Resin compositions for sliding members, extruded articles, automotive parts, and weatherstrips

Abstract

To provide a resin composition for a sliding member which is excellent in followability and slidability under a high load, and is also excellent in moldability and workability, and an extrusion molding, a component for an automobile and a weather strip which are made of the resin composition for the sliding member.SOLUTION: A resin composition for a sliding member contains a non-crosslinked olefinic resin component including a propylene unit and an ethylene unit, and polyorganosiloxane, wherein the polyorganosiloxane is composed of polyorganosiloxane (P1) having dynamic viscosity (25°C) of 100,000 mm2 / s or more and polyorganosiloxane (P2) having dynamic viscosity (25°C) of 50,000 mm2 / s or less. There is also provided an extrusion molding of the resin composition for the sliding member. A component for an automobile has the resin composition for the sliding member. A weather strip has a base material, and a sliding member made of the resin composition for the sliding member.SELECTED DRAWING: Figure 1

Description

[Technical Field] 【0001】 The present invention relates to a resin composition for sliding members, and to an extruded article, an automobile part, and a weatherstrip made from this resin composition for sliding members. [Background technology] 【0002】 Weatherstrips, which are installed on the window frames of car doors, are automotive parts designed to prevent rain, wind, foreign objects, and other elements from entering the vehicle. A weatherstrip has a base material made of a resin such as a propylene polymer, and a sliding part that is laminated on a portion of the base material. This sliding part is sealed to the window frame so that it contacts the glass window. Therefore, the sliding members that make up the sliding part are required to have sliding properties that do not hinder the smooth operation of the glass window when it is opened and closed. As sliding members, those generally known to consist of compositions in which various additives are added to an olefin-based resin component are known. 【0003】 One method has been proposed to use ultra-high molecular weight polyethylene as an additive to impart sliding properties to sliding members (see Patent Document 1). Furthermore, when an olefin-based resin component contains an ethylene-based resin, a method is known in which a portion of the ethylene-based resin is crosslinked to form an uneven surface on the molded article, thereby imparting sliding properties (see Patent Document 2). [Prior art documents] [Patent Documents] 【0004】 [Patent Document 1] Japanese Patent Publication No. 2016-204405 [Patent Document 2] Japanese Patent Publication No. 2002-20558 [Overview of the project] [Problems that the invention aims to solve] 【0005】 In recent years, in order to reduce vehicle noise, measures have been taken to strengthen the sealing performance by pressing the weatherstrip firmly against the window glass. In such operating conditions, the sliding members of the weatherstrip are required to have sliding properties that allow them to slide even under high loads against the glass, while ensuring that they can follow the glass and adequately seal the glass window. 【0006】 While the addition of ultra-high molecular weight polyethylene as a lubrication agent, as described in Patent Document 1, does indeed improve lubrication, the ultra-high molecular weight polyethylene is in powder form and difficult to handle. Furthermore, Patent Document 1 does not describe conformability, and the technology described in Patent Document 1 does not consider achieving both conformability and lubrication. 【0007】 The elastomer composition described in Patent Document 2 does not have sufficient sliding properties under high load. Furthermore, Patent Document 2 does not describe conformability, and the technology described in Patent Document 2 does not take into consideration the balance between conformability and sliding properties. 【0008】 While there is a technique that uses polyorganosiloxanes to achieve both conformability and sliding properties, polyorganosiloxanes have poor compatibility with olefin resins and tend to migrate to the surface side of the molded body. As a result, the polyorganosiloxanes become unevenly distributed on the surface of the molded body, and during use as a sliding member, the polyorganosiloxanes on the surface are discharged from the sliding member into the system. Therefore, over time, the desired sliding properties of the molded body may not be achieved. Furthermore, when manufacturing resin compositions, increasing the amount of polyorganosiloxane added to improve sliding properties tends to cause the polyorganosiloxane to migrate more easily to the surface of the resulting resin composition. When molded articles are made using such resin compositions, there is a problem where the pellets slide against each other in the resin input section during molding, resulting in poor pellet feeding into the molding machine and unstable product shape. In addition, during extrusion molding, polyorganosiloxane segregates, resulting in a processing defect called plate-out where deposits derived from polyorganosiloxane adhere to the outlet part of the molding machine. There was also a problem that the deposits generated by plate-out adhered to the surface of the molded body, deteriorating the appearance. 【0009】 An object of the present invention is to solve the problems of the above-mentioned conventional technologies, and to provide a resin composition for a sliding member that is excellent in followability and sliding property under high load, and also excellent in moldability and processability, an extruded molded body made of this resin composition for a sliding member, a component for an automobile, and a weatherstrip. 【Means for Solving the Problems】 【0010】 The present inventor has found that in a resin composition for a sliding member containing a non-crosslinked olefin resin component containing propylene units and ethylene units and polyorganosiloxane, by using two types of polyorganosiloxanes having different viscosities in combination, the resin composition for a sliding member can realize an extruded molded body, a component for an automobile, and a weatherstrip that are excellent in followability and sliding property under high load, and also excellent in moldability and processability, and has reached the present invention. 【0011】 That is, the gist of the present invention is as follows. 【0012】 [1] A resin composition for a sliding member containing a non-crosslinked olefin resin component containing propylene units and ethylene units and polyorganosiloxane, where the polyorganosiloxane is a resin composition for a sliding member comprising polyorganosiloxane (P1) having a kinematic viscosity (25°C) of 100,000 mm 2 / s or more and polyorganosiloxane (P2) having a kinematic viscosity (25°C) of 50,000 mm 2 / s or less. 【0013】 [2] The resin composition for a sliding member according to [1], wherein the ratio T1 / T2 of the content rate T1 (mass%) of propylene units and the content rate T2 (mass%) of ethylene units in the olefin resin component is 0.5 to 0.8. 【0014】 [3] A resin composition for sliding members according to [1] or [2], wherein the DuroD hardness (ISO 868) is 40 or more and 56 or less. 【0015】 [4] A resin composition for sliding members according to any one of [1] to [3], wherein the melt flow rate measured at a measurement temperature of 230°C and a measurement load of 21.2N in accordance with the JIS K7210 standard is 0.5 / 10 min or more and 25 g / 10 min or less. 【0016】 [5] A resin composition for sliding members according to any one of [1] to [4], comprising a total of 2 to 10 parts by mass of the polyorganosiloxane per 100 parts by mass of the olefin resin component. 【0017】 [6] The resin composition for sliding members according to any one of [1] to [5], wherein the olefin resin component contains the following components (A) and (B). Component (A): Propylene polymer Component (B): Ethylene polymer 【0018】 [7] The resin composition for sliding members according to [6], wherein, of 100% by mass of the olefin resin component, the content of component (A) is 30 to 60% by mass, and the content of component (B) is 40 to 70% by mass. 【0019】 [8] If the above component (B) has a density of 0.91 to 0.97 g / cm³ 3 A resin composition for sliding members according to [6] or [7], comprising polyethylene. 【0020】 [9] An extruded article of a resin composition for sliding members as described in any of [1] to [8]. 【0021】 Automotive part comprising an extruded body

[10] [9]. 【0022】

[11] A weatherstrip comprising a base material and a sliding member made of a resin composition for sliding members described in any of [1] to [8]. [Effects of the Invention] 【0023】 According to the present invention, it is possible to provide a resin composition for sliding members that is excellent in followability and sliding performance under high load, as well as excellent in moldability and processability, and an extruded molded article, an automobile part, and a weatherstrip made from this resin composition for sliding members. 【0024】 The resin composition and extruded articles for sliding members of the present invention are useful as sealing materials for automobiles and building materials due to their excellent conformability to glass and sliding properties under high loads. They are particularly useful as automotive parts such as automotive weatherstrips. [Brief explanation of the drawing] 【0025】 [Figure 1] This is a photograph showing the occurrence of plate-out during the processability evaluation of the resin composition of Example 1. [Figure 2] This is a photograph showing the occurrence of plate-out during the processability evaluation of the resin composition of Comparative Example 7. [Modes for carrying out the invention] 【0026】 The present invention will be described in detail below. The present invention is not limited to the following description and can be modified and implemented as appropriate without departing from the spirit of the invention. In this specification, when "~" is used to enclose numerical values ​​or physical properties, it is used to include the values ​​before and after it. 【0027】 [Resin composition for sliding components] The present invention relates to a resin composition for sliding members comprising a non-crosslinked olefin resin component containing propylene units and ethylene units, and a polyorganosiloxane, wherein the polyorganosiloxane has a kinematic viscosity (JIS Z8803, 25℃) of 100,000 mm². 2 Polyorganosiloxane (P1) with a viscosity of 50,000 mm² or higher (JIS Z8803, 25℃)2 It is composed of a polyorganosiloxane (P2) with a viscosity of less than / s. 【0028】 The kinematic viscosity (JIS Z8803, 25°C) of the polyorganosiloxane (P1) is preferably 300,000 mm 2 / s or more, more preferably 500,000 mm 2 / s or more. By using such a polyorganosiloxane (P1) with a relatively high viscosity, high effects can be expected in improving sliding durability and wear resistance. The upper limit of the kinematic viscosity (JIS Z8803, 25°C) of the polyorganosiloxane (P2) is preferably 20,000 mm 2 / s or less, more preferably 15,000 mm 2 / s or less. On the other hand, from the perspective of moldability, the lower limit of the kinematic viscosity (JIS Z8803, 25°C) of the polyorganosiloxane (P2) is preferably 10 mm 2 / s, more preferably 50 mm 2 / s. By using such a polyorganosiloxane (P2) with a relatively low viscosity, high effects can be expected in improving sliding properties and suppressing plate-out during molding. By using these polyorganosiloxanes (P1) and polyorganosiloxane (P2) in combination, it is possible to achieve high levels of both sliding properties, sliding durability, wear resistance, and the effect of suppressing plate-out during molding. 【0029】 [Mechanism] The details of the reason why the resin composition for a sliding member of the present invention exhibits the above-described effects are not clear, but are presumed as follows. It is presumed that the high-viscosity polyorganosiloxane (P1) has an effect of suppressing the precipitation of the low-viscosity polyorganosiloxane on the surface of the resin composition due to the thickening effect. It is considered that this effect suppresses molding defects caused by poor biting of the resin composition pellets into the molding machine. The low-viscosity polyorganosiloxane (P2) is presumed to function as a lubricant and a dispersant for the high-viscosity polyorganosiloxane (P1). It is considered that this effect suppresses processing defects caused by plate-out due to segregation of the high-viscosity polyorganosiloxane (P1) during molding. Also, by using two types of polyorganosiloxanes (P1) and (P2) with high and low viscosities in combination, it is presumed that these double effects occur, and a resin composition excellent in workability and moldability can be obtained while maintaining high slidability. 【0030】 Furthermore, in a resin composition containing a non-crosslinked olefin resin component containing propylene units and ethylene units and a polyorganosiloxane, when the ratio T1 / T2 of the content rate T1 (mass%) of propylene units and the content rate T2 (mass%) of ethylene units is 0.50 to 0.80, a co-continuous structure of polyethylene and polypropylene is formed, and a large number of interfaces where the polyorganosiloxane can be unevenly distributed can be designed to be formed in this structure. In a molded body using a resin composition having such a co-continuous structure, the polyorganosiloxane gradually seeps out to the sliding surface along the interface of the co-continuous structure from within the molded body due to repeated sliding. It is considered that excellent slidability can be obtained in this way. 【0031】 [Physical Properties of Resin Composition for Sliding Member] <DuroD Hardness> The resin composition for a sliding member of the present invention preferably has a DuroD hardness of 40 to 56 measured in reference to the ISO 868 standard. When the DuroD hardness is 40 or more, the slidability is excellent. The DuroD hardness of the resin composition for a sliding member of the present invention is preferably 43 or more. On the other hand, when the DuroD hardness is 56 or less, the followability is excellent. The DuroD hardness of the resin composition for a sliding member of the present invention is preferably 55 or less. Particularly, when the DuroD hardness is in the range of 43 to 55, a sliding member with an even better balance of slidability and followability under high load can be obtained. 【0032】 <Meltflow Rate> The resin composition for sliding members of the present invention preferably has a melt flow rate (MFR) of 0.5 g / 10 min or more, measured at a temperature of 230°C and a load of 21.2 N, based on the JIS K7210 standard, from the viewpoint of reducing the load on the molding machine, more preferably 0.7 g / 10 min or more, and even more preferably 1 g / 10 min or more. On the other hand, from the viewpoint of moldability during molding, the melt flow rate (MFR) of the resin composition for sliding members of the present invention is preferably 25 g / 10 min or less, more preferably 20 g / 10 min or less, and even more preferably 15 g / 10 min or less. 【0033】 [Olefin-based resin components] The resin composition for sliding members of the present invention contains a non-crosslinked olefin resin component containing propylene units and ethylene units. Preferably, the resin composition for sliding members of the present invention contains the olefin resin component such that the ratio T1 / T2 (hereinafter sometimes simply referred to as "T1 / T2") of the propylene unit content T1 (mass%) to the ethylene unit content T2 (mass%) is 0.50 to 0.80. More preferably, T1 / T2 is 0.55 to 0.80, and even more preferably 0.60 to 0.80. By setting T1 / T2 within the above range, it is possible to achieve a higher level of both the ability to follow glass windows and the sliding performance under high loads required for sliding members. 【0034】 The olefin resin component is not particularly limited as long as it is a non-crosslinked olefin resin component containing propylene units and ethylene units. However, from the viewpoint of easily controlling the T1 / T2 ratio described above, the olefin resin component according to the present invention preferably contains the following components (A) and (B). Details of these components (A) and (B) will be described later. Component (A): Propylene polymer Component (B): Ethylene polymer 【0035】 The propylene unit content T1 and the ethylene unit content T2 in an olefin resin component containing the above components (A) and (B) can be determined, for example, as follows. In an olefin-based resin component, component (A) contains component (A-1), component (A-2)... component (An), and component (B) contains component (B-1), component (B-2)... component (Bn), the olefin-based resin component content (mass%) of each component, the propylene unit content (mass%) in each component, and the ethylene unit content (mass%) are as follows: Content of component (A-1) in the olefin resin component: M(A-1) by mass % Content of component (A-2) in the olefin resin component: M(A-2) by mass % : : Content of component (An) in olefin resin components: M(An) by mass % Content of component (B-1) in olefin resin components: M(B-1) by mass % Content of component (B-2) in olefin resin components: M(B-2) by mass % : : Content of component (Bn) in olefin resin components: M(Bn) by mass % Propylene unit content in component (A-1): P(A-1) by mass % Propylene unit content in component (A-2): P(A-2) by mass % : : Propylene unit content in component (An): P(An) mass% Ethylene unit content in component (A-1): E(A-1) by mass % Ethylene unit content in component (A-2): E(A-2) by mass % : : Ethylene unit content in component (An): E(An) mass% Propylene unit content in component (B-1): P(B-1) by mass % Propylene unit content in component (B-2): P(B-2) by mass % : : Propylene unit content in component (Bn): P(Bn) mass% Ethylene unit content in component (B-1): E(B-1) by mass % Ethylene unit content in component (B-2): E(B-2) by mass % : : Ethylene unit content in component (Bn): E(Bn) mass% Therefore, the content T1 of propylene units and T2 of ethylene units as olefin resin components can be calculated as follows. T1={M(A-1)×P(A-1)+M(A-2)×P(A-2)+………+M(An)×P(An)+M(B-1)×P(B-1)+M(B-2)×P(B-2)………+M(Bn)×P(Bn)} / 100 T2={M(A-1)×E(A-1)+M(A-2)×E(A-2)+………+M(An)×E(An)+M(B-1)×E(B-1)+M(B-2)×E(B-2)………+M(Bn)×E(Bn)} / 100 【0036】 As described above, the T1 / T2 ratio in the resin composition for sliding members of the present invention is preferably 0.50 to 0.80, more preferably 0.55 to 0.80, and even more preferably 0.60 to 0.80. Therefore, the T1 / T2 ratio of the olefin resin component contained in the resin composition for sliding members of the present invention is preferably 0.50 to 0.80, more preferably 0.55 to 0.80, and even more preferably 0.60 to 0.80. 【0037】 <Component (A): Propylene polymer> The propylene polymer of component (A) used in the olefin resin component is not particularly limited, and any propylene homopolymer, propylene copolymer (block copolymer or random copolymer of propylene units and other monomer units) can be used. Here, a propylene copolymer refers to a copolymer in which the propylene unit content is 50% by mass or more. 【0038】 If the propylene polymer of component (A) is a propylene copolymer, other monomers copolymerized with propylene include 2- or 4-12 carbon olefins such as ethylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene; cyclic olefins such as cyclopentene, norbornene, and tetracyclo[6,2,11,8,13,6]-4-dodecene; and 5-methylene-2-norbornene. Examples of other copolymer components include norbornene such as 5-ethylidene-2-norbornene; dienes such as 1,4-hexadiene, methyl-1,4-hexadiene, and 7-methyl-1,6-octadiene; and vinyl monomers such as vinyl chloride, vinylidene chloride, acrylonitrile, vinyl acetate, acrylic acid, methacrylic acid, maleic acid, ethyl acrylate, butyl acrylate, methyl methacrylate, maleic anhydride, styrene, methylstyrene, vinyltoluene, and divinylbenzene, but are not particularly limited to these. These other copolymer components may be used individually or in combination of two or more. 【0039】 The polypropylene polymer of component (A) preferably has a melt flow rate (MFR; ASTM D 1238, 230°C, load 21.2N) of 0.3 to 25 g / 10 min, and more preferably 0.3 to 20 g / 10 min. By using a polypropylene polymer of component (A) having such an MFR, good moldability and excellent appearance can be ensured. 【0040】 Furthermore, the propylene polymer of component (A) has a density (JIS K7112) of 0.85 to 0.92 g / cm³. 3 It is preferable that it be within the range. 【0041】 The propylene polymer of component (A) can be obtained by known manufacturing methods. These manufacturing methods are disclosed in detail in, for example, Japanese Patent Publication No. 50-108385, Japanese Patent Publication No. 50-126590, Japanese Patent Publication No. 51-20297, Japanese Patent Publication No. 51-28189, and Japanese Patent Publication No. 52-151691, and the techniques described therein can also be used in the present invention. 【0042】 Furthermore, the propylene polymer of component (A) may be a commercially available product. Examples of commercially available components (A) include PRIME Polypro® from Prime Polymer, Sumitomo Noblen® from Sumitomo Chemical, Polypropylene Block Copolymer from Sun Allomer, Novatec® PP from Nippon Polypropylene, Tuffmer® and Waymax® from Mitsui Chemicals, Moplen® from LyondellBasell, ExxonMobil PP from ExxonMobil, Versify® from Dow Chemical, Formolene® from Formosa Plastics, Borealis PP from Borealis, Seetec PP from LG Chemical, ASI Polypropylene from A. Schulman, INEOS PP from INEOS Olefins & Polymers, Braskem PP from Braskem, and Samsung Total Petrochemicals from Samsung Examples include Total, Sabic® PP manufactured by Sabic, TOTAL PETROCHEMICALS Polypropylene manufactured by TOTAL PETROCHEMICALS, and YUPLENE® manufactured by SK. 【0043】 The propylene polymer of component (A) described above may be used alone, or two or more polymers with different compositions and physical properties may be used in combination. 【0044】 [Component (B): Ethylene polymer] The ethylene polymer of component (B) used in the olefin resin component is not particularly limited, and any ethylene homopolymer, ethylene copolymer (block copolymer or random copolymer of ethylene units and other monomer units) can be used. Here, ethylene copolymer refers to a copolymer having an ethylene unit content of 50% by mass or more. 【0045】 When the ethylene-based polymer of component (B) is an ethylene-based copolymer, other monomers copolymerized with ethylene include, but are not limited to, α-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, and 1-heptene; and non-conjugated polyenes such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decanediene, 3,6-dimethyl-1,7-octadiene, 4,5-dimethyl-1,7-octadiene, 5-methyl-1,8-nanodiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 2,5-norbornadiene, and 4-ethylidene-8-methyl-1,7-nanodiene. These other copolymerization components may be used individually or in combination of two or more. 【0046】 As ethylene-based polymers, ethylene homopolymers and ethylene-α-olefin copolymers are preferred. 【0047】 Ethylene polymers have a density (JIS K6922) of 0.91 to 0.97 g / cm³. 3 It is preferable that component (B) has a density of 0.94 to 0.97 g / cm³. 3 The inclusion of polyethylene tends to make it easier to obtain excellent sliding properties and wear resistance as a resin composition for sliding members. 【0048】 Ethylene polymers can be classified in terms of density into high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (L-LDPE, LDPE), ethylene plastomers, and ethylene elastomers. 【0049】 In this specification, high-density polyethylene refers to a density of 0.94 g / cm³. 3 or more (0.98g / cm 3 Polyethylene polymers (less than 0.93 g / cm³), medium-density polyethylene has a density of 0.93 g / cm³. 3 More than 0.94g / cm 3Polyethylene polymers with a density of less than 0.91 g / cm³, and low-density polyethylene, have a density of 0.91 g / cm³. 3 More than ~0.93g / cm 3 Polyethylene polymers and ethylene plastomers with a density of less than 0.89 g / cm³ 3 More than 0.91g / cm 3 Polyethylene polymers with a density of less than 0.89 g / cm³, such as ethylene elestomers. 3 Less than (0.85 g / cm³) 3 This refers to polyethylene polymers as described above. Among these, high-density polyethylene (HDPE) is preferred from the viewpoint of sliding properties. 【0050】 In this invention, since the ethylene polymer exists in a non-crosslinked state, it is easier to maintain a co-continuous structure and obtain the desired sliding properties compared to when the ethylene polymer exists in a crosslinked state. 【0051】 The ethylene polymer of component (B) preferably has a melt flow rate (MFR; ASTM D1238, 230°C, load 21.2N) of 0.1 to 13 g / 10 min, more preferably 0.1 to 12 g / 10 min. By using an ethylene polymer of component (B) having such an MFR, it becomes easier to fuse with other components molded from polypropylene resin materials, making it suitable for applications such as sliding components for weatherstrips. 【0052】 Furthermore, commercially available ethylene polymers may be used for component (B). Examples of commercially available components (B) include the Novatec® series from Nippon Polyethylene Co., Ltd., the Creolex® series from Asahi Kasei Micals Corporation, JSR EP from JSR Corporation, Mitsui EPT® from Mitsui Chemicals Inc., Esprene® from Sumitomo Chemical Corporation, and Keltan® from ARLANXEO. 【0053】 The ethylene polymer of component (B) described above may be used alone, or two or more polymers with different compositions and physical properties may be used in combination. 【0054】 [Polyorganosiloxane] The type of substituent bonded to the siloxane main chain in the molecular structure of the polyorganosiloxane contained in the resin composition for sliding members of the present invention is not particularly limited, but dimethyl silicone (dimethylpolysiloxane), methylphenyl silicone, or alkyl-modified silicone is preferably used. 【0055】 Polyorganosiloxanes are designed to improve moldability and processability while providing sliding properties, sliding durability, and wear resistance, with a kinematic viscosity (JIS Z8803, 25℃) of 100,000 mmHg. 2 Polyorganosiloxane (P1) with a relatively high viscosity of 0.5 / s or more, and a kinematic viscosity (JIS Z8803, 25℃) of 50,000 mm². 2 Use a relatively low viscosity polyorganosiloxane (P2) with a viscosity of less than / s in combination. 【0056】 Polyorganosiloxane (P1) is available commercially. Examples of such commercially available products include the "DOW CORNING TORAY™" series and "DOW CORNING™" series from DuPont-Toray Specialty Materials, and "X-22-2101" from Shin-Etsu Chemical Co., Ltd. The appropriate product can be selected and used from among these as needed. Polyorganosiloxanes (P2) are available commercially. Examples of such commercially available products include the "KF-96" series from Shin-Etsu Silicone Co., Ltd. and the "DOWSIL" series from Dow Chemical Co., Ltd., and the appropriate product can be selected and used from among these. 【0057】 Polyorganosiloxanes (P1) and (P2) may be used individually, or two or more may be used in any combination and ratio. 【0058】 [Composition ratio] The resin composition for sliding members of the present invention preferably contains 2 to 10 parts by mass of polyorganosiloxane (P1) and polyorganosiloxane (P2) in total, per 100 parts by mass of olefin resin component. Setting the lower limit of the total polyorganosiloxane content to 2 parts by mass or more further improves sliding durability, provides superior water removal performance in applications such as sliding members for weatherstrips, and further reduces the generation of abnormal noise during sliding. It is more preferable that the lower limit of the total polyorganosiloxane content be 3 parts by mass or more. Furthermore, setting the upper limit of the total polyorganosiloxane content to 10 parts by mass or less improves the moldability of the resin composition for sliding members and tends to suppress the occurrence of bleeding. It is more preferable that the upper limit of the total polyorganosiloxane content be 6 parts by mass or less. 【0059】 Furthermore, from the viewpoint of effectively obtaining the aforementioned effects by using a high-viscosity polyorganosiloxane (P1) and a low-viscosity polyorganosiloxane (P2) in combination, it is preferable that the content of polyorganosiloxane (P1) is 40-80% by mass and the content of polyorganosiloxane (P2) is 20-60% by mass in the total 100% by mass of polyorganosiloxane (P1) and polyorganosiloxane (P2), and more preferably that the content of polyorganosiloxane (P1) is 50-80% by mass and the content of polyorganosiloxane (P2) is 20-50% by mass. 【0060】 The content of the propylene polymer in component (A) of 100% by mass of the olefin resin component is preferably 30 to 60% by mass, more preferably 35 to 60% by mass, and even more preferably 35 to 55% by mass. Furthermore, the content of the ethylene polymer in component (B) of 100% by mass of the olefin resin component is preferably 40 to 70% by mass, more preferably 40 to 65% by mass, and even more preferably 45 to 65% by mass. 【0061】 Preferably, the olefin resin component is composed of 100% by mass of the total amount of component (A) and component (B) combined. Component (A) is preferably 30-60% by mass, more preferably 35-60% by mass, and even more preferably 35-55% by mass, relative to the 100% by mass of the combined component (A) and component (B). Furthermore, component (B) is preferably 40-70% by mass, more preferably 40-65% by mass, and even more preferably 45-65% by mass, relative to the 100% by mass of the combined component (A) and component (B). 【0062】 The polyorganosiloxane is preferably contained in an amount of 2 to 10 parts by mass, particularly 3 to 6 parts by mass, per 100 parts by mass of the total of components (A) and (B). 【0063】 By incorporating each component in the above-mentioned proportions, it becomes easier to achieve higher levels of conformability to glass windows and sliding performance under high loads. 【0064】 [Other ingredients] The resin composition for sliding members of the present invention may optionally contain other components (referred to as "other components" in this specification) other than olefin resin components and polyorganosiloxanes, as long as the objectives of the present invention are not impaired. Examples of other components include resins and elastomers other than components (A) and (B) (referred to as "other resins" in this specification) and various additives. 【0065】 Other resins that may be contained in the resin composition for sliding members of the present invention include polyolefin resins (excluding those corresponding to components (A) and (B) above), polyester resins, polyamide resins, styrene resins, acrylic resins, polycarbonate resins, polyvinyl chloride resins, and other resins; polyamide elastomers such as polyamide-polyol copolymers; polyvinyl chloride elastomers and polybutadiene elastomers, hydrogenated versions thereof, or those modified with acid anhydrides to introduce polar functional groups, and further, those obtained by grafting, randomly and / or block copolymerizing other monomers. The other resins listed above are 1 It may contain only seeds or two or more types of seeds. 【0066】 Among these, polyolefin resins include α-olefins having 2 to 4 carbon atoms, such as ethylene, propylene, and 1-butene, either individually or as copolymers mainly composed of these. Specifically, these polyolefin resins are not limited to homopolymers such as poly-1-butene, but also include copolymers with other α-olefins having 5 to 20 carbon atoms or vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, and styrene, as long as α-olefins having 2 to 4 carbon atoms are the main component. Furthermore, graft copolymers modified with unsaturated carboxylic acids such as maleic anhydride, maleic acid, and acrylic acid, or their derivatives, are also acceptable. Moreover, these polyolefin resins may be mixtures. 【0067】 If the resin composition for sliding members of the present invention contains other resins, the total content of the other resins in the resin composition for sliding members of the present invention is preferably 30 parts by mass or less, and more preferably 20 parts by mass or less, based on 100 parts by mass of the total of components (A) and (B). 【0068】 Furthermore, additives that may be contained in the resin composition for sliding members of the present invention include lubricants used together with polyorganosiloxane, as well as molding aids such as antioxidants and nucleating agents, light stabilizers such as ultraviolet absorbers and hindered amine compounds, hydrolysis resistance improvers, colorants such as pigments and dyes, antistatic agents, conductive agents, flame retardants, reinforcing agents, fillers, plasticizers, release agents, and foaming agents. 【0069】 The resin composition for sliding members of the present invention may contain, as an antioxidant, dithiocarbamate-based antioxidants, hindered phenol-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like. These antioxidants may be used individually or in combination of two or more. 【0070】 When the resin composition for sliding members of the present invention contains an antioxidant, the amount of antioxidant is preferably 0.01 to 5 parts by mass per 100 parts by mass of the total of components (A) and (B). An antioxidant content of 0.01 parts by mass or more is preferable from the viewpoint of improving heat degradation resistance, while an antioxidant content of 5 parts by mass or less is preferable from the viewpoint of not causing problems such as bleeding and the mechanical strength of the composition. 【0071】 Furthermore, the resin composition for sliding members of the present invention preferably contains a coloring agent such as carbon black to improve design and weather resistance. In this case, the coloring agent is preferably added in an amount of 0.1 to 5 parts by mass, and particularly 0.3 to 3 parts by mass, per 100 parts by mass of the total of components (A) and (B). Note that trace components such as coloring agents such as carbon black are preferably added as a masterbatch of the resin such as polyolefin resin in terms of uniform dispersion in the resin composition for sliding members. 【0072】 Furthermore, the resin composition for moving and sliding members of the present invention may contain fillers to improve manufacturing stability, dimensional stability, and flame retardancy. In this case, examples of fillers include glass fibers, hollow glass spheres, carbon fibers, talc, calcium carbonate, mica, clay, potassium titanate fibers, silica, metal soap, titanium dioxide, and carbon black (carbon black can be used as both a colorant and a filler). When a filler is included, it is usually used in an amount of 0.1 to 200 parts by mass per 100 parts by mass of the total of components (A) and (B). 【0073】 [Molding of resin compositions for sliding members] Any of the molding methods, including extrusion molding, injection molding, compression molding, and blow molding, can be applied to the molding of the resin composition for sliding members of the present invention. 【0074】 [Extruded product] The extruded article of the present invention can be manufactured by extruding the resin composition for sliding members of the present invention. 【0075】 When forming a sliding portion of a weatherstrip, which has a base portion made of a resin such as a propylene polymer and a sliding portion laminated on a part of the base portion, using the resin composition for sliding members of the present invention, the molding order of the base portion and the sliding portion may be one molded first and the other molded later, or they may be molded simultaneously, but co-extrusion molding is particularly preferred. 【0076】 [Sliding member] The sliding member made from the resin composition for sliding members of the present invention has excellent surface appearance, flexibility, weather resistance, heat resistance, hot water resistance, and scratch resistance, making it suitable for composite resin molded products used indoors and outdoors, particularly for automotive exterior parts such as roof moldings, weatherstrips, window moldings, flush mount moldings, side moldings, and glass run channels; automotive interior parts such as protective covers for seat rails, assist grips, and shift knobs; building gaskets such as entrance door seals and packing materials; handrails, table edges, and desk edges, but is especially suitable for automotive molding applications such as automotive weatherstrips. [Examples] 【0077】 The specific embodiments of the present invention will be described in more detail below using examples, but the present invention is not limited to the following examples as long as it does not exceed its gist. The various manufacturing conditions and evaluation result values ​​in the following examples are meant as preferred upper or lower limits in the embodiments of the present invention, and the preferred range may be defined by a combination of the aforementioned upper or lower limits and the values ​​of the following examples or the values ​​of the examples themselves. 【0078】 〔raw materials〕 The raw materials used in the following examples and comparative examples are as follows. 【0079】 [Component (A): Propylene polymer] <Propylene homopolymer> • A-1: ​​Manufactured by Nippon Polypropylene Co., Ltd. Product name: Novatec (registered trademark) MFR (230℃, 21.2N): 2.5g / 10min Density (JIS K7112): 0.90g / cm 3 Flexural modulus (JIS K7171): 1400 MPa • A-2: Manufactured by Nippon Polypropylene Co., Ltd. Product name: Novatec (registered trademark) MFR (230℃, 21.2N): 11g / 10min Density (JIS K7112): 0.90g / cm 3 Flexural modulus (JIS K7171): 1500 MPa • A-3: Manufactured by Nippon Polypropylene Co., Ltd. Product name: Novatec (registered trademark) MFR (230℃, 21.2N): 0.4g / 10min Density (JIS K7112): 0.90g / cm 3 Flexural modulus (JIS K7171): 1950 MPa • A-4: Manufactured by Nippon Polypropylene Co., Ltd. Product name: Novatec (registered trademark) MFR (230℃, 21.2N): 40g / 10min Density (JIS K7112): 0.90g / cm 3 Flexural modulus (JIS K7171): 1450 MPa 【0080】 <Propylene copolymer> • A-5: Manufactured by Dow Chemical Company, Product name: Versify (registered trademark) Propylene ethylene copolymer Propylene unit content: 90% by mass MFR (230℃, 21.2N): 25g / 10min Density (JIS K7112): 0.88g / cm 3 Flexural modulus (JIS K7171): 120 MPa • A-6: Manufactured by Dow Chemical Company, Product name: Versify (registered trademark) Propylene ethylene copolymer Propylene unit content: 90% by mass MFR (230℃, 21.2N): 2g / 10min Density (JIS K7112): 0.87g / cm 3 Flexural modulus (JIS K7171): 100 MPa • A-7: Manufactured by Mitsui Chemicals, Inc. Product name: Toughmer (registered trademark) Propylene-1-butene copolymer Propylene unit content: 65-75% by mass MFR (230℃, 21.2N): 7g / 10min Flexural modulus (JIS K7171): 200 MPa <Other polypropylene polymers> • A-8: Product name: MULTIBASE (registered trademark) MB50-001G2 (polypropylene pellets with a 50% polypropylene content, in which silicone gum is dispersed in polypropylene) manufactured by DuPont-Toray Specialty Materials, Inc. Propylene unit content: 100% by mass 【0081】 [Component (B): Ethylene polymer] • B-1: Manufactured by Nippon Polychem Co., Ltd. Product name: Novatec (registered trademark) High-density polyethylene Density (JIS K6922): 0.96g / cm 3 MFR (230℃, 21.2N): 12g / 10min Flexural modulus (JIS K7171): 1000 MPa • B-2: Manufactured by Nippon Polychem Co., Ltd. Product name: Novatec (registered trademark) High-density polyethylene Density (JIS K6922): 0.96g / cm 3 MFR (230℃, 21.2N): 0.3g / 10min Flexural modulus (JIS K7171): 1600 MPa • B-3: Manufactured by Asahi Kasei Corporation. Product name: Creolex (registered trademark). High-density polyethylene Density (JIS K6922): 0.97g / cm 3 MFR (230℃, 21.2N): 12g / 10min Flexural modulus (JIS K7171): 1120 MPa • B-4: Manufactured by Nippon Polychem Co., Ltd. Product name: Novatec (registered trademark) Low-density polyethylene Density (JIS K6922): 0.92g / cm 3 MFR (230℃, 21.2N): 12g / 10min Flexural modulus (JIS K7171): 200 MPa • B-5: Manufactured by Mitsui Chemicals, Inc. Product name: Mitsui EPT (registered trademark) Ethylene elastomer Ethylene unit content: 66% by mass Propylene unit content: 29% by mass Density (JIS K6922): 0.87g / cm 3 Flexural modulus (JIS K7171): <200MPa 【0082】 [Ingredients (C): Polyorganosiloxane] <Polyorganosiloxane (P1)> • C-1(P1): Manufactured by DuPont-Toray Specialty Materials, Ltd. Product name: MULTIBASE (registered trademark) Grade name: MB50-001G2 Dimethylpolysiloxane masterbatch (silicone gum in polypropylene) (Dispersed pellets) Dimethylpolysiloxane content: 50% by mass Kinematic viscosity of dimethylpolysiloxane (25°C): 1,000,000 mm² 2 / s or more <Polyorganosiloxane (P2)> • C-2(P2): Manufactured by Shin-Etsu Silicone Co., Ltd. Product name: KF-96 (registered trademark) Dimethyl silicone oil Kinematic viscosity of dimethylpolysiloxane (25°C): 100 mm² 2 / s • C-3(P2): Manufactured by Shin-Etsu Silicone Co., Ltd. Product name: KF-96 (registered trademark) Dimethyl silicone oil Kinematic viscosity of dimethylpolysiloxane (25°C): 1,000 mm² 2 / s • C-4(P2): Manufactured by Dow Chemical Co., Ltd. Product name: DOWSIL (registered trademark) Dimethyl silicone oil Kinematic viscosity of dimethylpolysiloxane (25°C): 12,500 mm² 2 / s 【0083】 [Other ingredients] • BF300 (filler, manufactured by Bihoku Powdering Industry Co., Ltd.) • ArmoSlip CP (lubricant, manufactured by Lion Specialty Chemicals Co., Ltd.) • Irganox 1010 (antioxidant, manufactured by BASF Japan Ltd.) • TACKIROL 201 (crosslinking agent, manufactured by Taoka Chemical Industry Co., Ltd.) • Zinc oxide (crosslinking activator, manufactured by Wako Pure Chemical Industries, Ltd.) • Stannous chloride (crosslinking activator, manufactured by Wako Pure Chemical Industries, Ltd.) 【0084】 [Evaluation Method] The evaluation method for the sliding material in the following examples and comparative examples is as follows. 【0085】 [Pellet manufacturing] The components shown in Tables 1 to 3 were blended in the proportions shown in Tables 1 to 3, and the mixture was fed into a coaxial twin-screw extruder (Japan Steel Works "TEX30", L / D = 52.5, number of cylinder blocks: 14). The mixture was heated from the upstream to the downstream section in the range of 120 to 210°C for melt mixing, and the strands discharged from the die were cut with a pelletizer to obtain uniformly shaped pellets made of the resin composition. 【0086】 [DuroD hardness] Using the obtained pellets, injection molding was performed using an in-line screw-type injection molding machine (Toshiba Machine Co., Ltd. "IS130") under the conditions of injection pressure of 50 MPa, cylinder temperature of 220°C, and mold temperature of 40°C to obtain a sheet with a thickness of 2 mm, a width of 120 mm, and a length of 80 mm. The DuroD hardness of this sheet was measured according to the ISO 868 standard. A DuroD hardness in the range of 40 to 56 is considered to have excellent conformability required for sliding components. 【0087】 [MFR] The obtained pellets were subjected to a melt indexer (model "L220", manufactured by Tateyama Kagaku Kogyo Co., Ltd.) to measure the MFR at a load of 21.2 N and a measurement temperature of 230 °C. 【0088】 [Coefficient of dynamic friction] Using the obtained pellets, a single-screw extruder was set to a temperature of 180°C to 230°C and extruded to form test pieces for sliding materials with a width of 25 mm and a thickness of 1 mm. The coefficient of dynamic friction of the obtained test specimens was measured using a HEIDON friction tester manufactured by Shinto Scientific Co., Ltd., in accordance with the ASTM D1894 standard. The test conditions were as follows: mating material: glass plate, speed: 100 mm / s, distance: 6 cm, load: 500 g, measurement ambient temperature: 23 °C. A smaller value indicates superior sliding performance under high load. 【0089】 [Workability] Using the obtained pellets, extrusion molding was performed by setting the temperature of a single-screw extruder to 180°C to 230°C. After 15 minutes from the start of molding, the amount of plate-out (amount of precipitate) adhering to the die exit, which was 25 mm wide and 1 mm thick, was visually checked. Plate-out occurred and precipitates were confirmed as "×", and no precipitates were confirmed as "〇". A lower amount of plate-out indicates less deterioration of the molded product's appearance due to precipitates and is considered to have superior processability. 【0090】 Figures 1 and 2 show the plate-out occurrences during the processability evaluation of Example 1 and Comparative Example 7. The white areas are precipitates. In Example 1 (Figure 1), there are no precipitates at the die exit 15 minutes after the start of molding. In contrast, in Comparative Example 7 (Figure 2), a large amount of precipitate is attached to the die exit 15 minutes after the start of molding. 【0091】 [Moldability] Using the obtained pellets, extrusion molding was performed by setting the temperature of a single-screw extruder to 180°C to 230°C. Pellets were fed into the extruder hopper, and those that could be molded with stable discharge were judged as "○", while those where the pellets slipped against each other, did not feed well into the molding machine, and were difficult to mold due to low discharge were judged as "×". Pellets that fed well into the molding machine and could be molded with stable discharge were evaluated as having superior moldability. 【0092】 [Evaluation Results] The evaluation results for Examples 1-6 and Comparative Examples 1-13 are shown in Tables 1-3. 【0093】 [Table 1] 【0094】 [Table 2] 【0095】 [Table 3] 【0096】 Tables 1 to 3 show that the resin composition for sliding members of the present invention exhibits excellent conformability and sliding properties under high loads, as well as excellent processability and moldability. In contrast, Comparative Examples 1-12 showed a high rate of plate-out and inferior processability. In Comparative Example 13, low-viscosity silicone precipitated on the pellet surface, causing the pellets to slip against each other during molding. As a result, the pellets did not engage with the molding machine, making molding impossible and preventing the production of a molded product.

Claims

[Claim 1] A resin composition for sliding members comprising a non-crosslinked olefin resin component containing propylene units and ethylene units, and a polyorganosiloxane, The ratio T1 / T2 of the propylene unit content T1 (mass%) to the ethylene unit content T2 (mass%) in the olefin resin component is 0.5 to 0.

8. The aforementioned polyorganosiloxane has a kinematic viscosity (25°C) of 100,000 mm². ２ Polyorganosiloxane (P1) with a kinematic viscosity (25°C) of 100 mm² / s or more and 50,000 mm² ２ It consists of polyorganosiloxanes (P2) with a coefficient of / s or less, The above-mentioned olefin resin component contains a total of 2 to 10 parts by mass of polyorganosiloxane (P1) and polyorganosiloxane (P2) per 100 parts by mass. A resin composition for sliding members, wherein the content of polyorganosiloxane (P1) is 40 to 80% by mass of the total 100% by mass of polyorganosiloxane (P1) and polyorganosiloxane (P2). [Claim 2] The resin composition for sliding members according to claim 1, wherein the DuroD hardness (ISO 868) is 40 or more and 56 or less. [Claim 3] The resin composition for sliding members according to claim 1 or 2, wherein the melt flow rate measured in accordance with the JIS K7210 standard at a measurement temperature of 230°C and a measurement load of 21.2 N is 0.5 g / 10 min or more and 25 g / 10 min or less. [Claim 4] The resin composition for sliding members according to any one of claims 1 to 3, wherein the olefin resin component contains the following component (A) and component (B). Component (A): Propylene polymer Component (B): Ethylene polymer [Claim 5] The resin composition for sliding members according to claim 4, wherein, of the 100% by mass of the olefin resin component, the content of component (A) is 30 to 60% by mass, and the content of component (B) is 40 to 70% by mass. [Claim 6] The aforementioned component (B) has a density of 0.91 to 0.97 g / cm³. ３ A resin composition for sliding members according to claim 4 or 5, comprising polyethylene. [Claim 7] An extruded article of a resin composition for sliding members according to any one of claims 1 to 6. [Claim 8] Automotive part comprising an extruded body according to claim 7. [Claim 9] A weatherstrip comprising a base material and a sliding member made of a resin composition for sliding members according to any one of claims 1 to 6.

Images