JP2022109002A - Resin composition for sliding member, extrusion molded body, car member, and weather strip - Google Patents

Abstract

To provide a resin composition for sliding members excellent in followability and slidability under high load, an extrusion molded body formed of the resin composition for sliding members, vehicle components, and weather strips.SOLUTION: A resin composition for sliding members containing a non-crosslinked olefinic resin component containing propylene units and ethylene units, and polyorganosiloxane, wherein a ratio T1/T2 of a content ratio T1 (mass%) of the propylene units and a content ratio T2 (mass%) of the ethylene units in the olefinic resin component is 0.30 to 0.70. An extruded body of the resin composition for sliding members. An automobile part comprising the resin composition for sliding members. A weather strip comprising a substrate and a sliding member made of the resin composition for the sliding members.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a resin composition for sliding members, and an extruded product, an automobile part, and a weather strip made of the resin composition for sliding members.

A weatherstrip attached to a window frame of an automobile door is an automobile part provided to prevent rain, wind, foreign matter, etc. from entering the automobile. The weather strip has a base material made of a resin such as a propylene-based polymer, and a sliding part provided so as to be laminated on a part of the base material so that the sliding part is in contact with the glass window. It is used by being sealed to the window frame. Therefore, the sliding member that constitutes the sliding portion is required to have slidability that does not hinder the smooth operation when opening and closing the glass window.
As a sliding member, there is generally known one made of a composition obtained by adding various additives to an olefinic resin component.

As one of additives for imparting slidability to a sliding member, a method of using ultra-high molecular weight polyethylene has been proposed (see Patent Document 1).
In addition, when an ethylene resin is contained in the olefin resin component, a method of imparting slidability by cross-linking a part of the ethylene resin to form an uneven shape on the surface of the molded body is also known. (see Patent Document 2).

JP 2016-204405 A JP-A-2002-20558

In recent years, in order to reduce the running noise of a car, it has been devised to press the weather strip strongly against the window glass to strengthen the sealing performance. In such a usage environment, the sliding member of the weatherstrip should be able to adhere to the glass and sufficiently seal the glass window, but at the same time, it should be able to slide against the glass window even under a high load. Sliding property to move is required.

The addition of ultra-high molecular weight polyethylene as a slidability imparting material described in Patent Document 1 certainly improves slidability, but ultra-high molecular weight polyethylene is powdery and difficult to handle. Further, Patent Document 1 does not describe followability, and the technology described in Patent Document 1 does not consider compatibility between followability and slidability.

The elastomer composition described in Patent Document 2 does not have sufficient slidability under high load. Further, Patent Document 2 does not describe followability, and the technology described in Patent Document 2 does not consider compatibility between followability and slidability.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a resin composition for sliding members which is excellent in followability and slidability under high load, and an extruded article made of this resin composition for sliding members. , automobile parts, and weather strips.

The present inventor has developed a resin composition for a sliding member containing a non-crosslinked olefinic resin component containing propylene units and ethylene units, and polyorganosiloxane, wherein the propylene unit content T1 and the ethylene unit content Extruded articles, automobile parts, and weathers, which are excellent in followability and slidability under high load, are produced by the resin composition for sliding members in which the mass ratio T1/T2 of the ratio T2 is 0.30 to 0.70. The inventors have found that a strip can be realized and have arrived at the present invention.

That is, the gist of the present invention is as follows.

[1] A resin composition for a sliding member containing a non-crosslinked olefinic resin component containing propylene units and ethylene units, and polyorganosiloxane, wherein the content of propylene units in the olefinic resin component is T1 ( %) to the ethylene unit content T2 (% by mass), wherein the ratio T1/T2 is from 0.30 to 0.70.

[2] The resin composition for sliding members according to [1], which has a DuroD hardness (ISO 868) of 40 or more and 55 or less.

[3] A melt flow rate of 0.5/10 minutes or more and 25 g/10 minutes or less measured at a measurement temperature of 230° C. and a measurement load of 21.2 N in accordance with the JIS K7210 standard, [1] or [2] ] The resin composition for sliding members as described in .

[4] The resin composition for sliding members according to any one of [1] to [3], which contains 5 to 15 parts by mass of the polyorganosiloxane with respect to 100 parts by mass of the olefinic resin component.

[5] The resin composition for sliding members according to any one of [1] to [4], wherein the olefinic resin component contains the following component (A) and component (B).
Component (A): Propylene polymer Component (B): Ethylene polymer

[6] Among 100% by mass of the olefin resin component, the content of component (A) is 25 to 60% by mass, and the content of component (B) is 40 to 75% by mass. ] The resin composition for sliding members as described in .

[7] The resin composition for sliding members according to [5] or [6], wherein the component (B) contains polyethylene having a density of 0.91 to 0.97 g/cm ³ .

[8] An extruded body of the resin composition for sliding members according to any one of [1] to [7].

[9] Automobile parts comprising the extruded body of [8].

[10] A weatherstrip comprising a substrate and a sliding member made of the resin composition for sliding members according to any one of [1] to [7].

According to the present invention, there are provided a resin composition for a sliding member that is excellent in followability and slidability under a high load, and an extruded product, an automobile part, and a weather strip made of the resin composition for a sliding member. can provide.

INDUSTRIAL APPLICABILITY The resin composition for sliding members and the extruded product of the present invention are useful as sealing materials for automobiles and sealing materials for building materials because of their excellent conformability to glass and slidability under high load. It is particularly useful as automotive parts such as automotive weather strips.

The present invention will be described in detail below. The present invention is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.
In this specification, when a numerical value or a physical property value is sandwiched before and after the "~", it is used to include the values before and after it.

[Resin composition for sliding member]
The resin composition for sliding members of the present invention is a resin composition for sliding members containing a non-crosslinked olefinic resin component containing propylene units and ethylene units, and polyorganosiloxane, wherein the olefinic resin component is The ratio T1/T2 of the propylene unit content T1 (mass%) and the ethylene unit content T2 (mass%) (hereinafter sometimes simply referred to as "T1/T2") is 0.30 to 0.3 70. This T1/T2 is preferably 0.35 to 0.70, more preferably 0.35 to 0.68. By setting T1/T2 within the above range, it is possible to achieve a higher level of both followability to the glass window and slidability under high load, which are required for the sliding member.

[mechanism]
Although the details of the reason why the resin composition for sliding members of the present invention exhibits the above effects are not clear, the reason is presumed as follows.
Generally, polyorganosiloxane has poor dispersibility in an olefinic resin component, and when molding a molded body using a resin composition containing an olefinic resin component and polyorganosiloxane, the polyorganosiloxane is As a result, the polyorganosiloxane is unevenly distributed on the surface layer of the molded body, and the polyorganosiloxane present on the surface layer is discharged from the sliding member to the outside of the system during use as a sliding member. It will be done. Therefore, desired slidability cannot be obtained as a molded article.

On the other hand, in the resin composition containing a non-crosslinked olefin resin component containing propylene units and ethylene units and polyorganosiloxane, the content of propylene units T1 (mass%) and the content of ethylene units T2 (mass%) ) is 0.30 to 0.70, a co-continuous structure of polyethylene and polypropylene is formed, and a large amount of interfaces in which polyorganosiloxane can be unevenly distributed are formed in this structure. be able to. In a molded body using a resin composition having such a co-continuous structure, repeated sliding causes polyorganosiloxane to gradually exude from the molded body to the sliding surface along the interface of the co-continuous structure. , it is considered that excellent slidability can be obtained.

[Physical properties of resin composition for sliding member]
<Duro D hardness>
The resin composition for sliding members of the present invention preferably has a DuroD hardness of 40 to 55 as measured with 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 sliding members of the present invention is preferably 45 or more. On the other hand, when the DuroD hardness is 55 or less, the followability is excellent. The DuroD hardness of the resin composition for sliding members of the present invention is preferably 53 or less. In particular, when the DuroD hardness is in the range of 45 to 53, it is possible to obtain a sliding member having a better balance between slidability and followability under high load.

The DuroD hardness of the resin composition for sliding members is defined by the content C1 (% by mass) of the resin component having a bending elastic modulus (JIS K7171) of 1000 MPa or more, for example, 1000 to 2300 MPa in the resin composition for sliding members, and the bending elasticity. It can be adjusted by controlling the content C2 (% by mass) of the resin component with a rate (JIS K7171) of less than 1000 MPa, for example, 20 to 950 MPa. Specifically, controlling C1/C2 within the range of 1.5 to 5.0 makes it easier to obtain the desired hardness. The resin component having a flexural modulus of 1000 MPa or more and the resin component having a flexural modulus of less than 1000 MPa can be appropriately selected from component (A) and component (B) to be used later.

<Melt flow rate>
The resin composition for sliding members of the present invention has a melt flow rate (MFR) of 0.5 g/10 minutes or more measured at a measurement temperature of 230° C. and a measurement load of 21.2 N with reference to the JIS K7210 standard. , preferably from the viewpoint of reducing the load on the molding machine, more preferably 0.7 g/10 minutes or more, still more preferably 1 g/10 minutes or more. On the other hand, from the viewpoint of formability during molding, the melt flow rate (MFR) of the resin composition for sliding members of the present invention is preferably 25 g/10 minutes or less, more preferably 24 g/10 minutes or less, and 23 g/10 minutes or less. More preferably 10 minutes or less.

[Olefin resin component]
The resin composition for sliding members of the present invention contains a non-crosslinked olefinic resin component containing propylene units and ethylene units. In the resin composition for sliding members of the present invention, the ratio T1/T2 of the propylene unit content T1 (% by mass) and the ethylene unit content T2 (% by mass) is 0.30. It is preferable to contain an olefin-based resin component so that the value becomes 0.70.

The olefin-based resin component is not particularly limited as long as it is a non-crosslinked olefin-based resin component containing propylene units and ethylene units. It is preferable to contain the following component (A) and component (B). Details of these components (A) and (B) will be described later.
Component (A): Propylene polymer Component (B): Ethylene polymer

The propylene unit content T1 and the ethylene unit content T2 in the olefin resin component containing the component (A) and the component (B) are obtained, for example, as follows.
Component (A) includes component (A-1), component (A-2) ………… component (An), and component (B) includes component (B-1), component (B- 2) In the olefinic resin component containing the component (Bn), the content (% by mass) of 100% by mass of the olefinic resin component of each component, the content of propylene units in each component ( mass%), the content of ethylene units (mass%),
Content of component (A-1) in olefin resin component: M (A-1) % by mass
Content of component (A-2) in olefin resin component: M (A-2) % by mass
: :
Content of component (An) in olefin resin component: M (An) mass %
Content of component (B-1) in olefin resin component: M (B-1) % by mass
Content of component (B-2) in olefin resin component: M (B-2) % by mass
: :
Content of component (Bn) in olefin resin component: M (Bn) % by mass
Propylene unit content in component (A-1): P(A-1)% by mass
Content of propylene units in component (A-2): P(A-2)% by mass
: :
Content of propylene units 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
Content of propylene units in component (B-2): P(B-2)% by mass
: :
Content of propylene units in component (Bn): P(Bn)% by mass
Ethylene unit content in component (B-1): E (B-1) % by mass
Ethylene unit content in component (B-2): E (B-2) mass%
: :
Ethylene unit content in component (Bn): E (Bn) mass %
Then, the propylene unit content T1 and the ethylene unit content T2 as the olefinic resin component are calculated as follows.
T1={M(A-1)×P(A-1)+M(A-2)×P(A-2)+…………+M(A-n)×P(A-n)+M( B-1)×P(B-1)+M(B-2)×P(B-2)…………+M(B-n)×P(B-n)}/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(B-n)×E(B-n)}/100

As described above, T1/T2 in the resin composition for sliding members of the present invention is 0.30 to 0.70, preferably 0.35 to 0.70, more preferably 0.35 to 0.68. , T1/T2 of the olefin resin component contained in the resin composition for sliding members of the present invention is 0.30 to 0.70, particularly 0.35 to 0.70, and particularly 0.35 to 0.68. Preferably.

<Component (A): Propylene-based polymer>
The propylene-based polymer of component (A) used in the olefin-based resin component is not particularly limited, and may be a propylene homopolymer, a propylene-based copolymer (a block copolymer of propylene units and other monomer units, or random copolymer) and the like can be used.
Here, the propylene-based copolymer means a copolymer having a propylene unit content of 50% by mass or more.

When the propylene-based polymer of component (A) is a propylene-based copolymer, other monomers to be copolymerized with propylene include ethylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl -α-olefins having 2 or 4 to 12 carbon atoms such as 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene; cyclopentene, norbornene, tetracyclo[6,2,11, Cyclic olefins such as 8,13,6]-4-dodecene; norbornenes such as 5-methylene-2-norbornene and 5-ethylidene-2-norbornene; 1,4-hexadiene, methyl-1,4-hexadiene, 7- Dienes such as methyl-1,6-octadiene; vinyl chloride, vinylidene chloride, acrylonitrile, vinyl acetate, acrylic acid, methacrylic acid, maleic acid, ethyl acrylate, butyl acrylate, methyl methacrylate, maleic anhydride, styrene, methyl Vinyl monomers such as styrene, vinyltoluene, and divinylbenzene may be used, but are not particularly limited thereto. These other copolymerization components may be used singly or in combination of two or more.

The polypropylene-based polymer of component (A) preferably has a melt flow rate (MFR; ASTM D 1238, 230° C., load 21.2 N) of 0.3 to 26 g/10 minutes, more preferably 0.3. ~15 g/10 min. Good moldability and excellent appearance can be ensured by using the component (A) polypropylene polymer having such MFR.

Further, the propylene-based polymer of component (A) preferably has a density (JIS K7112) within the range of 0.85 to 0.92 g/cm ³ .

The propylene-based polymer of component (A) can be obtained by a known production method. The manufacturing method, for example, JP-A-50-108385, JP-A-50-126590, JP-A-51-20297, JP-A-51-28189, JP-A-52-151691 , and the techniques described therein can be used in the present invention.

A commercially available propylene polymer may be used as the component (A). Examples of commercially available products of component (A) include PRIME Polypro (registered trademark) manufactured by Prime Polymer Co., Ltd., Sumitomo Noblen (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., polypropylene block copolymer manufactured by SunAllomer Co., Ltd., and Novatec manufactured by Nippon Polypro Co., Ltd. (registered trademark) PP, Toughmar (registered trademark) manufactured by Mitsui Chemicals, WAYMAX (registered trademark), Moplen (registered trademark) manufactured by LyondellBasell, ExxonMobil PP manufactured by ExxonMobil, Dow Chemical Versify®, Formolene® from Formosa Plastics, Borealis PP from Borealis, SEETEC PP from LG Chemical, A.I. Ｓｃｈｕｌｍａｎ社製のＡＳＩ ＰＯＬＹＰＲＯＰＹＬＥＮＥ、ＩＮＥＯＳ Ｏｌｅｆｉｎｓ＆Ｐｏｌｙｍｅｒｓ社製のＩＮＥＯＳ ＰＰ、Ｂｒａｓｋｅｍ社製のＢｒａｓｋｅｍ ＰＰ、ＳＡＭＳＵＮＧ ＴＯＴＡＬ ＰＥＴＲＯＣＨＥＭＩＣＡＬＳ社製のＳｕｍｓｕｎｇ Ｔｏｔａｌ、Ｓａｂｉｃ社製のＳａｂｉｃ（登録商標）ＰＰ、ＴＯＴＡＬ ＰＥＴＲＯＣＨＥＭＩＣＡＬＳ社製のＴＯＴＡＬ ＰＥＴＲＯＣＨＥＭＩＣＡＬＳ Ｐｏｌｙｐｒｏｐｙｌｅｎｅ , and YUPLENE (registered trademark) manufactured by SK.

The propylene-based polymer of component (A) may be used alone, or may be used in combination of two or more with different compositions and physical properties.

[Component (B): ethylene polymer]
The ethylene-based polymer of component (B) used in the olefin-based resin component is not particularly limited, and may be an ethylene homopolymer, an ethylene-based copolymer (a block copolymer of ethylene units and other monomer units, or random copolymer) and the like can be used.
Here, the ethylene-based copolymer means one having an ethylene unit content of 50% by mass or more.

When the ethylene-based polymer of component (B) is an ethylene-based copolymer, other monomers to be copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, α-olefins having 3 to 20 carbon atoms such as 4-methyl-1-pentene and 1-heptene; 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, 4-ethylidene-8-methyl-1,7-nanodiene, and other non-conjugated polyenes, but are not particularly limited thereto. These other copolymer components may be used singly or in combination of two or more.

As the ethylene polymer, an ethylene homopolymer and an ethylene/α-olefin copolymer are preferable.

The ethylene polymer preferably has a density (JIS K6922) of 0.91 to 0.97 g/cm ³ . Further, by containing polyethylene having a density of 0.94 to 0.97 g/cm ³ as at least a part of the component (B), excellent slidability and abrasion resistance can be obtained as a resin composition for sliding members. tends to be easier.

Ethylene-based polymers can be classified into high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (L-LDPE, LDPE), ethylene plastomers, and ethylene elastomers in terms of density.

In this specification, high-density polyethylene is a polyethylene-based polymer having a density of 0.94 g/cm ³ or more (less than 0.98 g/cm ³ ), and medium-density polyethylene is a density of 0.93 g/cm ³ or more and 0.94 g/cm 3 or more. cm ³ or less, low-density polyethylene is a polyethylene polymer with a density of 0.91 g/cm ³ or more and less than 0.93 g/cm ³ , ethylene plastomer is a density of 0.89 g/cm ³ or more and 0.91 g A polyethylene polymer having a density of less than 0.85 g/cm ³ and an ethylene elastomer mean a polyethylene polymer having a density of less than 0.89 g/cm ³ (0.85 g/cm ³ or more). Among these, high-density polyethylene (HDPE) is preferable from the viewpoint of slidability.

In the present invention, since the ethylene polymer exists in a non-crosslinked state, it is easier to maintain the co-continuous structure and obtain the desired slidability compared to the case where the ethylene polymer exists in a crosslinked state. can be done.

The ethylene polymer of component (B) preferably has a melt flow rate (MFR; ASTM D1238, 230° C., load 21.2 N) of 0.1 to 13 g/10 min, more preferably 0.1 to 12 g/10 minutes. By using the ethylene-based polymer of component (B) having such an MFR, it becomes easier to fuse with another member molded from a polypropylene-based resin material, making it suitable for applications such as sliding members for weather strips. can be used.

A commercially available ethylene polymer may be used as the component (B). Commercially available products of component (B) include, for example, Novatec (registered trademark) series manufactured by Japan Polyethylene Corporation, Creolex (registered trademark) series manufactured by Asahi Kasei Chemicals, JSR EP manufactured by JSR, and Mitsui EPT manufactured by Mitsui Chemicals ( (registered trademark), Esprene (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., and Keltan (registered trademark) manufactured by ARLANXEO.

The ethylene-based polymer of component (B) may be used alone, or two or more of which have different compositions and physical properties may be used in combination.

[Polyorganosiloxane]
The type of substituents 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.

Polyorganosiloxane is preferably used as a masterbatch of a propylene-based polymer or an ethylene-based polymer in order to sufficiently mix with other materials constituting the resin composition for sliding members of the present invention. As a propylene-based polymer that can be used as a masterbatch, for example, the propylene-based polymer of component (A) described above can be used.

The polyorganosiloxane preferably has a kinematic viscosity (JIS Z8803, 25° C.) of 100,000 cSt or more, and the upper limit of this kinematic viscosity is not particularly limited. The higher the kinematic viscosity of the polyorganosiloxane, the higher the effect of improving the scratch resistance and wear resistance, which is preferable.

Polyorganosiloxanes are commercially available. Applicable commercial products include, for example, DuPont Toray Specialty Materials "DOW CORNING TORAYTM (registered trademark)" series, "Versify (registered trademark)" series, "DOW CORNINGTM (registered trademark)" series, Shin-Etsu Chemical "X-22-2101" manufactured by Kogyosha Co., Ltd. can be mentioned, and the applicable product can be appropriately selected and used from among these.

Polyorganosiloxane may use only 1 type, or may use 2 or more types by arbitrary combinations and a ratio.

[Blending ratio]
The resin composition for sliding members of the present invention preferably contains 5 to 15 parts by mass of polyorganosiloxane with respect to 100 parts by mass of the olefinic resin component. By setting the lower limit of the polyorganosiloxane content to 5 parts by mass or more, the sliding durability is further improved, and the water removal performance in applications such as sliding members of weather strips is further improved. The occurrence of abnormal noise during operation is further reduced. More preferably, the lower limit of the polyorganosiloxane content is 8 parts by mass or more. Further, by setting the upper limit of the polyorganosiloxane content to 15 parts by mass or less, the moldability of the resin composition for sliding members is further improved, and the occurrence of bleeding tends to be suppressed. More preferably, the upper limit of the polyorganosiloxane content is 13 parts by mass or less.

The content of the propylene-based polymer of component (A) in 100 parts by mass of the olefin-based resin component is preferably 25 to 60 mass%, more preferably 25 to 50 mass%, and still more preferably 30 to 50 mass%. %. In addition, the content of the ethylene-based polymer of component (B) in 100 parts by mass of the olefin-based resin component is preferably 40 to 75% by mass, more preferably 50 to 75% by mass, and still more preferably 50 to 75% by mass. 70% by mass.

It is preferable that 100% by mass of the total amount of the olefinic resin component is composed of 100% by mass of the total of component (A) and component (B). Component (A) is more preferably 25 to 60% by mass, still more preferably 30 to 50% by mass, based on the total 100% by mass of component (A) and component (B). Component (B) is more preferably 40 to 75% by mass, still more preferably 50 to 70% by mass, based on the total 100% by mass of component (A) and component (B).

Polyorganosiloxane is preferably contained in an amount of 5 to 15 parts by weight, particularly 8 to 13 parts by weight, per 100 parts by weight of components (A) and (B) combined.

By containing each component in the above-described blending ratio, it becomes easier to achieve a higher level of conformability to a glass window and slidability under a high load.

[Other ingredients]
The resin composition for sliding members of the present invention may optionally contain components other than the olefinic resin component and the polyorganosiloxane (hereinafter simply referred to as "other may be referred to as "components of"). Other components include resins and elastomers other than components (A) and (B) (in this specification, these may be collectively referred to simply as "other resins") and various additives.

Other resins that may be contained in the resin composition for sliding members of the present invention include polyolefin resins (excluding those corresponding to the components (A) and (B)), polyester resins, polyamide resins, Resins such as styrene resins, acrylic resins, polycarbonate resins, and polyvinyl chloride resins; polyamide-based elastomers such as polyamide-polyol copolymers; polyvinyl chloride-based elastomers and polybutadiene-based elastomers, hydrogenated products thereof, acid anhydrides, etc. modified with a polar functional group, and those obtained by grafting, random and/or block copolymerizing other monomers. The other resins listed above may contain only one type or two or more types.

Among these, examples of polyolefin resins include α-olefins having 2 to 4 carbon atoms such as ethylene, propylene and 1-butene, and copolymers thereof as main components. Specifically, these polyolefin resins are not limited to homopolymers such as poly-1-butene, and other α-olefins having 5 to 20 carbon atoms as long as they are mainly composed of α-olefins having 2 to 4 carbon atoms. - Also includes copolymers with olefins or vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, styrene. Furthermore, graft copolymers graft-modified with unsaturated carboxylic acids such as maleic anhydride, maleic acid and acrylic acid or their derivatives may also be used. Furthermore, these polyolefin resins may be mixtures.

When 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 the total of component (A) and component (B). ) is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, with respect to the total 100 parts by mass.

Additives that may be contained in the resin composition for sliding members of the present invention include lubricants used together with polyorganosiloxane, antioxidants, molding processing aids such as crystal nucleating agents, ultraviolet absorbers, and hindered amines. Light stabilizers such as system compounds, hydrolysis resistance modifiers, coloring agents such as pigments and dyes, antistatic agents, conductive agents, flame retardants, reinforcing agents, fillers, plasticizers, release agents, foaming agents, etc. be done.

The resin composition for a sliding member of the present invention may contain, as an antioxidant, a dithiocarbamate-based antioxidant, a hindered phenol-based antioxidant, a sulfur-based antioxidant, a phosphorus-based antioxidant, or the like. can be done.
These antioxidants may be used individually by 1 type, and may use 2 or more types together.

When the resin composition for a sliding member of the present invention contains an antioxidant, the content of the antioxidant is preferably 0.01 per 100 parts by mass of component (A) and component (B) combined. ~5 parts by mass. When the content of the antioxidant is 0.01 parts by mass or more, it is preferable from the viewpoint of improving the resistance to heat deterioration. It is preferable from the viewpoint of mechanical strength and the like.

Further, the resin composition for sliding members of the present invention preferably contains a coloring agent such as carbon black in order to improve design and weather resistance. It is preferable to add 0.1 to 5 parts by mass, particularly 0.3 to 3 parts by mass, per 100 parts by mass of component (B). It should be noted that it is preferable to mix a trace component such as a colorant such as carbon black as a masterbatch of a resin such as a polyolefin resin in terms of uniform dispersibility in the resin composition for sliding members.

Further, the resin composition for a dynamic sliding member of the present invention may contain a filler in order to improve manufacturing stability, dimensional stability and flame retardancy. , hollow glass spheres, carbon fiber, talc, calcium carbonate, mica, clay, potassium titanate fiber, silica, metal soap, titanium dioxide, carbon black, etc. (Carbon black can be used as both a coloring agent and a filler.) available.). When a filler is blended, the filler is usually used in an amount of 0.1 to 200 parts by mass per 100 parts by mass of component (A) and component (B).

[Molding of Resin Composition for Sliding Member]
Any of extrusion molding, injection molding, compression molding and blow molding can be applied to molding the resin composition for sliding members of the present invention.

[Extruded body]
The extruded body of the present invention can be produced by extruding the resin composition for sliding members of the present invention.

An extruded body integrated with another member using the resin composition for a sliding member of the present invention, for example, a substrate portion made of a resin such as a propylene-based polymer, and a part laminated on the substrate portion When forming the sliding portion of the weatherstrip having the sliding portion provided as described above, the molding order of the base portion and the sliding portion may be such that one is molded first and then the other. , may be molded at the same time, but a co-extrusion molding method is particularly suitable.

[Sliding member]
Sliding members made of the resin composition for sliding members of the present invention are excellent in surface appearance, flexibility, weather resistance, heat resistance, hot water resistance, and scratch resistance. In particular, automotive exterior parts such as roof moldings, weather strips, window moldings, flush mount moldings, side moldings, glass run channels, automotive interior parts such as protective covers for seat rails, assist grips, and shift knobs, entrance door seals, packing materials, etc. It is suitable for architectural gaskets, handrails, table edges, desk edges and the like, but is particularly well suited for use in automotive molding applications such as automotive weatherstrips.

Specific embodiments of the present invention will be described in more detail below using examples, but the present invention is not limited by the following examples as long as the gist thereof is not exceeded. Various production conditions and values of evaluation results in the following examples have the meaning of preferred values of the upper limit or the lower limit in the embodiments of the present invention, and the preferred range is the above-described upper limit or lower limit value. , the range defined by the values in the following examples or a combination of the values in the examples.

〔raw materials〕
Raw materials used in the following examples and comparative examples are as follows.

[Component (A): propylene-based polymer]
<Propylene homopolymer>
・A-1: Made by Japan Polypropylene Corporation Product name: Novatec (registered trademark)
MFR (230° C., 21.2 N): 2.5 g/10 minutes Density (JIS K7112): 0.90 g/cm ³
Flexural modulus (JIS K7171): 1400 MPa
・A-2: Made by Japan Polypropylene Corporation Product name: Novatec (registered trademark)
MFR (230° C., 21.2 N): 11 g/10 minutes Density (JIS K7112): 0.90 g/cm ³
Flexural modulus (JIS K7171): 1500 MPa
・A-3: Made by Japan Polypropylene Corporation Product name: Novatec (registered trademark)
MFR (230° C., 21.2 N): 0.4 g/10 minutes Density (JIS K7112): 0.90 g/cm ³
Flexural modulus (JIS K7171): 1950 MPa
・A-4: Made by Japan Polypropylene Corporation Product name: Novatec (registered trademark)
MFR (230° C., 21.2 N): 40 g/10 minutes Density (JIS K7112): 0.90 g/cm ³
Flexural modulus (JIS K7171): 1450 MPa

<Propylene copolymer>
・A-5: manufactured by Dow Chemical Co., Ltd. Product name: Versify (registered trademark)
Propylene/ethylene copolymer propylene unit content: 80 to 90% by mass
MFR (230° C., 21.2 N): 25 g/10 minutes Density (JIS K7112): 0.88 g/cm ³
Flexural modulus (JIS K7171): 120 MPa
・A-6: manufactured by Dow Chemical Co., Ltd. Product name: Versify (registered trademark)
Propylene/ethylene copolymer propylene unit content: 80 to 90% by mass
MFR (230° C., 21.2 N): 2 g/10 minutes Density (JIS K7112): 0.87 g/cm ³
Flexural modulus (JIS K7171): 100 MPa
・A-7: Made by Mitsui Chemicals, Inc. Product name: Toughmer (registered trademark) XM-7070
Propylene/1-butene copolymer Propylene unit content: 65 to 75% by mass
MFR (230° C., 21.2 N): 7 g/10 minutes Flexural modulus (JIS K7171): 200 MPa

[Component (B): ethylene polymer]
・B-1: Made by Japan Polychem Co., Ltd. Product name: Novatec (registered trademark)
High density polyethylene density (JIS K6922): 0.96g/ ^cm3
MFR (230° C., 21.2 N): 12 g/10 minutes Flexural modulus (JIS K7171): 1000 MPa
・B-2: Made by Japan Polychem Co., Ltd. Product name: Novatec (registered trademark)
High density polyethylene density (JIS K6922): 0.96g/ ^cm3
MFR (230° C., 21.2 N): 0.3 g/10 minutes Flexural modulus (JIS K7171): 1600 MPa
・B-3: Asahi Kasei Corporation Product name: Creolex (registered trademark)
High density polyethylene density (JIS K6922): 0.97g/ ^cm3
MFR (230° C., 21.2 N): 12 g/10 minutes Flexural modulus (JIS K7171): 1120 MPa
・B-4: Made by Japan Polychem Co., Ltd. Product name: Novatec (registered trademark)
Low density polyethylene density (JIS K6922): 0.92g/ ^cm3
MFR (230° C., 21.2 N): 12 g/10 minutes 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/ ^cm3
Flexural modulus (JIS K7171): <200 MPa

[Polyorganosiloxane]
DuPont Toray Specialty Materials Product name: Versify (registered trademark) MB50-001G2
Dimethylpolysiloxane masterbatch Dimethylpolysiloxane content: 50% by mass
Dynamic viscosity of dimethylpolysiloxane (25°C): 1,000,000 cSt or more

[Other ingredients]
・ BF300 (filler, manufactured by Bihoku Funka Kogyo 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 Co., Ltd.)
・ Zinc oxide (crosslinking activator, manufactured by Wako Pure Chemical Industries, Ltd.)
・ Stannous chloride (crosslinking activator, manufactured by Wako Pure Chemical Industries, Ltd.)

〔Evaluation method〕
Evaluation methods for the sliding materials in the following examples and comparative examples are as follows.

[Production of pellets]
The components shown in Table 1 were blended in the proportions shown in Table 1, and the mixture was put into a co-rotating twin-screw extruder (Japan Steel Works "TEX30", L/D = 52.5, number of cylinder blocks: 14). Melt-kneading was performed by raising the temperature from the upstream portion to the downstream portion in the range of 120 to 210° C., and the strand discharged from the die was cut with a pelletizer to obtain pellets of a resin composition having a uniform shape.

[DuroD hardness]
Using the obtained pellets, injection molding is performed using an in-line screw type injection molding machine ("IS130" manufactured by Toshiba Machine Co., Ltd.) under the conditions of an injection pressure of 50 MPa, a cylinder temperature of 220 ° C., and a mold temperature of 40 ° C. A sheet of thickness 2 mm×width 120 mm×length 80 mm was obtained.
The DuroD hardness of this sheet was measured with reference to the ISO 868 standard.
Those having a DuroD hardness in the range of 40 to 55 are evaluated as excellent in followability required for sliding members.

[MFR]
The MFR of the obtained pellets was measured using a melt indexer (model name "L220", manufactured by Tateyama Kagaku Kogyo Co., Ltd.) at a load of 21.2 N and a measurement temperature of 230°C.

[Dynamic friction coefficient]
The obtained pellets were extruded with a single-screw extruder at a resin temperature of 180° C. to form test pieces for sliding materials having a width of 25 mm and a thickness of 1 mm.
The dynamic friction coefficient of the obtained test piece was measured using a HEIDON friction tester manufactured by Shinto Kagaku Co., Ltd. with reference to the ASTM D1894 standard.
The test conditions were as follows: opponent material: glass plate, speed: 100 mm/s, distance: 6 cm, load: 500 g, measurement environment temperature: 23°C. The smaller this value, the better the slidability under high load.

〔Evaluation results〕
Table 1 shows the evaluation results in Examples 1-6 and Comparative Examples 1-5.

From Table 1, it can be seen that the resin composition for sliding members of the present invention is excellent in followability and slidability under high load.
On the other hand, in Comparative Examples 1 and 2, T1/T2 is outside the range of the present invention. Poor slidability.
In Comparative Examples 3 to 5, the olefinic resin component is crosslinked with a crosslinking agent, the coefficient of dynamic friction is large, and the slidability under high load is poor.

Claims (10)

A resin composition for a sliding member containing a non-crosslinked olefinic resin component containing propylene units and ethylene units, and polyorganosiloxane, wherein the propylene unit content T1 (% by mass) in the olefinic resin component and an ethylene unit content T2 (% by mass) in a ratio T1/T2 of 0.30 to 0.70. The resin composition for a sliding member according to claim 1, having a DuroD hardness (ISO 868) of 40 or more and 55 or less. 3. The slide according to claim 1 or 2, which has a melt flow rate of 0.5/10 minutes or more and 25 g/10 minutes or less measured at a measurement temperature of 230° C. and a measurement load of 21.2 N in accordance with the JIS K7210 standard. A resin composition for moving parts. The resin composition for a sliding member according to any one of claims 1 to 3, containing 5 to 15 parts by mass of said polyorganosiloxane with respect to 100 parts by mass of said olefinic resin component. The resin composition for sliding members according to any one of claims 1 to 4, wherein the olefin-based resin component contains the following component (A) and component (B).
Component (A): Propylene polymer Component (B): Ethylene polymer 6. The content of component (A) is 25 to 60% by mass and the content of component (B) is 40 to 75% by mass out of 100% by mass of the olefin resin component, according to claim 5. The resin composition for the sliding member of. 7. The resin composition for a sliding member according to claim 5, wherein said component (B) contains polyethylene having a density of 0.91 to 0.97 g/cm ³ . An extruded body of the resin composition for sliding members according to any one of claims 1 to 7. An automobile part comprising the extruded body according to claim 8. A weatherstrip comprising a substrate and a sliding member made of the resin composition for a sliding member according to any one of claims 1 to 7.