US4259402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bonding with foamed hot melt adhesives
Assignee: Nordson Corp
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Filing: 1979-01-25
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Granted: 1981-03-31
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Expires: 1999-01-25
Abstract
Abstract Foamed hot melt adhesives are made and employed by methods which offer significant advantages and economies. The method employs surfactant stabilizers in making hot melt adhesive foams which are very useful in bonding substrates with efficiency and superior bond strengths. Continuous and reliable foaming operations are achieved with a uniform quality and output of foamed materials. Hot melt adhesives are also capable of being foamed with relatively simple mechanical apparatus and under conditions which provide considerable savings of energy. The number of hot melts which can be foamed employing the present technique in a controlled manner is unlimited. The method of stabilization is conducted at low or ambient pressures and resulting stabilized hot melt adhesive gas dispersions may then be pumped with pressurization and dispensed with immediate foaming.
Inventors
- 👤 Walter H. Cobbs, Jr.
- 👤 Robert G. Shong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:10
CPC Classifications
C; C09; C09J; C09J5/00; C09J5/08; C08; C08J; C08J9/00; C08J9/04; C08J9/12; Y; Y10; Y10S; Y10S516/00; Y10S516/01; Y10S521/00; Y10S521/908; Y10S521/911; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249982; Y10T428/249984; Y10T428/249986
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
95 words
The method of bonding with a foamed thermoplastic adhesive which comprises first stabilizing a dispersion of gas bubbles in a molten thermoplastic by incorporating in the molten thermoplastic a surfactant in a sufficient gas-stabilizing amount, subsequently pressurizing said dispersion to form a hot solution of the gas in the molten thermoplastic, dispensing said hot solution under lower pressure whereby said gas is released from said solution to form a hot foamed material, and compressing the hot foam between two substrates to force the gas from the foam and to form a bond between the substrates.
Claim 2
Independent Claim
95 words
The method of bonding with a foamed thermoplastic adhesive which comprises first stabilizing a dispersion of gas bubbles in a molten thermoplastic by incorporating in the molten thermoplastic a surfactant in a sufficient gas-stabilizing amount, subsequently pressurizing said dispersion to form a hot solution of the gas in the molten thermoplastic, dispensing said hot solution under lower pressure whereby said gas is released from said solution to form a hot foamed material, and compressing the hot foam between two substrates to force the gas from the foam and to form a bond between the substrates.
Claim 3
Dependent Claim
10 words
The method of claim 1 wherein said gas is air.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein said pressurizing step is conducted at pressures on an order of about 100 to about 2,000 psig.
Claim 5
Dependent Claim
16 words
The method of claim 1 wherein said pressurizing step is conducted by means of a pump.
Claim 6
Dependent Claim
32 words
The method of claim 1 wherein air is dispersed in the molten thermoplastic material and stabilized under substantially atmospheric pressure followed by said pressurization by means of a fluid pressure translating device.
Claim 7
Dependent Claim
11 words
The method of claim 5 wherein said device is a pump.
Claim 8
Dependent Claim
21 words
The method of claim 1 wherein said surfactant is contained in an amount of about 0.1% to about 5% by weight.
Claim 9
Dependent Claim
13 words
The method of claim 1 wherein said surfactant is a solid phase surfactant.
Claim 10
Dependent Claim
16 words
The method of claim 8 wherein said solid phase surfactant is a finely divided inert material.
Claim 11
Dependent Claim
30 words
The method of claim 1 wherein said surfactant is a mixture of a surfactant soluble in the molten thermoplastic and a finely divided solid surfactant insoluble in the molten thermoplastic.
Claim 12
Dependent Claim
25 words
The method of claim 10 wherein said soluble and solid surfactants are present in a ratio to provide a synergistic stabilizing effectiveness to said dispersion.
Claim 13
Dependent Claim
39 words
The method of claim 10 wherein said soluble surfactant is contained in an amount of about 0.1 to about 5% by weight and said solid surfactant is contained in an amount of about 0.01 to about 1% by weight.
Claim 14
Dependent Claim
23 words
The method of claim 1 wherein said surfactant is selected from the group consisting of anionic,, cationic and nonionic surfactants, and mixtures thereof.
Claim 15
Dependent Claim
38 words
The method of claim 1 wherein said thermoplastic material comprises a polymer selected from the group consisting of polymers of ethylenically unsaturated monomers, polymers of conjugated diene monomers, polyesters, polyamides, polyesteramides and polyurethanes, and copolymers of said monomers.
Claim 16
Dependent Claim
59 words
The method of claim 1 wherein said stabilization is conducted by controlling the surface tension of said molten material within the range of about 10-40 dynes/cm., the viscosity being controlled within the range of about 500-1,000,000 cps and wherein the gas solubility at said dispensing pressure is within the range of about 1/2-20 cm 3 gas/gm of thermoplastic material.
Claim 17
Dependent Claim
9 words
The product produced by the method of claim 1.
Claim 18
Dependent Claim
9 words
The product produced by the method of claim 10.
Claim 19
Dependent Claim
9 words
The product produced by the method of claim 11.
Claim 20
Dependent Claim
9 words
The product produced by the method of claim 13.
Claim 21
Dependent Claim
9 words
The product produced by the method of claim 14.
Claim 22
Dependent Claim
23 words
The method of claim 1 wherein the molten thermoplastic comprises a copolymer of ethylene and vinylacetate and said surfactant is an anionic surfactant.
Claim 23
Dependent Claim
13 words
The method of claim 21 wherein said surfactant is dioctyl alkali metal sulfosuccinate.
Claim 24
Dependent Claim
22 words
The method of claim 22 wherein said molten thermoplastic includes a finely divided inert material to achieve a synergistic foam stabilizing effectiveness.
Claim 25
Dependent Claim
13 words
The method of claim 1 wherein said surfactant is an anionic hydrocarbon polymer.
Claim 26
Dependent Claim
39 words
The method of claim 1 wherein the molten thermoplastic comprises polyethylene and said surfactant is selected from the class of surfactant soluble in the molten thermoplastic and finely divided solid surfactant, insoluble in the molten thermoplastic, and mixtures thereof.
Claim 27
Dependent Claim
18 words
The method of claim 25 wherein said mixtures are in a ratio to provide synergistic foam stabilizing effectiveness.
Claim 28
Dependent Claim
16 words
A method of claim 1 wherein the molten thermoplastic comprises a polyester and an anionic surfactant.
Claim 29
Dependent Claim
13 words
The method of claim 27 wherein said surfactant contains a solid phase surfactant.
Claim 30
Dependent Claim
16 words
The method of claim 28 wherein said solid phase surfactant is a finely divided inert material.
Claim 31
Dependent Claim
27 words
A method of claim 1 wherein the molten thermoplastic comprises a polyolefin polymer having a group containing oxygen as the surfactant in an effective foam stabilizing amount.
Claim 32
Dependent Claim
13 words
The method of claim 30 wherein said group is carboxyl, carbonyl or oxygen.
Claim 33
Dependent Claim
18 words
The method of claim 30 wherein said polyolefin is selected from the group consisting of polyethylene and polypropylene.
Claim 34
Dependent Claim
19 words
The method of claim 1 wherein said molten thermoplastic comprises a hot melt polymer and a polymeric surfactant stabilizer.
Claim 35
Dependent Claim
35 words
The method of claim 33 wherein said polymer is selected from the group consisting of polymers of ethylenically unsaturated monomers, polymers of conjugated diene monomers, polyesters, polyamides, polyesteramides and polyurethanes, and copolymers of said monomers.
Claim 36
Dependent Claim
12 words
The method of claim 34 wherein said surfactant is an ionic polymer.
References Cited (Backward Citations)
US2323831A
Cited
US2860377A
Cited
US3140266A
Cited
US3151427A
Cited
US3270032A
Cited
US3251092A
Cited
US3554932A
Cited
US3681253A
Cited
US3823104A
Cited
US3790510A
Cited
US4156754A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-30 | 1984-09-29 | 1985-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-30 | 1988-09-29 | 1989-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-30 | 1992-09-29 | 1993-03-31 | $7700.00 | Window Closed / Lapsed |