Interlayers for laminated safety glass with superior de-airing and laminating properties and process for making the same

• US 6,800,355 B2
• Filed: 08/16/2002
• Issued: 10/05/2004
• Est. Priority Date: 03/29/2000
• Status: Expired due to Term

• Current Assignee: Performance Materials NA, Inc. (Dow, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Wong, Bert C.
• Primary Examiner(s): Nakarani, D. S.
• Application Number:
  US10/204,287
• Publication Number:
  US 20030022015A1
• Time in Patent Office: 781 Days
• Field of Search: 156/102, 156/209, 428/141, 428/156, 428/172, 428/183, 428/436, 428/437, 428/441, 428/442
• US Class Current: 428/141
• CPC Class Codes: B32B 17/10018 comprising only one glass sheet
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10577 Surface roughness
• CPC Class Codes: B32B 17/10688 Adjustment of the adherence to the glass layers
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/10816 by pressing
• CPC Class Codes: B32B 17/10853 the membrane being bag-shaped
• CPC Class Codes: B32B 17/10972 Degassing during the lamination B32B17/10816 takes precedence
• CPC Class Codes: B32B 2315/08 Glass
• CPC Class Codes: B32B 2329/06 PVB, i.e. polyinylbutyral
• CPC Class Codes: B32B 37/003 to avoid air inclusion
• CPC Class Codes: B32B 38/06 Embossing
• CPC Class Codes: Y10T 156/1023 Surface deformation only [e.g., embossing]
• CPC Class Codes: Y10T 428/12604 Film [e.g., glaze, etc.]
• CPC Class Codes: Y10T 428/131 Glass, ceramic, or sintered, fused, fired, or calcined metal oxide or metal carbide containing [e.g., porcelain, brick, cement, etc.]
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/24702 with locally deformed crests or intersecting series of corrugations
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer
• CPC Class Codes: Y10T 428/249969 : Of silicon-containing material [e.g., glass, etc.]
• CPC Class Codes: Y10T 428/252 : Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
• CPC Class Codes: Y10T 428/31518 : Next to glass or quartz
• CPC Class Codes: Y10T 428/31525 : Next to glass or quartz
• CPC Class Codes: Y10T 428/31627 : Next to aldehyde or ketone condensation product
• CPC Class Codes: Y10T 428/3163 : Next to acetal of polymerized unsaturated alcohol [e.g., formal butyral, etc.]
• CPC Class Codes: Y10T 428/31645 : Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31649 : Ester, halide or nitrile of addition polymer

Abstract

This invention relates to thermoplastic interlayers for laminated safety glass with superior vacuum de-airing at elevated temperatures and superior tacking and edge sealing properties. The sheeting has surface pattern on at least one of the surfaces characterized by flat surfaces with substantially uninterrupted channels for air flow in at least two intersecting directions. The channels allow for rapid de-airing while the area roughness parameter ratio AR_p/AR_t in the range of 0.52 to 0.62, AR_t being less than 32 μm, and area kurtosis less than 2.5, allow for ease of tacking of the interlayer onto glass and edge sealing after de-airing has been completed. Said surface pattern may also be superimposed onto a pattern which is generated by melt fracture or other means on at least one side to enhance de-airing and aid edge sealing.

Claims

1. A glass/adhesive sheet laminate comprising at least one layer of glass and a sheet of plastic interlayer, said plastic interlayer having at least one surface with a pattern which provides relatively uninterrupted channels for de-airing in at least two intersecting directions, said channels having depth between 20 μ

m and 80 μ

m, and width 30 μ

m to 300 μ

m and spaced between 0.1 mm and 1 mm apart.

2. A plastic interlayer as in claim 1 having roughness parameters such that the area roughness peak height, AR_p, is less than 32 μ

m, and the ratio of the of AR_p to the total area roughness, AR_t is between 0.52 and 0.62, and the area kurtosis is less than 2.5.

3. The laminar structure of claim 1 wherein said interlayer is an ionomeric polymer.

4. The laminar structure of claim 1 wherein said interlayer is a polyvinylbutyral (PVB) sheeting plasticized with one or more glycol-di-ester plasticizers and contains suitable amounts of adhesion control additive and surface active agents.

5. The laminar structure of claim 4 wherein said adhesion control agent is a potassium or an alkali earth metal salt of an organic acid or inorganic acid, or a combination thereof.

6. A process for imparting the surface pattern onto the interlayer in claim 1 where the pattern is transferred via embossing an interlayer material with an existing pattern.

7. A process for imparting the surface pattern onto the interlayer in claim 1 whereby the molten interlayer is calendered between embossing rolls, at least one of the rolls is engraved with the pattern described in claim 1.