POM composition as well as preparation method and application thereof

Abstract

The invention provides a POM composition as well as a preparation method and application thereof. The POM composition comprises the following components in parts by weight: 100 parts of polyformaldehyde resin; 10 to 20 parts of SEBS resin; 1-5 parts of a lubricant; wherein the lubricant is glyceryl monostearate and / or 2-monopalmitic acid glycerol. According to the invention, the polyformaldehyde resin is adopted as matrix resin, and the SEBS resin and the specific lubricant are added, so that the wear resistance and noise problems can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and more specifically, to a POM composition and a preparation method and application thereof. Background Art

[0002] Polyoxymethylene resin (POM) is a resin with excellent mechanical properties, heat resistance, chemical resistance and wear resistance, so it is widely used in industrial equipment, office equipment, home appliances, automobiles and other fields. However, with the complexity and diversification of various parts, higher requirements are placed on the sliding performance and wear resistance of parts. For example, the wear loss of door stoppers and gears in printers is required to reach 100*10 -3 mm 3 / N·km, friction noise is required to be below 75dB.

[0003] In the prior art, lubricants are often added to POM resin to improve sliding performance and wear resistance, but the improvement of wear resistance and noise value is limited, and it cannot meet higher requirements, which limits its application. Therefore, the art needs a wear-resistant POM composition with lower noise. Summary of the invention

[0004] The object of the present invention is to provide a POM composition in order to overcome the defects or shortcomings in the above-mentioned prior art.

[0005] Another object of the present invention is to provide a method for preparing the POM composition.

[0006] Another object of the present invention is to provide applications of the POM composition.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] A POM composition, comprising the following components calculated in parts by weight:

[0009] 100 parts of polyoxymethylene resin;

[0010] 10-20 parts of SEBS resin;

[0011] 1 to 5 parts of lubricant;

[0012] Wherein, the lubricant is glyceryl monostearate and / or 2-monopalmitoylglycerol.

[0013] The present invention provides a POM composition, which adopts POM resin as a base resin, is added with hydrogenated styrene-butadiene-styrene block copolymer resin (SEBS resin) and a specific lubricant, wherein the main chain of the hydrogenated styrene-butadiene-styrene copolymer is a polyethylene segment with a relatively low polarity, which can provide wear resistance, and can be used as an elastomer to give full play to its damping effect, effectively reduce noise in friction, and make the prepared POM composition have good wear resistance and a relatively low noise value.

[0014] It should be noted that the content of polyoxymethylene resin in the POM composition of the present invention is preferably not less than 75 wt %.

[0015] It should be noted that the SEBS resin described in the present invention is 10 to 20 parts, specifically 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts or 20 parts, etc., as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the specific points included in the range are no longer exhaustively listed in the present invention.

[0016] The lubricant is 1 to 5 parts, specifically 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.2 parts, 3.5 parts, 3.8 parts, 4 parts, 4.2 parts, 4.5 parts, 4.8 parts or 5 parts, etc., as well as specific point values ​​between the above points. Due to space limitations and for the sake of simplicity, the specific point values ​​included in the said range are no longer exhaustively listed in the present invention.

[0017] Furthermore, the POM composition comprises the following components calculated by weight:

[0018] 100 parts of polyoxymethylene resin;

[0019] 12-17 parts of SEBS resin;

[0020] 1.5 to 3 parts of lubricant.

[0021] Furthermore, the lubricant is a mixture of glyceryl monostearate and 2-monopalmitoylglycerol. The POM composition prepared by using the compounded lubricant has better wear resistance and lower noise value.

[0022] Specifically, the lubricant is glyceryl monostearate and 2-monopalmitoylglycerol in a mass ratio of 1:(0.3-2), for example but not limited to 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.2, 1:1.4, 1:1.5, 1:1.8, 1:2, etc., as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the specific point values ​​included in the range are no longer exhaustively listed in the present invention.

[0023] Furthermore, the lubricant is glyceryl monostearate and 2-monopalmitoylglycerol in a mass ratio of 1: (0.5-1).

[0024] Furthermore, the melt flow rate of the polyoxymethylene resin at 190° C. and 2.16 kg is 5 to 25 g / 10 min.

[0025] Specifically, the test standard of the melt flow rate is ISO 1133-2022.

[0026] Specifically, the polyoxymethylene resin may be a homopolymer polyoxymethylene resin and / or a copolymer polyoxymethylene resin.

[0027] Furthermore, the viscosity of the SEBS resin is not less than 400 cP.

[0028] Furthermore, the viscosity of the SEBS resin is not higher than 2000 cP.

[0029] Specifically, the viscosity of the SEBS resin is tested according to standard ASTM D2196-2015.

[0030] Specifically, the viscosity is measured at 25° C. with a 20 wt % toluene solution.

[0031] Furthermore, the styrene content in the SEBS resin is not less than 25wt%.

[0032] Furthermore, the styrene content in the SEBS resin is 25-40wt%.

[0033] Specifically, the method for determining the styrene content is infrared absorption spectroscopy.

[0034] Specifically, the SEBS resin is star-shaped SEBS and / or linear SEBS.

[0035] Furthermore, the POM composition further includes 0.1 to 5 parts of auxiliary agents.

[0036] Specifically, the auxiliary agent includes but is not limited to one or more of an antioxidant, a formaldehyde absorber, a weathering agent or a toner.

[0037] The present invention can select commonly used antioxidants according to the prior art, for example, but not limited to, the antioxidant is one or more of hindered phenols, phosphite antioxidants or thioester antioxidants.

[0038] Specifically, the hindered phenol antioxidant is one or more of N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide) (Irganox 1098), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1010), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (Irganox 259), β-(4-hydroxy-3,5-di-tert-butylphenyl)propionic acid n-octadecyl (Irganox 1076) or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylate]-1,1-dimethyl}-2,4,8,10-tetraoxaspirocycloundecane (ADK AO-80).

[0039] The phosphite antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite (Irganox 168), bis(2,6-di-tert-butyl-4-tolyl) pentaerythritol phosphite (PEP-36) or 627A.

[0040] The thioether antioxidant is one or more of distearyl thiodipropionate, dilauryl thiodipropionate or pentaerythritol dodecapropylthioate.

[0041] The present invention can select commonly used formaldehyde absorbents according to the prior art, for example but not limited to, the formaldehyde absorbent is one or more of allantoin, dicyandiamide or melamine.

[0042] The present invention can select commonly used weathering agents according to the prior art, for example but not limited to, the weathering agent is an ultraviolet absorber and / or a light stabilizer.

[0043] The present invention also provides a method for preparing the above-mentioned POM composition, comprising the following steps:

[0044] The components are mixed uniformly according to proportion, and the POM composition is obtained by melt extrusion, cooling and granulation.

[0045] Specifically, the melt extrusion adopts a twin-screw extruder.

[0046] Specifically, the temperature of zone 1 of the twin-screw extruder is 130-170°C, the temperature of zone 2 is 190-210°C, the temperature of zone 3 is 190-220°C, the temperature of zone 4 is 200-220°C, the temperature of zones 5 to 9 is 190-220°C, and the temperature of zone 10 is 180-200°C; the screw speed of the twin-screw extruder is 250-350rpm.

[0047] The present invention also protects the use of the above-mentioned POM composition in the preparation of automobile accessories or office accessories, especially gears, shafts, door stoppers, rearview mirror steering shafts or steering wheel steering columns.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The invention provides a POM composition. By adopting POM resin as a base resin and adding SEBS resin and a specific lubricant, the noise value of POM can be further reduced and the wear resistance of POM can be improved. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present invention will be described clearly and completely below, but the implementation manner of the present invention is not limited thereto.

[0051] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0052] 1. The raw materials used in the following examples and comparative examples are as follows:

[0053] Polyoxymethylene resin:

[0054] POM1: M90-44, purchased from Polytechnics Co., Ltd.;

[0055] POM2: POM 3010, purchased from Asahi Kasei Corporation;

[0056] SEBS resin:

[0057] SEBS resin 1: GLOBALPRENE 7551, viscosity 2000 cP, styrene content 30 wt%, purchased from Huizhou Li Changrong Rubber Co., Ltd.;

[0058] SEBS resin 2: GLOBALPRENE 7550, viscosity 1850 cP, styrene content 30 wt%, purchased from Huizhou Li Changrong Rubber Co., Ltd.;

[0059] SEBS resin 3: GLOBALPRENE 7533, viscosity 400 cP, styrene content 30 wt%, purchased from Huizhou Li Changrong Rubber Co., Ltd.;

[0060] SBS resin 1: KTR 301, styrene content 31.5 wt%, purchased from Kumho Petrochemical Co., Ltd., South Korea;

[0061] Lubricant:

[0062] Lubricant 1: glyceryl monostearate, purchased from MacLean Reagent Company;

[0063] Lubricant 2: 2-monopalmitoylglycerol, purchased from MacLean Reagent Company;

[0064] Lubricant 3: laurin, purchased from MacLean Reagent Company;

[0065] Additives:

[0066] Antioxidant: Irganox 168; commercially available;

[0067] Formaldehyde absorbent: allantoin, commercially available; it should be noted that the same raw materials are used in the parallel experiments of various embodiments and comparative examples.

[0068] 2. The POM compositions described in the examples and comparative examples were prepared according to the formulations in Tables 1 to 2 by the following preparation methods:

[0069] The components are put into a high-speed mixer in proportion and mixed evenly, and the POM composition is obtained by melt-extrusion and cooling and granulation through a twin-screw extruder; the temperature of zone 1 of the twin-screw extruder is 150°C, the temperature of zone 2 is 200°C, the temperature of zone 3 is 205°C, the temperature of zone 4 is 210°C, the temperature of zones 5 to 9 is 205°C, and the temperature of zone 10 is 190°C; the screw speed of the twin-screw extruder is 300rpm.

[0070] 3. Performance Testing

[0071] Wear resistance and noise test: The POM compositions prepared in the examples and comparative examples were tested with reference to JISK 7218-1986, with a rotation speed of 0.8 m / s, a load of 10 N, a rotation distance of 3 km, and the noise was tested using a noise tester during friction; each sample was measured twice and the average value was taken.

[0072] Examples 1 to 11 and Comparative Examples 1 to 2

[0073] Table 1 Formulation (unit: weight parts) and properties of POM compositions in Examples 1 to 11

[0074]

[0075] Table 2 Formula (unit: weight parts) and properties of POM compositions in Comparative Examples 1 to 2

[0076] Comparative Example 1 2 POM1 100 100 SEBS1 / 12.5 SBS 12.5 / Lubricant 1 2 / Lubricant 2 1 / Lubricant 3 / 3 Antioxidants 1 1 Formaldehyde absorbent 1 1 <![CDATA[Specific wear rate (10 -3 mm 3 / N·km)]]> 196.3 143.5 Noise(dB) 92 81

[0077] It can be seen from Table 1 that the POM composition prepared in the present invention has good wear resistance and low noise performance, specifically: the specific wear amount does not exceed 100*10 -3 mm 3 / N·km, noise level is not higher than 75dB.

[0078] It can be seen from Example 1 and Examples 5 to 7 and 11 that when the lubricant is a mixture of glyceryl monostearate and 2-monopalmitin, the comprehensive performance of the obtained POM composition is better; the preferred lubricant is glyceryl monostearate and 2-monopalmitin in a mass ratio of 1: (0.5 to 1).

[0079] It can be seen from Comparative Example 1 that if other resins are used instead of the SEBS resin in the present invention, the wear resistance of the prepared POM composition decreases and the noise value increases.

[0080] It can be seen from Comparative Example 2 that if other lubricants are used instead of the lubricant in the present invention, a POM composition with lower specific wear and noise cannot be prepared.

[0081] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A POM composition, characterized in that: The composition comprises the following components calculated by weight: 100 parts of polyoxymethylene resin; 10-20 parts of SEBS resin; 1 to 5 parts of lubricant; Wherein, the lubricant is glyceryl monostearate and / or 2-monopalmitoylglycerol.

2. The POM composition according to claim 1, characterized in that: The composition comprises the following components calculated by weight: 100 parts of polyoxymethylene resin; 12-17 parts of SEBS resin; 1.5 to 3 parts of lubricant.

3. The POM composition according to claim 1 or 2, characterized in that: The lubricant is a mixture of glyceryl monostearate and 2-monopalmitoylglycerol.

4. The POM composition according to claim 1 or 2, characterized in that: The lubricant is glyceryl monostearate and 2-monopalmitoylglycerol in a mass ratio of 1: (0.3-2).

5. The POM composition according to claim 1 or 2, characterized in that: The melt flow rate of the polyoxymethylene resin at 190° C. and 2.16 kg is 5 to 25 g / 10 min.

6. The POM composition according to claim 1 or 2, characterized in that: The styrene content in the SEBS resin is not less than 25wt%.

7. The POM composition according to claim 1 or 2, characterized in that: The SEBS resin is star-shaped SEBS and / or linear SEBS.

8. The POM composition according to claim 1 or 2, characterized in that: It also includes 0.1 to 5 parts of auxiliary agents.

9. A method for preparing the POM composition according to any one of claims 1 to 8, characterized in that: The steps include: The components are mixed uniformly according to proportion, and the POM composition is obtained by melt extrusion, cooling and granulation.

10. Use of the POM composition according to any one of claims 1 to 8 in the preparation of automobile accessories or office supplies accessories.

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