JP4351191B2 - Non-crystalline polyester sheet and molded product with excellent slip and printability - Google Patents

Description

  The present invention relates to an amorphous polyester sheet suitable for use in various packaging applications, and a molded article made therefrom, and more specifically, a substantially non-crystalline resin sheet as a core layer, A non-crystalline polyester skin layer containing inorganic particles in a certain size range is provided on both sides, and a functional polymer resin, water and an organic solvent, and a high slip functional addition are provided on at least one side of the skin layer. By forming a coating layer comprising a composition containing an agent and an adhesive functional resin, it has excellent slip and anti-blocking properties, and has excellent ink adhesion, hot melt adhesion, and transparency. A crystalline polyester sheet and a processed product produced therefrom are provided.

  Usually, an amorphous (amorphous) polyester sheet is made by extruding amorphous polyethylene terephthalate. Such amorphous polyester sheet has excellent mechanical strength, thermal properties, chemical resistance, electrical properties, moisture resistance, water resistance, transparency, etc., various packaging materials, advertising prints, foods It is used for various purposes in packaging materials. For example, high transparency has an effect of increasing the value of a packaged product, and is excellent in suitability with a printing ink during printing, and is applied to various printed materials. The low temperature and impact resistance properties enable it to be usefully applied to refrigerated and frozen product packaging. In addition, since no harmful gas is emitted during combustion, it has been used in many industrial fields as an environmentally friendly material in recent years.

  However, such polyester sheets or films are exposed to heat and pressure when they are processed, rolled up and distributed, used by the final consumer, or in particular in the process of storing them. Sometimes, blocking occurs between other adjacent sheets or films, or the adhesion of the printed ink is weakened on one side of the sheet or film, and the printed ink does not adhere to the adjacent sheet or film. The phenomenon of sticking to the back appears. In this case, if the blocked film is pulled away, any one of the ink, the film and the substrate may be damaged, so the printing ink is more adsorbed on the film or sheet that needs to be printed. It may be required to provide slipperiness or to provide slip and activity through, for example, seat stop or reduction of the coefficient of friction of motion.

  The prior art for improving such slip property and activity is as follows.

  In Japanese Patent Laid-Open No. 63-312319, silicon particles produced by hydrolyzing and condensing alkoxysilane are added to a polyester polycondensation reaction product in the form of a slurry dispersed in ethylene glycol. A magnetic recording film with increased wear is disclosed.

  In Japanese Patent Laid-Open No. 5-239424, a polyester resin composition for producing a thermoformed sheet in which silica and alumina particles having a diameter of 0.01 to 5 microns are added to a polyester resin in which 0.1 to 0.5% by weight and isophthalic acid occupy 5 to 20% by mole are used. Is disclosed.

  In U.S. Pat.Nos. 5,863,647, 5,316,714, 5,304,324 and 5,236,622, the size is specified, for example, a diameter of 0.05 to 5 Apply a glycol suspension of amorphous inorganic oxide particles with a micron particle size standard deviation in the range of 1.0 to 1.5 and 0.03 to 5 moles of glycolol per gram of particles to the surface and slip onto a polyester film Disclosed to increase sex. Its use is mainly used for magnetic recording media.

  In JP-A-3-95779, a silicon oxide slipping layer was formed by coating a polyester film with a coating solution containing 2 to 40% by weight of reactive ethyl silicate and thermosetting dimethylpolysiloxane. A sheet is disclosed.

  Japanese Patent Application Laid-Open No. 7-85631 discloses a polyester sheet that provides slip properties with a coating layer containing a partial hydrolyzate of polysyloric acid, a silicone resin, and an interfacial slip agent.

  U.S. Pat.No. 5,370,930 is oriented, having a biaxially oriented layer with improved slip properties by applying an aqueous solution or dispersion containing a polysiloxane-polyvinyl graft copolymer to at least one surface. A polyester film is disclosed, wherein the coating layer comprises an organic polymer and 0.002-1.5% by weight of porous particles of 0.5-4.5 micron size, for example, calcined polysiloxane particles.

  USH1982 discloses an amorphous plastic film in which a water-dispersed copolyester resin is primer-coated on one side of a polyester sheet for the purpose of improving printability. The coating layer consists of 5-sulfoisophthalic acid 8-25 mol%, dicarboxylic acid component composed of 75-92 mol% isophthalic acid, and diethylene glycol 25-100 mol%, 1,4-cyclohexanedimethanol 0-30 A resin produced with a diol component composed of mol% and ethylene glycol 0-30 mol% is applied.

In JP-A-8-15619, a polyester polymer is blended with 0.01 to 5% by weight of an ester product of a polyvalent alcohol having 3 or more hydroxyl groups and an aliphatic monocarboxylic acid having 12 or more carbon atoms. And a highly active, substantially non-crystalline polyester sheet having a skin layer with surface protrusions of 0.1 to 5 microns in height of 1 to 2,000 / mm ² .

  However, the above patents mostly relate to stretched or oriented polyester films, and do not satisfy slip properties, transparency, ink adhesion and printability, and hot melt adhesion at the same time. A technology that can further advance the properties together is still necessary for the non-crystalline polyester sheet field.

  The present invention improves the above-mentioned conventional problems, and after manufacturing a coating composition having transparency, printability, slip, anti-blocking and hot melt adhesion at the same time, By coating the substrate with various coating methods (inline or offline coating), it not only has excellent printability and ink adhesion, but also has excellent slip and anti-blocking properties when in contact with other sheets It is to produce an amorphous polyester sheet excellent in adhesiveness with a hot melt adhesive and transparency.

  Another object of the present invention is to provide a substantially non-crystalline polyester sheet molded article that is excellent in activity and excellent in transparency and printability.

  The polyester sheet according to the present invention for achieving the above object is a substantially non-crystalline multilayer laminate. As shown in FIG. 1, the laminate sheet has a structure having a core layer 1 and a coating layer 3 having a skin layer 2 on both sides and a coating agent applied to at least one side of the skin layer.

  As used herein, “substantially amorphous” refers to a film substrate having a low degree of crystallinity, ie, a film or sheet that gradually crystallizes. The substantially amorphous polyester of the present invention has a crystallinity of 15%, desirably 10%, and more desirably 5% or less. Since the method for determining the crystallinity is known in the art, the description thereof will be omitted.

  The preferred core layer of the present invention is a poly (ethylene terephthalate) and a poly (ethylene naphthalene dicarboxylate) homopolymer as an amorphous polyester, poly (ethylene terephthalate) containing 1,4-cyclohexanedimethanol, Any one of poly (ethylene naphthalene dicarboxylate) containing 1,4-cyclohexanedimethanol.

  The skin layer acts as an amorphous polyester and serves to support the coating layer. In order to provide activity, the skin layer contains 0.01 to 10% by weight of inorganic particles having a size of 0.5 to 50 microns. Desirably, inorganic particles having a size of 1.0 to 10 microns are contained in an amount of 0.1 to 3.0% by weight, and a surface roughness of about 0.01 to 10 microns is formed on one or both sides of the skin layer. For example, for the skin layer, inorganic particles such as silica, talc, calcium carbonate, and titanium dioxide in the range of 0.5 to 50 microns are placed in a master batch form, and 0.01 to 10% by weight based on the weight of the skin layer is added. The surface roughness of 0.01 to 10 microns is uniformly formed on one or both surfaces of the sheet skin layer.

  The coating layer is manufactured in various coating methods (in-line or off-line coating) after manufacturing a coating composition having transparency, printability, slip property, anti-blocking property and hot melt adhesive property at the same time. To the substrate.

  As coating composition, functional polymer resin, especially acrylic urethane copolymer binder 2.0-20% by weight, water and organic solvent 20-90% by weight, high slip functional resin 0.1-5.0% by weight, hot melt adhesive function It is produced by blending 0.5 to 5.0% by weight of a functional resin. In order to provide coating properties, transparency and printability at the time of coating, a functional binder excellent in adhesiveness is required. As the functional binder, a binder having a functional group excellent in mutual chemical action with an ester functional group of polyethylene terephthalate (PET) is required. Functional binders include polyvinyl alcohol having epoxy group, urethane group, acrylic group, ester group, ether group, styrene group, amide group, polyacrylic acid, polymethacrylic acid, styrene-maleic anhydride (copolymer). Polymer, polystyrenesulfonic acid, polyethyleneimine, polyvinylpyridine, polydimethylaminoethyl acrylate, polyacrylamide, polyvinylpyrrolidone, alkyd, polyethylene glycol, polyethylene oxide, polyvinyl methyl ether, alkyl cellulose, acrylic resin, urethane resin, epoxy resin, etc. These are produced by mixing one or more selected from these and their copolymers.

  In high slip non-crystalline polyester sheet coating, the selection of a high slip functional additive having excellent interaction with the above-described functional binder-non-crystalline polyester of the coating composition is most important. The high slip surface properties on the substrate surface are related to the chemical structure and molecular arrangement of the polymer resin and the interaction with the described surface. Among them, in particular, in order to provide a high slip function, studies have been made to change the surface characteristics by introducing silicon element or fluorine element. In the case of functional polymers with silicon introduced, the incompatibility between silicon and the polymer causes silicon elements to be aligned toward the surface, reducing surface energy and improving properties such as adhesion and friction resistance. However, the processability and mechanical properties are inferior. On the other hand, in the case of a functional polymer containing fluorine, a high surface orientation such as that of fluorine element appears due to incompatibility between the polymer substrate material and fluorine. In addition, fluorine-containing resins are excellent in thermal, chemical safety, and resistance to chemicals, and are suitable as a high slip property imparting agent.

The high slip resin in the present invention is characterized by adding 0.1 to 5.0% by weight of a functional resin in the form of a fluorine-urethane copolymer polymer to the coating composition. The high slip resin is a fluoro-urethane copolymer polymer in the form of a perfluorinated alkyl alcohol and a functional isocyanate comonomer produced by polymerizing a urethane reaction of a hydroxyl group and an isocyanate group by a free radical polymerization reaction. A fluorine-containing urethane copolymer, a compound having at least one fluorine-containing terminal group, or a fluorine composition containing an oligomer and a polymer that is a continuous unit thereof is included. In particular, in the present invention, the functional high slip resin is preferably in the form of a fluorine-urethane copolymer. In a fluorine-urethane copolymer, it is desirable that n is 1 to 20 in a perfluorinated group, that is, a perfluoroalkyl group [CF ₃ (CF ₂ ) _n functional functional group]. The average molecular weight of the polymer is preferably from 1,000 to 10,000.

  When manufacturing non-crystalline polyester sheets suitable for use in various packaging applications, it is possible to improve printability in post-processing processes such as printing processes, and to provide ink adhesion and hot melt adhesion. It is most important in the merchantability and workability.

  As the functional resin for improving the adhesive force, an olefin copolymer containing an acyloxy group in the molecule, an ethylene copolymer such as an ethylene-vinyl acetoate copolymer, an ethylene-ethylene diacetate copolymer, Propylene copolymers such as propylene-vinyl acetate copolymer and propylene-ethylene diacetate copolymer, and copolymers such as poly (vinyl pyrrolidone), poly (oxyethylene) and derivatives thereof can be used. . In particular, in the present invention, as the hot melt adhesive functional resin, poly (vinyl pyrrolidone), poly (oxyethylene), poly (vinyl alcohol), acrylic acid, poly (ethylene acrylic acid), poly (ethylene vinyl copolymer) 1) or 2 or more kinds of resins selected from the above are prepared and then added to the coating composition in an amount of 0.5 to 5.0% by weight. As a solvent for the coating composition, a lower alcohol having 5 or less carbon atoms is used. Examples thereof include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, isopentanol and the like, and isopropanol is most desirable in view of economy and dispersibility.

  The amorphous polyester sheet or film is usually produced by a melt extrusion method, which is known in the art. Examining the manufacturing process, in the melt extrusion process, the thermoplastic component is plasticized (melted or mixed) in the extruder, melted and extruded through a T-die, and then the base material through a cooling and solidifying process. Sheets will be manufactured. After applying the above-described coating liquid to at least one surface of the sheet, the product is completed by winding it with a roll type or cutting it with a flat type depending on the application.

  As a coating method, any technique known in the art can be used. Examples of coating techniques include roll coating, reverse roll coating, gravure roll coating, reverse gravure roll coating, brush coating, spray coating, air knife coating, and the like.

  The thickness of the coating layer is less than 10 microns and does not give any orientation to the sheet after it is formed as a sheet.

  Therefore, according to the present invention, not only is it excellent in printability, hot melt adhesive strength, and ink adhesive strength, but also exhibits excellent slip properties and anti-blocking properties when in contact with other sheets, and is excellent in transparency. An amorphous polyester sheet is provided.

  The characteristic values and all physical properties in the present invention were measured by the following methods.

(1) Transparency (Haze)
The amorphous polyester coating sheet was measured by the ASTM D1003 method using a haze measuring device (Nippon Denshhoku 300A), and the haze value was a value calculated by total scattered light / total transmitted light × 100.

(2) Average particle size of inorganic particles The average particle size of the inorganic particles used was measured using a particle size distribution measuring device (Granulometer HR-850) in a state of being dispersed in methanol.

(3) Slip property The slip property between the upper surface and the lower surface of the sheet was measured by using HEIDON's STATIC FRICTION TESTER measuring equipment to measure the angle at which the sheet starts to slide.

(4) Anti-blocking property After the produced sheet fabric is loaded on a pallet and left to stand for 10 days at a load of 1 ton, the blocking phenomenon is based on ASTM D1893 standards, ◎: Best, ○: Good, △: Normal, x: Evaluated to 4 grades of failure.

(5) Ink adhesion strength Using a thick tape having a printing ink applied to the slip coating surface, it was evaluated according to ASTM D3359 standard, in four stages: ◎: best, ○: good, Δ: normal, ×: poor.

(6) Number of friction systems The friction coefficient between the upper and lower surfaces of the sheet was measured by the HEIDON STATIC FRICTION TESTER measurement equipment when the sheet started to slide.

(7) Surface Roughness The center line average roughness of the surface of the sheet was measured using a three-dimensional surface roughness measuring instrument manufactured by KOSAKA, Japan.

  According to the non-crystalline polyester sheet according to the present invention as described above, the non-crystalline polyester sheet comprises a coating composition having transparency, coating properties, slip properties and hot melt adhesive properties at the same time. In addition to being excellent in printability and ink adhesion in the post-processing step, it has excellent slip and anti-blocking properties when in contact with other sheets. It provides the effect of having excellent hot melt adhesive strength. Therefore, the sheet | seat of this invention can be used very useful for the molding and processed material of the amorphous polyester in which antiblocking property and activity are requested | required.

  Preferred examples and comparative examples according to the present invention are as follows, and the physical property results of each example are as shown in Table 1.

Example 1
A polyester resin core layer, 0.3 wt% Si-based inorganic particles with an average particle size of 4 microns in the skin layer, and 13% by weight of acrylic urethane copolymer binder, which is a functional polymer resin, is extruded into a sheet. %, Water 71.5% by weight, isopropyl alcohol 15% by weight, fluorine-urethane copolymer additive 0.5% by weight as a high slip functional additive, poly (ethylene vinyl copolymer) additive as a hot melt adhesive functional resin A coating composition prepared by adding 3% by weight was applied to a sheet using a 200 mesh gravure roll coater (Coater) and then dried through hot air drying to produce an unstretched coated sheet. The coated sheet was cut in-line so that the thickness was 0.3 mm, the width was 1,100 mm, and the length was 800 mm, and then the product was manufactured.

Example 2
A sheet was produced in the same manner as in Example 1 except that the average particle diameter of the Si-based inorganic particles introduced into the skin layer in Example 1 was changed to 10 microns.

Example 3
A sheet was produced in the same manner as in Example 1 except that the amount of Si-based inorganic particles added to the skin layer in Example 1 was changed to 0.1% by weight.

Example 4
A sheet was produced in the same manner as in Example 1 except that 3.0 wt% of the fluorine-urethane copolymer additive, which is a high slip functional additive in Example 1, was added.

Example 5
A sheet was produced in the same manner as in Example 1 except that 1.0% by weight of the poly (ethylene vinyl copolymer) additive which is a hot-melt adhesive functional resin in Example 1 was added.

Comparative Example 1
Polyester resin is used as the core layer, and after 0.3% by weight of Si-based inorganic particles with an average particle size of 4 microns are injected into the skin layer and extruded, the thickness becomes 0.3mm, width 1, 100mm, length 800mm. After cutting in-line, the product was manufactured.

Comparative Example 2
A sheet was produced in the same manner as in Example 1, except that Si-based inorganic particles were not added to the skin layer in Example 1.

It is a schematic diagram which shows the cross section of the polyester sheet by the Example of this invention.

Explanation of symbols

1; Core layer
2; Skin layer
3; coating layer

Claims (6)

A core layer composed of an amorphous resin sheet having a crystallinity of 15% or less at most;
An amorphous polyester skin layer containing inorganic particles in the range of 0.01 to 10 microns on both sides of the core layer;
On at least one side of the skin layer, 2-20% by weight of a polymer resin, 20-90% by weight of water and an organic solvent, 0.1-5% by weight of a high slip functional additive, and a hot melt adhesive functional resin A coating layer uniformly coated with a composition containing 0.5 to 5% by weight,
Of the above coating compositions,
Hot melt adhesive functional resins include poly (vinyl pyrrolidone), poly (oxyethylene), poly (vinylalcohol Lumpur), poly (acrylic acid), poly (ethylene acrylic acid), poly (ethylene vinyl copolymer) Containing at least one or more of these copolymers ,
The non-crystalline polyester sheet, wherein the high slip functional additive contains a copolymerized polymer having a perfluoroalkyl group [CF ₃ (CF ₂ ) _n functional functional group] and n is 1 to 20 .   The resin sheet is any one of a polyethylene terephthalate resin sheet, a polyolefin resin sheet, a polystyrene resin sheet, a polycarbonate resin sheet, a polyvinyl chloride resin sheet, and an acrylic resin sheet. Item 4. The amorphous polyester sheet according to Item 1.   The size of the inorganic particles used in the skin layer is 0.01 to 10 microns, and the amount of the particles is 0.01 to 1.0% by weight based on the skin layer. The amorphous polyester sheet according to claim 1.   Among the coating compositions, the polymer resin includes at least one or more of functional groups among epoxy groups, urethane groups, acrylic groups, ester groups, ether groups, styrene groups, and amide groups. The amorphous polyester sheet according to claim 1, comprising a copolymer of: A core layer consisting essentially of an amorphous resin sheet;
An amorphous polyester skin layer containing inorganic particles in the range of 0.01 to 10 microns on both sides of the core layer;
On at least one side of the skin layer, 2-20% by weight of a polymer resin, 20-90% by weight of water and an organic solvent, 0.1-5% by weight of a high slip functional additive, and a hot melt adhesive functional resin A coating layer uniformly coated with a composition containing 0.5 to 5% by weight,
Of the above coating compositions,
High slip functional additives, among n perfluoroalkyl group [CF ₃ (CF _{2) n} functional group] is from 1 to 20 der Ru copolymerized polymer, containing at least at least one or two, Containing these copolymers ,
Hot melt adhesive functional resins are poly (vinyl pyrrolidone), poly (oxyethylene), poly (vinyl alcohol), poly (acrylic acid), poly (ethylene acrylic acid), poly (ethylene vinyl copolymer), A non-crystalline polyester sheet comprising these copolymers including at least one or two or more .   A molded product produced from the amorphous polyester sheet according to any one of claims 1 to 5.

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