Coating liquid, packaging film with coating liquid and production method of packaging film

Abstract

The invention discloses a coating liquid, a packaging film with the coating liquid and a production method of the packaging film, and the coating liquid is prepared from the following raw materials in parts by weight: 5 parts of nano zinc oxide powder, 76 parts of absolute ethyl alcohol, 5 parts of water and 5 parts of ultraviolet light absorber UV-P. Comprising a contact film used for making contact with food, a printing film arranged on the contact film and anti-ultraviolet antibacterial glue arranged between the contact film and the printing film, and the anti-ultraviolet antibacterial glue comprises an adhesive and coating liquid mixed in the adhesive and used for enhancing the anti-ultraviolet function and the antibacterial function.

Description

Technical Field

[0001] The invention relates to the technical field of food packaging, and in particular to a coating liquid, a packaging film having the coating liquid, and a production method of the packaging film. Background Art

[0002] In modern society, in order to allow consumers to directly observe the appearance of food, so that consumers can more easily understand food, and in order to better attract consumers, manufacturers usually use transparent packaging film to vacuum pack food when producing some snacks such as chicken legs, duck legs, and sausages. However, not all foods packaged with transparent packaging film are placed in supermarkets. Most foods are inevitably exposed to direct sunlight during transportation and display. The ultraviolet rays will cause the packaging film and food to change color, especially the collagen-rich casings. The color change is particularly serious, which can easily mislead consumers that the food is damaged, making the product unsaleable and finally destroyed, causing economic losses to the merchants while wasting social resources. Summary of the invention

[0003] Therefore, in view of the above problems, the present invention provides a coating liquid, a packaging film having the coating liquid, and a method for producing the packaging film.

[0004] To achieve the above object, the technical solution of the present invention is to provide a coating liquid, comprising the following raw materials in parts by weight: 5 parts of nano zinc oxide powder, 76 parts of anhydrous ethanol, 5 parts of water, and 5 parts of ultraviolet absorber UV-P.

[0005] A packaging film with a coating liquid comprises a contact film for contacting food, a printing film arranged on the contact film, and an anti-ultraviolet and antibacterial glue arranged between the contact film and the printing film. The anti-ultraviolet and antibacterial glue comprises: an adhesive and a coating liquid mixed in the adhesive for enhancing the anti-ultraviolet and antibacterial functions.

[0006] A further improvement is that the contact film is a RCPP film.

[0007] A further improvement is that the printing film is a PET film.

[0008] A method for producing a packaging film with a coating liquid comprises the following steps: Step S1, weighing nano zinc oxide powder, anhydrous ethanol, water, and ultraviolet absorber UV-P to prepare a coating solution; Step S2, mixing the coating liquid and the adhesive evenly to form an anti-ultraviolet and antibacterial glue, and adding the mixture into a dry laminating machine; Step S3: installing the contact film and the printed film on a dry laminating machine and performing dry lamination with anti-ultraviolet and antibacterial adhesive to obtain a packaging film.

[0009] A further improvement is that step S1 further includes the following steps: Step S11, placing the nano zinc oxide powder in a vacuum drying oven for vacuum drying at a temperature of 60° C. for a drying time of 6 h; Step S12, adding 5 mL of deionized water to 95 mL of anhydrous ethanol solution to prepare an ethanol solution with a volume fraction of 95% as a reaction solvent, and then weighing 5 g of dried nano zinc oxide powder and 5 g of UV-P anti-ultraviolet absorber, and adding them to the reaction solvent; Step S13, oscillating the reaction solvent by an ultrasonic oscillator until the nano zinc oxide powder is evenly dispersed, the oscillation time is 1 hour; Step S14, transferring the reaction solvent after the shaking to a constant temperature water bath for stirring, the stirring time is 1.5 hours, the stirring temperature is 85° C., and the stirring speed is 600 r / min; Step S15, using an ultrasonic degasser to degas the stirred reaction solvent to obtain a coating solution, and the degassing time is 0.5 h.

[0010] A further improvement is that in step S2, the ratio of the coating liquid to the adhesive is 1:5.

[0011] A further improvement is that the adhesive is a two-component polyurethane high-temperature cooking adhesive.

[0012] A further improvement is that the two-component polyurethane high-temperature cooking adhesive comprises: glue A and glue B added into glue A together with the coating liquid, and the ratio of glue A to glue B is 5:1.

[0013] Further improvement is that: the density of the A glue is 1.02g / ml, and the viscosity is 800-1000MPa.s at 25°C.

[0014] Further improvement is that: the B glue has a density of 1.27g / ml and a viscosity of 25-50MPa.s at 25°C.

[0015] A further improvement is that in step S2, the coating liquid and the adhesive need to be stirred at a stirring speed of 2800 r / min and a stirring time of 15 min.

[0016] A further improvement is that the temperature of the hot pressing roller of the dry laminating machine in step S3 is 50-90°C.

[0017] A further improvement is that in step S3, the drying tunnel temperature of the dry compound machine is set in three stages, and the three stages are 45-65°C, 65-75°C, and 75-85°C respectively.

[0018] A further improvement is that the method further comprises the following steps: placing the packaging film obtained after dry compounding into a curing chamber for curing at a curing temperature of 50° C. for a curing time of 48 hours.

[0019] A further improvement is that in step S3, 3 g of anti-ultraviolet and antibacterial glue is coated on each square meter of packaging film.

[0020] The advantages and beneficial effects of the present invention are: 1. Nano zinc oxide powder is added to the coating liquid, which can enhance the coating liquid's anti-ultraviolet and antibacterial properties. On the one hand, it can extend the shelf life of the food itself, and on the other hand, it reduces the effect of ultraviolet rays on food discoloration, solves the discoloration problem of products with collagen casings, avoids the waste of sausages being discarded due to discoloration, and saves social resources.

[0021] 2. The coating liquid can be mixed with polyurethane adhesive to ensure that the coating liquid is more evenly distributed. It can also reduce the number of coatings, reduce production processes, and reduce production costs.

[0022] 3. The anti-ultraviolet and antibacterial glue with coating liquid is located in the middle of the packaging film and does not directly contact the physical object or human body. It is highly safe and can be directly used in the existing production process, making it easy to use.

[0023] 4. The nano zinc oxide contained in the anti-ultraviolet antibacterial glue can inhibit or kill bacteria, prevent them from multiplying and growing on the surface of the packaging film, destroy the bacterial cell wall and cell membrane, leading to bacterial death, and interfere with the bacterial metabolic process, preventing the normal growth and reproduction of bacteria. It can disinfect a wide range of bacteria such as Gram-positive bacteria and Gram-negative bacteria; fungi: Candida albicans, etc., and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of a coating liquid, a packaging film having the coating liquid, and a production method of the packaging film of the present invention; Figure 2 It is a schematic diagram of a dry composite process of a coating liquid, a packaging film having the coating liquid and a production method of the packaging film of the present invention; In the figure: 101, contact film; 102, printing film; 103, anti-ultraviolet and antibacterial glue; 104, first unwinding; 105, second unwinding; 106, glue tank; 107, glue coating roller; 108, drying tunnel; 109, hot pressing roller; 110, winding section. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention. Example 1

[0026] like Figure 1-Figure 2As shown, a coating liquid is characterized in that it includes the following raw materials in parts by weight: 5 parts of nano zinc oxide powder, 76 parts of anhydrous ethanol, 5 parts of water, and 5 parts of ultraviolet absorber UV-P.

[0027] A packaging film with a coating liquid comprises a contact film 101 for contacting food, a printed film 102 arranged on the contact film 101, and an anti-ultraviolet and antibacterial adhesive 103 arranged between the contact film 101 and the printed film 102. The anti-ultraviolet and antibacterial adhesive 103 comprises: an adhesive and a coating liquid mixed in the adhesive for enhancing the anti-ultraviolet and antibacterial functions.

[0028] In order to improve the safety of food, the contact film 101 is a RCPP film.

[0029] In order to facilitate printing of various patterns on the outside of the packaging film, the printing film 102 is a PET film.

[0030] A method for producing a packaging film with a coating liquid comprises the following steps: Step S1, weighing nano zinc oxide powder, anhydrous ethanol, water, and ultraviolet absorber UV-P to prepare a coating solution; Step S2, mixing the coating liquid and the adhesive evenly to form the anti-ultraviolet and antibacterial glue 103, and adding the anti-ultraviolet and antibacterial glue 103 to the dry compound machine; Step S3: Install the contact film 101 and the printed film 102 on a dry laminating machine and perform dry lamination with the anti-ultraviolet and antibacterial adhesive 103 to obtain a packaging film.

[0031] In order to facilitate the production of the coating liquid so that the nano zinc oxide powder is evenly spread, step S1 also includes the following steps: Step S11, placing the nano zinc oxide powder in a vacuum drying oven for vacuum drying at a temperature of 60° C. for a drying time of 6 h; Step S12, adding 5 mL of deionized water to 95 mL of anhydrous ethanol solution to prepare an ethanol solution with a volume fraction of 95% as a reaction solvent, and then weighing 5 g of dried nano zinc oxide powder and 5 g of UV-P anti-ultraviolet absorber, and adding them to the reaction solvent; Step S13, oscillating the reaction solvent by an ultrasonic oscillator until the nano zinc oxide powder is evenly dispersed, the oscillation time is 1 hour; Step S14, transferring the reaction solvent after the shaking to a constant temperature water bath for stirring, the stirring time is 1.5 hours, the stirring temperature is 85° C., and the stirring speed is 600 r / min; Step S15, using an ultrasonic degasser to degas the stirred reaction solvent to obtain a coating solution, and the degassing time is 0.5 h.

[0032] In step S2, the ratio of the coating liquid to the adhesive is 1:5.

[0033] In order to facilitate the bonding of the contact film 101 and the printed film 102, the adhesive is a two-component polyurethane high-temperature cooking adhesive; the two-component polyurethane high-temperature cooking adhesive includes: A glue, B glue added to A glue together with the coating liquid, and the ratio of A glue to B glue is 5:1; the density of A glue is 1.02g / ml, and the viscosity is 800-1000MPa.s at 25°C; the density of B glue is 1.27g / ml, and the viscosity is 25-50MPa.s at 25°C.

[0034] In order to evenly mix the coating liquid and the adhesive, in step S2, the coating liquid and the adhesive need to be stirred at a stirring speed of 2800 r / min and a stirring time of 15 min.

[0035] In step S3, the temperature of the hot pressing roller 109 of the dry laminating machine is 50-90°C.

[0036] In step S3, the temperature of the drying tunnel 108 of the dry laminating machine is set in three stages, and the three stages are 45-65° C., 65-75° C., and 75-85° C. respectively.

[0037] like Figure 2 As shown, when performing step S3, the contact film 101 and the printed film 102 are respectively installed at the first unwinding 104 and the second unwinding 105, and the anti-ultraviolet antibacterial glue 103 is added into the glue tank 106. At this time, the contact film 101 can be coated with the anti-ultraviolet antibacterial glue 103 under the action of the glue coating roller 107, and then dried in the drying tunnel 108 to volatilize the solvent and enhance the adhesion. Then, the contact film 101 coated with the anti-ultraviolet antibacterial glue 103 and the printed film 102 are compounded together by the hot pressing roller 109 to complete the dry compounding. Finally, the winding section 110 winds up the composite packaging film.

[0038] The method also includes the following steps: placing the packaging film obtained after dry compounding into a curing chamber for curing at a curing temperature of 50° C. for a curing time of 48 hours.

[0039] In order to save costs and improve the use effect of the packaging film, in the step S3, 3 g of anti-ultraviolet and antibacterial glue 103 is coated on each square meter of the packaging film; At this time, every 3 g of the anti-ultraviolet and antibacterial glue 103 contains 0.5 g of the coating liquid.

[0040] The product of Example 1 was tested as follows: The test products are: bagged crispy sausage; Control group 1: packaging film without coating liquid added; Control group 2: packaging film containing 0.4 g of coating liquid per 3 g of anti-ultraviolet and antibacterial glue; Control group 3: packaging film containing 0.6 g of coating liquid per 3 g of anti-ultraviolet and antibacterial glue;

[0041] Table 1

[0042] Table 2 As can be seen from Table 1, as the coating amount of the coating liquid increases, the shelf life of the crispy sausage increases by 3-4 months, which proves that the coating liquid has certain antibacterial properties; As can be seen from Table 2, as the coating amount of the coating liquid increases, the discoloration of the crispy sausage is significantly alleviated during the shelf life, proving that the coating liquid has a certain UV resistance; In combination with Table 1 and Table 2, the coating amount of Example 1 can achieve the optimal solution of production cost and use efficacy, ensuring that the sausage will not change color due to sunlight during the shelf life, thereby misleading consumers.

[0043] The basic principles, main features and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention shall be defined by the attached claims and their equivalents.

Claims

1. A coating liquid, characterized in that: The invention comprises the following raw materials in parts by weight: 5 parts of nano zinc oxide powder, 76 parts of anhydrous ethanol, 5 parts of water and 5 parts of ultraviolet absorber UV-P.

2. A packaging film having a coating liquid, characterized in that: It includes a contact film for contacting food, a printed film arranged on the contact film, and an anti-ultraviolet and antibacterial glue arranged between the contact film and the printed film. The anti-ultraviolet and antibacterial glue includes an adhesive and a coating liquid mixed in the adhesive for enhancing the anti-ultraviolet and antibacterial functions.

3. The packaging film with coating liquid according to claim 2, characterized in that: The contact film is a RCPP film.

4. The packaging film with coating liquid according to claim 2, characterized in that: The printing film is a PET film.

5. A method for producing a packaging film having a coating liquid, characterized in that: The steps include: Step S1, weighing nano zinc oxide powder, anhydrous ethanol, water, and ultraviolet absorber UV-P to prepare a coating solution; Step S2, mixing the coating liquid and the adhesive evenly to form an anti-ultraviolet and antibacterial glue, and adding the mixture into a dry laminating machine; Step S3: installing the contact film and the printed film on a dry laminating machine and performing dry lamination with anti-ultraviolet and antibacterial adhesive to obtain a packaging film.

6. The method for producing a packaging film with a coating liquid according to claim 5, characterized in that: Step S1 also includes the following steps: Step S11, placing the nano zinc oxide powder in a vacuum drying oven for vacuum drying at a temperature of 60° C. for a drying time of 6 h; Step S12, adding 5 mL of deionized water to 95 mL of anhydrous ethanol solution to prepare an ethanol solution with a volume fraction of 95% as a reaction solvent, and then weighing 5 g of dried nano zinc oxide powder and 5 g of UV-P anti-ultraviolet absorber, and adding them to the reaction solvent; Step S13, oscillating the reaction solvent by an ultrasonic oscillator until the nano zinc oxide powder is evenly dispersed, the oscillation time is 1 hour; Step S14, transferring the reaction solvent after the shaking to a constant temperature water bath for stirring, the stirring time is 1.5 hours, the stirring temperature is 85° C., and the stirring speed is 600 r / min; Step S15, using an ultrasonic degasser to degas the stirred reaction solvent to obtain a coating solution, and the degassing time is 0.5 h.

7. The method for producing a packaging film with a coating liquid according to claim 5, characterized in that: In step S2, the ratio of the coating liquid to the adhesive is 1:

5.

8. The method for producing a packaging film with a coating liquid according to claim 5, characterized in that: The adhesive is a two-component polyurethane high-temperature cooking adhesive.

9. The method for producing a packaging film with a coating liquid according to claim 8, characterized in that: The two-component polyurethane high-temperature cooking adhesive comprises: A glue and B glue added into A glue together with the coating liquid, and the ratio of A glue to B glue is 5:

1.

10. The method for producing a packaging film with a coating liquid according to claim 9, characterized in that: The A glue has a density of 1.02 g / ml and a viscosity of 800-1000 MPa.s at 25°C.

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