Slidability improver for resin and resin composition using the same

Abstract

To provide a slidability improver for a resin which can impart slidability to a resin composition without lowering mechanical properties of a resin, when being added to a resin and formed into a resin composition, and can maintain slidability, bending characteristics and dimension of the resin composition even under the environment that a wide range of temperature and humidity change is repeated.SOLUTION: A slidability improver for a resin contains dialkyl ketone A having 29 to 61 carbon atoms and an average carbon number represented by a, and dialkyl ketone B having 25 to 57 carbon atoms and an average carbon number represented by b, wherein a difference (a-b) between the a and the b is 4 or more and 8 or less, and a mass ratio of the dialkyl ketone A to the dialkyl ketone B is 95:5 to 99.9:0.1.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a sliding property improver for resins and a resin composition using the same.

Background Art

[0002] Polypropylene resins, polyethylene resins, polyacetal resins, polyamide resins, polycarbonate resins, polyimide resins, phenolic resins, thermoplastic polyimide resins, polyetherimide resins, etc. are used in many applications. The above resins are also used in applications such as electrical and electronic component applications using surface mounting technology, automotive component applications such as electrical components in the engine room, and sliding members such as gears and bearings. In these applications, it is required to maintain the performance inherent in the resin.

[0003] Patent Document 1 discloses a technique for improving the sliding property while maintaining the bending characteristics of a resin member by adding an organic peroxide to a polyacetal resin. However, due to the further expansion of the applications of the above resin members, the required performance has become even higher. In particular, in the automotive industry, since the shift to electric vehicles has started to be rapidly promoted, the reduction of vehicle weight has become an urgent issue. For the weight reduction of automobiles, the replacement of metal members with resin members is effective, and the resinization of sliding parts and especially exterior parts with a large volume contributes greatly to the weight reduction. Therefore, automobile manufacturers are strengthening such efforts.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Automobiles are expected to be used in various environments. For example, it is assumed that the temperature and humidity differ significantly between summer and winter. However, resins are prone to dimensional changes due to temperature and humidity variations. Also, when resin members are used in sliding parts, in cold regions, the temperature difference between the sliding parts during use and non-use becomes large. Therefore, there is a problem that temperature cycles at high and low temperatures are repeated, resulting in a decrease in the slidability and flexural modulus of the resin member.

[0006] The present invention has been made in view of the above problems. When added to a resin to form a resin composition, it is possible to impart slidability to the resin composition without degrading the mechanical properties of the resin. Furthermore, an object of the present invention is to provide a slidability improver for resins that can maintain the slidability, bending characteristics, and dimensions of the resin composition even in an environment where wide temperature and humidity changes are repeated.

Means for Solving the Problems

[0007] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by a slidability improver for resins containing a plurality of specific dialkyl ketones, and have completed the present invention.

[0008] That is, the present invention provides a slidability improver for resins containing a dialkyl ketone A having 29 to 61 carbon atoms and an average carbon number of a, and a dialkyl ketone B having 25 to 57 carbon atoms and an average carbon number of b, wherein the difference (a - b) between a and b is 4 or more and 8 or less, and the mass ratio of the dialkyl ketone A to the dialkyl ketone B is 95:5 to 99.9:0.1.

[0009] The present invention also provides a resin composition containing the above slidability improver for resins and a resin, and containing 0.1 to 20 parts by mass of the slidability improver for resins with respect to 100 parts by mass of the resin.

Effects of the Invention

[0010] When the sliding property improver for resins of the present invention is added to a resin to form a resin composition, it can impart sliding property to the resin composition without degrading the mechanical properties of the resin. Further, even when the resin composition is used in an environment where wide temperature and humidity changes are repeated, the sliding property, bending characteristics, and dimensions can be maintained.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described. In this specification, a numerical range defined using the symbol "~" includes the numerical values at both ends (upper limit and lower limit) of "~". For example, "2~10" represents a range of 2 or more and 10 or less.

[0012] The sliding property improver for resins of the present invention (hereinafter, also simply referred to as "sliding property improver") contains at least two types of dialkyl ketones, namely dialkyl ketone A and dialkyl ketone B. Dialkyl ketones generally may have a molecular weight distribution when analyzed by gel permeation chromatography (GPC). Therefore, in this specification, the "number of carbon atoms" of dialkyl ketone means the distribution of the number of carbon atoms when each dialkyl ketone is analyzed by gel permeation chromatography (GPC). Also, the number of carbon atoms being 29~61 means that the number of carbon atoms (distribution of the number of carbon atoms) is within this range, and does not mean that the distribution of the number of carbon atoms necessarily spreads from 29 to 61. Further, in this specification, the "average number of carbon atoms" refers to the number of carbon atoms at the peak in the distribution of the number of carbon atoms seen when dialkyl ketone is measured by GPC.

[0013] Incidentally, the sliding property improver of the present invention may contain three or more types of dialkyl ketones. Here, in this specification, among the plurality of dialkyl ketones contained in the sliding property improver, the dialkyl ketone having 29 to 61 carbon atoms and the highest content is treated as dialkyl ketone A. On the other hand, a dialkyl ketone having an average carbon number (b) that is 4 to 8 less than the average carbon number a of dialkyl ketone A and having 25 to 57 carbon atoms is treated as dialkyl ketone B. Note that the sliding property improver only needs to contain at least one kind of dialkyl ketone B, and may contain two or more kinds. Furthermore, the sliding property improver may further contain a dialkyl ketone having 25 to 61 carbon atoms that does not correspond to the above-mentioned dialkyl ketone A and dialkyl ketone B (hereinafter, also referred to as "other dialkyl ketone") as long as the object and effect of the present invention are not impaired.

[0014] In addition, the sliding property improver of the present invention may contain components other than dialkyl ketones, and may contain, for example, fatty acid amide C or β-ketocarboxylic acid D described later. Each component will be described below.

[0015] 〔Dialkyl ketone A〕 The dialkyl ketone A used in the present invention is a compound containing one carbonyl group and having aliphatic chains (alkyl groups) bonded to both sides thereof, and any compound having 29 to 61 carbon atoms and an average carbon number a is acceptable. Dialkyl ketone A may be composed of a single component, or may be a mixture having a certain molecular weight distribution as described above. The carbon number and the average carbon number a of the dialkyl ketone are preferably 29 to 51, and more preferably 29 to 41.

[0016] Here, the two aliphatic chains in the dialkyl ketone A may be the same or different. However, from the perspective of the crystallinity of the dialkyl ketone A, the difference in the number of carbon atoms between the two aliphatic chains is preferably 2 or less, more preferably 0. Each aliphatic chain may be linear or branched, but a linear chain is preferred. Also, each aliphatic chain may be either saturated or unsaturated, but saturation is preferred.

[0017] Examples of the ketone used in the dialkyl ketone A include dipentadecyl ketone, dihexadecyl ketone, diheptadecyl ketone, heptadecyl pentadecyl ketone, dioctadecyl ketone, dinonadecyl ketone, dieicosyl ketone, diheneicosyl ketone, didocosyl ketone, ditricosyl ketone, ditetracosyl ketone, dioctacosyl ketone, didecacosyl ketone, etc.

[0018] The method for preparing the above dialkyl ketone A is not particularly limited. For example, in the presence of a metal oxide catalyst, a carboxylic acid having a desired aliphatic chain can be reacted at a high temperature (preferably a temperature of 300 to 350 °C) and under high pressure (preferably 0.1 to 5 MPa), and decarboxylated to obtain it. Examples of the metal oxide catalyst that can be used include magnesium oxide, calcium oxide, zinc oxide, etc. The carboxylic acid is appropriately selected according to the desired number of carbon atoms, and examples thereof include palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, etc.

[0019] On the other hand, when preparing the above dialkyl ketone A, instead of the above carboxylic acid and metal oxide catalyst, a metal carboxylate such as magnesium carboxylate, calcium carboxylate, zinc carboxylate, etc. may be used. Representative examples thereof include magnesium stearate, calcium stearate, zinc stearate, magnesium behenate, calcium behenate, zinc behenate, magnesium palmitate, magnesium montanate, magnesium eicosanoate, magnesium hexacosanoate, magnesium heptadecanoate, etc.

[0020] [Dialkyl ketone B] The dialkyl ketone B used in the present invention is a compound containing one carbonyl group and having aliphatic chains bonded to both sides thereof, having 25 to 57 carbon atoms, and having an average number of carbon atoms b that is 4 to 8 less than the average number of carbon atoms a of the above dialkyl ketone A. As long as it is a compound, it is sufficient. The number of carbon atoms and the average number of carbon atoms b of the dialkyl ketone B are preferably 25 to 47, more preferably 25 to 39. As described above, the sliding property improver may contain only one kind of compound corresponding to the dialkyl ketone B, or may contain two or more kinds.

[0021] The difference (a - b) between the average number of carbon atoms a of the above dialkyl ketone A and the average number of carbon atoms b of the above dialkyl ketone B may be 4 to 8, preferably 4 to 6. When the difference between the average number of carbon atoms a of the dialkyl ketone A and the average number of carbon atoms b of the above dialkyl ketone B is within this range, the crystallinity of the dialkyl ketone A can be appropriately reduced by the dialkyl ketone B. As a result, when the sliding property improver is added to the resin, the dialkyl ketone is more likely to be uniformly dispersed. And it is possible to impart high sliding property to the resin composition without impairing the original mechanical properties of the resin. In addition, the dialkyl ketone A and the dialkyl ketone B are excellent in hydrolysis resistance and the like. Therefore, when these are uniformly dispersed in the resin composition, the performance of the resin composition does not change locally even when the temperature and humidity change, and excellent sliding property and various properties can be maintained over a long period of time. Incidentally, if the average number of carbon atoms of the above dialkyl ketone A and the dialkyl ketone B are too far apart, the crystal system of the dialkyl ketone A will decrease too much, but by setting the difference (a - b) to 4 to 8, the performance of the resin composition can be enhanced in a well-balanced manner.

[0022] Here, the two aliphatic chains in the dialkyl ketone B may be the same or different. However, the difference in the number of carbon atoms between the two aliphatic chains is preferably 2 or less, more preferably 0. Each aliphatic chain may be linear or branched, but a linear chain is preferred. Also, each aliphatic chain may be either saturated or unsaturated, but is preferably saturated.

[0023] Examples of the ketone used for the dialkyl ketone B include didecyl ketone, diundecyl ketone, didodecyl ketone, ditridecyl ketone, ditetradecyl ketone, dipentadecyl ketone, dihexadecyl ketone, diheptadecyl ketone, heptadecyl pentadecyl ketone, dioctadecyl ketone, dinonadecyl ketone, dieicosyl ketone, diheneicosyl ketone, didocosyl ketone, ditricosyl ketone, ditetracosyl ketone, dioctacosyl ketone, and the like.

[0024] The method for preparing the dialkyl ketone B is not particularly limited, and it can be the same as the method for preparing the above dialkyl ketone A.

[0025] 〔Content of dialkyl ketone A and dialkyl ketone B〕 In the sliding property improver of the present invention, the mass ratio of the dialkyl ketone A and the dialkyl ketone B is 95:5 to 99.9:0.1, preferably 99:1 to 99.5:0.5. When two or more compounds corresponding to the dialkyl ketone B are included, the ratio of the content of the dialkyl ketone A to the total amount of the compounds corresponding to the dialkyl ketone B preferably falls within the above range. When the sliding property improver contains the above dialkyl ketone A and dialkyl ketone B within such ranges, the crystallization rate of the sliding property improver is easily controlled, and local crystallization is suppressed. Thereby, it is possible to enhance the sliding property of the resin composition using the sliding property improver, and furthermore, it becomes difficult for the sliding property, bending characteristics, and dimensions of the resin composition to change due to temperature and humidity changes.

[0026] As described above, the sliding property improver of the present invention may further contain other dialkyl ketones other than dialkyl ketone A and dialkyl ketone B. The total amount of the other dialkyl ketones is preferably 5% by mass or less, more preferably 2% by mass or less, based on the total amount of dialkyl ketone A and dialkyl ketone B.

[0027] [Fatty acid amide C] As described above, the sliding property improver of the present invention may further contain a fatty acid amide C composed of a tertiary amide compound obtained from a monovalent monocarboxylic acid and a dialkylamine. By using the fatty acid amide C in combination with the above-mentioned dialkyl ketone A and dialkyl B, the sliding property of the resin composition using the sliding property improver can be enhanced, or the dimensional stability of the resin composition in an environment where repeated wide-range temperature and humidity changes occur can be enhanced.

[0028] The monovalent monocarboxylic acid used for the fatty acid amide C preferably has 16 to 24 carbon atoms, more preferably 16 to 22 carbon atoms. Examples of the monovalent monocarboxylic acid include stearic acid, arachidic acid, behenic acid, palmitic acid, and the like. The dialkylamine used for the synthesis of the fatty acid amide C may be an amine having two alkyl groups, and the two alkyl groups may be the same or different. These alkyl groups preferably have 1 to 3 carbon atoms. Examples of the dialkylamine include dimethylamine, diethylamine, dipropylamine, and the like.

[0029] Specific examples of the fatty acid amide C include N,N-diethyl stearic acid amide, N,N-dipropyl stearic acid amide, N,N-diethyl behenic acid amide, N,N-dipropyl behenic acid amide, N,N-diethyl palmitic acid amide, N,N-dipropyl palmitic acid amide, and the like.

[0030] The blending amount of the fatty acid amide C in the sliding property improver is preferably 0.1 to 5% by mass based on the total amount of the above-mentioned dialkyl ketone A and dialkyl ketone B.

[0031] The method for producing the fatty acid amide is not particularly limited. For example, it can be obtained by subjecting the aforementioned carboxylic acid and dialkylamine to dehydration condensation under the conditions of 80 to 250 °C.

[0032] 〔β-ketocarboxylic acid D〕 As described above, the sliding property improver of the present invention preferably contains β-ketocarboxylic acid D represented by the following general formula (I). By using the above dialkyl ketone A and the above dialkyl ketone B in combination with the β-ketocarboxylic acid D, the sliding property of the resin composition containing the sliding property improver can be enhanced, or the dimensional stability of the resin composition in an environment where repeated wide-range temperature and humidity changes occur can be enhanced.

[0033] In particular, by using fatty acid amide C and β-ketocarboxylic acid D in combination with dialkyl ketone A and dialkyl ketone B, the sliding property and the dimensional stability after use in an environment where repeated wide-range temperature and humidity changes occur can be further enhanced.

Chemical formula

[0034] Specific examples of β-ketocarboxylic acid D include 2-hexadecyl-3-oxoeicosanoic acid, 2-tetradecyl-3-oxooctadecanoic acid, 2-icosyl-3-oxotetracosanoic acid, and the like.

[0035] The preferred amount of β-ketocarboxylic acid D in the sliding property improver is preferably 0.01 to 2% by mass based on the total amount of dialkyl ketone A and dialkyl ketone B.

[0036] The method for synthesizing the β-ketocarboxylic acid represented by the above general formula (I) is not particularly limited and can be carried out by a method known per se or a method analogous thereto. For example, it can be obtained by dimerizing a fatty acid chloride in an organic base and then hydrolyzing it. At this time, the organic base is not particularly limited, but in order to obtain the target product in good yield, it is preferable to use a tertiary amine compound in view of its reactivity with the fatty acid chloride. Examples thereof include triethylamine, triisopropylamine, triphenylamine and the like. Among these, it is preferable to use triethylamine from the viewpoint of easy separation from the product.

[0037] Also, for hydrolysis, it is preferable to use a basic aqueous solution. In order to suppress the excessive formation of the neutralization salt with the produced β-ketocarboxylic acid compound, the base is preferably 1 mol% or less, more preferably 0.5 mol% or less, based on the theoretical amount of the β-ketocarboxylic acid compound to be produced. There is no particular specification for the base to be used, and examples thereof include potassium hydroxide, sodium hydroxide, potassium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate and the like.

[0038] [Method for Preparing Sliding Property Improver] To obtain the sliding property improver of the present invention, the above-described dialkyl ketone A, dialkyl ketone B, and other components such as fatty acid amide C and β-ketocarboxylic acid D, if necessary, may be individually synthesized and then mixed. On the other hand, those that can be synthesized in one batch may be synthesized in one batch. When mixing the individually mixed components, it is preferable to produce the sliding property improver of the present invention by heating and dissolving at a temperature equal to or higher than the melting point of each component, mixing uniformly, and then cooling and solidifying followed by pulverizing or granulating.

[0039] The ketone wax composition for resin of the present invention is contained in the ketone wax composition together with the resin.

[0040] 2. Resin Composition The resin composition of the present invention only needs to contain a resin and the above-mentioned sliding property improver. The above-mentioned sliding property improver is used in the range of 0.01 to 20 parts by weight, preferably in the range of 0.05 to 10 parts by weight, and more preferably in the range of 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin.

[0041] The resin is not particularly limited, and examples include those conventionally used as general-purpose resins, such as polyethylene, polypropylene, those conventionally used as engineering plastics, such as polycarbonate, polyethylene terephthalate, polyamide, polyacetal, modified polyphenylene ether, those conventionally used as thermosetting resins, such as phenol resin, epoxy resin, those conventionally used as super engineering plastics, such as aromatic polyamide, polyphenylene sulfide, etc. Preferably, those conventionally used as engineering plastics, such as polycarbonate, polyethylene terephthalate, polyamide, polyacetal, modified polyphenylene ether, etc. are mentioned.

Examples

[0042] Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

[0043] 1. Preparation of materials (1) Synthesis of dialkyl ketone (Synthesis Example 1) Synthesis of dialkyl ketone A1 (diheptadecyl ketone) 700.0 g of magnesium stearate was weighed into a 1 L separable flask made of SUS, and the temperature was raised to 250 °C while blowing nitrogen. Then, nitrogen was injected at a pressure of 2 MPa, the temperature was raised to 340 - 350 °C, and the reaction was continued for 8 hours. Subsequently, it was cooled to 100 °C to obtain a crude dialkyl ketone compound. While blowing nitrogen, at 100 °C, using a 100-mesh metal strainer, the obtained crude dialkyl ketone compound was filtered to remove magnesium oxide produced as a by-product. Also, the dialkyl ketone compound obtained by filtration was discharged into a stainless steel vat, solidified at room temperature, and pulverized with a mixer to obtain dialkyl ketone A1 (diheptadecyl ketone).

[0044] (Synthesis Example 2) Synthesis of dialkyl ketone A2 (diheneicosyl ketone) 600.0 g (1.8 mol) of behenic acid and 35.6 g (0.9 mol) of magnesium oxide were weighed into a 1 L separable flask made of SUS, and the temperature was raised to 250 °C while blowing nitrogen. Then, nitrogen was injected at a pressure of 2 MPa, the temperature was raised to 340 - 350 °C, and the reaction was continued for 8 hours. Subsequently, it was cooled to 100 °C to obtain a crude dialkyl ketone compound. While blowing nitrogen, at 100 °C, using a 100-mesh metal strainer, the obtained crude dialkyl ketone compound was filtered to remove excess magnesium oxide. Also, the dialkyl ketone compound obtained by filtration was discharged into a stainless steel vat, solidified at room temperature, and pulverized with a mixer to obtain dialkyl ketone A2 (diheneicosyl ketone).

[0045] (Synthesis Example 3) Synthesis of dialkyl ketone A3 / B1 (dipentadecyl ketone) Dialkyl ketone A3 / B1 (dipentadecyl ketone) was obtained in the same manner as in Synthesis Example 1, except that an equimolar amount of magnesium palmitate was used instead of magnesium stearate.

[0046] (Synthesis Example 4) Synthesis of dialkyl ketone A4 (dioctacosyl ketone) Dialkyl ketone A4 (dioctacosyl ketone) was obtained in the same manner as in Synthesis Example 2, except that an equimolar amount of montanic acid was used instead of behenic acid.

[0047] (Synthesis Example 5) Synthesis of dialkyl ketone B2 (dieicosyl ketone) Dialkyl ketone compound B2 (dieicosyl ketone) was obtained in the same manner as in Synthesis Example 2, except that an equimolar amount of arachidic acid was used instead of behenic acid.

[0048] (Synthesis Example 6) Synthesis of dialkyl ketone B3 (ditridecyl ketone) Dialkyl ketone compound B3 (ditridecyl ketone) was obtained in the same manner as in Synthesis Example 1, except that an equimolar amount of magnesium myristate was used instead of magnesium stearate.

[0049] (Synthesis Example 7) Synthesis of dialkyl ketone B4 (dihexacosyl ketone) Dialkyl ketone B4 (dihexacosyl ketone) was obtained in the same manner as in Synthesis Example 2, except that an equimolar amount of serotic acid was used instead of behenic acid.

[0050] (2) Synthesis of fatty acid amide (Synthesis Example 8) Synthesis of fatty acid amide C1 (N,N - diethyl stearic acid amide) Stearic acid (100 g, 0.35 mol) was charged into a 300 mL five - necked flask equipped with a thermometer, a nitrogen inlet tube, and an air - cooling tube, and diethylamine (102 g, 1.4 mol) was gradually added dropwise through a dropping funnel. Then, the reaction was carried out at 220°C, and the reaction was terminated when the decrease in acid value per hour was 0.5 mgKOH / g or less, and 80 g of fatty acid amide C1 (N,N - diethyl stearic acid amide) was obtained.

[0051] (Synthesis Example 9) Synthesis of fatty acid amide C2 (N,N - diethyl behenic acid amide) Fatty acid amide C2 (N,N - diethyl behenic acid amide) was obtained in the same manner as in Synthesis Example 8, except that an equimolar amount of behenic acid was used instead of stearic acid.

[0052] (3) Synthesis of Other Compounds (Synthesis Example 10) Synthesis of β-Ketocarboxylic Acid D1 (2-Hexadecyl-3-oxoeicosanoic Acid) To a 500 mL four-necked flask equipped with a thermometer, a nitrogen inlet tube, a stirring blade, and a condenser, 300 mL of toluene and 50 g (0.17 mol) of stearic acid chloride were added. While stirring the system, 18.2 g (0.18 mol) of triethylamine was added dropwise. After completion of the dropwise addition, the reaction was continued for 2 hours, and then liquid separation treatment using 50 g of water was carried out 10 times. Then, 1.2 g (0.01 mol) of potassium carbonate and water (118.8 g) were added thereto, and the reaction was carried out at 70 °C for 15 minutes. After standing, the aqueous layer was removed. Further, it was allowed to stand at 50 °C, and the resulting precipitate and the residue of potassium carbonate were removed by filtration. By distilling off toluene from the filtrate under reduced pressure, 10 g of β-ketocarboxylic acid D1 (2-hexadecyl-3-oxoeicosanoic acid) was obtained.

[0053] (4) Summary of Each Compound The compound names and the like prepared in the above Synthesis Examples 1 to 9 are shown in Tables 1 to 3 below.

Table 1

[0054]

Table 2

[0055]

Table 3

[0056] 2. Preparation of Sliding Property Improver for Resin Into a 0.3 L separable flask equipped with a stirring blade and a nitrogen inlet tube, dialkyl ketone A, dialkyl ketone B, fatty acid amide C, and β-ketocarboxylic acid compound D prepared in the above synthesis example were placed in the mass ratios shown in Table 4. Then, these were melt-mixed and stirred at 150 °C for 1 hour under a nitrogen stream. Thereafter, through cooling, solidification, and pulverization, Compositions 1 to 9 were obtained.

[0057]

Table 4

[0058] 3. Preparation of Evaluation Specimens The sliding property improvers for resins of Examples 1 to 7 and Comparative Examples 1 and 2 were blended with the resins shown in Table 5 in the combinations shown in Table 6 to prepare evaluation specimens. Specifically, 1 part by mass of the sliding property improver for resin was dry-blended with 99 parts by mass of each resin. Then, a resin composition was obtained by kneading and pelletizing at a set temperature of 250 °C using a twin-screw extruder (PCM-30, manufactured by Ikegai Corporation). The obtained resin composition was injection-molded using an injection molding machine at a cylinder temperature of 290 °C and a mold temperature of 90 °C to prepare evaluation specimens (80 mm × 55 mm × 2 mm).

[0059]

Table 5

[0060] 4. Evaluation of Sliding Property Improver for Resin For each sliding property improver for resin, the following items were evaluated.

[0061] <Evaluation of Sliding Property (Evaluation of Coefficient of Friction)> For the evaluation specimens obtained above, the coefficient of friction under the conditions of a contactor (semicylindrical stainless steel, 1 cm), load: 100 g, speed: 2.5 mm / s, measurement distance: 25 mm, and number of test runs: 5 times was measured using a Boudet tester, and the average value was calculated. The evaluation criteria are as follows. ◎: Average coefficient of friction is less than 0.050 ○: Average coefficient of friction is 0.050 or more and less than 0.075 △: Coefficient of average friction is 0.075 or more and less than 0.100 ×: Coefficient of average friction is 0.1 or more

[0062] <Evaluation of flexural modulus> For the evaluation material obtained above, in accordance with JIS K-7203, the flexural modulus was measured at a test speed of 2 mm / min. The evaluation criteria are as follows. ◎: Flexural modulus is 2.5 GPa or more ○: Flexural modulus is 2.25 or more and less than 2.5 GPa △: Flexural modulus is 2.0 or more and less than 2.25 GPa ×: Flexural modulus is less than 2.0 GPa

[0063] <Accelerated test> (Thermal cycling test) For the evaluation material obtained above, a thermal cycling test was conducted with the conditions of -25°C and 80% humidity for 48 hours, a heating time of 1 hour, 60°C and 10% humidity for 48 hours, and a cooling time of 1 hour as one cycle, and the cycle was repeated 10 times. The change rates of the sliding property (evaluation of coefficient of friction), mechanical properties (flexural modulus), and dimensional stability of the evaluation material before and after the test were evaluated respectively. The evaluation criteria for the sliding property and flexural modulus are the same as above.

[0064] The calculation formula and evaluation criteria for the change rate of the coefficient of friction before and after the thermal cycling test are as follows. Change rate (%) = |(Initial value) - (Value after accelerated test)| / (Initial value) × 100 ◎: Change rate is less than 10.0 ○: Change rate is 10.0 or more and less than 15.0 △: Change rate is 15.0 or more and less than 30.0 ×: Change rate is 30.0 or more

[0065] The calculation formula and evaluation criteria for the change rate of the flexural modulus before and after the thermal cycling test are as follows. Change rate (%) = |(Initial value) - (Value after accelerated test)| / (Initial value) × 100 ◎: Change rate is less than 3.5 ○: Change rate is 3.5 or more and less than 7.0 △: The change rate is 7.0 or more and less than 10 ×: The change rate is 10 or more

[0066] Regarding the dimensional stability before and after the thermal cycle test, the value of the longest part in the evaluation material was used to calculate the change rate from the following formula. Change rate (%) = |(initial value) - (value after the acceleration test)| / (initial value) × 100 The evaluation criteria for dimensional stability are as follows. ◎: The change rate is less than 0.75 ○: The change rate is 0.75 or more and less than 1.00 △: The change rate is 1.00 or more and less than 1.50 ×: The change rate is 1.50 or more

[0067] Table 6 shows the evaluation results for the evaluation materials according to Examples 1 to 9 and Comparative Examples 1 and 2.

[0068]

Table 6

[0069] The sliding property improver for resin (Compositions 1 to 7) used in Examples 1 to 9 contains a dialkyl ketone A having 29 to 61 carbon atoms and an average carbon number of a, and a dialkyl ketone B having 25 to 57 carbon atoms and an average carbon number of b. The difference (a - b) between a and b is 4 or more and 8 or less, and the mass ratio of dialkyl ketone A to the dialkyl ketone B is 95:5 to 99.9:0.1, which is the sliding property improver for resin of the present invention. According to the above evaluation results, when the sliding property improver for resin (Compositions 1 to 7) of the present invention was used, the resin had a good flexural modulus of elasticity and a good coefficient of kinetic friction (sliding property) was obtained (Examples 1 to 9). Furthermore, the sliding property, flexural properties, and dimensions were maintained even in an environment where wide temperature and humidity changes were repeated.

[0070] On the other hand, the sliding property improver for resin (Composition 8) of Comparative Example 1 did not contain dialkyl ketone B. In Comparative Example 1, although the initial sliding property and bending properties were excellent, after being placed in an environment where wide-ranging temperature and humidity changes were repeated, the sliding property and dimensional stability decreased.

[0071] Also, the sliding property improver for resin (Composition 9) of Comparative Example 2 did not contain dialkyl ketone B. Even in Comparative Example 2, although the initial sliding property and bending properties were excellent, after being placed in an environment where wide-ranging temperature and humidity changes were repeated, the sliding property, bending properties, and dimensional stability decreased.

Claims

1. A dialkyl ketone A having 29 to 61 carbon atoms and an average carbon number of a, and a dialkyl ketone B having 25 to 57 carbon atoms and an average carbon number of b, wherein the difference (a - b) between a and b is 4 or more and 8 or less, and the mass ratio of the dialkyl ketone A to the dialkyl ketone B is 95:5 to 99.9:0.1, A sliding property improver for resins.

2. Further comprising a fatty acid amide C obtained from a monovalent carboxylic acid having 16 to 24 carbon atoms and a dialkylamine, The sliding property improver for resins according to Claim 1.

3. Further comprising β-ketocarboxylic acid, The sliding property improver for resins according to Claim 1.

4. A resin composition comprising the sliding property improver for resins according to any one of Claims 1 to 3 and a resin, and containing 0.01 to 20 parts by mass of the sliding property improver for resins with respect to 100 parts by mass of the resin. A resin composition.

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