JPH0689139B2 - Polyamide packaging - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyamide package which has good transparency and is uniform, and does not impair printability.

[Conventional technology]

Polyamide packaging has excellent properties such as pinhole resistance, oil resistance, and oxygen barrier properties, but due to the crystallinity of polyamide, it becomes cloudy when cooled, impairing transparency and causing nonuniform transparency. There was a drawback.

Attempts have been made to improve the above-mentioned drawbacks by the conventional cooling method and the use of additives, but they have not been sufficient.

[Object of the Invention]

The present inventors have prepared an aliphatic or alicyclic hydrocarbon group having 6 to 22 carbon atoms at the end of the polyamide so that the number of the hydrocarbon group is 1% or more of the total number of end groups of the polyamide. It was found that the prepared product is extremely effective in improving transparency without impairing printability and is useful as a package.

That is, the present invention is a good and uniform transparency, polyamide print without impairing the printability, specifically to provide a film, a sheet, a blow container, etc. The effect is remarkable for the film formed by the water cooling method.

The gist thereof is a polyamide having an aliphatic or alicyclic hydrocarbon group having 6 to 22 carbon atoms at the end, and (a) the number of the hydrocarbon group is 1 of the total number of end groups of the polyamide. -100%, and (b) a relative viscosity of 2-6. A polyamide package formed by molding a polyamide resin.

[Structure of Invention]

The polyamide referred to in the present invention is a polyamide obtained by polycondensation of a lactam having three or more membered rings, a polymerizable ω-amino acid, or a dibasic acid and a diamine, or a copolymerization thereof. Specific examples of the raw materials for these polyamides include ε-caprolactam, enantolactam, capryllactam, lauryllactam, α-pyrrolidone and α.
-Lactams such as piperidone, 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-
Ω-amino acids such as aminoundecanoic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecadioic acid, hexadecadiodioic acid, hexadecenedioic acid, eicosandioic acid, Dibasic acids such as eicosadienedionic acid, diglycolic acid, 2,2,4-trimethyladipic acid, xylylenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, hexamethylenediamine, tetra Methylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4 (or 2,4,4) -trimethylhexamethylenediamine, bis- (4,4'-aminocyclohexyl) methane, metaxylyl Examples thereof include diamines such as diamine.

Examples of the hydrocarbon group having 6 to 22 carbon atoms at the end of the polyamide of the present invention include hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group. Group, tetradecylene group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, octadecylene group, eicosyl group, alicyclic hydrocarbon group such as docosyl group, cyclohexyl group, methylcyclohexyl group, cycloaliphatic group such as cyclohexylmethyl group Examples thereof include a hydrocarbon group.

These hydrocarbon groups are introduced by using the carboxylic acids and / or amines described below during the production of the polyamide.

As the terminal group of the polyamide, in addition to the above hydrocarbon group,
Amino groups and / or derived from the above-mentioned polyamide raw materials
Or there is a carboxyl group.

Hydrocarbon group, after hydrolysis of the polyamide with hydrochloric acid,
Measured by gas chromatography. The amino group is measured by dissolving polyamide in phenol and titrating it with 0.05N hydrochloric acid. The carboxyl group is measured by dissolving polyamide in benzyl alcohol and titrating with 0.1N caustic soda.

The number of all terminal groups means the above hydrocarbon group, amino group and / or
Alternatively, it is the sum of the numbers of carboxyl groups.

In the present invention, the number of hydrocarbon groups is 1 to 100% of the total number of end groups. If this number is too small, a sufficient effect of improving transparency cannot be obtained.

It is preferable that the number of the hydrocarbon groups is close to 100% of the total number of the terminal groups because the transparency is rather deteriorated under certain cooling conditions and the production is not easy industrially.
%, More preferably 10 to 30%.

Regarding the degree of polymerization of the polyamide resin of the present invention, JIS K 6810
According to the above, the relative viscosity value measured at 98% sulfuric acid concentration of 1% at a temperature of 25 ° C can be arbitrarily selected in the range of 2.0 to 6 and preferably 2.5 to 6, but when the relative viscosity is low, the melt viscosity is too small and molding is performed. Becomes difficult and the strength is impaired. On the other hand, if it is too high, the melt fluidity is impaired, which is not preferable, and therefore it is more preferably 3 to 5.5.

In order to produce the polyamide resin of the present invention, the above polyamide raw material is prepared by using a monocarboxylic acid having 7 to 23 carbon atoms, a monoamine having 6 to 22 carbon atoms and / or a diamine having 2 to 22 carbon atoms, or 6 to 6 carbon atoms. 22 monoamine and dicarboxylic acid having 3 to 24 carbon atoms Polycondensation is performed in the presence of monoamine having 6 to 22 carbon atoms or monocarboxylic acid having 7 to 23 carbon atoms.

Examples of the monocarboxylic acid having 7 to 23 carbon atoms include enanthic acid, caprylic acid, capric acid, pelargonic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid,
Aliphatic monocarboxylic acids such as myristoleic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, and behenic acid, alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid, and methylcyclohexanecarboxylic acid. To be Corresponding derivatives, such as acid anhydrides, esters, amides, which can play the same role as the acids mentioned above during the reaction for the production of polyamides can also be used.

As the monoamine having 6 to 22 carbon atoms, hexylamine,
Heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, octadecyleneamine, eicosylamine, Examples thereof include aliphatic monoamines such as docosylamine, cyclohexylamine, and alicyclic monoamines such as methylcyclohexylamine.

The diamine having 2 to 22 carbon atoms includes ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine. , Dodecamethylenediamine, tridecamethylenediamine, hexadecamethylenediamine, octadecamethylenediamine, 2,2,4 (or 2,4,
4) -aliphatic diamines such as trimethylhexamethylenediamine, cyclohexanediamine, methylcyclohexanediamine, alicyclic diamines such as bis- (4,4'-aminocyclohexyl) methane, aromatic diamines such as xylylenediamine And so on.

Examples of the dicarboxylic acid having 3 to 24 carbon atoms include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,
Suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecadioic acid, tetradecadioic acid, hexadecadioic acid, hexadecenedioic acid, octadecadioic acid, octadecenedioic acid, eicosandioic acid, eicosenoic acid Aliphatic dicarboxylic acids such as sendionic acid, docosandionic acid, 2,2,4-trimethyladipic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid,
Examples thereof include aromatic dicarboxylic acids such as phthalic acid and xylylenedicarboxylic acid.

The reaction for producing the polyamide resin of the present invention may be carried out by using the above-mentioned polyamide raw material and starting the reaction according to a conventional method, and the carboxylic acid and / or amine may be used from the start of the reaction until the reaction under reduced pressure is started. It can be added at any stage. The carboxylic acid and amine may be added simultaneously or separately.

The amount of carboxylic acid and / or amine used is 0.03 to 22 meq / mol, preferably 0.3 to 10 meq / mol based on the polyamide raw material, as the amount of the carboxyl group and amino group.
It is meq / mol. If this amount is too small, it becomes impossible to produce a polyamide resin having the effect of the present invention. On the other hand, if the amount is too large, it becomes difficult to produce a polyamide having a high viscosity, and the physical properties of the polyamide resin are adversely affected.

The term "packaging body" as used in the present invention refers to a packaging material including a film, a sheet, a blow container, and the like. In addition to extrusion molding such as T-die method and inflation method, injection molding, blow molding,
Molded by subjecting a thermoplastic resin to a known molding method such as vacuum molding. In addition, other components such as pigments, dyes, heat-resistant agents, antioxidants, weathering agents, lubricants, crystal nucleating agents, antistatic agents, plasticizers, other polymers, etc. may be used as long as they do not impair the moldability and physical properties. Addition can be introduced.

When the polyamide package of the present invention is a film or a sheet, it may be used without being stretched or may be stretched by a known method.

A known resin may be laminated on the polyamide package of the present invention by a known method such as a co-extrusion method or a laminating method.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

Examples 1 to 3 and Comparative Example 1 Into a 200 l autoclave, 60 kg of ε-caprolactam and water were added.
1.2 kg and stearic acid and octadecylamine in the amounts shown in Table 1 below were charged, and the mixture was sealed in a nitrogen atmosphere.
After the temperature was raised to 260 ° C and the reaction was carried out under pressure for 2 hours with stirring, the pressure was gradually released to a pressure shown in Table 1 below.
The reaction was performed under reduced pressure for 2 hours.

After introducing nitrogen and returning the pressure to normal pressure, stirring was stopped, and the mixture was extracted as a strand to form a pellet, and unreacted monomer was extracted and removed using boiling water and dried.

Comparative Example 2 Pellets were obtained in exactly the same manner as in Example 1 except that benzylamine was used instead of octadecylamine and stearic acid was not used.

Using the obtained pellets, a film was formed into a film as described below using a three-layer inflation film forming machine (manufactured by Placo Co., Ltd.).

The pellets obtained were used as the outer layer, and the modified polyolefin admer was used.
NF300 (Mitsui Petrochemical Co., Ltd.) is the middle layer, low density polyethylene Novatec F121 (Mitsubishi Kasei Co., Ltd.) is the inner layer, and the thickness of each layer is outer layer / middle layer / inner layer = 50μ / 10μ / 20μ
And

The film forming temperature was 250 ° C., and the cooling method was to bring the outer layer into contact with water at 18 ° C. for cooling. As for the physical property measurement method in Table 1, haze is JIS
According to K 6714, the degree of uneven haze (nonuniformity) of the haze unevenness of the film was visually evaluated, and the unevenness was evaluated as ×, the intermediate degree was evaluated as Δ, and the unevenness was evaluated as ○.

The water droplet contact angle was measured using an Elma Goniometer type contact angle measuring instrument manufactured by Elma Optical Co., Ltd., and pure water was used as a sample solution. If this is large, the printability will deteriorate.

The results are shown in Table 1 below.

The term "end termination rate" in the table means the ratio of the hydrocarbon groups having 6 to 22 carbon atoms at the end of all the polyamide end groups.

For comparison, the results of the same operation as in Example 1 except that stearic acid and octadecylamine were not used are also shown.

Examples 1, 2, and 3 have a lower haze than Comparative Example 1 and are good with no haze unevenness.

Examples 4 to 6 and Comparative Example 2 In Examples 1 to 3 and Comparative Example 1, the thickness of the film was set to outer layer / intermediate layer / inner layer = 150 μ / 50 μ / 100 μ, and this film was used with a film stretcher manufactured by Long Co. Temperature 80 ℃
Outer layer / middle layer / inner layer = 17μ / 6μ / 11
was set to μ. Otherwise, the same operations as in Examples 1 to 3 and Comparative Example 1 were performed to obtain Examples 4 to 6 and Comparative Example 2. The results are shown in Table 2.

It can be seen that the same effect can be obtained when the film is stretched as when it is not stretched.

[Effects of the Invention] As described above, a molded product obtained by molding the polyamide resin of the present invention has a remarkable effect of improving transparency without impairing printability, and is extremely useful as a packaging material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiichi Kamoshida 1447-2 Fujita, Hachimansai-ku, Kitakyushu, Fukuoka Prefecture Mitsubishi Kasei Kogyo Co., Ltd. Kurosaki Plant (56) Reference JP-A-50-63098 (JP, A) )

Claims (1)

[Claims] 1. A polyamide having an aliphatic or alicyclic hydrocarbon group having 6 to 22 carbon atoms at the terminal, wherein (a) the number of the hydrocarbon group is 1 to 100 of the total number of the terminal groups of the polyamide. %, And (b) a relative viscosity of 2 to 6, a polyamide package formed by molding a polyamide resin.