CA2016014A1

Amorphous polyamide having excellent oxygen barrier properties

Abstract

08CT04835 AMORPHOUS POLYAMIDE HAVING EXCELLENT OXYGEN BARRIER PROPERTIES ABSTRACT OF THE DISCLOSURE An amorphous polyamide resin is provided havingthe combined properties of a high glass transitiontemperature and excellent oxygen barrier properties.The polyamide is obtained from the reaction productsof para-xylylene diamine, adipic acid andisophthalic acid, and finds particular utility as acontainer layer for hot fill packaging of fruitjuices.

CA2016014A1, drawing sheet 1 — Sheet 1 of 42

Term

Term ended

Projected expiry passed 3 May 2010, 16.4 years ago.

1 claim: 1 independent, 0 dependent

1
Claim 13 continued :- 17 - (b) a di carboxylic acid consisting essentially of: (i) adipic acid present at a level of from 20 to 60 mole% based on the total moles of di carboxylic acid;and (ii) a phthalic acid composition present at a level of from 40 to 80 mole% based on the total moles of di carboxylic acid;said phthalic acid composition having respective amounts of isophthalic acid and terephthalic acid, said isophthalic acid being present at a level of from 60 to 99 mole% based on the total moles of phthalic acid composition, said terephthalic acid being present at a level of from 1 to 40 mole% based on the total moles of phthalic acid composition. 14) The invention as defined in any of the preceding claims including any further features of novelty disclosed. SUBSTITUTE REMPLACEMENT SECTION is not Present Cette Section est Absente

334 paragraphs in 28 sections, as filed

This invention relates to amorphous polyamides and, more particularly, relates to amorphous polyamides obtained by reacting p-xylylene diamine with adipic acid and isophthalic acid.

BACKGROUND- OF THE INVENTION

Retort packaging is common in the fruit juice industry where hot juices, typically at temperatures ranging from 80°C to 120°C, are filled directly into the final disposable commercial packaging. By filling with hot juice, the container is 10 simultaneously filled and sanitized. The use of polyamides as layers in such retort packaging has generally been unsuitable for a number of reasons, namely, many polyamides are crystalline in nature, lacking the level of clarity necessary for 15 aesthetically pleasing clear containers; some polyamides lack a glass transition temperature sufficiently high enough to maintain the shape of the container and prevent deformation thereof during hot fill; and some polyamides lack the oxygen 20 barrier properties necessary to prevent oxidation and discoloration of fruit juices held by containers made therefrom. Conventional polyamides include those set forth in NL Pat. No. 7,212,060; U.S. Pat. No. 4,018,746; U.S. Pat. No. 4,482,695; and U.S.

Pat. No. 4,640,973; these polyamides generally suffer from either having a relatively low glass transition temperature, employing relatively high

08CT04335

- 2 2016014 cost monomers, or exhibiting relatively low levels of clarity.

Accordingly, one object of the present invention is to provide a polyamide which has the combined properties of a high glass transition temperature, excellent clarity, and a low oxygen transmission rate.

Another object of the present invention is to provide an amorphous polyamide resin suitable as a container layer for hot filled fruit juices or other hot filled, oxygen sensitive liquids.

S.U.MMARY„QF THE INVENTION

The present invention provides a novel polyamide which is transparent, has a glass transition temperature which is sufficiently high to handle hot fill packaging, and has oxygen barrier properties which are juice from oxidation permitting containers extended shelf lives sufficient to protect fruit and discoloration, thereby made therefrom to provide to fruit juices contained therein. The polyamide of the present invention is obtained from reaction products of para-xylylene diamine, adipic acid and a phthalic acid composition.

The present polyamide is prepared by reacting a diamine with a di carboxylic acid. The term di carboxylic acid is meant to include di aryl esters and di halides thereof. The diamine is para-xylylene diamine; and the dicarboxylic acid is a mixture of respective amounts of a phthalic acid composition and adipic acid. The phthalic acid composition contains isophthalic acid and optionally terephthalic acid. Preferably, the phthalic acid composition is present at a level of from about 80

08CT04835

- 3 mole% to 40 mole% based on the total moles of di carboxylic acid; more preferably at a level of from about 80 to 60 mole% thereof; and most preferably at a level of from about 80 mole% thereof. Preferably the adipic acid is present at a level of from about 20 to 60 mole% based on the total moles of dicarboxylic acid; more preferably at a level of from about 20 to 40 mole% thereof and most preferably at a level of 20 mole% thereof. The phthalic acid composition may consist of isophthalic acid or may comprise respective amounts of isophthalic acid and terephthalic acid. The phthalic acid composition may include isophthalic acid present at a level of from 60 to 100 mole% based on the total moles of phthalic acid composition, more preferably at a level of from 80 to 100 mole% thereof, and most preferably at a level of 100% thereof. The terephthalic acid may be present at a level of from 0 to 40 mole percent based on the total moles of phthalic acid composition, more preferable at a level of from 0 to 20 mole percent thereof, and most preferably at a level of 0 mole percent thereof. Suitable phthalic acid compositions containing a mixture of isophthalic acid and terephthalic acid may have terephthalic acid present at a level of from 1 to 40 mole% based on the total moles of phthalic acid composition, more preferably from 1 to 20 mole% thereof; and have isophthalic acid present at a level of from 60 to 99 mole% based on the total moles of phthalic acid composition, more preferably from 80 to 99 mole% thereof. If excess levels of terephthalic acid are present in the phthalic acid composition then the polyamide will more likely be a crystalline polyamide. The desired amorphous

08CT04835

- 4 polyamide is obtained from the reaction products of the para-xylylene diamine, phthalic acid composition and adipic acid. The diamine and dicarboxylic acid are reacted in mole ratios of from between 48:52 and 5 52:48 and preferable in a mole ratio of 50:50.

The para-xylylene diamine has the following structural formula:

(I)

H2NH2C—CH2NH2 and can be prepared by oxidizing p-xylylene in the 10 presence of ammonia to obtain a cyano compound which upon hydrogenation forms para-xylylene diamine. These reactions can be represented as follows:

(Π)

This reaction produces high yields, often greater 15 than 90% yields, of para-xylylene diamine thereby potentially permitting low-cost production of para-xylylene diamine.

Isophthalic acid can be represented by the following chemical structure:

08CT04835

- 5 (HI)

C—OH

Ο and has the properties of being in the form of colorless crystals and has a melting point of 34-5’C to 348’C. Isophthalic acid can be derived from the oxidation of m-xylene.

Terephthalic acid can be represented by the following chemical structure:

(IV)

Adipic acid has the chemical formula of HOOCCCHg^COOH and is commercially available.

The polyamides of the present invention are prepared by methods generally known in the art for producing polyamides such as by conventional salt processes which involve reacting a diamine with a di carboxylic acid in a solvent to form a solid polyammonium salt which precipitates from the reaction mixture. The solid is then heated successively in an autoclave reactor under pressure to control explosive initial dehydration and subsequently under reduced pressure to effect

08CT04835

- 6 conversion of the polyammonium salt to a polyamide. The diamine and di carboxylic acid component are preferably reacted in approximately stoichiometric quantities.

The polyamides may also be prepared by a melt process involving the reaction of the diamine and a di aryl ester of the di carboxylic acid. A suitable melt process is set forth in Fox et al U.S. Patent 4,567,249.

The preferred polyamide resin of the present invention has first moi eties represented by the following formula:

(V)

H [ N·

and second moi eties formula:

represented by the following (VI)

H !

•N.

Preferably, the first moi eties are present in the polyamide at a level of from 80 mole% to 40 mo1e% based on the total moles of first and second moi eties in the polyamide and preferably the second moi eties are present at a level of from 20 mole% to

08CT04835

- 7 60 mole% based on the total moles of first and second moi eties in the polyamide. More preferably, the polyamide has from about 80 mole% to about 60 mole% of the first moi eties based on the total moles of first and second moieties and from about 20 mole% to about 40 mole% of the second moieties based on the total moles of first and second moieties. Most preferably, the polyamide consists essentially of about 80 mole% of the first moieties based on the total moles of first and second moieties and about 20 mole% of the second moieties based on the total moles of first and second moieties. The most preferred polyamide resin has a glass transition temperature of at least 170°C and an oxygen transmission rate of at most about 0.50 cc-mi1/100 in -day-atm. The preferred polyamide is obtained from the reaction products of a mixture consisting essentially of about 50 mole% of para-xylylene diamine based on the total moles of diamine and dicarboxylic acid; from about 40 mole% to about 20 mole% of adipic acid based on the total moles of diamine and dicarboxylic acid; and from about 10 mole% to about 30 mole% of the isophthalic acid based on the total moles of diamine and di carboxylic acid.

The polyamide resin of the present invention is clear, amorphous having no distinct melting point and preferably has an intrinsic viscosity in deciliters per gram (dl/g) of between about 0.40 and 30 about 1.60 as measured in 40:60 weight mixture of tetrachloroethylene and phenol; preferably a glass transition temperature of at least 130’C, more preferably a glass transition temperature of between 150 and 180°C, and most preferably a glass 35 transition temperature of about 174eC; and

08CT04835

- 8 preferably has an oxygen transmission rate of at most about 1.0 cc-mil/100in^-24hr-atm, more preferably has an oxygen transmission rate of at most about 0.5 cc~mil/100in2-24hr”atm, and most preferably has an oxygen transmission rate of at most about 0.3cc-mil/100in2-24hr-atm.

The oxygen transmission rate or permeability of the resin is measured as cubic centimeters of oxygen permeating a 1 mil thick sample, 100 inches square, for a 24-hour period under an oxygen partial pressure difference of 1 atmosphere at 30°C.

The polyamide resin of the present invention may be made into film or sheet, may be used as a laminating layer between two permeable layers of film, may be used to make molded containers by coextrusion blow molding or other molding techniques, and may be employed to form a coextruded layer.

Containers employing a layer of the polyamide resin of the present invention are suitable for the hot fill of fruit juices therein. Hot filling of juices involves filling of the container with juices having temperatures of from about 80°C to about 120°C. These high temperatures permit simultaneous filling and sanitizing of the interiors of the containers. The high glass transition temperature of the resin enables the containers to keep their shapes and avoid deformation during hot fill. The oxygen barrier properties of the resin enable the containers to provide long shelf life to the fruit juices therein by preventing oxidation thereof by atmospheric oxygen, the amorphous character of the polyamide resin results in containers made therefrom being clear thereby enhancing the aesthetics of the container, allowing the consumer to see the true

08CT04835

- 9 appearance of the juice to be purchased, and the potentially relatively low cost diamine and diacids employed potentially enhance the cost competitiveness of containers made from the resin. Preferably containers employ the amorphous polyamide as an intermediate layer between inner and outer layers of aromatic polycarbonate. Suitable containers may be made by coextrusion blow molding. Suitable aromatic polycarbonate resins are made by reacting phosgene with bisphenol A.

The invention is further described in the examples which follow. These examples are illustrative of the invention and are not to be construed in limitation thereof.

Table 1 sets forth polyamides obtained by reacting para-xylylene diamine with isophthalic acid, adipic acid and mixtures thereof. Note that the polyamides of examples 1, 5 and 6 were crystalline whereas the polyamides of examples, 2, 3 and 4 were amorphous having no distinct melting point.

Table 2 sets forth polyamides obtained from reacting various diamines with various di aryl esters. Note that the polyamides derived from para-xylylene diamine typically had higher glass transition temperatures than corresponding polyamides derived from meta-xylylene diamine.

08CT04835

- 10 ο σι ω no >-*

nd ο ο

ο Ά ο co Ο) λ πυ ο ο ο ο ο ο

Mole% ofvc/ Mole% of

[►«Η 4I » VO *M CO ΟI

rd cm i

Cd i

08CT04835

CO

cn CO

4b r\3

CFÎ M3

Ü1

Example^7 Diamine* ' Diary] Ester* 7 Tg(*C)* 7 IV*a7 OXTR

08CT04835 ri

HW W

CO

TABLE 2 - CONTINUED

O

CO co

08CT04835

2010014

τι s § •Μ

08CT04835

- 14 3016014

What is claimed:

A polyamide consisting essentially of first moi eties having a formula of:

and second moi eties having a formula of:

I

()4—C—

said first moi eties being present in said polyamide at a level of from 80 mole% to 40 mole% based on the total moles of first moi eties and second moi eties in said polyamide, said second moi eties being present at a level of 20 mole% to about 60 mole% based on the total moles of first moi eties and second moi eties in said polyamide.

The polyamide of Claim 1 wherein said polyamide consists essentially of from about 80 mole% to about 60 mole% of said first moi eties based on the total moles of first and second moi eties, and from about 20 mole% to about 40 mole% of said second moi eties based on the total moles of first and second moi eties.

The polyamide of Claim 1 wherein said first moi eties are present at a level of about 80

08CT04835

- 15 mole% and said second moi eties are present at a level of about 20 mole%.

4. The polyamide of Claim 3 wherein said polyamide has a glass transition temperature of at least 170eC and an oxygen transmission rate of at most about .50 cc-mi1/100 in^-day-atm.

5. A polyamide obtained from the reaction products of a mixture consisting essentially of para-xylylene diamine, adipic acid, and isophthalic acid.

6. The polyamide of Claim 5 wherein said mixture consists essentially of about 50 mole% of said para-xylylene diamine based on the total moles of diamine, adipic acid and isophthalic acid;

5 from about 40 mole% to about 20 mole% of said adipic acid based on the total moles of diamine, adipic acid and isophthalic acid; and from 10 mole% to 30 mole% of said isophthalic acid based on the total moles of diamine, io adipic acid and isophthalic acid.

7. A packaging material for fruit juices, said packaging material comprising a layer of amorphous polyamide, said polyamide consisting essentially of from about 80 mole% to about 40 mole% of first moi eties and from about 20 mole% to about 60 mole% of second moi eties, said first moi eties having a formula of:

said second moieties having a formula of:

08CT04835

8. The packaging material of Claim 6 wherein said layer has an oxygen transmission rate of less than about 0.50 cc-mi1/100 in^-day-atm, and said polyamide has a glass transition temperature of at least 130.

9. A polyamide consisting essentially of the reaction products of:

(a) para-xylylene diamine;

(b) adipic acid; and (c) isophthalic acid, said adipic acid and said isophthalic acid being in a mole ratio of from between 20:80 and 60:40.

10. The polyamide of claim 9 wherein said adipic acid and said isophthalic acid are in a mole ratio of from between 20:80 and 80:60.

11. The polyamide of claim 10 wherein said adipic acid and said isophthalic acid are in a mole ratio of 20:80.

12. An amorphous polyamide consisting essentially of the reaction products of:

(a) para-xylylene diamine;

(b) adipic acid;

13. A polyamide consisting essentially of the reaction products of:

(a) para-xylylene diamine; and

08CT04835

10 members in 6 offices

This recordMember, by publication datePriority claim

Priority claims4

Priority claims
Document	Office	Kind	Date
383841	United States of America	–	1989-07-21
38384189	United States of America	A	1989-07-21
383841	–	–	–
US19890383841	–	–	–

Members10

Family members, oldest first
Document	Office	Kind
US4983719A	United States of America	A	1991-01-08
CA2016014A1This record	Canada	A1	1991-01-21
EP0408925A2	European Patent Office (EPO)	A2	1991-01-23
JPH03103438A	Japan	A	1991-04-30
EP0408925A3	European Patent Office (EPO)	A3	1991-09-18
EP0408925B1	European Patent Office (EPO)	B1	1994-11-02
DE69013782D1	Germany	D1	1994-12-08
ES2064535T3	Spain	T3	1995-02-01
JPH0733439B2	Japan	B2	1995-04-12
DE69013782T2	Germany	T2	1995-06-01

Amorphous polyamide having excellent oxygen barrier properties

Abstract

Term

BACKGROUND- OF THE INVENTION

08CT04335

08CT04835

08CT04835

(I)

08CT04835

- 5 (HI)

C—OH

(IV)

08CT04835

(V)

08CT04835

08CT04835

08CT04835

08CT04835

08CT04835

CO

HW W

CO

TABLE 2 - CONTINUED

O

08CT04835

08CT04835

I

()4—C—

08CT04835

08CT04835

08CT04835

Priority claims4

Members10

Events

Numbers

Titles2

Classification