A silicon-free anti-webbing agent for latex gloves and its preparation method and application

Abstract

The present application relates to the technical field of functional additives, in particular to a silicone-free anti-webbing agent for latex gloves, and its preparation method and application. A silicone-free anti-webbing agent for latex gloves comprises the following raw materials in weight percentage: raw material A: 5-15%, raw material B: 5-15%, raw material C: 5-10%, and the balance is water; the raw material A is one or more of lipids and higher-carbon alcohols; the raw material B is a fatty acid; and the raw material C comprises a pH regulator and a fatty amine. The anti-webbing agent of the present application can achieve a cloud point of 80.6-85.3°C and a surface tension of 33.4-30.7 dynes / cm, and has good compatibility with release agent salt solutions and does not float oil. The anti-webbing agent of the present application is completely miscible with natural latex and nitrile latex, and does not float oil at high temperatures; the qualified rate of latex gloves made with the anti-webbing agent of the present application can reach 97.5-99.8%.

Description

Technical Field

[0001] The present application relates to the technical field of functional additives, and in particular to a silicon-free anti-webbing agent for latex gloves, and a preparation method and application thereof. Background Art

[0002] China is a major producer of natural / nitrile latex gloves. The glove-making process is very mature. The resins are all natural resins from Malaysia or nitrile resins from Thailand, and the stability is guaranteed. The biggest impact on the yield of gloves is the defect of the film forming "webs".

[0003] The mechanism of web formation is as follows: when preparing thin gloves, after the hand mold is dipped in the glue liquid and pulled out of the glue liquid, a "web"-like liquid film appears between the fingertips. When the "web" breaks, it leaves uneven thickness or tiny holes in the fingertips. In worse cases, there may be parts without glue. The gloves thus made have thin spots, pinholes, or even holes, which seriously affect the protective performance of the gloves. Such gloves are defective. If defective gloves enter the medical system, medical staff wearing poorly protected gloves are very likely to suffer from bacterial infection, which is a serious medical malpractice.

[0004] To prevent or reduce the formation of webs, anti-webbing agents are added to the latex. The commonly used anti-webbing agent, n-butanol, is not suitable for use in latex gloves because it is a volatile solvent that easily evaporates during the latex manufacturing process. This can cause changes in the composition of the latex mixture, affecting the physical properties and chemical stability of the gloves. In addition, some silicon-containing defoaming agents, such as organosiloxane emulsion defoamers and polysiloxane polyether copolymer defoamers, can also have a certain degree of anti-webbing effect while defoaming.

[0005] Regarding the above-mentioned related art, the applicant believes that the use of the aforementioned silicon-containing defoaming agent will leave some silicon residue on latex gloves. Latex gloves are used not only in medical systems but also in the electronics industry. Electrical components are sensitive to silicon, and gloves containing silicon may have a negative impact on these components. Summary of the Invention

[0006] In order to solve the problem of "webbing" in the production of latex gloves and avoid the influence of silicon on electrical components, the present application provides a silicon-free anti-webbing agent for latex gloves and its preparation method and application.

[0007] In the first aspect, the present application provides a silicone-free anti-webbing agent for latex gloves, which adopts the following technical solution:

[0008] A silicon-free anti-webbing agent for latex gloves, comprising the following raw materials in percentage by weight: raw material A: 5-15%, raw material B: 5-15%, raw material C: 5-10%, and the balance being water;

[0009] The raw material A is one or more of lipids and higher alcohols;

[0010] The raw material B is fatty acid;

[0011] The raw material C includes a pH regulator and a fatty amine.

[0012] By employing the above-mentioned technical solution, the lipids and higher alcohols in the anti-webbing agent reduce surface tension and improve the fluidity of the latex; the fatty acids act as a lubricant; and the fatty amines enhance the compatibility of the anti-webbing agent with the latex. The anti-webbing agent disclosed herein has a cloud point exceeding 80°C, a surface tension below 33.4 dynes / cm, and an appropriate viscosity. It exhibits excellent compatibility with release agent salt solutions, exhibits no oil scumming, and evenly wets the hand mold. It is fully miscible with natural latex and nitrile latex, exhibits no oil scumming at high temperatures, and does not cause film cratering. This effectively addresses the problem of web formation, enabling customers to achieve a yield rate exceeding 97%.

[0013] Lipids are generally glycerol lipids containing long-chain saturated or unsaturated fatty acids. They are lipophilic and hydrophilic, and can form a thin film at the gas-liquid interface, reducing surface tension. They include natural lipids and mineral oils. Natural lipids are used in this application.

[0014] Higher alcohols are alcohol compounds containing six or more carbon atoms, typically represented by the chemical formula CnH2n+1OH. They are a class of alcohols with long carbon chains. Physically, higher alcohols are colorless or slightly yellowish liquids with a distinctive odor. They have low solubility in water but high solubility in organic solvents. Chemically, higher alcohols can undergo reactions such as esterification and etherification to form derivatives such as esters, ethers, and acids. In industrial applications, higher alcohols are often used as solvents, lubricants, and antifreeze agents, and are also raw materials for synthetic materials and surface lubricants. Higher alcohols can effectively control foaming during latex processing, ensuring the quality and efficiency of latex glove production. By adding higher alcohols, production problems caused by excessive foaming, such as latex viscosity increase, gelation, thickening, or gelation, can be avoided, thereby ensuring stable production of latex gloves and improving product quality. Furthermore, higher alcohol defoamers maintain good defoaming effectiveness even under high temperature conditions, helping to stabilize the process, reduce the amount of defoamer used, and improve the quality of latex gloves.

[0015] Fatty acids are a class of compounds composed of three elements: carbon, hydrogen, and oxygen. Depending on the number of double bonds in their carbon chains, fatty acids can be categorized as either saturated or unsaturated. Fatty acids can reduce the interfacial tension between water and latex, promoting the dispersion of latex particles in water and forming a stable emulsion. Fatty acid molecules adsorb on the surface of latex particles, forming a protective film that prevents aggregation and coagulation, maintaining the stability of the latex system. The addition of fatty acids can improve the processing properties of latex, such as increasing its fluidity and reducing its viscosity during processing, making it easier to coat and shape the latex, thereby enhancing the production efficiency and quality of latex gloves.

[0016] Fatty amines are a broad class of organic amine compounds with carbon chain lengths ranging from C8 to C22. Like general amines, they are classified into four categories: primary, secondary, tertiary, and polyamines. The degree of primary, secondary, and tertiary amines depends on the number of alkyl groups replacing hydrogen atoms in the ammonia. Fatty amine molecules can adsorb onto the surface of latex particles, forming a protective film that synergizes with fatty acids to further enhance the stability of the latex system and prevent aggregation and coagulation of latex particles.

[0017] Furthermore, the weight ratio of raw material A: raw material B: raw material C is 1: (0.8-1.2): (0.5-1).

[0018] In some specific embodiments, the weight ratio of raw material A: raw material B: raw material C is any ratio of 1: (0.8-1.2): (0.5-1). For example, in some specific embodiments, the weight ratio of raw material A: raw material B: raw material C is 1:0.8:1; in some specific embodiments, the weight ratio of raw material A: raw material B: raw material C is 1:1.2:0.5; and in some specific embodiments, the weight ratio of raw material A: raw material B: raw material C is 1:1:0.7.

[0019] Furthermore, the raw material A comprises lipids and higher carbon alcohols in a weight ratio of (10-25):1.

[0020] In some specific embodiments, raw material A comprises lipids and higher alcohols in a weight ratio of any ratio between (10-25):1. For example, in some specific embodiments, raw material A comprises lipids and higher alcohols in a weight ratio of 10:1; in some specific embodiments, raw material A comprises lipids and higher alcohols in a weight ratio of 18:1; and in some specific embodiments, raw material A comprises lipids and higher alcohols in a weight ratio of 25:1.

[0021] Furthermore, the lipids in the raw material A include one or more of castor oil, palm oil, coconut oil, and lanolin;

[0022] The higher carbon alcohol in the raw material A includes one or more of lauryl alcohol, octadecyl alcohol, and behenyl alcohol.

[0023] The lipids in the anti-webbing agent of this application are limited to one or more of castor oil, palm oil, coconut oil, and lanolin. Castor oil is a vegetable oil extracted from castor seeds. Its main component is ricinoleic acid, a rare monounsaturated fatty acid. Palm oil is a vegetable oil extracted from the pulp of oil palm fruits and is primarily composed of saturated and monounsaturated fatty acids. Coconut oil is a vegetable oil extracted from the pulp of coconuts and is primarily composed of medium-chain saturated fatty acids. Lanolin is a natural fatty substance extracted from sheep wool. It is primarily composed of esters of fatty acids and alcohols and has excellent moisturizing and nourishing properties.

[0024] Furthermore, the fatty acids include saturated fatty acids and unsaturated fatty acids;

[0025] The saturated fatty acid includes one or more of stearic acid, ricinoleic acid, and nonanoic acid;

[0026] The unsaturated fatty acids include one or more of linolenic acid and oleic acid.

[0027] Furthermore, the weight ratio of the pH regulator to the fatty amine in the raw material C is 1:(30-40).

[0028] Furthermore, the pH regulator includes one or more of natural alkali, small molecule alkaline substances, and amine salts;

[0029] The small molecule alkaline substance includes one or more of triethylamine, trimethylamine, and dimethylacetamide;

[0030] The amine salt includes octylamine salt.

[0031] In a second aspect, the present application provides a method for preparing a silicone-free anti-webbing agent for latex gloves, which adopts the following technical solution:

[0032] A method for preparing a silicon-free anti-webbing agent for latex gloves comprises the following steps:

[0033] S1. Raw material A, raw material B, and raw material C are mixed and heated to melt to obtain an initial mixed solution;

[0034] S2. Heat water to 80-90°C;

[0035] S3. Under stirring, the initial mixture obtained in S1 was added to the heated water in S2 and mixed to obtain a mixture;

[0036] S4. The mixture obtained in the above S3 is cooled to 25-30°C and filtered through a 200-mesh filter to obtain a silicon-free anti-webbing agent.

[0037] In a third aspect, the present application provides a process for preparing latex gloves, which adopts the following technical solution:

[0038] A process for preparing latex gloves comprises the following steps: washing a hand mold, drying, dipping in a coagulation bath, drying again, dipping in latex, vulcanizing, anti-sticking isolation treatment, and demoulding; wherein any of the above-mentioned silicon-free anti-webbing agents for latex gloves is added to the latex in the latex dipping step, and the amount of the anti-webbing agent added is 0.08-0.015% of the latex.

[0039] Furthermore, the immersion bath in the coagulation bath immersion step comprises gel and a surfactant, wherein the surfactant has a cloud point higher than 70° C., and the amount of the surfactant added is 0.15-0.25% of the gel.

[0040] In some embodiments, the surfactant is one or more of isomeric tridecanol and isomeric nonanol.

[0041] In summary, this application has the following beneficial effects:

[0042] The anti-webbing agent obtained by using specific raw materials and proportions in the present application can achieve a cloud point of 80.6-85.3°C and a surface tension of 33.4-30.7 dynes / cm. It also has good compatibility with release agent salt solutions and does not cause oil floating. The anti-webbing agent of the present application is completely miscible with natural latex and nitrile latex and does not cause oil floating at high temperatures. The qualified rate of latex gloves made using the anti-webbing agent of the present application can reach 97.5-99.8%. DETAILED DESCRIPTION

[0043] The present application is further described in detail below with reference to the embodiments.

[0044] raw material

[0045] The raw materials in the examples of this application can be obtained commercially:

[0046] Coconut oil, analytical grade, molecular formula C 10 H 12 O4;

[0047] Octadecanol, analytically pure, molecular formula: C 18 H 38 O;

[0048] Stearic acid, analytical grade, analytical grade C 18 H 36 O2, flash point 235°F; water solubility: 0.5g / 100mL at 23°C;

[0049] Linolenic acid, analytically pure, α-linolenic acid, molecular formula CH3-(CH2CH=CH)3-(CH2)7COOH

[0050] Natural alkali, analytically pure, with the molecular formula of Na2CO3·NaHCO3·2H2O;

[0051] Stearylamine, analytical grade, molecular formula C 18 H 39 N;

[0052] Castor oil, the main component is fatty acid glyceride, of which ricinoleic acid content is 85%, and the rest are other fatty acids such as oleic acid, linoleic acid, palmitic acid, and stearic acid;

[0053] Palm fat, palmitic acid glyceride formed by the reaction of palmitic acid and glycerol;

[0054] Dodecanol, analytically pure, molecular formula C 12 H 26 O;

[0055] Lanolin, chemical name is hexadecyl stearate, chemical formula is C 44 H 88 O2;

[0056] Docosanol, analytically pure, molecular formula: C 22 H 46 O;

[0057] Dimethylacetamide, analytically pure, molecular formula C4H9NO;

[0058] Octylamine nitrate, an organic compound with the chemical formula C8H 19 NO3, produced by the reaction of octylamine (a primary amine, chemical formula C8H19N) and nitric acid;

[0059] Stearylamine, also known as hexadecylamine, analytically pure, with the molecular formula C 16 H 35 N. Example

[0060] Examples 1-7

[0061] A silicon-free anti-webbing agent for latex gloves, and a preparation method thereof is as follows:

[0062] S1. According to the raw material ratio in Table 1, raw material A, raw material B, and raw material C are mixed and heated until all the raw materials are melted to obtain an initial mixed liquid;

[0063] S2. Heat water to 80°C;

[0064] S3. Under stirring, the initial mixture obtained in S1 was added to the heated water in S2 and mixed to obtain a mixture;

[0065] S4. The mixture obtained in S3 is cooled to 27° C. and filtered through a 200-mesh filter to obtain a silicon-free anti-webbing agent.

[0066] Table 1 Raw material ratios for Examples 1-7 (kg)

[0067]

[0068] Among them, raw material A is coconut oil and stearyl alcohol in a weight ratio of 15:1; raw material B is stearic acid and linolenic acid in a weight ratio of 6:1; raw material C is natural alkali and stearylamine in a weight ratio of 1:35.

[0069] Example 8

[0070] Different from Example 2, in Example 8, raw material A comprises castor oil, palm fat and dodecanol in a weight ratio of 5:5:1.

[0071] Example 9

[0072] Different from Example 2, the raw material A in Example 9 is lanolin and behenyl alcohol in a weight ratio of 25:1.

[0073] Example 10

[0074] Different from Example 2, in Example 10, raw material C is natural alkali, dimethylacetamide, octylamine nitrate and stearylamine in a weight ratio of 1:1:1:90.

[0075] Example 11

[0076] Different from Example 2, in Example 11, hot water is heated to 85° C. in step S2.

[0077] Example 12

[0078] Different from Example 2, in Example 12, the hot water is heated to 87° C. in step S2.

[0079] Example 13

[0080] Different from Example 2, in Example 13, hot water is heated to 90° C. in step S2.

[0081] Example 14

[0082] Different from Example 2, in Example 14, hot water is heated to 95° C. in step S2.

[0083] Comparative Example

[0084] Comparative Example 1

[0085] The difference from Example 1 is that the raw material ratio in Comparative Example 1 is: 25 kg of raw material A, 15 kg of raw material B, 10 kg of raw material C, and 50 kg of water.

[0086] Comparative Example 2

[0087] Different from Example 1, the raw material ratio in Comparative Example 2 is: 5 kg of raw material A, 25 kg of raw material B, 10 kg of raw material C, and 60 kg of water.

[0088] Comparative Example 3

[0089] Different from Example 1, the raw material ratio in Comparative Example 3 is: 5 kg of raw material A, 15 kg of raw material B, 15 kg of raw material C, and 65 kg of water.

[0090] Performance testing

[0091] The cloud point, surface tension and compatibility of the anti-webbing agents in the examples and comparative examples with the release agents were tested. The test results are shown in Table 2.

[0092] Cloud point detection method:

[0093] 1. Preparation of water:ether solution

[0094] Prepare water:ether solution according to the ratio of water:ether = 2:1 (mass ratio) and set aside;

[0095] 2. Sample Preparation

[0096] Take 5 grams of anti-web agent and dissolve it in 95 grams of water: ether solution, stir until transparent (the temperature should be below 25℃);

[0097] 3. Measure 20 ml of the above solution, place it in a test tube, insert a thermometer, and heat it in a water bath. Gently stir with the thermometer until the solution becomes completely turbid (the solution temperature does not exceed the turbidity temperature by 5°C). Stop heating, remove the test tube, and cool it down while stirring with the thermometer. Record the temperature when the turbidity completely disappears. Repeat the test three times. The difference between the three parallel results should not exceed 0.5°C. The arithmetic mean is the turbidity point measurement.

[0098] Surface tension testing method: KRUSS BPT dynamic tension meter is used for testing;

[0099] The compatibility test method with the release agent is: mix the anti-webbing agent with the release agent (a fine slurry substance with calcium stearate as the main release component) and then observe the changes in the appearance of the mixture.

[0100] Table 2 Anti-web agent performance test results

[0101]

[0102] Combining Examples 1-14 with Comparative Examples 1-3 and Table 2, it can be seen that the cloud points of the anti-webbing agents in Examples 1-14 are higher than those in Comparative Examples 1-3, and the surface tensions of the anti-webbing agents in Examples 1-14 are lower than those in Comparative Examples 1-3.

[0103] Combining Examples 1-7 with Comparative Examples 1-3 and Table 2, it can be seen that changes in the ratio of Raw Materials A, B, and C affect the performance of the anti-webbing agent. In Comparative Examples 1-3, when the ratio of Raw Materials A, B, and C exceeds the ratio range specified in this application, the anti-webbing agents in Comparative Examples 1-3 have a significantly lower cloud point than Examples 1-7 and a significantly higher surface tension than Examples 1-7. This demonstrates that anti-webbing agents with high cloud points and low surface tensions can be obtained within the range specified in this application. Furthermore, the anti-webbing agents in Examples 1-7 all exhibit superior performance, with the ratio in Example 2 being even superior.

[0104] Combining Example 2 with Examples 11-14 and Table 2, it can be seen that the preparation temperature of the anti-webbing agent affects the performance of the anti-webbing agent. When the temperature is 80-90°C, the requirements of the present application can be met. When the temperature is 80-85°C, the anti-webbing agent has better performance. This may be because the reaction is complete within this temperature range without causing high-temperature yellowing.

[0105] Application Examples

[0106] Application Example 1

[0107] A latex glove, the preparation process of which comprises the following steps:

[0108] S1.Handwashing mold

[0109] Clean the surface of the hand mold to ensure that it is clean and free of impurities;

[0110] S2. Drying

[0111] Dry the cleaned hand mold at 80℃ to ensure the surface of the hand mold is dry;

[0112] S3. Coagulation bath immersion

[0113] Immerse the hand model in a mixture of gel and release agent (a fine slurry with calcium stearate as the main release component) to coat it with a layer of gel, forming a uniform film on the hand model. The amount of release agent added is 0.2% of the gel.

[0114] S4. Dry again

[0115] Use the oven to dry the hand model that has been stained with a layer of gel again to ensure that the gel is completely cured;

[0116] S5. Latex impregnation

[0117] The glove forming mold is immersed in a latex tank formed by mixing natural latex and the anti-webbing agent obtained in Example 1 to be stained with latex, and then dried in an oven to form the initial form of the latex glove; the mixed liquid in the latex tank is heated to 55° C., and the anti-webbing agent is added in an amount of 0.1% of the natural latex;

[0118] S6. Vulcanization

[0119] The initially formed latex glove film is heated and vulcanized;

[0120] S7. Anti-sticking isolation treatment

[0121] The gloves are coated with a polymer to prevent the inner layers of the gloves from sticking together during demoulding, ensuring that the gloves are easy to demould and have a smooth surface;

[0122] S8. demoulding;

[0123] The gloves are completely separated from the glove forming mold to form the final shape of ordinary latex gloves.

[0124] Application Example 2-14

[0125] The difference from Application Example 1 is that the anti-webbing agents in Application Examples 2-14 are from Examples 2-14, respectively.

[0126] Application Example 15

[0127] Different from Application Example 2, in Application Example 15, an isomeric nonanol surfactant is further added to the mixed solution in step S3, and the added amount of the surfactant is 0.2% of the gelling agent.

[0128] Application Example 16

[0129] Different from Application Example 2, in Application Example 16, an equal amount of nitrile latex is used to replace natural rubber.

[0130] Comparative Application Examples

[0131] Comparative Application Examples 1-3

[0132] The difference from Application Example 1 is that the anti-webbing agents in the comparative application examples are from Comparative Examples 1-3 respectively.

[0133] Performance testing

[0134] After heating, the mixed liquid in the latex tank in S3 was observed and its appearance was recorded. The results are shown in Table 3.

[0135] The qualified rate of latex gloves produced is tested. Professionals inspect the produced latex gloves and screen out unqualified products. Unqualified products include uneven film between the fingers, thickness that does not meet the requirements, thin spots, holes, etc. Calculate the qualified rate:

[0136] .

[0137] Table 3 Performance test results

[0138]

[0139] As can be seen from Table 3, the anti-webbing agent of the present invention is completely miscible with natural latex and chemical latex, and does not cause oil scumming at high temperatures. After using the anti-webbing agent of the present invention, the qualified rate of latex gloves produced can reach 97.5-99.8%. This is probably because the anti-webbing agent of the present invention has low surface tension, completely and evenly wets the hand mold, is completely miscible with natural latex and nitrile latex, does not cause oil scumming at high temperatures, and does not cause shrinkage holes in the film. This successfully solves the "webbing" problem and improves the qualified rate of products.

[0140] This specific embodiment is merely an explanation of the present application and is not intended to limit the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment as needed, even if they do not contribute to creativity. However, as long as such modifications fall within the scope of the claims of the present application, they will be protected by the patent law.

Claims

1. A silicone-free anti-webbing agent for latex gloves, characterized in that: The method comprises the following raw materials in the following weight percentages: raw material A: 5-15%, raw material B: 5-15%, raw material C: 5-10%, and the balance is water; The raw material A comprises lipids and higher carbon alcohols in a weight ratio of (10-25):1; The lipids include one or more of castor oil, palm oil, coconut oil, and lanolin; The higher alcohols include one or more of lauryl alcohol, octadecanol, and behenyl alcohol; The raw material B includes saturated fatty acids and unsaturated fatty acids; The saturated fatty acid includes one or more of stearic acid, ricinoleic acid, and nonanoic acid; The unsaturated fatty acids include one or more of linolenic acid and oleic acid; The raw material C comprises a pH regulator and a fatty amine in a weight ratio of 1:(30-40); The fatty amine is an organic amine compound with a carbon chain length of C8-C22.

2. The silicon-free anti-webbing agent for latex gloves according to claim 1, characterized in that: The weight ratio of the raw material A: the raw material B: the raw material C is 1: (0.8-1.2): (0.5-1).

3. The silicon-free anti-webbing agent for latex gloves according to claim 1, characterized in that: The pH regulator includes one or more of natural alkali, small molecule alkaline substances, and amine salts; The small molecule alkaline substance includes one or more of triethylamine, trimethylamine, and dimethylacetamide; The amine salt is an octylamine salt.

4. A method for preparing a silicon-free anti-webbing agent for latex gloves according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Raw material A, raw material B, and raw material C are mixed and heated to melt to obtain an initial mixed solution; S2. Heat water to 80-90°C; S3. Under stirring, the initial mixture obtained in S1 was added to the heated water in S2 and mixed to obtain a mixture; S4. The mixture obtained in the above S3 is cooled to 25-30°C and filtered through a 200-mesh filter to obtain a silicon-free anti-webbing agent.

5. A process for preparing latex gloves, comprising the following steps: Washing the hand mold, drying, dipping in a coagulation bath, drying again, dipping in latex, vulcanizing, anti-sticking isolation treatment, and demoulding; characterized in that the silicon-free anti-webbing agent for latex gloves according to any one of claims 1 to 3 is added to the latex in the latex dipping step, and the amount of the anti-webbing agent added is 0.08-0.015% of the latex.

6. The process for preparing latex gloves according to claim 5, characterized in that: The immersion bath in the coagulation bath immersion step comprises gel and a surfactant, wherein the surfactant has a cloud point higher than 70° C. and the added amount of the surfactant is 0.15-0.25% of the gel.

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