Holographic anti-counterfeiting film as well as preparation method and application thereof

Abstract

The invention provides a holographic anti-counterfeiting film as well as a preparation method and application thereof. The holographic anti-counterfeiting film comprises a carrier, a connecting layer, a base film, an imaging layer, a plating layer and an adhesive layer which are sequentially overlapped and arranged, a coating of the adhesive layer is prepared from the following preparation raw materials in parts by mass: 15 to 25 parts of isosorbide-based polyurethane, 10 to 20 parts of fluorine-containing polyimide, 60 to 70 parts of a solvent and 1 to 3 parts of a first catalyst; wherein the isosorbide-based polyurethane is prepared from the following raw materials in parts by mass: 19 to 22 parts of isosorbide-based polyester polyol, 41 to 43 parts of polyester polyol, 20 to 25 parts of polyether polyol, 14 to 16 parts of isocyanate, 0.15 to 0.3 part of an antioxidant, 0.2 to 0.35 part of a chain extender and 0.45 to 0.55 part of a second catalyst. The holographic anti-counterfeiting film provided by the invention has good adhesive force when being attached to a PC base material, and has relatively high tensile strength and toughness.

Description

Technical Field

[0001] The present invention relates to the technical field of anti-counterfeiting films, and in particular to a holographic anti-counterfeiting film, a preparation method thereof and applications thereof. Background Art

[0002] In order to improve the anti-counterfeiting performance of various ID cards, hot stamping holographic anti-counterfeiting film on their surface is one of the important means at present. At present, the card substrates of bank cards and membership cards are mostly PVC materials, but PVC is not an environmentally friendly product. Polycarbonate (PC) is an engineering plastic with excellent comprehensive performance. It has excellent impact toughness, dimensional stability, transparency and non-toxicity. It is a suitable substrate for ID cards.

[0003] In daily use, ID cards are inevitably subjected to various degrees of bending, so the card's anti-bending property is also essential, which determines that the adhesive layer we use must have good tensile strength and toughness. Patch film is a double PET structure. The adhesive layer of the anti-counterfeiting patch film mainly plays a connecting role, connecting the plating layer and the card layer. In order to prevent the uniqueness of the card from being imitated and tampered with, it is required that if the holographic anti-counterfeiting patch film is damaged and peeled off, it must be torn to achieve the purpose of protecting the document information and preventing secondary use. This also requires that the adhesion between the adhesive layer and the polycarbonate card layer must be excellent, which is a test of the bonding property of its adhesive.

[0004] However, the PC card substrate has few grafting active sites on its surface, so it is a challenge for the adhesive used in the patch film. At present, the existing domestic card anti-counterfeiting films have problems such as insufficient glossiness of the laser holographic pattern, poor bending resistance, and weak adhesion to the polycarbonate substrate.

[0005] Based on this, the present invention proposes a holographic anti-counterfeiting film, a preparation method and application thereof. Summary of the invention

[0006] Based on the above description, the present invention provides a holographic anti-counterfeiting film, a preparation method and application thereof, to develop a holographic anti-counterfeiting film having a modified polyurethane polyimide block copolymer with good toughness and excellent bonding performance with a PC substrate, which is used for the adhesive layer of the anti-counterfeiting film, effectively solving the problem of the card anti-counterfeiting film being not resistant to bending and having a weak bonding with the PC substrate.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: In a first aspect, the present invention provides a holographic anti-counterfeiting film, comprising a carrier, a connecting layer, a base film, an imaging layer, a coating layer and an adhesive layer which are stacked and arranged in sequence; The coating of the adhesive layer comprises the following raw materials in parts by weight: 15-25 parts of isosorbide-based polyurethane, 10-20 parts of fluorine-containing polyimide, 60-70 parts of solvent and 1-3 parts of a first catalyst; The isosorbide-based polyurethane comprises the following raw materials in parts by weight: 19-22 parts of isosorbide-based polyester polyol, 41-43 parts of polyester polyol, 20-25 parts of polyether polyol, 14-16 parts of isocyanate, 0.15-0.3 parts of antioxidant, 0.2-0.35 parts of chain extender and 0.45-0.55 parts of second catalyst.

[0008] Based on the above technical solution, the present invention can also be improved as follows.

[0009] Furthermore, the coating of the adhesive layer comprises the following raw materials in parts by mass: 20 parts of isosorbide-based polyurethane, 17 parts of fluorinated polyimide, 60 parts of solvent and 3 parts of the first catalyst.

[0010] Furthermore, the first catalyst is one or more of ethylenediamine, N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl)ether, and N,N-dimethylbenzylamine; And / or, the solvent is one or two of N,N-dimethylformamide, tetrahydrofuran, and N-methylpyrrolidone.

[0011] Furthermore, the isosorbide-based polyurethane contains the following raw materials in parts by weight: 21 parts of isosorbide-based polyester polyol, 41 parts of polyester polyol, 21 parts of polyether polyol, 16 parts of isocyanate, 0.2 parts of antioxidant, 0.3 parts of chain extender and 0.5 parts of second catalyst.

[0012] Further, the isosorbide polyester polyol is a polyol synthesized by reacting isosorbide and 1,3-propylene glycol with one of the aliphatic dicarboxylic acids succinic acid, sebacic acid and dodecanedioic acid; And / or, the polyester polyol is one or two of 1,3-propylene glycol, ethylene glycol, trimethylolpropane, pentaerythritol and a polymerization product of phthalic acid, phthalic anhydride, adipic acid, and a halogenated phthalic acid; And / or, the polyether polyol is polyoxypropylene glycol; and / or, the isocyanate is 4,4-diphenylmethane diisocyanate, and / or, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and / or, the chain extender is 1,4-butanediol, And / or, the second catalyst is tetrabutyl titanate.

[0013] Furthermore, the isosorbide polyester polyol is a polyol having a molecular weight Mn of 3500-4000 synthesized by reacting isosorbide and 1,3-propylene glycol with one of the aliphatic dicarboxylic acids succinic acid, sebacic acid and dodecanedioic acid.

[0014] In a second aspect, the present invention provides a method for preparing the holographic anti-counterfeiting film as described in the first aspect, characterized in that it comprises the following steps: S1, sequentially coating the base film with images to obtain an imaging layer, and then plating the medium after molding to obtain a coating layer; S2, sequentially adding a solvent, isosorbide-based polyurethane, a fluorinated polyimide and a first catalyst into a reaction kettle, and fully stirring at a temperature of 100° C. to obtain a glue layer coating liquid; S3, coating the adhesive layer coating liquid obtained in step S2 on the coating layer obtained in step S1, and drying to obtain an adhesive layer; S4, coating a connecting layer on the carrier, and compounding the connecting layer with the adhesive layer to obtain a holographic anti-counterfeiting film.

[0015] Based on the above technical solution, the present invention can also be improved as follows.

[0016] Further, in step S2, the preparation of the isosorbide-based polyurethane comprises the following steps: Slowly add the following weight parts of isosorbide polyester polyol 19-22 parts, polyester polyol 41-43 parts, polyether polyol 20-25 parts, antioxidant 0.15-0.3 parts in the reaction kettle, stir and dehydrate under vacuum at 150°C, and cool naturally to 80°C; Add 14-16 parts of isocyanate, heat to 140-160°C and stir under vacuum, then stop stirring and cool to 70°C under vacuum; Then, 0.2-0.35 parts of a chain extender and 0.45-0.55 parts of a second catalyst are added, stirred evenly, and then cooled to room temperature to obtain an isosorbide-based polyurethane.

[0017] In a third aspect, the present invention provides a use of the holographic anti-counterfeiting film as described in the first aspect on an anti-counterfeiting card.

[0018] Furthermore, the holographic anti-counterfeiting film is thermally transferred onto a PC substrate, the connecting layer is peeled off from the base film, and the adhesive layer is melted by heat and bonded to the PC substrate. The imaging layer wraps the coating layer and is bonded to the surface of the PC substrate through the adhesive layer to form the anti-counterfeiting card.

[0019] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: The present invention provides a holographic anti-counterfeiting film, a preparation method and application thereof, wherein the holographic anti-counterfeiting film comprises a carrier, a connecting layer, a base film, an imaging layer, a plating layer and a glue layer which are stacked and arranged in sequence; the coating of the glue layer comprises the following preparation raw materials in parts by weight: 15-25 parts of isosorbide-based polyurethane, 10-20 parts of fluorine-containing polyimide, 60-70 parts of solvent and 1-3 parts of a first catalyst; wherein the isosorbide-based polyurethane comprises the following preparation raw materials in parts by weight: 19-22 parts of isosorbide-based polyester polyol, 41-43 parts of polyester polyol, 20-25 parts of polyether polyol, 14-16 parts of isocyanate, 0.15-0.3 parts of antioxidant, 0.2-0.35 parts of chain extender and 0.45-0.55 parts of a second catalyst.

[0020] After the anti-counterfeiting film provided by this solution comes into contact with the PC substrate, the adhesive layer plays a good bonding role when exposed to heat. Under the action of a certain temperature and pressure, the hot-melt silicone resin connecting layer and the adhesive of the adhesive layer melt when heated. After the connecting layer melts, its bonding force decreases and it is peeled off from the base film. At the same time, the adhesive bonds the anti-counterfeiting film to the PC substrate. In this way, the imaging layer wrapped with the coating is bonded to the surface of the PC substrate through the adhesive layer, which plays a certain anti-counterfeiting and decorative role.

[0021] Compared with the existing method, this scheme has the following advantages: the mechanical properties (tensile strength, toughness) of the anti-counterfeiting film are improved, because the introduction of isosorbide groups with a rigid structure in the adhesive layer improves the rigidity of the polyurethane molecular chain, reduces the crystallinity, and thus improves the toughness; and due to the synergistic effect of the rigid benzene ring structure of the polyimide in the adhesive layer and the isosorbide groups, the tensile strength of the adhesive layer is significantly enhanced and the toughness is increased; because the benzene ring and the isosorbide groups increase the rigidity of the molecular chain, the difficulty of rotation within the molecular chain increases, and the presence of the carboxyl group on the fluorinated polyimide side group hinders the relative slip between the molecular chains, so that the molecular chain itself and the relative slip motion between the molecular chains are both hindered, resulting in an increase in the tensile strength and toughness of the sample. Therefore, the holographic anti-counterfeiting film provided by the present invention has good adhesion when it is bonded to the subsequent PC substrate, and has high tensile strength and toughness. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a holographic anti-counterfeiting film provided in an embodiment of the present invention; Figure 2 A schematic diagram of the application of the holographic anti-counterfeiting film provided by an embodiment of the present invention; Figure 3 A schematic diagram of the preparation process of the holographic anti-counterfeiting film provided in an embodiment of the present invention; Figure 4 The test results of tensile strength of the mechanical properties test of the holographic anti-counterfeiting films provided in the embodiments and comparative examples of the present invention; Figure 5The test results of the toughness of the mechanical properties test of the holographic anti-counterfeiting films provided in the embodiments and comparative examples of the present invention are shown. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the prior art, the coating is generally vacuum-plated zinc sulfide. After zinc sulfide vapor is deposited on the surface of an object, it will quickly react with oxygen molecules to form a zinc oxide film. This reaction can improve the adhesion and hardness of the film. In addition, zinc sulfide has high transmittance and reflectivity, and can strongly reflect light, so that the color light reflected by the imaging layer becomes a colorful light with the participation and contrast of metallic luster. The adhesive layer is used as an adhesive to connect the electroplated aluminum to the PC substrate. However, the existing anti-counterfeiting film has problems such as insufficient glossiness of the laser holographic pattern, poor bending resistance, and weak adhesion to the polycarbonate substrate.

[0025] Based on this, the embodiments of the present invention provide a new holographic anti-counterfeiting film, a preparation method and application thereof.

[0026] The following is combined with Figures 1 to 5 The embodiments of the present invention are further described in detail with examples. The following examples are used to illustrate the present invention but cannot be used to limit the scope of the present invention.

[0027] like Figure 1 As shown, an embodiment of the present invention provides a holographic anti-counterfeiting film, comprising a carrier, a connecting layer, a base film, an imaging layer, a coating layer and an adhesive layer which are stacked in sequence.

[0028] The coating of the adhesive layer comprises the following raw materials in parts by mass: 15-25 parts of isosorbide-based polyurethane, 10-20 parts of fluorine-containing polyimide, 60-70 parts of solvent and 1-3 parts of the first catalyst.

[0029] Preferably, the coating of the adhesive layer comprises the following raw materials in parts by mass: 20 parts of isosorbide-based polyurethane, 17 parts of fluorinated polyimide, 60 parts of solvent and 3 parts of the first catalyst.

[0030] The isosorbide-based polyurethane comprises the following raw materials in parts by weight: 19-22 parts of isosorbide-based polyester polyol, 41-43 parts of polyester polyol, 20-25 parts of polyether polyol, 14-16 parts of isocyanate, 0.15-0.3 parts of antioxidant, 0.2-0.35 parts of chain extender and 0.45-0.55 parts of second catalyst.

[0031] Wherein, the first catalyst is one or more of ethylenediamine, N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, and N,N-dimethylbenzylamine.

[0032] And / or, the solvent is one or two of N,N-dimethylformamide, tetrahydrofuran, and N-methylpyrrolidone.

[0033] Preferably, the isosorbide-based polyurethane comprises the following raw materials in parts by weight: 21 parts of isosorbide-based polyester polyol, 41 parts of polyester polyol, 21 parts of polyether polyol, 16 parts of isocyanate, 0.2 parts of antioxidant, 0.3 parts of chain extender and 0.5 parts of second catalyst.

[0034] Isosorbide polyester polyol is a polyol synthesized by the reaction of isosorbide and 1,3-propylene glycol with one of the aliphatic dicarboxylic acids succinic acid, sebacic acid and dodecanedioic acid; And / or, the polyester polyol is one or two of 1,3-propylene glycol, ethylene glycol, trimethylolpropane, pentaerythritol and a polymerization product of phthalic acid, phthalic anhydride, adipic acid, or a halogenated phthalic acid; and / or, the polyether polyol is polyoxypropylene glycol; and / or, the isocyanate is 4,4-diphenylmethane diisocyanate, and / or, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and / or, the chain extender is 1,4-butanediol, And / or, the second catalyst is tetrabutyl titanate.

[0035] The isosorbide polyester polyol is a polyol having a molecular weight Mn of 3500-4000 synthesized by reacting isosorbide and 1,3-propylene glycol with one of aliphatic dicarboxylic acids succinic acid, sebacic acid and dodecanedioic acid.

[0036] In order to better explain the holographic anti-counterfeiting film provided in the embodiment of the present invention, Figure 3 As shown, the embodiment of the present invention also provides a method for preparing the above-mentioned holographic anti-counterfeiting film, comprising the following steps: S1. The base film is coated with images in sequence to obtain an imaging layer, and then molded and plated with a medium to obtain a plated layer.

[0037] S2. Add a solvent, isosorbide-based polyurethane, fluorinated polyimide and a first catalyst into a reaction kettle in sequence, and fully stir at 100° C. to obtain a glue layer coating liquid.

[0038] The preparation of isosorbide-based polyurethane comprises the following steps: Slowly add the following weight parts of isosorbide polyester polyol 19-22 parts, polyester polyol 41-43 parts, polyether polyol 20-25 parts, antioxidant 0.15-0.3 parts in the reaction kettle, stir and dehydrate under vacuum at 150°C, and cool naturally to 80°C; Add 14-16 parts of isocyanate, heat to 140-160°C and stir under vacuum, then stop stirring and cool to 70°C under vacuum; Then, 0.2-0.35 parts of a chain extender and 0.45-0.55 parts of a second catalyst are added, stirred evenly, and then cooled to room temperature to obtain an isosorbide-based polyurethane.

[0039] S3, coating the adhesive layer coating liquid obtained in step S2 on the coating layer obtained in step S1, and after drying, obtaining the adhesive layer.

[0040] S4. Coating a connecting layer on the carrier, and compounding the connecting layer with the adhesive layer to obtain a holographic anti-counterfeiting film.

[0041] The holographic anti-counterfeiting film obtained above can be applied to anti-counterfeiting cards.

[0042] Specifically, Figure 2 As shown, the holographic anti-counterfeiting film is thermally transferred to the polycarbonate (PC) substrate, the connecting layer is peeled off from the base film, and the adhesive layer is melted by heat and bonded to the PC substrate. The imaging layer wraps the coating layer and is bonded to the surface of the PC substrate through the adhesive layer to form the anti-counterfeiting card.

[0043] Among them, the connecting layer has a weak bonding force. During the thermal transfer lamination process, since the bonding force between the connecting layer and the base film is smaller than the bonding force between the base film and the imaging layer, the connecting layer will be separated from the base film.

[0044] The following is further introduced in conjunction with specific embodiments: First, the composition and performance of the glue layer in the holographic anti-counterfeiting film are explained with specific examples: Example 1 This embodiment provides a holographic anti-counterfeiting film adhesive layer - polyimide-isosorbide-based polyurethane block copolymer, and its specific preparation process is as follows: In a reaction kettle, 21 parts of isosorbide polyester polyol, 41 parts of polyester polyol, 21 parts of polyoxypropylene glycol and 0.2 parts of antioxidant were slowly added in sequence, and vacuum-stirred and dehydrated at 150°C for 3 hours; then naturally cooled to 80°C, 16 parts of 4,4-diphenylmethane diisocyanate were added, the temperature was raised to 140°C and vacuum-stirred for 50 minutes, stirring was stopped, and vacuum-stirred and cooled to 70°C; then 0.3 parts of chain extender and 0.5 parts of second catalyst were added, stirred evenly and cooled to room temperature to obtain isosorbide polyurethane.

[0045] Afterwards, the above-mentioned 60 parts of solvent were added into the reactor, and then 20 parts of isosorbide-based polyurethane prepared above, 17 parts of fluorinated polyimide, and then 3 parts of the first catalyst were added. After stirring at 100°C for 30 minutes, the adhesive layer coating was obtained for use. The obtained adhesive layer was recorded as PU-PI-1.

[0046] Example 2 This embodiment provides a holographic anti-counterfeiting film adhesive layer - polyimide-isosorbide-based polyurethane block copolymer, and its specific preparation process is as follows: In a reaction kettle, 21 parts of isosorbide polyester polyol, 41 parts of polyester polyol, 21 parts of polyoxypropylene glycol and 0.2 parts of antioxidant were slowly added in sequence, and vacuum-stirred and dehydrated at 150°C for 3 hours, and then naturally cooled to 80°C, and then 16 parts of 4,4-diphenylmethane diisocyanate were added, and the temperature was raised to 160°C and vacuum-stirred for 50 minutes, and then stirring was stopped, and vacuum-stirred and cooled to 70°C, and then 0.3 parts of chain extender and 0.5 parts of the second catalyst were added, and the mixture was stirred evenly and cooled to room temperature to obtain isosorbide polyurethane.

[0047] Then add 70 parts of the above solvent into the reactor, then add 15 parts of the above prepared isosorbide-based polyurethane, 14 parts of fluorinated polyimide, and then add 1 part of the first catalyst. After stirring at 100°C for 30 minutes, the adhesive layer coating is obtained for use. The obtained adhesive layer is recorded as PU-PI-2.

[0048] Example 3 This embodiment provides a holographic anti-counterfeiting film adhesive layer - polyimide-isosorbide-based polyurethane block copolymer, and its specific preparation process is as follows: In a reaction kettle, 21 parts of isosorbide polyester polyol, 41 parts of polyester polyol, 21 parts of polyoxypropylene glycol and 0.2 parts of antioxidant were slowly added in sequence, and vacuum-stirred and dehydrated at 150°C for 3 hours, and then naturally cooled to 80°C, and then 16 parts of 4,4-diphenylmethane diisocyanate were added, and the temperature was raised to 150°C and vacuum-stirred for 50 minutes, and then the stirring was stopped, and the vacuum-stirred and cooled to 70°C, and then 0.3 parts of chain extender and 0.5 parts of the second catalyst were added, and the mixture was stirred evenly and cooled to room temperature to obtain isosorbide polyurethane.

[0049] Then add 65 parts of the above solvent into the reactor, then add 18 parts of the above prepared isosorbide-based polyurethane, 20 parts of fluorinated polyimide, and then add 2 parts of the first catalyst. After stirring at 100°C for 30 minutes, the adhesive layer coating is obtained for use. The obtained adhesive layer is recorded as PU-PI-3.

[0050] Comparative Example 1 This comparative example provides a holographic anti-counterfeiting film adhesive layer - polyimide-polyurethane block copolymer, and its specific preparation process is as follows: In the reaction kettle, 62 parts of polyester polyol, 21 parts of polyoxypropylene glycol and 0.2 parts of antioxidant were slowly added in sequence, and vacuum-stirred and dehydrated at 150°C for 3 hours, and then naturally cooled to 80°C, and then 16 parts of 4,4-diphenylmethane diisocyanate were added, and the temperature was raised to 140°C and vacuum-stirred for 50 minutes, and then the stirring was stopped, and the vacuum-stirred and cooled to 70°C, and then 0.3 parts of chain extender and 0.5 parts of catalyst were added, and the mixture was stirred evenly and cooled to room temperature to obtain polyurethane.

[0051] Then, 60 parts of the above solvent were added into the reaction kettle, followed by 37 parts of the above prepared polyurethane, and then 3 parts of the catalyst. After stirring at 100° C. for 30 minutes, a glue layer coating was obtained for use. The obtained glue layer was recorded as PU-PI-4.

[0052] Comparative Example 2 This comparative example provides a holographic anti-counterfeiting film adhesive layer - polyimide-polyurethane block copolymer, and its specific preparation process is as follows: In the reaction kettle, 62 parts of polyester polyol, 21 parts of polyoxypropylene glycol and 0.2 parts of antioxidant were slowly added in sequence, and vacuum-stirred and dehydrated at 150°C for 3 hours, then naturally cooled to 80°C, and then 16 parts of 4,4-diphenylmethane diisocyanate were added, and the temperature was raised to 140°C and vacuum-stirred for 50 minutes, and then the stirring was stopped, and the vacuum-stirred was cooled to 70°C, and then 0.3 parts of chain extender and 20.5 parts of catalyst were added, and the mixture was evenly stirred and cooled to room temperature to obtain polyurethane.

[0053] Then add 60 parts of the above solvent into the reactor, then add 20 parts of the above prepared polyurethane, 17 parts of fluorinated polyimide, and then add 3 parts of the first catalyst. After stirring at 100°C for 30 minutes, the adhesive layer coating is obtained for use. The obtained adhesive layer is recorded as PU-PI-5.

[0054] Comparative Example 3 This comparative example provides an adhesive layer of a holographic anti-counterfeiting film, namely, isosorbide-based polyurethane, and the specific preparation process thereof is as follows: In a reaction kettle, 21 parts of isosorbide-based polyester polyol, 41 parts of polyester polyol, 21 parts of polyoxypropylene glycol, and 0.2 parts of antioxidant were slowly added in sequence, and vacuum-stirred and dehydrated at 150°C for 3 hours, and then naturally cooled to 80°C, and then 16 parts of 4,4-diphenylmethane diisocyanate were added, and the temperature was raised to 140°C-160°C and vacuum-stirred for 50 minutes, and then the stirring was stopped, and the vacuum-stirred and cooled to 70°C, and then 0.3 parts of chain extender and 20.5 parts of catalyst were added, and the mixture was evenly stirred and cooled to room temperature to obtain isosorbide-based polyurethane.

[0055] Then add 60 parts of the above solvent into the reactor, then add 37 parts of the isosorbide-based polyurethane prepared above, then add 3 parts of the first catalyst, stir at 100°C for 30 minutes to obtain the adhesive layer coating for use, and the obtained adhesive layer is recorded as PU-PI-6. In order to test the adhesion of the adhesive layer provided in the above embodiments and comparative examples, the samples were specifically prepared as follows: a layer of the prepared coatings of the six schemes was scraped on a polycarbonate card (it should be noted that except for the different types of adhesive layer coatings, other coating conditions and coating amounts were the same).

[0056] After painting, place in oven to dry.

[0057] Then, the adhesion between the adhesive layer and the substrate was tested using the 100-grid method (according to ASTM grade classification): Use a grid knife to cut a 1mm×1mm cross grid shape on the coating, and cut to the bottom layer of the coating; Then use a brush to remove small debris in the diagonal direction, and then stick 3M tape on the cut and pull it upwards. The adhesion of the tape is about 350-400g / square meter. Finally, use a magnifying glass to observe the condition of the grid area and determine the adhesion level based on the peeling condition. The results are shown in Table 1.

[0058] Table 1

[0059] From the above test results, it can be seen that the polyimide isosorbide-based polyurethane block copolymer in the example has excellent adhesion to the PC substrate; the blank sample result of comparative example 1 (PU-PI-4) shows that the synergistic effect of polyimide isosorbide-based polyurethane can effectively enhance the adhesion of the coating to the PC substrate; comparative examples 2 and 3 (PU-PI-5 and PU-PI-6) show that the modification of a single component has limited effect on improving the adhesion of the coating.

[0060] This is because the introduction of isosorbide and fluorinated polyimide improves polarity and enhances the cohesion of the resin, thereby effectively improving adhesion. The carbonate groups on the surface of the polycarbonate card substrate can react with the urethane groups in the isosorbide-based polyurethane to form hydrogen bonds, increasing the adhesion strength between the adhesive and the PC substrate.

[0061] Furthermore, the adhesive layer coating is used in the holographic anti-counterfeiting film structure of ID cards to verify the effect.

[0062] Preparation of holographic anti-counterfeiting film: Prepare a 23u thick PET base film, and apply an equal thickness of the formulated adhesive layer in the above embodiment according to the aforementioned holographic anti-counterfeiting film structure and the corresponding coating route map. Then use a laminating machine to cover the holographic anti-counterfeiting film on the surface of the PC card at 180°C. The film has good adhesion and good toughness.

[0063] Material toughness test: Test sample preparation: Take an appropriate amount of PU-PI adhesive layer coating, pour it into a polytetrafluoroethylene mold (10cm×10cm), put it in an 80℃ oven for 11 hours, and place it at room temperature for 3 days to obtain the PU-PI sample. (When preparing the sample, except for the type of adhesive layer coating, the other temperature, time, mold and other conditions are the same).

[0064] Mechanical properties testing equipment: The mechanical properties of polymers were tested using an electronic universal testing machine at a test speed of 300 mm / min. The test results are as follows: Figure 4 and Figure 5 As shown, Figure 4 and Figure 5 The results are respectively the test results of tensile strength and toughness. It can be seen that the adhesion of Examples 1 to 3 is very good, and the toughness is also good, especially Example 1.

[0065] In summary, combined with the test results, it can be seen that the mechanical properties (tensile strength, toughness) of the holographic anti-counterfeiting film provided in the embodiment of the present invention are better than those of the samples in the comparative examples. This is because the introduction of isosorbide groups with a rigid structure improves the rigidity of the polyurethane molecular chain, reduces the crystallinity, and thus improves the toughness; and due to the synergistic effect of the rigid benzene ring structure of polyimide and the isosorbide groups, the tensile strength of PU-PI-1 is significantly enhanced and the toughness is increased. Because the benzene ring and isosorbide groups increase the rigidity of the molecular chain, the difficulty of rotation within the molecular chain increases, and the presence of carboxyl groups on the PI side groups hinders the relative slip between the molecular chains, so that the molecular chain itself The movement and the relative slip movement between the molecular chains are both increased, resulting in an increase in the tensile strength and toughness of the sample.

[0066] Therefore, the holographic anti-counterfeiting film provided by the embodiment of the present invention has good adhesion when attached to the PC substrate, and has high tensile strength and toughness.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A holographic anti-counterfeiting film, characterized in that: It includes a carrier, a connecting layer, a base film, an imaging layer, a coating layer and a glue layer which are stacked and arranged in sequence; The coating of the adhesive layer comprises the following raw materials in parts by weight: 15-25 parts of isosorbide-based polyurethane, 10-20 parts of fluorine-containing polyimide, 60-70 parts of solvent and 1-3 parts of a first catalyst; The isosorbide-based polyurethane comprises the following raw materials in parts by weight: 19-22 parts of isosorbide-based polyester polyol, 41-43 parts of polyester polyol, 20-25 parts of polyether polyol, 14-16 parts of isocyanate, 0.15-0.3 parts of antioxidant, 0.2-0.35 parts of chain extender and 0.45-0.55 parts of second catalyst.

2. The holographic anti-counterfeiting film according to claim 1, characterized in that: The coating of the adhesive layer comprises the following raw materials in parts by mass: 20 parts of isosorbide-based polyurethane, 17 parts of fluorine-containing polyimide, 60 parts of solvent and 3 parts of the first catalyst.

3. The holographic anti-counterfeiting film according to claim 1 or 2, characterized in that: The first catalyst is one or more of ethylenediamine, N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, and N,N-dimethylbenzylamine; And / or, the solvent is one or two of N,N-dimethylformamide, tetrahydrofuran, and N-methylpyrrolidone.

4. The holographic anti-counterfeiting film according to claim 1, characterized in that: The isosorbide-based polyurethane comprises the following raw materials in parts by weight: 21 parts of isosorbide-based polyester polyol, 41 parts of polyester polyol, 21 parts of polyether polyol, 16 parts of isocyanate, 0.2 parts of antioxidant, 0.3 parts of chain extender and 0.5 parts of second catalyst.

5. The holographic anti-counterfeiting film according to claim 1 or 4, characterized in that: The isosorbide polyester polyol is a polyol synthesized by reacting isosorbide and 1,3-propylene glycol with one of the aliphatic dicarboxylic acids succinic acid, sebacic acid and dodecanedioic acid; And / or, the polyester polyol is one or two of 1,3-propylene glycol, ethylene glycol, trimethylolpropane, pentaerythritol and a polymerization product of phthalic acid, phthalic anhydride, adipic acid, and a halogenated phthalic acid; And / or, the polyether polyol is polyoxypropylene glycol; and / or, the isocyanate is 4,4-diphenylmethane diisocyanate, and / or, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and / or, the chain extender is 1,4-butanediol, And / or, the second catalyst is tetrabutyl titanate.

6. The holographic anti-counterfeiting film according to claim 5, characterized in that: The isosorbide polyester polyol is a polyol having a molecular weight Mn of 3500-4000 synthesized by reacting isosorbide and 1,3-propylene glycol with one of aliphatic dicarboxylic acids succinic acid, sebacic acid and dodecanedioic acid.

7. A method for preparing a holographic anti-counterfeiting film according to any one of claims 1 to 6, characterized in that: The steps include: S1, sequentially coating the base film with images to obtain an imaging layer, and then plating the medium after molding to obtain a coating layer; S2, sequentially adding a solvent, isosorbide-based polyurethane, a fluorinated polyimide and a first catalyst into a reaction kettle, and fully stirring at a temperature of 100° C. to obtain a glue layer coating liquid; S3, coating the adhesive layer coating liquid obtained in step S2 on the coating layer obtained in step S1, and drying to obtain an adhesive layer; S4, coating a connecting layer on the carrier, and compounding the connecting layer with the adhesive layer to obtain a holographic anti-counterfeiting film.

8. The method for preparing a holographic anti-counterfeiting film according to claim 7, characterized in that: In step S2, the preparation of the isosorbide-based polyurethane comprises the following steps: Slowly add the following weight parts of isosorbide polyester polyol 19-22 parts, polyester polyol 41-43 parts, polyether polyol 20-25 parts, antioxidant 0.15-0.3 parts in the reaction kettle, stir and dehydrate under vacuum at 150°C, and cool naturally to 80°C; Add 14-16 parts of isocyanate, heat to 140-160°C and stir under vacuum, then stop stirring and cool to 70°C under vacuum; Then, 0.2-0.35 parts of a chain extender and 0.45-0.55 parts of a second catalyst are added, stirred evenly, and then cooled to room temperature to obtain an isosorbide-based polyurethane.

9. Use of the holographic anti-counterfeiting film according to any one of claims 1 to 6 on anti-counterfeiting cards.

10. The use according to claim 9, characterized in that: The application on the anti-counterfeiting card specifically includes: thermally transferring the holographic anti-counterfeiting film to a PC substrate, peeling off the connecting layer and the base film, and at the same time, the adhesive layer is melted by heat and bonded to the PC substrate, and the imaging layer wraps the coating layer and is bonded to the surface of the PC substrate through the adhesive layer to form the anti-counterfeiting card.

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