mixture was diluted with an organic solvent comprising toluene as a principal ingredient and then, was incorporated with a platinum base catalyst (solid content of 100% by weight, manufactured by Dow Corning Toray Silicone Co., Ltd. under the trade name “SRX-212”) in an amount of 2 parts by weight based on 100 parts by weight of the silicone based releasing agent to prepare a coating solution having a solid content of 2% by weight.
• a platinum base catalyst solid content of 100% by weight, manufactured by Dow Corning Toray Silicone Co., Ltd. under the trade name “SRX-212”
• the coating solution was uniformly applied through gravure coat method, to a biaxially oriented PET film having a thickness of 38 ⁇ m so as to form a coating amount expressed in terms of solid content being 0.1 g/m 2 . Subsequently the coated PET film was heat-treated for 30 seconds in a hot air circulation type dryer at 110° C. to cure the coating solution and prepare a casting film.
• Various characteristics of the casting film thus obtained are given in Table 1.
• Example 1 The procedure in Example 1 was repeated to prepare a casting film except that acetophenone as a photosensitizer in an amount expressed in terms of solid content of 0.1 part by weight was added to 100 parts by weight of the silicone based releasing agent, the coated PET film was heat-treated for 20 seconds in a hot air circulation type dryer at 90° C., and immediately thereafter was irradiated with ultraviolet ray by using a conveyor type ultraviolet irradiating machine equipped with a fusion H bulb of 240 W/cm and an irradiation distance of 102 mm at a conveyor speed of 100 meter per minute.
• Various characteristics of the casting film thus obtained are given in Table 1.
• Example 2 The procedure in Example 2 was repeated to prepare a casting film except that the solid content ratio by weight of the silicone based releasing agent/ethyl cellulose was set on 85:15 instead of 75:25.
• Various characteristics of the casting film thus obtained are given in Table 1.
• Example 2 The procedure in Example 2 was repeated to prepare a casting film except that the solid content ratio by weight of the silicone based releasing agent/ethyl cellulose was set on 25:75 instead of 75:25.
• Various characteristics of the casting film thus obtained are given in Table 1.
• Example 2 The procedure in Example 2 was repeated to prepare a casting film except that the solid content ratio by weight of the silicone based releasing agent/ethyl cellulose was set on 5:95 instead of 75:25.
• Various characteristics of the casting film thus obtained are given in Table 1.
• PM-10A in an amount of 5 parts by weight based on 100 parts by weight of the silicone based releasing agent, and a solution of carboxymethyl cellulose in water, while regulating the solid content ratio by weight of the silicone based releasing agent/carboxymethyl cellulose to 80:20 to prepare a coating solution having a solid content of 6% by weight.
• the coating solution was uniformly applied through gravure coat method, to a biaxially oriented PET film having a thickness of 38 ⁇ m so as to form a coating amount expressed in terms of solid content being 0.3 g/m 2 . Subsequently the coated PET film was heat-treated for 30 seconds in a hot air circulation type dryer at 120° C. to cure the coating solution and prepare a casting film.
• Various characteristics of the casting film thus obtained are given in Table 1.
• the coating solution was uniformly applied through gravure coat method, to a biaxially oriented PET film having a thickness of 38 ⁇ m so as to form a coating amount expressed in terms of solid content being 0.1 g/m 2 . Subsequently the coated PET film was heat-treated for 30 seconds in a hot air circulation type dryer at 110° C. to cure the coating solution and prepare a casting film.
• Various characteristics of the casting film thus obtained are given in Table 1.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Wood Science & Technology (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• Structural Engineering (AREA)
• Laminated Bodies (AREA)
• Producing Shaped Articles From Materials (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)
• Moulding By Coating Moulds (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=18693891

Family Applications (2)

Family Applications After (1)

Country Status (9)

Cited By (12)

Families Citing this family (11)

Family Cites Families (10)

• 2000
  • 2000-06-28 JP JP2000195196A patent/JP3910344B2/ja not_active Expired - Fee Related
• 2001
  • 2001-06-05 US US09/873,254 patent/US20020015850A1/en not_active Abandoned
  • 2001-06-05 SG SG200103697A patent/SG114490A1/en unknown
  • 2001-06-25 MX MXPA01006556A patent/MXPA01006556A/es active IP Right Grant
  • 2001-06-26 MY MYPI20013000A patent/MY127617A/en unknown
  • 2001-06-27 KR KR1020010036870A patent/KR100733651B1/ko not_active Expired - Fee Related
  • 2001-06-27 ID ID20010497D patent/ID30595A/id unknown
  • 2001-06-27 TW TW90115547A patent/TW546202B/zh not_active IP Right Cessation
  • 2001-06-28 CN CNB011218215A patent/CN1197703C/zh not_active Expired - Fee Related
• 2002
  • 2002-10-24 US US10/278,873 patent/US6890603B2/en not_active Expired - Lifetime

Also Published As

Similar Documents

Legal Events