JP2000178368A - Polyamide sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel polyamide sheet which is excellent in all of the performances including heat resistance, chemical resistance, and low water absorption as compared with a conventional polyamide sheet (film). SOLUTION: This sheet is obtained by extruding a polyamide comprising dicarboxylic acid units containing 60-100 mol% terephthalic acid units and diamine units containing 60-100 mol% 9-12C aliphatic alkylenediamine units and having a limiting viscosity number [η] of 1.1-2.5 di/g as measured in concentrated sulfuric acid at 30 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semi-aromatic polyamide sheet. More specifically, the present invention relates to a semi-aromatic polyamide sheet having excellent heat resistance, chemical resistance, and low water absorption.

[0002]

2. Description of the Related Art Polyamide sheets (films) are used as packaging materials or industrial materials because they have excellent toughness, heat resistance, cold resistance, printing characteristics, chemical resistance and the like. However, the demands of the market are increasing year by year,
There is an increasing demand for a sheet that is more heat-resistant, has excellent dimensional stability under high temperature or high humidity, and has high durability against chemicals.

[0003] In response to such a demand in the world, all aliphatic polyamides comprising adipic acid and 1,4-butanediamine (hereinafter sometimes abbreviated as PA4-6) and terephthalic acid and 1,6-hexanediamine are used. A polyamide film comprising a semi-aromatic polyamide (hereinafter sometimes abbreviated as PA6-T) as a main component has been proposed.

For example, JP-A-2-248433 discloses that the ratio of PA4-6: semi-aromatic polyamide is 99.
It is disclosed that a polyamide film comprising a polyamide composition having a ratio of 9: 0.1 to 30:70 has excellent heat resistance. JP-A-3-253324 discloses that a polyamide film containing PA6-T as a main component is excellent in gas barrier properties, strength, heat resistance and transparency.

[0005]

According to the study of the present inventors, Japanese Patent Application Laid-Open Nos. 2-248433 and 3-
Although the polyamide film described in JP-A-253324 has improved heat resistance as compared with the conventional polyamide film, it has a large water absorption and therefore a large dimensional change and a large decrease in strength. Insufficient durability limits applications when used as industrial materials.

An object of the present invention is to provide a polyamide sheet which is superior in all of heat resistance, chemical resistance and low water absorption performance as compared with a conventional polyamide film (sheet).

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, a polyamide comprising terephthalic acid and an aliphatic alkylenediamine having 9 to 12 carbon atoms as a main component. It has been found that a sheet satisfying the above object can be obtained only by producing an extruded sheet from a polyamide having a specific intrinsic viscosity [η], and the present invention has been completed.

That is, the present invention provides a dicarboxylic acid unit containing 60 to 100 mol% of a terephthalic acid unit and an aliphatic alkylenediamine unit having 9 to 12 carbon atoms in an amount of 60 to 1%.
And a limiting viscosity [η] of 1.1 to 2.5 dl measured in concentrated sulfuric acid at 30 ° C.
/ G by extrusion molding of a polyamide.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
As the dicarboxylic acid unit constituting the polyamide used in the present invention, a terephthalic acid unit is 60 to 100 mol%.
It must be contained, and preferably 70 to 100 mol%. When the terephthalic acid unit is less than 60 mol%, the heat resistance and low water absorption of the obtained polyamide sheet are reduced.

Other dicarboxylic acid units other than the terephthalic acid unit include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dimethylmalonic acid,
Aliphatic dicarboxylic acids such as 3,3-diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methyladipic acid and trimethyladipic acid; 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like Alicyclic dicarboxylic acid; isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,
4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid, 4,4′-biphenyldicarboxylic acid, 4,4 ′
And units derived from aromatic dicarboxylic acids such as -oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid, and diphenylsulfone-4,4'-dicarboxylic acid. One or more of these units can be used. Of these, units derived from aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid and isophthalic acid, and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid are preferred. Further, a unit derived from a polycarboxylic acid such as trimellitic acid, trimesic acid, and pyromellitic acid can be contained in a range where the polyamide can be melt-molded.

The diamine unit constituting the polyamide used in the present invention must contain an aliphatic alkylenediamine unit having 9 to 12 carbon atoms in an amount of 60 to 100 mol%, and 75 to 100 mol%. And more preferably 90 to 100 mol%. When the content of the aliphatic alkylenediamine unit having 9 to 12 carbon atoms is less than 60 mol%, the heat resistance, low water absorption and chemical resistance of the obtained polyamide sheet are reduced. As the aliphatic alkylenediamine unit having 9 to 12 carbon atoms, for example, 1,9-nonanediamine, 1,10-
Decanediamine, 1,11-undecanediamine, 1,
Linear aliphatic alkylenediamines such as 12-dodecanediamine; 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2,4-diethyl- 1,6-hexanediamine, 2,2-dimethyl-1,7-heptanediamine,
2,3-dimethyl-1,7-heptanediamine, 2,4
-Dimethyl-1,7-heptanediamine, 2,5-dimethyl-1,7-heptanediamine, 2-methyl-1,8
-Octanediamine, 3-methyl-1,8-octanediamine, 4-methyl-1,8-octanediamine, 1,
3-dimethyl-1,8-octanediamine, 1,4-dimethyl-1,8-octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,
8-octanediamine, 4,5-dimethyl-1,8-octanediamine, 2,2-dimethyl-1,8-octanediamine, 3,3-dimethyl-1,8-octanediamine, 4,4-dimethyl- 1,8-octanediamine, 5
Branched aliphatic alkylenediamines such as -methyl-1,9-nonanediamine; norbornanedimethylamine;
Units derived from alicyclic diamines such as isophoronediamine and tricyclodecanedimethylamine can be mentioned, and one or more of these units can be used.

Among the above aliphatic alkylenediamine units, 2-methyl-1,8-octanediamine, 1,9
-Nonanediamine, 1,10-decanediamine, 1,1
Units derived from 1-undecanediamine and 1,12-dodecanediamine are preferred, and 1,9-nonanediamine (NMDA) units and 2-methyl-1,8-octanediamine (MODA) units are more preferred. Preferably, the NMDA unit and the MODA unit are such that the NMDA unit: MODA unit is 100: 0 to 30:70 (molar ratio), especially 99: 1 to 40:60, particularly 98: 2 to 4
It is preferable to use them at a ratio of 5:55. NM
By using DA units and MODA units together in the above proportions, heat resistance, moldability,
A sheet excellent in low water absorption can be obtained.

The diamine units which can be used in addition to the above-mentioned aliphatic alkylenediamine units having 9 to 12 carbon atoms include, for example, aliphatic diamines such as ethylenediamine, propylenediamine and 1,4-butanediamine; cyclohexanediamine, methyl Alicyclic diamines such as cyclohexanediamine; p-phenylenediamine, m-
Phenylenediamine, p-xylylenediamine, m-xylylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4 '
And units derived from aromatic diamines such as -diaminodiphenyl ether. One or more of these units can be used.

The polyamide used in the present invention has at least 10%, more preferably at least 40%, particularly preferably at least 70%, of the terminal groups of the molecular chain blocked by a terminal blocking agent. When the terminal sealing ratio is 10% or more, the change in viscosity of the polyamide at the time of melt molding is small, and the resulting sheet has excellent physical properties such as appearance and hot water resistance. In obtaining the terminal capping rate, the number of carboxyl group terminals, amino group terminals and the number of terminals capped by the terminal capping agent present in the polyamide are measured, and the number of terminals capped by the following formula (1) is determined. The sealing rate can be determined. The number of each terminal group is preferably determined from the integrated value of the characteristic signal corresponding to each terminal group by ¹ H-NMR from the viewpoint of accuracy and simplicity.

[0015] Terminal blocking ratio (%) = [(AB) ÷ A] × 100 (1) [wherein A is the total number of molecular chain terminal groups (this is usually equal to twice the number of polyamide molecules) ), And B represents the total number of carboxyl group terminals and amino group terminals. ]

The terminal blocking agent is not particularly limited as long as it is a monofunctional compound having reactivity with the amino group or carboxyl group at the terminal of the polyamide, and acid anhydrides such as monocarboxylic acid, monoamine and phthalic anhydride are used. , Monoisocyanates, monoacid halides, monoesters, monoalcohols and the like can be used, but a monocarboxylic acid or a monoamine is preferred from the viewpoint of reactivity and stability of a sealed end, and easiness of handling. In view of this, monocarboxylic acids are more preferred.

The monocarboxylic acid used as the terminal blocking agent is not particularly limited as long as it has reactivity with an amino group. Examples thereof include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, Aliphatic monocarboxylic acids such as caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutylic acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; benzoic acid, toluic acid, α And aromatic monocarboxylic acids such as -naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid. One or more of these can be used. Among them, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid are preferred from the viewpoints of reactivity, sealed terminal stability, and price. Benzoic acid is preferred.

The monoamine used as the terminal blocking agent is not particularly limited as long as it has reactivity with a carboxyl group. Examples thereof include methylamine, ethylamine, propylamine, butylamine, hexylamine and octylamine. Aliphatic monoamines such as decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine and dibutylamine; cycloaliphatic monoamines such as cyclohexylamine and dicyclohexylamine; aniline, toluidine, diphenylamine,
Examples thereof include aromatic monoamines such as naphthylamine. One or more of these can be used. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are preferable from the viewpoints of reactivity, boiling point, stability of the sealed terminal, and price.

The polyamide used in the present invention has an intrinsic viscosity [η] of 1.1 to 2.5 d measured in concentrated sulfuric acid at 30 ° C.
1 / g, preferably 1.15 to 2.0 dl / g
, More preferably in the range of 1.2 to 1.8 dl / g. When the intrinsic viscosity [η] of the polyamide is within the above range, a sheet having excellent moldability into a sheet and excellent mechanical properties, heat resistance, and the like can be obtained.

The polyamide used in the present invention preferably has a density of less than 1.16. When the density is in this range, a sheet excellent in low water absorption, chemical resistance, and toughness can be obtained, which is preferable.

In order to further improve the properties of the finally obtained sheet, the polyamide used in the present invention has a range in which the formability of the sheet of the present invention or the properties of the sheet are not sacrificed. Within, if necessary, a colorant; an ultraviolet absorber; a light stabilizer; an organic antioxidant such as a hindered phenol-based, thio-based, phosphorus-based, or amine-based; copper iodide, copper acetate, potassium iodide Inorganic antioxidants such as; antistatic agents; fluorescent whitening agents; brominated polymers;
Flame retardants such as antimony oxide and metal hydroxide; plasticizers;
Lubricants; PPS, liquid crystal polymers, polyolefins, polyesters, aliphatic polyamides, other polymers such as PPO; organic and inorganic powdery or fibrous fillers can also be added.

Examples of the method of adding the above-mentioned various additives include a method of adding during polymerization of polyamide, a method of dry-blending with polyamide and melt-kneading, and a method of adding during extrusion molding into a sheet.

The polyamide sheet of the present invention is produced by subjecting the above polyamide to a T-die extrusion molding method usually applied to the production of a sheet. For example, the above polyamide is melted at a melting point of 370 or more by an extruder.
After being melted at a temperature of not more than ℃, it is extruded with a T-die and usually cooled on a pressure roll to form a sheet thicker than 200 μm.

The polyamide sheet of the present invention can also be used in a state where the surface is laminated with a paint, a metal layer, another polymer or the like.

The polyamide sheet of the present invention has features not found in conventional polyamide sheets (films).
Electrical insulating materials such as motors, transformers and cables; dielectric materials such as capacitors; electronic board materials such as printed circuit boards and flat cables; magnetic materials such as sheet magnets; decorative materials such as signboards; It can be suitably used as a sheet for household and industrial materials, such as materials for civil engineering, materials for construction, and filtration membranes.

[0026]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. The intrinsic viscosity [η], melting point, high temperature elastic modulus, chemical resistance, and water absorption in the examples were measured by the following methods.

1. Intrinsic viscosity [η] in concentrated sulfuric acid at 30 ° C, 0.05, 0.1, 0.2,
The intrinsic viscosity (ηinh) of each concentration of 0.4 g / dl was determined from the following equation, and the value obtained by extrapolating the intrinsic viscosity to 0 was defined as the intrinsic viscosity [η]. ηinh = [ln (t1 / t0)] / c [wherein, ηinh represents the intrinsic viscosity (dl / g), t0 represents the flow time of the solvent (second), and t1 is the flow time of the sample solution (second). And c is the concentration of the sample in the solution (g / dl)
Represents ]

2. Melting point Using a differential scanning calorimeter (“DS30” manufactured by Mettler), the resin was placed in a DSC furnace at 350 ° C. under a nitrogen stream at 350 ° C.
After heating for 100 minutes to completely melt, the temperature was cooled to 50 ° C. at a rate of 100 ° C./min, and the position of an endothermic peak appearing when the temperature was raised again at a rate of 10 ° C./min was measured and defined as the melting point. .

3. High Temperature Elastic Modulus Dynamic Viscoelasticity Measurement Device (Rheological Inc.
VE-V4 ") was used to measure the storage modulus of the sheet at 250C.

4. Chemical resistance Appearance after immersing a 4cm x 4cm sheet in various chemicals (methanol at 23 ° C, 10% sulfuric acid at 23 ° C, 50% aqueous sodium hydroxide at 23 ° C, hot water at 80 ° C) for 7 days Changes were observed.

5. Water absorption The saturated water absorption of a sheet of 4 cm × 4 cm when immersed in distilled water at 23 ° C. was determined by weight measurement.

Reference Example 1 [Production of polyamide] 3272.9 g (19.80 mol) of terephthalic acid,
1582.9 g of 1,9-nonanediamine (10.0 mol
l), 2-methyl-1,8-octanediamine 158
2.9 (10.0 mol), 48.85 g of benzoic acid
(0.40 mol), 6.5 g of sodium hypophosphite monohydrate (0.1% by weight based on the total weight of the above four polyamide raw materials) and 2.2 liters of distilled water with an internal volume of 2
It was placed in a 0 liter autoclave and purged with nitrogen. 1
After stirring at 00 ° C for 30 minutes, the internal temperature was raised to 210 ° C over 2 hours. At this time, the autoclave is 22k
g / cm ² . After continuing the reaction for 1 hour, the temperature was raised to 230 ° C., and then maintained at 230 ° C. for 2 hours, and the pressure was reduced to 22 kg / cm ² by gradually removing steam.
The reaction was carried out while keeping Next, the pressure is increased to 1 over 30 minutes.
The pressure was lowered to 0 kg / cm ² , and the mixture was further reacted for 1 hour to obtain a prepolymer having an intrinsic viscosity [η] of 0.30 dl / g. This was dried at a temperature of 100 ° C. under reduced pressure for 12 hours, and then pulverized to a size of 2 mm or less. Next, this was subjected to solid-state polymerization under the conditions of a temperature of 230 ° C. and a pressure of 0.1 mmHg for 10 hours to obtain a melting point of 265 ° C. and an intrinsic viscosity [η] of 1.45.
dl / g of white polyamide was obtained.

Reference Examples 2 to 8 [Production of Polyamide] A dicarboxylic acid component, a diamine component and a terminal blocking agent (benzoic acid) shown in Table 1 were used in the proportions shown in Table 1, respectively. Polyamide was produced by the method.
Table 1 shows the intrinsic viscosity [η] and melting point of the obtained polyamide.
Shown in

[0034]

[Table 1]

Examples 1 to 5 and Comparative Example 2 The polyamides of Reference Examples 1 to 6 were supplied to a twin-screw extruder ("Laboplast Mill 2D25W" manufactured by Toyo Seiki Seisaku-sho, Ltd.), and 10 to 40 ° C. higher than the melting point of each polyamide. The mixture was heated and melted at a high temperature and extruded from a T-die to produce a polyamide sheet having a width of 50 mm and a thickness of 2 mm. Next, each item shown in Table 2 was evaluated using the obtained polyamide sheet.

Comparative Example 1 A sheet was produced in the same manner as in Examples 1 to 5 and Comparative Examples 1 and 2, using commercially available nylon 6 ("Amilan CM1021XF" manufactured by Toray) as a polyamide.
Using the sheet thus obtained, each item shown in Table 2 was evaluated.

Comparative Example 3 The polyamide of Reference Example 7 was supplied to a twin-screw extruder ("Laboplast Mill 2D25W" manufactured by Toyo Seiki Seisaku-sho, Ltd.), and the temperature was 280.degree.
The mixture was heated and melted at ２290 ° C. and extruded from a T-die. However, the viscosity was low and a sheet could not be produced.

Comparative Example 4 The polyamide of Reference Example 8 was supplied to a twin-screw extruder ("Laboplast Mill 2D25W" manufactured by Toyo Seiki Seisaku-sho, Ltd.) and the temperature was 280.degree.
The mixture was heated and melted at ２290 ° C. and extruded from a T-die, but the viscosity was high and a sheet could not be produced.

[0039]

[Table 2]

[0040]

The polyamide sheet of the present invention is excellent in heat resistance, chemical resistance and low water absorption performance as compared with the conventional polyamide sheet (film), and is suitable for industrial materials, industrial materials and households. It can be suitably used for applications such as supplies.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA55 AA88 AF02 AF10 AF45 AH04 BB06 BC01 4J001 DA01 DB04 DC14 EB04 EB05 EB06 EB07 EB08 EB09 EB13 EB14 EB36 EB37 EB46 EB55 EB60 EC09 EC13 EC14 EC15 FA05 FB01 JB32 JB50 JC01 4J002 CL031 GB01 GL00 GQ01 GQ05

Claims (2)

[Claims] 1. A terephthalic acid unit having a content of 60 to 100 mol%
It comprises a dicarboxylic acid unit to be contained and a diamine unit containing 60 to 100 mol% of an aliphatic alkylenediamine unit having 9 to 12 carbon atoms, and has an intrinsic viscosity [η] of 1.1 to 10 as measured at 30 ° C. in concentrated sulfuric acid. A sheet obtained by extruding a 2.5 dl / g polyamide. 2. The aliphatic alkylenediamine unit having 9 to 12 carbon atoms is composed of 1,9-nonanediamine unit and 2-methyl-1,8-octanediamine unit, and 1,9-nonanediamine unit: 2-methyl The molar ratio of -1,8-octanediamine units is from 100: 0 to 30:70
The sheet according to claim 1, which is: