High-air-tightness anti-oxidation composite balloon and continuous production process thereof

Abstract

The invention discloses a high-airtightness antioxidant composite balloon and a continuous production process thereof, and belongs to the technical field of balloon manufacturing. Aiming at the problems that the traditional latex balloon is easy to oxidize and age and insufficient in air tightness, the latex balloon adopts a double-layer composite structure design: the inner layer is a natural latex base film layer, and the outer layer is a waterborne polyurethane protective layer; according to the technology, a wet film continuous impregnation process is adopted; by utilizing a multi-interface cross-linking mechanism of a natural latex film layer and polyurethane molecular chain active groups (-NH,-OH and-COOH) in a wet film state, molecular-level combination of two-phase materials is realized in a latex film forming stage, so that a finished product has excellent gas barrier property and antioxidant stability, and efficient production of balloons is realized through a continuous impregnation process.

Description

Technical Field

[0001] This application relates to the technical field of balloon production, and specifically to a high-airtightness antioxidant composite balloon and its continuous production process. Background Art

[0002] Natural latex balloons are inflatable rubber products, usually used as toys or for decoration in celebration activities. After inflation, they need to be exposed to air and indoor environment for a long time. In the professional balloon field, inflation and production of various models usually need to be completed 3 - 5 days in advance. However, ultraviolet rays, heat, light, and ozone in the atmosphere will all affect latex balloons. After inflation, the surface color of the latex balloon will show fogging, oxidation, and distortion phenomena after being exposed to sunlight and air for 2 - 4 hours, and air leakage and deflation phenomena will occur after 24 hours of storage. In order to maintain the decorative effect of the balloons, technicians usually spray brighteners, organic silicone oils and other products on the balloon surface, replace and remanufacture the leaking and deflating balloons, resulting in a large amount of time waste and material loss.

[0003] Patent CN 110697017A discloses a composite floating balloon and its preparation method. After inflating the formed meteorological balloon, a polyurethane is applied on the surface to make the floating balloon. This method cannot adapt to the ordinary balloon dipping production line.

[0004] Aiming at the above existing problems, especially simultaneously solving the antioxidant problem of ordinary latex balloons, improving the airtightness of balloons, and adapting to continuous dipping production is an urgent problem for those skilled in the art. Summary of the Invention

[0005] Aiming at the problems of easy oxidation and aging and insufficient airtightness of traditional latex balloons, the present invention adopts a double-layer composite structure design: the inner layer is a vulcanized natural rubber latex film, and the outer layer is a waterborne polyurethane protective layer. Combining with the wet film continuous dipping process, using the multiple interface cross-linking mechanism of the sulfur bonds in the natural rubber latex film layer and the active groups (-NH2, -OH, -COOH) of the polyurethane molecular chain in the wet film state, molecular-level combination of the two-phase materials is achieved at the latex film forming stage, making the finished product have both excellent gas barrier properties and antioxidant stability, and realizing the continuous production of high-airtightness and antioxidant balloons. The technical solution of the present invention is as follows.

[0006] Further, the inner layer of the composite balloon is a vulcanized natural latex film layer; the outer layer is a waterborne polyurethane film layer.

[0007] Further, the solid content of the waterborne polyurethane is 10 - 50%, preferably 10 - 30%, and more preferably 20%.

[0008] Further, the waterborne polyurethane film layer is characterized in that: the waterborne polyurethane film layer has a thickness of 0.01 - 1 mm, a tensile elongation at break of ≥ 400%, and a tensile strength of ≥ 5 MPa.

[0009] Further, the wet film refers to a film that is not dry but does not flow on the surface of the film after drying.

[0010] Further, it is prepared by a wet film impregnation process: cleaning the mold → dipping in the coagulant → drying → dipping in the natural rubber latex in the above step → baking into a wet film → dipping in the waterborne polyurethane emulsion in the above step → surface drying → curling the edge → leaching → drying → demolding.

[0011] Further, the coagulant is one of calcium nitrate type and calcium chloride type.

[0012] Advantages of the present invention.

[0013] The present invention solves the problems of poor bonding strength between the vulcanized natural latex film and the polyurethane film and the inability to continuously produce through the wet film continuous dipping and double-layer film forming process, and solves the problem of oxidation and discoloration of latex balloons within 24 hours in an exposed environment. Specific embodiments

[0014] It should be understood that the terms described in the present invention are only for describing specific embodiments to facilitate the understanding of those skilled in the art, and are not used to limit the present invention. In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range and each smaller range between any other stated value or intermediate value within the stated range are also included in the present invention.

[0015] Example 1 I. Preparation of raw materials (taking 100 kg as an example, all raw materials used are commercially available products if not otherwise specified) Step 1: Preparation of vulcanized natural rubber latex According to the proportion, 92.2 wt% of natural rubber latex (DRC 60%), 1.0 wt% of sulfur, 1 wt% of zinc oxide, 2.5 wt% of compound accelerator / antioxidant (ZDBC / 616 = 2:1), 0.2% of potassium hydroxide, 0.1% of Peregal; 3% of modified nano-silica. After fully stirring the above raw materials evenly, pre-vulcanization is carried out at a vulcanization temperature of 50 °C and a chloroform value of three ends and four beginnings. After the natural rubber latex undergoes pre-vulcanization treatment to reach the specified value, it is reserved for use; Step 2: Preparation of waterborne polyurethane WPU emulsion According to the proportion, waterborne polyurethane (Wanhua Chemical WANATE 7112) 95.5 wt%, polycarbodiimide (Evonik XL-29) 4.0 wt%, silicone wetting agent (BYK-349) 0.5 wt%. After fully stirring the above raw materials evenly, filter and reserve; Step 3: Preparation of coagulant aqueous solution According to the proportion, calcium nitrate 20 wt%, diatomaceous earth 15 wt%, defoaming agent 0.5 wt%, water 55.5%. After fully stirring the above raw materials evenly, filter and reserve; II. Wet film continuous dipping production process: After alternately cleaning the balloon mold with acid and alkali, move it into the oven. After drying at 70 °C for 30 seconds, immerse the balloon mold in the coagulation bath aqueous solution for 10 seconds; move it into the oven and bake at 70 °C for 30 seconds. After the surface of the coagulant is dry, take it out; immerse it in the pre-vulcanized natural rubber latex pool for 10 seconds and take it out; move it into the oven and bake at 60 °C for 1.5 minutes and take it out. Immerse the balloon mold with the non-drying but non-flowing rubber film on the surface into the waterborne polyurethane latex pool, stay for 10 seconds and then take it out; move it into the oven, dry at 70 °C for 5 minutes and then crimp the edge. After crimping, immerse it in the leaching pool composed of 80 °C pure water for 3 minutes and then take it out. Move it into the oven and bake at 110 °C for 45 minutes. After the composite rubber film is completely dry, demold to obtain a balloon product with oxidation resistance and good airtightness.

[0016] Example 2 I. Configuration of raw materials (taking 100 kg as an example, all raw materials used are commercially available products without explanation) Step 1: Preparation of pre-vulcanized natural rubber latex According to the proportion, natural rubber latex (DRC 60%) 89.6 wt%, reinforcing agent (SiO2 30%) 6.0 wt%, sulfur 1.5 wt%, zinc oxide 0.8 wt%, compound accelerator / antioxidant (ZDC / 2264 = 1:1) 2 wt%, Peregal 0.1% wt%; after fully stirring the above raw materials evenly, carry out pre-vulcanization, the vulcanization temperature is 50 °C, and the chloroform value is three ends and four beginnings. After the natural rubber latex passes through the pre-vulcanization treatment and reaches the specified value, reserve it.

[0017] Step 2: Preparation of waterborne polyurethane WPU emulsion According to the proportion, waterborne polyurethane polyether type WPU (Wanhua Chemical WANATE 7351) 95.5 wt%, aziridine (Haodeng DENGGAO HD100) 4.0 wt%, silicone wetting agent (HP-1471) 0.5 wt%; after fully stirring the above raw materials evenly, filter and reserve; Step 3: Reserve the coagulant aqueous solution; Calcium chloride 20 wt%, diatomaceous earth 20 wt%, defoamer 0.5 wt%, water 49.5% by proportion; after fully stirring the above raw materials evenly, filter and reserve.

[0018] II. Wet film continuous dipping production process Take out the balloon mold after alternately cleaning it with acid and alkali; move it into the oven, dry it at 70°C for 30 seconds, then immerse the balloon mold in the aqueous solution of the coagulation bath for 10 seconds; move it into the oven and bake it at 70°C for 60 seconds, take it out after the surface of the coagulant is dry; immerse it in the pre-vulcanized natural rubber latex bath for 10 seconds and take it out; move it into the oven and bake it at 65°C for 1 minute and take it out, immerse the balloon mold with the non-dry but non-flowing rubber film on the surface into the aqueous polyurethane latex bath, stay for 10 seconds and then take it out; move it into the oven, dry it at 75°C for 4 minutes and then crimp the edge, after crimping, immerse it in the leaching bath composed of 80°C pure water for leaching for 3 minutes and then take it out, move it into the oven and bake it at 105°C for 50 minutes, demold after the composite rubber film is completely dry, and a balloon product with oxidation resistance and good airtightness can be obtained.

[0019] Example 3 I: Preparation of raw materials (taking 100 kg as an example, all raw materials used are commercially available products without explanation) Step 1: Preparation of pre-vulcanized natural rubber latex Natural rubber latex (DRC 60%) 75.7 wt%, nano calcium carbonate emulsion (50%) 20.0 wt%, sulfur 1 wt%, zinc oxide 1 wt%, compound accelerator / antioxidant (ZDEC / 264 = 1:1) 2 wt%, potassium hydroxide 0.2%, Peregal 0.1% by proportion; after fully stirring the above raw materials evenly, carry out pre-vulcanization, the vulcanization temperature is 50°C, the chloroform value is three ends and four beginnings, and the natural rubber latex is reserved after reaching the specified value after pre-vulcanization treatment; Step 2: Aqueous polyurethane WPU emulsion Aqueous polyurethane polycarbonate type WPU (Wanhua Chemical WANATE 3249) 94.5 wt%, amino resin (CYMEL-385) 5.0 wt%, silicone wetting agent (HP-1471) 0.5 wt% by proportion; after fully stirring the above raw materials evenly, filter and reserve.

[0020] Step 3: Reserve the aqueous solution of the coagulant Calcium nitrate 20 wt%, diatomaceous earth 20 wt%, defoamer 0.5 wt%, water 49.5% by proportion. After fully stirring the above raw materials evenly, filter and reserve.

[0021] II. Wet film continuous dipping production process Take out the balloon mold after alternating acid and alkali cleaning; transfer it to an oven, dry it at 70 °C for 30 seconds, then immerse the balloon mold in the coagulation bath aqueous solution for 10 seconds; transfer it to the oven and bake at 75 °C for 20 seconds, take it out after the coagulant surface is dry; immerse it in the pre-vulcanized natural rubber latex pool for 10 seconds and take it out; transfer it to the oven and bake at 70 °C for 0.5 minutes and take it out. Immerse the balloon mold with a non-drying but non-flowing rubber film on the surface into the aqueous polyurethane latex pool, stay for 10 seconds and then take it out; transfer it to the oven, dry it at 80 °C for 3 minutes and then crimp the edge. After crimping, immerse it in a leaching pool composed of 80 °C pure water for leaching for 3 minutes and then take it out. Transfer it to the oven and bake at 115 °C for 40 minutes. After the composite rubber film is completely dry, demold it to obtain a balloon product with oxidation resistance and good airtightness.

[0022] Comparative Example 1 Take out the balloon mold after alternating acid and alkali cleaning; transfer it to an oven, dry it at 70 °C for 30 seconds, then immerse the balloon mold in an aqueous solution composed of 20% calcium chloride, 0.2% wetting agent and 10% release agent for 10 seconds and then take it out; transfer it to the oven and bake at 70 °C for 30 seconds, take it out after the coagulant surface is dry; immerse it in a pre-vulcanized treatment mixed rubber latex pool composed of 96.9% natural rubber latex, 1% sulfur, 0.8% zinc oxide, 0.5% accelerator ZDBC, 0.5% antioxidant 2264, 0.2% potassium hydroxide, and 0.1% surfactant for 10 seconds and take it out; transfer it to the oven, dry it at 70 °C for 5 minutes and then crimp the edge. After crimping, immerse it in a leaching pool composed of 80 °C pure water for leaching for 3 minutes and then take it out. Transfer it to the oven and bake at 110 °C for 45 minutes. After the rubber film is completely dry, demold it to obtain a natural latex balloon product as Comparative Example 1.

[0023] Comparative Example 2 Take out the balloon mold after alternating acid and alkali cleaning; transfer it to an oven, dry it at 70 °C for 30 seconds, then immerse the balloon mold in an aqueous solution composed of 20% calcium nitrate, 0.3% wetting agent and 15% release agent for 10 seconds and then take it out; transfer it to the oven and bake at 70 °C for 30 seconds, take it out after the coagulant surface is dry; immerse it in a pre-vulcanized treatment mixed rubber latex pool composed of 97.2% natural rubber latex, 1% sulfur, 0.5% zinc oxide, 0.5% accelerator ZDC, 0.5% antioxidant 616, 0.2% potassium hydroxide, and 0.1% surfactant for 10 seconds and take it out; transfer it to the oven, dry it at 70 °C for 5 minutes and then crimp the edge. After crimping, immerse it in a leaching pool composed of 80 °C pure water for leaching for 3 minutes and then take it out. Transfer it to the oven and bake at 110 °C for 45 minutes. After the rubber film is completely dry, demold it to obtain a natural latex balloon product as Comparative Example 2.

[0024] The physical and mechanical properties of the finished balloons in Examples 1 to 3 and Comparative Examples 1 to 2 were measured before and after aging with reference to the national standard GB / T 528-2009, and the results are shown in Table 1. 。

[0025] From the results recorded in Table 1, the airtightness performance of the balloons produced by the present invention is more than twice that of the comparative example, and the discoloration test is more than 10 times that of the comparative example. The comprehensive performance is superior to that of natural rubber balloons.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A high-airtightness antioxidant composite balloon and its continuous production process, characterized in that: The inner layer of the balloon is a vulcanized natural latex film layer; the outer layer is a waterborne polyurethane film layer; its preparation method includes the following steps: a. Prepare pre-vulcanized natural rubber latex: It consists of 20-100% natural rubber latex, 0.1-10% accelerator, 0.1-10% anti-aging agent, 0.1-2% sulfur, 0.1-2% zinc oxide, 0.1-1% antioxidant, 0.1-1% potassium hydroxide, 0.1-1% surfactant, and 0-20% reinforcing agent. Pre-vulcanize at 45-60°C until the chloroform value reaches the third end and the fourth beginning. b. Prepare the outer layer emulsion: 90-100% waterborne polyurethane emulsion, 1-10% crosslinking agent, 0.1-2% wetting agent, 0.1-2% defoaming agent. c. Prepare by wet film dipping process: Clean the mold → Dip in the coagulant → Dry → Dip in the emulsion in step b → Bake into a wet film → Dip in the emulsion in step c → Surface dry → Crimp the edge → Leach → Dry → Demold.

2. The balloon according to claim 1, characterized in that: The elongation at break of the waterborne polyurethane film layer is ≥450%, and the tensile strength is ≥5 MPa.

3. The balloon according to claim 1, wherein: The wet film is in a state of a rubber film that is not dry on the surface but does not flow.