JP2023132751A - Resin composition for sliding member, extrusion molding, component for automobile, and weather strip - Google Patents

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

The present invention relates to a resin composition for a sliding member, an extrusion molded article, an automobile part, and a weather strip made of the resin composition for a sliding member.

A weather strip attached to the window frame of an automobile door is an automobile component installed to prevent rain, wind, foreign objects, etc. from entering the interior of the automobile. The weather strip has a base material made of a resin such as a propylene polymer, and a sliding part provided so as to be laminated on a part of the base material part, and the weather strip has a base material part 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 part. It is used by being sealed on the window frame. Therefore, the sliding member constituting the sliding portion is required to have sliding properties that do not interfere with the smooth operation of the glass window when it is opened and closed.
Sliding members are generally known that are made of a composition in which various additives are added to an olefin resin component.

A method of using ultra-high molecular weight polyethylene as one of the additives for imparting sliding properties to a sliding member has been proposed (see Patent Document 1).
In addition, when the olefin resin component contains an ethylene resin, a method of imparting sliding properties by crosslinking a portion of the ethylene resin to form an uneven shape on the surface of the molded product is also known. (See Patent Document 2).

JP2016-204405A Japanese Patent Application Publication No. 2002-20558

In recent years, in order to reduce the sound of cars running, efforts have been made to firmly press weather strips against window glass to strengthen their sealing properties. In such a usage environment, the sliding member of the weather strip has the ability to adhere to the glass and sufficiently seal the glass window, but it also has the ability to slide against the glass window even under high loads. Sliding properties are required.

Although the ultra-high molecular weight polyethylene described in Patent Document 1 is added as a sliding property imparting material, the sliding property is certainly improved, but the ultra-high molecular weight polyethylene is powdery and difficult to handle. Moreover, Patent Document 1 does not describe followability, and the technology described in Patent Document 1 does not consider achieving both followability and sliding property.

The elastomer composition described in Patent Document 2 does not have sufficient sliding properties under high loads. Further, Patent Document 2 does not describe followability, and the technique described in Patent Document 2 does not consider achieving both followability and sliding property.

There is a technology that uses polyorganosiloxane to achieve both conformability and sliding properties, but polyorganosiloxane has poor compatibility with olefin resins and tends to migrate toward the surface of the molded product. As a result, polyorganosiloxane is unevenly distributed on the surface layer of the molded body, and during use as a sliding member, the polyorganosiloxane present on the surface layer is discharged from the sliding member to the outside of the system. Therefore, over time, the molded article may not have the desired sliding properties.
Furthermore, when producing a resin composition, if the amount of polyorganosiloxane added is increased for the purpose of improving sliding properties, the polyorganosiloxane tends to migrate to the surface of the resulting resin composition. When a molded article is made using such a resin composition, the pellets may slip against each other at the resin input section during molding, resulting in poor biting of the pellets into the molding machine, which causes molding defects such as unstable product shape. There was also.
Additionally, due to the segregation of polyorganosiloxane during extrusion molding, a processing defect called plate-out occurs, in which precipitates derived from polyorganosiloxane adhere to the exit part of the molding machine, and the precipitates generated by plate-out occur. There was also the problem that it adhered to the surface of the molded product, deteriorating its appearance.

The purpose of the present invention is to solve the above-mentioned problems of the prior art and provide a resin composition for sliding members that has excellent followability and sliding properties under high loads, as well as excellent moldability and workability, and An object of the present invention is to provide an extrusion molded article, an automobile part, and a weather strip made of a resin composition for parts.

The present inventor has proposed that two types of polyorganosiloxanes having different viscosities be used together in a resin composition for a sliding member containing a non-crosslinked olefin resin component containing propylene units and ethylene units, and polyorganosiloxane. Accordingly, the resin composition for sliding members can realize extrusion molded bodies, automobile parts, and weather strips that have excellent followability and sliding properties under high loads, and also have excellent moldability and workability. This discovery led to 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 olefin resin component containing propylene units and ethylene units, and a polyorganosiloxane,
The polyorganosiloxane is composed of a polyorganosiloxane (P1) having a kinematic viscosity (25°C) of 100,000 mm ² /s or more and a polyorganosiloxane (P2) having a kinematic viscosity (25°C) of 50,000 mm ² /s or less. Resin composition for sliding members.

[2] In [1], the ratio T1/T2 of the content T1 (mass%) of propylene units and the content T2 (mass%) of ethylene units in the olefin resin component is 0.5 to 0.8. The resin composition for sliding members described above.

[3] The resin composition for a sliding member according to [1] or [2], which has a DuroD hardness (ISO 868) of 40 or more and 56 or less.

[4] The melt flow rate measured in accordance with the JIS K7210 standard at a measurement temperature of 230°C and a measurement load of 21.2N is 0.5/10 minutes or more and 25 g/10 minutes or less, [1] to [3] ] The resin composition for a sliding member according to any one of the above.

[5] The resin composition for a sliding member according to any one of [1] to [4], which contains a total of 2 to 10 parts by mass of the polyorganosiloxane based on 100 parts by mass of the olefin resin component.

[6] The resin composition for a sliding member 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

[7] Out 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, [6 ] The resin composition for a sliding member according to.

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

[9] An extrusion molded article of the resin composition for a sliding member according to any one of [1] to [8].

[10] An automobile part comprising the extrusion molded article of [9].

[11] A weatherstrip comprising a base material and a sliding member made of the resin composition for sliding members according to any one of [1] to [8].

According to the present invention, there is provided a resin composition for a sliding member that has excellent conformability and slidability under high loads, and is also excellent in moldability and workability, and an extrusion molding made of the resin composition for a sliding member. bodies, automotive parts, and weather strips.

The resin composition for sliding members and the extrusion molded article of the present invention are useful as sealing materials for automobiles and building materials due to their excellent conformability to glass and slidability under high loads. It is particularly useful as automobile parts such as automobile weather strips.

2 is a photograph showing the occurrence of plate-out in the processability evaluation of the resin composition of Example 1. 3 is a photograph showing the occurrence of plate-out in the processability evaluation of the resin composition of Comparative Example 7.

The present invention will be explained in detail below. The present invention is not limited to the following description, and can be implemented with arbitrary modifications within the scope of the gist of the present invention.
In this specification, when a numerical value or physical property value is placed before and after "~", it is used to include the values before and after it.

[Resin composition for sliding members]
The resin composition for sliding members of the present invention is a resin composition for sliding members containing a non-crosslinked olefin resin component containing propylene units and ethylene units, and polyorganosiloxane, wherein the resin composition contains polyorganosiloxane. However, polyorganosiloxane (P1) has a kinematic viscosity (JIS Z8803, 25°C) of 100,000 mm ² /s or more, and polyorganosiloxane (P2) has a kinematic viscosity (JIS Z8803, 25°C) of 50,000 mm ² /s or less. It consists of:

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 polyorganosiloxane (P1) having such a relatively high viscosity, a high effect in improving sliding durability and abrasion resistance can be expected.
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, the lower limit of the kinematic viscosity (JIS Z8803, 25°C) of polyorganosiloxane (P2) is preferably 10 mm ² /s, more preferably 50 mm ² /s from the viewpoint of moldability. By using polyorganosiloxane (P2) having such a relatively low viscosity, high effects on sliding properties and suppressing plate-out during molding can be expected.
By using polyorganosiloxanes such as polyorganosiloxane (P1) and polyorganosiloxane (P2) together, we achieve a high level of sliding properties, sliding durability, abrasion resistance, and the effect of suppressing plate out during molding. can do.

[mechanism]
Although the details of the reason why the resin composition for sliding members of the present invention exhibits the above-described effects are not clear, it is presumed as follows.
It is presumed that the high viscosity polyorganosiloxane (P1) has the effect of suppressing the precipitation of the low viscosity polyorganosiloxane on the surface of the resin composition due to its thickening effect. It is thought that this effect suppresses molding defects due to poor biting of the resin composition pellets into the molding machine.
It is presumed that the low-viscosity polyorganosiloxane (P2) has the effect of acting as a lubricant and a dispersant for the high-viscosity polyorganosiloxane (P1). This effect is thought to suppress processing defects due to plate-out due to segregation of the high-viscosity polyorganosiloxane (P1) during molding.
In addition, by using two types of polyorganosiloxanes (P1) and (P2) with high viscosity and low viscosity, these dual effects occur, thereby improving processability while maintaining high sliding properties. It is presumed that a resin composition with excellent moldability can be obtained.

Furthermore, in a resin composition containing a non-crosslinked olefin resin component containing propylene units and ethylene units and a polyorganosiloxane, the content T1 (mass %) of propylene units and the content T2 (mass %) of ethylene units. When the ratio T1/T2 is 0.50 to 0.80, a co-continuous structure of polyethylene and polypropylene is formed, and the design is such that a large number of interfaces where polyorganosiloxane can be unevenly distributed are formed within this structure. I can do it. In a molded body using a resin composition having such a co-continuous structure, repeated sliding causes polyorganosiloxane to gradually seep out from the molded body through the interface of the co-continuous structure onto the sliding surface. , it is thought that better sliding properties can be obtained.

[Physical properties of resin composition for sliding members]
<DuroD hardness>
The resin composition for sliding members of the present invention preferably has a DuroD hardness of 40 to 56 as measured with reference to the ISO 868 standard. When the DuroD hardness is 40 or more, it has excellent sliding properties. The DuroD hardness of the resin composition for sliding members of the present invention is preferably 43 or more. On the other hand, when the DuroD hardness is 56 or less, the trackability is excellent. The DuroD hardness of the resin composition for sliding members of the present invention is preferably 55 or less. In particular, when the DuroD hardness is in the range of 43 to 55, it is possible to obtain a sliding member with an even better balance between slidability and followability under high loads.

<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 when measured at a measurement temperature of 230°C and a measurement load of 21.2N with reference to the JIS K7210 standard. , is preferable 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 20 g/10 minutes or less, and 15 g/10 minutes or less. More preferably, the heating time is 10 minutes or less.

[Olefin resin component]
The resin composition for a sliding member of the present invention contains a non-crosslinked olefin resin component containing propylene units and ethylene units. The resin composition for sliding members of the present invention is a resin composition for sliding members that has a ratio T1/T2 (hereinafter simply referred to as It is preferable to contain an olefin resin component so that the ratio (sometimes referred to as "T1/T2") is 0.50 to 0.80. This T1/T2 is more preferably 0.55 to 0.80, and still 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 a glass window and the sliding ability under high load, both of which are required of a sliding member.

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, but from the viewpoint of easy control of the above-mentioned T1/T2, the olefin resin component according to the present invention is It is preferable to contain 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

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

As mentioned above, T1/T2 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 still more preferably 0.60 to 0.80. Therefore, T1/T2 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 is 0.60 to 0.80.

<Component (A): Propylene polymer>
The propylene polymer used as component (A) for the olefin resin component is not particularly limited, and may include a propylene homopolymer, a propylene copolymer (a block copolymer of propylene units and other monomer units, or Random copolymers), etc. can be used.
Here, the propylene-based copolymer means one in which the content of propylene units is 50% by mass or more.

When the propylene polymer of component (A) is a propylene copolymer, other monomers copolymerized with propylene include ethylene, 1-butene, 2-methylpropylene, 1-pentene, and 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 Examples include vinyl monomers such as styrene, vinyltoluene, and divinylbenzene, but are not particularly limited thereto. These other copolymerization components may be used alone or in combination of two or more.

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 minutes, more preferably 0.3 ~20g/10 minutes. By using the polypropylene polymer of component (A) having such an MFR, good moldability and excellent appearance can be ensured.

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

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

Moreover, a commercially available propylene polymer may be used as the component (A). Commercially available products of component (A) include, for example, 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 Sun Allomer Co., Ltd., and Novatec manufactured by Nippon Polypro Co., Ltd. (registered trademark) PP, Tafmer (registered trademark) manufactured by Mitsui Chemicals, WAYMAX (registered trademark), Moplen (registered trademark) manufactured by LyondellBasell, ExxonMobil PP manufactured by ExxonMobil, manufactured by Dow Chemical Versify (registered trademark), Formolene (registered trademark) manufactured by Formosa Plastics, Borealis PP manufactured by Borealis, SEETEC PP manufactured by LG Chemical, A. ASI POLYPROPYLENE manufactured by Schulman, INEOS PP manufactured by INEOS Olefins & Polymers, Braskem PP manufactured by Braskem, Sumsun manufactured by SAMSUNG TOTAL PETROCHEMICALS g Total, Sabic (registered trademark) PP manufactured by Sabic, TOTAL PETROCHEMICALS Polypropylene manufactured by TOTAL PETROCHEMICALS , YUPLENE (registered trademark) manufactured by SK Corporation.

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

[Component (B): Ethylene polymer]
The ethylene polymer used as component (B) for the olefin resin component is not particularly limited, and may include an ethylene homopolymer, an ethylene copolymer (a block copolymer of ethylene units and other monomer units, or Random copolymers), etc. can be used.
Here, the ethylene copolymer means one in which the content of ethylene units is 50% by mass or more.

When the ethylene polymer of component (B) is an ethylene copolymer, other monomers 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 Non-conjugated polyenes such as -vinyl-2-norbornene, 2,5-norbornadiene, and 4-ethylidene-8-methyl-1,7-nanodiene are mentioned, but are not particularly limited thereto. These other copolymerization components may be used alone or in combination of two or more.

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

The ethylene polymer preferably has a density (JIS K6922) of 0.91 to 0.97 g/cm ³ . Furthermore, by containing polyethylene with a density of 0.94 to 0.97 g/cm ³ as at least a part of component (B), excellent sliding properties and wear resistance can be obtained as a resin composition for sliding members. There is a tendency to become more easily affected.

In terms of density, ethylene polymers can be classified into high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (L-LDPE, LDPE), ethylene plastomer, and ethylene elastomer.

In this specification, high-density polyethylene is a polyethylene polymer with a density of 0.94 g/cm ³ or more (less than 0.98 g/cm ³ ), and medium-density polyethylene is a polyethylene polymer with a density of 0.93 g/cm 3 or more (less than 0.94 g/cm ³ ). Polyethylene polymers with a density of less than cm ³ , low density polyethylene have a density of 0.91 g/cm ³ or more to less than 0.93 g/cm ³ Polyethylene polymers, ethylene plastomers have a density of 0.89 g/cm ³ or more and 0.91 g A polyethylene polymer having a density of less than 0.89 g/cm ³ (0.85 g/cm 3 or more) 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 preferred from the viewpoint of sliding properties.

In the present invention, since the ethylene polymer exists in a non-crosslinked state, it is easier to maintain a co-continuous structure and obtain desired sliding properties compared to when 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 21.2N) of 0.1 to 13 g/10 min, more preferably 0.1 to 13 g/10 min. It is 12g/10 minutes. By using the ethylene polymer of component (B) having such an MFR, it becomes easy to fuse with another member molded from a polypropylene resin material, making it suitable for applications such as sliding members for weather strips. Can be used.

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

The ethylene polymer of component (B) may be used alone or in combination of two or more having different compositions and physical properties.

[Polyorganosiloxane]
The types 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 are not particularly limited, but include dimethyl silicone (dimethyl polysiloxane), methylphenyl silicone, or alkyl Modified silicone is preferably used.

Polyorganosiloxane has a kinematic viscosity (JIS Z8803, 25°C) of 100,000 mm ² /s or more in order to improve moldability and processability while imparting sliding properties, sliding durability, and abrasion resistance. A relatively high viscosity polyorganosiloxane (P1) and a relatively low viscosity polyorganosiloxane (P2) having a kinematic viscosity (JIS Z8803, 25°C) of 50,000 mm ² /s or less are used together.

Polyorganosiloxane (P1) can be obtained as a commercial product. Applicable commercial products include, for example, the "DOW CORNING TORAYTM (registered trademark)" series manufactured by DuPont Toray Specialty Materials, the "DOW CORNING TM (registered trademark)" series, and the "X-22-2101" manufactured by Shin-Etsu Chemical Co., Ltd. '', and the appropriate product can be selected and used from these.
Polyorganosiloxane (P2) is available as a commercial product. Applicable commercial products include, for example, the "KF-96" series manufactured by Shin-Etsu Silicone Co., Ltd. and the "DOWSIL" series manufactured by Dow Chemical Co., Ltd., and a suitable product can be appropriately selected from these and used.

Each of the polyorganosiloxanes (P1) and (P2) may be used alone, or two or more thereof may be used in any combination and ratio.

[Blending ratio]
The resin composition for sliding members of the present invention contains 2 to 10 parts by mass of polyorganosiloxane in total of polyorganosiloxane (P1) and polyorganosiloxane (P2) per 100 parts by mass of the olefin resin component. is preferred. By setting the lower limit of the total content of polyorganosiloxane to 2 parts by mass or more, sliding durability is further improved, and water removal performance is further improved in applications such as sliding members of weather strips. Further, the generation of abnormal noise during sliding is further reduced. The lower limit of the total content of polyorganosiloxane is more preferably 3 parts by mass or more. Further, by setting the upper limit of the total content of polyorganosiloxane to 10 parts by mass or less, the moldability of the resin composition for a sliding member becomes even better, and the occurrence of bleeding tends to be suppressed. The upper limit of the total content of polyorganosiloxane is more preferably 6 parts by mass or less.

In addition, from the viewpoint of effectively obtaining the above-mentioned effects by using high viscosity polyorganosiloxane (P1) and low viscosity polyorganosiloxane (P2) together, polyorganosiloxane (P1) and polyorganosiloxane (P2) It is preferable that the content of polyorganosiloxane (P1) is 40 to 80% by mass, and the content of polyorganosiloxane (P2) is 20 to 60% by mass, in the total 100% by mass of polyorganosiloxane (P1). ) is preferably 50 to 80% by mass, and the content of polyorganosiloxane (P2) is preferably 20 to 50% by mass.

The content of the propylene polymer as component (A) in 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. %. Further, the content of the ethylene polymer as component (B) in 100% by mass of the olefin resin component is preferably 40 to 70% by mass, more preferably 40 to 65% by mass, and still more preferably 45 to 70% by mass. It is 65% by mass.

It is preferable that 100% by mass of the total amount of the olefin resin component is composed of a total of 100% by mass of component (A) and component (B). Component (A) is preferably 30 to 60% by mass, more preferably 35 to 60% by mass, even more preferably 35 to 60% by mass, based on the total of 100% by mass of components (A) and (B). It is 55% by mass. Further, component (B) is preferably 40 to 70% by mass, more preferably 40 to 65% by mass, and even more preferably It is 45 to 65% by mass.

The polyorganosiloxane is preferably contained in an amount of 2 to 10 parts by weight, particularly 3 to 6 parts by weight, based on the total of 100 parts by weight of components (A) and (B).

By containing each component in the above-mentioned proportions, it becomes easier to achieve a higher level of conformability to glass windows and slidability under high loads.

[Other ingredients]
The resin composition for sliding members of the present invention may contain other components other than the olefin resin component and the polyorganosiloxane (herein simply referred to as "other components"), as necessary, to the extent that the object of the present invention is not impaired. ). Examples 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 falling under the above components (A) and (B)), polyester resins, polyamide resins, and styrene resins. Resins such as resins, acrylic resins, polycarbonate resins, and polyvinyl chloride resins; polyamide elastomers such as polyamide/polyol copolymers; polyvinyl chloride elastomers and polybutadiene elastomers; hydrogenated products of these, acid anhydrides, etc. Examples include those that have been modified to have a polar functional group introduced thereto, and those that have been grafted, random and/or block copolymerized with other monomers. The other resins listed above are 1
It may contain only seeds or two or more kinds.

Among these, examples of the polyolefin resin include α-olefins having 2 to 4 carbon atoms, such as ethylene, propylene, and 1-butene, alone or copolymers containing these as main components. Specifically, these polyolefin resins are not limited to homopolymers such as poly-1-butene, but as long as the main component is an α-olefin having 2 to 4 carbon atoms, other α-olefins having 5 to 20 carbon atoms can be used. - It also includes copolymers with olefins or vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, and styrene. Furthermore, a graft copolymer graft-modified with an unsaturated carboxylic acid such as maleic anhydride, maleic acid, or acrylic acid or a derivative thereof may also be used. Furthermore, these polyolefin resins may be a mixture.

When the resin composition for sliding members of the present invention contains other resins, the content of the other resins in the resin composition for sliding members of the present invention is the total content of component (A) and component (B). ) is preferably 30 parts by mass or less, more preferably 20 parts by mass or less.

In addition, additives that may be contained in the resin composition for sliding members of the present invention include, in addition to lubricants used together with polyorganosiloxane, antioxidants, molding aids such as crystal nucleating agents, ultraviolet absorbers, and hindered amines. Light stabilizers such as type compounds, hydrolysis resistance improvers, colorants such as pigments and dyes, antistatic agents, conductive agents, flame retardants, reinforcing agents, fillers, plasticizers, mold release agents, foaming agents, etc. It will be done.

The resin composition for sliding members of the present invention may contain a dithiocarbamate-based antioxidant, a hindered phenol-based antioxidant, a sulfur-based antioxidant, a phosphorus-based antioxidant, etc. as an antioxidant. I can do it.
These antioxidants may be used alone or in combination of two or more.

When the resin composition for sliding members of the present invention contains an antioxidant, the content of the antioxidant is preferably 0.01 parts by mass based on a total of 100 parts by mass of components (A) and (B). ~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 heat deterioration resistance, while when it is 5 parts by mass or less, problems such as bleeding are less likely to occur and the composition is improved. Preferable from the viewpoint of mechanical strength.

Furthermore, 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. In this case, the coloring agent is combined with component (A). It is preferably blended in an amount of 0.1 to 5 parts by weight, particularly 0.3 to 3 parts by weight, based on a total of 100 parts by weight of component (B). Note that it is preferable to blend a small amount of components such as a coloring agent such as carbon black as a master batch of a resin such as a polyolefin resin in terms of uniform dispersibility in the resin composition for a sliding member.

Furthermore, the resin composition for dynamic sliding members of the present invention may contain a filler in order to improve manufacturing stability, dimensional stability, and flame retardancy. In this case, the filler may include glass fibers. , hollow glass bulbs, carbon fibers, talc, calcium carbonate, mica, clay, potassium titanate fibers, silica, metal soaps, titanium dioxide, carbon black, etc. (carbon black can be used both as a coloring agent and as a filler). ). When blending a filler, the filler is usually used in an amount of 0.1 to 200 parts by weight based on a total of 100 parts by weight of components (A) and (B).

[Molding of resin composition for sliding member]
Any molding method such as extrusion molding, injection molding, compression molding, or blow molding can be applied to molding the resin composition for a sliding member of the present invention.

[Extrusion molded product]
The extrusion molded article of the present invention can be manufactured by extrusion molding the resin composition for a sliding member of the present invention.

Using the resin composition for sliding members of the present invention, an extrusion molded product integrated with other members, for example, a base material made of a resin such as a propylene polymer, and a part of the base material laminated. When forming the sliding part of a weatherstrip that has a sliding part provided so as to Although they may be molded simultaneously, a coextrusion molding method is particularly suitable.

[Sliding member]
The sliding member made of 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, so it can be used as a composite resin molded product used indoors or outdoors. In particular, we manufacture automotive exterior parts such as roof moldings, weather strips, window moldings, flush mount moldings, side moldings, and glass run channels, automotive interior parts such as seat rail protective covers, assist grips, and shift knobs, entrance door seals, and packing materials. It is suitable for construction gaskets, handrails, table edges, desk edges, etc., and is especially suitable for automotive molding applications such as automotive weather strips.

Hereinafter, specific embodiments of the present invention will be explained in more detail using Examples, but the present invention is not limited by the following Examples unless the gist thereof is exceeded. In addition, the values of various manufacturing conditions and evaluation results in the following examples have the meaning as preferable upper or lower limits in the embodiments of the present invention, and the preferable ranges are different from the above-mentioned upper or lower limits. , it may be a range defined by the values of the following examples or a combination of values of the examples.

〔raw materials〕
The raw materials used in the following Examples and Comparative Examples are as follows.

[Component (A): Propylene polymer]
<Propylene homopolymer>
・A-1: Manufactured by Nippon Polypro Co., Ltd. Product name: Novatec (registered trademark)
MFR (230°C, 21.2N): 2.5g/10min Density (JIS K7112): 0.90g/ ^cm3
Flexural modulus (JIS K7171): 1400MPa
・A-2: Manufactured by Nippon Polypro Co., Ltd. Product name: Novatec (registered trademark)
MFR (230°C, 21.2N): 11g/10min Density (JIS K7112): 0.90g/ ^cm3
Flexural modulus (JIS K7171): 1500MPa
・A-3: Manufactured by Nippon Polypro Co., Ltd. Product name: Novatec (registered trademark)
MFR (230°C, 21.2N): 0.4g/10min Density (JIS K7112): 0.90g/ ^cm3
Flexural modulus (JIS K7171): 1950MPa
・A-4: Manufactured by Nippon Polypro Co., Ltd. Product name: Novatec (registered trademark)
MFR (230°C, 21.2N): 40g/10min Density (JIS K7112): 0.90g/ ^cm3
Flexural modulus (JIS K7171): 1450MPa

<Propylene copolymer>
・A-5: Manufactured by Dow Chemical Co., Ltd. Product name: Versify (registered trademark)
Propylene/ethylene copolymer Propylene unit content: 90% by mass
MFR (230°C, 21.2N): 25g/10min Density (JIS K7112): 0.88g/ ^cm3
Flexural modulus (JIS K7171): 120MPa
・A-6: Manufactured by Dow Chemical Co., Ltd. Product name: Versify (registered trademark)
Propylene/ethylene copolymer Propylene unit content: 90% by mass
MFR (230°C, 21.2N): 2g/10min Density (JIS K7112): 0.87g/ ^cm3
Flexural modulus (JIS K7171): 100MPa
・A-7: Manufactured by Mitsui Chemicals, Inc. Product name: Tafmer (registered trademark)
Propylene/1-butene copolymer Propylene unit content: 65-75% by mass
MFR (230°C, 21.2N): 7g/10min Flexural modulus (JIS K7171): 200MPa
<Other polypropylene polymers>
・A-8: Manufactured by DuPont Toray Specialty Materials, Inc. Product name: MULTIBASE (registered trademark) MB50-001G2 (pellets with a polypropylene content of 50%, in which silicone gum is dispersed in polypropylene) Contains polypropylene propylene units Rate: 100% by mass

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

[Component (C): Polyorganosiloxane]
<Polyorganosiloxane (P1)>
・C-1 (P1): Manufactured by DuPont Toray Specialty Materials, Inc. Product name: MULTIBASE (registered trademark)
Grade name: MB50-001G2
Dimethylpolysiloxane masterbatch (pellets of silicone gum dispersed in polypropylene)
Dimethylpolysiloxane content: 50% by mass
Kinematic viscosity of dimethylpolysiloxane (25°C): 1,000,000 mm 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 dimethyl polysiloxane (25°C): 100 mm ² /s
・C-3 (P2): Manufactured by Shin-Etsu Silicone Co., Ltd. Product name: KF-96 (registered trademark)
Dimethyl silicone oil Kinematic viscosity of dimethyl polysiloxane (25°C): 1,000 mm ² /s
・C-4 (P2): Manufactured by Dow Chemical Company Product name: DOWSIL (registered trademark)
Dimethyl silicone oil Kinematic viscosity of dimethyl polysiloxane (25°C): 12,500 mm ² /s

[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 Co., Ltd.)
・TACKIROL 201 (crosslinking agent, manufactured by Taoka Chemical Co., Ltd.)
・Zinc oxide (crosslinking activator, manufactured by Wako Pure Chemical Industries, Ltd.)
・Stannic chloride (crosslinking activator, manufactured by Wako Pure Chemical Industries, Ltd.)

〔Evaluation methods〕
The evaluation method of sliding materials in the following Examples and Comparative Examples is as follows.

[Manufacture of pellets]
The ingredients shown in Tables 1 to 3 were mixed in the proportions shown in Tables 1 to 3, and the mixture was put into a co-directional twin screw extruder (Japan Steel Works "TEX30", L/D = 52.5, number of cylinder blocks: 14). Pour the mixture. Melt-kneading was performed by raising the temperature from the upstream part to the downstream part in the range of 120 to 210°C, and the strand discharged from the die was cut with a pelletizer to obtain uniformly shaped pellets made of the resin composition.

[DuroD hardness]
Using the obtained pellets, injection molding was performed using an in-line screw type injection molding machine ("IS130" manufactured by Toshiba Machine Co., Ltd.) under conditions of an injection pressure of 50 MPa, a cylinder temperature of 220 ° C., and a mold temperature of 40 ° C., A sheet with a thickness of 2 mm x width of 120 mm x length of 80 mm was obtained.
DuroD hardness of this sheet was measured with reference to the ISO 868 standard. Those with DuroD hardness in the range of 40 to 56 are evaluated as having excellent 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 using a single-screw extruder at a set temperature of 180° C. to 230° C. to form a test piece for a sliding material with a width of 25 mm and a thickness of 1 mm.
Regarding the obtained test piece, the coefficient of dynamic friction 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: counterpart material: glass plate, speed: 100 mm/s, distance: 6 cm, load: 500 g, and measurement environment temperature: 23°C. It is evaluated that the smaller this value is, the better the sliding properties under high loads are.

[Workability]
The obtained pellets were extruded using a single-screw extruder with a set temperature of 180°C to 230°C, and 15 minutes after the start of molding, the pellets adhered to the exit of a die with a width of 25 mm and a thickness of 1 mm. The amount of plate-out (amount of precipitate) generated was visually confirmed. A case in which plateout occurred and a precipitate was confirmed was judged as "×", and a case in which no precipitate was confirmed was judged as "○". It is evaluated that the smaller the amount of plate-out occurrence, the less deterioration of the appearance of the molded product due to precipitates and the better the workability.

The occurrence of plate-out in the processability evaluation of Example 1 and Comparative Example 7 is shown in FIGS. 1 and 2. The white spots are precipitates. In Example 1 (FIG. 1), there is no precipitate at the die exit 15 minutes after the start of molding. On the other hand, in Comparative Example 7 (FIG. 2), a large amount of precipitates adhered to the die outlet 15 minutes after the start of molding.

[Moldability]
Using the obtained pellets, extrusion molding was carried out by setting the temperature of a single screw extruder to 180°C to 230°C. If the pellets were put into the hopper of the extruder and could be molded with stable discharge, the rating would be "〇."If the pellets slipped against each other and were not well-bited into the molding machine, resulting in poor discharge and difficulty in molding, the rating would be "○." ×” was determined. The better the pellets penetrate into the molding machine and can be molded with stable discharge, the better the moldability is evaluated.

〔Evaluation results〕
The evaluation results in Examples 1 to 6 and Comparative Examples 1 to 13 are shown in Tables 1 to 3.

From Tables 1 to 3, it can be seen that the resin composition for sliding members of the present invention has excellent followability and slidability under high loads, and is also excellent in processability and moldability.
On the other hand, in Comparative Examples 1 to 12, a large amount of plate-out occurred and the workability was poor.
In Comparative Example 13, low-viscosity silicone precipitated on the pellet surface, causing the pellets to slip against each other during molding, and the pellets did not bite into the molding machine, so molding could not be performed and a molded product could not be obtained.

Claims (11)

A resin composition for a sliding member comprising a non-crosslinked olefin resin component containing propylene units and ethylene units, and a polyorganosiloxane,
The polyorganosiloxane is composed of a polyorganosiloxane (P1) having a kinematic viscosity (25°C) of 100,000 mm ² /s or more and a polyorganosiloxane (P2) having a kinematic viscosity (25°C) of 50,000 mm ² /s or less. Resin composition for sliding members. The print according to claim 1, wherein the ratio T1/T2 of the content T1 (mass%) of propylene units and the content T2 (mass%) of ethylene units in the olefin resin component is 0.5 to 0.8. Resin composition for moving parts. The resin composition for a sliding member according to claim 1 or 2, having a DuroD hardness (ISO 868) of 40 or more and 56 or less. Any one of claims 1 to 3, 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 21.2N is 0.5/10 minutes or more and 25 g/10 minutes or less. The resin composition for sliding members as described in 2. The resin composition for a sliding member according to any one of claims 1 to 4, which contains a total of 2 to 10 parts by mass of the polyorganosiloxane based on 100 parts by mass of the olefin resin component. The resin composition for a sliding member according to any one of claims 1 to 5, wherein the olefin resin component contains the following components (A) and (B).
Component (A): Propylene polymer Component (B): Ethylene polymer According to claim 6, of the 100% by mass of the olefin resin component, the content of the component (A) is 30 to 60% by mass, and the content of the component (B) is 40 to 70% by mass. Resin composition for sliding members. The resin composition for a sliding member according to claim 6 or 7, wherein the component (B) contains polyethylene having a density of 0.91 to 0.97 g/cm ³ . An extrusion molded article of the resin composition for a sliding member according to any one of claims 1 to 8. An automobile part comprising the extrusion molded article according to claim 9. A weather strip comprising a base material and a sliding member made of the resin composition for sliding members according to any one of claims 1 to 8.

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