Oxygen-absorbing resin composition containing organic oxygen absorber

Abstract

An oxygen-absorbing resin composition containing an ethylene terephthalate type polyester resin and an organic oxygen absorber and, further, containing cobalt in an amount of 5 to 50 ppm and titanium in an amount of 1 to 15 ppm calculated as elements.

Claims

1. An oxygen-absorbing resin composition containing an ethylene terephthalate polyester resin and an organic oxygen absorber and, further, containing cobalt in an amount of 5 to 50 ppm and titanium in an amount of 1 to 15 ppm calculated as elements, wherein the organic oxygen absorber is a bisimide compound derived from an acid anhydride and a diamine.

2. The oxygen-absorbing resin composition according to claim 1, wherein said cobalt is contained at a concentration of 10 to 30 ppm.

3. The oxygen-absorbing resin composition according to claim 1, wherein said organic oxygen absorber is contained in an amount of 0.5 to 2.0% by mass.

4. The oxygen-absorbing resin composition according to claim 1, wherein said acid anhydride is represented by the following formula (1): ##STR00005## wherein the ring X is an aliphatic ring having an unsaturated bond, and Y is an alkyl group.

5. The oxygen-absorbing resin composition according to claim 1, wherein said organic oxygen absorber has a molecular weight of not more than 1000.

6. The oxygen-absorbing resin composition according to claim 4, wherein said organic oxygen absorber is an aliphatic bisimide compound derived from said acid anhydride and an aliphatic diamine.

7. A formed body of a single-layer or a multilayer structure having a layer formed by using the oxygen-absorbing resin composition described in claim 1.

8. The formed body according to claim 7, wherein the formed body is a container.

9. The formed body according to claim 7, wherein the formed body is a preform for forming a container.

Description

EXAMPLES

(1) The invention will be, further, described by using Examples to which only, however, the invention is in no way limited.

(2) Determining the Amounts of Elements;

(3) Elements such as titanium (Ti), antimony (Sb) and cobalt (Co) contained in the polyester resin used for the experiments were determined for their amounts by the method described below.

(4) The sample was crushed into a powder by using a freeze-crushing machine. The powder was weighed to be about 0.5 g and was introduced into a sealed container equipped with a Teflon (registered trademark)-coated stainless steel jacket. After 6 ml of sulfuric acid and 3 ml of nitric acid were added thereto, the container was sealed. By using an electric furnace, the container was heated at 220° C. for 20 hours, and the powder was completely decomposed. Yttrium was added thereto as an internal standard substance. The mixture thereof was put into a graduated cylinder and to which ultra-pure water was added up to a graduate of 20 ml to obtain a solution for measurement. The solution was then measured by using an ICP emission analyzer (manufactured by Thermo Fisher Scientific Inc.)

(5) Measuring the Concentration of Dissolved Oxygen;

(6) Oxygen-free water having an oxygen concentration of almost zero was produced by using an apparatus for producing oxygen-free water (LOW DISSOLVED OXYGEN: manufactured by MIURA Co., Ltd.), and was introduced into a bottle that was obtained up to its full volume. The bottle was then sealed with a plastic cap. After stored in an air-conditioned room maintained at 23° C. 50% RH for one week, the water in the bottle was measured for its concentration of oxygen dissolved therein by using an instrument for measuring the concentration of oxygen dissolved in water (Oxygen Indicator: manufactured by Orbisphere Laboratories Co.).

(7) <Polyester Resins (A) That are Used>

(8) (A1) Ethylene terephthalate type polyester resin (5015W) produced by Shin-Kogosen Co., polymerization catalyst Sb (A2) Ethylene terephthalate type polyester resin (5512T) produced by Shin-Kogosen Co., polymerization catalyst Ti (A3) Ethylene terephthalate type polyester resin (CR8839T) produced by Kajun Co., polymerization catalyst Ti
<Oxygen-Absorbing Component (B)>

(9) In a nitrogen atmosphere, 6 kg of a hexamethylenediamine (produced by Toray Industries Co.) was dissolved in 57 kg of a 2-propanol, and to which was slowly added a mixture of methyltetrahydrophthalic anhydrides (HN-2200, manufactured by Hitachi Chemical Co.) containing 45% by weight of a 4-methyl-Δ.sup.3-tetraydrophthalic anhydride and 21% by weight of a cis-3-methyl-Δ.sup.4-tetrahydrophthalic anhydride.

(10) After the whole amount thereof was thrown in, the reaction was carried out at 100 to 160° C. for about 7 hours while removing the water that was formed and the solvent. There was obtained 16.7 kg of the oxygen-absorbing component (B).

(11) <Transition Metal Catalyst (C)>

(12) Cobalt neodecanoate (produced by OMG Co.)

(13) <Production of Oxygen-Absorbing Resin Pellets>

(14) By using a twin screw extruder equipped with a granulating facility (TEM-35B: manufactured by Toshiba Machine Co., Ltd.) with its barrel being set at a temperature of 260 to 280° C., the polyester resin (A) was mixed and kneaded with the oxygen-absorbing component (B) at a ratio of 10%, and was extruded in a stranded manner to thereby obtain oxygen-absorbing resin pellets. The oxygen-absorbing component (B) was added through an opening in the extruder by using a liquid feeder (Moineau pump, manufactured by Heishin Ltd.).

Example 1

(15) An oxygen-absorbing resin composition prepared by dry-blending together the components of the following recipe was thrown into the hopper of a forming machine, and was injection-formed into a 25 g single-layer preform for forming a bottle.

(16) TABLE-US-00001 Polyester resin (A3) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A3) as the base material) Transition metal catalyst (C) 0.015 parts by mass. 

(17) Next, the preform that was formed was biaxially stretch-blow-formed into a 500-mL bottle.

(18) Table 1 shows the amounts (ppm) of elements contained in the bottle that was formed, amount of oxygen absorbed (% by weight) and concentration (ppm) of oxygen dissolved after one week has passed.

Example 2

(19) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(20) TABLE-US-00002 Polyester resin (A3) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A3) as the base material) Transition metal catalyst (C) 0.010 parts by mass. 

Example 3

(21) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(22) TABLE-US-00003 Polyester resin (A3) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A3) as the base material) Transition metal catalyst (C) 0.005 parts by mass. 

Example 4

(23) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(24) TABLE-US-00004 Polyester resin (A3) 85 parts by mass, Oxygen-absorbing resin pellets 15 parts by mass, (using the polyester resin (A3) as the base material) Transition metal catalyst (C) 0.030 parts by mass. 

Example 5

(25) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(26) TABLE-US-00005 Polyester resin (A3) 85 parts by mass, Oxygen-absorbing resin pellets 15 parts by mass, (using the polyester resin (A3) as the base material) Transition metal catalyst (C) 0.015 parts by mass. 

Example 6

(27) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(28) TABLE-US-00006 Polyester resin (A3) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A1) as the base material) Transition metal catalyst (C) 0.015 parts by mass. 

Example 7

(29) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(30) TABLE-US-00007 Polyester resin (A1) 45 parts by mass, Polyester resin (A3) 45 parts by mass, Oxygen-absorbing resin pellets 5 parts by mass, (using the polyester resin (A1) as the base material) Oxygen-absorbing resin pellets 5 parts by mass, (using the polyester resin (A3) as the base material) Transition metal catalyst (C) 0.030 parts by mass.

Comparative Example 1

(31) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(32) TABLE-US-00008 Polyester resin (A1) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A1) as the base material) Transition metal catalyst (C) 0.050 parts by mass. 

Comparative Example 2

(33) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(34) TABLE-US-00009 Polyester resin (A1) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A1) as the base material) Transition metal catalyst (C) 0.015 parts by mass. 

Comparative Example 3

(35) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(36) TABLE-US-00010 Polyester resin (A3) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A3) as the base material) Transition metal catalyst (C) 0.050 parts by mass. 

Comparative Example 4

(37) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(38) TABLE-US-00011 Polyester resin (A3) 85 parts by mass, Oxygen-absorbing resin pellets 15 parts by mass, (using the polyester resin (A3) as the base material) Transition metal catalyst (C) 0.050 parts by mass. 

Comparative Example 5

(39) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(40) TABLE-US-00012 Polyester resin (A2) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A2) as the base material) Transition metal catalyst (C) 0.050 parts by mass. 

Comparative Example 6

(41) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(42) TABLE-US-00013 Polyester resin (A2) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A2) as the base material) Transition metal catalyst (C) 0.015 parts by mass. 

Comparative Example 7

(43) A bottle was prepared by the same method as that of Example 1 but changing the recipe of the oxygen-absorbing resin composition as described below. The results were as shown in Table 1.

(44) TABLE-US-00014 Polyester resin (A2) 90 parts by mass, Oxygen-absorbing resin pellets 10 parts by mass, (using the polyester resin (A2) as the base material)

(45) TABLE-US-00015 TABLE 1 Oxygen-absorbing Concentration of Ti Sb Co component dissolved oxygen Example 1 7 0 21 1.0 0.220 Example 2 7 0 14 1.0 0.207 Example 3 7 0 7 1.0 0.345 Example 4 7 0 42 1.5 0.118 Example 5 7 0 21 1.5 0.106 Example 6 6 17 22 1.0 0.266 Example 7 3 87 47 1.0 0.141 Com. Ex. 1 0 173 80 1.0 0.272 Com. Ex. 2 0 173 31 1.0 0.940 Com. Ex. 3 7 0 70 1.0 0.747 Com. Ex. 4 7 0 70 1.5 0.348 Com. Ex. 5 21 0 70 1.0 0.949 Com. Ex. 6 21 0 21 1.0 0.860 Com. Ex. 7 21 0 0 1.0 1.006