Injection molded multiple layer glazings

• US 9,242,401 B2
• Filed: 08/23/2006
• Issued: 01/26/2016
• Est. Priority Date: 08/23/2006
• Status: Active Grant

• Current Assignee: Solutia Incorporated (Eastman Chemical Company)
• Original Assignee: Solutia Incorporated (Eastman Chemical Company)
• Inventors: Karagiannis, Aristotelis, Koran, Francois Andre, Yuan, Ping
• Primary Examiner(s): SCHATZ, CHRISTOPHER T
• Application Number:
  US11/466,765
• Publication Number:
  US 20080047655A1
• Time in Patent Office: 3,443 Days
• Field of Search: 156/104, 156/109, 156/99, 156/102, 156/103, 264/261
• US Class Current: 1/1
• CPC Class Codes: B29C 45/0001 characterised by the choice of material
• CPC Class Codes: B29C 45/14467 Joining articles or parts of a single article B29C45/14377, B29C45/14385, B29C45/14581, B29C45/14614 and B29C45/006 take precedence
• CPC Class Codes: B29C 45/14778 the article consisting of a material with particular properties, e.g. porous, brittle
• CPC Class Codes: B29K 2031/04 Polymers of vinyl acetate, e.g. PVAc, i.e. polyvinyl acetate
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2709/08 Glass
• CPC Class Codes: B29K 2995/0088 Molecular weight
• CPC Class Codes: B29L 2031/7782 Glazing
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10743 containing acrylate (co)polymers or salts thereof
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/1077 containing polyurethane
• CPC Class Codes: B32B 17/10788 containing ethylene vinylacetate
• CPC Class Codes: B32B 17/10917 between two pre-positioned glass layers

Abstract

The present invention is directed to the use of injection molding to form polymeric interlayers directly between two rigid substrates that are positioned so that after injection of the melted polymeric material and after cooling, the resulting multiple layer panel functions as a safety panel that can be used in any appropriate conventional safety glazing application. Methods of the present invention utilize a relatively low molecular weight polymer, multiple injection points, mold compression, and/or a heated substrate in order to facilitate the injection of polymer into the relatively narrow space between glazing substrates that is typically found in safety glazings.

Claims

1. A method of making a multiple layer glazing panel, the method comprising:

providing two rigid glazing substrates;

positioning said glazing substrates in a position relative to each other, thereby forming a space devoid of any material between the entire interior surface areas of said glazing substrates; and

,

injecting a polymer melt into said space between said glazing substrates until the entirety of said space is filled with said polymer melt to create a polymer interlayer, thereby forming said multiple layer glazing panel;

wherein said polymer melt comprises poly(vinyl butyral) having a molecular weight of less than 70,000 Daltons;

wherein one or both of said rigid glazing substrates are heated to at least 80°

C. prior to said injecting; and

wherein said polymer melt is injected into said space between said glazing substrates through at least at least one point of injection located at or within the perimeter of said space between said glazing substrates.

2. The method of claim 1, wherein one or both of said rigid glazing substrates are heated to at least 150°

C. prior to said injecting, and wherein at least four points of injection are used.

3. The method of claim 1, wherein said substrates are glass.

6. The method of claim 1, at least one point of injection includes at least two separate points of injection that are located on opposite sides of said glazing substrates.

7. The method of claim 1, wherein said polymer melt is injected into said space between said glazing substrates through at least four separate points of injection located at or within the perimeter of said space between said glazing substrates.

8. The method of claim 1, further comprising, prior to said injecting, melting a solidified polymer material to form said polymer melt.

9. The method of claim 1, wherein said injecting comprises feeding said polymer melt into a nozzle, runner, and gating system that directs said melt, under pressure, into said space between said glazing substrates.

4. A method of making a multiple layer glazing panel, the method comprising:

providing two rigid glazing substrates;

positioning said two rigid glazing substrates in a position relative to each other inside an injection molding mold, thereby forming a space devoid of any material between the entire interior surface areas of said glazing substrates, wherein the width of said space between the entire interior surface areas of said glazing substrates corresponds to the desired thickness of a polymer layer in said multiple layer glazing panel;

injecting a polymer melt into said space between said glazing substrates until the entirety of said space is filled with said polymer melt to create said polymer interlayer, thereby forming said multiple layer glazing panel;

wherein said polymer melt comprises poly(vinyl butyral) having a molecular weight of less than 70,000 Daltons;

wherein one or both of said rigid glazing substrates are heated to at least 80°

C. prior to said injecting; and

wherein said polymer melt is injected into said space between said glazing substrates through at least one point of injection located at or within the perimeter of said space between said glazing substrates.

5. The method of claim 4, wherein a vacuum is used to secure each of said glass substrates against a respective half of the injection molding mold in said position relative to each other.