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
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • 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
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
  • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
• • 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
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/302—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• • 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
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
• • 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
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • 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
  • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
• • 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
  • B32B2250/00—Layers arrangement
  • B32B2250/24—All layers being polymeric
• • 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
  • B32B2255/00—Coating on the layer surface
  • B32B2255/10—Coating on the layer surface on synthetic resin layer or on natural or synthetic rubber layer
• • 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
  • B32B2270/00—Resin or rubber layer containing a blend of at least two different polymers
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
  • B32B2307/202—Conductive
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
  • B32B2307/21—Anti-static
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
  • B32B2307/31—Heat sealable
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/40—Properties of the layers or laminate having particular optical properties
  • B32B2307/412—Transparent
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/54—Yield strength; Tensile strength
• • 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
  • B32B2405/00—Adhesive articles, e.g. adhesive tapes
• • 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
  • B32B2553/00—Packaging equipment or accessories not otherwise provided for

Definitions

• the present invention relates to a heat-sealing film and a cover tape which is made from the same and heat-sealable to a plastic carrier tape having storing pockets formed therein, which carrier tape is one of the packages having such a function that when electronic components are stored, transported or mounted, the electronic components are protected from contamination, and they are arranged and taken out for assembling on an electronic circuit substrate.
• peeling the cover tape from the carrier tape is called “peel-off strength", and when this strength is too low, there is such a problem that the cover tape gets off during the transportation of the package and the electronic components packed fall off.
• Antistatic property is another key property because the static could damage the electronic units, and could cause difficulties in the process. Transparency of the cover tape is also important because people need to check the status of the electronic component through the cover tape. Moreover, the cover tape should not contaminate the electronic component.
• the mechanism by which the cover tape now on the market peels from the carrier tape is classified into three types of interfacial peeling type, transfer-peeling type and cohesive failure type.
• the interfacial peeling type refers to such a type that the cover tape and the carrier tape are peeled from each other at the sealing face
• the transfer peeling type refers to such a type that the bonding layer per se is transferred to the carrier tape during the peeling
• the cohesive failure type refers to such a type that a layer different from the bonding layer or the bonding layer per se (the two being referred to hereinafter as the cohesive failure layer) is broken to cause peeling.
• each of these types has both merits and demerits; however, when they are compared only in respect of the state in which the cover tape sealed to the carrier tape is peeled, the interfacial peeling type tends to be affected by the shape, material and properties of the carrier tape because the sealing face and the peeling face are the same, and hence the peel-off strength tends to become instable.
• the bonding layer In the case of the transfer-peeling type, the bonding layer must be a thin film in view of the mechanism and the so-called heat-sealing lacquer must be used. Therefore, the peel-off strength tends to become sensitive to sealmg temperature, and hence sealing conditions for suitable peel-off strength are hardly obtained.
• the cohesive failure type In the case of the cohesive failure type, the sealing face and the peeling layer are different, and hence the dependency of the peel-off strength upon the sealing conditions is low. Also, the cohesive failure type has such a great advantage that the peel-off strength is not affected by the shape, material and properties of the carrier tape. However, in some cases, during the peeling, the cohesive failure layer is affected by a layer other than the cohesive failure layer including the bonding layer and interfacial peeling takes place without causing cohesive failure.
• the cohesive failure layer per se is designed so as to be easily broken, and hence in many cases, it is composed of a mixture of a plurality of resins which are hardly miscible with one another and these resins are not mixed uniformly. This results in a deterioration of the transparency of the cover tape and in a disadvantage due to agglomerates in some cases. Also, in such uses, a resin inferior in heat resistance is contained in the resin mixture in some cases. For these reasons, the agglomerates or degradation products appear during the formation of the cohesive failure layer and decrease the productivity in many cases.
• An object of the invention is to develop a heat-sealing film which can be cut into cover tapes, has stable peel-off strength, good antistatic performance, does not contaminate the electronic component and has a transparent appearance.
• Another object of the invention is to provide a cohesive failure type or transfer-peeling type cover tape made of the heat-sealing film. According to the invention, it provided a heat-sealing film for packaging an electronic element, comprising:
• At least one intermediate layer which is provided on the base layer and comprises a mixture comprising, in terms of 100% by weight of the total weight of the intermediate layer,
• At least a heat-sealing layer which is provided on the surface of the intermediate layer opposite to the base layer.
• the invention further provides a cover tape for heat-sealing to a carrier tape that comprises an electronic element, the cover tape comprising:
• the cover tape having an average optical transmittance of at least 75%, an optical haze of no more than about 50%, and a surface resistivity of no more than about 1 x 10 11 ; such that when the cover tape is heat-sealed to a carrier tape to form an article, an average peel strength of the cover tape to the carrier tape is at least 20 gf/mm, the peel strength reducing by no more than about 10% when the article is subjected to a temperature of no less than about 50 ° C and a relative humidity of no less than about 90% for at least 5 days.
• the antistatic heat-sealing film of the invention has an excellent electrostatic dissipation performance, a good optical performance, a good mechanical performance, as well as an excellent heat-sealing performance for the surfaces of the substrates of polycarbonate, polystyrene, polypropylene or the like.
• the thermosensitive cover tape made from the heat-sealing film of the invention has many advantages, such as, a permanent antistatic performance for both sides, a high light transmittancy, a low haze, a stable peel-off force with a carrier tape and an excellent sealing aging performance.
• thermosensitive cover tape In the case where the thermosensitive cover tape is utilized, the adhesive face after aging under high temperature and high humidity is not prone to adhere to the surface of the carrier tape, and a tape-opening problem is unlikely to be produced after the thermosensitive cover tape is sealed with the carrier tape.
• the adhesive layer After the cover tape made from the heat-sealing film is sealed with a earner tape, the adhesive layer will be left on the supporting tape upon peeling, and the adhesive layer can be separated from the functional layer.
• the cover tapes on market where the adhesive layer is separated from the carrier tape layer because the producing process has controlled the surface of the functional layer and the adhesive layer excellently, the excellent controllable peel-off effect of the cover tape product made by the method can be ensured. Additionally, the roughness of the surface of the carrier tape is relatively high, if the adhesive layer is separated from the carrier tape layer upon peeling, the stability of the peel-off force will be inferior.
• Figure 1 is a cross-section view of an antistatic heat-sealing film of the invention
• Figure 2 is a cross-section view of another antistatic heat-sealing film of the invention.
• Figure 3 is a cross-section view of a still another antistatic heat-sealing film of the invention.
• thermosensitive adhesive means a heat sealable polymeric resin.
• additional type cationic antistatic coating means a coating with antistatic performance obtained by adding a cationic antistatic agent into a coating.
• the present invention provides a heat-sealing film for packaging an electronic element, comprising:
• At least one intermediate layer which is provided on the base layer and comprises a mixture comprising, in terms of 100% by weight of the total weight of the intermediate layer,
• At least a heat-sealing layer which is provided on the surface of the intermediate layer opposite to the base layer.
• the base layer is mainly used to provide the mechanical strength of the film.
• the base layer is not particularly limited and the base layers commonly used to produce the heat-sealing films can be used in the invention.
• the base layer is selected from biaxial stretched polyesters, polyolefins or nylons.
• the base layer has a thickness of about 10-30 ⁇ .
• the film preferably has a optical transmittance not less than 85%, and a tensile strength not less than 50 MPa.
• the intermediate layer used in the heat-sealing film of the invention is relatively soft and can be conductive, which can be composed of a material in one layer or a plurality of layers.
• the polyethylene applicable to the intermediate layer is preferably a linear low density polyethylene (LLDPE), more preferably, a linear low density polyethylene with a weight-average molecular weight above 100,000 and a melt index (the testing condition is 190 °C ,2.16 kilograms, ASTM D1238) of 1-100 g/10 minutes.
• An applicable polyethylene is, for example, LLDPE(1002-YB) from Exxon Mobil.
• the polyethylene has a content of 0-60 wt%, preferably, 10-60%, more preferably, 20-60%, and most preferably, 50-60% in the intermediate layer.
• a suitable vinyl acetate copolymer is a vinyl acetate copolymer wherein the molar percentage of the vinyl acetate-derived units is at least 10%, preferably above 15%, most preferably above 20%.
• the suitable comonomer is preferably selected from olefins, more preferably, ethylene.
• the suitable vinyl acetate copolymer has a melt index (the testing condition is 190 ° C ,2.16 kilograms, ASTM D1238) of preferably 1-250 g/10 minutes, more preferably 1 -100 g/10 minutes, and most preferably 2-50 g/10 minutes.
• the vinyl acetate copolymer has a content of 5-70 wt%, preferably 5-50%o, more preferably 10-60%), more preferably 10-40%), further preferably 20-40% and most preferably 20-30%) in the intermediate layer.
• the styrene-butadiene copolymer applicable to the intermediate layer is preferably a block copolymer wherein the styrene-derived units comprise above 50 mole %, more preferably above 60 mole %>, and most preferably above 70 mole % of the total units of the copolymer.
• the suitable styrene-butadiene copolymer has a weight-average molecular weight of preferably 20000-500000, more preferably 40000-300000, and most preferably 50000-150000, as well as a molecular weight distribution of preferably 1-2.
• the styrene-butadiene copolymer comprises 20-90%), preferably 30-70% of the total weight of the intermediate layer.
• the intermediate layer has a thickness of preferably 10-50 microns and the surface thereof can be conductive by adding a conductive polymer as desired.
• the surface resistivity thereof can be less than 1 X 10 11 ohm/D, more preferably less than 1 X 10 10 ohm/D , and most preferably less than 1 X 10 9 ohm/D .
• the suitable conductive polymers include, but not limited to polyacetylene, polypyrrole, polythiophene, polyaniline, polyether amides-based or polyester amides-based intrinsic antistatic polymers or the like, or combinations thereof.
• an adhesion layer can be provided between the intermediate layer and the base layer.
• an adhesion layer is provided between the polyethylene layer and the base layer.
• the adhesion layer can be a common curable polyurethane type adhesive.
• the intermediate layer is mainly a polymer alloy formed by blend-extruding an ethylene- vinyl acetate copolymer, a styrene-butadiene block copolymer and a certain amount of an intrinsic conductive or antistatic polymer by an extruder.
• the surface resistivity of the layer is preferably 1 X 10 6 -1 X 10 14 ohm/rj.
• the ethylene type copolymer used in the intermediate layer can be poly (vinyl acetate).
• the poly (vinyl acetate) has a VA chain segment content above 10% and comprises 10-60 wt% of the polymer alloy in the whole functional layer.
• the styrene-butadiene copolymer to be used has a polystyrene chain segment content above 50%.
• the block copolymer has a weight average molecular weight of 20000-500000, as well as a molecular weight distribution of 1-2.
• the copolymer comprises 30-90 wt% of the polymer alloy in the whole functional layer.
• the intrinsic conductive or antistatic polymer to be used can be ICP (inherently conductive polymer) or IDP (inherently dissipative polymer), including polyacetylene, polypyrrole, polythiophene, polyaniline, polyether amides-based or polyester amides-based intrinsic antistatic polymers or the like, or combinations thereof, which comprises 0-40 wt% of the polymer alloy in the whole functional layer.
• ICP inherently conductive polymer
• IDP inherently dissipative polymer
• a heat-sealing layer (in the invention, it is also referred to as "thermosensitive adhesive layer") is provided on the surface of the intermediate layer opposite to the base layer.
• This heat-sealing layer can be composed of a material in one layer or a plurality of layers, and can be conductive or non-conductive as desired.
• the heat-sealing layer is composed of a material selected from polyacrylate or the copolymers thereof and the glass-transition temperature of the polymer should be above 30 ° C , more preferably above 60 ° C , and most preferably 70-90 ° C .
• the intermediate layer is not added with a conductive or antistatic polymer
• a certain amount of conductive particles can be added into the heat-sealing layer
• the heat-sealing layer can be a coating of polyacrylate or the copolymers thereof added with a certain amount of a conductive filler.
• the heat-sealing layer can have a thickness of 0.01- 10 microns and a surface resistivity of 1 X 10 7 -1 X 10 12 ohm/a, more preferably 1 X 10 7 -1 X 10 1 1 ohm/rj.
• the conductive filler can be a nanometer oxide, for example, titanium dioxide, silica, alumina, zinc oxide, tin oxide, antimony oxide, indium tin oxide or the like.
• the conductive filler can also be carbon nanotubes, carbon powder, metal powder or the like.
• the conductive filler particles added in the layer comprise preferably 0-60 wt%, more preferably 0-30 wt% of the whole thermosensitive adhesive layer.
• the polyacrylate or the copolymers thereof to be used in the heat-sealing layer has a preferable glass-transition temperature of 30-90 ° C and a preferable heat activation temperature of 90 ° C or more.
• an antistatic coating can be coated on a surface of the base layer.
• the dry film thickness of the antistatic coating can be, for example, 0.01-2 microns, preferably, 0.05-1 microns, and most preferably, 0.1-0.8 microns.
• the surface resistivity of the antistatic coating can be 1 X 10 6 — 1 X 10 12 ohm/n, more preferably, 1 X 10 9 ⁇ 1 X 10 11 ohm/ ' ⁇ .
• the antistatic coating on the base layer can be realized by a gravure coating process.
• the surface resistivity of the antistatic coating is not higher than 1 X 10 12 ohm/
• This coating can be an addition type cationic antistatic coating or a polymer grafting type cationic antistatic agent coating, and it can also be a polymer coating with relatively good temperature resistance added with a conductive filler.
• the conductive filler can be selected from metal oxides, carbon nanotubes or other conductive particles.
• Figure 1 is a cross-section view of a cover tape of an embodiment according to the invention.
• 2 is a base layer with a thickness of about 10-30 microns and is mainly used to provide the mechanical strength of the film.
• a surface of the base layer 2 is coated with an antistatic coating 1 with a dry film thickness of 0.01-2 microns and a surface resistivity of 1 X 10 6 ⁇ 1 X 10 12 ohm/D .
• the surface of the base layer 2 opposite to the antistatic coating 1 is cast with a functional layer 3 (in the invention, the functional layer means the intermediate layer) with a conductive surface.
• the functional layer 3 has a thickness of 10-50 microns and a surface resistivity of 1 X 10 3 ⁇ 1 X 10 10 o m/a.
• thermosensitive adhesive layer 4 (in the invention, the thermosensitive adhesive layer is equal to the heat-sealing layer) with a thickness of 0.01-10 microns and a surface resistivity of 1 X 10 5 -1 X 1012 ohm/D .
• the base layer 2 can be a plastic film with a certain mechanical strength selected from biaxial stretched polyesters, polyolefms or nylons. This film has a optical transmittance not less than 85%, and a tensile strength not less than 50 MPa.
• the antistatic coating 1 on the base layer is realized by a gravure coating process. When the environmental humidity is 50%, the surface resistivity of the surface is not higher than 1 X 10 ohm/ ⁇ .
• This coating can be an addition type cationic antistatic coating or a polymer grafting type cationic antistatic agent coating, and it can also be a polymer coating with relatively good temperature resistance added with a conductive filler.
• the conductive filler can be selected from metal oxides, carbon nanotubes or other conductive particles.
• the functional layer 3 is mainly a polymer alloy formed by blend-extruding an ethylene copolymer, a styrene-butadiene block copolymer and a certain amount of an intrinsic conductive or antistatic polymer by an extruder.
• the surface resistivity of the layer is 1 X 10 6 - 1 X 10 14 ohm/D .
• the thermosensitive adhesive layer 4 is mainly a coating of polyacrylate or the copolymers thereof added with a certain amount of conductive particles, which has a thickness of 0.01-10 microns and a surface resistivity of 1 X 10 -1 X 10 ohm/D .
• the ethylene type copolymer used in the functional layer 3 can be poly (vinyl acetate).
• the poly (vinyl acetate) has a VA chain segment content above 10% and comprises 10-60 wt% of the polymer alloy in the whole functional layer 3.
• the styrene-butadiene copolymer to be used has a polystyrene chain segment content above 50%.
• the block copolymer has a weight average molecular weight of 20000-500000, as well as a molecular weight distribution of 1-2.
• the copolymer comprises 30-90 wt% of the polymer alloy in the whole functional layer.
• the intrinsic conductive or antistatic polymer to be used can be ICP or IDP, including polyacetylene, polypyrrole, polythiophene, polyaniline, polyether amides-based or polyester amides-based intrinsic antistatic polymers or the like, or combinations thereof, which comprises 0-40 wt% of the polymer alloy in the whole functional layer.
• the polyacrylate or the copolymers thereof to be used in the thermosensitive adhesive layer 4 has a glass-transition temperature of 30-90 ° C and a heat activation temperature of 90 ° C or more.
• the conductive filler particles added in the layer comprise 0-60 wt% of the whole thermosensitive adhesive layer.
• the conductive filler can be a nanometer oxide, for example, titanium dioxide, silica, alumina, zinc oxide, tin oxide, antimony oxide, indium tin oxide or the like.
• the conductive filler can also be carbon nanotubes, carbon powder, metal powder or the like.
• Figure 2 is a cross-section view of another cover tape of the invention.
• a surface of a base layer 2 is coated with an antistatic coating 1.
• the surface of the base layer 2 opposite to the antistatic coating 1 is coated with a functional layer 3 via an adhesion layer 5.
• the surface of the functional layer 3 opposite to the adhesion layer 5 is coated with a thermosensitive adhesive layer 4.
• Figure 3 is a cross-section view of still another cover tape of the invention.
• a surface of a base layer 2 is coated with an antistatic coating 1.
• a polyethylene layer 6 and a functional layer 3 are blowing formed by coextrusion.
• a surface of the polyethylene layer 6 is combined with the base layer 2 via an adhesion layer 5.
• the surface of the functional layer 3 opposite to the polyethylene layer 6 is coated with a thermosensitive adhesive layer 4.
• the invention further provides a cover tape for heat-sealing to a carrier tape that comprises an electronic element, the cover tape comprising:
• the cover tape having an average optical transmittance of at least 75%, an optical haze of no more than about 50%, and a surface resistivity of no more than about 1 x 10"; such that when the cover tape is heat-sealed to a carrier tape to form an article, an average peel strength of the cover tape to the carrier tape is at least 20 gf/mm, the peel strength reducing by no more than about 10% when the article is subjected to a temperature of no less than about 50 ° C and a relative humidity of no less than about 90% for at least 5 days.
• thermosensitive cover tape of the invention has many advantages, such as, a permanent antistatic performance for both sides, a high light transmittance, a low haze, a stable peel-off force with a carrier tape and an excellent sealing aging performance.
• the adhesive face after aging under high temperature and high humidity is not prone to adhere to the surface of the carrier tape, and a tape-opening problem is unlikely to be produced after the thermosensitive cover tape is sealed with the carrier tape.
• the adhesive layer will be left on the supporting tape upon peeling, and the adhesive layer can be separated from the functional layer.
• a switch is adjusted to a desired voltage position ( 10 V or 100 V) and a testing button is pressed persistently with a pressure of about 5 pounds. Then a LCD screen will show the measured surface resistivity.
• the unit of the surface resistivity is ohm/D .
• Optical transmittance and haze they are measured by a haze meter HM- 150.
• Peel-off force at 180° A 5.4 mm-wide cover tape and a 8 mm-wide carrier tape are sealed at 160 ° C by a heat-sealing machine. Then, the peel-off force at 180° is measured by a peel-off force testing meter PT-45.
• Aging test for peel-off force at 180° A 5.4 mm-wide cover tape and a 8 mm-wide carrier tape are sealed at 160 ° C by a heat-sealing machine. Then, the peel-off force at 180° is measured by a peel-off force testing meter PT-45; Put the sample into an aging chamber at 52 ° C/95rh%, after 5days aging, the sample is taken out and do the peel-off force test.
• Aging test for anti-sticking property at 60 ° C A sample to be tested is adhered to a surface of a polycarbonate sheet and both sides thereof are fixed by an adhesive tape. The obtained sample is put into an aging box at 60 ° C . After a period of time, the sample is taken out and observed whether an adhesion phenomenon occurs on the heat-sealing film and the surface of the polycarbonate sheet.
• a 16 ⁇ -thick single side corona discharge treated biaxial stretched polyester thin film was prepared.
• the corona discharge treated surface was coated with a primer coating of polyurethane type with a thickness of about 0.2 ⁇ , and then baked in an oven.
• a prepared polymer alloy for a functional layer was melt-coated on the polyester thin film coated with the primer coating, and then the obtained product was subjected to cooling and winding.
• the functional layer had a thickness of 30 ⁇ and a surface resistivity of 1 X 10 9 ohm/D .
• An antistatic coating solution with a solid content of 5% (K 104A-2, Qingdao Trade Import and Export Co., Ltd.) was coated on a PET surface of the heat-sealing film opposite to the functional layer, and was baked on an oven for curing.
• the antistatic coating had a dry film thickness of 0.2 ⁇ and a surface resistivity of 1 X 10" o m/a under an environment of normal temperature and normal humidity.
• the optical transmittance thereof was 85%
• the haze value thereof was 10%
• the surface resistivity on the surface of the thermosensitive adhesive was I X 10 10 ohm/D
• the surface resistivity on the other surface was 1 X 10 11 ohm/ ⁇ .
• a 16 ⁇ -thick single side corona discharge treated biaxial stretched polyester thin film was prepared.
• the corona discharge treated surface was coated with a primer coating of polyurethane type with a thickness of about 0.2 ⁇ , and then baked in an oven.
• a prepared polymer alloy for a functional layer was melt-coated on the polyester thin film coated with the primer coating, and then the obtained product was subjected to cooling and winding.
• the functional layer had a thickness of 30 ⁇ and a surface resistivity of 1 X 10 9 ohm/a .
• An antistatic coating solution with a solid content of 5% (K 104A-2, Qingdao Trade Import and Export Co., Ltd.) was coated on a PET surface of the heat-sealing film opposite to the functional layer, and was baked on an oven for curing.
• the antistatic coating had a dry film thickness of 0.2 ⁇ and a surface resistivity of 1 X 10 11 ohm/ ⁇ under an environment of normal temperature and normal humidity.
• the optical transmittance thereof was 85%
• the haze value thereof was 10%
• the surface resistivity on the surface of the thermosensitive adhesive was 1 X 10 10 ohm/D
• the surface resistivity on the other surface was 1 X 10 11 ohm/D.
• a styrene-butadiene block copolymer (CHI MEI, PB-5903), 20 kg of a poly(vinyl acetate) (HyunDai, VA60), and 0.4 kg of an antioxidant A5 (Jinhai Albemarle, Shanghai Jinhai Albemarle Fine Chemicals Co,. Ltd.) were uniformly stirred, and melt mixed at 180 ° C , and then subjected to cooling and granulation for further application.
• CHI MEI styrene-butadiene block copolymer
• HyunDai poly(vinyl acetate)
• an antioxidant A5 Jinhai Albemarle, Shanghai Jinhai Albemarle Fine Chemicals Co,. Ltd.
• a prepared material for a functional layer was formed into a film by blow molding and wound for further application.
• the thickness of the thin film was 35 ⁇ .
• a 12 ⁇ -thick single side corona discharge treated biaxial stretched polyester thin film was prepared.
• the corona discharge treated surface was coated with a polyurethane glue (35%, adhesive from MITSUI TAKEDA CHEMICALJNC, A-969V/A-5 is 3/1).
• the glue had a thickness of about 2 ⁇ after baking.
• a prepared functional layer thin film was combined with a surface of the polyester thin film coated with the glue and then cured at room temperature.
• An antistatic coating solution with a solid content of 5% (K104A-2, Qingdao Trade Import and Export Co., Ltd.) was coated on a PET surface of the heat-sealing film opposite to the functional layer, and was baked on an oven for curing.
• the antistatic coating had a dry film thickness of 0.2 ⁇ and a surface resistivity of 1 X 10 11 ohm/D under an environment of normal temperature and normal humidity.
• the optical transmittance thereof was 75%
• the haze value thereof was 10%
• the surface resistivity on the surface of the thermosensitive adhesive was 1 X 10 9 ohm/ ⁇
• the surface resistivity on the other surface was 1 X 10 11 ohm/a.
• styrene-butadiene block copolymer 60 kg
• 40 kg of a poly( vinyl acetate) 40 kg
• a poly( vinyl acetate) (HyunDai , VA60)
• an antioxidant A5 Jinhai Albemarle, Shanghai Jinhai Albemarle Fine Chemicals Co,. Ltd.
• a prepared material for a functional layer and a linear low density polyethylene LLDPE (1002-YB, Exxon Mobil) were coextruded and formed into a film by a specific method and then wound for further application.
• the thin film had a total thickness of 35 ⁇ , wherein the thickness of the functional layer was 12 ⁇ and the thickness of the polyethylene layer was 23 ⁇ .
• a 12 ⁇ -thick single side corona discharge treated biaxial stretched polyester thin film was prepared.
• the corona discharge treated surface was coated with a polyurethane glue (35%, adhesive from MITSUI TAKEDA CHEMICAL,INC, A-969V/A-5 is 3/1).
• the glue had a thickness of about 2 ⁇ after baking.
• the polyethylene surface of the two-layered thin film as described above was combined with a surface of the polyester thin film coated with the glue and then cured at room temperature.
• the surface of the thermosensitive adhesive layer had a surface resistivity of 1 X 10 9 ohm/a. 4.
• An antistatic coating solution with a solid content of 5% (K104A-2, Qingdao Trade Import and Export Co., Ltd.) was coated on a PET surface of the heat-sealing film opposite to the functional layer, and was baked on an oven for curing.
• the antistatic coating had a dry film thickness of 0.2 ⁇ and a surface resistivity of 1 X 10 11 o m/a under an environment of normal temperature and normal humidity.
• the optical transmittance thereof was 85%
• the haze value thereof was 15%
• the surface resistivity on the surface of the thermosensitive adhesive was 1 X 10 9 ohm/rj
• the surface resistivity on the other surface was 1 X 10 11 ohm/a.
• a styrene-butadiene block copolymer (CHI MEI, PB-5903), 75 kg of a poly( vinyl acetate) (HyunDai, VA60), 45 kg of an intrinsic antistatic polymer (IDP:PolyNova PNC300R-M) and 0.6 kg of an antioxidant A5 (Jinhai Albemarle, Shanghai Jinhai Albemarle Fine Chemicals Co,. Ltd.) were uniformly stirred, and melt mixed at 180 ° C , and then subjected to cooling and granulation for further application.
• CHI MEI styrene-butadiene block copolymer
• HyunDai poly( vinyl acetate)
• IDP intrinsic antistatic polymer
• an antioxidant A5 Jinhai Albemarle, Shanghai Jinhai Albemarle Fine Chemicals Co,. Ltd.
• a 16 ⁇ -thick single side corona discharge treated biaxial stretched polyester thin film was prepared.
• the corona discharge treated surface was coated with a primer coating of polyurethane type with a thickness of about 0.2 ⁇ , and then baked in an oven.
• a prepared polymer alloy for a functional layer was melt-coated on the polyester thin film coated with the primer coating, and then the obtained product was subjected to cooling and winding.
• the functional layer had a thickness of 30 ⁇ and a surface resistivity of 1 X 10 9 ohm/D .
• An antistatic coating solution with a solid content of 5% (K 104A-2, Qingdao Trade Import and Export Co., Ltd.) was coated on a PET surface of the heat-sealing film opposite to the functional layer, and was baked on an oven for curing.
• the antistatic coating had a dry film thickness of 0.2 ⁇ and a surface resistivity of 1 X 10 11 ohm/a under an environment of normal temperature and normal humidity.
• the optical transmittance thereof was 85%
• the haze value thereof was 10%
• the surface resistivity on the surface of the thermosensitive adhesive was 1 X 10 10 ohm/a
• the surface resistivity on the other surface was 1 X 10 11 ohm/ ⁇ .
• styrene-butadiene block copolymer CHI MET PB-5903
• 70 kg of a poly(vinyl acetate) HyunDai , VA60
• an antioxidant A5 Jinhai Albemarle, Shanghai Jinhai Albemarle Fine Chemicals Co,. Ltd.
• a prepared material for a functional layer and a linear low density polyethylene LLDPE (1002-YB, Exxon Mobil) were coextruded and formed into a film by a specific method and then wound for further application.
• the thin film had a total thickness of 35 ⁇ , wherein the thickness of the functional layer was 12 ⁇ and the thickness of the polyethylene layer was 23 ⁇ .
• a 12 ⁇ -thick single side corona discharge treated biaxial stretched polyester thin film was prepared.
• the corona discharge treated surface was coated with a polyurethane glue (35%, adhesive from MITSUI TAKEDA CHEMICAL,INC, A-969V/A-5 is 3/1).
• the glue had a thickness of about 2 ⁇ after baking.
• the polyethylene surface of the two-layered thin film as described above was combined with a surface of the polyester thin film coated with the glue and then cured at room temperature.
• An antistatic coating solution with a solid content of 5% (K 104A-2, Qingdao Trade Import and Export Co., Ltd.) was coated on a PET surface of the heat-sealing film opposite to the functional layer, and was baked on an oven for curing.
• the antistatic coating had a dry film thickness of 0.2 ⁇ and a surface resistivity of 1 X 10 11 ohm/a under An environment of normal temperature and normal humidity.
• the optical transmittance thereof was 85%
• the haze value thereof was 15%
• the surface resistivity on the surface of the thermosensitive adhesive was 1 X 10 9 ohm/a
• the surface resistivity on the other surface was 1 X 10 11 ohm/a .
• the peel-off force at 180° can be increased by increasing the content of the styrene-butadiene block copolymer, while the fluctuating scope of the peel-off force is kept constant substantially.
• a conductive polymer is added into the functional layer, because the heal-sealing layer is very thin, the surface resistivity of the surface will change a little and will still remain in 1 X 10 12 ohm/n. If the glass-transition temperature of the heat-sealing layer is increased adequately, the anti-sticking effect of the cover tape can be improved. If inorganic filler is added into the heat-sealing layer, the cover tape can be provided with an antistatic property and increased anti-sticking effect, but the haze value thereof is increased at the same time.

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• 2010
  • 2010-12-17 WO PCT/CN2010/079964 patent/WO2012079258A1/en active Application Filing
  • 2010-12-17 CN CN201080070735.1A patent/CN103260873B/zh active Active
  • 2010-12-17 JP JP2013543491A patent/JP5762556B2/ja not_active Expired - Fee Related
  • 2010-12-17 MY MYPI2013002143A patent/MY190586A/en unknown
• 2011
  • 2011-12-16 TW TW100146984A patent/TWI584951B/zh not_active IP Right Cessation

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