Water-based adhesive for soft body armor core and preparation method and application thereof

Abstract

The application discloses a water-based adhesive for soft bulletproof vest core pieces and a preparation method and application thereof, and belongs to the technical field of adhesives. The water-based adhesive is made of raw materials including the following components: a water-based polyurethane emulsion, an itaconate rubber emulsion, a water-based silicone oil, a polyurethane thickening agent, a silicone leveling agent, a defoaming agent, an antioxidant, an ultraviolet absorber, a wetting agent and 3-aminopropyltrimethoxysilane. The itaconate rubber emulsion is synthesized through free radical emulsion polymerization, the synthesized itaconate rubber emulsion is added into the water-based polyurethane for modification, the water-based polyurethane and the itaconate rubber are synergistically used, the adhesion performance of the water-based adhesive to UHMWPE fibers is improved, and the low-temperature resistance of the adhesive is improved.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, specifically to a water-based adhesive for a soft bulletproof vest chip, its preparation method, and its application. Background Technology

[0002] Waterborne polyurethane is a novel polyurethane system formed by dispersing polyurethane in water as a solvent. Based on its appearance, waterborne polyurethane can be a waterborne polyurethane solution, a waterborne polyurethane dispersion, or a waterborne polyurethane emulsion. Waterborne polyurethane can be classified into aromatic and aliphatic types depending on the main raw material (diisocyanate) used in its preparation; or into polyether, polyester, and polyether / polyester hybrid types depending on the main raw material (polyol). Waterborne polyurethane dispersions use water as the dispersion medium and possess advantages such as being non-toxic, non-polluting, having good bonding strength, hardness, and adhesion, being safe and reliable, easy to modify, and having good biocompatibility, thus meeting the needs of green industrial development. When used as an adhesive, waterborne polyurethane dispersions have been widely applied in footwear, vacuum forming, automotive interiors, and textile bonding.

[0003] Currently, most soft bulletproof vest chips use waterborne polyurethane as an adhesive to prepare unidirectional polyethylene (PEUD) fabric. Due to the properties of waterborne polyurethane, this adhesive offers advantages such as a wide operating temperature range, strong design flexibility, and environmental friendliness. However, the urethane and urea bonds contained in waterborne polyurethane are polar groups, resulting in poor interfacial bonding with ultra-high molecular weight polyethylene (UHMWPE) fibers. Furthermore, waterborne polyurethane has a higher glass transition temperature than rubber-based adhesives, making it difficult to maintain its original performance in extremely cold environments. Summary of the Invention

[0004] This invention provides a water-based adhesive for soft bulletproof vest chips, its preparation method, and its application. This invention synthesizes itaconic acid ester rubber emulsion through free radical emulsion polymerization, and modifies itaconic acid ester rubber emulsion by adding it to waterborne polyurethane. Through the synergistic effect of waterborne polyurethane and itaconic acid ester rubber, its adhesion performance with UHMWPE fibers is improved, and the service temperature of the adhesive is reduced.

[0005] This invention first provides a water-based adhesive, which is made from raw materials comprising the following components:

[0006] Waterborne polyurethane emulsions, itaconic acid ester rubber emulsions, waterborne silicone oils, polyurethane thickeners, silicone leveling agents, defoamers, antioxidants, ultraviolet absorbers, wetting agents, and 3-aminopropyltrimethoxysilane.

[0007] In the above-mentioned water-based adhesives, the water-based silicone oil is a polyether-modified polydimethylsiloxane; specifically, it can be 204 silicone oil.

[0008] The polyurethane thickener is hydroxyethyl cellulose;

[0009] The organosilicon leveling agent is an organically modified polysiloxane; specifically, it may be Glide410 and / or KEMET 5502.

[0010] The defoamer is a hydrophilic modified organosilicon; specifically, it may be at least one of Moteng Chemical DF116, DF118, DC65 and D201.

[0011] The antioxidant is 2,6-di-tert-butyl-4-methylphenol;

[0012] The ultraviolet absorber is a benzotriazole compound; specifically, it can be Moteng Chemical U383.

[0013] The wetting agent is sodium dioctyl sulfonate.

[0014] The above-mentioned water-based adhesive, by weight, is made of the following components in parts by weight: 50 parts of waterborne polyurethane emulsion, 50 parts of itaconic acid ester rubber emulsion, 10-20 parts of waterborne silicone oil, 1-2 parts of polyurethane thickener, 0.02-0.03 parts of silicone leveling agent, 0.005-0.01 parts of defoamer, 0.2-0.3 parts of antioxidant, 0.1-0.4 parts of ultraviolet absorber, 1-2 parts of wetting agent, and 0.8-1 parts of 3-aminopropyltrimethoxysilane.

[0015] Specifically, by weight, the water-based adhesive is made of the following components in parts by weight: 50 parts of waterborne polyurethane emulsion, 50 parts of itaconic acid ester rubber emulsion, 10 parts of waterborne silicone oil, 1 part of polyurethane thickener, 0.02 parts of silicone leveling agent, 0.005 parts of defoamer, 0.2 parts of antioxidant, 0.15 parts of ultraviolet absorber, 1 part of wetting agent, and 0.8 parts of 3-aminopropyltrimethoxysilane.

[0016] In the above-mentioned water-based adhesives, the waterborne polyurethane emulsion is a modified polyether polyurethane emulsion or a polyester polyurethane emulsion.

[0017] The itaconic acid ester rubber latex is prepared from the following raw materials in parts by weight: 50-60 parts dibutyl itaconic acid, 40-50 parts butadiene, 4-5 parts mixed soap, 0.05-0.2 parts activator, 0.8-1 parts electrolyte, 0.01-0.03 parts sodium hydrosulfite, 0.03-0.05 parts p-menthol peroxide, 0.1-0.3 parts hydroxylamine, and 190-200 parts water;

[0018] Specifically, the composition includes 60 parts itaconic acid dibutyl ester, 40 parts butadiene, 4.675 parts mixed soap, 0.07 parts activator, 0.9 parts electrolyte, 0.023 parts sodium hydrosulfite, 0.04 parts hydroperoxide p-menthane, 0.2 parts hydroxylamine, and 195 parts water.

[0019] The butadiene is 1,3-butadiene; the sodium dithionite is sodium dithionite.

[0020] In the above-mentioned water-based adhesive, the soap mixture is potassium disproportionate and sodium stearate; specifically, the mass ratio of potassium disproportionate and sodium stearate is 10:1.

[0021] The activator is ferrous sulfate and sodium formaldehyde sulfoxylate; specifically, the mass ratio of ferrous sulfate to sodium formaldehyde sulfoxylate is 0.4:1.

[0022] The electrolyte is ethylenediaminetetraacetic acid (EDTA) and potassium chloride; specifically, the mass ratio of EDTA to potassium chloride is 1:8.

[0023] In the above-mentioned water-based adhesives, the itaconic acid ester rubber latex is prepared by a method comprising the following steps:

[0024] The soap, activator, electrolyte, sodium hydrosulfite and water are mixed, and then dibutyl itaconic acid is added under stirring. Butadiene is added under an inert atmosphere for pre-emulsification. During the pre-emulsification process, the system temperature is reduced to 5-7°C. After pre-emulsification, hydrogen peroxide is added to react with menthol. After the reaction is completed, hydroxylamine is added to terminate the reaction to obtain itaconic acid ester rubber latex.

[0025] In the above-mentioned water-based adhesive, the stirring speed is 250-300 r / min;

[0026] The pre-emulsification time is 1 to 1.5 hours;

[0027] The reaction is carried out under stirring conditions, specifically at a stirring speed of 250–300 r / min;

[0028] The reaction time is 8 to 9 hours.

[0029] The present invention also provides a method for preparing the above-mentioned water-based adhesive, comprising the following steps:

[0030] A water-based polyurethane emulsion, itaconic acid ester rubber emulsion, water-based silicone oil, polyurethane thickener, silicone leveling agent, defoamer, antioxidant, ultraviolet absorber, wetting agent and 3-aminopropyltrimethoxysilane are mixed and stirred to obtain the water-based adhesive.

[0031] In the above preparation method, the stirring speed is 400-500 r / min;

[0032] The stirring time is 20 to 120 minutes.

[0033] Finally, this invention provides the application of the above-mentioned water-based adhesive in the preparation of soft bulletproof vest chips;

[0034] Specifically, the soft bulletproof vest chip is made of polyethylene unidirectional fabric.

[0035] More specifically, the soft bulletproof vest chip is made of multiple layers of ultra-high molecular weight (1.5 million to 5 million) polyethylene fiber unidirectional non-woven fabric.

[0036] The present invention has the following advantages:

[0037] (1) The water-based adhesive of the present invention contains itaconic acid ester rubber, which contains a large number of ester groups that can form hydrogen bonds with the active groups in polyurethane, thus playing a good role in the mutual solubility of water-based polyurethane; and the side chain of itaconic acid ester contains a large number of n-butyl groups, which are similar to the structure of UHMWPE fiber, and can well wet the fiber, thereby improving the interfacial interaction between the adhesive and the fiber.

[0038] (2) The water-based adhesive preparation method of the present invention uses dibutyl itaconic acid with biomass source and avoids the use of a large amount of organic reagents. The product has the advantages of being environmentally friendly and having low environmental pollution.

[0039] (3) The water-based adhesive of the present invention is simple to formulate, pollution-free, and has a bonding ability with UHMWPE fibers that is increased by more than 50%. The ballistic performance of the bulletproof vest decreases less at lower temperatures and has a high elongation at break. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0041] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0042] In the quantitative experiments in the following examples, three replicate experiments were set up, and the average value of the results was taken.

[0043] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0044] Example 1

[0045] 1) Synthesis of itaconic acid ester rubber latex

[0046] Clean the reactor thoroughly and add 390g of deionized water, 8.5g of potassium disproportionated rosinate, 0.85g of sodium stearate, 0.04g of ferrous sulfate, 0.1g of sodium formaldehyde sulfoxylate, 0.2g of ethylenediaminetetraacetic acid, 0.046g of sodium dithionite, and 1.6g of potassium chloride. Use a polytetrafluoroethylene (PTFE) stirrer, turn on the stirring control, and set the speed to 280 rpm. Then add 120g of dibutyl itaconic acid, purge the air in the reactor with nitrogen, and then add 80g of 1,3-butadiene. Stir at 280 rpm for pre-emulsification for one hour, and slowly cool to 6°C during this process. After one hour of pre-emulsification, add 0.08g of p-menthol hydrogen peroxide, and react for 8 hours at 280 rpm. Then add 0.4g of hydroxylamine to terminate the reaction, obtaining an itaconic acid ester rubber latex.

[0047] 2) Blending of waterborne polyurethane

[0048] A modified waterborne polyurethane resin adhesive was prepared by adding 100g of modified polyether polyurethane emulsion (purchased from Hefei Anke Fine Chemical Co., Ltd., item number 3630), 100g of itaconic acid ester rubber emulsion obtained in step 1), 20g of waterborne silicone oil, 2g of polyurethane thickener, 0.04g of silicone leveling agent, 0.01g of defoamer, 0.4g of antioxidant 264, 0.3g of ultraviolet absorber, 2g of wetting agent, and 1.6g of 3-aminopropyltrimethoxysilane to a beaker and stirring at 400r / min for 30min to obtain a modified waterborne adhesive. UHMWPE fibers were then coated using a coating device during the weaving process of polyethylene nonwoven fabric.

[0049] The specific substances used in this embodiment are as follows: the water-based silicone oil is polyether-modified polydimethylsiloxane (Longsheng Sihai 204 silicone oil). Since it is a non-polar chain segment, it can increase the affinity between polyethylene fiber and emulsion molecules. In addition, polydimethylsiloxane has good high and low temperature resistance, which can enhance the operating temperature range of bulletproof chips.

[0050] The polyurethane thickener is hydroxyethyl cellulose (Mok Chemical), used to adjust the viscosity of aqueous emulsions and improve processability;

[0051] The silicone leveling agent is an organic modified polysiloxane (Dega 410), which is a polyether siloxane copolymer. Its function is to increase the smoothness and leveling properties of this product during use.

[0052] The defoamer is a hydrophilic modified silicone (Motian Chemical DF116), which can play a defoaming role for a long time and can prevent bubbles from appearing on the fabric surface during the non-woven fabric production stage.

[0053] Antioxidant 264 is 2,6-di-tert-butyl-4-methylphenol (Sigma-Aldrich), which can increase the product's UV resistance;

[0054] The ultraviolet absorber is a benzotriazole compound (Modal Chemical U383, which is specifically used in this invention to improve the product's aging resistance and weather resistance).

[0055] The wetting agent is sodium dioctyl sulfonate (Motian Chemical OT-75), which is suitable for water-based polyurethanes. It can improve the wetting properties of the present invention, and also has the functions of defoaming and smoothing.

[0056] Example 2

[0057] The difference between this embodiment and Embodiment 1 is that the polyurethane emulsion is different. In this embodiment, the polyurethane emulsion is a polyester-type polyurethane emulsion (purchased from Hefei Anke Fine Chemical Co., Ltd., product number 3860). The other steps and conditions are the same as in Embodiment 1.

[0058] Comparative Example 1

[0059] The difference between this comparative example and Example 1 is that itaconic acid ester rubber latex was not added in the compounding step of the waterborne polyurethane in this comparative example.

[0060] Comparative Example 2

[0061] The difference between this comparative example and Example 1 is that: in the compounding step of waterborne polyurethane, itaconic acid ester rubber latex was not added in this comparative example, and the polyurethane latex in this comparative example is a polyester-type polyurethane latex.

[0062] Comparative Example 3

[0063] The difference between this comparative example and Example 1 is that 100g of itaconic acid ester rubber latex in Example 1 is replaced with 100g of natural rubber latex (purchased from Shanghai Hechang Chemical Co., Ltd.), while the other steps and conditions are the same as in Example 1.

[0064] Comparative Example 4

[0065] The difference between this comparative example and Example 2 is that 100g of itaconic acid ester rubber latex in Example 2 was replaced with natural rubber latex (purchased from Shanghai Hechang Chemical Co., Ltd.), while the other steps and conditions were the same as in Example 2.

[0066] Example 3

[0067] The standard samples prepared by the above embodiments and comparative examples were subjected to the following tests. The test results are detailed in Table 1.

[0068] 1. Tensile strength, elongation at break, and tensile modulus: The tensile strength, elongation at break, and tensile modulus shall be tested in accordance with "GB / T528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0069] 2. Bonding strength: The bonding strength was tested according to "GB / T 2791-1995 Adhesives T Peel Strength Test Method Flexible Materials to Flexible Materials". Ultra-high molecular weight polyethylene fiber nonwoven fabric was used as the bonding substrate.

[0070] 3. V50 value: The adhesives of Example 1 and Comparative Examples 1 and 3, and the control example adhesives, were applied to high-density, high-modulus polyethylene fiber UD fabric composite material for bulletproof vests, with an areal density of 5 kg / m², and subjected to the GA141 standard V50 ballistic resistance test.

[0071] Table 1

[0072]

[0073] As shown in Table 1, the difference between Example 1 and Comparative Example 1, and between Example 2 and Comparative Example 2, lies in whether or not rubber latex was added. The experimental results show that the addition of rubber latex significantly increased the adhesion of the water-based adhesive to polyethylene fibers. The difference between Example 1 and Comparative Example 3, and between Example 2 and Comparative Example 4, lies in the type of rubber latex added. Comparative Examples 3 and 4 used natural rubber latex, while Examples 1 and 2 used itaconic acid ester rubber latex. The experimental results show that, compared to natural rubber latex, the addition of itaconic acid ester rubber latex significantly increased the adhesion of the water-based adhesive to polyethylene fibers.

[0074] Based on the V50 value, in Example 1, the addition of itaconic acid ester rubber latex resulted in better ballistic performance under the same conditions. Furthermore, the ballistic performance did not show a significant decrease at -30°C, indicating that the product has excellent low-temperature resistance.

Claims

1. A water-based adhesive, made from raw materials comprising the following components: Waterborne polyurethane emulsions, itaconic acid ester rubber emulsions, waterborne silicone oils, polyurethane thickeners, silicone leveling agents, defoamers, antioxidants, ultraviolet absorbers, wetting agents, and 3-aminopropyltrimethoxysilane; By weight, the composition includes 50 parts of waterborne polyurethane emulsion, 50 parts of itaconic acid ester rubber emulsion, 10-20 parts of waterborne silicone oil, 1-2 parts of polyurethane thickener, 0.02-0.03 parts of silicone leveling agent, 0.005-0.01 parts of defoamer, 0.2-0.3 parts of antioxidant, 0.1-0.4 parts of ultraviolet absorber, 1-2 parts of wetting agent, and 0.8-1 parts of 3-aminopropyltrimethoxysilane. The aqueous polyurethane emulsion is a modified polyether polyurethane emulsion or a polyester polyurethane emulsion. The itaconic acid ester rubber latex is prepared from the following raw materials in parts by weight: 50-60 parts of dibutyl itaconic acid, 40-50 parts of butadiene, 4-5 parts of mixed soap, 0.05-0.2 parts of activator, 0.8-1 parts of electrolyte, 0.01-0.03 parts of sodium hydrosulfite, 0.03-0.05 parts of p-menthol peroxide, 0.1-0.3 parts of hydroxylamine, and 190-200 parts of water.

2. The water-based adhesive according to claim 1, characterized in that: The aqueous silicone oil is a polyether-modified polydimethylsiloxane; The polyurethane thickener is hydroxyethyl cellulose; The organosilicon leveling agent is an organically modified polysiloxane; The defoamer is a hydrophilic modified organosilicon; The antioxidant is 2,6-di-tert-butyl-4-methylphenol; The ultraviolet absorber is a benzotriazole compound; The wetting agent is sodium dioctyl sulfonate.

3. The water-based adhesive according to claim 1, characterized in that: The soap mixture is potassium disproportionated rosinate and sodium stearate; The activator is ferrous sulfate and sodium formaldehyde sulfoxylate. The electrolyte is ethylenediaminetetraacetic acid and potassium chloride.

4. The water-based adhesive according to claim 3, characterized in that: The mass ratio of potassium disproportionated rosinate to sodium stearate is 10:1; The mass ratio of ferrous sulfate to sodium formaldehyde sulfoxylate is 0.4:1; The mass ratio of ethylenediaminetetraacetic acid to potassium chloride is 1:

8.

5. The water-based adhesive according to claim 1, characterized in that: The itaconic acid ester rubber latex is prepared by a method comprising the following steps: The soap, activator, electrolyte, sodium hydrosulfite and water are mixed, and then dibutyl itaconic acid is added under stirring. Butadiene is added under an inert atmosphere for pre-emulsification. During the pre-emulsification process, the system temperature is reduced to 5-7°C. After pre-emulsification, hydrogen peroxide is added to react with menthol. After the reaction is completed, hydroxylamine is added to terminate the reaction to obtain itaconic acid ester rubber latex.

6. The water-based adhesive according to claim 5, characterized in that: The stirring speed is 250~300 r / min; The pre-emulsification time is 1~1.5h; The reaction time is 8-9 hours.

7. A method for preparing the water-based adhesive according to any one of claims 1-6, comprising the following steps: A water-based polyurethane emulsion, itaconic acid ester rubber emulsion, water-based silicone oil, polyurethane thickener, silicone leveling agent, defoamer, antioxidant, ultraviolet absorber, wetting agent and 3-aminopropyltrimethoxysilane are mixed and stirred to obtain the water-based adhesive.

8. The preparation method according to claim 7, characterized in that: The stirring speed is 400~500 r / min; The stirring time is 20-120 minutes.

9. The use of the water-based adhesive according to any one of claims 1-6 in the preparation of a soft bulletproof vest chip.

10. The application according to claim 9, characterized in that: The soft bulletproof vest chip is made of polyethylene unidirectional fabric.

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