Composite nylon powder for printing rubber roller and preparation method thereof

Abstract

This application relates to the field of nylon powder, specifically disclosing a composite nylon powder for printing rollers and its preparation method. The composite nylon powder for printing rollers is composed of 82-90% nylon powder, 1-3% a wetting and dispersing agent mixture, 2-5% a binder strengthening agent, and 5-10% filler. The wetting and dispersing agent mixture includes two or more of hydroxyethyl ethylene bis-stearamide, zinc stearate, and lubricant CYD-816A. The preparation method is as follows: nylon powder and the wetting and dispersing agent mixture are mixed, then a mixture of the binder strengthening agent and filler is added, and the mixture is stirred to obtain a mixture. The mixture is then melt-co-extruded, granulated, and pulverized to obtain the composite nylon powder for printing rollers. The wetting and dispersing agent mixture of this application can coat the surface of the nylon powder, improving powder flowability and facilitating the uniform dispersion of filler in the nylon powder, resulting in a composite nylon powder with both excellent mechanical properties and film-forming properties.

Description

Technical Field

[0001] This application relates to the field of nylon powder technology, and more specifically, to a composite nylon powder for printing rollers and a method for preparing the same. Background Technology

[0002] As a key component in printing equipment, the surface properties of printing rollers directly affect the ink transfer accuracy, the uniformity of printed products, and the stability of equipment operation.

[0003] Nylon materials, especially nylon processed in powder form, have become one of the important base materials for manufacturing high-performance printing rollers due to their excellent wear resistance, high temperature resistance, solvent resistance, resilience, and moderate hardness. Typically, this type of nylon powder is prepared through methods such as melt extrusion, cooling and pulverizing, or direct polymerization and precipitation, and then adhered to the surface of a metal roller substrate through processes such as sintering, spraying, or molding to form a functional coating.

[0004] Currently, the mechanical properties of nylon powder are generally improved by adding fillers. However, the polarity difference between fillers and nylon powder is large, and their compatibility is poor. Therefore, fillers are prone to agglomeration in nylon powder, which makes the functional coating formed by nylon powder on the surface of the rubber roller substrate relatively rough, which may affect the printing accuracy. Summary of the Invention

[0005] To improve the dispersibility of fillers in nylon powder, this application provides a composite nylon powder for printing rollers and its preparation method.

[0006] In a first aspect, this application provides a composite nylon powder for printing rollers, employing the following technical solution:

[0007] A composite nylon powder for printing rollers comprises the following components by weight percentage:

[0008] 82-90% nylon powder;

[0009] 1-3% of the wetting and dispersing agent mixture;

[0010] Adhesion reinforcing agent 2-5%;

[0011] Filler content: 5-10%;

[0012] The wetting and dispersing agent mixture includes two or more of hydroxyethyl ethylene bis-stearamide, zinc stearate, and lubricant CYD-816A.

[0013] By adopting the above technical solution, the dispersants hydroxyethyl ethylene bis-stearamide and zinc stearate can coat the surface of nylon particles and fillers, improving the dispersibility of fillers in nylon powder, reducing filler agglomeration, and improving the flowability of nylon particles and fillers. Simultaneously, during the processing of composite nylon powder, the above-mentioned mixture of wetting and dispersing agents can improve the melt flowability of the composite nylon powder and have good penetrating and wetting effects on the fillers, promoting uniform dispersion of fillers in the composite nylon powder, which is beneficial to improving the mechanical properties and film-forming properties of the composite nylon powder.

[0014] Therefore, by attaching the composite nylon powder of this application to the surface of the printing roller, the composite nylon powder is evenly dispersed and can form a uniform functional coating on the surface of the roller, so that it can work continuously at 150°C without deformation and has excellent mechanical properties and high temperature resistance.

[0015] Preferably, the wetting and dispersing agent mixture is composed of hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A.

[0016] Preferably, the wetting and dispersing agent mixture is composed of hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A in a weight ratio of 1:(0.6 to 1.0).

[0017] By employing the above technical solution, the hydroxyl groups in the hydroxyethyl ethylene bis-stearamide structure enhance the affinity with the surface of polar fillers, achieving wetting. The long-chain alkyl groups form a separating film on the filler surface, preventing re-agglomeration and achieving steric dispersion, while simultaneously lubricating the nylon molecular chains. The lubricant CYD-816A is a dendritic polymer whose molecules can penetrate deep into the nylon molecular chains, reducing interchain friction and effectively coating the filler to improve dispersion.

[0018] Therefore, by compounding hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A in the above proportions, the hydroxyethyl ethylene bis-stearamide first wets and initially coats the filler, while CYD-816A, with its stronger penetrating lubrication ability, further promotes the dispersion and separation of the filler in the melt, effectively improving the mechanical properties of the composite nylon powder. Adhering the composite nylon powder to the surface of the roller substrate forms a uniform functional coating with good printing accuracy.

[0019] Preferably, the filler comprises silicon dioxide or silicon carbide micro powder.

[0020] By adopting the above technical solutions, both silica or silicon carbide micro powders have good wear resistance and heat resistance. Using them as fillers can improve the wear resistance and heat resistance of composite nylon powder.

[0021] Preferably, the bonding enhancer is an aminosilane coupling agent.

[0022] Preferably, the aminosilane coupling agent is γ-aminopropyltriethoxysilane or N-phenyl-γ-aminopropyltrimethoxysilane.

[0023] Silica possesses excellent heat resistance and adsorption capacity. By employing the aforementioned technical solution, silica can adsorb γ-aminopropyltriethoxysilane or N-phenyl-γ-aminopropyltrimethoxysilane. Some of the adsorbed γ-aminopropyltriethoxysilane or N-phenyl-γ-aminopropyltrimethoxysilane can migrate to the silica surface and react during the melting process with nylon powder, effectively improving the dispersibility and interfacial bonding of silica in the nylon powder, and further enhancing the mechanical properties and film-forming properties of the composite nylon powder.

[0024] Preferably, the composite nylon powder used for the printing roller is composed of the following components in weight percentage:

[0025] 82-90% nylon powder;

[0026] 1-3% of the wetting and dispersing agent mixture;

[0027] 2-3% N-phenyl-γ-aminopropyltrimethoxysilane;

[0028] 8-10% silica.

[0029] By adopting the above technical solution, the content of N-phenyl-γ-aminopropyltrimethoxysilane and silica is preferably controlled in the composite nylon powder formulation. The silica fully adsorbs N-phenyl-γ-aminopropyltrimethoxysilane, which can effectively improve the mechanical properties and film-forming properties of the composite nylon powder.

[0030] Secondly, this application provides a method for preparing composite nylon powder for printing rollers, using the following technical solution:

[0031] A method for preparing composite nylon powder for printing rollers includes the following steps:

[0032] S1: After mixing the adhesive reinforcing agent and filler, a filler mixture is obtained;

[0033] After mixing the nylon powder and wetting and dispersing agent mixture, the filler mixture is added and stirred to obtain the mixture.

[0034] S2: The mixture is melt-co-extruded, granulated, and crushed to obtain composite nylon powder for printing rollers.

[0035] By employing the above technical solution, mixing the binder and filler facilitates the adsorption of the binder by the filler. Mixing the nylon powder and wetting / dispersing agent mixture allows most of the wetting / dispersing agent mixture to coat the surface of the nylon powder, improving powder flowability and promoting uniform dispersion of the filler mixture within the nylon powder. Then, the mixture is melted to form a melt with excellent flow properties. After the components are uniformly mixed and reacted, it is extruded to form a dense composite structure. Finally, it is granulated and pulverized to obtain a composite nylon powder for printing rollers, exhibiting excellent film-forming and mechanical properties.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. Since this application uses one or more of hydroxyethyl ethylene bis-stearamide, zinc stearate and lubricant CYD-816A as a dispersion and wetting mixture, it can not only wet and disperse nylon powder and improve the agglomeration of fillers in nylon powder, but also effectively reduce the viscosity of nylon powder melt, improve processing fluidity, and further promote the dispersion of fillers in nylon powder melt. Therefore, the composite nylon powder has no cracks or delamination defects after being formed on the surface of the rubber roller.

[0038] 2. The strong interfacial interaction between silica and nylon can fill the gaps between nylon molecular chains, further enhancing the mechanical properties and film-forming properties of the composite nylon powder. When it adheres to the surface of the rubber roller, it can effectively extend the wear resistance of the rubber roller.

[0039] 3. The preparation method of this application is simple. After mixing each component in steps, they are melt-blended. The components are fully mixed, which is conducive to forming composite nylon powder with excellent film-forming properties and mechanical properties. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the embodiments.

[0041] Performance testing

[0042] The composite nylon powder prepared in the embodiments and comparative examples of this application was applied to a metal substrate (0Cr15Ni5Cu2Ti precipitation-hardening martensitic stainless steel, with dimensions of 60mm×20mm×3mm, the surface of which was sandblasted with 36# white corundum and then wiped with ethyl acetate to remove grease and dust) using a fluidized bed dip coating method. After full curing at 260-300℃ and natural cooling to room temperature, the wear resistance, bonding strength and impact resistance were tested. The testing methods are as follows:

[0043] Abrasion resistance: The amount of wear on the coating after 2 hours was tested according to the method in GB / T 3960-2016;

[0044] Bond strength: The test shall be conducted in accordance with the test method specified in GB / T7124-2008 Determination of tensile shear strength of adhesives (rigid material to rigid material), and the test rate shall be 5 mm / s.

[0045] Impact resistance: Refer to the heavy hammer impact test method described in GB / T1732-93 Test Method for Impact Resistance of Coating Film, observe whether the coating on the surface of the test piece shows cracks, wrinkles and peeling; record the first time the coating shows cracks, wrinkles and peeling under heavy hammer.

[0046] Example

[0047] Example 1

[0048] A composite nylon powder for printing rollers, the components and their corresponding weights (kg) are shown in the table below.

[0049]

[0050] The preparation method of the above-mentioned composite nylon powder for printing rollers includes the following steps:

[0051] S1: After stirring and mixing the adhesive reinforcing agent and filler for 20 minutes, a filler mixture is obtained;

[0052] First, dry the nylon powder until the moisture content is less than 0.1%, then mix it with the wetting and dispersing agent mixture for 20 minutes, and finally add the filler mixture and stir for 20 minutes to obtain the mixture.

[0053] S2: The mixture is melt-co-extruded at 240-280℃, water-cooled and pelletized, and then crushed to obtain composite nylon powder for printing rollers with a particle size of 80μm.

[0054] Examples 2-5

[0055] A composite nylon powder for printing rollers differs from Example 1 in that the components and their corresponding weights (kg) are shown in the table below.

[0056]

[0057] The abrasion resistance, bonding strength and impact resistance of the composite nylon powders for printing rollers prepared in Examples 1 to 5 were tested, and the test results are shown in the table below.

[0058] Test item group Wear amount / mg Bond strength / MPa Impact resistance / cm Example 1 175 30.0 14.5 Example 2 177 29.5 14.2 Example 3 180 29.1 13.8 Example 4 195 26.4 9.9 Example 5 192 27.0 10.6

[0059] Data analysis of the table above shows that the composite nylon powder for printing rollers prepared in Examples 1-3 has a wear amount as low as 175-180 mg, a bonding strength as high as 29.1-30.0 MPa, and an impact resistance as high as 13.8-14.5 cm. Compared with the composite nylon powder for printing rollers prepared in Examples 4 and 5, the composite nylon powder for printing rollers prepared in Examples 1-3 has a lower wear amount, higher bonding strength, and higher impact resistance. This indicates that by optimizing the addition amount of each raw material in the total raw materials for preparing the composite nylon powder for printing rollers in this application, the mechanical properties and bonding strength of the composite nylon powder for printing rollers can be improved.

[0060] Example 6

[0061] A composite nylon powder for printing rollers differs from Example 1 in that the wetting and dispersing agent mixture is composed of hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A mixed in a weight ratio of 1:0.6.

[0062] Example 7

[0063] A composite nylon powder for printing rollers differs from Example 1 in that the wetting and dispersing agent mixture is composed of hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A mixed in a weight ratio of 1:1.0.

[0064] Example 8

[0065] A composite nylon powder for printing rollers differs from Example 1 in that the wetting and dispersing agent mixture is composed of zinc stearate and lubricant CYD-816A mixed in a weight ratio of 1:0.8.

[0066] Example 9

[0067] A composite nylon powder for printing rollers differs from Example 1 in that the adhesive reinforcing agent is γ-aminopropyltriethoxysilane.

[0068] The abrasion resistance, bonding strength and impact resistance of the composite nylon powder for printing rollers prepared in Examples 1, 6 to 9 were tested, and the test results are shown in the table below.

[0069] Test item group Wear amount / mg Bond strength / MPa Impact resistance / cm Example 1 175 30.0 14.5 Example 6 185 28.2 13.0 Example 7 183 28.5 13.5 Example 8 190 27.5 11.8 Example 9 188 27.8 12.4

[0070] Data analysis of the table above shows that the composite nylon powders for printing rollers prepared in Examples 1, 6, and 7 exhibit a wear rate as low as 175–185 mg, a bonding strength as high as 28.2–30.0 MPa, and an impact resistance as high as 13.0–14.5 cm. This indicates that the wetting and dispersing agent mixture in the total raw materials for preparing the composite nylon powders for printing rollers in this application, composed of hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A mixed at a weight ratio of 1:(0.6–1.0), all possess excellent mechanical properties and adhesive strength.

[0071] Meanwhile, compared to the composite nylon powder for printing rollers prepared in Example 8, the composite nylon powders for printing rollers prepared in Examples 1, 6, and 7 exhibit lower wear, higher bonding strength, and better impact resistance. This indicates that the wetting and dispersing agent mixture consisting of hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A in the total raw materials for preparing the composite nylon powder for printing rollers in this application can improve the mechanical properties and adhesive strength of the composite nylon powder for printing rollers.

[0072] Meanwhile, compared to the composite nylon powder for printing rollers prepared in Example 9, the composite nylon powder for printing rollers prepared in Example 1 exhibits lower wear, higher bonding strength, and better impact resistance. This indicates that, in the total raw materials for preparing the composite nylon powder for printing rollers of this application, the bonding enhancer, N-phenyl-γ-aminopropyltrimethoxysilane, can improve the bonding strength of the composite nylon powder for printing rollers.

[0073] Comparative Example

[0074] Comparative Example 1

[0075] A composite nylon powder for printing rollers differs from Example 1 in that the wetting and dispersing agent mixture is composed of hydroxyethyl ethylene bis-stearamide and polyethylene wax in a weight ratio of 1:0.8.

[0076] Comparative Example 2

[0077] A composite nylon powder for printing rollers differs from Example 1 in that the wetting and dispersing agent mixture is composed of polyethylene wax and lubricant CYD-816A mixed in a weight ratio of 1:0.8.

[0078] The abrasion resistance, bonding strength, and impact resistance of the composite nylon powders for printing rollers prepared in Example 1, Comparative Examples 1 and 2 were tested, and the test results are shown in the table below.

[0079] Test item group Wear amount / mg Bond strength / MPa Impact resistance / cm Example 1 175 30.0 14.5 Comparative Example 1 256 23.4 7.6 Comparative Example 2 247 24.1 8.0

[0080] Data analysis of the table above shows that the composite nylon powder for printing rollers prepared in Comparative Examples 1 and 2 has an abrasion amount as high as 247-256 mg, a bonding strength as low as 23.4-24.1 MPa, and an impact resistance as low as 7.6-8.0 cm.

[0081] Compared to the composite nylon powder for printing rollers prepared in Comparative Examples 1 and 2, the composite nylon powder for printing rollers prepared in Example 1 exhibits lower wear, higher bonding strength, and better impact resistance. This indicates that the wetting and dispersing agent mixture in the total raw materials for preparing the composite nylon powder for printing rollers of this application, comprising two or more of hydroxyethyl ethylene bis-stearamide, zinc stearate, and lubricant CYD-816A, can improve the mechanical properties and adhesive strength of the composite nylon powder for printing rollers.

[0082] When testing the abrasion resistance of the composite nylon powder for printing rollers prepared in Examples 1-9 and Comparative Examples 1 and 2, visual inspection of the coating surface revealed that the coatings formed in Examples 1-9 had smooth and flat surfaces, while the coatings formed in Comparative Examples 1 and 2 were relatively rough. This indicates that the composite nylon powder for printing rollers prepared in Examples 1-9 of this application, after adhesion, exhibits good printing accuracy.

[0083] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A composite nylon powder for printing rollers, characterized in that, It consists of the following components by mass percentage: 82-90% nylon powder; 1-3% of the wetting and dispersing agent mixture; Adhesion reinforcing agent 2-5%; Filler content: 5-10%; The wetting and dispersing agent mixture includes two or more of hydroxyethyl ethylene bis-stearamide, zinc stearate, and lubricant CYD-816A.

2. The composite nylon powder for printing rollers according to claim 1, characterized in that, The wetting and dispersing agent mixture is composed of hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A.

3. The composite nylon powder for printing rollers according to claim 2, characterized in that, The wetting and dispersing agent mixture is composed of hydroxyethyl ethylene bis-stearamide and lubricant CYD-816A mixed in a weight ratio of 1:(0.6 to 1.0).

4. The composite nylon powder for printing rollers according to claim 1, characterized in that, The filler includes silicon dioxide or silicon carbide micro powder.

5. The composite nylon powder for printing rollers according to claim 4, characterized in that, The bonding enhancer is an aminosilane coupling agent.

6. The composite nylon powder for printing rollers according to claim 5, characterized in that, The aminosilane coupling agent is γ-aminopropyltriethoxysilane or N-phenyl-γ-aminopropyltrimethoxysilane.

7. The composite nylon powder for printing rollers according to claim 5, characterized in that, The composite nylon powder for the printing rollers is composed of the following components by mass percentage: 82-90% nylon powder; 1-3% of the wetting and dispersing agent mixture; 2-3% N-phenyl-γ-aminopropyltrimethoxysilane; 8-10% silica.

8. The method for preparing the composite nylon powder for printing rollers according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1: After mixing the adhesive reinforcing agent and filler, a filler mixture is obtained; After mixing the nylon powder and wetting and dispersing agent mixture, the filler mixture is added and stirred to obtain the mixture. S2: The mixture is melt-co-extruded, granulated, and crushed to obtain composite nylon powder for printing rollers.

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