A hydrophobic and oleophobic high-barrier food packaging composite film and a preparation method thereof

Abstract

The application relates to a hydrophobic and oleophobic high-barrier food packaging composite film and a preparation method thereof, which comprises, from outside to inside, a support layer, a high-stability adhesive layer and a double-repellent anti-adhesion layer; the high-stability adhesive layer comprises the following raw materials in parts by weight: 75-95 parts of vinyl silicone oil, 45-60 parts of vinyl MQ resin, 2-8 parts of a stabilizer, 0.5-1.5 parts of a crosslinking agent, 0.5-3 parts of a silane coupling agent, 1-3 parts of a platinum gold catalyst and 30-60 parts of a solvent; the stabilizer is prepared by ring-opening graft reaction of octakis(aminophenyltrisiloxane) and allyl glycidyl ether under alkaline conditions in tetrahydrofuran; the molar ratio of octakis(aminophenyltrisiloxane) to allyl glycidyl ether is 1:8-8.5; the reaction temperature of the ring-opening graft reaction is 60-66 DEG C; and the application effectively solves the problems of corrosion of the adhesive layer to water and oil in food, the phenomenon of peel strength reduction and separation of the multilayer structure.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-barrier food packaging composite film preparation, and particularly relates to a hydrophobic and oleophobic high-barrier food packaging composite film and a preparation method thereof. BACKGROUND

[0002] The existing composite film comprises a multi-layer structure, and the multi-layer structure is bonded through an adhesive layer. For example, patent publication CN110641097B discloses a hydrophobic and oleophobic high-barrier food packaging composite film and a preparation method thereof. Specifically, glue is coated on a support layer, a barrier layer, a toughening layer, and a heat-sealing layer layer by layer, and then the composite film is obtained by performing lamination, winding, and curing. The liquefied wax oil is uniformly coated on the semi-finished product under the action of a magnetic field and hot-pressed, and then cooled to form the double-repellent anti-adhesive layer closely attached to the semi-finished product, thereby obtaining the finished product.

[0003] The multi-layer structure film is prone to separation during use. The reason is that the adhesive layer is corroded by water and oil in food, resulting in a decrease in peeling force and separation of the multi-layer structure. SUMMARY

[0004] To solve the above problems, the application provides a hydrophobic and oleophobic high-barrier food packaging composite film and a preparation method thereof.

[0005] A first object of the application is to provide a hydrophobic and oleophobic high-barrier food packaging composite film, which comprises, from the outside to the inside, a support layer, a high-stability adhesive layer, and a double-repellent anti-adhesive layer.

[0006] The high-stability adhesive layer comprises:

[0007] The following raw materials are used by weight: 75-95 parts of vinyl silicone oil, 45-60 parts of vinyl MQ resin, 2-8 parts of a stabilizer, 0.5-1.5 parts of a crosslinking agent, 0.5-3 parts of a silane coupling agent, 1-3 parts of a platinum gold catalyst, and 30-60 parts of a solvent.

[0008] The stabilizer is prepared by ring-opening grafting reaction of octakis(aminophenyltrisiloxane) and allyl glycidyl ether under alkaline conditions in tetrahydrofuran.

[0009] The molar ratio of octakis(aminophenyltrisiloxane) to allyl glycidyl ether is 1:8-8.5.

[0010] The reaction temperature of the ring-opening grafting reaction is 60-66℃, the reaction time is 1-24h, and the alkaline condition is 9.5-10.5.

[0011] As a further technical solution of the application, the molecular weight of the vinyl silicone oil is 200-300 thousand, and the vinyl content is 2-5wt%.

[0012] As a further technical solution of the present application: the vinyl MQ resin is a MQ resin containing vinyl with M / Q chain segment ratio of 0.5-0.8, and its molecular weight is 5000-10000, and the vinyl content is 0.5-1.5wt%.

[0013] As a further technical solution of the present application: the crosslinking agent is a silicone oil containing silicon-hydrogen bond in side groups, with hydrogen content of 5-12wt%, and molecular weight of 2000-4000.

[0014] As a further technical solution of the present application: the coupling agent is one or a mixture of any of vinyl silane coupling agent or epoxy silane coupling agent.

[0015] As a further technical solution of the present application: the platinum catalyst has Pt weight percentage of 1-5%.

[0016] As a further technical solution of the present application: the preparation process of the high-stability adhesive layer comprises the following steps:

[0017] Mixing the vinyl silicone oil, the vinyl MQ resin, the stabilizer and the solvent uniformly at 15-30℃, then adding the silane coupling agent, the crosslinking agent and the platinum catalyst in turn every 5-10min, stirring uniformly to obtain the mixed glue solution;

[0018] Coating the mixed glue solution on the surface of the substrate, curing to obtain the high-stability silicone protective film.

[0019] As a further technical solution of the present application: the curing temperature is 150-200℃, and the curing time is 1-3min.

[0020] A preparation method of a high-stability silicone protective film comprises the following steps:

[0021] Uniformly coating the support layer and the double-repellent anti-adhesive layer on the high-stability adhesive layer and hot pressing, and then cooling to obtain the hydrophobic and oleophobic high-barrier food packaging composite film.

[0022] The beneficial effects of the present application are:

[0023] The present application provides a hydrophobic and oleophobic high-barrier food packaging composite film and a preparation method thereof, which uses vinyl silicone oil and vinyl MQ resin as the main network components of the high-stability adhesive layer in the packaging composite film, crosslinking agent and silane coupling agent as the network aid of the adhesive film, and introduces a stabilizer to improve the stability of the peel strength of the packaging composite film in a high-temperature and high-humidity environment.

[0024] The stabilizer is prepared by ring-opening grafting reaction of octakis(aminophenyltrioxysilane) and allyl glycidyl ether under alkaline conditions in tetrahydrofuran, has the inner core of octakis(aminophenyltrioxysilane) which is resistant to high temperature and the flexible carbon chain (provided by allyl glycidyl ether), the flexible carbon chain makes the stabilizer have high blending reactivity, meanwhile, the stabilizer has high functionality (containing eight moles of double bonds per mole), improves the complexity and crosslinking degree of the interpenetrating network of the high-stability adhesive layer, improves the strength of the adhesive and the moisture and heat resistance; finally, the inner core of octakis(aminophenyltrioxysilane) improves the high-temperature resistance of the interpenetrating network of the protective film, and further improves the stability of the peeling force.

[0025] Therefore, the phenomenon of peeling force reduction caused by the corrosion of the adhesive layer to water and oil in food is effectively solved, and the problem of separation of the multi-layer structure is solved.

[0026] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be achieved and obtained by the structure indicated in the specification, claims. DETAILED DESCRIPTION

[0027] To make the purposes, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0028] Embodiment 1

[0029] Preparation of the stabilizer:

[0030] After 0.01 mol of octakis(aminophenyltrioxysilane), 0.08 mol of allyl glycidyl ether and 60 mL of tetrahydrofuran are uniformly mixed, the pH value of the reaction system is adjusted to 9.5, the reaction system is heated to the reaction temperature under condensation condition, and the reaction is carried out at 66 DEG C under insulation stirring for 12 h.

[0031] Embodiment 2

[0032] Preparation of the stabilizer:

[0033] After 0.01 mol of octakis(aminophenyltrioxysilane), 0.085 mol of allyl glycidyl ether and 60 mL of tetrahydrofuran are uniformly mixed, the pH value of the reaction system is adjusted to 10, the reaction system is heated to the reaction temperature under condensation condition, and the reaction is carried out at 60 DEG C under insulation stirring for 24 h.

[0034] Example 3

[0035] Preparation of high-stability adhesive layer

[0036] First step, preparation of raw materials: the following weight parts of raw materials: 75 parts of vinyl silicone oil, 60 parts of vinyl MQ resin, 2 parts of stabilizer prepared in Example 1, 0.5 parts of crosslinking agent, 0.5 parts of silane coupling agent, 1 part of platinum gold catalyst and 30 parts of solvent;

[0037] The molecular weight of the vinyl silicone oil is 200-250 thousand, the vinyl content is 3wt%, and the brand is DOWSIL TM 7667;

[0038] The vinyl MQ resin is a vinyl-containing MQ resin with a M / Q chain segment ratio of 0.6, and its molecular weight is 5000, the vinyl content is 0.5wt%, and the brand is SYL-OFF TM 7660;

[0039] The crosslinking agent is a silicone oil containing silicon-hydrogen bonds in the side group, with a hydrogen content of 5wt%, a molecular weight of 2000-2500, and a brand of Syl-Off 7028;

[0040] The coupling agent is vinyltrimethoxysilane

[0041] The platinum gold catalyst contains 5wt% of Pt;

[0042] The solvent is xylene;

[0043] Second step, mix the above prepared vinyl silicone oil, vinyl MQ resin, stabilizer and solvent uniformly at 15-30℃, then add the silane coupling agent, crosslinking agent and platinum gold catalyst in turn every 5-10min, stir uniformly, and get the mixed glue solution;

[0044] Third step, coat the mixed glue solution on the surface of the substrate (PET substrate), and cure to get the high-stability adhesive layer, wherein the curing temperature is 150℃ and the curing time is 3min.

[0045] Example 4

[0046] Preparation of high-stability adhesive layer

[0047] First step, preparation of raw materials: the following weight parts of raw materials: 80 parts of vinyl silicone oil, 50 parts of vinyl MQ resin, 5 parts of stabilizer prepared in Example 2, 1 part of crosslinking agent, 1.5 parts of silane coupling agent, 1.5 parts of platinum gold catalyst and 45 parts of solvent;

[0048] The molecular weight of the vinyl silicone oil is 23-28 million, the vinyl content is 5wt%, and the brand is DOWSILTM 7667;

[0049] The vinyl MQ resin is a vinyl-containing MQ resin with a M / Q chain segment ratio of 0.7, and its molecular mass is 8000-10000, the vinyl content is 1wt%, and the brand is SYL-OFF TM 7660;

[0050] The crosslinking agent is a silicon oil containing silicon-hydrogen bonds in side groups, with a hydrogen content of 10wt%, a molecular mass of 3000-4000, and the brand is Syl-Off 7028;

[0051] The coupling agent is γ-(2,3-epoxypropoxy)propyl trimethoxysilane;

[0052] The platinum gold catalyst has a Pt weight percentage of 3%;

[0053] The solvent is toluene;

[0054] Second step, mix the above prepared vinyl silicone oil, vinyl MQ resin, stabilizer and solvent uniformly at 15-30℃, then add the silane coupling agent, crosslinking agent and platinum gold catalyst in turn with an interval of 5-10min each time, and stir uniformly to obtain a mixed glue solution;

[0055] Third step, coat the mixed glue solution on the surface of the substrate (PET substrate), and cure to obtain a high-stability adhesive layer, wherein the curing temperature is 170℃, and the curing time is 2min.

[0056] Example 5

[0057] Preparation of high-stability adhesive layer

[0058] First step, prepare raw materials: the following raw materials in weight parts: 95 parts of vinyl silicone oil, 45 parts of vinyl MQ resin, 8 parts of the stabilizer prepared in Example 1, 1.5 parts of crosslinking agent, 3 parts of silane coupling agent, 3 parts of platinum gold catalyst and 60 parts of solvent;

[0059] The molecular mass of the vinyl silicone oil is 270-300 thousand, the vinyl content is 5wt%, and the brand is DOWSIL TM 7667;

[0060] The vinyl MQ resin is a vinyl-containing MQ resin with a M / Q chain segment ratio of 0.8, and its molecular mass is 9000-10000, the vinyl content is 1.5wt%, and the brand is SYL-OFF TM 7660;

[0061] The cross-linking agent is a silicon oil with a silicon-hydrogen bond in the side group, with a hydrogen content of 5-12wt%, a molecular weight of 3000-4000, and a brand of Syl-Off 7028;

[0062] The coupling agent is vinyltriethoxysilane;

[0063] The platinum gold catalyst has a Pt weight percentage of 4%;

[0064] The solvent is ethyl acetate;

[0065] In the second step, the above prepared vinyl silicone oil, vinyl MQ resin, stabilizer and solvent are uniformly mixed at 15-30°C, and then the silane coupling agent, cross-linking agent and platinum gold catalyst are added in turn with an interval of 5-10 min each time. After stirring uniformly, a mixed glue solution is obtained;

[0066] In the third step, the mixed glue solution is coated on the surface of the substrate (PET substrate), and then cured to obtain a high-stability adhesive layer, wherein the curing temperature is 200°C and the curing time is 1 min.

[0067] Example 5

[0068] Preparation of a hydrophobic and oleophobic high-barrier food packaging composite film

[0069] The support layer and the dual-repellent anti-adhesive layer are uniformly coated on the high-stability adhesive layer and hot-pressed, and then cooled to obtain a hydrophobic and oleophobic high-barrier food packaging composite film.

[0070] The support layer is a PET film, and the dual-repellent anti-adhesive layer is the dual-repellent anti-adhesive layer in the patent CN110641097B.

[0071] Comparative Example 1

[0072] Preparation of a hydrophobic and oleophobic high-barrier food packaging composite film

[0073] Compared with Example 3, the stabilizer in the raw materials is deleted, and the rest is the same.

[0074] Comparative Example 2

[0075] Preparation of a hydrophobic and oleophobic high-barrier food packaging composite film

[0076] Compared with Example 3, the equivalent amount of vinyl MQ resin in the raw materials is replaced by vinyl silicone oil, and the rest is the same.

[0077] The hydrophobic and oleophobic high-barrier food packaging composite films obtained in Examples 3-5 and Comparative Examples 1-2 are subjected to physical property tests, and the results are shown in Table 1.

[0078] Peeling force test: a group of the above-mentioned hydrophobic and oleophobic high-barrier food packaging composite films (marked as non-aging group) were attached to the surface of the optical film to perform the peeling force test, wherein the test conditions were: pulling force 50 N, 100 mm / min, 90° peeling;

[0079] Aging test: another group of the above-mentioned hydrophobic and oleophobic high-barrier food packaging composite films (marked as aging group) were placed in the test box to perform the aging test, wherein the test conditions were: temperature 100℃, humidity 80%, and the films were placed for 24 h, then taken out and subsequently subjected to the peeling force test;

[0080] Meanwhile, whether the film surface was residual glue or naturally shed after the above-mentioned two peeling force tests was observed.

[0081] The change of the peeling force was calculated, and the peeling force change rate (%) = (non-aging peeling force-aging peeling force) / non-aging peeling force*100%. The obtained test results are shown in Table 1.

[0082] Table 1

[0083]

[0084] From the data in Table 1, it can be seen that the peeling force of the hydrophobic and oleophobic high-barrier food packaging composite film of the embodiment of the present application has good moisture and heat resistance.

[0085] Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A hydrophobic and oleophobic high-barrier food packaging composite film, characterized in that, include: From the outside in, it includes a support layer, a high-stability adhesive layer, and a double-hydrophobic anti-stick layer; The high-stability adhesive layer includes: The following raw materials are contained in parts by weight: 75-95 parts vinyl silicone oil, 45-60 parts vinyl MQ resin, 2-8 parts stabilizer, 0.5-1.5 parts crosslinking agent, 0.5-3 parts silane coupling agent, 1-3 parts platinum catalyst, and 30-60 parts solvent. The stabilizer is prepared by a ring-opening grafting reaction of octa(aminophenyltrioxosilane) and allyl alcohol glycidyl ether in tetrahydrofuran under alkaline conditions; The molar ratio of octa(aminophenyltrioxosilane) to allyl alcohol glycidyl ether is 1:8-8.5; The ring-opening grafting reaction is carried out at a temperature of 60-66℃ for 1-24 hours, and the alkaline conditions are 9.5-10.

5.

2. The hydrophobic and oleophobic high-barrier food packaging composite film according to claim 1, characterized in that, The vinyl silicone oil has a molecular weight of 200,000-300,000 and a vinyl content of 2-5 wt%.

3. The hydrophobic and oleophobic high-barrier food packaging composite film according to claim 1, characterized in that, The vinyl MQ resin is a vinyl-containing MQ resin with an M / Q chain length ratio of 0.5 to 0.8, a molecular weight of 5000-10000, and a vinyl content of 0.5 to 1.5 wt%.

4. The hydrophobic and oleophobic high-barrier food packaging composite film according to claim 1, characterized in that, The crosslinking agent is a silicone oil with silane-hydrogen bonds in its side groups, containing 5-12 wt% hydrogen and having a molecular weight of 2000-4000.

5. The hydrophobic and oleophobic high-barrier food packaging composite film according to claim 1, characterized in that, The silane coupling agent is one or a mixture of several of vinyl silane coupling agents or epoxy silane coupling agents.

6. The hydrophobic and oleophobic high-barrier food packaging composite film according to claim 1, characterized in that, The platinum catalyst contains 1-5% Pt by weight.

7. The hydrophobic and oleophobic high-barrier food packaging composite film according to claim 1, characterized in that, The preparation process of a high-stability adhesive layer includes the following steps: At 15-30℃, after mixing vinyl silicone oil, vinyl MQ resin, stabilizer and solvent evenly, add silane coupling agent, crosslinking agent and platinum catalyst in sequence at 5-10 min intervals, and stir evenly to obtain mixed adhesive solution. The mixed adhesive solution is applied to the surface of the substrate and cured to obtain a highly stable silicone protective film.

8. The hydrophobic and oleophobic high-barrier food packaging composite film according to claim 7, characterized in that, The curing temperature is 150-200℃, and the curing time is 1-3 minutes.

9. A method for preparing a hydrophobic and oleophobic high-barrier food packaging composite film according to any one of claims 1-8, characterized in that, Includes the following steps: The support layer and the double hydrophobic anti-stick layer are uniformly coated on both sides of the high-stability adhesive layer, and then hot-pressed and cooled to obtain a hydrophobic and oleophobic high-barrier food packaging composite film.

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