N-butyl cyanoacrylate flexible adhesive and preparation method thereof

Abstract

The invention discloses an n-butyl cyanoacrylate flexible adhesive and a preparation method thereof. The flexible adhesive is prepared from the following raw materials in parts by weight: 80 to 90 parts of alpha-cyanoacrylate, 0.004 to 0.03 part of a polymerization inhibitor, 0.1 to 0.3 part of an accelerator, 3 to 10 parts of a thickening agent, 0.1 to 0.6 part of an antioxidant and 0.5 to 4.5 parts of a thixotropic agent. The invention provides an n-butyl cyanoacrylate flexible adhesive and a preparation method thereof. The flexible adhesive is convenient to use and still keeps certain elasticity after being cured; and the preparation steps are simple and the cost is low.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of adhesives, and particularly relates to a n-butyl cyanoacrylate flexible adhesive and a preparation method thereof. BACKGROUND

[0002] Adhesives are widely used in daily life and industrial fields. Although existing cyanoacrylate adhesives (such as ethyl alpha-cyanoacrylate) have a fast curing speed, they have the problems of high brittleness and poor flexibility, and are prone to cracking under dynamic stress.

[0003] In addition, the flexible glue commonly seen on the market usually uses chloroprene rubber or water-based glue as the main body, and generally has an extremely slow curing speed and needs 24 hours to complete preliminary curing. Moreover, the flexible glue often contains toxic solvents, and is not convenient and friendly enough. Furthermore, the conventional fast-drying adhesives on the market are hard and brittle after curing, which may damage the fibers of cloth, affect the appearance and cause secondary cracking. In addition, the flexible hot melt adhesives on the market need professional equipment for bonding, which has a high cost, and the flexible adhesives commonly seen on the market have a stimulating odor, which affects the use experience.

[0004] Based on the above problems, the present application further studies the flexible adhesive. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a n-butyl cyanoacrylate flexible adhesive and a preparation method thereof. The flexible glue is convenient to use and still has a certain elasticity after curing. Moreover, the preparation steps are simple and the cost is low.

[0006] The present application is solved by the following technical solutions.

[0007] The n-butyl cyanoacrylate flexible adhesive comprises the following materials by weight: ɑ-cyanoacrylate 80-90 parts, polymerization inhibitor 0.004-0.03 parts, accelerator 0.1-0.3 parts, thickening agent 3-10 parts, antioxidant 0.1-0.6 parts, and thixotropic agent 0.5-4.5 parts.

[0008] In a preferred embodiment, the ɑ-cyanoacrylate is n-butyl alpha-cyanoacrylate or a mixture of n-butyl alpha-cyanoacrylate and alpha-cyanoacrylate methoxyethyl ester.

[0009] In a preferred embodiment, the accelerator is dibenzo-18-crown-6 ether-6.

[0010] In a preferred embodiment, the polymerization inhibitor is one or more of hydroquinone, pyrogallol, methyl sulfonic acid, propyl gallate, boron trifluoride etherate, and sulfur dioxide.

[0011] In a preferred embodiment, the thickening agent is one or more of polymethyl methacrylate, polyethyl methacrylate, and polybutyl methacrylate.

[0012] In a preferred embodiment, the antioxidant is tetrahydrophthalic anhydride.

[0013] In a preferred embodiment, the thixotropic agent is fumed silica.

[0014] The preparation method of the n-butyl cyanoacrylate flexible adhesive in the application comprises the following steps: S10: drying the raw materials or part of the raw materials, and weighing the raw materials according to the formula proportion; S20: sequentially adding the α-cyanoacrylate, the accelerator, the polymerization inhibitor and the thickening agent in the raw materials into a reaction kettle, and stirring under heating and vacuum until complete dissolution; S30: cooling to room temperature, adding the antioxidant and the thixotropic agent into the reaction kettle, and discharging after uniform stirring to obtain the adhesive.

[0015] In a preferred embodiment, in step S10, the thickening agent is placed in a blast drying oven at 82℃ for drying treatment for 4H; in step S20, after adding the α-cyanoacrylate, the stirring speed of the reaction kettle is 300rpm~500rpm, and the accelerator and the polymerization inhibitor are added at the speed, and the stirring is continuously performed; then the thickening agent is added, the heating is started, and as the temperature rises, the stirring speed is gradually increased until the temperature reaches 65~70℃, and the stirring speed gradually reaches 800rpm; in step S30, after adding the antioxidant and the thixotropic agent, the stirring speed is 700rpm~800rpm.

[0016] Compared with the prior art, the application has the following beneficial effects: a n-butyl cyanoacrylate flexible adhesive and a preparation method thereof are provided, the flexible adhesive is convenient to use, still maintains a certain elasticity after curing, and the preparation steps are simple and the cost is low. DETAILED DESCRIPTION

[0017] The application will be further described in detail below in combination with specific embodiments.

[0018] The n-butyl cyanoacrylate flexible adhesive involved in the application, the raw materials of the flexible adhesive comprise the following materials in parts by weight: α-cyanoacrylate 80~90 parts, polymerization inhibitor 0.004~0.03 parts, accelerator 0.1~0.3 parts, thickening agent 3~10 parts, antioxidant 0.1~0.6 parts, and thixotropic agent 0.5~4.5 parts.

[0019] The α-cyanoacrylate is n-butyl α-cyanoacrylate or a mixture of n-butyl α-cyanoacrylate and methoxyethyl α-cyanoacrylate. The accelerator is dibenzo-18-crown-6 ether-6. The polymerization inhibitor is one or more of hydroquinone, pyrogallol, methyl sulfonic acid, propyl gallate, boron trifluoride etherate, sulfur dioxide. The thickening agent is one or more of polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate. The antioxidant is tetrahydrophthalic anhydride. The thixotropic agent is fumed silica.

[0020] The following are specific examples, and the material parts in the examples are all weight parts. Example

[0021] Pre-treatment: A mixture of polymethyl methacrylate, polyethyl methacrylate, and polybutyl methacrylate in a weight ratio of 8:1:1 was placed in a 82℃ air drying oven for drying treatment for 4H to obtain a polymethyl methacrylate mixture.

[0022] Environmental treatment: dehumidification, control the environmental humidity below 60%RH.

[0023] n-Butyl α-cyanoacrylate 90 parts by weight was weighed and added to the reaction kettle, and stirring was started at a stirring speed of 300rpm.

[0024] Boron trifluoride etherate 0.004 parts by weight and dibenzo-18-crown-6 ether-6 0.2 parts by weight were added to the reaction kettle, and stirring was continued at a stirring speed of 300rpm.

[0025] To ensure strength, pyrogallol 0.015 parts by weight was added to the reaction kettle, and stirring was continued at a stirring speed of 300rpm.

[0026] To ensure the flowability of the adhesive, 9 parts by weight of the polymethyl methacrylate mixture was added, and the temperature was raised, and the stirring speed was gradually increased as the temperature rose, until the temperature reached 65-70℃ and the stirring speed reached 800rpm.

[0027] After the liquid was clear, the temperature was lowered, and tetrahydrophthalic anhydride 0.1 parts by weight and fumed silica 0.5 parts by weight were added after the temperature was lowered to room temperature, and stirring was continued at a stirring speed of 800rpm.

[0028] The discharge was checked, and a flexible glue instant adhesive was obtained. Example

[0029] Pre-treatment: The polymethyl methacrylate was placed in a 82℃ air drying oven for drying treatment for 4H.

[0030] Environmental treatment: dehumidification, control the environmental humidity below 60%RH.

[0031] Take methoxyethyl α-cyanoacrylate 45 parts, n-butyl α-cyanoacrylate 45 parts, and add them to the reaction kettle. Start stirring at a stirring speed of 300 rpm.

[0032] Put 0.004 parts of boron trifluoride ether, 0.1 parts of dibenzo-18-crown ether-hexa, and 0.015 parts of hydroquinone into the reaction kettle. Stir at a stirring speed of 300 rpm.

[0033] To ensure basic strength, put 0.02 parts of pyrogallic acid into the reaction kettle. Control the stirring speed at 300 rpm and continue stirring.

[0034] To ensure the flowability of the adhesive, put 3.5 parts of polymethyl methacrylate, 0.5 parts of polyethyl methacrylate, and 0.5 parts of polybutyl methacrylate into the reaction kettle. Start heating and gradually increase the stirring speed as the temperature rises until the temperature reaches 65-70°C and the stirring speed reaches 800 rpm.

[0035] After the liquid is clear, cool it down to room temperature, then add 0.1 parts of tetrahydrophthalic anhydride and 3 parts of fumed silica at 800 rpm and stir thoroughly.

[0036] Check the discharge and get the flexible glue instant adhesive. Example

[0037] Pre-treatment: Dry the polymethyl methacrylate in a forced air drying oven at 82°C for 4 hours.

[0038] Environmental treatment: Dehumidify and control the environmental humidity below 60% RH.

[0039] Select 90 parts of methoxyethyl α-cyanoacrylate and add it to the reaction kettle. Start stirring at a stirring speed of 300 rpm.

[0040] Put 0.002 parts of boron trifluoride ether, 0.1 parts of dibenzo-18-crown ether-hexa, and 0.015 parts of hydroquinone into the reaction kettle. Control the stirring speed at 300 rpm and continue stirring.

[0041] Put 0.03 parts of pyrogallic acid into the reaction kettle and increase the stirring speed to 500 rpm.

[0042] Put 3 parts of polymethyl methacrylate into the reaction kettle. Start heating and gradually increase the stirring speed as the temperature rises until the temperature reaches 65-70°C and the stirring speed reaches 800 rpm.

[0043] After the liquid is clear, cool it down to room temperature, then add 0.1 parts of tetrahydrophthalic anhydride and 3 parts of fumed silica at 800 rpm and stir thoroughly.

[0044] Check the discharge, get flexible glue instant adhesive.

[0045] The products in the above embodiment 1 to embodiment 3, the comparison data are as follows.

[0046] Batch No. Appearance Cloth Speed ABS Speed PMMA Speed ABS Strength PMMA Strength Boiling in 45°C water for 10 days Hardness Example 1 Colorless transparent liquid 4s 4s 5s 6.95 MPa 3.91 MPa Normal, no peeling 55D Example 2 Colorless transparent liquid 6s 5s 10s 8.67 MPa 3.83 MPa Normal, no peeling 62D Example 3 Colorless transparent liquid 4s 4s 6s 6.23 MPa 3.98 MPa Normal, no peeling 58D As can be seen from the above examples and tables, the products in the embodiments of the application are all colorless transparent liquids with certain viscosity. The curing speed of the adhesives prepared in the three embodiments on materials such as cloth, ABS and PMMA is all ≤10 seconds, and the curing time is fast. The bonding strength of the three adhesives on ABS material is the best, and the bonding strength on PMMA material is also very good, which is enough to meet the use requirements and does not fall off after a long time.

[0047] As can be seen from the above description, by using n-butyl cyanoacrylate (NBCA) or the synergistic compounding of methoxyethyl cyanoacrylate (MECA) and n-butyl cyanoacrylate (NBCA), the flexibility and fatigue resistance of the adhesive layer are significantly improved while the fast curing property is maintained. Specifically, the technical solution in the application has the following beneficial effects: The application adopts a snatch reaction type curing method, so that the flexible glue can be quickly cured, reducing the equipment and time requirements and increasing the convenience.

[0048] The application introduces a thixotropic agent, which makes it more convenient to apply glue and operate on porous materials such as cloth while ensuring the bonding strength.

[0049] The thickening agent and thixotropic agent introduced in the application inhibit the flowability, making the operation more controllable and reducing the flow and dripping to a certain extent.

[0050] The α-cyanoacrylate monomer introduced in the application has no irritating odor, is convenient to use, and has excellent moisture and heat resistance, meeting the use requirements in different environments.

[0051] The protection scope of the application includes but is not limited to the above embodiments, and the protection scope of the application is subject to the claims, and any replacement, deformation and improvement of the technology in the art that can be easily thought of by those skilled in the art falls within the protection scope of the application.

Claims

1. A flexible adhesive of n-butyl cyanoacrylate, characterized by, The raw materials of the flexible adhesive include the following materials by weight: ɑ-cyanoacrylate 80~90 parts, Inhibitor 0.004~0.03 parts, Accelerator 0.1~0.3 parts, Thickening agent 3~10 parts, Antioxidant 0.1~0.6 parts, Thixotropic agent 0.5~4.5 parts.

2. The n-butyl cyanoacrylate flexible adhesive according to claim 1, characterized in that, The ɑ-cyanoacrylate is n-butyl ɑ-cyanoacrylate or a mixture of n-butyl ɑ-cyanoacrylate and methoxyethyl ɑ-cyanoacrylate.

3. The n-butyl cyanoacrylate flexible adhesive according to claim 2, wherein the n-butyl cyanoacrylate is 0.1 to 0.3 g. The accelerator is dibenzo-18-crown-6 ether.

4. The n-butyl cyanoacrylate flexible adhesive according to claim 3, characterized in that, The inhibitor is one or more of hydroquinone, pyrogallol, methyl sulfonic acid, propyl gallate, boron trifluoride ether, sulfur dioxide.

5. The n-butyl cyanoacrylate flexible adhesive according to claim 4, wherein The thickening agent is one or more of polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate.

6. The n-butyl cyanoacrylate flexible adhesive according to claim 5, wherein The antioxidant is tetrahydrophthalic anhydride.

7. The n-butyl cyanoacrylate flexible adhesive according to claim 6, wherein the n-butyl cyanoacrylate is 0.5 to 1.5 wt% of the total weight of the adhesive. The thixotropic agent is fumed silica.

8. A process for the preparation of n-butyl cyanoacrylate flexible adhesive as claimed in any one of claims 1 to 7, characterized in that, The method comprises the following steps: S10: drying the raw materials or part of the raw materials, and weighing the raw materials according to the formula proportion; S20: sequentially adding ɑ-cyanoacrylate, accelerator, inhibitor, and thickening agent in the raw materials into a reaction kettle, and stirring under heating and vacuum until completely dissolved; S30: cooling to room temperature, adding antioxidant and thixotropic agent into the reaction kettle, and discharging after uniform stirring to obtain the adhesive.

9. The method for preparing the butyl cyanoacrylate flexible adhesive according to claim 8, characterized in that, In step S10, the thickening agent is dried in a blast drying oven at 82℃ for 4H; In step S20, after adding ɑ-cyanoacrylate, the stirring speed of the reaction kettle is 300rpm~500rpm, and the accelerator and inhibitor are added at the speed, and the stirring is continued; then the thickening agent is added, the temperature is raised, and the stirring speed is gradually increased until the temperature reaches 65~70℃, and the stirring speed gradually reaches 800rpm; In step S30, after adding the antioxidant and thixotropic agent, the stirring speed is 700rpm~800rpm.