JP2022143890A - Resin composition, and molding composed of the same - Google Patents

Abstract

To provide a resin composition that gives a molding having excellent slidability and wear resistance and also having sufficiently high mechanical strength.SOLUTION: A resin composition contains polybutylene terephthalate (A), modified ultrahigh-molecular-weight polyethylene (B), and fibrous filler (C). The fibrous filler (C) contains fiber and epoxy resin.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a resin composition and a molded article made therefrom, and more particularly to a resin composition containing polybutylene terephthalate and a molded article made therefrom.

Polybutylene terephthalate is a thermoplastic polyester plastic and is known as one of engineering plastics. Polybutylene terephthalate is widely used in the fields of automobiles and electrical/electronics because of its excellent moldability, electrical properties, heat resistance, chemical resistance, mechanical properties, and the like. This polybutylene terephthalate is often used in the form of glass fiber-reinforced polybutylene terephthalate, which is blended with glass fibers in order to improve mechanical properties.

On the other hand, attempts have been made to blend modified polyolefin compositions and fibrous fillers in order to improve physical properties of engineering plastics. For example, Patent Document 1 discloses a resin composition obtained by blending a modified polyolefin composition in a specific ratio with a composition containing polyphenylene sulfide and a fibrous filler. Here, in Patent Document 1, by blending a modified polyolefin composition with a composition containing polyphenylene sulfide and a fibrous filler, molding that has high slidability and excellent mechanical properties such as Charpy impact strength is performed. It is shown that the body is obtained.

Patent Document 2 discloses a resin material containing a base resin and modified ultra-high molecular weight polyethylene, and a gear made of the resin material. Here, in Patent Document 2, when polyamide, polyacetal, etc. are used as the base resin, by blending modified ultra-high molecular weight polyethylene, noise when used as a gear is reduced, and higher wear resistance is also achieved. shown to be obtained.

On the other hand, attempts have been made to improve the physical properties of glass fiber reinforced resins by using surface-treated glass fibers. For example, Patent Document 3 discloses a glass fiber obtained by coating glass with a sizing agent containing an epoxy resin. When this glass fiber is blended with a polyester resin, the glass has good mechanical strength and heat and humidity resistance. It has been shown that a fiber reinforced polyester resin material can be obtained.

JP 2019-218568 A Japanese Patent Application Laid-Open No. 2020-056506 JP 2014-019583 A

Although polybutylene terephthalate is often used in the form of glass fiber-reinforced polybutylene terephthalate, there is still room for improvement in sliding properties and abrasion resistance. On the other hand, when glass fiber-reinforced polybutylene terephthalate is blended with modified ultra-high molecular weight polyethylene, a sufficiently high mechanical strength may not be obtained depending on the type of glass fiber used to reinforce the polybutylene terephthalate.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resin composition that provides a molded article that has good slidability and high wear resistance as well as sufficiently high mechanical strength.

As a result of intensive studies under such circumstances, the present inventors have found that by using a resin composition containing polybutylene terephthalate, modified ultra-high molecular weight polyethylene, and a specific fibrous filler, good slidability and The inventors have found that it is possible to obtain a molded article having high wear resistance and sufficiently high mechanical strength, and have completed the present invention.

That is, the present invention relates to the following [1] to [6].
[1]
Polybutylene terephthalate (A);
A modified ultra-high molecular weight polyethylene (B);
including a fibrous filler (C),
The resin composition, wherein the fibrous filler (C) contains fibers and an epoxy resin.

[2]
The resin composition according to [1], wherein the modified ultra-high molecular weight polyethylene (B) is an acid-modified ultra-high molecular weight polyethylene.

[3]
The resin composition according to [1] or [2], wherein the fibrous filler (C) has an epoxy resin on the surface of the fiber.

[4]
Any one of [1] to [3], wherein in the fibrous filler (C), the fiber is at least one selected from the group consisting of glass fiber, carbon fiber, aramid fiber, metal fiber and ceramic fiber. The resin composition according to .

[5]
A molded article containing the resin composition according to any one of [1] to [4].
[6]
The molded article according to [5], which is a covering material or a sliding material.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a resin composition which gives a molded article having good slidability and high wear resistance and also having sufficiently high mechanical strength.

Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments at all, and can be carried out with appropriate modifications within the scope of the purpose of the present invention. be able to.
Here, in the present specification, a numerical range represented using "-" means a range including the numerical values described before and after "-" as lower and upper limits.

[Resin composition]
The resin composition according to the present invention is
Polybutylene terephthalate (A);
A modified ultra-high molecular weight polyethylene (B);
including a fibrous filler (C),
The fibrous filler (C) contains fibers and an epoxy resin.
The resin composition of the present invention will be described in detail below.

<Constituent Components of Resin Composition>
Polybutylene terephthalate (A)
The polybutylene terephthalate (A) used in the present invention is not particularly limited as long as it is polybutylene terephthalate, and it may be a commercially available product.

Commercially available examples of polybutylene terephthalate include NOVADURAN manufactured by Mitsubishi Engineering-Plastics Co., Ltd., TPS-PBT manufactured by Toray Plastics Seiko Co., Ltd., and DURANEX 500FP manufactured by Polyplastics.

The content of polybutylene terephthalate (A) in the resin composition of the present invention is the sum of polybutylene terephthalate (A), modified ultra-high molecular weight polyethylene (B) described later, and fibrous filler (C) described later. It is usually 52 to 88 parts by mass, preferably 55 to 82 parts by mass, per 100 parts by mass.

Modified ultra-high molecular weight polyethylene (B)
The modified ultra-high molecular weight polyethylene (B) used in the present invention is a polymer obtained by modifying ultra-high molecular weight polyethylene. The modified ultra-high molecular weight polyethylene (B) is preferably an ultra-high molecular weight polyethylene into which a functional group has been introduced. The functional group may be either a polar group or a non-polar group, but a polar group is preferred. Moreover, the modified ultra-high molecular weight polyethylene (B) is preferably an acid-modified ultra-high molecular weight polyethylene.

Functional groups to be introduced include, for example, carboxyl groups, amino groups, hydroxyl groups, silanol groups, and the like.
A polar group is introduced into the ultra-high molecular weight polyethylene by modifying it with an acid.

Acids used for modification include, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acid (trademark) and derivatives thereof. .

In the resin composition of the present invention, such modified ultra-high molecular weight polyethylene (B) tends to disperse in the polybutylene terephthalate (A). Since the resin composition of the present invention contains such a modified ultra-high molecular weight polyethylene (B), the slidability of the molded article is improved.

The content of the modified ultra-high molecular weight polyethylene (B) in the resin composition of the present invention is such that the polybutylene terephthalate (A) and the modified It is 2 parts by mass or more, preferably 3 parts by mass or more with respect to a total of 100 parts by mass of the ultra-high molecular weight polyethylene (B) and the fibrous filler (C) described later. On the other hand, from the viewpoint of maintaining sufficiently high mechanical properties, the contents of the polybutylene terephthalate (A) and the fibrous filler (C) in the resin composition of the present invention are preferably set to a certain level or more. Therefore, the content of the modified ultra-high molecular weight polyethylene (B) in the resin composition of the present invention is the polybutylene terephthalate (A), the modified ultra-high molecular weight polyethylene (B), and the fibrous filler (C) described later. 8 parts by mass or less, preferably 5 parts by mass or less per 100 parts by mass of the total of

Fibrous filler (C)
The fibrous filler (C) used in the present invention contains fibers and epoxy resin.
Examples of fibers constituting the fibrous filler (C) include glass fibers, carbon fibers, aramid fibers, metal fibers, ceramic fibers, boron fibers, potassium titanate whiskers, polyester fibers, and polyamide fibers. Examples of metal fibers include aluminum fibers and stainless steel fibers. In one preferred aspect of the present invention, the fiber is at least one selected from the group consisting of glass fiber, carbon fiber, aramid fiber, metal fiber and ceramic fiber.

These fibers have a fiber diameter of 1 to 30 μm, preferably 5 to 20 μm, a fiber length of 1,000 to 10,000 μm, preferably 2,000 to 6,000 μm, and an aspect ratio of 33 to 10,000, preferably 150 to 1,200. is desirable.

Examples of epoxy resins constituting the fibrous filler (C) include tris-hydroxyphenylmethane type epoxy, tetraglycidyldiaminidiphenylmethane, dolyglycidyl isocyanurate, and 1,3-bis(N,N-glycidyl amonomethyl). Examples include tri- to penta-functional epoxy resins such as cyclohexane, tetra-phenylolethane type epoxy, and N,N,N',N'-tetraglycidyl-1,3-benzene (methanamine). These can be used individually by 1 type, or can use 2 or more types together.

In addition to the epoxy resin, the fibrous filler (C) may contain a polyurethane resin, an olefin resin, or the like.
Here, in a preferred aspect of the present invention, the fibrous filler (C) has the epoxy resin on the surface of the fiber. In this aspect, the fibrous filler (C) has a core containing the fibers and a surface containing the epoxy resin. Here, the core portion may contain the epoxy resin in the gaps between the fibers. Such a fibrous filler (C) can be obtained by applying a sizing agent containing the epoxy resin to the fibers, followed by drying. The sizing agent may contain binders such as polyurethane resins and olefin resins, silane coupling agents such as aminosilane, ureidosilane, epoxysilane, acrylsilane, and vinylsilane, lubricants, antistatic agents, and the like.

Examples of such fibrous fillers (C) include glass fibers described in JP-A-2014-019583.
By containing such a fibrous filler (C), the resin composition of the present invention is improved in mechanical strength such as tensile strength. Even in the resin composition containing the polybutylene terephthalate (A) and the modified ultra-high molecular weight polyethylene (B), the surface treatment is performed with a resin other than an epoxy resin instead of the fibrous filler (C). In the resin composition containing the fibrous filler, the fibrous filler may not be sufficiently dispersed in the polybutylene terephthalate (A), and sufficient mechanical strength may not be obtained when formed into a molded article. be.

The content of the fibrous filler (C) in the resin composition of the present invention is 100 in total of the polybutylene terephthalate (A), the modified ultra-high molecular weight polyethylene (B), and the fibrous filler (C). It is usually 10 to 40 parts by mass, preferably 15 to 40 parts by mass.

<Configuration of resin composition>
The resin composition of the present invention contains the polybutylene terephthalate (A), the modified ultra-high molecular weight polyethylene (B), and the fibrous filler (C).

Here, the resin composition of the present invention may consist only of the polybutylene terephthalate (A), the modified ultra-high molecular weight polyethylene (B), and the fibrous filler (C), In addition to these components, other components (hereinafter referred to as "other components ”) may further be included.

Examples of "other ingredients" include inorganic fillers such as activated carbon, porous magnesium silicate, carbon black, calcium carbonate, barium sulfate, talc, kaolin, quartz, chalk, and mica, as well as fluororesin powder, graphite, etc. and solid lubricants. Additives conventionally used in plastics such as lubricants, flow auxiliaries, release agents, stabilizers, UV absorbers, inorganic pigments, organic dyes can also be "other ingredients". .

Examples of such additives include fatty acid amides. Fatty acid amides (D) are usually fatty acid amides having 12 or more carbon atoms, and specifically saturated fatty acid amides such as lauric acid amide, palmitic acid amide, stearic acid amide and behenic acid amide; erucic acid amide, olein Unsaturated fatty acid amides such as acid amides, brassic acid amides and elaidic acid amides; fatty acid bisamides such as methylenebisstearic acid amide, ethylenebisstearic acid amide and ethylenebisoleic acid amide; saturated or unsaturated fatty acid methylamides and fatty acid ethylamides. and fatty acid alkylamides.

Among these fatty acid amides, erucic acid amide is particularly preferable from the viewpoint of slidability. Such "other components" may be used singly or in combination of two or more.

The content of "other components" that can be contained in the resin composition of the present invention is preferably less than 10% by mass with respect to the entire resin composition of the present invention. Here, when two or more "other components" are used, the total content of "other components" is preferably less than 10% by mass with respect to the entire resin composition of the present invention. Become.

When the resin composition of the present invention contains "other components", the total amount of the polybutylene terephthalate (A), the modified ultra-high molecular weight polyethylene (B), and the fibrous filler (C) is It is preferably 90% by mass or more and less than 100% by mass with respect to the entire resin composition of the present invention.

<Method for producing resin composition>
The resin composition of the present invention is obtained by mixing the polybutylene terephthalate (A), the modified ultra-high molecular weight polyethylene (B), the fibrous filler (C), and the optional "other components". obtained by Here, the polybutylene terephthalate (A) may be blended separately from the fibrous filler (C), or a composite to which the fibrous filler (C) has been added in advance ( That is, it may be blended in the form of a composite containing the polybutylene terephthalate (A) and the fibrous filler (C).

This mixing can be performed by a conventionally known method, for example, by melt-kneading with a twin-screw extruder. When this mixing is performed by melt-kneading, this melt-kneading can be performed at a temperature of, for example, 240°C to 280°C.

[Molded body]
The molded article according to the present invention contains the resin composition of the present invention described above.
Such a molded article of the present invention can be obtained by molding the resin composition of the present invention described above. The molding can be performed using a suitable molding method generally used in the field to which the present invention belongs, for example, injection molding.

The molded article of the present invention contains the polybutylene terephthalate (A), the modified ultra-high molecular weight polyethylene (B), and the fibrous filler (C), thereby having excellent mechanical strength and good slidability. can have Therefore, its uses include covering materials and sliding materials.

EXAMPLES The present invention will be described in more detail based on examples below, but the present invention is not limited to these examples. In addition, each physical property was measured as follows in an Example.

[Methods for measuring various physical properties of compacts]
For each of the following examples and comparative examples, the obtained resin composition was injection molded into a multi-purpose test piece (type A1 dumbbell-shaped tensile test piece defined in JIS K7139) and a length of 120 mm x width of 130 mm. A flat plate test piece having a thickness of × 3 mm was produced, and the following physical properties were evaluated.

Here, in the tests described in "Bending Strength", "Dynamic Friction Coefficient", and "Specific Abrasion Amount" below, a flat plate test piece (resin member) was used as a test piece. In other tests, multi-purpose specimens were used as specimens.

<Tensile test>
A tensile test was performed at a tensile speed of 50 mm/min according to ISO-527-1, 2 to determine the tensile strength and elongation at break of the test piece.

<Charpy impact strength>
Charpy impact strength was measured using notched test pieces according to ISO-179. Here, the notched test piece was obtained by cutting a multi-purpose test piece.

<Bending strength>
The bending strength of the flat test piece was determined according to ISO-178 with a bending span of 48.0 mm and a test speed of 5.0 mm/min.

<Coefficient of dynamic friction>
The dynamic friction coefficient of the flat plate test piece was measured using a Matsubara type friction and wear tester according to JIS K7218 "Plastic sliding wear test method A".

The test conditions were as follows.
Mating material: carbon steel (S45C), speed: 50 cm/sec, distance: 3 km, load: 30 kgf, measurement environment temperature: 23°C.

<Specific wear amount>
The specific wear amount of the flat plate test piece was measured using a Matsubara type friction and wear tester according to JIS K7218 "Plastic sliding wear test method A".

The test conditions were as follows.
Mating material: carbon steel (S45C), speed: 50 cm/sec, distance: 3 km, load: 30 kgf (dynamic friction coefficient), measurement environment temperature: 23°C.

[material]
In the examples and comparative examples, the following components were used for each component constituting the composition.

<Polybutylene terephthalate (PBT)>
The following products were used as polybutylene terephthalate (A) (component (A)):
LONGLITE (trademark) 1100 (hereinafter “PBT-1100”) manufactured by Chang Chun Plastics Co., Ltd.

<Modified ultra-high molecular weight polyethylene>
The following products were used as modified ultra-high molecular weight polyethylene (B) (component (B)):
Modified ultra-high molecular weight polyethylene Lubmer (registered trademark) LY1040 manufactured by Mitsui Chemicals, Inc.

<Fibrous filler>
As the fibrous filler (C) (component (C)), the following epoxy resin-coated glass fibers or epoxy/urethane resin-coated glass fibers were used:
・ Epoxy resin-coated glass fiber T-717H manufactured by Nippon Electric Glass Co., Ltd. (chopped strand with a filament diameter of 10 μm and a strand length of 3.0 mm; hereinafter “epoxy-based GF”)
・ Epoxy / urethane resin coated glass fiber T-127H manufactured by Nippon Electric Glass Co., Ltd. (chopped strand with a filament diameter of 10 μm and a strand length of 3.0 mm; hereinafter “urethane / epoxy GF”)
As a fibrous filler (component (C')) that does not correspond to the fibrous filler (C) used in the present invention, the following acid-treated glass fibers were used:
・ Acid-treated glass fiber T-262H manufactured by Nippon Electric Glass Co., Ltd. (chopped strand with a filament diameter of 10 μm and a strand length of 3.0 mm; hereinafter “acid-based GF”)

[Examples 1-2 and Comparative Examples 1-4]
PBT, modified ultra-high molecular weight polyethylene, and fibrous filler were melt-kneaded by a twin-screw extruder set at 250° C. according to the blending amounts shown in Table 1 to obtain a resin composition.

The physical properties of the obtained resin composition were evaluated as described above in the "Methods for measuring various physical properties of molded articles". Table 1 shows the results.

Claims (6)

Polybutylene terephthalate (A);
A modified ultra-high molecular weight polyethylene (B);
including a fibrous filler (C),
The resin composition, wherein the fibrous filler (C) contains fibers and an epoxy resin. 2. The resin composition according to claim 1, wherein said modified ultra-high molecular weight polyethylene (B) is acid-modified ultra-high molecular weight polyethylene. 3. The resin composition according to claim 1, wherein said fibrous filler (C) has an epoxy resin on the surface of said fibers. 4. Any one of claims 1 to 3, wherein in the fibrous filler (C), the fiber is at least one selected from the group consisting of glass fiber, carbon fiber, aramid fiber, metal fiber and ceramic fiber. The resin composition according to . A molded article comprising the resin composition according to any one of claims 1 to 4. 6. The molded article according to claim 5, which is a covering material or a sliding material.