Hot melt adhesive composition and use thereof

Patent metadata

Field	Value
Publication number	US-2018002579-A1
Application number	US-201715708543-A
Country	US
Kind code	A1
Filing date	Sep 19, 2017
Priority date	Mar 20, 2015
Publication date	Jan 4, 2018
Grant date	—

Abstract

The sprayable olefin-based hot melt adhesive and absorbent articles comprising the adhesive are disclosed. The sprayable olefin-based hot melt adhesive is particularly suitable for spraying at low application temperatures. The sprayable low application temperature hot melt adhesives have high green strength, excellent bond strength and aging performance. Moreover, the sprayable low application temperature hot melt adhesives allows for thin bond lines without bleed-through and burn-through risks for heat-sensitive substrates.

First claim

I claim:

1 . A hot melt adhesive comprising:
(a) about 5 to about 40 wt % of a polypropylene-polyethylene (co) polymer having (i) a propylene content of about 70 to about 95 wt % of the (co)polymer, (ii) a polydispersity (Mw/Mn) index of less than about 3.0, (iii) a melt flow rate of about 20 to about 300 g/10 min measured at 230° C./2.16 kg in accordance with ASTM D1238, (iv) a melting point of less than about 90° C., measured in accordance with ASTM 3418, and (v) a heat of fusion value of less than about 35 J/g measured at 1° C./min heating and cooling rate in accordance with ASTM D3418-12; (b) about 30 to about 70 wt % of a tackifier; and (c) optionally up to about 30 wt % of a wax or a plasticizer;
wherein the adhesive has (i) a tan(δ) value of greater than about 30 at 140° C., 10 rad/s and (ii) a melt viscosity of about 2,000 to about 11,000 cps at 150° C., measured in accordance with ASTM 3236-88.

2 . The hot melt adhesive of claim 1 , wherein the polypropylene-polyethylene (co) polymer has (i) a propylene content of about 75 to about 92 wt % of the (co)polymer, (ii) a polydispersity index of less than 2.5, (iii) a melting point of less than about 70° C., and (iv) heat of fusion values of less than 20 J/g.

3 . The hot melt adhesive of claim 1 , wherein the polypropylene-polyethylene (co) polymer has (i) a propylene content of about 81 to about 91 wt % of the (co)polymer, (ii) a melting point of less than about 65° C., and (iii) heat of fusion values of less than 15 J/g.

4 . The hot melt adhesive of claim 1 , wherein the tackifier is selected from the group consisting of C 5 resins, petroleum distillates, hydrogenated hydrocarbons, C 5 /C 9 resins, C 9 resins, polyterpenes, rosins, hydrogenated rosins, rosin esters and mixtures thereof.

5 . The hot melt adhesive of claim 4 , wherein the tackifier is selected for the group consisting of C 5 resins, petroleum distillates, hydrogenated hydrocarbons, C 5 /C 9 resins, C 9 resins, polyterpenes and mixtures thereof.

6 . The hot melt adhesive of claim 1 , wherein the wax is selected from the group consisting of paraffin, microcrystalline, polyethylene, polypropylene Fischer-Tropsch wax, oxidized Fischer-Tropsch, functionalized wax, and mixtures thereof.

7 . The hot melt adhesive of claim 1 , wherein the plasticizer is selected from the group consisting of polybutenes, polyisobutylene, paraffinic oil, naphthenic oil, phthalates, benzoates, adipic esters, mineral oil, aliphatic oils, aromatic oil, long chain partial ether ester, alkyl monoesters, epoxidized oils, dialkyl diesters, aromatic diesters, alkyl ether monoester and mixtures thereof.

8 . The hot melt adhesive of claim 1 comprising:
(a) about 15 to about 25 wt % of the polypropylene-polyethylene (co) polymer having (i) a propylene content of about 81 to about 91 wt % of the (co)polymer (iii) a melt flow rate of about 40 to about 150 g/10 min, (iv) a melting point of less than about 65° C. and (v) a heat of fusion value of less than about 20 J/g
(b) about 50 to about 60 wt % of the tackifier; and
(c) about 25 to about 35 wt % of the wax or the plasticizer.
wherein the adhesive has (i) both initial and aged bond strength at 2.5 gsm add-on greater than 100 g/in and (ii) Green strength per static peel time greater than 300 seconds at 2.5 gsm add-on.

9 . A hot melt adhesive consisting essentially of:
(a) about 5 to about 40 wt % of a polypropylene-polyethylene (co) polymer having (i) a propylene content of about 70 to about 95 wt % of the (co)polymer, (ii) a polydispersity (Mw/Mn) index of less than about 3.0, (iii) a melt flow rate of about 20 to about 300g/min measured at 230° C./2.16 in accordance with ASTM D1238, (iv) a melting point of less than about 90° C., measured in accordance with ASTM 3418, and (v) a heat of fusion value of less than about 35 J/g measured at 10° C./min heating and cooling rate in accordance with ASTM D3418-12; (b) about 30 to about 70 wt % of a tackifier (c) about 1 to about 50 wt % of an amorphous poly alpha olefin polymer; and (d) about 1 to about 30 wt % of the wax and/or a plasticizer;
wherein the adhesive has (i) a tan(δ) value of greater than about 30 at 140° C., 10 rad/s and (ii) a melt viscosity of about 2,000 to about 11,000 cps at 150° C., measured in accordance with ASTM 3236-88.

10 . The hot melt adhesive of claim 9 , wherein the polypropylene-polyethylene (co) polymer has (i) a propylene content of about 75 to about 92 wt % of the (co)polymer, (ii) a polydispersity index of less than 2.5, (iii) a melting point of less than about 70° C., and (iv) heat of fusion values of less than 20 J/g.

11 . The hot melt adhesive of claim 9 , wherein the polypropylene-polyethylene (co) polymer is has (i) a propylene content of about 81 to about 91 wt % of the (co)polymer, (ii) a polydispersity index of less than 2.5, (iii) a melting point of less than about 65° C., and (iv) heat of fusion values of less than 15 J/g.

12 . The hot melt adhesive of claim 9 , wherein the tackifier is selected from the group consisting of C 5 resins, petroleum distillates, hydrogenated hydrocarbons, C 5 /C 9 resins, C 9 resins, polyterpenes, rosins, hydrogenated rosins, rosin esters and mixtures thereof.

13 . The hot melt adhesive of claim 12 , wherein the tackifier is selected for the group consisting of C 5 resins, petroleum distillates, hydrogenated hydrocarbons, C 5 /C 9 resins, C 9 resins, polyterpenes and mixtures thereof.

14 . The hot melt adhesive of claim 9 , wherein the wax is selected from the group consisting of paraffin, microcrystalline, polyethylene, polypropylene Fischer-Tropsch wax, oxidized Fischer-Tropsch, functionalized wax, and mixtures thereof.

15 . The hot melt adhesive of claim 9 , wherein the plasticizer is selected from the group consisting of polybutenes, polyisobutylene, phthalates, benzoates, adipic esters, mineral oil, aliphatic oils, paraffinic oil, naphthenic oil, aromatic oil, long chain partial ether ester, alkyl monoesters, epoxidized oils, dialkyl diesters, aromatic diesters, alkyl ether monoester and mixtures thereof.

16 . The hot melt adhesive of claim 9 consisting essentially of:
(a) about 15 to about 25 wt % of the polypropylene-polyethylene (co) polymer having (i) a propylene content of about 81 to about 91 wt % of the (co)polymer (ii) a polydispersity (Mw/Mn) value of less than about 2.5, (iii) a melt flow rate of about 40 to about 150 g/10 min, (iv) a melting point of less than about 65° C. and (v) a heat of fusion value of less than about 15 J/g;
(b) about 50 to about 60 wt % of the tackifier;
(c) about 1 to about 20 wt % of the amorphous poly alpha olefin polymer; and
(d) about 25 to about 35 wt % of the wax and/or the plasticizer.
wherein the adhesive has (i) both initial and aged bond strength at 2.5 gsm add-on greater than 100 g/in and (ii) Green strength per static peel time greater than 300 seconds at 2.5 gsm add-on.

17 . An article comprising the adhesive of claim 1 interposed in between two substrates.

18 . The article of claim 17 , where in the substrate is selected from the group consisting of nonwoven, polymer film, elastic film, and tissue.

19 . The article of claim 17 , which is a diaper, training pant, absorbent underpant, sanitary napkin, medical gown, mead pad or disinfecting wipe.

20 . A method of forming a bonded article comprising the steps of:
1) spraying the hot melt adhesive compositions of claim 1 onto at least a portion of a first substrate at a temperature of about 155° C.

Assignees

• Henkel IP & Holding GmbH

Inventors

• Hu Yuhong
• Desai Darshak R
• Chen Jinyu
• Sharak Matthew L

Classifications

• A61L15/58

  Adhesives · CPC title

• C09J123/10 Primary

  Homopolymers or copolymers of propene · CPC title

• B32B5/26

  another layer {next to it} also being fibrous or filamentary {(relative arrangement of fibres or filaments of different layers B32B5/12)} · CPC title

• C09J5/06

  involving heating of the applied adhesive · CPC title

• C09J123/18

  Homopolymers or copolymers of hydrocarbons having four or more carbon atoms · CPC title