JP2017101180A - Polyamide and molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide which has, in the constitution thereof, 2,5-furandicarboxylic acid and furthermore can be produced by melt polymerization or solid phase polymerization, and which is excellent in heat resistance and mechanical properties.SOLUTION: Polyamide is provided which is composed of: a dicarboxylic acid component having 2,5-furandicarboxylic acid as a main component; and a diamine component having xylylenediamine as a main component. Polyamide is provided in which the xylylene diamine is paraxylylene diamine and the melting energy is preferably 30 J/g or more. Polyamide is provided in which the content of the 2,5-furandicarboxylic acid is 50 to 100 mol%, preferably 80 to 100 mol%, and most preferably 100 mol% for the total dicarboxylic acid component. Polyamide is provided in which the content of xylylenediamine is 50 to 100 mol%, preferably 80 to 100 mol%, and most preferably 100 mol%, for the total diamine component.SELECTED DRAWING: None

Description

  The present invention relates to a polyamide using 2,5-furandicarboxylic acid.

  The problems of global warming and the depletion of petroleum resources are becoming serious, and the use of biomass plastics is attracting attention from the viewpoint of global environmental conservation. As the biomass plastic, polylactic acid, polybutylene succinate, and more recently biopolyethylene have been developed. However, these biomass plastics have a melting point of less than 180 ° C. and are inferior in heat resistance. As a method for improving the heat resistance of plastics, it is effective to introduce an aromatic ring into the molecular chain, but monomers derived from biomass and having an aromatic ring are limited. Among them, 2,5-furandicarboxylic acid is obtained from biomass while being aromatic, and polyamides using this are expected to have higher heat resistance than the biomass plastic.

  As a polyamide using 2,5-furandicarboxylic acid, for example, Patent Document 1 discloses a polyamide using 2,5-furandicarboxylic acid and an aliphatic diamine or an alicyclic diamine. Discloses a polyamide comprising 2,5-furandicarboxylic acid and paradiaminobenzene.

JP 2013-006963 A

POLYMER COMMUNICATIONS, vol. 26, p246-249 (1985)

  However, since the polyamide of Patent Document 1 has low crystallinity, it has low mechanical properties when used as a molded body, and its use is limited. Further, the polyamide of Non-Patent Document 1 needs to be subjected to interfacial polymerization after converting the carboxylic acid to an acid chloride with a chlorinating agent, and cannot be produced by industrially advantageous melt polymerization or solid phase polymerization. The resulting polyamide could not be melt molded.

  An object of the present invention is to provide a polyamide which has 2,5-furandicarboxylic acid in its configuration and can be produced by melt polymerization or solid phase polymerization and has excellent heat resistance and mechanical properties.

  As a result of intensive studies in order to solve such problems, the present inventors have found that the mechanical properties in the case of forming a molded body are improved by setting the melting energy of polyamide to 30 J / g. The present invention has been reached.

That is, the gist of the present invention is as follows.
(1) A polyamide comprising a dicarboxylic acid component mainly composed of 2,5-furandicarboxylic acid and a diamine component mainly composed of xylylenediamine.
(2) The polyamide as described in (1), wherein the xylylenediamine is paraxylylenediamine.
(3) The polyamide as described in (1) or (2), wherein the melting energy is 30 J / g or more.
(4) A molded article made of the polyamide according to any one of (1) to (3).

  According to the present invention, polyamide having excellent heat resistance and mechanical properties can be provided which can be produced by melt polymerization or solid phase polymerization while having 2,5-furandicarboxylic acid in its configuration.

  The polyamide of the present invention is composed of a dicarboxylic acid component and a diamine component.

  As the dicarboxylic acid component, 2,5-furandicarboxylic acid must be the main component. In the present invention, 2,5-furandicarboxylic acid as a main component means that the copolymerization amount of 2,5-furandicarboxylic acid is 50 to 100 mol% with respect to the total dicarboxylic acid component. Say. The copolymerization amount of 2,5-furandicarboxylic acid is more preferably 80 to 100 mol%, and further preferably 100 mol%. By using 2,5-furandicarboxylic acid as a main component, the merit in the environment is increased.

  2,5-furandicarboxylic acid can be obtained by hydrolyzing the ester derivative. The ester derivative can be synthesized from, for example, galactaric acid obtained by oxidizing galactose with nitric acid (for example, JP 2008-127282 A), or synthesized from a monosaccharide such as fructose (for example, (Topics in Catalysis, vol. 13, p237-242, 2000).

  As the dicarboxylic acid component, an aromatic dicarboxylic acid, an alicyclic dicarboxylic acid, or an aliphatic dicarboxylic acid different from 2,5-furandicarboxylic acid may be used as the other dicarboxylic acid.

  Examples of aromatic dicarboxylic acids different from 2,5-furandicarboxylic acid include terephthalic acid, isophthalic acid, 4,4′-biphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, Diphenyl ether-4,4′-dicarboxylic acid, diphenoxyethane-4,4′-dicarboxylic acid, diphenoxybutane-4,4′-dicarboxylic acid, diphenylethane-4,4′-dicarboxylic acid, diphenyl ether-3,3 Examples include '-dicarboxylic acid, diphenoxyether-3,3'-dicarboxylic acid, and diphenylethane-3,3'-dicarboxylic acid. Among these, terephthalic acid is preferable from the viewpoint of versatility.

  Examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and 2,5-norbornene dicarboxylic acid.

  Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, hydrogenated dimer acid, fumaric acid, maleic acid , Itaconic acid, citraconic acid, dimer acid.

  As a diamine component, it is necessary to have xylylenediamine as a main component. In addition, in this invention, xylylenediamine means that the copolymerization amount of xylylenediamine is 50-100 mol% with respect to all the diamine components. The copolymerization amount of xylylenediamine is more preferably 80 to 100 mol%, and further preferably 100 mol%. When xylylenediamine is not the main component, the heat resistance is lowered, and the mechanical properties when formed into a molded product are lowered, which is not preferable.

  Examples of xylylenediamine include paraxylylenediamine, metaxylylenediamine, and orthoxylylenediamine. Of these, paraxylylenediamine is preferred because of its high heat resistance and mechanical properties when formed into a molded body.

  As the diamine component, an aromatic diamine, an alicyclic diamine, or an aliphatic diamine different from xylylenediamine may be used as the other diamine.

  Examples of aromatic diamines different from xylylenediamine include paradiaminobenzene, metadiaminobenzene, and orthodiaminobenzene.

  Examples of the alicyclic diamine include 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,2-cyclohexanediamine, isophoronediamine, 4,4′-methylenebis (cyclohexylamine), and 4,4′-methylenebis. (2-methylcyclohexylamine).

  Examples of the aliphatic diamine include 1,5-pentanediamine, 2-methyl-1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, and 2-methyl. Examples include -1,8-octanediamine, 1,9-nonaneamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine.

  Among the above diamines, since heat resistance and moldability can be increased, aliphatic diamines having 5 to 12 carbon atoms or alicyclic diamines having 6 or more carbon atoms are preferable, and the ratio of biologically derived raw materials is increased. Therefore, a linear aliphatic diamine having 5, 8, 9, or 10 carbon atoms is more preferable. A linear aliphatic diamine having 5, 8, 9, 10 carbon atoms is synthesized by synthesizing a corresponding dicarboxylic acid from a plant-derived raw material by biofermentation or ozonolysis, and then aminating it. Can be obtained. For example, 1,5-pentanediamine can be obtained by amination of L-lysine obtained by fermentation of molasses. If 1,8-octanediamine or 1,9-nonanediamine is used, olive oil It can be obtained by amination of oleic acid obtained from rice bran oil or 1,10-decanediamine, and can be obtained by amination of ricinoleic acid obtained from castor oil.

  Although it does not specifically limit as a manufacturing method of the polyamide of this invention, For example, after producing a salt, the method of superposing | polymerizing the salt can be mentioned.

  Examples of a method for obtaining a salt of polyamide include a method in which a dicarboxylic acid component and a diamine component are reacted in water or an organic solvent to obtain a salt. The amount of the solvent to be used is preferably 2 parts by mass or more, and more preferably 10 parts by mass or more with respect to 100 parts by mass in total of the dicarboxylic acid component and the diamine component. The reaction temperature is preferably 80 to 100 ° C. under normal pressure, and preferably 100 to 150 ° C. under pressure. The reaction time is preferably 0.1 to 5 hours, more preferably 0.1 to 3 hours after reaching the reaction temperature.

  The salt polymerization may be performed at a temperature equal to or higher than the melting point of the resulting polyamide, or may be performed at a temperature lower than the melting point of the obtained polyamide. The pressure may be performed under normal pressure or under pressure. When performing melt polymerization, the reaction temperature is preferably {(melting point of the resulting polyamide) + 10 ° C.} to 350 ° C., and the reaction time is 0.5 to 6 hours after reaching the reaction temperature. It is preferable. In the case of performing solid-state polymerization, the reaction temperature is preferably {(melting point of the resulting polyamide) −100 ° C.} or more and less than (melting point of the resulting polyamide), and the reaction time reaches the reaction temperature. From 0.5 to 100 hours is preferable. In the polymerization of the salt, since the diamine may volatilize during the polymerization, a diamine component corresponding to the volatilization may be added in advance before the polymerization of the salt or during the polymerization.

  In order to further increase the molecular weight after polymerization of the salt, the polymerization may be continued under normal pressure or under an inert gas flow, or may be continued under reduced pressure. When polymerization is continued under an inert gas flow, the flow rate of the inert gas is preferably 0.01 to 10 L / (kg · min). Moreover, when continuing superposition | polymerization under pressure reduction, it is preferable that a pressure reduction degree shall be 1000 Pa or less.

  When polymerizing polyamide, it is preferable to use a catalyst from the viewpoint of improving the polymerization rate. Examples of the catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid, and salts thereof. These may be used alone or in combination of two or more. It is preferable that the usage-amount of a catalyst shall be 2 mol% or less with respect to the total number of moles of all the dicarboxylic acid components and all the diamine components.

  Moreover, you may use terminal blocker for the purpose of a polymerization degree adjustment, decomposition | disassembly, coloring suppression, etc. Examples of the terminal blocking agent include monocarboxylic acids and monoamines. Examples of the monocarboxylic acid include acetic acid, lauric acid, and benzoic acid, and examples of the monoamine include octylamine, cyclohexylamine, and aniline. These may be used alone or in combination of two or more. It is preferable that the usage-amount of terminal blocker shall be 5 mol% or less with respect to the total number of moles of all the dicarboxylic acid components and all the diamine components.

  The biomass ratio of the polyamide of the present invention is preferably 25% or more, and more preferably 50% or more. By setting the biomass ratio to 25% or more, the environmental merit is increased.

  The relative viscosity of the polyamide of the present invention in 96% concentrated sulfuric acid at a concentration of 1 g / dL and 25 ° C. is preferably 1.5 or more, and more preferably 2.0 or more. By setting the relative viscosity to 1.5 or more, it is possible to further improve the mechanical properties when formed into a molded body. The relative viscosity can be controlled by adjusting the polymerization time and the content of the end-capping agent.

  The melting point of the polyamide of the present invention is preferably 220 ° C. or higher, and more preferably 250 ° C. or higher. If the melting point of polyamide is 220 ° C., it can be said that the heat resistance is sufficiently high as compared with conventional bioplastics. The melting energy of the polyamide of the present invention is preferably 30 J / g or more, and more preferably 50 J / g or more. By setting the melting energy to 30 J / g or more, the crystallinity is increased, and the mechanical properties when formed into a molded body can be improved. The melting point and melting energy tend to be increased by using xylylenediamine as paraxylenediamine or increasing the copolymerization amount of xylylenediamine.

  The water absorption when the polyamide of the present invention is used as a molded article is preferably 1% or less, and more preferably 0.5% by mass or less. By making the water absorption rate 1% or less, dimensional changes during long-time storage can be further suppressed. Further, the tensile strength when polyamide is used as a molded body is preferably 50 MPa or more, and more preferably 55 MPa or more. By setting the tensile strength to 50 MPa or more, the performance as a molded body can be further improved. The water absorption rate tends to decrease as the melting energy increases, and the tensile strength tends to increase as the melting energy increases.

  To the polyamide of the present invention, additives such as an antioxidant, an antistatic agent, a flame retardant, a flame retardant aid, a heat stabilizer, a fibrous reinforcing material, a filler, and a pigment may be added. Examples of the fibrous reinforcing material include glass fiber and carbon fiber, and examples of the filler include talc, swellable clay mineral, silica, alumina, glass beads, graphite, and filler. Examples thereof include titanium oxide and carbon black. As for an additive, 20 mass% or less is preferable with respect to the sum total of all the dicarboxylic acid components and all the diamine components.

  The polyamide of the present invention can be processed into various molded products by known molding methods such as injection molding, extrusion molding, blow molding and the like.

The polyamide molded article of the present invention can be suitably used as an automobile part or an electric / electronic part.
Examples of automobile parts include a base plate and an engine cover used for a base such as a shift lever and a gear box.
Examples of electrical / electronic components include connectors, LED reflectors, switches, sensors, sockets, capacitors, jacks, fuse holders, relays, coil bobbins, resistors, IC and LED housings.

  Moreover, the polyamide of the present invention can be processed into a film, sheet, or fiber by a known film forming method or spinning method.

The film and sheet can be used as, for example, a speaker diaphragm, a film capacitor, an insulating film, and various packaging films.
The fiber can be used, for example, as an air bag base fabric or a filter.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

1. Analysis Method (1) Resin Composition Using a high resolution nuclear magnetic resonance apparatus (ECA500 NMR manufactured by JEOL Ltd.), ¹ H-NMR analysis was performed to obtain a resin composition from the peak intensity of each copolymer component (resolution) : 500 MHz, solvent: trifluoroacetic acid-d / heavy water = 9/1 (volume ratio)), temperature: 25 ° C.).

(2) Biomass ratio It calculated | required by the following formula | equation.
Biomass ratio (%) = dry weight of biomass-derived raw material used / dry weight of polyamide × 100

(3) Relative viscosity Measured at a concentration of 1 g / dL and 25 ° C. using 96% sulfuric acid as a solvent.

(4) Melting point and melting energy Using a differential scanning calorimeter DSC-7 manufactured by PerkinElmer, Inc., the temperature was raised from room temperature to 300 ° C. at 20 ° C./minute, held for 5 minutes, and then kept at 500 ° C./minute at 25 ° C. The temperature was raised to 300 ° C. at a rate of 20 ° C./min. The peak peak derived from the melting of the curve obtained at the second temperature increase was taken as the melting point, and the area was taken as the melting energy.

(5) Water absorption rate After the polyamide was sufficiently dried, it was molded using an injection molding machine (EC-100 type manufactured by Toshiba Machine Co., Ltd.) to prepare a test piece of length 125 mm × width 12 mm × thickness 0.8 mm. The cylinder temperature was (melting point of the resulting polyamide + 20 ° C.), and the mold temperature was 100 ° C.
The obtained test piece was allowed to stand in water at 25 ° C. for 24 hours, and the water absorption was calculated according to the following formula based on the value of the mass of the test piece before standing.
Water absorption rate (%) = (mass of test piece after standing) / (mass of test piece before standing) × 100

(6) Tensile strength After the polyamide was sufficiently dried, it was molded using an injection molding machine (EC-100 type manufactured by Toshiba Machine Co., Ltd.) to prepare a test piece having a length of 150 mm, a width of 10 mm, and a thickness of 0.8 mm. The cylinder temperature was (melting point of the resulting polyamide + 20 ° C.), and the mold temperature was 100 ° C.
It measured using model-2020 (made by INTESCO) based on JISK-7127 using the obtained test piece. The cell used was 1000 N, the test speed was 50 mm / powder, and the chuck spacing was 100 mm.

2. Raw material (1) 2,5-furandicarboxylic acid (FDCA) (plant-derived)
To the reaction vessel, 250 parts by mass of galactaric acid (extract from lemon or apple fruit), 2500 parts by mass of 1-butanol, and 500 parts by mass of sulfuric acid were added and heated to reflux for 8 hours in an oil bath. The produced water was removed azeotropically. After the reaction, 1500 parts by mass of diisopropyl ether and 1000 parts by mass of distilled water were added for washing, and further, 1000 parts by mass of a 1% by mass aqueous sodium hydrogencarbonate solution was added once, and 1000 parts by mass of distilled water was added to wash twice. did. Then, the organic layer was taken out and distilled under reduced pressure (150 ° C./1.4 mmHg) to obtain dibutyl 2,5-furandicarboxylate. The yield was 48 mol%. The obtained dibutyl 2,5-furandicarboxylate was recrystallized using methanol and then hydrolyzed to obtain 2,5-furandicarboxylic acid.

(2) Isophthalic acid (IPA) (derived from petroleum)
(3) Paraxylylenediamine (PDXA) (derived from petroleum)
(4) Metaxylylenediamine (MXDA) (derived from petroleum)
(5) 1,6-hexanediamine (HMDA) (derived from petroleum)
(6) 4,4'-methylenebis (cyclohexylamine) (MBCHA) (derived from petroleum)

Example 1
A solution prepared by dissolving 17.1 parts by mass of paraxylylenediamine in 700 parts by mass of N-methylpyrrolidone (NMP) was dropped into a solution in which 19.7 parts by mass of FDCA was dissolved in 400 parts by mass of NMP, and heated at 80 ° C. for 3 hours. Stir. Thereafter, the precipitate was filtered off and dried with a vacuum dryer to obtain a polyamide salt.
The obtained polyamide salt was put into a polymerization apparatus equipped with a stirring blade, a heater, a nitrogen inlet and an outlet, and heated and stirred at 250 ° C. for 12 hours under a nitrogen stream to obtain a polyamide.

Examples 2 to 4, Comparative Examples 1 and 2
Except for changing the resin composition, polyamide polymerization or solid phase polymerization was performed in the same manner as in Example 1.

  Table 1 shows the resin compositions and characteristic values of the polyamides obtained in the examples and comparative examples.

  All of the polyamides of Examples 1 to 4 were capable of melt polymerization and solid phase polymerization, had a high melting point, and had high tensile strength when formed into molded bodies.

Since the polyamide of Comparative Example 1 was mainly composed of 1,6-hexanediamine in the diamine component, the melting point was low and the tensile strength was low.
Since the polyamide of Comparative Example 2 was mainly composed of 4,4′-methylenebis (cyclohexylamine) in the diamine component, the melting point was low and the tensile strength was low.

Claims (4)

A polyamide comprising a dicarboxylic acid component mainly composed of 2,5-furandicarboxylic acid and a diamine component mainly composed of xylylenediamine. The polyamide according to claim 1, wherein the xylylenediamine is paraxylylenediamine. The polyamide according to claim 1 or 2, wherein the melting energy is 30 J / g or more. The molded object which consists of polyamide in any one of Claims 1-3.