JP6827815B2 - Polyamide resin composition and molded product - Google Patents

Description

The present invention relates to a polyamide resin composition and a molded product using the polyamide resin composition.

Conventionally, it has been studied to use a polyamide resin for sliding parts. For example, Patent Document 1 describes a sliding member made of a polyamide resin composition containing 100 parts by mass of a polyamide composed of a terephthalic acid component and a 1,10-decanediamine component and 0.5 to 60 parts by mass of a slidability improving material. (Sliding parts) are disclosed. Further, in Patent Document 2, the fibrous fillers are bundled in a state of being aligned in the length direction, and the bundle of the fibrous fillers is impregnated with polyamide in a molten state and integrated, and then the length is 5 to 15 mm. A resin composition containing a resin-impregnated fiber bundle cut into a resin composition, wherein the polyamide is an aromatic polyamide obtained from an aromatic dicarboxylic acid and an aliphatic diamine or an aliphatic dicarboxylic acid and an aromatic diamine, and the fibrous filling The material is selected from carbon fiber, glass fiber, aramid fiber, and genbuiwa fiber, and it can be visually confirmed that the epidermis does not turn over in the abrasion resistance test using the resin composition. Abrasion resistant molding Resin compositions for the body are disclosed.

Japanese Unexamined Patent Publication No. 2013-64420 Japanese Unexamined Patent Publication No. 2012-131918

As described above, the sliding parts using the polyamide resin need to have excellent wear resistance. However, as a result of examination by the present inventor, it has been found that the wear resistance may be insufficient, or even if the wear resistance is excellent, the mechanical strength may be inferior. An object of the present invention is to solve such a problem, and a polyamide resin composition capable of providing a molded product having excellent wear resistance while maintaining high mechanical strength, and the polyamide resin. An object of the present invention is to provide a molded product using the composition.

Under such circumstances, as a result of diligent studies by the present inventor, it has been found that the above problems can be solved by the following means <1>, preferably <2> to <14>.
<1> (A) Polyamide resin and (B) Polyamide wax are contained, and the (A) polyamide resin is (a-1) semi-aromatic polyamide resin 10 to 90% by mass, and (a-2) the above (a-2). a-1) A polyamide resin composition containing 10 to 90% by mass of an aliphatic polyamide resin having a lower melting point than a semi-aromatic polyamide resin and a glass transition temperature of 20 ° C. or higher.
<2> The (A) polyamide resin further contains (a-3) a polyamide resin having a higher melting point than the (a-1) semi-aromatic polyamide resin in a proportion of 1 to 50% by mass. <1> The polyamide resin composition according to.
<3> The polyamide resin composition according to <1> or <2>, wherein the content of the (B) polyolefin wax is 1 to 50 parts by mass with respect to 100 parts by mass of the (A) polyamide resin.
<4> The polyamide resin composition according to any one of <1> to <3>, further comprising an inorganic filler in a ratio of 10 to 200 parts by mass with respect to 100 parts by mass of the (A) polyamide resin.
<5> The polyamide resin composition according to <4>, wherein the inorganic filler is glass fiber.
<6> The (a-1) semi-aromatic polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 70 mol% or more of the diamine-derived structural unit is m-xylylenediamine and para. A polyamide resin derived from α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms, in which 70 mol% or more of the constituent units derived from dicarboxylic acid, which are derived from at least one of xylylenediamine, are <1. > The polyamide resin composition according to any one of <5>.
<7> The polyamide resin composition according to any one of <1> to <6>, wherein the (A) polyamide resin contains the (a-2) aliphatic polyamide resin in a proportion of 15 to 55% by mass. Stuff.
<8> The polyamide resin composition according to any one of <1> to <7>, wherein the (a-2) aliphatic polyamide resin contains polyamide 6.
<9> The polyamide resin composition according to any one of <1> to <8>, wherein the polyamide resin (a-3) is polyamide 66.
<10> The polyamide resin composition according to any one of <1> to <9>, further comprising a nucleating agent in a ratio of 0.1 to 10 parts by mass with respect to 100 parts by mass of the (A) polyamide resin. ..
<11> The polyamide resin composition according to any one of <1> to <10>, further comprising a black colorant in a ratio of 0.1 to 10 parts by mass with respect to 100 parts by mass of the (A) polyamide resin. Stuff.
<12> A molded product formed from the polyamide resin composition according to any one of <1> to <11>.
<13> The molded product according to <12>, which is a sliding component.
<14> The polyamide resin composition according to any one of <1> to <11> above, further comprising at least one metal salt selected from an alkali metal salt and an alkaline earth metal salt. Polyamide resin composition.

INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to provide a polyamide resin composition capable of providing a molded product having excellent wear resistance while maintaining high mechanical strength, and a molded product using the polyamide resin composition.

The contents of the present invention will be described in detail below. In addition, in this specification, "~" is used in the meaning that the numerical values described before and after it are included as the lower limit value and the upper limit value.

The polyamide resin composition of the present invention contains (A) a polyamide resin and (B) a polyolefin wax, and the (A) polyamide resin is (a-1) semi-aromatic polyamide resin 10 to 90% by mass. a-2) It is characterized by containing 10 to 90% by mass of an aliphatic polyamide resin having a lower melting point than the (a-1) semi-aromatic polyamide resin and having a glass transition temperature lower than 20 ° C. or more. With such a configuration, a molded product having excellent wear resistance can be obtained while maintaining high mechanical strength. In this mechanism, the (a-1) semi-aromatic polyamide resin maintains high mechanical strength, the melting point is lower than that of the (a-1) semi-aromatic polyamide resin, and the glass transition temperature is 20 ° C. or higher. It is presumed that the aliphatic polyamide resin (a-2) is softened by the frictional heat of the sliding surface, making it difficult to scrape the sliding parts.

<(A) Polyamide resin>
<< (a-1) Semi-aromatic polyamide resin >>
The (A) polyamide resin in the present invention includes (a-1) semi-aromatic polyamide resin. By including the semi-aromatic polyamide resin, it becomes possible to maintain high mechanical strength and deflection temperature under load of the obtained molded product.
Here, the semi-aromatic polyamide resin is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 30 to 70 mol% of the total structural unit of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit is 30 to 70 mol%. It means that the structural unit contains an aromatic ring, and it is preferable that 40 to 60 mol% of the total structural unit of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit is the structural unit containing an aromatic ring.

Examples of the semi-aromatic polyamide resin used in the present invention include polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene isophthalamide (polyamide 6I), polyamide 66 / 6T, polyxylylene adipamide, and polyxylylene. Examples thereof include bacamide, polyxylylene decamide, polyamide 9T, polyamide 9MT, and polyamide 6I / 6T.

Among the above-mentioned polyamide resins, from the viewpoint of moldability and heat resistance, they are composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 70 mol% or more of the diamine-derived structural unit is m-xylylenediamine. And paraxylylenediamine, and 70 mol% or more of the constituent units derived from dicarboxylic acid are derived from α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms (hereinafter, It is sometimes referred to as "XD-based polyamide").

The XD-based polyamide contains at least 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 95 mol% or more of the diamine-derived constituent units of metaxylylenediamine and paraxylylenediamine. Α, which is derived from one of them and has 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol%, still more preferably 95 mol% or more of the constituent units derived from dicarboxylic acid, having 4 to 20 carbon atoms. Derived from ω-linear aliphatic dicarboxylic acid.

Examples of diamines other than m-xylylenediamine and paraxylylenediamine that can be used as the raw material diamine component of XD-based polyamide include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, and octa. An aliphatic diamine such as methylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,3-bis (amino) Methyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane , Bis (aminomethyl) decarin, bis (aminomethyl) tricyclodecane and other alicyclic diamines, bis (4-aminophenyl) ether, paraphenylenediamine, bis (aminomethyl) naphthalene and other diamines having an aromatic ring, etc. Can be exemplified, and one kind or a mixture of two or more kinds can be used.
When a diamine other than xylylenediamine is used as the diamine component, it is preferably less than 20 mol%, more preferably 10 mol% or less of the diamine-derived structural unit.

Examples of α, ω-linear aliphatic dicarboxylic acids having 4 to 20 carbon atoms that are preferable to be used as the raw material dicarboxylic acid component of the polyamide resin include succinic acid, glutaric acid, pimeric acid, suberic acid, azelaic acid, and adipic acid. , Sebacic acid, undecanedioic acid, dodecanedioic acid and other aliphatic dicarboxylic acids can be exemplified, and one kind or a mixture of two or more kinds can be used. Among these, the melting point of the polyamide resin is suitable for molding. Since it is in the range, adipic acid or sebacic acid is preferable, and adipic acid is more preferable.

Examples of the dicarboxylic acid component other than the α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms include phthalic acid compounds such as isophthalic acid, terephthalic acid, and orthophthalic acid, 1,2-naphthalenedicarboxylic acid, 1, 3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3- Examples thereof include naphthalenedicarboxylic acids such as isomers such as naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid, and one kind or a mixture of two or more kinds can be used. When a dicarboxylic acid component other than α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms is used, it is preferably less than 20 mol% of the dicarboxylic acid-derived constituent unit, and preferably 10 mol% or less. Is more preferable.

Although the constituent units derived from diamine and the constituent units derived from dicarboxylic acid are the main components, the constituent units other than these are not completely excluded, and lactams such as ε-caprolactam and laurolactam, aminocaproic acid. It goes without saying that a constituent unit derived from an aliphatic aminocarboxylic acid such as aminoundecanoic acid may be contained. Here, the main component means that the total of the diamine-derived structural units and the dicarboxylic acid-derived structural units in the (a-1) semi-aromatic polyamide resin is the largest of all the structural units. In the present invention, the total of the diamine-derived structural units and the dicarboxylic acid-derived structural units in the (a-1) semi-aromatic polyamide resin preferably occupies 90% or more of all the structural units, and preferably 95% or more. More preferred.

The melting point of the semi-aromatic polyamide resin (a-1) is preferably 150 to 310 ° C., more preferably 180 to 300 ° C., and even more preferably 180 to 250 ° C.
The glass transition temperature of the (a-1) semi-aromatic polyamide resin is preferably 50 to 150 ° C., more preferably 55 to 120 ° C., and particularly preferably 60 to 100 ° C. Within this range, the heat resistance of the molded product tends to be better.

The lower limit of the number average molecular weight (Mn) of the semi-aromatic polyamide resin (a-1) is preferably 6,000 or more, more preferably 8,000 or more, and 10,000 or more. Is even more preferable, 15,000 or more is even more preferable, 20,000 or more is even more preferable, and 22,000 or more is even more preferable. The upper limit of Mn is preferably 35,000 or less, more preferably 30,000 or less, further preferably 28,000 or less, and even more preferably 26,000 or less. Within such a range, heat resistance, elastic modulus, dimensional stability, and molding processability become better.

The semi-aromatic polyamide resin (a-1) has a molecular weight distribution (weight average molecular weight / number average molecular weight (Mw / Mn)) of preferably 1.8 to 3.1. The molecular weight distribution is more preferably 1.9 to 3.0, still more preferably 2.0 to 2.9. By setting the molecular weight distribution in such a range, it tends to be easy to obtain a three-dimensional structure having excellent mechanical properties.
(A-1) The molecular weight distribution of the semi-aromatic polyamide resin can be adjusted by appropriately selecting, for example, the type and amount of the initiator and catalyst used at the time of polymerization and the polymerization reaction conditions such as reaction temperature, pressure and time. .. Further, it can be adjusted by mixing a plurality of kinds of polyamide resins having different average molecular weights obtained under different polymerization conditions, or by separately precipitating the (a-1) semi-aromatic polyamide resin after polymerization.

The number average molecular weight and the weight average molecular weight can be determined by GPC measurement. Specifically, two Tosoh "HLC-8320GPC" as an apparatus and two "TSK gel Super HM-H" manufactured by Tosoh as a column are used. Hexafluoroisopropanol (HFIP) eluent with sodium trifluoroacetate concentration of 10 mmol / L, resin concentration of 0.02% by mass, column temperature of 40 ° C., flow velocity of 0.3 mL / min, refractive index detector (RI) conditions. It can be obtained as a value converted to standard polymethylmethacrylate. In addition, the calibration curve is prepared by dissolving 6 levels of PMMA in HFIP and measuring.

The lower limit of the content of the (a-1) semi-aromatic polyamide resin in the polyamide resin composition of the present invention is 10% by mass or more, preferably 20% by mass or more, preferably 25% by mass or more in the (A) polyamide resin. It is more preferably mass% or more, and further preferably 30 mass% or more. The upper limit of the content is 90% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less, further preferably 60% by mass or less, and further preferably 50% by mass. It may be less than%, particularly 40% by mass or less.
The (A) polyamide resin in the present invention may contain only one type of (a-1) semi-aromatic polyamide resin, or may contain two or more types. When two or more kinds are included, the total amount is preferably in the above range.

<< (a-2) Aliphatic Polyamide Resin >>
The (A) polyamide resin in the present invention has an aliphatic polyamide resin having a lower melting point than the (a-1) semi-aromatic polyamide resin and a glass transition temperature of 20 ° C. or higher (hereinafter, “(a-2)). (Sometimes referred to as "aliphatic polyamide resin"). (A-2) Since the aliphatic polyamide resin has a low glass transition temperature and a low melting point, when it is used for a sliding component, the surface softens when the sliding surface generates heat, and the surface of the sliding component becomes soft. Wear can be effectively suppressed.
The (a-2) aliphatic polyamide resin has a lower melting point than the (a-1) semi-aromatic polyamide resin, but is preferably 10 ° C. or higher, more preferably 15 ° C. or higher. The difference in melting point between the (a-2) aliphatic polyamide resin and the (a-1) semi-aromatic polyamide resin is preferably within 30 ° C.
The (a-2) aliphatic polyamide resin has a glass transition temperature lower than that of the (a-1) semi-aromatic polyamide resin by 20 ° C. or higher, preferably 25 ° C. or higher, and more preferably 26 ° C. or higher. The difference in glass transition temperature between the (a-2) aliphatic polyamide resin and the (a-1) semi-aromatic polyamide resin is preferably 35 ° C. or less.

The melting point of the aliphatic polyamide resin (a-2) is preferably 180 to 300 ° C., more preferably 190 to 290 ° C., and even more preferably 200 to 280 ° C.
The glass transition temperature of the (a-2) aliphatic polyamide resin is preferably 30 to 120 ° C., more preferably 35 to 100 ° C., and particularly preferably 40 to 80 ° C.
(A-2) The lower limit of the number average molecular weight (Mn) of the aliphatic polyamide resin is preferably 4,000 or more, more preferably 4,000 or more, and preferably 5,000 or more. Even more preferably, it is more preferably 7,000 or more, further preferably 8,000 or more, and even more preferably 10,000 or more. The upper limit of Mn is preferably 20,000 or less, more preferably 17,000 or less, further preferably 15,000 or less, and even more preferably 13,000 or less.

Here, the aliphatic polyamide resin means that 60% or more of the constituent units constituting the polyamide resin are constituent units derived from the aliphatic, and preferably 60% or more of the constituent units are derived from the aliphatic. More preferably, 80% or more of the constituent units are aliphatic-derived constituent units, more preferably 90% or more of the constituent units are aliphatic-derived constituent units, and even more preferably 95% or more of the constituent units. It means that it is a constituent unit derived from an aliphatic.

As the aliphatic polyamide resin (a-2), polyamide 6, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 11 and polyamide 12 are preferable, and polyamide 6 is more preferable.

Polyamide 6 includes Zytel 1011FB (trade name) manufactured by DuPont, UBE nylon 1011B, 1015B, 1022B, 1018SE (trade name) manufactured by Ube Industries, and Amiran CM1007, CM1017, CM1021, CM1026, CM1014 manufactured by Toray. (Product name), ULtramid 8200, 8202, 8270, B27, B3K, B3S, 8232G (trade name) manufactured by BASF, GRILON BS series, BZ series, BRZ series (trade name) manufactured by EMS can be mentioned.

The lower limit of the content of the (a-2) aliphatic polyamide resin in the polyamide resin composition of the present invention is 10% by mass or more, preferably 15% by mass or more, preferably 20% by mass in the (A) polyamide resin. % Or more is more preferable, 25% by mass or more is further preferable, 30% by mass or more is further preferable, and 40% by mass or more may be used. The upper limit of the content is 90% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less, further preferably 60% by mass or less, and 55% by mass or less. Is more preferable. However, the total amount of the (a-1) semi-aromatic polyamide resin and the (a-2) aliphatic polyamide resin does not exceed 100% by mass.
The (A) polyamide resin in the present invention may contain only one type of (a-2) aliphatic polyamide resin, or may contain two or more types. When two or more kinds are included, the total amount is preferably in the above range.

<< (a-3) Polyamide resin >>
The (A) polyamide resin in the present invention may contain a polyamide resin having a melting point higher than that of the (a-1) semi-aromatic polyamide resin (hereinafter, may be referred to as “(a-3) polyamide resin”). .. By blending such a polyamide resin, it is possible to compensate for the decrease in the thermal deformation temperature of the resin composition that may occur in the (a-2) aliphatic polyamide resin.
The (a-3) polyamide resin has a higher melting point than the (a-1) semi-aromatic polyamide resin, but is preferably 10 ° C. or higher, and more preferably 20 ° C. or higher. The difference in glass transition temperature between the (a-3) aliphatic polyamide resin and the (a-1) semi-aromatic polyamide resin is preferably 35 ° C. or less.

The melting point of the polyamide resin (a-3) is preferably 180 to 300 ° C., more preferably 190 to 290 ° C., and even more preferably 200 to 280 ° C.
The glass transition temperature of the (a-3) polyamide resin is preferably 30 to 120 ° C., more preferably 35 to 100 ° C., and particularly preferably 40 to 80 ° C.
(A-3) The lower limit of the number average molecular weight (Mn) of the polyamide resin is preferably 6,000 or more, more preferably 8,000 or more, and further preferably 10,000 or more. , 16,000 or more, more preferably 21,000 or more, and even more preferably 23,000 or more. The upper limit of Mn is preferably 35,000 or less, more preferably 30,000 or less, further preferably 28,000 or less, and even more preferably 26,000 or less.

The polyamide resin (a-3) is preferably polyamide 66, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 11 and polyamide 12, with polyamide 66 being more preferred.

Polyamide 66 includes UBE Nylon 2015B, 2020B, 2026B (trade name) manufactured by Ube Industries, Ltd., Amiran CM3007, CM3001, CM3001-N, CM3006, CM3301, CM3304, CM3004 (trade name) manufactured by Toray, and Asahi Kasei Co., Ltd. Leona 1200S, 1300S, 1500, 1700 (trade name), ULTRAMID 1000, 1003, A3, N322, A3X2G5 (trade name) manufactured by BASF, GRILON AS series, AZ series, AR, AT series manufactured by EMS (trade name). (Product name), Zytel 101, 103, 42A, 408 (trade name) manufactured by DuPont can be mentioned.

When blended, the lower limit of the content of the (a-3) polyamide resin in the polyamide resin composition of the present invention is preferably 1% by mass or more, preferably 3% by mass or more in the (A) polyamide resin. More preferably, it is more preferably 5% by mass or more, further preferably 8% by mass or more, and even more preferably 10% by mass or more. The upper limit of the content is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, and particularly preferably 20% by mass or less. However, the total amount of (a-1) semi-aromatic polyamide resin, (a-2) aliphatic polyamide resin and (a-3) polyamide resin does not exceed 100% by mass.
The (A) polyamide resin in the present invention may contain only one type of (a-3) polyamide resin, or may contain two or more types. When two or more kinds are included, the total amount is preferably in the above range.

<< Blend of polyamide resin >>
The polyamide resin (A) in the present invention may contain one or more polyamide resins other than the above-mentioned polyamide resins (a-1) to (a-3).
In the present invention, the total amount of (a-1) semi-aromatic polyamide resin, (a-2) aliphatic polyamide resin and (a-3) polyamide resin accounts for 90% by mass or more of (A) polyamide resin. It is preferable to occupy 95% by mass or more, and even more preferably 99% by mass or more.
In the present invention, (a-1) / (a-2), which is the mass ratio of (a-1) semi-aromatic polyamide resin and (a-2) aliphatic polyamide resin, is 0.5 to 5.0. It is preferably 0.5 to 3.0, more preferably 0.5 to 2.0. With such a ratio, the specific wear amount tends to be smaller.
Further, in the present invention, the ratio of (a-1) / (a-3), which is the mass ratio of the (a-1) semi-aromatic polyamide resin and the (a-3) polyamide resin, is 2.0 to 5. It is preferably 5, and more preferably 2.0 to 4.4. With such a ratio, the specific wear amount tends to be smaller.

The lower limit of the total amount of the (A) polyamide resin in the polyamide resin composition of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 25% by mass or more. It is preferably 30% by mass or more, more preferably 30% by mass or more. The upper limit of the total amount is preferably 90% by mass or less, more preferably 80% by mass or less, further preferably 60% by mass or less, still more preferably 50% by mass or less. It is even more preferably 45% by mass or less, and even more preferably 40% by mass or less.

<(B) Polyolefin wax>
The polyamide resin composition of the present invention contains a polyolefin wax. By containing the polyolefin wax, the friction coefficient of the resin composition can be reduced and the wear of the sliding surface of the material can be reduced.
Examples of polyolefin waxes include low molecular weight polyethylene, low molecular weight polyethylene copolymers, or modified polyethylene waxes in which polar groups have been introduced by oxidative modification or acid modification thereof. Further, when the modified polyethylene wax having a polar group introduced by oxidative modification or acid modification is blended in an amount of 1 to 10% by mass of the (B) polyolefin wax, the dispersibility in the polyamide resin can be improved. It can be done and is more preferable. The number average molecular weight (Mn) of the polyolefin wax may be appropriately selected and determined, but is preferably less than 20000, more preferably 500 to 15000, further preferably 1000 to 10000, and 1000 to 9000. It is particularly preferable to have. The Mn of the polyolefin wax can be measured by gel permeation chromatography (GPC).
The polyolefin wax used in the present invention preferably has a melting point of 60 to 145 ° C.

Examples of the polyolefin wax include polyethylene wax, polypropylene wax, polyethylene oxide wax, acid-modified polyethylene wax, and acid-modified polypropylene wax.
Examples of commercially available polyolefin waxes include 800P, 400P, 200P, 100P, 720P, 420P, 320P, 405MP, 320MP, 4051E, 2203A, 1140H, NL800, NP055, NP105, of "Mitsui High Wax" manufactured by Mitsui Chemicals. NP505, NP805, 1105A, 2203A, NP0555A and the like can be used.

The lower limit of the content of the polyolefin wax in the polyamide resin composition of the present invention is preferably 1 part by mass or more, more preferably 3 parts by mass or more, with respect to 100 parts by mass of the (A) polyamide resin. It is more preferably parts by mass or more, more preferably 7 parts by mass or more, and even more preferably 9 parts by mass or more. The upper limit of the content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, further preferably 20 parts by mass or less, and particularly preferably 15 parts by mass or less.
The polyamide resin composition of the present invention may contain only one type of polyolefin wax, or may contain two or more types of polyolefin wax. When two or more kinds are included, the total amount is preferably in the above range.

<Inorganic filler>
The polyamide resin composition of the present invention preferably contains an inorganic filler for the purpose of reinforcing the polyamide resin composition and improving rigidity, heat resistance, dimensional stability and the like. The shape of the inorganic filler is not particularly limited and may be fibrous, plate-shaped, granular or needle-shaped, but fibrous is preferable. However, the inorganic filler in the present invention is intended to exclude the nucleating agent and the metal salt described later.
Specific examples of the inorganic filler include glass-based inorganic fillers (glass fibers, glass flakes, glass beads, milled fibers), alumina fibers, and carbon fibers, and glass-based inorganic fillers are preferable. Agents are more preferred, and glass fibers are even more preferred.

The glass fibers preferably used in the present invention preferably have a number average fiber diameter of 20 μm or less, and those having a number average fiber diameter of 1 to 15 μm further enhance the physical balance (heat resistance, impact strength) and further improve the molding warpage. It is preferable in that it is further reduced.
The composition of the raw material glass is preferably non-alkali, and examples thereof include E glass, C glass, and S glass. In the present invention, E glass is preferably used.

The glass fiber shall be surface-treated with a surface treatment agent such as a silane coupling agent such as γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, or γ-aminopropyltriethoxysilane. Is preferable. The amount of the surface treatment agent adhered is preferably 0.01 to 1% by mass of the glass fiber. Further, if necessary, a fatty acid amide compound, a lubricant such as silicone oil, an antistatic agent such as a quaternary ammonium salt, a resin having a film-forming ability such as an epoxy resin and a urethane resin, a resin having a film-forming ability, and heat. It is also possible to use a surface-treated mixture of a stabilizer, a flame retardant and the like.

When the polyamide resin composition of the present invention contains an inorganic filler, the content thereof is preferably 10 parts by mass or more, preferably 50 parts by mass or more, with respect to 100 parts by mass of the (A) polyamide resin. More preferably, it is more preferably 100 parts by mass or more, further preferably 130 parts by mass or more, and even more preferably 150 parts by mass or more. The upper limit of the content is preferably 200 parts by mass or less, more preferably 190 parts by mass or less, and further preferably 185 parts by mass or less.
The polyamide resin composition of the present invention may contain only one kind of inorganic filler, or may contain two or more kinds of inorganic fillers. When two or more kinds are included, the total amount is preferably in the above range.

<Metal salt>
The polyamide resin composition of the present invention may contain at least one metal salt selected from alkali metal salts and alkaline earth metal salts. By blending the metal salt, elution of polyolefin wax can be effectively suppressed, the hardness of the sliding surface when made into a sliding component can be maintained higher, and wear resistance can be improved. Can be done. The metal salt used in the present invention is preferably an alkaline earth metal salt.
Examples of the alkali metal include sodium and potassium. Examples of the alkaline earth metal include calcium, magnesium and barium, and calcium or barium is preferable.
In the present invention, as the metal salt, carbonates such as calcium carbonate, magnesium carbonate and barium carbonate, and sulfates such as calcium sulfate and magnesium sulfate are preferable, carbonates are more preferable, and calcium carbonate and barium carbonate are further preferable. Calcium carbonate is more preferred.
The particle size of the metal salt is preferably 0.1 to 50 μm, more preferably 0.5 to 30 μm, and even more preferably 1 to 10 μm.
The metal salt used in the present invention is preferably particles having an aspect ratio of less than 5. With such an aspect ratio, the metal salt approaches a spherical shape, and the effect of the present invention is more effectively achieved.
Examples of commercially available products of the metal salt include NS100 manufactured by Nitto Flour Chemical Co., Ltd.

The lower limit of the content of the metal salt in the polyamide resin composition of the present invention is preferably 1 part by mass or more, more preferably 3 parts by mass or more, based on 100 parts by mass of the (A) polyamide resin. It is more preferably 5 parts by mass or more, further preferably 6 parts by mass or more, and further preferably 9 parts by mass or more. The upper limit of the content is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, further preferably 30 parts by mass or less, still more preferably 20 parts by mass or less. It is even more preferably 15 parts by mass or less.
The polyamide resin composition of the present invention may contain only one kind of the above metal salt, or may contain two or more kinds of the above metal salts. When two or more kinds are included, the total amount is preferably in the above range.

<Nuclear agent>
The polyamide resin composition of the present invention may contain a nucleating agent in order to increase the crystallization rate and enhance the moldability. The type of nucleating agent is not particularly limited, but talc, boron nitride, mica, kaolin, calcium carbonate, barium sulfate, silicon nitride, potassium titanate and molybdenum disulfide are preferable, and talc and boron nitride are more preferable. Preferably, talc is even more preferred.
The average particle size of the nucleating agent is preferably 4 to 10 μm.
When the polyamide resin composition of the present invention contains a nucleating agent, the content thereof is preferably 0.1 to 10 parts by mass, and 0.5 to 8 parts by mass with respect to 100 parts by mass of the (A) polyamide resin. Is more preferable, and 1 to 5 parts by mass is further preferable.
The polyamide resin composition of the present invention may contain only one kind of nucleating agent, or may contain two or more kinds of nucleating agents. When two or more kinds are included, the total amount is preferably in the above range.

<Black colorant>
The polyamide resin composition of the present invention may contain a black colorant. Examples of the black colorant used in the present invention include carbon black. For details of carbon black, the description in paragraph 0021 of JP-A-2011-57977 can be referred to, and these contents are incorporated in the present specification.
Further, when a black colorant such as carbon black is blended in the polyamide resin composition of the present invention, the description in paragraphs 0038 to 0042 of JP2011-57977A can be referred to in the production of the polyamide resin composition. The contents are incorporated herein by reference.
The carbon black used in the present invention preferably has a DBP oil absorption of 40 to 60 g / cm ³ .
When the polyamide resin composition of the present invention contains a black colorant, the content thereof is preferably 0.1 to 10 parts by mass, and 0.5 to 8 parts by mass with respect to 100 parts by mass of the (A) polyamide resin. Parts are more preferable, and 1 to 5 parts by mass are further preferable.
The polyamide resin composition of the present invention may contain only one type of black colorant, or may contain two or more types of black colorant. When two or more kinds are included, the total amount is preferably in the above range.

<Other additives>
The polyamide resin composition of the present invention may contain other additives generally used for the polyamide resin in addition to the above, as long as the gist of the present invention is not impaired. Examples of such other additives include resins other than polyamide resins, mold release agents, lubricants, stabilizers, flame retardants, fluorescent bleaching agents, plasticizers, antioxidants, UV absorbers, antistatic agents, and fluidized agents. Examples include sex improvers. The total content of the other additives is preferably 5% by mass or less of the polyamide resin composition. Details of these additives can be referred to in JP-A-2011-57977 and JP-A-2015-129244, the contents of which are incorporated in the present specification.
Examples of other resins include polyester resin, polyphenylene sulfide resin, polyphenylene ether resin, polycarbonate resin, polyarylate resin, phenol resin, epoxy resin and the like.

<Manufacturing method of polyamide resin composition>
The method for producing the polyamide resin composition of the present invention is not particularly specified, and a known method for producing a thermoplastic resin composition can be widely adopted. Specifically, each component is premixed using various mixers such as a tumbler and a Henschel mixer, and then melt-kneaded with a Banbury mixer, roll, brabender, single-screw extruder, twin-screw extruder, kneader, or the like. Can produce a polyamide resin composition.

Further, for example, the polyamide resin composition can be produced without premixing each component or by premixing only a part of the components and supplying the components to an extruder using a feeder for melt kneading. ..
Further, for example, a resin composition obtained by premixing some components and supplying them to an extruder to be melt-kneaded is used as a masterbatch, and this masterbatch is mixed with the remaining components again and melt-kneaded. Polyamide resin compositions can also be produced.

<Molded product>
Next, a molded product formed from the polyamide resin composition of the present invention will be described. The pellet obtained by pelletizing the polyamide resin composition of the present invention is molded by various molding methods to obtain a molded product. Further, the resin composition melt-kneaded by an extruder can be directly molded into a molded product without passing through pellets.
The shape of the molded product is not particularly limited and may be appropriately selected depending on the intended use and purpose of the molded product. For example, plate-shaped, plate-shaped, rod-shaped, sheet-shaped, film-shaped, cylindrical, annular, etc. Examples thereof include a circular shape, an elliptical shape, a gear shape, a polygonal shape, a deformed product, a hollow product, a frame shape, a box shape, and a panel shape.

The method for molding the molded product is not particularly limited, and a conventionally known molding method can be adopted. For example, an injection molding method, an injection compression molding method, an extrusion molding method, a deformed extrusion method, a transfer molding method, a hollow molding method, etc. Gas assist hollow molding method, blow molding method, extrusion blow molding, IMC (in-mold coating molding) molding method, rotary molding method, multi-layer molding method, two-color molding method, insert molding method, sandwich molding method, foam molding method , Pressurization molding method and the like.

Since the polyamide resin composition of the present invention is a resin material having high wear resistance while maintaining high mechanical strength, a molded product obtained by molding the same is preferably used as a sliding part.
Specific examples of sliding parts include gears for electrical equipment, office equipment and power equipment, rotating shafts, bearings, various gears, cams, end face materials for mechanical seals, valve seats such as valves, V-rings, rod packing, and pistons. It can be suitably used for sealing members such as rings and rider rings, rotating shafts of compressors, rotating sleeves, pistons, impellers, rollers and the like.

Hereinafter, the present invention will be described in more detail with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

<Raw materials>
(A) Polyamide resin (a-1) Semi-aromatic polyamide resin: Polyamide MXD6 (polycondensate of metaxylylenediamine and adipic acid), "Polyamide MXD6 # 6000" manufactured by Mitsubishi Gas Chemicals, melting point 243 ° C, glass Transition temperature 75 ° C, Mn25000
(A-2) Aliphatic polyamide resin: Polyamide 6, manufactured by DuPont, Zytel 1011FB, melting point 225 ° C, glass transition temperature 48 ° C, Mn11000
(A-3) (a-1) Polyamide resin having a higher melting point than the semi-aromatic polyamide resin: Polyamide 66, manufactured by Toray Industries, Inc., Amylan CM3001, melting point 268 ° C, glass transition temperature 50 ° C, Mn24000

(B) Polyolefin wax LDPE-WAX: Mitsui Chemicals, Inc., high wax 720P, Mn7200
HDPE-WAX: Mitsui Chemicals, High Wax 800P, Mn8000
Acid-modified LDPE-WAX: Mitsui Chemicals, Inc., High Wax 1105A, Mn1500

Inorganic filler glass fiber: Nippon Electric Glass Co., Ltd., ECS03T-296GH, number average fiber diameter 10 μm
Nuclear agent talc: manufactured by Hayashi Kasei Co., Ltd., Micron White 5000A, average particle size 7μm
Black colorant Carbon black: Mitsubishi Chemical Corporation, # 45, DBP oil absorption 53g / 10cm ³

<Measurement method of melting point and glass transition temperature of polyamide resin>
The melting point of the polyamide resin was measured as the temperature of the peak top of the endothermic peak at the time of temperature rise observed by the DSC (differential scanning calorimetry) method. The glass transition temperature of the polyamide resin was measured as the peak top temperature measured by heating and melting the polyamide resin once to eliminate the influence of the thermal history on the crystallinity and then raising the temperature again.
Specifically, using a DSC measuring device, the amount of the polyamide resin as a sample is about 1 mg, nitrogen is flowed as an atmospheric gas at 30 mL / min, and the temperature rise rate is expected from room temperature under the condition of 10 ° C./min. The melting point was determined from the temperature at the top of the heat absorption peak observed when the mixture was heated to a temperature above the melting point and melted. Next, the molten polyamide resin was rapidly cooled with dry ice and heated again to a temperature equal to or higher than the melting point at a rate of 10 ° C./min to determine the glass transition temperature. As the DSC measuring instrument, DSC-60 manufactured by SHIMADZU CORPORATION was used.

<Example 1>
<< Compound of thermoplastic resin composition >>
Each component is weighed so that the final composition has the composition shown in the table described later (the amount of each component in the table is a mass ratio), the components excluding glass fiber are blended with a tumbler, and biaxial extrusion is performed. It was put in from the root of the machine (manufactured by Toshiba Machine Co., Ltd., TEM26SS) and melted. Carbon black was added after producing a 50% by mass masterbatch with a polyamide resin and kneaded. After kneading, the glass fibers were side-fed to prepare resin pellets (polyamide resin composition). The set temperature of the extruder was 280 ° C.

<< Measurement method of flexural strength and flexural modulus >>
The resin pellets obtained by the above-mentioned production method were dried at 120 ° C. for 4 hours, and then an ISO tensile test piece having a thickness of 4 mm was injection-molded using NEX140III manufactured by Nissei Resin Industry Co., Ltd. The cylinder temperature was 280 ° C. and the mold temperature was 130 ° C. Bending strength (unit: MPa) and flexural modulus (unit: GPa) were measured at a temperature of 23 ° C. using the above ISO tensile test piece (4 mm thickness) in accordance with ISO178.

<< Load Deflection Temperature (DTUL) >>
According to ISO75-1 and 2, the deflection temperature under load was measured under the condition of bending stress of 1.80 MPa using the above ISO tensile test piece (thickness 4 mm).

<< Specific wear amount >>
The resin pellets obtained by the above-mentioned production method were dried at 120 ° C. for 4 hours, and then a hollow cylindrical test piece having a contact area of 2 cm ² was injection-molded using NS-40 manufactured by Nissei Resin Industry Co., Ltd. At this time, the cylinder temperature was 280 ° C. and the mold temperature was 130 ° C.
In accordance with the JISK7218 (A) method, a frictional wear test between hollow cylindrical test pieces was carried out under the conditions of a linear velocity of 100 mm / sec and a pressurized load of 5 kgf for 20 hours in an environment of a temperature of 23 ° C. and a humidity of 50%. , The specific wear amount for the same material was measured for each test piece on the fixed side and the movable side of the device. The specific wear amount was calculated by dividing the volume of the test piece whose wear was reduced by the total mileage and the pressurized load.

<< Limit PV value >>
The friction and wear test between the hollow cylindrical test pieces obtained by the above molding method was performed under the condition of a linear velocity of 100 mm / sec, with an initial pressurizing load of 5 kgf, and the pressurizing load was increased by 5 kgf every minute. This was performed, and the limit PV value was determined. The limit PV value was determined by the product of the linear velocity and the pressurized load when the test piece was melted.

As is clear from the above results, when the polyolefin wax was not blended (Comparative Example 1), the specific wear amount of the molded product increased. Further, when the (a-2) aliphatic polyamide resin was not blended as the (A) polyamide resin (Comparative Example 2), the specific wear amount of the molded product increased.
On the other hand, when the (A) polyamide resin contains (a-1) a semi-aromatic polyamide resin and (a-2) an aliphatic polyamide resin in a predetermined blend ratio and also contains a polyolefin wax (Example). 1-6), a molded product with a small amount of specific wear was obtained while maintaining high mechanical strength. In particular, by reducing the content of the (a-2) aliphatic polyamide resin in the (A) polyamide resin to 55% by mass or less (Examples 1 to 5), a molded product having a smaller specific wear amount was obtained.

The molded product formed from the polyamide resin composition of the present invention has high mechanical strength and excellent wear resistance, so that gears, rotating shafts, bearings, various gears, etc. for electrical appliances, office equipment, power equipment, etc. Can be suitably used for cams, end face materials of mechanical seals, valve seats such as valves, seal members such as V-rings, rod packings, piston rings, rider rings, rotating shafts of compressors, rotating sleeves, pistons, impellers, rollers, etc. ..

Claims (12)

Contains (A) polyamide resin and (B) polyolefin wax
The (A) polyamide resin
(A-1) Semi-aromatic polyamide resin 10 to 90% by mass and
(A-2) wherein (a-1) a lower melting point than the semi-aromatic polyamide resin, and, viewed contains 10 to 90 wt% glass transition temperature of 20 ° C. or more lower aliphatic polyamide resin,
The mass ratio of (a-1) semi-aromatic polyamide resin and (a-2) aliphatic polyamide resin, (a-1) / (a-2), is 0.5 to 3.0.
The content of the (B) polyolefin wax is 5 to 50 parts by mass with respect to 100 parts by mass of the (A) polyamide resin.
Polyamide resin composition for sliding parts . The first aspect of claim 1, wherein the (A) polyamide resin further contains (a-3) a polyamide resin having a melting point higher than that of the (a-1) semi-aromatic polyamide resin in a proportion of 1 to 50% by mass. Polyamide resin composition. The polyamide resin composition according to claim 1 or 2, further comprising an inorganic filler in a ratio of 10 to 200 parts by mass with respect to 100 parts by mass of the (A) polyamide resin. The polyamide resin composition according to claim 3, wherein the inorganic filler is glass fiber. The semi-aromatic polyamide resin (a-1) is composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, and 70 mol% or more of the diamine-derived structural unit is m-xylylenediamine and paraxylylenediamine. 1 to 4, wherein 70 mol% or more of the constituent unit derived from the dicarboxylic acid is a polyamide resin derived from an α, ω-linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. The polyamide resin composition according to any one of the above items. The polyamide resin composition according to any one of claims 1 to 5, wherein the (A) polyamide resin contains the (a-2) aliphatic polyamide resin in a proportion of 15 to 55% by mass. The polyamide resin composition according to any one of claims 1 to 6, wherein the aliphatic polyamide resin (a-2) contains a polyamide 6. The polyamide resin composition according to claim 2, wherein the polyamide resin (a-3) is polyamide 66. The polyamide resin composition according to any one of claims 1 to 8, further comprising a nucleating agent in a ratio of 0.1 to 10 parts by mass with respect to 100 parts by mass of the (A) polyamide resin. The polyamide resin composition according to any one of claims 1 to 9, further comprising a black colorant in a ratio of 0.1 to 10 parts by mass with respect to 100 parts by mass of the (A) polyamide resin. A molded product formed from the polyamide resin composition according to any one of claims 1 to 10. The molded product according to claim 11, which is a sliding component.