JPS6335647A - Container made of polyester and having improved flavor retention - Google Patents

Abstract

PURPOSE:To reduce the concn. of acetaldehyde left in a container to thereby improve flavor retention, by incorporating a predetermined amount of a specified thermoplastic polyamide in a material for a container made of a thermoplastic polyester mainly composed of ethylene terephthalate units. CONSTITUTION:100pts.wt. thermoplastic polyester (A) mainly composed of ethylene terephthalate units is mixed with 5X10<-7>-10pts.wt. thermoplastic polyamide (B) having a terminal amino group concn. of 0.05-50mmol/100g of resin (e.g., nylon 6). The resin mixture is molded to obtain the title container. The component B acts as an agent for lowering the concn. of acetaldehyde. Acetaldehyde formed by the heat decomposition of polyethylene terephthalate is trapped by the terminal amino group of the component B to thereby reduce the concn. of acetaldehyde in the container. Thus, the flavor retention of contents can be improved.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a polyester container with improved flavor retention, and more specifically, by reducing the acetaldehyde concentration in the container wall, Flavor (
Regarding a polyester container with improved flavor retention.

(Prior art) Containers made of polyethylene terephthalate made by biaxial stretch blow molding have excellent pressure resistance, rigidity, transparency, and impact resistance, and also have relatively low gas permeability to oxygen, carbon dioxide, etc., so they can be used for various purposes. They are widely used as containers for liquid foods, seasonings, cosmetics, etc., and plastic cans with a polyethylene terephthalate container body sealed with a metal lid are also on the verge of being put into practical use. .

However, polyethylene terephthalate generates acetaldehyde due to thermal decomposition during its thermoforming.
There is a problem in that acetaldehyde in the container wall migrates into the contents, impairing the flavor of the contents.

As a means to reduce the acetaldehyde concentration due to thermal decomposition in polyethylene terephthalate, conventional methods include solid-phase polymerization of broken ethylene terephthalate in a fire after normal polymerization to reduce low molecular weight components, or methods to slightly increase molecular weight 1, and thermoforming. A method of lowering the molding temperature during thermoforming as much as possible and a method of reducing the shear (shear stress) during thermoforming as much as possible have been considered.

(Problems to be Solved by the Invention) However, in the production of containers made of polyester such as polyethylene terephthalate, general polyester is melted and then injected into an injection mold to form a substantially amorphous preform. This is done by stretch blowing the preform at a stretch molding temperature, so increasing the molecular weight of the polyester tends to reduce the injection moldability of the polyester, and lowering the molding temperature is This is undesirable because it increases the load on the injection machine, and lowering the shear tends to lower the molding speed and cause bubble entrainment, which is undesirable.

Therefore, it is an object of the present invention to provide a polyester container with improved flavor retention by reducing the acetaldehyde concentration contained in the wall of the polyester container without any particular adverse effect on the molding performance or physical properties of the polyester. The original title is

(Means for Solving the Problems) The present inventors have developed a thermoplastic polyester mainly containing ethylene terephthalate unit gold, with a terminal amino group concentration of 0.0.
A thermoplastic polyamide in the range of 5 to 50 mmol/100 g resin was added to 5 x 1 mol/100 parts by weight of polyester.
It has been found that when a container is formed from a composition containing as an acetaldehyde concentration lowering agent in an amount of 0 to 10 parts by weight, preferably 5 x 10 to 10 parts by weight, the acetaldehyde concentration in the container wall can be significantly reduced. I found it.

(Function) The mechanism by which acetaldehyde is produced by thermal decomposition of polyethylene terephthalate is as shown in the following formula.
This is said to be due to the decomposition of the primer hydroxy end group or the decomposition of the primer main chain as shown in the following formula.

The present invention is based on the finding that the incorporation of a certain amount of polyamide with a certain terminal amino group concentration into polyethylene terephthalate can significantly reduce the acetaldehyde concentration in the thermoformed container wall. That is, the terminal amino group-containing polyamide used in the present invention acts as a concentration lowering agent for acetaldehyde in polyethylene terephthalate. It is thought that one of the reasons is that acetaldehyde is trapped at the amino group terminal of the polyamide by the reaction shown in .

The polyamide used in the present invention is a polymeric substance and is dispersed in polyester, so unlike low molecular weight amino compounds, it does not migrate into the contents of the container by extraction or volatilization. , itself also has the advantage of not having an adverse effect on the flavor of the contents.

The polyamide containing 7 terminal amino groups used in the present invention has terminal amino groups of 0.05 to 50 mmol/100. ! It is important to contain the i+ polyamide resin in a particularly preferred concentration of 0.1 to 40 mmol/100.9 polyamide resin. When the terminal amino group concentration is lower than the above range, the ability to capture acetaldehyde is insufficient, while when the terminal amino group concentration is higher than the above range, 2
There is a tendency for the problem of deterioration of the flavor of the container due to the incorporation of Lyamide.

In the present invention, the polyamide is polyester 1
5 x 10” to 10! parts per 00 parts by weight, especially 5
It is also necessary to blend in an amount of X 10-' to 10ffi parts. Figure 1 shows the addition amount ratio (5.0 x 10 to 15.0 parts by weight (PHR) of each thermoplastic polyamide to 100 parts by weight of polyethylene terephthalate).
) and the residual rate of acetaldehyde in polyester (the ratio of the residual amount of acetaldehyde to the acetaldehyde concentration when no polyamide is added). The results shown in FIG. 1 show that as the amount of 4-lyamide added increases, the acetaldehyde residual rate decreases, but as the amount added increases, the acetaldehyde residual rate tends to gradually become saturated. It is estimated that the effect of lowering the acetaldehyde concentration is large even when the amount ratio is smaller than the above range, while on the other hand, when the amount ratio is larger than the above range, the degree of reduction in acetaldehyde concentration due to the amount ratio is not much improved. Furthermore, there is a tendency for the transparency or mechanical properties of the IJ ester container to decrease.

In the present invention, the terminal amino group concentration in the polyamide is set to 100 C millimorphs! ! Resin and polyester 100I
When the number of blended parts of polyamide per I is S, the product CX
Polyester 100, expressed as SX 100. li
It is most desirable that the amount of 4-lyamide per ' is in the range of 2 x 10-' to 20 mmol, particularly 6 x 10-' to 1 mmol.

In addition, the adjustment of the terminal amino group frequency can be done by using the molecule! This can be carried out by adjusting the reaction molar ratio between diamino components and diamino components, terminal treatment at the time of termination of polymerization, etc.

(Description of preferred embodiments of the invention) Polyester In the present invention, a polyester containing ethylene terephthalate units as a main component is used as the polyester. This is because this polyester has excellent stretch formability and is also excellent in mechanical properties and transparency. As a polyester mainly composed of ethylene terephthalate units, polyesters in which 80 or more moles of the acid component are terephthalic acid components, and 80 or more moles of the diol component are ethylene glycol components are preferred. ◎Polyethylene terephthalate is the most preferred, but modified copolyesters can also be used within a range that does not lose the essence of polyethylene terephthalate. For example, inphthalic acid, P
-β-oxyethoxybenzoic acid, naphthalene 2,6-dicarganic acid, diphenoxyethane-4,4'-dicarmenic acid, 5-sodium sulfoisophthalic acid, adipic acid, sepacic acid or alkyl ester derivatives thereof, etc. Diamino components, propylene glycol, 1.4-
Copolyesters containing glycol components such as butanediol, neopentyl glycol, 1,6-hexylene glycol, cyclohexane dimetatool, ethylene oxide adduct of bisphenol A, etc. may also be used.

The polyester used should have a molecular weight sufficient to form a film, and for this purpose the intrinsic viscosity (
1, V, ) is 0.55 to 1.9 dt7#, especially 0
．． A range of 65 to 1.4 dllI is desirable. Among these, those with a relatively low molecular weight are used for injection molding, and those with a relatively high molecular weight are used for extrusion molding.

Examples of the polyamide polyamide include various homo-I lyamides, co-polyamides, and blends thereof, as long as the above-mentioned conditions are satisfied.

As such polyamides, in particular the following may be used for the purposes of the present invention: (1) For example, the following amide repeat units, namely -Co-R-NH-... (4) or -Co-R, -CONH-R2-NH-... (5) In the formula, R represents a linear alkylene group, and R1 and R2 are an alkylene group or an arylene group, provided that at least one of them is an alkylene group. or a combination thereof.

Mention may be made of homopolyamides having amide repeating units or blends thereof.

From the viewpoint of scavenging ability for acetaldehyde, the number of amide groups per 100 carbon atoms in polyamide is 1.
Preference is given to using homopolyamides, copolyamides or blends thereof in the range from 30 to 30, especially from 2 to 25. Examples of suitable homopolyamides include polycapramide (nylon 6), poly-ω-aminohebutanoic acid (nylon 7),
- aminononanoic acid (nylon 9), polyundecaneamide (nylon 11), polylaurinlactam (nylon 12), polyethylene upamide (nylon 2.6),
polytetrametele/azonomamide (nylon 4.6),
Polyhexamethylene adipamide (nylon 6 + 6
) 1, IH+) Hexamethyleneadipamide (Cairo 76
．． 10), polyhexamethylene dodecamide (nylon 6
．． 12), polyoctamethyleneazino 4mide (nylon 8.6), polydecamethylene azino 9mide (nylon 10.6),
Polydodecamethyleneazino9mide (nylon 12.6)
, Polydobyl Methylene Sepacamide (Nylon 12.8), etc.

Examples of suitable co-polyamides include caprolactam/laurinlactam copolymers, caprolactam/hexamethylenediammonium azo 4-to copolymers, laurinlactam/hexamethylenediammonium adipate copolymers, hexamethylenediammonium azobate. /hexamethylene diammonium cefucate copolymer, ethylene diammonium a-/″2-)/hexamethylene diammonium anovate copolymer, caprolactam/hexamethylene diammonium anoate/hexa/ethylene diammonium sebacate copolymer Combination etc.

Further, in the following formula (6) as described in, for example, JP-A-60-159052, R3 and rt4 each mean a hydrogen atom or a lower alkyl group.

The structural unit represented by is 1 to 100 mol, and the following formula (
7) % Formula % (7) In the formula, p means an integer from 2 to 11.

A thermoplastic polyamide comprising 0 to 99 moles of the structural unit represented by For example, a copolymer of α-(N, N-dimethylamino)-ε-caprolactam and α-(N, N-dimethylamino)-ε-caprolactam and ε-caprolactam.

Furthermore, aromatic polyamides may be used instead of the aliphatic polyamides mentioned above, such as those described in Japanese Patent Publication No. 1156/1980, Japanese Patent Publication No. 5751/1982, Japanese Patent Publication No. 50/1982. Publication No. 5753, Japanese Patent Publication No. 10196/1983, Japanese Patent Application Publication No. 50-29/1983
Meta-xylylene diamino or mixed xylylene diamino containing meta-xylylene diamino and para-xylylene diamino in an amount of 30% or less of the total amount as described in Publication No. 697, etc., and having 6 to 10 carbon atoms. An aromatic polyamide containing in its molecular chain at least 70 moles of a structural unit formed from α,ω-aliphatic aliphatic decals. For example, polymethaxylylene azinamide.

These homopolyamides and copolyamides can also be used in the form of so-called blends, for example blends of polycapramide and polyhexamethylene adipamide, blends of polycapramide and caprolactam/hexamethylene diammonium adipate copolymers, Blend of polycapramide and poly[α-(N,N dimethylamino)-ε-caglolactam], polyhexamethyleneazide iJ? Blends of mido and polymethaxylylene adipamide, etc., may all be used for the purpose of the present invention.

(11) Socarboxylic acid component units containing isophthalic acid component units in the range of 30 to 100 molti as described in, for example, JP-A-60-232952, JP-A-60-240452, etc. 50 to 50 moles, 35 to 50 moles of diamino component units mainly composed of metaxylylene diamino component units, and an aminocarboxylic acid having a carbon atom number of 5 to 12. A substantially linear co-condensed polyamide comprising 0 to 30 moles of phosphoric acid component units.

(ii+) A polyamide resin obtained by condensation polymerization of a diamino compound with a polymerized fatty acid obtained by polymerizing an unsaturated fatty acid (for example, linoleic acid, lily/acid, etc.) under heating and melting. That is, it is a polymerized fatty acid polyamide, such as a condensation polymer of riluic acid 2i1 and hexamethylene diamino.

The molecular weight of these polyamides can be used without any particular limitations as long as they are within a range that has general film-forming ability.
As described later, the relative viscosity (η
It is generally desirable that REL) be in the range of 0.4 to 4.5.

Blends The blends of the present invention contain the above-mentioned polyesters and polyamides containing terminal amino groups, but the blends contain additives known per se, such as colorants, fillers, surfactants, lubricants, ultraviolet absorbers, etc. One or more of antioxidants, antioxidants, nucleating agents, etc. can be blended in a known blending ratio.

The blend used in the present invention may contain 19 or 2s or more of a thermoplastic resin other than those mentioned above for the purpose of modification, such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-1 copolymer, etc. It can contain polymers, ionomers (olefin resins such as ionically crosslinked olefin copolymers; polycargenates; polyarylates, etc.).These other resins may be contained in amounts of up to 9100 parts by weight, particularly 80 parts by weight, per 100 parts by weight of the blend. It is recommended to use the following amounts.

Blends can be prepared by tri-blending pellets or powders of multiple resins to be blended, then melt-kneading and pelletizing, but it is desirable to mix both of them evenly. Therefore, a method is advantageously adopted in which a plurality of types of pellets or powders are intimately mixed using a Henschel mixer or the like, and then melt-kneaded. Alternatively, a method may be advantageously used in which a small amount of polyester and the polyamide to be blended are blended and melt-kneaded to prepare a masterbatch, and this masterpatch is blended with the remaining polyester and then melt-kneaded.

Containers and Forming Methods Containers according to the invention are produced by means known per se, except that the blends described above are used.

For example, sheets, pipes, or bottomed preforms for forming hollow containers are easily manufactured by extrusion molding, injection molding, compression molding, blow molding, or a combination thereof. When manufacturing these sheets, sheets, or bottomed preforms, it is preferable that the polyester in at least the four-stretched portion be substantially amorphous.

Of course, the portions of the cuttle that are not stretch-molded, such as the neck and bottom, may be thermally crystallized. The method for forming the container is not particularly limited. For example, by stretch-molding a sheet, a bottomed plastic can body can be obtained which is used by wrapping a cup-shaped container with a side wall oriented uniaxially or a metal lid. In addition, by forming the bottom of the pipe, a bottomed glyform for stretch blow molding can be obtained, and furthermore, by stretching the mother tube in a uniaxial direction or by stretch blow molding in a biaxial direction, both ends can be formed with metal lids. A plastic can body for seaming is obtained. Furthermore, a biaxially oriented glass bottle can be obtained by stretching the bottomed preform in the axial direction and expanding and stretching it in the circumferential direction. In order to improve the heat resistance of these stretch-molded containers, the orientation can be thermally fixed by heat treatment in a mold or the like under conditions of shape restriction.

The blend of the present invention can also be applied to film containers. In this case, the blend is formed into a film by a T-die method or the like, and this film is stretched in the longitudinal direction at a stretching temperature, and then The film is stretched in the same direction using a tenter or other means to form a biaxially stretched film, and this biaxially stretched film is used for manufacturing containers.

In addition, this blend can also be used as a tray-shaped container for cooking food in a microwave oven and/or an open toaster, for example, by forming the blend into a tray shape and then thermally crystallizing it. Improves heat resistance.

The blend of the present invention can be used alone for manufacturing the containers mentioned above, but also with other materials such as aluminum foil, steel foil,
Manufacture of containers in the form of laminates with metal foils such as iron foil, tin foil, and TFS foil, and garipary resins, such as ethylene-vinyl alcohol copolymers containing ethylene with a fi of 20 to 7 omol, xylylene group-containing polyamide resins, etc. It can also be used for.

Special K: The former ethylene/vinyl alcohol copolymer and the blend of the present invention are used in coextrusion molding or co-injection molding, and the blend also contains acetaldehyde generated by thermal decomposition of the ethylene/vinyl alcohol copolymer. It has the advantage that the terminal amino groups of the thermoplastic preamides in it are trapped.

(Application゛) 3? of the present invention? The 1J ester fissure container contains a small amount of thermoplastic polyamide as an acetaldehyde concentration lowering agent, and is used as a container for storing contents that substantially impairs flavor due to the presence of acetaldehyde.
Useful for retaining their flavor.

Therefore, for example, oil and fat foods such as tempura oil and Kirada oil; seasonings such as mayonnaise, dressing, and ketchup; various syrups such as ice syrup; sweets such as mizuyokan and jelly; and alcoholic beverages such as shochu. Beverages: Various carbonated drinks including cola, cider, plain soda, etc.;
lemon juice, orange juice, plum juice,
Butouji.

Straight juice such as -su, ichikono, -su, or fruit juice drinks such as fruit juice drinks containing nectar or agar; Retort drinks such as coffee and tea; vitamin-fortified drinks, aloe drinks, herp drinks, health vinegar drinks, and isotonic drinks Health-oriented beverages such as green tea, kombucha, oolong tea, amachiyazuru tea, barley tea, matte tea, persimmon leaf tea, ginseng tea, corn potage,
It is useful as a container for storing sugar-free drinks such as consommé soup, shellfish Φ string, mineral water, lactic acid bacteria drinks, fermented milk drinks, etc.

(Example) The present invention will be explained by the following example. In addition, each measurement in each Example was performed according to the following method.

(1) Intrinsic viscosity (1, V,) of thermoplastic polyester # (Pli'r) An Upero R-type viscometer was used. Measurement was performed at 30° C. using a mixed solvent of phenol/tetrachloroethane=6/4 (weight ratio).

(11) Relative viscosity (η
R3L) Thermoplastic polyamide resin II was dissolved in 100 d of 96% by weight sulfuric acid and measured at 25°C.

Terminal and amino groups were determined by potentiometric titration.

That is, about 11 samples of each thermoplastic polyamide (PA) used were distilled, the special grade reagent was redistilled, and 50 ml of 9m-cresol (10 lHg% 95-96°C fraction) was distilled.
was added and dissolved in a vacuum r-fusicator for 24 hours. next,
A special grade perchloric acid reagent (60% ethyl alcohol solution) was added to a mixed solution of purified isopropyl alcohol and propylene glycol as a potential adjusting agent at a volume ratio of 2:1 to make a concentration of 0.005N. It was used as a titration reagent. Quantification of terminal amino groups was determined from the inflection point obtained from a plot of apparent potential versus perchloric acid consumption. The potentiometric titration was carried out using an HM-5 type meter manufactured by Toa Denpa Kogyo.

(V) The terminal cal of PA has a xyl group concentration ([: -COO
H] ) Quantification of the xyl terminal group was performed for each sample at approximately I
Benzylflucol (10 m I (g, 9Cr-93°C fraction) 50
m/ was added and allowed to dissolve at approximately 150°C. Next, a 0.0 IN potassium hydroxide titration solution using phenolphthalein as an indicator was used in each solution, and the terminal carboxyl group was determined from the amount consumed by subtracting the amount consumed by pencil alcohol.

Acetaldehyde in M material It (AA) The amount of acetaldehyde in material was determined by Celanese method. That is, the body and mouth part 1 of the sample described in each example.
y each at the same time in liquid nitrogen, and 30
After filling ~40 ~ into a pre-drilled glass insert, it was directly introduced into the injector section of a schromatograph (GC-6A model manufactured by Shimadzu Corporation), and 14
After heating at 5°C for 20 minutes to volatilize the acetaldehyde in the material, a column (Po1apaek Q) was added.

Acetaldehyde was analyzed by raising the temperature of the tube (3φ×2m) from room temperature to 140'C. After the measurement, the weight of (sample + glass insert) was weighed, and the weight of the test sample was calculated from the difference from the weight of the glass insert. Results are average values of three repeated measurements.

υ> Container transparency (haze, H2) Transparency (haze) was measured using a new direct reading haze meter manufactured by Toyo Seiki. haze value (thickness)
H2) was measured. The results show the average of five measurements for each sample.

(VIL) 7 Raper Test (FEO) Samples with thermoplastic polyamide addition and P as described in Examples 5 and 6
A sample of ET alone was filled with a toning amount of salad oil in a commercially available 1400.9 square can, the mouth was sealed, and 37
It was stored in a constant temperature room (dark place) at ℃ for 14 days. After that, add about 200rR1 of those salad oils to a 300d beaker.
The mixture was transferred and kept at about 60°C on a hot plate. on the other hand,
The salad oil in the square can immediately after opening is also 300rI11.
The mixture was transferred to a beaker with a capacity of about 20°C and kept at about 60°C on a hot plate in the same way as before. Then, 21 participants were asked which of the following: the salad oil filled in a sample container with thermoplastic polyamide added, or (B) the salad oil 1 packed in a PET container alone, which was in a square can immediately after opening. The participants were asked to judge whether the flavor was similar to Sun's salad oil.

Example 1 For 100 parts by weight of polyethylene terephthalate (PET-A) with an intrinsic viscosity (1, V, ) 7510.75 di/I, a relative viscosity (ηRgL) of 3.42 and a terminal amino group concentration ((-N )12] ) is 1.637 m-mol
/100.9, terminal carboxyl group concentration < (-COO
H: ) ) is 1.669 m-mol / 1001 of 4
1.0 Jii parts of ricapramide (nylon 6) [hereinafter referred to as
It is sometimes written as PHR. ] and tumble
The mixture was triblended for 10 minutes at room temperature using a mold triblend.

The obtained tri-blend product was manufactured by Nissei Resin Kogyo FS.
-17ON type injection molding machine makes the weight 37, liter
, a preform with a wall thickness of 4 days was molded.

In addition, the injection conditions at this time are: ■Barrel setting temperature: (rear) 250℃, (middle part) 26
5°C, (front part) 271°C, (nozzle part) 272°C ■Scree rotation speed: 70 rpm ■Injection pressure crab 44 kg7cm2 ■Cooling water temperature: 11°C ■Molding cycle: 36 sec.

For comparison, preforms of Pff-A alone (weight 1;
7I, wall thickness: 4-) was also molded using the above injection molding machine and injection conditions.

The P-edition-A single preform obtained in this way,
Two types of blend preforms containing 1.0 PHR of nylon 6 and 1.0 PHR of nylon 6 were mixed into OBM-
The tonal internal volume is approximately 1 by IG type biaxial stretch blow molding machine.
A cylindrical tor of 0351d (weight: 37I) was molded.

The bottle molding conditions are a preform temperature of 100℃ and a temperature of 3.
After heating for 0 seconds, blow molding was performed in the mold for 4 seconds.

Regarding the obtained biaxially stretched blow bottles of type 2a, each yt? The amount of acetaldehyde (AA) in the tor material was measured.

The AA in the P edition-A single bottle material was 5.90Pl)m, while the AA in the nylon 6 was 1.90Pl)m. AA in OPHR-added blend/gattle material is 1.26 ppm
Met.

It has been found that adding 1.0 PHR of nylon 6 reduces the AA in the material to about 20%.

Example 2 Polyethylene terephthalate (PET-B) having an intrinsic viscosity (1, V, ) of 0.65 di/g was pulverized in liquid nitrogen to 10% polyhexamethylene azino J?
Mid (nylon 6.6: ηREL = 1.27, [
-Nf(2)=4.429 m-mol/l 001
, (-CooH)=4.486 m-mol/10
After adding 10.9 liters of powder and homogeneously mixing it using a Henschel mixer, pelletizing was carried out (setting temperature of each part of the cylinder: 265°C, screw rotation speed:
PET-B/
I got a master patch (pellet) of nylon 6.6.

The master patch obtained in this way and PET-B
Using the tampler-type dry blender described in Example 1, three types of tri-blends were obtained using the chips (pellets): ■Master patch: PET-B
= 1:200=0.0005PHR.

■Master patch: PET-B= 1: 100=
0.001 PHR.

■Master patch: PET-B=1: 10=0.
0IPHR.

A total of four types of materials, including the three types of triblends obtained in this way and PET-B alone, were processed using the injection molding machine and biaxial stretch blow molding machine described in Example 1.
Under the same injection and blow molding conditions as in Example 1, a cylindrical dill having an internal volume of about 1035 d (weight 37 g) was molded.

The acetaldehyde t(AA) in each bottle material was measured for the four types of biaxially stretched blow bottles obtained, according to the method described in Section 90 above. The results are shown in Table 1.

Even if the amount of nylon 6.6 added is in such a low concentration range,
It is known from Table 1 that the AA in the material was reduced to 70 or less, and the effect of reducing acetaldehyde was excellent.

Table 1 M plasticity yFe +) varnish: PET-B (I
V==0.65) Thermoplastic polyamide: Nylon 66
(C-NH2J')=4.429>Example 3 Polyethylene terephthalate described in Example 1) (P
ET-A) and relative viscosity (ηREL) of 2.24.
, the terminal amino group concentration (CN) (2”l) is 0.47
1 mmol/1ooy, terminal cardegyl group concentration (
[-COOHI) is 0.483 m-mol/10
01 polymethaxylylene azide/4'mido (nylon M
XD6) was triblended using the tumbler described in Example 1 and a dry blender at the following blending ratio (jugoku ratio): ■PET-A:M)■6=100:0.5 =0
．． 5PHR.

■PET-A two MXD6 = 100:
2.0 = 2.0 PHR.

■PET-A: MXD6= 100: 4. O=
4.0 PHR.

■PET-A: MXD6= 100: 8. O=
8.0 PHR.

■PET-A: Nu■6=100: 15.0=15
．． 0 PHR.

Then, a tri-blend of these five woodcutter species was prepared in Example 1.
Using the injection molding machine and biaxial stretch blow molding machine described in Example 1, under the same injection and blow molding conditions as in Example 1,
A cylindrical yl? with an internal volume of about 1035 mJ (weight 371 mJ). ) was molded.

The acetadehyde f (AA) in each bottle material was measured for the obtained five strains of biaxially stretched blow dettles according to the method of M mentioned above. The results are shown in Table 2. Table 2 also shows AA in the PET-A single bottle material described in Example 1.

Within this range of addition of nylon MXD 6, the AA in the material is reduced to around 20 inches, but it can be seen from this table that even if the amount of MXD 6 added is increased beyond this, the effect of reducing AA will be reduced. It will be done.

Table 2 Thermoplastic polyester: PF, TA (IV=0.7
5) Thermoplastic polyamide: Nyloha [D6 ((-N
H2) = 0.471) Next, these five types of biaxial stretching protocols and the PI? Regarding the total of 6fli types of r-A single biaxially stretched broach,
Transparency (haze) of the center part of the body was determined according to the method described in (■1) above.

Hz) was measured. The results are also shown in Table 2.

It is known from Table 2 that when the amount of added nylon H6 exceeds l Q PHR, the transparency (FIZ) of the container is rapidly lost.

Example 4 Two types of polyethylene terephthalate (PET-A and PET-B) described in Examples 1 and 2, respectively, with a relative viscosity (ηREL) of 0.52 and a terminal amino group concentration (C-NH2)) is 31.08 m-mol/100
．． ! i', terminal cal? Xyl group concentration is 31.22m-m
o17100I polymerized fatty acid polyamide (i gold muscle fatty acid P
PET-A: Polymerized fatty acid PA = 100:10 (weight ratio) ■PET-B: x Polymerized fatty acid PA-1100:1
After tri-blending at a weight ratio of 0 (weight ratio), it was made into pellets using the covertizer described in Example 2, and
Obtained different types of master patches (pellets).

And further PET-A:■Master patch=10:1=1.
0 PHR.

PET-B:■Master patch=10:1=1.
0 PHR.

Two types of triblends consisting of were made using the tumbler type dry blender mentioned above, and using the injection molding machine and biaxial stretch blow molding machine described in Example 1,
Under the same injection and blowing conditions as in Example 1, a cylindrical yt" with an internal volume of about 10,351 Ll (weight: 37 g) was prepared.
) were molded respectively.

The acetaldehyde (AA) in each of the biaxially stretched blow bottles of the two food products obtained was measured in accordance with the method of M mentioned above. The results are shown in Table 3. Table 3 shows the PET-
AA in each material of A alone and PET-B alone
is also shown.

It is known from the results in Table 3 that in thermoplastic polyamides with a high concentration of terminal amino groups, such as polymerized fatty acid polyamides, the effect of reducing acetaldehyde is significantly large even when a small amount is added.

Also, these yf? I mentioned earlier about Toru (■1)
Transparency (haze) of the mid-torso according to the method of

Hz) and the results are also shown in Table 3. It is known that there is virtually no significant difference in transparency.

Example 5 Two types of PET-B single g) described in Example 2 and 7Ie containing 0.0 IP plate of nylon 6.6 were subjected to a flavor test for salad oil according to the method of (vlo) described above. was implemented.

The results show that the flavor (smell) of salad oil immediately after opening the can.
”, (1) 2 out of 21 respondents answered that the “smell” of salad oil filled in a single bottle of P-edition B was closer to that of the salad oil, (II) Added 0.01 PHR of nylon 6.6 did? 16 out of 21 panelists answered that the "smell" was closer to that of salad oil filled in a toru, while 3 out of 21 panelists answered that they were unsure.
This is the name of the salad oil flavor (
The smell) was clearly superior.

Table 3 Thermoplastic polyester fh: PET-A (IV=0.7
5) PET-B (IV=0.65) Thermoplastic polyamide double fatty acid PA ((-NH2)
= 31.08) Example 6 The above-mentioned (via A flavor test was conducted on salad oil according to the method of .

The results show that the flavor (smell) of salad oil immediately after opening the can.
(1) The "smell" of PET-A alone and the salad oil filled in the toru were more similar/4'Nel was 21
(II) 19 out of 21 panel members answered that the "smell" of salad oil filled in a bottle containing 2.0 PHR of Naio 7 MXD 6 was similar, (2)
Two of the 21 respondents answered that they were unsure about the flavor of the salad oil filled in the kettle of the present invention.
The smell) was clearly superior.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the ratio of the amount of polyamide added to the lateral portion of polyethylene terephthalate 100 and the residual rate of acetaldehyde in the polyester.

Claims (1)

[Claims] (1) Thermoplastic polyester mainly composed of ethylene terephthalate units has a terminal amino group concentration of 0.05 to 5.
Thermoplastic polyamide in the range of 0 mmol/100 g resin, 5 x 10^-^ per 100 parts by weight of polyester.
A polyester container with improved flavor retention, characterized by comprising a composition containing 7 to 10 parts by weight of an acetaldehyde concentration lowering agent.