Caulks

Abstract

A composite caulk comprising paper wool, perlite, a particulated wood material having a particle size below 2 mm, a particulated fire retardant bark material having at least one axis of length with a dimension below 2 mm and a polyvinyl-acetate based aqueous dispersion adhesive; and wherein said composite caulk forms a heterogeneous caulk which can be dispensed using a handheld caulking gun.

Claims

1. A composite caulk comprising cellulose insulation, perlite, a particulated wood material having a particle size below 2 mm, a particulated fire retardant bark material having at least one axis of length with a dimension below 2 mm and a polyvinyl-acetate based aqueous dispersion adhesive; and wherein said composite caulk forms a heterogeneous caulk which can be dispensed using a handheld caulking gun.

2. The composite caulk according to claim 1 further comprising an aqueous modified starch dispersion adhesive or an aqueous modified starch dispersion adhesive reinforced with an aqueous acrylic dispersion.

3. A composite caulk according to claim 1 wherein the particulated fire retardant bark material is cork.

4. A composite caulk according to claim 1 wherein the polyvinyl-acetate based aqueous dispersion adhesive is a water resistant adhesive in class D3 of DIN EN 204.

5. A composite caulk according to claim 1 comprising on a weight/total weight basis: Cellulose insulation: 3-10%; Perlite: 10-20%; Particulated Wood: 15-25%; Particulated Bark: 10-35%; The balance adhesive.

6. A composite caulk according to claim 1 comprising on a weight/total weight basis: Cellulose insulation: 4-7%; Perlite: 11-16%; Particulated Wood: 17-23%; Particulated Bark: 13-29%; The balance adhesive.

7. A composite caulk according to claim 1 comprising on a weight/total weight basis: Cellulose insulation: 5%; Perlite: 13%; Particulated Wood: 20%; Particulated Cork: 15%; The balance adhesive.

8. A composite caulk according to claim 1 comprising on a weight/total weight basis: Cellulose insulation: 5%; Perlite: 13%; Particulated Wood: 20%; Particulated Cork: 27%; The balance adhesive.

9. A composite caulk according to claim 2, wherein said aqueous modified starch dispersion adhesive or said aqueous modified starch dispersion adhesive reinforced with an aqueous acrylic dispersion constitutes up to 10% of the total mass of adhesive.

10. A composite caulk according to claim 1; further comprising at least one fungicide in an amount biologically efficient to retard or hinder growth of fungus in said composite caulk.

11. A method of preparing a composite caulk comprising cellulose insulation, perlite, a particulated wood material having a particle size below 2 mm, a particulated fire retardant bark material having at least one axis of length with a dimension below 2 mm and a polyvinyl-acetate based aqueous dispersion adhesive; and wherein the composite caulk forms a heterogeneous caulk which can be dispensed using a handheld caulking gun; the method comprising dry mixing cellulose insulation, perlite, particulated wood and particulated bark are prior to mixing with said polyvinyl-acetate based aqueous dispersion adhesive; wherein optionally at least one fungicide is mixed into said composite caulk with or after addition of said polyvinyl-acetate based aqueous dispersion adhesive; wherein optionally, an aqueous modified starch dispersion adhesive and/or an aqueous modified starch dispersion adhesive reinforced with an aqueous acrylic dispersion is added after said polyvinyl-acetate based aqueous dispersion adhesive and wherein said polyvinyl-acetate based aqueous dispersion adhesive alone or with said optional aqueous modified starch adhesives is/are added in an amount sufficient to obtain a heterogeneous caulk which can be dispensed using a handheld caulking gun.

12. Use of a composite caulk according to claim 1 for caulking a joint or a gap between separate building objects in a building.

Description

DETAILED DESCRIPTION

(1) According to the present invention, there is suggested novel caulks comprising paper wool, perlite, a particulated wood material having a particle size below 2 mm, a particulated fire retardant bark material having at least one axis of length with a dimension below 2 mm and a polyvinyl-acetate based aqueous dispersion adhesive; and wherein the composite caulk forms a heterogeneous caulk which can be dispensed using a handheld caulking gun; and the use such caulks for caulking joints between building objects during building construction or during building maintenance.

(2) Paper wool, or as it is also known cellulose insulation, consists of about 85% cellulosic materials, typically recycled newspaper, and about 15% of fire retardant minerals such as e.g. boric acid, ammonium sulfate or aluminum hydroxide. In the experimental compositions of the present invention the paper wool consisted of 87.5% recycled newspaper, 8.7% aluminum hydroxide, 0.9% borax and 2.9% boric acid. While paper wool having a composition as described above is preferably used in the composite caulks of the invention, the exact composition of the comprised paper wool is not considered limiting on the invention.

(3) The use of paper wool in the composite caulks of the present invention serves several purposes. Paper wool enhances the caulk matrix, is fire retarding as well as insulating and further provides a color palette which allows the composite caulks of the present invention to approach that of mortar.

(4) Paper wool is present in the composite caulks of the present invention in an amount based on weight/total weight of between 3 to 10%, more preferably between 4 to 7%, and most preferably around 5%.

(5) Perlite is used for enhancing the porosity of the caulk as is known in the art as well as for structural stability of the hardened caulk. In addition thereto, the addition of a mineral component enhances the visual aspect and the desired visual mortar-like appearance of the enhanced caulks.

(6) Perlite is present in the composite caulks of the present invention in an amount based on weight/total weight of between 10 to 20%, more preferably between 11 to 16%, and most preferably around 14%.

(7) Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. In the context of the present disclosure, wood (while sometimes defined as only the secondary xylem in the stems of trees) is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. The present invention utilizes wood as a composite filler to add tensional strength and resilience against compression.

(8) In the context of the present disclosure there is used particulated wood having a particle size below 2 mm. One way of obtaining such particulated wood material could be by using sawdust, which is a cheap and abundant surplus material from the wood and carpentry industries. The skilled person will understand that some fraction of the particulated wood material can be larger than 2 mm without influencing the quality and flow properties of both the fresh as well as the hardened caulk. However, in order to achieve a suitable heterogeneous caulk which can be dispensed using a handheld caulking gun, it is important that the fraction of oversized particles is kept to a minimum.

(9) Particles smaller than 1 mm influence the caulk very little, however it is preferable that the majority of wood particles have sizes in the range of 1 mm to 2 mm in order to maximize the influence of the particulated wood on the structural properties of the hardened caulk. A preferred range as measured by sieving shall have at least 80%, preferably 90%, of all wood particles in the range from 1 to 2 mm.

(10) No particular limitation is placed on the source of wood used in the present invention. Likewise, two or more sources of wood may be present in the composite caulks of the invention without influencing the final product. It has been found that in order to optimize the composite caulk, wood from so-called softwood (such as elder wood) is less preferable, while wood from so-called medium hardness wood (such as pinewood, birch, beech) or hardwood (such as oak, teak) are more suitable. Particulated wood which is naturally fire retardant is preferred.

(11) Particulated wood is present in the composite caulks of the present invention in an amount based on weight/total weight of between 15 to 25%, more preferably between 17 to 23%, and most preferably around 20%.

(12) Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines, and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner bark, which in older stems is living tissue, includes the innermost area of the periderm. The outer bark in older stems includes the dead tissue on the surface of the stems, along with parts of the innermost periderm and all the tissues on the outer side of the periderm. The outer bark on trees is also called the rhytidome.

(13) In the context of the present disclosure there is used a particulated fire retardant bark material having at least one axis of length with a dimension below 2 mm. One way of obtaining such particulated fire retardant bark material could be by using sawdust, which is a cheap and abundant surplus material from the wood and carpentry industries. The skilled person will understand that some fraction of the particulated fire retardant bark material can be larger than 2 mm without influencing the quality and flow properties of both the fresh as well as the hardened caulk. However, in order to achieve a suitable heterogeneous caulk which can be dispensed using a hand held caulking gun, it is important that the fraction of oversized particles is kept to a minimum.

(14) Particles smaller than 1 mm influence the caulk very little, however it is preferable that the majority of particulated fire retardant bark particles have sizes in the range of 1 mm to 2 mm in order to maximize the influence of the particulated fire retardant bark on the structural properties of the hardened caulk. A preferred range as measured by sieving shall have at least 80%, preferably at least 90%, of all wood particles in the range from 1 to 2 mm.

(15) One very suitable bark material in relation to the present invention is cork. Cork is an impermeable, buoyant material, a prime-subset of bark tissue that is harvested for commercial use primarily from Quercus suber (the Cork Oak), which is endemic to southwest Europe and northwest Africa. Cork is composed of suberin, a hydrophobic substance, and because of its impermeable, buoyant, elastic, and fire retardant properties, it is used in a variety of products, the most common of which is for wine stoppers. However, other sources of fire retardant bark exit and are equally suitable for use in the context of the present invention. Nevertheless, cork is preferred.

(16) Particulated fire retardant bark is present in the composite caulks of the present invention in an amount based on weight/total weight of between 10 to 35%, preferably 10 to 30%, more preferably between 13 to 29%, and most preferably around 21%.

(17) The composite caulk comprising paper wool, perlite, a particulated wood material having a particle size below 2 mm, a particulated fire retardant bark material having at least one axis of length with a dimension below 2 mm further comprises a polyvinyl-acetate based aqueous dispersion adhesive.

(18) The aqueous dispersion adhesive constitutes the matrix of the composite caulk and hence constitutes the sealing material of the caulk. Aqueous polyvinyl-acetate dispersions are known to form good adhesives for porous stone, e.g. such as bricks or concrete, and further advantageous in the improved caulks of the present invention as cross-linking and curing of the adhesive is enhanced by the presence of boric acid in the paper wool. The aqueous dispersions suitable for the present invention have a dry matter content of from 40 to 50% by weight of the dispersion, most preferably between 44 to 46% dry matter.

(19) It is preferable, that the polyvinyl-acetate based aqueous dispersion adhesives suitable for the present invention have a water resistance durability class below D2 according to DIN EN 204 as in place at the filing date of the present application (2014). Preferably, the durability class of the adhesive is not below D3 according to DIN EN 204, and most preferably, the adhesive is classifiable as a D3 adhesive according to DIN EN 204. A suitable example of a commercially available adhesive is ProFect 2343 from PKI Industrilim of Fredericia, Denmark.

(20) It is further advantageous, but not required, to modify and adjust the flow properties of the composite caulk using aqueous modified starch dispersion adhesives or aqueous modified starch dispersion adhesives reinforced with an aqueous acrylic dispersion. Such adhesives are well known as wall paper adhesives and form a good connecting matrix between the paper, wood, and bark components of the composite caulk and the inorganic components of both the composite caulk of the invention as well as the building objects where-between the caulk is applied.

(21) If present, the aqueous modified starch dispersion adhesives or aqueous modified starch dispersion adhesives reinforced with an aqueous acrylic dispersion are present in an amount up to 10% of the total mass of adhesive, preferably up to 5% of the total mass of the adhesive. Suitable aqueous modified starch dispersion adhesives or aqueous modified starch dispersion adhesives reinforced with an aqueous acrylic dispersion in general have between 15 and 25% by weight of the aqueous modified starch dispersion adhesive dry matter, most preferably about 20% by weight of dry matter. A suitable example of a commercially available adhesive is DANA LIM vdrumslim 216 from Dana Lim of Kge, Denmark.

(22) Adhesive is present in balancing amounts sufficient to reach 100% by weight when the weight percentage sum of the dry matter components is compiled.

(23) While in general cured polyvinyl-acrylates have a good resistance to fungi, it can in circumstances be advantageous to further include at least one fungicide in an amount biologically efficient to retard or hinder growth of fungus in the composite caulks of the invention. Such fungicides are preferentially added to the adhesives prior to mixing with the dry matter components in the composite caulks of the invention. Suitably, commercially available adhesives comprising premixed adhesive and fungicide can be used for ease of manufacturing.

(24) It is further required that the composite caulk forms a heterogeneous caulk which can be dispensed using a handheld caulking gun.

(25) Handheld caulking guns are well-known in the art. They permit a person so desiring to dispense a viscous liquid, composition or complex fluid from a container, wherein the viscous liquid is contained, and onto a surface. The container usually has a moveable bottom and usually an oppositely positioned opening in the container. During use the caulking gun exerts a pressure through a piston action on the moveable bottom of the container, which causes a displacement of the bottom and of the viscous liquid in the container, causing the viscous liquid to leave the container as long as the piston action is maintained on the bottom.

(26) Such caulking guns are used on viscous liquids of a broad viscosity range. Usually, the viscosity of the liquid is determined by the liquid's intended use and is not limited by the construction of the caulking guns. In the context of the present invention, the requirement that the composite caulk of the invention shall form a heterogeneous caulk which can be dispensed using a handheld caulking gun shall therefore be understood broadly as being a composite caulk which requires the use of a handheld caulking gun for dispensing, and therefore that the handheld caulking gun must be compressible by a person of normal strength, yet not being so liquid that upon application into a joint or gap in a building, the composite caulk of the invention will lack the necessary viscosity to remain in place in the joint during hardening, i.e. cease being a caulk.

(27) According to the invention there is further disclosed a method of preparing a composite caulk comprising paper wool, perlite, a particulated wood material having a particle size below 2 mm, a particulated fire retardant bark material having at least one axis of length with a dimension below 2 mm and a polyvinyl-acetate based aqueous dispersion adhesive; and wherein the composite caulk forms a heterogeneous caulk which can be dispensed using a handheld caulking gun; wherein paper wool, perlite, particulated wood and particulated bark are dry mixed prior to mixing with the adhesive(s); wherein when present the at least one fungicide is mixed into the composite caulk with or after addition of the adhesive(s); wherein when present the aqueous modified starch dispersion adhesive or the aqueous modified starch dispersion adhesive reinforced with an aqueous acrylic dispersion is added after the polyvinyl-acetate based aqueous dispersion adhesive and wherein the adhesive or adhesives is/are added in an amount sufficient to obtain a heterogeneous caulk which can be dispensed using a handheld caulking gun.

(28) Further, there is disclosed the use of a composite caulk according to any of the embodiments of the invention for caulking a joint or a gap between separate building objects in a building.

EXAMPLES

(29) Below are given several examples which will allow the skilled person to manufacture composite caulks according to the invention. The skilled person will understand that the composite caulks of the present invention comprise a significant portion of an aqueous phase from the adhesive. During curing and hardening of the applied caulk, this water evaporates and the final, hardened caulk will therefore have a weight distribution different from the composite caulks described in the below examples.

Example 1

(30) A composite caulk according to the present invention comprising on a weight/total weight basis: Paper wool: 3-10%; Perlite: 10-20%; Particulated Wood: 15-25%; Particulated Bark: 10-35%; The balance adhesive.

Example 2

(31) A composite caulk according to the present invention comprising on a weight/total weight basis: Paper wool: 3-10%; Perlite: 10-20%; Particulated Wood: 15-25%; Particulated Bark: 10-20%; The balance adhesive.

Example 3

(32) A composite caulk according to the present invention comprising on a weight/total weight basis: Paper wool: 4-7%; Perlite: 11-16%; Particulated Wood: 17-23%; Particulated Bark: 13-18%; The balance adhesive.

Example 4

(33) A composite caulk according to the present invention comprising on a weight/total weight basis: Paper wool: 3-10%; Perlite: 10-20%; Particulated Wood: 15-25%; Particulated Bark: 24-30%; The balance adhesive.

Example 5

(34) A composite caulk according to the present invention comprising on a weight/total weight basis: Paper wool: 5%; Perlite: 13%; Particulated Wood: 20%; Particulated Cork: 15%; The balance adhesive.

Example 6

(35) A composite caulk according to the present invention comprising on a weight/total weight basis: Paper wool: 5%; Perlite: 13%; Particulated Wood: 20%; Particulated Cork: 27%; The balance adhesive.

Example 7

(36) The composition of any of the above examples comprising an aqueous modified starch dispersion adhesives or aqueous modified starch dispersion adhesives reinforced with an aqueous acrylic dispersion in an amount of 10% of the total mass of adhesive.

Example 8

(37) The composition of any of the above examples comprising an aqueous modified starch dispersion adhesives or aqueous modified starch dispersion adhesives reinforced with an aqueous acrylic dispersion in an amount of 5% of the total mass of adhesive.

(38) Tests

(39) The composite caulks of examples 5 and 6 were prepared according to the above described method by dry mixing the solids and adding the polyvinyl-acetate based aqueous dispersion adhesive (ProFect 2343 from PKI Industrilim of Fredericia, Denmark) in an amount to reach 100%, the test also including adding 10% of an aqueous modified starch dispersion adhesive (DANA LIM vdrumslim 216 from Dana Lim of Kge, Denmark) to the polyvinyl-acetate based aqueous dispersion adhesive.

(40) Test 1: Standard Test for Strength of Caulked Joints

(41) The tests for the strength of the caulked joints using the two above compositions were performed according to DS/EN 196-1: 2005: Methods for testing cement. This testing standard was chosen, although the caulks of the invention are not cements in the sense of the standard, as it is the regularly testing standard for cement caulks used for jointing and therefore, in the absence of a standard test for joint strengths for caulks of the present invention, was considered most appropriate in the present context.

(42) Six prisms of size 1604040 mm.sup.3 were formed and dried in a climate bench at 20 C. and 65% RH, each prism of composite caulk according to examples 5 and 6 prepared in triplicate. The resulting compressive strengths varied between 5.8 and 6.6 MPa and the resulting flexural strengths varied between 2.0 and 2.4 MPa, cf. Table 1 and Table 2.

(43) TABLE-US-00001 TABLE 1 Density f.sub.c1 f.sub.c2 f.sub.cm Example 5 (kg/m.sup.3) f.sub.flex (MPa) (MPa) (MPa) 1 609 2.1 6.8 6.4 6.6 2 596 2.0 6.2 6.1 6.2 3 614 2.1 5.9 5.8 5.8 Average 606 2.0 6.2 Standard 8 0.1 0.4 Deviation

(44) TABLE-US-00002 TABLE 2 Density f.sub.c1 f.sub.c2 f.sub.cm Example 6 (kg/m.sup.3) f.sub.flex (MPa) (MPa) (MPa) 4 620 2.0 6.0 5.9 6.0 5 617 2.3 6.4 5.8 6.0 6 606 2.4 6.4 6.6 6.5 Average 614 2.2 6.2 Standard 6 0.2 0.3 Deviation
Test 2: Strength of Caulked Joints Between Bricks

(45) In a separate test, the caulks of examples 5 and 6 were used to joint three sets of two bricks together; total of six samples; and stored in a climate chamber for 28 days at 20 C. at 65% RH.

(46) The average static load to cause disjoining was measured at 30.2 kg/joint4.1 kg/joint; which is comparable to the binding strength of cement.

(47) Disjoining was primarily in the caulk (68%7%) with less than 10% of all disjoining being in the adhesive contact zone between caulk and brick, thus indicating a strong adhesion between caulk and brick wherein the strength of the joint is primarily determined by the rupture strength of the caulk and not by the rupture strength of the bond between caulk and brick.

(48) Test 3: Weather-Test

(49) In an outdoors test a joint of 20 mm between two planks of 2000 mm was created and the caulks of examples 5 and 6 were applied to the joint respectively over a stretch of the length of the joint between the planks.

(50) The planks with caulks were placed in an outdoors, open gateway, thereby simulating an installation of a window frame in a new build house. The assembly was subjected to the weather conditions as is (autumn in Denmark).

(51) The experiment showed that a relatively homogeneous drying and hardening of the caulk took place over the observation period without the caulks retracting from contact with the surfaces of the planks.

(52) Conclusions from Tests:

(53) Based on the above test it can be concluded that the caulks as described herein are suitable for jointing wooden window frames to bricks as intended, since the caulks will neither disjoin from bricks nor wood within the rupture strength of the caulk itself.

(54) Closing Comments

(55) The term comprising as used in the claims does not exclude other elements or steps. The term a or an as used in the claims does not exclude a plurality. A single processor or other unit may fulfill the functions of several means recited in the claims.

(56) Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the scope of the invention.