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US-12624194-B2 - Aqueous binder compositions for mineral wool products

US12624194B2US 12624194 B2US12624194 B2US 12624194B2US-12624194-B2

Abstract

A method of manufacturing an insulation product is provided that includes collecting a plurality of inorganic fibers comprising at least 25 wt. % of bi- and tri-valent metal oxides on a substrate, applying a formaldehyde-free aqueous binder composition that includes a nitrogen-based protective agent to the collection of inorganic fibers, removing the nitrogen-based protective agent by heating the binder-coated inorganic fibers; and curing the aqueous binder composition via an esterification reaction.

Inventors

  • Xiujuan Zhang
  • Liang Chen
  • Charlotte Pettersson

Assignees

  • OWENS CORNING INTELLECTUAL CAPITAL, LLC
  • PAROC GROUP OY

Dates

Publication Date
20260512
Application Date
20210830

Claims (11)

  1. 1 . A method of manufacturing an insulation product comprising; collecting a plurality of inorganic fibers on a substrate, said inorganic fibers being formed of a composition comprising at least 25 wt. % of bi- and tri-valent metal oxides; applying an aqueous binder composition to the collection of inorganic fibers, forming binder-coated inorganic fibers, the aqueous binder composition comprising: from more than 50 wt. % to less or equal to 88.75 wt. % solids of a crosslinking agent comprising at least two carboxylic acid groups, wherein the crosslinking agent comprises polyacrylic acid; from 10.0 to 40.0 wt. % solids of a polyol component having at least two hydroxyl groups; from 1.25 to 40.0 wt. % solids of a nitrogen-based protective agent, wherein said nitrogen-based protective agent comprises at least one of an amine-based protective agent or an ammonium based protective agent and temporarily blocks at least 40% the carboxylic acid groups of the crosslinking agent; removing the nitrogen-based protective agent by heating the binder-coated inorganic fibers to a temperature of at least 150° C.; and curing the aqueous binder composition via an esterification reaction between the crosslinking agent and the polyhydroxy component, forming an inorganic fibrous insulation product, wherein said aqueous binder composition is free of added formaldehyde.
  2. 2 . The method of claim 1 , wherein the crosslinking agent is present in the binder composition in an amount from 55 to 85 wt. % solids, based on the total solids content of the aqueous binder composition.
  3. 3 . The method of claim 1 , wherein the polyol component comprises a sugar alcohol, an alkanolamine, pentaerythritol, or mixtures thereof.
  4. 4 . The method of claim 1 , wherein the nitrogen-based protective agent comprises ethylenediamine, ammonium hydroxide, or mixtures thereof.
  5. 5 . The method of claim 1 , wherein the aqueous binder composition has an uncured pH of 4.0 to 7.0.
  6. 6 . The method of claim 1 , wherein the aqueous binder composition has an uncured pH of 4.2 to 6.5.
  7. 7 . The method of claim 1 , wherein the insulation product has a tensile strength in the machine direction according to EN1607 of at least 30 kPa immediately upon manufacture.
  8. 8 . The method of claim 7 , wherein the insulation product maintains at least 50% of the tensile strength after 7 days in a tropic box with a temperature of 65° C. and 95% relative humidity.
  9. 9 . The method of claim 7 , wherein the insulation product maintains at least 60% of the tensile strength after 7 days in a tropic box with a temperature of 65° C. and 95% relative humidity.
  10. 10 . The method of claim 1 , wherein the insulation product has a compressive strength at 10% strain according to EN826 of at least 10 kPa.
  11. 11 . The method of claim 1 , wherein the aqueous binder composition has a ratio of crosslinking agent to nitrogen-based protective agent of from 4:1 to 1.5:1.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims priority to and any benefit of U.S. Provisional Application No. 63/073,013, filed Sep. 1, 2020, the content of which is incorporated herein by reference in its entirety. BACKGROUND Aqueous binder compositions are conventionally utilized in the formation of woven and non-woven fibrous products, such as insulation products, composite products, wood fiber board, and the like. Insulation products, for example insulation products formed of inorganic fibers, are typically manufactured by fiberizing a molten glass or mineral-based composition and spinning fibers from a fiberizing apparatus, such as a rotating spinner. To form an insulation product, fibers produced by a rotating spinner are drawn downwardly from the spinner towards a conveyor by a blower. As the fibers move downward, a binder material is sprayed onto the fibers and the fibers are collected into a high loft, continuous blanket on the conveyor. The binder material gives the insulation product resiliency for recovery after packaging and provides stiffness and handleability so that the insulation product can be handled and applied as needed in the insulation cavities of buildings. The binder composition also provides protection to the fibers from interfilamentous abrasion and promotes compatibility between the individual fibers. The blanket containing the binder-coated fibers is then passed through a curing oven and the binder is cured to set the blanket to a desired thickness. After the binder has cured, the fiber insulation may be cut into lengths to form individual insulation products, and the insulation products may be packaged for shipping to customer locations. Insulation products prepared in this manner can be provided in various forms including batts, blankets, and boards (heated and compressed batts) for use in different applications. Mineral fiber products generally comprise man-made vitreous fibers (MMVF), such as, for example, glass fibers, ceramic fibers, basalt fibers, slag wool, mineral wool, and stone wool, which are bound together by a polymeric binder composition. Traditional binder compositions used for mineral fiber insulation, and particularly particular mineral wool insulation, are based on phenol-formaldehyde (PF) resins, as well as PF resins extended with urea (PUF resins). However, while such binder compositions provide suitable properties to the insulation products, formaldehyde binders emit undesirable emissions during the manufacturing process and there has been a desire to move away from the use of formaldehyde-based binders. As an alternative to formaldehyde-based binders, certain formaldehyde-free formulations have been developed for use as a binder in insulation products. Such formaldehyde-free formulations may include a polycarboxylic acid with a polyhydroxy component that are intended to crosslink via an esterification reaction. Such polycarboxylic acid-based binder compositions are often acidic in nature, with a pH less than 5. Mineral wool fibers, however, are highly alkaline, with a higher concentration of bi- and tri-valent metal oxides in the fibers than other inorganic fibers, such as fiberglass. Thus, polycarboxylic acid groups in the traditional binder compositions irreversibly react with the metal oxides of the mineral wool fibers upon application, which blocks the acid groups from being available for an esterification reaction with the polyhydroxy crosslinking agents. Accordingly, acidic binders tend to lack the strength of PF binder when used with mineral wool and products formed therefrom demonstrate insufficient performance. Accordingly, there is a need for a formaldehyde-free binder composition for use in the production of high alkalinity fibrous insulation products, such as mineral wool. SUMMARY Various exemplary aspects of the inventive concepts are directed to a method of manufacturing an insulation product comprising collecting a plurality of inorganic fibers on a substrate, the inorganic fibers being formed of a composition comprising at least 25 wt. % of bi- and tri-valent metal oxides; applying an aqueous binder composition to the collection of inorganic fibers; and forming binder-coated inorganic fibers. The aqueous binder composition comprises at least 50 wt. % solids of a crosslinking agent comprising at least two carboxylic acid groups; 10.0 to 40.0 wt. % solids of a polyol component having at least two hydroxyl groups; and 1.25-50.0 wt. % solids of a nitrogen-based protective agent. The nitrogen-based protective agent temporarily blocks at least 40% the carboxylic acid groups of the crosslinking agent. The method further includes removing the nitrogen-based protective agent by heating the binder-coated inorganic fibers to a temperature of at least 150° C.; and curing the aqueous binder composition via an esterification reaction between the crosslinking agent and the polyol component, forming an inorganic fibrous insulation produ