WO2009158493A1

WO2009158493A1 - Restoring and repairing damaged and/or defective wood structures

Info

Publication number: WO2009158493A1
Application number: PCT/US2009/048651
Authority: WO
Inventors: Omar Tiba; Annarebecca Crary; David W. Evarts; Robert M. Loomis; Emily K. May
Original assignee: Willamette Valley Company
Priority date: 2008-06-25
Filing date: 2009-06-25
Publication date: 2009-12-30

Abstract

A method for restoring and/or repairing of a damaged and/or defective wooden structure during or after installation. The method comprises applying a flowable, multi-component polymeric material comprising at least one amine compound and an isocyanate to at least one damaged and/or defective area of the wooden structure. The flowable polymeric material is gelled in situ. The gelled polymeric material is then shaped so that it substantially conforms to the profile of the wooden structure. Finally, the gelled polymeric material is cured to form the restored and/or repaired wood structure.

Description

RESTORING AND REPAIRING DAMAGED AND/OR DEFECTIVE WOOD STRUCTURES

BACKGROUND Currently, many patching products for defective wood are on the market.

Solvent and/or water based putties fill the shelves of hardware and other stores. These putties can fill small defects such as small knotholes and/or narrow splits. However, they do not do well in large knotholes or big splits. Upon curing, they shrink and crack and eventually fall out of the defects. Some manufacturers recommend that the defects be filled twice for adequate repairs. Also they are not suitable for harsh environments and have very poor water resistance.

The use of polymers to repair or restore wood has been described. This technology deals with resins which are designed to flow to fill horizontally- extending defective wood structures such as plywood, or solid and laminated wood. These repairs can be performed before installation of these wood structures in their end use applications.

Once a wood structure is installed in a non-horizontal plane, and particularly wood structures which extend in a substantially vertical plane, any missed defects or wood damaged during or after installation present severe if not insurmountable problems if one were to attempt to restore or repair them. This is because presently available commercial resins will not effectively and efficiently completely fill defects or damaged areas in installed wooden structures which extend from in a substantially non-horizontal plane or in a substantially vertical plane.

Current products on the market such as polyurethanes, polyureas, epoxies, and other systems do not satisfy customer's needs to repair and/or restore installed wooden structures that have to be filled when they are positioned in a substantially non-horizontal plane or a vertical plane. The resins when applied to fill such defects or damaged areas can flow, run, and/or leak out. Some manufacturers suggest the use of plastic or rubber dams to contain the liquid resins until they gel and solidify. SUMMARY

A method for restoring and/or repairing of a damaged and/or defective wooden structure, in one embodiment, which can be implemented prior to, during or after installation in an end use application, in a location which is a substantially horizontal plane, a substantially non-horizontal plane, or a substantially vertical plane, and which overcomes the problems outlined above, has now been provided. The method comprises providing the wooden structure during or after the end use application, in a location which is a substantially horizontal plane, a substantially non-horizontal plane, or a substantially vertical plane. Then, a flowable, multi-component polymeric material comprising at least one amine compound and an isocyanate is applied to at least one damaged and/or defective area of the wooden structure, In one embodiment, the polymeric material comprises a poly(urethane-urea) material. In another embodiment, the polymeric material comprises a hybrid poly(urethane-urea) material. In still a further embodiment, the poly(urethane-urea) is formed employing a polyamine and at least one hydroxyl capped polyol.

The flowable polymeric material then forms in situ a gelled polymeric material. The gelled polymeric material is substantially sag resistant and maintains its shape without substantial runoff during the restoring and/or repairing of the wooden structure. In one embodiment, the flowable multi-component polymeric material is applied to the damaged and/or defective area of the wooden structure in liquid form. In another embodiment, the flowable multi-component polymeric material substantially completely fills the damaged and/or defective area of the wooden structure. The gelled polymeric material is then shaped so that it substantially conforms to the profile of the wooden structure. In an embodiment herein, the Gel Time of the polymeric material is not more than about five seconds. In a further embodiment, the Set Time of the polymeric material is sufficient for shaping the polymeric material in situ so it substantially conforms to the profile of the wooden structure.

The gelled polymeric material is cured to form the restored and/or repaired wood structure. In one embodiment, auxiliary non-ambient heat is used for curing the polymeric material. In another embodiment, the defective and/or damaged wood structure is restored and/or repaired without requiring the use of auxiliary non-ambient temperature conditions. In still another embodiment, the defective and/or damaged wood structure is restored and/or repaired without requiring the use of auxiliary non-ambient pressure conditions. In still a further embodiment, the cured gelled polymeric material does not substantially shrink or crack after curing.

DETAILED DESCRIPTION As stated above, a method for restoring and repairing damaged or defective wooden structures during or after installation in an end use application in a non- horizontal or a substantially vertical plane has been developed which solves the problems described above which remain in the marketplace. In one embodiment, wooden structures installed in a non-horizontal or substantially vertical plane can include columns, utility poles, I-beams and other such wood structures. The method in one embodiment comprises an in-place application of a multi-component polymeric material to the damaged or defective wooden structures. In another embodiment, the multi-component polymeric material can be a two-component polymeric material, In still another embodiment, the multi- component polymeric material can be a polymeric hybrid material. The multi- component polymeric material is not a polymeric foam material.

The first stage of the two-component polymeric material is designed to allow the material, which is in flowable form, and in an embodiment herein is in liquid form. In a further embodiment, the polymeric material substantially completely fill the defects. It can then gel in place without substantial sagging or running.

The gelled material is readily shapeable in place within the confines of the defect or damaged area of the wooden structure before it cures and hardens in the second stage. This shaping of the gelled material contours it so that it can substantially conform to the profile of the wooden structure. In one embodiment, this is done under ambient temperature conditions, in another embodiment as low as about 45 degrees F., and in a further embodiment under ambient pressure conditions. In an embodiment herein, the flowable material can be gelled in a relatively short period of time. One measure of this property is the extremely short Gel Time. In one embodiment, the gel time of the polymeric material is not more than about five seconds, in another embodiment not more than about three seconds, and in a further embodiment not more than about one second. This allows for placement and retention of the gelled polymeric material in the repair or restoration site without substantial run-off of the polymeric material therefrom. In other words, the polymeric material can be maintained in a fixed position in damaged and/or defective area of the wooden structure during the course of the repair and/or restoration procedure. In a further embodiment, the Set Time of the polymeric material is sufficient for shaping it to form the restored and/or repair wood structure without requiring the use of non-ambient heat and/or non-ambient pressure. Set Time is typically dependent upon temperature conditions and the thickness of applied polymeric material. In the second stage, the multi-component polymeric material will set up and cure and then harden to form the restored wood structure. In a further embodiment, the set up and/or curing steps can be conducted at ambient temperature and/or ambient pressure conditions without requiring any auxiliary heating or pressing. The multi-component polymeric material in one embodiment can comprise a polyurea-polyurethane material. The use of a polyurea material as a constituent of the polyurea-polyurethane material allows the polymeric material to function as set forth above as the first stage of the multi-component polymeric material. More specifically, the polyurea-polyurethane material can fill the defects in the defective wooden structure, and then gel without substantial sagging or running.

Then, the polyurethane material portion of the polyurea-polyurethane multi- component material can permit the multi-component polymeric material to function as set forth above for the second stage of the subject method. More specifically, the polyurethane can set up and cure and then harden to form a restored and/or repaired wood structure.

In one embodiment, the multi-component polymeric material has excellent adhesion to the wooden structure. In another embodiment, it can also be applied to the defect so that it will not peel or fall off from the wooden structure after curing is completed and a hardened polymeric patch is formed. In still another embodiment, the subject polymeric patch does not shrink or crack after curing.

The multi-component polymeric material can also be a Green Product. It can be produced of substantially 100 % reactive ingredients without incorporation of any solvents or volatile organic compounds. The subject material can also be filled with organic and inorganic pigments, dyes and fillers. The cured multi-component polymeric material can be machineable. The cured system can also accept paint or stain.

Polymeric materials particularly useful in this invention can be prepared from various combinations of amine-terminated resins that are reacted with an isocyanate material. These polymeric materials in one embodiment comprise at least one amine compound and an isocyanate.

In one embodiment, the polymeric material can be a poly(urethane-urea). In another embodiment the poly(urethane-urea) can be formed employing at least one polyol compound. In still another embodiment, the polyol can be a hydroxyl capped polyol. In a further embodiment, the polymeric material can include a hydroxyl chain extender. In one embodiment the polyol is present in the polymeric material in an amount from about 20 %, in another embodiment from about 25 %, and in a further embodiment from about 30 %, in an embodiment herein up to about 45 %, in still another embodiment up to about 40 %, and in still a further embodiment up to about 35 %, by weight based on the weight of the polymeric material.

The poly(urethane-urea) also comprises at least one amine compound. In an embodiment herein the amine compound can be an amine chain extender. In one embodiment, the amine compound is present in the poly(urethane-urea) in an amount up to about 15 %, in another embodiment up to about 12 %, and in still another embodiment up to about 10 %, by weight based on the weight of the polymeric material.

The poly(urethane-urea) also comprises at least one isocyanate compound. In an embodiment, the isocyanate compound is an isocyanate prepolymer. In one embodiment, the isocyanate compound is present in an amount of from about 10 %, in another embodiment from about 15 %, and in still another embodiment from about 20 %, in one embodiment up to about 50 %, in a further embodiment up to about 45 %, and in still a further embodiment up to about 40 %, by weight based on the weight of the polymeric material.

Typical polyol compounds can be hydroxyl capped multi-functional polyether oxides, in an embodiment herein di- and tri-functional polyether oxides, and in further embodiments hydroxyl capped polypropylene oxides, hydroxyl capped di- and tri-functional polyethylene oxides, hydroxyl capped di- and tri- functional poly(propylene-ethylene)oxides, and hydroxyl capped di- and tri- functional polyesters. Examples of polyols which can be employed herein are Bayer LHT-240, PPG-425, Arch 20-280, Dow Voranol 230-238, and BASF Quadrol. In one embodiment, the polyol compound has a molecular weight of from about 200 grams/mol, and in another embodiment from about 300 grams/mol, and in still another embodiment from about 400 grams/mol, and in a certain embodiment up to about 4,000 grams/mol, in another embodiment up to about 3500 grams/mol, and in still another embodiment up to about 3000 grams/mol. Typical amine compounds can be amine compounds such as amine chain extenders including di-and tri-polyoxypropylenediamines, liquid aromatic diamines, isophronediamine, and diethylenetriamine or amine capped compounds such as amine capped bi- or tri-functional amine compounds. Examples of amines which can be employed herein are Shell Epi-Cure 3271, Vestamine IPD, Huntsman D-230, and Dorf Ketal Unilink 4100.

Typical isocyanate compounds are di- and tri-functional aromatic isocyanates, polymeric modified 4,4-diphenylmethane diisocyanates, and 1 ,6- hexamethylene diisocyanates (aliphatic isocyanates). Examples of isocyanates which can be employed herein are Bayer Desmodure N 3400, Huntsman Rubinate 1209, Bayer Mondur ML, Bayer Mondur MR and MR Light. Also, the isocyanate compound can be a prepolymer isocyanate blend such as Bayer Mondur MA- 2300, Bayer Mondur MA-2600, and Baytec ME-040. The functionality of the isocyanate in one embodiment can be at least about 2.0, in another embodiment at least about 2.2, in a further embodiment at least about 2.4, and in still a further embodiment up to about 2.6.

The poly(urethane-urea) reaction can include a catalyst system to accelerate the reaction between the isocyanate and the hydroxyl groups of each polyol. These catalysts can include tin, mercury, lead, bismuth, zinc and various amine compounds such as are described in U.S. 5,011,902, which is incorporated herein in its entirety by reference. A preferred catalyst employed herein is a metal carboxylate.

In certain instances it may be desirable to add a chain extender to complete the formulation of poly(urethane-urea) polymers by reacting isocyanate groups of adducts or prepolymers. Examples of some types of polyol and amine chain extenders include 1,3-butanediol, 1,4-butanediol, 2-ethyl-l,3-hexanediol, diethylene glycol, trimethylol propane and hydroquinone di(beta hydroxyethyl ether). The subject polyurethane, polyurea, and poly(urethane-urea) compositions may additionally incorporate diluents, fillers, compatibilizers, thixotropes, pigments, plasticizers, colorants, de-foaming agents, rheological modifiers, and anti settling agents. Suitable fillers include barium sulfate, calcium sulfate, calcium carbonate, silica, and clay particles, such as aluminum silicates, magnesium silicates, ceramic and glass micro-spheres and kaolin. Suitable compatibilizers are hydroxy containing organic compounds, preferably hydroxy containing monocyclic arenes such as ethoxylated nonyl phenol, which compatibilize the polyol and aromatic diisocyanate reactants in the formulation. Suitable diluents include hydrotreated paraffinic oils, phthlates, carbonates, hydrotreated naphthenic oils, petroleum solvents, aliphatic solvents and propylene carbonate. The multi-component polymeric material can be dispensed using cartridges with hand held dispensers and/or can be dispensed using a metering system for production or for large projects. In a further embodiment, dispensers can be employed for limited or small or hard to reach defects. Equipment for dispensing the isocyanate and polyol(s)/amines employed in producing the poly(urethane- urea) materials, such as the WVCO dispensing equipment manufactured by Willamette Valley Company of Eugene, Oregon, is commercially available. Typically, the two components which form the poly(urethane-urea) filler material is pumped from storage tanks to a proportioning unit where the components are measured out according to a specified ratio. A known amount of each material is then separately pumped to a dispensing unit. The components are mixed in the dispensing unit and then introduced into the defect in the non-horizontally- extending wooden member. The components of the polymeric materials can also be mixed together using a cartridge system with a static mixing tube along with standard proportioning equipment. Dual and universal cartridge systems, including mixing tubes for uniformly combining the multi-components of the polymeric material, are available from TAH Industries, Inc. of Robbinsville, NJ.

Many wood structures are installed in outdoor applications such as decking, sun rooms and the like. Customers often seek to improve weather resistance, and prevent mold and mildew formation in such structures. Therefore, in an embodiment herein, the polymeric material can be formulated by the addition of biocide materials to facilitate or substantial enhance weather resistance and/or to prevent mold and mildew formation. In this way, one can promote long term durability in adverse environments. For example, several types of biocides can be employed. Some Organic Chemicals such as Dow' s Vinyzene, and

DCOIT (Dichloro Octyl Isothiazolone) are approved for use in the USA and EU. Other inorganic salts such as Borogard ZB (zinc borates) are also registered for use.

Many wood structures such as schools, theaters, and the like are required to be constructed from fire resistant materials. In an embodiment, the polymeric material can be formulated with special additives which meet such fire resistant requirements. For example, in one embodiment the addition of organophosphorus esters and other like compounds to the polymeric material can provide the requisite fire resistant properties in such wood structures. In a further embodiment, the incorporation of inorganic systems such as aluminum tri-hydrate in combination with antimony tri-oxide with polyurethane resins also can provide such fire resistant protection.

Illustrative Example Chemicals Amounts (grams)

1500 M. W. Polyether Triol 400

700 M.W. Polyether Triol 508

2-Ethyl-l,3-hexanediol 59

Defoamer 2 EPI-KURE 3271 8.7

VESTAMINE IPDA 19

Molecular Sieve 20

WV-90 Catalyst (bismuth catalyst) 0.25 WV-50 Catalyst (zinc catalyst) 6

The ingredients listed above were mixed until the mixture became substantially homogenous. The mixed liquid and a Polymeric Isocyanate (MDI) were dispensed directly into the defects in wood structures such as Utility Posts, Columns, and Beams, etc. The mixed liquid and Polymeric Isocyanate (MDI) in a 2:1 mix ratio by volume (2 parts resin and 1 part isocyanate) to form the above described hybrid resin were dispersed using a two-component cartridge system or two-component metering system.

The dispensed two-component polymeric material in stage one displayed an instantaneous thixotropic property and remained in place without flowing, running or leaking. However, it maintained the ability to be shaped to conform to the profile of the wood structure using a trowel or a utility knife. Stage one was facilitated through the use of the above-described polyurea material which permits the hybrid resin to function in the manner set forth above. The two-component polymeric material was cured and hardened in about 2 to 3 minutes and was tack free in about 1-2 hours depending on the ambient temperature. Stage two was facilitated through the use of the above-described polyurethane material which permits the hybrid resin to function in the manner set forth above. The repaired and restored wood structures were machinable in a similar manner to wood. Also, the repaired and restored wood structures accepted stain and/or paint without any problems.

It is to be understood that the above-referenced arrangements are only illustrative of the application for the principles of the present invention. Numerous modifications and alternative arrangements can be devised without departing from the spirit and scope of the present disclosure. While embodiments of the present invention have been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications can be made without departing from the principles and concepts as set forth herein. We claim all modifications and variation coming within the spirit and scope of the following claims.

Claims

Claims:

1. A method for restoring and/or repairing of a damaged and/or defective wooden structure prior to, during or after installation in an end use application, in a location which is a substantially a horizontal plane, a substantially non-horizontal plane, or a substantially vertical plane, which comprises providing said wooden structure during or after said end use application in said location which is a substantially horizontal plane, a substantially non- horizontal plane, or a substantially vertical plane; applying a flowable, multi-component polymeric material comprising at least one amine compound and an isocyanate to at least one damaged and/or defective area of the wooden structure; gelling said flowable polymeric material in situ, said gelled polymeric material being substantially sag resistant and maintaining its shape without substantial runoff during said restoring and/or repairing of the wooden structure; shaping the gelled polymeric material so that it substantially conforms to the profile of the wooden structure; and curing the gelled polymeric material to form the restored and/or repaired wood structure.

2. The method of claim 1 , which further includes the step of using auxiliary non-ambient heat for curing the polymeric material.

3. The method of claim 1 , wherein the worn wood structure is restored and/or repaired without requiring the use of auxiliary non-ambient pressure.

4. The method of claim 1 , wherein the Gel Time of the polymeric material is not more than about five seconds.

5. The method of claim 1, wherein the polymeric material comprises a poly(urethane-urea) material.

6. The method of claim 1, wherein the Set Time of the polymeric material is sufficient for shaping the polymeric material in situ so it substantially conforms to the profile of the wooden structure.

7. The method of claim 1, wherein the flowable multi-component polymeric material is applied to said damaged and/or defective area of the wooden structure in liquid form.

8. The method of claim 1 , wherein the flowable multi-component polymeric material is substantially completely fills said damaged and/or defective area of the wooden structure.

9. The method of claim 1 , wherein the worn wood structure is restored and/or repaired without requiring the use of auxiliary non-ambient temperature.

10. The method of claim 1 , wherein the polymeric material comprises a hybrid poly(urethane-urea) material.

11. The method of claim 1 , wherein the polymeric material further includes a biocide material to facilitate or substantial enhance weather resistance and/or to prevent mold and mildew formation.

12. The method of claim 1 , wherein the polymeric material further includes a fire resistant additive which provides fire resistant properties in said wood structure.

13. A method for restoring and/or repairing of a damaged and/or defective wooden structure, during or after installation in an end use application, in a location which is a substantially horizontal plane, a substantially non- horizontal plane, or a substantially vertical plane, which comprises providing said wooden structure during or after said end use application in said location which is a substantially horizontal plane, a substantially non- horizontal plane, or a substantially vertical plane; applying a flowable multi-component polymeric material comprising a hybrid poly(urethane-urea) material to at least one damaged and/or defective area of the wooden structure; gelling said flowable polymeric material in situ, said gelled polymeric material being substantially sag resistant and maintaining its shape without substantial runoff during said restoring and/or repairing of the wooden structure; shaping the gelled polymeric material so that it substantially conforms to the profile of the wooden structure; and curing the gelled polymeric material to form the restored and/or repaired wood structure.

14. The method of claim 13, which further includes the step of using auxiliary non-ambient heat for curing the polymeric material.

15. The method of claim 13 , wherein the worn wood structure is restored and/or repaired without requiring the use of auxiliary non-ambient pressure.

16. The method of claim 13, wherein the Gel Time of the polymeric material is not more than about five seconds.

17. The method of claim 13, wherein the poly(urethane-urea) is formed employing a hydroxyl capped polyol.

18. The method of claim 13 , wherein the Set Time of the polymeric material is sufficient for shaping the polymeric material in situ so it substantially conforms to the profile of the wooden structure.

19. The method of claim 13, wherein the flowable multi-component polymeric material is applied to said damaged and/or defective area of the wooden structure in liquid form.

20. The method of claim 13, wherein the flowable multi-component polymeric material is substantially completely fills said damaged and/or defective area of the wooden structure.

21. The method of claim 13, wherein the worn wood structure is restored and/or repaired without requiring the use of auxiliary non-ambient temperature.

22. The method of claim 13, wherein the cured polymeric material does not substantially shrink or crack after curing.

23. The method of claim 13, wherein the polymeric material further includes a biocide material to facilitate or substantial enhance weather resistance and/or to prevent mold and mildew formation.

24. The method of claim 13, wherein the polymeric material further includes a fire resistant additive which provides fire resistant properties in said wood structure.