JP5187069B2 - Coated polyester film - Google Patents

Description

  The present invention relates to an aqueous coated polyester film comprising at least one hydrophilic polyester made from at least one dicarboxylic acid, polyalkylene glycol and a monofunctional alcohol. The film of the present invention is characterized by a unique hydrophilic surface, and this surface has a small contact angle with water and excellent hydrophilicity, and the hydrophilic property has water resistance, high temperature water resistance and resistance. Has outstanding properties for abrasion. Furthermore, this coated film has a feature that it is excellent in terms of manufacturing cost because it can use the self-regenerating polyester raw material in the manufacturing process without seriously deteriorating the quality.

  A biaxially oriented polyester film may be used as a diffusive cover film to cover a greenhouse as a cover film or to adjust the direction of light in the greenhouse. When a high humidity and a large temperature difference occur in the greenhouse, condensation occurs and water droplets are easily formed on the film. These drops can cause damage to sensitive plants by falling. The formation of relatively large water droplets on the cover film or diffusive cover film can be sufficiently avoided by using a hydrophilic coating layer. Since it is uneconomical to frequently replace the cover film or the diffusive cover film, when applying the hydrophilic coating layer, the hydrophilicity has water resistance, high temperature water resistance and abrasion resistance, It is desirable to have good sustained resistance of the adhesive coating layer.

  As a field where the surface needs to be hydrophilized, there are medical applications. In a diagnostic rod made of polyester film, the applied liquid such as blood must spread quickly and uniformly on the surface. This can be achieved using a hydrophilic coating layer. At this time, an important condition is that the components contained in the coating layer do not affect the progress of the diagnostic detection reaction. For example, when using nitrogen-containing substances (such as amines, amides or imides), such interfering influences due to changes in the pH value of the analyte liquid or in the form of complexing reactions of ions important for the detection reaction May occur. In order to be able to apply the hydrophilic coating film as universally as possible for diagnostic applications, the coating layer should not contain nitrogen-containing components. In addition, since the surface of the diagnostic rod is frequently exposed to mechanical loads (for example, when the diagnostic rod is inserted into the evaluation device), the coating layer is resistant to wear, eliminating variations in measurement results. can do.

  Another important area of application of biaxially oriented polyester films is transparent food packaging. When packaging food containing moisture with a polyester film, particularly in the case of a refrigerated product, there may be a disadvantage that the film becomes cloudy with water droplets. This phenomenon makes the packaged food very difficult to see. A decrease in transparency of the film can be avoided by a hydrophilic coating layer, also called an antifogging layer. Since food packaging is often sterilized by high temperature action for a short time, it is desirable that the hydrophilicity of the coating layer has good temperature resistance.

  The hydrophilic nature of the plastic surface can be realized, for example, using two different techniques. That is, adding an additive to the polymer and applying an antifogging layer to the film surface.

  Addition of additives to the polymer is possible for polyolefin products, particularly films (Patent Document 1, etc.). In this case, the principle of action is due to the movement of the additive, which is mostly an amphiphilic molecule, on the surface and the orientation of the polar ends of this molecule, so that it forms an inherently hydrophilic surface. Diversion of this principle to a polyester film is not possible due to the high polarity of the polyester.

  On the other hand, coating layers based on hydrophilic water-soluble polymers or surfactants are well known. In this case, since these are substances having chemical properties very different from those of polyester, the adsorption action of the coating layer to the polyester film is small, and the coating layer is easily washed away or scraped off. . The adsorptive action is often improved by coating layer components and optionally additives having crosslinkability on the polyester surface, although such crosslinked coating layers are no longer meltable, so the film produced during the film production process. You cannot play the chips.

  Nitrogen-containing components that limit the possibility of using coated films and cause yellowing when regenerating polyester films so coated are often also used in hydrophilic coating layers. It is uneconomical to produce such a coated film by in-line coating (coating within the film manufacturing process) without using the resulting film chips.

  Therefore, it is particularly suitable for in-line coating of biaxially oriented polyester film, has good properties for hydrophilic water resistance, high temperature water resistance and abrasion resistance, and properties of film when using coated film as recycled polyester raw material It is desirable to obtain a hydrophilic coating layer that does not deteriorate the thickness. However, so far, such a coating layer is not yet known.

  Patent Document 2 describes a transparent hydrophilic coating layer. The composition comprises a) polyvinylpyrrolidone, polydimethylacrylamide or a polyvinylpyrrolidone-copolymer with an α-olefin, b) a polyisocyanate-precursor polymer, c) a surfactant and d) an organic solvent. The disadvantage of this invention is that it uses a nitrogen-containing polymer, so the use of self-regenerating polyester raw materials in the film manufacturing process leads to yellowing of the new film, with limited use of coated films in the medical field. It becomes possible.

  Patent Document 3 describes a hydrophilic composition containing polyvinylpyrrolidone, polyvinyl alcohol, melamine as a crosslinking agent, and a mineral acid or a strong organic acid. Cross-linking to a hard transparent film requires a temperature of at least 75 ° C, and in this example a temperature of 130-150 ° C is used. This coating layer is therefore not suitable for in-line coating on polyester films because its components are already cross-linked during the drying or orientation of the film and thus the coating layer can tear and lead to film peeling. Because it is described that the cross-linked layer is hard, it is unsuitable for use on flexible substrates.

  Patent Document 4 describes a hydrophilic coating layer having a persistent resistance composed of silicon dioxide or zirconium dioxide nanoparticles carrying a hydrophilic side chain. The hydrophilic side chain can be a group such as amino, sulfonate, sulfato, sulfite, sulfonamide, sulfoxide, carboxylate, polyol, polyether, phosphato or phosphonate. In addition, the nanoparticles carry functional groups such as glycidyl, acryloyloxy, methacryloyloxy, glycidyloxy, allyl, vinyl, carboxy, mercapto, amide, amino, isocyano, hydroxy or silanol and are drying via these functional groups. The nanoparticles are crosslinked. The examples describe a drying time of 10 minutes to several hours at a temperature of 130-200 ° C. Therefore, this coating layer is not suitable for in-line coating of a polyester film in a production process for forming a film at high speed. Since the nanoparticles in the dry coating layer are cross-linked with each other, the film so coated does not melt and cannot be regenerated.

  Furthermore, a coating layer derived from hydrophilic polyester is known.

  Patent Document 5 describes a water-resistant coating layer composed of a polyester containing 40 to 90% by weight of hydrophilic polyether in the main chain and at least 3 equivalents of unsaturated structural units. The hydrophilic molecules can be radically cross-linked with each other through the structural unit. Since this coating layer cannot be melted due to crosslinking, the coated film cannot be regenerated.

Patent Document 6 describes a hydrophilic coating layer having a continuous resistance for fibers or fabrics, which is composed of a mixture of a hydrophilic copolyester with a polypropylene glycol compound. This hydrophilic polyester comprises polyalkylene diesters and 10-50% polyoxyethylene diester segments. Polypropylene glycol compounds composed of at least 4 propylene oxide units have a molecular weight of at least 300 g / mol and carry alkyl or ester end groups at one or both molecular ends. Alternatively, polypropylene glycols having a molecular weight _Mn greater than 1100 g / mol can be used. This coating solution may be water-soluble or may contain a solvent that cannot form hydrogen bridges. This coating layer should be equally suitable for surface modification of polyester, polyethylene and polypropylene fibers, but only polypropylene fabric is described in the examples. There is no disclosure of applicability for in-line application of biaxially oriented polyester films. There is no mention of the achievable contact angle or wear resistance of the coating layer.

  Patent Document 7 describes a stable hydrophilic coating layer for fibers, fabrics or wool products comprising a polyoxypropylamine or polypropylene oxide polymer having a carbamate end group or a hydrophilic polyoxypropylene glycol polyester. Yes. The coating layer can further comprise a hydrophilic copolyester composed of a polyalkylene diester and 10-50% polyoxyalkylene diester segments. According to Patent Document 7, this coating layer is suitable for hydrophilization of polyester, polypropylene, polyethylene, cotton, polyamide or polyaramid fiber, fabric or wool. Again, there is no disclosure regarding the applicability of the biaxially oriented polyester film for in-line coating, and there is a lack of mention of the achievable contact angle and wear resistance of the claimed coating layer.

International Publication No. 2002/0745535 (WO2002 / 0774535) JP 61-502762 A (US Pat. No. 4,467,073) Japanese translation of PCT publication No. 7-508059 (US Pat. No. 5,262,475) US Patent Application Publication No. 2004/0237833 JP 51-47070 (US Pat. No. 3,932,256) US Pat. No. 5,976,995 US Pat. No. 6,359,079

  An object of the present invention is to provide a transparent coated polyester film having hydrophilicity, specifically, a small contact angle with water, excellent hydrophilicity, hydrophilic water resistance, high temperature water resistance and resistance. A coating film that has outstanding characteristics with respect to abrasion, does not contain a nitrogen-containing component in the coating layer, and has a feature that yellowing is small despite the use of a self-regenerating polyester raw material during production. It is to provide.

  As a result of intensive studies in view of the above problems, the present inventors have found that the above problems can be easily solved by a film having a specific configuration, and have completed the present invention.

That is, the gist of the present invention, at least one dicarboxylic acid, have a dry film of the coating solution containing a hydrophilic polyester obtained from at least one polyalkylene glycol and at least one monofunctional alcohol, and water, and group polyester film comprising a timber includes a self-renewal polyester material, consists in applying a polyester film whose ratio is characterized der Rukoto 50% or less.

  According to the present invention, the water contact angle is small, the hydrophilicity is excellent, the hydrophilic water resistance, the high temperature water resistance and the abrasion resistance are outstanding, and the coating layer does not contain a nitrogen-containing component. In spite of using a self-regenerating polyester raw material during production, it is possible to provide a coated film having a feature that yellowing is small, and the industrial value of the present invention is high.

  Hereinafter, the present invention will be described in detail.

  For the coated polyester film of the present invention, an aqueous coating solution in which components such as an aqueous dispersion or a solution are uniformly mixed is used.

  The term “transparent” as used in the present invention means that the haze of the film increases by less than 0.8%, particularly less than 0.5%, depending on the coating layer. If the haze of the film is increased by 0.8% or more by the coating layer, the continuity of the coating layer may be impaired, and it may be difficult to obtain an excellent state in coating appearance. Furthermore, it may not be possible to provide sustained resistance to the hydrophilic properties of the coating (hydrophilic water resistance, high temperature water resistance and abrasion resistance).

  The small water contact angle and excellent hydrophilicity means that the contact angle formed between the coated polyester film surface and the water droplets placed is preferably less than 35 degrees, particularly less than 25 degrees. . If the water droplet contact angle is 35 degrees or more, water droplets can be formed on the surface when used in a greenhouse, causing damage to plants, blood, etc. not spreading quickly and uniformly when used in medical applications. When refrigerated for use, water droplets may form on the surface, making visual confirmation of the contents difficult.

  For the good properties of the coating layer on hydrophilic water resistance, high temperature water resistance and abrasion resistance, the good hydrophilic nature of the coated polyester film is due to moisture and / or high temperature water (95 ° C.) and / or mechanical It remains to be kept as completely as possible after the effects of loading. The contact angle of the coating layer with respect to water varies preferably by less than 15 degrees, in particular by less than 8 degrees, due to the influence of this load factor. If this change angle is 15 degrees or more, it may not be possible to provide continuous resistance of the coating film hydrophilic properties (hydrophilic water resistance, high temperature water resistance and abrasion resistance), There is a risk of hindering repeated use.

  The phrase “the coating layer does not contain a nitrogen-containing component” means that the coating solution contains a substance having a functional group such as amino, amide or imide, preferably less than 5% by weight, particularly less than 2% by weight. When these nitrogen-containing components are contained in the coating layer, when the coated polyester film is used as a recycled material, yellowing of the film tends to increase, and the film hue and roll appearance hue may increase.

  The fact that the yellowing is small despite the use of the self-regenerating polyester raw material at the time of production means that the yellowness of the polyester film used up to 50% of the self-regenerating polyester raw material produced from the coated film described in the present invention. In some cases, it is preferably less than 7, in particular less than 5.

  In the coating liquid composition of the present invention, at least a polycondensation compound comprising at least a polyfunctional carboxylic acid or an anhydride thereof, a polyalkylene glycol and a monofunctional alcohol is used as the hydrophilic polyester.

  Particular preference is given to using aliphatic or aromatic dicarboxylic acids with 2 to 12 carbon atoms as carboxylic acids. Examples of aliphatic carboxylic acids are succinic acid, glutaric acid, corkic acid, azelaic acid, adipic acid and sebacic acid, and examples of aromatic carboxylic acids are phthalic acid, isophthalic acid and terephthalic acid. The carboxylic acids can be used alone or as a mixture of at least two carboxylic acids. Instead of carboxylic acids, their anhydrides or esters can also be used.

  In particular, the products of addition of alkylene oxides, preferably propylene oxide and particularly preferably ethylene oxide or mixtures of these alkylene oxides to each other diol, are used as polyalkylene glycols. The diol is preferably an alkane diol having 2 to 10 carbon atoms, preferably 2 to 6 carbon atoms customary for the production of polyalkylene glycols, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol. 1,5-pentanediol and / or 1,6-hexanediol are used. The polyalkylene glycol preferably contains 4 to 40, particularly preferably 8 to 30 carbon atoms.

Preferably linear, cyclic or branched aliphatic or aromatic alkanols having 1 to 20 carbon atoms are used as monofunctional alcohols. Suitable monofunctional alcohols are for example methanol, ethanol, n- or iso-propanol, n- or iso-butanol, n- or iso-pentanol, cyclo-, n- or iso-hexanol, n- or iso-heptanol. N- or iso-octanol, 3-, n- or iso-nonanol, n- or iso-decanol, n- or iso-undecanol and n- or iso-dodecanol. Furthermore, substitution products of monoalcohols with alkylene oxides having a molecular weight M _n in the range from 150 to 1500 g / mol, in particular ethylene oxide, can be used. It is also possible to use bifunctional or polyfunctional alcohols in which the remaining alcohol groups are substituted.

  The production of the hydrophilic polyester is carried out by esterification while discharging water generated by raising the temperature according to a well-known method. This method is described in Plastic Handbook (Kunststoffhandbuch), Volume 7, Karl Hanser Publishing, Munich, 3rd edition, pages 70-71.

Dicarboxylic acid (HOOC—R ² —COOH), polyalkylene glycol (HO—R ³ —OH, where R ³ represents a polyether residue of polyalkylene glycol) and monofunctional alcohol (R ¹ —OH) are: In that case, the products having the general structure (I) are produced, since they are used in the desired ratio to one another.

First, a substituted product is formed from a dicarboxylic acid (HOOC-R ² —COOH) and a polyalkylene glycol (HO—R ³ —OH), which is then separated into a monofunctional alcohol (R ¹ —OH) in a separate step. ) To give the final product of structure (I).

In the hydrophilic polyester used in the present invention, x is preferably 1 to 10, particularly preferably 2 to 5, and the number average molecular weight _Mn is preferably 500 to 5000 g / mol, particularly preferably 1000 to 3000 g / mol. Become. When x is 10 or more, or the number average molecular weight _Mn is larger than 5000 g / mol, it is difficult to process due to its viscosity. When the number average molecular weight _Mn is less than 500 g / mol, the hydrophilic continuous resistance may be impaired in the case of a coated film, which is not preferable. The hydrophilic polyester used in the present invention preferably contains the general structure (I) as a main component, and may contain a small amount of by-products. The by-product, end or when the dicarboxylic acid ^(HOOC-R 2 -COOH), polyalkylene glycol ^(HO-R 3 -OH) are considered. If these by-products are too much, the hydrophilic persistent resistance of the coated film may be impaired. The acid value of the hydrophilic polyester of the present invention is preferably less than 10 mgKOH / g, particularly preferably less than 5 mgKOH / g. The hydroxyl value of the hydrophilic polyester of the present invention is preferably less than 10 mgKOH / g, particularly preferably less than 5 mgKOH / g. When the acid value is 10 mgKOH / g or more and the hydroxyl value is 10 mgKOH / g or more, the hydrophilic continuous resistance may be impaired when a coated film is formed.

In a particularly preferred embodiment, a product from phthalic acid, polyethylene glycol and iso-nonanol having a M _{n of} about 1500 g / mol and a hydroxyl value of <1 mg KOH / g is used as the hydrophilic polyester. Such a product is available from Kawasaki Kasei Kogyo Co., Ltd. under the name “S100”.

  Note that all the descriptions in wt% are for the finished product, the finished coating layer composition or the coating liquid composition, respectively, unless otherwise specified.

  The surfactants or surfactant mixtures mentioned in the above coating liquid compositions are preferably used at a concentration of less than 10% by weight, in particular less than 7% by weight, preferably ionic, particularly preferably anionic interfaces. Activators, particularly preferably selected from the group of alkyl sulfonates, alkyl benzene sulfonates, alkyl sulfates, alkyl benzene sulfates, alkyl ether sulfates or sulfosuccinates.

  The coating liquid composition of the present invention can optionally contain an organic solvent or organic solvent mixture, preferably at a concentration of less than 70% by weight, in particular less than 60% by weight. In that case, an organic solvent miscible with water is preferred, and alcohol is particularly preferred. Suitable solvents are, for example, methanol, ethanol, n- or iso-propanol or n- or iso-butanol.

  The coating liquid composition can contain additional polymers, preferably added in the form of an aqueous solution or dispersion, to further improve its properties. The concentration of this polymer in the finished coating layer composition is preferably less than 10% by weight, in particular less than 5% by weight. Suitable polymers are, for example, acrylates, methacrylates, polyesters or polyurethanes.

  Optionally, the coating solution can contain an antiblocking agent. Conventional antiblocking agents are inorganic and / or organic particles such as silicon dioxide, calcium carbonate, aluminum oxide, aluminum silicate, kaolin or crosslinked polystyrene or acrylate particles. Porous silicon dioxide such as amorphous silicic acid is preferred because it facilitates water dispersion on the film surface.

  The coating solution may further contain other additives such as an antistatic agent, an antioxidant and / or a foaming regulator.

  The coating liquid composition is composed of hydrophilic polyester obtained from water and at least one dicarboxylic acid, at least one polyalkylene glycol and at least one monofunctional alcohol. “Composition” means here that the composition comprises at least 50% by weight, preferably at least 65% by weight, particularly preferably at least 95% by weight, in particular up to 100% by weight, of the aforementioned substances. The balance up to 100% by weight is composed of the other substances mentioned above.

  After the in-line coating, the coating layer is composed of a dried film (dried product) of the coating liquid composition.

  The coating layer can be applied to one side or both sides of the polyester film. However, it is also possible to provide the coating layer of the present invention only on one side of the film and apply another surface layer on the opposite side.

  The coating liquid composition of the present invention is preferably used for applying an oriented polyester film in-line. In-line means that the coating layer is applied before longitudinal and / or transverse stretching in the film production process.

  In order to improve the wetting of the film using an aqueous coating solution, the film can be corona treated before coating.

  This coating layer can be applied by a conventional appropriate method such as a die coater or a spray coater. Application using a gravure coater in which the application layer is uniformly applied (reverse) is particularly preferred. Similarly, application by a bar coater using a Mayer rod on which a relatively thick application layer is easily formed is also preferable.

  The dry coating thickness on the finished film preferably has a thickness of 5 to 1000 nm, in particular 50 to 750 nm. When the dry coating thickness is 1000 nm or more, the coating layer tends to block, which is not preferable. Moreover, when the dry coating thickness is 5 nm or less, the function of the coating layer: hydrophilicity and its sustained resistance are insufficient, which is not preferable.

  The coating layer components can react with each other and / or with the polyester on the film surface and / or penetrate into the polyester film surface structure during the drying and stretching of the polyester film and in particular during subsequent heat treatments. It is.

  This coating layer provides hydrophilicity with good sustained resistance, especially on biaxially oriented polyester films, with outstanding properties for hydrophilic water resistance, high temperature water resistance and abrasion resistance.

  Even more surprisingly, this good sustained resistance of the coating layer is achieved here without the addition of additional crosslinkers (melamine, radical initiators, etc.).

  The polyester film on which the coating layer is formed may be, for example, a single layer, two layers consisting of one basic layer (B) and one cover layer (A), one basic layer (B) and two or more of them. The cover layer (A ′ to C) can be also composed of three layers or multiple layers.

  When the polyester film has a multilayer structure, the thickness of the cover layer (A, A ′ to C) is preferably in the range of 0.1 to 10 μm, particularly 0.2 to 5 μm. Correspondingly, the thickness of the base layer is determined from the difference between the total thickness of the film and the thickness of the applied cover layer.

  The total thickness of the polyester film is usually in the range of 5 to 750 μm, preferably 10 to 500 μm.

  The polyester film of the present invention contains a thermoplastic polyester as a main component. Such polyesters are listed in "Handbook of Thermoplastic Polyesters, Editor S. Fakirov, Willet VCH, 2002". Examples are polyesters from ethylene glycol and terephthalic acid (polyethylene terephthalate, PET), polyesters from ethylene glycol and naphthalene-2,6-dicarboxylic acid (polyethylene-2,6-naphthalate, PEN), and 1,4-bis. Polyester from hydroxymethylcyclohexane and terephthalic acid (poly (1,4-cyclohexanedimethylene terephthalate), PCDT). According to the invention, polyesters are understood as homopolyesters, copolyesters, blends of different polyesters, recycled polyester raw materials and mixtures of other polyesters. A film whose main component is polyethylene terephthalate (PET) is particularly preferred.

  The polyester film of the present invention may contain additives such as antiblocking agents in one or multiple layers. Typical antiblocking agents are inorganic and / or organic particles such as silicon dioxide (precipitation or pyrogenic), calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, Titanium dioxide (goldenite or pyrite), kaolin (hydrated or calcined), aluminum oxide, aluminum silicate, lithium fluoride, calcium, barium, zinc or manganese salt of dicarboxylic acid used or polystyrene or polymethyl methacrylate Cross-linked polymer particles such as particles mainly composed of

  In addition, a mixture of two or more particle systems or a mixture of particle systems of equal chemical composition and different particle sizes can be selected. The particles are already added to the polyester for the purpose before melting.

Insofar as an antiblocking agent is included in one layer of the polyester film, the total concentration of these particles is less than 20% by weight, preferably less than 15% by weight, particularly preferably based on the total weight of the finished layer. Less than 5% by weight. The particles preferably have an average particle size (d ₅₀ value) of 0.01 to 15 μm, in particular 0.03 to 10 μm, particularly preferably 0.05 to 5 μm.

  The polyester film of the present invention can contain other additives such as UV stabilizers, flame retardants, hydrolysis stabilizers and antioxidants.

  UV stabilizers, ie UV absorbers as sunscreens, are chemical compounds that can intervene in the physical and chemical processes of light-induced polymer degradation. Suitable UV stabilizers are, for example, 2-hydroxybenzophenone, 2-hydroxybenzotriazole, nickel organic compounds, salicylic acid esters, cinnamic acid ester derivatives, monobenzoic acid resorcin, oxalic acid anilide, hydroxybenzoic acid ester, benzoxazinone, Steric hindered amines and triazines, with 2-hydroxybenzotriazole, benzoxazinone and triazine being preferred. In a particularly preferred embodiment, the polyester film of the invention has the following formula as UV stabilizer:

2- (4,6-diphenyl- [1,3,5] triazin-2-yl) -5-hexyloxyphenol of 0.1 to 5.0% by weight, or the following formula

Of 2,2′-methylene-bis- [6-benzotriazol-2-yl] -4- (1,1,2,2-tetramethylpropyl) -phenol in an amount of 0.1 to 5.0% by weight, or Following formula:

Of 2,2 '-(1,4-phenylene) -bis-([3,1] benzoxazin-4-one).

  In other embodiments, a mixture of these UV stabilizers or a mixture of at least one of these UV stabilizers with another UV stabilizer is also used, in which case the total concentration of the sunscreen agent is Preferably it is 0.1 to 5.0 weight% with respect to weight, Most preferably, it exists in the range of 0.5 to 3.0 weight%.

  In other embodiments, the polyester film of the present invention is fire proofed. By flameproofing is meant that the film reaches at least the VTM-2 rating in the so-called fireproof test according to UL94VTM.

  The polyester film accordingly has one flame retardant in one or more layers, 0.2-30% by weight, preferably 1.0-20% by weight, based on the total weight of the finished layer. Includes in a range of concentrations. Suitable flame retardants are, for example, organophosphorus compounds such as carboxyphosphinic acid, its anhydride and methanephosphonic acid dimethyl ester. In that case, the phosphorus compound is chemically bonded to the polyester, for example the formula:

Flame retardants such as [(6-oxide-6H-dibenzo [c, e] [1,2] oxaphosphorin-6-yl) methyl] butanedicarboxylic acid-bis- (2-hydroxyethyl) ester Suitable for

  Since flameproofing agents are generally sensitive to some degree of hydrolysis, it is important to add a hydrolysis stabilizer. A suitable hydrolysis stabilizer in this case is a polymerized carbodiimide, such as Stabaxol P® from Rheinchemy (Germany).

  Furthermore, the polyester film can be hermetic or peelable in the case of a multilayer structure. This is usually accomplished by using a low glass transition temperature polyester or other sealing polymer in at least one of the cover layers.

  Polyester film production methods are described in "Handbook of Thermoplastic Polyesters, Editor S. Fakirov, Willet VCH, 2002" or "Encyclopedia of Polymer and Science 12 Encyclopedia of Polymer and Science. Volume, John Wiley & Sons, 1988 ”,“ Polyesters, Films ”and the like. In a preferred extrusion process for film production, the molten polymer material, optionally containing additives, is extruded through a slot die and quenched on a chill roller as a broad amorphous pre-film. The film is then reheated and stretched (“orientation”) in at least one direction, preferably the machine and transverse directions, in the machine direction (MD) or transverse direction (TD). The film temperature in the stretching process is generally 10 to 60 ° C. higher than the glass transition temperature Tg of the polyester used, the stretching ratio for longitudinal stretching is usually 2 to 6, particularly 3 to 4.5, and the stretching ratio for transverse stretching is 2 to 5. In particular, the stretching ratio of the second longitudinal stretching that is optionally performed is 3 to 4.5 and is 1.1 to 5.

  The longitudinal stretching can be performed simultaneously with the lateral stretching (simultaneous biaxial stretching), or can be performed in the order considered (sequential biaxial stretching). After stretching, the film is thermoset preferably at a temperature of 180-260 ° C, in particular 220-250 ° C. Subsequently, the film is cooled and wound up.

  Table 1 below summarizes the most important preferred properties of the coating layer.

  In order to test the effect of the coating layer, this property is examined by the following measuring method using the coated polyester film.

・ Measurement of contact angle:
In order to measure the contact angle, a measuring device “OCA20” from Data Physics GmbH (Germany) is used with deionized water (electrical conductivity <0.1 μS / cm). A 2 microliter water droplet is placed on the surface to be measured. After 10 seconds, the droplet is photographed with the video camera of the apparatus. Subsequently, the contact angle is calculated using Data Physics software “SCA20”. The drop shape is then approximated using a “round fit” adjustment for contact angles less than 30 degrees and an “elliptical fit” adjustment for contact angles greater than 30 degrees.

・ Measurement of paint film haze:
The haze of the coated polyester film is measured using “Hazegard Hazemeter XL-211,” manufactured by BYK Gardner GmbH (Germany), in accordance with ASTM-D 1003-61. The coating film haze (referred to as Hz) is measured as a difference in haze between a coated film and an uncoated film as a reference film (haze = 0.6%, see Table 2).

  Hz = total haze of coated film−haze of reference film (= 0.6%)

・ Measurement of yellowness:
The yellowness of the coated film is determined with a standard light type D65, 10 degree standard observer using a spectrophotometer “Lamda12” model from Perkin Elmer (USA) according to ASTM-D 1925-70. From the measured standard color values X, Y, Z the equation:

YID = [100 · (1.28 · X−1.06 · Z)] / Y
Calculate the yellowness according to

・ Evaluation of coating appearance:
The appearance of the coating is evaluated visually in three stages: “excellent”, “excellent”, and “good”.

-Determination of molecular weight _Mn :
The number average molecular weight _Mn is determined using gel permeation chromatography. The test is performed with a 0.1% tetrahydrofuran solution on a Latek (Germany) column (PL gel, 5 and 10 micrometers). A differential refractometer R401 from Waters GmbH (Germany) and a UV detector model 2500 from Knauer GmbH (Germany) are used as detectors. Calibration is performed using polystyrene standards from PSS GmbH (Germany).

-Determination of hydroxyl value (OH value):
With respect to the hydroxyl value, it is understood that the amount of KOH in mg is equivalent to the amount of acetic acid associated with acetylation of 1 g of substance. Calculate according to DIN 53240-2. A known exact amount of acetic anhydride is added to a sample dissolved in tetrahydrofuran. After 1 hour, the acetylation reaction is complete and water is added to hydrolyze the unsubstituted acetic anhydride. The total amount of acetic acid produced in both reactions is then titrated with 0.5 mol / l ethanol KOH solution. The same amount of acetic anhydride is hydrolyzed with water as a blank sample, and the resulting acetic acid is titrated with KOH. The hydroxyl value is calculated from the difference between the titration results of the blank sample and the analytical sample.

・ Water resistance evaluation:
In order to evaluate the water resistance of the coating layer, a sample of coated polyester film measuring 5 cm × 10 cm is placed in a beaker filled with 1000 ml of deionized water (temperature: 25 ° C.). After 10 minutes, the sample is removed from the beaker and dried at 25 ° C./50% relative humidity for 12 hours. Subsequently, the contact angle is measured according to the method described above. Measure at five different positions on the sample. The distance between the two measurement points is 2 cm each, and the measurement points are at least 1 cm away from the outer edge of the sample. The maximum contact angle (CA _max ) measured at that time is evaluated. The water resistance of the coating layer results from the difference in contact angle before and after storage in water. The smaller the contact angle difference dCA _{water resistance, the} better.

dCA _{water resistance} = CA _max (after storage) −CA (before storage)

・ Evaluation of water resistance at high temperature:
Evaluation of water resistance at high temperature is performed in a manner similar to “Evaluation of water resistance” except that deionized water is warmed to 95 ° C. The resistance of the sample to _{elevated temperatures} is better when the contact angle difference dCA _{high temperature} is smaller under these conditions.

dCA _{high temperature} = CA _max (after storage) −CA (before storage)

・ Evaluation of wear resistance:
In order to test the resistance of the coated layer to abrasion, a sample of coated film with a size of 5 × 10 cm is fixed on a test bench using a double-sided adhesive tape. A 5 × 5 cm sponge sponge (Kalle, Germany) moistened with 5 ml of deionized water is placed on the surface of the coating layer film and loaded with a weight of 200 g. Subsequently, this sponge cloth is moved 50 times back and forth by 5 cm each. In this case, the speed is 1 cm / s. The sample is subsequently dried at 25 ° C./50% relative humidity for 12 hours. The contact angle of the coating layer is then measured at five different positions on the sample, as described in “Evaluation of water resistance”. Wear resistance of the sample in which case the lower, the better the smaller the contact angle difference dCA _wear.

dCA abrasion _resistance = CA _max (after wear) −CA (before wear)

  Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited thereto. The characterization results of the coated film samples are summarized in Table 2 below.

In the examples, “S100” type from Kawasaki Kasei Kogyo Co., Ltd. manufactured from phthalic acid, polyethylene glycol and iso-nonanol was used as the hydrophilic polyester. The molecular weight M _n is about 1500 g / mol and the hydroxyl value is <1 mg KOH / g.

  Other hydrophilic polyesters were produced according to the following instructions.

  Dimethyl phthalate (“DMP”, Sigma-Aldrich, Germany), polyethylene glycol (“PEG”, Sigma-Aldrich, Germany) and 7 mmol of titanium tetraisopropylate (Sigma-Aldrich, Germany) A 1 liter three-necked flask equipped with a thermometer, distillation head and reflux valve was charged. The apparatus was carefully cleaned with nitrogen. Subsequently, the temperature was raised to 180 ° C. with stirring and held for 4 hours. At that time, methanol was liquefied in the cooled receiver. Subsequently, the temperature was lowered to 140 ° C. Monofunctional alcohol (“MA”, Sigma-Aldrich, Germany) 0.3 mol and 1.5 mmol of titanium tetraisopropylate were added dropwise with stirring. The deposit was cooled after 2 hours. The reaction product was received with 500 ml of chloroform and washed 3 times in a separatory funnel with 50 ml of deionized water each. The organic phase was separated, dried over magnesium sulfate and filtered. Finally, the solvent was removed with a rotary evaporator. The resulting hydrophilic polyester was used to apply a polyethylene terephthalate film as described below.

  As the surfactant, sodium alkylsulfonate of “Latemul PS” type manufactured by Kao Corporation was used.

Example 1:
The coating solution was produced from the following components. This coating liquid composition was coated on a polyester film according to the following method.

  A melt was made from polyethylene terephthalate containing 0.5% by weight of silicon dioxide particles (SL320, Fujifilm) as an antiblocking agent, and extruded through a slot die onto a cooling roll held at about 20 ° C. Coagulated into a preliminary film. This preliminary film was stretched longitudinally at a stretching ratio of 3.6 times while maintaining the temperature at 95 ° C. Subsequently, the above-described coating solution was applied to this longitudinally stretched film to a thickness of 4.7 μm using a Mayer bar. The longitudinally stretched and coated film was dried at a temperature of 100 ° C. and then transversely stretched by a factor of 4.2, whereby a biaxially oriented film was obtained. This biaxially stretched film was heat-cured at 230 ° C. The final film thickness was 38 μm. The dry coating thickness was determined by calculation from the solid ratio of the coating solution, the coating thickness (wet), and the transverse draw ratio with respect to 168 nm.

  The coated film was characterized using the method described above. This film is characterized by small coating haze, small water contact angle and excellent hydrophilicity, and outstanding properties for hydrophilic water resistance, high temperature water resistance and abrasion resistance.

Example 2:
Similar to Example 1, the following coating solutions were used.

  The coated film was characterized using the method described above. This coated film has a small coating haze, a small contact angle with water and excellent hydrophilicity, and has outstanding properties for hydrophilic water resistance, high temperature water resistance and abrasion resistance.

Example 3:
Similar to Example 1, the following coating solutions were used.

  The coated film was characterized using the method described above. This coated film has a small coating haze, a small contact angle with water and excellent hydrophilicity, and has outstanding properties for hydrophilic water resistance, high temperature water resistance and abrasion resistance.

Example 4:
The film made in Example 3 was melted at 280 ° C. This melt was formed into a strand shape, quenched in water and processed into a granular material. This granule was mixed with the polyester used for the production of the basic film up to 50% by weight. The film was applied analogously to Example 3 and subsequently characterized. This coated film had properties similar to those of Example 3. The yellowness of the film did not increase significantly compared to Example 3 despite the use of recycled polyester raw material.

Example 5:
Similar to Example 1, the following coating solutions were used.

  The coated film was characterized using the method described above. This coated film has a small coating haze, a small contact angle with water and excellent hydrophilicity, and has outstanding properties for hydrophilic water resistance, high temperature water resistance and abrasion resistance.

Example 6:
Similar to Example 1, the following coating solutions were used.

  The coated film was characterized using the method described above. This coated film has a small coating haze, a small contact angle with water and excellent hydrophilicity, and has outstanding properties for hydrophilic water resistance, high temperature water resistance and abrasion resistance.

Example 7:
Similar to Example 1, the following coating solutions were used.

  The coated film was characterized using the method described above. This coated film has a small coating haze, a small contact angle with water and excellent hydrophilicity, and has outstanding properties for hydrophilic water resistance, high temperature water resistance and abrasion resistance.

Comparative Example 1:
Similar to Example 1, the following coating solutions were used here.

  The coated film was characterized using the method described above. The hydrophilic water resistance, high temperature water resistance and abrasion resistance showed obvious changes in the properties of the coating layer.

Comparative Example 2:
The film made in Comparative Example 1 was melted at 280 ° C. This melt was formed into a strand shape, quenched in water and processed into a granular material. This granule was mixed with the polyester used for the production of the basic film up to 50% by weight. The film was applied analogously to Comparative Example 1 and subsequently characterized. The yellowness of the film was clearly increased by using a recycled polyester raw material containing polyvinylpyrrolidone.

Comparative Example 3:
Similar to Example 1, the following coating solutions were used here.

  The coated film was characterized using the method described above. The hydrophilic water resistance, high temperature water resistance and abrasion resistance showed obvious changes in the properties of the coating layer.

Comparative Example 4:
The film made in Comparative Example 3 was melted at 280 ° C. This melt was formed into a strand shape, quenched in water and processed into a granular material. This granule was mixed with the polyester used for the production of the basic film up to 50% by weight. The film was applied analogously to Comparative Example 3 and subsequently characterized. The yellowness of the film was clearly increased by using a recycled polyester raw material containing alkylol melamine.

Comparative Example 5:
Similar to Example 1, the following coating solutions were used.

  The coated film was characterized using the method described above. There was a clear change in the properties of the hydrophilic water resistance, high temperature water resistance and abrasion resistance.

  The results of Examples and Comparative Examples are summarized in the following table.

  The film of the present invention can be suitably used as, for example, a light control film, a medical film, and a food packaging film.

Claims (5)

At least one dicarboxylic acid, polyester film have a dry film of the coating solution containing a hydrophilic polyester obtained from at least one polyalkylene glycol and at least one monofunctional alcohol, and water, and the substrate is self-renewal includes a polyester material, coated polyester film the ratio is characterized der Rukoto 50% or less. The coated polyester film according to claim 1, wherein the hydrophilic polyester has a structure represented by the following formula (I).

(In Formula I, R ¹ is the residue of the monofunctional alcohol R ¹ —OH, R ² is the residue of the dicarboxylic acid HOOC-R ² —COOH, and R ³ is the residue of the polyalkylene glycol HO—R ³ —OH. A group, and x represents 1 to 10, respectively) The coated polyester film according to claim 2, wherein R ² is a residue of phthalic acid. The coated polyester film according to claim 2 or 3, wherein R ³ is a residue of polyethylene glycol. The coated polyester film according to any one of claims 2 to 4, wherein R ¹ is a residue of iso-nonanol.