AQUEOUS POLYOLEFIN DISPERSION

Abstract

The invention relates to an aqueous polyolefin dispersion having a pH value from 8.6-12.5 containing a from 50 to 100 wt. % of an aqueous dispersion A comprising the following ingredients: i. from 31 to 90 wt. % of A1, a copolymer of ethylene and (meth)acrylic acid having a content of (meth)acrylic based groups of at least 11 wt. % based on the total weight of the copolymer or a mixture of different copolymers of ethylene and (meth)acrylic acid each having a content of (meth)acrylic based groups of at least 11 wt. % based on the total weight of the copolymer, ii. from 10 to 69 wt. % of A2, another olefinic structure units containing polymer, not being a copolymer of ethylene and (meth)acrylic acid, or a mixture of other olefinic structure units containing polymers not being a copolymers of ethylene and (meth)acrylic acid, and iii. from 0-35 wt. % of additive different from A1 and A2, b. from 0 to 50 wt. % of other ingredient(s) B, where compound B is a material dispersible or soluble in water and different from any of the ingredients of dispersion A wherein—the wt. % of A and B is based on the solid content of the whole aqueous polyolefin dispersion,—the wt. % of the ingredients of dispersion A is based on the solid content of dispersion A,—the sum of the wt. % of ingredients i to iii of dispersion A is 100% and wherein the pH of the dispersion is in the range of 9.5 to 11 and/or the dispersion contains, as an ingredient of B, more than 5 and less than 35 wt. % of PEG, based on the solid content of the whole aqueous dispersion.

Claims

1. Aqueous polyolefin dispersion containing a. from 50 to 100 wt. % of an aqueous dispersion A comprising the following ingredients: i. from 31 to 90 wt. % of A1: a copolymer of ethylene and (meth)acrylic acid having a content of (meth)acrylic based groups of at least 11 wt. % based on the total weight of the copolymer, or a mixture of different copolymers of ethylene and (meth)acrylic acid, each copolymer of the mixture of different copolymers having a content of (meth)acrylic based groups of at least 11 wt. % based on the total weight of the copolymer, ii. from 10 to 69 wt. % of A2: another polymer containing olefinic structure units, but not being a copolymer of ethylene and (meth)acrylic acid, or a mixture of other polymers containing olefinic structure units but not being copolymers of ethylene and (meth)acrylic acid, and iii. from 0-35 wt. % of additive different from A1 and A2, b. from 0 to 50 wt. % of other ingredient(s) B, wherein the wt. % of the aqueous dispersion A and the other ingredient(s) B is based on the solid content of the whole aqueous polyolefin dispersion, the wt. % of the ingredients of the aqueous dispersion A is based on the solid content of the aqueous dispersion A, the sum of the wt. % of ingredients i to iii of the aqueous dispersion A is 100%, and wherein one or both of the following conditions are met: 1) the pH of the aqueous polyolefin dispersion is in the range of 9.5 to 11; 2) the aqueous polyolefin dispersion contains, as an ingredient of the other ingredient(s) B, more than 5 and less than 35 wt. % of PEG, based on the solid content of the whole aqueous polyolefin dispersion.

2. Aqueous polyolefin dispersion according to claim 1, wherein at least 70 Mol.-% of the copolymer of ethylene and (meth)acrylic acid or each copolymer of the mixture of different copolymers of ethylene and (meth)acrylic acid of A1 have a content of (meth)acrylic based groups of at least 15 wt. % based on the total weight of the copolymer.

3. Aqueous polyolefin dispersion according to claim 1, wherein the aqueous dispersion A comprises from 41 to 90 wt. % of A1 and from 10 to 59 wt. % of A2 based on the solid content of the aqueous dispersion A.

4. Aqueous polyolefin dispersion according to claim 1, further containing KOH and/or NaOH.

5. Aqueous polyolefin dispersion according to claim 1, wherein A2 includes one or more of a copolymer of ethylene and vinyl acetate (EVA), a copolymer of ethylene and vinyl acetate (EVA) modified with maleic anhydride, a polyolefin modified with maleic anhydride, a polyolefin elastomer, a styrene butadiene block copolymer (SBS), an ethylene-propylene-non-conjugated diene terpolymer (EPDM), a maleic anhydride modified ethylene-propylene-non-conjugated diene terpolymer, a copolymer of ethylene and propylene (EPM),and a terpolymer of ethylene, propylene, and 1-butene.

6. Aqueous polyolefin dispersion according to claim 1, wherein the aqueous polyolefin dispersion contains dispersed hybrid particles containing both A1 the copolymer of polyethylene and (meth)acrylic acid having a content of (meth)acrylic based groups of at least 11 wt. % and A2 the another polymer containing olefinic structure units but not being a copolymer of polyethylene and (meth)acrylic acid.

7. Process for the preparation of an aqueous polyolefin dispersion, the process comprising: intimately mixing ingredients of an aqueous dispersion A at a temperature in the range of 50° C. to 200° C. after which a homogenous compound of the ingredients is obtained, the aqueous dispersion A comprising the ingredients: i. from 31 to 90 wt. % of A1: a copolymer of ethylene and (meth)acrylic acid having a content of (meth)acrylic based groups of at least 11 wt. % based on the total weight of the copolymer, or a mixture of different copolymers of ethylene and (meth)acrylic acid, each copolymer of the mixture of different copolymers having a content of (meth)acrylic based groups of at least 11 wt. % based on the total weight of the copolymer, ii. from 10 to 69 wt. % of A2: another polymer containing olefinic structure units but not being a copolymer of ethylene and (meth)acrylic acid, or a mixture of other polymers containing olefinic structure units but not being copolymers of ethylene and (meth)acrylic acid, and iii. from 0-35 wt. % of additive different from A1 and A2, mixing the homogeneous compound with water, optional other ingredient(s) B, and a neutralizing agent at a temperature which is 2 to 20° C. above the highest melting temperature of the components of the aqueous dispersion A until the aqueous polyolefin dispersion is obtained and cooling down the aqueous polyolefin dispersion below a temperature which is below the melting temperature or the melting range of A1, wherein the aqueous polyolefin dispersion comprises 50 to 100 wt. % of the aqueous dispersion A and from 0 to 50 wt. % of the optional other ingredient(s) B based on the solid content of the whole aqueous polyolefin dispersion, the wt. % of the ingredients of the aqueous dispersion A is based on the solid content of the aqueous dispersion A, the sum of the wt. % of ingredients i to iii of the aqueous dispersion A is 100%, and one or both of the following conditions are met: 1) the pH of the aqueous polyolefin dispersion is in the range of 9.5 to 11; 2) the aqueous polyolefin dispersion contains, as an ingredient of the optional other ingredient(s) B, more than 5 and less than 35 wt. % of PEG, based on the solid content of the whole aqueous polyolefin dispersion.

8. A recyclable article comprising: paper, and the aqueous polyolefin dispersion according to claim 1 applied to the paper as a binder and/or as a coating composition, where the recyclability of the recyclable article is assessed and verified with PTS Method RH:021/97.

9. (canceled)

Description

EXAMPLES

[0072] Various aqueous dispersions were prepared using the following procedure: [0073] In a first step a compound was prepared by mixing and kneading the individual ingredients in a Leistritz ZSE 18 Maxx twin-screw extruder at a temperature in the range of 80-150° C. (temperature was selected based on the ingredients), where different temperature zones were created inside the extruder. The pressure inside the extruder was 35 bar maximum. [0074] In a next step the extruded compound was fed into a Buchi 2 l Pressure reactor, equipped with a dissolver mixer operating at speeds between 100-1000 rpm. The dispersion was prepared at elevated temperature in the range of 90-150° C. at sometimes elevated pressure (additional pressure in the range of 0-100 bar). After the formation of a homogeneous dispersion the cooling of the mixture is essential. The cooling has to be quickly as possible at crystallization temperature of the polymers until maximum temperature of 40° C.

[0075] The ingredients and conditions for each example are given in Table 1 below.

TABLE-US-00001 TABLE 1 Example # 1 # 2 # 3 # 4 # 5* # 6* EAA #3 (wt. %) 43.5 60 60 60 60 60 EPM #82 (wt. %) 40 RT #53 RP EVA #2 (wt. %) 40 40 40 EVA #4 (wt. %) 29 40 PVP #33 (wt. %) 1.25 PEG #40 (wt. %) 26.25 Solid content (%) 31 31 32 29 27 30 Base NaOH NaOH NaOH NaOH NaOH NH.sub.3 Temperature (° C.) 90 90 90 120  90 100 pH value 9.5 10   9.7   9.6   9.2 8.5 Recyleability yes yes yes yes no no Sealing Strength (N/m) 169 513 387  187  693  609 *Comparative example

[0076] EAA#3: PRIMACOR® 5980; dispersible polymer which is an ethylene acrylic acid copolymer (20 wt % comonomer), “DOW”

[0077] EPM#82: Dutral CO 034, ethylene propylene copolymer (28 wt % propylene), “Versalis”

[0078] RT #53: Lotader AX 8750, random terpolymer of ethylene, butylacrylate, glycidyl methacrylate (23-28 wt % butylacrylat), “Arkema”

[0079] RP EVA #2: OREVAC® T 9305, a random terpolymer of ethylene, vinyl acetate and maleic anhydride, “ARKEMA”

[0080] EVA #4: Escorene FL 00328, ethylene, vinyl acetate copolymer, “ExxonMobil”

[0081] PVP #33: Kollidon 90, polyvinylpyrrolidone, Mw: 790000-1350000, “BASF”

[0082] PEG#40: Polyethylenglycol 10000, Mw: 9000-12500, “Merck”