JP2016130304A - Polyamide resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel polyamide resin using a dicarboxylic acid compound that achieves both an adequate glass transition temperature for heat resistance and an adequate melting point for moldability and therefore has excellent heat resistance and moldability.SOLUTION: A polyamide resin comprises dicarboxylic acid compound (A) represented by formula (1) and/or formula (2) and diamine compound (B). The diamine compound is aliphatic diamine compound or aromatic diamine compound, preferably, C4-9 linear aliphatic amine compound, more preferably, 1,4-butane diamine or 1,6-hexane diamine.SELECTED DRAWING: None

Description

The present disclosure relates to a polyamide resin using a novel dicarboxylic acid compound.

A polyamide resin is a plastic obtained by polycondensation of a polycarboxylic acid compound and a polyamine compound, and many products are used as thermoplastics. The range of use of plastics has expanded with improvements in their properties. In particular, a plastic having excellent heat resistance is useful for greatly expanding the range of use. Adoption of plastic parts that can reduce vehicle weight tends to accelerate with the recent reduction in fuel consumption and hybridization of automobiles. However, these parts are used to transmit heat from machine parts such as engine rooms. Also, heat resistance that can be used is required.

Examples of the initial polyamide resin include aliphatic nylons such as a polycondensate of adipic acid and hexamethylenediamine (nylon 66) and a polycondensate of ε-caprolactam (nylon 6). These polyamide resins are unreinforced and have a low load deflection temperature of 60 to 80 ° C. and are excellent in moldability, but are unsuitable for applications where they are exposed to high temperatures.

In order to improve heat resistance, a polycondensate of terephthalic acid, which is an aromatic dicarboxylic acid, and hexamethylene diamine (nylon 6T, Patent Documents 1 and 2) has been developed. Since this polyamide resin has a high melting point only with terephthalic acid, it is used as a copolymer with isophthalic acid or adipic acid. The temperature drops. In addition, terephthalic acid is highly dependent on the manufacturing method from petroleum-derived resources, and is a resin that cannot cope with the trend of reducing environmental burdens with renewable resources.

JP 59-155436 A JP 59-53536 A

  When the polyamide resins described in Patent Documents 1 and 2 are used, molding with terephthalic acid alone is difficult due to the high melting point. In addition, in the case of a polyamide resin copolymerized with isophthalic acid or adipic acid, the glass transition temperature is lowered, so that it is difficult to achieve both a melting point and a glass transition temperature, and a compatibility between moldability and heat resistance. I found it.

In view of the above circumstances, the present disclosure provides a polyamide resin having both a glass transition temperature excellent in heat resistance and a melting point excellent in moldability and excellent in heat resistance and moldability.

The present disclosure is based on the following (1) to (4).
(1) A polyamide resin comprising a dicarboxylic acid compound (A) represented by the following formula (1) and / or the following formula (2) and a diamine compound (B).


(2) The polyamide resin according to (1), wherein the diamine compound (B) is an aliphatic diamine compound or an aromatic diamine compound.
(3) The polyamide resin according to (2), wherein the aliphatic diamine compound includes a linear aliphatic diamine compound having 4 to 9 carbon atoms.
(4) The polyamide resin according to (2) or (3), wherein the aliphatic diamine compound contains 1,4-butanediamine or 1,6-hexanediamine.

By using a dicarboxylic acid having a specific structure, it was possible to obtain a polyamide resin having excellent heat resistance and moldability and useful as an engineering plastic.

<Dicarboxylic acid compound (A)>
The present disclosure relates to a polyamide resin using a dicarboxylic acid compound having a specific structure. The dicarboxylic acid compound having a specific structure has a structure represented by the following formula.



This dicarboxylic acid compound can be obtained by reacting a protocatechuic acid ester with a dihalogenated propanoic acid ester in the presence of an alkali and then removing the ester group which is a protective group.

The dicarboxylic acid compound uses protocatechuic acid and dihalogenated propanoic acid as raw materials, and non-petroleum-derived raw materials can also be used as these raw materials. For the non-petroleum-derived production method of protocatechuic acid, see WO2014 / 007273 or J.A. AM. CHEM. SOC. , Vol 127, pp 2874-2882 (2005). Moreover, although dihalogenated propanoic acid can be derived from acrylic acid, the non-petroleum-derived production method of acrylic acid is disclosed in JP 2012-162471 A and JP 2013-505727 A. Use of these non-petroleum-derived raw materials is preferable because a polyamide resin can reduce the environmental load.

In addition to the dicarboxylic acid compound, a dicarboxylic acid compound that is generally used for polyamide resins can be used in combination with the polyamide resin of the present invention. For example, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, adipic acid, 1,5-dicarboxylpentane, 1,6-dicarboxylhexane, 1,7-dicarboxylheptane, 1,8-dicarboxyloctane, 1 , 9-dicarboxyl nonane, 1,10-dicarboxyl decane, 1,11-dicarboxyl undecane, 1,12-dicarboxyl dodecane and the like linear alkyl dicarboxylic acids. The dicarboxylic acids may be used as ester-forming derivatives such as aryl esters and acid chlorides.

<Diamine compound (B)>
The polyamide resin of the present invention can be obtained by polymerizing the above-described dicarboxylic acid compound and a diamine compound. Examples of the diamine compound include 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10- Aliphatic diamines such as decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,4-diaminocyclohexane, aromatics such as 1,4-phenylenediamine, 4,4′-diaminodiphenyl ether, and benzidine A diamine or the like can be used, but an aliphatic diamine is preferable because the polyamide resin can have flexibility, an appropriate melting point can be obtained as a thermoplastic resin, and handling as a molding resin is excellent. Moreover, it is preferable to use a linear alkyldiamine having 4 to 9 carbon atoms as the aliphatic diamine because the above-described flexibility-imparting effect is excellent. Among these linear alkyldiamines, 1,4-butanediamine and 1,6-hexanediamine are easily available and particularly preferable.

<Polyamide polymerization>
A commonly used technique can be used for the polymerization of polyamide. For example, in the thermal polycondensation method, raw material dicarboxylic acid compound, diamine compound, and water are charged into an autoclave, and the reaction apparatus is replaced with an inert gas. Thereafter, the temperature is raised to a temperature of 300 ° C. or higher at normal pressure, and the pressure is reduced as necessary to remove unreacted substances and moisture, whereby a polyamide resin can be obtained. Alternatively, the prepolymerized product can be charged into an apparatus capable of being heated and kneaded, such as an extruder, which can be heated to 300 ° C. or higher, and a heat polymerization reaction can be advanced in this apparatus to obtain a polyamide resin.

In this reaction, the raw material dicarboxylic acid compound and the diamine compound may be charged alone, or may be charged as a nylon salt obtained by reacting in advance with an aqueous solution or the like.
When a polyamide resin is obtained by thermal polycondensation, an additive can be used to improve the reactivity. As such an additive, a phosphorus compound can be used. As the phosphorus compound, phosphoric acid, its salt or ester, phosphorous acid, its salt or ester, hypophosphorous acid, its salt or ester is used. The addition amount of these additives is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the total weight of the dicarboxylic acid compound and the diamine compound.

In the solution polymerization method, a dicarboxylic acid compound is reacted with thionyl chloride or the like to be converted to acid chloride, and then reacted with a diamine compound in a solvent to obtain a polyamide resin. As another solution polymerization method, a dicarboxylic acid compound, a diamine compound, and a condensing agent can be reacted in a solvent to obtain a polyamide resin. As such a condensing agent, a well-known thing, such as a triazine compound and an organic phosphorus compound, can be used.

The material amount of the diamine compound (B) is used at a ratio close to 1 mol with respect to 1 mol of the total amount of the dicarboxylic acid compound (A) used in the polyamide resin and other dicarboxylic acids used in combination. Is preferred. It is preferable to use 0.95 to 1.2 mol of the diamine compound in consideration of the diamine activity effective in the reaction.

Further, in the polymerization of the polyamide resin, a monofunctional component such as monocarboxylic acid or monoamine can be used in combination so as not to leave the terminal reactive group of the polyamide resin. These monofunctional components are preferably used at a ratio of 0.1 to 5 mol% with respect to the dicarboxylic acid compound.

The polyamide resin of the present invention is a composite material that uses, in combination, inorganic fillers such as glass, silica, alumina, mica, kaolin, clay, zinc oxide, and talc, and organic fillers such as wood powder and resin powder. Can also be used. These fillers can be used in a spherical shape, powder shape, needle shape, fiber shape, scale shape, flat plate shape, cloth shape, or an indefinite shape.

The polyamide resin of the present invention can be used by adding a lubricant, an antioxidant, a release agent, a high-temperature stabilizer, a coupling agent and the like, if necessary.

The polyamide resin of the present invention can be used by mixing with other resins as required. For example, polyphenylene sulfide resin, semi-aromatic polyamide resin, aliphatic polyamide resin, polyester resin, liquid crystal polymer, modified polyphenylene ether and the like can be mentioned.

Since the polyamide resin of the present invention has thermoplasticity, it can be molded into a desired shape by using a molding apparatus. Examples of such a molding machine include a compression molding machine, an injection molding machine, and an extrusion molding machine.

Since this compound is contained in the resin, it can be used for the purpose of adjusting the material properties of the resin. Specifically, it can be used as a plasticizer for adjusting the molecular weight of the resin and improving moldability.

The present invention is illustrated by examples. However, the present invention is not limited to these examples.

Below, it describes about the various raw materials used in the Example and the comparative example.
Protocatechuic acid: Wako Pure Chemical Industries methanol: Wako Pure Chemical Industries ethyl 2,3-dibromobenzoate: Tokyo Kasei Kogyo N, N-dimethylformamide: Wako Pure Chemical Industries potassium carbonate: Wako Pure Chemical Industries ethyl acetate : Sodium hydroxide manufactured by Wako Pure Chemical Industries: 1,6-hexanediamine manufactured by Wako Pure Chemical Industries: 1,4-butanediamine manufactured by Wako Pure Chemical Industries: 1,4-xylylenediamine manufactured by Wako Pure Chemical Industries: Tokyo Chemical Industry N-methyl-2-pyrrolidone manufactured by: Wako Pure Chemical Industries, Ltd. Pyridine: Wako Pure Chemical Industries, Ltd. Triphenyl phosphite: Wako Pure Chemical Industries, Ltd. Hydrochloric acid: Wako Pure Chemical Industries, Ltd. Concentrated sulfuric acid: Wako Pure Chemical Industries, Ltd.

The dicarboxylic acid compound represented by the formula (1) and / or the formula (2) used in the present invention is prepared by the following method.

Protocatechuic acid was used after methyl esterification according to the following procedure. Protocatechuic acid 84 g and methanol 350 mL were mixed in a 500 mL eggplant type flask, 7 mL of concentrated sulfuric acid was added, and the mixture was heated and refluxed for 8 hours. After the reaction, methanol was evaporated, the obtained solid was dissolved in ethyl acetate, ion-exchanged water was added, and liquid separation was performed until the aqueous layer became neutral. Thereafter, the organic layer was separated, and the organic layer was evaporated to obtain a solid. The solid was dried under reduced pressure to obtain 82 g (yield 90%) of methyl protocatechuate.
In a 1 L reaction vessel, 78 g of methyl protocatechuate and 146 g of ethyl 2,3-dibromopropionate and 500 mL of N, N-dimethylformamide were dissolved. 78 g of potassium carbonate was added, the temperature was raised at 90 ° C. in a nitrogen atmosphere, and the reaction was allowed to proceed for 5 hours. Ion exchange water was added to the reaction solution, and insoluble components were extracted with ethyl acetate. Ethyl acetate was evaporated and dried under reduced pressure. To 92 g of the solid dried under reduced pressure, 500 mL of a 2.5 mol / L aqueous sodium hydroxide solution was added and stirred at room temperature for 24 hours. Hydrochloric acid was added dropwise to the obtained aqueous solution to acidify the system, and the released solid was collected by vacuum filtration and washed with ion-exchanged water. The obtained solid was dried under reduced pressure. Thereby, 75 g (yield 98%) of 2,6-dicarboxy-1,4-benzodioxane and 2,7-dicarboxy-1,4-benzodioxane mixture (formula (1) and formula (2)) Obtained.

Example 1
Charge and dissolve 68.8 g of dicarboxylic acid compound represented by formula (1) and formula (2), 31.2 g of 1,6-hexanediamine, 200 g of N-methyl-2-pyrrolidone and 50 g of pyridine in a reactor equipped with a reflux tube. I let you. Thereafter, 93 g of triphenyl phosphite was added and reacted at 90 ° C. for 6 hours in a nitrogen atmosphere. The reaction solution was added to 1000 g of methanol, and the precipitated solid was recovered. As a result, 92 g of a polyamide resin was obtained.

(Examples 2 to 4)
Except having used the combination of Table 1 as a dicarboxylic acid compound and a diamine compound, operation was performed like Example 1 and the polyamide resin of Examples 2-4 was obtained.

(Comparative example)
As Comparative Examples 1 and 2, an aromatic polyamide resin (PA6T resin, manufactured by DuPont, Zytel HTN52, unreinforced grade) in which the dicarboxylic acid compound and the diamine compound are 1,6-hexanediamine and terephthalic acid, respectively, the dicarboxylic acid compound And an aliphatic polyamide resin (PA66 resin, manufactured by DuPont, Zytel 101L, non-reinforced grade) in which the diamine compound is 1,6-hexanediamine and 1,6-hexanedicarboxylic acid.

The resins of Examples 1 to 4 and Comparative Examples 1 and 2 were evaluated by the following methods.

(1) Glass transition temperature
Based on JIS K7121, it calculated | required from the DSC curve of the temperature increase rate of 5 degree-C / min and the 2nd cycle by DSC by Seiko Instruments (model DSC6100R).

(2) Melting point Measured with a DSC (model DSC6100R) manufactured by Seiko Instruments Inc. at a rate of temperature increase of 5 ° C./min, and the melting endothermic peak temperature was taken as the melting point.

  As can be seen from Table 1, compared to conventional polyamide resins using terephthalic acid and aliphatic polyamide resins, it has both a glass transition temperature excellent in heat resistance and a melting point excellent in moldability, and has excellent heat resistance and moldability. An excellent resin can be obtained.

Claims (4)

A polyamide resin comprising a dicarboxylic acid compound (A) represented by the following formula (1) and / or the following formula (2) and a diamine compound (B).


The polyamide resin according to claim 1, wherein the diamine compound (B) is an aliphatic diamine compound or an aromatic diamine compound.
The polyamide resin according to claim 2, wherein the aliphatic diamine compound contains a linear aliphatic diamine compound having 4 to 9 carbon atoms.
The polyamide resin according to claim 2 or 3, wherein the aliphatic diamine compound contains 1,4-butanediamine or 1,6-hexanediamine.