Corrugated carton functional inner paper oil treatment method and gloss oil system

Abstract

The invention relates to the technical field of packaging material processing, in particular to a corrugated carton functional inner paper oil treatment method and a gloss oil system.The corrugated carton functional inner paper oil treatment method comprises the steps that a corrugated carton is put into the gloss oil system to be subjected to gradient coating oil treatment, the gradient comprises the first temperature gradient and the second temperature gradient, and the second temperature gradient comprises the first temperature gradient and the second temperature gradient; the temperature of the first temperature gradient is greater than that of the second temperature gradient; the gloss oil system comprises the following components in parts by weight: 45-55 parts of an acrylic copolymer, 15-20 parts of a styrene copolymer and 8-12 parts of an ethylene oxide homopolymer, and the elongation at break of the ethylene oxide homopolymer is gt; 5-8 parts of nano silica sol, 0.5-1.2 parts of a pH response type cross-linking agent and 2-3 parts of an organic silicon modifier, and the contact angle of the organic silicon modifier is gt; the temperature is 110 DEG C, and the balance is deionized water.

Description

Technical Field

[0001] The invention relates to the technical field of packaging material processing, in particular to a method for oiling functional lining paper of a corrugated paper box and a varnish system. Background Art

[0002] With the rapid development of the logistics industry and the improvement of people's living standards, the requirements for packaging materials are getting higher and higher. Especially in the food and fast-moving consumer goods industries, such as beer boxes, milk boxes, fruit boxes, etc., the packaging materials are not only required to have good protection properties, but also to have certain waterproof and heat preservation functions. Although traditional corrugated boxes are light and low in cost, they do not perform well in humid environments or when the temperature of the internal items needs to be kept stable for a long time. Therefore, the development of a new type of corrugated box with waterproof and heat preservation functions has become an urgent problem to be solved in the industry.

[0003] The solutions currently available on the market mainly include using special coatings or adding additional waterproof layers to enhance the waterproof capabilities of corrugated boxes; and improving their thermal insulation performance is often achieved by increasing the thickness of the box or adopting a more complex structural design.

[0004] The traditional corrugated box surface treatment process has the following technical bottlenecks: waterproof treatment mostly uses PE coating, which makes recycling difficult and reduces thermal insulation performance; existing water-based coatings are difficult to balance flexibility and wear resistance; the varnish system has poor compatibility with printing inks and is prone to delamination; conventional drying processes have high energy consumption and affect the fiber strength of paper. Summary of the invention

[0005] The main purpose of the present invention is to overcome the defects of the existing corrugated box functional liner oil treatment method and varnish system, and provide a new corrugated box functional liner oil treatment method and varnish system. The technical problems to be solved are that the method can handle the problems that PE coating is mostly used for waterproofing, which leads to recycling difficulties and reduced thermal insulation performance; the existing water-based coatings are difficult to balance flexibility and wear resistance; the varnish system has poor compatibility with printing inks and is prone to delamination; the conventional drying process has high energy consumption and affects the strength of paper fibers, so it is more suitable for practical use and has industrial utilization value.

[0006] On the one hand, a method for oiling functional lining paper of a corrugated box is provided, comprising:

[0007] Put the corrugated paper box into the varnish system for gradient coating and oil treatment.

[0008] Wherein, the gradient includes a first temperature gradient and a second temperature gradient, and the temperature of the first temperature gradient is greater than the temperature of the second temperature gradient;

[0009] The varnish system comprises the following components in parts by weight: 45-55 parts of acrylic copolymer, 15-20 parts of styrene copolymer, 8-12 parts of ethylene oxide homopolymer, wherein the elongation at break of the ethylene oxide homopolymer is greater than 150%, 5-8 parts of nano-silica sol, 0.5-1.2 parts of pH-responsive cross-linking agent, 2-3 parts of organosilicon modifier, the contact angle of the organosilicon modifier is greater than 110°, and the balance is deionized water.

[0010] In an optional embodiment, the acrylic copolymer is a high temperature resistant water-soluble acrylic copolymer formed by copolymerization of butyl acrylate, hydroxyethyl methacrylate and acrylic acid monomers.

[0011] In an alternative embodiment, the styrene copolymer includes acrylonitrile-butadiene-styrene copolymer or polyethylene oxide.

[0012] In an alternative embodiment, the ethylene oxide homopolymer includes polyethylene oxide or a flexible acrylate monomer.

[0013] In an optional embodiment, the nano-silica sol is a nano-zinc oxide dispersed emulsion or a silicon dioxide nano-sol.

[0014] In an optional embodiment, the pH responsive cross-linking agent is a microencapsulated melamine organophosphate or a carboxylic acid / amine cross-linking agent.

[0015] In an optional embodiment, the carboxylic acid / amine crosslinking agent includes 1,2,3,4-tetracarboxylic acid butane, ethyl orthosilicate, methyl orthosilicate, trimethoxysilane, 1,4-butylene glycol diacrylate or ethylene glycol dimethacrylate.

[0016] In an optional embodiment, the organosilicon modifier is polydimethylsiloxane.

[0017] In an optional embodiment, the first temperature gradient is 80°C to 90°C, and the second temperature gradient is 50°C to 60°C.

[0018] On the other hand, a varnish system is provided, comprising the following components in parts by weight: 45-55 parts of an acrylic copolymer, 15-20 parts of a styrene copolymer, 8-12 parts of an ethylene oxide homopolymer, wherein the elongation at break of the ethylene oxide homopolymer is >150%, 5-8 parts of a nano-silica sol, 0.5-1.2 parts of a pH-responsive cross-linking agent, 2-3 parts of an organosilicon modifier, the contact angle of the organosilicon modifier being >110°, and the balance being deionized water.

[0019] By means of the above technical solution, the method for treating the functional lining paper of a corrugated paper box and the varnish system of the present invention have at least the following advantages:

[0020] The varnish system provided by the embodiment of the present invention uses acrylic copolymer as the main film-forming substance to provide basic mechanical properties for the corrugated paper box treated with the varnish system; uses styrene copolymer as a hardness regulator to enhance the surface wear resistance of the corrugated paper box; uses ethylene oxide homopolymer as a flexible network builder, and the elongation at break is greater than 150%, so as to improve the flexibility of the varnish film layer of the corrugated paper box; uses nano-silica sol as an inorganic reinforcing phase to improve the thermal stability of the corrugated paper box, wherein the temperature resistance can reach 120°C; uses a pH-responsive cross-linking agent as a dynamic cross-linking agent to achieve a controllable curing reaction of the varnish system on the surface of the corrugated paper box; uses an organosilicon modifier as a surface property regulator, and its contact angle is greater than 110°, so that the corrugated paper box treated with the varnish system has a super-hydrophobic effect; uses deionized water as a solvent carrier, which is environmentally friendly and non-toxic, so that the remaining components can be better dissolved and dispersed.

[0021] The corrugated paper box prepared by the method provided in the embodiment of the present invention can form an alternating structure of hard segments and soft segments based on the sequence-controlled copolymerization of acrylic acid and styrene, and realize the dual thermal insulation effects of "hydrophobic lock" and "aerogel" based on the organic-inorganic hybrid system; based on the selection of the above components, a fast curing system suitable for high-speed production lines (≥200m / min) can be developed. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following embodiments are combined to describe in detail the characteristics and effects of the oil treatment method for the functional lining paper of the corrugated box proposed by the present invention.

[0023] On the one hand, an embodiment of the present invention provides a method for oiling functional lining paper of a corrugated box, comprising: placing the corrugated box into a varnish system for gradient coating and oiling, wherein the gradient comprises a first temperature gradient and a second temperature gradient, and the temperature of the first temperature gradient is greater than the temperature of the second temperature gradient.

[0024] The varnish system comprises the following components in parts by weight: 45-55 parts of acrylic copolymer, 15-20 parts of styrene copolymer, 8-12 parts of ethylene oxide homopolymer, wherein the elongation at break of the ethylene oxide homopolymer is greater than 150%, 5-8 parts of nano-silica sol, 0.5-1.2 parts of pH-responsive cross-linking agent, 2-3 parts of organosilicon modifier, the contact angle of the organosilicon modifier is greater than 110°, and the balance is deionized water.

[0025] The method provided by the embodiment of the present invention has at least the following beneficial effects:

[0026] The varnish system provided by the embodiment of the present invention uses acrylic copolymer as the main film-forming substance to provide basic mechanical properties for the corrugated paper box treated with the varnish system; uses styrene copolymer as a hardness regulator to enhance the surface wear resistance of the corrugated paper box; uses ethylene oxide homopolymer as a flexible network builder, and the elongation at break is greater than 150%, so as to improve the flexibility of the varnish film layer of the corrugated paper box; uses nano-silica sol as an inorganic reinforcing phase to improve the thermal stability of the corrugated paper box, wherein the temperature resistance can reach 120°C; uses a pH-responsive cross-linking agent as a dynamic cross-linking agent to achieve a controllable curing reaction of the varnish system on the surface of the corrugated paper box; uses an organosilicon modifier as a surface property regulator, and its contact angle is greater than 110°, so that the corrugated paper box treated with the varnish system has a super-hydrophobic effect; uses deionized water as a solvent carrier, which is environmentally friendly and non-toxic, so that the remaining components can be better dissolved and dispersed.

[0027] The corrugated paper box prepared by the method provided in the embodiment of the present invention can form an alternating structure of hard segments and soft segments based on the sequence-controlled copolymerization of acrylic acid and styrene, and realize the dual thermal insulation effects of "hydrophobic lock" and "aerogel" based on the organic-inorganic hybrid system; based on the selection of the above components, a fast curing system suitable for high-speed production lines (≥200m / min) can be developed.

[0028] The method provided by the embodiment of the present invention will be further explained and described below through optional embodiments.

[0029] The corrugated paper box is placed in a varnish system for gradient coating and oil treatment, wherein the gradient includes a first temperature gradient and a second temperature gradient, and the temperature of the first temperature gradient is greater than the temperature of the second temperature gradient.

[0030] The embodiment of the present invention sets up a two-stage coating and oiling treatment, wherein the first temperature gradient is used for hot air treatment and the second gradient temperature is used for infrared curing treatment, so that the corrugated cardboard box treated with the varnish system not only has good basic mechanical properties and can support the weight of a preset weight, but also has a certain flexibility and can support bending under certain conditions and ensure that the basic mechanical properties remain unchanged after bending.

[0031] The varnish system includes the following components in parts by weight: the weight of acrylic copolymer can be 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts or 55 parts, etc. The weight of styrene copolymer can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts, etc. The weight of ethylene oxide homopolymer can be 8 parts, 9 parts, 10 parts, 11 parts or 12 parts, etc. The weight of nano silica sol can be 5 parts, 6 parts, 7 parts or 8 parts, etc. The weight of pH responsive crosslinking agent can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 parts, 1.1 parts or 1.2 parts, etc. The weight of organosilicon modifier can be 2 parts, 2.5 parts or 3 parts, and the balance is deionized water.

[0032] In an optional embodiment, the acrylic copolymer is a water-soluble acrylic copolymer formed by copolymerization of butyl acrylate, hydroxyethyl methacrylate, and acrylic acid monomers.

[0033] The water-soluble acrylic copolymer formed by copolymerization of butyl acrylate, hydroxyethyl methacrylate and acrylic acid monomer has high temperature resistance (can withstand 160-220℃ laminating temperature) and good water solubility, which can meet the pre-printed varnish requirements of corrugated boxes.

[0034] In an alternative embodiment, the styrene copolymer includes acrylonitrile-butadiene-styrene copolymer or polyethylene oxide.

[0035] Acrylonitrile butadiene Styrene copolymers (ABS): It has high strength, impact resistance and surface gloss, and can improve the strength, impact resistance and surface gloss of corrugated boxes.

[0036] In an alternative embodiment, the ethylene oxide homopolymer includes polyethylene oxide or a flexible acrylate monomer.

[0037] For example, the ethylene oxide homopolymer may be polyethylene oxide or a flexible acrylate monomer, or may be a mixture of polyethylene oxide and a flexible acrylate monomer, and the mixing ratio may be 1:2.

[0038] In an optional embodiment, the nano-silica sol is a nano-zinc oxide dispersed emulsion or a silicon dioxide nano-sol.

[0039] The particle size of the nano silica sol can be between 20nm and 50nm. The nano zinc oxide with a particle size of 20nm-50nm can enhance the high temperature resistance of the surface coating of the corrugated paper box and has good compatibility with acrylic resin. Exemplarily, the particle size of the nano silica sol can be 20nm, 25nm, 27nm, 30nm, 34nm, 35nm, 37nm, 40nm, 42nm, 45nm, 47nm, 48nm or 50nm, etc.

[0040] Nano-silica sol can further improve the thermal stability and mechanical strength of the surface coating of corrugated boxes.

[0041] In an optional embodiment, the pH responsive cross-linking agent is a microencapsulated melamine organic phosphate or a carboxylic acid / amine cross-linking agent.

[0042] In an optional embodiment, the carboxylic acid / amine crosslinking agent includes 1,2,3,4-tetracarboxylic acid butane, ethyl orthosilicate, methyl orthosilicate, trimethoxysilane, 1,4-butylene glycol diacrylate or ethylene glycol dimethacrylate.

[0043] In an optional embodiment, the organosilicon modifier is polydimethylsiloxane.

[0044] In an optional embodiment, the first temperature gradient is 80° C. to 90° C., and the second temperature gradient is 50° C. to 60° C. For example, the temperature in the first temperature gradient may be 80° C., 81° C., 82° C., 83° C., 84° C., 85° C., 86° C., 87° C., 88° C., 89° C., or 90° C. The temperature in the second temperature gradient may be 50° C., 51° C., 52° C., 53° C., 54° C., 55° C., 56° C., 57° C., 58° C., 59° C., or 50° C.

[0045] On the other hand, an embodiment of the present invention provides a varnish system, comprising the following components in parts by weight: 45-55 parts of acrylic copolymer, 15-20 parts of styrene copolymer, 8-12 parts of ethylene oxide homopolymer, wherein the elongation at break of the ethylene oxide homopolymer is >150%, 5-8 parts of nano-silica sol, 0.5-1.2 parts of pH-responsive cross-linking agent, 2-3 parts of silicone modifier, the contact angle of the silicone modifier is >110°, and the balance is deionized water.

[0046] The method provided by the embodiment of the present invention will be further explained and described below through specific examples.

[0047] Example 1

[0048] The corrugated paper box is placed in the varnish system for gradient coating and oil treatment, wherein the components of the varnish system are as follows:

[0049] 52 parts of water-soluble acrylic copolymer, 18 parts of acrylonitrile-butadiene-styrene copolymer, 10 parts of polyethylene oxide, 6 parts of nano zinc oxide dispersion emulsion, 3 parts of polydimethylsiloxane, 1 part of microencapsulated melamine organic phosphate, and 10 parts of deionized water.

[0050] The corrugated paper box is dusted and polished before being reverse coated with a double roller in a varnish system (coating amount 8-10g / m 2 )→ Stage drying: (1) 85℃ hot air drying for 30s→(2) 55℃ infrared curing for 45s→natural cooling→winding to obtain coated corrugated paper boxes.

[0051] After testing, the water vapor permeability of the corrugated paper box prepared by the method provided in the embodiment of the present invention is 10g / (m 2 24h): ≤10g / (m 2 24h), Cobb value (60min) is 15g / m 2 :≤15g / m 2 , peel strength retention rate after wet heat cycle (40℃ / 95%RH): 92%.

[0052] Example 2

[0053] The corrugated paper box is placed in the varnish system for gradient coating and oil treatment, wherein the components of the varnish system are as follows:

[0054] 51 parts of water-soluble acrylic copolymer, 19 parts of acrylonitrile-butadiene-styrene copolymer, 11 parts of polyethylene oxide, 7 parts of nano zinc oxide dispersion emulsion, 3 parts of polydimethylsiloxane, 1 part of microencapsulated melamine organic phosphate, and 10 parts of deionized water.

[0055] The corrugated paper box is dusted and polished before being reverse coated with a double roller in a varnish system (coating amount 8-10g / m 2 )→ Stage drying: (1) 90℃ hot air drying for 30s→(2) 60℃ infrared curing for 45s→natural cooling→winding to obtain coated corrugated paper boxes.

[0056] After testing, the water vapor permeability of the corrugated paper box prepared by the method provided in the embodiment of the present invention is 9.1g / (m 2 24h): ≤10g / (m 2 24h), Cobb value (60min) is 14g / m 2 :≤15g / m 2 , peel strength retention rate after wet heat cycle (40℃ / 95%RH): 91%.

[0057] Example 3

[0058] The corrugated paper box is placed in the varnish system for gradient coating and oil treatment, wherein the components of the varnish system are as follows:

[0059] 50 parts of water-soluble acrylic copolymer, 17 parts of acrylonitrile-butadiene-styrene copolymer, 10 parts of polyethylene oxide, 9 parts of nano zinc oxide dispersion emulsion, 3 parts of polydimethylsiloxane, 0.8 parts of microencapsulated melamine organic phosphate, and 10 parts of deionized water.

[0060] The corrugated paper box is dusted and polished before being reverse coated with a double roller in a varnish system (coating amount 8-10g / m 2 )→ Stage drying: (1) 85℃ hot air drying for 30s→(2) 55℃ infrared curing for 45s→natural cooling→winding to obtain coated corrugated paper boxes.

[0061] After testing, the water vapor permeability of the corrugated paper box prepared by the method provided in the embodiment of the present invention is 9.5g / (m 2 24h): ≤10g / (m 2 24h), Cobb value (60min) is 14g / m 2 :≤15g / m 2 , peel strength retention rate after wet heat cycle (40℃ / 95%RH): 91.5%.

[0062] Example 4

[0063] By adjusting the content of nano-silica sol to 8% and increasing the content of ethylene oxide homopolymer to 12%, the following results were obtained: thermal conductivity: 0.038W / (m·K); thermal reflectivity: ≥85% (400-2500nm band); temperature difference holding capacity of 5mm thick paperboard: ΔT≥15℃ (23℃ environment).

[0064] Comparative Example

[0065] The varnish system includes 85 parts of a copolymer of acrylic acid and styrene, 3 parts of purified water, and 9 parts of an oxidized homopolymer. The corrugated paper box is treated with varnish in the varnish system provided in the comparative example.

[0066] After testing, the water vapor permeability of the corrugated paper box prepared by the method provided in the comparative example is 15g / (m 2 24h):>10g / (m 2 24h), Cobb value (60min) is 18g / m 2 :>15g / m 2 , peel strength retention rate after wet heat cycle (40℃ / 95%RH): 80.5%.

[0067] The key performance index tests were performed on the corrugated paper boxes provided in Examples 1 to 4:

[0068] Optical properties: transmittance ≥ 92% (ASTM D1003), yellowing index ΔYI <1.5 (3000h xenon lamp aging); Mechanical properties: Taber abrasion resistance (CS-10 wheel, 500g load) ≤ 50mg / 1000 times; Environmental tolerance: tested by immersion in 5% NaOH / 5% HCl solution for 48h; Thermal properties: thermal conductivity ≤ 0.045W / (m·K) (GB / T 10295); Adhesion: cross-hatch test level 0 (GB / T9286).

[0069] The key performance index tests were conducted on the corrugated paper boxes provided by the comparative example:

[0070] Optical properties: transmittance = 82% (ASTM D1003), yellowing index ΔYI>1.5 (3000h xenon lamp aging); Mechanical properties: Taber abrasion resistance (CS-10 wheel, 500g load) ≤50mg / 1000 times; Environmental tolerance: tested by immersion in 5% NaOH / 5% HCl solution for 48h; Thermal properties: thermal conductivity equal to 0.056W / (m·K) (GB / T 10295); Adhesion: cross-hatch test level 1 (GB / T9286).

[0071] It can be seen from Examples 1 to 4 and the comparative example that the water vapor permeability, Cobb value, peel strength retention rate after wet heat cycle (40°C / 95% RH), and key performance indicators of the corrugated cardboard boxes prepared by the method provided in the embodiments of the present invention are better than those of the corrugated cardboard boxes treated with the varnish system provided in the comparative example.

[0072] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for oiling functional lining paper of corrugated paperboard, characterized in that: include: Put the corrugated paper box into the varnish system for gradient coating and oil treatment. Wherein, the gradient includes a first temperature gradient and a second temperature gradient, and the temperature of the first temperature gradient is greater than the temperature of the second temperature gradient; The varnish system comprises the following components in parts by weight: 45-55 parts of acrylic copolymer, 15-20 parts of styrene copolymer, 8-12 parts of ethylene oxide homopolymer, wherein the elongation at break of the ethylene oxide homopolymer is greater than 150%, 5-8 parts of nano-silica sol, 0.5-1.2 parts of pH-responsive cross-linking agent, 2-3 parts of organosilicon modifier, the contact angle of the organosilicon modifier is greater than 110°, and the balance is deionized water.

2. The method for oiling the functional lining paper of a corrugated box according to claim 1, characterized in that: The acrylic copolymer is a water-soluble acrylic copolymer formed by copolymerization of butyl acrylate, hydroxyethyl methacrylate and acrylic acid monomers.

3. The method for oiling the functional lining paper of a corrugated box according to claim 1, characterized in that: The styrene copolymer includes acrylonitrile-butadiene-styrene copolymer or polyethylene oxide.

4. The method for oiling the functional lining paper of a corrugated box according to claim 1, characterized in that: The ethylene oxide homopolymer includes polyethylene oxide or a flexible acrylate monomer.

5. The method for oiling the functional lining paper of a corrugated box according to claim 1, characterized in that: The nano-silica sol is a nano-zinc oxide dispersed emulsion or a silicon dioxide nano-sol.

6. The method for oiling the functional lining paper of a corrugated box according to claim 1, characterized in that: The pH responsive cross-linking agent is a microencapsulated melamine organic phosphate or a carboxylic acid / amine cross-linking agent.

7. The method for oiling the functional lining paper of a corrugated box according to claim 6, characterized in that: The carboxylic acid / amine crosslinking agent includes 1,2,3,4-tetracarboxylic acid butane, ethyl orthosilicate, methyl orthosilicate, trimethoxysilane, 1,4-butylene glycol diacrylate or ethylene glycol dimethacrylate.

8. The method for oiling the functional lining paper of a corrugated box according to claim 6, characterized in that: The organosilicon modifier is polydimethylsiloxane.

9. The method for oiling the functional lining paper of a corrugated box according to claim 6, characterized in that: The first temperature gradient is 80°C to 90°C, and the second temperature gradient is 50°C to 60°C.

10. A varnish system, characterized in that: The invention comprises the following components in parts by weight: 45-55 parts of acrylic copolymer, 15-20 parts of styrene copolymer, 8-12 parts of ethylene oxide homopolymer, wherein the elongation at break of the ethylene oxide homopolymer is greater than 150%, 5-8 parts of nano-silica sol, 0.5-1.2 parts of pH-responsive cross-linking agent, 2-3 parts of organosilicon modifier, the contact angle of the organosilicon modifier is greater than 110°, and the balance is deionized water.