Thermoformed articles from polypropylene polymer compositions

Patent metadata

Field	Value
Publication number	US-2016000243-A1
Application number	US-201514733091-A
Country	US
Kind code	A1
Filing date	Jun 8, 2015
Priority date	Jul 3, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

Thermoformed fluid material container closures, such as reclosable dome-shaped beverage lids, having an inner “plug fit” securement groove for removably securing the fluid material container closure to an upper rim of a beverage cup and which have a drip rate of about 1 g or less per 20 seconds. These closures such as beverage lids are made by a thermoforming process from a thermoformable web (e.g., sheet) to provide a generally dome-shaped upper fluid material-dispensing portion from polypropylene polymers having a flexural modulus of at least about 230,000 kpsi and in which a fluid-dispensing orifice in formed in the fluid material-dispensing portion which is substantially aligned with the machine direction (MD) of the thermoformable web.

First claim

What is claimed is:

1 . An article in the form of a thermoformed fluid material container closure, the fluid material container closure comprising:
a lower container-securing portion having an inner plug fit securement groove for removably securing the fluid material container closure to an upper rim of a fluid material container; and an upper generally dome-shaped fluid material-dispensing portion extending generally upwardly from the lower container-securing portion and having a fluid material-dispensing orifice formed therein; wherein the fluid material container closure comprises a polypropylene polymer composition which includes from about 50 to 100% polypropylene polymer having a flexural modulus of at least about 230,000 kpsi; wherein the fluid material container closure has a wall thickness in the range of from about 10 to about 30 mils; wherein when the fluid material container closure is removably secured to the upper rim of the fluid material container, the removably secured fluid material container closure provides a drip rate of about 1 gram or less per 20 seconds.

2 . The article of claim 1 , wherein the wall thickness is in the range of from about 14 to about 24 mills.

3 . The article of claim 1 , wherein the polypropylene polymer has a flexural modulus in the range of from about 230,000 to about 350,000 kpsi.

4 . The article of claim 3 , wherein the polypropylene polymer has a flexural modulus in the range of from about 250,000 to about 300,000 kpsi.

5 . The article of claim 1 , wherein the polypropylene polymer composition includes one or more β-phase polypropylene polymer crystal inducing nucleating agents in an amount effective to induce β-phase crystal formation in the polypropylene polymer composition.

6 . The article of claim 5 , wherein the one or more β-phase polypropylene polymer crystal inducing nucleating agents are one or more of: quinacridones; the bisodium salt of o-phthalic acid; the aluminum salt of 6-quinizarin sulfonic acid; isophthalic acid; terephthalic acid; N′,N′-dicyclohexyl-2,6-naphthalene dicarboxamide; tetraoxaspiro compounds; iron oxide having a nano-scale size; potassium 1,2-hydroxystearate; magnesium benzoate; magnesium succinate; magnesium phthalate; phthalocyanine blue; or a combination of pimelic acid, azelaic acid, o-phthalic acid, terephthalic acid, or isophthalic acid with an oxide, hydroxide or an acid salt of magnesium, calcium, strontium, or barium.

7 . The article of claim 6 , wherein the amount of the one or more β-phase polypropylene polymer crystal inducing nucleating agents is in the range of from about 0.5 to about 10% by weight of the polypropylene polymer composition.

8 . The article of claim 5 , wherein the polypropylene polymer composition includes from about 83 to 100% by weight polypropylene polymer and up to about 17% by weight of a mineral filler.

9 . The article of claim 8 , wherein the polypropylene polymer composition includes from about 90 to 100% by weight polypropylene polymer and from 0 to about 10% by weight mineral filler.

10 . An article in the form of a thermoformed reclosable beverage sip lid, the reclosable beverage sip lid comprising:
a lower generally annular cup rim-securing portion having an inner plug fit annular securement groove for removably securing the fluid material container closure to an upper rim of a beverage cup; and an upper generally frustoconical-shaped beverage-dispensing portion extending generally upwardly from the lower portion and having a beverage-dispensing sip hole formed therein; wherein the reclosable beverage sip lid comprises a polypropylene polymer composition which includes from about 50 to 100% polypropylene having a flexural modulus of at least about 230,000 kpsi; wherein the reclosable beverage sip lid has a wall thickness in the range of from about 10 to about 30 mils; wherein when the reclosable beverage sip lid is removably secured to the upper rim of the beverage cup, the reclosable beverage lid provides a drip rate of about 1 gram or less per 20 seconds.

11 . The article of claim 10 , wherein the wall thickness is in the range of from about 14 to about 24 mills.

12 . The article of claim 11 , wherein the polypropylene polymer has a flexural modulus in the range of from about 250,000 to about 300,000 kpsi.

13 . The article of claim 11 , wherein the polypropylene polymer composition includes one or more β-phase polypropylene polymer crystal inducing nucleating agents in an amount in the range of from about 1 to about 3% by weight of the polypropylene polymer composition, the one or more β-phase polypropylene polymer crystal inducing nucleating agents are one or more of: quinacridones; the bisodium salt of o-phthalic acid; the aluminum salt of 6-quinizarin sulfonic acid; isophthalic acid; terephthalic acid; N′,N′-dicyclohexyl-2,6-naphthalene dicarboxamide; tetraoxaspiro compounds; iron oxide having a nano-scale size; potassium 1,2-hydroxystearate; magnesium benzoate; magnesium succinate; magnesium phthalate; phthalocyanine blue; or a combination of pimelic acid, azelaic acid, o-phthalic acid, terephthalic acid, or isophthalic acid with an oxide, hydroxide or an acid salt of magnesium, calcium, strontium, or barium.

14 . The article of claim 11 , wherein polypropylene polymer composition includes from about 90 to 100% by weight polypropylene polymer and from 0 to about 10% by weight mineral filler.

15 . A process for preparing a thermoformed fluid material container closure which comprises the following steps of:
(a) providing a thermoformable web comprising from about 50 to 100% polypropylene polymer having a flexural modulus of at least about 230,000 kpsi and having a machine direction (MD) and a cross machine direction (CD) orthogonal to the machine direction (MD) with a web width in the range of from about 20 to about 55 inches in the cross machine direction (CD); (b) thermoforming the thermoformable web of step (a) with a fluid material closure-forming mold having a lower fluid material container-securing forming mold section which forms an inner plug fit securement groove and a generally dome-shaped upper fluid material-dispensing forming mold section extending generally upwardly from the lower mold section to provide a thermoformed fluid material container closure having a lower container-securing portion having formed therein the inner a plug fit securement groove for removably securing the fluid material container closure to an upper rim of a fluid material container and a generally dome-shaped upper fluid material-dispensing portion extending generally upwardly from the lower container-securing portion; and (c) forming a fluid-dispensing orifice in the upper fluid material-dispensing portion which is substantially aligned with the machine direction (MD) of the thermoformable web; wherein the thermoformed article of step (c) has:
a wall thickness in the range of from about 10 to about 30 mils;
when removably secured to the upper rim of the fluid material container, a drip rate of about 1 gram or less per 20 seconds.

16 . The process of claim 15 , wherein the web width in step (a) is in the range of from about 24 to about 50 inches.

17 . The process of claim 15 , wherein the polypropylene polymer composition of step (a) comprises polypropylene polymer having a flexural modulus in the range of from about 230,000 to about 350,000 kpsi.

18 . The process of claim 17 , wherein the polypropylene polymer composition of step (a) includes one or more β-phase polypropylene polymer crystal inducing nucl

Assignees

• Int Paper Co

Inventors

• Tedford Jr Richard A

Classifications

• B65D43/0212 Primary

  only on the outside, or a part turned to the outside, of the mouth (B65D43/0206 takes precedence) · CPC title

• A47G19/2205 Primary

  Drinking glasses or vessels (A47G19/23 takes precedence) · CPC title

• B29C51/10

  Forming by pressure difference, e.g. vacuum · CPC title

• B29K2023/14

  Copolymers of polypropylene (B29K2023/16 takes precedence) · CPC title

• B65D2543/00537

  on the outside, or a part turned to the outside of the mouth of the container · CPC title