JP2949805B2 - Terminally modified polyether amide resin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a terminal-modified polyetheramide resin. More specifically, the present invention relates to a polyether amide resin having reduced heat-extractable low-molecular compounds, less generation of low-molecular compounds after molding (after heat history), and good thermal stability.

[Prior art and problems] Polyetheramide resins are excellent in antistatic property, heat resistance, moldability and mechanical strength and are used for various applications (for example, Japanese Patent Publication No. 45-7559). Due to its mechanical strength and mechanical strength, its use in the food packaging field, particularly in food packaging films and sheets, is being studied.

However, the use of polyetheramide resins in the food-related field has been avoided since low-molecular compounds such as low-molecular odor substances and polyamide oligomers are generated during melt polymerization. In addition, even if the low-molecular compound is once removed with an appropriate solvent, it is generated again by melt molding, which is not preferable in terms of thermal stability. Therefore, further improvement has been desired.

[Means for Solving the Problems] The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, among the amino groups and carboxyl groups which are the polymer molecule terminals necessarily held by the polyetheramide resin, It has been found that the amino group is more involved in the generation of low-molecular odor substances and other low-molecular compounds. Then, the present inventors have found that the carboxylation of this amino group with a specific carboxylic acid greatly suppresses the generation of the low-molecular compound and the like, and thus completed the present invention.

That is, an object of the present invention is to provide a polyetheramide resin having a large industrial value, and the gist of the present invention is to provide the following structural formula [I], [II], [III] or [IV] consists structural units represented by, the molecular weight terminus is an amino group (-NH ₂₎ and / or carboxyl group (-COOH) is 10,0
A terminal-modified polyether amide resin characterized by having a polyether amide of 100 to 100,000 and an amount of terminal amino groups of 40 μeq / g (equivalent to 1 g of polyether amide) or less (However, R ¹ , R ² , and R ³ are linear or branched alkylene groups having 2 to 4 carbon atoms, and R ⁴ , R ⁵ , and R ⁶ are aliphatic, alicyclic, or aromatic having 2 to 36 carbon atoms.) Represents a hydrocarbon group, n is 0 to 180, m
Is 1 to 400. ).

 Hereinafter, the present invention will be described in detail.

The terminal-modified polyether amide resin of the present invention mainly comprises a poly (ether amide) unit represented by the following general formula [I], [II], [III] or [IV] in which a polyether unit and a polyamide unit are linked. It is a constituent unit.

Poly (ether amide) can be easily obtained, for example, by amide-bonding a polyether having an amino group or a carboxyl group at a terminal to a polyamide having a carboxyl group or an amino group at a terminal by a condensation reaction.

Each of the structural units represented by [I] to [IV] alone forms the polyetheramide of the present invention. In some cases, the polyetheramide of the present invention is a copolymer containing two or more of these. It may be.

Represents an alkylene group in the above general formulas [I] to [IV]
R ¹ , R ² and R ³ are a linear or branched alkylene group having 2 to 4 carbon atoms such as an ethylene group, a propylene group, an isopropylene group, and a tetramethylene group, and the carbon number is 2 to 4. . Further, the integer n is 0 to 180, preferably about 0 to 60.

In the above general formula, R ⁴ has 2 to 36 carbon atoms, preferably 2 to 2 carbon atoms.
5, more preferably 2 to 11 aliphatic, alicyclic or aromatic hydrocarbon groups, which are the residues of lactams or aminocarboxylic acids used in the production of polyamides described below. R ⁵ is an aliphatic, alicyclic or aromatic hydrocarbon group having 2 to 36 carbon atoms, preferably 2 to 22 carbon atoms, and more preferably 2 to 7 carbon atoms, and is a diamine residue described below. R ⁶ has 2 to 36 carbon atoms, preferably 2 carbon atoms.
To 24, more preferably 2 to 11, aliphatic, alicyclic or aromatic hydrocarbon groups, and is a residue of a dicarboxylic acid described below. The integer m is 1 to 400, preferably 1 to 120.

In the present invention, the content of the polyether unit constituting the poly (ether amide) is 5 to 75% by weight, preferably 10 to 50% by weight, from the viewpoint of a balance between mechanical strength and flexibility. It is suitable.

The terminal-modified polyetheramide resin of the present invention has a terminal amino group concentration (equivalent to 1 g of polymer) of all terminal groups (total of amino groups and carboxyl groups) of the polyetheramide composed of poly (etheramide) units of 40. (Μ
eq / g)
It is a terminal modified one.

Further, [COOH] ≧ [NH ₂ ] +5 (μeq / g) (where,
[COOH] represents the equivalent of the terminal carboxyl group, and [NH ₂ ] represents the equivalent of the terminal amino group. ) Are preferred.

That is, in the present invention, [NH ₂ ] ≦ 40 (μeq / g). If the number is large, it is not preferable because generation of reducing impurities during melt polymerization and melt molding cannot be suppressed. The preferred amount of [NH ₂ ] is 30 (μeq / g) or less, more preferably 20 (μeq / g) or less.

The terminal-modified polyetheramide resin of the present invention has a molecular weight (n) of 10,000 to 100,000, preferably 15,000 to 50,000.
It is 0. This molecular weight is a value obtained by calculating the total number of terminal groups (sum of amino groups and carboxyl groups) (μeq / g) and calculating by the following equation.

[COOH] ≧ [NH 2] +5 (μeq / g) is preferable, and more preferably [COOH] ≧ [NH ₂ ] +10 (μeq / g) in order to adjust the molecular weight to a range suitable for processing such as melt molding.
g).

The poly (ether amide) of the present invention is obtained, for example, by condensing a polyether having an amino group at a terminal with a polyamide having a terminal carboxyl group, or a polyether having a terminal carboxyl group and a polyamide having a terminal amino group. It can be easily obtained by amide condensation in the reaction.

Polyethers having an amino group or a carboxyl group at the terminal include, for example, ethylene oxide, propylene oxide, and the like, by ring-opening polymerization of alkylene oxide and tetrahydrofuran, polyethylene oxide, polypropylene oxide, polyether such as polytetramethylene oxide. It can be easily obtained by substituting the terminal hydroxyl group of this compound with an amino group and / or a carboxyl group.

Examples of the above-mentioned amino group substitution method include a method in which a hydroxyl group is directly aminated or cyanoethylated and then reductive amination, and a method in which a carboxyl group is substituted is a method by carbonyl oxidation.

In the present invention, as the raw material polyether, one end may be an amino group and the other end may be a carboxyl group, but the polyether (a) in which both ends are amino groups or both ends are a carboxyl group. Certain polyethers (b) are preferably used.

(The same R ^1, R ^2, R ³ is) whereas _{^{H 2 N-R 1 OR 2}} O n R 3 -NH 2 (a) HOOC-R 1 OR 2 O n R 3 -COOH (b), terminal The polyamide having a carboxyl group or an amino group can be directly obtained by ring-opening polymerization of a lantam having three or more rings, polycondensation of a polymerizable aminocarboxylic acid, or polycondensation of a dicarboxylic acid and a diamine.

Specific examples of the lactam include ε-caprolactam, enantholactam, capryllactam, lauryl lactam, α-pyrrolidone, α-piperidone and the like.

As the polymerizable aminocarboxylic acid, preferably ω
-Amino acids, and usually ω-amino acids having 2 to 25 carbon atoms are used. Specifically, 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminocaproic acid,
Aminoundecanoic acid and the like.

As the dicarboxylic acid, a dicarboxylic acid having 2 to 36 carbon atoms is usually used, and specifically, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelanic acid, sebacic acid, undecandioic acid , Dodecandionic acid, tridecadionic acid, tetradecadionic acid, hexadecadionic acid, hexadecenedionic acid, octadecadionic acid, octadescedionic acid, eicosandioic acid, eicosendioic acid, eicosadienedioic acid, docosandioic acid , Aromatic dicarboxylic acids such as 2,2,4-trimethyladipic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, aromatics such as terephthalic acid, isophthalic acid, phthalic acid and xylene dicarboxylic acid Group dicarboxylic acids and the like.

Further, as the dicarboxylic acid having 36 carbon atoms, dimerized fatty acid can be mentioned. The dimerized fatty acid is a polymerized fatty acid obtained by polymerizing a fatty acid, for example, a saturated, ethylenically unsaturated, acetylenically unsaturated, natural or synthetic monobasic fatty acid having 8 to 24 carbon atoms.

As the diamine, a diamine having 2 to 24 carbon atoms is usually used.Specifically, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, Such as nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, hexadecamethylenediamine, octadecamethylenediamine, 2,24 (or 2,4,4) -trimethylhexamethylenediamine And aliphatic alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, bis- (4,4'-aminocyclohexyl) methane, and aromatic diamines such as xylylenediamine. Examples of the diamine having 36 carbon atoms include a dimer amine obtained by converting a carboxyl group of a dimer fatty acid into an amino acid.

Specific examples of the above polyamide, for example,
Nylon 4,6,7,8,11,12,6.6,6.9,6.10,6.11,6.12,6T, 6 /
66, 6/12, 6 / 6T and the like.

Among the above polyamides, polyamides represented by the following general formula (c) or (d) are preferably used as those obtained by ring-opening polycondensation of lactam or polycondensation of ω-amino acid.

The polyamide having a carboxyl group at both ends represented by the general formula (c) is obtained by adding the above-mentioned dicarboxylic acid to a basic polyamide by ring-opening polycondensation of a lactam, and is represented by the general formula (d). The polyamide having both terminal amino groups can be obtained by adding the above-described diamine to the same basic polyamide.

On the other hand, a polyamide obtained by polycondensation of a dicarboxylic acid and a diamine can be used as a polyamide (e) having a carboxyl group at both terminals or a polyamide (f) having an amino group at both terminals by directly using any one of the raw materials in a stoichiometric amount or more. Obtainable.

As described above, the poly (ether amide) of the present invention
The above general formula [I], [II], [III] or [IV] obtained by condensing the above-mentioned polyether having an amino group or a carboxyl group at the end with a polyamide having a carboxyl group or an amino group at the end. ] Is a structural unit represented by the following formula: That is, the general formula [I] or [II] is a polyether having amino groups at both terminals represented by the above general formula (a) and a polyamide having carboxyl groups at both terminals represented by the general formula (c) or (e). And a recurring structural unit obtained by condensation of the general formula [III] or [I
V] is a repeating structural unit obtained by condensing a polyether having a carboxyl group at both terminals represented by the above general formula (b) and a polyamide having both amino groups at both terminals represented by the general formula (d) or (f). It is.

The terminal-modified polyether amide resin of the present invention can be obtained by, for example, modifying the terminal amino group of such poly (ether amide) with a dicarboxylic acid. The dicarboxylic acid used for the terminal modification is selected from the above-listed dicarboxylic acids having 2 to 36 carbon atoms as raw materials for polyamide. Preferably, the same dicarboxylic acid as the raw material for the polyamide is used.

The production of the terminal-modified polyetheramide resin of the present invention comprises:
It can be performed by a known condensation reaction.

First, a polyamide to be reacted with a polyether is obtained from a polyamide raw material, and then the above-mentioned polyether having an appropriately modified end group is added thereto to carry out a condensation reaction. The dicarboxylic acid used for terminal modification of the poly (ether amide) can be added at any stage from the start of the condensation reaction to the start of the reaction under reduced pressure. In the initial stage of the polymerization, the amount of the amino group-derived compound (polyamide or polyether having amino groups at both ends) is reduced by a small ratio with respect to the carboxyl group-derived compound (polyamide or polyether having a quantity terminal of carboxyl group). By charging, the terminal modification of the poly (ether amide) of the present invention can be achieved without adding a dicarboxylic acid for terminal modification.

The terminal-modified polyetheramide resin of the present invention can be used in a food-related field, mainly as a package requiring direct contact with food, specifically, as a film, sheet, blow, container or the like.

Further, the term "package" as used in the present invention refers to a packaging material including a film, a sheet, a blow, a container, and the like, and generally includes a thermoforming method such as an injection molding such as a T-die method and an inflation method, a blow molding, and a vacuum molding. It is molded by subjecting it to a known molding method with a plastic resin. Further, other components, such as pigments, dyes, heat-resistant agents, antioxidants, weathering agents, lubricants, crystal nucleating agents, antistatic agents, plasticizers, other polymers, etc., as long as they do not impair moldability or physical properties. It can be added and introduced.

When the package comprising the terminal-modified polyetheramide resin of the present invention is a film or a sheet, it may be used without stretching or stretched by a known method. Further, a known resin such as a co-extrusion method and a laminating method may be laminated on the package and used. [Examples] Hereinafter, the present invention will be described in more detail with reference to Examples. Is not limited to these examples.

In the examples, various measured values were obtained by the following methods.

(1) Terminal group analysis The amino group is obtained by dissolving the polymer in phenol and adding 0.05N
It was measured by titration with hydrochloric acid. The carboxyl group was measured by dissolving the polymer in benzyl alcohol and titrating with 0.1N sodium hydroxide.

(2) Relative viscosity; measured at 1% concentration in m-cresol using an Ubbelohde viscosity tube. (30 ° C).

(3) Measurement of low molecular weight compound 10 g of polymer pellets were extracted with demineralized water at 100 ° C. for 121 ° C. × 20 minutes, cooled to room temperature, passed through a 0.2 μm Teflon filter, and the filtrate was dried to dryness. It was measured.

(4) Measurement of Odor Substances 10 g of a polymer was placed in a glass tube equipped with a septum, replaced with N ₂ , heated at 100 ° C. for 30 minutes, and 0.5 ml of gas remaining in the head space was sampled with a Gaitite cylinder and analyzed by gas chromatography.

[Examples 1 to 6] Into an autoclave of 200, the polyamide raw materials shown in Table 1 were charged, sealed in an N ₂ atmosphere, and kept at a constant pressure (10KG).
After raising the temperature to 240 ° C. and reacting under pressure for 2 hours with stirring, the polyether and the terminal modifier described in Table 1 were added,
Further, a pressurized reaction was performed for 2 hours with stirring. The pressure was gradually released to a predetermined pressure, and the reaction was performed under reduced pressure for 2 hours.

The stirring was stopped, N ₂ was introduced, and the pressure was restored to normal pressure.

The pellets thus obtained were extracted with hot water at 100 ° C. (water ratio 3.0, 50 min × 10 batch extraction) and dried, and then subjected to a resin temperature of 24 using a 3.6 oz injection molding machine (manufactured by Toshiba Machine Co., Ltd.).
A test piece was molded at 0 ° C. and a mold temperature of 60 ° C., and an easily extracted low molecular compound and an odor were measured before and after the molding. The results are shown in Table 1.

Comparative Examples 1 and 2 The same operation as in Examples 1 to 6 was performed except that no terminal modifier was added. The results are shown in Table 1.

[Effects of the Invention] The terminal-modified polyetheramide resin of the present invention is significantly suppressed in generation of low-molecular odorous substances and low-molecular compounds during melt polymerization and molding, and is excellent in heat stability. It is suitable for packaging films and containers. Further, since it has antithrombotic properties, it is suitably used for medical equipment and the like.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08G 69/00-69/50

Claims (1)

(57) [Claims] 1. It comprises a structural unit represented by the following structural formula [I], [II], [III] or [IV], and is terminated with an amino group (—NH ₂ ) and / or a carboxyl group (—COOH). A terminal-modified polyetheramide resin, which is a polyetheramide having a certain molecular weight of 10,000 to 100,000 and having an amount of terminal amino groups of 40 μeq / g (equivalent to 1 g of polyetheramide). (However, R ¹ , R ² , and R ³ are linear or branched alkylene groups having 2 to 4 carbon atoms, and R ⁴ , R ⁵ , and R ⁶ are aliphatic, alicyclic, or aromatic having 2 to 36 carbon atoms.) Represents a hydrocarbon group, n is 0 to 180, m
Is 1 to 400. )