US4996103A
Expired / Lapsed
US
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Composite elements having improved resistance against stress cracking corrosion, most preferably for low temperature housing compartments
Assignee: BASF SE
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Filing: 1990-03-30
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Granted: 1991-02-26
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Expires: 2010-03-30
Abstract
Abstract The invention deals with composite elements having improved resistance against stress cracking corrosion especially for low temperature housing compartments, comprising: (a) at least one top layer of polystyrene, preferably toughened polystyrene, having certain mechanical properties; and (B) a layer of polyurethane foam, preferably polyurethane rigid foam; said polyurethane rigid foam prepared while using difluorochloromethane as a blowing agent or a blowing agent mixture which essentially comprises water, difluorochloromethane, and optionally trichlorofluoromethane.
Inventors
- 👤 Rolf Henn
- 👤 Reinhard Leppkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:07
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/18; B32B5/20; B32B27/00; B32B27/06; B32B27/065; B32B27/30; B32B27/302; C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/14; C08J9/143; B32B2266/00; B32B2266/02; B32B2266/0214; B32B2266/0278; B32B2305/00; B32B2305/02; B32B2305/022; B32B2307/00; B32B2307/50; B32B2307/51; B32B2307/54; B32B2307/546; B32B2307/558; B32B2325/00; C08J2375/00; C08J2375/04; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249954; Y10T428/249987; Y10T428/249991; Y10T428/249992
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
38 words
Composite elements having improved resistance against stress cracking corrosion, comprising: (A) at least one top layer of polystyrene; and (B) a layer of polyurethane foam, wherein the polyurethane foam is prepared while using difluorochloromethane as a blowing agent.
Claim 2
Dependent Claim
38 words
Composite elements having improved resistance against stress cracking corrosion, comprising: (A) at least one top layer of polystyrene; and (B) a layer of polyurethane foam, wherein the polyurethane foam is prepared while using difluorochloromethane as a blowing agent.
Claim 3
Dependent Claim
47 words
The composite element of claim 1 wherein the polyurethane foam is prepared while using a blowing agent mixture comprising: (i) 0.05 to 4.0 parts by weight of water; (ii) 5 to 30 parts by weight of difluorochloromethane; and (iii) 0 to 30 parts by weight of trichlorofluoromethane.
Claim 4
Dependent Claim
140 words
The composite element of claim 1 wherein said top layer (A) comprises a toughened polystyrene having: a tensile strength according to DIN 53455 of from 20 to 45 N/mm 2; a percentage elongation break according to DIN 53455 of from 15 to 45 percent; a modulus of elasticity (tensile test) according to DIN 53457 of from 1650 to 2800 N/mm 2; a flexural strength according to DIN 53452 of from 36 to 78 N/mm 2; an impact strength according to DIN 53453 at 23° C. without break, of up to 65 kJ/m 2 and greater and at -40° C. without break, up to 65 kJ/m 2 and greater; and a notched bar impact strength according to DIN 53453 of from 4 to 10.5 kJ/m 2; measured on injection molded, normal small, bars or according to DIN 53455 on shoulder bars.
Claim 5
Dependent Claim
17 words
The composite element of claim 1 wherein layer (B) comprises a polyurethane rigid foam blown using difluorochloromethane.
Claim 6
Dependent Claim
128 words
The composite element of claim 1 wherein the polyurethane foam of layer (B) is prepared by reacting: (a) organic preferably aromatic polyisocyanates with: (b) at least one polyhydroxyl compound having a functionality of from 2 to 8 and a hydroxyl number of from 150 to 850 and optionally; (c) chain extending agents and/or crosslinking agents; in the presence of: (d) catalysts; (e) difluorochloromethane or a blowing agent mixture comprising: (ei) 0.05 to 4.0 parts by weight of water; (eii) 5 to 30 parts by weight of difluorochloromethane; and (eiii) 0 to 30 parts by weight of trichlorofluoromethane; said mixture is used in a quantity of from 10 to 35 parts by weight, based on 100 parts by weight of polyhydroxyl compound (b); and (f) optionally auxiliaries and/or additives.
Claim 7
Dependent Claim
42 words
Composite element of claim 1 wherein a mixture of diphenylmethane diisocyanates and polyphenyl polymethylenepolyisocyanates having a diphenylmethane diisocyanate isomeric content of from 30 to 80 weight percent is used as the organic polyisocyanate (a) to prepare the polyurethane rigid foam layer (B).
Claim 8
Dependent Claim
136 words
The composite element of claim 1 wherein to prepare layer (B) from polyurethane rigid foam a mixture of the following is used as the polyhydroxyl compound, said mixture, based on 100 parts by weight, comprises: (bi) 0 to 95 parts by weight of a polyether polyol initiated with sucrose having a hydroxyl number of from 300 to 500; (bii) 0 to 15 parts by weight of a polyether polyol initiated with sorbitol having a hydroxyl number of from 400 to 600; (biii) 0 to 20 parts by weight of a polyether polyol initiated with ethylenediamine having a hydroxyl number of from 700 to 850; and (biv) 0 to 60 parts by weight of a polyether polyol having a hydroxyl number of from 400 to 600, prepared while using a sucrose triethanolamine mixture as an initiator molecule.
Claim 9
Dependent Claim
107 words
Composite elements having improved resistance against stress cracking corrosion for low temperature compartment housings, comprising: (A) a covering layer of toughened polystyrene; and (B) a intermediate layer of polyurethane rigid foam; said composite elements are prepared by foaming the hollow space of toughened polystyrene wherein said polyurethane rigid foam is prepared by reacting: (a) aromatic polyisocyanates with: (b) at least one polyhydroxyl compound having a functionality of from 2 to 8 and a hydroxyl number of from 150 to 850 and optionally; (c) chain extending agents and/or crosslinking agents; in the presence of: (d) catalysts; (e) difluorochloromethane as a blowing agent; and (f) optionally auxiliaries and/or additives.
Claim 10
Dependent Claim
107 words
Composite elements having improved resistance against stress cracking corrosion for low temperature compartment housings, comprising: (A) a covering layer of toughened polystyrene; and (B) a intermediate layer of polyurethane rigid foam; said composite elements are prepared by foaming the hollow space of toughened polystyrene wherein said polyurethane rigid foam is prepared by reacting: (a) aromatic polyisocyanates with: (b) at least one polyhydroxyl compound having a functionality of from 2 to 8 and a hydroxyl number of from 150 to 850 and optionally; (c) chain extending agents and/or crosslinking agents; in the presence of: (d) catalysts; (e) difluorochloromethane as a blowing agent; and (f) optionally auxiliaries and/or additives.
Claim 11
Dependent Claim
39 words
The composite elements of claim 8 wherein said reaction mixture is introduced into a covering layer A) shaped to form a hollow compartment and allowed to foam under compression utilizing a degree of compression of from 1.2 to 6.
Claim 12
Dependent Claim
72 words
The composite elements of claim 8 wherein a mixture of the following is used as said blowing agent (e): (ei) 0.05 to 4.0 parts by weight of water; (eii) 5 to 30 parts by weight of difluorochloromethane; and (eiii) 0 to 30 parts by weight of trichlorofluoromethane; said mixture, based on 100 parts by weight of polyhydroxyl compound (b), is used in a quantity of from 10 to 35 parts by weight.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-25 | 1994-08-27 | 1995-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-25 | 1998-08-27 | 1999-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-25 | 2002-08-27 | 2003-02-26 | $7700.00 | Window Closed / Lapsed |