Use of a prepolymer in transparent thermoplastic compositions, compositions comprising same and uses thereof

Patent metadata

Field	Value
Publication number	US-2018291202-A1
Application number	US-201615759009-A
Country	US
Kind code	A1
Filing date	Sep 20, 2016
Priority date	Sep 22, 2015
Publication date	Oct 11, 2018
Grant date	—

Abstract

The invention relates to the use of at least one prepolymer in a composition which includes: a matrix of at least one transparent semi-crystalline polyamide, and optionally at least one additive, for improving the crystallisation kinetics and reducing the warping of the composition while preserving or improving the transparency properties thereof as well as the mechanical properties thereof, in comparison with the same composition without a prepolymer, wherein the composition does not contain a nucleating agent.

First claim

1 . A method, wherein the method comprises a step of compounding or a step of dry blending at least one prepolymer having a number-average molecular mass of from 1000 to 10 000 g/mol into a composition to form a prepolymer-polyamide, wherein the composition comprises:
a matrix comprising at least one semicrystalline transparent polyamide, and optionally at least one additive, whereby the crystallization kinetics of said composition are improved and the warpage of said composition is reduced while at the same time the transparency properties of said composition are improved or conserved and the mechanical properties of said composition are improved or conserved, when compared with the same composition free of the prepolymer, said composition being free of nucleating agent.

2 . The method according to claim 1 , wherein said semicrystalline transparent polyamide has a transmittance ≥75% (measured at a wavelength of 560 nm and for a plate thickness of 2 mm).

3 . The method according to claim 1 , wherein said prepolymer-polyamide comprises
said matrix constituted of said at least one semicrystalline transparent polyamide in a proportion of from 60 to 99.95% by weight; said prepolymer in a proportion of 0.05% to 20% by weight; wherein the weight proportion of the semicrystalline transparent polyamide matrix and that of the prepolymer is, respectively, from 60% to 99.9% and from 40% to 0.1%, relative to the sum of the semicrystalline transparent polyamide and the prepolymer weights; and said additive in a weight proportion of 0 to 20%; wherein the sum of the semicrystalline transparent polyamide, of the prepolymer and optionally of the additive are equal to 100%.

4 . The method according to claim 1 wherein said matrix comprises at least one semicrystalline transparent homopolyamide.

5 . The method according to claim 4 , wherein said semicrystalline transparent homopolyamide is of formula X.Y, selected from the group consisting of P.12, B.12, and mixtures thereof.

6 . The method according to claim 1 wherein said matrix comprises at least one semicrystalline transparent copolyamide.

7 . The method according to claim 6 , wherein said semicrystalline transparent copolyamide has formula A/X.Y; and wherein the molar proportion of unit A in said semicrystalline transparent copolyamide A/X.Y is from 91% to less than 100%.

8 . The method according to claim 7 , wherein the molar proportion of unit A in the copolyamide A/X.Y is from 95% to less than 100%.

9 . The method according to claim 7 , wherein the unit A is selected form PA11 or PA12, and wherein the unit X.Y is a homopolyamide comprising a cycloaliphatic diamine.

10 . The method according to claim 1 , wherein the prepolymer is compatible with the polyamide.

11 . The method according to claim 1 wherein the prepolymer is an aliphatic polyamide, wherein the aliphatic polyamide is selected from the group consisting of PA6, PA11, PA12, PA11/6, PA6/12, and blends thereof.

12 . The method according to claim 1 , wherein the weight proportion of the prepolymer is from 0.1% to 20%, relative to the weight of the composition.

13 . The method according to claim 1 , wherein the weight proportion of the prepolymer is from 1% to 30%, relative to the weight of the prepolymer-polyamide.

14 . The method according to claim 1 , wherein the prepolymer comprises PA11.

15 . The method according to claim 1 , wherein the at least one additive is selected from the group consisting of modifiers of core-shell type, stabilizers, dyes, plasticizers, flame retardants, fibers, fillers, and mixtures thereof.

16 . The method according to claim 1 , wherein the prepolymer is selected from the group consisting of diCH 3 prepolymer, diNH 2 prepolymer, monoNH 2 prepolymer, monoacid prepolymer, and diacid prepolymer.

17 . A composition comprising:
from 60 to 99.95% by weight of at least one semicrystalline transparent copolyamide; from 0.05% to 20% by weight of at least one prepolymer with a number-average molecular mass from 1000 to 15 000 g/mol, wherein the weight proportion of the semicrystalline transparent copolyamide is from 60% to 99.9% and the weight proportion of the prepolymer, is 40% to 0.1%, relative to the sum of the weight of the semicrystalline transparent copolyamide and the weight of the prepolymer; from 0 to 20% by weight of one or more additives; wherein said composition is free of nucleating agent and is free of impact modifier.

18 . The composition according to claim 17 , wherein the semicrystalline transparent copolyamide is of formula A/X.Y and wherein the molar proportion of unit A in the copolyamide A/X.Y is from 91% to less than 100%.

19 . The composition according to claim 18 , wherein the molar proportion of unit A in the copolyamide A/X.Y is from 95% to less than 100%.

20 . The composition according to claim 17 , wherein the unit A is selected from PA11 or PA12, and the unit X.Y is a homopolyamide comprising a cycloaliphatic diamine.

21 . The composition according to claim 17 , wherein the prepolymer is compatible with the polyamide.

22 . The composition according to claim 17 , wherein the prepolymer has a number-average molecular mass from 1000 to 10 000 g/mol.

23 . The composition according to claim 17 , wherein the weight proportion of prepolymer is from 0.1% to 20%, relative to the total weight of the composition.

24 . The according to claim 17 , wherein the weight proportion of prepolymer is from 1% to 30%, relative to the total weight of the prepolymer and the polyamide.

25 . The composition according to claim 17 , wherein the prepolymer comprises PA11.

26 . The composition according to claim 17 , wherein the one or more additives are selected from the group consisting of stabilizers, dyes, plasticizers, flame retardants, fibers, fillers and mixtures thereof.

27 . A method for the manufacture of articles wherein the method comprises at least one step of extrusion, injection, or molding of a composition comprising:
at least one prepolymer with a number-average molecular mass of from 1000 to 10 000 g/mol; a matrix comprising at least one semicrystalline transparent polyamide, and optionally at least one additive; said composition being free of nucleating agent.

28 . The method according to claim 27 wherein the articles are selected from sports shoes and the method comprises injection.

29 . A process for preparing a composition, wherein the process comprises a step of placing a prepolymer in contact with at least one semicrystalline transparent polyamide and optionally at least one additive, wherein
said polyamide is present in a proportion of from 60% to 99.95% by weight, relative to the sum of the weights of the polyamide and the prepolymer; said prepolymer being present in a proportion of 0.05% to 20% by weight, relative to the sum of the weights of the polyamide and the prepolymer; said additive being in a proportion by weight of 0 to 20%; the sum of the weights of the polyamide, the prepolymer and optionally the additive being equal to 100%, said composition being free of nucleating agent, whereby said composition has improved crystallization kinetics and reduced warpage and the same or improved transparency properties and the same or improved mechanical properties, when compared with the same composition free of prepolymer.

Assignees

• Arkema France

Inventors

• Deyrail Yves
• Sabard Mathieu
• Blondel Philippe
• Eustache René-Paul

Classifications

• C08L77/06

  Polyamides derived from polyamines and polycarboxylic acids (C08L77/10 takes precedence) · CPC title

• C08L2201/10

  Transparent films; Clear coatings; Transparent materials · CPC title

• C08G69/36 Primary

  derived from amino acids, polyamines and polycarboxylic acids · CPC title

• C08L77/02 Primary

  Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C08L77/10 takes precedence) · CPC title