JP6951208B2 - Polyamide resin composition - Google Patents

Description

The present invention relates to a polyamide resin composition having excellent flexibility.

Polyamide resins have excellent mechanical and chemical properties as engineering plastics, and are widely used in various industrial fields such as parts for automobiles and electrical and electronic equipment, food films, clothing, and building materials.

When a polyamide resin is used for an automobile fuel hose, a hydraulic or pneumatic tube, or a building material that requires flexibility, a plasticizer is added to give flexibility.

Generally, N-butylbenzenesulfonamide and the like are known as plasticizers for polyamide resins. However, if the amount of this plasticizer added is increased in order to increase the plasticization efficiency, the surface of the molded product may be bleeded and sticky, or these plasticizers may seep out of the hose or tube, resulting in loss of flexibility. Since the heat resistance is poor, there is a problem that the plasticizer volatilizes during molding and the working environment is deteriorated.

Further, as a plasticizer for a polyamide resin, an ester of a fatty alcohol having 12 to 22 carbon atoms having a branched chain with p-hydroxybenzoic acid such as 2-hexyldecanol ester of p-hydroxybenzoic acid has been proposed (Patent Documents). 1).

However, the compound having a branched chain structure has high volatility, and when it is blended with a polyamide resin as a plasticizer, there is also a problem that it bleeds to the surface during molding and becomes sticky. In addition, there is a problem that the plasticizer volatilizes from the molded product with the passage of time, the physical properties of the molded product are impaired, and the volatile components adversely affect the human body and the environment. Further, there is a problem that the molded product is warped over time.

Japanese Unexamined Patent Publication No. 2003-160728

An object of the present invention is to provide a polyamide resin composition which is excellent in flexibility and in which surface bleeding and volatilization of a plasticizer are suppressed.

As a result of diligent studies on a plasticizer for a polyamide resin, the present inventors have found that a specific hydroxyaromatic amide compound having a linear structure is excellent in suppressing surface bleeding and volatilization, and complete the present invention. I arrived.

（Ａｒは２価の芳香族基を示し、ｎは１２〜２０の整数を示す）
で表されるヒドロキシ芳香族アミド化合物１〜７０質量部を含む、ポリアミド樹脂組成物を提供する。 That is, in the present invention, 100 parts by mass of the polyamide resin and the formula (1)

(Ar represents a divalent aromatic group and n represents an integer of 12 to 20)
Provided is a polyamide resin composition containing 1 to 70 parts by mass of a hydroxyaromatic amide compound represented by.

According to the present invention, it is possible to provide a polyamide resin composition which is excellent in flexibility and in which surface bleeding and volatilization of a plasticizer are suppressed. Further, according to the present invention, it is possible to provide a polyamide resin composition which does not adversely affect the human body or the environment without impairing the physical properties of the molded product. Further, according to the present invention, it is possible to provide a polyamide resin composition capable of suppressing warpage of a molded product.

The polyamide resin used in the present invention is a polymer having an amide group in the molecule, and is α-pyrrolidone, α-piperidone, ε-caprolactam, 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12 Polymer obtained by polymerizing −aminododecanoic acid, ω-laurolactam, etc .; hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediamine, 1,4-bis (aminomethyl) Examples thereof include a polymer obtained by decomposing a diamine such as cyclohexane with a dicarboxylic acid such as adipic acid, azelaic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid and isophthalic acid.

Specific examples of the polyamide resin used in the present invention include polyamide 6 obtained by polymerizing ε-caprolactam, polyamide 66 obtained by condensing hexamethylenediamine and adipic acid, hexamethylenediamine and sebacic acid. Polyamide 610 obtained by shrink-polymerizing the above, polyamide 6T obtained by shrink-polymerizing hexamethylenediamine and terephthalic acid, polyamide 6I obtained by shrink-polymerizing hexamethylenediamine and isophthalic acid, diaminobutane and adipic acid. Polyamide 46 obtained by shrink-polymerizing the above, polyamide MXD6 obtained by shrink-polymerizing metaxylylene diamine and adipic acid, polyamide 9T obtained by shrink-polymerizing nonanediamine and terephthalic acid, and 11-aminoundecanoic acid. Examples thereof include the polyamide 11, 12-aminododecanoic acid, and the polyamide 12 obtained by polymerizing ω-laurolactam. Of these, polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 6T, polyamide 6I and polyamide 9T are preferable because there are few changes in physical properties and dimensions due to moisture absorption and excellent compatibility with plasticizing agents. , Polyamide 12 is more preferable. These polyamide resins can be used alone or in admixture of two or more.

The polyamide resin composition of the present invention contains a hydroxyaromatic amide compound represented by the formula (1) as a plasticizer. By blending the hydroxyaromatic amide compound represented by the formula (1) with the polyamide resin, surface bleeding and volatilization of the plasticizer in the molded product can be suppressed. In addition, the polyamide resin composition of the present invention can improve workability during molding, retain the physical properties of the molded product for a long period of time, and prevent adverse effects on the human body and the environment due to volatile substances.

Specific examples of the hydroxyaromatic amide compound represented by the formula (1) include N- (n-dodecyl) -4-hydroxybenzamide, N- (n-tridecyl) -4-hydroxybenzamide, and N-. (N-Tetradecyl) -4-hydroxybenzamide, N- (n-pentadecyl) -4-hydroxybenzamide, N- (n-hexadecyl) -4-hydroxybenzamide, N- (n-heptadecyl) -4-hydroxybenzamide, N- (n-octadecyl) -4-hydroxybenzamide, N- (n-nonadecil) -4-hydroxybenzamide, and N- (n-icosyl) -4-hydroxybenzamide, and N- (n-tridecyl)- 6-Hydroxynaphthamide, N- (n-tetradecyl) -6-hydroxynaphthamide, N- (n-pentadecyl) -6-hydroxynaphthamide, N- (n-hexadecyl) -6-hydroxynaphthamide, N- (N-Heptadecyl) -6-hydroxynaphthamide, N- (n-octadecyl) -6-hydroxynaphthamide, N- (n-nonadecil) -6-hydroxynaphthamide, and N- (n-icosyl) -6 -Hydroxynaphthoamide can be mentioned.

Among them, in a preferred embodiment of the present invention, the hydroxyaromatic amide compound represented by the formula (1) is excellent in the effect of suppressing surface bleeding and volatilization of the plasticizer and the effect of improving the physical properties and warpage of the molded product. , A compound in which n represents an integer of 14 to 18 in the formula (1) is preferable, and a compound in which n represents an integer of 15 to 17 is more preferable.

または、式（Ｂ）

で表される２価の芳香族基を示す化合物が好ましい。 Further, in a preferred embodiment of the present invention, the hydroxyaromatic amide compound represented by the formula (1) is excellent in the effect of suppressing surface bleeding and volatilization of the plasticizer and the effect of improving the physical properties and warpage of the molded product. In the formula (1), Ar is the formula (A).

Or, equation (B)

A compound showing a divalent aromatic group represented by is preferable.

In a particularly preferable embodiment of the present invention, the hydroxyaromatic amide compound represented by the formula (1) is a compound in which Ar is represented by the formula (A) and n is 15, that is, the following formula (2). Examples thereof include N- (n-hexadecyl) -4-hydroxybenzamide, which is a compound represented by.

Further, in a particularly preferable embodiment of the present invention, as the hydroxyaromatic amide compound represented by the formula (1), a compound in which Ar is represented by the formula (B) and n is 17, that is, the following formula ( Examples thereof include N- (n-octadecyl) -6-hydroxynaphthamide, which is a compound represented by 3).

The hydroxyaromatic amide compounds represented by these formulas (1) may be used alone or in combination of two or more selected from the above group.

The method for obtaining the compound represented by the formula (1) is not particularly limited, but a commercially available compound may be used, and an aromatic carboxylic acid halide and a linear alkylamine having 12 to 20 carbon atoms [NH ₂ ( Those obtained by reacting with CH ₂ ) _n CH _{3] may be used.}

The hydroxyaromatic amide compound represented by the formula (1) is blended in an amount of 1 to 70 parts by mass, preferably 3 to 60 parts by mass, and more preferably 5 to 50 parts by mass with respect to 100 parts by mass of the polyamide resin. Therefore, the polyamide resin composition of the present invention containing a predetermined amount of the hydroxy aromatic amide compound represented by the formula (1) can be obtained.

When the content of the hydroxyaromatic amide compound represented by the formula (1) in the polyamide resin composition is less than 1 part by mass, sufficient flexibility is not imparted, and when it exceeds 70 parts by mass, the molded product is mechanically formed. Not only is the strength reduced, but it is also disadvantageous in terms of cost.

The method for producing the polyamide resin composition of the present invention is not particularly limited, and is a method of adding the above-mentioned plasticizing agent when producing the polyamide resin by polymerization, and a method of dry-blending the above-mentioned plasticizing agent with the polymerized polyamide resin. , The above-mentioned plasticizing agent is attached to the pellet surface of the polyamide resin, and the above-mentioned plasticizing agent is melt-kneaded with the polyamide resin by any method. Examples of the melt-kneading method include a known method, for example, a method of melt-kneading using a Banbury mixer, a mixing roll, a single-screw or twin-screw extruder, or the like to obtain pellets of a mixture of a polyamide resin and a plasticizer. Be done.

The polyamide resin composition of the present invention has other components such as other polyamide components, heat stabilizers, weathering agents, inorganic fillers, reinforcing agents, antioxidants, and impact resistance to the extent that its moldability and physical properties are not impaired. Improvement agents, pigments, lubricants, flame retardants and the like can be added.

The polyamide resin composition of the present invention is processed into molded products, films, fibers and the like by known molding methods such as injection molding, compression molding, extrusion molding and blow molding.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.
In the examples, each evaluation was performed by the following method.

[Flexibility]
Using an injection molding machine (UH1000-110 manufactured by Nissei Resin Industry Co., Ltd.), a strip-shaped test piece having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm was molded, and the melt viscosity was determined in accordance with ISO178. Bending strength and flexural modulus were measured. The lower these numbers, the more flexible it is.

〔volatility〕
Using the test piece prepared in the same manner as in the evaluation of flexibility, the test piece was dried in a constant temperature dryer at a temperature of 120 ° C. for 3 days, and the mass reduction rate (%) was calculated based on the following formula.
Mass reduction rate (%) = {(mass before drying-mass after drying) / mass before drying} x 100
The smaller the mass reduction rate, the lower the volatility.

〔warp〕
The dried test piece obtained by the volatility evaluation is placed on a flat surface with both ends facing down, and the height of the highest part of the test piece from the flat surface is determined by the height gauge (HDM manufactured by Mitutoyo Co., Ltd.). It was measured using -30).

<Synthesis of hydroxyaromatic amides>
(Synthesis Example 1) N- (n-hexadecyl) -4-hydroxybenzamide (BA-16)
To a 3.0 L 4-neck flask equipped with a stirrer, a temperature sensor and a reflux tube, 200 g (1.11 mol) of 4-acetoxy-benzoic acid, 145 g (1.21 mol) of thionyl chloride, 0.8 g of DMF and 600 g of THF were added. The temperature was raised to 50 ° C. under a nitrogen stream, and the mixture was stirred for 2 hours. After completion of stirring, the reaction solution was cooled to room temperature, and the pressure was reduced to 60 mmHg to distill off THF.

2000 g of THF was added thereto again, and 135 g (1.33 mol) of triethylamine was added dropwise under a nitrogen stream while stirring at room temperature. Subsequently, 281 g of hexadecylamine was added. The temperature was raised to 60 ° C., and the mixture was stirred at the same temperature for 1 hour. Then, hot filtration was performed at 60 ° C. The obtained filtrate was concentrated to obtain crystals.

The obtained crystals were transferred to a 3.0 L 4-neck flask, 806 g of water, 806 g of methanol, and 167 g of a 48% NaOH aqueous solution were added, the temperature was raised to 75 ° C. under a nitrogen stream, and the mixture was stirred for 2 hours. After completion of stirring, the reaction solution was cooled to 60 ° C., 70% sulfuric acid was added over 1 hour until the pH of the solution reached 4, and crystals were precipitated. Then, it was cooled to room temperature and filtered to obtain crystals.

The obtained crystals were transferred to a 5.0 L 4-neck flask, 2734 g of methanol was added, and the mixture was stirred at 60 ° C. After that, the crystals were precipitated by cooling to 25 ° C. The obtained crystals were separated by filtration, washed with 600 g of methanol, and then dried under the condition of 80 ° C. to obtain 298 g of N- (n-hexadecyl) -4-hydroxybenzamide crystals (yield 74 mol%, purity). 98%).

(Synthesis Example 2) N- (n-octadecyl) -6-hydroxynaphthamide (NA-18)
In a 5.0 L 4-neck flask equipped with a stirrer, a temperature sensor and a reflux tube, 200 g (0.87 mol) of 6-acetoxy-2-naphthoic acid, 113 g (0.95 mol) of thionyl chloride, 0.8 g of DMF and 800 g of THF were placed. In addition, the temperature was raised to 50 ° C. under a nitrogen stream, and the mixture was stirred for 2 hours. After completion of stirring, the reaction solution was cooled to room temperature, and the pressure was reduced to 60 mmHg to distill off THF.

2000 g of THF was added thereto again, and 176 g (1.74 mol) of triethylamine was added dropwise under a nitrogen stream while stirring at room temperature. Subsequently, 246 g of octadecylamine was added over 100 minutes. The temperature was raised to 60 ° C., and the mixture was stirred at the same temperature for 1 hour. Then, hot filtration was performed at 60 ° C.

The obtained filtrate was transferred to a 5.0 L 4-neck flask, 108 g of a 48% NaOH aqueous solution and 2000 g of water were added, the temperature was raised to 50 ° C. under a nitrogen stream, and the mixture was stirred for 2 hours. After the stirring was completed, the reaction solution was cooled to room temperature, and 70% sulfuric acid was added until the pH of the solution reached 7. Then, the temperature was raised to 50 ° C., and the organic layer was extracted.

The obtained organic layer was transferred to a 3.0 L 4-neck flask and cooled to 25 ° C. with stirring to precipitate crystals. The obtained crystals were separated by filtration, washed with 600 g of methanol, and then dried under the conditions of 70 ° C. and 10 Torr to obtain 208 g of crystals of N- (n-octadecyl) -6-hydroxynaphthamide (yield 53 mol). %, Purity 97.4%).

Example 1
100 parts by mass of polyamide 12 (nylon 12, Rilsamide manufactured by ARKEMA) and 5 parts by mass of N- (n-hexadecyl) -4-hydroxybenzamide (BA-16) were mixed, and this was mixed with a twin-screw extruder (Kurimoto Co., Ltd.). Using an S1 KRC reactor manufactured by Iron Works), melt-kneading was performed at 220 ° C. to obtain pellets of the resin composition.
After drying the obtained pellets, strip-shaped test pieces were prepared using an injection molding machine, and each evaluation of flexibility, volatility and warpage was performed. The results are shown in Table 1.

Example 2
Example 1 except that 5 parts by mass of N- (n-octadecyl) -6-hydroxynaphthamide (NA-18) was used instead of N- (n-hexadecyl) -4-hydroxybenzamide (BA-16). A test piece was prepared in the same manner as in the above, and each evaluation was performed. The results are shown in Table 1.

Example 3
Except for changing the amount of N- (n-hexadecyl) -4-hydroxybenzamide (BA-16) added to 20 parts by mass and changing polyamide 12 (nylon 12) to polyamide 11 (nylon 11, ARKEMA's Rilsan). Prepared test pieces in the same manner as in Example 1, and each evaluation was performed. The results are shown in Table 1.

Reference example 1
Test pieces were prepared in the same manner as in Example 1 except that N- (n-hexadecyl) -4-hydroxybenzamide (BA-16) was not added, and each evaluation was performed. The results are shown in Table 1.

Reference example 2
Test pieces were prepared in the same manner as in Example 3 except that N- (n-hexadecyl) -4-hydroxybenzamide (BA-16) was not added, and each evaluation was performed. The results are shown in Table 1.

Comparative Example 1
Example 1 except that 5 parts by mass of 2-ethylhexyl 4-hydroxybenzoate (EHPB) (manufactured by Ueno Fine Chemicals Industry Co., Ltd.) was used instead of N- (n-hexadecyl) -4-hydroxybenzamide (BA-16). A test piece was prepared in the same manner as in the above, and the mass reduction rate and warpage were evaluated. The results are shown in Table 1.

（Ａｒは２価の芳香族基を示し、ｎは１２〜２０の整数を示す）
で表されるヒドロキシ芳香族アミド化合物１〜７０質量部を含むポリアミド樹脂組成物。
〔２〕式（１）において、ｎは１４〜１８の整数を示す、〔１〕に記載のポリアミド樹脂組成物。
〔３〕式（１）において、Ａｒは、式（Ａ）
［化２］

または、式（Ｂ）
［化３］

で表される２価の芳香族基を示す、請求項１または２に記載のポリアミド樹脂組成物。
〔４〕ポリアミド樹脂が、ポリアミド６、ポリアミド１１、ポリアミド１２、ポリアミド６６、ポリアミド６１０、ポリアミド６Ｔ、ポリアミド６Ｉおよびポリアミド９Ｔからなる群から選択される、〔１〕〜〔３〕のいずれかに記載のポリアミド樹脂組成物。
〔５〕ポリアミド樹脂がポリアミド１２である、〔１〕〜〔４〕のいずれかに記載のポリアミド樹脂組成物。
〔６〕〔１〕〜〔５〕のいずれかに記載のポリアミド樹脂組成物からなる成形品。

It is understood that in Examples 1 to 3 using the polyamide resin composition of the present invention, the flexibility was excellent and the volatilization of the plasticizer was suppressed. In addition, since there is little warpage, the physical characteristics of the molded product are not impaired even under high temperature conditions and long-term use. On the other hand, in Reference Examples 1 and 2 in which no plasticizer was used, good flexibility could not be obtained. Further, in Comparative Example 1 in which 4-hydroxybenzoic acid ester having a 2-ethylhexyl group as a branched chain was used as a plasticizer, the amount of volatile amount of the plasticizer was large and the warp was also large.
Preferred embodiments of the present invention include:
[1] 100 parts by mass of polyamide resin and formula (1)
[Chemical 1]

(Ar represents a divalent aromatic group and n represents an integer of 12 to 20)
A polyamide resin composition containing 1 to 70 parts by mass of a hydroxyaromatic amide compound represented by.
[2] The polyamide resin composition according to [1], wherein n represents an integer of 14 to 18 in the formula (1).
[3] In the formula (1), Ar is the formula (A).
[Chemical 2]

Or, equation (B)
[Chemical 3]

The polyamide resin composition according to claim 1 or 2, which exhibits a divalent aromatic group represented by.
[4] Described in any one of [1] to [3], wherein the polyamide resin is selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 6T, polyamide 6I and polyamide 9T. Polyamide resin composition.
[5] The polyamide resin composition according to any one of [1] to [4], wherein the polyamide resin is polyamide 12.
[6] A molded product comprising the polyamide resin composition according to any one of [1] to [5].

Claims (5)

Polyamide resin 100 parts by mass, and formula (1)

(Ar represents a divalent aromatic group and n represents an integer of 12 to 20)
Here, in the formula (1), Ar is the formula (A).

Or, equation (B)

Indicates a divalent aromatic group represented by,
A polyamide resin composition containing 1 to 70 parts by mass of a hydroxyaromatic amide compound represented by. The polyamide resin composition according to claim 1, wherein in the formula (1), n represents an integer of 14 to 18. The polyamide resin composition according to claim 1 or 2 , wherein the polyamide resin is selected from the group consisting of polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 610, polyamide 6T, polyamide 6I and polyamide 9T. The polyamide resin composition according to any one of claims 1 to 3 , wherein the polyamide resin is polyamide 12. A molded product comprising the polyamide resin composition according to any one of claims 1 to 4.