Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44C—PRODUCING DECORATIVE EFFECTS; MOSAICS; TARSIA WORK; PAPERHANGING
  • B44C1/00—Processes, not specifically provided for elsewhere, for producing decorative surface effects
  • B44C1/16—Processes, not specifically provided for elsewhere, for producing decorative surface effects for applying transfer pictures or the like
  • B44C1/165—Processes, not specifically provided for elsewhere, for producing decorative surface effects for applying transfer pictures or the like for decalcomanias; sheet material therefor
  • B44C1/17—Dry transfer
  • B44C1/1712—Decalcomanias applied under heat and pressure, e.g. provided with a heat activable adhesive
  • B44C1/1716—Decalcomanias provided with a particular decorative layer, e.g. specially adapted to allow the formation of a metallic or dyestuff layer on a substrate unsuitable for direct deposition
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/04—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the partial melting of at least one layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D1/00—Processes for applying liquids or other fluent materials
  • B05D1/28—Processes for applying liquids or other fluent materials performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B15/08—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/18—Layered products comprising a layer of metal comprising iron or steel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/20—Layered products comprising a layer of metal comprising aluminium or copper
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44C—PRODUCING DECORATIVE EFFECTS; MOSAICS; TARSIA WORK; PAPERHANGING
  • B44C1/00—Processes, not specifically provided for elsewhere, for producing decorative surface effects
  • B44C1/10—Applying flat materials, e.g. leaflets, pieces of fabrics
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44C—PRODUCING DECORATIVE EFFECTS; MOSAICS; TARSIA WORK; PAPERHANGING
  • B44C5/00—Processes for producing special ornamental bodies
  • B44C5/04—Ornamental plaques, e.g. decorative panels, decorative veneers
  • B44C5/0415—Ornamental plaques, e.g. decorative panels, decorative veneers containing metallic elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D2508/00—Polyesters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/06—Coating on the layer surface on metal layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/26—Polymeric coating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/40—Properties of the layers or laminate having particular optical properties
  • B32B2307/402—Coloured
  • B32B2307/4023—Coloured on the layer surface, e.g. ink
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles
  • B32B2439/70—Food packaging

Definitions

• the present invention relates to a process for decorating a metal substrate , in particular a metal substrate that can be used as a container for food —general line or aerosol cans .
• Metal packaging is the key to many food safety concerns or to maintain the correct shel f li fe of chemicals or cosmetics .
• Such packaging is strong and seamless and provides a durable solution for storing food, blocking out contaminants or light ( e . g . , UV radiation) .
• Aluminum, electrolytic tinplate or tin tree steel are most often used as the metal substrate for such packaging .
• a coating, clear or white is applied to the substrate and thereafter a decoration is printed on the substrate using a well-known printing technique , for example by of fset lithographic printing .
• ink is trans ferred in the desired pattern from the surface of a aluminum plate to a rubber blanket and then to the metal substrate .
• This process has a number of drawbacks , for example :
• a multicolor off set printing machine is composed by many single-color stages aligned .
• the substrate passes over every stage and each color of ink is applied separately, there is one image plate per color .
• the image needs to be aligned for each color .
• the density of the color needs to be carefully adj usted regarding the particular run .
• the operator needs to adj ust the ink/water balance to ensure full and steady ink flow for accurate color reproduction . This setup process consumes a lot of time .
• WO2008 / 152137 a method for decorating a substrate using a printed adhesive film is disclosed .
• a decoration is printed onto a thermoplastic adhesive film and then the adhesive film is appl ied to the substrate . Since the decoration is on the opposite side of the adhesive , this means that once the adhesive film is applied to the substrate , the decoration is in direct contact with the environment .
• This process shows the same drawbacks as the process of US20180164718 , vi z . the absence of any protection of the image once applied on the substrate .
• An alternative process is also disclosed wherein the decoration is further protected with a second adhesive film . This makes this process more complex and prone to failure . Further, such a film or multiple layers of film, including the decoration, are easily removed from the substrate .
• the process for decorating a metal substrate comprises the following steps : a ) Applying a coating composition to the metal substrate ; b ) Curing the coating composition applied in step a ) at a temperature T1 for a time suf ficient to obtain a tack- free coating; c ) Printing the decoration on a polymer film using a digital printer ; d) Laminating the polymer film with the decoration onto the coated metal substrate , whereby the decoration is positioned between the surface of the coated metal substrate and the polymer film, and e ) During lamination heating to a temperature T2 and applying a pressure Pl , and f) After the lamination exposing the substrate to a temperature T3 a time sufficient to fully cure the coating .
• a multicolor decoration means a decoration that is not just a combination of white and black, but that has at least one further color, like, cyan, magenta, yellow, etc . ;
• Peak metal temperature refers to the temperature of the relevant metal substrate. In general, the peak metal temperature is lower that the temperature of the oven or other means that is used to heat the substrate, and depends, i.a., on the residence time in the oven or more general on the time the substrate is heated.
• Shelf life of a coating means the time wherein the coating shows an increase in viscosity of less than 10% when stored under ambient conditions (23°C, 65% r.h.) ;
• a tack-free coating means that a stack of coated metal substrates can be formed and that thereafter the individual coated metal substrates can be separated without any visible damage to the coating and without any noticeable sticking of adjacent coated substrates.
• a coating composition means a mixture of different ingredients that can be transferred into a coating film by exposure to elevated temperatures and/or evaporation of solvent that is present in the composition.
• the metal substrate that is used in the process of the present invention can be a thin metal plate suitable for use as a food or general line or aerosol cans.
• Aluminum, electrolytic tinplate or Tin Free Steel is normally used for such metal substrate.
• Metal substrates used for food or beverage packaging normally have a thickness in the range from 0,1 - 0,5 mm.
• the metal substrate that is used in the process of the present invention can be flat or curved. If the substrate is flat, it can be formed into the desired shape as a food or beverage container in a further process step. However, it is also possible to use the process of the present invention to put a decoration on a pre-formed can or container.
• the coating composition that is applied to the metal substrate can be a clear coating composition or a white coating composition.
• a clear coating composition is typically used when it is desired to have the surface of the container visible in combination with the decoration.
• a white coating composition is typically used to completely cover the surface of the substrate.
• the coating composition is applied to protect the substrate from corrosion, and to act as an adhesive layer for the polymer film carrying the decoration.
• the initial curing temperature of the coating composition should be in the range of 130 - 140°C peak metal temperature (PMT) , preferably in the range from 130 - 140°C PMT.
• PMT peak metal temperature
• the coating should be tack-free. If the temperature for this initial step is higher than 140°C PMT, the amount of energy needed to cure the coating would be rather high, if the curing temperature is below 90°C the storage stability of the coating will be affected, and the self-life of the coating would be limited. Normally for these types of coatings a shelf-life of at least 3 months, more preferably of at least 6 months is desired.
• the initial curing is done for 10 - 12 minutes at the PMT in the range of 130 - 140°C.
• a coating composition that contains from 75 - 80 wt . % of a saturated polyester resin (where the wt . % is based on the solid content of the coating without any pigment (s) ) is highly suitable to be used as a coating composition in the process according to the present invention.
• the coating composition is normally solvent based, where solvent naphtha and butyl-glycol are some of the preferred solvents.
• Other ingredients that are optionally present in the coating composition are epoxy acrylate resins, blocked polyisocyanate resins, and melamine resins.
• the coating composition also contains a small amount of lanolin, normally the lanolin content if from 0,02 to 0,06 wt . % (where the wt . % is based on the solid content of the coating without any pigment (s) ) .
• the decoration it printed on a polymer film using a digital printer.
• the polymer film is flexible and has a thickness in the range from 5 to 50 pm.
• a type of film is used that is well known in the art, such as a polyester film or a polycarbonate film.
• any suitable digital printer can be used to print the decoration on the polymer film.
• the decoration that is printed on the polymer film can have a single color, is a black and white image (plus various shades of gray) or is a multicolor image.
• the polymer film with the decoration printed thereon is then laminated on the tack- free coated metal substrate .
• this lamination process the side of the polymer film that carries the decoration is laminated on the coated substrate , so after completion of this lamination process , the decoration is positioned between the surface of the coated substrate and the polymer film .
• care should be taken that the decoration and/or the polymer film remain their original dimensions , so care should be taken that no stretching or wrinkling of the polymer film occurs in this lamination process .
• this lamination process is done in two steps .
• step 1 the polymer film with the decoration is laminated onto the coated substrate at a gentle pressure at a PMT in the range from 110 - 140 ° C, thereafter, in step 2 , the pressure is increased, and lamination is continued at a PMT in the range from 130 - 170 ° C . At this latter temperature , the coating is f inally fully cured for about 10 minutes .
• the two-step lamination process can be described as a process wherein the polymer film with the decoration i s laminated onto the coated metal substrates , wherein in step 1 the lamination is done at a temperature T2 , I and a pressure P2, i, and in step 2 , the lamination is continued at a temperature T2,2 and a pressure P2,2 , wherein T2 , I ⁇ T2,2 and P2, i ⁇ ?2,2 .
• the metal substrate that is obtained through the process of the present invention can thereafter be formed into any form or shape, for example it can be formed into a container or packaging material for food or beverages.
• the metal substrate is a thin plate, it can be formed into a container through a metal shaping process, such as a deep-drawing technique or through stamping.
• FIG. 1 an embodiment for decorating the polymer film is illustrated.
• a clear polymer film (1) is passed through a digital printer (2) to be decorated.
• the decorated polymer film (3) is then collected by rolling it onto a bobbin.
• FIG. 2 an embodiment for coating the metal sheet is illustrated.
• the raw metal sheet (5) is put in a roll coater (6) .
• the metal sheet is coated with a coating composition (7) .
• the coated metal sheet passes through an oven to cure the coating composition.
• the coated sheets (10) are stacked (9) .
• FIG 3 an embodiment for decorating the coated metal sheet is illustrated.
• the coated sheets (10) are put in a feeder system (11) to pass, together with the decorated polymer film (3) , through a heated calender roll (12) and a pressure roll (13) . Through heat and pressure, the decorated film is laminated to the coated sheet.
• the now laminated coated sheet is discharged on a conveyor belt (14) equipped with a heating system (15) above the belt.
• a heat separator (16) the decorated metal sheets (18) are collected on a stack ( 17 ) .

Landscapes

• Laminated Bodies (AREA)
• Coating Apparatus (AREA)
• Printing Methods (AREA)
• Application Of Or Painting With Fluid Materials (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=81344411

Family Applications (1)

Country Status (8)

Citations (6)

Family Cites Families (4)

• 2023
  • 2023-04-19 AU AU2023258056A patent/AU2023258056A1/en active Pending
  • 2023-04-19 CN CN202380034780.9A patent/CN119053456A/zh active Pending
  • 2023-04-19 US US18/857,639 patent/US20250249702A1/en active Pending
  • 2023-04-19 JP JP2024561939A patent/JP2025514077A/ja active Pending
  • 2023-04-19 EP EP23718964.2A patent/EP4511239A1/en active Pending
  • 2023-04-19 WO PCT/BR2023/050123 patent/WO2023201408A1/en not_active Ceased
  • 2023-04-19 IL IL316345A patent/IL316345A/en unknown
• 2024
  • 2024-10-16 MX MX2024012811A patent/MX2024012811A/es unknown

Patent Citations (6)

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