阅读说明：本技术 一种硅橡胶涂覆材料及其制备方法和应用 (Silicone rubber coating material and preparation method and application thereof ) 是由 王庆国 董志彬 牟文良 王超 刘凌霄 于 2020-08-10 设计创作，主要内容包括：本发明公开了一种多功能硅橡胶涂覆材料及其制备方法和应用。该多功能材料由基材、硅橡胶涂层两部分组成,其中硅橡胶涂层中添加有功能性活性添加剂吸水剂、1-甲基环丙烯(1-MCP)、乙烯利、杀菌剂中的一种或几种。硅橡胶覆于打孔基材上具有透气以及气体调节的作用,可以代替硅窗使用；此外在硅橡胶涂层中添加不同种类的添加剂可达到不同效果,如在硅橡胶涂层中添加乙烯利,便可以释放出乙烯来达到催熟包装袋内果蔬的效果,本发明工艺简单,具有操作简便、成本低的优势。(The invention discloses a multifunctional silicone rubber coating material, a preparation method and application thereof. The multifunctional material consists of a base material and a silicon rubber coating, wherein the silicon rubber coating is added with one or more of a functional active additive water absorbent, 1-methylcyclopropene (1-MCP), ethephon and a bactericide. The silicon rubber is covered on the perforated base material, has the functions of ventilation and gas regulation, and can replace a silicon window; in addition, different types of additives are added into the silicone rubber coating to achieve different effects, for example, if ethephon is added into the silicone rubber coating, ethephon can be released to achieve the effect of ripening fruits and vegetables in the packaging bag.)

1. A silicon rubber coating material is formed by coating a silicon rubber film on the surface of a base material; preferably, the thickness of the base material is more than or equal to 0.02mm, and the thickness of the silicon rubber film is more than or equal to 0.01 mm; more preferably, the thickness of the silicone rubber coating is 0.03-0.1 mm.

2. The silicone rubber coating material according to claim 1, wherein the substrate is a plastic film; preferably, the substrate is: polyethylene (PE) film, polypropylene (PP) film, polyvinyl chloride (PVC) film, polyethylene terephthalate (PET) film, ethylene-vinyl acetate copolymer film, polyolefin heat shrinkable film, and composite films of two or three thereof.

3. The silicone rubber coating material according to claim 1 or 2, wherein the surface of the base material is perforated with pores having a diameter of 3.6mm or less.

4. The silicone rubber coating material according to claim 3, wherein the substrate of the silicone rubber coating material has a porosity of generally 1% to 50%.

5. The silicone rubber coating material according to any one of claims 1 to 4, wherein the structural unit of the silicone rubber film is:

wherein n is 20-4000, and m is 10-1350;

the number average molecular weight Mn of the silicon rubber membrane is 1000-; the weight average molecular weight Mw is 1500-; preferably, the number average molecular weight Mn is from 5 to 12 ten thousand and the weight average molecular weight Mw is from 7 to 18 ten thousand.

6. The silicone rubber coating material according to claim 5, wherein the silicone rubber film is obtained by crosslinking vinyl silicone oil. Preferably, the silicone rubber film comprises the following raw materials in percentage by weight: 49-95 parts of vinyl silicone oil, 5-30 parts of a cross-linking agent and parts by weight.

7. The silicone rubber coating material according to claim 5, wherein in the vinyl silicone oil, the vinyl group content is 0.05% to 1.1%;

the cross-linking agent is methyl hydrogen-containing silicone oil, and the side group of the cross-linking agent contains a hydrogen bond; the hydrogen content is: 0.05 to 1.2 percent.

8. The silicone rubber coating material according to any one of claims 1 to 7, wherein the method for synthesizing the silicone rubber membrane comprises the steps of: 1) mixing vinyl silicone oil and a cross-linking agent according to a preset proportion, fully mixing for 5-10 min by using a mixing roll to uniformly mix all the components, and 2) adding a catalyst, and fully stirring.

9. The silicone rubber coating material of claim 8, wherein the catalyst is a platinum catalyst having a platinum content of: 0.05-10% of viscous transparent clear liquid; the main component of the platinum catalyst is a platinum complex, the viscosity is 500cp, the density is about 0.97-0.99, the volatile component is less than 0.2%, and the flash point is more than 40 ℃.

10. The silicone rubber coating material according to claim 8 or 9, wherein in step 1), 49 to 95 parts of vinyl silicone oil and 5 to 30 parts of a crosslinking agent are added; adding 0.1-0.5 part of catalyst in the step 2); are all in parts by weight.

11. The silicone rubber coating material according to any one of claims 1 to 10, wherein the silicone rubber film further comprises an additive component which is one or more of a silicone inhibitor, a reinforcing agent and/or a reactive additive.

12. The silicone rubber coating material according to claim 11, wherein the method for synthesizing the silicone rubber membrane comprises the steps of: 1) mixing vinyl silicone oil, a cross-linking agent and an additive component according to a preset proportion, fully mixing for 5-10 min by using a mixing roll to uniformly mix the components, and 2) adding a catalyst, and fully stirring.

13. The silicone rubber coating material of claim 11, wherein the silicone gum inhibitor, the principal component being a vinyl silicone oil and a silicone oil modifier, has a viscosity of about 500cp, a density of 0.97 to 0.99, and a flash point of > 40 ℃;

the strengthening agent includes: diatomite, white carbon black, calcium carbonate, titanium dioxide and zeolite powder; the mesh number is generally 100-325 meshes; SiO 2₂Including gas phase method of SiO₂And precipitation method of SiO₂The specific surface area is generally 120-380m²(ii)/g; the dosage of the reinforcing agent is 0.1-30 parts;

the active additive comprises a water absorbent, 1-methylcyclopropene, ethephon and a bactericide; the dosage of the functional active additive is 0.1-50 parts;

commonly used water-absorbing agents include: calcium chloride, magnesium chloride, ammonium acetate, urea, sodium chloride, glucose, potassium chloride;

ethephon is solid powder, and the mesh number is generally 100-325 meshes;

1-methylcyclopropene (1-MCP) refers to 1-methylcyclopropene (1-MCP) inclusion complex, white solid powder, with the mesh number of 325 meshes generally being 100-;

the bactericide is sodium pyrosulfite which is white solid powder, and the mesh number is generally 100-325 meshes.

14. A method of synthesizing a silicone rubber membrane as defined in claim 13 comprising the steps of:

1) mixing vinyl silicone oil, a cross-linking agent and additive components according to the proportion, fully mixing for 5-10 min by using a mixing roll to uniformly mix the components,

2) adding platinum catalyst and stirring.

15. A method for producing the silicone rubber coating material as defined in any one of claims 1-14, comprising the steps of:

1) mixing vinyl silicone oil, a cross-linking agent and an additive component according to the proportion, fully mixing for 5-10 min by using a mixing roll to uniformly mix the components, then adding a platinum catalyst, and fully stirring;

2) perforating the base material to make the diameter of the small hole less than or equal to 3.6mm,

3) coating the mixed material obtained in the step 1) on the surface of the base material by using a coating machine, wherein the thickness of the silicone rubber coating is 0.03-1 mm, and heating the silicone rubber coating at 50-120 ℃ to enable the silicone rubber coating to react completely;

4) and aging the base material coated with the silicon rubber coating in a forced air drying oven at 50-120 ℃ for 0.5-6 h to finish the process.

16. A silicone rubber coating composition comprising, by weight: 49-95 parts of vinyl silicone oil, 5-30 parts of a cross-linking agent and 0.1-0.5 part of a catalyst.

17. The silicone rubber coating composition of claim 16, further comprising 0.1 to 5 parts of a silicone gum inhibitor.

18. The silicone rubber coating composition according to claim 16 or 17, wherein in the vinyl silicone oil, the vinyl content is 0.05% to 1.1%; the cross-linking agent is methyl hydrogen-containing silicone oil, and the side group of the cross-linking agent contains a hydrogen bond; the hydrogen content is: 0.05 percent to 1.2 percent;

the catalyst is a platinum catalyst, and the using amount is 0.1-0.5 part; the platinum content in the platinum catalyst is as follows: 0.05 to 10 percent.

19. The silicone rubber coating composition of claim 18, further comprising one or more of the following:

0.1-30 parts of a reinforcing agent; 0.1-50 parts of functional active additive;

the functional active additive comprises a water absorbent, 1-methylcyclopropene, ethephon and a bactericide; the water absorbing agent includes: calcium chloride, magnesium chloride, ammonium acetate, urea, sodium chloride, glucose, potassium chloride; the bactericide is sodium metabisulfite.

20. Use of the silicone rubber coating material as defined in any one of claims 1 to 13 for the manufacture of packaging materials; preferably, the fruit and vegetable packaging material is used.

21. A silicone rubber composite packaging material, characterized in that at least a part of the silicone rubber composite packaging material uses the silicone rubber coating material according to any one of claims 1 to 13, the porosity of the base material of the silicone rubber coating material is 1% to 50%, and the silicone rubber coating material accounts for 2% to 70% of the total surface area of the silicone rubber composite packaging material.

22. The silicone rubber composite packaging material of claim 21, wherein the fruit and vegetable packaging material is a packaging bag or a packaging box.

Technical Field

The invention belongs to the field of fruit and vegetable preservation, relates to a silicone rubber coating material, a preparation method and application thereof, provides a multifunctional preservation material, and particularly relates to a silicone rubber coating material with ventilation and gas regulation functions, and a preparation method and application thereof.

Background

With the improvement of living standard of people, the demand of people on fruits and vegetables is gradually changed from pursuit of quantity and price to pursuit of quality, multiple varieties, cleanness, safety and nutrition of products. As the seasonal nature of the fruit and vegetable production is obvious, a system technology of preservation, packaging and circulation is needed to guarantee the annual market circulation consumption needs. The lack of proper fresh-keeping method and fresh-keeping package makes the fresh quality of the product unable to be controlled due to the influence of market development. After the 21 st century, although high O was developed₂The fresh-keeping technology, the ice-temperature storage and transportation technology, the special chemical substance application technology (edible packaging materials of animal and plant sources, growth regulating substances and the like), the radiation technology, the CAP (controlled adhesion package) technology, the high-pressure technology, the microwave technology and the like effectively improve the safety quality of fresh fruit and vegetable products, but the requirements of people on the functional fresh-keeping packaging materials and the packaging treatment technology matched with the functional fresh-keeping packaging materials are higher and higher.

On the premise of having a sterilization function, the functional fresh-keeping packaging material or the fresh-keeping packaging container can release gas components beneficial to fresh keeping, and absorb some fresh-keeping damaging gases generated in product metabolism; the packaging technology is extended to the processing field, and the integration of fresh-keeping packaging and processing is a future development trend.

The silicon rubber film is a film made of silicon rubber, also called silicon rubber air-conditioning film, which is stuck on the window opened by the plastic tent (bag) for storing fruits, vegetables and grains to regulate the gas components in the environment, so it is also called silicon window. However, for different varieties of fruits and vegetables, the optimum storage temperature, silicon window area and appropriate window opening time are selected to achieve the optimum effect. In order to meet the requirements of products, various improvements have been made to silicon windows and silicon rubber.

CN102041688A discloses a waterproof breathable organic silicon synthetic leather and a manufacturing method thereof, wherein the waterproof breathable organic silicon synthetic leather is prepared from a cloth base material or a fiber base material and at least one layer of organic silicon rubber compounded on the surface, wherein the organic silicon rubber is prepared from 50-70% of vinyl-containing polydiorganosiloxane base polymer, 2-5% of oligomeric siloxane vulcanization cross-linking agent containing silicon-hydrogen bonds, 0.5-2% of platinum compound vulcanization catalyst, 0.5-2% of alkynol hydrosilation addition reaction inhibitor, 5-10% of white carbon black, 5-10% of calcium carbonate and 10-20% of 100-mesh sodium chloride; selecting a base material; gluing; drying and curing; cooking leaches out sodium chloride. After the synthetic leather is formed, the sodium chloride is completely dissolved in the water through boiling in the water, so that the synthetic leather generates certain air holes, and certain air permeability of the synthetic leather can be ensured. The pore diameter of the generated pores is very small, so that water cannot penetrate through the pores of the synthetic leather, and the waterproof function is very good.

CN107141502B discloses an antibacterial silicone rubber, a preparation method and an application thereof, wherein functional macromolecules are chemically bonded on the surface of the silicone rubber, the functional macromolecules contain vinyl or ethynyl, and the functional macromolecules are chemically bonded with the surface of the silicone rubber through the vinyl or ethynyl; the functional macromolecule includes a polyamino acid macromolecule. The antibacterial silicone rubber disclosed by the invention has the advantages that the polyamino acid macromolecules are chemically bonded on the surface of the silicone rubber, the antibiosis is realized through the interaction of the polyamino acid macromolecules and negatively charged cell membranes of bacteria, the antibiosis is lasting, and the bacteria are not easy to generate drug resistance; meanwhile, the polyamino acid macromolecules are combined with the surface of the silicon rubber in a chemical bonding mode, the macromolecules cannot be separated out and enter cells, and the high biocompatibility is achieved.

However, the above methods all focus on improvements of the colloidal silica itself, and do not involve the binding of the colloidal silica to the substrate, and since the colloidal silica itself is polar, it is difficult to apply it to a non-polar substrate to form a composite material. In addition, the original silicon window has large silicon window area, difficult processing and high cost, and the silicon window area and the window opening time are difficult to adjust, so that the silicon window is difficult to adapt to the requirements of different fruits and vegetables.

Disclosure of Invention

The invention aims to provide a silicone rubber coating material and a preparation method thereof aiming at the defects of the prior art, and further provides a silicone rubber composite packaging material which is simple and convenient to process and low in cost, and can be processed and accurately adjusted according to the requirements of different fruits and vegetables.

It is also an object of the present invention to provide a silicone rubber coating composition. The silicone rubber coating composition is used for preparing a silicone rubber coating material.

The invention provides a silicon rubber coating material which is formed by coating a silicon rubber film on the surface of a base material. Preferably, the thickness of the base material is more than or equal to 0.02mm, and the thickness of the silicon rubber film is more than or equal to 0.01 mm. More preferably, the thickness of the silicone rubber coating is 0.03-0.1 mm.

The base material is a plastic film. The base material mainly comprises: polyethylene (PE) films, polypropylene (PP) films (including uniaxially and biaxially oriented polypropylene films), polyvinyl chloride (PVC) films, polyethylene terephthalate (PET) films, ethylene-vinyl acetate copolymer films, polyolefin heat shrinkable films, and composite films of the above listed films. The polyolefin heat-shrinkable film is generally a film with a PP/LLDPE/PP structure, which is prepared by three-layer co-extrusion by using polypropylene copolymer (PP) and linear low-density polyethylene (LLDPE) resin as main raw materials. Polyethylene (PE) includes low density polyethylene and linear polyethylene, which generally includes high density polyethylene, ultra high molecular weight polyethylene, linear low density polyethylene, very low density polyethylene, and the like; the Polyethylene (PE) film is a film made of the above polyethylene material.

Preferably, the surface of the base material is perforated, the diameter of the small hole is less than or equal to 3.6mm, and the diameter of the small hole is preferably 1.2mm, 1.6mm, 2.0mm, 2.4mm, 2.8mm, 3.2mm, 3.6mm or the range formed by any two of the above numerical values. More preferably, the diameter of the small hole is 1.2-3.6 mm. Optionally perforating the entire area of the substrate, or perforating a part of the surface of the substrate; the pores can be distributed regularly or irregularly, for example, the pores can be arranged in a triangular, rectangular, square or circular shape or in a random shape.

The porosity of the substrate of the silicone rubber coating material is generally 1% to 50%. The pores are generally 1mm or more. Different porosities can be selected according to the preservation requirements of different fruits and vegetables, so that the modified atmosphere is realized on the basis of preservation.

Porosity is the ratio of the total area of the pores to the total area of the substrate.

The structural unit of the silicone rubber membrane is as follows:

wherein n is 20-4000, and m is 10-1350. The number average molecular weight Mn of the silicon rubber membrane is 1000-; the weight average molecular weight Mw is 1500-330000, and the dispersion coefficient is 1.5-2. Preferably, the number average molecular weight Mn is from 5 to 12 ten thousand and the weight average molecular weight Mw is from 7 to 18 ten thousand.

Preferably, the silicone rubber membrane is obtained by crosslinking vinyl silicone oil. Preferably, the silicone rubber film comprises the following raw materials in percentage by weight: 50-95 parts of vinyl silicone oil, 5-30 parts of a cross-linking agent and parts by weight. Unless otherwise specified, the parts of each raw material (or component) in the present invention are parts by weight.

In the vinyl silicone oil, the content of vinyl is 0.05-1.1%. More preferably, the vinyl silicone oil comprises: the double-end vinyl silicone oil and the side chain vinyl silicone oil have two types, and the viscosity ranges are as follows: 110-110000 mpa.s; the appearance is as follows: a colorless transparent liquid. The molecular weight is generally: 1500-300000. Preferably, the molecular weight is: 20000-110000.

The cross-linking agent is methyl hydrogen-containing silicone oil, and the side group of the cross-linking agent contains a hydrogen bond. The hydrogen content is: 0.05 to 1.2 percent. The viscosity ranges are: 10-140 mpa.s; the appearance is as follows: a colorless transparent liquid. The molecular weight is generally: 100-100000. Preferably, the molecular weight is: 10000-50000.

The synthetic reaction formula of the silicone rubber membrane is as follows:

in the above formula, the reactants are vinyl silicone oil and hydrogen-containing silicone oil, and m and n in the reaction formula represent the number average molecular weight of the reactants. Wherein n is 20-4000, and m is 10-1350.

The synthetic method of the silicone rubber membrane comprises the following steps: 1) mixing vinyl silicone oil and a cross-linking agent according to a preset proportion, fully mixing for 5-10 min by using a mixing roll to uniformly mix all the components, and 2) adding a catalyst, and fully stirring.

The catalyst is a platinum catalyst, and the platinum content in the platinum catalyst is as follows: 0.05 to 10 percent. Is a viscous transparent clear liquid. The main component of the platinum catalyst is a platinum complex, the viscosity is 500cp, the density is about 0.97-0.99, the volatile component is less than 0.2%, and the flash point is more than 40 ℃. The catalyst does not participate in the reaction, and can activate the hydrogen bond on the methyl hydrogen-containing silicone oil to ensure that the methyl hydrogen-containing silicone oil becomes active, and then the hydrogen bond on the methyl hydrogen-containing silicone oil and the vinyl silicone oil generate addition crosslinking reaction.

Preferably, in the step 1), 50-95 parts of vinyl silicone oil and 5-30 parts of cross-linking agent are added. 0.1-0.5 part of catalyst is added in the step 2). Are all in parts by weight.

Preferably, the silicone rubber membrane further comprises an additive component, wherein the additive component is one or more of a silicone inhibitor, a reinforcing agent and/or an active additive. The synthetic method of the silicone rubber membrane comprises the following steps: 1) mixing vinyl silicone oil, a cross-linking agent and an additive component according to a preset proportion, fully mixing for 5-10 min by using a mixing roll to uniformly mix the components, and 2) adding a catalyst, and fully stirring.

Preferably, the silica gel inhibitor, the main component of the vinyl silicone oil and the silicone oil modifier have the viscosity of about 500cp, the density of 0.97-0.99 and the flash point of more than 40 ℃. The silica gel inhibitor does not participate in the reaction, but can inhibit the activity of the catalyst, weaken the activity of the catalyst and prolong the reaction time. The dosage of the silica gel inhibitor is 0.1-5 parts.

Preferably, the reinforcing agent includes: diatomite, white carbon black, calcium carbonate, titanium dioxide and zeolite powder. The mesh size is generally 100-325 mesh. SiO 2₂Including gas phase method of SiO₂And precipitation method of SiO₂The specific surface area is generally 120-380m²(ii) in terms of/g. The reinforcing agent does not participate in the reaction, and can reinforce the strength and the toughness of the silicon rubber film. The reinforcing agent is used in an amount of 0.1-30 parts.

The active additive comprises a water absorbent, 1-methylcyclopropene, ethephon and a bactericide. The addition of reactive additives to the silicone rubber allows the silicone rubber coating to perform functions other than breathability. The dosage of the functional active additive is 0.1-50 parts.

Commonly used water-absorbing agents include: calcium chloride, magnesium chloride, ammonium acetate, urea, sodium chloride, glucose and potassium chloride. The solid powder has the mesh number of generally 100-325 meshes. The water absorbent is added into the silicon rubber, so that the water in the packaging bag can be absorbed under low humidity, the aim of keeping the substances in the bag dry is fulfilled, and the moisture absorption film can be manufactured by adding the water absorbent into the silicon rubber.

Ethephon is solid powder, and the mesh number is generally 100-325 meshes. When added into silicon rubber, the ethylene gas can be released under certain conditions, and the function of ripening fruits and vegetables is achieved.

1-methylcyclopropene (1-MCP) refers to 1-methylcyclopropene (1-MCP) inclusion complex, white solid powder, with the mesh number of 325 meshes being generally 100-. 1-methylcyclopropene (1-MCP) is added into silicon rubber, and can release 1-MCP under certain conditions to delay the maturity of fruits and vegetables, so as to achieve the aim of fresh keeping.

The bactericide is sodium metabisulfite. The bactericide is added into the silicon rubber, can kill fungus in the bag, and prolongs the fresh-keeping period of fruits and vegetables. The sodium pyrosulfite is white solid powder, and the mesh number is generally 100-325 meshes.

More preferably, the method for synthesizing the silicone rubber membrane comprises the following steps: 1) mixing vinyl silicone oil, a cross-linking agent and the additive components according to the proportion, fully mixing for 5-10 min by using a mixing roll to uniformly mix the components, and 2) adding a platinum catalyst, and fully stirring. The vinyl silicone oil cross-linking reaction can form a layer of silicone rubber film, and the reinforcing agent and/or the active additive are added into the silicone rubber film, do not participate in the reaction and exist in the silicone rubber film in the form of powder solid. The silicone rubber film is coated on the surface of a substrate, and the silicone rubber film can be adhered on the substrate to form the multifunctional silicone rubber coating material.

The preparation method of the silicone rubber coating material comprises the following steps:

1) mixing vinyl silicone oil, a cross-linking agent and the additive components according to the proportion, fully mixing for 5-10 min by using a mixing roll to uniformly mix the components, then adding a platinum catalyst, and fully stirring.

2) Perforating the base material to make the diameter of the small hole less than or equal to 3.6mm,

3) coating the mixed material obtained in the step 1) on the surface of the base material by using a coating machine, wherein the thickness of the silicone rubber coating is 0.03-1 mm, and heating the silicone rubber coating at 50-120 ℃ to enable the silicone rubber coating to react completely.

4) And aging the base material coated with the silicon rubber coating in a forced air drying oven at 50-120 ℃ for 0.5-6 h to finish the process.

Generally, the surface pretreatment is not needed for coating the PS (polystyrene) and PVC (polyvinyl chloride) films with polar structures, but the surface treatment is needed for the PP, PE, PET and the like with non-polar surface structures, the chemical stability is extremely high, the bonding fastness with the silicone rubber film is very low, and the surface treatment is generally needed to activate the plastic surface layer to generate new chemical bonds to roughen the surface, so that the bonding adhesion fastness between the base material and the coating layer is improved. The following methods are commonly used for surface treatment of plastics: chemical method, solvent treatment, corona treatment. The invention controls the uniformity among all components and the prepolymerization degree of the product through the selection of the proportion of the vinyl silicone oil and the cross-linking agent and the selection of the mixing time of the mixing roll, so that the silicone rubber film can be coated on the surfaces of various base materials and combined with the base materials to form a novel silicone rubber coating material.

When the silicon rubber coating material is used, the silicon rubber coating has a breathable effect on the small holes of the perforated base material, an airtight surface is formed in other places, the breathability can be adjusted through the number of the perforated holes and the total area of the perforated holes, and the total area of different holes can be designed according to the requirements of different fruits and vegetables to meet the breathability requirements of different fruits and vegetables. It also hasCan adjust CO in the bag₂And O₂The concentration plays a role in gas regulation, anaerobic respiration of the fruits and vegetables can be effectively prevented, and a good respiration environment is provided for the fruits and vegetables, so that the aims of long preservation time and good preservation effect are fulfilled; the effect of the window is equivalent to that of a silicon window, and the window can replace the silicon window and has the advantages of simple and convenient operation and low cost. Meanwhile, according to different required functions, corresponding active additives are added to prepare the silicone rubber coating materials with different functions, and double effects are achieved on the basis of modified atmosphere. For example, the purposes of delaying the maturity and the preservation of fruits and vegetables are achieved by adding 1-MCP; the ethephon is added to play a role in ripening fruits and vegetables; the moisture absorption film can be prepared by adding the water absorbent; the bactericide is added to kill fungus in the bag, so that the preservation period of the fruits and vegetables is prolonged.

The silicon rubber coating material has low production cost and simple and convenient use, and can be used for large-scale industrial production. Compared with the traditional silicon window, the invention saves the production cost by about 20 percent, can select products with proper specifications according to the requirements of fruits and vegetables, saves manpower and material resources for adjusting the silicon window area and the windowing time in logistics and storage, and saves the management cost in logistics and storage by about 15 percent.

The invention also provides a silicon rubber coating composition, which comprises the following components in parts by weight: 50-95 parts of vinyl silicone oil, 5-30 parts of a cross-linking agent and 0.1-0.5 part of a catalyst. Preferably, the silicone rubber coating composition further comprises 0.1-5 parts of a silicone rubber inhibitor. The silicone rubber coating composition is used for preparing a silicone rubber membrane.

Preferably, the vinyl silicone oil has a vinyl content of 0.05% to 1.1%. The vinyl silicone oil is a reactant and participates in the reaction, and the chain end of the vinyl silicone oil contains vinyl. More preferably, the vinyl silicone oil comprises: the double-end vinyl silicone oil and the side chain vinyl silicone oil have two types, and the viscosity ranges are as follows: 110-110000 mpa.s; the appearance is as follows: a colorless transparent liquid. The molecular weight is generally: 200-300000. Preferably, the molecular weight is: 20000-110000.

The cross-linking agent is methyl hydrogen-containing silicone oil, and the side group of the cross-linking agent contains a hydrogen bond. The hydrogen content is: 0.05 to 1.2 percent. The viscosity ranges are: 10-140 mpa.s; the appearance is as follows: a colorless transparent liquid. The molecular weight is generally: 100-100000.

Preferably, the catalyst is a platinum catalyst, and the using amount is 0.1-0.5 part. The platinum content in the platinum catalyst is as follows: 0.05 to 10 percent. Is a viscous transparent clear liquid. The main component of the platinum catalyst is a platinum complex, the viscosity is 500cp, the density is about 0.97-0.99, the volatile component is less than 0.2%, and the flash point is more than 40 ℃. The catalyst does not participate in the reaction, and can activate the hydrogen bond on the methyl hydrogen-containing silicone oil to ensure that the methyl hydrogen-containing silicone oil becomes active, and then the hydrogen bond on the methyl hydrogen-containing silicone oil and the vinyl silicone oil generate addition crosslinking reaction.

Preferably, the silicone rubber coating composition further comprises 0.1-30 parts of a reinforcing agent.

Preferably, the silicone rubber coating composition further comprises 0.1-50 parts of a functional active additive. The functional active additive comprises a water absorbent, 1-methylcyclopropene, ethephon and a bactericide. The water absorbing agent includes: calcium chloride, magnesium chloride, ammonium acetate, urea, sodium chloride, glucose and potassium chloride. The bactericide is sodium metabisulfite.

The invention also provides the application of the silicon rubber coating material in manufacturing packaging materials, in particular to fruit and vegetable packaging materials.

The invention also provides a silicon rubber composite packaging material, which is characterized in that at least one part of the silicon rubber composite packaging material uses the silicon rubber coating material, the porosity of the base material of the silicon rubber coating material is 1% -50%, and the silicon rubber coating material accounts for 2% -70% of the total surface area of the silicon rubber composite packaging material.

More preferably, the fruit and vegetable packaging material is a packaging bag or a packaging box. The silicon rubber composite packaging material is suitable for packaging bags of various materials and specifications, such as PVC bags, PE bags and PET bags; and (5) thermally sealing the bag and pricking the bag. The packing box with various structural shapes can be coated on the inner side. More preferably, the porosity of the base material can be adjusted by those skilled in the art according to the requirements of fruits and vegetables, for example, the porosity of the garlic sprout packaging bag is 2-3%, and the porosity of the banana packaging bag is 5-15%.

The silicon rubber composite packaging material is a novel silicon rubber packaging material, different additives have different effects, and the porosity and the effect of the packaging bag can be adjusted according to the requirements of different fruits and vegetables on the basis of reaching the level of products sold in the market. The silicon rubber composite packaging material of the invention compounds the silicon rubber mold on the base material, has certain tightness while ventilating, and can fully play the role of various functional active additives to achieve the best effect. If the functional active additive is added into a common silicon window and is not compounded with a base material, the functional active additive can volatilize outwards when in use, and cannot achieve the ideal concentration and the effect. In the mode of the invention, the silicone rubber mold added with the functional active additive is compounded on the inner layer of the base material, and the functional active additive is firstly released into the bag, thereby achieving good effect, and the mode is more convenient to use than other modes.

Drawings

FIG. 1 is a GPS spectrum of the silicone rubber membrane obtained in example 6.

Fig. 2 is a schematic structural view of a silicone rubber membrane. Wherein 1: a substrate; 2: and (4) a small hole. After coating, the small hole 2 is a silicon rubber mold, and the substrate 1 is also coated with a layer of silicon rubber mold.

Detailed Description

The following examples are further illustrative of the present invention, but the present invention is not limited thereto.

The double-end vinyl silicone oil used by the invention comprises RH-Vi304, RH-Vi320, RH-Vi305, RH-Vi302 and RH-Vi301 of Ningbo Runghe high-new material science and technology Limited, and RH-Vi series of Ningbo Runghe high-new material science and technology Limited: a colorless transparent liquid; the viscosity is 1000 +/-50-10 ten thousand +/-5000 mpa.s; the content of vinyl is 0.06 + -0.01-0.32 + -0.02% (wt); the volatile matter is less than or equal to 1 percent. The double-end vinyl silicone oil used by the invention also comprises DY-V401-10.9 ten thousand, DY-V401-2 ten thousand and DY-V401-1 ten thousand of Shandong Dayihua chemical industry Co. DY-V401 series of Shandong Dayi chemical industries, Ltd: colorless or light yellow transparent liquid; viscosity of 100-100000cp (25 deg.C); a vinyl content of 0.17 to 2.81% (wt); the volatile matter is less than or equal to 1.5 percent.

The side chain vinyl silicone oil used in the present invention includes: DY-V411 by Shandong Dayihua chemical Co., Ltd; DY-V411 series of Shandong Dayihua chemical Co., Ltd: colorless or light yellow transparent liquid; viscosity of 1000-; a vinyl content of 0.5 to 1.8% (wt); the volatile matter is less than or equal to 1.5 percent.

The methyl hydrogen-containing silicone oil used in the invention comprises: RH-H33, RH-H57, RH-H23, RH-H510 and RH-H502 of Ningbo Runzhe Gaoxin materials science and technology Limited; DY-H212 of Shandong Dai chemical engineering Co., Ltd. RH-H series of Ningbo Runghe high and new materials science and technology Limited: a colorless transparent liquid; the viscosity is 20-130 cs; hydrogen content of 0.1-1.3% (wt); the volatile matter is less than or equal to 5 percent. DY-H212 of Shandong Dayihua chemical Co., Ltd: a colorless transparent oily liquid; viscosity of 50-100cp (25 deg.C); hydrogen content of 0.1-1.0% (wt); the density is 0.98-1.0.

The platinum catalyst used in the invention comprises PC-12, PC-11, PC-13, PC-14, PC-15 and PC-16 of Shanghai Miyaxing chemical technology Co. The platinum catalyst has platinum complex as main component, viscosity of 500cp, density of 0.97-0.99, volatile component less than 0.2% and flash point over 40 deg.c.

The silica gel inhibitor used in the invention comprises: PC-611, PC-613, PC-614 and PC-615 of Shanghai Michelson chemical technology, Inc. The silica gel inhibitor, the main component of vinyl silicone oil and silicone oil modifier has viscosity of about 500cp, density of 0.97-0.99 and flash point higher than 40 deg.c.

1-MCP has a boiling point of about 10 ℃ and exists in a gaseous state at normal temperature, and is inconvenient to use. In order to increase the stability of 1-MCP during storage and maintain the active ingredient, 1-MCP is generally used as an inclusion complex using a certain technique, thereby expanding the range of applications of 1-MCP and its derivatives. The most common inclusion complex of 1-methylcyclopropene (1-MCP) is the Cyclodextrin (CDs) inclusion complex of 1-methylcyclopropene (1-MCP). However, any 1-methylcyclopropene (1-MCP) inclusion compound of the prior art may be used as the 1-methylcyclopropene (1-MCP) inclusion compound of the present invention.

Molecular weight of the silicone rubber was determined using GPC waters1515, detector: waters 2414; a chromatographic column: agilent PLGel 5um MIXED-C (made in GB); mobile phase: chloroform; flow rate: 1 ml/min; temperature: 35 ℃; and (3) standard substance: PS (Polystyrene ).