EP2162479A1

EP2162479A1 - Flooring adhesive

Info

Publication number: EP2162479A1
Application number: EP08736449A
Authority: EP
Inventors: Jyothi Varkey; Brock Groth
Original assignee: Construction Research and Technology GmbH
Current assignee: Construction Research and Technology GmbH
Priority date: 2007-06-01
Filing date: 2008-04-22
Publication date: 2010-03-17
Also published as: JP2010529221A; AU2008257890A1; WO2008145458A1; BRPI0812180A2; CN101679577A

Abstract

Provided is an adhesive composition for adhesively bonding floor coverings to floor base elements. A floor and method for constructing the floor using the adhesive composition to adhesively and securely bond floor coverings to the floor are also provided.

Description

FLOORING ADHESIVE

This is a Provisional Application for Patent pursuant to 35 U.S. C. § 119(e).

TECHNICAL FIELD

Disclosed is a one component moisture curable adhesive composition. The moisture curable adhesive composition may be used to securely adhere floor coverings to a wide variety of flooring substrates.

BACKGROUND

Curable adhesives are used to adhere floor coverings to floor substrates.

Currently available wood floor adhesives are primarily based on urethane chemistry. Urethane -based adhesives are derived from isocyanates and involve the use solvents in the formulation process. Thus, urethane adhesive formulation employs hazardous chemicals and results in presence of environmentally unfriendly volatile organic content (VOC) in the final adhesive product. The presence of the VOCs in the final adhesive contributes to an adhesive having a noxious odor.

Urethane -based adhesive compositions are also difficult to clean up. It is difficult to remove wet urethane adhesives from floor covering with a simple cloth or rag. Furthermore, it is often necessary to utilize hazardous chemicals or tools to remove cured adhesive from the floor coverings. The use of harsh chemicals or tools to remove urethane adhesives may accidentally alter the aesthetic appearance of the floor covering, or even result in irreparable damage to the floor covering. Accordingly, it is desirable in the flooring industry to minimize the use of hazardous chemicals in the preparation of floor adhesives to reduce the VOC content of the final adhesive product. It is also desirable to provide an adhesive composition that is easily cleaned from the floor covering without causing damage or compromising the aesthetic finish of the floor covering.

SUMMARY

Disclosed is an adhesive for adhesively bonding floor covering elements to a floor substrate, said adhesive comprising a one component moisture curable polymer comprising a polyether terminated with reactive silane groups.

Also disclosed is a floor comprising a floor substrate, an adhesive comprising a one component moisture curable polymer comprising a polyether terminated with reactive silane groups applied to at least a portion of said floor substrate, and at least one floor covering element applied over said adhesive.

Further disclosed is a method for constructing a floor, the method comprising applying an adhesive comprising a one component moisture curable polymer comprising a polyether terminated with reactive silane groups to at least a portion of a surface of a floor substrate, and applying at least one floor covering element over said adhesive.

DETAILED DESCRIPTION

The floor adhesive comprises a one component moisture curable composition. Without limitation, according to certain illustrative embodiments, the polymer used in the formulation of the floor adhesive composition comprises a polyether modified with silane groups. More particularly, the polymer used in the formulation of the floor adhesive composition comprises a polyether terminated or end-capped with reactive silane groups. A suitable polymer that may be utilized to formulate the floor adhesive composition comprises a polyether polymer terminated with reactive silane groups commercially available from Kaneka Belgium (Westerlo-Oevel, Belgium). This polymer comprises a moisture curable liquid polymer having a polypropylene glycol backbone and terminated with hydro lysable silane groups. The chemical structure of the illustrative silane modified polyether polymer is shown in formula I below:

cm cm cm

(CH₃O)₂ Si(CH₂)₃O (CHCH₂O)n (CH₂)₃Si(OCH₃)₂

(I) wherein n comprises an integer greater than 2.

In the presence of a suitable catalyst, the hydro lysable silane groups react with moisture to form cross links, thereby curing the adhesive composition. The curing mechanism of the silane modified polyether polymer is set forth below:

CH₃ CH₃ CH₃

(CH₃O)₂ -Sι(CH₂)₃O (CHCH₂O )n (CH₂)₃Sι(OCH₃)₂

catalyst H₂O

~~~~SιOH CH₁OH

^<~~'-SιOH

^SiOCH₃

v ~Sι O Si^^^^ The floor adhesive composition is a solvent free composition that preferably contains 1% or less VOCs. According to certain embodiments, the adhesive composition is substantially free of VOCs.

The floor adhesive composition may be applied in either low or high humidity conditions without affecting the performance. Without limitation, the floor adhesive may be applied to a flooring substrate at a humidity level in the range from about 30 to about 100% relative humidity.

The floor adhesive composition is easily applied to a surface of a floor substrate by conventional application tools known to those having ordinary skill in the art. By way of illustration, and not in limitation, the floor adhesive composition may be applied to the surface of a floor substrate with a hand trowel.

The floor adhesive composition possesses a working time of at least one hour.

The term "working time" as used herein refers to the period of time from time that the adhesive composition is exposed to moisture from the external environment until the adhesive composition cures. According to illustrative embodiments, the adhesive composition possesses a working time of about 60 to about 120 minutes at 70°F and 40% relative humidity.

The adhesive composition exhibits excellent moisture resistance. The moisture resistance of the adhesive composition is less than about 3 lbs/1000 sq ft/24 hours, as measured in accordance with an anhydrous calcium chloride moisture test according to the ASTM F- 1869 test method.

The floor adhesive composition possesses a green grab property. The term "green grab" refers to the high early strength of the adhesive that has immediate grab of the floor covering elements. The floor adhesive composition is easily cleaned from the surface of the floor covering or other areas, even after about 48 to about 72 hours from the time of application.

The floor adhesive composition may include additional components to improve processing of the batch formulation or the performance characteristics of the final product. Without limitation, these additional components may include plasticizers, pigments, fillers, including lightweight fillers, diluents, rheology modifiers, cross linkers, moisture scavengers, curing catalysts and combinations thereof. Without limitation, lightweight fillers include ceramic, glass or polymeric microspheres. Suitable microspheres include those commercially available under the trademark EXPANDCEL™.

The polyether polymer may be included in the floor adhesive formulation in an amount from about 15 to about 40 percent by weight based on the total weight of the adhesive formulation. Other suitable ranges for the polyether polymer include from about 15 to about 30 weight percent, from about 20 to about 30 weight percent, from about 25 to about 30 weight percent, from about 16-18 weight percent and from about 19-25 weight percent.

The plasticizer may be included in the floor adhesive formulation in an amount from about 5 to about 20 weight percent based on the total weight of the adhesive formulation. Other suitable ranges for plasticizer include from about 9 to about 15 weight percent and from about 10 to about 15 weight percent.

The pigment may be included in the floor adhesive composition in an amount from about 0.1 to about 1 weight percent based on the total weight of the adhesive formulation. According to illustrative embodiments, the pigment may be included in the floor adhesive composition in an amount from about 0.1 to about 0.5 weight percent. The rheology modifier may be present in an amount from about 0.1 to about 5 weight percent based on the total weight of the adhesive formulation. Other suitable ranges for the rheology modifier include from about 0.1 to about 4 weight percent, from about 0.1 to about 3 and from about 0.2 to about 3.

Fillers, such as surface treated and untreated calcium carbonate, may be included in the floor adhesive composition in an amount from about 15 to about 70 weight percent based on the total weight of the adhesive formulation.

Additional silanes may be included in the floor adhesive composition in an amount from about 0.1 to about 20 weight percent based on the total weight of the adhesive formulation. Other suitable ranges for the additional silanes include 0.3 to about 20, 0.5 to about 20, 5 to about 20, 10 to about 20 and 15 to about 20.

Without limitation, the curing catalyst may be included in the floor adhesive composition in an amount from about 0.1 to about 1 weight percent based on the total weight of the adhesive formulation.

The cured floor adhesive composition exhibits a Shore A hardness value of 25 or greater. According to certain illustrative embodiments, the floor adhesive composition exhibits a Shore A hardness in the range of about 25 to about 70.

According to other illustrative embodiments, the floor adhesive composition exhibits a Shore A hardness that is greater than 40 or 50.

Without limitation, the cured floor adhesive composition exhibits a tensile strength of 100 psi or greater, as measured by ASTM D-412. According to certain embodiments, the cured floor adhesive composition exhibits a tensile strength in the range of about 100 to about 300 psi as measured by ASTM D-412.

The cured floor adhesive composition exhibits an elongation at break value in the value of about 25 to about 300% as measured by ASTM D-412. The cured floor adhesive composition exhibits a 100% modulus value in the range of greater than 0 to about 250 as measured by ASTM D-412.

Without limitation, the cured floor adhesive composition exhibits a wood to wood lap shear value in the range from about 50 to about 300 psi.

Without limitation, the cured floor adhesive composition exhibits a wood to concrete lap shear value in the range from about 20 to about 200 psi.

According to certain illustrative embodiments, a wooden floor is provided.

The wooden floor comprises a floor substrate (ie -sub-floor), the adhesive composition based on a silane modified polyether polymer applied to at least a portion of a surface of the floor substrate, and at least one floor covering element adhesively bonded to the floor substrate by the adhesive composition.

According to certain illustrative embodiments, a wooden floor is provided. The wooden floor comprises a floor substrate (ie -sub-floor), the adhesive composition based on a silane modified polypropylene glycol applied to at least a portion of a surface of the floor substrate, and at least one floor covering element adhesively bonded to the floor substrate by the adhesive composition.

The adhesive composition may be applied to the surface of the sub-floor in a continuous or discontinuous pattern. According to certain embodiments, the adhesive composition is applied to the surface of the sub-floor as a continuous layer that covers substantially the entire surface of the sub-floor.

The adhesive composition may be utilized to secure a wide variety of floor covering elements to a sub-floor. Without limitation, the adhesive composition may be utilized to adhesively secure wooden floor covering elements, vinyl floor coverings, VCT and like floor coverings. According to a certain illustrative embodiment, the adhesive composition may be utilized to adhesively bond a plurality of wooden floor covering elements to a floor substrate. Without limitation, the wooden floor elements include wooden parquet pieces, engineered wood plank, acrylic impregnated plank, prefinished and unfinished fiat milled solids and shorts, bamboo and other exotic wood species.

The floor covering elements may be bonded to a wide variety of different base sub-floor elements. Without limitation, for example, the floor covering elements maybe adhesively bonded to plywood sheathing, oriented strand board, particle board, wafer board, cork under layments, existing vinyl tile and sheet flooring, cementitious underlayments, concrete, masonry, terrazzo, anhydrous underlayments, radiant heat subfioors where temperatures do not exceed about 85⁰F, and like flooring substrates. According to certain embodiments, the floor covering elements comprise wooden parquet pieces that are adhesively bonded to a wooden sub-floor with the adhesive composition.

Also provided is a method for constructing a floor using the adhesive composition in combination with wooden floor covering elements. The method comprises applying an adhesive composition to at least a portion of the surface of the flooring substrate and applying the wooden floor covering elements to the layer of the adhesive.

According to certain embodiments, the method comprises applying a silane modified poly ether polymer adhesive composition to at least a portion of the surface of the flooring substrate and applying the wooden floor covering elements to the layer of the adhesive.

According to illustrative embodiments, the method comprises applying a silane modified polypropylene glycol polymer based adhesive composition to at least a portion of the surface of the flooring substrate and applying the wooden floor covering elements to the layer of the adhesive. Irregular flooring substrates may optionally be leveled prior to the application of the adhesive composition to the floor substrate surface. Any cementitious or polymer-modified cementitious patching or leveling underlayment materials may be utilized to level the flooring substrate prior to application of the adhesive composition. Without limitation, suitable polymer modified cementitious patching compositions that may be utilized are commercially available from BASF Building Systems (Shakopee, MN) under the trademark CHEMREX LEVELPREP and CHEMREX LEVELPREP. A suitable polymer modified cementitious self-leveling underlayment composition commercially available under the trade designation CX- SLU may be utilized to level the flooring substrate. The patching or leveling composition is applied to at least a portion of the flooring substrate surface and is allowed to cure prior to the application of the adhesive composition.

EXAMPLES

The following examples are set forth to describe the floor adhesive in further detail and to illustrate the methods of the preparation. The examples should not be construed as limiting the floor adhesive composition, the floor structure or method for constructing the floor structure in any manner. Throughout the examples, all percentages are by weight and are based on the total weight of the components of the adhesive composition unless otherwise specifically stated. Unless otherwise indicated, the tensile strength, elongation at break and 100% modulus testing was carried out in accordance with ASTM D-412.

Examples 1-4

One component moisture curable floor adhesives were prepared from the following components: Formulation A

Commercially available from Kaneka. bDiisooctyl Phthlate

Commercially available under the trade designation SUPERCOAT.

Commercially available under the trade designation DRIKALITE. Commercially available under the trade designation DISPARLON 6500. Commercially available under the trade designation SILQUEST A 171. Commercially available under the trade designation SILQUEST A 1120.

Commercially available under the trade designation NEOSTANN U-220.

Briefly, the silane modified polyether polymer and plasticizer are combined and mixed under medium speed under nitrogen. The surface treated and untreated calcium carbonate is added to the mixture of the silane modified polyether polymer and plasticizer, and mixing is continued at medium speed and under nitrogen. Once the silane modified polyether polymer, plasticizer and calcium carbonate are evenly mixed, TiO₂ is added and mixing at medium speed under nitrogen is continued. The rheology modifier (DISPARLON 6500) is added to the mixture of the other components and mixed under nitrogen. The rheology modifier is activated by heating the mixture to a temperature of about 17O⁰F for about 25 to about 30 minutes. The mixture is then cooled to about 9O⁰F and the silanes A 171 and A 1120 are added to the batch and mixed for about 10 minutes. The curing catalyst NEOSTANN U-220 is added and the entire batch is mixed for about 25 minutes under vacuum. The product is then packaged in suitable packaging to avoid exposure to moisture from the external environment.

Four separate specimens were prepared from Formulation A and were tested for maximum load, tensile strength, elongation at break, and 100% modulus after a 7 day cure period. The results of the testing are reported in Table I below:

TABLE I

The floor adhesive composition exhibited an average Shore A hardness of about 42.

Examples 5-38

Tan-colored one component moisture curable floor adhesives were prepared from the following formulation is given below. Formulation B

Commercially available from Kaneka. bDiisooctyl Phthlate Commercially available under the trade designation KOTAMITE.

Commercially available under the trade designation DRIKALITE. Commercially available under the trade designation CRAVALLAC SLX. Commercially available under the trade designation SILQUEST A 171. Commercially available under the trade designation SILQUEST A 1120.

Commercially available under the trade designation NEOSTANN U-220.

The Formulation B employs a pigment mix in order to acheive a tan color to the final adhesive product. The surface treated calcium carbonate (KOTAMITE), which is a 3 micron surface treated calcium carbonate, was substituted for the 7 micron surface treated calcium carbonate utilized for Formulation A (SUPERCOAT). In addition, Formulation B employs Cravallac SLX, which is micronised amide wax rheology modifier. The silane modified polyether polymer and plasticizer are combined and mixed under medium speed under nitrogen. The surface treated and untreated calcium carbonate is added to the mixture of the silane modified polyether polymer and plasticizer, and mixing is continued at medium speed and under nitrogen. Once the silane modified polyether polymer, plasticizer and calcium carbonate are evenly mixed, pigment mix is added and mixing at medium speed under nitrogen is continued. The rheology modifier (CRAVALLAC SLX)) is added to the mixture of the other components and mixed under nitrogen. The rheology modifier is activated by heating the mixture to a temperature of about 17O⁰F for about 25 to about 30 minutes. The mixture is then cooled to about 9O⁰F and the silanes A 171 and A 1120 are added to the batch and mixed for about 10 minutes. The curing catalyst NEOSTANN U-220 is added and the entire batch is mixed for about 25 minutes under vacuum. The product is then packaged in suitable packaging to avoid exposure to moisture from the external environment.

Six separate specimens were prepared from Formulation B and were tested for tensile strength, elongation at break, 100% modulus, and Shore A hardness after 7 and 14 day cure periods. The results of the testing are reported in Tables IIA and HB below: Table IIA

Table IIB

The floor adhesive composition exhibited an average Shore A hardness of

49.3.

Additionally, lap shear tests were conducted to evaluate the adhesive strength of the product with wood and concrete floor substrates. The adhesive was applied between two plywood pieces according to ASTM D 1002 test standard, and between plywood and concrete. The strength of the adhesive was measured as the maximum load the material can take before it breaks. The wood/wood tests are denoted as wd- wd and wood/concrete tests are denoted as wd-conc. The measurements were taken after 7, 14 and 28 day cures of the adhesive. The results of the wd-wd testing after 7 and 14 day cure period of the floor adhesive is reported in Tables IIIA and IIIB below:

TABLE IIIA

coh = cohesive failure sub = substrate failure (i.e.- the substrate breaks) TABLE IIIB

Specimens prepared in accordance with Formulation B above were tested for lap shear strength for wd-wd after a 29 day cure period. The results are reported in Table III C below.

TABLE III C

The results of the wd-conc testing after 7 and 14 day cure periods of the floor adhesive is reported in Tables IVA and IVB below: Table IVA

TABLE IVB

Specimens prepared in accordance with Formulation B above were tested for lap shear strength for wd-conc after a 29 day cure period. The results are reported in Table IV C below.

TABLE IV C

Example 43

Tan-colored one component moisture curable floor adhesives were prepared from the following formulation: Formulation C

Commercially available from Kaneka. bDiisooctyl Phthlate

Commercially available under the trade designation KOTAMITE.

Commercially available under the trade designation DRIKALITE.

Commercially available under the trade designation CRAVALLAC SLX.

Commercially available under the trade designation SILQUEST A 171. Commercially available under the trade designation SILQUEST A 1120.

Commercially available under the trade designation NEOSTANN U-220.

Example 43 of the adhesive composition prepared from Formulation C set forth above was prepared in accordance with the method described for Examples 5-42 above. Specimens of the adhesive composition prepared from Formulation C were tested for tensile strength, elongation at break, 100% modulus, Shore hardness and lap shear tests with wood/wood ("wd-wd") and wood/concrete ("wd-conc") after a 7 day cure period. Table V reports the testing results for the tensile strength, elongation at break, and 100% modulus.

TABLE V

The cured floor adhesive exhibited a Shore A hardness of about 57.

Table VI reports the results of the wd-wd adhesion testing for specimens of the floor adhesive composition prepared from the above formulation.

TABLE VI

Table VII reports the results of the wd-conc adhesion testing for specimens of the floor adhesive composition prepared from the above Formulation C.

TABLE VII

Example 62

A tan-colored one component moisture curable floor adhesive was prepared from the following formulation:

Formulation D

Commercially available under the trade designation DRIKALITE. Commercially available under the trade designation CRAVALLAC SLX.

Commercially available under the trade designation NEOSTANN U-220.

Example 62 of the adhesive composition prepared from Formulation D set forth above was prepared in accordance with the method described for Examples 5-42 above. The properties of this batch was tested against tensile strength, elongation at break, 100% modulus, Shore A hardness, Lap shears test with wood/wood and wood/concrete. The performance properties of Example 62 were compared to Example 63 (prepared from Formulation C above) and a prior art urethane floor adhesive C64. The results of the testing are reported in Table VIII below. TABLE VIII

The floor adhesive of Examples 62 and 63 were subjected to the wood-wood wood-concrete lap shear testing using exotic woods including bamboo, Kempas (Mahagani), and African teak. The results of the testing is reported in Table IX below.

TABLE IX

Additionally, side -by-side testing between Example 62 and Comparative Example 64 (urethane adhesive sold under the trade designation Bostik's Best) to evaluate day-by-day performance of the adhesive for four days. The results of this testing are reported in Table X.

TABLE X

* Commercially available polyurethane adhesive under the trade designation Bostik's Best.

While the floor adhesive, wooden floor and method for constructing the floor have been described above in connection with certain illustrative embodiments, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiments for performing the same function without deviating therefrom. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments may be combined to provide the desired characteristics. Variations can be made by one having ordinary skill in the art without departing from the spirit and scope hereof. Therefore, the floor adhesive, wooden floor and method should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the attached claims.

Claims

WE CLAIM:

1. An adhesive for adhesively bonding floor covering elements to a floor substrate, said adhesive comprising a one component moisture curable polymer comprising a polyether terminated with reactive silane groups.

2. The adhesive of claim 1, wherein said polyether terminated with reactive silane groups comprises polypropylene glycol terminated with reactive silane groups.

3. The adhesive of claim 2, further comprising at least one plasticizer, pigment, filler, diluent, rheology modifier, cross linker, moisture scavenger, curing catalyst and combinations thereof.

4. The adhesive of claim 3, wherein the amount of said polypropylene glycol terminated with reactive silane groups present in the floor adhesive formulation comprises about 15 to about 40 percent by weight based on the total weight of the adhesive composition.

5. The adhesive of claim 4, wherein the amount of plasticizer present in the floor adhesive formulation comprises from about 5 to about 20 weight percent based on the total weight of the adhesive composition.

6. The adhesive of claim 5, wherein the amount of said pigment is present in the floor adhesive composition comprises from about 0.1 to about 1 weight percent based on the total weight of the adhesive composition.

7. The adhesive of claim 6, wherein the amount of said rheology modifier present in the adhesive composition comprises an amount from about 0.1 to about 5 weight percent based on the total weight of the adhesive composition.

8. The adhesive of claim 7, wherein the amount of said filler present in the floor adhesive composition comprises an amount from about 15 to about 70 weight percent based on the total weight of the adhesive composition.

9. The adhesive of claim 8, wherein the amount of said curing catalyst present in the floor adhesive composition comprises an amount from about 0.1 to about 1 weight percent based on the total weight of the adhesive composition.

10. The adhesive of claim 2, wherein after cured exhibits a Shore A hardness value of 25 or greater.

11. The adhesive of claim 10, wherein after cured exhibits a Shore A hardness greater than 40.

12. The adhesive of claim 2, wherein after cured exhibits a tensile strength of 100 psi or greater, as measured by ASTM D-412.

13. The adhesive of claim 2, wherein after cured exhibits an elongation at break value in the value of about 25 to about 300% as measured by ASTM D-412.

14. The adhesive of claim 2, wherein after cured exhibits a 100% modulus value in the range of greater than 0 to about 250 as measured by ASTM D-412.

15. The adhesive of claim 2, wherein after cured exhibits a wood to wood lap shear value in the range from about 50 to about 300 psi.

16. The adhesive of claim 2, wherein after cured floor exhibits a wood to concrete lap shear value in the range from about 20 to about 200 psi.

17. A floor structure comprising: a floor substrate; an adhesive comprising a one component moisture curable polymer comprising a polyether terminated with reactive silane groups applied to at least a portion of said floor substrate; and at least one floor covering element applied over said adhesive.

18. The floor of claim 17, wherein said polyether terminated with reactive silane groups comprises polypropylene glycol terminated with reactive silane groups.

19. The of claim 18, wherein said floor substrate is selected from the group consisting of plywood sheathing, oriented strand board, particle board, wafer board, cork underlayments, existing vinyl tile and sheet flooring, cementitious underlayments, concrete, masonry, terrazzo, anhydrous underlayments, and radiant heat subfloors where temperatures do not exceed about 85⁰F.

20. The floor of claim 19, wherein said floor covering is selected from the group consisting of wooden floor covering elements, vinyl floor coverings, VCT and combinations thereof.

21. The floor of claim 20, wherein said wood floor covering is selected from the group consisting of wooden parquet pieces, engineered wood plank, acrylic impregnated plank, prefinished and unfinished flat milled solids and shorts, bamboo and combinations thereof.

22. The floor of claim 21, wherein said floor substrate comprises wood and said floor covering comprising a wood floor covering.

3. A method for constructing a floor comprising: applying an adhesive comprising a one component moisture curable polymer comprising a polyether terminated with reactive silane groups to at least a portion of a surface of a floor substrate; and applying at least one floor covering element over said adhesive.