A pom composition, its preparation and use

Abstract

The application provides a POM composition, a preparation method and application thereof. The POM composition comprises the following components in parts by weight: 100 parts of polyoxymethylene resin; 10-20 parts of SEBS resin; and 1-5 parts of lubricant; wherein the lubricant is glycerol monostearate and / or 2-glycerol monopalmitate. The application can effectively improve the wear resistance and noise problem by using polyoxymethylene resin as a base resin, adding SEBS resin and specific lubricant.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and more specifically, to a POM composition, its preparation method, and its application. Background Technology

[0002] Polyoxymethylene (POM) resin is a resin with excellent mechanical properties, heat resistance, chemical resistance, and wear resistance, and is therefore widely used in industrial equipment, office equipment, home appliances, automobiles, and other fields. However, with the increasing complexity and diversity of various parts, higher requirements are being placed on the sliding performance and wear resistance of components. For example, door limiters and gears in printers require a wear tolerance of 100*10 mm. -3 mm 3 / N·km, friction noise requirement is below 75dB.

[0003] Existing technologies often improve sliding and wear resistance by adding lubricants to POM resin. However, the improvement in wear resistance and noise levels is limited, failing to meet higher requirements and restricting its application. Therefore, there is a need in the art for a wear-resistant POM composition with lower noise. Summary of the Invention

[0004] The purpose of this invention is to provide a POM composition in order to overcome the defects or deficiencies existing in the 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 the application of the POM composition.

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

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

[0009] 100 parts of polyoxymethylene resin;

[0010] 10-20 parts of SEBS resin;

[0011] 1-5 parts lubricant;

[0012] The lubricant is glyceryl monostearate and / or glyceryl 2-monopalmitoate.

[0013] This invention provides a POM composition using POM resin as the base resin, with the addition of hydrogenated styrene-butadiene-styrene block copolymer resin (SEBS resin) and a specific lubricant. The main chain of the hydrogenated styrene-butadiene-styrene copolymer is polyethylene segment with low polarity, which provides wear resistance. At the same time, it can act as an elastomer, which can fully exert its damping effect and effectively reduce noise during friction. This results in a POM composition with good wear resistance and low noise level.

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

[0015] It should be noted that the SEBS resin mentioned in this 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, as well as specific point values ​​between the above-mentioned point values. Due to space limitations and for the sake of brevity, the specific point values ​​included in the range will not be exhaustively listed in this 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, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the specific values ​​included in the range will not be exhaustively listed in this invention.

[0017] Further, the POM composition comprises the following components in parts 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 glyceryl 2-monopalmitoate. POM compositions prepared using this compounded lubricant exhibit better wear resistance and lower noise levels.

[0022] Specifically, the lubricant is glyceryl monostearate and glyceryl 2-monopalmitoate in a mass ratio of 1:(0.3-2), such as, 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 values ​​between the above values. Due to space limitations and for the sake of brevity, the specific values ​​included in the range will not be exhaustively listed in this invention.

[0023] Furthermore, the lubricant is glyceryl monostearate and glyceryl 2-monopalmitoate 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 5–25 g / 10 min.

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

[0026] Specifically, the polyoxymethylene resin may be homopolymer polyoxymethylene resin and / or 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 was tested according to standard ASTM D2196-2015.

[0030] Specifically, the viscosity of the 20wt% toluene solution was measured at 25°C.

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

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

[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 additives.

[0036] Specifically, the additives include, but are not limited to, one or more of antioxidants, formaldehyde absorbents, weathering agents, or colorants.

[0037] The present invention can select commonly used antioxidants based on existing technology, such as, but not limited to, one or more of hindered phenolic, phosphite antioxidants or thioester antioxidants.

[0038] Specifically, the hindered phenolic antioxidant is one or more of N,N'-hexamethylene bis(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), octadecyl β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate (Irganox 1076), or 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)acrylic acid]-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 antioxidants include one or more of distearate thiodipropionate, dilaurate thiodipropionate, or pentaerythritol-based dodecathiopropyl ester.

[0041] The present invention can select commonly used formaldehyde absorbents based on existing technology, such as, but not limited to, allantoin, dicyandiamide or melamine, one or more of these.

[0042] The present invention may select commonly used weathering agents based on existing technology, such as, but not limited to, ultraviolet absorbers and / or light stabilizers.

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

[0044] The components are mixed evenly in proportion, and then melt-extruded, cooled and granulated to obtain the POM composition.

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

[0046] Specifically, the temperature of the twin-screw extruder is 130-170℃ in zone one, 190-210℃ in zone two, 190-220℃ in zone three, 200-220℃ in zone four, 190-220℃ in zones five to nine, and 180-200℃ in zone ten; the screw speed of the twin-screw extruder is 250-350 rpm.

[0047] This invention also protects the use of the above-mentioned POM composition in the manufacture of automotive or office supplies parts, especially gears, shafts, door limiters, rearview mirror steering shafts or steering column.

[0048] Compared with the prior art, the beneficial effects of the present invention are:

[0049] This invention provides a POM composition that, by using POM resin as the base resin and adding SEBS resin and a specific lubricant, can further reduce the noise level of POM and improve its wear resistance. Detailed Implementation

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

[0051] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[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 31.5wt%, purchased from Kumho Petrochemical Co., Ltd., South Korea;

[0061] Lubricant:

[0062] Lubricant 1: Glyceryl monostearate, purchased from Maclean's Reagent Company;

[0063] Lubricant 2: 2-Monopalmitoylglycerol, purchased from Maclean's Reagent Company;

[0064] Lubricant 3: Glyceryl laurate, purchased from Maclean's 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 were used in the parallel experiments of each example and comparative example.

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

[0069] The components are added to a high-speed mixer in proportion and mixed evenly. The mixture is then melt-extruded through a twin-screw extruder, cooled, and granulated to obtain a POM composition. The temperature of the twin-screw extruder is 150°C in zone 1, 200°C in zone 2, 205°C in zone 3, 210°C in zone 4, 205°C in zones 5 to 9, and 190°C in zone 10. The screw speed of the twin-screw extruder is 300 rpm.

[0070] 3. Performance Testing

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

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

[0073] Table 1. Formulations (parts by weight) and properties of the POM compositions in Examples 1-11

[0074]

[0075] Table 2. Formulations (parts by weight) and properties of the POM compositions in Comparative Examples 1-2

[0076] 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 abrasion (10 -3 mm 3 / N·km)]]> 196.3 143.5 Noise (dB) 92 81

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

[0078] As can be seen from Examples 1 and 5-7, 11, the POM composition has better overall performance when the lubricant is a mixture of glyceryl monostearate and glyceryl 2-monopalmitoate; the preferred lubricant is glyceryl monostearate and glyceryl 2-monopalmitoate in a mass ratio of 1:(0.5-1).

[0079] As can be seen from Comparative Example 1, if other resins are used instead of the SEBS resin in this invention, the wear resistance of the resulting POM composition decreases and the noise level increases.

[0080] As can be seen from Comparative Example 2, if other lubricants are used instead of the lubricant in this invention, it is impossible to obtain a POM composition with lower specific wear and noise.

[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 implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A POM composition, characterized in that, Includes the following components, calculated in parts by weight: 100 parts of polyoxymethylene resin; 10-20 parts of SEBS resin; 1-5 parts lubricant; The lubricant is a mixture of glyceryl monostearate and glyceryl 2-monopalmitoate; the styrene content in the SEBS resin is not less than 25 wt%.

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

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

4. The POM composition according to claim 1 or 2, characterized in that, The polyoxymethylene resin has a melt flow rate of 5~25g / 10min at 190℃ and 2.16kg.

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

6. The POM composition according to claim 1 or 2, characterized in that, It also includes 0.1 to 5 parts of adjuvants.

7. A method for preparing the POM composition according to any one of claims 1 to 6, characterized in that, Includes the following steps: The components are mixed evenly in proportion, and then melt-extruded, cooled and granulated to obtain the POM composition.

8. The use of the POM composition according to any one of claims 1 to 6 in the preparation of automotive parts or office supplies parts.

Images