Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/0006—Cover layers for image-receiving members; Strippable coversheets
  • G03G7/002—Organic components thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/0427—Coating with only one layer of a composition containing a polymer binder
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/043—Improving the adhesiveness of the coatings per se, e.g. forming primers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/04—Coating
  • C08J7/044—Forming conductive coatings; Forming coatings having anti-static properties
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/0006—Cover layers for image-receiving members; Strippable coversheets
  • G03G7/002—Organic components thereof
  • G03G7/0026—Organic components thereof being macromolecular
  • G03G7/004—Organic components thereof being macromolecular obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/006—Substrates for image-receiving members; Image-receiving members comprising only one layer
  • G03G7/0073—Organic components thereof
  • G03G7/008—Organic components thereof being macromolecular
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
  • G11B5/62—Record carriers characterised by the selection of the material
  • G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
  • G11B5/739—Magnetic recording media substrates
  • G11B5/73923—Organic polymer substrates
  • G11B5/73927—Polyester substrates, e.g. polyethylene terephthalate
  • G11B5/73929—Polyester substrates, e.g. polyethylene terephthalate comprising naphthalene ring compounds, e.g. polyethylene naphthalate substrates
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
  • G11B5/62—Record carriers characterised by the selection of the material
  • G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
  • G11B5/739—Magnetic recording media substrates
  • G11B5/73923—Organic polymer substrates
  • G11B5/73927—Polyester substrates, e.g. polyethylene terephthalate
  • G11B5/73931—Two or more layers, at least one layer being polyester
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
  • C08J2367/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds

Definitions

• This invention is directed to an improved polyester film having excel- lent antistatic properties as well as improved mechanical strength and stiff ⁇ ness, and dimensional stability and to a method for producing such film. More specifically, the invention deals with improved biaxially oriented co ⁇ polyester films having improved antistatic properties coupled with altered surface properties which render the film printable or coatable with additional coatings such as photosensitive compositions, while exhibiting the improved dimensional and mechanical properties.
• PET biaxially oriented polyethylene terepht- halate
• PET polyethylene terepht- halate
• Another problem associated with the use of such film is the tendency of these materials to accumulate an electrostatic charge on the surface as the result of handling or processing of the film, particularly at low relative humidity. This electrostatic charge attracts not only dust and other contaminants, but additionally attracts other film.
• electrostatic charges may interfere with the colla- ting, sorting and developing of microfiche cards or transparent supports and cause these materials to stick together.
• Antistatic films have been develo ⁇ ped.
• Antistatic films are usually formed by the application of an antistatic coating onto the surface of the film. Many of these coatings have success- fully reduced the electrostatic charging properties of the film to satisfactorily low levels. However, many of these coatings can cause blocking. That is, the film coated with an antistatic layer has a coefficient of friction high enough so that one layer of the film does not slip over another or over rollers and other equipment over which the film moves during manufacture and use.
• U.S. Pat. No. 4,214,035 teaches the application to PET film of an antistatic coating based on a mixture of stearamidopropyldimethyl- ?-hydroxyethylam- monium nitrate and a cross-linkable acrylic terpolymer binder, present in an approximately three to one ratio respectively.
• the antistatic surface of such film is not readily susceptible to the application of additional coatings, parti ⁇ cularly in reprographic applications.
• A is lower alkyl
• R is an aliphatic radical having 1 to 22 carbons
• x and y are integers having the sum of 2 to 5
• X " is an anion.
• plastic film material having improved antistatic properties as well as good blocking properties and low haze.
• Another object is to provide an antistatic coating on at least one surface of a film providing improved dimensional and mechanical stability, which coating may provide a suitable base coat or primer coat for the ap ⁇ plication of additional coatings.
• the present invention relates to an antistatic biaxially oriented PENBB film and the process for producing the film. More particularly, the present invention relates to an antistatic biaxially oriented PENBB film having excel- lent antistatic properties, and/or excellent adhesivity, and excellent mechani ⁇ cal and dimensional stability, and a process for producing the film.
• the improved mechanically and dimensionally stable PENBB base film of the present invention carries an antistatic coating composition containing
• U.S. Patent No. 3,008,934 disclo ⁇ ses copolyesters containing as acid derived units 4,4'-bibenzoate and a host of other dicarboxylates including 2,6-naphthalic dicarboxylate. It also disclo ⁇ ses oriented fibers and films prepared from these copolyesters, however, biaxially oriented PENBB films are not disclosed or envisioned. In particular, those films with improved stiffness (tensile modulus) and tensile strength in both MD and TD as well as thermostability, UV stability, hydrophobicity. dimensional stability and impermeability toward gases in comparison to PET film are not disclosed in U.S. Patent No. 3,008,934.
• the biaxially oriented copolyester film base for the purpose of this invention is made from PENBB.
• PENBB as mentioned hereinbefore is a copolyester containing as acid- derived unit at least 5 mole percent of a radical of the formula:
• PENBB is a copolyester wherein at least 80 mole percent of the acid derived units (NBB) consist of bibenzoate (20 to 80 mole percent, preferably 40 to 60 mole percent) and napthalate (80 to 20 mole percent, preferably 60 to 40 mole percent). The remaining 20 or less mole percent may consist of other acid derived units, which e.g. affect the melting point or the crystallization kinetics.
• NNB acid derived units
• napthalate 80 to 20 mole percent, preferably 60 to 40 mole percent
• the remaining 20 or less mole percent may consist of other acid derived units, which e.g. affect the melting point or the crystallization kinetics.
• at least 80 mole percent of the diol-derived units consist of - O(CH 2 ) 2 -O-units. The remaining
• 20 or less mole percent consist of other diol-derived units, which e.g. may also affect the melting point or the crystallization kinetics. It may also be desirable to replace minor amounts of the acid- and/or diol-derived units with hydroxycarboxylic-acid-derived units, e.g. such derived from p-hydroxyben- zoic acid.
• the IV value (inherent viscosi ⁇ ty, as measured in a 1 : 1 weight-ratio mixture of pentafluorophenol and hexafluoroisopropanol at a concentration of 0.2 g/dl and a temperature of 25 ° C) of the PENBB polymer after extrusion be > 0.5 dl/g and preferably > 0.55 dl/g.
• the polymer melt is extruded through a die onto a chill roll where it solidifies, is then biaxially oriented, heat set, optionally post treated and the wound on a roll.
• a chill roll for a multilayer film known methods for coextrusion, in-line or off-line coating can be used.
• the solidified film as extruded on the chill roll should be obtained in an essentially amorphous state.
• the melt film must be pinned to the chill roll by a known method such as electrostatic pinning or vacuum, air knife or the like.
• the biaxial orientation of the film is achieved by stretching the film at elevated temperature in the machine (MD) and transverse direction (TD). This stretching can be either simultaneous or sequential.
• the first stretching step can be in either MD or TD, followed by stretching in the other direction.
• the orientation in MD can also be achieved in several steps, either one after another prior to stretching in TD, or before and after the TD stretching.
• Preferred temperatures for stretching lie bet ⁇ ween the glass transition temperature (T g ) and about 30°C above the cold crystallization temperature (T cc ) of the PENBB copolymer composition in use (both temperatures can easily be measured on amorphous films by DSC).
• the total stretch ratios ( ⁇ ) in MD and TD lie between 1 : 2 and 1 : 10, prefe ⁇ rably between 1 : 2.5 and 1 : 5.
• the product of the total stretch ratios should be between 1 to 30 preferably between 5 to 20.
• Biaxial drawing is performed such that the birefringeance is ⁇ 0.2, preferably ⁇ 0.1 to ensure adequately isotropic properties.
• Birefringeance as mentioned herein is the absolute value of the difference between the maximum and minimum refracti ⁇ ve indices in the plane of the film, as measured on common instruments such as Abbe refractometer, optical bench or compensators.
• relaxation steps can be included in the orientation and heat setting processes.
• the heat setting takes place at a temperature between the cold crystal ⁇ lization temperature (T cc ) and the melt temperature (T m ) of the copolymer composition.
• T cc cold crystal ⁇ lization temperature
• T m melt temperature of the copolymer composition.
• a surface treatment such as corona, plasma or flame treatment should be employed before winding the film on a roll.
• the film Prior to coating the biaxially oriented PENBB film surface with the antistatic coating composition, the film may be surface treated in a conven- tional manner by exposure to, e.g. an electric corona discharge, plasma or flame treatment.
• Electric corona discharge is a conventional surface treat ⁇ ment which is commonly performed on films to enhance their surface quali ⁇ ties, especially their adhesive and printing properties.
• Electronic corona discharge methods and apparatus are described in U.S. Patent Nos. 3,057,792 and 4,239,973. If the corona treatment followed by the coating occurs before stretch orientation, heating the film before stretch orientation will drive off the water.
• the corona treat ⁇ ment followed by the antistatic coating may occur during the in-line manu ⁇ facturing process, either before stretch orientation, or between the machine draw and transverse draw of biaxial stretch orientation, or after biaxial stretch orientation. If the corona treatment and coating steps occur after stretch orientation, it is necessary to completely dry the PENBB film before winding. If the corona treatment and coating occur before orientation, or between draw during orientation, the later orientation steps which require the film to be heated would drive off the excess water from the antistatic coa ⁇ ting. Preferably, for biaxially oriented FENBB film the corona treatment and subsequent antistatic coating occur between draws during the stretch orien ⁇ tation step.
• the PENBB film is coated on the electric corona discharge treated surface preferably with an aqueous dispersion of the antistatic coating com ⁇ position described below.
• the coating composition may conveniently be applied as an aqueous dispersion or emulsion using any of the well known coating techniques.
• the film may be coated by roller coating, spray coating, gravure coating, or slot coating.
• the heat applied to the film during the subsequent preheating, stretching, and heat setting stages is generally sufficient to evaporate the water and cross-link the antistatic coating, if a cross-linkable monomer comprises a portion of the antistatic coating.
• the coated, biaxially oriented PENBB film may then be heat treated for a period of time necessary to crystallize the film. Crystallization imparts the improved dimensional stability and excellent tensile properties to the PENBB film.
• the so coated crystallized, biaxially oriented PENBB film is then wound onto a roll.
• the antistatic coating can be composed of: I. a composition containing a quarternary ammonium salt (QAS), or II. a composition containing an acrylate, styrene derivative or acrylonitrile and an eth ⁇ lenically unsaturated sulfonate salt, or III. a composition containing an organically substituted phosphate.
• QAS quarternary ammonium salt
• the abovementioned coating compositions are preferably dissolved or dispersed in a liquid medium, such as water, alcohols, ethers, ketones and the like.
• a liquid medium such as water, alcohols, ethers, ketones and the like.
• the following data on weight ratios refer to the solids content of the solutions or dispersions only.
• the solids content of the solutions or dispersion depends on the film use intended and the physical parameters of the solutions/dispersions and may vary from about 1 to 99 wt.-%, preferably 5 to 70 wt.-%.
• the QAS is of the formula
• R 1 is stearamido, -N + (R 5 ),X '
• R 6 , R 7 , R 8 being identical or
• R 2 , R 3 , R 4 are identical or different and denote H, C
• X ' is an anion selected from the group consisting of halogens, sulfates, sulfonates, alkyl sulfonates, carbonates, alkyl carbonates, nitrates, phospha ⁇ tes, alkyl phosphates, and mixtures thereof and n is an integer ranging from 1 to 8.
• Preferred QAS are those wherein R 1 is N(CH 3 ) 3 + or an acryiate or methacrylate radical, R 2 and R 3 are 0,-0 4 alkyl, especially preferred -CH 3 , R 4 is -CH 3 , -CH 2 CH 2 OH, C 14 -C 18 alkyl, especially tallow, X " is 01 ' , C--C 3 alkyl sulfate, especially methyl sulfate or tosylate, and n is 3. Moreover, it is preferred that the QAS is present in the composition in an amount of from about 10 to 80 wt.-% (based on the total weight of the active ingredients of the coating composition). The remainder of the active part of the composition (20 to 90 wt.-%) is a polymeric binder. It may further be desirable to include a suitable self-cross-linking moiety in an amount of up to about 10 wt.-% in the binder.
• composition containing the acryiate, styrene derivati ⁇ ve or acrylonitrile (II) these are of the formula
• R 9 is -H or -CH 3 and R 0 is -COOR 11 (with R 11 being an alkyl group of 1 to 20 carbon atoms), phenyl or -ON.
• the ethylenically unsaturated sulfonate salt is preferably one according to the formula:
• R 12 , R 13 and R 14 are -H or C C 4 alkyl
• R 15 is di-C,-C 3 -alkylene amine ether or thioether, p-phenylene, 0,-0 3 alkyl amido, C,-C 3 -carboxy or C,-C 6 alkylene, Y is an alkali metal or -NH(R 16 ) 2 with R 16 being H or C,-C 3 alkyl and m being 0 or 1.
• H 2 C C- coo H ⁇ - S0 3 Ns
• the composition contains the acryiate, styrene derivative or acryloni trile in about equal amounts based on weight as the ethylenically unsatur ⁇ ated sulfonate salt.
• the acryiate based part of the composition II contains a suitable self- cross-linking moeity in an amount of from about 1 to 10 wt.-% based on the acryiate part of the composition.
• the acryiate based part of composition II may contain up to 5 wt.-% of an ethylenic compound having a carboxy group, which com ⁇ pound is different from the acryiate described above.
• Suitable ethylenic carboxy-containing compounds are a- ⁇ -mono- or di-unsaturated carboxylic acids having 3 to 5 carbon atoms, either in the form of the free acids or their anhydrides or C,-C 3 alkyl esters.
• the acrylic part of the composition II may include 0 to
• copolymerizable compounds may include, for example, amides of ethylenic carboxylic acids, such as acrylamide, methacrylamide, diaceto- ne acrylamide and the like; esters between an ethylenic carboxylic acid and an epoxy group-containing alcohol, such as glycidyl acryiate, glycidyl me- thacrylate and the like; hydroxyalkyl esters of ethylenic carboxylic acids, such as 2-hydroxyethyl acryiate, 2-hydroxypropyl acryiate, 2-hydroxyethyl methacrylate and the like; esters between ethylenic carboxylic acid and amino group-containing alcohol, such as dimethylaminoethyl methacrylate, diethylaminoethy
• the ethylenically unsaturated sulfonate salt part of composition II may include 0 to 70 wt.-% (based on the ethylenically unsaturated sulfona ⁇ te salt part of the composition) of a different compound copolymerizable with the ethylenically unsaturated sulfonate salt.
• Such compounds may include ⁇ JJ-mono- or diunsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, citraconic acid, itaconic acid, maleic acid, fumaric acid and the like; anhydrides of cr, ?-diunsaturated carboxylic acids, such as maleic anhydride and the like; monoalkyl esters of ⁇ , ?-diunsatur- ated carboxylic acids, such as monobutyl maleate, monobutyl fumarate.
• carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, citraconic acid, itaconic acid, maleic acid, fumaric acid and the like
• anhydrides of cr ?-diunsaturated carboxylic acids, such as maleic anhydride and the like
• monoalkyl esters of ⁇ , ?-diunsatur- ated carboxylic acids such as monobutyl maleate, monobutyl fum
• these phosphates are of the formula:
• R 17 is C,-C, 0 alkyl
• R 18 is C.
• M is alkali metal, ammonium, an amine cation or hydrogen.
• the organically substituted phosphates according to the above for- mula are present in the coating composition III in an amount of from about 12 to 100 %, preferably 50 to 75 % by weight based on the weight of the coating composition.
• the remaining portion of the composition is a suit ⁇ able polymeric binder.
• Suitable polymeric binders which may be used include acrylic or methacrylic polymers such as polymethylmethacrylate, copolymers of me ⁇ thyl methacrylate with acrylates such as ethyl acryiate or butyl acryiate, and terpolymers of methyl methacrylate, ethyiacrylate and either acrylami ⁇ de or methacrylamide, or either N-methylolacrylamide or N-methylolmetha- crylamide. In many cases it is desirable that the polymeric binder be cross- linkable.
• This may be accomplished by employing up to about 10 mole-% of a "self cross-linking" functional comonomer into the binder, such as N- methylolacrylamide, or by incorporating a suitable amount of cross linking agent such as melamine formaldehyde or urea formaldehyde condensate capable of reacting with a functional group present in the polymer chain, such as amido, carboxyl, epoxy or hydroxy groups.
• a self cross-linking functional comonomer such as N- methylolacrylamide
• Suitable binders include vinyl acetate polymers such as polyvinylacetate and copolymers based on vin ⁇ lacetate, copolymers containing polymerized vinylidene chlori ⁇ de, i.e., copolymers of vinylidene chloride, acrylic ester and itaconic acid as disclosed in U.S. Pat. No. 2,698,240; and vinylaromatic polymers such as polystyrene, copolymers containing polymerized styrene and polyurethane resin produced from c ⁇ cloaliphatic, araliphatic, aromatic or preferably an aliphatic polyisocyanate.
• vinyl acetate polymers such as polyvinylacetate and copolymers based on vin ⁇ lacetate, copolymers containing polymerized vinylidene chlori ⁇ de, i.e., copolymers of vinylidene chloride, acrylic ester and itaconic acid as disclosed in U.S. Pat. No. 2,698,240
• Suitable polyfunctional isocyanates include ethylene diisocyanate, 1 ,6-hexamethylene diisocyanate, isophorone diisocyanate, cyclohexane-1 ,4-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, p-xylylene diisocyanate, 1 ,4-phenylene diisocyanate, 2,4- toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane dii ⁇ socyanate, 2,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanates and 1 ,5-napthylene diisocyanate.
• 1 ,6-hexamethylene diisocyanate is particularly preferred.
• Mixtures of polyfunctional isocyana- tes may be used as well as polyfunctional isocyanates which have been modified by the introduction of urethane, allophanate, urea, biuret, carbo- diimide, uretonimine or isocyanurate residues.
• the polymeric polyol component of the polyurethane resin may be a member of any of the chemical classes of polymeric polyols used or propo ⁇ sed to be used in polyurethane formulations.
• the polymeric polyol may be a polycarbonate, polyesteramide, polyether, polythioether, polyacetal or polyolefin, but preferably a polyester.
• the polyester suitably comprises a copolyester, preferably derived from one or more, preferably aromatic, polycarboxylic acids and one or more polyhydric alcohols.
• Suitable aromatic polycarboxylic acids for incorporation into the polyester portion of the pol ⁇ urethane resin include phthaiic acid, isophthalic acid, terephthalic acid, 4,4'-bibenzoic acid and 2,6-naphthalic acid or the acid anhydrides or lower-alkyl (up to 10 carbon atoms) esters thereof.
• terephthalic acid isophthalic acid, 4,4'- bibenzoic acid and/or 2,6-naphthalic acid
• the aromatic dicarboxylic acid components may be present in an amount greater than 50 mole %, and preferably greater than 80 mole %, of the total acidic components of the polyester.
• the polyester may comprise at least one aliphatic or cycloaliphatic dicarboxylic acid, such as cyclohexane-1 ,4-dicarboxyiic acid, adipic acid, sebacic acid, trimeliitic acid and/or itaconic acid, and/or polyester-forming equivalents thereof.
• Adipic acid is particularly preferred.
• the aliphatic or c ⁇ cloaliphatic dicarboxylic acid components ma ⁇ be present in an amount of up to about 30 mole % preferabl ⁇ from 0 to 10 mole % of the total acidic components of the pol ⁇ ester.
• the pol ⁇ ester ma ⁇ additionall ⁇ comprise a sulphonated pol ⁇ carbox- ⁇ lic acid, for example, the ammonium and alkali metal, particularl ⁇ sodium, salts of 4-sulphophthalic acid, 5-sulpho-isophthalic acid and sulphoterepht- halic acid, or the acid anh ⁇ drides or lower alk ⁇ l (up to 10 carbon atoms) esters thereof.
• Such acids, or derivatives are available as alkali metal salts, particularl ⁇ the sodium sulphonate salt, and are convenientl ⁇ incorpo ⁇ rated in salt form into the pol ⁇ ester portion of the pol ⁇ urethane resin.
• the sulphonic acid component is preferabl ⁇ present in a concentration of from 0 to 20 mole %, particularl ⁇ from 1 to 10 mole %, of the total acidic com- ponents of the pol ⁇ ester.
• Suitable pol ⁇ h ⁇ dric alcohols for incorporation into the pol ⁇ ester in ⁇ clude aliphatic, c ⁇ cloaliphatic and aromatic alk ⁇ lene gl ⁇ cols, such as eth ⁇ le ⁇ ne gl ⁇ col, 1 ,2-prop ⁇ lene gl ⁇ col, neopent ⁇ l gl ⁇ col, c ⁇ clohexane-1 ,4-dimetha- nol and 1 ,3-propane diol, and particularl ⁇ aliphatic alk ⁇ lene-ox ⁇ -gl ⁇ cols, such as dieth ⁇ lene gl ⁇ col.
• eth ⁇ lene gl ⁇ col and/or dieth ⁇ lene gl ⁇ col ma ⁇ also be emplo ⁇ ed.
• the pol ⁇ hydric alcohol is present in a stoichiometricall ⁇ equivalent amount of approximately 100 mole %.
• the pol ⁇ ester ma ⁇ be modified b ⁇ the inclusion therein of one or more monoh ⁇ dric alcohols, such as eth ⁇ lene gl ⁇ col monobut ⁇ l ether, benz ⁇ l alcohol and c ⁇ clohexanol.
• a preferred pol ⁇ ester for incorporation into the pol ⁇ urethane resin comprises residues of terephthalic acid, isophthalic acid, eth ⁇ lene gl ⁇ col, dieth ⁇ lene gl ⁇ col and optionali ⁇ a sulphonated polycarboxylic acid.
• Adipic acid may also be included in the polyester component.
• the polymeric polyol is of low molecular weight, particu ⁇ larly from about 450 to 9000, and particularly from about 900 to 4500.
• the pol ⁇ urethane resin ma ⁇ be made with one or more compounds containing a pluralit ⁇ of isoc ⁇ anate-reactive groups.
• a suitable additional iso ⁇ anate-reactive compound comprises an organic polyol, parti ⁇ cularly a short chain aliphatic polyol, preferably neopentyl gl ⁇ col.
• An or- ganic diamine, particularl ⁇ an aliphatic diamine, ma ⁇ also be included either independentl ⁇ or together with the organic pol ⁇ ol.
• a catal ⁇ st for urethane formation such as dibut ⁇ ltin dilau- rate and/or stannous octoate ma ⁇ be used to assist formation of the pol ⁇ u- rethane resin, and a non-reactive solvent ma ⁇ be added before or after for ⁇ mation of the medium to control viscosit ⁇ .
• Suitable non-reactive solvents which ma ⁇ be used include acetone, meth ⁇ leth ⁇ lketone, dimeth ⁇ lformami- de, eth ⁇ lene carbonate, prop ⁇ lene carbonate, digl ⁇ me, N-meth ⁇ lp ⁇ rrolidone, eth ⁇ l acetate, eth ⁇ iene and prop ⁇ lene gl ⁇ col diacetates, alk ⁇ l ethers of eth ⁇ lene and prop ⁇ lene gl ⁇ col monoacetates, toluene, x ⁇ lene and stericall ⁇ hindered alcohols such as t-butanol and diacetone alcohol.
• the preferred solvents are water-miscible solvents such as N-meth ⁇ lp ⁇ rrolidone, dimeth ⁇ l sulphoxide and dialk ⁇ l ethers of gl ⁇ col acetates or mixtures of N-meth ⁇ l- p ⁇ rroiidone and meth ⁇ l eth ⁇ l ketone.
• Other suitable solvents include vin ⁇ l monomers which are subsequentl ⁇ pol ⁇ merised.
• the pol ⁇ urethane resins are water dispersible, and a medium com ⁇ prising an aqueous pol ⁇ urethane dispersion ma ⁇ be prepared b ⁇ dispersing the water dispersible, pol ⁇ urethane resin in an aqueous medium, preferabl ⁇ in the presence of an effective amount of a pol ⁇ functional active h ⁇ drogen- containing chain extender.
• the resin ma ⁇ be dispersed in water using techniques well known in the art. Preferabl ⁇ , the resin is added to the water with agitation or, alter- nativel ⁇ , water ma ⁇ be stirred into the resin.
• the pol ⁇ functional active h ⁇ drogen-containing chain extender if emplo ⁇ ed, is preferabl ⁇ water-soluable, and water itself ma ⁇ be effective.
• Suitable extenders include a pol ⁇ ol, an amino alcohol, ammonia, a primar ⁇ or secondar ⁇ aliphatic, alic ⁇ clic, aromatic, araliphatic or heteroc ⁇ -root amine especiall ⁇ a diamine, h ⁇ drazine or a substituted h ⁇ drazine.
• chain extenders useful herein include eth ⁇ lene diamine, dieth ⁇ lene triamine, trieth ⁇ lene tetramine, prop ⁇ lene diamine, but ⁇ lene diamine, hexameth ⁇ lene diamine, c ⁇ clohex ⁇ lene diamine, piperazi- ne, 2-meth ⁇ l piperazine, phen ⁇ lene diamine, tol ⁇ lene diamine, x ⁇ l ⁇ lene diamine, tris (2-aminoeth ⁇ l) amine, 3,3'-dinitrobenzidine, 4,4'-meth ⁇ lene- bis(2-chloroaniline), 3,3'-dichloro-4,4'-biphen ⁇ l diamine, 2,6'-diaminop ⁇ ridi- ne, 4,4'-diaminodiphen ⁇ lmethane, menthane diamine, m-xylene diamine, isophorone diamine, and adducts of dieth ⁇ lene triamine with acr ⁇ late or its
• materials such as h ⁇ drazine, azines such as acetone azine, substituted h ⁇ drazines such as, for example, dimeth ⁇ l h ⁇ drazine, 1,6-hexameth ⁇ lene-bis-h ⁇ drazine, carbodih ⁇ drazine, h ⁇ drazides of dicarbox ⁇ lic acids and sulfonic acids such as adipic acid mono- or dih ⁇ - drazide, oxalic acid dih ⁇ drazide, isophthalic acid dih ⁇ drazide, tartaric acid dih ⁇ drazide, 1 ,3-phenylene disulfonic acid dih ⁇ drazide, ⁇ -amino-caproic acid dih ⁇ drazide, h ⁇ drazides made b ⁇ reacting lactones with h ⁇ drazines such as -h ⁇ droxylbutyric h ⁇ drazide, bis-semi-carbazide and bis-h ⁇ drazide carbonic
• chain extender is a substance other than water, for ex- ample a diamine or h ⁇ drazide, it ma ⁇ be added to the aqueous dispersion of the pol ⁇ urethane resin or, alternatively, it may already be present in the aqueous medium when the resin is dispersed therein.
• the pol ⁇ functional chain extender should be capable of intra-molecular cross-linking, to improve durabilityit ⁇ and resistance to sol- vents.
• Suitable resinous intra-molecular cross-linking agents comprise epox ⁇ resins, aik ⁇ d resins and/or condensation products of an amine, e.g.
• melamine diazine, urea, c ⁇ clic eth ⁇ lene urea, c ⁇ clic prop ⁇ lene urea, thiou ⁇ rea, c ⁇ ciic eth ⁇ lene thiourea, alk ⁇ l melamines, ar ⁇ l melamines, benzoguana- mines, guanamines, alk ⁇ l guanamines and ar ⁇ l guanamines with an aldeh ⁇ - de, e.g. formaldehyde.
• a useful condensation product is that of melamine with formaldehyde.
• the condensation product may optionally be partially or totally alkox ⁇ lated, the alkoxy group preferabl ⁇ being of low molecular weight, such as methox ⁇ , ethox ⁇ , n-butox ⁇ or iso-butox ⁇ .
• alkoxy group preferabl ⁇ being of low molecular weight, such as methox ⁇ , ethox ⁇ , n-butox ⁇ or iso-butox ⁇ .
• a hexamethox- ⁇ meth ⁇ l melamine condensate is particularl ⁇ suitable.
• Another particularl ⁇ suitable cross-linking agent is a pol ⁇ aziridine.
• Such pol ⁇ functional chain extenders preferabl ⁇ exhibit at least tri functionalit ⁇ (i.e. three functional groups) to promote inter-molecular cross- linking with the functional groups present in the pol ⁇ urethane resin.
• the chain extension ma ⁇ be conducted at elevated, reduced or am ⁇ bient temperature. Convenient temperatures are from about 5° to 95 " C or more, preferabl ⁇ from about 10" to about 45 * C.
• the amount of chain extender emplo ⁇ ed should be approximatel ⁇ equivalent to the free NCO groups in the resin, the ratio of active h ⁇ dro- gens in the chain extender to NCO groups in the resin preferabl ⁇ being in the range from 1-2 : 1.
• the antistatic la ⁇ er ma ⁇ be cross-linked to improve its durabilit ⁇ , hardness, cohesive strength and adhesion to the sub ⁇ strate, and to provide resistance to attack b ⁇ solvents.
• Cross-linking ma ⁇ be promoted b ⁇ incorporation into the antistatic composition of an ⁇ cross- linking agent known to be effective with the binder s ⁇ stem in use.
• Suit- able cross-linking agents include the conden ⁇ sation product of an amine with an aldeh ⁇ de.
• the condensation product is preferabl ⁇ aikox ⁇ lated, e.g. ethox ⁇ lated.
• a preferred cross-lin ⁇ king agent is a meth ⁇ lated melamine-formaldeh ⁇ de resin.
• the amount of cross-linking agent necessary to promote the required degree of cross-linking may be readily determined by simple experimenta- tion.
• the cross-linking agent suitable comprises up to 10% and preferably from 2 to 8%, by weight of the total components of the anti ⁇ static adherent composition.
• a preferred cata- I ⁇ st for use with an amine-formaldeh ⁇ de cross-linking agent comprises ammonium chloride, ammonium nitrate, phosphoric acid, citric acid, p- toluene sulphonic acid or p-dodec ⁇ lbenzenesulphonic acid.
• the antistatic coating compositions (I), (II) or (III) ma ⁇ be applied to one or both sides of the biaxially oriented PENBB film material at any suit ⁇ able stage during the manufacture, i.e., after extrusion of the sheet materi ⁇ al or before, during, or after biaxially orientation of the sheet.
• the resul- tant biaxially oriented PENBB film is found to posess markedly enhanced antistatic properties, good clarity good slip properties and ma ⁇ have good adhesive properties and durabilit ⁇ . In addition it exhibits improved mechani ⁇ cal, thermal, h ⁇ drol ⁇ tic and UV stabilit ⁇ in comparison to similarl ⁇ coated biaxially oriented PET film.

Landscapes

• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• General Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Laminated Bodies (AREA)
• Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)

Applications Claiming Priority (1)

Publications (2)

Family

ID=22231619

Family Applications (1)

Country Status (3)

Families Citing this family (3)

Citations (3)

Family Cites Families (1)

• 1992
  • 1992-12-09 WO PCT/US1992/010701 patent/WO1994013477A1/en not_active Application Discontinuation
  • 1992-12-09 EP EP93901464A patent/EP0674583A1/de not_active Withdrawn
  • 1992-12-09 JP JP6514083A patent/JPH08504384A/ja active Pending

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events