JPS606785B2 - Film with good printability and heat sealability - Google Patents

Description

Detailed Description of the Invention The present invention is a film coated with a paint that has good heat sealability and printability, and is made of polyester film deposited with aluminum as a base material. Concerning a good film.

Conventionally, when printing on polyester film, the adhesion to the base film is not sufficient with normal one-component printing inks, so curable two-component inks such as polyester and isocyanate are used.
Liquid-based ink is used. When using two-component ink, the drying properties are worse than those of one-component ink, and the pot life is short and the viscosity increases significantly, making printing workability extremely poor.In addition to the high ink cost, the remaining liquid after printing hardens. The disadvantage is that it cannot be used repeatedly and the printing cost becomes higher the more colors are printed.

Furthermore, since polyester film cannot be heat-sealed, it is generally laminated with polyethylene and used in order to provide heat-sealability after printing. Lamination methods include extrusion lamination of polyethylene and bonding of polyethylene films with adhesive. For this reason, polyester film for packaging has the drawback of being extremely expensive, including printing and laminating costs. However, the present invention uses a polyester film as a base material and forms a resin layer with good printability and heat-sealability by coating it, allowing the use of a wide range of ordinary one-component inks, good printing workability, and low printing costs. At the same time, it provides heat sealability in automatic packaging machines or automatic bag making machines. The heat sealability here refers not only to the bonding strength under optimal conditions (temperature, pressure, time), but also to the initial bonding temperature. This has made it possible to provide a light packaging film that can be heat-sealed at a relatively low initial bonding temperature, which is related to the working speed of the machine and governs productivity, and has good productivity. Next, with reference to FIG. 1, the present invention will be described in detail, including an example of the structure and an example of the relationship between printing and heat sealing. FIG. 1 is a partially enlarged cross-sectional view in the case where front printing is performed on the vapor-deposited side of a polyester film on which aluminum is vapor-deposited, and the seal portion is used only on the back side or both the back side and the front side with respect to the printed surface.

After forming an anchor layer 2 on the film side 1 of a polyester film 1 having an aluminum vapor deposited layer 5 formed thereon, heat sealing layers 3 and 3' are formed on the vapor deposited layer and the anchor layer, respectively. The printing 4 is printed on the surface of the heat sealing layer 3.
It can also be used vice versa. The configuration of the present invention will be explained in detail.

The polyester film on which aluminum is vapor-deposited is usually a polyethylene terephthalate film on which aluminum is vapor-deposited, and the thickness of the film is not determined depending on the application, but is usually in the range of 6 to 100 mm.

Aluminum evaporation is deposited by vacuum evaporation method,
The film thickness is usually used in the range of 0.01 to 0.10 mm.

For the anchor layer, if the heat-sealing resin layer is directly coated on the polyester film for the purpose of use, the adhesive strength after heat-sealing is not sufficient, so a material that has good adhesion to the polyester film and has good adhesion to the heat-sealing resin layer is selected. As the anchor agent, alkyl titanate type, aluminum alcoholate type, isocyanate type, ethyleneimine type, etc. are used.

The thickness of the anchor layer ranges from 0.01 to 1.0 mm.
The heat seal layer is the main point of the invention.

The resin content consists of vinyl chloride-vinyl acetate-maleic acid copolymer resin or vinyl chloride-vinyl acetate copolymer resin alone or in combination, an adhesion aid, and a lubricant. The purpose of this is that the EP sheet U ink has good adhesion to the anchor layer or aluminum vapor deposited layer on the polyester film surface, has a wide range of uses as a one-component EO ink, and has good heat sealing strength and can be heat sealed at low temperatures. It has good heat-sealing workability.

Vinyl chloride-vinyl acetate. Regarding the maleic acid copolymer resin, for every 10 parts of the copolymer resin (the same applies below weight parts), it contains 90 to 70 parts of vinyl chloride and 1 part of vinyl acetate.
0 to 30 parts of maleic acid, ranging from 0.5 to 5 parts.

Regarding the vinyl chloride-vinyl acetate copolymer resin, the content of the copolymer resin 10 is in the range of 90 to 7 parts of vinyl chloride and 10 to 3 parts of vinyl acetate. If the amount is more or less than these ranges, adhesiveness, heat sealability, and printability will deteriorate. Adhesion aids are rosin and modified rosin.Modified rosin refers to rosin amine, maleic acid modified rosin, phenol modified rosin, aldehyde modified rosin, etc.These are used alone or in combination.The use of adhesion aids is For the above copolymer resin 10 Makoto Ikari, 2~
This is the range of Part 2. If the amount is less than this range, the printability will be bad and if it is more than this range, the adhesive strength of the heat seal will decrease. Furthermore, the adhesion aid has the effect of adjusting the initial adhesion temperature. Lubricants include paraffin waxes, kaolin, silica, and zinc stearate.

The amount used is 0.2 to 5 per 10 parts of the above-mentioned copolymer resin.
This is within the scope of the department. The purpose of this is to impart toughness and prevent blocking. If the amount is less than this range, the lubricity and blocking prevention will be insufficient, and if it is more than this, the transparency will deteriorate. The solvent used for coating the heat sealing resin is aromatic hydrocarbons,
Appropriately selected from alcohols, esters, and ketones. Coating is carried out by conventional methods such as gravure coating, trawl coating, reverse roll coating, and dipping. The thickness of the coating layer usually ranges from 0.5 to 3 mm.

If it is thinner than 0.5 mm, the heat sealing strength will be insufficient and the
Even if it is thicker than the thickness, it has no effect on heat sealing strength and is unnecessary.

Regarding printing ink, one-component printing ink is a vehicle made of commonly used thermoplastic resins such as nitrocellulose-based, vinyl chloride-based, polyamide-based, synthetic rubber-based, etc.

Next, an example will be described.

Example 1 See Figure 1, 25 mm thick! A solution prepared by dissolving 2 parts (by weight) of urethane resin in 98 parts of ethyl acetate was coated on the side surface of the film with the aluminum vapor deposited layer 5 on one side of the J ethylene terephthalate film wing using a gravure coating method. Next, it was dried to form an anchor layer 2 with a thickness of 0.4 μm, and on the aluminum vapor deposited surface, 10 parts of a copolymer resin of 8 parts of vinyl chloride, 8 parts of Noto-2 parts of vinyl acetate, 5 parts of rosin, and 2 parts of paraffin wax were added. A solution with a concentration of 15% by weight was made using a mixed solvent of 60 parts of toluene and 2 parts of ethyl acetate and 2 parts of butyl acetate.
A heat-sealing layer 3 of # is provided, and on the surface of the anchor layer 2, a copolymer resin of 5 parts of vinyl chloride, 8 parts of vinyl acetate, 18 parts of vinyl acetate, and 2 parts of maleic acid, and a copolymer resin of 75 parts of vinyl chloride, and 25 parts of vinyl acetate are coated. A solution with a concentration of 15% by weight was made using a mixed melt of copolymer resin 5, 5 parts of phenol-modified rosin, and 3 parts of zinc stearate, 60 parts of toluene, ethyl acetate, 5 parts, and butyl acetate. The film was coated by a gravure coating method and then dried to form a heat-sealing layer 3' having a thickness of 2 mm, thereby obtaining a film with good printability and heat-sealability of the present invention.

The surfaces of the wind heat seal layer 3 are similar, the surfaces of the leg mature seal layer 3' are similar.
and } Overlap the surfaces of heat seal layer 3 and heat seal layer 3' respectively, seal width 3 bars, seal temperature 90 to 1600.
0, pressure 15k9', and heat sealing for 2 seconds each.
An Instron tensile tester was used to measure the peel strength. The measurement results were as shown in the following table, with no difference in B, 'B-, and {C}. (Measured at a tensile speed of 30 minutes) In addition, gravure printing was performed on the surfaces of the heat-sealing layers 3 and 3' using a one-component printing ink, and a cellophane tape test was conducted, and no peeling occurred.

As mentioned above, a film made of polyester film with aluminum vapor-deposited and coated with a paint that has good printability and heat sealability can be easily printed with ordinary one-component ink and the printing cost is low. In addition, because it has good thermal stability, it can take advantage of the mechanical strength, moisture and oxygen barrier properties of polyester film, gloss transparency, and blue retention, as well as metallic effects.

These applications include food packaging, such as packaging for dry foods, packaging for bread and rice crackers, and overwrapping for chocolate and caramel.They can also be used for light packaging for daily necessities and miscellaneous goods.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged sectional view showing the structure of an embodiment of the film with good printability and heat sealability of the present invention. (Drawing code) 1... Polyester film 2...
Anchor layer, 3, 3'... Heat sealing layer, 4... Printing, 5
...Aluminum vapor deposited layer. Undersecretary map

Claims (1)

[Claims] 1 An anchor coating layer is formed on one side of the polyester film, an aluminum vapor deposited layer is formed on the other side, and a vinyl chloride-vinyl acetate-maleic acid copolymer resin or a vinyl chloride-vinyl acetate copolymer resin is further applied on each layer. A film with good printability and heat sealability formed by coating a paint consisting of a polymeric resin alone or a combination of resins, an adhesion aid, and a lubricant.