Wet formed mat having improved hot wet tensile strengths

Abstract

Wet-laid chopped strand glass mats for use in roofing applications that have improved hot wet tensile strengths are provided. The chopped strand mats are formed by the application or inclusion of at least one coupling agent to the chopped strand mat during a wet-laid mat forming process. The coupling agent may be added to the chopped strand mat as part of a two-part binder composition that includes a binder and at least one coupling agent. Alternatively, the coupling agent may be added directly to the chopped strand mat independent of the binder. As a further alternative, the coupling agent(s) may be added to the white water in the wet-laid mat forming process and incorporated into the formed glass mat via the glass fibers. The binder may be a modified urea-formaldehyde binder, a non-modified urea-formaldehyde binder, and / or a formaldehyde-free binder. The coupling agent(s) may be silane coupling agents and / or reactive siloxanes.

Description

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION [0001] The present invention relates generally to chopped strand mats utilized in roofing applications, and more particularly, to chopped strand glass mats that have improved hot wet tensile strengths. BACKGROUND OF THE INVENTION [0002] Glass fibers are commonly used as reinforcements in the building composite industry because they do not shrink or stretch in response to changing atmospheric conditions. Roofing materials such as roofing shingles, roll roofing, and commercial roofing, are typically constructed of a glass fiber mat, an asphalt coating on the fibrous mat, and a surface layer of granules embedded in the asphalt coating. [0003] To form a chopped strand mat suitable for use in a roofing material, glass fibers are first formed by attenuating streams of a molten glass material from a bushing or orifice. The molten glass may be attenuated by a winder which collects gathered filaments into a package or by rollers w...

AI Technical Summary

Benefits of technology

[0020] It is an advantage of the present invention that chopped strand mats formed according to any embodiment of the present invention as disclosed herein may be formed with fibers treated with a size composition that does or does not include a coupling agent. As a result, virtually any glass fiber may be utilized in forming the chopped strand glass mats of the present invention.

[0021] It is another advantage of the present invention that the two-part binder composition of the present invention may utilized in a chopped strand mat forming process without having to change process parameters or modify the equipment on existing wet-laid mat processing lines.

[0022] It is yet another advantage of the present invention that the application or inclusion of at least one coupling agent to the chopped strand mat during a wet-laid mat forming process improves the hot wet tensile strengths of the chopped strand mats.

[0023] It is a further advantage of the present that the inclusion of a coupling agent or agents to the chopped strand mat during the wet-laid process results in an improvement in the dry tensile strength of the formed shingles. As a result, permit manufacturers can run their shingle production lines at a faster rate with less tearing or “break up” of the shingles and increase productivity may be achieved by.

Problems solved by technology

However, some of the conventional binders utilized to form the roofing mats, such as urea-formaldehyde resins, tend to deteriorate under wet conditions such as would be found in an external environment in which the roofing mat would be used.

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