Membrane separation method for rubber coated rubber plug

Abstract

The invention discloses a membrane separation method of a rubber laminated rubber plug, and solves the problems that the recovery efficiency of leftover materials and wastes of the rubber laminated rubber plug is low, the pollution is serious and a regenerated material cannot meet the cleaning standard in the traditional process. According to the method, separation is realized through chemical and physical synergistic effects: a natural or organic release agent and a cleaned laminated rubber plug are mixed and infiltrated in a chemical path, and a matrix and a laminated film are separated after the binding power is weakened through swelling; according to the physical path, supercritical fluid is utilized to swell the film-covered rubber plug under specific conditions, and the base body and the covering film are directly stripped. The method is suitable for density-matched single-layer film-coated rubber plugs, and film-coated materials comprise polyester, fluoroplastic and the like. The release agent and the fluid can be recycled, so that no pollution risk is caused. The separated material is stable in performance and meets the regeneration requirement. The method breaks through the limitation of high energy consumption and high pollution in the traditional technology, has the advantages of environmental protection, low energy consumption and industrial adaptation, and provides an innovative scheme for recycling leftover materials and wastes of the rubber laminated rubber plug.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling of waste rubber and plastic products, and particularly provides a film separation method for rubber-coated stoppers. Background Art

[0002] With the rapid development of the pharmaceutical, chemical, and food industries, the output of coated bottle stoppers has been increasing year by year. A large amount of surplus materials are generated during the production of coated bottle stoppers, which not only causes waste of raw materials, occupies a large amount of space, but also may cause environmental pollution. At present, the surplus materials generated during the production of coated bottle stoppers at home and abroad are mainly used to produce low-value products and cannot be reused for pharmaceutical, chemical, and food bottle stoppers, with low added value. The main reason is that the recycled rubber prepared by existing recycling technologies cannot meet the cleaning requirements of bottle stoppers for pharmaceuticals, chemicals, and food. Developing the recycling of waste rubber and plastic products is an important way to separate and reuse the matrix and coating of rubber-coated stoppers, turn waste into treasure, protect the environment, and save resources.

[0003] In order to achieve the film separation of coated rubber, a variety of film separation methods have been developed in China. For example, Chinese Patent CN112706503 B discloses a composition for PET composite film separation and recycling. The invention uses a composition including 40 - 12% sodium hydroxide, 8 - 30% dichloromethane, 2 - 10% alcohol, and the balance being water for the film separation of PET-coated stoppers. The invention can effectively separate the material layers of the PET composite film. Another example is Chinese Patent CN 106832393 A, which discloses a separation method for aluminum-plastic composite films. The raw materials are cut and packed, and then the packed raw materials are put into a stainless steel tank. Water and a surfactant are added to the stainless steel tank and heated to a predetermined temperature to soak the raw materials. The soaked raw materials are taken out for the first separation to separate the PE film, but this invention cannot completely separate the PE film and requires secondary treatment. CN109608704A discloses a method for preparing composite conductive rubber using supercritical fluid technology. The preparation method of the present invention includes the following steps: putting rubber and conductive nanoparticles into a high-pressure container; adding a solvent medium to the high-pressure container, controlling the temperature and pressure in the high-pressure container to reach above the supercritical point of the solvent medium, keeping the temperature and pressure constant, and swelling the rubber sufficiently in the supercritical fluid medium; stirring or ultrasonically treating the mixture in the high-pressure container for a certain time; quickly releasing the pressure after the reaction is completed to obtain a composite conductive rubber material impregnated with conductive nanoparticles. The present invention has the advantages of simple and easy preparation method, green and environmentally friendly reaction, and great industrial application prospects. Summary of the Invention

[0004] In view of the above problems and to overcome the above-mentioned defects, the object of the present invention is to provide a film separation method for rubber-coated stoppers. The film separation method provided by the present invention can achieve the separation of the coating film from the rubber matrix, and the obtained rubber matrix and coating film plastic can be recycled and reused.

[0005] To achieve the object of the present invention, the present invention provides the following technical solutions:

[0006] A film separation method for rubber-coated stoppers, including chemical demoulding and physical demoulding, wherein the chemical demoulding includes the following steps:

[0007] (1): Clean the rubber-coated stopper to obtain a pure treated product;

[0008] (2): Immerse and mix the treated product with a demoulding agent;

[0009] (3): Separate the separated rubber matrix from the coating film, and dry the matrix and the coating film. After completion, the rubber matrix and the coating film are obtained.

[0010] Preferably, the physical demoulding includes the following steps:

[0011] (1): Clean the rubber-coated stopper to obtain a pure treated product;

[0012] (2): Place the treated product in a supercritical fluid environment for swelling treatment;

[0013] (3): Separate the separated rubber matrix from the coating film. After completion, the rubber matrix and the coating film are obtained.

[0014] Preferably, the rubber-coated stopper is one or several of medical coated stoppers, industrial coated stoppers, food coated stopper scraps and waste materials.

[0015] Preferably, the rubber-coated stopper in steps (1) of the chemical demoulding and physical demoulding is a single-layer coating, the density of the coating stopper matrix is 1.29 - 1.37 g / cm3, and the density of the single-layer coating is 1.1 - 1.8 g / cm3.

[0016] Preferably, the film material of the rubber-coated stopper in steps (1) of the chemical demoulding and physical demoulding is one or several of PET, FEP, ETFE, PP, PE, PVC.

[0017] Preferably, the demoulding agent in step (2) of the chemical demoulding is one or several of p-cymene, α-terpinene, β-terpinene, α-pinene, chloroform.

[0018] Preferably, the mass ratio of the treated product to the demoulding agent in step (2) of the chemical demoulding is 100:(10 - 70), preferably 100:(20 - 50).

[0019] Preferably, the temperature of the infiltration mixing in the chemical demoulding step (2) is 20-70°C, preferably 30-60°C, the mixing time is 3h-22h, preferably 5h-15h; the drying temperature is 30-120°C, preferably 40-80°C, and the drying time is 2h-8h, preferably 3h-6h.

[0020] Preferably, the supercritical fluid in the physical demoulding step (2) is one or more of supercritical carbon dioxide, supercritical nitrogen, supercritical hydrogen, supercritical oxygen, etc.

[0021] Preferably, the density of the supercritical fluid during the swelling treatment in the physical demoulding step (2) is 0.466-0.6 g / cm 3 , preferably 0.513-0.589 g / cm 3 .

[0022] Preferably, the temperature of the physical demoulding swelling treatment is 60-120°C, preferably 60-100°C, the pressure is 8-14 MPa, preferably 8-12 MPa, and the time is 20-60 min, preferably 20-40 min.

[0023] Preferably, the volume ratio of the coated rubber stopper to the supercritical fluid environment space during the swelling treatment in the physical demoulding step (2) is 1:(6-12), preferably 1:(8-10).

[0024] The technical solution of the present invention has at least the following advantages and beneficial effects:

[0025] (1) A membrane separation method for a rubber-coated rubber stopper disclosed by the present invention includes chemical demoulding and physical demoulding. The demoulding agent and supercritical fluid used in its components do not cause environmental pollution during use, which is conducive to energy conservation and environmental protection;

[0026] (2) The demoulding agent is synthesized from vegetable oil, which is non-toxic and environmentally friendly. The supercritical fluid is a green, efficient and environmentally friendly swelling medium. It does not affect the various properties of rubber and the coating during use, and can greatly reduce the production cost of enterprises.

[0027] (3) The demoulding agent and supercritical fluid used during the demoulding process of the chemical demoulding and physical demoulding methods provided by the present invention can be recycled again, will not become waste to pollute the environment, and at the same time reduce the production cost, which is in line with the national green development policy.

[0028] (4) The membrane separation method provided by the present invention has simple process operation, can realize the high-value recycling of the coating and the rubber matrix, provides a new way for the resource utilization of rubber-coated rubber stoppers, and greatly reduces the production cost, reduces the environmental pollution of the coated rubber stoppers, and is suitable for industrial production. Description of the Drawings

[0029] Figure 1: Swelling picture of the coated rubber stopper;

[0030] In Figure 1, a1 is before the swelling of the coated rubber stopper, and a2 is after the swelling of the coated rubber stopper. Detailed Description of the Invention

[0031] The present invention will be described below in conjunction with the drawings and specific embodiments.

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0033] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of the present invention.

[0034] To make the above objectives, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0035] The photos of the rubber-coated rubber stopper before and after swelling in Figure 1 show that after swelling, its volume increases nearly eight times. When the coated rubber stopper is in the swelling system, the additives or supercritical molecules penetrate into the rubber cross-linked network, resulting in the swelling of the matrix. At the same time, inside the swollen matrix, the cross-linked network relaxes, the intermolecular force decreases, the distance between molecular chains increases, the molecular chains change from the natural state to the loose state, and the macroscopic manifestation is volume expansion. The film on the surface of the coated rubber stopper has high chemical stability, resulting in no swelling effect, and the volume of the film does not change. Due to the difference in volume change between the film and the matrix, a swelling force is generated at the interface between the two, weakening the adhesion between the film and the matrix, resulting in the separation of the two.

[0036] Example 1

[0037] Clean 100 g of rubber PET-coated rubber stoppers, soak and mix the treated products with 50 g of a demolding agent. The demolding agent is p-cymene, the soaking and mixing temperature is 35 °C, the mixing time is 8 h, the drying temperature is 60 °C, and the drying time is 4 h.

[0038] Example 2

[0039] Perform membrane separation of the rubber-coated rubber stopper according to the method of Example 1. The difference from Example 1 is that the material of the coated rubber stopper is FEP.

[0040] Example 3

[0041] The film separation of the rubber-coated stopper was carried out according to the method of Example 1. The difference from Example 1 is that the material of the coated stopper is ETFE.

[0042] Example 4

[0043] The film separation of the rubber-coated stopper was carried out according to the method of Example 1. The difference from Example 1 is that the mold release agent is α-pinene.

[0044] Example 5

[0045] The film separation of the rubber-coated stopper was carried out according to the method of Example 1. The difference from Example 1 is that the mold release agent is β-terpinene.

[0046] Example 6

[0047] The film separation of the rubber-coated stopper was carried out according to the method of Example 1. The difference from Example 1 is that the mass ratio of the rubber-coated stopper to the mold release agent is 100:40.

[0048] Example 7

[0049] The film separation of the rubber-coated stopper was carried out according to the method of Example 1. The difference from Example 1 is that the mass ratio of the rubber-coated stopper to the mold release agent is 100:30.

[0050] Example 8

[0051] The film separation of the rubber-coated stopper was carried out according to the method of Example 1. The difference from Example 1 is that the infiltration mixing temperature is 50 °C.

[0052] Example 9

[0053] The rubber PET-coated stopper was cleaned, and the treated product was placed in a supercritical carbon dioxide environment for infiltration and mixing. The density of gaseous carbon dioxide is 0.4722 g / cm 3 , the reaction pressure is 8 MPa, the reaction temperature is 60 °C, and the reaction treatment time is 20 min.

[0054] Example 10

[0055] The film separation of the rubber-coated stopper was carried out according to the method of Example 9. The difference from Example 9 is that the film material of the coated stopper is FEP.

[0056] Example 11

[0057] The film separation of the rubber-coated stopper was carried out according to the method of Example 9. The difference from Example 9 is that the reaction pressure is 10 MPa.

[0058] Example 12

[0059] The film separation of the rubber-coated rubber stopper was carried out according to the method of Example 9. The difference from Example 9 was that the reaction temperature was 80 °C.

[0060] Example 13

[0061] The film separation of the rubber-coated rubber stopper was carried out according to the method of Example 9. The difference from Example 9 was that the reaction treatment time was 30 min.

[0062] The test results are shown in Table 1

[0063] Table 1 Film separation test results of the rubber-coated rubber stoppers of Examples 1 to 13

[0064] Project Degree of separation Membrane material condition Example 1 100％ The PET membrane is clean and intact Example 2 100％ The FEP membrane is clean and intact Example 3 12％ The ETFE membrane is not separated Example 4 100％ The PET membrane is clean and intact Example 5 24％ The PET membrane is not separated Example 6 100％ The PET membrane is clean and intact Example 7 60％ Most of the PET membrane is separated Example 8 100％ The PET membrane is clean and intact Example 9 100％ The PET membrane is clean and intact Example 10 100％ The FEP membrane is clean and intact Example 11 100％ The PET membrane is clean and intact Example 12 100％ The PET membrane is clean and intact Example 13 100％ The PET membrane is clean and intact

[0065] In the preferred embodiment of the present invention, the advantage of the film separation method of the coated rubber stopper provided by the present invention is that by using chemical and physical methods, without destroying the raw material components, under the swelling action of the demolding agent and supercritical fluid, the coated rubber stopper is fully infiltrated and swollen, and the bonding effect of the binder and the adsorption effect of the coating film in the coated rubber stopper are weakened, so that the film separation of the coated rubber stopper is achieved, solving the problem of air pollution in the traditional separation method. Moreover, the auxiliaries used in the separation method of the present invention can all be recycled and reused, without generating polluting waste, which is beneficial to environmental protection.

[0066] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Any modification or partial replacement without departing from the spirit of the present invention shall be covered within the scope of the claims of the present invention.

Claims

1. A method for membrane separation of rubber-coated stoppers, including chemical demoulding and physical demoulding. The chemical demoulding includes the following steps: (1): Clean the rubber-coated stopper to obtain a pure treated product; (2): Immerse and mix the treated product with a demoulding agent; (3): Separate the rubber matrix from the coating film, and dry the matrix and the coating film. After completion, obtain the rubber matrix and the coating film; The physical demoulding includes the following steps: (1) Clean the rubber-coated stopper to obtain a pure treated product; (2) Place the treated product in a supercritical fluid environment for swelling treatment; (3) Separate the rubber matrix from the coating film. After completion, obtain the rubber matrix and the coating film.

2. The method for membrane separation of a rubber-coated stopper according to claim 1, wherein: The rubber-coated stopper is one or more of medical coated stoppers, industrial coated stoppers, food coated stopper scraps and waste materials; The rubber-coated stopper in the chemical and physical film removal steps (1) is a single-layer coated stopper, and the density of the coated stopper matrix is 1.29 - 1.37 g / cm 3 , and the density of the single-layer coating is 1.1 - 1.8 g / cm 3 ; The membrane material of the rubber-coated stopper in step (1) of the chemical demoulding and physical demoulding is one or more of PET, FEP, ETFE, PP, PE, PVC.

3. The method for membrane separation of a rubber-coated stopper according to claim 1, wherein: The demoulding agent in step (2) of the chemical demoulding is one or more of p-cymene, α-terpinene, β-terpinene, α-pinene, chloroform.

4. The method for membrane separation of a rubber-coated stopper according to claim 1, wherein: The mass ratio of the treated product to the demoulding agent in step (2) of the chemical demoulding is 100:(20 - 50).

5. The method for membrane separation of a rubber-coated stopper according to claim 1, wherein: The temperature of the immersion mixing in step (2) of the chemical demoulding is 30 - 60 °C, and the mixing time is 5h - 15h; the drying temperature is 40 - 80 °C, and the drying time is 3h - 6h.

6. The method for membrane separation of a rubber-coated stopper according to claim 1, wherein: The supercritical fluid in step (2) of the physical demoulding is one or more of supercritical carbon dioxide, supercritical nitrogen, supercritical hydrogen, supercritical oxygen, etc.; In the swelling treatment during the physical film stripping step (2), the density of the supercritical fluid is 0.513 - 0.589 g / cm 3 .

7. The method for membrane separation of a rubber-coated stopper according to claim 1, wherein: The temperature of the swelling treatment in the physical demoulding is 60 - 100 °C, the pressure is 8 - 12 MPa, and the time is 20 - 40 min; In the swelling treatment of step (2) of the physical demoulding, the volume ratio of the coated stopper to the supercritical fluid environment space is 1:(8 - 10).

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