Preparation method of ultrathin natural latex sheet
阅读说明：本技术 一种超薄天然胶乳片材的制备方法 (Preparation method of ultrathin natural latex sheet ) 是由 田勇 贾成浩 仇必顺 于 2020-07-17 设计创作，主要内容包括：一种超薄天然胶乳片材的制备方法。涉及胶乳工业领域,具体涉及一种超薄天然胶乳海绵片材的制备方法。提供了一种保证产品质量,提高生产效率的超薄天然胶乳片材的制备方法。本发明在原料中,通过将胶凝剂使用氟硅酸钠和氯化钾混合,形成氟硅酸钾,氟硅酸钾的水溶性较差,水解度较低,从而能够减少因胶凝快导致的产生死胶颗粒的问题,能够使发泡胶乳加速胶凝,从而使其在进入硫化阶段前内部能够充分的胶凝。本发明在不影响产品质量的前提下,提高生产效率,降低成本。(A method for preparing an ultrathin natural latex sheet. Relates to the field of latex industry, in particular to a preparation method of an ultrathin natural latex sponge sheet. Provides a preparation method of the ultrathin natural latex sheet, which ensures the product quality and improves the production efficiency. In the raw materials, the gelling agent is mixed by using sodium fluosilicate and potassium chloride to form potassium fluosilicate, the potassium fluosilicate has poor water solubility and low hydrolysis degree, so that the problem of dead latex particles caused by fast gelation can be reduced, the foaming latex can be gelled in an accelerated way, and the inner part of the foaming latex can be gelled fully before entering a vulcanization stage. The invention improves the production efficiency and reduces the cost on the premise of not influencing the product quality.)
1. The preparation method of the ultrathin natural latex sheet is characterized by comprising the following steps of:
1) the raw material preparation comprises the following components in parts by weight: 90-100 parts of natural latex, 4-7 parts of vulcanized rubber bag dispersoid, 2-5 parts of potassium oleate aqueous solution, 0.5-2 parts of potassium ricinoleate aqueous solution, 3-8 parts of zinc oxide and 0.5-2 parts of gelling agent;
2) stirring and mixing the raw materials, and curing at 20-30 ℃ for 6-12 hours;
3) foaming and hot air setting for 5-20 min;
4) the steam box is vulcanized for 10 to 30 minutes,
5) and finally drying.
2. The method of claim 1, wherein the natural rubber latex has a solid content of 60% and an ammonia content of 0.2%.
3. The method of claim 1, wherein the bale dispersion comprises sulfur, accelerator M, accelerator ZDC, a dispersant, and water.
4. The method of claim 1, wherein said aqueous solution of potassium oleate has a solids content of 20%.
5. The method of claim 1, wherein the aqueous solution of potassium ricinoleate has a solid content of 35%.
6. The method of claim 1, wherein the zinc oxide is a 50% zinc oxide dispersion.
7. The method of claim 1, wherein the gelling agent is a mixture of sodium fluorosilicate and potassium chloride in a ratio of 8:1 to 12: 1.
8. The method as claimed in claim 1, wherein in the step 4), the hot air is mixed with carbon dioxide gas during the hot air forming process, and the flow rate of the hot air is 3864-7728m3The flow rate of carbon dioxide is 100-3/h。
Technical Field
The invention relates to the field of latex industry, in particular to a preparation method of an ultrathin natural latex sponge sheet.
Background
Latex sponge is a low-density porous open material comprising 1.5 × 10 per 1cm of weight4-2×105And air holes, wherein 90% -95% of the air holes are connected with each other, and the air bubbles are filled with air. The structure ensures that the latex sponge discharges air when being pressed, and heat is easily dissipated. When in use, sweat can be directly volatilized, no sweat condensation phenomenon exists on the inner wall of the bubble, and meanwhile, certain heat conduction can be kept, so that the effects of being warm in winter and cool in summer are achieved. The natural latex has the functions of antibiosis and mite prevention, and the natural latex sponge is flexible, elastic and has special comfortable touch. These advantages make it particularly suitable as a core material for air-conditioning quilts and summer sleeping mats. However, air-conditioning quilts and summer sleeping mats are mostly light and thin, so the natural latex sponge required as an inner core has low density and thin thickness.
Most of latex sponge sheets in the market are produced by mixing natural latex and synthetic latex, and the thickness is 0.7cm at most, and few natural latex sponge sheets with the thickness of 0.3-0.5cm are available. Because dead glue particles caused by uneven dispersion of the gelling agent are easy to appear when the natural latex is used for producing thin sheets, the stability of the synthetic latex is higher than that of the natural latex, and the dead glue particles are not easy to appear, so the production efficiency is higher. When natural latex is used for producing thin sheets in the industry, the solid content of the gelling agent sodium fluosilicate dispersion is mostly reduced. This not only results in increased moisture in the foamed latex, reduced foam stability, increased density, but also affects the rate of gelation. The gel rate is reduced, so that the foaming latex is not completely gelled before entering a vulcanization stage, the foam collapse phenomenon can occur in the vulcanization stage, only the upper and lower layers of surface skins are left, and a cavity is formed in the middle. In order to avoid the phenomenon, production enterprises mostly reduce the production speed to fully shape the product in the hot air shaping stage, so that the production efficiency is low, and the cost is increased.
Disclosure of Invention
Aiming at the problems, the invention provides a preparation method of an ultrathin natural latex sheet, which ensures the product quality and improves the production efficiency.
The technical scheme of the invention is as follows: the method comprises the following steps:
1) the raw material preparation comprises the following components in parts by weight: 90-100 parts of natural latex, 4-7 parts of vulcanized rubber bag dispersoid, 2-5 parts of potassium oleate aqueous solution, 0.5-2 parts of potassium ricinoleate aqueous solution, 3-8 parts of zinc oxide and 0.5-2 parts of gelling agent;
2) stirring and mixing the raw materials, and curing at 20-30 ℃ for 6-12 hours;
3) foaming and hot air setting for 5-20 min;
4) the steam box is vulcanized for 10 to 30 minutes,
5) and finally drying.
The natural rubber latex has a solid content of 60% and an ammonia content of 0.2%.
The vulcanization package dispersion comprises sulfur, an accelerator M, an accelerator ZDC, a dispersant and water.
The aqueous potassium oleate solution has a solids content of 20%.
The solid content of the potassium ricinoleate aqueous solution is 35%.
The zinc oxide was a 50% zinc oxide dispersion.
The gelling agent is a mixture of sodium fluosilicate and potassium chloride, and the mixing ratio is 8:1-12: 1.
In the step 4), hot air and carbon dioxide gas are mixed in the hot air shaping process, and the flow rate of the hot air is 3864-7728m3The flow rate of carbon dioxide is 100-3/h。
The invention has the beneficial effects that: in the raw materials, the gelling agent is mixed by using sodium fluosilicate and potassium chloride to form potassium fluosilicate, the water solubility of the potassium fluosilicate is poor, the hydrolysis degree is low, and therefore the problem of generating dead glue particles caused by fast gelation can be reduced. In hot air setting, the foamed latex is set by mixing carbon dioxide and hot air. The foaming latex is preliminarily gelled on the surface of the front section of hot air shaping, has certain strength, and carbon dioxide enters the foaming latex along with hot air permeation to be combined with moisture in the foaming latex to form carbonic acid when passing through the middle section, forms ammonium carbonate with ammonia, reduces pH, can accelerate the gelling of the foaming latex, and thus can be fully gelled in the foaming latex before entering a vulcanization stage. Therefore, the production efficiency can be improved and the cost can be reduced on the premise of not influencing the product quality.
Detailed Description
The invention comprises the following steps:
1) the raw material preparation comprises the following components in parts by weight: 90-100 parts of natural latex, 4-7 parts of vulcanized rubber bag dispersoid, 2-5 parts of potassium oleate aqueous solution, 0.5-2 parts of potassium ricinoleate aqueous solution, 3-8 parts of zinc oxide and 0.5-2 parts of gelling agent;
2) stirring and mixing the raw materials, and curing at 20-30 ℃ for 6-12 hours;
3) foaming and hot air setting for 5-20 min;
4) the steam box is vulcanized for 10 to 30 minutes,
5) and finally drying.
In the raw materials, the gelling agent is mixed by using sodium fluosilicate and potassium chloride to form potassium fluosilicate, the water solubility of the potassium fluosilicate is poor, the hydrolysis degree is low, and therefore the problem of generating dead glue particles caused by fast gelation can be reduced. In hot air setting, the foamed latex is set by mixing carbon dioxide and hot air. The foaming latex is preliminarily gelled on the surface of the front section of hot air shaping, has certain strength, and carbon dioxide enters the foaming latex along with hot air permeation to be combined with moisture in the foaming latex to form carbonic acid when passing through the middle section, forms ammonium carbonate with ammonia, reduces pH, can accelerate the gelling of the foaming latex, and thus can be fully gelled in the foaming latex before entering a vulcanization stage. Therefore, the production efficiency can be improved and the cost can be reduced on the premise of not influencing the product quality.
Between the steps 2) and 3), also comprises the steps of preparing the lac resin calcium salt aggregate, introducing the lac resin calcium salt aggregate into the mixed glue solution for stirring,
wherein the preparation process of the lac resin calcium salt aggregate comprises the following steps: the lac resin sodium salt is prepared into 6wt% lac resin sodium salt solution (namely, the lac resin sodium salt is dissolved in water), and 0.1mol/L CaCl is prepared by distilled water2Slowly stirring the solution at 20 deg.C, and slowly adding CaCl2Mixing the solution, stirring for 20min, standing at room temperature for 6h, filtering to obtain precipitated solid, and freeze drying to obtain lac resin calcium salt aggregate;
introducing lac resin calcium salt aggregate into mixed gel solution before latex foaming, wherein the lac resin sodium salt is of a quasi-asymmetric Gemini (Gemini) surfactant structure, and Ca2+The lac resin is composed of lactone and lactide formed by lac eleostearic acid and chitosan acid, and the lac eleostearic acid is a straight-chain macromolecule and contains a polyhydroxy saturated carbon chain, so that a large number of hydroxyl groups exist on the surface of the lac resin calcium salt, and the adsorption of organic compounds (such as alcohols, amines and the like) is facilitated through the hydrogen bond effect.
Therefore, the produced sheet meets the requirements of low odor and low VOC environmental protection.
The natural rubber latex has a solid content of 60% and an ammonia content of 0.2%.
The vulcanization package dispersion comprises sulfur, an accelerator M, an accelerator ZDC, a dispersing agent and water, and is prepared by mixing the sulfur, the accelerator M, the accelerator ZDC, the dispersing agent and the water in a ratio of 2: 1: 1: 0.16: 3.84.
the aqueous potassium oleate solution has a solids content of 20%.
The solid content of the potassium ricinoleate aqueous solution is 35%.
The zinc oxide was a 50% zinc oxide dispersion.
The gelling agent is a mixture of sodium fluosilicate and potassium chloride, the mixing ratio is 8:1-12:1, and the solid content of the gelling agent is 20%.
In the step 4), hot air and carbon dioxide gas are mixed in the hot air shaping process, and the flow rate of the hot air is 3864-7728m3The flow rate of carbon dioxide is 100-3/h。
The present invention will be described in detail with reference to examples.