Modifier for polyacetal resin and resin composition

Abstract

To provide a modifier for polyacetal resin and a resin composition with enhanced slidability.SOLUTION: A modifier for polyacetal resin comprises a compound represented by the following general formula (1), wherein the ratio of the number of moles b of a group represented by A2O to the total number of moles (a+c) of groups represented by A1O per molecule of the compound [b / (a+c)] is 5 / 95 to 20 / 80. HO-(A1O)a-(A2O)b-(A1O)c-OH (1). (In the formula, A1O represents an ethyleneoxy group, A2O represents a tetramethyleneoxy group, the total of a and c is a number of 500 or less, and b is a number of 100 or less.)SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a modifier for polyacetal resin and a resin composition.

Background Art

[0002] Polyacetal resins have conventionally been used as engineering plastics for materials such as mechanical parts, automotive parts, and electrical and electronic equipment parts. In recent years, their application has been expanding to uses other than the above (exterior and appearance parts). However, since members made of only polyacetal resin may have insufficient physical properties such as mechanical properties, composites composed of polyacetal resin and other materials have been studied (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Members using polyacetal resin are often used for parts such as gears, so excellent slidability is required, and there is room for improvement.

[0005] An object of the present invention is to provide a modifier for polyacetal resin and a resin composition with improved slidability.

Means for Solving the Problems

[0006] As a result of intensive studies to solve the above problems, the present inventor has reached the present invention. That is, the present invention is as follows. [1] Containing a compound represented by the following general formula (1), and per molecule of the compound, A 1The ratio of the total number of moles (a + c) of the groups represented by O to A 2 A modifier for polyacetal resin in which the ratio [b / (a + c)] of the number of moles b of the group represented by O is 5 / 95 to 20 / 80. HO-(A 1 O)a-(A 2 O)b-(A 1 O)c-OH (1) (In the formula, A 1 O is an ethyleneoxy group, A 2 O is a tetramethyleneoxy group, the sum of a and c is a number of 500 or less, and b is a number of 100 or less). A resin composition containing the modifier for polyacetal resin according to [2][1] and a polyacetal resin.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a modifier for polyacetal resin and a resin composition with improved slidability.

Modes for Carrying Out the Invention

[0008] The modifier for polyacetal resin of the present invention contains a compound represented by the following general formula (1), and for each molecule of the compound, the ratio [b / (a + c)] of the number of moles b of the group represented by A 1 O to the total number of moles (a + c) of the groups represented by A 2 O is 5 / 95 to 20 / 80. HO-(A 1 O)a-(A 2 O)b-(A 1 O)c-OH (1) (In the formula, A 1 O is an ethyleneoxy group, A 2 O is a tetramethyleneoxy group, the sum of a and c is a number of 500 or less, and b is a number of 100 or less). That is, the present invention is a modifier for polyacetal resin containing a polyalkylene oxide diol composed of a block of tetramethyleneoxy groups and a block of oxyethylene groups. The modifier for polyacetal resin contains diols with different addition molar numbers of alkylene oxide as the polyalkylene oxide diol. The general formula (1) is a chemical formula showing the polyalkylene oxide diol contained in the modifier for polyacetal resin of the present invention using the average value of the addition molar number of alkyleneoxy groups. And, in the polyalkylene oxide diol contained in the modifier for polyacetal resin, the ratio of the molar number of tetramethyleneoxy groups to the total molar number of ethyleneoxy groups is 5 / 95 to 20 / 80.

[0009] A 1 With respect to the total molar number (a + c) of the groups represented by O, A 2 By using those in which the ratio [b / (a + c)] of the molar number b of the group represented by O is 5 / 95 to 20 / 80, the slidability can be improved compared to those composed only of polyacetal resin. In this specification, the "modifier for polyacetal resin" may be referred to as the "modifier". Also, in this specification, the "compound represented by the general formula (1) (that is, the polyalkylene oxide diol contained in the modifier for polyacetal resin of the present invention)" may be referred to as the "compound (A)".

[0010] From the viewpoint of excellent slidability, the ratio [b / (a + c)] is preferably 6 / 94 to 17 / 83, and more preferably 12 / 98 to 17 / 83.

[0011] a is a number of 0 or more, c is a number exceeding 0, and the sum of a and c is preferably 45 to 460, and more preferably 48 to 454 from the viewpoint of slidability. From the viewpoint of slidability, b is a number of 1 or more, preferably 13 to 42, and more preferably 13.9 to 41.7.

[0012] The production method of the compound represented by the general formula (1) is not particularly limited. For example, it can be produced by reacting polytetramethylene glycol (PTMG) with polyethylene glycol (PEG) and / or ethylene oxide. A 1 The ratio [b / (a + c)] of the number of moles b of the group represented by A 2 O to the total number of moles (a + c) of the groups represented by O can be calculated as the ratio of the number of moles of the tetramethyleneoxy group constituting polytetramethylene glycol to the total number of moles of the polyethyleneoxy group and / or ethylene oxide constituting polyethylene glycol.

[0013] As PTMG serving as a raw material for the compound represented by the general formula (1), those having an Mn (number average molecular weight) of 1000 to 5000 are preferred, and those having an Mn of 1000 to 3000 are more preferred.

[0014] As PEG serving as a raw material for the compound represented by the general formula (1) obtained by reacting polytetramethylene glycol (PTMG) with polyethylene glycol (PEG), those having an Mn (number average molecular weight) of 2000 to 20000 are preferred, and those having an Mn of 3000 to 15000 are more preferred.

[0015] The compound represented by the general formula (1) may be used alone or in combination of two or more. The modifier may contain other components other than the compound represented by the general formula (1).

[0016] By adding the modifier of the present invention to the polyacetal resin, the slidability can be improved compared to that composed only of the resin, so it is suitable for applications where slidability is required.

[0017] The resin composition of the present invention contains the modifier of the present invention and a polyacetal resin. From the viewpoint of slidability, the addition amount of the modifier of the present invention is preferably 1% by weight to 7% by weight, more preferably 1% by weight to 5% by weight, based on the total weight of the polyacetal resin and the modifier.

[0018] The polyacetal resin constituting the resin composition of the present invention is a high molecular compound having an oxymethylene group (-CH 2 O-) as a main constituent unit. Although there is no particular limitation on the polyacetal resin, examples thereof include polyacetal homopolymers composed only of oxymethylene units, and polyacetal copolymers containing oxymethylene units and comonomer units.

[0019] Commercially available polyacetal resins may be used. Examples of such commercially available products include polyacetal homopolymers such as "Delrin (trade name)" manufactured by DuPont, Inc. and "TENAC (trade name)" manufactured by Asahi Kasei Corporation, and polyacetal copolymers such as "Duracon (trade name)" manufactured by Polyplastics Co., Ltd. and "TENAC-C (trade name)" manufactured by Asahi Kasei Corporation.

[0020] The resin composition of the present invention may contain components other than the polyacetal resin and the modifier. Other components can be selected according to the use of the resin composition. When the resin composition is used for a sliding member, examples of other components include lubricants and the like. Examples of the lubricant include those described in JP-A-2022-83337. As other components, lubricating oils, antioxidants, mold release agents, antistatic agents, surfactants, colorants such as pigments, and the like may be used.

[0021] The resin composition of the present invention can be used for a desired application by weighing each component constituting the composition, mixing them with a mixer (for example, Henschel mixer, super mixer, ball mill, tumbler mixer, etc.) to prepare a mixture, and molding the mixture into a desired shape.

Examples

[0022] Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto. Hereinafter, unless otherwise specified, % represents weight %, and parts represent parts by weight.

[0023] <Production Example 1: Production of (A-1)> 100 parts (0.1 mol) of polytetramethylene glycol [“PTMG-1000” manufactured by Mitsubishi Chemical Corporation, Mn: 1000] and 0.4 part of potassium hydroxide catalyst were charged into a stainless steel autoclave equipped with a stirring function and a temperature control function, and stirred and mixed. Next, after replacing the inside of the mixing system with nitrogen, dehydration was carried out at 130 °C under reduced pressure (3 kPa) for 1 hour. After dehydration, 300 parts (6.8 mol) of ethylene oxide (EO) was introduced under the temperature condition of 130 °C. After the reaction was completed, it was neutralized with phosphoric acid to obtain a compound (A-1) represented by the general formula (1). (A-1) is a compound in which b in the general formula (1) is 13.9 and (a + c) is 68.

[0024] <Production Example 2: Production of (A-2)> In Production Example 1, the same operations as in Production Example 1 were carried out except that the type and amount of PTMG and the amount of EO used were changed to the embodiments described in Table 1, to obtain a compound (A-2) represented by the general formula (1). (A-2) is a compound in which b in the general formula (1) is 27.8 and (a + c) is 136.

[0025] <Production Example 3: Production of (A-3)> In Production Example 1, the same operations as in Production Example 1 were carried out except that the type and amount of PTMG and the amount of EO used were changed to the embodiments described in Table 1, to obtain a compound (A-3) represented by the general formula (1). (A-3) is a compound in which b in the general formula (1) is 41.7 and (a + c) is 204.

[0026] <Production Example 4: Production of (A-4)> In Production Example 1, the same operations as in Production Example 1 were carried out except that the type and amount of PTMG and the amount of EO used were changed to the embodiments described in Table 1, to obtain a compound (A-4) represented by the general formula (1). (A-4) is a compound in which b in the general formula (1) is 27.8 and (a + c) is 227.

[0027] <Production Example 5: Production of (A-5)> In Production Example 1, the same operations as in Production Example 1 were carried out except that the type and amount of PTMG and the amount of EO used were changed to the embodiments described in Table 1, to obtain a compound (A-5) represented by the general formula (1). (A-5) is a compound in which b in the general formula (1) is 27.8 and (a + c) is 454.

[0028] <Raw materials of compound (A)> The raw materials described in Table 1 are as follows. PTMG-1000: "PTMG-1000" manufactured by Mitsubishi Chemical Corporation, Mn: 1000 PTMG-2000: "PTMG-2000" manufactured by Mitsubishi Chemical Corporation, Mn: 2000 PTMG-3000: "PTMG-3000" manufactured by Mitsubishi Chemical Corporation, Mn: 3000

[0029]

Table 1

[0030] <Production of resin compositions of Examples 1 to 7> Using the compounds (A-1) to (A-5) obtained in Production Examples 1 to 5 as modifiers, "Duracon M-90" manufactured by Polyplastics Co., Ltd. was used as a polyacetal resin (POM-A), and a resin composition was produced by the following method. The compounds (A) of the types described in Table 2 and the polyacetal resin (POM-A) were mixed in the amounts described in Table 2 to prepare the resin compositions of Examples 1 to 7, and the following evaluation tests were conducted.

[0031] <Evaluation test> (1) Preparation of test pieces The resin compositions of Examples 1 to 7 were each melt-kneaded at 200°C using a twin-screw extruder to obtain a pelletized composition. Using the pelletized composition, plate-shaped test pieces (square plates with a length of 30 mm, a width of 30 mm, and a thickness of 3 mm) were prepared at a molding temperature of 190°C and a mold temperature of 80°C using an injection molding machine. For Comparative Example 1, the same operations as in Examples 1 to 7 were carried out using only the polyacetal resin to prepare test pieces. Each of the obtained test pieces was subjected to an evaluation test.

[0032] (2) Evaluation test Using test pieces, a sliding quietness test was conducted under the conditions shown below and evaluated according to the following evaluation criteria. (Test conditions) Motion form: Thrust one-way rotation Load: 100 kg / cm 2 Speed: 1 m / min Time: 3 minutes Counter material: SUS304 (Ra 0.1 (μm)) Lubrication condition: Non-lubricated (Evaluation criteria) 〇: No abnormal noise generated ×: Abnormal noise generated

[0033]

Table 2

[0034] As shown in Table 2, according to the resin composition using the modifier of the example containing the compound represented by the general formula (1), the sliding quietness was superior to that of the resin of the comparative example not containing the compound represented by the general formula (1). From this result, it was found that according to the present invention, a modifier for polyacetal resin with improved slidability can be provided.

Claims

1. The compound includes a compound represented by the following general formula (1): A per molecule of the compound １ A relative to the total number of moles (a + c) of groups represented by O ２ A modifier for polyacetal resins, in which the ratio [b / (a+c)] of the number of moles b of groups represented by O is 5 / 95 to 20 / 80. HO-(A １ O)a-(A ２ O)b-(A １ O)c-OH (1) (In the formula, A １ O is an ethyleneoxy group, A ２ O is a tetramethyleneoxy group, the sum of a and c is a number of 500 or less, and b is a number of 100 or less).

2. A resin composition comprising the polyacetal resin modifier according to claim 1 and a polyacetal resin.